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  • Immunocytochemistry  (262)
  • maize  (201)
  • Inversion
  • Rat
  • Springer  (516)
  • 3
  • Wiley
  • 1990-1994  (516)
  • 1
    Digitale Medien
    Digitale Medien
    Orogenic evolution of the Hellenides: new aspects (1994)
    Springer
    International journal of earth sciences 83 (1994), S. 249-256 
    Details
    ISSN: 1437-3262
    Schlagwort(e): Mediterranean microplates ; Pre-Alpidic rifting ; Inversion ; Low angle faulting ; Intracrustal shearing
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Abstract This progress report is based on investigations of the tectonometamorphic development of crystalline complexes and is restricted to a few key problems of the Hellenides: 1. ‘Hinterland’. Rhodopia is strongly affected by Alpidic metamorphism, granitoid intrusions, orogenic deformation and intracrustal delamination. Therefore, close relations between the Balkanides and Hellenides have to be considered. 2. External zones. The Phyllite-Quartzite Series probably originated in a Late Palaeozoic rift within Apulia. In Middle Triassic times rifting stopped and the area became the basement on an extended carbonate platform (Late Triassic-Liassic). From the Dogger to Palaeocene, parts of that platform subsided, forming the Ionian pelagic basin. The Eocene orogenesis within the central Hellenides then caused an inversion of the buried Phyllite-Quartzite rift zone, whereas from the Late Oligocene onwards the previous rift zone underwent continental (A-) subduction. Finally, uplift of the Phyllite-Quartzite Series and nappe emplacement started in Miocene times. 3. Late orogenic intracrustal shearing. Structural analyses of crystalline complexes of Attica have shown that neotectonic extension and the large vertical displacement of the Aegean region were caused by low angle faulting and large-scale shearing within the deeper crust, probably along former overthrust planes. These results reveal the mechanisms of intracratonic tectonics, remobilization of continental crust and intracrustal detachment throughout the evolution of the Hellenides.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210543
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  • 2
    Digitale Medien
    Digitale Medien
    Effects of aflatoxin B1 on in vitro cultures ofNicotiana tabacum var. Samsun (1994)
    Springer
    Mycopathologia 125 (1994), S. 107-117 
    Details
    ISSN: 1573-0832
    Schlagwort(e): Aflatoxin B1 ; Immunocytochemistry ; Regeneration ; Tissue culture ; Tobacco plantlets
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The effects of aflatoxin B1, (0.5–25 µg ml−1) on in vitro root and shoot development in young tobacco explants were investigated. Despite an initial apparent stimulatory effect on most measured parameters at 0.5 µg ml−1 AFB1, the number of leaves, root and leaf mass per plantlet were progressively inhibited with increasing AFB1 concentration. The number of explants developing roots was reduced to 34% at the highest (25 µg ml−1) AFB1 concentration, following 3 weeks exposure to the toxin. Leaf chlorophyll content at this toxin concentration was significantly lower than that measured for control plantlets. Thin layer chromatography confirmed the absorption of AFB1 by the plantlets. Using immunocytochemical techniques, AFB1 was immunolocated predominantly in the vacuoles, the nucleus and the cytoplasm (possibly intravesicularly). The results are discussed in terms of this immunolocation within the cell.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01371099
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  • 3
    Digitale Medien
    Digitale Medien
    Renal eicosanoids and blood pressure in genetically hypertensive rats of the lyon strain (1994)
    Springer
    Journal of biomedical science 1 (1994), S. 201-203 
    Details
    ISSN: 1423-0127
    Schlagwort(e): Hypertension ; Eicosanoid ; Rat ; Genetics ; Kidney
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The present paper reviews the evidence for a possible involvement of renal eicosanoids in the pathophysiology of high blood pressure in genetically hypertensive rats of the Lyon strain. Both in vivo and in vitro experiments suggest that an increased ability to synthesize the vasoconstrictor prostaglandin H2 and/or thromboxane A2 in renal vessels (1) acts as an autocrine amplifier of pressor agents and (2) may contribute to resetting the pressure natriuresis curve which is a prerequisite for the development and maintenance of hypertension.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02253302
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  • 4
    Digitale Medien
    Digitale Medien
    Seasonal variations in the production of the egg-jelly macromolecule, a fucose sulphate glycoconjugate, by the accessory cells in the ovary of the sea urchin Hemicentrotus pulcherrimus (1994)
    Springer
    Development genes and evolution 203 (1994), S. 402-410 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Sea urchin ; Egg jelly ; Ovary ; Development ; Immunocytochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In the sea urchin Hemicentrotus pulcherrimus, the egg-jelly macromolecule, a fucose sulphate glycoconjugate (FSG) that induces the acrosome reaction in spermatozoa, originates from the accessory cells in the ovary. In the present study we examined the seasonal variations in the distribution of FSG in the ovary by immunocytochemistry with a polyclonal antibody. An enzyme-linked immunosorbent assay indicated that FSG was present in supernatants of extracts of ovaries throughout the development of the ovary. However, the immunohistochemical study showed that there are marked seasonal changes in the distribution of FSG in ovaries. The polyclonal antibody reacted strongly with globules of accessory cells before the beginning of the breeding season (August to December). During the breeding season (February to April), the immunohistochemical reaction was found on the surface of oocytes but was weak in the accessory cells. At the ultrastructural level, the antibody reacted with globules of variable density in accessory cells. Intense immunolabelling was observed in the vacuole-like structures of the globules. Sometimes, products of the specific immunocytochemical reaction were found in the Golgi apparatus in these globules. Quantitative examination indicated that FSG was actively produced by the accessory cells from the late non-breeding season to the pre-breeding season. These results suggest that there are marked seasonal variations in the production of FSG by the accessory cells in the sea urchin ovary. These findings also provide new evidence that accessory cells exhibit dynamic changes during the reproductive process in the sea urchin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00188689
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  • 5
    Digitale Medien
    Digitale Medien
    Noninvasive loading of the rat ulna in vivo induces a strain-related modeling response uncomplicated by trauma or periostal pressure (1994)
    Springer
    Calcified tissue international 54 (1994), S. 241-247 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Loading ; Strain ; Modeling ; Rat ; Ulna
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract Adaptive changes in bone modeling in response to noninvasive, cyclic axial loading of the rat ulna were compared with those using 4-point bending of the tibia. Twenty cycles daily of 4-point bending for 10 days were applied to rat tibiae through loading points 23 and 11 mm apart. Control bones received nonbending loads through loading points 11 mm apart. As woven bone was produced in both situations, any strain-related response was confounded by the response to direct periosteal pressure. Four-point bending is not, therefore, an ideal mode of loading for the investigation of strain-related adaptive modeling. The ulna's adaptive response to daily axial loading over 9 days was investigated in 30 rats. Groups 1–3 were loaded for 1200 cycles: Group 1 at 10 Hz and 20 N, Group 2 at 10 Hz and 15 N, and Group 3 at 20 Hz and 15 N. Groups 4 and 5 received 12,000 cycles of 20 N and 15 N at 10 Hz. Groups 1 and 4 showed a similar amount of new bone formation. Group 4 showed the same pattern of response but in reduced amount. The responses in Groups 2 and 3 were either small or absent. Strains were measured with single-element, miniature strain gauges bonded around the circumference of dissected bones. The 20 N loading induced peak strains of 3500–4500 μstrain. The width of the periosteal new bone response was proportional to the longitudinal strain at each point around the bone's circumference. It appears that when a bone is loaded in a normal strain distribution, an osteogenic response occurs when peak physiological strains are exceeded. In this situation the amount of new bone formed at each location is proportional to the local surface strain. Cycle numbers between 1200 and 12,000, and cycle frequencies between 10 and 20 Hz have no effect on the bone's adaptive response.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00301686
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  • 6
    Digitale Medien
    Digitale Medien
    Immunocytochemical identification of androgen receptor in mouse osteoclast-like multinucleated cells (1994)
    Springer
    Calcified tissue international 54 (1994), S. 325-326 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Androgen Receptor ; Osteoclast ; Mouse ; Immunocytochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Expression of androgen receptor (AR) in mouse osteoclast-like multi-nucleated cells (OCs) was examined with immunocytochemical techniques. Murine OCs were obtained by co-culturing mouse osteoblastic cells and bone marrow cells. Three preparations of polyclonal anti-AR antibody which were raised in rabbit against different parts of the human AR were employed for the experiments. Specific staining for AR was demonstrated in the nuclei and the perinuclear area of mouse OCs. This is the first report demonstrating the presence of AR in osteoclast-like cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00295958
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  • 7
    Digitale Medien
    Digitale Medien
    Effect of running exercise on the bone loss induced by orchidectomy in the rat (1994)
    Springer
    Calcified tissue international 55 (1994), S. 33-37 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Osteoporosis ; Rat ; Orchidectomy ; Exercise ; Strength
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract The effect of exercise on castration-induced osteoporosis in 3-month-old male rats weighing 264±4 g at the beginning of the experiment was studied. A testosterone deficiency was induced by orchidectomy (ORC), and the exercise group ran 10 m/minute for 1 hour a day on a treadmill at 0% grade. There were seven groups of eight rats (n=56) randomized into a control group killed at time 0, and sham, ORC and ORC and exercise groups killed at 4 and 8 weeks. ORC reduced body weight gain (with analysis of variance (ANOVA) P〈0.001), and at 4 weeks the body weight was 343±14 g in ORC group and 301±4 g in the ORC and exercise group (P〈0.01). The increase in femoral length was slower in the ORC+exercise groups. The ash weight of the tibia did not decrease significantly after ORC or ORC+ exercise. ORC did not affect 45Ca incorporation, but exercise slightly increased it in the whole tibia 8 weeks after ORC (with ANOVA P=0.057). ORC had significantly lowered the trabecular bone volume in the secondary spongiosa of the distal femur at 4 and 8 weeks, and exercise did not prevent this. This is an opposite finding to our previous study with ovariectomized female rats [12]. ORC also significantly had reduced the osteoblast-lined trabecular bone surface and the number of osteoclasts by 8 weeks after the operation. Exercise increased the osteoblast-lined surface and the number of osteoclasts. The mechanical strength of the femoral neck also was reduced after ORC and this was not prevented by exercise either. In conclusion, ORC reduces bone growth and turnover which leads to osteopenia in growing rats. Moderate treadmill exercise does not reverse the ORC-induced loss of trabecular bone and the reduced mechanical strength of the femoral neck, although it has a positive effect on the osteoblast and osteoclast indices and on calcium incorporation into bone.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00310166
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  • 8
    Digitale Medien
    Digitale Medien
    The in vivo effect of a new, in vitro, extremely potent vitamin D3 analog KH1060 on the suppression of renal allograft rejection in the rat (1994)
    Springer
    Calcified tissue international 54 (1994), S. 150-154 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Vitamin D analog ; KH1060 ; Kidney transplantation ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract KH1060 is a new 20-epi-vitamin D3 analog, which has exerted a considerable immunosuppressive potency in vitro. We have tested in vivo the effect of KH1060 on the suppression of renal allograft rejection in the rat. Allogenic kidney transplantation from DA donor rats to Lewis recipient rats treated intraperitoneally with KH1060 in doses from 0.2 to 6 μg/kg/day, or saline (placebo group), or CyA 10 mg/kg/day for 10 days (positive control group), was performed. Median graft survival time in KH1060-treated groups was 7–9 days, in the placebo group 6 days, whereas CyA led to long-term graft survival, 34 days in 50% of rats and 〉100 days in 50% of rats. In vivo, KH1060 failed to prolong renal allograft survival considerably, and led to development of hypercalcemia. Our results stress the existence of a large discrepancy between the in vitro and in vivo immunoregulatory effects of this vitamin D analog.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00296066
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  • 9
    Digitale Medien
    Digitale Medien
    Effect of 1α-vitamin D3 on bone strength and composition in growing rats with and without corticosteroid treatment (1994)
    Springer
    Calcified tissue international 55 (1994), S. 443-450 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone mechanics ; Bone composition ; Vitamin D3 ; Corticosteroid ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract The effects of 1α-vitamin D3 were studied for 6 months in 2-month-old male and female rats on a moderately low calcium diet with or without low-dose prednisolone treatment. Both cortical bone mechanical and biochemical properties were examined. Femoral bone specimens were subjected to torsional loading tests. With age, bone strength and stiffness increased in both sexes, accompanied by an increased degree of mineralization (bone ash and calcium concentrations). During growth, strength and stiffness increased more in male than in female rats. When 1α-vitamin D3 (0.5 μg/kg/day) was given alone, bone mechanical competence improved significantly whereas insulin-like growth factor-I (IGF-I) and calcium concentrations in the bone matrix were significantly reduced. Treatment with low-dose prednisolone (0.5 mg/kg/day) alone did not influence bone mechanical properties compared with intact control rats (without prednisolone) although a significant reduction in calcium concentration and an increased phosphorus concentration were measured. A combined therapy with prednisolone and 1α-vitamin D3 significantly increased bone strength, toughness, and stiffness compared with control bones. Both mineralization degree (ash and calcium concentration) and IGF-I concentration were decreased. We conclude that (1) mechanical properties of rat cortical bones improve relatively more in males compared with agematched females during growth which is related to increased bone mass and size, (2) low-dose prednisolone treatment does not change mechanical properties in males, and altered them only nonsignificantly in females despite a change in mineralization degree in both sexes; (3) treatment with 1α-vitamin D3 results in a consistent increase in mechanical competence of the bone accompanied by a significant decrease in IGF-I concentration in the bone matrix.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00298558
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  • 10
    Digitale Medien
    Digitale Medien
    Characterization of four new β-tubulin genes and their expression during male flower development in maize (Zea mays L.) (1994)
    Springer
    Plant molecular biology 24 (1994), S. 295-315 
    Details
    ISSN: 1573-5028
    Schlagwort(e): β-tubulin ; microtubules ; maize ; gene expression
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Four different β-tubulin coding sequences were isolated from a cDNA library prepared from RNA from maize seedling shoots. The four genes (designated tub4, tub6, tub7 and tub8) represented by these cDNA clones together with the tub1 and tub2 genes reported previously encode six β-tubulin isotypes with 90–97.5% amino acid sequence identity. Results from phylogenetic analysis of 17 β-tubulin genes from monocot and dicot plant species indicated that multiple extant lines of β-tubulin genes diverged from a single precursor after the appearance of the two major subfamilies of α-tubulin genes described previously. Hybridization probes from the 3′ non-coding regions of six β-tubulin clones were used to quantify the levels of corresponding tubulin transcripts in different maize tissues including developing anthers and pollen. The results from these dot blot hybridization experiments showed that all of the β-tubulin genes were expressed in most tissues examined, although each gene showed a unique pattern of differential transcript accumulation. The tub1 gene showed a high level of transcript accumulation in meristematic tissues and almost no accumulation in the late stages of anther development and in pollen. In contrast, the level of tub4 transcripts was very low during early stages of male flower development but increased markedly (more than 100 times) during the development of anthers and in pollen. Results from RNAse protection assays showed that this increased hybridization signal resulted from expression of transcripts from one or two genes closely related to tub4. The tub4-related transcripts were not present in shoot tissue. Transcripts from the tub2 gene accumulated to very low levels in all tissues examined, but reached the highest levels in young anthers containing microspore mother cells. RNAse protection assays were used to measure the absolute levels of α- and β-tubulin transcripts in seedling shoot and in pollen. The α-tubulin gene subfamily I genes (tua1, tua2, tua4) contributed the great majority of α-tubulin transcripts in both shoot and pollen. Transcripts from the β-tubulin genes tub4, tub6, tub7, and tub8 were predominant in shoot, but were much less significant than the tub4-related transcripts in pollen.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00020169
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  • 11
    Digitale Medien
    Digitale Medien
    Addition of A- and U-rich sequence increases the splicing efficiency of a deleted form of a maize intron (1994)
    Springer
    Plant molecular biology 24 (1994), S. 449-463 
    Details
    ISSN: 1573-5028
    Schlagwort(e): AU-rich ; intron ; maize ; splicing
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Plant introns are generally short (〈200 nt) and AU-rich, and an elevated AU content is necessary for efficient splicing. Further, an intron in some plant genes enhances gene expression by a post-transcriptional mechanism that results in an increase of cytoplasmic mRNA. The specific intron features responsible for efficient splicing and enhancement are not well characterized in plants. Internal deletions of up to 80% of two maize introns, Adh1 intron 1 and maize actin intron 3, indicate that large segments of these introns are dispensable for normal function. However, extensive deletion (〉75%) of Adh1 intron 1 diminishes both intron enhancement and splicing efficiency. This finding suggests that there are internal sequence motifs required for intron function, and that these motifs are redundant. We attempted to repair a deletion-impaired Adh1 intron 1 variant by adding back either oligomers of defined sequence content or fragments of maize internal intron sequence. The addition of AU-rich oligomers improved splicing efficiency and in one example, a U-rich oligomer activated a cryptic 3′ splice acceptor. We also found that replacing the region proximal to the Adh1 intron 1 3′ acceptor with U-rich sequence improved splicing. We found that adding G- and C-rich oligomers did not improve intron function, but a C-rich oligomer activated a cryptic 3′ acceptor. The addition of internal intron sequence to an impaired intron improved splicing, and in one case, resulted in the activation of a cryptic 3′ acceptor. We present evidence that U-rich sequence immediately upstream of the 3′ splice junction increases splicing efficiency and contributes to, but does not uniquely specify, 3′ acceptor AG choice.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00024113
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  • 12
    Digitale Medien
    Digitale Medien
    Differential transcription of plastome-encoded genes in the mesophyll and bundle-sheath chloroplasts of the monocotyledonous NADP-malic enzyme-type C4 plants maize and Sorghum (1994)
    Springer
    Plant molecular biology 25 (1994), S. 669-679 
    Details
    ISSN: 1573-5028
    Schlagwort(e): C4 photosynthesis ; maize ; plastid gene expression ; Sorghum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The transcription of plastome-encoded genes in mesophyll and bundle-sheath chloroplasts of the monocotyledonous NADP-malic enzyme-type C4 species Zea mays L. (maize) and Sorghum bicolor (L.) Moench. was investigated. RNA accumulation and transcription were assayed starting from isolated mesophyll and bundle-sheath chloroplasts and using quantitative northern and run-on transcription analysis. Determination of the mesophyll to bundle-sheath ratios of transcript abundance in maize and Sorghum chloroplasts showed that the mRNAs of the plastome-encoded photosystem II genes analysed (psbA, psbB, psbD, psbH and psbE/F) varied from 2.5- to 4.0-fold (maize) and 3.1- to 5.2-fold (Sorghum), respectively. The rbcL transcript, in contrast, was more abundant in bundle-sheath chloroplasts of both species, about 3-fold in maize and more than 10-fold in Sorghum. On the other hand, transcripts of genes encoding the 16S ribosomal RNA (r16) and subunits of photosystem I (psaA) and the cytochrome b/f complex (petB, petA) accumulated to similar levels in both types of chloroplasts. Determination of absolute transcript levels for rbcL and psbA in chloroplasts from maize and Sorghum demonstrated that for both genes, the mesophyll to bundle-sheath differences in transcript abundance were more pronounced in Sorghum. Measurements of the transcriptional activities of rbcL and psbA showed that the transcription rate of rbcL is higher in bundle-sheath chloroplasts while psbA is more actively transcribed in mesophyll chloroplasts. The differences in the transcription rates between the two chloroplast types were again more pronounced in Sorghum, thus reflecting the differences between maize and Sorghum in the relative levels of the rbcL and psbA transcripts. However, although transcription rate and mRNA abundance are correlated, they did not exactly match one another. This indicates additional regulation of transcript abundance at the level of RNA stability.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00029605
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  • 13
    Digitale Medien
    Digitale Medien
    Structure and function of selectable and non-selectable transgenes in maize after introduction by particle bombardment (1994)
    Springer
    Plant molecular biology 25 (1994), S. 951-961 
    Details
    ISSN: 1573-5028
    Schlagwort(e): Cell biology ; epigenetics ; maize ; transformation ; transgenes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Zea mays transformants produced by particle bombardment of embryogenic suspension culture cells of the genotype A188 × B73 and selected on kanamycin or bialaphos were characterized with respect to transgene integration, expression, and inheritance. Selection on bialaphos, mediated by thebar orpat genes, was more efficient than selection on kanamycin, mediated by thenptII gene. Most transformants contained multicopy, single locus, transgene insertion events. A transgene expression cassette was more likely to be rearranged if expression of that gene was not selected for during callus growth. Not all plants regenerated from calli representing single transformation events expressed the transgenes, and a non-selectable gene (uidA) was expressed in fewer plants than was the selectable transgene. Mendelian inheritance of transgenes consistent with transgene insertion at a single locus was observed for approximately two thirds of the transformants assessed. Transgene expression was typically, but not always, predictable in progeny plants-transgene silencing, as well as poor transgene transmission to progeny, was observed in some plant lines in which the parent plants had expressed the transgene.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00014669
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  • 14
    Digitale Medien
    Digitale Medien
    Partial sequencing and mapping of clones from two maize cDNA libraries (1994)
    Springer
    Plant molecular biology 26 (1994), S. 1085-1101 
    Details
    ISSN: 1573-5028
    Schlagwort(e): cDNA clones ; EST sequencing ; maize ; RFLP mapping
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract As one component of a maize genome project, we report the analysis of a number of randomly selected cDNAs, by a combination of measuring mRNA expression, ‘single-pass’ sequencing (SPS), and genome mapping. Etiolated seedling (490) and membrane-free polysomal endosperm cDNA clones (576) were evaluated for their transcription levels by hybridizing with a probe prepared from total mRNA and categorized as corresponding to abundantly or rarely expressed mRNAs and as either constitutive or tissue-specific. A total of 313 clones from the two libraries were submitted to ‘single-pass’ sequencing from the presumed 5′ end of the mRNA and the nucleotide sequence compared with the GenBank database. About 61% of the clones showed no significant similarities within GenBank, 14% of the clones exhibited a high degree of similarity, while the remaining 25% exhibited a lesser degree of similarity. The chromosomal location of more than 300 clones was determined by RFLP mapping using standard populations. The results demonstrate that a combination of analyses provides synergistic information in eventually deducing the actual function of these types of clones.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00040691
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  • 15
    Digitale Medien
    Digitale Medien
    Non-systemic expression of a stress-responsive maize polyubiquitin gene (Ubi-1) in transgenic rice plants (1994)
    Springer
    Plant molecular biology 26 (1994), S. 1007-1012 
    Details
    ISSN: 1573-5028
    Schlagwort(e): cell cycle ; maize ; non-systemic expression ; polyubiquitin gene ; stress response
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We have used the promoter, 1st exon and 1st intron of the maize polyubiquitin gene (Ubi-1) for rice transformation experiments and revealed the characteristic expression of Ubi-1 gene: (1) Ubi-1 gene is not regulated systemically but rather individual cells respond independently to the heat or physical stress; (2) Ubi-1 gene changes its tissue-specific expression in response to stress treatment; (3) the expression of Ubi-1 gene is dependent on cell cycle.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00028868
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  • 16
    Digitale Medien
    Digitale Medien
    Isolation and characterisation of a maize cDNA that complements a 1-acyl sn-glycerol-3-phosphate acyltransferase mutant of Escherichia coli and encodes a protein which has similarities to other acyltransferases (1994)
    Springer
    Plant molecular biology 26 (1994), S. 211-223 
    Details
    ISSN: 1573-5028
    Schlagwort(e): maize ; 1-acyl-sn-glycerol-3-phosphate acyltransferase ; complementation cloning
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We selected cDNA plasmid clones that corrected the temperature-sensitive phenotype of Escherichia coli strain JC201, which is deficient in 1-acyl-sn-glycerol-3-phosphate acyltransferase activity. A plasmid-based maize endosperm cDNA library was used for complementation and a plasmid that enabled the cells to grow at 44°C on ampicillin was isolated. Addition of this plasmid (pMAT1) to JC201 restored 1-acyl-sn-glycerol-3-phosphate acyltransferase activity to the cells. Total phospholipid labelling showed that the substrate for the enzyme, lysophosphatidic acid, accumulated in JC201 and was further metabolised to phosphatidylethanolamine in complemented cells. Membranes isolated from such cells were able to convert lysophosphatidic acid to phosphatidic acid in acyltransferase assays. The cDNA insert of pMAT1 contains one long open reading frame of 374 amino acids which encodes a protein of relative molecular weight 42 543. The sequence of this protein is most similar to SLC1, which is thought to be able to acylate glycerol at the sn-2 position during synthesis of inositol-containing lipids. Homologies between the SLC1 protein, the 1-acyl-sn-glycerol-3-phosphate acyltransferase of E. coli (PlsC) and the maize ORF were found with blocks of conserved amino acids, whose spacing was conserved between the three proteins, identifiable.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00039533
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  • 17
    Digitale Medien
    Digitale Medien
    In vivo analysis of intron processing using splicing-dependent reporter gene assays (1994)
    Springer
    Plant molecular biology 26 (1994), S. 1785-1795 
    Details
    ISSN: 1573-5028
    Schlagwort(e): intron ; maize ; splicing ; vectors ; Zea mays
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The mechanisms of intron recognition and processing have been well-studied in mammals and yeast, but in plants the biochemistry of splicing is not known and the rules for intron recognition are not clearly defined. To increase understanding of intron processing in plants, we have constructed new pairs of vectors, pSuccess and pFail, to assess the efficiency of splicing in maize cultured cells. In the pFail series we use translation of pre-mRNA to monitor the amount of unspliced RNA. We inserted an ATG codon in the Bz2 (Bronze-2) intron in frame with luciferase: this construct will express luciferase activity only when splicing fails. In the pSuccess series the spliced message is monitored by inserting an ATG upstream of the Bz2 intron in frame with luciferase: this construct will express luciferase activity only when splicing succeeds. We show here, using both the wild-type Bz2 intron and the same intron with splice site mutations, that the efficiency of splicing can be estimated by the ratio between the luciferase activities of the vector pairs. We also show that mutations in the unique U-rich motif inside the intron can modulate splicing. In addition, a GC-rich insertion in the first exon increases the efficiency of splicing, suggesting that exons also play an important role in intron recognition and/or processing.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00019492
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  • 18
    Digitale Medien
    Digitale Medien
    Immunocytochemical study of seminal γ-glutamyltransferase using monoclonal antibodies (1994)
    Springer
    Cell & tissue research 277 (1994), S. 33-38 
    Details
    ISSN: 1432-0878
    Schlagwort(e): γ-Glutamyl transpeptidase ; Seminal γ-glutamyltransferase ; Prostate gland ; Seminal vesicle ; Monoclonal antibodies ; Immunocytochemistry ; Reproductive organs, male ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract We produced three monoclonal antibodies, SG1, SG2 and SG3, specific for human seminal γ-glutamyltransferase when characterized by enzyme-linked immunosorbent assay and immunoblotting. Seminal γ-glutamyltransferase was localized, by immunostaining, to the epithelial cells of the ductus epididymidis, seminal vesicle and prostate gland with SG1, those of the prostate gland with SG2, and those of the seminal vesicle with SG3. Rabbit polyclonal anti-seminal γ-glutamyltransferase serum reacted with the proximal convolution of the kidney and the bile capillaries of the liver, and with the epithelial cells of the reproductive organs. However, immunoreactivity was not observed in the kidney or liver with the monoclonal antibodies. Thus, these monoclonal antibodies are probably all specific to seminal γ-glutamyltransferase but recognize different epitopes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00303078
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  • 19
    Digitale Medien
    Digitale Medien
    Localization of mammary-derived growth inhibitor in capillary endothelial cells of the bovine mammary gland (1994)
    Springer
    Cell & tissue research 277 (1994), S. 457-464 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Mammary-derived growth inhibitor ; Fatty acid-binding proteins ; Differentiation ; Vascularization ; Immunohistochemistry ; Immunocytochemistry ; Mammary gland ; Cow
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Mammary-derived growth inhibitor (MDGI) has previously been localized in the mammary parencyma, dependent on the stage of differentiation of the mammary gland. Here, we have elucidated the distribution of MDGI in the mammary stroma by a combined immunohisto-and cytochemical analysis with antibodies raised against MDGI. Distinct staining of capillary endothelial cells has been revealed. Although its subcellular distribution resembles former observations in secretory epithelial cells, the expression of MDGI in capillary endothelial cells clearly precedes that in secretory epithelial cells. On the other hand, no endothelial MDGI staining has been detected in bovine heart, which contains a fatty acid-binding protein almost identical to MDGI. The localization of MDGI in the mammary capillary endothelium is discussed in terms of its possible involvement in the intracellular transport of hydrophobic ligands or in the regulation of endothelial cell proliferation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300218
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  • 20
    Digitale Medien
    Digitale Medien
    C-PON immunoreactive neurons in the neostriatum of the hedgehog (Erinaceus europaeus): a correlated light- and electron-microscopic study (1994)
    Springer
    Cell & tissue research 277 (1994), S. 177-181 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: C-PON ; Neuropeptide Y ; Neostriatum ; Immunocytochemistry ; Ultrastructure ; Erinaceus europaeus (Insectivora)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. The present study provides light- and electron-microscopic immunocytochemical data on the presence of neurons that are immunoreactive to the C-terminal flanking peptide of neuropeptide Y, C-PON, in the neostriatum of the hedgehog (Erinaceus europaeus). Positive neurons have mostly fusiform or round perikarya from which two to four poorly branched processes arise. Immunostained fibers and puncta are also evenly distributed throughout the neostriatum. Ultrastructurally, each neuron exhibits a deeply invaginated nucleus surrounded by abundant cytoplasm with a well-developed rough endoplasmic reticulum and Golgi apparatus. Positive neurons receive symmetric and asymmetric synapses from unlabeled terminals. The results of this study can be correlated with previous findings, as the C-PON-positive neurons of the hedgehog resemble medium-sized neostriatal neurons that are known to be local circuit neurons exhibiting C-PON in the rat. Thus, a high degree of C-PON neuronal system phylogenetic conservation and function can be postulated for the neostriatum of mammals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00303094
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  • 21
    Digitale Medien
    Digitale Medien
    Ontogeny of some endocrine cells of the digestive tract in sea bass (Dicentrarchus labrax): An immunocytochemical study (1994)
    Springer
    Cell & tissue research 277 (1994), S. 373-383 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Endocrine cells ; Gut ; Ontogeny ; Regulatory peptides ; Immunocytochemistry ; Dicentrarchus labrax (Teleostei)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Serotonin- and ten peptide-immunoreactive (IR) cell types were identified in the digestive tract of sea bass (Dicentrarchus labrax L.) larvae of four morphofunctional phases ranging in age from hatching to 61 days. The sequence of appearance and location of endocrine cells during ontogenetic development of the larvae was determined. The differentiation of endocrine cells followed a distal-proximal gradient in the gut which paralleled the morphofunctional differentiation. Serotonin-IR cells were identified in the last portion of the digestive tract from phase I onwards and in the gastric region from phase III, before these regions were morphofunctionally differentiated; met-enkephalin-IR cells were identified from phase II onwards in both the differentiated rectum and the undifferentiated intestine; cholecystokinin (CCK)- and synthetic human gastrin-34-IR cells were located only in the intestine and first found in the undifferentiated intestine of phase II; human gastrin-17-, peptide YY (PYY)- and neuropeptide Y (NPY)-IR cells appeared in the intestine from phase II and in stomach in phase IV, when it showed gastric glands; pancreatic polypeptide (PP)- and glucagon-IR cells were observed in both intestine and stomach, but insulin- and somatostatin-IR cells only in stomach, from phase III, during which the intestine but not the stomach was differentiated. PP- and PYY-, PP- and glucagon-, and PYY- and glucagon-like immunoreactivities coexisted from their first appearance in some cells of the gut.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00327785
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  • 22
    Digitale Medien
    Digitale Medien
    Ontogeny of some endocrine cells of the digestive tract in sea bass (Dicentrarchus labrax): An immunocytochemical study (1994)
    Springer
    Cell & tissue research 277 (1994), S. 373-383 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Endocrine cells ; Gut ; Ontogeny ; Regulatory peptides ; Immunocytochemistry ; Dicentrarchuslabrax (Teleostei)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. Serotonin- and ten peptide-immunoreactive (IR) cell types were identified in the digestive tract of sea bass (Dicentrarchus labrax L.) larvae of four morphofunctional phases ranging in age from hatching to 61 days. The sequence of appearance and location of endocrine cells during ontogenetic development of the larvae was determined. The differentiation of endocrine cells followed a distal-proximal gradient in the gut which paralleled the morphofunctional differentiation. Serotonin-IR cells were identified in the last portion of the digestive tract from phase I onwards and in the gastric region from phase III, before these regions were morphofunctionally differentiated; met-enkephalin-IR cells were identified from phase II onwards in both the differentiated rectum and the undifferentiated intestine; cholecystokinin (CCK)- and synthetic human gastrin-34-IR cells were located only in the intestine and first found in the undifferentiated intestine of phase II; human gastrin-17-, peptide YY (PYY)- and neuropeptide Y (NPY)-IR cells appeared in the intestine from phase II and in stomach in phase IV, when it showed gastric glands; pancreatic polypeptide (PP)- and glucagon-IR cells were observed in both intestine and stomach, but insulin- and somatostatin-IR cells only in stomach, from phase III, during which the intestine but not the stomach was differentiated. PP- and PYY-, PP- and glucagon-, and PYY- and glucagon-like immunoreactivities coexisted from their first appearance in some cells of the gut.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050164
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  • 23
    Digitale Medien
    Digitale Medien
    Chemically defined collateral projections from the pons to the central nucleus of the amygdala and hypothalamic paraventricular nucleus in the rat (1994)
    Springer
    Cell & tissue research 277 (1994), S. 289-295 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Serotonin ; Substance P ; Choline-acetyltransferase ; Retrograde tracers ; Immunocytochemistry ; Laterodorsal tegmental nucleus ; Dorsal raphe nucleus ; Rat (Sprague Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. Triple fluorescence labelling was employed to reveal the distribution of chemically identified neurons within the pontine laterodorsal tegmental nucleus and dorsal raphe nucleus which supply branching collateral input to the central nucleus of the amygdala and hypothalamic paraventricular nucleus. The chemical identity of neurons in the laterodorsal tegmental nucleus was revealed by immunocytochemical detection of choline- acetyltransferase or substance P; in the dorsal raphe nucleus, the chemical content of the neurons was revealed with antibody recognizing serotonin. The projections were defined by injections of two retrograde tracers, rhodamine- and fluorescein-labelled latex microspheres, in the central nucleus of the amygdala and paraventricular nucleus, respectively. Neurons projecting to both the central nucleus of the amygdala and the paraventricular nucleus were distributed primarily within the caudal extensions of the laterodorsal tegmental nucleus and dorsal raphe nucleus. Approximately 11% and 7% of the labelled cells in the laterodorsal tegmental nucleus and dorsal raphe nucleus projected via branching collaterals to the paraventricular nucleus and central nucleus of the amygdala. About half of these neurons in the laterodorsal tegmental nucleus were cholinergic, and one-third were substance-P-ergic; in the dorsal raphe nucleus, approximately half of the neurons containing both retrograde tracers were serotonergic. These results indicate that pontine neurons may simultaneously transmit signals to the central nucleus of the amygdala and paraventricular nucleus and that several different neuroactive substances are found in the neurons participating in these pathways. This coordinated signalling may lead to synchronized responses of the central nucleus of the amygdala and paraventricular nucleus for the maintenance of homeostasis. Interactions between different neuroactive substances at the target site may serve to modulate the responses of individual neurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050155
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  • 24
    Digitale Medien
    Digitale Medien
    Ultrastructural, cytochemical, and immunocytochemical characterization of haemocytes of the hard tick Ixodes ricinus (Acari; Chelicerata) (1994)
    Springer
    Cell & tissue research 277 (1994), S. 493-504 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Haemocytes ; Immunocytes ; invertebrate ; Immunity ; Immunocytochemistry ; Ixodes ricinus (Chelicerata)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. Haemocytes of the hard tick Ixodes ricinus were characterized on the basis of their ultrastructure, their ability to ingest foreign material, and to produce or store molecules of the immune defence. Distinction was made between types of haemocytes according to the absence or presence of granular inclusions, shape and size of the lysosomal compartment or the rough endoplasmic reticulum, and ultrastructural and functional similarity to the corresponding haemocytes of insects. Three types of haemocytes were found in adult ticks: plasmatocytes and type-I and type-II granular haemocytes, respectively. The precipitated reaction product of acid phosphatase activity revealed the shape of the lysosomal compartment. The additional injection of particulate materials into the haemocoel further revealed the endocytic activity of the haemocytes. The lysozyme-like immunoreactivity of the haemocytes suggests bactericidal potential. Detection of immunoreactivity in haemocytes to a 25 kDa antigenic protein involved in cuticle formation further suggests their involvement in wound healing and encapsulation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300222
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  • 25
    Digitale Medien
    Digitale Medien
    Development of sensory innervation in chick skin: comparison of nerve fibre and chondroitin sulphate distributions in vivo and in vitro (1994)
    Springer
    Cell & tissue research 277 (1994), S. 519-529 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Skin ; Development ; ontogenetic ; Chondroitin sulphate proteoglycan ; Neuritic guidance ; Immunocytochemistry ; Chicken
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. In bird skin, nerve fibres develop in the dermis but do not enter the epidermis. In co-cultures of 7-day-old chick embryo dorsal root ganglia and epidermis, the neurites also avoid the epidermis. Previous studies have shown that chondroitin sulphate proteoglycans may be involved. Chondroitin sulphate has therefore been visualized by immunocytochemistry, using the monoclonal antibody CS-56, both in vivo and in vitro using light and electron microscopy. Its distribution was compared to those of 2 other chondroitin sulphate epitopes and to that of the growing nerve fibres. In cultures of epidermis from 7-day-old embryonic chicks, immunoreactivity is found uniformly around the epidermal cells while at 7.5 days the distribution in dermis is heterogeneous, and particularly marked in feather buds. In vivo, chondroitin sulphate immunoreactivity is detected in the epidermis, on the basal lamina, on the surfaces of fibroblasts and along collagen fibrils. This localization is complementary to the distribution of cutaneous nerves. Chondroitin sulphate in the basal lamina could prevent innervation of the epidermis and the dermal heterogeneities could partly explain the nerve fibres surrounding the base of the feathers. Chondroitin sulphate could therefore be important for neural guidance in developing chick skin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300225
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  • 26
    Digitale Medien
    Digitale Medien
    Immunoreactivity of the corpuscles of Stannius of the garpike, Lepisosteus osseus, to antisera against salmon and trout stanniocalcins (1994)
    Springer
    Cell & tissue research 277 (1994), S. 511-518 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Corpuscles of Stannius ; Stanniocalcin ; Immunocytochemistry ; Immunohistochemistry ; Western blot ; Lepisosteus osseus (Holostei)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. Stanniocalcin-immunoreactive cells were localized in the corpuscles of Stannius of a holostean fish, the garpike (Lepisosteus osseus), using antisera against salmon and trout stanniocalcins and the peroxidase-antiperoxidase and protein A-gold immunohistochemical methods. The stanniocalcin-immunoreactive cells were periodic acid-Schiff-positive, and antibody staining was abolished if the antiserum was preabsorbed with corpuscle homogenate. Immunocytochemistry revealed two reactive cell types in the glandular parenchyma, and immunoreactivity was confined to the secretory granules. Staining of the granules was also abolished when the antisera were blocked with crude corpuscle homogenate. When corpuscle extracts from garpike were subjected to sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blot analysis, a single dense band was evident with a molecular weight of ∼68 kDa under non-reducing conditions, whereas three bands were observed (∼29, ∼31, and ∼34 kDa) under reducing conditions. Staining of all bands disappeared following preabsorption of the antiserum with salmon stanniocalcin, trout stanniocalcin, or garpike corpuscle extract. The results are compared with stanniocalcins from another extant holostean, the bowfin (Amia calva), and from more modern bony fishes, the teleosts.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300224
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  • 27
    Digitale Medien
    Digitale Medien
    Immunoreactivity of the corpuscles of Stannius of the garpike, Lepisosteus osseus, to antisera against salmon and trout stanniocalcins (1994)
    Springer
    Cell & tissue research 277 (1994), S. 511-518 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Corpuscles of Stannius ; Stanniocalcin ; Immunocytochemistry ; Immunohistochemistry ; Western blot ; Lepisosteus osseus (Holostei)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Stanniocalcin-immunoreactive cells were localized in the corpuscles of Stannius of a holostean fish, the garpike (Lepisosteus osseus), using antisera against salmon and trout stanniocalcins and the peroxidase-antiperoxidase and protein A-gold immunohistochemical methods. The stanniocalcin-immunoreactive cells were periodic acid-Schiff-positive, and antibody staining was abolished if the antiserum was preabsorbed with corpuscle homogenate. Immunocytochemistry revealed two reactive cell types in the glandular parenchyma, and immunoreactivity was confined to the secretory granules. Staining of the granules was also abolished when the antisera were blocked with crude corpuscle homogenate. When corpuscle extracts from garpike were subjected to sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blot analysis, a single dense band was evident with a molecular weight of ∼68 kDa under non-reducing conditions, whereas three bands were observed (∼29, ∼31, and ∼34 kDa) under reducing conditions. Staining of all bands disappeared following preabsorption of the antiserum with salmon stanniocalcin, trout stanniocalcin, or garpike corpuscle extract. The results are compared with stanniocalcins from another extant holostean, the bowfin (Amia calva), and from more modern bony fishes, the teleosts.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300224
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  • 28
    Digitale Medien
    Digitale Medien
    Keratin expression: a measure of phenotypic modulation of human prostatic epithelial cells by growth inhibitory factors (1994)
    Springer
    Cell & tissue research 277 (1994), S. 11-18 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Prostate gland ; Keratin ; Vitamin A ; Epithelium ; Immunocytochemistry ; Man
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Expression of certain cytokeratins can be indicative of the state of differentiation of epithelial cells. The basal cells in the normal adult human prostatic epithelium are characterized by the expression of cytokeratins 5 and 14, whereas the secretory luminal cells contain cytokeratins 8 and 18. Cells cultured from the prostatic epithelium expressed cytokeratins 5, 8, and 18, and thus had features of both basal and luminal cells. Certain growth-inhibitory conditions altered keratin expression in conjunction with growth modulation. Deletion of peptide factors and hormones from the culture medium induced the expression of cytokeratins 1 and 10, associated with a squamous phenotype. These same squamous keratins were found in very dense, stratified cultures that were maintained at confluency in standard, complete medium for extended periods. Retinoic acid enhanced the expression of secretory luminal cell-associated cytokeratins 8 and 18 in semi-confluent cultures. Other growth inhibitory factors such as suramin, transforming growth factor-β, and interferon-γ had no effect on keratin expression. These observations indicate that the differentiation of prostatic epithelial cells can be directed toward alternate pathways, either squamous or secretory, by different growth-inhibitory conditions. However, not all growth inhibitory factors altered differentiation, demonstrating that growth inhibition in itself is not a sufficient inducer of differentiation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00303075
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  • 29
    Digitale Medien
    Digitale Medien
    Intra-acrosomal organization of a 90-kilodalton antigen during spermiogenesis in the rat (1994)
    Springer
    Cell & tissue research 277 (1994), S. 61-67 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Acrosome development ; Antigen localization ; Intra-acrosomal migration ; Golgi apparatus ; Spermiogenesis ; Immunocytochemistry ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The localization of an acrosomal protein was studied using a monoclonal antibody MN7 raised against mouse spermatozoa. MN7 specifically recognized the anterior acrosome of several mammalian (mouse, rat, hamster) spermatozoa fixed with paraformaldehyde. An immunoblot study with periodate treatment showed that MN7 recognized a carbohydrate region of a 90 kDa protein in an extract of mouse and rat cauda epididymal spermatozoa. The change in distribution of the MN7 antigen during acrosome development was investigated in the rat testis using the pre-embedding immunoperoxidase technique. The antigen first appeared in the proacrosomic granules of spermatids in steps 1–2. Small vesicles adjacent to the outer acrosomal membrane and the developing acrosomic system were immunoreactive during steps 4–7. The majority of the antigen was then redistributed to the head-cap portion during steps 8–18, and finally restricted to the anterior acrosome in the step 19-spermatid. These results suggest that the antigen is transported to the acrosome by way of the vesicles that originate from the Golgi apparatus during early spermiogenesis, and are then delivered to the final destination within the acrosome by the intra-acrosomal migration during late spermiogenesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00303081
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  • 30
    Digitale Medien
    Digitale Medien
    Functional morphology of the neuropeptidergic light-yellow-cell system in pulmonate snails (1994)
    Springer
    Cell & tissue research 277 (1994), S. 531-538 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Light yellow neuropeptidergic cells ; Immunocytochemistry ; Blood pressure regulation ; Pulmonata ; Lymnaea stagnalis ; Helix aspersa (Mollusca)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. The light yellow neuropeptidergic cell system of the basommatophoran snail Lymnaea stagnalis is homologous to the R3-R14 system of the opisthobranch Aplysia californica, and produces three different neuropeptides. Systems homologous to the light yellow cells of Lymnaea stagnalis have been investigated morphologically in two Basommatophora (Lymnaea ovata, Bulinus truncatus) and three Stylommatophora (Helix aspersa, Cepaea nemoralis, Deroceras reticulatum). To this end, an antibody to synthetic light-yellow-cell peptide-II and oligonucleotides to mRNAs encoding parts of peptide-I and peptide-III, were used. The in situ hybridization probes gave negative results. On the other hand, neuronal cell clusters were observed in the central nervous system of all species studied by immunocytochemistry. These clusters were located in the ganglia of the visceral complex. The neurons project axons into all nerves of these ganglia, especially into the pallial nerves, into the connective tissue of the central nervous system, and into the neuropile of various ganglia. The morphology of the systems is similar to that of the light-yellow-cell system of Lymnaea stagnalis. In all species, the wall of the aorta was innervated by immunoreactive axons. Peripheral innervation by the light-yellow-cell system was investigated in Helix aspersa and Deroceras reticulatum. Serial and alternate sections of whole snails were studied. Reconstructions were made of the heart-kidney-lung complex of these animals. In both species, the muscular vessels of the pulmonary system at the right side of the body were strongly innervated by immunoreactive axons. Furthermore, immunopositive innervation was observed to muscles in the secondary ureter-pneumostome area. The light-yellow-cell system of pulmonates is thus probably involved in the regulation of blood pressure and urine release.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300226
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  • 31
    Digitale Medien
    Digitale Medien
    The infundibular organ of the lancelet (Branchiostoma lanceolatum, Acrania): an immunocytochemical study (1994)
    Springer
    Cell & tissue research 277 (1994), S. 107-114 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Reissner's fiber ; Infundibular organ ; Immunocytochemistry ; Lectin binding ; Flexural organ ; Amphioxus, Branchiostoma lanceolatum (Acrania)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Reissner's fibers are secretions produced by different ependymal areas of the chordate brain, viz., in adult vertebrates, by the dorsal subcommissural organ, and in all stages of cephalochordates (Branchiostoma lancelets), by the ventral infundibular organ. Fibers produced by these different organs are seemingly identical and the two fiber sources also share some immunocytochemical and lectin-binding properties. The secretions in these two glands are, however, not identical; the infundibular organ cells are strongly reactive with antibodies against vertebrate Reissner's fibers, but they do not react with antibodies raised against the source of the vertebrate fibers, viz., the subcommissural organ. The results support the possibility that, in adult vertebrates, the Reissner's fibers are composed of material not only from the subcommissural organ, but also from another, not yet identified, source that is identical or equivalent to the infundibular organ of the lancelet. There are indications that the infundibular organ is immunocytochemically closely akin to some secretory cells in the vertebrate embryonic brain and also to those that produce the juvenile vertebrate Reissner's fibers, viz., secretory cells in the flexural organ.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00303086
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  • 32
    Digitale Medien
    Digitale Medien
    Chemically defined collateral projections from the pons to the central nucleus of the amygdala and hypothalamic paraventricular nucleus in the rat (1994)
    Springer
    Cell & tissue research 277 (1994), S. 289-295 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Serotonin ; Substance P ; Choline-acetyltransferase ; Retrograde tracers ; Immunocytochemistry ; Laterodorsal tegmental nucleus ; Dorsal raphe nucleus ; Rat (Sprague Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Triple fluorescence labelling was employed to reveal the distribution of chemically identified neurons within the pontine laterodorsal tegmental nucleus and dorsal raphe nucleus which supply branching collateral input to the central nucleus of the amygdala and hypothalamic paraventricular nucleus. The chemical identity of neurons in the laterodorsal tegmental nucleus was revealed by immunocytochemical detection of choline-acetyltransferase or substance P; in the dorsal raphe nucleus, the chemical content of the neurons was revealed with antibody recognizing serotonin. The projections were defined by injections of two retrograde tracers, rhodamine-and fluorescein-labelled latex microspheres, in the central nucleus of the amygdala and paraventricular nucleus, respectively. Neurons projecting to both the central nucleus of the amygdala and the paraventricular nucleus were distributed primarily within the caudal extensions of the laterodorsal tegmental nucleus and dorsal raphe nucleus. Approximately 11% and 7% of the labelled cells in the laterodorsal tegmental nucleus and dorsal raphe nucleus projected via branching collaterals to the paraventricular nucleus and central nucleus of the amygdala. About half of these neurons in the laterodorsal tegmental nucleus were cholinergic, and one-third were substance-P-ergic; in the dorsal raphe nucleus, approximately half of the neurons containing both retrograde tracers were serotonergic. These results indicate that pontine neurons may simultaneously transmit signals to the central nucleus of the amygdala and paraventricular nucleus and that several different neuroactive substances are found in the neurons participating in these pathways. This coordinated signalling may lead to synchronized responses of the central nucleus of the amygdala and paraventricular nucleus for the maintenance of homeostasis. Interactions between different neuroactive substances at the target site may serve to modulate the responses of individual neurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00327776
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  • 33
    Digitale Medien
    Digitale Medien
    Distribution and anatomy of GABA-like immunoreactive neurons in the central and peripheral nervous system of the snail Helix pomatia (1994)
    Springer
    Cell & tissue research 277 (1994), S. 189-198 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: GABA ; Glutamate ; Immunocytochemistry ; Nervous system ; central ; Nervous system ; peripheral ; Helix pomatia (Mollusca)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. Gamma-aminobutyric acid (GABA)-like immunoreactive neurons were studied in the central and peripheral nervous system of Helix pomatia by applying immunocytochemistry on whole-mount preparations and serial paraffin sections. GABA-immunoreactive cell bodies were found in the buccal, cerebral and pedal ganglia, but only GABA-immunoreactive fibers were found in the viscero-parietal-pleural ganglion complex. The majority of GABA-immunoreactive cell bodies were located in the pedal ganglia but a few could be found in the buccal ganglia. Varicose GABA-ir fibers could be seen in the neuropil areas and in distinct areas of the cell body layer of the ganglia. The majority of GABA-ir axonal processes run into the connectives and commissures of the ganglia, indicating an important central integrative role of GABA-immunoreactive neurons. GABA may also have a peripheral role, since GABA-immunoreactive fibers could be demonstrated in peripheral nerves and the lips. Glutamate injection did not change the number or distribution of GABA-immunoreactive neurons, but induced GABA immunoreactivity in elements of the connective tissue ensheathing the muscle cells and fibers of the buccal musculature. This shows that GABA may be present in different non-neural tissues as a product of general metabolic pathways.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00303096
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  • 34
    Digitale Medien
    Digitale Medien
    Immunologicalization of complement C1s and matrix metalloproteinase 9 (92kDa gelatinase/type IV collagenase) in the primary ossification center of the human femur (1994)
    Springer
    Cell & tissue research 277 (1994), S. 239-245 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Bone ; Ossification ; Cartilage ; Matrix ; Chondrocytes ; Complement ; Matrix metalloproteinase ; Immunocytochemistry ; Man
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The first component of complement $$C\bar 1s$$ has been shown to degrade type I and type II collagens (Yamaguchi et al. 1990), the latter of which is a major constituent of the cartilage matrix. In order to understand the physiological roles of $$C\bar 1s$$ in cartilage resorption, the expression of C1s was examined by immunohistochemistry in the primary ossification center where the matrix is removed and replaced by bone marrow. Hypertrophic chondrocytes, endothelium and hematogenous elements in the capillary buds were intensely stained by a monoclonal antibody against C1s. Matrix metalloproteinase 9 (MMP-9, 92kDa gelatinase/type IV collagenase) was also immunolocalized in hypertrophic chondrocytes, mesenchymal cells in the primitive bone marrow and the cartilage matrix adjacent to the marrow. In addition, $$C\bar 1s$$ was found to activate the zymogen of MMP-9. These observations suggest that $$C\bar 1s$$ and MMP-9 coordinately participate in matrix degradation in cartilage.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00327771
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  • 35
    Digitale Medien
    Digitale Medien
    Basement membrane components of bronchial epithelium in humans suffering from chronic nonspecific lung diseases (1994)
    Springer
    Cell & tissue research 277 (1994), S. 505-510 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Collagen IV ; Laminin ; Immunocytochemistry ; Basement membrane ; Bronchial epithelium ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Collagen IV and laminin are important constituents of the basement membrane (BM). By use of immunocytochemistry we examined the occurrence and distribution of these two components in the BM beneath normal, mucoid and metaplastic epithelium of large bronchi in 22 adults suffering from chronic nonspecific lung diseases. Both collagen IV and laminin were expressed as a thin and continuous layer beneath the epithelium in most tissue specimens with normal epithelium. In a few specimens the layer showed interruptions with a patchy distribution of the immunoreactivity. Three patterns of distribution of BM components were found under the metaplastic epithelium. Total absence of immunoreactive collagen IV and laminin was the most common variant. Weak and scarce staining for both proteins in the BM characterized the second pattern. The third variant showed strong collagen IV immunoreactivity but lack of laminin. The BM beneath the mucoid epithelium was characterized by irregular distribution of collagen IV and laminin. We suggest that the occurrence and distributional pattern of the BM components are related to the type of overlying epithelium and connected with an altered synthesis of these components.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300223
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  • 36
    Digitale Medien
    Digitale Medien
    Distribution and anatomy of GABA-like immunoreactive neurons in the central and peripheral nervous system of the snail Helix pomatia (1994)
    Springer
    Cell & tissue research 277 (1994), S. 189-198 
    Details
    ISSN: 1432-0878
    Schlagwort(e): GABA ; Glutamate ; Immunocytochemistry ; Nervous system, central ; Nervous system, peripheral ; Helix pomatia (Mollusca)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Gamma-aminobutyric acid (GABA)-like immunoreactive neurons were studied in the central and peripheral nervous system of Helix pomatia by applying immunocytochemistry on whole-mount preparations and serial paraffin sections. GABA-immunoreactive cell bodies were found in the buccal, cerebral and pedal ganglia, but only GABA-immunoreactive fibers were found in the viscero-parietal-pleural ganglion complex. The majority of GABA-immunoreactive cell bodies were located in the pedal ganglia but a few could be found in the buccal ganglia. Varicose GABA-ir fibers could be seen in the neuropil areas and in distinct areas of the cell body layer of the ganglia. The majority of GABA-ir axonal processes run into the connectives and commissures of the ganglia, indicating an important central integrative role of GABA-immunoreactive neurons. GABA may also have a peripheral role, since GABA-immunoreactive fibers could be demonstrated in peripheral nerves and the lips. Glutamate injection did not change the number or distribution of GABA-immunoreactive neurons, but induced GABA immunoreactivity in elements of the connective tissue ensheathing the muscle cells and fibers of the buccal musculature. This shows that GABA may be present in different non-neural tissues as a product of general metabolic pathways.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00303096
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  • 37
    Digitale Medien
    Digitale Medien
    C-PON immunoreactive neurons in the neostriatum of the hedgehog (Erinaceus europaeus): a correlated light- and electron-microscopic study (1994)
    Springer
    Cell & tissue research 277 (1994), S. 177-181 
    Details
    ISSN: 1432-0878
    Schlagwort(e): C-PON ; Neuropeptide Y ; Neostriatum ; Immunocytochemistry ; Ultrastructure ; Erinaceus europaeus (Insectivora)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The present study provides light- and electronmicroscopic immunocytochemical data on the presence of neurons that are immunoreactive to the C-terminal flanking peptide of neuropeptide Y, C-PON, in the neostriatum of the hedgehog (Erinaceus europaeus). Positive neurons have mostly fusiform or round perikarya from which two to four poorly branched processes arise. Immunostained fibers and puncta are also evenly distributed throughout the neostriatum. Ultrastructurally, each neuron exhibits a deeply invaginated nucleus surrounded by abundant cytoplasm with a well-developed rought endoplasmic reticulum and Golgi apparatus. Positive neurons receive symmetric and asymmetric synapses from unlabeled terminals. The results of this study can be correlated with previous findings, as the C-PON-positive neurons of the hedgehog resemble medium-sized neostriatal neurons that are known to be local circuit neurons exhibiting C-PON in the rat. Thus, a high degree of C-PON neuronal system phylogenetic conservation and function can be postulated for the neostriatum of mammals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00303094
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  • 38
    Digitale Medien
    Digitale Medien
    Ultrastructural, cytochemical, and immunocytochemical characterization of haemocytes of the hard tick Ixodes ricinus (Acari; Chelicerata) (1994)
    Springer
    Cell & tissue research 277 (1994), S. 493-504 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Haemocytes ; Immunocytes, invertebrate ; Immunity ; Immunocytochemistry ; Ixodes ricinus (Chelicerata)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Haemocytes of the hard tick Ixodes ricinus were characterized on the basis of their ultrastructure, their ability to ingest foreign material, and to produce or store molecules of the immune defence. Distinction was made between types of haemocytes according to the absence or presence of granular inclusions, shape and size of the lysosomal compartment or the rough endoplasmic reticulum, and ultrastructural and functional similarity to the corresponding haemocytes of insects. Three types of haemocytes were found in adult ticks: plasmatocytes and type-I and type-II granular haemocytes, respectively. The precipitated reaction product of acid phosphatase activity revealed the shape of the lysosomal compartment. The additional injection of particulate materials into the haemocoel further revealed the endocytic activity of the haemocytes. The lysozyme-like immunoreactivity of the haemocytes suggests bactericidal potential. Detection of immunoreactivity in haemocytes to a 25 kDa antigenic protein involved in cuticle formation further suggests their involvement in wound healing and encapsulation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300222
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  • 39
    Digitale Medien
    Digitale Medien
    Functional morphology of the neuropeptidergic light-yellow-cell system in pulmonate snails (1994)
    Springer
    Cell & tissue research 277 (1994), S. 531-538 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Light yellow neuropeptidergic cells ; Immunocytochemistry ; Blood pressure regulation ; Pulmonata ; Lymnaea stagnalis, Helix aspersa (Mollusca)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The light yellow neuropeptidergic cell system of the basommatophoran snail Lymnaea stagnalis is homologous to the R3-R14 system of the opisthobranch Aplysia californica, and produces three different neuropeptides. Systems homologous to the light yellow cells of Lymnaea stagnalis have been investigated morphologically in two Basommatophora (Lymnaea ovata, Bulinus truncatus) and three Stylommatophora (Helix aspersa, Cepaea nemoralis, Deroceras reticulatum). To this end, an antibody to synthetic light-yellow-cell peptide-II and oligonucleotides to mRNAs encoding parts of peptide-I and peptide-III, were used. The in situ hybridization probes gave negative results. On the other hand, neuronal cell clusters were observed in the central nervous system of all specias studied by immunocytochemistry. These clusters were located in the ganglia of the visceral complex. The neurons project axons into all nerves of these ganglia, especially into the pallial nerves, into the connective tissue of the central nervous system, and into the neuropile of various ganglia. The morphology of the systems is similar to that of the light-yellow-cell system of Lymnaea stagnalis. In all species, the wall of the aorta was innervated by immunoreactive axons. Peripheral innervation by the light-yellow-cell system was investigated in Helix aspersa and Deroceras reticulatum. Serial and alternate sections of whole snails were studied. Reconstructions were made of the heart-kidney-lung complex of these animals. In both species, the muscular vessels of the pulmonary system at the right side of the body were strongly innervated by immunoreactive axons. Furthermore, immunopositive innervation was observed to muscles in the secondary ureter-pneumostome area. The light-yellow-cell system of pulmonates is thus probably involved in the regulation of blood pressure and urine release.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300226
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  • 40
    Digitale Medien
    Digitale Medien
    Merkel cell distribution in human hair follicles of the fetal and adult scalp (1994)
    Springer
    Cell & tissue research 277 (1994), S. 131-138 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Merkel cells ; Cytokeratins ; Immunocytochemistry ; Nerve growth factor receptor ; Hair follicles ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The distribution of Merkel cells in fetal and adult terminal hair follicles of human scalp was studied immunohistochemically using cytokeratin (CK) 20 as a specific Merkel cell marker. In hair follicles of adult scalp, abundant Merkel cells were found enriched in two belt-like clusters, one in the deep infundibulum and one in the isthmus region. No Merkel cells were found in the deep follicular portions including the bulb, or in the dermis. In early fetal hair follicles (bulbous peg stage), Merkel cells were only detected in the basal layer of the developing infundibulum but not in deeper follicular areas. In later stages, Merkel cells were also present in the isthmus and bulge. No Merkel cells were seen in the dermis around developing hair follicles. Nerve growth factor receptor was not only present in nerves but was found to be widely distributed within fetal skin. In adult skin, this receptor was localized to the basal cell layers of the outer root sheath of the bulb and the suprabulbar area, but was not detectable in the areas containing Merkel cells. The present study localizing Merkel cells within the permanent hair follicle structures close to their possible stem cells suggests that they have paracrine functions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00303089
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  • 41
    Digitale Medien
    Digitale Medien
    Development of sensory innervation in chick skin: comparison of nerve fibre and chondroitin sulphate distributions in vivo and in vitro (1994)
    Springer
    Cell & tissue research 277 (1994), S. 519-529 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Skin ; Development, ontogenetic ; Chondroitin sulphate proteoglycan ; Neuritic guidance ; Immunocytochemistry ; Chicken
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract In bird skin, nerve fibres develop in the dermis but do not enter the epidermis. In co-cultures of 7-day-old chick embryo dorsal root ganglia and epidermis, the neurites also avoid the epidermis. Previous studies have shown that chondroitin sulphate proteoglycans may be involved. Chondroitin sulphate has therefore been visualized by immunocytochemistry, using themonoclonal antibody CS-56, both in vivo and in vitro using light and electron microscopy. Its distribution was compared to those of 2 other chondroitin sulphate epitopes and to that of the growing nerve fibres. In cultures of epidermis from 7-day-old embryonic chicks, immunoreactivity is found uniformly around the epidermal cells while at 7.5 days the distribution in dermis is heterogeneous, and particularly marked in feather buds. In vivo, chondroitin sulphate immunoreactivity is detected in the epidermis, on the basal lamina, on the surfaces of fibroblasts and along collagen fibrils. This localization is complementary to the distribution of cutaneous nerves. Chondroitin sulphate in the basal lamina could prevent innervation of the epidermis and the dermal heterogeneities could partly explain the nerve fibres surrounding the base of the feathers. Chondroitin sulphate could therefore be important for neural guidance in developing chick skin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300225
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  • 42
    Digitale Medien
    Digitale Medien
    Localization of mammary-derived growth inhibitor in capillary endothelial cells of the bovine mammary gland (1994)
    Springer
    Cell & tissue research 277 (1994), S. 457-464 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Mammary-derived growth inhibitor ; Fatty acid-binding proteins ; Differentiation ; Vascularization ; Immunohistochemistry ; Immunocytochemistry ; Mammary gland ; Cow
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. Mammary-derived growth inhibitor (MDGI) has previously been localized in the mammary parenchyma, dependent on the stage of differentiation of the mammary gland. Here, we have elucidated the distribution of MDGI in the mammary stroma by a combined immunohisto- and cytochemical analysis with antibodies raised against MDGI. Distinct staining of capillary endothelial cells has been revealed. Although its subcellular distribution resembles former observations in secretory epithelial cells, the expression of MDGI in capillary endothelial cells clearly precedes that in secretory epithelial cells. On the other hand, no endothelial MDGI staining has been detected in bovine heart, which contains a fatty acid-binding protein almost identical to MDGI. The localization of MDGI in the mammary capillary endothelium is discussed in terms of its possible involvement in the intracellular transport of hydrophobic ligands or in the regulation of endothelial cell proliferation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00300218
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  • 43
    Digitale Medien
    Digitale Medien
    Developmental expression of transforming growth factor-α and epidermal growth factor receptor proteins in the human pancreas and digestive tract (1994)
    Springer
    Cell & tissue research 278 (1994), S. 439-450 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Transforming growth factor alpha ; Epidermal growth factor receptor ; Development, ontogenetic ; Digestive tract ; Endocrine cells ; Immunocytochemistry ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract This study was designed to localize transforming growth factor alpha (TGF-α) and epidermal growth factor receptor (EGFR) expression in the developing human gastrointestinal tract and pancreas. Immunohistochemical techniques using specific antibodies against human TGF-α and EGFR were performed on digestive tissues of fetuses from 9 to 10 to 24 weeks of gestation, children and adults. In fetuses, TGF-α and EGFR proteins were expressed in all epithelial tissues studied with a good correlation and from an age as early as 9 to 10 weeks of gestation, except for TGF-α in the esophagus. The strongest TGF-α immunostaining was noted in the stomach and the proximal colon. Unexpectedly, immunoreactive gut endocrine cells were observed with the two antibodies used. Relatively numerous in fetuses, they decreased in number with age and were rare in adults particularly along the colon. Enteroglucagon-secreting cells were shown to express TGF-α while some gastrin, somatostatin and pancreatic glucagon cells were immunostained with EGFR antibodies. The presence of TGF-α and of its recetor in digestive tract epithelium and pancreatic tissues early in fetal life suggests a functional role for TGF-α during the developmental process of the digestive system. We demonstrate that TGF-α is also produced by endocrine cells and might have an additional mode of action other than paracrine, at least during fetal life.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00331362
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  • 44
    Digitale Medien
    Digitale Medien
    Expression of the α-subunit of glycoprotein hormones in the pars tuberalis-specific glandular cells in rat, mouse and guinea-pig (1994)
    Springer
    Cell & tissue research 278 (1994), S. 617-624 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Pituitary ; Pars tuberalis ; α-Subunit ; Immunocytochemistry ; In situ hybridization ; Rat ; Mouse ; Guinea-pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. The nature of the hormone(s) secreted by the pars tuberalis (PT) is still unknown. This pituitary lobe is mainly formed by specific glandular cells that differ in their ultrastructural features from the other adenohypophysial cell types. Data from the literature indicate the presence of thyroid-stimulating hormone immunoreactivity in the PT-specific cells of the rat and the Djungarian hamster but not of other species, including the mouse and guinea-pig. The PT also encloses variable numbers of pars distalis cells, essentially gonadotrophs that are mainly dispersed in its caudal area. We studied the expression of the glycoprotein hormone α-subunit in the PT of the rat, mouse and guinea-pig by in situ hybridization and immunocytochemistry. In situ hybridization, using an oligonucleotide probe complementary to rat cDNA sequence 196–237 revealed the expression of the α-subunit gene throughout the PT of the rat and the mouse; in the guinea-pig, the probe labelled no pituitary cells. Light- and electron-microscopic immunocytochemistry demonstrated α-subunit immunoreactivity in the secretory granules of the PT-specific cells in the three species examined. These cells did not react with a specific antibody against the β-subunit of luteinizing hormone, an antibody that labelled scattered gonadotrophs. The present data suggest that hormone(s) produced by the PT-specific glandular cells are, at least partly, related to glycoprotein hormones.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050253
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  • 45
    Digitale Medien
    Digitale Medien
    A comparative study of leucokinin-immunoreactive neurons in insects (1994)
    Springer
    Cell & tissue research 276 (1994), S. 69-83 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Immunocytochemistry ; Vasopressin ; Diuresis ; Neurohemal organ ; Evolution ; Nauphoeta cinerea ; Aedes aegypti ; Acheta domesticus ; Schistocerca americana (Insecta)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Antisera were raised against leucokinin IV, a member of the leucokinin peptide family. Immunohistochemical localization of leucokinin immunoreactivity in the brain of the cockroach Nauphoeta cinerea revealed neurosecretory cells in the pars intercerebralis and pars lateralis, several bilateral pairs of interneurons in the protocerebrum, and a group of interneurons in the optic lobe. Several immunoreactive interneurons were found in the thoracic ganglia, while the abdominal ganglia contained prominent immunoreactive neurosecretory cells, which projected to the lateral cardiac nerve. The presence of leucokinins in the abdominal nerve cord was confirmed by HPLC combined with ELISA. Leucokinin-immunoreactive neurosecretory cells were also found in the pars intercerebralis of the cricket Acheta domesticus and the mosquito Aedes aegypti, but not in the locust Schistocerca americana or the honey bee Apis mellifera. However, all these species have leucokinin-immunoreactive neurosecretory cells in the abdominal ganglia. The neurohemal organs innervated by abdominal leucokinin-immunoreactive cells were different in each species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00354786
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  • 46
    Digitale Medien
    Digitale Medien
    Sex difference in the neurotensin-immunoreactive cell populations of the preoptic area in quail (Coturnix japonica) (1994)
    Springer
    Cell & tissue research 276 (1994), S. 99-116 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Reproduction ; Immunocytochemistry ; Neurotensin ; Sexually dimorphic nucleus ; Sex differences, hypothalamus ; Japanese quail (Coturnix japonica)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The distribution of neurotensin-immunoreactive cells and fibers was analyzed by immunocytochemistry in the forebrain of male and female Japanese quail (Coturnix japonica) by using an antibody directed against the C-terminal part of the molecule. Immunoreactive perikarya were located almost exclusively in the medial preoptic area with small populations also being present in the nucleus paraventricularis and in the tuberal region. Immunoreactive fibers were observed not only throughout the preoptic area-hypothalamus, but also in the septal region, nucleus intercollicularis, substantia grisea centralis and the classical catecholaminergic areas of the mesencephalon, such as the area ventralis of Tsai and the nucleus tegmenti pedunculo-pontinus, pars compacta. The preoptic neurotensin-immunoreactive cells were exclusively located within the boundaries of the sexually dimorphic medial preoptic nucleus. They were significantly more numerous in females than in males. In females, the number of neurotensin cells varied during the ovulatory cycle: fewer cells were observed in birds that were about to lay an egg (they had a calcified egg in the oviduct) than in those that had already laid or were not going to lay on that day. These data indicate major variations in the expression of neurotensin in response to neurochemical or neuroendocrine changes associated with ovulation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00354789
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  • 47
    Digitale Medien
    Digitale Medien
    Presence of an oxytocin-like peptide in the hypothalamus and neurohypophysis of a turtle (Mauremys caspica) and a snake (Natrix maura) (1994)
    Springer
    Cell & tissue research 279 (1994), S. 75-84 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Oxytocin ; Neurophysin ; Vasotocin ; Mesotocin ; Suprachiasmatic nucleus ; Medial nucleus of the infundibular recess ; Immunocytochemistry ; Natrix maura (Serpentes) ; Mauremys caspica (Chelonia)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. The probable presence of oxytocin in the hypothalamo-hypophysial system of two reptilian species, the snake Natrix maura and the turtle Mauremys caspica, was re-investigated. A high-pressure liquid chromatographic analysis of the turtle neural lobe revealed the existence of vasotocin, mesotocin, and a third compound co-eluting with oxytocin. Brains from both species were fixed by vascular perfusion with Bouin's fluid. Adjacent paraffin sections were immunostained using antisera against the following substances: (1) bovine oxytocin-neurophysin; (2) a mixture of bovine oxytocin-neurophysin and vasopressin-neurophysin; (3) dogfish neurophysins; (4) oxytocin; (5) arginine-vasotocin; (6) mesotocin; (7) somatostatin. Immunoreactivity against oxytocin was found in parvocellular neurons of the snake suprachiasmatic nucleus and cerebrospinal-fluid contacting neurons of the medial nucleus of the infundibular recess of both species, the latter immunoreactivity being much more conspicuous in the turtle. Numerous fibers containing immunoreactive oxytocin extended between the medial nucleus of the infundibular recess, and the internal region of the medium eminence and the neural lobe. The oxytocin-immunoreactivity in all locations was completely abolished by preabsorption of the anti-oxytocin serum with three different oxytocin preparations. None of the neurons of the suprachiasmatic and medial nucleus of the infundibular recess, including the oxytocin-immunoreactive elements, reacted with either the antineurophysin sera used, or the anti-vasotocin or anti-mesotocin antibodies. The possible existence of a reptilian oxytocin-neurophysin different from the mammalian oxytocin-neurophysin is discussed. The alternative that, in the reptilian hypothalamus, neurons synthesize a compound closely related to, but different from oxytocin is also considered.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050263
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  • 48
    Digitale Medien
    Digitale Medien
    The biased intracellular accumulation of the β-subunit of salmon gonadotropin (GTH II) in the pituitary of rainbow trout Oncorhynchus mykiss, during gametogenesis (1994)
    Springer
    Cell & tissue research 279 (1994), S. 93-99 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Pituitary gland ; Gonadotropin ; Subunits ; Gonadotropes ; Immunocytochemistry ; Immunoblotting ; Oncorhynchus mykiss (Teleostei)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. Salmon gonadotropin (GTH II) is a heterodimeric glycoprotein hormone (α and IIβ subunits), serving as a maturational GTH, and is produced in a specific gonadotropic cell-type (GTH II-cells) containing small granules and large globules. In trout GTH II-cells, double immunolabeling for the α- and IIβ-subunits shows that colocalization of the α- and IIβ-immunolabeling is confined to the small granules, indicating storage of functional GTH II. On the other hand, α-immunolabeling is absent in the large globules, even though IIβ-labeling is abundant throughout the period of seasonal gametogenesis. The α-specific antiserum recognizes the intact α-subunit as well as the reduced and deglycosylated α-subunits by immunoblotting. These results indicate that an accumulation of the IIβ-subunit is specifically generated in the large globules of these cells. In fact, with sexual maturity, the quantity of IIβ-subunits becomes elevated in the trout pituitary due to a marked increase in GTH II-cells containing many large globules. However, the derivation and function of the large globules and the fate of their contained IIβ-subunits remains unknown.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050265
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  • 49
    Digitale Medien
    Digitale Medien
    Localisation of sulfakinin neuronal pathways in the blowfly Calliphora vomitoria (1994)
    Springer
    Cell & tissue research 275 (1994), S. 177-186 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Callisulfakinins ; Immunocytochemistry ; Neuropeptides ; Neurosecretory cells ; Evolution of cholecystokinin/gastrin ; Blowfly, Calliphora vomitoria (Insecta)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The distribution of neurones immunoreactive to antisera raised against the undecapeptide C-terminal fragment of drosulfakinin II (DrmSKII), Asp-Gln-Phe-Asp-Asp-Tyr(SO3H)-Gly-His-Met-Arg-Phe-NH2, has been studied in the blowfly Calliphora vomitoria. Antisera were preabsorbed with combinations of the parent antigen, the tetrapeptide Phe-Met-Arg-Phe-NH2 and cholecystokinin, the vertebrate sulfated octapeptide (CCK-8), Asp-Tyr(SO3H)-Met-Gly-Trp-Met-Asp-Phe-NH2, in order to ensure specificity for the sulfakinin peptides of C. vomitoria (the nonapeptide callisulfakinin I is identical to drosulfakinin I and callisulfakinin II differs from DrmSK II only by the presence of -Glu3-Glu4- in place of -Asp3-Asp4-). Only four pairs of sulfakinin-immunoreactive neurones have been visualised in the entire nervous system. These occur in the brain: two pairs of cells situated medially in the caudo-dorsal region close to the roots of the ocellar nerve and two other pairs at the same level but positioned more laterally. Despite the small number of sulfakinin-immunoreactive cells, there are extensive projections to many areas of neuropile in the brain and the thoracic ganglion. The pathway of the medial sulfakinin cells extends into each of the three thoracic ganglia and a metameric arrangement of sulfakinin neuronal projections is also seen in the abdominal ganglia. Neither the dorsal neural sheath of the thoracic ganglion, nor the abdominal nerves contain sulfakinin-immunoreactive material. These observations suggest that the sulfakinins of the blowfly function as neurotransmitters or neuromodulators. They do not appear to have a direct role in gut physiology, as has been shown by in vitro bioassays for the sulfakinins of orthopterans and blattodeans. In addition to the neurones that display specific sulfakinin immunoreactivity, other cells within the brain and thoracic ganglion are immunoreactive to cholecystokinin/gastrin antisera. There are, therefore, at least two types of dipteran neuropeptides with amino acid sequences that are similar to the vertebrate molecules cholecystokinin and gastrin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305385
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  • 50
    Digitale Medien
    Digitale Medien
    Immunolabeled neuroactive substances in the osphradium of the pond snail Lymnaea stagnalis (1994)
    Springer
    Cell & tissue research 275 (1994), S. 269-275 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Enkephalins ; FMRFamide ; Serotonin (5HT) ; Immunocytochemistry ; Sensory organ ; Osphradium ; Lymnaea stagnalis (Mollusca)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The osphradium of molluscs is assumed to be a sensory organ. The present investigation in Lymnaea stagnalis has established two ultrastructurally different types of dendrites in the sensory epithelium. Cells immunoreactive to leucine-enkephalin and FMRFamide send processes to the sensory epithelium. These neurons of the osphradial ganglion are thus considered to be part of the sensory system, as are methionine-enkephalin-immunoreactive cells in the mantle wall in the vicinity of the osphradium. The complexity of the osphradial ganglion is further demonstrated by serotonin-immunoreactive neurons innervating the muscular coat around the osphradial canal and methionine-enkephalin-immunoreactive cells sending projections to the central nervous system.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00319424
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  • 51
    Digitale Medien
    Digitale Medien
    The effects of pregnancy on the mouse thymic epithelium (1994)
    Springer
    Cell & tissue research 275 (1994), S. 309-318 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Thymus ; Pregnancy ; Involution ; Epithelial cells ; Immunocytochemistry ; Mouse (Swiss)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Changes in the murine thymus during pregnancy were studied using immunocytochemistry with monoclonal antibodies against thymic epithelial, neuroendocrine, and thymulin-producing cells, fibroblasts, blood vessels and connective tissue components. Extensive alterations occur in mid-pregnancy. The medulla was greatly enlarged in the involuted thymus, and there were greater numbers of epithelial cells. These epithelial cells had an altered distribution forming large structures surrounding spherical masses of mononulear cells, lacked epithelial cells and often contained a central blood vessel with fibroblasts and connective tissue. We have called these structures ‘medullary epithelial rings’ (MERs). To our knowledge these structures have not been described before. Late in pregnancy the loss of the central mononuclear cells leaves collapsed structures in a smaller medulla that nevertheless retains many epithelial cells. In virgins and early-pregnancy, there are cortical channels free of epithelial cells that are very infrequent later in pregnancy. This may reflect the loss of steroid-sensitive thymocytes from the cortex. The influence of sex-steroids neurological impulses and immune activity in causing the changes are discussed, as are the possible consequences in pregnancy of a reduced, thymocyte-depleted cortex and an enlarged medulla that shows great complexity and activity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00319429
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  • 52
    Digitale Medien
    Digitale Medien
    Functional morphology of the light yellow cell and yellow cell (sodium influx-stimulating peptide) neuroendocrine systems of the pond snail Lymnaea stagnalis (1994)
    Springer
    Cell & tissue research 275 (1994), S. 361-368 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Sodium influx-stimulating peptide, mollusc ; Neuroendocrine cells, mollusc ; Light yellow cells ; Yellow cells ; In situ hybridization ; Immunocytochemistry ; Osmoregulation ; Lymnaea stagnalis (Mollusca)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Neuroendocrine light yellow cells of the pond snail Lymnaea stagnalis express a neuropeptide gene encoding three different peptides. The morphology of the cell system has been studied by in situ hybridization, using two synthetic oligonucleotides encoding parts of light yellow cell peptides I and III, and by immunocytochemistry with antisera to synthetic light yellow cell peptide II and to two fragments of light yellow cell peptide I. One large cluster of light yellow cells was observed in the ventro-lateral protrusion of the right parietal ganglion, smaller clusters lying in the posterior dorsal part of this ganglion and in the visceral ganglion. The cells had an extended central neurohaemal area. Immunopositive axons projected into all nerves of the ganglia of the visceral complex, into the superior cervical and the nuchal nerves, and into the connective tissue surrounding the central nervous system. Axon tracts ramified between the muscle cells of the walls of the anterior aorta and of smaller blood vessels. Peripheral innervation by the light yellow cell system was only found in muscular tissue of the ureter papilla. The antisera to the two peptide fragments of light yellow cell peptide I not only stained the light yellow cells, but also the identified yellow cells, which have previously been shown to produce the sodium influx-stimulating neuropeptide. The latter cells were negative to the in situ hybridization probes and antisera specific to the light yellow cell system. It is therefore unlikely that the yellow cells express the light yellow cell neuropeptide gene. Nevertheless, the cells contain a neuropeptide sharing antigenic determinants with light yellow cell peptide I. Our observations support the hypothesis that light yellow cells are involved in maintaining the shape of the animal via the regulation of ion- and waterbalance processes and blood pressure.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00319435
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  • 53
    Digitale Medien
    Digitale Medien
    Developmental expression of transforming growth factor-α and epidermal growth factor receptor proteins in the human pancreas and digestive tract (1994)
    Springer
    Cell & tissue research 278 (1994), S. 439-450 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Transforming growth factor alpha ; Epidermal growth factor receptor ; Development ; ontogenetic ; Digestive tract ; Endocrine cells ; Immunocytochemistry ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. This study was designed to localize transforming growth factor alpha (TGF-α) and epidermal growth factor receptor (EGFR) expression in the developing human gastrointestinal tract and pancreas. Immunohistochemical techniques using specific antibodies against human TGF-α and EGFR were performed on digestive tissues of fetuses from 9 to 10 to 24 weeks of gestation, children and adults. In fetuses, TGF-α and EGFR proteins were expressed in all epithelial tissues studied with a good correlation and from an age as early as 9 to 10 weeks of gestation, except for TGF-α in the esophagus. The strongest TGF-α immunostaining was noted in the stomach and the proximal colon. Unexpectedly, immunoreactive gut endocrine cells were observed with the two antibodies used. Relatively numerous in fetuses, they decreased in number with age and were rare in adults particularly along the colon. Enteroglucagon-secreting cells were shown to express TGF-α, while some gastrin, somatostatin and pancreatic glucagon cells were immunostained with EGFR antibodies. The presence of TGF-α and of its receptor in digestive tract epithelium and pancreatic tissues early in fetal life suggests a functional role for TGF-α during the developmental process of the digestive system. We demonstrate that TGF-α is also produced by endocrine cells and might have an additional mode of action other than paracrine, at least during fetal life.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050234
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  • 54
    Digitale Medien
    Digitale Medien
    Leucokinin and diuretic hormone immunoreactivity of neurons in the tobacco hornworm, Manduca sexta, and co-localization of this immunoreactivity in lateral neurosecretory cells of abdominal ganglia (1994)
    Springer
    Cell & tissue research 278 (1994), S. 493-507 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Neuropeptides ; Diuresis ; insects ; Neurosecretory cells ; Immunocytochemistry ; Manduca sexta (Insecta)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. Because leucokinins stimulate diuresis in some insects, we wished to identify the neurosecretory cells in Manduca sexta that might be a source of leucokinin-like neurohormones. Immunostaining was done at various stages of development, using an antiserum to leucokinin IV. Bilateral pairs of neurosecretory cells in abdominal ganglia 3–7 of larvae and adults are immunoreactive; these cells project via the ipsilateral ventral nerves to the neurohemal transverse nerves. The immunoreactivity and size of these lateral cells greatly increases in the pharate adult, and this change appears to be related to a period of intensive diuresis occurring a few days before adult eclosion. Relationships of these neurons to cells that are immunoreactive to a M. sexta diuretic hormone were also investigated. Diuretic hormone and leucokinin immunoreactivity are co-localized in the lateral neurosecretory cells and their neurohemal projections. A median pair of leucokinin-immunoreactive, and a lateral pair of diuretic hormone-immunoreactive neurons in the larval terminal abdominal ganglion project to neurohemal release sites within the cryptonephridium. The immunoreactivity of these cells is lost as the cryptonephridium is eliminated during metamorphosis. This loss appears to be related to the change from the larval to adult pattern of diuresis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410050238
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  • 55
    Digitale Medien
    Digitale Medien
    Expression of the α-subunit of glycoprotein hormones in the pars tuberalis-specific glandular cells in rat, mouse and guinea-pig (1994)
    Springer
    Cell & tissue research 278 (1994), S. 617-624 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pituitary ; Pars tuberalis ; α-Subunit ; Immunocytochemistry ; In situ hybridization ; Rat ; Mouse ; Guinea-pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The nature of the hormone(s) secreted by the pars tuberalis (PT) is still unknown. This pituitary lobe is mainly formed by specific glandular cells that differ in their ultrastructural features from the other adenohypophysial cell types. Data from the literature indicate the presence of thyroid-stimulating hormone immunoreactivity in the PT-specific cells of the rat and the Djungarian hamster but not of other species, including the mouse and guinea-pig. The PT also encloses variable numbers of pars distalis cells, essentially gonadotrophs that are mainly dispersed in its caudal area. We studied the expression of the glycoprotein hormone α-subunit in the PT of the rat, mouse and guinea-pig by in situ hybridization and immunocytochemistry. In situ hybridization, using an oligonucleotide probe complementary to rat cDNA sequence 196–237 revealed the expression of the α-subunit gene throughout the PT of the rat and the mouse; in the guinea-pig, the probe labelled no pituitary cells. Light-and electron-microscopic immunocytochemistry demonstrated α-subunit immunoreactivity in the secretory granules of the PT-specific cells in the three species examined. These cells did not react with a specific antibody against the β-subunit of luteinizing hormone, an antibody that labelled scattered gonadotrops. The present data suggest that hormone(s) produced by the PT-specific glandular cells are, at least partly, related to glycoprotein hormones.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00331382
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  • 56
    Digitale Medien
    Digitale Medien
    Immunocytochemical localization and characterization of mammalian prolactin- and somatotropin-like material in the pituitary of the Australian lungfish, Neoceratodus forsteri (1994)
    Springer
    Cell & tissue research 276 (1994), S. 117-121 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Mammalian-type prolactin ; Mammalian-type somatotropin ; Pituitary ; Immunocytochemistry ; Light microscopy ; Neoceratodus forsteri (Australian lungfish)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The aim of the present study was to define at the light-microscopic level expression of prolactin and somatotropin material in the pituitary gland of the Australian lungfish, Neoceratodus forsteri, by use of polyclonal antibodies against ovine prolactin (oPRL) and bovine somatotropin (bSTH). Substances immunologically related to mammalian oPRL as well as bSTH were detected in two morphologically different cell types in the distal lobe, corresponding to the acidophilic cells. The specificity of the antibodies was initially confirmed in a porcine tissue control system. First, our absorption studies confirm that in Neoceratodus the anti-oPRL identifies part of an oPRL-like molecule different from bSTH. Secondly, the anti-bSTH identifies both part of a bSTH-like molecule proper to bovine and Neoceratodus STH, and part of a bSTH-like molecule having antigenic determinants in common with both bSTH and oPRL. This part of the oPRL is, however, not shared with the Neoceratodus PRL as revealed by the anti-oPRL. Altogether these observations support the concepts: (1) that mammalian PRL and STH, or part of those, were established early in evolution, and (2) that dipnoans as living sarcopterygians have an ancestor in common with the early amphibians. The exact nature and physiological functions of the substances detected remain to be defined.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00354790
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  • 57
    Digitale Medien
    Digitale Medien
    Localisation of substance P-like immunoreactivity in the ciliary ganglia of monkey (Macaca fascicularis) and cat: a light- and electron-microscopic study (1994)
    Springer
    Cell & tissue research 276 (1994), S. 163-171 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Substance P ; Immunocytochemistry ; Ciliary ganglion ; Monkey, Macaca fascicularis (Primates) ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The present study describes substance P-like immunoreactivity in the ciliary ganglia of monkey (Macaca fascicularis) and cat. About 60% of neurons in the monkey ciliary ganglion and 40% in the cat ciliary ganglion were substance P-like immunoreactive, ranging from faint to moderate staining. Substance P-like immunoreactivity was located in cell bodies, dendritic profiles and axons. In the monkey, substance P-like immunoreactive pericellular arborisations were associated with about 0.5%–3% of the ganglion cells, which were either negatively, faintly or moderately stained. An electron-microscopic study demonstrated the presence of either substance P-like immunoreactive positive or negative axon terminals synapsing or closely associated with positive dendritic profiles in both the monkey and cat ciliary ganglia. The results suggest that substance P plays an important role in the ciliary ganglion, perhaps as a modulator or transmitter.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00354796
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  • 58
    Digitale Medien
    Digitale Medien
    Different patterns of retinal cone topography in two genera of rodents, Mus and Apodemus (1994)
    Springer
    Cell & tissue research 276 (1994), S. 143-150 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Retina ; Cone fields ; Photoreceptor mosaic ; Colour vision ; Immunocytochemistry ; Mus spicilegus, Apodemus sylvaticus, Apodemus microps (Rodentia)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Recently, we have reported the peculiar topographic separation of shortwave- and middlewave-sensitive (S and M) cones in the retina of the common house mouse (Mus musculus) and in a number of inbred laboratory mouse strains derived from the same species. In an attempt to follow the phylogeny of the complementary cone fields, we have investigated the retina of other mouse-like rodents. Two monoclonal anti-visual pigment antibodies, OS-2 and COS-1, specific to the S and M cones, respectively, have been used to identify the two cone types. Immunocytochemistry on retinal sections and on whole-mount preparations have shown that, as in the house mouse, the two cone types in the mound builder mouse (Mus spicileugus) occupy opposite halves of the retina. In contrast, in the wood mouse (Apodemus sylvaticus), both cone types are scattered uniformly across the whole retinal surface. Another distinguishing feature between the two genera is the frequency of the S cones. Whereas their density in the Mus species is above 7 000/mm2 in the S-field, the maximum density of the S cones in A. sylvaticus is one order of magnitude smaller. In another species of this genus (the herb field mouse, A. microps), the S cones are completely missing.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00354793
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  • 59
    Digitale Medien
    Digitale Medien
    Substance P immunoreactivity in sensory structures and the central and pharyngeal nervous system of Stenostomum leucops (Catenulida) and Microstomum lineare (Macrostomida) (1994)
    Springer
    Cell & tissue research 276 (1994), S. 173-180 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Immunocytochemistry ; Substance P ; Sensory structures ; Nervous system ; Stenostomum Leucops, Microstomum lineare (Plathelminthes)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Immunoreactivity (IR) obtained by monoclonal antibodies to substance P (SP) was studied in the asexually reproducing microturbellarians Stenostomum leucops and Microstomum lineare. The IR pattern was studied by confocal and ordinary fluorescence microscopy. In both species, IR occurs in the brain in peripheral cells, neuropilar fibres, in longitudinal cords and in the pharyngeal nervous system. The IR patterns reveal neuroanatomical details not observed with other neuroactive substances. In both species, immunopositive cells send fibers to the ciliary pits. In M. lineare, additional fibres run to more frontally located sensory structures. In S. leucops, two pharyngeal nerve rings are visualized. The pharyngeal nerve ring close to the surface associated with symmetrical immunopositive cell pairs is demonstrated for the first time, while the deeper-lying pharyngeal nerve ring has been previously demonstrated by antibodies to the molluscan cardioactive peptide FMRF-amide. Two cells with strong IR are connected by short fibres to the pharyngeal nerve ring in M. lineare. In the developing new individuals, i.e., the zooids of M. lineare, IR to SP is first revealed in nerve fibres growing out from parental lateral nerve cords towards the centre of the worm where the new brain commissure will appear. Immunopositive cells in the brain periphery and close to the developing ciliary pits appear later. Simultaneous staining by antibodies to SP and 5-HT shows that IR to SP appears later than IR to 5-HT.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00354797
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  • 60
    Digitale Medien
    Digitale Medien
    Location of PHM/VIP mRNA in human gastrointestinal tract detected by in situ hybridization (1994)
    Springer
    Cell & tissue research 276 (1994), S. 229-238 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Gastrointestinal tract ; Prepro-VIP mRNA ; Prepro-VIP-derived peptides ; In situ hybridization ; Northern blots ; Immunocytochemistry ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The expression of the gene for vasoactive intestinal polypeptide (VIP) and peptide histidine methionine (PHM) in the human gastrointestinal tract was studied by in situ hybridization and Northern blotting for PHM/ VIP mRNA and immunocytochemistry using specific antisera against the bioactive peptides PHM and VIP. In the colon sigmoideum, antisera against all five putative processing products of the VIP precursor (prepro-VIP) were used, namely prepro-VIP 22–79, PHM, prepro-VIP 111–122, VIP and prepro-VIP 156–170. Furthermore, RNA extracted from various regions of the gastrointestinal tract was examined by Northern blots and hybridization to a VIP-cDNA probe. Throughout the gastrointestinal tract, PHM/VIP mRNA was found in neurons only. Using single-or double-staining methods, we demonstrated both PHM/VIP mRNA and the corresponding peptides PHM and VIP in the neurons. In the sigmoideum, the single-staining methods were extended to investigate whether the neurons simultaneously contained PHM/VIP mRNA and each of the five prepro-VIP-derived peptides. Only one major band of PHM/VIP mRNA (1.9 kb) was found by Northern blotting in the tissue of the gastrointestinal tract.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306108
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  • 61
    Digitale Medien
    Digitale Medien
    Distribution and functional significance of Leu-callatostatins in the blowfly Calliphora vomitoria (1994)
    Springer
    Cell & tissue research 276 (1994), S. 367-379 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Callatostatins ; Leu-callatostatins ; Allatostatins ; Immunocytochemistry ; Myotropic peptides ; Neuropeptides ; Neurosecretory cells ; Hindgut ; Blowfly, Calliphora vomitoria (Insecta)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The Leu-callatostatins are a series of four neuropeptides isolated from nervous tissues of the blowfly Calliphora vomitoria that show C-terminal sequence homology to the allatostatins of cockroaches. The allatostatins have an important role in the reproductive processes of insects as inhibitors of the synthesis and release of juvenile hormone from the corpus allatum. In this study, the distribution of the Leu-callatostatin-immunoreactive neurones and endocrine cells has been mapped in C. vomitoria and, in contrast to the cockroach allatostatins, it has been shown that there is no cytological basis to suggest that the dipteran peptides act as regulators of juvenile hormone. Although occurring in various neurones in the brain and thoracico-abdominal ganglion, there is no evidence of Leu-callatostatin-immunoreactive pathways linking the brain to the corpus allatum, or of immunoreactive terminals in this gland. Three different types of functions for the Leu-callatostatins are suggested by the occurrence of immunoreactive material in cells and by the pathways that have been identified. (1) A role in neurotransmission or neuromodulation appears evident from immunoreactive neurones in the medulla of the optic lobes, and from immunoreactive material in the central body and in descending interneurones in the suboesophageal ganglion that project to the neuropile of the thoracico-abdominal ganglion. (2) Leu-callatostatin neurones directly innervate muscles of the hindgut and the heart. Immunoreactive fibres from neurones of the abdominal ganglion pass by way of the median abdominal nerve to ramify extensively over several areas of the hindgut. Physiological experiments with synthetic peptides show that the Leu-callatostatins are potent inhibitors of peristaltic movements of the ileum. Leu-callatostatin 3 is active at 10-16 to 10-13 M. This form or regulatory control over gut motility appears to be highly specific since the patterns of contraction in other regions are unaffected by these peptides. (3) Evidence that the Leu-callatostatins act as neurohormones comes from the presence of varicosities in axons passing through the corpus cardiacum (but not the corpus allatum) and also from material in extraganglionic neurosecretory cells in the thorax. Fibres from these peripheral neurones are especially prominent over the large nerve bundles supplying the legs. There are also a considerable number of Leu-callatostatin-immunoreactive endocrine cells in a specific region of the midgut. The conclusion from this study is that although conservation of the structure of the allatostatin-type of peptides is evident through a long period of evolution it cannot be assumed that all of their functions have also been conserved. Several different types of functions for the Leu-callatostatins of the blowfly are proposed in this study, but there is no evidence to suggest a role in the regulation of juvenile hormone synthesis and release.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306122
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  • 62
    Digitale Medien
    Digitale Medien
    Localisation of gamma aminobutyric acid (GABA)-like immunoreactivity in the echinoderm Asterias rubens (1994)
    Springer
    Cell & tissue research 278 (1994), S. 177-185 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: GABA ; Immunocytochemistry ; Radial nerve cord ; Tube feet ; Digestive system ; Asterias rubens (Echinodermata)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. Gamma amino butyric acid (GABA) is believed to be the principal inhibitory neurotransmitter in the mammalian central nervous system, a function that has been extended to a number of invertebrate systems. We have used a specific antiserum raised against GABA to demonstrate GABA-like immunoreactivity in the radial nerve cord (RNC), tube feet and the digestive system of the asteroid Asterias rubens. In the RNC, immunoreactivity was restricted to ectoneural fibres and cell bodies while in the tube feet fibres were revealed in the basal nerve ring and longitudinal nerve. In the gut, extensive labelling was apparent in the basi-epithelial plexus as well as in mucosal perikarya.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305790
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  • 63
    Digitale Medien
    Digitale Medien
    Immunocytochemical localization of Na+/K+-ATPase and V-H+-ATPase in the salivary glands of the cockroach, Periplaneta americana (1994)
    Springer
    Cell & tissue research 278 (1994), S. 161-170 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Salivary glands ; Na+/K+-ATPase ; H+-ATPase ; Epithelial transport ; Polarity ; Immunocytochemistry ; Periplaneta americana (Insecta)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. The acinous salivary glands of the cockroach (Periplaneta americana) consist of four morphologically different cell types with different functions: the peripheral cells are thought to produce the fluid component of the primary saliva, the central cells secrete the proteinaceous components, the inner acinar duct cells stabilize the acini and secrete a cuticular intima, whereas the distal duct cells modify the primary saliva via the transport of water and electrolytes. Because there is no direct information available on the distribution of ion transporting enzymes in the salivary glands, we have mapped the distribution of two key transport enzymes, the Na+/K+-ATPase (sodium pump) and a vacuolar-type H+-ATPase, by immunocytochemical techniques. In the peripheral cells, the Na+/K+-ATPase is localized to the highly infolded apical membrane surface. The distal duct cells show large numbers of sodium pumps localized to the basolateral part of their plasma membrane, whereas their highly folded apical membranes have a vacuolar-type H+-ATPase. Our immunocytochemical data are supported by conventional electron microscopy, which shows electron-dense 10-nm particles (portasomes) on the cytoplasmic surface of the infoldings of the apical membranes of the distal duct cells. The apically localized Na+/K+-ATPase in the peripheral cells is probably directly involved in the formation of the Na+-rich primary saliva. The latter is modified by the distal duct cells by transport mechanisms energized by the proton motive force of the apically localized V-H+-ATPase.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305788
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  • 64
    Digitale Medien
    Digitale Medien
    Alterations in the subcellular distribution of 17β-estradiol dehydrogenase in porcine endometrial cells over the course of the estrous cycle (1994)
    Springer
    Cell & tissue research 278 (1994), S. 227-233 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Endometrium ; Dehydrogenase ; Cytoskeleton ; Estrous cycle ; Immunocytochemistry ; Immunofluorescence microscopy ; Pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. The uteri of German landrace gilts slaughtered at different days of the cycle were processed for immunocytochemistry and biochemical analyses. Plasma was collected for hormone assays. The monoclonal antibody F1 against the structure-bound 17β-estradiol dehydrogenase of porcine endometrial epithelium was applied to rehydrated paraffin sections either as a direct, peroxidase-linked probe or in combination with a fluorescing secondary antibody. The oxidation of estradiol was measured in homogenates of tissue powdered in liquid nitrogen. Immunoreactivity was restricted to endometrial epithelium. In the glandular epithelium, faint dots of fluorescence became visible at day 4, which apparently coalesced to spherical structures of 2-4 μm diameter at the cell basis between days 11 through 17 before disappearing by day 18. A similar distribution was observed for the oxidation products of diaminobenzidine beginning with a faint uniform staining and followed by the appearance of intensely stained basal bodies persisting until day 17. Essentially the same time course was seen in the luminal epithelium but with a different distribution. Immunoreactive material amassed in the apical region of the cells, but the conspicuous aggregations were absent. Time course and intensities of the immunological responses are matched by the enzymatic activity measured in parallel. Both correlate with the plasma progesterone levels, suggesting an induction of the enzyme by the hormone. An involvement of the cytoskeleton in the sequence of subcellular distribution patterns is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00414164
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  • 65
    Digitale Medien
    Digitale Medien
    The immunolocalization of small nuclear ribonucleoprotein particles in testicular cells during the cycle of the seminiferous epithelium of the adult rat (1994)
    Springer
    Cell & tissue research 278 (1994), S. 363-378 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: snRNPs ; Testis ; Spermatocytes ; Spermatids ; Immunocytochemistry ; Chromatoid body ; Intermitochondrial nuage ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. The objective of this study was to determine the cellular and subcellular distribution of small nuclear ribonucleoprotein particles (snRNPs) in the adult rat testis in relation to the different cell types at the various stages of the cycle of the seminiferous epithelium. The distribution of snRNPs in the nucleus and cytoplasm of germ cells was quantitated in an attempt to correlate RNA processing with morphological and functional changes occurring during the development of these cells. Light-microscopic immunoperoxidase staining of rat testes with polyclonal anti-Sm and monoclonal anti-Y12 antibodies localized spliceosome snRNPs in the nuclei and cytoplasm of germ cells up to step 10 spermatids. Nuclear staining was intense in Sertoli cells, spermatogonia, spermatocytes, and in the early steps of round spermatid development. Although comparatively weaker, cytoplasmic staining for snRNPs was strongest in mid and late pachytene spermatocytes and early round spermatids. Quantitative electron-microscopic immunogold labeling of Lowicryl embedded testicular sections confirmed the light-microscopic observations but additionally showed that the snRNP content peaked in the cytoplasm of mid-pachytene spermatocytes and in the nuclei of late pachytene spermatocytes. The immunogold label tended to aggregate into distinct loci over the nuclear chromatin. The chromatoid body of spermatids and spermatocytes and the finely granular material in the interstices of mitochondrial aggregates of spermatocytes were found to be additional sites of snRNP localization and were intensely labeled. This colocalization suggests that these dense cytoplasmic structures may be functionally related. Anti-U1 snRNP antibodies applied to frozen sections showed the same LM localization pattern as spliceosome snRNPs. Anti-U3 snRNP antibodies applied to frozen sections stained nucleoli of germ cells where pre-rRNA is spliced.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00414179
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  • 66
    Digitale Medien
    Digitale Medien
    Immunolocalization of Na,K-ATPase in blowfly photoreceptor cells (1994)
    Springer
    Cell & tissue research 275 (1994), S. 225-234 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Compound eye ; Photoreceptor cells ; Ion pumps ; Polarity ; Spectrin ; Cytoskeleton ; Immunocytochemistry ; Calliphora erythrocephala (Insecta)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The Na,K-ATPase (sodium pump) plays a central role in the physiology of arthropod photoreceptors as it re-establishes gradients for Na+ and K+ after light stimulation. We have mapped the distribution of the Na,K-ATPase in the photoreceptors of the blowfly (Calliphora erythrocephala) by immunofluorescent and immunogold cytochemistry, and demonstrate that the distribution pattern is more complex than previously presumed. High levels of sodium pumps have been detected consistently in all photoreceptors R1-8 on the nonreceptive surface, but no sodium pumps are found on the microvillar rhabdomere. Within the nonreceptive surface of the cells R1-6, however, the sodium pumps are confined to sites juxtaposed to neighboring photoreceptor or glial cells; no sodium pumps have been detected on the parts of the nonreceptive surface exposed to the intra-ommatidial space. In R7 and R8, the sodium pumps are found over the entire nonreceptive surface. The cytoskeletal protein spectrin colocalizes with the sodium pumps suggesting that linkage of the pump molecules to the spectrin-based submembrane cytoskeleton contributes to the maintenance of the complex pattern of pump distribution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00319420
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  • 67
    Digitale Medien
    Digitale Medien
    Expression and translation of the egg-laying neuropeptide hormone genes during post-embryonic development of the pond snail Lymnaea stagnalis (1994)
    Springer
    Cell & tissue research 275 (1994), S. 369-375 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Post-embryonic development ; Gene expression ; Caudodorsal cell hormones (CDCH) ; In situ hybridization ; Immunocytochemistry ; Immunogold labelling ; Lymnaea stagnalis (Mollusca)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The neuroendocrine caudodorsal cells of Lymnaea stagnalis express two homologous genes, each encoding a polypeptide precursor. The precursors give rise to “cocktails” of neuropeptides that regulate egg-laying. The expression and translation of both egg-laying hormone genes during post-embryonic development were investigated by in situ hybridization and by electron-microscopic immunocytochemistry. Gene-II-specific transcripts and translation products were not found in caudodorsal cells in animals with shell heights smaller than 10 mm, in contrast to gene-I products that were present even at 3-mm shell height. The onset of expression of gene II coincides with the onset of release of products from the caudodorsal cells into the blood. Large electron-dense granules were found in caudodorsal cells of snails of all developmental stages investigated. These granules form part of the Golgi sorting and packaging pathway. Their presence suggests that differential sorting and packaging is possible during post-embryonic development, like in adults. The relationship of the differential expression of the two genes to the development of the caudodorsal cell system and its targets is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00319436
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  • 68
    Digitale Medien
    Digitale Medien
    Immunocytochemical distribution of neuropeptide F (NPF) in the gastropod mollusc, Helix aspersa, and in several other invertebrates (1994)
    Springer
    Cell & tissue research 275 (1994), S. 383-393 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Immunocytochemistry ; Neuropeptide F ; Neuropeptide Y ; Pancreatic polypeptide ; FMRFamide ; Helix aspersa (Mollusca)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The distribution of neuropeptide F (NPF) immunoreactivity in the snail, Helix aspersa, has been demonstrated by immunocytochemistry using 2 regionspecific antisera. One, designated NPF3, was raised against a synthetic N-terminal fragment of Helix aspersa NPF; the other, designated PP221, was raised against the C-terminal hexapeptide amide of mammalian pancreatic polypeptide (PP) but cross-reacts fully with the analogous C-terminal region of Helix aspersa NPF. The distribution of NPF immunoreactivity has also been compared with that of FMRFamide using alternate serial sections of Helix aspersa ganglia. Results showed that NPF immunoreactivity was abundant and widespread in the central and peripheral nervous systems and the pattern of immunostaining obtained using both region-specific antisera was similar. Likewise, immunocytochemistry of neural tissues of a congeneric species, Helix pomatia, and 2 prosobranch gastropods, Buccinum undatum and Littorina littorea, produced similar staining patterns with both antisera. However, in the cephalopod mollusc, Loligo vulgaris, and the cestode, Moniezia expansa, positive immunostaining was only obtained with the C-terminal PP antiserum. Immunostaining of alternate serial sections of Helix aspersa ganglia with NPF3, and an antiserum raised to FMRFamide, showed that while a few neurones were immunoreactive with one antiserum only, in the majority, both immunoreactivities were co-localised. NPF thus appears to be an important neuropeptide of widespread distribution in Helix aspersa and the differential immunocytochemical staining obtained using the 2 region-specific antisera would suggest a high degree of primary structural conservation within the gastropod molluscs, but lack of conservation of the N-terminal region of the peptide in other invertebrate groups.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00319438
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  • 69
    Digitale Medien
    Digitale Medien
    Leucokinin and diuretic hormone immunoreactivity of neurons in the tobacco hornworm, Manduca sexta, and co-localization of this immunoreactivity in lateral neurosecretory cells of abdominal ganglia (1994)
    Springer
    Cell & tissue research 278 (1994), S. 493-507 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Neuropeptides ; Diuresis, insects ; Neurosecretory cells ; Immunocytochemistry ; Manduca sexta (Insecta)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Because leucokinins stimulate diuresis in some insects, we wished to identify the neurosecretory cells in Manduca sexta that might be a source of leucokinin-like neurohormones. Immunostaining was done at various stages of development, using an antiserum to leucokinin IV. Bilateral pairs of neurosecretory cells in abdominal ganglia 3–7 of larvae and adults are immunoreactive; these cells project via the ipsilateral ventral nerves to the neurohemal transverse nerves. The immunoreactivity and size of these lateral cells greatly increases in the pharate adult, and this change appears to be related to a period of intensive diuresis occurring a few days before adult eclosion. Relationships of these neurons to cells that are immunoreactive to a M. sexta diuretic hormone were also investigated. Diuretic hormone and leucokinin immunoreactivity are co-localized in the lateral neurosecretory cells and their neurohemal projections. A median pair of leucokinin-immunoreactive, and a lateral pair of diuretic hormone-immunoreactive neurons in the larval terminal abdominal ganglion project to neurohemal release sites within the cryptonephridium. The immunoreactivity of these cells is lost as the cryptonephridium is eliminated during metamorphosis. This loss appears to be related to the change from the larval to adult pattern of diuresis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00331367
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  • 70
    Digitale Medien
    Digitale Medien
    Selective association of nerve fibres immunoreactive for substance P or bombesin with putative cholinergic neurons of the male rat major pelvic ganglion (1994)
    Springer
    Cell & tissue research 278 (1994), S. 589-594 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Autonomic ganglia ; Neuropeptides ; Pelvic plexus ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The male rat major pelvic ganglion contains both sympathetic and parasympathetic neurons that supply the lower urinary and digestive tracts, and the reproductive organs. The aim of this study was to describe the distribution and identify potential targets of sensory and intestinofugal axons in this ganglion. Two putative markers of these projections were chosen, substance P for primary sensory axons and bombesin for myenteric intestinofugal projections. Varicose substance P-immunoreactive axons were associated only with non-noradrenergic (putative cholinergic) somata, and most commonly with those that contained vasoactive intestinal peptide. Immunoreactivity for substance P was also present in a small group of non-noradrenergic somata, many of which were immunoreactive for enkephalins, neuropeptide Y or vasoactive intestinal peptide. Bombesin immunoreactivity was found only in preterminal and terminal (varicose) axons, the latter of which were exclusively associated with non-noradrenergic somata that contain neuropeptide Y-immunoreactivity. Some varicose axons containing either substance P-or bombesin-immunoreactivity were intermingled with clumps of small, intensely fluorescent cells. These studies indicate that substance P-and bombesin-immunoreactive axons are likely to connect with numerically small, but discrete, populations of pelvic neurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00331378
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  • 71
    Digitale Medien
    Digitale Medien
    Problems encountered when immunocytochemistry is used for quantitative glial cell identification in autoradiographic studies of cell proliferation in the brain of the unlesioned adult mouse (1994)
    Springer
    Cell & tissue research 278 (1994), S. 85-95 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Autoradiography ; Immunocytochemistry ; Astrocytes ; Oligodendrocytes ; Cell proliferation ; Mouse (Han: NMRI)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract We have used sections of adult mouse brain to determine whether antibodies specific for oligodendroglia (anti-carbonic anhydrase II, CA II; anti-galactocerebroside, GC; anti-myelin basic protein, MBP) and astroglia (anti-glial fibrillary acidic protein, GFAP; anti-S 100 protein) are suitable for quantitative studies of the proliferation and subsequent differentiation of these cells. Unlesioned adult mice received a single injection of 3H-thymidine (TdR) and were killed between 1 h and 70 days later. Quantitative evaluations of autoradiographs of 2-μm-thick serial sections stained immunocytochemically with the antibodies mentioned above or with Richardson's method for histological control led to the following conclusions. Anti-GC and anti-MBP stained only the oligodendrocytic processes and, thus, cannot be used in well-myelinated brain areas. Anti-CA II stained only a portion of the differentiated oligodendrocytes, but no proliferating cells. Anti-S 100 protein recognized all the astrocytes, but also many (interfascicular) oligodendrocytes. Anti-GFAP stained only a few astrocytes in the unlesioned mouse: all astrocytes may become GFAP-immunopositive only after wounding the brain. Thus, in contrast to in vitro studies, immunocytochemical studies with these antibodies on sections of adult animals cannot be recommended for the quantitative analysis of cell proliferation. In addition, our results show that differentiated glial cells proliferate in adult mice. Astro- and oligodendrocytes divide with the same cell cycle parameters and mode of proliferation up to about 1 month after 3H-TdR injection. In contrast to oligodendrocytes, some astrocytes might re-enter the cycle after a few weeks of quiescence.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305780
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  • 72
    Digitale Medien
    Digitale Medien
    Localisation of gamma aminobutyric acid (GABA)-like immunoreactivity in the echinoderm Asterias rubens (1994)
    Springer
    Cell & tissue research 278 (1994), S. 177-185 
    Details
    ISSN: 1432-0878
    Schlagwort(e): GABA ; Immunocytochemistry ; Radial nerve cord ; Tube feet ; Digestive system ; Asterias rubens (Echinodermata)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Gamma amino butyric acid (GABA) is believed to be the principal inhibitory neurotransmitter in the mammalian central nervous system, a function that has been extended to a number of invertebrate systems. We have used a specific antiserum raised against GABA to demonstrate GABA-like immunoreactivity in the radial nerve cord (RNC), tube feet and the digestive system of the asteroid Asterias rubens. In the RNC, immunoreactivity was restricted to ectoneural fibres and cell bodies while in the tube feet fibres were revealed in the basal nerve ring and longitudinal nerve. In the gut, extensive labelling was apparent in the basi-epithelial plexus as well as in mucosal perikarya.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305790
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  • 73
    Digitale Medien
    Digitale Medien
    Immunocytochemical localization of Na+/K+-ATPase and V-H+-ATPase in the salivary glands of the cockroach, Periplaneta americana (1994)
    Springer
    Cell & tissue research 278 (1994), S. 161-170 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Salivary glands ; Na+/K+-ATPase ; H+-ATPase ; Epithelial transport ; Polarity ; Immunocytochemistry ; Periplaneta americana (Insecta)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The acinous salivary glands of the cockroach (Periplaneta americana) consist of four morphologically different cell types with different functions: the peripheral cells are thought to produce the fluid component of the primary saliva, the central cells secrete the proteinaceous components, the inner acinar duct cells stabilize the acini and secrete a cuticular, intima, whereas the distal duct cells modify the primary saliva via the transport of water and electrolytes. Because there is no direct information available on the distribution of ion transporting enzymes in the salivary glands, we have mapped the distribution of two key transport enzymes, the Na+/K+-ATPase (sodium pump) and a vacuolar-type H+-ATPase, by immunocytochemical techniques. In the peripheral cells, the Na+/K+-ATPase is localized to the highly infolded apical membrane surface. The distal duct cells show large numbers of sodium pumps localized to the basolateral part of their plasma membrane, whereas their highly folded apical membranes have a vacuolar-type H+-ATPase. Our immunocytochemical data are supported by conventional electron microscopy, which shows electrondense 10-nm particles (portasomes) on the cytoplasmic surface of the infoldings of the apical membranes of the distal duct cells. The apically localized Na+/K+-ATPase in the peripheral cells is probably directly involved in the formation of the Na+-rich primary saliva. The latter is modified by the distal duct cells by transport mechanisms energized by the proton motive force of the apically localized V-H+-ATPase.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305788
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  • 74
    Digitale Medien
    Digitale Medien
    Problems encountered when immunocytochemistry is used for quantitative glial cell identification in autoradiographic studies of cell proliferation in the brain of the unlesioned adult mouse (1994)
    Springer
    Cell & tissue research 278 (1994), S. 85-95 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Autoradiography ; Immunocytochemistry ; Astrocytes ; Oligodendrocytes ; Cell proliferation ; Mouse (Han: NMRI)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. We have used sections of adult mouse brain to determine whether antibodies specific for oligodendroglia (anti-carbonic anhydrase II, CA II; anti-galactocerebroside, GC; anti-myelin basic protein, MBP) and astroglia (anti-glial fibrillary acidic protein, GFAP; anti-S 100 protein) are suitable for quantitative studies of the proliferation and subsequent differentiation of these cells. Unlesioned adult mice received a single injection of 3H-thymidine (TdR) and were killed between 1 h and 70 days later. Quantitative evaluations of autoradiographs of 2-μm-thick serial sections stained immunocytochemically with the antibodies mentioned above or with Richardson's method for histological control led to the following conclusions. Anti-GC and anti-MBP stained only the oligodendrocytic processes and, thus, cannot be used in well-myelinated brain areas. Anti-CA II stained only a portion of the differentiated oligodendrocytes, but no proliferating cells. Anti-S 100 protein recognized all the astrocytes, but also many (interfascicular) oligodendrocytes. Anti-GFAP stained only a few astrocytes in the unlesioned mouse; all astrocytes may become GFAP-immunopositive only after wounding the brain. Thus, in contrast to in vitro studies, immunocytochemical studies with these antibodies on sections of adult animals cannot be recommended for the quantitative analysis of cell proliferation. In addition, our results show that differentiated glial cells proliferate in adult mice. Astro- and oligodendrocytes divide with the same cell cycle parameters and mode of proliferation up to about 1 month after 3H-TdR injection. In contrast to oligodendrocytes, some astrocytes might re-enter the cycle after a few weeks of quiescence.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305780
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  • 75
    Digitale Medien
    Digitale Medien
    Zona glomerulosa of the adrenal gland in a transgenic strain of rat: a morphologic and functional study (1994)
    Springer
    Cell & tissue research 278 (1994), S. 21-28 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words: Adrenal cortex ; Renin-angiotensin system ; Steroidogenesis ; Electron microscopy ; Morphometry ; Rat ; transgenic (mRen2) 27
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract. Transgenic rats for the murine Ren-2 gene display high blood pressure, low circulating levels of angiotensin II, and high renin content in the adrenal glands. Moreover, transgenic rats possess an increased aldosterone secretion (maximal from 6 to 18 weeks of age), paralleling the development of hypertension. To investigate further the cytophysiology of the adrenal glands of this strain of rats, we performed a combined morphometric and functional study of the zona glomerulosa of 10-week-old female transgenic rats. Morphometry did not reveal notable differences between zona glomerulosa cells of transgenic and age- and sex-matched Sprague-Dawley rats, with the exception of a marked accumulation of lipid droplets, in which cholesterol and cholesterol esters are stored. The volume of the lipid-droplet compartment underwent a significant decrease when transgenic rats were previously injected with angiotensin II or ACTH. Dispersed zona glomerulosa cells of transgenic rats showed a significantly higher basal aldosterone secretion, but their response to angiotensin II and ACTH was similar to that of Sprague-Dawley animals. Angiotensin II-receptor number and affinity were not dissimilar in zona glomerulosa cells of transgenic and Sprague-Dawley rats. These data suggest that the sustained stimulation of the adrenal renin-angiotensin system in transgenic animals causes an increase in the accumulation in zona glomerulosa cells of cholesterol available for steroidogenesis, as indicated by the expanded volume of the lipid-droplet compartment and the elevated basal steroidogenesis. However, the basal hyperfunction of the zona glomerulosa in transgenic animals does not appear to be coupled with an enhanced responsivity to its main secretagogues, at least in terms of aldosterone secretion.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305774
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  • 76
    Digitale Medien
    Digitale Medien
    Alterations in the subcellular distribution of 17β-estradiol dehydrogenase in porcine endometrial cells over the course of the estrous cycle (1994)
    Springer
    Cell & tissue research 278 (1994), S. 227-233 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Endometrium ; Dehydrogenase ; Cytoskeleton ; Estrous cycle ; Immunocytochemistry ; Immunofluorescence microscopy ; Pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The uteri of German landrace gilts slaughtered at different days of the cycle were processed for immunocytochemistry and biochemical analyses. Plasma was collected for hormone assays. The monoclonal antibody F1 against the structure-bound 17β-estradiol dehydrogenase of porcine endometrial epithelium was applied to rehydrated paraffin sections either as a direct, peroxidase-linked probe or in combination with a fluorescing secondary antibody. The oxidation of estradiol was measured in homogenates of tissue powdered in liquid nitrogen. Immunoreactivity was restricted to endometrial epithelium. In the glandular epithelium, faint dots of fluorescence became visible at day 4, which apparently coalesced to spherical structures of 2–4 μm diameter at the cell basis between days 11 through 17 before disappearing by day 18. A similar distribution was observed for the oxidation products of diaminobenzidine beginning with a faint uniform staining and followed by the appearance of intensely stained basal bodies persisting until day 17. Essentially the same time course was seen in the luminal epithelium but with a different distribution. Immunoreactive material amassed in the apical region of the cells, but the conspicuous aggregations were absent. Time course and intensities of the immunological responses are matched by the enzymatic activity measured in parallel. Both correlate with the plasma progesterone levels, suggesting an induction of the enzyme by the hormone. An involvement of the cytoskeleton in the sequence of subcellular distribution patterns is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00414164
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  • 77
    Digitale Medien
    Digitale Medien
    Nitric oxide synthase immunoreactivity in the enteric nervous system of the developing human digestive tract (1994)
    Springer
    Cell & tissue research 275 (1994), S. 235-245 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Nitric oxide ; Nitric oxide synthase ; NADPH-diaphorase ; Vasoactive intestinal polypeptide ; Immunocytochemistry ; Enteric nervous system ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract We have investigated indirectly the presence of nitric oxide in the enteric nervous system of the digestive tract of human fetuses and newborns by nitric oxide synthase (NOS) immunocytochemistry and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) histochemistry. In the stomach, NOS immunoactivity was confined to the myenteric plexus and nerve fibres in the outer smooth musculature; few immunoreactive nerve cell bodies were found in ganglia of the outer submucous plexus. In the pyloric region, a few nitrergic perikarya were seen in the inner submucous plexus and some immunoreactive fibres were found in the muscularis mucosae. In the small intestine, nitrergic neurons clustered just underneath or above the topographical plane formed by the primary nerve strands of the myenteric plexus up to the 26th week of gestation, after which stage, they occurred throughout the ganglia. Many of their processes contributed to the dense fine-meshed tertiary nerve network of the myenteric plexus and the circular smooth muscle layer. NOS-immunoreactive fibres directed to the circular smooth muscle layer originated from a few NOS-containing perikarya located in the outer submucous plexus. In the colon, caecum and rectum, labelled nerve cells and fibres were numerous in the myenteric plexus; they were also found in the outer submucous plexus. The circular muscle layer had a much denser NOS-immunoreactive innervation than the longitudinally oriented taenia. The marked morphological differences observed between nitrergic neurons within the developing human gastrointestinal tract, together with the typical innervation pattern in the ganglionic and aganglionic nerve networks, support the existenc of distinct subpopulations of NOS-containing enterice neurons acting as interneurons or (inhibitory) motor neurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00319421
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  • 78
    Digitale Medien
    Digitale Medien
    Serotonin-and FMRFamide-immunoreactive nerve elements in the chiton Lepidopleurus asellus (Mollusca, Polyplacophora) (1994)
    Springer
    Cell & tissue research 275 (1994), S. 277-282 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Serotonin (5HT) ; FMRFamide ; Immunocytochemistry ; Invertebrate nervous system ; Chiton, Lepidopleurus asellus (Mollusca)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The distribution of serotonin-like and FMRFamide-like immunoreactive (5HT-ir and FMRFa-ir, respectively) neurons in the nervous system of the chiton Lepidopleurus asellus (Mollusca, Polyplacophora) was studied using an immunocytochemical technique. The neurons were distributed in characteristic patterns in the central nervous system, the 5HT-ir neurons predominating in the ventral (pedal) cords and FMRFa-ir neurons in the lateral cords. In the body wall including the foot, a tight network of 5HT-ir and FMRFa-ir nerve fibers is found, the former being mostly attributed to the musculature whereas the latter seems to be associated with the blood sinuses. Intraepithelial neurons of both types are abundant in the fore-and hindgut. The presence and general distribution in the central and peripheral nervous system of the 5HT-ir and FMRFa-ir elements seems thus to be similar in simple and advanced molluscs. The relationship between these neurons and their targets in the body also appears to be well conserved in molluscs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00319425
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  • 79
    Digitale Medien
    Digitale Medien
    Octopamine-like immunoreactive neurones in locust genital abdominal ganglia (1994)
    Springer
    Cell & tissue research 275 (1994), S. 299-308 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Immunocytochemistry ; Amines, biogenic ; DUM neurones ; Sexual dimorphism ; Locusta migratoria (Insecta)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Using a well characterized anti-serum, the distribution of octopamine-like immunoreactive neurones is described in the locust seventh abdominal (A7) and terminal ganglia (TG), which are associated with genital organs. Apart from 4 paired ventral somata occasionally observed in the TG, all labelled cells could be identified as efferent dorsal- and ventral unpaired median (DUM/VUM) neurones by virtue of the characteristic large size and position of their somata, projections of their primary neurites in DUM-cell tracts, and bifurcating axons which arise from dorsal T-junctions and enter peripheral nerves. For the examined ganglia our data indicate that the whole population of efferent DUM and VUM-cells, defined here as progeny of the segment specific unpaired median neuroblast with peripheral axons, are octopaminergic, and that equal numbers of these cells occur in both sexes: 8 in A7 and 11 in TG. Sex-specific differences are probably restricted to the axonal projections of 5 octopamine-like immunoreactive DUM-somata in A7, and 5 in TG, which in females project into their segment specific sternal nerves, but in males into the genital nerve of the TG. Numerous intersegmentally projecting octopamine-like immunoreactive fibres traverse both ganglia. The majority probably stem from previously described octopamine-like immunoreactive neurones in the thoracic and suboesophageal ganglia.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00319428
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  • 80
    Digitale Medien
    Digitale Medien
    Immunocytochemical identification of photoreceptor proteins in hypothalamic cerebrospinal fluid-contacting neurons of the larval lamprey (Petromyzon marinus) (1994)
    Springer
    Cell & tissue research 275 (1994), S. 319-326 
    Details
    ISSN: 1432-0878
    Schlagwort(e): α-Transducin ; Cerebrospinal fluid (CSF)-contacting neurons ; Immunocytochemistry ; Opsin ; Photoreceptors ; Pineal complex ; Retina ; Petromyzon marinus (Cyclostomata)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Antibodies directed against different visual pigment opsins, and an antibody raised against the C terminal of the α-subunit of retinal G protein (transducin) labelled cerebrospinal fluid-contacting cells located within the hypothalamus (postoptic commissural nucleus and ventral hypothalamic nucleus) of ammocoete lampreys (Petromyzon marinus). These antibodies also labelled photoreceptor cells within the retina and the pineal and parapineal organs, but no other areas of the brain. Despite considerable behavioural and physiological evidence for the existence of deep brain photoreceptors, numerous studies have failed to identify photoreceptor proteins within the basal brain. The results presented in this paper support our recent results in the lizard Anolis carolinensis, suggesting that a group of cerebrospinal fluid-contacting neurons within the vertebrate brain have a photosensory capacity. We speculate that these cells mediate extraocular and extrapineal photoreception in nonmammalian vertebrates.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00319430
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  • 81
    Digitale Medien
    Digitale Medien
    Nitric oxide (NO) synthase immunoreactivity in the starfish Marthasterias glacialis (1994)
    Springer
    Cell & tissue research 275 (1994), S. 599-603 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Nitric oxide synthase ; Nervous system ; Gut ; Endocrine cells ; Immunocytochemistry ; Marthasterias glacialis (Echinodermata)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The neuroendocrine system of the starfish Marthasterias glacialis was investigated immunocytochemically using antisera specific for rat neuronal, bovine aortic endothelial, and mouse macrophage, nitric oxide (NO) synthases. Immunoreactivity was detected only with the antibodies specific for the neural enzyme, in the ectoneural and hyponeural tissues of the radial nerve cords and in the basiepithelial plexus and endocrine cells of the digestive tract. The pyloric stomach showed more immunoreactive structures than the other digestive organs, with the rectal caeca showing the least activity. Immunoreactive endocrine cells were located in the cardiac and pyloric stomachs and in the pyloric caeca. Co-localization of the enzyme immunoreactivity, and the staining for NADPH-diaphorase, demonstrate the presence of NO synthase in echinoderms. These results provide further evidence that NO is a neuronal messenger of early phylogenetic origin which has been conserved throughout evolution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00318828
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  • 82
    Digitale Medien
    Digitale Medien
    Double immunofluorescence staining of Fos and Jun in the hypothalamus of the rat (1994)
    Springer
    Cell & tissue research 276 (1994), S. 1-6 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Immunofluorescence microscopy ; Gene expression ; Immunocytochemistry ; Supraoptic nucleus ; Paraventricular nucleus ; Fos ; Jun ; Rat (Long Evans)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The nuclear factor Fos participates in the transcriptional regulation of genes that contain a functional AP-1 binding site. Hyperosmotic stress induces Fos-like immunoreactivity in neurons of the hypothalamus. Fos appears to depend on the co-expression of the nuclear factor Jun, with which it dimerizes, to complete its regulatory role. The immunocytochemical co-localization of both peptides, however, has not been reported. The present study was designed to analyze the distribution of Fos and Jun by double immunofluorescence staining in Long-Evans rats that were osmotically challenged by a single intraperitoneal injection of 1.5 M NaCl. Non-injected and isotonic saline-injected animals were used as controls. Hypertonic saline injection induced Jun immunoreactivity in cell nuclei in the supraoptic nucleus, paraventricular nucleus, and median preoptic nucleus. The immunofluorescence for Jun was strong in the supraoptic and paraventricular nuclei, but weak in the median preoptic nucleus. The immunofluorescence for Fos in all 3 nuclei followed a similar pattern to that for Jun. Double immunofluorescence staining revealed colocalization of Jun with Fos in 87.4% of the cells of the supraoptic nucleus. Neither Jun nor Fos immunofluorescence was detected in control animals. The data support a role for Jun in transcriptional regulation of genes in hypothalamic neurons during acute hyperosmotic stress. Moreover, the findings are compatible with the suggestion that Fos and Jun act cooperatively in the regulation of gene transcription in neuroendocrine systems involved in the control of water balance during acute hyperosmotic stimulation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00354777
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  • 83
    Digitale Medien
    Digitale Medien
    Localization of GABAA receptors in the rabbit retina (1994)
    Springer
    Cell & tissue research 276 (1994), S. 295-307 
    Details
    ISSN: 1432-0878
    Schlagwort(e): GABAA receptors ; Light microscopy ; Electron microscopy ; α1 subunit ; β2/3 subunit ; γ2 subunit ; Immunocytochemistry ; Rabbit (New Zealand)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The distribution of gamma-aminobutyric acidA (GABAA) receptors in the rabbit retina is investigated and compared with the distribution of GABAergic neurons using immunocytochemical methods. Antibodies against the α1, β2/3, and γ2 subunits of the GABAA receptor label subpopulations of bipolar, amacrine and ganglion cells. Double labeling experiments show that the γ2 subunit is colocalized with the α1 and the β2/3 subunits in bipolar, amacrine and ganglion cells. Electron microscopy reveals that in the outer plexiform layer, GABAA receptor immunoreactivity is present on dendrites of cone bipolar cells adjacent to the cone pedicles. Bipolar cell dendrites are also receptor-positive at synapses from interplexiform cells. Some receptor immunoreactivity is found intracellularly in processes of horizontal cells. In the inner plexiform layer, GABAA receptor immunoreactivity is present on both rod bipolar and cone bipolar axon terminals at putative GABAergic input sites. Amacrine and ganglion cell processes in sublamina a and b are also labeled.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306115
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  • 84
    Digitale Medien
    Digitale Medien
    Immunolocalization of albumin and transferrin in germ cells and Sertoli cells during rat gonadal morphogenesis and postnatal development of the testis (1994)
    Springer
    Cell & tissue research 276 (1994), S. 347-351 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Albumin ; Transferrin ; Germ cells ; Sertoli cells ; Testis ; Immunocytochemistry ; Ontogenesis ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The localization of albumin and transferrin was examined immunohistochemically in germ cells and Sertoli cells during rat gonadal morphogenesis and postnatal development of the testis. These proteins appeared as early as the 13th day of gestation in migrating primordial germ cells before Sertoli cell differentiation. In the fetal testis, strong immunoreactivity was only detected in the gonocytes. In the prepubertal testis, spermatogonia, primary spermatocytes, and some Sertoli cells accumulate albumin and transferrin. At puberty, different patterns of immunostaining of the germ cells were observed at the various stages of the cycle of the seminiferous epithelium. Diplotene spermatocytes at stage XIII, spermatocytes in division at stage XIV, and round spermatids at stages IV–VIII showed maximal staining. Labeling was evident in the cytoplasm of adult Sertoli cells. Albumin and transferrin staining patterns paralleled each other during ontogenesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306119
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  • 85
    Digitale Medien
    Digitale Medien
    Immunocytochemical localization of aromatase-containing neurons in the rat brain during pre- and postnatal development (1994)
    Springer
    Cell & tissue research 278 (1994), S. 29-39 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Aromatase ; Brain ; Development, ontogenetic ; Immunocytochemistry ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract the present immunohistochemical study demonstrates the ontogenetic appearance of aromatase-immunoreactive neurons in several discrete regions of the hypothalamus and limbic system in the rat brain, using a purified antibody against human placental aromatase cytochrome P450. Immunoreactive cells were first detected in the preoptic area on the 13th day of embryonic life (E 13), and additionally in the bed nucleus of the stria terminalis on E 15. Labeled cells were also found in the medial amygdaloid nucleus and the ventromedial nucleus on E 16, and some were detected in the arcuate nucleus on E 19. As gestation progressed, the number and the immunoreactivity of these cells gradually increased and peaked within definite periods of perinatal life and there-after declined or disappeared. The immunoreactive cells were also found in the central amygdaloid nucleus and the lateral septal nucleus, and in the ventral pallidum, after the 14th day of postnatal life (P 14) and 30th day (P 30), respectively. The distribution of aromatase-immunoreactive neurons was similar between the sexes, while the immunoreactivity was higher in males than in females after late gestational days. No immunoreaction was detectable in other regions of the telencephalon or midbrain at any time periods studied. The aromatase-immunoreactive neurons in the specific regions may be involved in the sexual differentiation of the brain.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305775
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  • 86
    Digitale Medien
    Digitale Medien
    Taurine, amino acid transmitters, and related molecules in the retina of the Australian lungfish Neoceratodus forsteri: a light-microscopic immunocytochemical and electron-microscopic study (1994)
    Springer
    Cell & tissue research 278 (1994), S. 311-326 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Retina ; Taurine ; GABA ; Glycine ; Glutamate ; Immunocytochemistry ; Lungfish, Neoceratodus forsteri (Dipnoi)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The morphology of the retina of the Australian lungfish Neoceratodus forsteri was investigated by means of light- and electron microscopy, whilst immunocytochemical studies were performed to determine the cellular distributions of the major amino acid neurotransmitters and other amino acids. The distributions of glycine and GABA were similar to those previously described for teleost, amphibian and mammalian retinae. Labelling was abundant in amacrine cells, whilst GABA was also present in one layer of horizontal cells and some bipolar cells. Taurine was present in both rods and cones, but, unlike the mammalian or avian retina, was absent from other cellular structures, including glial elements. Unexpectedly, the photoreceptor terminals lacked an apparent content of the excitatory amino acid transmitter glutamate. The glutamate that was present in the rods and cones occupied a crescentic arc corresponding to the location of glycogen-rich paraboloids. Asparagine was also present in rods, albeit in the modified mitochondria that formed the elipsoids of the rod inner segments. Arginine, the precursor for formation of nitric oxide, was present in glial cells, and in the paraboloids of both rods and cones.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00414175
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  • 87
    Digitale Medien
    Digitale Medien
    Descending neurons with dopamine-like or with substance P/FMRFamide-like immunoreactivity target the somata of olfactory interneurons in the brain of the spiny lobster, Panulirus argus (1994)
    Springer
    Cell & tissue research 278 (1994), S. 337-352 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Immunocytochemistry ; Dopamine ; Substance P ; Brain, invertebrate ; Olfactory system ; Panulirus argus (Crustacea)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Two sets of descending neurons primarily target the somata of neurons in the olfactory deutocerebrum of the spiny lobster, Panulirus argus. Hundreds to thousands of dopamine-like immunoreactive fibers originate in the lateral protocerebrum and terminate among the clustered somata of the olfactory deutocerebrum projection neurons (lateral soma cluster) and those of the olfactory deutocerebrum local interneurons (medial soma cluster). A pair of giant neurons with substance P-and FMRFamide-like immunoreactivity from the median protocerebrum terminate primarily in the lateral soma cluster, but also branch in the core of the olfactory lobe itself. Neurons of both types terminate in numerous bouton-like swellings. The terminals in the lateral cluster at least contain numerous, large, dense-core and small, clear vesicles. The terminals contact the somata and the primary neurites through both traditional chemical synapses and large zones of direct membrane appositions. In most instances, a vesicle-containing profile forms a triadic arrangement with a neurite and a soma the latter being frequently connected via large gap-junction-like structures. Rosette-like arrangements formed by a vesicle-containing profile surrounded by up to eight neurites are also common. Dissociated lateral cluster somata support both fast inward and sustained outward voltage-activated currents. Substance P, but not dopamine or FMRFamide-related peptides, alters the fast inward current. The somata of the olfactory projection neurons, and possibly those of the olfactory local interneurons, appear to serve an integrative, and not merely a supportive role in these invertebrate central neurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00414177
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  • 88
    Digitale Medien
    Digitale Medien
    The immunolocalization of small nuclear ribonucleoprotein particles in testicular cells during the cycle of the seminiferous epithelium of the adult rat (1994)
    Springer
    Cell & tissue research 278 (1994), S. 363-378 
    Details
    ISSN: 1432-0878
    Schlagwort(e): snRNPs ; Testis ; Spermatocytes ; Spermatids ; Immunocytochemistry ; Chromatoid body ; Intermitochondrial nuage ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The objective of this study was to determine the cellular and subcellular distribution of small nuclear ribonucleoprotein particles (snRNPs) in the adult rat testis in relation to the different cell types at the various stages of the cycle of the seminiferous epithelium. The distribution of snRNPs in the nucleus and cytoplasm of germ cells was quantitated in an attempt to correlate RNA processing with morphological and functional changes occurring during the development of these cells. Light-microscopic immunoperoxidase staining of rat testes with polyclonal anti-Sm and monoclonal anti-Y12 antibodies localized spliceosome snRNPs in the nuclei and cytoplasm of germ cells up to step 10 spermatids. Nuclear staining was intense in Sertoli cells, spermatogonia, spermatocytes, and in the early steps of round spermatid development. Although comparatively weaker, cytoplasmic staining for snRNPs was strongest in mid and late pachytene spermatocytes and early round spermatids. Quantitative electron-microscopic immunogold labeling of Lowicryl embedded testicular sections confirmed the light-microscopic observations but additionally showed that the snRNP content peaked in the cytoplasm of midpachytene spermatocytes and in the nuclei of late pachytene spermatocytes. The immunogold label tended to aggregate into distinct loci over the nuclear chromatin. The chromatoid body of spermatids and spermatocytes and the finely granular material in the interstices of mitochondrial aggregates of spermatocytes were found to be additional sites of snRNP localization and were intensely labeled. This colocalization suggests that these dense cytoplasmic structures may be functionally related. Anti-U1 snRNP antibodies applied to frozen sections showed the same LM localization pattern as spliceosome snRNPs. Anti-U3 snRNP antibodies applied to frozen sections stained nucleoli of germ cells where pre-rRNA is spliced.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00414179
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  • 89
    Digitale Medien
    Digitale Medien
    Molecular and physiological evaluation of transgenic tobacco plants expressing a maize phosphoenolpyruvate carboxylase gene under the control of the cauliflower mosaic virus 35S promoter (1994)
    Springer
    Transgenic research 3 (1994), S. 287-296 
    Details
    ISSN: 1573-9368
    Schlagwort(e): C4-plant ; maize ; phosphoenolpyruvate carboxylase ; quantum yield ; transgenic tobacco
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The expression of maize (Zea mays) phosphoenolpyruvate carboxylase (PEPC) gene constructs in transgenic tobacco plants (Nicotiana tabacum) was studied. Where transcription was under the control of a CaMV 35S promoter, maize PEPC transcripts of the correct size were detected. Western blot analysis indicated that the transgenic plants contained about twice as much PEPC as non-transformed plants. Furthermore, the enzymatic activity of PEPC in the leaves of these transgenic plants was up to twice as high as that in non-transformed plants. Two forms of PEPC with different kinetic properties were identified in leaf extracts of the transgenic plants: one form (the maize isoform) gave a high apparentK m value for phosphoenolpyruvate (PEP) and a high maximum activity, and the other (the tobacco isoform) exhibited a low apparentK m value for PEP and a low maximum activity. These biochemical differences resulted in several significant physiological changes in the transgenic plants: (1) the growth rate of the transgenic plants was lower than that of non-transgenic plants: (2) chlorophyll content per leaf area was relatively lower in the transgenic plants; and (3) the quantum yield of photosynthesis in the transgenic plants was not affected by changes in leaf temperature.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01973588
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  • 90
    Digitale Medien
    Digitale Medien
    Structural and immunocytochemical characterization of microtubule organizing centers in pteridophyte spermatogenous cells (1994)
    Springer
    Protoplasma 179 (1994), S. 46-60 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Blepharoplast ; Gamma tubulin ; Microtubule organizing centers ; Multilayered structure ; Pteridophyte spermatid ; Immunocytochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary During the development of the spermatogenous cells, the pteridophyteCeratopteris richardii produces three structurally well-defined microtubule organizing centers (MTOCs). The blepharoplast, a spherical body that occurs during the last two spermatogenous divisions, organizes two microtubule (MT) arrays, one associated with a nuclear indentation and the other that organizes the spindle apparatus for the final divisions. After the last spermatogenous division, the blepharoplast reorganizes to produce two new putative MTOCs: the lamellar strip (LS) of the multilayered structure (MLS), which apparently organizes the spline microtubule array, and an amorphous zone (AM), that connects the basal bodies. Thin and semi-thin sections of this tissue were probed with antisera which recognize MTOCs in lower eukaryotes and animals to determine if any of these structures contain MTOC-associated proteins or epitopes recognized by monoclonal antisera. Gamma tubulin antibodies, which recognizeonly the minus ends of MTs in mammalian cells, label along the MT in all arrays found in the pteridophyte spermatogenous cells. Kinetochore MTs are unlabelled near the kinetochore, however. The monoclonal antibodies MPM-2 and C-9, that recognize centrosomal and nuclear epitopes in mammalian cells, label the interphase nucleus, the cytoplasm of mitotic cells, and the blepharoplast during both nuclear indentation and spindle formation. Double labelling of the blepharoplast-containing cells with anti-tubulin and either MPM-2 or C-9 reveals that the blepharoplast-associated fluorescence is the focus of the tubulin arrays. Centrin labels the reorganizing blepharoplast, the MLS, the AM, and a stellate pattern in the transition region of the flagella. These data indicate the usefulness of the structurally well-recognized MTOCs in pteridophyte spermatogenous cells in investigation of land plant MTOCs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01360736
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  • 91
    Digitale Medien
    Digitale Medien
    The tubulin cytoskeleton and its sites of nucleation in hyphal tips ofAllomyces macrogynus (1994)
    Springer
    Protoplasma 182 (1994), S. 19-31 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Allomyces macrogynus ; Hyphal tip growth ; Immunocytochemistry ; Immunoblot ; Microtubules ; Nocodazole ; Spitzenkörper
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The tubulin cytoskeleton in hyphal tip cells ofAllomyces macrogynus was detected with an α-tubulin monoclonal antibody and analyzed with microscopic and immunoblot techniques. The α-tubulin antibody identified a 52 kilodalton polypeptide band on immunoblots. Immunfluorescence data were collected from formaldehyde-and cryofixed hyphae. Both methods provided similar images of tubulin localization. However, cryofixation yielded more consistent labeling and did not require detergent extraction or cell-wall lytic treatments. Tubulin was primarily localized as microtubules observed in the peripheral and central cytoplasmic regions and in mitotic spindles. Cytoplasmic microtubules were oriented parallel to the cells' longitudinal axis, with central microtubules more often varied in their alignment, and emanated from a region in the hyphal apex resulting in an apical zone of bright fluorescence. A thin layer of microtubules appearing as bands of fluorescence encircled many nuclei. Discrete spots of fluorescence were also associated with nuclei. The MPM-2 antibody, which recognizes phosphorylated epitopes of several proteins that may be involved in the regulation of microtubule nucleation, stained centrosomes but not apical regions of hyphae. Nocodazole was used to depolymerize the microtubule network and reveal its regions of origin. A hocodazole concentration of 0.01 μg/ ml (3.3× 10−8M) provided a 70 to 75% inhibition of hyphal tip growth and was used throughout this study. The number of cells having an apical zone of fluorescence declined by 15 min of exposure. This zone was present in only a few cells after 60 min. After 30 min, the central cytoplasm consisted of small microtubule fragments and nuclear-associated spots. A small number of peripheral microtubules and nuclear-associated spots persisted throughout nocodazole treatments. Spindle microtubules were restored by 30 min after removal of nocodazole. This was followed by the reappearance of the apical zone of fluorescence and then by central and peripheral cytoplasmic microtubules. Apical fluorescence coincided with the presence of a Spitzenkörper. The results suggest that the Spitzenkörper and centrosome function as centers of microtubule nucleation and organization during hyphal tip growth in this fungus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01403685
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  • 92
    Digitale Medien
    Digitale Medien
    Cell surface antigens ofPhytophthora spores: biological and taxonomic characterization (1994)
    Springer
    Protoplasma 181 (1994), S. 213-232 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Oomycetes ; Pythium ; Phytophthora ; Monoclonal antibodies ; Surface antigens ; Immunocytochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The oomycetes are a class of protists that produce biflagellate asexual zoospores. Members of the oomycetes have close phylogenetic affinities with the chromophyte algae and are widely divergent from the higher fungi. This review focuses on two genera,Phytophthora andPythium, which belong to the family Pythiaceae, and the order Peronosporales. These two genera contain many species that cause serious diseases in plants. Molecules on the surface of zoospores and cysts of these organisms are likely to play crucial roles in the infection of host plants. Knowledge of the properties of the surface of these cells should thus help increase our understanding of the infection process. Recent studies ofPhytophthora cinnamomi andPythium aphanidermatum have used lectins to analyse surface carbohydrates and have generated monoclonal antibodies (MAbs) directed towards a variety of zoospore and cysts surface components. Labelling studies with these probes have detected molecular differences between the surface of the cell body and of the flagella of the zoospores. They have been used to follow changes in surface components during encystment, including the secretion of an adhesive that bonds the spores to the host surface. Binding of lectin and antibody probes to the surface of living zoospores can induce encystment, giving evidence of cell receptors involved in this process. Freeze-substitution and immunolabelling studies have greatly augmented our understanding of the synthesis and assembly of the zoospore surface during zoosporogenesis. Synthesis of a variety of zoospore components begins when sporulation is induced. Cleavage of the multinucleate sporangium is achieved through the progressive extension of partitioning membranes, and a number of surface antigens are assembled onto the zoospore surface during cleavage. Comparisons of antibody binding to many isolates and species ofPhytophthora andPythium have revealed that surface components on zoospores and cysts exhibit a range of taxonomic specificities. Surface antigens or epitopes may occur on only a few isolates of a species; they may be species-specific, genus-specific or occur on the spores of both genera. Spore surface antigens thus promise to be of significant value for studies of the taxonomy and phylogeny of these protists, as well as for disease diagnosis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01666397
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  • 93
    Digitale Medien
    Digitale Medien
    Response of root mRNA population to sulphate shortage in maize seedlings (1994)
    Springer
    Plant and soil 162 (1994), S. 309-313 
    Details
    ISSN: 1573-5036
    Schlagwort(e): in vitro translation ; maize ; nutrient stress proteins ; Poly(A)+RNA ; sulphate deprivation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Roots of ten-days-old seedlings obtained from a maize hybrid grown in complete or in sulphate-deprived medium were used to extract Poly(A)+RNA. The response to sulphate deprivation, which is known to increase the uptake capacity up to ten times, was manifested also by the expression of three mRNA species, as shown by the in vitro translation of the mRNA population. One hour after transfer to complete nutrient medium all three mRNAs were still present.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01347719
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  • 94
    Digitale Medien
    Digitale Medien
    Plagiogravitropism of maize roots (1994)
    Springer
    Plant and soil 165 (1994), S. 327-332 
    Details
    ISSN: 1573-5036
    Schlagwort(e): gravitropism ; maize ; nodal roots ; plagiogravitropism ; seminal roots ; Zea mays L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The direction of root growth can be studied by analyzing the trajectories of roots growing in soil. Both the primary seminal root and nodal roots of maize attain a preferred, or liminal, angle of growth that deviates from the vertical. These roots are said to be plagiogravitropic. Experiments using plants grown in soil-filled boxes revealed that the primary seminal root is truly plagiogravitropic. It shows both positive and negative gravitropism in response to gravity stimuli and tends to maintain its direction even after growing around obstacles. These are experimental results suggesting that plagiogravitropic growth is controlled by internal factors. The orientation of the grain affects the establishment of the liminal angle of the primary seminal root, and both the position of their node of origin and the root diameter are closely related to the plagiogravitropic behaviour of nodal roots. Several external factors are also known to influence plagiogravitropism. Low soil water content causes a decrease in the angle of growth and soil mechanical resistance suppresses the gravitropic curvature. Plagiogravitropic behaviour of both seminal and nodal roots plays a significant role in shaping the root system.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00008077
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  • 95
    Digitale Medien
    Digitale Medien
    Genetic and environmental effects on abscisic acid accumulation in leaves of field-grown maize (1994)
    Springer
    Euphytica 78 (1994), S. 81-89 
    Details
    ISSN: 1573-5060
    Schlagwort(e): abscisic acid ; inheritance ; drought stress ; Zea mays ; maize
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary This study analyzes the components of phenotypic variation for abscisic acid (ABA) content in maize (Zea mays L.) leaves and the correlations with drought sensitivity index (DSI) and silk delay (SD), involved in the reaction to water deficit. Eight early- and seven medium-maturity inbreds were examined in field trials: in 1990 with low irrigation volume and in 1991 with low and high irrigation volumes. ABA concentration and DSI were investigated at growth stages (S) corresponding to stem elongation (S3), appearance of the first husks (S4), and mid-end of silking (S5). The ABA concentration was significantly higher in conditions of water deficit and in the later growth stage. The genetic component for ABA concentration attained higher relative values than those shown by DSI in the same growth stages and by SD; moreover, it increased from growth stage 3 to stage 5. The genotype × year and genotype × irrigation volume interactions were smaller for ABA concentration than for DSI and SD. The broad sense heritability on a plant basis, estimated in drought conditions, for ABA concentration ranged from 21.4 to 55.1% according to maturity group and growth stage. A wide variation was observed among lines for ABA concentration: the medium-maturity group showed a three-fold range (from 219 to 605 ng ABA g−1 dry weight). No clear relationships between ABA concentration, DSI and SD were found. These results indicate the feasibility of a selection for ABA concentration within segregating populations derived from crosses between the inbred lines herein tested.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00021401
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  • 96
    Digitale Medien
    Digitale Medien
    Feedback control of gene expression (1994)
    Springer
    Photosynthesis research 39 (1994), S. 427-438 
    Details
    ISSN: 1573-5079
    Schlagwort(e): acetate ; glucose ; maize ; metabolic repression ; photosynthetic genes ; transcription regulation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Although feedback regulation of photosynthesis by carbon metabolites has long been recognized and investigated, its underlying molecular mechanisms remain unclear. The recent discovery that glucose and acetate trigger global repression of maize photosynthetic gene transcription provides the first direct evidence that a fundamental mechanism is used for feedback regulation of photosynthesis in higher plants. The metabolic repression of photosynthetic genes has now been found in many higher plants and is likely universal. It overrides other regulation by light, tissue type and developmental stage, and serves potentially as the molecular basis of interactions between sink and source tissues. Using simplified and convenient cellular systems and transgenic plants, the study of metabolic regulation of gene expression offers an excellent opportunity for the understanding of global and coordinate gene control and metabolite-mediated signal transduction in higher plants.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00014596
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  • 97
    Digitale Medien
    Digitale Medien
    Evaluation of parameters describing the root system architecture of field grown maize plants (Zea mays L.) (1994)
    Springer
    Plant and soil 164 (1994), S. 155-167 
    Details
    ISSN: 1573-5036
    Schlagwort(e): axile roots ; maize ; nodal roots ; root length ; root system ; seminal roots ; Zea mays L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The objective of this work was to study elongation curves of maize axile roots throughout their elongation period under field conditions. Relationships between their elongation rate and the extension rate of their branched region were also studied. Maize, early-maturing cultivar Dea, was grown on a deep, barrier-free clay loam (depth 1.80m). Trenches were dug during four periods until after silking and axile roots were excavated. Parameters measured were total length and the lengths of basal and apical unbranched zones. The rank of the bearing phytomer and general data about the carrying plant were also recorded. Results showed that axile roots from lower phytomers had similar elongation rates irrespective of the rank of the carrying phytomer. This elongation rate declined with root age. A monomolecular elongation model was fitted to the experimental data. Elongation was much slower in roots from upper phytomers. A rough linear relationship was found between the elongation rate of axile roots and the length of the apical unbranched zone. This result suggests that laterals appeared on a root segment a constant time after it was formed. Possible mechanisms with may account for the declining elongation rate with root age (increasing distance from aerial parts or adverse environmental conditions in deep soil layers) and variability between individual roots are also discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00010067
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  • 98
    Digitale Medien
    Digitale Medien
    Evaluation of parameters describing the root system architecture of field grown maize plants (Zea mays L.) (1994)
    Springer
    Plant and soil 164 (1994), S. 169-176 
    Details
    ISSN: 1573-5036
    Schlagwort(e): branching ; growth ; lateral roots ; maize ; root morphology ; Zea mays L.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The architecture of the root system is related to its water and mineral uptake. In this paper, the number, growth, and branching of first-order lateral roots are studied on field grown maize (early maturing cultivar ‘Dea’), mainly in relation to the depth and to the rank of the bearing phytomer. The soil was a deep clay loam, without any barrier until 1.80 m. The branching density was studied along axile roots until 1.40 m from the base, on a sample of individually excavated axile roots. A strong gradient of density was shown: the mean branching density decreased from 12 roots.cm−1 near the base to 4 roots.cm−1 at a 60 cm depth. Seminal roots were less densely branched than nodal roots. The mean difference was about 4 roots.cm−1. The length and branching density of lateral roots were studied on mature parts of the root systems where the growth and branching of the laterals were completed, using samples extracted from large soil monoliths. The length distribution of lateral roots was highly asymmetrical, for every source phytomer (mean: 25 mm; median: 16 mm). Many lateral roots were very short, and only 2 % reached a length higher than 10 cm. Only 29 % of all the laterals bore second-order lateral roots. Vigorous laterals branched more systematically and more profusely: the branching density varied from 2 to 5 roots.cm−1 according to the length of the mother lateral root. Both the number and length of lateral roots appeared to be affected by the soil bulk density which varied with the depth.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00010068
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  • 99
    Digitale Medien
    Digitale Medien
    Amino-acid influx at the soil-root interface of Zea mays L. and its implications in the rhizosphere (1994)
    Springer
    Plant and soil 163 (1994), S. 1-12 
    Details
    ISSN: 1573-5036
    Schlagwort(e): amino-acids ; maize ; rhizosphere ; root exudates
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The aim of the study was to investigate the ability of intact Zea mays. L. roots to regulate the amount of free amino-acids present in the rhizosphere. Using metabolic inhibitors it was demonstrated that the release of amino-acids from the root occurred by passive diffusion, whilst free amino-acids outside the root could be re-captured by an active transport mechanism. The influx of amino-acids into the root was shown to be relatively independent of spatial location along the root and was little affected by the presence of other organic compounds in solution. It was deduced from root concentration gradients that the main site of amino-acid exudation was at root tips. Amino-acid uptake by the root was shown to be independent of both inorganic-N concentration and the presence of other organic solutes in solution. A computer simulation model was constructed to assess the contribution of organic-N uptake (acidic, basic and neutral amino-acids) to the plant's N budget, in comparison to the inorganic solutes NO3 and NH4. Simulations of N uptake from a 0.5 mm radius rhizosphere indicated that when inorganic-N concentrations in soil were limiting (≤0.1 μmoles cm-3 soil), the uptake of amino-N accounted for up to 90% the total N taken up by the roots. In situations where fertilizer inputs are high, and levels of organic matter in soil are low, the contribution of amino-N might still be expected to form 〈30% of the total N taken up by the root system. It was concluded that the uptake of amino-acids from the rhizosphere may be important in both N nutrition and in the minimization of root C and N losses to the soil. Consequently this may be important in governing the size of the rhizosphere microbial population.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00033935
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  • 100
    Digitale Medien
    Digitale Medien
    Light differentially regulates lateral and longitudinal auxin transport in the mesocotyl of etiolated maize seedlings (1994)
    Springer
    Plant growth regulation 14 (1994), S. 167-171 
    Details
    ISSN: 1573-5087
    Schlagwort(e): auxin-transport ; indoleacetic acid ; maize ; photoinhibition ; transport ; Zea mays
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The uptake of IAA into excised mesocotyls of non-irradiated maize seedlings was linear up to a concentration of about 4×M and in this range there was a tight coupling between the IAA in the stele and the cortex. Prior irradiation with white light of intact seedlings unbalanced this coupling. Lateral and longitudinal transport were affected differently. In the stele, the effect of prior irradiation on longitudinal transport was multiphasic, with an initial stimulatory effect followed by a negative effect at longer prior irradiation times. The lateral transport from the stele to the cortex showed no stimulatory effect and appeared to be inhibited within at least 15 min. The effect of the prior irradiation on longitudinal transport in the stele appeared to be a high intensity effect. In contrast, the effect of the prior irradiation on the lateral transport from the stele to the cortex was saturated at much lower intensities. The data suggest that the light induced change in the lateral transport of IAA between the two tissues may be due to changes either in the number of open lateral transport channels/carriers or in the conductivity of these channels/carriers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00025219
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