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  • 1
    Digitale Medien
    Digitale Medien
    Identification of brain tumours in rats using laser-induced fluorescence and haematoporphyrin derivative (1989)
    Springer
    Lasers in medical science 4 (1989), S. 241-249 
    Details
    ISSN: 1435-604X
    Schlagwort(e): Brain tumour ; Rat ; Detection ; Fluorescence ; Laser ; Haematoporphyrin derivative
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin , Physik , Technik allgemein
    Notizen: Abstract Laser-induced fluorescence has been used for the identification of brain tumours in rats, which have been previously given tumour-seeking haematoporphyrin derivative. A pulsed nitrogen laser (λ=337 nm) was used in conjunction with an optical multichannel analyzer. For both inoculated RG-2 and TCVC rat-brain-tumour models, the blue autofluorescence was strongly reduced in the tumour compared with normal brain tissue, and at the same time the characteristic red-drug signal increased. The contrast between tumour and normal tissue was strongly enhanced by forming the ratio between the two signals. Implications for possible improvement of tumour delineation in brain tumour surgery are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02032454
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  • 2
    Digitale Medien
    Digitale Medien
    The effect of homogenization temperature upon the apparent cellular compartmentalization of unoccupied estrogen receptor (1989)
    Springer
    Cellular and molecular life sciences 45 (1989), S. 171-173 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Estrogen receptor ; homogenization ; temperature ; nucleus ; uterus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Homogenization of rat uterus at elevated temperatures results in an increased nuclear localization of unoccupied estrogen receptor. This is a nonlinear effect which is accounted for by an increased population of KCl-resistant nuclear binding sites at the elevated homogenization temperatures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01954864
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  • 3
    Digitale Medien
    Digitale Medien
    Inhibition of temperature-induced spermatogenic proliferation by a brain factor in hibernatingHelix aspersa (Mollusca) (1989)
    Springer
    Cellular and molecular life sciences 45 (1989), S. 349-351 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Spermatogenesis ; temperature ; brain ; hibernation ; Helix aspersa
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Ablation of the brain from hibernatingHelix aspersa maintained at 25°C causes a significant increase in the proliferation of male cells in the gonad, whereas the ablation of the optic tentacles has no effect. The brain, therefore, produces a factor which specifically inhibits the multiplication of spermatogonia and spermatocytes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01957474
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  • 4
    Digitale Medien
    Digitale Medien
    Effects of photoperiod, temperature and testosterone-treatment on plasma T3 and T4 levels in the Djungarian hamster,Phodopus sungorus (1989)
    Springer
    Cellular and molecular life sciences 45 (1989), S. 102-103 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Djungarian hamster ; photoperiod ; temperature ; T3 ; T4 ; testosterone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effects of photoperiod, temperature and testosterone treatment on plasma T3 and T4 levels were investigated in the Djungarian hamster. Plasma T3 level was affected by temperature (25°C〈7°C) but not by photoperiod. Plasma T4 level was affected by photoperiod (short day 〈 long day) at 25°C. Administration of testosterone increased plasma T4 level under short photoperiod at 25°C. Thus, higher plasma T4 level under long photoperiod at 25°C might be induced by testosterone.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01990462
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  • 5
    Digitale Medien
    Digitale Medien
    Melatonin accelerates reentrainment of the circadian rhythm of its own production after an 8-h advance of the light-dark cycle (1989)
    Springer
    Journal of comparative physiology 166 (1989), S. 97-102 
    Details
    ISSN: 1432-1351
    Schlagwort(e): Rat ; Melatonin ; Circadian rhythm ; 5-hydroxytryptophan
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The rhythm in melatonin production in the rat is driven by a circadian rhythm in the pineal N-acetyltransferase (NAT) activity. Rats adapted to an artificial lighting regime of 12 h of light and 12 h of darkness per day were exposed to an 8-h advance of the light-dark regime accomplished by the shortening of one dark period; the effect of melatonin, triazolam and fluoxetine, together with 5-hydroxytryptophan, on the reentrainment of the NAT rhythm was studied. In control rats, the NAT rhythm was abolished during the first 3 cycles following the advance shift. It reappeared during the 4th cycle; however, the phase relationship between the evening rise in activity and the morning decline was still compressed. Melatonin accelerated the NAT rhythm reentrainment. In rats treated chronically with melatonin at the new dark onset, the rhythm had already reappeared during the 3rd cycle, in the middle of the advanced night, and during the 4th cycle, the phase relationship between the evening onset and the morning decline of the NAT activity was the same as before the advance shift. In rats treated chronically with melatonin at the old dark onset or in those treated with melatonin 8 h, 5 h and 2 h after the new dark onset during the 1st, 2nd and 3rd cycle, respectively, following the advance shift, the NAT rhythm reappeared during the 3rd cycle as well but in the last third of the advanced night only. Neither triazolam nor fluoxetine together with 5-hydroxytryptophan administered around the new dark onset facilitated NAT rhythm reentrainment after the 8-h advance of the light-dark cycle.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00190214
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  • 6
    Digitale Medien
    Digitale Medien
    Ultrastructural changes induced by precocene II and 3,4-dihydroprecocene II in the corpora allata of Blattella germanica (1989)
    Springer
    Cell & tissue research 258 (1989), S. 91-99 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Corpora allata ; Ultrastructure ; Precocenes ; Juvenile hormone ; Blattella germanica (Insecta)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Ultrastructural studies on corpora allata (CA) from different stages during the first gonadotropic cycle of the cockroach Blattella germanica have shown well defined changes which have a correspondence with oocyte length, CA volume and juvenile hormone (JH) biosynthesis. The most significant variations concern the mitochondria and the endoplasmic reticulum. Topically applied precocene II (P II) at a dose of 200 ⧎g induced a transient arrest of CA function, although cytotoxic effects were occasionally observed. When CA were maintained in vitro with 10-3 M of P II, a relationship between the time of treatment (3, 6 or 9 h) and the intensity of the effects was apparent. The 9-h treatment led to an irreversible inhibition of JH production which parallels the severe damages observed in the CA (membrane lysis, nuclear pyknosis, vacuolization). Equivalent studies performed with the chroman derivative 3,4-dihydroprecocene II (DHP II) showed that it is less active than P II. Only treatments as severe as 12 h of incubation with a 10-3 M concentration elicited cytotoxic effects which could be due to radical species involved in the in situ oxidative bioactivation of DHP II. Thus, this compound could be regarded as a new type of pro-allatocidin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00223148
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  • 7
    Digitale Medien
    Digitale Medien
    Structural features of the epididymis in a dasyurid marsupial (Antechinus stuartii) (1989)
    Springer
    Cell & tissue research 258 (1989), S. 203-210 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Epididymis ; Histology ; Ultrastructure ; Antechinus stuartii (Marsupialia)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ductus epididymidis of the marsupial mouse Antechinus stuartii was divided into caput, corpus, and caudal regions using several constant morphological landmarks. Tubule diameter and epithelial height increased gradually from caput to cauda. In contrast, the surface area of the lumen of the ductus epididymidis increased to a maximum in the distal caput region, but decreased markedly in the distal cauda in association with characteristic changes in lumen shape (from circular to slit-shaped) and epithelial height. Epithelial cells of the ductus epididymidis were generally similar in structure to those described in other mammalian species. Principal and basal cells were common throughout the epithelium. Clear and mitochondria-rich cells were also identified, but occurred less frequently. Regional variations in cell ultrastructure were observed only in principal cells. Numerous vesicular inclusions occurred in the apical cytoplasm of cells in caput segments, membrane-bounded, electron-dense bodies were common in distal corpus regions, and a brush border of microvilli characterized the luminal surface of principal cells in caudal segments. Sperm index increased in the proximal caput, declined to basal levels in the distal caput and proximal corpus, and then increased to a maximum in segment 9 of the distal corpus and remained at about this level throughout the cauda epididymidis. Nuclear rotation, loss of cytoplasmic droplets, and other sperm maturational changes were observed along the epididymis. Discarded cytoplasmic droplets collected in large masses interspersed between aggregates of spermatozoa throughout the distal regions of the duct. There was no evidence of phagocytosis by principal cells of cytoplasmic droplets. The epididymis of A. stuartii differs from that of other mammals. The unusual caudal region, which has little storage capacity for sperm, is an unusual adaptation in a species in which the male is known to be polygamous.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00223158
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  • 8
    Digitale Medien
    Digitale Medien
    System-specific distribution of zinc in the chick brain (1989)
    Springer
    Cell & tissue research 258 (1989), S. 247-257 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Zinc ; Timm method ; Ultrastructure ; Synapses ; Avian brain ; Domestic fowl
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The brain of young domestic chicks was investigated using a Timm sulfide silver method. Serial Vibratome sections were analyzed under the light microscope, and the localization of zinc-positive structures in selected areas was determined at the ultrastructural level. Both strong and differential staining was visible in the avian telencephalon whereas most subtelencephalic structures showed a pale reaction. The highest staining intensity was found in the nonprimary sensory regions of the telencephalon such as the hyperstriatum dorsale, hyperstriatum ventrale, hippocampus, palaeostriatum augmentatum, lobus parolfactorius and caudal parts of neostriatum. There was an overall gradient of staining intensity in neostriatal areas from rostral to caudal with the heaviest zinc deposits in the caudal neostriatum. Primary sensory projection areas, such as the ectostriatum (visual), hyperstriatum intercalatum superius (visual), nucleus basalis (beak representation), the input layer L2 of the auditory field L and the somatosensory area rostral to field L were selectively left unstained. Fiber tracts throughout the brain were free of zinc deposits except for glial cells. In electron micrographs of stained regions, silver grains were localized in some presynaptic boutons of asymmetric synapses (Gray type I), within the cytoplasm of neuronal somata and sporadically in the nucleus. The possible involvement of zinc in synaptic transmission and other processes is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00239445
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  • 9
    Digitale Medien
    Digitale Medien
    Cellular origin and distribution of transforming growth factor-β1 in the normal rat myocardium (1989)
    Springer
    Cell & tissue research 256 (1989), S. 553-558 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Transforming growth factor (TGF)-β ; Myocardium ; mRNA ; Fibroblast ; Cardiomyocyte ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Transforming growth factor-β (TGF-β) is a biologically active polypeptide present in normal tissues as well as transformed cells. Two structurally related forms of this peptide are TGF-β 1 and TGF-β 2. Using freshly isolated cardiomyocytes and non-myocyte heart cells, and a [32P]-labelled cDNA probe to human TGF-β 1, we demonstrated that mRNA for TGF-β 1 could be detected only in the nonmyocyte fraction of heart cells. In the present study, the distribution of TGF-β 1 in the heart was determined by immunofluorescence staining by use of a polyclonal antibody to porcine TGF-β 1 in cryostat sections of rat heart. Immunofluorescence staining was intense around the blood vessels and radially diffuse in the surrounding myocardium.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00225603
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  • 10
    Digitale Medien
    Digitale Medien
    Effects of long-term hypergastrinaemia on the ultrastructure of enterochromaffin-like cells in the stomach of the rat, hamster and guinea pig (1989)
    Springer
    Cell & tissue research 256 (1989), S. 247-257 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Enterochromaffin-like cells ; Ultrastructure ; Hypertrophy ; Hypergastrinaemia ; Gastrin infusion ; Omeprazole ; Rat (Sprague Dawley) ; Syrian hamster ; Guinea pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The present report describes the ultrastructure of the enterochromaffin-like (ECL) cells in the stomach of the rat, hamster and guinea pig, and the ultrastructural consequences of long-term hypergastrinaemia evoked either by continuous infusion of synthetic human (Leu15)-gastrin-17 for 4 weeks (rats) or by daily treatment with large doses of the antisecretory agent omeprazole for 2–10 weeks (rats, hamsters and guinea pigs). As a result, the ECL cells increased greatly in size (maximal effect after 2 weeks of omeprazole treatment, no further gain in size after 4 or 10 weeks). Also the endoplasmic reticulum and Golgi area were enlarged. The most conspicuous feature of the ECL cells is the cytoplasmic vesicles, which are of varying size and either devoid of a dense core or with a small, often eccentrically located dense core. The vesicles probably represent the main storage site of the secretory products of the ECL cell. In addition, the cytoplasm contains granules, which differ from the vesicles in that they possess a more or less electron-dense core, surrounded by a narrow halo. The size of the vesicles ranged from small to very large, while the granules were uniformly small. Many vesicles were seen to lie very close together, some displaying an irregular outline (vacuole-like vesicles), at times giving the impression that they were undergoing fusion. The profile size (median value) of the vesicles was unaffected by gastrin infusion for 4 weeks. However, there was a tendency to a relative increase in the number of very small vesicles. In contrast, the vesicles became larger during the omeprazole treatment. Also, the number of vesicles that seemed to be engaged in fusion increased after omeprazole treatment but not after gastrin infusion. The observations support the view that ECL cells are influenced by gastrin. The effects of gastrin infusion and of omeprazole treatment on ECL cell ultrastructure were not completely identical. It cannot be excluded that the omeprazole-evoked achlorhydria evokes effects unrelated to those of hypergastrinaemia on the ECL cells, or that endogenous gastrins may evoke effects that are in some ways distinct from those of synthetic human (Leu15)-gastrin-17. Alternatively, the additional effects seen after long-term omeprazole treatment may reflect simply the duration of the hypergastrinaemic stimulus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218882
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  • 11
    Digitale Medien
    Digitale Medien
    Morphological changes in the junctional complex of cells in the arachnoid layer of the rat after cold injury (1989)
    Springer
    Cell & tissue research 256 (1989), S. 303-307 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Arachnoid cells ; Tight and gap junctions ; Cold injury ; Ultrastructure ; Freeze-fracture technique ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The junctional complexes of cells in the outer arachnoid layer overlying the cerebral cortex of 2-week-old rats were examined with freeze-fracture electron microscopy up to 60 min after transcranial cold injury to the dorsal surface of the brain. Within 30 min after injury, areas of gap and tight junctions with morphological features characteristic of junction formation and/or junction disruption were found scattered among normal junctional complexes in some arachnoid cells. Within 60 min after injury, tight junctions with features typical of less leaky zonulae occludentes were present in all arachnoid cells examined. These morphological features include increases in the number of tight junctional strands and the number of strand-to-strand anatomoses. Gap junctions were interspersed among the tight junctional strands, and many were completely encircled by the strands. The increase in the number and complexity of the tight junctional strands in response to brain injury may be the morphological basis for the maintenance of the cerebrospinal fluid-blood dural barrier.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218887
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  • 12
    Digitale Medien
    Digitale Medien
    Axonal tracing of autonomic nerve fibers to the superficial temporal artery in the rat (1989)
    Springer
    Cell & tissue research 256 (1989), S. 559-565 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Retrograde tracing ; Immunocytochemistry ; Vascular innervation ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The origin of nerve fibers to the superficial temporal artery of the rat was studied by retrograde tracing with the fluorescent dye True Blue (TB). Application of TB to the rat superficial temporal artery labeled perikarya in the superior cervical ganglion, the otic ganglion, the sphenopalatine ganglion, the jugular-nodose ganglionic complex, and the trigeminal ganglion. The labeled perikarya were located in ipsilateral ganglia; a few neuronal somata were, in addition, seen in contralateral ganglia. Judging from the number of labeled nerve cell bodies the majority of fibers contributing to the perivascular innervation originate from the superior cervical, sphenopalatine and trigeminal ganglia. A moderate labeling was seen in the otic ganglion, whereas only few perikarya were labeled in the jugular-nodose ganglionic complex. Furthermore, TB-labeled perikarya were examined for the presence of neuropeptides. In the superior cervical ganglion, all TB-labeled nerve cell bodies contained neuropeptide Y. In the sphenopalatine and otic ganglia, the majority of the labeled perikarya were endowed with vasoactive intestinal polypeptide. In the trigeminal ganglion, the majority of the TB-labeled nerve cell bodies displayed calcitonin gene-related peptide, while a small population of the TB-labeled neuronal elements contained, in addition, substance P. In conclusion, these findings indicate that the majority of peptide-containing nerve fibers to the superficial temporal artery originate in ipsilateral cranial ganglia; a few fibers, however, may originate in contralateral ganglia.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00225604
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  • 13
    Digitale Medien
    Digitale Medien
    Distribution of MAP 2 in dendritic spines and its colocalization with actin (1989)
    Springer
    Cell & tissue research 256 (1989), S. 447-456 
    Details
    ISSN: 1432-0878
    Schlagwort(e): MAP2 ; Actin ; Dendritic spines ; Spine apparatus ; Spine synapses ; Postsynaptic density ; Synaptic plasticity ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The distribution of MAP2 and actin in dendritic spines of the visual and cerebellar cortices, dentate fascia, and hippocampus was determined by using immunogold electron microscopy. By this approach, we have confirmed the presence of MAP2 in dendritic spines and identified substructures within the spine compartment showing MAP2 immunoreactivity. MAP2 immunolabeling was mainly associated with filaments which reacted with a monoclonal anti-actin antibody. Also, by immunogold double-labeling we colocalized MAP2 with actin on the endomembranes of the spine apparatus, smooth endoplasmic reticulum, and in the postsynaptic density. Labeling was nearly absent in axons and axonal terminals. These results indicate that MAP2 is an actin-associated protein in dendritic spines. Thus, MAP2 may organize actin filaments in the spine and endow the actin network of the spine with dynamic properties that are necessary for synaptic plasticity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00225592
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  • 14
    Digitale Medien
    Digitale Medien
    The effect of low- and high-density lipoprotein cholesterol on steroid hormone production and ACTH-induced differentiation of rat adrenocortical cells in primary culture (1989)
    Springer
    Cell & tissue research 256 (1989), S. 487-494 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adrenal cortex ; Differentiation ; Tissue culture ; Steroids ; Ultrastructure ; Lipoproteins ; Rat (Sprague-Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary We studied the effects of lipoprotein-derived cholesterol on the ACTH-induced differentiation of cultured fetal rat adrenocortical cells. For this purpose human plasma high-density lipoprotein3 (HDL3) or low-density lipoprotein (LDL) was added to culture media devoid of cholesterol, and thereafter the morphological changes in cells were monitored and the amounts of steroids synthesized were measured. It could be demonstrated that, ultrastructurally, upon ACTH-stimulation the adrenocortical cells differentiated into fasciculata-like cells even in the absence of lipoproteins in the culture medium. The addition of either HDL3 or LDL caused an increase in the number and size of cytoplasmic lipid droplets suggesting uptake and deposition of lipoprotein-derived cholesterol into the differentiating cells. The amount of steroids secreted from cells differentiating in media devoid of cholesterol was only half that observed in cells differentiating in serum-supplemented medium. Addition of either HDL3 or LDL increased the ACTH-stimulated steroid synthesis to the levels observed in serum-supplemented medium. This study demonstrates that both HDL3 and LDL are able to provide cholesterol for steroid synthesis accompanying the ACTH-induced differentiation of fetal rat adrenocortical cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00225596
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  • 15
    Digitale Medien
    Digitale Medien
    The effect of bromocriptine on the intermediate lobe of the rat pituitary: an electron-microscopic, morphometric study (1989)
    Springer
    Cell & tissue research 255 (1989), S. 405-410 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pituitary gland, pars intermedia ; Bromocriptine ; Secretory granules ; Golgi apparatus ; Ultrastructure ; Rat (Sprague-Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The morphological effect of chronic synthetic and secretory inhibition of the intermediate lobe of the rat pituitary induced by bromocriptine treatment was studied using morphometric techniques in combination with electron microscopy. On the basis of granule diameters, a heterogeneous cell population was shown in the normal intermediate lobe. Bromocriptine treatment did not induce any change in the volume fraction, number or location of electron-dense secretory granules. Instead, there was a shift toward a more homogeneous cell population containing smaller granules, the mean granule volume being reduced by ∼30%. The volume fraction of electron-lucent granules or vacuoles was markedly reduced, indicating a functional significance of these organelles. The volume of the Golgi apparatus was not significantly altered, but the number of condensing granules within the Golgi area was reduced. The volume of the intermediate lobe was decreased, apparently due to a decrease in the mean cell volume.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00224124
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  • 16
    Digitale Medien
    Digitale Medien
    Distribution of peroxidase and iodination activity in the endostyles of Oikopleura albicans and Oikopleura longicauda (Appendicularia, Chordata) (1989)
    Springer
    Cell & tissue research 255 (1989), S. 505-510 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Endostyle ; Peroxidase cytochemistry ; Autora diography ; Ultrastructure ; Oikopleura albicans, Oikopleura longicauda (Appendicularia)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Oikopleura albicans and O. longicauda belong to the two subgenera Vexillaria and Coecaria, respectively. The morphology and ultrastructure of their endostyles were investigated with conventional microscopic procedures as well as with DAB cytochemistry and 125I autoradiography at both light- and electron-microscopic levels. As expected, the general morphology of these endostyles is similar to all hitherto examined endostyles. They possess a ventral portion consisting of alternating glandular and ciliated cell zones, probably serving food capture, and a dorsal region, the corridor. Autoradiographic grains were found mainly in the corridor lumen associated with the apical surface of the two central rows of corridor cells. The same cells also gave strong positive reactions for peroxidase, the iodinating enzyme. Peroxidase activity was found in the apical plasma membrane as well as in the nuclear envelope, rough endoplasmic reticulum, Golgi area and cytoplasmic vesicles. Definitive conclusions concerning an apical uptake and subsequent release into the body fluid of iodinated material could not be made from the present experiments. Our investigations indicate that the two central rows of corridor cells in both subgenera of oikopleurids constitute the protothyroid region, possibly homologous to the vertebrate thyroid gland.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218785
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  • 17
    Digitale Medien
    Digitale Medien
    Morphogenesis of rat cranial meninges (1989)
    Springer
    Cell & tissue research 257 (1989), S. 207-216 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Morphogenesis ; Meninges ; Mesenchyme ; Ultrastructure ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The meninges of albino Wistar rat embryos, aged between the 11th embryonic day (ED) and birth, were sectioned using a specially constructed device. This technique permits optimal microanatomical preservation of all tissues covering the convexity of the brain: skin, muscle, cartilage or bone, and the meninges. At ED11, the zone situated between the epidermis and the brain is occupied by a mesenchymal network. At ED12, part of this delicate network develops as a dense outer cellular layer, while the remainder retains its reticular appearance, thus forming an inner layer (the future meningeal tissue). At ED13, the dura mater starts to differentiate. At ED14, the bony anlage of the skull can be identified, and along with the proceeding maturation of dura mater some fibrillar structures resembling skeletal muscle fibers appear in the developing arachnoid space. At ED15–17, a primitive interface zone — dura mater/ arachnoid — is formed, comprised by an outer electronlucent and an inner electron-dense layer marking the outer aspect of the arachnoidal space. At ED18–19, the innermost cellular row of the inner durai layer transforms into neurothelium, which is separated from the darker arachnoidal cells by an electron-dense band. The arachnoidal trabecular zone with the leptomeningeal cells is formed at ED19. By the end of the prenatal period (ED20–21), its innermost part organizes into an inner arachnoidal layer and an outer and inner pial layer. The results from this study indicate (i) that dura mater and leptomeninges develop from an embryonic network of connective tissue-forming cells, and (ii) that the formation of cerebrospinal fluid (CSF)-containing spaces accompanies the differentiation of the meningeal cellular layers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221652
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  • 18
    Digitale Medien
    Digitale Medien
    Terminal processes of serotonin neurons in the caudal spinal cord of the molly, Poecilia latipinna, project to the leptomeninges and urophysis (1989)
    Springer
    Cell & tissue research 255 (1989), S. 619-625 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Serotonin-containing cells ; Urophysis ; Spinal Cord ; Ultrastructure ; Leptomeninges ; Poecilia latipinna (Teleostei)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The caudal neurosecretory complex of poeciliids has previously been shown to be innervated by extranuclear and intrinsic serotonergic projections. In the present study, immunohistochemical techniques were used to characterize fibers originating from serotonin neurons intrinsic to the caudal spinal cord. Bipolar and multipolar neurons were oriented ventromedially, and contained numerous large granular vesicles. Three types of serotonergic fibers were distinguished based on their distribution and morphology. Intrinsic Type-A fibers branched into varicose segments near the ventrolateral surface of the spinal cord and contacted the basal lamina beneath the leptomeninges. Type-B fibers coursed longitudinally to enter the urophysis, where they diverged and terminated around fenestrated capillaries. Labelled vesicles in Type-A and Type-B terminals were the same size as those in labelled cells and in unlabelled neurosecretory terminals in the urophysis. Type-C small varicose fibers branched within the neuropil of the caudal neurosecretory complex. Serotonin may be secreted into the submeningeal cerebrospinal fluid, the urophysis, and the caudal vein by Type-A and Type-B fibers, whereas, Type-C fibers may be processes of serotonergic interneurons in the neuroendocrine nucleus. The possibility that urotensins I and II or arginine vasotocin were colocalized in the processes of the intrinsic serotonin neurons was investigated immunohistochemically. The negative results of these experiments suggest that serotonin-containing neurons may represent a neurochemically distinct subpopulation in the caudal neurosecretory complex.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218799
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  • 19
    Digitale Medien
    Digitale Medien
    Neural activity pattern is not necessary for the development of adult ultrastructure in katydid (Neoconocephalus robustus) singing muscles (1989)
    Springer
    Cell & tissue research 255 (1989), S. 641-644 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Insect muscle ; Denervation ; Ultrastructure ; Development, ontogenetic ; Neoconocephalus robustus (Insecto)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The singing muscles of the katydid Neoconocephalus robustus develop adult ultrastructure late in the last nymphal instar and during the first few days of adult life. The ultrastructural changes during early adulthood were not affected by unilateral axotomy shortly after the adult molt. Both denervated and innervated muscles developed adult proportions of mitochondria, myofibril, and sarcoplasmic reticulum and transverse tubules.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218802
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  • 20
    Digitale Medien
    Digitale Medien
    Specific adhesion between pheochromocytoma (PC12) cells and adrenal medullary endothelial cells in co-culture (1989)
    Springer
    Cell & tissue research 256 (1989), S. 365-372 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adrenal medullary endothelial cells ; Pheochromocytoma (PC12) cells ; Co-culture ; Cell surface extracts ; Adhesion ; Cell-cell interactions ; Bovine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Chromaffin cells in the adrenal medulla are found in close proximity to capillary endothelial cells, thereby forming the classical endocrine complex. To examine the possible chemical basis of their interaction in more detail, we have grown bovine adrenal medullary endothelial (BAME) cells in monolayer cultures and added to them pheochromocytoma (PC12) cells, a chromaffin tumor cell line of rats. The PC12 cells were chosen because of the similarities they share with adrenal medullary chromaffin cells. PC12 cells rapidly attached to BAME cells cultures, their rate of adhesion being significantly enhanced over binding of PC12 cells to either uncoated plates or to monolayers of unrelated cell cultures. Consistent with this observation, we noted that the extracellular matrix (ECM) derived from the BAME cells did not enhance PC12 cell adhesion and did not promote neurite sprouting as previously described for ECM derived from corneal endothelial cells. The specific adhesion between PC12 and BAME cells could be abolished by cell surface extracts derived from these two cells but not by extracts derived from unrelated cell types. This activity was heat-labile, sensitive to trypsin and, to a lesser extent, to neuraminidase. We therefore conclude that PC12 cells may interact with BAME cells by specific proteinaceous adhesive factors associated with their plasma membranes. These interactions might represent the formative role of cell-cell contacts in the organization of the developing adrenal gland.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218894
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  • 21
    Digitale Medien
    Digitale Medien
    Three-dimensional observation of the fibroblast-like cells associated with the rat myenteric plexus, with special reference to the interstitial cells of Cajal (1989)
    Springer
    Cell & tissue research 255 (1989), S. 343-351 
    Details
    ISSN: 1432-0878
    Schlagwort(e): SEM ; TEM ; Interstitial cell ; Myenteric plexus ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary An extensive cellular network becomes visible over the myenteric plexus of the rat after removal of the overlying tissues under the scanning electron microscope. The cells are mainly stellate and have many slender processes via which they interconnect. They form a three-dimensional network and are closely associated with the ganglia and nerve bundles, and also extend over the smooth muscle cells. They are considered to correspond to the interstitial cells of Cajal because of their peculiar arrangement and their topography. Transmission electron-microscopic evidence demonstrates that the majority of those cells have features of fibroblasts. Gap junctions and intermediate junctions are observed between these fibroblast-like cells, and also between them and smooth muscle cells. Examination of serial thin sections reveals that single fibroblast-like interstitial cells connect to both circular and longitudinal muscle cells via gap junctions. It is suggested that the network of interstitial cells conducts electrical signals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00224117
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  • 22
    Digitale Medien
    Digitale Medien
    The relationship between gastrin cells and bombesin-like immunoreactive nerve fibres in the gastric antral mucosa of guinea-pig, rat, dog and man (1989)
    Springer
    Cell & tissue research 257 (1989), S. 171-178 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Gastrin ; Gastrin-releasing peptide ; Bombesin ; Stomach ; Autonomic innervation ; Immunohistochemistry ; Guinea pig ; Rat ; Dog ; Man
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The relationship between bombesin-like immunoreactive (bombesin-LI) nerve fibres and gastrin-LI G-cells was examined in gastric antral mucosa from guineapig, rat, dog and man using a double-labelling fluorescence immunohistochemical technique. The greatest density of bombesin-LI nerve fibres was found within the basal mucosa in all species and the density of innervation decreased towards the luminal surface. Most G-cells were in a band occupying approximately the middle third of the mucosa. The proportion of G-cells found within a distance of 2 μm from bombesin-LI nerve fibres was low in all species (6% in the guinea-pig, 22% in the rat, 14% in the dog, and 9% in the human). It is proposed that the neuropeptide released from bombesin-LI antral mucosal nerve fibres traverses distances of greater than several μm to reach the target G-cells. This may be achieved by passage through the mucosal microcirculation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221648
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  • 23
    Digitale Medien
    Digitale Medien
    The three-dimensional structure of the zona pellucida in growing and atretic ovarian follicles of the mouse (1989)
    Springer
    Cell & tissue research 257 (1989), S. 247-253 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Zona pellucida ; Ovarian follicles ; Atresia ; Ultrastructure ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The present study provides further details on the fine-structural three-dimensional architecture of the zona pellucida (ZP) in growing and atretic follicles of mice by use of ruthenium red in combination with the detergents Triton X100 and saponin. These detergents were used for extraction of the “soluble” fraction of the zonal proteins in an attempt to expose the “structural” zonal glycoproteins, which in turn can be viewed as minute three-dimensional networks upon transmission- and scanning electron-microscopic examination. By use of these methods, the ZP of growing follicles appeared to be formed by interconnected filaments which also bind to globular structures building up a three-dimensional lattice. In contrast, the ZP of stage I as well as other (II and III) stages of atretic follicles showed a structure characterized by the presence of closely packed granules connected with short filaments to form a close-mesh reticulum. This structural change of the ZP, which in the present study is also associated with the disappearance of “gap junctions” within the granulosa and cumulus cell population, might represent one of the early events involved in the onset of atresia. These changes, most probably depending on an altered secretory activity of both oocytes and follicle cells, might lead to a degradation of the ZP network structure and to its subsequent increased density (condensation). All these morphodynamic events eventually contribute to a sequestration of the oocyte in the early stage of atresia.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00261827
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  • 24
    Digitale Medien
    Digitale Medien
    Immunohistochemistry of vacuoles occurring in rat hepatocytes after retinol administration (1989)
    Springer
    Cell & tissue research 257 (1989), S. 263-268 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Retinol ; Vacuoles ; Immunohistochemistry ; Plasma proteins ; Hepatocytes ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The vacuoles occurring in rat hepatocytes after intraportal injection of retinol (33 or 67 μg) were examined immunohistochemically using respective antibodies against rat albumin, human retinol-binding protein, human ceruloplasmin, human α 1-antitrypsin, human transferrin, and human prealbumin as representative plasma proteins. The occurrence of the vacuoles reached a numerical maximum 30 min after injection of 67 μg retinol, followed by a temporal decrease. Hepatocytes from control rats, which had been intraportally injected with either blood plasma diluted to 2/3 concentration or with retinol palmitate solvent (castor oil) dissolved in blood plasma, showed immunoreactive fine granules without the occurrence of vacuoles in the cytoplasm. Identical vacuoles in serial sections appeared immunohistochemically either immunoreactive or non-immunoreactive for all the antibodies used, with rare exceptions. The occurrence of several rare exceptions suggested that 2 kinds of vacuoles might be formed in different cytoplasmic compartments. A zonal distribution of vacuoles was apparent in the hepatic laminae (or acini) within the liver lobules. The vacuoles were predominantly distributed in zone 2, and to a lesser extent in zone 3 and zone 1 in that order.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00261829
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  • 25
    Digitale Medien
    Digitale Medien
    Smooth muscle fiber types and a novel pattern of thick filaments in the wing of the pteropod mollusc Clione limacina (1989)
    Springer
    Cell & tissue research 257 (1989), S. 405-414 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Mollusc ; Ultrastructure ; Musculature ; Hydroskeleton ; Retraction reflex ; Clione limacina (Mollusca)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Wing (parapodial) retraction in the pteropod mollusc Clione limacina is a reflex triggered by tactile stimulation. Light and transmission electron microscopy revealed three groups of smooth muscles in the wing hemocoel that participate in retraction movements: transverse, longitudinal, and dorsoventral. Among these, two subtypes of muscle cells were identified. The first (type A) appears in all three groups and forms a well-organized lattice-like structure. The second (type B) is the major component of transverse muscles and runs in one direction only. Quantitative ultrastructural comparisons of dimensions, abundance, and organization of dense bodies, thick and thin filaments, membrane invaginations, sarcoplasmic reticulum, and mitochondria suggest that type A cells are able to contract and relax more quickly with less endurance whereas type B cells are capable of generating stronger contractions with more endurance and slower relaxation speed. Furthermore, type A cells have a unique pattern of thick filament organization, here referred to as pseudosarcomeres. The roles played by the different cell types in wing retraction are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00261843
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  • 26
    Digitale Medien
    Digitale Medien
    Ultrastructural changes in granule cell somata and mossy fibers of the rat hippocampus during picrotoxin-induced convulsions (1989)
    Springer
    Cell & tissue research 255 (1989), S. 261-267 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Hippocampus ; Mossy fibers ; Picrotoxin ; Ultrastructure ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Ultrastructural changes in hippocampal granule cells, mossy fibers and mossy fiber boutons were examined following the administration of picrotoxin in adult rats. Generalized seizures occurred within 5–10 min after the intraperitoneal injection of picrotoxin. The electron-microscopic examination of hippocampal tissues from rats that had been perfused with fixative during the seizure revealed that the large dense-core vesicles increased in number and accumulated on the presynaptic membranes of mossy fiber boutons; some of these vesicles appeared to be fused with the membranes, and omega-shaped exocytotic profiles were frequently seen. Furthermore, greatly increased numbers of coated vesicles (60–90 nm in diameter) were observed on the maturing faces of Golgi fields of granule cells. Thus, our study not only indicates an increased incidence of exocytosis of large dense-core vesicles during picrotoxin-induced seizures, but also suggests that these vesicles are replaced in excess from the perikaryon of the granule cell.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00224107
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  • 27
    Digitale Medien
    Digitale Medien
    Theamylase gene-enzyme system of fishes (1989)
    Springer
    Journal of comparative physiology 159 (1989), S. 237-242 
    Details
    ISSN: 1432-136X
    Schlagwort(e): Amylase ; Mosquitofish ; Rat ; Drosophila ; Structure ; Function
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Amylases from the mosquitofish (Gambusia affinis holbrooki, Pisces: Poeciliidae) and rat were purified and compared withDrosophila amylases in terms of structure and function. At the structural level, amino acid compositions of the three amylases were compared. At the functional level, amylase activities were compared on various substrates and in the presence of inhibitors. While the amylases from all three organisms had properties typical of alpha-amylases, both structural and functional differences were observed. Using resemblance coefficients of distance and similarity from numerical taxonomy, it was determined that the amylases from the rat andDrosophila were more similar to each other than either was to amylase from the mosquitofish, and that structural differences between the amylases did not reflect functional differences, i.e. there was no correlation between amylase structural and functional distances.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00691744
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  • 28
    Digitale Medien
    Digitale Medien
    Epilepsy and electromagnetic fields: effects of simulated atmospherics and 100-Hz magnetic fields on audiogenic seizure in rats (1988)
    Springer
    International journal of biometeorology 32 (1988), S. 17-20 
    Details
    ISSN: 1432-1254
    Schlagwort(e): Epilepsy ; Electromagnetic fields ; Rat ; Audiogenic seizure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geographie , Physik
    Notizen: Abstract In order to study the possible association between epileptic seizures and natural electromagnetic fields, 32 female audiogenic seizure (AGS)-susceptible rats were exposed to simulated 10 kHz and 28 kHz atmospherics and to a sinusoidally oscillating magnetic field with a frequency of 100 Hz and field strength of 1 A/m. After the electromagnetic exposure, seizures were induced in the rats with a sound stimulus. The severity of the seizure was determined on an ordinal scale, the audiogenic response score (ARS). The time from the beginning of the sound stimulus to the onset of the seizure (seizure latency) and the duration of the convulsion was measured. No differences from the control experiments were found in the experiments with simulated atmospherics, but the 100 Hz magnetic field increased the seizure latency by about 13% (P〈0.02). The results do not support the hypothesis that natural atmospheric electromagnetic signals could affect the onset of epileptic seizures, but they suggest that AGS-susceptible rats may be a useful model for studying the biological effects of electromagnetic fields.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01623987
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  • 29
    Digitale Medien
    Digitale Medien
    Demonstration of correlations between the 8 and 10 kHz atmospherics and the inflammatory reaction of rats after carrageenan injection (1988)
    Springer
    International journal of biometeorology 32 (1988), S. 201-204 
    Details
    ISSN: 1432-1254
    Schlagwort(e): Atmospherics ; Carrageenan inflammation ; Rat ; Susceptibility ; Correlations
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geographie , Physik
    Notizen: Abstract Between the mean daily density of 28 kHz atmospherics and the onset of epileptic fits there is a highly significant correlation coefficient (r) of 0.30; there is a negative coefficient of −0.20 between the fits and the mean daily density of 10 kHz atmospherics. The onset of heart infarction is correlated with 28 kHz atmospherics (r=0.15). Furthermore, we have discovered that sudden deafness is also correlated with certain configurations of atmospherics. In this paper we report the following correlation coefficients between the inflammatory reaction of rats to a carrageenan injection (rci) into a hind paw and the mean daily pulse rate of atmospherics of the same day:r=0.49 for the 8 kHz atmospherics (P〈0.02) andr=0.44 for the 10 kHz atmospherics (P〈0.04). The correlations between rci reaction and other atmospherics (12 and 28 kHz) are smaller and not significant. By the method of multiple linear regression we found a multipleR=0.54 between rci reaction and the 8 and 10 kHz atmospherics (the regression function for the rci reaction is 0.15+0.004×8 kHz+0.002×10 kHz,P〈0.05).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01045280
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  • 30
    Digitale Medien
    Digitale Medien
    Lipid detection by malachite green-aldehyde in the dental basement membrane in the rat incisor (1988)
    Springer
    Cell & tissue research 253 (1988), S. 685-687 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Basement membrane ; Lipids ; Ultrastructure ; Rat (Sprague-Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Developing rat incisors were treated with malachite green-aldehyde fixative solution (MGA), which retains and stains lipids. We observed positive staining occurring as dots in the basement membrane. Most of these dots (2–3.5 nm in diameter) were grouped in the lamina densa but some were also present in the lamina lucida and the lamina fibroreticularis. These data provide evidence for the existence of lipids in the dental basement membrane and suggest that they are distributed together with the various groups of proteins so far detected.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00219762
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  • 31
    Digitale Medien
    Digitale Medien
    Catecholaminergic nerves in the embryonic chick ovary: co-localization with β2-adrenoceptor-bearing steroidogenic cells (1988)
    Springer
    Cell & tissue research 254 (1988), S. 1-9 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adrenergic nerves ; Steroidogenic cells ; Embryonic ovary ; β 2Adrenoceptors ; Cytochemistry ; Ultrastructure ; Chicken
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The present study investigates the innervation of the embryonic chick ovary with regard to (i) development and compartmentalization of catecholaminergic nerves, and (ii) presence of adrenoceptors on steroidogenic target cells of catecholaminergic nerve terminals. Catecholaminergic nerve fibers visualized by glyoxylic acid-induced histofluorescence first appeared at embryonic day (E) 13. From E15 through E21 the density of fluorescent aminergic nerves increased markedly in parallel with the concentration of catecholamines and numbers of nerve bundles and single axons seen at the electron-microscopic level. Catecholaminergic nerves were confined to the ovarian medulla and closely associated with interstitial cells. Nerve terminals approached interstitial cells up to a distance of 20 nm and, in their majority, exhibited uptake of the false adrenergic transmitter 5-hydroxydopamine. Although adrenaline amounted to 14% of the total catecholamine content at E21, adrenaline immunoreactivity was only detected in adrenal chromaffin cells, but not in nerve fibers or cell bodies within the ovary. Interstitial cells structurally matured between E15 and E21 as documented by an increase of smooth endoplasmic reticulum and tubular mitochondria. Monoclonal antibodies mAB 120 and BRK 2 raised against avian β 1 and mammalian β 2-adrenergic receptors revealed the presence of β 2-adrenoceptor-like immunoreactivity on the surface of interstitial cells, but not on any other cell type. The results are consistent with the notion of a dense adrenergic innervation of the embryonic chick ovarian medulla and its steroidogenic interstitial cells, and suggest the chick ovary as an excellent model for elucidating the functional role of a neural input to steroidogenic cells during development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220010
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  • 32
    Digitale Medien
    Digitale Medien
    The pattern of organization of intermediate filaments and their asymmetrical association with dense bodies in smooth muscle of an ascidian Halocynthia roretzi (1988)
    Springer
    Cell & tissue research 252 (1988), S. 23-32 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Smooth muscle ; Intermediate filaments ; Dual network ; Ultrastructure ; Ascidian ; Halocynthia roretzi
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary An extensive network of intermediate filaments that interconnected cytoplasmic dense bodies and connected the dense bodies to the cell surface was revealed in double-fixed, tannic acid-stained preparations of ascidian smooth muscle. The filament network ran through spaces in the continuous network of myofibrils, connecting them longitudinally, obliquely and transversely to form an intimately associated, dual network. In their transverse passage, the intermediate filaments ran across myofibrils along I-zones exclusively, interconnecting successive dense bodies. The pattern of attachment of intermediate filaments to dense bodies was predominantly “one-sided.” The filaments, which themselves were not incorporated into the contractile apparatus, remained folded or unfolded between myofibrils and between sarcomere-like structures in synchrony with the contraction-relaxation cycles. These results suggest that the intermediate filaments mechanically maintain the organization and arrangement of myofibrils via an intimate association with the myofibrils in the regions of the dense bodies, in such a way that the filaments do not impede muscle function. Based on these observations, a new model for the network of intermediate filaments in smooth muscle cells is proposed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213822
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  • 33
    Digitale Medien
    Digitale Medien
    Interendothelial junctions of cardiac capillaries in rats: their structure and permeability properties (1988)
    Springer
    Cell & tissue research 252 (1988), S. 57-66 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Heart ; Endothelium ; Tracer studies ; Junctional structures ; Permeability ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The isolated perfused heart model was used to examine the structure of rat cardiac capillaries and their permeability to macromolecules of various sizes. Haemoglobin (diameter 6.4 nm) and catalase (10.4 nm) did not cross the endothelium but remained on the luminal side. Cytochrome C (3 nm) and horseradish peroxidase (6 nm) both crossed the endothelium to the subendothelial space and filled the caveolae on the abluminal side as well as the entire length of the lateral intercellular spaces. The membranes of the endothelial cells are separated by an intercellular gap of mean width 18.2 nm. At one or more zonular regions within each lateral intercellular space the two membranes approach each other more closely and frequently appear to fuse. However, tilting the specimen shows that, in these regions, there is a gap of mean width 5.4 nm (in lanthanum- and tannic acid-treated tissue, 3.8 nm in ferrocyanide-treated tissue) between the membranes. We conclude that these narrow regions sieve macromolecules on the basis of size although other factors may determine their permeability properties.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213826
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  • 34
    Digitale Medien
    Digitale Medien
    Ultrastructure of the tentacles of the apodous holothurian Leptosynapta spp (Holothurioidea: Echinodermata) with special reference to the epidermis and surface coats (1988)
    Springer
    Cell & tissue research 251 (1988), S. 387-397 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Tentacles ; Ultrastructure ; Adhesion ; Leptosynapta spp (Holotheorie) ; Echinodermata
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The tentacles of the apodous holothurian Genus Leptosynapta have been studied by use of transmission and scanning electron microscopy. The gross anatomy, water vascular system, fibre systems and ectoneural nerve ring are described. A fuzzy coat of attenuated filaments covers the surface of the tentacle, broken only by secretory ducts. A cuticle underlies the fuzzy coat. Bacteria are common in the subcuticular space. Fixation without osmium gives poor preservation of the surface coats. The epidermis consists of a single layer of columnar cells consisting of Type-1, Type-2, support, goblet and uniciliated cells. Type-1 cells secrete electron-dense material and appear to be homologous to adhesive cells of the tentacles of other holothurians. The support cells contain large, granular vesicles not found in other holothurians. Goblet cells contain flocculent mucus and have an apical cilium. Goblet cells are not found in other holothurian tentacles and may function to lubricate and wrap adhering particles to aid their ingestion. The uniciliated cells are rare, poorly developed and the cilium does not extend past the cuticle. The ultrastructure of the tentacles is discussed in relation to those of other holothurians.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215848
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  • 35
    Digitale Medien
    Digitale Medien
    Lymphocyte number and distribution in the rat uterine epithelium during estrous cycle and early pregnancy (1988)
    Springer
    Cell & tissue research 253 (1988), S. 241-244 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Uterus ; Intraepithelial lymphocytes ; Estrous cycle ; Early pregnancy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The number of intraepithelial lymphocytes (IEL) in the luminal and glandular epithelium of the uterus of virgin rats was analysed in diestrus, proestrus and estrus, and in nulliparous rats on days 5, 7 and 9 of pregnancy. IEL number was calculated either with respect to the number of epithelial cells or to the length of epithelium section. It was found that in diestrus, the number of IEL was, on average, 3.7 per 100 luminal epithelial cells or 6.7 per 1 mm of epithelium section, whereas in proestrus, it decreased to 0.9 and 1.2 IEL, respectively. On day 5 of pregnancy (before implantation) the number of IEL decreased further to 0.45 per 100 luminal epithelial cells or 0.9 per 1 mm of epithelium. On days 7 and 9 of pregnancy, IEL number further decreased in implantation sites, whereas in interimplantation sites it remained at the level calculated for day 5 of pregnancy. The population of uterine IEL consisted of small (82–99%) and large (1–18%) lymphocytes. In all stages of the estrous cycle, IEL occurred with a frequency of 68–87% in the basal region, 8–20% in the middle region and 4–12% in the apical region of the luminal epithelium width.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221759
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  • 36
    Digitale Medien
    Digitale Medien
    The ultrastructure of the lung of two newborn marsupial species, the northern native cat, Dasyurus hallucatus, and the brushtail possum, Trichosurus vulpecula (1988)
    Springer
    Cell & tissue research 252 (1988), S. 683-685 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Lung ; Ultrastructure ; Marsupial ; Newborn ; Surfactant ; Dasyurus hallucatus, Trichosurus vulpecula
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The lungs of newborn northern native cats, Dasyurus hallucatus and newborn brushtail possums, Trichosurus vulpecula were examined by both light and electron microscopy. The native cat has a birth weight of 18 mg after a gestation of about 21 days, whereas the brushtail possum weights 200 mg at birth and has a gestation period of 17.5 days. The lungs of the native cat are two large respiratory sacs, with a respiratory lining of squamous cells and surfactant-secreting cells. The capillaries are located within the connective tissue just below this respiratory epithelium. The visceral covering of the lung is formed by squamous cells. The lungs of the possum are composed of numerous large respiratory sacs which are separated by connective tissue septa in which the capillaries are located. The sacs, as in other species, are lined with squamous cells and surfactant secreting cells. It is proposed that the structure of the lung of the newborn marsupial is related more to the size of the newborn rather than to the length of the gestation period.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216657
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  • 37
    Digitale Medien
    Digitale Medien
    Vascular response in a non-uterine site to implantation-stage embryos in the rat and guinea-pig: in vivo and ultrastructural studies (1988)
    Springer
    Cell & tissue research 254 (1988), S. 217-224 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Implantation ; Embryo ; Ultrastructure ; Vasculature ; Rat (Sprague-Dawley) ; Guinea pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Preimplantation-stage embryos were transferred to the anterior eye chamber of recipient rats and guinea-pigs. After implantation had occurred the influence of the embryo on the iris vasculature was examined ultrastructurally. In both species, the earliest effect of embryonic implantation was an increased stromal oedema. Under increasing embryonic influence the vascular endothelial cells showed an increased number of projections into the vascular lumen, while in the rat, endothelial projections were also found pushing back into the basement membrane. In the rat, the endothelium became very irregular in thickness prior to complete disintegration and loss during more advanced stages of implantation. Rat embryonic trophoblast was found invading iris vasculature, particularly in areas where the iridial endothelium was partially or completely missing. Other cells in the iris, including the stroma, appeared to be less affected. In the guinea-pig, however, trophoblast cells appeared to be capable of invading the vasculature by displacing endothelial cells that still appeared morphologically normal.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220037
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  • 38
    Digitale Medien
    Digitale Medien
    Morphological, histochemical, and ultrastructural characterization of the accessory cells of neuromasts in the salamander Pleurodeles waltlii (1988)
    Springer
    Cell & tissue research 254 (1988), S. 233-240 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Lateral-line sense organs ; Mechanoreceptors ; Supporting cells ; Ultrastructure ; Pleurodeles waltlii (Urodela)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructural and histochemical features of the accessory cells of the neuromast of the salamander P. waltlii have been examined. Three types of accessory cells, supporting, mantle, and basal, were found, but only the first 2 are considered in this article. Supporting cells characterized by a highly dilated endoplasmic reticulum occur among and surrounding sensory cells. Mantle cells, morphologically different from the supporting cells, surround the remainder of the neuromast. Both types of accessory cells exhibit histochemically different secretory materials. Our morphological results suggest that both accessory cells contribute to the formation of cupular material.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220039
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  • 39
    Digitale Medien
    Digitale Medien
    Influence of a short light pulse at night on the ultrastructure of the rat pinealocyte: a quantitative study (1988)
    Springer
    Cell & tissue research 254 (1988), S. 247-249 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pinealocyte ; Light exposure ; Ultrastructure ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Although it is generally known that light strongly influences N-acetyltransferase activity and melatonin production in the pineal gland, little information is available concerning morphological changes following light exposure. As exposure of rats to a short light pulse at night rapidly depresses melatonin synthesis, we decided to determine whether this experimental condition produces rapid changes in the pinealocyte organelles. A 30-min light pulse at night (six hours after lights out) provoked rapid changes in the relative volumes of some pinealocyte organelles. The volume fractions of mitochondria, Golgi apparatus and lipid droplets, and the numbers of dense-core vesicles and “synaptic” ribbons decreased, whereas the volume fraction of lysosomes increased. There were no differences in the volumes of granular endoplasmic reticulum and vacuoles containing flocculent material in those animals exposed to light compared with control animals. These results indicate that a short light pulse at night causes ultrastructural changes that can be interpreted as morphological features of diminished activity of pinealocytes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220041
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  • 40
    Digitale Medien
    Digitale Medien
    Cytoskeletons of retinal pigment epithelial cells: Interspecies differences of expression patterns indicate independence of cell function from the specific complement of cytoskeletal proteins (1988)
    Springer
    Cell & tissue research 254 (1988), S. 301-315 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Retinal pigment epithelium ; Cytoskeleton ; Cytokeratins ; Vimentin ; Desmosomes ; Anura (Rana ridibunda, Xenopus laevis) ; Chicken ; Bovine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In vertebrate tissue development a given cell differentiation pathway is usually associated with a pattern of expression of a specific set of cytoskeletal proteins, including different intermediate filament (IF) and junctional proteins, which is identical in diverse species. The retinal pigment epithelium (RPE) is a layer of polar cells that have very similar morphological features and practically identical functions in different vertebrate species. However, in biochemical and immunolocalization studies of the cytoskeletal proteins of these cells we have noted remarkable interspecies differences. While chicken RPE cells contain only IFs of the vimentin type and do not possess desmosomes and desmosomal proteins RPE cells of diverse amphibian (Rana ridibunda, Xenopus laevis) and mammalian (rat, guinea pig, rabbit, cow, human) species express cytokeratins 8 and 18 either as their sole IF proteins, or together with vimentin IFs as in guinea pig and a certain subpopulation of bovine RPE cells. Plakoglobin, a plaque protein common to desmosomes and the zonula adhaerens exists in RPE cells of all species, whereas desmoplakin and desmoglein have been identified only in RPE desmosomes of frogs and cows, including bovine RPE cell cultures in which cytokeratins have disappeared and vimentin IFs are the only IFs present. These challenging findings show that neither cytokeratin IFs nor desmosomes are necessary for the establishment and function of a polar epithelial cell layer and that the same basic cellular architecture can be achieved by different programs of expression of cytoskeletal proteins. The differences in the composition of the RPE cytoskeleton further indicate that, at least in this tissue, a specific program of expression of IF and desmosomal proteins is not related to the functions of the RPE cell, which are very similar in the various species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00225803
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  • 41
    Digitale Medien
    Digitale Medien
    Neurosecretory centers from the eyestalk of Siriella armata M. Edw. (Crustacea: Mysidacea): ultrastructural variations during normal and experimentally inhibited molt cycle (1988)
    Springer
    Cell & tissue research 254 (1988), S. 381-391 
    Details
    ISSN: 1432-0878
    Schlagwort(e): X-organ ; Sinus gland ; Ultrastructure ; Cyclic activity ; Siriella armata (Crustacea)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of the medulla interna-medulla externa X-organ (MI-ME Xo)-sinus gland (SG) complex in the eyestalk of Siriella armata is described during the normal and the experimentally inhibited molt cycle. In the normal SG, four types of neurosecretory axon terminals, each containing distinguishable neurosecretory granules, can be described. Thus, type-2 granules are synthesized by G1 neurons forming the MI-ME Xo. The cell bodies and axonal endings of these cells in the sinus gland have been examined at the following molt stages: intermolt (stage C4), premolt (D0 and D2), and postmolt (A1, A2 and B). Changes in ultrastructure of the G1 cells have been monitored and correlated to inhibitions of the molt-and reproductive cycle produced by electrocauterization of the MI-ME Xo. The results obtained suggest that the neurosecretion from the G1 cells exerts a positive influence on molt and brood preparation. The occurrence of a distal group of G1 cells whose axons terminate at a different site from the SG suggests that the neural factors of the MI-ME Xo are diverse and control different physiological activities.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00225810
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  • 42
    Digitale Medien
    Digitale Medien
    Study of neuropeptide Y-containing nerve fibers in the human penis (1988)
    Springer
    Cell & tissue research 254 (1988), S. 69-74 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Neuropeptide Y (NPY) ; Penis erection ; Perivascular nerve fibers immunocytochemistry ; Ultrastructure ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Neuropeptide Y 1–36 (IR-NPY) immunoreactive nerve-fiber processes have been observed in tunicae of veins and arteries and in smooth muscles of the human penis taken at autopsy or during surgery by use of light-and electron-microscopic immunohistochemical techniques. Numerous IR-NPY nerve fibers were mostly concentrated in the inner part of the adventitia close to the media of the arterial and venous vessels and among the intracavernous smooth muscle cells. IR-NPY nerve fibers were less abundant in veins than in arteries. Positive somata were not observed in the penises. At the ultrastructural level, IR-NPY were localized exclusively in large, dense granules of nerve terminals by means of the postembedding immunogold technique. In the deep dorsal vein, IR-NPY nerve fibers were also located in the media formed by an outer circular and an inner longitudinal layer. In the intracavernous and dorsal arteries, they showed the highest density in the inner part of the adventitia. In the corpora cavernosa and in the corpus spongiosum, IR-NPY nerve processes were intermingled between the smooth-muscle fibers around the sinusoid spaces. IR-NPY nerve fibers were present in the cavernous nerves close to the central arteries. The urethra did not show any IR-NPY-positive nerve fibers. This peculiar distribution of IR-NPY nerve fibers suggested that they could participate in regulating arterial and venous blood flow and intracavernous smooth-muscle tone. NPY may therefore be of importance in some of the mechanisms of penile erection especially during detumescence.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220018
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  • 43
    Digitale Medien
    Digitale Medien
    Protein and collagen content of rat skeletal muscle following space flight (1988)
    Springer
    Cell & tissue research 254 (1988), S. 251-253 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Space flight ; Skeletal muscle ; Collagen ; Protein ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Biochemical determinations of non-collagenous protein and hydroxyproline were made on rat skeletal muscles following 7 days of space flight aboard the NASA space shuttle mission SL-3. Relative to ground-based controls, the wet weight of each experimental muscle was significantly reduced. This was concomitant with a reduction in noncollagenous protein in the muscles. Protein concentration, however, was reduced only in slow-twitch muscles. The effect of space flight on the concentration and hydroxyproline content was different among the muscles. As a result, the loss of muscle mass in some muscles was the consequence of a reduction in both collagenous and non-collagenous proteins, while in others it was primarily the result of a non-collagenous protein loss.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220042
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  • 44
    Digitale Medien
    Digitale Medien
    Implantation of cultured thymic fragments in congenitally athymic (nude) rats (1988)
    Springer
    Cell & tissue research 254 (1988), S. 283-294 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Thymus ; Cultured thymic fragments ; Epithelial cells ; Microenvironment ; Ultrastructure ; Rat (nude)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Cultured thymic fragments correspond to the thymic microenvironment depleted of lymphocytes and dendritic cells. When these fragments are implanted under the kidney capsule of congenitally athymic rats, lymphocytes and dendritic cells of host origin enter the graft and induce thymus-dependent immunity in the recipient. This paper describes the ultrastructure of the fragments and the changes that occur during the restoration of normal thymic architecture. At the end of the culture period of 6–9 days and in the early stages after implantation, the grafts consist of keratin-containing epithelial cells of unusual morphology that can be labelled with antibodies raised against the epithelium of the mid/deep cortex and the subcapsule/medulla. Normal thymic architecture develops, including nerves and blood vessels, as lymphocytes populate the environment, and by 4–6 weeks the epithelial cells are the same phenotypically and ultrastructurally as those found in normal rat thymus. However, some areas without lymphocytes still contain the atypical epithelial cells seen before implantation. Large multinucleated giant cells are also present with a few associated epithelial cells of subcapsular/medullary phenotype. In conclusion, the cultured thymic fragments contain a hitherto unknown precursor epithelial cell with an atypical ultrastructure and phenotype that is not seen in normal development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00225801
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  • 45
    Digitale Medien
    Digitale Medien
    Pinealocytes immunoreactive with antisera against secretory glycoproteins of the subcommissural organ: A comparative study (1988)
    Springer
    Cell & tissue research 254 (1988), S. 469-480 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pineal complex ; Pinealocytes, receptor line ; Subcommissural organ ; Immunocytochemistry ; Protein secretion ; Neuroendocrine system Geotria australis (Cyclostomata) ; Onkorhynchus kisutch (Teleostei) ; Eupsophus roseus (Anura) ; Heloderma suspectum, Varanus monitor (Lacertilia) ; Domestic fowl ; Rat ; Bovine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary By means of light-microscopic immunocyto-chemistry two polyclonal antibodies (AFRU, ASO; see p. 470) directed against secretory glycoproteins of the subcom-missural organ were shown to cross-react with cells in the pineal organ of lamprey larvae, coho salmon, a toad, two species of lizards, domestic fowl, albino rat and bovine (taxonomic details, see below). The AFRU-immunoreactive cells were identified as pinealocytes of the receptor line (pineal photoreceptors, modified photoreceptors or classical pinealocytes, respectively) either due to their characteristic structural features or by combining AFRU-immunoreaction with S-antigen and opsin immunocytochemistry in the same or adjacent sections. Depending on the species, AFRU- or ASO-immunoreactions were found in the entire perikaryon, inner segments, perinuclear area, and in basal processes facing capillaries or the basal lamina. In most cases, only certain populations of pinealocytes were immunolabeled; these cells were arranged in a peculiar topographical pattern. In lamprey larvae, immunoreactive pinealocytes were observed only in the pineal organ, but not in the parapineal organ. In coho salmon, the immunoreaction occurred in S-antigen-positive pinealocytes of the pineal end-vesicle, but was absent from S-antigen-immunoreactive pinealocytes of the stalk region. In the rat, AFRU-immunoreaction was restricted to S-antigen-immunoreactive pinealocytes found in the deep portion of the pineal organ and the habenular region. These findings support the concept that several types of pinealocytes exist, which differ in their molecular, biochemical and functional features. They also indicate the possibility that the AFRU- and ASO-immunoreactive material found in certain pinealocytes might represent a proteinaceous or peptidic compound, which is synthesized and released from a specialized type of pinealocyte in a hormone-like fashion. This cell type may share functional characteristics with peptidergic neurons or paraneurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00226496
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  • 46
    Digitale Medien
    Digitale Medien
    Ultrastructure of the meninges at the site of penetration of veins through the dura mater, with particular reference to Pacchionian granulations (1988)
    Springer
    Cell & tissue research 251 (1988), S. 621-631 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Perivascular space ; Cerebrospinal fluid compartments ; Dura mater ; Pacchionian granulations ; Rat ; Cebus apella, Callitrix jacchus (Primates)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary At the sites where a vein penetrates through the dura mater, two aspects deserve particular attention: (i) The delineation of the perivascular cleft, a space belonging to the interstitial cerebrospinal fluid (CSF) compartment, toward the interior hemal milieu of the dura mater. (ii) The relationship between the perivascular arachnoid layer and the subdural neurothelium at the point of vascular penetration. These problems were investigated in the rat and in two species of New-World monkeys (Cebus apella, Callitrix jacchus). Concerning the first aspect, tight appositions of meningeal cells to the vessel wall, the basal lamina of which is widened and enriched with microfibrils, prevent communication between the interstitial CSF in the perivascular cleft and the hemal milieu in the dura mater. With reference to the second aspect, the perivascular arachnoid cells are transformed into neurothelial cells at the point where they become exposed to the hemal milieu of the dura mater and subsequently continuous with the subdural neurothelium. Leptomeningeal protrusions encompassing outer CSF space can penetrate into the dura mater. These protrusions may expand and branch repeatedly, forming along the wall of the durai sinus Pacchionian granulations. At these sites, however, the structural integrity of the sinus wall and the Pacchionian granulation is not lost. Numerous vesiculations not only in the sinus and vascular walls, but also in the cellular arrays of the Pacchionian granulations or paravascular leptomeningeal protrusions indicate mechanisms of transcellular fluid transport. Moreover, the texture of the leptomeningeal protrusions favors an additional function of these structures as a “volume” buffer.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00214011
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  • 47
    Digitale Medien
    Digitale Medien
    Binding of intravenously injected antibodies against laminin to developing and mature endocrine glands (1988)
    Springer
    Cell & tissue research 251 (1988), S. 171-181 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adrenal cortex ; Basal lamina ; Laminin ; Anterior pituitary gland ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary To determine whether circulating antibodies against laminin can bind in vivo to basement membranes within endocrine glands, affinity-purified sheep or rabbit anti-laminin IgG was intravenously injected into rats. One to five hours after injection, anti-laminin IgG was bound to all basement membranes of adrenal and anterior pituitary glands of mature as well as 2-day-old newborn rats as shown by immunofluorescence microscopy. After the injection of anti-laminin conjugated directly to horseradish peroxidase (HRP), HRP reaction product was also present throughout adrenal and pituitary basement membranes in mature and immature glands 1–5 h post-injection. Ultrathin Lowicryl sections from rats that received unconjugated rabbit anti-laminin IgG 1 h prior to fixation with paraformaldehyde were labeled directly with anti-rabbit IgG-colloidal gold. In these cases, gold also bound specifically over the lamina densa and lamina rara. When adrenal or pituitary glands from mature rats were examined by immunofluorescence 1 week after the injection of sheep anti-laminin IgG, the patterns and amounts of bound sheep IgG were indistinguishable from those observed 1 h after injection. In contrast, significantly less fluorescence was present in glands from 7-day-old rat pups that had received anti-laminin IgG 5 days earlier. In addition, when anti-laminin IgG-HRP was injected into newborns and glands were fixed 5 days later, lengths of labeled endothelial and epithelial basement membranes were often interspersed with unlabeled lengths in zones of cellular proliferation in the outer adrenal cortex and throughout the pituitary gland. These results indicated that unlabeled basement membranes in these regions were probably assembled after the injection of anti-laminin IgG, which would also explain diminished labeling of basement membranes in these animals. Despite the continued presence of heterologous anti-laminin IgG within endocrine basement membranes, however, rat IgG, rat C3, inflammatory cells, or histologic abnormalities were observed in neither newborn nor adult glands under the conditions examined here. Sections from rats injected with control IgG or control IgG-HRP were entirely negative by immunofluorescence, immunoperoxidase, and immunogold techniques. We therefore conclude that (1) apparently large amounts of circulating anti-laminin IgG can bind to adrenal and pituitary basement membranes, and (2) at least some of these basement membranes are assembled during development by progressive splicing of newly synthesized matrix into that already present.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215462
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  • 48
    Digitale Medien
    Digitale Medien
    Nerve growth factor-inducible, large external (NILE) glycoprotein in developing rat cerebral cells in culture (1988)
    Springer
    Cell & tissue research 252 (1988), S. 181-190 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Embryonic rat brain ; Cell culture ; Development ; NILE-glycoprotein ; Neurons ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Fetal rat cerebral cells underwent neuronal differentiation in culture. This process was accompanied by distinct changes in the cellular glycoprotein pattern. The incorporation of [3H]-fucose into two proteins of apparent molecular weights of 30000 and 60000 daltons was significantly decreased and specific developmental changes were observed in a group of glycoproteins with high molecular weights (150000–250000 dalton). By means of indirect immunoprecipitation one of them was identified as NILE gp (nerve growth factor-inducible large external) glycoprotein (200000 dalton), a marker of central and peripheral neurons. Its developmental expression on neurons of dissociated rat cerebral cultures was studied using the indirect immunofluorescence technique and compared to the fluorescent-labeling pattern of other neuronal markers. Neurons expressing NILE gp were detected as early as after one day in culture. No preferential staining of neuntes versus cell bodies was observed. Two classes of NILE gp-positive cells were identified. One group consisted of a rounded cell-type, whereas the other group was represented by larger, more spindle-shaped neurons with a limited number of neuritic processes. In most cases one of these neuritic processes was preferentially labeled. Astroglia cells, as identified by immunolabeling with antisera against the glial acidic fibrillary protein, were observed to develop and mature after the first week in culture. NILE-positive neurons were found to be positioned in close association with glial cell processes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213840
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  • 49
    Digitale Medien
    Digitale Medien
    Study on the origin of apical tubules in ileal absorptive cells of suckling rats using concanavalin-A as a membrane-bound tracer (1988)
    Springer
    Cell & tissue research 251 (1988), S. 511-521 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Endocytosis ; Absorptive cells ; Ileum ; Intestine, small ; Apical tubules ; Membrane recycling ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ileal absorptive cells of suckling rats exhibit high levels of endocytic activity being engaged in nonselective uptake of macromolecules from the intestinal lumen. The apical cytoplasm usually contains an extensive network of small, membrane-limited tubules (apical tubules: AT), in addition to newly formed endocytic vesicles and large endocytic vacuoles. To determine whether the AT are directly involved in the endocytic process by carrying the tracer into the cell, we have analysed movements of the apical cell membrane of the ileal absorptive cells by using a membrane-bound tracer (horseradish peroxidase-labelled cancanavalin-A: Con-A HRP). The ileal absorptive cells were exposed in vitro to Con-A HRP for 10 min at 4° C, incubated for different times in Con-A free medium at 37° C, and prepared for electron microscopy. After 1 min incubation at 37° C, invaginations of the apical cell membrane, including coated pits, and endocytic vesicles were labelled with HRP-reaction product, whereas the AT and large endocytic vacuoles were negative. After 2.5 min, almost all the large endocytic vacuoles were labelled with reaction product, which was seen in their vacuolar lumen and along the luminal surface of their limiting membrane. A few AT with reaction product were seen in the apical cytoplasm; they were in frequent connection with the reaction-positive large endocytic vacuoles. With increasing incubation time, the number of the labelled AT increased. Thus, after 15 min at 37° C, the apical cytoplasm was fully occupied by the reaction-positive AT. The ends of these AT were often continuous with small spherical coated vesicles. No reaction product was detected in the Golgi complex at any time after incubation. These observations indicate that the AT located in the apical cytoplasm probably originate by budding off from the large endocytic vacuoles, rather than being involved in the process of endocytosis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213998
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  • 50
    Digitale Medien
    Digitale Medien
    Innervation of periodontal ligament and dental pulp in the rat incisor: An immunohistochemical investigation of neurofilament protein and glia-specific S-100 protein (1988)
    Springer
    Cell & tissue research 251 (1988), S. 13-21 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Periodontal ligament ; Incisor ; Neurofilament protein ; S-100 protein ; Immunohistochemistry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Nervous elements in the periodontal ligament and dental pulp of rat incisors were investigated by means of immunohistochemistry for neurofilament protein (NFP) and glia-specific S-100 protein. The periodontal ligament in the incisors was densely innervated by NFP-immunoreactive nerve fibers; the distribution of the nerve fibers and their terminations differed markedly from those in molars. NFP-positive, thick nerve bundles entered the lingual periodontal ligament through slits located in the mid-region of the alveolar socket, and immediately formed numerous Ruffini-like corpuscles. In the labial periodontal ligament, all of the NFP-immunoreactive nerve fibers terminated in free endings. The restricted location of the stretch receptor, Ruffini-like corpuscle, in the lingual periodontal ligament appears to be an essential element, because this region is regularly extended during mastication. The nervous elements were restricted to the alveolar half of the periodontal ligament in every region; they avoided the dental half of the periodontal ligament, which presumably moves continuously with the tooth. Pulpal nerve fibers in incisors also showed a characteristic distribution different from those in molars; individual nerve fibers with beaded structures ran in the center of the pulp toward the incisai edge, and did not form the subodontoblastic nerve plexus of Raschkow. Immunostaining for S-100 protein revealed a distribution pattern of nervous elements similar to that for NFP, suggesting that the nerves supplying the periodontal ligament and dental pulp were mostly covered by a Schwann sheath.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215442
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  • 51
    Digitale Medien
    Digitale Medien
    Abundant GABAergic innervation of rat posterior pituitary revealed by inhibition of GABA-transaminase (1988)
    Springer
    Cell & tissue research 251 (1988), S. 59-64 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Posterior pituitary ; Immunocytochemistry ; Anti-GABA ; GABA-transaminase ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary An antibody against gamma-aminobutyric acid (GABA) was used to identify GABAergic elements immunocytochemically in the rat posterior pituitary. In order to increase the intracellular concentration of GABA, rats were treated with the GABA-transaminase inhibitor gamma-vinyl-GABA (GVG). Light-microscopic observations of Vibratome and semithin sections revealed the presence of numerous immunoreactive nerve fibers throughout the neural lobe; the mean number and length of these fibers increased by 90% after GVG treatment. Electron microscopy demonstrated the immunostained axons to be of small diameter. The reaction product was confined to small vesicles. No immunostaining occurred in pituicytes. The richness of the GABAergic innervation of the neural lobe contrasts with previous reports using antibodies against glutamate decarboxylase and supports the idea that GABA participates in the presynaptic control of neurosecretion.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215447
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  • 52
    Digitale Medien
    Digitale Medien
    Evidence for neuroendocrine regulation of preadipocyte proliferation and differentiation (1988)
    Springer
    Cell & tissue research 251 (1988), S. 65-70 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adipose tissue ; Cell proliferation ; Cell differentiation ; Histochemistry ; Swine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Cells in fetal adipose tissue and cells in vitro are characterized by rapid proliferation. Serum factors have been shown to be important for the rapid proliferation of cells in vitro. The present experiment was performed to determine if neuroendocrine regulatory mechanisms of the fetus can influence the actions of serum factors on preadipocyte proliferation and differentiation in vitro. Sera were obtained from decapitated fetal pigs and intact littermates during gestation. Sera were tested for their effects on primary cultures of preadipocytes and stromalvascular cells derived from inguinal adipose tissue of young Sprague-Dawley rats. Coverslip cultures were used for histochemical analysis of enzymes after 12 days of incubation with test media. Analysis of growth curves produced from sequential [3H]-thymidine labeling indicated that fetal age influences rates of proliferation. Sera from decapitated fetal pigs specifically reduced the number of proliferating preadipocytes in culture. Sera from decapitated fetal pigs induced a minimum of 50% less differentiation of sn-glycerol-3-phosphate dehydrogenase activity than sera from intact pigs at all fetal ages. Histochemical staining for enzymes of differentiating preadipocytes was also reduced in cultures incubated with sera from decapitated fetal pigs in comparison to sera from intact pigs. The present study has demonstrated that the in vivo effect of decapitation on fetal adipose tissue development is a consequence of alterations in systemic factors present in serum in response to removal of central regulation by the hypothalamic-pituitary axis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215448
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  • 53
    Digitale Medien
    Digitale Medien
    Immumochemical and immunocytochemial characterization of a novel monoclonal antibody recognizing a 140 kDa protein in cerebral pericytes of the rat (1988)
    Springer
    Cell & tissue research 252 (1988), S. 543-555 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Monoclonal antibody ; Blood-brain barrier ; Cerebral pericytes ; Transporting epithelia ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary A monoclonal antibody that recognizes a 140 kDa peripheral plasma membrane protein in pericytes of nervous tissues of the rat is described. Microvessels of brain cortex and perineurium of peripheral nerves are shown to react positively to this antibody. The antigen is absent in brain regions that lack a blood-brain barrier, i.e., choroid plexuses and area postrema. Antigen expression starts as early as day 18 of embryonic development. By means of immuno-electron microscopy the 140 kDa antigen was detected as clusters along the entire circumference of cerebral pericytes. The same antigenic determinant is also expressed in apical domains of plasma membranes of a variety of transporting epithelia, such as hepatocytes, enterocytes of the small intestine, and epithelial cells of proximal tubules of the kidney. We postulate the 140 kDa protein as being a constituent of the pericytes involved in regulative functions of the blood-brain barrier.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216641
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  • 54
    Digitale Medien
    Digitale Medien
    An ultrastructural study of mitosis and cytokinesis in normal ‘resting’ human breast (1988)
    Springer
    Cell & tissue research 252 (1988), S. 581-587 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Normal resting breast ; Ultrastructure ; Mitosis ; Cytokinesis ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The parenchyma of the normal “resting” human breast was examined by electron microscopy to characterize the cells undergoing mitosis and the mechanism by which the normal tissue architecture is maintained during this process. In this study of 112 mitotic cells, it was found that the mitotic cells were luminally positioned, polarised epithelial cells with no evidence of myoepithelial cell division. Ultrastructurally, the nuclear and cytoplasmic changes were consistent with previous reports of mitosis in other tissues. However, unlike all previous reports, two specific orientations of the nuclear spindle and thus the planes of cytokinesis were observed. In a few cases the spindle formed parallel to the lumen and division resulted in two luminally positioned daughter cells. However, in the majority of mitotic cells the spindle was approximately at right angles to the lumen and this orientation resulted in a luminally and a basally positioned daughter cell. It is proposed that the abnormally positioned basal daughter cell could develop into a myoepithelial cell or undergo deletion (apoptosis). Thus the two orientations of mitosis may explain the mechanism by which the epithelial and myoepithelial cell populations were maintained by a single progenitor cell without disrupting the integrity of the tissue architecture.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216645
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  • 55
    Digitale Medien
    Digitale Medien
    Ultrastructure of the ovarian medulla in the newly hatched chick treated with human chorionic gonadotropin (1988)
    Springer
    Cell & tissue research 253 (1988), S. 665-670 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Ovary ; Steroid-secreting cells ; Ultrastructure ; Chorionic gonadotropin ; Chicken
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructural characteristics of the ovarian medulla of the newly hatched white leghorn chick were studied in control animals and compared with chicks that were treated with human chorionic gonadotropin during embryonic development. The ovarian medulla was mainly occupied by epithelial cells which formed cords or islets surrounded by a basal lamina. Within this epithelial compartment, steroidogenic cells, poorly differentiated cells and a lacunary system could be recognized. When chicks were treated with human chorionic gonadotropin, steroidogenic cells became discernible; there was an increment in the amount of cytoplasm and the area of mitochondria. Poorly differentiated cells exhibited signs of stimulation, and transitional images suggested the transformation of these cells into steroidogenic cells. The epithelial cells of the lacunar system also displayed stimulated cytoplasmic organelles. Evidence was supplied suggesting that relatively undifferentiated cells persist in the ovarian medulla until hatching and can develop into steroidogenic cells under gonadotropic stimulation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00219758
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  • 56
    Digitale Medien
    Digitale Medien
    Orthogonal arrays of particles in non-pigmented cells of rat ciliary epithelium: Relation to distribution of filipin- and digitonin-induced alterations of the basolateral membrane (1988)
    Springer
    Cell & tissue research 252 (1988), S. 165-173 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Ciliary epithelium ; Orthogonal arrays of particles ; Filipin ; Freeze-fracture ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary It has been suggested that orthogonal arrays of particles may increase the rigidity of plasma membrane, as does cholesterol. Therefore, using freeze-fractured non- pigmented ciliary epithelium, the distribution of such arrays was compared to the distribution of membrane deformations induced by the sterol-probes filipin and digitonin in different domains of the basolateral plasma membrane. The distribution of orthogonal arrays of particles was homogeneous between different regions of the basolateral membrane of the non-pigmented ciliary epithelium, while the number of filipin-induced alterations was nearly 4 times higher in the membrane domains not in contact with the basal lamina than in domains in contact with it. Contrary to the homogeneous distribution of arrays, digitonin-induced deformations also differed markedly in these two basolateral membrane domains. Considering that a marked positive response to sterol probes implies a high sterol content, we conclude that orthogonal arrays of particles can occur in plasma membrane regions well-provided with cholesterol and not in direct contact with the basal lamina. Other possible roles of these arrays are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213838
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  • 57
    Digitale Medien
    Digitale Medien
    Electron-microscopic immunocytochemistry of 5-hydroxytryptamine in the ascidian endostyle (1988)
    Springer
    Cell & tissue research 253 (1988), S. 137-143 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Endostyle ; Ultrastructure ; Immunocytochemistry ; 5-Hydroxytryptamine ; Granules ; Ciona intestinalis ; Corella parallelogramma, (Tunicata) ; Ascidia mentula (Tunicata)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The cellular and subcellular distribution of serotonin (5-hydroxytryptamine, 5-HT) in the endostyle of three species of ascidians, Ciona intestinalis, Corella parallelogramma, Ascidia mentula, was studied by light-(immunoperoxidase) and electron-microscopic (immunogold) immunocytochemistry. At the light-microscopic level 5-HT-like immunoreactivity (5-HT-LI) was exclusively found in cells located in the lateral portion of the endostyle, between zone 7, known to have iodinating capacity, and zone 8, which consists of ciliated cells. At the electron-microscopic level, the 5-HT-immunoreactive cells were found to correspond to cells containing polymorphous, dense granules, 100–300 nm in diameter. The granules were located in the supranuclear cytoplasm facing the endostyle lumen as well as in the infranuclear cytoplasm facing the extracellular space. Quantification showed that the 5-HT-LI was considerably higher (13–67 times) in cytoplasmic areas containing granules as compared to areas devoid of granules. Most, but not all, of the 5-HT-LI was associated with the dense core of the granules. In conclusion, serotonin-containing cells are located in the peripheral portion of the endostyle, between zones 7 and 8. Serotonin is stored in cytoplasmic granules that are present both in the apical and basal cytoplasm. This suggests the possibility that the cells are bipolar and secrete serotonin both in a basal direction to the extracellular space, and in an apical direction to the pharyngeal lumen.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221748
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  • 58
    Digitale Medien
    Digitale Medien
    44-kDal bone phosphoprotein (osteopontin) antigenicity at ectopic sites in newborn rats: kidney and nervous tissues (1988)
    Springer
    Cell & tissue research 251 (1988), S. 23-30 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Bone phosphoprotein ; Osteopontin ; Kidney ; Inner ear ; Trigeminal nerve ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Previous immunohistochemical data have shown that the 44-kDal bone phosphoprotein (44K BPP, also called sialoprotein I or oestopontin) recently isolated in our laboratory was synthesized by osteoblasts and osteocytes and was expressed early during differentiation of boneforming cells. We report here the presence of 44K BPP antigenicity at certain ectopic sites, namely, the proximal-convoluted tubule of the kidney, neurons, sensory and secretory cells in the internal ear. To insure specificity and reproducibility, different immunohistochemical methods were used and affinity-purified antibodies against two separate preparations of pure 44K BPP were tested. In the cells of the proximal-convoluted tubule, 44K BPP immunoreactivity was observed within apical endocytotic vacuoles and within lysosomes. This staining thus correlates with the degradation of the 44K BPP epitope which we previously demonstrated to occur in serum. On the other hand, in the neurons of the acoustic ganglion and the sensory cells of the macula, 44K BPP immunoreactivity was associated with the Golgi apparatus indicating synthesis and secretion by these cells. The finding that the 44K BPP (or a structurally related molecule) is synthesized by neurons and neuroepithelial cells deserves further investigation with respect to a possible embryologie relationship between neuroectodermal cells and the precursors of some bone forming-cells of the skull.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215443
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  • 59
    Digitale Medien
    Digitale Medien
    Effect of live and heat-killed bacteria on the secretory activity of Paneth cells in germ-free mice (1988)
    Springer
    Cell & tissue research 251 (1988), S. 87-93 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Paneth cells ; Ultrastructure ; Morphometry ; Facultative anaerobes ; Germ-free mice
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Germ-free mice were given live or heat-killed facultative anaerobes, and the ultrastructure of ileal Paneth cells was quantitatively examined with special reference to secretory granules showing a bipartite substructure (central core and peripheral halo). After administering live or heatkilled bacteria, there was a decrease in the area occupied by the cores of secretory granules in Paneth cells, and exocytosed core material was observed in the crypt lumen. There were no changes in the area occupied by the halo of secretory granules. None of the examined Paneth cells phagocytosed bacteria. It is concluded that certain bacteria may affect the secretion of antibacterial agents contained in the secretory granules of Paneth cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215451
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  • 60
    Digitale Medien
    Digitale Medien
    The lattice arrangement of the collagen fibres in the submucosa of the rat small intestine: scanning electron microscopy (1988)
    Springer
    Cell & tissue research 251 (1988), S. 117-121 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Collagen ; Submucosa ; Intestine ; Scanning electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The three-dimensional architecture of the submucosal collagen fibres of the rat (3 weeks old) small intestine was examined by scanning electron microscopy using a selective microdissection method. The main framework of the submucosa was composed of two arrays of collagen fibre bundles running diagonally around the intestinal wall, one set in a clockwise direction, the other counterclockwise. These fibre bundles were about 5 μm in diameter and were oriented at a range of angle ± 30°–50° to the longitudinal axis of the intestine. With the advantage of the SEM observation it was demonstrated that these fibres in different arrays did not constitute two separate layers but interwove to form a unified lattice sheet. An irregular network of fine collagen fibrils over the main framework was also seen. The significance of their arrangement is discussed with respect to the skeletal function of the submucosa in the intestine.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215455
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  • 61
    Digitale Medien
    Digitale Medien
    Adhesion, proliferation, and adipogenesis in primary rat cell cultures: effects of collagenous substrata, fibronectin, and serum (1988)
    Springer
    Cell & tissue research 251 (1988), S. 123-128 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adipocyte ; Primary culture ; Collagen ; Fibronectin ; Serum ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effects of collagenous substrata, fibronectin, and fetal bovine serum on the adhesion, proliferation, and adipogenesis of rat stromal-vascular cells are reported. There was no effect on initial stromal-vascular cell-attachment by fetal bovine serum or fibronectin. The number of cells attached to a hydrated collagen-gel was almost twice (P〈0.04) the number attached to dried collagen-gel or dried denatured collagen-gel. Total number of cells after 5 days in culture was similar among the collagenous substrata and among the treatments with or without fibronectin in the growth media. Total number of cells increased significantly (P〈0.02) with 10% FBS. Adipocytic formation was inhibited by hydrated collagen-gel (P〈0.02) compared to dried collagen-gel or dried, denatured collagenous substrata. An interaction occurred between dried, denatured gel and fetal bovine serum so that total formation of adipocytes increased by increasing the level of fetal bovine serum (P〈0.07). Adipocytic formation was inhibited by hydrated collagen-gel at all levels of fetal bovine serum. The percentage of cells that converted to adipocytes was significantly lower (P〈0.01) on hydrated collagen-gel compared to dried, denatured or dried collagen-gel. Percentage of conversion was not significantly different among levels of fetal bovine serum, although this percentage increased as fetal bovine serum level increased. Adipocytic conversion was not different between fibronectin-treated or untreated cells. Morphology of stromal vascular cells was similar on dried collagen and dried, denatured collagen-gel, but tended to remain bipolar on hydrated collagen-gel. These studies indicate that fetal bovine serum in combination with the extracellular matrix (dried, denatured collagen) increased the differentiation of rat stromal-vascular cells into adipocytes, and that hydrated collagen inhibited differentiation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215456
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  • 62
    Digitale Medien
    Digitale Medien
    Ventricular and atrial myocytes of newborn rats synthesise and secrete atrial natriuretic peptide in culture: Light-and electron-microscopical localisation and chromatographic examination of stored and secreted molecular forms (1988)
    Springer
    Cell & tissue research 251 (1988), S. 161-169 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Atrial natriuretic peptide ; Ventricular myocytes ; Atrial myocytes ; Cell culture ; Secretion ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary We have demonstrated that atrial natriuretic peptide-like immunoreactivity is stored and secreted by ventricular and atrial myocytes in dissociated cell culture preparations from the heart of newborn rat. Culture preparations were maintained in either foetal calf serum-supplemented medium 199 or in hormone-supplemented, serum-free medium 199. The presence of atrial natriuretic peptidelike immunoreactivity in the cultured myocytes was demonstrated at both light-and electron-microscopical levels. Release of atrial natriuretic peptide-like immunoreactivity into the culture medium was measured by radioimmunoassay; molecular forms of the stored and secreted peptide were determined by gel column chromatography. The atrial natriuretic peptide-like immunoreactivity of cultured atrial and ventricular myocytes was concentrated in the perinuclear cytoplasm and was localised to electron-dense secretory granules. The number of immunoreactive ventricular myocytes and the intensity of their immunofluorescence changed with time in culture and was higher in cultures in foetal calf serum-supplemented medium than in serum-free medium. Gamma-atrial natriuretic peptide was stored and released by cultured atrial and ventricular myocytes, but was broken down to alpha-atrial natriuretic peptide in the growth medium. This process was foetal calf serum-independent, since it occurred in both the media used, indicating that cardiac myocytes in culture may release a factor that cleaves gamma-atrial natriuretic peptide to form alphaatrial natriuretic peptide.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215461
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  • 63
    Digitale Medien
    Digitale Medien
    Transient involvement of enkephalins in both the sympathetic and parasympathetic innervations of the submandibular gland of rats (1988)
    Springer
    Cell & tissue research 253 (1988), S. 529-537 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Enkephalin-nerves ; Transient appearance ; Submandibular gland ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary A time course study with enkephalin(Enk)-like immunoreactivity has revealed that nerve fibers intensely immunoreactive for Enk-8 appeared transiently only during the postnatal week 2 and 4 within the acini as well as in the inter- and intralobular connective tissues of the submandibular gland of rats. At these stages numerous nerve fibers immunoreactive for tyrosine hydroxylase (TH) appeared also in the inter- and intralobular connective tissues and within the acini. Coincidently with these postnatal stages, abundant Enk-immunoreactive principal ganglion cells appeared in the superior cervical ganglion. These were not immunoreactive for neuropeptide tyrosine (NPY). A substantial number of Enk-immunoreactive ganglion cells were also present in the submandibular ganglia at these younger postnatal stages. Superior cervical ganglionectomy at these stages resulted in a marked decrease in number of the inter- and intralobular Enk-immunoreactive nerve fibers, a slight decrease in number of the intraacinar Enk-immunoreactive nerve fibers, and almost complete disappearance of intraglandular TH-immunoreactive nerve fibers. Immuno-electron-microscopic analysis revealed that Enk-immunoreactive nerve fibers in the submandibular gland were identified as electron-dense neuronal profiles enclosed by Schwann cells in the inter- and intralobular connective tissues and those directly apposed to secretory cells within the acini. They contained small clear vesicles mixed with some large granular vesicles. After postnatal week 6, no Enk-immunoreactive nerve fibers were detected in the submandibular gland, and no TH-immunoreactive nerve fibers were seen within the acini, while TH-immunoreactive nerve fibers remained numerous in the inter- and intralobular connective tissues. These findings indicate that both sympathetic and parasympathetic nerve fibers exhibit Enk-like immunoreactivity transiently during postnatal weeks 2 and 4. It is further indicated that the inter- and intralobular nerve fibers lose Enk-like immunoreactivity while the intraacinar fibers disappear at the adult stage.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00219743
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  • 64
    Digitale Medien
    Digitale Medien
    Morphometrical analysis of the gap-junctional area in parenchymal cells of the rat liver after administration of dibutyryl cAMP and aminophylline (1988)
    Springer
    Cell & tissue research 252 (1988), S. 611-618 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Gap junctions ; cAMP ; Theophylline ; Freeze-fracture ; Liver ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In view of the presumed involvement of gap junctions in the coordination of metabolic activities, the influence of cAMP as a regulatory signal of cell metabolism on gap junctions of hepatocytes has been examined. Male rats received two intraperitoneal doses of 10 mg dibutyryl cAMP/100 g body weight with a time interval of 2.5 h and were decapitated 2.5 h later. After this 5-h interval, analysis of freeze-fracture replicas of fixed liver tissue revealed an increase in the mean (± SEM) gap-junctional membrane portion on the lateral hepatocyte membranes from 0.049 + 0.003 (n = 66) in controls to 0.061 ± 0.003 (n = 70) in treated rats, while the configuration of the connexons appeared unaltered. This effect could not be reinforced by prior administration of aminophylline: the relative gapjunctional area is similarly extended from 0.054 ± 0.003 (n = 126) in the control group to 0.065 ± 0.004 (n = 105) in the experimental animals. Probing for the time course of the junctional response, a group of rats was sacrificed 3 h after the onset of treatment. Already within this time, the gapjunctional area is augmented from 0.042 ± 0.004 (n = 63) in the concurrent controls to 0.069 ± 0.006 (n = 42) in the treated rats. These statistically significant increases in area may suggest a stimulating effect of cAMP on gap junctions of hepatocytes in vivo.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216648
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  • 65
    Digitale Medien
    Digitale Medien
    Three-dimensional organization of the plasmalemmal vesicular system in directly frozen capillaries of the rete mirabile in the swim bladder of the eel (1988)
    Springer
    Cell & tissue research 254 (1988), S. 17-24 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Endothelium ; Swim bladder ; Capillaries ; Vesicles ; Ultrastructure ; Cryofixation ; Anguilla rostrata (Teleostei)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Several recent studies comparing chemically fixed and cryofixed endothelium have indicated that glutaraldehyde fixation may result in increases in the population of “vesicles” in the cytoplasm. Other reports based on ultrathin serial-section reconstruction of chemically fixed endothelium have revealed that the vesicular system is comprised of interconnected membranous compartments, which are ultimately continuous with either cell surface but do not extend across the endothelial cell. In this study, we have investigated the three-dimensional organization of the vesicular system in directly frozen, freeze-substituted capillaries of the rete mirabile from the swim bladder of the eel, specifically using the same block of embedded capillaries in which frozen capillaries had previously been found to contain less “vesicles” than chemically fixed capillaries. The results show that essentially all vesicles remain inter-connected with each other and are part of two separate sets of invaginations from the luminal and abluminal cell surface like in chemically fixed tissue. Any increase in vesicle number resulting from glutaraldehyde fixation does not affect the overall three-dimensional organization of the vesicular system in these endothelial cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220012
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  • 66
    Digitale Medien
    Digitale Medien
    Immunohistochemical identification of supportive cell types in the enteric nervous system of the rat colon and rectum (1988)
    Springer
    Cell & tissue research 251 (1988), S. 523-529 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Glial fibrillary acidic (GFA) protein ; S-100 protein ; Supportive cells ; Intestine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The non-neuronal, supportive cells of the enteric nerve plexus were investigated in the colon and rectum of adult and developing rats by means of immunohistochemistry, utilizing antisera against GFA protein and S-100 protein. Immunoreactivity to GFA protein was almost exclusively found in cells associated with the myenteric plexus and a small number of cells within the submucous ganglia. On the other hand, the use of S-100 protein antiserum resulted in the visualization of all supportive elements in the enteric nervous system. However, two types of supportive cells could be tentatively differentiated in the enteric nerve plexus during the second week of postnatal development, using GFA protein and S-100 protein antisera; GFA protein-positive cells were clearly discernible from S-100 protein-positive cells in terms of both the morphological profiles and immunohistochemical properties. It was assumed that at least two different types of supportive cells are contained in the enteric nerve plexus. We suggest that in the enteric nervous system the terms “glial cells” and “Schwann cells” should be employed to designate the supportive cells containing GFA and S-100 proteins, and cells containing S-100 protein, respectively. We discuss the possibility that glial cells are associated with the parasympathetic preganglionic fibres directly derived from the central nervous system, while Schwann cells originate from the neural crest.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213999
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  • 67
    Digitale Medien
    Digitale Medien
    Immunohistochemical evidence for the presence of calcium-binding proteins in enteric neurons (1988)
    Springer
    Cell & tissue research 252 (1988), S. 79-87 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Calcium-binding protein ; Enteric nervous system ; Intestine ; Immunocytochemistry ; Guinea-pig ; Rat ; Man
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Immunoreactivity for vitamin D-dependent calcium-binding protein (CaBP) has been localized in nerve cell bodies and nerve fibres in the gastrointestinal tracts of guinea-pig, rat and man. CaBP immunoreactivity was found in a high proportion of nerve cell bodies of the myenteric plexus, particularly in the small intestine. It was also found in submucous neurons of the small and large intestines. Immunoreactive nerve fibres were numerous in the myenteric ganglia, and were also common in the submucous ganglia and in the intestinal mucosa. Immunoreactive fibres were rare in the circular and longitudinal muscle coats. In the myenteric ganglia of the guinea-pig small intestine the immunoreactivity is restricted to one class of nerve cell bodies, type-II neurons of Dogiel, which display calcium action potentials in their cell bodies. These neurons were also immunoreactive with antibodies to spot 35 protein, a calcium-binding protein from the cerebellum. From the distribution of their terminals and the electrophysiological properties of these neurons it is suggested they might be sensory neurons, or perhaps interneurons. The discovery of CaBP in restricted sub-groups of enteric neurons may provide an important key for the analysis of their functions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213828
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  • 68
    Digitale Medien
    Digitale Medien
    Changes in proteins synthesized by rabbit endometrial epithelial cells following primary culture (1988)
    Springer
    Cell & tissue research 252 (1988), S. 123-132 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Uterine epithelium ; Cell culture ; Proteins ; Ultrastructure ; Rabbit
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Morphological and biochemical changes occurring in rabbit endometrial epithelial cells when placed in culture were investigated. Cells were examined by scanning- and transmission electron microscopy and freeze-fracture. Morphologically, cultured cells are shorter and broader than the columnar epithelial cells in vivo, but retain their polarity as indicated by the presence of apical microvilli and a well-developed junctional belt. To study changes in biochemical function, proteins synthesized by cells in primary culture were analyzed by two-dimensional gel electrophoresis. Proteins were labeled during a 24-h incubation with 35S-methionine and gels examined by fluorography. The pattern of proteins changed after cells had been in culture for 48 h. On day 3 new proteins were synthesized and several protein species labeled during days 1 or 2 of culture, including uteroglobin, no longer appeared. On days 3–8 of culture the protein patterns were similar. Addition of progesterone, estradiol, prolactin, or combinations of these hormones to the culture medium for 24–144 h failed to elicit consistent changes in the pattern of labeled proteins established after 3 days of culture. Minor differences in protein patterns among unrelated cultures appear to have been derived from the original cells of the culture. These results indicate that after 48 h in primary culture, cells grown in vitro resemble endometrial epithelial cells morphologically, but no longer reflect functionally the character of epithelial cells in the uterus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213833
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  • 69
    Digitale Medien
    Digitale Medien
    Formation of desmosomes and other contact specializations in cultured skin of the frog (Rana esculenta) (1988)
    Springer
    Cell & tissue research 252 (1988), S. 157-163 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Frog skin culture ; Desmogenesis ; Interdigitations ; Lamellipodia ; Ultrastructure ; Rana esculenta
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Small trypsinized explants from ventral skin of frogs (Rana esculenta) were maintained in culture for 4 days during which a newly formed epithelium differentiated along the cut edges of the dermis. During the first 6 h adjacent cells produced numerous interdigitating lamellipodia. After 2 days, epithelial polarity was restored by the formation of zonulae occludentes and the epithelial cells were joined by a few small newly formed desmosomes and by numerous interdigitations. Bipartite junctional complexes consisting of a zonula occludens, followed by a series of typical desmosomes, and characteristic of adult frog epidermis were formed only after 4 days. When cultured in the presence of an inhibitor of protein synthesis (cycloheximide) the trypsinized epidermis no longer formed desmosomes. Therefore pools of one or more crucial desmosomal proteins must be very low or non-existent. However, cycloheximide did not prevent the formation of cell contact specializations, consisting of a highly developed system of complex lamellar interdigitations, between adjacent cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213837
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  • 70
    Digitale Medien
    Digitale Medien
    Pathway of nerves with vasoactive intestinal polypeptide-like immunoreactivity to the major cerebral arteries of the rat (1988)
    Springer
    Cell & tissue research 251 (1988), S. 275-280 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Cerebral arteries ; Vasoactive intestinal polypeptide ; Vascular innervation ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The pathway of nerves with vasoactive intestinal polypeptide(VIP)-like immunoreactivity to the major cerebral arteries was studied in rats by means of the indirect immunofluorescent method. The fibers are densely distributed in the ethmoidal nerves and in the adventitia of both the external and internal ethmoidal arteries. Section of both ethmoidal nerves and external ethmoidal arteries before they enter the cranial cavity induced a marked reduction of VIP-like immunoreactive fibers in the walls of the vessels of the circle of Willis and its major branches. However, section of the external ethmoidal artery alone did not result in visible changes of the nerves around major cerebral arteries. The present study suggests that VIP-like immunoreactive fibers surrounding major cerebral arteries of the rat arise from fibers in the ethmoidal nerve showing immunoreactivity to VIP.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215834
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  • 71
    Digitale Medien
    Digitale Medien
    Morphology of smooth muscle cells in the rat thoracic duct (1988)
    Springer
    Cell & tissue research 251 (1988), S. 243-248 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Thoracic duct ; Smooth muscle cell ; Ultrastructure ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The three-dimensional cytoarchitecture and ultrastructure of the smooth muscle cells in the wall of the rat thoracic duct were investigated by scanning and transmission electron microscopy. The muscle layer basically consists of a single layer of circularly arranged cells. The smooth muscle cell is fusiform or ribbon-like in shape, as in veins or venules with a similar or smaller diameter. Connections by spinous processes are observed between adjacent muscle cells along their length. Spot-like membrane contacts frequently occur in areas where facing membranes are closely apposed. These are thought to be gap junctions and may be responsible for electrical coupling and mechanical attachment. Large invaginations arranged regularly in rows on the surface of the smooth muscle cells can be observed. These invaginations are closely associated with a flattened sarcoplasmic reticulum, and caveolae tend to open into the invaginations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215831
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  • 72
    Digitale Medien
    Digitale Medien
    Ultrastructural immunocytochemical localization of l-glutamate decarboxylase and GABA in rat pancreatic zymogen granules (1988)
    Springer
    Cell & tissue research 252 (1988), S. 191-197 
    Details
    ISSN: 1432-0878
    Schlagwort(e): GABA ; Glutamate decarboxylase ; GABA transaminase ; Exocrine pancreas ; Immunocytochemistry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructural immunohistochemical localization of gamma aminobutyric acid (GABA) and its regulating enzymes, l-glutamate decarboxylase (GAD) and gamma aminobutyrate-α-ketoglutarate transaminase, was determined utilizing an immunogold post-embedding protocol in pancreatic exocrine tissue. Within the acinar cell, GABA and its biosynthetic enzyme, GAD, were localized in zymogen granules. Quantitative analysis of the GABA immunoreactivity in the acinar cell revealed 1.7±0.5 gold particles/μm2 over the cytoplasm, 36.6±14.1 gold particles/ μm2 over the zymogen granules, and 2.9±2.1 gold particles /μm2 over the mitochondria. Quantitative analysis of the distribution of colloidal gold particles, representing glutamate decarboxylase immunoreactivity in the acinar cells, revealed 38.4±2.5 gold particles/μm2 over the zymogen granules, 4.7±1.1 gold particles/μm2 over the mitochondria and 6.3±0.5 gold particles/μm2 over the remainder of the cytoplasm. Substitution of normal sheep serum for the sheep anti-glutamate decarboxylase serum revealed a significant (p〈 0.001) decrease of the colloidal gold particle distribution over the zymogen granules and cytoplasmic compartments of the acini. Gamma aminobutyrate -α-ketoglutarate transaminase, the catabolic enzyme for GABA, was not detected in the mitochondria, zymogen granules, and cytoplasm of the acinar cell, suggesting that GABA is not catabolized within the acinar cell. Preabsorption and substitution controls resulted in an absence of labeling. These results suggest that GABA may act extracellularly and/or have a role within the zymogen granule in the exocrine pancreas.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213841
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  • 73
    Digitale Medien
    Digitale Medien
    Selective decrease of immunoreactive tyrosine hydroxylase in nigrostriatum of adult male rats after N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine treatment (1988)
    Springer
    Cell & tissue research 253 (1988), S. 251-258 
    Details
    ISSN: 1432-0878
    Schlagwort(e): MPTP ; Rat ; Nigrostriatum ; Parkinsonism ; Immunocytochemistry ; Tyrosine hydroxylase ; Animal model ; Rat (Sprague-Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Several laboratories have reported that N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine causes damage to the nigral dopamine neurons of man, monkey, and mouse. Controversial data suggest that a rat model of Parkinsonism may be possible. Although loss of dopamine cells has not been detected in the rat brain, our immunocytochemical studies show that immunoreactive tyrosine hydroxylase, the rate-limiting enzyme which synthesizes dopamine, is significantly reduced in concentration, or its antigenicity altered, in substantia nigra/pars compacta as well as the caudate nucleus. Optical density measurements demonstrate the reduction or alteration of immunoreactive tyrosine hydroxylase in nigro-striatal neurons, indicating that axonal terminals, as well as parent perikarya, may be sensitive to the drug. After treatment, abnormal morphological remodelling may result in the affected neuronal processes, perhaps indicating sublethal toxicity, followed by slow recovery. Despite the lack of nigral cell death, it is proposed that the present data support the use of the rat as a model to investigate the early effects of Parkinsonism induced by this agent, and the biological mechanisms of cellular recovery.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221761
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  • 74
    Digitale Medien
    Digitale Medien
    TRH-like immunoreactivity in endocrine cells and neurons in the gastro-intestinal tract of the rat and guinea pig (1988)
    Springer
    Cell & tissue research 253 (1988), S. 347-356 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pancreas, endocrine ; Stomach ; Intestine ; Immunohistochemistry ; Thyrotropin-releasing hormone (TRH) ; Somatostatin ; Avian pancreatic polypeptide ; Insulin ; Gastrin ; Rat ; Guinea pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary By use of the indirect immunofluorescence technique, the cellular localization of thyrotropin-releasing hormone (TRH) was studied in the gastrointestinal tract of rats and guinea pigs of different ages. TRH-like immunoreactivity (LI) was observed in many pancreatic islet cells of young rats and guinea pigs but only in single cells of 6-month-old rats. In aged guinea pigs, a reduction in the number of TRH-positive cells was evident; however, numerous strongly fluorescent cells were still present. In the guinea pig, TRH-LI was in addition observed in gastrin cells in the stomach. TRH-positive nerve fibers occurred in the myenteric plexus of the oesophagus, stomach and intestine of the rat, and in the muscle layers of the guinea pig. These results suggest a functional role of TRH both as hormone and neuroactive compound in various portions and sites of the gastro-intestinal tract of the rat and guinea pig
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00222291
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  • 75
    Digitale Medien
    Digitale Medien
    Atropine inhibits the degranulation of Paneth cells in ex-germ-free mice (1988)
    Springer
    Cell & tissue research 253 (1988), S. 397-402 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Paneth cells ; Ultrastructure ; Morphometry ; Atropine ; Germ-free/Ex-germ-free ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Previous studies have shown that the secretory products of Paneth cells contain antibacterial agents (lysozyme, IgA) that are affected by the bacterial milieu in the intestine. To investigate whether Paneth-cell secretion is controlled via cholinergic mechanisms, the ultrastructure of Paneth cells was studied in four animal groups: (1) germfree (GF) control mice (Jcl: ICR [GN], male, 13 weeks old), (2) GF mice injected subcutaneously with atropine sulfate (200 mg/kg body weight, dissolved in physiological saline 20 mg/ml), (3) ex-GF mice inoculated with feces from specific-pathogen-free (SPF) mice, and (4) ex-GF mice injected with atropine and inoculated with feces from SPF mice. In ex-GF mice inoculated with feces, 70–90% of the Paneth cells showed fewer secretory granules than those from GF mice (p〈0.01). Approximately 30% of the Paneth cells had a large vacuole (3–10 μm diameter) in the apical cytoplasm. Exocytosed electron-dense material from secretory granules was observed in a few crypt lumens. In ex-GF mice inoculated with feces and given atropine, about 90% of the Paneth cells contained numerous secretory granules, like those in GF control mice, but vacuolated Paneth cells and exocytotic figures were rare; thus the secretion of Paneth cells was blocked by atropine. It is therefore possible that the bacterial milieu in the intestine affects the secretory activity of Paneth cells via cholinergic mechanisms.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00222296
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  • 76
    Digitale Medien
    Digitale Medien
    Lymphocytes of the intestinal mucosa of chickens (1988)
    Springer
    Cell & tissue research 251 (1988), S. 189-195 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Lymphocytes ; Epithelium ; Mast cells ; Granular leukocytes ; Basophils ; Ultrastructure ; Chicken
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Examination, by light and electron microscopy, of the morphology and the staining properties of intraepithelial lymphocytes from the intestine of the chicken revealed a population of lymphoid cells, of which a proportion (up to 20%) is granulated. The majority of cells were immunoreactive with anti-T cell serum and can therefore be considered to be related to T-lymphocytes, but they did not proliferate when cultured with phytohaemagglutinin. The granulated cells were identical to those previously designated globule-containing leukocytes, but were distinct from mast cells in their morphology, staining reactions and the stability of the granules in different fixatives and buffers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215464
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  • 77
    Digitale Medien
    Digitale Medien
    Structural changes produced in Kupffer cells in the rat liver by injection of lipopolysaccharide (1988)
    Springer
    Cell & tissue research 251 (1988), S. 205-214 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Kupffer cells ; Granulocytes ; Ultrastructure ; Lipopolysaccharide ; Liver ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The fine structure of Kupffer cells has been studied at various times after an intravenous injection of lipopolysaccharide of Salmonella abortus equii. The most prominent effects were: an increase in the number and dimensions of phagocytic vacuoles (often containing ingested LPS and neutrophilic granulocytes); mitochondrial damage, including disintegration of the matrix and cristae; an increase in the amount of dilated, lucent rough endoplasmic reticulum; presence of fat droplets in the cytoplasm. Five days after injection of lipopolysaccharide, the Kupffer cells had resumed their normal ultrastructure. Several minutes after injection of lipopolysaccharide, platelets adhered to the Kupffer and endothelial cells. Between one and six hours, neutrophilic granulocytes accumulated in the liver sinusoids. The resulting obstruction of the hepatic microcirculation most probably affected cellular ultrastructure by ischaemia. At three days, the number of Kupffer cells was doubled, and increased further at later time intervals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215466
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  • 78
    Digitale Medien
    Digitale Medien
    Fine-structural localization of neuropeptide tyrosine (NPY)-like immunoreactivity in the neuronal somata of colchicine-pretreated celiac ganglia of rats (1988)
    Springer
    Cell & tissue research 251 (1988), S. 221-224 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Neuropeptide ; Intracellular localization ; Sympathetic ganglia ; Colchicine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In colchicine-pretreated cells of sympathetic ganglia, intensely NPY-immunoreactive material was localized within vacuoles and vesicles of the disorganized, widely dispersed Golgi apparatus. Intensely positive large granular vesicles, which are known to be one of major storage sites of various peptides in the autonomic nerve endings, were essentially unobserved in the perikaryal cytoplasm. The present finding provides evidence that one pool of NPY-like immunoreactivity is localized in the Golgi apparatus of colchicine-pretreated as well as normal sympathetic ganglion cells. It is also clear that visualization of NPY-immunoreactive somata by colchicine-pretreatment in the sympathetic ganglia is due to the accumulation of the neuropeptide in the disorganized Golgi stacks instead of increased amount of the large granular vesicles containing NPY.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215468
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  • 79
    Digitale Medien
    Digitale Medien
    Morphological studies on endocytosis of chondroitin sulphate proteoglycan by rat liver endothelial cells (1988)
    Springer
    Cell & tissue research 253 (1988), S. 39-45 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Receptor-mediated endocytosis ; Chondroitin sulphate ; Colloidal gold ; Liver endothelial cells ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Endocytosis via the hyaluronic acid/chondroitin sulphate receptor of rat liver endothelial cells was studied ultrastructurally, by use of a probe consisting of chondroitin sulphate proteoglycan attached to 15-nm gold particles. The probe bound to the surface of the cells exclusively in coated regions of the plasma membrane. Internalization at 37° C took place in less than one minute during which time interval the bound probe was transferred to coated vesicles. Further transfer to lysosomes was delayed in association with an accumulation of probes in a prelysosomal compartment consisting of large vacuoles in which probes lined the inner aspect of the membrane. Transport to lysosomes occurred only after a lag phase of at least 40–60 min at 37° C.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221737
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  • 80
    Digitale Medien
    Digitale Medien
    Melanophore death and disappearance produces color metamorphosis in the polychromatic Midas cichlid (Cichlasoma citrinellum) (1988)
    Springer
    Cell & tissue research 253 (1988), S. 9-14 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Chromatophores ; Color change ; Ultrastructure ; Melanophores ; Macrophages ; Xanthophores ; Cichlasoma citrinellum (Teleostei: Cichlidae)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary We describe the histological basis of color metamorphosis in the polychromatic Midas cichlid, Cichlasoma citrinellum. Eight percent of the individuals in a natural population transform from gray with black markings to orange, simultaneously losing their ability to adjust coloration in response to background and social context. This trait is inherited. Light- and electron microscopy revealed that this transformation is a two-step process. First, the melanophores die, then macrophage-like cells remove the debris. As a result of this initial process, the underlying xanthophores become visible, producing the orange coloration. A similar process may occur in individuals that further transform to white, or go directly from gray to white.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221733
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  • 81
    Digitale Medien
    Digitale Medien
    Hydrodynamic model of the urinary bladder derived from stepwise cystometry in the rat (1988)
    Springer
    Medical & biological engineering & computing 26 (1988), S. 267-270 
    Details
    ISSN: 1741-0444
    Schlagwort(e): Compliance ; Curve fitting ; Rat ; Stepwise cystometry ; Urinary bladder ; Viscoelasticity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract The urinary bladder of the rat was examined by nearly ideal, unit step volume infusions. Spontaneous detrusor contractions occurred in vivo but ceased soon after death. A hydrodynamic model of the post mortem bladder wall was evaluated. Elastic properties were described by introducing two types of compliances; a dynamic compliance for fast response characteristics and a static compliance for the relaxed bladder wall. These compliances were easy to measure and found to vary with the degree of bladder expansion. The influence of viscosity was well described by a model with two relaxation time constants and was the optimal model in almost 50 per cent of the measurements. The long time constant was found to increase with bladder expansion.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02447079
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  • 82
    Digitale Medien
    Digitale Medien
    Effect of lighting conditions on circadian rhythm of rectal temperature in mice (1988)
    Springer
    Bulletin of experimental biology and medicine 106 (1988), S. 1337-1340 
    Details
    ISSN: 1573-8221
    Schlagwort(e): temperature ; natural conditions ; continuois light ; circadian rhythm ; segregation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00834513
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  • 83
    Digitale Medien
    Digitale Medien
    Distribution of vitamin A in various organs of rats in relation to the quality and the quantity of dietary proteins (1987)
    Springer
    European journal of nutrition 26 (1987), S. 43-51 
    Details
    ISSN: 1436-6215
    Schlagwort(e): Dietary protein ; Vitamin A ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft , Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Es wurde der Einfluß von Qualität und Quantität von Nahrungsproteinen auf die Verteilung einer einzigen massiven Dosis von Vitamin A in verschiedenen Organen wachsender Wistar-Ratten untersucht. Die Untersuchungen wurden mit Casein- und Bengal-Gram-Diäten mit 20 % und 10 % Proteingehalt und auch mit radioaktiv markiertem Retinylacetat durchgeführt. Die Ergebnisse zeigen, daß die Leberspeicherung sowohl von Vitamin A aus der Nahrung als auch die einer einzigen starken Vitamin-A-Gabe (20 000 I.U.) stark herabgesetzt war bei Ratten, die nach der Bengal-Gram-Diät gefüttert wurden, verglichen mit Ratten, die auf Casein-Diät gesetzt waren. Im Gegensatz zur Leberspeicherung ist das Vitamin-A-Niveau im Plasma in allen Gruppen vergleichbar. Füttern niedriger Protein-Qualität reduzierte die Gewebeverteilung von [3H]-Retinylacetat sowohl bei Kontrollratten als auch bei solchen, denen eine massive Dosis Vitamin A gegeben wurde. Diese Untersuchung läßt vermuten, daß sowohl schlechte Qualität als auch unzureichende Mengen von Nahrungsproteinen nachteilige Einflüsse auf den Vitamin-A-Zustand wachsender Ratten haben.
    Notizen: Summary The influence of the quality and the quantity of dietary proteins on the distribution of a single massive dose of vitamin A in various organs of growing Wistar strain rats has been studied by using casein and bengal gram diets at 20 % and 10 % protein levels. The distribution of [3H]-retinyl acetate in various tissues was also investigated in these dietary conditions. The results show that the hepatic storage of dietary as well as a single massive dose (20,000 I.U.) of vitamin A was profoundly decreased in the rats fed on bengal gram diets as compared to those fed on casein diets. Regardless of hepatic stores, the plasma vitamin A levels were comparable in all the groups. Feeding of low quality of protein reduced the tissue distribution of [3H]-retinyl acetate in control as well as rats given a massive dose of vitamin A. This study suggests that both the poor quality and the inadequate quantity of dietary protein are detrimental influences on the vitamin A status of the growing rats.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02023818
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  • 84
    Digitale Medien
    Digitale Medien
    Analysis and in situ detection of cholecalcin messenger RNA (9000 Mr CaBP) in the uterus of the pregnant rat (1987)
    Springer
    Cell & tissue research 247 (1987), S. 51-57 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Cholecalcin (vitamin D-dependent calcium-binding protein) ; mRNA ; Uterus ; In situ hybridisation ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The molecular cloning of a cDNA fragment synthesised from rat duodenal mRNA coding for cholecalcin (calbindin), a 9000 Mr vitamin D-induced calcium-binding protein (CaBP), has been previously described. DNA/RNA hybridisation assays have been used to examine CaBP mRNA production in the uterine horns and duodena of pregnant (21 day) rats using the cloned CaBP cDNA. Northern hybridisation studies showed that the 32P cDNA sequence hybridised to a single 500–600 nucleotide species in both the uterus and the duodenum, thus demonstrating identical CaBP mRNA processing in both tissues. Dot blot hybridisation studies showed that the CaBP mRNA concentration was greatest in the duodenum while that of the uterine horns was about 10% of the duodenal level. The observed differences in CaBP mRNA levels correlate well with the in vivo CaBP concentrations. In situ hybridisation histochemistry using 3H cDNA revealed that CaBP mRNA visualised by silver grains was found in all the parts of the endometrium and the myometrium. However, CaBP mRNA was more concentrated in the outer and inner muscular fibres and in the luminal cells of the endometrium than in the stroma cells. These results demonstrate that the CaBP gene is expressed in specific cells of the rat uterus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216546
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  • 85
    Digitale Medien
    Digitale Medien
    Immunocytochemical and ultrastructural evidence for a neurophysinergic innervation of the subcommissural organ of the snake Natrix maura (1987)
    Springer
    Cell & tissue research 248 (1987), S. 473-478 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Subcommissural organ ; Innervation ; Neu rophysins ; Mesotocin ; Immunocytochemistry ; Ultrastructure ; Snake, Natrix maura
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The subcommissural organ (SCO) of the snake Natrix maura was studied by use of the immunoperoxidase procedure. Primary antisera against bovine neurophysins (Nps I + II, OXY-Np), oxytocin (OXY), mesotocin (MST), arginine-vasotocin (AVT), somatostatin (SOM), β-endorphin (END) and bovine Reissner's fiber were used. A conventional ultrastructural study, with special emphasis on the nerve fibers present in the SCO, was also performed. Nerve fibers containing immunoreactive OXY-Np and MST were seen to reach the SCO. The staining of adjacent sections with the anti-Reissner's fiber serum showed that the OXY-Np- and MST-immunoreactive fibers were distributed among the cell bodies and processes of the ependymal secretory cells. No fibers containing immunoreactive OXY, AVT, SOM or END were found in the SCO. The ultrastructural analysis revealed in the SCO the presence of nerve fibers filled with electron-dense granules, 170–210 nm in diameter. Although a direct apposition between these fibers and the SCO cells was frequently seen, no synaptic differentiations were identified. Structures identical to the Herring bodies (found in the neurohypophysis) were seen in the SCO.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218215
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  • 86
    Digitale Medien
    Digitale Medien
    Effects of a prolonged treatment with aminoglutethimide on the zona fasciculata of rat adrenal cortex: A morphometric investigation (1987)
    Springer
    Cell & tissue research 248 (1987), S. 519-525 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adrenal cortex ; Aminoglutethimide ; Corticosterone ; Morphometry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effects of a 7-day administration of aminoglutethimide (AG) on the adrenal zona fasciculata were examined in “normal” and dexamethasone/ACTH-treated rats. There was a 70–74% decrease in the concentration of corticosterone in blood, but no conspicuous qualitative changes suggesting cell degeneration occurred. Morphometry showed that AG induced a significant hypertrophy of the zona fasciculata and its parenchymal cells only in “normal” animals, which was due to an increase in the volume of the mitochondrial compartment and to proliferation of the smooth endoplasmic reticulum. This response to AG was considered to be non-specific and mediated by the enhanced secretion of ACTH following the decrease in the blood level of corticosterone. AG administration significantly increased the volume of the lipid-droplet compartment and the number of intramitochondrial lipid-like inclusions in both groups of animals. These changes were interpreted as the morphological counterpart of the AG-induced block of cholesterol utilization in steroid synthesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216478
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  • 87
    Digitale Medien
    Digitale Medien
    Relationship between orthogonal arrays of particles and tight junctions as demonstrated in cells of the ventricular wall of the rat brain (1987)
    Springer
    Cell & tissue research 248 (1987), S. 619-625 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Astrocytes ; Ependymal cells ; Circumventricular organs ; Tight junctions ; Orthogonal arrays of particles ; Freeze-fracturing ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Ependymal cells in the ventricular wall and in several circumventricular organs of the rat were compared by means of freeze-fracturing. In principle, tight junctions and orthogonal arrays of particles (OAP) do not coexist in the cells bordering the ventricular wall: (1) Ordinary ependymal cells of the rat possess OAP and are devoid of tight junctions. (2) Epithelial cells of the rat choroid plexus are connected by tight junctions; OAP are lacking here. In some cases, however, tight junctions and OAP coexist in the same cell. In the boundary zone between choroid plexus and ependyma of the rat, the density of OAP is very low, whereas the tight junctions are well developed. In the subfornical and the subcommissural organ (SCO) of the rat both structures are poorly developed; in the SCO they occur segregated in different membranous areas. An overview of the literature confirms that tight junctions and OAP mostly exclude each other. The possibility that in astrocytes and ependymal cells tight junctions may have been replaced by OAP during phylogeny is briefly discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216492
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  • 88
    Digitale Medien
    Digitale Medien
    Distribution of nerve fibers immunoreactive to neurofilament protein in rat molars and periodontium (1987)
    Springer
    Cell & tissue research 249 (1987), S. 13-23 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Teeth ; Dental pulp ; Periodontium ; Neurofilament protein ; Immunohistochemistry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The distribution of nerve fibers in molars, periodontal ligament and gingiva of the rat shows a complex pattern. Decalcified material including the alveolar bone was sectioned in three different planes and stained by means of immunohistochemistry for detection of the neurofilament protein (NFP); the immunoreactive neural elements were clearly visualized in three-dimensional analyses. NFP-positive nerve fibers formed a subodontoblastic plexus in the roof area of the dental pulp; some of them entered the predentin and dentin directly through the dentinal tubules. This penetration was found mainly in the pulp horn, and was limited to a distance of about 100 μm from the pulpo-dentinal junction. In the periodontal ligament, NFP-positive nerve fibers were found densely distributed in the lower half of the alveolar socket. Two types of nerve terminals were recognized in the periodontal ligament: free nerve endings with tree-like ramifications, and expanded nerve terminals showing button- or glove-like shapes. The former tapered among the periodontal fibers, some even reaching the cementoblastic layer. The latter were located, frequently in groups, within the ligament restricted to the lower third of the alveolar socket. A well-developed plexus of NFP-positive nerves was revealed in the lamina propria of the free gingiva, the innervation being denser toward the epithelium of the gingival crevice. The characteristic distribution of NFP-immunoreactive nerve fibers revealed in this study is discussed in relation to region-specific sensations in the teeth and surrounding tissues.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215413
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  • 89
    Digitale Medien
    Digitale Medien
    Postnatal development of epididymis and ductus deferens in the rat (1987)
    Springer
    Cell & tissue research 249 (1987), S. 257-265 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Epididymis ; Ductus deferens ; Myosin ; Actin ; Fibronectin ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The postnatal maturation of regions of the epididymis and intragonadal segment of the deferens duct was studied in the rat by light-and transmission electron microscopy. Maturation of the genital duct starts in the distal cauda epididymidis and ductus deferens after one week of life, and one week later, in the more cranial segments of the epididymis. Epithelial principal cells and peritubular contractile cells are structurally mature 35 days after birth. The synchronous changes of these cells indicate that the same factors control their postnatal maturation. The epithelial principal cells obtain an endocytotic apparatus and long stereocilia, whereas peritubular cells acquire contractile features. These changes are associated with a progressive increase in the immunoreaction for smooth muscle actin in both cell types. Smooth muscle myosin is detected in the apical region of the epithelial cells and the peritubular cell cytoplasm by day one of postnatal development. The differentiation of contractile cells in the wall is accompanied by progressive organization of the pericellular matrix into a continuous basement membrane. Although fibronectin is visible at birth, it is gradually removed from the tubule wall.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215508
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  • 90
    Digitale Medien
    Digitale Medien
    Morphology, composition, and function of struts between cardiac myocytes of rat and hamster (1987)
    Springer
    Cell & tissue research 249 (1987), S. 247-255 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Cardiac muscle cells ; Extracellular matrix ; Collagen fibers and filaments ; Immunohistochemistry ; Rat ; Hamster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The morphology, composition, and function of struts that interconnect the lateral surfaces of cardiomyocytes were examined in the hearts of rats and hamsters. Methods included brightfield and fluorescent light microscopy, secondary and backscatter scanning electron microscopy, and transmission electron microscopy in conjunction with silver stain, cationic dye, and antibody to type-I collagen. These studies reveal a twisted, beaded appearance and a complex substructure of collagen fibrils embedded in a ground substance that has a positive reaction with cationic dye. A hierarchy of patterns of branching and attachment was seen among intercellular struts ranging in diameter from 0.1 μm to several urn. The hypothesis that struts tether not only the surfaces but the contractile lattices of laterally adjacent myocytes is supported by the following: (a) the attachments of struts to the collagen weave of the sarcolemma, often lateral to the level of Z bands, (b) the presence of collagen type I in a composite material arrangement, (c) the relative dispositions and configurational changes of struts and myocyte surfaces in various physiological states and induced, non-physiological perturbations of cardiac muscle, (d) the corrugated sarcolemmas with infoldings near Z bands, and (e) the continuity of intracellular filaments from Z bands to the inner aspect of the sarcolemma in relaxed and contracted myocytes. Implications of struts acting as tethers and sites for storage of energy in the motions of myocytes during the cardiac cycle are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215507
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  • 91
    Digitale Medien
    Digitale Medien
    Fine-structural changes of synapses in the superior cervical ganglion of adult rats after long-term administration of GABA (1987)
    Springer
    Cell & tissue research 249 (1987), S. 267-275 
    Details
    ISSN: 1432-0878
    Schlagwort(e): GABA-treatment ; Superior cervical ganglion ; Synaptic plasticity ; Morphometry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The superior cervical ganglion (SCG) of adult rats was exposed to γ-aminobutyric acid (GABA) by means of long-term microapplication. Serial sections were cut from GABA-treated and control ganglia, and subsequently the fine structure of individual synapses was investigated. The quantitative analysis of structural parameters of studied synapses showed that significant changes consisting of (1) a reduction in size of presynaptic axon terminals, (2) a decrease in the number of synaptic vesicles, and (3) a diminution in the extent of the postsynaptic membrane thickening at the dendritic side developed as an effect of GABA-treatment. These results provide morphological evidence that long-term application of GABA to the SCG exerts a combination of effects on both presynaptic and postsynaptic elements. It is suggested that the structural changes observed in the fine structure of individual synapses within the SCG may play an integral role in the development of the synaptogenetic action of GABA.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215509
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  • 92
    Digitale Medien
    Digitale Medien
    Effects of extracellular osmolality on renin release and on the ultrastructure of the juxtaglomerular epithelioid cell granules (1987)
    Springer
    Cell & tissue research 249 (1987), S. 325-329 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Renin release ; Epithelioid cells ; Osmosensitivity of renin release ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Superfusion with hypoosmotic solutions stimulates renin release from rat epithelioid cells adherent to isolated glomeruli. This stimulatory effect may be related to the observed swelling of the secretory granules; the swelling may markedly increase the probability of pre-exocytotic fusions between the granule and cell membranes, and consequently increase the frequency of exocytotic events.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215515
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  • 93
    Digitale Medien
    Digitale Medien
    ‘Neurosecretion’ by a classic cholinergic innervation apparatus (1987)
    Springer
    Cell & tissue research 249 (1987), S. 421-425 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Cholinergic synapses ; Ultrastructure ; Exocytosis ; Non-synaptic release ; Neuropeptides ; Carassius auratus ; Rana pipiens ; Wistar white rat ; Hamster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Nerve terminals forming typical synapses with adrenal chromaffin tissues have been examined in the goldfish, frog (Rana pipiens), hamster and rat. Presumptive secretory inclusions present in the terminals are of two distinct types. Electron-lucent synaptic vesicles 30–50 nm in diameter are densely clustered adjacent to membrane thickenings and presumably discharge their contents into the synaptic clefts. Secretory granules (i.e. large dense-cored vesicles) 60–100 nm in diameter are more abundant in other parts of the terminals. Sites of granule exocytosis have been observed in each of the animals investigated. They are usually encountered within apparently undifferentiated areas of plasmalemma and only rarely occur within synaptic thickenings. Granule exocytosis from within synaptic terminals and chromaffin gland cells is most readily observed in specimens exposed, prior to fixation, to saline solutions containing both tannic acid, and 4-aminopyridine and/or elevated levels of K+. These findings show that the pattern of secretory discharge, involving both synaptic and non-synaptic release, which is widespread in invertebrate central nervous systems, is also characteristic of vertebrate, peripheral cholinergic terminals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215526
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  • 94
    Digitale Medien
    Digitale Medien
    Changes in the size and number of secretion granules in the rat exocrine pancreas induced by feeding or stimulation in vitro (1987)
    Springer
    Cell & tissue research 249 (1987), S. 427-436 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Exocrine pancreas ; Secretion granules ; Effect of feeding ; Carbachol ; Stereology ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The size, number and volume per cell of secretion granules in rat exocrine pancreas have been measured using stereological techniques. The changes which occur as a result of feeding starved animals (90 min) or stimulating lobular fragments in vitro with carbachol are documented. In fasted animals mean acinar cell volume was estimated as 1670 μm3 and the cells contained an average of around 450 secretion granules with a corrected mean diameter of 0.70 μm. They occupied around 7% of cell volume. After feeding mean cell volume was about 1300 μm3 and the cells contained an average of about 190 granules per cell with a mean diameter of 0.58 μm. They occupied 3% of cell volume. A shift in the size frequency distribution of granule diameters occurred as a result of feeding. In vitro experiments in which lobules were induced to secrete with carbachol (10μM, 3 h, 37° C) had a similar effect. Mean cell volume was reduced from around 1760 μm3 to 1360 μm3, mean granule number from around 420 per cell to 180 per cell and the volume density of granules was reduced from about 8% to 3% of cell volume. There was no significant change in mean granule diameter or shift in the size-frequency distribution of granule diameters. Incubation of tissues with cycloheximide (1 mM, 3 h, 37° C) did not prevent secretion by carbachol but it prevented replacement of granules. As a consequence, depletion by carbachol was greater in the presence of cycloheximide, the granules being reduced to around 110 per cell and to only 2.5% of cell volume. We conclude that feeding causes a preferential loss of larger granules and that during secretion replacement of granules occurs. Some of these granules are smaller than those evident in the glands of starved animals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215527
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  • 95
    Digitale Medien
    Digitale Medien
    Glomerular ultrastructure of the trout, Salmo gairdneri: Effects of angiotensin II and adaptation to seawater (1987)
    Springer
    Cell & tissue research 249 (1987), S. 437-442 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Angiotensin II ; Glomerulus ; Salmo gairdneri ; Seawater-adaptation ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effect of angiotensin infusion on the glomerular ultrastructure of freshwater- and seawater-adapted rainbow trout, Salmo gairdneri, has been examined by scanning and transmission electron microscopy. Adaptation of trout to seawater resulted in epithelial podocyte flattening, primary process broadening and apparent loss of foot processes in almost all glomeruli, features which were uncommon in freshwater-adapted trout. Similar changes were induced by infusion of freshwater-adapted animals with angiotensin, suggesting that the renin-angiotensin system plays a role in the modification of glomerular epithelial ultrastructure. Adaptation of trout to seawater also reduced glomerular diameter, but infusion of freshwater-adapted animals with angiotensin did not mirror this effect. Infusion of angiotensin into seawater-adapted animals increased the overall thickness of glomerular basement membrane by increasing the lamina rara interna and lamina densa. This did not occur when freshwater-adapted fish were either infused with angiotensin or adapted to seawater. These findings suggest that other humoral systems are involved in the control of glomerular diameter and basement membrane thickness as part of an integrated response to increased environmental salinity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215528
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  • 96
    Digitale Medien
    Digitale Medien
    Sex differences in adrenocortical structure and function (1987)
    Springer
    Cell & tissue research 249 (1987), S. 443-449 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Different strains ; Adrenal cortex ; Zonation ; Cellular composition ; Sex differences ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The zonation and cellular composition of the adrenal cortex of intact mature male and female rats of different strains (Chbb Thomm, CFY) and three strains of Wistar rats (W1, W2 and W3) at the age of 84–90 days were compared using morphometry. Both absolute and relative adrenal gland weights were higher in female than male rats. Rats of W3 and Chbb Thomm strains had the largest adrenals. These differences depended upon the higher volume of the zona fasciculata (ZF) and zona reticularis (ZR) in the W3 and Chbb Thomm strains than in the remaining animals. Females had larger adrenocortical zones than corresponding males. The average volume of the ZF cell ranged in males from 1589 μm3 (W1 strain) to 2111 μm3 (Chbb Thomm) and in females from 2249 μm3 (W1 strain) to 2894 μm3 (W3 strain). The average nuclear volume of the ZF cells was higher in female rats whereas there were no strain-and sex-differences in the size of zona glomerulosa (ZG) and ZR cells. The total number of parenchymal cells per pair of adrenals varied markedly among the studied strains, with the highest number in W3 and Chbb Thomm females. W3, Chbb Thomm and CFY females had larger number of parenchymal cells than males; the reverse was true for W1 strain whereas no differences were found among W2 male and female rats.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215529
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  • 97
    Digitale Medien
    Digitale Medien
    Ultrastructural analysis of the effect of ethane dimethanesulphonate on the testis of the rat, guinea pig, hamster and mouse (1987)
    Springer
    Cell & tissue research 249 (1987), S. 451-457 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Leydig cells ; Ethane dimethanesulphonate ; Ultrastructure ; Degeneration ; Resistance ; Rodents
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The morphological response of the testis of rats, guinea pigs, Syrian hamsters and mice to treatment with the cytotoxin ethane dimethanesulphonate was examined using light and electron microscopy. One to two days after a single administration of ethane dimethanesulphonate to adult rats, guinea pigs, and hamsters, the Leydig cells showed marked ultrastructural alterations suggestive of degeneration and cell death. The former alterations included karyopyknosis, cytoplasmic vesiculation and accumulation of lipid inclusions and large lipofuscin bodies. Fragments of necrotic Leydig cells were often engulfed by the interstitial tissue macrophages. The morphology of the seminiferous epithelium of these three species was unchanged from the morphology observed in vehicle-injected control animals. In contrast, multiple injections of ethane dimethanesulphonate given to mice produced no ultrastructural alterations to Leydig cells yet the seminiferous epithelium exhibited disruption of spermatogenesis. Although the Leydig cells of the mouse appear resistant to ethane dimethanesulphonate, this agent exerts a selective cytotoxic action upon Leydig cells of the rat, guinea pig and hamster thus identifying ethane dimethanesulphonate as a useful chemical for future endocrine and physiological studies of testicular function in three common laboratory species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215530
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  • 98
    Digitale Medien
    Digitale Medien
    Intercellular spaces between macula densa cells: An ultrastructural study comparing high pressure perfusion fixation with in situ drip-fixation of rat kidney (1987)
    Springer
    Cell & tissue research 250 (1987), S. 461-464 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Macula densa ; Intercellular spaces ; Ultrastructure ; Frusemide ; Tubulo-glomerular feedback ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In situ drip-fixation of superficial glomeruli and tubules in the rat kidney verified the results obtained from high pressure perfusion fixation studies indicating that distinct spaces normally exist between the cells of the macula densa. Following treatment with frusemide these intercellular spaces between the macula densa cells became closed in both drip-fixed and perfusion-fixed kidneys. These findings suggest that the variability of extracellular compartmentation found in the macula densa is unlikely to be an artifact but most likely represents changes in the in vivo status of the macula densa.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00219092
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  • 99
    Digitale Medien
    Digitale Medien
    Nucleolar alterations induced by 4-aminopyrazolo(3,4-d)pyrimidine in adrenal cortex and liver cells of rat (1987)
    Springer
    Cell & tissue research 248 (1987), S. 231-234 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adrenal cortex ; Liver ; Nucleolus ; 4-amino-pyrazolo(3,4-d)pyrimidine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The nucleolar ultrastructural changes produced in adrenal zona fasciculata cells and hepatocytes of rats by 4-aminopyrazolo(3,4-d) pyrimidine (4-APP), an inhibitor of the lipoprotein synthesis, are described. Male rats were injected intraperitoneally for three consecutive days with 4-APP in sodium phosphate buffer (50 mg/Kg/day). On the 4th day, the animals were sacrificed and their adrenals and liver were processed for EM. The nucleoli of the adrenal zona fasciculata cells showed nucleolar fragmentation with loss of their normal reticular appearance, separation of fibrillar and granular components, extensive vacuolization and evidence of fibrillar centers. The hepatocyte nucleoli also exhibited fragmentation. These changes seem to be the morphological counterpart of alterations in rRNA synthesis and processing, since 4-APP inhibits “de novo” purine synthesis and thus interferes with its incorporation into RNA and DNA.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01239986
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
    Digitale Medien
    Digitale Medien
    Distribution of anti-Leu-7, anti-Leu-11a and anti-Leu-M1 immunoreactivity in the brain of the adult rat (1987)
    Springer
    Cell & tissue research 248 (1987), S. 305-313 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Brain ; Immunohistochemistry ; Natural killer cells ; Monocytes ; Granulocytes ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary This study reports a specific cross-reactivity of the three anti-human-hematopoetic-cell monoclonal antibodies, anti-Leu-7 (HNK-1), anti-Leu-11a (NKP-15), and anti-Leu-M1 (MMA), with different epitopes in the brain of the adult rat. The distribution of these epitopes in rat brain is determined by means of immunohistochemistry in paraffin-embedded frontal serial sections. The reaction pattern of anti-Leu-11a monoclonal antibody is very similar to that of polyclonal antibodies against the myelin basic protein. Both antisera give a specific reaction with myelinated fibers. Immunoreaction products with the anti-Leu-7 monoclonal antibody are found as diffuse, mostly punctiform material in the neuropil and even more evident as small granules coating the cell surface of many neurons. In the white matter anti-Leu-7 reveals a moderate reactivity, which occurs predominantly as spots and fine-stranded material within the myelinated fiber tracts. Anti-Leu-M1 immunoreactivity is present between myelinated fiber bundles of the white matter, where it has a reticulate appearance, and as fine-granulated material within the grey matter of the cortex and the nuclei. The characteristic feature in the grey matter is that of irregularly shaped immunopositive plaques, which are often located around small blood vessels. The cytoplasm of glial and neuronal cells appeared negative with this MAB. The exact topographical distribution of the Leu-7 and Leu-M1 epitopes throughout the rat brain is described. The present hypotheses concerning the nature of this shared antigenicity between hematopoetic cells and nervous tissue are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218197
    Standort Signatur Erwartet Verfügbarkeit
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