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  • Calcium  (195)
  • Development
  • Scanning electron microscopy
  • man
  • Springer  (604)
  • American Association for the Advancement of Science
  • American Geophysical Union
  • Irkutsk : Ross. Akad. Nauk, Sibirskoe Otd., Inst. Zemnoj Kory
  • Krefeld : Geologischer Dienst Nordhein-Westfalen
  • Wiley
  • 2015-2019
  • 2005-2009
  • 1985-1989  (177)
  • 1975-1979  (226)
  • 1970-1974  (201)
Collection
Keywords
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Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Lack of effect of dietary minerals on liver cholesterol concentrations in rats (1989)
    Springer
    European journal of nutrition 28 (1989), S. 316-318 
    Details
    ISSN: 1436-6215
    Keywords: dietarycalcium ; dietarymagnesium ; dietaryphosphorus ; serumcholesterol ; livercholesterol ; fecalbile acids ; rats ; Calcium ; Magnesium ; Phosphor ; Serumcholesterin ; Lebercholesterin ; Gallensäure im Kot ; Ratten
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Während 28 Tagen wurden an Ratten cholesterinfreie halbgereinigte Diäten, die verschiedene Konzentrationen von Calcium (0,13–0,75 g/100 g), Magnesium (0,02–0,04 g/100 g) oder Phosphor (0,2–0,8 g/100 g) enthielten, verabreicht. Die unterschiedlichen Mineralkonzentrationen hatten keinen Einfluß auf Serum- und Lebercholesterin oder die Ausscheidung von Gallensäuren im Kot.
    Notes: Summary Female rats were fed cholesterol-free, purified diets with different concentrations of calcium (0.13–0.75%, w/w), magnesium (0.02 or 0.04%) or phosphorus (0.2–0.8 %) as the only dietary variable. After 28 days, no effects of the minerals were found on liver cholesterol concentrations and rates of fecal excretion of bile acids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02019394
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  • 2
    Electronic Resource
    Electronic Resource
    Iron chelators of the pyridoxal isonicotinoyl hydrazone class (1989)
    Springer
    BioMetals 2 (1989), S. 161-167 
    Details
    ISSN: 1572-8773
    Keywords: Fe chelation ; Thalassemia ; Fe overload ; Calcium ; Magnesium ; Zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Formation constants for the calcium(II), magnesium(II) and zinc(II) complexes of the orally effective iron chelator, pyridoxal isonicotinoyl hydrazone (PIH) and three analogues, pyridoxal benzoyl hydrazone (PBH), pyridoxalp-methoxybenzoyl hydrazone (PpMBH) and pyridoxalm-fluorobenzoyl hydrazone (PmFBH) have been determined by potentiometry at 25\dg C andI=0.1 M [KNO3]. The four ligands bind calcium(II) weakly and magnesium(II) only slightly more strongly, as a l: l complex which is formed at pH \s〉 8. The chelation of zinc(II) for all the ligands studied was greater than that for calcium(II) and magnesium(II), with complexation generally becoming significant at about pH 5. Thus, chelation of zinc(II) but not calcium(II) or magnesium(II) at physiological pH, 7.4 may be expected. Calculated values of the concentration of uncomplexed metal ion indicate that the selectivity of these ligands towards Fe(III) is comparable to that of the clinically used chelator desferrioxamine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01142555
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  • 3
    Electronic Resource
    Electronic Resource
    Influence of ethanol on calcium, inositol phospholipids and intracellular signalling mechanisms (1989)
    Springer
    Cellular and molecular life sciences 45 (1989), S. 407-413 
    Details
    ISSN: 1420-9071
    Keywords: Calcium ; inositol phospholipids ; Ca++ channels ; Ca++/Mg++-ATPase ; dihydropyridine receptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Studies have implicated Ca++ in the actions of ethanol at many biochemical levels. Calcium as a major intracellular messenger in the central nervous system is involved in many processes, including protein phosphorylation enzyme activation and secretion of hormones and neurotransmitters. The control of intracellular calcium, therefore, represents a major step by which neuronal cells regulate their activities. The present review focuses on three primary areas which influence intracellular calcium levels; voltage-dependent Ca++ channels, receptor-mediated inositol phospholipid hydrolysis, and Ca++/Mg++-ATPase, the high affinity membrane Ca++ pump. Current research suggests that a subtype of the voltage-dependent Ca++ channel, the dihydropyridine-sensitive Ca++ channel, is uniquely sensitive to acute and chronic ethanol treatment. Acute exposure inhibits, while chronic ethanol exposure increases45Ca++-influx and [3H]dihydropyridine receptor binding sites. In addition, acute and chronic exposure to ethanol inhibits, then increases Ca++/Mg++-ATPase activity in neuronal membranes. Changes in Ca++ channel and Ca++/Mg++-ATPase activity following chronic ethanol may occur as an adaptation process to increase Ca++ availability for intracellular processes. Since receptor-dependent inositol phospholipid hydrolysis is enhanced after chronic ethanol treatment, subsequent activation of protein kinase-C may also be involved in the adaptation process and may indicate increased coupling for receptor-dependent changes in Ca++/Mg++-ATPase activity. The increased sensitivity of three Ca++-dependent processes suggest that adaptation to chronic ethanol exposure may involve coupling of one or more of these processes to receptor-mediated events.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01952021
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  • 4
    Electronic Resource
    Electronic Resource
    Borate control of protein secretion from Petunia pollen exhibits critical temperature discontinuities (1989)
    Springer
    Sexual plant reproduction 2 (1989), S. 11-14 
    Details
    ISSN: 1432-2145
    Keywords: Boric acid ; Pollen ; Petunia hybrida ; Temperature discontinuities ; Protein release ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Energy-driven protein secretion from Petunia hybrida pollen in 10% sucrose solution shaking culture does not change markedly with temperature, except over a narrow (6° C) temperature range with a midpoint at 17° C. Over this narrow temperature range, there is a very rapid increase from a low secretion plateau at low temperatures to a plateau of higher secretion at higher temperatures. Addition of calcium ions decreases the overall amount secreted, but does not change the critical temperature where the rapid rise in secretion is observed. Boric acid, when added to the culture, also decreases the overall amount released, but in a different way to calcium. While there is a sharp discontinuity at 17° C as before, the increase in protein release at this temperature is smaller than before. In addition, after a plateau at temperatures higher than 20° C, there is a second sharp increase in secreted protein over another narrow temperature range with a midpoint of 28° C, followed by another plateau at higher temperatures. The effects of calcium and boric acid are additive. The sharp discontinuities in protein release are interpreted in terms of lipid thermotropism in membranes and a boron involvement in the movement of proteins into the extending pollen tube membranes from secretory vesicles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00190113
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  • 5
    Electronic Resource
    Electronic Resource
    Towards an in vitro bioassay for the self-incompatibility response in Brassica oleracea (1989)
    Springer
    Sexual plant reproduction 2 (1989), S. 277-280 
    Details
    ISSN: 1432-2145
    Keywords: Brassica oleracea ; Pollen germination ; In vitro assay ; Calcium ; Self-incompatibility ; S locus-specific glycoproteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Eluates of stigmas of Brassica oleracea that were known to contain S locus-specific glycoproteins (SLSG) discriminated between self and cross pollen in vitro in three different media. Discrimination was equally evident in experiments that were the in vitro equivalents of reciprocal pollinations. In a TAPS-buffered medium, self eluates depressed pollen germination in a dose-dependent manner. TAPS medium allowed a bioassay of the effects of SLSG in eluates because it optimized germination in a way that eliminated the complicating features of the stimulatory substances in the eluates. Stigma eluates affected percentage pollen germination and optimum calcium concentrations in vitro whether or not SLSG were present in the eluates, but differently in different media, and depending on whether the eluates were cross or self with respect to the pollen tested. Thus, the effect of stigma eluates on the in vitro germination of pollen in Brassica depends on the balance of stimulatory versus inhibitory substances in the eluates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00195588
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  • 6
    Electronic Resource
    Electronic Resource
    Long-term depletion of calcium and other nutrients in eastern US forests (1989)
    Springer
    Environmental management 13 (1989), S. 593-601 
    Details
    ISSN: 1432-1009
    Keywords: Acid precipitation ; Biomass nutrients ; Calcium ; Clearcutting ; Magnesium ; Nitrogen ; Phosphorus ; Potassium ; Soil leaching ; Soil nutrients ; Timber harvest ; Weathering ; Whole-tree harvest
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Both harvest removal and leaching losses can deplete nutrient capital in forests, but their combined long-term effects have not been assessed previously. We estimated changes in total soil and biomass N, Ca, K, Mg, and P over 120 years from published data for a spruce-fir site in Maine, two northern hardwood sites in New Hampshire, central hardwood sites in Connecticut and Tennessee, and a loblolly pine site in Tennessee. For N, atmospheric inputs counterbalance the outputs, and there is little long-term change on most sites. For K, Mg, and P, the total pool may decrease by 2%–10% in 120 years depending on site and harvest intensity. For Ca, net leaching loss is 4–16 kg/ha/yr in mature forests, and whole-tree harvest removes 200–1100 kg/ha. Such leaching loss and harvest removal could reduce total soil and biomass Ca by 20%–60% in only 120 years. We estimated unmeasured Ca inputs from rock breakdown, root-zone deepening, and dry deposition; these should not be expected to make up the Ca deficit. Acid precipitation may be the cause of current high leaching of Ca. Although Ca deficiency does not generally occur now in acid forest soils, it seems likely if anthropogenic leaching and intensive harvest removal continue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01874965
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  • 7
    Electronic Resource
    Electronic Resource
    Effects of calcium channel blockers and DCMU on motility and the photophobic response of Gyrodinium dorsum (1989)
    Springer
    Archives of microbiology 151 (1989), S. 187-190 
    Details
    ISSN: 1432-072X
    Keywords: Calcium ; Calcium channel blocker ; Dinoflagellate ; Gyrodinium dorsum ; Motility ; Phytochrome ; Stop-response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of the calcium channel blockers, verapamil, diltiazem and lanthanum ions and the Ca2+ dependency on motility as well as the photophobic response (stop-response) of Gyrodinium dorsum were studied. At Ca2+ concentrations below 10-3 M, motility was inhibited. La3+ inhibits the stop-response, in contrast to verapamil and diltiazem. The only calcium channel blocker that increased the amount of non-motile cells was verapamil. The results indicate that motility are Ca2+ dependent and that the stop-responses of G. dorsum could be affected by extracellular Ca2+. Effects of the photosythesis inhibitor (DCMU) on the stop-response was also determined. With background light of different wavelength (614, 658 and 686 nm) the stop-response increased. DCMU inhibited this effect of background light. Negative results with the monoclonal antibody Pea-25 directed to phytochrome and the results with DCMU, indicate that the stop-response of G. dorsum is coupled to photosynthesis rather than to a phytochrome-like pigment. Oxygen evolution, but not cell movement, was completely inhibited by 10-6 M DCMU.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00413128
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  • 8
    Electronic Resource
    Electronic Resource
    Subcellular localization of calcium in sporangiophores of Phycomyces blackesleeanus (1989)
    Springer
    Archives of microbiology 152 (1989), S. 468-472 
    Details
    ISSN: 1432-072X
    Keywords: Calcium ; Phycomyces blakesleeanus ; Sporangiophore
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The in situ localization of Ca2+ in stage I sporangiophores of the fungus Phycomyces blakesleeanus was achieved with the potassium pyroantimonate technique. Precipitates of calcium-antimonate were present in mitochondria, vacuoles, endoplasmic reticulum and adjacent cytoplasm, “Golgi-like” bodies, and nuclei but not cell walls. Material treated with the calcium chelator EGTA lacked these precipitates. The preferential localization of Ca2+ in mitochondria, endoplasmic reticulum and vacuoles suggests that these organelles modulate the level of this cation in sporangiophores of P. blakesleeanus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446931
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  • 9
    Electronic Resource
    Electronic Resource
    Innervation of the arteriovenous anastomoses in the dog tongue (1989)
    Springer
    Cell & tissue research 258 (1989), S. 425-428 
    Details
    ISSN: 1432-0878
    Keywords: Arteriovenous anastomoses ; Vascular innervation ; Tongue ; Transmission electron microscopy ; Scanning electron microscopy ; Dog
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Profiles of nerve plexuses in the arteriovenous anastomoses of the dog tongue were investigated by both transmission and scanning electron microscopy. Three-dimensional morphology of the vascular nerves was examined after removal of the connective tissue components by the HCl-hydrolysis method. Tight bending and a rich nerve supply were the most characteristic features of the anastomosing channels. The tunica media consisted of an outer circular layer of typical smooth-muscle cells and an inner region containing longitudinal plicae of ramified smoothmuscle cells. The tunica adventitia was exclusively occupied by nerve bundles; fibroblasts were poorly developed. Numerous nerve bundles of variable size were coiled around the anastomosing channels, and occasional bundles ran crosswise over the U-shaped bent vessels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239464
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  • 10
    Electronic Resource
    Electronic Resource
    Development of Xenopus laevis skin glands producing 5-hydroxytryptamine and caerulein (1989)
    Springer
    Cell & tissue research 258 (1989), S. 483-489 
    Details
    ISSN: 1432-0878
    Keywords: Development ; Skin glands ; Peptides ; Metamorphosis ; Xenopus laevis (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The granular glands in Xenopus laevis skin are known to contain large quantities of biogenic amines and bioactive peptides which closely resemble mammalian brain-gut peptides. We studied the development of glands producing 5-hydroxytryptamine (5-HT) and caerulein using immunohistochemistry, HPLC-fluorometric systems and RIA. The immunoreactivities of 5-HT and caerulein were first detected in the spherical gland rudiments in the stratum spongiosum at St. 58 (Nieuwkoop and Faber stage), or at the beginning of metamorphosis. Both immunoreactivities appeared in the same rudiment at the same time. Some of the gland rudiments have a small lumen filled with both immunoreactive materials at St. 58–59. During the rest of the metamorphic period, the glands grow in size, accumulating immunoreactive materials in the lumen. The concentrations of 5-HT and caerulein in the skin of tadpoles were below 1 ng per mg wet tissue at St. 58–59, increased as metamorphosis proceeded and reached 63 and 134 ng per mg wet tissue at St. 66, or at the end of metamorphosis, respectively. The amphibian granular glands where large quantities of biogenic amines and hormone-like peptides are rapidly synthesized may provide a useful model for the study of the development of amine- and peptide-producing cells including neurons and paraneurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218860
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  • 11
    Electronic Resource
    Electronic Resource
    An immunohistochemical study on the postnatal development of rat nasal-associated lymphoid tissue (NALT) (1989)
    Springer
    Cell & tissue research 256 (1989), S. 431-438 
    Details
    ISSN: 1432-0878
    Keywords: Mucosa ; Lymphoid tissue ; Nose ; Development ; Immunohistochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This study concerns the development of nasal-associated lymphoid tissue in the rat, using immuno- and enzyme-histochemical staining techniques on cryostat sections. Nasal-associated lymphoid tissue is present at birth as a small accumulation of mainly T lymphocytes and non-lymphoid cells; B cells are rare. Distinct areas of T and B cells appear at 10 days after birth; by that time high endothelial venules are also observed. Intra-epithelial lymphocytes are present, most of them being T-helper cells. ED1+ macrophages are seen throughout the tissue. The proportion of ED1+cells does not change during ontogeny. ED2+cells (tissue macrophages) are present predominantly at the border between the lymphoid tissue and the surrounding connective tissue, in all age-groups. ED3+mononuclear cells are scattered throughout the nasal-associated lymphoid tissue of young animals. Later on, the ED3+ cells migrate into the border-area between lymphoid and connective tissue. Ia+ non-lymphoid cells in the nasal lymphoid tissue increase in number during ontogeny. Only a few of them show acid phosphatase activity, indicating that the proportion of classical scavenger macrophages is low. Some of them may be antigen presenting (dendritic) cells. Ia+ dendritic cells also occur between the epithelial cells. Moreover, some epithelial cells express the Ia marker.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218901
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  • 12
    Electronic Resource
    Electronic Resource
    Expression of α and β tropomyosin subunits during early myogenesis in somites and limb buds of chick embryos (1989)
    Springer
    Cell & tissue research 256 (1989), S. 631-634 
    Details
    ISSN: 1432-0878
    Keywords: Development ; Skeletal muscle ; Tropomyosin ; Somites ; Limb buds ; Chick embryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The appearance of α and β subunits of skeletal tropomyosin in early myogenesis was studied histochemically using monoclonal antibody to α tropomyosin and affinity-purified polyclonal antibody to β tropomyosin. In muscle cells, in both somites and limb buds, the α and β subunits are simultaneously expressed and first appear in the somites at the 30–36 somites. The relatively greater amount of β than α tropomyosin found in early myogenesis is thus likely to result from a higher rate of β tropomyosin synthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225613
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  • 13
    Electronic Resource
    Electronic Resource
    Distribution and frequency of neuro-epithelial bodies in post-natal rabbit lung: Quantitative study with monoclonal antibody against serotonin (1989)
    Springer
    Cell & tissue research 255 (1989), S. 353-362 
    Details
    ISSN: 1432-0878
    Keywords: Development ; Intrapulmonary chemoreceptor ; Immunocytochemistry ; Morphometry ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution, frequency and size of neuroepithelial bodies (NEB) were studied in lungs of rabbits during different stages of development (27-day fetus, newborn, 6, 11, 21, 28 and 56 days postnatally). NEB were visualized by immunostaining with monoclonal antibody against serotonin. Detailed quantitiation of NEB was performed by use of camera lucida drawings of immunostained serial sections from the same anatomical region, i.e. the lower lobe of the left lung. The total number of NEB was counted and expressed per epithelial length of airway, surface area and volume. The size of NEB defined as surface area as well as the position of NEB in relation to the airway bifurcations was assessed in airways of different sizes. The overall number and size of NEB were found to increase during the immediate perinatal period followed by a sharp decline at 56 days of age. The number of NEB peaked at 6 days postnatally (mean 175.5 NEB/mm3 of airway epithelium) and declined significantly (3.0 NEB/mm3) at 56 days of postnatal age. The size of NEB reached its maximum at 11 days (mean surface area 659.54 μm2, with the largest NEB measuring 1839.98 μm2). By 56 days of age, NEB became significantly smaller (mean surface area 177.29 μm2) consisting of small clusters of cells situated deep within the airway epithelium. At all ages, about half of all NEB (mean 47.6%) were localized within the small peripheral airways with up to 63.9% located at airway bifurcations. These findings indicate that the “functional activity” of NEB may be confined predominantly to the perinatal period. The postulated functions of NEB include those of intrapulmonary hypoxia-sensitive chemoreceptors and/or endocrine-paracrine activity in the lung. Such function(s) may be important during adaptation to extrauterine life as well as for growth and development of the lung.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224118
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  • 14
    Electronic Resource
    Electronic Resource
    A scanning electron-microscopic study of the peripolar cell of the rat renal glomerulus (1989)
    Springer
    Cell & tissue research 257 (1989), S. 201-206 
    Details
    ISSN: 1432-0878
    Keywords: Peripolar cell ; Efferent arteriole ; Afferent arteriole ; Kidney ; Scanning electron microscopy ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The interior of Bowman's capsules of rat kidneys has been examined by scanning electron microscopy, and a distinctive population of cells around the exposed vascular poles of glomerular tufts were identified. The cells were situated in the annular groove at the root of the glomerulus, between the parietal epithelial cells and the podocytes. These peripolar cells were dendritic cells with long processes embracing the glomerular arterioles. Up to three peripolar cells were present at each vascular pole and they were mainly distributed in the glomeruli of the outer third of the renal cortex. This first detailed study of the surface morphology of the glomerular peripolar cell supports the suggestion that changes in the diameter of the polar region of the glomerular tuft may cause variations in stretching of the cuff of peripolar cells, and hence modulation of their secretory activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221651
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  • 15
    Electronic Resource
    Electronic Resource
    Localization of calcium and phosphorus in early predentin-matrix components by electron spectroscopic imaging (ESI)-analysis in rat molars (1989)
    Springer
    Cell & tissue research 255 (1989), S. 611-617 
    Details
    ISSN: 1432-0878
    Keywords: Mantle dentin matrix ; Electron spectroscopic imaging (ESI)-analysis ; Calcium ; Phosphorus ; Dentinogenesis ; Biomineralization ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The subcellular distribution of the inorganic elements calcium (Ca) and phosphorus (P) was studied in the first-formed dentin matrix during initial mineralization in neonatal rat molars. This most peripheral matrix region is comprised of a proteoglycan-rich ground substance, interwoven by a collagenous network, matrix vesicles, aperiodic fibrils derived from the dental basal lamina, and apical odontoblastic cell processes. All matrix components may possibly serve as templets for mineral deposition during initial calcification of first-formed mantle dentin and predentin. By means of the very sensitive ESI-analysis we studied the subcellular localization of Ca and P and their possible association with distinct organic extracellular matrix components and odontoblasts. Ca-signals were found in the ground substance, at striated collagen fibrils and plasma membranes of odontoblasts in the cuspal early matrix region, but occurred only sparsely in the ground substance of the more distal matrix region where odontoblast processes attach to aperiodic fibrils of the dental basal lamina. Ca was generally absent in matrix vesicles. In contrast, P-signals were found in matrix vesicles, at aperiodic fibrils and at the plasma membranes of odontoblasts. Ca and P co-localized at striated collagen fibrils (type I or II). These results suggest that striated collagen fibrils might serve as primary deposition sites for calcium phosphate during early biological calcification of organic extracellular macromolecules.
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    URL: http://dx.doi.org/10.1007/BF00218798
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  • 16
    Electronic Resource
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    High resolution scanning electron-microscopic study on the three-dimensional structure of the sarcoplasmic reticulum in the slow (tonic) muscle fibers of the frog, Rana nigromaculata (1989)
    Springer
    Cell & tissue research 255 (1989), S. 669-672 
    Details
    ISSN: 1432-0878
    Keywords: Muscle, striated, skeletal ; Slow muscle fibers ; Muscle cells ; Sarcoplasmic reticulum ; Scanning electron microscopy ; Rana n. nigromaculata (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The three-dimensional structure of the sarcoplasmic reticulum (SR) in the slow (tonic) fibers of the reclus abdominis muscle of the Japanese meadow frog (Rana nigromaculata nigromaculata Hallowell) was examined by high resolution scanning electron microscopy, after removal of the cytoplasmic matrices by the osmium-DMSO-osmium procedure. The SR forms a repetitive network throughout these fibers. At the level of the Z-line, a slender transverse tubule (T-tubule) runs transversely to the longitudinal axis of the myofibril. Small, spherical or ovoid terminal cisternae couple laterally with the T-tubule at intervals of 0.4–1.0 μm, and form a “terminal cisterna-T-tubule complex” on whose surface tiny indentations are occasionally seen. Each terminal cisterna gives rise to a few sarcotubules that run in various directions, divide frequently and form circular or oval meshes of diverse sizes in front of the A- and I-bands. The sarcotubules usually form small meshes in the middle of the A-band, but occasionally fuse and form a poorly developed H-band (fenestrated) collar.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218807
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  • 17
    Electronic Resource
    Electronic Resource
    Corrosion casts as a method for investigation of the insect tracheal system (1989)
    Springer
    Cell & tissue research 256 (1989), S. 1-6 
    Details
    ISSN: 1432-0878
    Keywords: Corrosion casts ; Tracheal system ; Respiration ; Scanning electron microscopy ; Insecta ; Cataglyphis bicolor, Apis mellifera, Musca domestica (Insecta) Tracheal system, insects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The tracheal systems of five insect species (two species of ants, worker bee, housefly and the cabbage butterfly) have been studied by scanning electron microscopy of corrosion casts. This technique, which is commonly used for the investigation of vertebrate vasculature, is adapted to demonstrate the ultrastructure of the insect respiratory organ. The problem of filling a “blind ending system” was solved by injecting the resin Mercox into the evacuated tracheae through a thoracal spiracle. After polymerization of the resin, the tissue was digested enzymatically and chemically. The three-dimensional structure of the tracheal system was investigated by scanning electron microscopy. The technique used here displays for the first time the complex morphology of the entire tracheal system in fine detail, especially the structure of spiracles, airsacs, tracheae and tracheoles. Smooth-walled terminal tracheoles show up in flight muscles. The finest tracheoles that could be identified have diameters of approximately 70 nm. This approaches the finest tracheoles portrayed by transmission electron micrographs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224712
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  • 18
    Electronic Resource
    Electronic Resource
    Lateral diffusion of proteins and lipids in the plasma membrane of rose protoplast (1989)
    Springer
    Protoplasma 152 (1989), S. 46-56 
    Details
    ISSN: 1615-6102
    Keywords: Calcium ; Fluorescence photobleaching recovery ; Lateral diffusion ; Lipid phase ; Plasma membrane ; Protoplast regeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Lateral diffusion measurements have been made on lipids and proteins in the plasma membrane of live protoplasts derived from rose (Rosa sp. “Paul's Scarlet”) suspension-cultured cells. Two different fluorescent lipid probes exhibited markedly different diffusion rates, indicating possible heterogeneity in the lipid domain of the membrane. Membrane proteins were labeled directly with covalently-reactive fluorophores, and factors that might perturb the lateral diffusion of these labeled proteins were investigated. Treatment of the protoplasts with various cytoskeleton-disrupting drugs generally had little effect on protein diffusion, although treatment with oryzalin, a microtubule-disrupting drug, did slightly reduce the mobile fraction of membrane proteins. Elevation of the CaCl2 concentration in the medium from 1 mM to 10 mM significantly reduced the mobile fraction of membrane proteins and also increased the fraction of protoplasts that were able to regenerate cell walls and divide in culture. These results are discussed in relation to reported evidence of lipid domains in the plasma membranes of other cells and protoplasts. The relative importance of lipid domains and membrane-cytoskeleton interaction in governing protein diffusion is considered.
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    URL: http://dx.doi.org/10.1007/BF01354239
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    The prestalk/prespore differentiation and polarized cell movement inDictyostelium discoideum slugs. A possible involvement of the intracellular Ca2+-concentration (1989)
    Springer
    Protoplasma 151 (1989), S. 175-178 
    Details
    ISSN: 1615-6102
    Keywords: Dictyostelium discoideum ; Cellular slime moulds ; Calcium ; Cyclic AMP ; Chemotaxis ; Differentiation ; Slug movement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Intracellular free calcium ion concentrations ([Ca2+]i) in the anterior prestalk and posterior prespore cells of theDictyostelium discoideum slug were determined, using the highly selective Ca2+ indicators, quin-2/AM and fura-2/AM. Temporal changes in [Ca2+]i in response to chemotactic stimulation with cAMP were also monitored at the single-cell level and compared between the two types of cells. The results obtained showed that resting [Ca2+]i in the prestalk cells is considerably higher than that in the prespore cells. Moreover, transient increase in [Ca2+]i upon stimulation with a low concentration of cAMP (20 nM) was noticed only in the prestalk cells, but not in the prespore cells. These facts are discussed in relation to the polarized movement and cellular differentiation in the migrating slug.
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    Characterising adhesiveness ofPhytophthora cinnamomi zoospores during encystment (1989)
    Springer
    Protoplasma 149 (1989), S. 24-30 
    Details
    ISSN: 1615-6102
    Keywords: Adhesion ; Calcium ; Lectins ; Phytophthora cinnamomi ; Secretion ; Zoospore
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary During encystment,Phytophthora cinnamomi zoospores bind firmly to the host surface. We have developed a microassay to study adhesion of the zoospores to solid surfaces, both biological and non-biological. The results show that timing of the acquisition of adhesiveness during encystment correlates closely with the secretion of high molecular weight glycoproteins. The adhesive phase is short lived, occurring between 1 and 4 min after induction of encystment. During this period, cells that come into contact with a variety of surfaces (glass, plastic, and onion epidermis) become firmly attached, while cells that come into contact with one of these substrata after this period are unable to bind. Our results also show that EGTA inhibits cyst adhesion, while addition of calcium promotes cyst adhesion, especially of cysts more than 4 min old. To help identify the cyst surface component involved in adhesion we tested a number of lectins for their ability to block cyst adhesion. Soybean agglutinin andHelix pomatia agglutinin, lectins which bind to the secreted high molecular weight glycoproteins, both inhibit adhesion in the presence and absence of the hapten sugar, indicating that inhibition was non-specific. Wheatgerm agglutinin, a lectin which does not bind to the cyst surface, also blocked adhesion non-specifically.
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    URL: http://dx.doi.org/10.1007/BF01623979
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    Pollen-pistil interactions inBrassica oleracea: Cell calcium in self and cross pollen grains (1989)
    Springer
    Protoplasma 151 (1989), S. 57-61 
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    ISSN: 1615-6102
    Keywords: Brassica ; Self-incompatibility ; Pollen ; Chlorotetracyline ; Energy-dispersive X-ray analysis ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The levels of calcium in pollen grains on the stigma, after self vs. cross pollinations, were compared inBrassica oleracea, a species showing sporophytic self-incompatibility. Self pollen was characterized by higher levels of chlorotetracycline fluorescence and by higher calcium signals in energy-dispersive analysis of X-rays than cross pollen. Cellular integrity of pollen grains was maintained after rejection, and self pollen could be rescued from the stigma to germinate 4 h after pollination, suggesting that the rejection response was not irreversible.
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    Rise in chlorotetracycline fluorescence accompanies tracheary element differentiation in suspension cultures ofZinnia (1989)
    Springer
    Protoplasma 152 (1989), S. 37-45 
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    ISSN: 1615-6102
    Keywords: Calcium ; Chlorotetracycline ; Endoplasmic reticulum ; Tracheary element ; Xylogenesis ; Zinnia elegans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Developing tracheary elements in suspension cultures ofZinnia elegans fluoresce intensely relative to non-differentiating cells when stained with chlorotetracycline (CTC), a fluorescent chelate probe for membrane associated calcium. This suggests that a change in calcium uptake or subcellular distribution accompanies the onset of tracheary element differentiation. A few cells in early differentiating cultures were brightly fluorescent, but did not have visible cell wall thickenings, suggesting that a rise in sequestered calcium may precede visible differentiation. Diffuse CTC fluorescence in early differentiation most likely results from sequestration of calcium in the endoplasmic reticulum. Late in differentiation, CTC fluorescence becomes punctate in appearance, probably due to loss of plasma membrane integrity occurring at the onset of autolysis.Zinnia suspension culture cells were found to be very sensitive to CTC and low concentrations (10 μM) were used to assure accurate localization of membrane-associated calcium in healthy cells.
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    Plasma membrane proteins associated with undifferentiated and embryonicDaucus carota tissue (1989)
    Springer
    Protoplasma 150 (1989), S. 139-149 
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    ISSN: 1615-6102
    Keywords: Biotinylation ; Daucus carota ; Development ; Embryogenesis ; Plasma membrane, SDS-PAGE
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Membranes and membrane proteins from undifferentiated cells and torpedo-stage embryos were compared. A comparison of marker enzyme profiles on linear sucrose gradients showed that the membrane vesicles obtained from 14-day-old embryos were consistently less dense than those obtained from undifferentiated carrot cells. The density of the endoplasmic reticulum, for instance, was 1.10g/cm3 in embryos and 1.12g/cm2 in undifferentiated cells. Proteins and glycoproteins from endoplasmic reticulum-, Golgi apparatus-, and plasma membrane-enriched fractions were compared from undifferentiated carrot cells with 14-day-old embryos by 2D SDS-PAGE. When these two tissues were compared, extensive qualitative and quantitative changes in the steady-state endomembrane and plasma membrane proteins were observed. The plasma membrane was examined further by labeling the plasma membrane proteins with sulfosuccinimidylbiotin. Using this specific label, plasma membrane proteins of 54 kD, 41 kD, 16 kD, and 15 kD were found to be uniquely associated with the embryonic state. Conversely, a 70 kD protein and a 45 kD glycoprotein were found to be associated with only undifferentiated cells. These results demonstrate that proteins of the plasma membrane exhibit distinct changes as a result of somatic embryogenesis in carrot.
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    Distribution of membrane-bound calcium and activated calmodulin during somatic embryogenesis of carrot (Daucus carota L.) (1989)
    Springer
    Protoplasma 153 (1989), S. 24-29 
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    ISSN: 1615-6102
    Keywords: Calcium ; Calmodulin ; Chlorotetracycline ; Daucus carota ; Fluphenazine ; Somatic embryogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The distribution of membrane-bound calcium and activated calmodulin was visualized during carrot somatic embryogenesis by chlorotetracycline (CTC) and fluphenazine fluorescence respectively. Somatic embryos of all stages possessed a higher CTC fluorescence in comparison with the signal from their precursors, the proembryogenic masses. The CTC fluorescence was evenly distributed in the somatic embryos. In contrast, fluphenazine was observed in some regions of the proembryogenic masses only. In the globular, heart-shaped and early torpedo-shaped stage its fluorescence was restricted to the basal part of the embryo. In the older torpedo-shaped embryos also the shoot apex showed fluphenazine fluorescence. It is concluded that during carrot somatic embryogenesis a polarity in the distribution of the activated calmodulin already exists before this polarity is morphologically expressed.
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    Calcium oxalate formation is a rapid and reversible process inLemna minor L. (1989)
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    Protoplasma 148 (1989), S. 130-137 
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    ISSN: 1615-6102
    Keywords: Calcium ; Calcium oxalate ; Crystals ; Lemna minor ; Roots
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Lemna minor root tips form raphide Ca oxalate crystals in both the root cap and root proper. An in vivo system was developed to examine raphide crystal bundle formation in the root of intact plants. By increasing the exogenous Ca concentration, crystal bundle formation could be induced. Entire new crystal bundles could be formed within 30 minutes of an inductive stimulus. The process was reversible with recently formed crystal bundles being dissolved over a period of about 3 hours. Older, previously existing bundles were more resistant to dissolution. The calmodulin antagonists, chlorpromazine and trifluoperazine (300 μM), prevented crystal formation and caused dissolution of some crystal bundles, even in the presence of exogenous Ca. When the antagonists were flushed out and replaced with fresh medium, crystals were formed in cells where dissolution had occurred under the influence of the antagonists. The Ca ionophore A 23187 (20 μM) caused slow dissolution of crystal bundles, even in the presence of exogenous Ca. A model describing the control of and physiological significance of Ca oxalate formation in plants is presented and discussed with respect to the results obtained in this study.
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    Cyclic development of contact behavior in apes and humans (1989)
    Springer
    Primates 30 (1989), S. 269-279 
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    ISSN: 0032-8332
    Keywords: Development ; Gorillas ; Orangutans ; Chimpanzees ; Apes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Nursing and mother-infant distance were observed in three orangutans, two gorillas, one chimpanzee and four humans. All four species showed periods of a recurrence of greater time spent nursing and in contact with the mother. The initial regressive or reattachment period occurred similarly in all four species at between 6–12 months of age. An orangutan observed for two years showed a second period at 19–21 months. Other studies of weight gain in the three ape species coincidently peaked at the same time. When estimated peaks of individuals of each species were summed, the resulting graphs showed a differentiation of species rates of development. Gorillas developed most rapidly, orangutans developed most slowly, while chimpanzees and humans developed within the middle range.
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    A longitudinal investigation of gestural communication in young chimpanzees (1989)
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    Primates 30 (1989), S. 35-50 
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    ISSN: 0032-8332
    Keywords: Chimpanzees ; Communication ; Development ; Social learning ; Culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A longitudinal study of chimpanzee gestural communication is reported. Subjects were seven 5- to 8-year-old members of a semi-natural group at the Yerkes Field Station. These were the same individuals observed byTomasello et al. (1985) four years previously. Nearly identical operational definitions and observational procedures were used in the two studies. Longitudinal comparisons between the two observation periods revealed that the development of chimpanzee gestural communication is best characterized as a series of ontogenetic adaptations: as particular social functions (e.g., nursing, playing, grooming, etc.) arise, decline, or change, gestural communication follows suit. Most gestures seem to be conventionalized by individuals in direct social interaction with conspecifics. Some gestures may be learned by “second-person imitation”—an individual copying a behavior directed to it by another individual. No evidence was found for “third-person imitation”—an individual copying a gesture used between two other individuals. Implications for the concept of chimpanzee “culture” are discussed.
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    Endogenous 24-hour cycle of core temperature and oxygen consumption in week-old Zucker rat pups (1989)
    Springer
    Journal of comparative physiology 159 (1989), S. 569-575 
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    ISSN: 1432-136X
    Keywords: Artificial rearing ; Circadian ; Development ; Newborn ; Thermoregulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Experiments were designed to test whether or not the 24-h core temperature fluctuations in week-old rat pups are of endogenous origin. Lean (Fa/-) Zucker rat pups born on the same day to mothers maintained in two different colonies with light/dark cycles 12 h out of phase with each other were mother-reared through the first 3–4 days of life and then artificially reared simultaneously in constant dim light. Continuous, automatic measurement of core temperature and oxygen consumption during artificial rearing showed clear 24-h rhythms in 5- to 8-day-old pups. Each rhythm reached a daily minimum at a time corresponding to the beginning of the light period in the colony of origin. The amplitude of these rhythms did not diminish during artificial rearing, nor did the phase difference between the rhythms of pups originating in the two colonies systematically change. The persistent 12-h phase differences between these two groups of pups prove that the observed rhythms are not caused by exogenous stimuli. We conclude that the rat pup possesses an endogenous time-keeping mechanism that permits the expression of overt rhythmicity at the age of 1 week.
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    Environmental modulation of calcium and phosphorus metabolism in embryonic snapping turtles (Chelydra serpentina) (1989)
    Springer
    Journal of comparative physiology 159 (1989), S. 501-508 
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    ISSN: 1432-136X
    Keywords: Calcium ; Embryos ; Phosphorus ; Turtles ; Water
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Eggs of common snapping turtles (Chelydra serpentina) were incubated on wet (−150 kPa water potential) and dry (−950 kPa) substrates in a laboratory study assessing the effects of the hydric environment on patterns of mobilization of calcium and phosphorus by developing embryos. We found that embryos developing in wet environments withdrew nutrients from their yolk faster, grew more rapidly, and incubated longer than embryos exposed to dry environments. Turtles developing in both environments absorbed calcium from the yolk at similar rates and depleted the yolk of almost its entire reserve of calcium prior to hatching. Calcium withdrawn from the yolk was supplemented with calcium mobilized from the eggshell, but embryos in wet environments obtained substantially more calcium from the eggshell than did those in dry settings. Embryos obtained all of the phosphorus used in skeletogenesis from the yolk, but those incubating in wet environments mobilized phosphorus from this compartment more rapidly than did those in dry settings. Exposing embryonic snapping turtles to wet environments apparently allows them to make more efficient use of the transitory source of calcium in the eggshell than is possible in dry environments. However, the residual yolk in hatchlings from both wet and dry environments contains too little calcium to support the growth of hard and soft tissues in neonates at rates similar to those characterizing the growth phase of development in embryogenesis.
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    Bone tissue formation in human bone marrow organ cultures (1989)
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    Bulletin of experimental biology and medicine 107 (1989), S. 684-686 
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    ISSN: 1573-8221
    Keywords: bone marrow ; man ; organ cultures ; osteogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1007/BF00841786
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    Tetramethylammonium-calcium-triazid. Darstellung und Kristallstruktur (1988)
    Springer
    Monatshefte für Chemie 119 (1988), S. 1245-1249 
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    ISSN: 1434-4475
    Keywords: Azide ; Calcium ; Crystal structure ; Tetramethylammonium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract [N(CH3)4]Ca(N3)3,M=240.29, was prepared from aqueous solutions of tetramethylammoniumazide with calciumazide at 298 K. The crystals are tetragonala=936.6(7) pm,c=694.7(5)pm, space group P4/nmm,Z=2, ρ(x)=1.31Mgm−3. The crystal structure was determined by single crystal x-ray diffraction (234 Mo-Kα-reflections, μ=0.469 mm−1,R=0.064). Calcium is octahedrally coordinated to six azide groups. The octahedra are connected via azide groups to a threedimensional array with the complex ammonium ions between. The terminal nitrogen atoms of the azide groups and the methyl groups are considerably disordered.
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    Die Kristallstruktur des Calciumazid-Dihydrates (1988)
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    Monatshefte für Chemie 119 (1988), S. 921-927 
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    ISSN: 1434-4475
    Keywords: Azide ; Calcium ; Crystal structure ; Dihydrate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Single crystals of Ca(N3)2·2 H2O have been prepared from aqueous solutions at room temperature. The crystals are monoclinic,a=1 159.0 (3),b=614.2 (2),c=785.5 (2) pm, β=106.52 (2)°,Z=4, space group P21/n. The crystal structure was determined by single crystal X-ray diffraction (1 109 Mo-Kα-reflexions,R=0.052). Calcium atoms are surrounded by four azide groups and four water molecules. The coordination polyhedra are antiprism which are sharing azide groups and water molecules to form layers. The lattice constants and powder pattern agree well with values reported earlier for Ca(N3)2 · 1.5 H2O [1]. It was also shown, that Sr(N3)2 · 2 H2O is isotypic with Ca(N3)2 · 2 H2O.
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    Transport processes in stimulated and non-stimulated leaves of Mimosa pudica (1988)
    Springer
    Trees 2 (1988), S. 65-72 
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    ISSN: 1432-2285
    Keywords: Calcium ; Chlorine ; Ion shifts ; Mimosa pudica ; Potassium ; Seismonastic movements ; X-ray microanalysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Using energy-dispersive X-ray microanalysis, the concentrations of ions, especially potassium and chlorine, were determined in different tissues of primary and tertiary pulvini of Mimosa pudica. It was shown that stimulating the leaf was followed by ion displacements which were most striking in the outer extensor cells, resulting in turgor loss. Since Ca concentration remains relatively constant in cell walls of collapsed cells, the changes of K concentration are best described by the K:Ca ratio. After stimulation the K:Ca ratio dropped in the outer extensor of the primary pulvinus from 775.3 to 2.37 in the cytoplasm, and from 542.2 to 9.25 in the cell wall. Changes in chlorine content were less striking in the primary pulvinus. The K∶Cl ratios in some cases were lower than 1.0, which indicates that Cl content can increase, while K content is diminished. In the non-stimulated tertiary pulvini the outer extensor cells show high concentrations of Cl, but much lower Cl concentrations were found after stimulation. In contrast to the primary pulvinus the K content of the tertiary pulvini is very low. In the vascular tissues of both primary and tertiary pulvini stimulation is followed by a release of K and Cl out of the sieve element cytoplasm into the apoplast. K then appears accumulated in the cell walls of the collenchymatous tissue. These displacements lead to the assumption that the collenchymatous apoplast temporarily functions as a reservoir for K and to a lesser extent for Cl. With regard to the mechanism of leaf movement after stimulation, the accumulation of ions in the apoplast seems to be initiated by the decrease of water potential triggered by an apoplastic accumulation of unloaded sucrose (Fromm and Eschrich 1988a). The resulting turgor release in the outer extensor is accompanied by an efflux of ions.
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    Microbeam analysis of Ca exchange and uptake in the fine roots of spruce: influence of pH and aluminum (1988)
    Springer
    Trees 2 (1988), S. 96-103 
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    ISSN: 1432-2285
    Keywords: Aluminum ; Calcium ; Fine roots ; Microbeam analysis ; Picea abies ; Soil acidification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A novel stable isotope labelling procedure for microbeam analysis was developed to monitor exchange and uptake of nutrients, primarily Mg, K and Ca, by root tips at the cellular level. Initially root samples were analysed from 2-year-old spruce trees, originating both from a nursery and from a polluted forest site, (1) for the cortex cell wall accessibility and nutrient binding properties, (2) for the influence of low pH and elevated aluminum concentrations on Ca binding to cortex cell walls, and (3) for long-range transport into the secondary xylem, proximal to the labelled root tip. In nursery control plants, Ca is localized mainly in the apoplast of the cortex. Exchange of Mg, K, Ca in the cell wall of the cortex and the primary xylem with label in incubation solutions is almost completed to equilibration within 30 min. In the secondary xylem we could detect Mg, K, and Ca from labelling solutions in minute amounts after 30 min, and as a major fraction after 48 h. This indicates that stable isotope labelling can be used to study both ion-exchange properties of the apoplast and long-range transport. Slight acidification of the labelling incubation media to pH 4.5 reduced Ca binding to the cortex cell walls slightly, but acidification to the extreme value of pH 2.3 reduced binding 41%. A combination of pH 4.5 and increased free aluminum reduced the binding by 83%. In a preliminary attempt to analyse the nutrient binding capability of the root-tip apoplast from pollution affected trees, we exposed fine roots of 2-year-old spruce from an acidified and polluted site showing typical low levels of Ca and Mg in the cortical cell walls to Ca-enriched media. Under these conditions the Ca content of cortex cell walls doubled upon incubation at pH 4.7, reaching 40% of the total binding capacity of our nursey control plants.
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    Monoamine oxidase activity in single nerve cell bodies from substantia nigra of rat and man (1988)
    Springer
    Cellular and molecular life sciences 44 (1988), S. 710-712 
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    ISSN: 1420-9071
    Keywords: MAO A ; MAO B ; substantia nigra ; rat ; man ; MPTP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In single nerve cell bodies isolated from the substantia nigra of man and rat the active forms of MAO A and MAO B were found by the use of the microdiver technique and specific inhibitors.
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    The reinforcement-extinction process of selector gene activity: a positive feed-back loop and cell-cell interactions in Ultrabithorax patterning (1988)
    Springer
    Development genes and evolution 197 (1988), S. 424-434 
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    ISSN: 1432-041X
    Keywords: Drosophila ; Ultrabithorax ; Development ; Regulation ; Protein distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Most viable alleles of homeotic genes cause partial transformations within given lineages in a topographically specific fashion. We study this phenomenon as a way to understand the normal mechanisms involved in the spatial regulation of homeotic gene expression. To this end we have investigated the distribution of Ultrabithorax (Ubx) proteins in imaginai discs mutant for hypomorphic and neomorphic alleles of Ubx and alleles of trans-acting genes. We find that the morphological discontinuities observed in the adult transformations are caused by corresponding new patterns of the Ubx proteins in the imaginai anlagen. These novel patterns of Ubx proteins are understood as a consequence of a process of reinforcement-extinction of Ubx expression. The evidence suggesting that this process results from a positive feed-back loop and cell-cell interactions is discussed.
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    Inhibition of muscarinic receptor-mediated Ca27#x002B; mobilization by phorbol 12-myristate 13-acetate in chick embryo cells (1988)
    Springer
    Development genes and evolution 197 (1988), S. 37-39 
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    ISSN: 1432-041X
    Keywords: Phorbol ester ; Muscarinic receptor ; Calcium ; Chick embryo ; Morphogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A muscarinic cholinergic receptor is present on undifferentiated cells of the chick embryo. Stimulation of the muscarinic receptor with muscarinic agonists triggers intracellular Ca2#x002B; mobilization. Here, we investigate the effect of phorbol 12-myristate 13-acetate (PMA) on the muscarinic receptor-mediated Ca2#x002B; mobilization, which is monitored in cell suspensions of chick embryos of stage 24 by chlorotetracycline fluorescence. PMA inhibits the Ca2#x002B; mobilization in a time-dependent and concentration-dependent manner without changing the ED50 of acetylcholine. The concentration of PMA that gives halfmaximal inhibition is 3.1×10−9 M PMA.
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    Cytosolic calcium in platelet activation (1988)
    Springer
    Cellular and molecular life sciences 44 (1988), S. 97-100 
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    ISSN: 1420-9071
    Keywords: Calcium ; platelet ; second messenger
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Experiments with permeabilised platelets, and with intact platelets loaded with fluorescent Ca2+-indicators, over the past several years have greatly extended our knowledge and understanding of cytosolic Ca2+ as a platelet activator and its interactions with other cytosolic regulators. This article outlines insights, gained from the use of the fluorescent dyes, into maintenance and restoration of basal [Ca2+]i, mechanisms of receptor-mediated Ca2+-mobilisation and quantitation of [Ca2+]i/response relations in intact human platelets.
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    URL: http://dx.doi.org/10.1007/BF01952188
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    Calcium-dependent protein kinase from apple fruit membranes is calmodulin-independent but has calmodulin-like properties (1988)
    Springer
    Planta 176 (1988), S. 91-97 
    Details
    ISSN: 1432-2048
    Keywords: Calcium ; Calmodulin ; Malus (protein kinase) ; Protein kinase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Crude Ca2+-activated protein kinase from membranes of apple (Malus domestica L. Borkh., Cox's Orange Pippin) fruit can be partially purified to yield a Ca2+-dependent protein kinase whose activity is apparently not regulated by calmodulin. The autophosphorylating catalytic subunit of this protein kinase shows a Ca2+-dependent mobility shift of approx. 10 kilodaltons (kDa) on sodium dodecyl sulphate-polyacrylamide gel electrophoresis; in the absence of added Ca2+ or ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA) its apparent molecular mass is approx. 50 kDa. The Ca2+-dependent protein kinase is inhibited by the calmodulin antagonists N-(6-aminohexyl)-5-chloro-1-naphthalenesulphonamide and trifluoperazine with IC50 values of approx. 45 μM and 15 μM, respectively. These similarities between the protein kinase and calmodulin indicate that the kinase may be a calmodulin-like protein.
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    URL: http://dx.doi.org/10.1007/BF00392484
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    The relationship among egg size, density and food level on larval development in the wood frog (Rana sylvatica) (1988)
    Springer
    Oecologia 75 (1988), S. 67-72 
    Details
    ISSN: 1432-1939
    Keywords: Rana sylvatica ; Egg size ; Development ; Density ; Food level
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Although inter- and intraspecific variation in egg size among amphibians has been well documented, the relationship between egg size and fitness remains unclear. Recent attempts to correlate egg size intraspecifically with larval developmental patterns have been equivocal. In this study the development of larvae derived from large eggs and small eggs, from a single population in Maryland were compared under a range of food levels and larval population densities. Both food level and density had significant effects on the length of the larval period and size at metamorphosis. However, the response among larvae derived from different egg sizes was not additive. At low densities and high food levels, larvae from small eggs had longer larval periods and a larger size at metamorphosis than larvae derived from large eggs. In contrast, at high densities larvae from small eggs had longer developmental periods but were smaller at metamorphosis than larvae from large eggs. In addition, larvae from small eggs were more sensitive to density irrespective of food level. These results suggest that optimal egg size is correlated with environmental factors, which may explain the maintenance of both geographic and within population variation in egg size commonly observed in amphibians.
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    URL: http://dx.doi.org/10.1007/BF00378815
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    Isolated generative cells in some angiosperms: a further study (1988)
    Springer
    Sexual plant reproduction 1 (1988), S. 97-102 
    Details
    ISSN: 1432-2145
    Keywords: Generative cell ; Isolation ; Scanning electron microscopy ; Immunofluorescence ; Video-enhanced microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Generative cells were isolated from the pollen grains of three angiosperm species by a method similar to that previously reported for Haemanthus katherinae (Baker). Both the external appearance and the internal structure of the isolated generative cells were observed by light and scanning electron microscopy. The dynamic changes occurring in the cells after they had been liberated from the pollen grains were recorded by video-enhanced microscopy. The distribution of microtubules in the isolated cells was revealed by immunofluorescence.
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    URL: http://dx.doi.org/10.1007/BF00189268
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    Calcium control of differentiation in Phytophthora palmivora (1988)
    Springer
    Archives of microbiology 149 (1988), S. 565-571 
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    ISSN: 1432-072X
    Keywords: Phytophthora ; Zoospores ; Calcium ; Encystment ; Differentiation ; Pectin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A method has been developed for the preparation of zoospores from Phytophthora palmivora which allows the ionic composition of the suspension medium to be closely controlled. Sub-micromolar concentrations of calcium ions have been shown to play a key role in maintaining the zoospore state and in the transition to the cyst stage. Restriction of free Ca2+ to between 0.2 and 1 μM resulted in zoospores which could be maintained for several hours before they finally encysted and germinated. When exposed to citrus-pectin, or 3 mM SrCl2, or to vigorous shaking, these zoospores underwent rapid synchronous encystment. At free Ca2+ concentrations below 0.1 μM, zoospores lysed slowly. If exposed to inducers of encystment before lysis had occurred, the zoospores failed to respond to pectin or to vigorous shaking. However, they did differentiate in response to SrCl2 addition. Provided the free Ca2+ was maintained between 0.02 and 0.2 μM, zoospores survived gentle centrifugation, a procedure which previously had resulted in encystment.
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    Specific binding of the calcium channel blocker [3H]verapamil to membrane fractions of Chlamydomonas reinhardtii (1988)
    Springer
    Archives of microbiology 149 (1988), S. 451-458 
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    ISSN: 1432-072X
    Keywords: Chlamydomonas reinhardtii ; Phototaxis ; Galvanotaxis ; Calcium ; Calcium channels ; Calcium channel blockers ; Radioligand binding ; Polymer twophase system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Specific binding of the calcium antagonist [3H]verapamil to a microsomal fraction, a presumptive plasma membrane fraction and an intracellular membrane fraction of the phototactic unicellular green alga Chlamydomonas reinhardtii has been demonstrated. The specific activity of the plasma membrane marker enzyme K+-stimulated, Mg2+-dependent ATPase was severalfold higher in the upper (polyethylene glycol-rich) than in the lower (dextran-rich) phase, and the reverse was established for the marker enzymes of intracellular membranes such as cytochrome c oxidase for mitochondria and antimycin Aresistant NADPH-cytochrome c reductase for endoplasmic reticulum. Chlorophyll as a marker for thylakoid fragments was exclusively found in the lower phase. In the microsomal fraction two specific binding sites of [3H]verapamil were found at 22°C, one with higher and a second with lower affinity to [3H]verapamil. Separation of plasma membranes from intracellular membranes revealed that the “highaffinity” binding site is attributed to the plasma membrane fraction whereas the “low-affinity” binding site can be attributed to the intracellular membrane fraction. Specific binding to both separated membrane fractions is saturable and reversible. [3H]Verapamil binding to plasma membranes was not inhibited by the calcium channel blockers diltiazem and nifedipine. However, in the intracellular membrane fraction [3H]verapamil could be displaced by diltiazem but not by nifedipine. Increasing concentrations of calcium chloride inhibited [3H]verapamil binding in both fractions.
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    Glycerol-3-phosphatase and the control of glycerol metabolism in Dunaliella tertiolecta cells (1988)
    Springer
    Archives of microbiology 150 (1988), S. 109-112 
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    ISSN: 1432-072X
    Keywords: Calcium ; Dunaliella tertiolecta ; Enzyme kinetics ; Glycerol ; Glycerol-3-phosphatase ; Metabolic regulation ; Osmoacclimation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Glycerol-3-phosphatase (EC 3.1.3.2.1) was studied by following the release of radioactive glycerol from L-(U-14C)glycerol-3-phosphate in Dunaliella tertiolecta enzyme extracts. The reaction showed a neutral pH optimum and had an absolute requirement for Mg2+. The substrate saturation curve was hyperbolic with an apparent K m value for glycerol-3-phosphate of 0.7 mM in the absence of phosphate. Inorganic orthophosphate was a competitive inhibitor of the enzyme with an estimated K j of 0.1 mM. The glycerol-3-phosphatase reaction was blocked nearly completely by millimolar Ca2+ concentrations. Ca2+ inhibition did not depend on the presence of calmodulin in the reaction medium. The characteristics of glycerol-3-phosphatase are discussed in relation to the regulation of the cyclic glycerol metabolism in Dunaliella cells during periods of osmotic stress.
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    URL: http://dx.doi.org/10.1007/BF00425148
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    Auxin causes oscillations of cytosolic free calcium and pH inZea mays coleoptiles (1988)
    Springer
    Planta 174 (1988), S. 495-499 
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    ISSN: 1432-2048
    Keywords: Auxin, calcium and pH ; Calcium ; Cytosolic pH ; Membrane potential (double-barrelled micro-electrode) ; Zea (auxin, Ca2+, pH)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In epidermal cells of maize (Zea mays L.) coleoptiles, cytosolic pH (pHc), cytosolic free calcium, membrane potential and changes thereof were monitored continuously and simultaneously (pHc/,ψ m, Ca2+/ψ m) using double-barrelled ion-sensitive microelectrodes. In the resting cells the cytosolic pH was 7.3–7.5 and the concentration of free calcium was 119±24 nM. One-micromolar indole-3-acetic acid (IAA), added to the external medium at pH 6.0 triggered oscillations inψ m, pHc and free calcium with a period of 20 to 30 min. Acidification of the cytosolic pH increased the cytosolic free calcium. Theψ m oscillations are attributed to changes in activity of the H+-extrusion pump at the plasmalemma, triggered off by ΔpH and controlled by pH regulation (pH oscillation). The origin of the pHc and Ca2+ changes remains unclear, but is possibly caused by auxin-receptor-induced lipid breakdown and subsequent second-messenger formation. It is suggested that the observed cytosolic pH and Ca2+ changes are intrinsically interrelated, and it is concluded that this onset of regulatory processes through the phytohormone IAA is indicative of calcium and protons mediating early auxin action in maize coleoptiles. It is further concluded that the double-barrelled ion-sensitive microelectrode is an invaluable tool for investigating in-vivo hormone action in plant tissues.
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    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 
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    ISSN: 1432-0878
    Keywords: Embryonic rat brain ; Cell culture ; Development ; NILE-glycoprotein ; Neurons ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
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    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 
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    ISSN: 1432-0878
    Keywords: Collagen ; Submucosa ; Intestine ; Scanning electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
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    Developmental appearance of the Ca2+-binding proteins parvalbumin, calbindin D-28K, S-100 proteins and calmodulin during testicular development in the rat (1988)
    Springer
    Cell & tissue research 252 (1988), S. 359-365 
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    ISSN: 1432-0878
    Keywords: Calcium ; Parvalbumin ; Calbindin D-28K ; S-100 proteins ; Calmodulin ; Testis ; Male sexual hormones ; Leydig cells ; Spermatogenesis ; Rat (SIV-50)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Calcium and intracellular Ca2+-binding proteins are possibly involved in hormone production and spermatogenesis in rat testis. Parvalbumin, calbindin D-28K, S-100 proteins and calmodulin were localized in the Leydig cells, which are sites of testosterone synthesis. Only the appearance of parvalbumin-immunoreactivity is closely correlated to testosterone production during development of the testes. Calbindin D-28K-immunoreactivity persisted in foetal-type Leydig cells and in adult-type Leydig cells at all stages of development. S-100-immunoreactivity was low during all foetal stages, absent between birth and puberty, and increased thereafter. Calmodulin staining is most prominent in the cytoplasm of developing spermatocytes and of maturing spermatids. All four proteins co-exist in the seminiferous tubules. The distinct localization and developmental appearance of these proteins suggests different regulatory roles in Leydig cell function and spermatogenesis.
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    Development of the esophageal muscles in embryos of the sea urchin Strongylocentrotus purpuratus (1988)
    Springer
    Cell & tissue research 252 (1988), S. 411-417 
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    ISSN: 1432-0878
    Keywords: Myogenesis ; Sea urchin embryo ; Development ; Muscle ; Mesenchyme ; Strongylocentrotus purpuratus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Development of the esophageal muscles in embryonic sea urchins is described using light- and electron microscopy. The muscles develop from processes of about 14 cells of the coelomic epithelium that become immunore-active to anti-actin at about 60 h (12–14° C). Initially, eachmyoblast extends a single process with numerous fine filopodia around the esophagus. By 72 h the processes have reached the midline and fused with those from cells of the contralateral coelomic sac. Myoblasts begin to migrate out of the coelomic epithelium between 72 and 84 h. By 72 h the processes stain with the F-actin specific probe NBD-phallacidin. The contractile apparatus is not evident in transmission electron-microscopic preparations of embryos at 70 h, but by 84 h the contractile apparatus is present and the muscle cells are capable of contraction. Because the myoblasts migrate free of the coelomic epithelium and are situated on the blastocoelar side of the basal lamina, it is suggested that that they should be considered as a class of mesenchymal cells.
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    Are lysosomal enzymes involved in rapid damage in vertebrate muscle cells? (1988)
    Springer
    Cell & tissue research 253 (1988), S. 447-455 
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    ISSN: 1432-0878
    Keywords: Lysosomes ; Muscle damage ; Calcium ; Lysosomotropic agents ; Phospholipase A2 ; Frog (Rana temporaria) ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Experiments with lysosomotropic agents suggest that the sarcotubular system subserves some of the functions of the lysosomal apparatus in frog skeletal muscle. Dinitrophenol or A23187 trigger lysosome labilization and myofilament damage in mammalian cardiac muscle. Lysolecithin labilizes isolated liver lysosomes, but has no action following phospholipase A2 activation in vivo. Zinc ions or a pHi of 7.5 do not protect against myofilament damage. In fractions from mammalian cardiac muscle, calcium and calmodulin do not cause lysosomal labilization whereas cGMP does but only at high concentration (10-4 M). It is concluded that lysosomal hydrolases play no significant part in rapid muscle damage. It is suggested that rises in [Ca]i activate two separate pathways causing (i) myofilament damage; (ii) sarcolemmal (and possibly lysosomal) membrane damage via phospholipase A2 and lipoxygenase activity. Dinitrophenol triggers both pathways independently and thus may cause lysosome labilization. The possibility that the sarcoplasmic reticulum is the site generating myofilament damage is discussed.
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    URL: http://dx.doi.org/10.1007/BF00222302
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    The role of phospholipase A2 in calcium-induced damage in cardiac and skeletal muscle (1988)
    Springer
    Cell & tissue research 253 (1988), S. 457-462 
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    ISSN: 1432-0878
    Keywords: Muscle damage ; Cardiac muscle ; Calcium ; Phospholipase A2 ; Lipoxygenase ; Cyclo-oxygenase ; Rana ttemporaria ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This study compares the action of inhibitors of the eicosanoid cascade on calcium-induced myofilament damage in cardiac muscle of the perfused frog heart and incubated frog ventricle slices, and in skeletal muscle of incubated mammalian diaphragm and isolated and saponin-skinned amphibian pectoris cutaneous muscle. Mepacrine (10-5M) and indomethacin (3×10-6M) protected completely against myofilament damage induced by entry of calcium in the ‘calcium-paradox’ in frog heart. However, inhibition of phospholipase A2 (PLA2) (with chlorpromazine, 2×10-4M, or mepacrine, 10-5M, 5x10-5M), of cyclo-oxygenase enzymes (with indomethacin, 3x10-6M to 10-5M or BW755C, 3.8x10-4M), or of lipoxygenase enzymes (with BW755C, 3.8x10-4M or nordihydroguaiaretic acid, 2x10-6M or 5x10-6M) all failed in intact cardiac or skeletal muscle cells to prevent the myofilament damage that is rapidly triggered by 10-2M caffeine, 6x10-6M ruthenium red, 10-4M DNP or 5 μg ml-1 A23187. These agents also failed completely to protect against myofilament damage in saponin-skinned amphibian skeletal muscle when [Ca]i was raised to 8x10-6M. Thus, inhibition of PLA2 does not protect the myofilament apparatus against calcium released intracellularly, and it is suggested that mepacrine and indomethacin can block entry of calcium in the calcium-paradox in the amphibian heart. Chlorpromazine (2x10-4M) and mepacrine (10-3M) at zero [Ca] caused severe myofilament damage in skinned muscle, possibly due to an effect on membranes. Since inhibitors of PLA2 and of lipoxygenases prevent efflux of creatine kinase and sarcolemma damage in mammalian skeletal muscle, it is evident that experimentally-induced rises in [Ca]i (by caffeine or A23187) can trigger two separate pathways: (i) PLA2 and the arachidonic acid cascade which culminate in membrane damage, and (ii) a different, Ca-activated system that causes rapid damage of myofilaments.
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    Distribution of peptide-immunoreactive nerves in the foetal and newborn guinea-pig caecum (1988)
    Springer
    Cell & tissue research 253 (1988), S. 105-114 
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    ISSN: 1432-0878
    Keywords: Enteric nervous system ; Autonomic nervous system ; Development ; Vasoactive intestinal polypeptide ; Substance P ; [Met]enkephalin ; Somatostatin ; Guinea pig, Dunkin-Hartley
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of vasoactive intestinal polypeptide-, substance P-, [met]enkephalin- and somatostatin-like immunoreactive nerves was studied in the caecum from foetal guinea-pigs of 6–9 weeks gestation (i.e., approximately 1–4 weeks before birth) and 4–5-day-old guinea-pigs. Peptide-immunoreactive nerves were first detected in the myenteric and submucous plexuses and circular muscle layer at 6 weeks of gestation and in the mucosa at 7 weeks of gestation. The density of fibres in these layers increased during prenatal development until, by 9 weeks of gestation, their distribution resembled that seen in the postnatal animals. This distribution was similar to that described previously in adult animals. A different pattern of development was observed in the caecal taenia coli muscle. Peptide-immunoreactive fibres were not detected until 8 weeks of gestation in this tissue layer, and were then only sparsely distributed. A dramatic increase in the number of labelled fibres, however, occurred between 8 and 9 weeks of gestation. Further, vasoactive intestinal polypeptide- and substance P-immunoreactive fibres were more numerous in the taeniae coli of 9-week-old embryos than in those of postnatal animals. Thus, the guinea-pig enteric nervous system, which in many respects is well-developed at the time of birth, may still be undergoing developmental changes at this time.
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    Developmental study of neuropeptide Y-like immunoreactivity in the neurohypophysis and intermediate lobe of the rhesus monkey (Macaca mulatta) (1988)
    Springer
    Cell & tissue research 254 (1988), S. 499-509 
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    ISSN: 1432-0878
    Keywords: Neuropeptide Y ; Immunohistochemistry ; Pituitary ; Development ; Aging ; Neurohypophysis ; Intermediate lobe ; Hypothalamo-hypophyseal portal vessels ; Neuroendocrine regulation ; Macaca mulatta (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The purpose of this study was to examine the development and distribution of neuropeptide Y-immunoreactive fibers in the neurohypophysis of the rhesus monkey (Macaca mulatta) throughout life and the relationship of these fibers to the hypothalamo-hypophyseal portal vasculature. In rhesus monkeys, which varied in age from fetal life to 34 years, neuropeptide Y-immunoreactive fibers were present at all ages examined. In adult monkeys, varicose neuropeptide Y-labeled fibers were concentrated in the upper infundibular stem in association with capillary loops of the portal vasculature and the long portal vessels. Other fibers travelled down the infundibular stem and were distributed at the junction of the lower infundibular stem and infundibular process in the vicinity of the short portal vessels. In the infundibular process, neuropeptide Y-immunoreactive fibers were concentrated along the border of the intermediate lobe. Other stained fibers were sparsely distributed in the infundibular process and were often associated with small vessels. Neuropeptide Y-immunoreactivity was also located in a few fibers and cells of the intermediate lobe. Very few labeled fibers were seen in the fetal neurohypophysis, but their number increased gradually during the first postnatal year. At two years of age, a high density of stained fibers was observed, especially in the infundibular process. The number of axons in the infundibular process was lower at 12 years and continued to decline until 34 years of age. Neuropeptide Y may modulate hormone release at these sites and may also be released directly into vessels in the infundibular process. The close association of neuropeptide Y-labeled fibers with capillaries of the portal vasculature strongly suggests that neuropeptide Y is released into the portal blood of monkeys throughout life and may influence hormone secretion from the anterior pituitary gland.
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    Analysis of the expression of extensin and p33-related cell wall proteins in carrot and soybean (1988)
    Springer
    Molecular genetics and genomics 211 (1988), S. 393-399 
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    ISSN: 1617-4623
    Keywords: Cell wall ; Wounding ; Proline-rich proteins ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have identified p33 as a cell wall protein in carrot storage roots that increases in the cell wall after wounding, using antibodies raised against a synthetic peptide derived from the p33 cDNA sequence. The mRNA encoding p33 increases markedly within 1 h after wounding in carrots, indicating that p33 may be involved in one of the early cellular responses to physical damage. In contrast with extensin, p33 mRNA does not accumulate in carrot roots in response to ethylene or in carrot suspension culture cells incubated in the presence of a crude endogenous elicitor fraction. These results indicate that the wound-induced signals responsible for the synthesis of p33 and extensin after wounding are different. Protein immunologically related to carrot p33 and RNA transcripts homologous to p33 cDNA sequences were detected in the apical hook of the soybean seedling indicating that a cell wall protein related to p33 is also synthesized during plant development.
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    Studies on α-D-mannosidase and ConA during jackbean development and germination (1988)
    Springer
    Protoplasma 144 (1988), S. 34-45 
    Details
    ISSN: 1615-6102
    Keywords: ConA, α-D-mannosidase ; Immunogold labelling ; Seed cotyledons ; Legumes ; Development ; Germination ; Membrane traffic ; Targeting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Changes in the level and activity of α-D-mannosidase and ConA have been followed during a time-course of development spanning seed formation, desiccation and germination. In parallel studies, immunogold labelling has enabled these changes to be placed within a structural context of the cotyledon parenchyma cells during protein body formation, dehydration and subsequent autolysis during germination. The results indicate that the exo-glycosidase and lectin accumulate in parallel during seed formation and are packaged within the same protein bodies. Several lines of evidence suggest that the function of both proteins is related to events that occur during seed development rather than germination.
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    Bioelectric and biosynthetic aspects of cell polarity inAllomyces macrogynus (1988)
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    Protoplasma 146 (1988), S. 118-126 
    Details
    ISSN: 1615-6102
    Keywords: Bioelectricity ; Calcium ; Polarity ; Hyphal growth ; Allomyces
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In contrast to all filamentous fungi examined to date, vegetative hyphae ofAllomyces macrogynus, whether extending or not, produced an outward flow of positive electrical current, at a maximum of 0.16 μA cm−2 around 40 μm behind the apex, as measured with a vibrating probe. Inward currents of up to 0.55 μA cm−2 were recorded around the rhizoids. Increases in outward current were observed in hyphae pre-grown under oxygen deficiency and then allowed to widen backwards to the hyphal base in sufficient oxygen. When spores were germinated in an applied electrical field they produced rhizoids predominantly towards the anode. Hyphae were produced initially towards the cathode but later bent around towards the anode. Experiments with a range of chemicals provided no evidence for the involvement of calcium in vegetative growth and development inA. macrogynus. Polyoxin and nikkomycin, inhibitors of chitin synthesis, had no effect on swimming zoospores, but inhibited wall formation of cysts, rhizoids and forward and backward growing hyphae.
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    Distortion of plant cell plate formation by the intracellular-calcium antagonist TMB-8 (1988)
    Springer
    Protoplasma 144 (1988), S. 92-100 
    Details
    ISSN: 1615-6102
    Keywords: Calcium ; Cell plate ; Funaria ; Phragmoplast ; TMB-8
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Caulonema tip cells ofFunaria deposit new oblique cross walls of specific morphology and placement by a highly defined reorientation mechanism. In the presence of the purported intracellular Ca2+ antagonist 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate (TMB-8), these cross walls form in the proper place but exhibit a distorted morphology. Video microscopy indicates that the deformation takes place during the reorientation of the cell plate from a perpendicular to an oblique configuration. Electron micrographs of TMB-8 treated cells indicate a stabilization of phragmoplast microtubules and a greater amount of vesicles and membrane in the developing cell plate. TMB-8 treated cells also show intense chlortetracycline fluorescence from mitochondria, vesicles and endoplasmic reticulum as compared to untreated cells indicating that TMB-8 is blocking release of Ca2+ from intracellular stores. It is concluded that this may cause distortation of cross walls as they form by delaying vesicle fusion, stabilizing microtubules, and increasing the amount of new wall material in the developing cell plate.
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    URL: http://dx.doi.org/10.1007/BF01637241
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    The ontogeny and phylogenetic conservation of MAP 2 forms (1988)
    Springer
    Protoplasma 145 (1988), S. 195-199 
    Details
    ISSN: 1615-6102
    Keywords: Microtubule-associated proteins ; Development ; Rat ; Quail ; Xenopus laevis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In the adult rat brain, MAP 2 is a high-molecular weight protein that is highly concentrated in dendrites. Immunoblots of homogenates of developing rat brain have indicated that a low-molecular weight form of MAP 2, MAP 2 c, is transiently expressed as the brain is undergoing morphogenesis. Using MAP 2-specific monoclonal antibodies, we have demonstrated that the compartmentalization of high-molecular weight MAP 2 and the developmental regulation of MAP 2 are conserved in mammalian, avian, and amphibian brain. We have also determined the distribution of MAP 2 c in developing neuronal tissue. MAP 2 c appears before high-molecular weight MAP 2 in developing neurons, and in contrast to the dendrite-specific high-molecular weight forms of MAP 2, MAP 2 c is present in axons and glia. We have also shown that MAP 2 c is present in the adult rat retina, where it is concentrated in regenerative photosensitive cells. The transient expression of MAP 2 c in the developing brain of three species as well as in adult photosensitive cells suggests a role for this protein in neurite growth and plasticity.
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    URL: http://dx.doi.org/10.1007/BF01349359
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    Sequential scanning electron microscopy of a growing plant meristem (1988)
    Springer
    Protoplasma 147 (1988), S. 77-79 
    Details
    ISSN: 1615-6102
    Keywords: Cell patterns ; Graptopetalum ; Nondestructive ; Replica ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A two-step replica technique has been developed for sequential study of the epidermal cell pattern of a living plant by scanning electron microscopy. This method is nondestructive, allows periodic high resolution observation of the same developing tissue, and can precede use of any destructive technique, such as transmission electron microscopy. The replicas can be trimmed allowing observation of occluded surfaces, such as the areas between leaves, which are inaccessible in continuousin vivo studies. Here we study the developing leaf primordium ofGraptopetalum and discuss potential uses of the technique.
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    URL: http://dx.doi.org/10.1007/BF01403879
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    Effects of Ga3 and Ca2+ on barley aleurone protoplasts: a freeze-fracture study (1988)
    Springer
    Protoplasma 146 (1988), S. 157-165 
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    ISSN: 1615-6102
    Keywords: Calcium ; Endomembrane system ; Enzyme secretion ; Freeze fracture ; Gibberellic acid ; Protoplasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Freeze-fracture electron microscopy was used to study changes in the endomembrane system of barley (Hordeum vulgare L. cv. Himalaya) aleurone protoplasts. Protoplasts were used for this study because their response to calcium and the plant hormone gibberellic acid (Ga3) can be monitored prior to rapid freezing of cells for electron microscopy. Protoplasts incubated in Ga3 plus Ca2+ secrete elevated levels of a-amylase relative to cells incubated in Ga3 or Ca2+ alone. The endoplasmic reticulum (ER) and Golgi apparatus of protoplasts incubated in Ga3 plus Ca2+ undergo changes that are well correlated with the synthesis and secretion of a-amylase. The ER, which appears as short, single sheets of membrane in Ca2+-and Ga3-treated protoplasts, exists as a series of long fenestrated stacks of membranes following incubation in Ga3 plus Ca2+. The Golgi apparatus is also more highly developed in protoplasts treated with Ga3 plus Ca2+. This organelle is larger and has more vesicles associated with its periphery in protoplasts that actively secrete a-amylase. Evidence that the Golgi apparatus participates in a-amylase secretion is also provided by experiments with the ionophore monensin, which causes pronounced swelling of Golgi cisternae and inhibits the secretion of a-amylase. We interpret these observations as showing that the ER and Golgi apparatus of barley aleurone participate in the intracellular transport and secretion of a-amylase. The plasmalemma (PF face) of barley aleurone protoplasts shows a high density of intramembranous particles (IMPs) which, in general, are evenly distributed. Occasionally, ordered arrays of IMPs are observed, possibly resulting fro m osmotic stress. after 48 hours the plasmalemma of some Ga3-treated protoplasts show particle-free areas considered to be indications of senescence.
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    URL: http://dx.doi.org/10.1007/BF01405925
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    Isolation of DNA from epithelial cells of the inner surface of the cheek (1988)
    Springer
    Bulletin of experimental biology and medicine 105 (1988), S. 84-85 
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    ISSN: 1573-8221
    Keywords: DNA ; genetic mapping ; polymorphism of length of restriction fragments ; buccal epithelium ; man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1007/BF00835466
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    Developmental changes of plasma alkaline phosphatase, calcium, and inorganic phosphorus in relation to the growth of bones in the Japanese macaque (Macaca fuscata) (1988)
    Springer
    Primates 29 (1988), S. 395-404 
    Details
    ISSN: 0032-8332
    Keywords: ALP ; Ca ; P ; Development ; Japanese macaque
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The plasma levels of alkaline phosphatase (ALP), calcium, and inorganic phosphorus in the Japanese macaque were measured during its growing period. The plasma ALP level within two days after birth was 818±186 IU/1, and the level showed a temporary peak at about 2 months of age (2747±763 IU/1). The ALP level formed a plateau from 1 to 3 years of age, then decreased again and reached finally an adult level (211±71 IU/1). Sex differences were observed twice during the animal's lifetime, from 6 to 9 months of age and from 3 to 7 years of age. On integration of this complicated curve, a correlation was observed with the development of the length of the bones. The plasma levels of calcium and inorganic phosphorus which were high within two days after birth, reached adult levels at 3 months and 5 years of age, respectively.
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    Development of tool use in a macaque and a gorilla (1988)
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    Primates 29 (1988), S. 413-416 
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    ISSN: 0032-8332
    Keywords: Tool use ; Sensorimotor intelligence ; Development ; Japanese macaque ; Gorilla
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The development of the capacity to use a stick as a tool was tested in a macaque (Macaca fuscata) and a gorilla (Gorilla gorilla gorilla) infants that had previously shown to be able to use strings and supports as dragging tools. Subjects were tested between 15 and 38 months of age. Different levels of competence between the subjects emerged over testing. The macaque developed a stereotyped strategy to cope with the problem, only getting random successes, whilst the gorilla developed a flexible strategy and revealed to be able to mentally represent the solution of the problem. In fact, when not successful using the stick, the gorilla thought out an alternative strategy, choosing and adapting a new object to use it as a tool.
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    Intrinsic variability in the frequency of embryonic diapauses of the annual fish Nothobranchius korthausae, regulated by light:dark cycle and temperature (1988)
    Springer
    Environmental biology of fishes 22 (1988), S. 211-224 
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    ISSN: 1573-5133
    Keywords: Development ; Environmental factors ; Parental influence ; Survival strategy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The influence of the light:dark cycle and temperature on the embryonic development, especially diapause, of the annual fish Nothobranchius korthausae was investigated. The variability of the frequency of diapause II during constant L:D cycle and temperature, but at different times of the year, was also studied. In agreement with previous studies it appeared that diapause I does practically not occur in N. korthausae (and other Nothobranchius species), even under sub-optimal conditions which are known to induce diapause II and III. Only at very low temperatures, a first developmental arrest could be induced during the dispersed phase, as well as during the reaggregation phase. Diapause II and III can be induced more easily, by exposing the embryos to low (sub-optimal) temperatures and short light periods (or constant darkness). Both diapauses are inhibited or terminated at high temperature and long light periods (12L:12D). The occurrence of an indirect light:dark response via the adult fishes could not be demonstrated. At moderate temperatures and in constant darkness (or short light periods) considerable variability in diapause II-frequency was observed. This could be an intrinsic feature of annual fish development, constituting a strategy for better survival of the species.
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    The need for conservation and management of Philippine coral reefs (1988)
    Springer
    Environmental biology of fishes 23 (1988), S. 141-154 
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    ISSN: 1573-5133
    Keywords: Cyanide ; Diversity ; Development ; Ecology ; Environment ; Fisheries ; Pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The biological diversity and productivity of Philippine coral reefs are threatened by siltation, destructive fishing methods, coral and shell collecting and overfishing. Destructive fishing includes: the widespread, illegal use of explosives; poisons such as sodium cyanide; muro-ami and kayakas fishing; and trawling. The recent decline in catch rates threatens the livelihood of 700 000 near-shore subsistence fishermen who catch 55% of the total landings. The new government under Corazon Aquino wishes to protect the marine environment through the creation of a viable marine conservation management plan, enforcement of existing laws and through cooperation between government, non-government and international agencies to provide education and research. The Department of Agriculture, which has the authority for fisheries, has designated the International Marinelife Alliance as the lead non-government agency involved with fund raising, net-training and finding alternatives to destructive fishing methods.
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    URL: http://dx.doi.org/10.1007/BF00000745
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    Detection of high concentration of Mg and Ca in the nematocysts of various cnidarians (1987)
    Springer
    Cellular and molecular life sciences 43 (1987), S. 1022-1025 
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    ISSN: 1420-9071
    Keywords: Calcium ; magnesium ; nematocysts ; Hydra ; Cnidaria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An X-ray spectral analysis (EDAX) of isolated undischarged nematocysts of various cnidarians (Hydrozoa, Scyphozoa, Anthozoa) revealed the presence of extremely high concentrations of divalent cations. InHydra nematocysts both Ca2+ (conc. 0.36 μmole/mg dry cysts) and Mg2+ (conc. 0.80 μmole/mg dry cysts) ions add up to a total in situ concentration of 0.5 to 1.0 M. More than 85% of the cations, which are believed to be involved in cyst discharge, are contained in the soluble fraction of the cysts, where they must be bound to high molecular weight molecules.
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    Differential colonization of Azospirillum lipoferum on roots of two varieties of rice (Oryza sativa L.) (1987)
    Springer
    Biology and fertility of soils 4 (1987), S. 3-7 
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    ISSN: 1432-0789
    Keywords: Azospirillum lipoferum ; Mucigel ; Oryza sativa ; Root colonization ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Seedlings of rice (IR42 and IR50) were aseptically dipped into Azospirillum lipoferum strain 34H suspension under dark, and the presence of bacteria on the differentiating regions of rice roots was observed by scanning electron microscopy. The bacterium did not colonize the root tips of IR42, while it colonized this region in the case of IR50, within 24 h after inoculation. In the early stages, most of the bacteria were embedded in the ruptured mucigel below the root cap cells of IR42. Mucigel was hardly detectable in IR50. While the root hair primordia of IR50 were colonized heavily with the bacterium within 24 h, the root hairs of IR42 were colonized 48 and 72 h after inoculation. This phenomenon in relation to plant varietal differences was discussed.
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    Organization and unusual expression of histone genes in the sea starPisaster ochraceus (1987)
    Springer
    Journal of molecular evolution 25 (1987), S. 29-36 
    Details
    ISSN: 1432-1432
    Keywords: Histone genes ; Echinoderms ; Maternal mRNA ; Development ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The organization and maternal expression of histone genes differ greatly between the two echinoderm classes represented by the sea stars and sea urchins. We have isolated and characterized a 5.3-kb genomic DNA fragment encoding core histone genes in the sea starPisaster ochraceus. The majority of histone genes are organized as tandem repeats of the 5.3-kb fragment, which is present in as many as 700 copies per haploid genome. The identity, precise location, and transcriptional polarity of individual core histone genes within the repeat were determined by DNA sequence analyses. The gene order in the sea star (H2B, H2A, H4, H3) is different from that in sea urchins (H2B, H3, H2A, H4). What is remarkable is the low level of maternal histone mRNA inP. ochraceus eggs relative to that in sea urchins. This observation supports a recent suggestion that major changes in mode of gene expression, rather than in gene organization or copy number, can be correlated with major events in echinoderm evolution.
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    Präparation und Kristallstrukturanalyse von Ca(N3)2(C5H5N)2 (1987)
    Springer
    Monatshefte für Chemie 118 (1987), S. 567-572 
    Details
    ISSN: 1434-4475
    Keywords: Azide ; Calcium ; Crystal structure ; Pyridine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Diazido-dipyridine-calcium was prepared by the reaction of Ca(N3)2 with pyridine. The crystals are tetragonal, space group I $$\bar 4$$ 2 m (121),N=2,a=699.7 (1),c=1 450.6 (5) pm. The crystal structure was determined by single crystal X-ray diffraction, 415 independent observed Mo-Kα-counter reflexions,R=0.049. The calcium atoms are sixcoordinated to four nitrogen atoms of azide groups and to two nitrogen atoms of pyridine. The coordination polyhedra are tetragonal bipyramids which are linked together by four azide groups to form sheets of composition Ca(N3)2. The pyridine rings are directed perpendicular to the sheets.
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    Catecholamines induce metamorphosis in the hydrozoan Halocordyle disticha but not in Hydractinia echinata (1987)
    Springer
    Development genes and evolution 196 (1987), S. 381-384 
    Details
    ISSN: 1432-041X
    Keywords: Metamorphosis ; Catecholamines ; Development ; Neurotransmitters ; Hydrozoa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Planula larvae of the marine hydroids Halocordyle disticha and Hydractinia echinata were treated with the catecholamines epinephrine, norepinephrine and dopamine, as well as with certain of their precursors and agonists. Norepinephrine, l-dopa, dopamine and the dopamine agonist ADTN at concentrations ranging from 0.1 to 0.001 mM induced metamorphosis within 24 h in Halocordyle disticha, with no observable morphogenetic abnormalities. Epinephrine, the adrenergic agonists phenylephrine, isoproterenol and methoxyamine, and the catecholamine precursors phenylalanine and tyrosine were found not to induce metamorphosis at the concentrations employed. None of the compounds was effective in inducing metamorphosis in Hydractinia echinata. A model is presented for neural control of metamorphosis in Halocordyle disticha
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    Net-building behaviour, tolerance and development of two caddisfly species from the river Rhine (Hydropsyche contubernalis and H. pellucidula) in relation to the oxygen content (1987)
    Springer
    Oecologia 73 (1987), S. 242-250 
    Details
    ISSN: 1432-1939
    Keywords: Net-building behaviour ; Development ; O2-deficiency tolerance ; Hydropsyche ; River Rhine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Tolerance, growth and development of H. contubernalis and H. pellucidula were analyzed at different O2-concentrations to determine the species specific potency amplitude in relation to O2-concentration. In addition netbouilding behaviour was compared at different O2-concentrations and current velocities. Under anaerobic conditions slightly greater tolerance was observed in H. contubernalis than in H. pellucidula. But at a higher O2-concentration H. contubernalis showed a distinctly higher O2-deficiency tolerance than H. pellucidula in relation to net-building activity, growth and development. In addition, more than 50% of H. contubernalis instars built capture nets with regular meshes at an O2-saturation of only 30% (15°C). High growth rates were also found at 50% O2-saturation and more than half the larvae developed into imagos. In addition to diminished net-spinning activity the mean growth rate started to decrease at an O2-saturation of 70% to 38% and the development into an imago was not possible in H. pellucidula. Because H. contubernalis corresponds to a regulative type, being able to maintain a high level of netbuilding activity, growth rate and development over a wide range (50% to 100% O2-saturation). On the other hand H. pellucidula corresponds to a conform type, because physiological efficiency decreases rapidly with falling O2-concentration, so that development into an imago is no longer possible below 85% O2-saturation. Positive correlation between net-spinning activity and tested current velocity between 10 cm/s and 25 cm/s (15°C) was found in H. pellucidula. H. contubernalis showed no change in net-building activity, over this range of current velocity. H. contubernalis can be classified as an euryoecious species with a great potency amplitude in relation to O2-concentration and current velocity. The high tolerance to O2-deficiency conditions probably allowed the early recolonization of the Mittel-and Niederrhein when a distinct O2-deficit (mean 29%, max 56%) could still be measured. H. contubernalis can be considered a bioindicator of O2-deficiency situations. Undisturbed development of H. pellucidula in this section of the river requires a further improvement in O2-content.
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    The calcium requirement for functional vesicle development and nitrogen fixation by Frankia strains EAN1pec and CpI1 (1987)
    Springer
    Archives of microbiology 149 (1987), S. 24-29 
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    ISSN: 1432-072X
    Keywords: Frankia ; Nitrogen fixation ; Calcium ; Vesicle development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A calcium requirement was shown for both vesicle development and nitrogenase activity by Frankia strains EAN1pec and CpI1. Washing cells with EGTA or EDTA inhibited both vesicle development and nitrogenase activity. The inhibition of both was reversed by the addition of calcium. A variety of agents known to affect calcium-dependent biological processes, such as a Ca-ATPase inhibitor, Ca-channel blockers, Ca-ionophores, calmodulin antagonists and the local anaesthetics, tetracaine and dibucaine, inhibited nitrogenase activity. Respiratory studies showed that a CN-insensitive respiration process occurred only under nitrogen derepressing conditions. Respiration by NH4Cl-grown cells was completely inhibited by KCN while N2-grown cells were inhibited by only 70%. Removal of calcium ions by EGTA or by the addition of dibucaine or tetracaine blocked the CN-insensitive respiration. This CN-insensitive respiration may be involved in protecting nitrogenase inside the vesicles from oxygen.
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    Redistribution of potassium, chloride and calcium during the gravitropically induced movement of Mimosa pudica pulvinus (1987)
    Springer
    Planta 170 (1987), S. 242-248 
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    ISSN: 1432-2048
    Keywords: Calcium ; Chloride ; Gravitropism ; Ion migration ; Mimosa ; Potassium ; Pulvinus ; Seismonasty
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract When the leaves of Mimosa pudica are changed from their normal position in the gravitational field, they perform reversible compensatory movements by means of pulvini. These movements are not the result of growth processes but involve reversible turgor variations. These variation are concomitant with ion migrations within pulvini: during the gravitropic movement, K+ and Cl- shift towards the adaxial half of the motor organ whereas Ca2+ shifts towards the abaxial half. Compounds known to affect K+ transport, tetraethylammonium chloride and valinomycin, do not hinder the gravitropic movement but inhibit strongly the seismonastic reaction. The same general result is obtained with compounds affecting anion transport, disulfonic stilbenes and 9-anthracene carboxylic acid. Calcium chelators inhibit the gravitropic movement more efficiently than the seismonastic reaction and the calcium ionophore A 23 187 increases both movements. The data obtained with these various compounds indicate that ions do not have the same functional importance in the regulation of the two different pulvinar movements.
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    Seed development and vivipary in Zea mays L. (1987)
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    Planta 171 (1987), S. 358-364 
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    ISSN: 1432-2048
    Keywords: Abscisic acid ; Development ; Seeds ; Vivipary ; Zea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Seed development was investigated in kernels of developing wild-type and viviparous (vp-1) Zea mays L. Embryos and endosperm of wild-type kernels began to dehydrate at approx. 35 d after pollination (DAP); viviparous embryos did not desiccate but accumulated fresh weight via coleoptile growth in the caryopses. Concentrations of endogenous abscisic acid (ABA) in the embryo were relatively high early in development, being approx. 150 ng·g-1 fresh weight at 20 DAP. The ABA content declined thereafter, falling to approx. 50 ng·g-1 at 30 DAP. Endosperm ABA content was always low, being less than 20 ng·g-1. There were no differences between wild-type and vp-1 tissues. Immature kernels did not germinate when removed from the ear until late in development. The ability to germinate was correlated with decreasing moisture content in the endosperm at the time of removal; premature drying of immature kernels resulted in greatly increased germination following imbibition. Excised embryos germinated precociously when removed from the endosperm as early as 25 DAP. Such germination could be prevented by treatment with 10-5 M ABA or by lowering the solute potential (Ψs) of the medium with 0.3 M mannitol. Treatment of excised embryos with ABA led to internal ABA concentrations comparable to those in embryos in which germination was inhibited in situ. Mannitol treatment did not have this effect, although water-deficit stress of excised embryos resulted in substantial ABA production. Germinated vp-1 embryos were less sensitive to growth inhibition by ABA or mannitol than germinating wild-type embryos. The vp-1 seedlings were not wilty and their transpiration rates were reduced in response to ABA or water shortage.
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    Scanning electron microscopy of the muscle coat of the guinea-pig small intestine (1987)
    Springer
    Cell & tissue research 250 (1987), S. 551-561 
    Details
    ISSN: 1432-0878
    Keywords: Small intestine ; Smooth muscle cells ; Enteric plexuses ; Interstitial cells of Cajal ; Scanning electron microscopy ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary We have studied the layers of the muscular coat of the guinea-pig small intestine after enzymatic and chemical removal of extracellular connective tissue. The cells of the longitudinal muscle layer are wider, have rougher surfaces, more finger-like processes and more complex terminations, but fewer intercellular junctions than cells in the circular muscle layer. A special layer of wide, flat cells with a dense innervation exists at the inner margin of the circular muscle layer, facing the submucosa. The ganglia of the myenteric and submucosal plexuses are covered by a smooth basal lamina, a delicate feltwork of collagen fibrils, and innumerable connective tissue cells. The neuronal and glial cell processes at the surface of ganglia form an interlocking mosaic, which is loosely packed in newborn and young animals, but becomes tightly packed in adults. The arrangement of glial cells becomes progressively looser along finer nerve bundles. Single varicose nerve fibres are rarely exposed, but multiaxonal bundles are common. Fibroblast-like cells of characteristic shape and orientation are found in the serosa; around nerve ganglia; in the intermuscular connective tissue layer and in the circular muscle, where they bridge nerve bundles and muscle cells; at the submucosal face of the special, flattened inner circular muscle layer; and in the submucosa. Some of these fibroblast like cells correspond to interstitial cells of Cajal. Other structures readily visualized by scanning electron microscopy are blood and lymphatic vessels and their periendothelial cells. The relationship of cellular elements to connective tissue was studied with three different preparative procedures: (1) freeze-cracked specimens of intact, undigested intestine; (2) ‘stretch preparations’ of longitudinal muscle with adhering myenteric plexus; (3) sheets of submucosal collagen bundles from which all cellular elements had been removed by prolonged detergent extraction.
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    Embryonic somatic nerve destruction with β-bungarotoxin (1987)
    Springer
    Cell & tissue research 247 (1987), S. 41-50 
    Details
    ISSN: 1432-0878
    Keywords: β-Bungarotoxin ; Peripheral nerve ; Development ; Regeneration ; Rat embryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects and time course of a single injection of β-bungarotoxin into E14 rat embryos were examined with an electron-microscopic study of development of the internal intercostal somatic nerve. Within 24 h of injection, axons in this nerve became swollen and fused at points along their length. By 48 h after injection no component of the nerve remained in distal segments of ribcage; complete loss of axons and components of the nerve sheath from proximal regions took slightly longer. At later times, no trace of peripheral nerve axons, Schwann cells or elements of the nerve sheath remained. β-Bungarotoxin applied on E17 destroyed developing axons in a similar manner, but the perineurium remained in place, and axons regenerated within the original nerve trunk. The study confirms that sensory and motor neurons are much less able to survive axon degeneration on E14 than after the major period of normal cell death (which is nearly over by E18), and that the maintenance and continued development of the perineurium during E14–E16 depends on the presence of peripheral nerve axons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00216545
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    The morphology of the lung of the African lungfish, Protopterus aethiopicus (1987)
    Springer
    Cell & tissue research 250 (1987), S. 191-196 
    Details
    ISSN: 1432-0878
    Keywords: Lung ; Scanning electron microscopy ; Pneumocyte ; Fish ; Dipnoi ; African lungfish (Protopterus aethiopicus)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The lung of the African lungfish (Protopterus aethiopicus) is paired, long and cylindrical. It is situated on the dorsal aspect of the coelomic cavity ventral to the ribs. Much of the gas exchange tissue is found in the proximal aspect of the lung with the caudal part largely taken up by a centrally situated air-duct with a few large peripherally located alveoli. Interalveolar septa, arranged at differing hierarchical levels from the air-duct, subdivide the lung into alveoli, the gas exchange compartments. The alveolar surface is covered by some cells characterized by microvilli on their free surface, while others are devoid of such structures. The general organization of the lung of Protopterus aethiopicus is similar to that of the other genera of Dipnoi, Neoceratodus and Lepidosiren, with the interalveolar septa increasing the surface area for gas exchange through pulmonary compartmentation. The abundant septal smooth muscle fibres and elastic tissue may contribute to the physiomechanical compliance of the lung. The undifferentiated alveolar pneumocytes and the double capillary system, observed in Protopterus, in general appear to characterize the very primitive lungs of the lower air-breathing vertebrates.
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    URL: http://dx.doi.org/10.1007/BF00214671
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    Development of the nervous system of the pluteus larva of Strongylocentrotus droebachiensis (1987)
    Springer
    Cell & tissue research 248 (1987), S. 335-343 
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    ISSN: 1432-0878
    Keywords: Pluteus ; Nervous system ; Development ; Neurotransmitter ; Strongylocentrotus droebachiensis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Development of the nervous system of the pluteus larva of Strongylocentrotus droebachiensis was investigated using indirect immunofluorescence with antibodies against dopamine, GABA, and serotonin, and glyoxylic acid-induced fluorescence of catecholamines. Serotonergic cells first appear in full gastrulae; dopaminergic and GABAergic cells are present in early four-arm plutei. The number of neurons and the complexity of the nervous system increases through development of the pluteus. In the pluteus the dopaminergic component of the nervous system includes a ganglion in the lower lip of the mouth and a pair of ganglia at the base of the post-oral arms which extend axons along the base of the circumoral ciliary band. The distribution of cells visualized by glyoxylic acid-induced fluorescence is similar to that of dopaminergic cells. GABAergic neurons occur in the upper lip and in the wall of the esophagus. Serotonergic neurons are present in the lower lip; the pre-oral hood contains an apical ganglion which extends axons along the base of the epidermis overlying the blastocoel. The dopaminergic and GABAergic components of the nervous system are associated with effectors involved in feeding and swimming. The serotonergic component is not associated with any apparent effectors but may have a role in metamorphosis.
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    URL: http://dx.doi.org/10.1007/BF00218200
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    Arterial supply of the choriocapillaris of anuran amphibians (Rana temporaria, Rana esculenta) (1987)
    Springer
    Cell & tissue research 249 (1987), S. 101-109 
    Details
    ISSN: 1432-0878
    Keywords: Eye ; Choriocapillaris ; Angioarchitecture ; Scanning electron microscopy ; Vascular microcorrosion casts ; Rana temporaria ; Rana esculenta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pattern of the vascular supply to the choroid of the frog eye was studied in toto with the use of the injection-replication-SEM technique. The choroid of anuran amphibians is composed mainly of the choriocapillaris. In both species studied (Rana temporaria, Rana esculenta), an independent arterial supply to the choriocapillaris supplemented that from the ciliary arteries. This additional vascular route arises from the optic artery, a separate branch of the arteria infundibularis superficialis. The optic artery, accompanied by its vein within the vascular sheath of the optic nerve, joins the rich arterial capillary network of the choriocapillaris and supplies the posterior pole of the ocular bulb. The superficial capillary network displays a dense collar around the entrance of the optic nerve into the eye and is composed of a circular meshwork of small capillaries, several layers deep. More peripherally, however, it becomes single layered. This capillary network, as a whole, establishes numerous connections with the adjacent choriocapillaris at the posterior pole of the ocular bulb. In anuran amphibians the complex arrangement of both arterial systems supporting the choriocapillaris may be regarded as a more complete equivalent of the short posterior ciliary arteries of mammals.
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    URL: http://dx.doi.org/10.1007/BF00215423
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    The superficial vascular hyaloid system in the eye of the frogs, Rana temporaria and Rana esculenta (1987)
    Springer
    Cell & tissue research 250 (1987), S. 465-473 
    Details
    ISSN: 1432-0878
    Keywords: Eye ; Angioarchitecture ; Hyaloid ; Scanning electron microscopy ; Vascular microcorrosion casts ; Rana temporaria, Rana esculenta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The angioarchitecture of the superficial vascular hyaloid system (membrana vasculosa retinae) of the frog eye was studied by means of scanning electron microscopy of vascular corrosion casts. The terminal vessels form a single-layered sheath intimately adjacent to the vitreal side of the avascular retina. The hyaloid system is subdivided by the ventral venous trunk into three central areas: the dorsal, the temporo-ventral, and the naso-ventral area. Toward the ora serrata, the hyaloid system is bordered by an arterial ring, and by nasal and temporal venous branches forming more or less complete hemicircles. A vascular zone composed of several tongue-like sectors establishes an inter-connection between the peripheral vascular rings and the central areas of the fundus. The arterial blood is supplied from the arterial ring. The drainage of the hyaloid system is provided via two routes: (1) the Y-shaped ventral trunk collects blood from the central areas, (2) the two peripheral venous branches drain the tongue-like sectors. The vessels within the dorsal area follow preferentially a dorso-ventral meridional direction. This densely capillarized territory corresponds in localization to the area centralis retinae. The ultrastructure of microvessels of the hyaloid system is characterized by features typical for capillaries of the central nervous system.
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    URL: http://dx.doi.org/10.1007/BF00219093
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    Thyroxine accelerates the differentiation of granular convoluted tubule cells and the appearance of epidermal growth factor in the submandibular gland of the neonatal mouse (1987)
    Springer
    Cell & tissue research 248 (1987), S. 351-358 
    Details
    ISSN: 1432-0878
    Keywords: Submandibular gland (mice) ; Granular convoluted tubule ; Development ; Thyroid hormone ; Epidermal growth factor ; Immunocytochemistry and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of the administration of thyroxine (T4) on the postnatal cytodifferentiation of granular convoluted tubule (GCT) cells of the submandibular gland (SMG) of Lewiss-Webster mice were studied by light and electron microscopy. From birth, mice of both sexes were injected daily with T4 (sc 0.4 μg/g BW) and were sacrificed 24 h after the last injection at 7, 9, 11, 14 and 21 days of age. Control mice received vehicle only. In control mice, granulated striated duct (SD) cells were first detected at 9 days and 7 days of age by light- and electron microscopy, respectively. Furthermore, a few scattered granulated SD cells were observed by light microscopy as early as day 7 in T4-treated mice of both sexes. At 21 days of age, in mice given T4, GCT cells were larger and more numerous and the Golgi apparatus, rough endoplasmic reticulum, and secretion granules were more abundant. In control mice, immunocytochemical staining for epidermal growth factor-(EGF) was first detectable at day 21 at the light- and electron-microscopic levels. However, positively stained cells were first observed in T4-treated mice by light- and electron-microscopic immunocytochemistry at 14 and 11 days of age, respectively. Moreover, in the 21-day-old T4-treated mice, the number of immunoreactive GCT cells, as well as the intensity of the staining per cell, was markedly increased as compared to controls. EGF immunostaining was restricted to GCT cells, and by immuno-electron-microscopy was only seen in apical secretory granules in granulated SD cells and GCT cells. There were no sex differences in the differentiation of the duct system under any conditions. It is concluded that T4 stimulates the biosynthesis of EGF by an acceleration of the differentiation of the GCT precursor cells to mature cells.
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    URL: http://dx.doi.org/10.1007/BF00218202
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    Three-dimensional organization of lymphatics and its relationship to blood vessels in rat small intestine (1987)
    Springer
    Cell & tissue research 248 (1987), S. 365-374 
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    ISSN: 1432-0878
    Keywords: Lymphatic vessels ; Small intestine ; Corrosion cast ; Scanning electron microscopy ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The lymphatic organization and its relationship to the vascular system in the rat small intestine was studied by scanning electron microscopy of corrosion casts and freeze-fractured tissues, and by light microscopy of injected preparations. The villus possessed 3–10 or more central lacteals depending upon the villous width. The lacteals in each villus possessed interconnections between adjacent ones and were surrounded externally by the villous capillary network. At the villous base, the lacteals fused and formed a wide sinus, from which 2 or 3 lymphatics descended and led into the submucosal ones. In the muscularis externa there was a coarse lymphatic network which, together with the submucosal one, drained into collecting lymphatics continuous with the mesenteric ones. The central lacteals and the sinus were lined with thin endothelial cells with cytoplasmic leaves interdigitating with those of adjacent ones. There were tissue channels in the villous interstitial space, which opened through the gaps between the lymphatic endothelial cells into the central lacteals. The voluminous lacteals in the villi suggest their great potential for lymph formation. The existence of collecting lymphatics with valves in the muscularis externa suggests that contraction of the layer is involved in transporting lymph towards the efferent lymphatics.
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    URL: http://dx.doi.org/10.1007/BF00218204
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    The pineal organ is the first differentiated light receptor in the embryonic salmon, Salmo salar L. (1987)
    Springer
    Cell & tissue research 249 (1987), S. 641-646 
    Details
    ISSN: 1432-0878
    Keywords: Pineal organ ; Development ; Photoreceptors ; Retinal S-antigen ; α-Transducin ; Opsin ; Serotonin ; Immunocytochemistry ; Teleosts (Salmo salar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The initial appearance of S-antigen, α-transducin, opsin and 5-HT during embryogenesis of the pineal organ and retina was studied by means of immunocytochemistry in the Atlantic salmon, Salmo salar L. The presence of these substances may be taken as a good indication of photoreceptor differentiation; α-transducin and S-antigen are involved in the phototransduction process, opsin is the proteinaceous component of the photopigment rhodopsin, and 5-HT is a neurotransmitter or neurohormone produced by pineal photoreceptors. Two days after the retinal pigment layer became visible in the eggs, the outer segments of a few pineal photosensory cells showed immunoreactivity to opsin and α-transducin. At the same time S-antigen and serotonin were present in pineal cells of the photoreceptor type. The number of immunoreactive cells in the pineal organ increased up to hatching. In the differentiating retina of the salmon, no immunoreactivity to antibodies raised against the mentioned substances was detectable until after hatching. These results indicate that in ontogeny the developing pineal organ of the salmon embryo has the ability to perceive light information much earlier than the retina.
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    URL: http://dx.doi.org/10.1007/BF00217336
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    The dorso-lateral recess of the hypothalamic ventricle in neonatal rats (1987)
    Springer
    Cell & tissue research 250 (1987), S. 197-204 
    Details
    ISSN: 1432-0878
    Keywords: Third ventricle ; Intraventricular vessels ; Recess ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light and electron microscopy of the hypothalamic ventricle in neonatal rats demonstrate morphological specializations of the ventricular wall at the level of the premammillary region of the third ventricle. The morphological features are: (1) A ventricular recess that we have called the “hypothalamic dorso-lateral recess” (HDR). (2) The presence of intraventricular capillaries near the dorsolateral recess. (3) The HDR possessing a specialized ependymal lining; this consists of non-ciliated cells with short microvilli and bleb-like processes. (4) The existence of cerebrospinal fluid-contacting neurons within the HDR. (5) The presence of numerous phagocytic supraependymal cells. The HDR is not found in adult rats. This indicates that the dorso-lateral recess may play a physiological role during development.
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    URL: http://dx.doi.org/10.1007/BF00214672
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    An immunohistochemical study of adenohypophyseal cells containing follicle-stimulating hormone and luteinizing hormone during the phase of selective follicle-stimulating hormone release in postnatal female rats (1987)
    Springer
    Cell & tissue research 250 (1987), S. 689-693 
    Details
    ISSN: 1432-0878
    Keywords: Anterior pituitary gland ; FSH cells ; LH cells ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Serum concentration of follicle-stimulating hormone (FSH) in the juvenile female rat increases independently from that of luteinizing hormone (LH). The objective of this study was to determine whether this increase in serum FSH is accompanied by a proliferation of FSH-cells greater than the proliferation of LH-cells. Thus, we measured circulating FSH and LH in female rats on days 3, 10, 13, 17, and 20, calculated the percentages of adenohypophyseal cells that contained FSH or LH on days 3, 10, and 20, and determined whether cells containing only FSH existed on day 10. Serum FSH concentrations on days 10 and 13 were significantly greater than those on days 3, 17, or 20. No differences existed in serum LH concentrations. Cells containing FSH or LH were distributed throughout the entire adenohypophyses of 3, 10, and 20-day-old females. Clusters of these cells were observed in the ventral regions of adenohypophyses of 3-day-old females. The percentages of adenohypophyseal cells containing FSH increased significantly from ∼9% in 3-day-old rats to ∼17% in 10-day-old rats and then decreased to ∼14% in 20-day-old animals. At all ages the percentages of adenohypophyseal cells containing FSH were similar to the percentages of cells containing LH. At 10 days of age, all cells containing FSH also contained LH and all cells containing LH also contained FSH. These data suggest that the increase in serum FSH in the juvenile female rat is associated with an increase in the percentage of adenohypophyseal cells containing FSH and that at this time all cells containing FSH also contain LH.
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    URL: http://dx.doi.org/10.1007/BF00218964
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    X-ray microanalysis of the mineral components in the scales of an amoeba, Cochliopodium sp. (Testacea) (1987)
    Springer
    Cell & tissue research 247 (1987), S. 633-637 
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    ISSN: 1432-0878
    Keywords: Scale ; Amoeba ; Mineral component ; Calcium ; X-ray microanalysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Mineral components of the scales in an amoeba, Cochliopodium sp., were examined by energy-dispersive X-ray microanalysis. The precipitates in potassium antimonate-treated material detected calcium in the scales. Calcium was also clearly detected in freeze-substituted thin sections. Similar deposits of calcium antimonate were detected in scales in formation within vacuoles, and also in Golgi cisternae, Golgi vesicles and special granules near the nucleus. There were only minute amounts of magnesium and potassium. This suggests that calcium is the main mineral component of the scales and that it is added in the Golgi complex during scale formation.
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    URL: http://dx.doi.org/10.1007/BF00215758
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    Immunohistochemical localization of laminin, neural cell adhesion molecule, collagen type IV and T-61 antigen in the embryonic retina of the Japanese quail by in vivo injection of antibodies (1987)
    Springer
    Cell & tissue research 249 (1987), S. 487-496 
    Details
    ISSN: 1432-0878
    Keywords: Retina ; Development ; Antigen detection ; Axonal pathfinding ; Retinal matrix ; Cell surface molecules ; Coturnix coturnix japonica
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Antibodies against laminin (LN), fibronectin (FN), collagen type IV (Col IV), neural cell adhesion molecule (N-CAM), T-61 antigen, actin, tubulin and neurofilament protein were injected into the eyes of quail embryos (Coturnix coturnix japonica) of different ages. Twenty h after injection, the heads of the embryos were fixed and the antibodies visualized in sections with the use of fluorescein-isothiocyanate (FITC) or peroxidase-labeled second antibodies by light- and electron microscopy. Antibodies against cell surface molecules, such as N-CAM, LN, Col IV and T 61, labeled matrix and membrane components of the retinal cells in different antigen-specific patterns. Antibodies against intracellular antigens, such as actin, tubulin and neurofilament protein labeled nonspecifically the vitreous body and the inner basal lamina of the retina, but resulted in only a very weak and diffuse labeling of retinal cells. N-CAM was detected in high concentration in the optic fiber layer on the surface of axons and on the membranes of all retinal cells. Col IV, LN and T 61 antigen were found predominantly in the optic fiber layer. LN and Col IV were located on the surface of axons and the endfeet of ventricular (neuroepithelial) cells in a patchy distribution. The T-61 antigen was found in early stages in the cell-free space of the optic fiber layer, on the surface of ventricular cells and axons, and at later stages also in high-density patches between nerve fibers. The distribution of LN and T-61 antigen together with data from in vitro experiments suggests a crucial role of these proteins in axon extension in the avian retina during early development of the optic fiber layer.
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    URL: http://dx.doi.org/10.1007/BF00217320
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    Microvasculature of the pineal organ of the rainbow trout (Salmo gairdneri) (1987)
    Springer
    Cell & tissue research 250 (1987), S. 425-429 
    Details
    ISSN: 1432-0878
    Keywords: Pineal organ ; Angioarchitecture (capillaries,arteries, veins) ; Corrosion-cast preparation method ; Scanning electron microscopy ; Salmo gairdneri
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The angioarchitecture of the pineal organ of the rainbow trout (Salmo gairdneri) was investigated by means of the corrosion-cast preparation method and scanning electron microscopy. Two main arteries (aa. epiphyseales) supply the pineal parenchyma. They emerge from the aa. cerebri anteriores and run in the fissure between the prosencephalon and the mesencephalon. After entering the pineal stalk, the aa. epiphyseales branch off into several arterioles, most of which extend to the pineal end-vesicle where they give rise to a lobular, bilaterally symmetric capillary network. Capillaries establishing the main portion of the pineal vessels appear widened in comparison to those supplying other portions of the brain and resemble capillaries in other endocrine organs. In Salmo gairdneri, no specialized system of portal vessels appears to exist between the pineal organ and other portions of the brain.
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    URL: http://dx.doi.org/10.1007/BF00219087
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    High -resolution scanning electron-microscopic studies on the three-dimensional structure of mitochondria and sarcoplasmic reticulum in the different twitch muscle fibers of the frog (1987)
    Springer
    Cell & tissue research 250 (1987), S. 489-497 
    Details
    ISSN: 1432-0878
    Keywords: Muscle cells ; Mitochondria ; Sarcoplasmic reticulum ; Scanning electron microscopy ; Frog (Rana n. nigromaculata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The three-dimensional structure of the mitochondria and sarcoplasmic reticulum (SR) in the three types of twitch fibers, i.e., the red, white and intermediate skeletal muscle fibers, of the vastus lateralis muscle of the Japanese meadow frog (Rana nigromaculata nigromaculata Hallowell) was examined by high resolution scanning electron microscopy, after removal of the cytoplasmic matrices. The small red fibers have numerous mitochondrial columns of large diameter, while the large white fibers have a small number of mitochondrial columns of small diameter. In the medium-size intermediate fibers, the number and diameter of the mitochondrial columns are intermediate between those of the red and white fibers. In all three types of fibers, the terminal cisternae and transverse tubules form triads at the level of each Z-line. The thick terminal cisternae continue into much thinner flat intermediate cisternae, through a transitional part where a row of tiny indentations can be observed. Numerous slender longitudinal tubules originating from the intermediate cisternae, extend longitudinally or obliquely and form elongated oval networks of various sizes in front of the A-band, then fuse to form the H-band collar (fenestrated collar) around the myofibrils. On the surface of the H-band collar, small fenestrations as well as tiny hollows are seen. The three-dimensional structure of SR is basically the same in all three muscle fiber-types. However, the SR is sparse on the surface of mitochondria, so the mitochondria-rich red fiber has a smaller total volume of SR than the mitochondria-poor white fiber. The volume of SR of the intermediate fiber is intermediate between other the two.
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    URL: http://dx.doi.org/10.1007/BF00218939
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    Peptide stimulation of phagocytosis in Amoeba proteus (1987)
    Springer
    Cell & tissue research 250 (1987), S. 589-593 
    Details
    ISSN: 1432-0878
    Keywords: Phagocytosis ; Chemotactic peptides ; Calcium ; Amoeba proteus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The tripeptide n-formylmethionylleucylphenylalanine (NFMLP) at low levels (10−9 M) localized in a glass micropipette elicits a positive chemotactic response in Amoeba proteus. Peptide in solution at higher concentrations (10−5 M) stimulates food vacuole formation. Vacuoles induced by NFMLP result from the fusion of pseudopods which, in turn, entrap a portion of the external medium. Food vacuole formation stimulated by NFMLP is dependent on the concentration of calcium in the external medium. The binding of NFMLP to the amoeba surface may bring about a movement of calcium into the cell which can be inhibited with calcium-channel blockers.
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    URL: http://dx.doi.org/10.1007/BF00218951
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    Scanning electron microscopy of vascular architecture in the gastric mucosa of the golden hamster (1987)
    Springer
    Cell & tissue research 250 (1987), S. 287-293 
    Details
    ISSN: 1432-0878
    Keywords: Stomach ; Corrosion cast ; Scanning electron microscopy ; Vascular architecture ; Hamster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The three-dimensional architectures and the regional differences of the vascular system in the mucosa of the hamster stomach were revealed by scanning electron microscopy of corrosion casts. In the forestomach, the vascular network spreads two-dimensionally in a thin lamina propria. In the corpus and the antrum, the capillaries in the thick lamina propria are well developed, extending three-dimensionally along the gastric pits and glands. In the corpus, the submucosal arteries enter the lamina propria to become ascending capillaries, which project toward the top of the lamina propria and anastomose to create a capillary network beneath the mucosal epithelium. A subepithelial capillary is much wider in diameter than an ascending capillary and is, therefore, a sinusoid capillary. Subepithelial capillaries join descending venules, which are less numerous than the ascending capillaries. Near the gastric lumen, the capillaries in the corpus can be classified into two types: arched type in the cephalic (upper) region and honeycomb type in the caudal (lower) region. In the antrum, the submucosal arterial plexus is less well developed than that in the corpus. The mucosal aspect of the corrosion cast shows many clumps, formed by a unit of capillary network. Functional significances of different vascular architectures in the gastric mucosa of the forestomach, corpus, and antrum are discussed.
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    URL: http://dx.doi.org/10.1007/BF00219073
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    Preliminary observations on the formation of the male germ unit inCatananche caerulea L. (Compositae: Lactuceae) (1987)
    Springer
    Protoplasma 138 (1987), S. 187-189 
    Details
    ISSN: 1615-6102
    Keywords: Catananche caerulea ; Compositae: Lactuceae ; Freezefracture and cytoplasmic maceration ; Male germ unit ; Scanning electron microscopy ; Sperm cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have used the freeze fracture and cytoplasmic maceration technique to study microsporogenesis inCatananche caerulea L. and here we present preliminary observations of the male germ unit (MGU)in situ. The technique has the advantage of enabling the complex structure of the MGU to be seen in a single fracture plane whereas previously this was only possible by the reconstruction of transmission electron micrographs of serial thin sections. The arrangement of the two generative cells and the vegetative nucleus closely resembles that described from other species includingPlumbago zeylanica.
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    URL: http://dx.doi.org/10.1007/BF01281028
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    Morphology and development of rhabdovirus-like particles inCuscuta odorata (Convolvulaceae) simultaneous infected with virus and mycoplasma-like organisms (1987)
    Springer
    Protoplasma 139 (1987), S. 130-140 
    Details
    ISSN: 1615-6102
    Keywords: Cytopathology ; Rhabdovirus ; Development ; Electron microscopy ; Cuscuta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Electron microscopic examination ofCuscuta odorata, used for transmission trials, revealed mycoplasma-like organisms (MLO) as well as rhabdovirus-like particles, unknown toCuscuta. The virus infection is confined to certain phloem-parenchyma cells and a 1–2 cell thick layer of parenchyma cells with thickened walls surrounding the central cylinder. Virus particles, mostly bacilliform, could be detected mainly in the nucleus but also in the cytoplasm. They reach a length of 350–400 nm and a diameter of approximately 75 nm. Virus assembly takes place exclusively in the nucleus. Virus maturation occurs in membrane bound areas within the nucleus, which have no connection with the perinuclear space. Formation of nucleocapsids is always associated with a nuclear viroplasm. Envelopment of virus particles occurs in these membrane bound areas. Budding into the perinuclear space does not occur. Virus infection leads to degeneration and finally to death of the protoplast.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01282283
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    Turgor regulation and cytoplasmic free Ca2+ in the algaLamprothamnium (1987)
    Springer
    Protoplasma 140 (1987), S. 67-71 
    Details
    ISSN: 1615-6102
    Keywords: Aequorin ; Calcium ; Characeae ; Lamprothamnium ; Turgor regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In internodal cells ofLamprothamnium succinctum, turgor regulation in response to hypotonie treatment is inhibited by lowering external Ca2+ concentration ([Ca2+]e) from 3.9 (normal) to 0.01 (low) mM. In order to clarify whether a change in the cytoplasmic free Ca2+ concentration ([Ca2+]c) is involved in turgor regulation, the Ca2+ sensitive protein aequorin was injected into the cytoplasm of internodal cells. A large transient light emission was observed upon hypotonic treatment under normal [Ca2+]e but not under low [Ca2+]e. Thus hypotonic treatment induces a transient increase in [Ca2+]c under normal [Ca2+]e but not under low [Ca2+]e.
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    URL: http://dx.doi.org/10.1007/BF01273256
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    The effect of Ca2+ antagonists on trichocyst release inParamecium tetraurelia (1987)
    Springer
    Protoplasma 140 (1987), S. 92-99 
    Details
    ISSN: 1615-6102
    Keywords: Calcium ; Dantrolene-Na ; Excoytosis ; Nifedipine ; Paramecium ; Trichocyst ; Trifluoperazine ; Verapamil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ca2+ dependent exocytosis inParamecium involves the release of numerous secretory organelles known as “trichocysts”. According toGarofalo et al. (1983) trichocysts pass through three stages of condensed (tmxI), partially expanded (stage II) before release, and fully expanded (stage III) or released trichocysts. We have therefore investigated the effect of two widely used Ca2+ channel blockers, verapamil and nifedipine and the muscular relaxant, dantrolene-Na, on the process of trichocyst release. Verapamil and nifedipine inhibited secretion in a dose dependent manner, but dantrolene-Na and the solvent, PEG-400, did not abolish it. Electron microscopic study of preincubatedParamecium cells in verapamil resulted in the appearance of tmxI, whereas untreated controls remained in partially expanded stage II. Pretreatment of isolated membrane free trichocysts with verapamil did not inhibit matrix expansion in the presence of increasing Ca2+ concentration. In a separate experiment, cells were pretreated with verapamil and the anti calmodulin compound, trifluoperazine. The cells were then induced to release their secretory contents by picric acid-Ca2+ treatment. Electron microscopic examination of cells captured by quick fixation with osmium tetroxide revealed that verapamil treated cells manifested the inhibition of membrane fusion, whereas in TFP treated cells there was no sign of a traceable exocytotic opening formation after membrane fusion. Based on present results we propose a role for calmodulin in the formation of exocytotic openings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01273717
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  • 96
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    An ultrastructural study of the viscin tissue ofPhthirusa pyrifolia (H.B.K.) Eichler (Loranthaceae) (1987)
    Springer
    Protoplasma 137 (1987), S. 145-155 
    Details
    ISSN: 1615-6102
    Keywords: Mistletoe fruit ; Phthirusa pyrifolia ; Ultrastructure ; Development ; Viscin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The viscin tissue ofPhthirusa pyrifolia consists at maturity of two different cell types. The first of these (viscin cells) are greatly elongated and have massive secondary walls, the microfibrils of which are arranged strictly transversely, and are soaked with mucilaginous noncellulosic polysaccharides. The second type of cells (vesicular cells) is much broader, with a very extensive vacuolar system and thin primary cell walls only. Viscin cells are capable of being stretched very greatly, the microfibrils of the secondary wall then becoming oriented more or less longitudinally. In nature, this corresponds to the time of attachement to the host surface, and is followed by drying and, possibly, shortening of the viscin cells. Developmental study of the tissue suggests that Golgi bodies are the major organelles participating in polysaccharide production. The actual mucilage seems to originate from three sources: an unorganized substance which accumulates between the plasmalemma and compound middle lamella; spherical vacuoles which seem to be embedded in the central vacuole, some of which are seen open to the outside of the cell; and from the dissolution at maturity of the compound middle lamella. It is suggested that the two types of cells may correspond to the two major functions of viscin, viz., host attachment (viscin cells) and nutrition of the disseminator (vesicular cells).
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    URL: http://dx.doi.org/10.1007/BF01281150
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  • 97
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    Endophyte differentiation inCasuarina actinorhizae (1987)
    Springer
    Protoplasma 136 (1987), S. 104-117 
    Details
    ISSN: 1615-6102
    Keywords: Actinomycete ; Casuarina ; Development ; Frankia ; Root ; nodules ; Symbiosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This is an ultrastructural study of development of infected cells in nitrogen fixing root nodules ofCasuarina spp. While several aspects of development are similar to those found in many other actinorhizae, unusual aspects of development of the host cell and differentiation of the endophyte inCasuarina are correlated with unusual changes in the wall of the infected cell. Instead of vesicles the endophyte forms atypical hyphae in mature infected cells. These unusual hyphal forms are termed intracellular hyphae. Intracellular hyphae are nonseptate hyphae which originate and terminate within the same host cell, and have a varying diameter and a multidirectional growth and branching pattern. A laminate surface layer previously undescribed on hyphae ofFrankia is a feature common to mostCasuarina endophytic hyphae and is probably similar chemically to the laminae comprising the multilamellate envelope of endophytic vesicles in other actinorhizae.
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    URL: http://dx.doi.org/10.1007/BF01276359
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  • 98
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    Local ion currents controlling the localized cytoplasmic movement associated with feeding initiation ofNoctiluca (1987)
    Springer
    Protoplasma 137 (1987), S. 125-133 
    Details
    ISSN: 1615-6102
    Keywords: Calcium ; Cytoplasmic movement ; Feeding behavior ; Ion current ; Noctiluca ; Vibrating probe
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We used an extracellular vibrating probe to investigate local transmembrane ion currents that occur just before and during localized cytoplasmic movement associated with feeding initiation in the marine dinoflagellateNoctiluca, Our results indicates that the currents flow only through a specialized cellular region, the sulcus, suggesting a heterogeneous distribution of an ion channel in the cell membrane. A current enters into the middle of the sulcus where the cytostome exists and leaves from both ends of the sulcus. The mean inward and outward current densities were approx. + 11 and — 1 μA·cm−2, respectively. The cytoplasm began to stream toward the cytostome in association with the currents and then aggregated around it. Removal of Ca2+, Na+, or Mg2+ ions from the external medium diminished the inward current. Ca2+ ions were proved to carry only 5% of the inward current. The Ca2+ current appears to be enough to raise Ca2+ concentration in a localized region of the cytoplasm, causing the cytostome-directed cytoplasmic movement. Rest of the current seems to be carried by Na+ ions. Most of the outward current was inhibited by an ion pump inhibitor, but the current-carrying ion species could not be identified.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01281147
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  • 99
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    Analysis of labeling of plant protoplast surface by fluorophore-conjugated lectins (1987)
    Springer
    Protoplasma 141 (1987), S. 33-46 
    Details
    ISSN: 1615-6102
    Keywords: Calcium ; Cell wall-degrading enzymes ; Lectin binding ; Plasma membrane ; Protoplasts ; Ricinus communis agglutinin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Fluorescein or rhodamine conjugates of seventeen different lectins were tested for their ability to label the plasma membrane of live plant protoplasts. During the investigation, a strong effect of calcium was observed on the binding of several lectins to protoplasts derived from suspension cultured rose cells (Rosa sp. “Paul's Scarlet”). The binding of these lectins was increased by elevating the calcium concentration from 1 to 10 mM in the buffer. Other divalent cations had variable, but similar, effects on lectin binding. The mechanism of this effect appeared to involve the protoplast surface rather than the lectins. Although the cell wall-degrading enzymes used to isolate protoplasts had generally no effect on lectin binding, one clear exception was observed. Binding ofArachis hypogaea agglutinin was markedly reduced on protoplasts isolated with Driselase as compared to protoplasts isolated with a combination of Cellulysin and Pectolyase Y-23. Although most of the lectins that labeled protoplasts derived from cultured rose cells or from corn root cortex (Zea mays L. WF9 × Mo17) had specificities for galactose or N-acetylgalactosamine, some differences in protoplast labeling between lectins of the same saccharide specificity were observed. Two different analyses of the interaction betweenRicinus communis agglutinin and rose protoplasts showed that binding was cooperative with an apparent association constant of 7.2 × 105M−1 or 9.8 × 105M−1 with a maximum of approximately 108 lectin molecules bound per protoplast. Treatment of protoplasts with glycosidases which hydrolyze either N- or O-glycosidic linkages of glycoproteins slightly enhanced labeling of protoplasts byRicinus communis agglutinin. Interpretation of these results are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01276786
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  • 100
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    Growth and development in relation to the cell cycle inPhysarum polycephalum (1987)
    Springer
    Protoplasma 141 (1987), S. 101-111 
    Details
    ISSN: 1615-6102
    Keywords: Cell cycle ; Development ; Physarum ; Slime mould
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In strain CL ofPhysarum polycephalum, multinucleate, haploid plasmodia form within clones of uninucleate, haploid amoebae. Analysis of plasmodium development, using time-lapse cinematography, shows that binucleate cells arise from uninucleate cells, by mitosis without cytokinesis. Either one or both daughter cells, from an apparently normal amoebal division, can enter an extended cell cycle (28.7 hours compared to the 11.8 hours for vegetative amoebae) that ends in the formation of a binucleate cell. This long cycle is accompanied by extra growth; cells that become binucleate are twice as big as amoebae at the time of mitosis. Nuclear size also increases during the extended cell cycle: flow cytometric analysis indicates that this is not associated with an increase over the haploid DNA content. During the extended cell cycle uninucleate cells lose the ability to transform into flagellated cells and also become irreversibly committed to plasmodium development. It is shown that commitment occurs a maximum of 13.5 hours before binucleate cell formation and that loss of ability to flagellate precedes commitment by 3–5 hours. Plasmodia develop from binucleate cells by cell fusions and synchronous mitoses without cytokinesis.
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    URL: http://dx.doi.org/10.1007/BF01272891
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