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  • Animals  (443)
  • Ultrastructure  (51)
  • Kinetics  (48)
  • Pregnancy  (30)
  • American Association for the Advancement of Science (AAAS)  (462)
  • Springer  (61)
  • 1980-1984  (523)
  • 1925-1929
  • 1982  (523)
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  • American Association for the Advancement of Science (AAAS)  (462)
  • Springer  (61)
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  • 1
    Electronic Resource
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    Colloid & polymer science 260 (1982), S. 641-642 
    ISSN: 1435-1536
    Keywords: Kinetics ; Nucleation ; Water ; Emulsion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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  • 2
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    Monatshefte für Chemie 113 (1982), S. 1087-1092 
    ISSN: 1434-4475
    Keywords: Dissolution ; Kinetics ; Pyrrhotite ; Rotating disc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Auflösungsgeschwindigkeit von natürlichem monoklinen Pyrrhotin, FeS1.14, wurde in sauerstofffreien LösungenS([H+]=0.1, [Na+]=0.9, [ClO 4 − ]=1.0 mol kg−1) mit Hilfe der Methode der rotierenden Scheibe bestimmt. Im Temperaturbereich von 40–90° erfolgt die Auflösungsreaktion kinetisch kontrolliert, wobei eine Aktivierungsenergie von 14±1 kcal mol−1 (59±5 kJ mol−1) gefunden wurde.
    Notes: Abstract Using the rotating disc method, the rates of dissolution of natural monoclinic pyrrhotite, FeS1.14, in oxygen-free aqueous solutionsS([H+]=0.1, [Na+]=0.9, [ClO 4 − ]=1.0 mol kg−1) were determined. In the temperature range 40–90 °C the dissolution reaction occurs under kinetic control; the activation energy being 14±1 kcal mol−1 (50±5 kJ mol−1).
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  • 3
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    Monatshefte für Chemie 113 (1982), S. 1239-1244 
    ISSN: 1434-4475
    Keywords: Allyl alcohol ; Kinetics ; Mechanism ; Oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Kinetik der Oxidation von Allylalkohol mitN-Bromsuccinimid (NBS) wurde bei 35 °C in wäßrigem Medium untersucht. Die Reaktion zeigt erste Ordnung gegenüberNBS und Allylalkohol. Bei relativ hoher Säurekonzentration zeigt sich keine Änderung der Reaktionsgeschwindigkeit, bei niedriger Säurekonzentration wird die Reaktionsgeschwindigkeit beträchtlich erhöht. Es wurde kein primärer Salzeffekt festgestellt. Bei varriierender Quecksilberacetatkonzentration bleibt die Reaktionsgeschwindigkeit gleich, bei Abwesenheit von Quecksilberacetat wird jedoch die Geschwindigkeitskonstante erhöht. Die kinetischen Parameter,E a, derArrheniusfaktorA, ΔH ≠, ΔG ≠ und ΔS ≠ wurden bestimmt. Ein Geschwindigkeitsgesetz in Übereinstimmung mit den experimentellen Befunden wurde abgeleitet und ein Mechanismus vorgeschlagen.
    Notes: Abstract The kinetics of oxidation of allyl alcohol byN-bromosuccinimide (NBS) has been studied at 35 °C in aqueous medium. The reaction shows first order dependence on bothNBS and allyl alcohol. In fairly high acid concentration, there is no change in the rate of the reaction but at low acid concentration, the rate is considerably enhanced. There is no primary salt effect. At varying mercuric acetate concentrations, the rate constant remains the same. But in the absence of mercuric acetate, the rate is enhanced. The kinetic parameters,E a,Arrhenius factorA, ΔH≠, ΔG≠ and ΔS≠ have been calculated. A rate law in agreement with experimental results has been derived. A mechanism is proposed.
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  • 4
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    Monatshefte für Chemie 113 (1982), S. 887-893 
    ISSN: 1434-4475
    Keywords: Diazotation ; Kinetics ; α-Naphthylamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Optimal diazotation conditions were determined by means of extinction measurements at various experimental conditions. The optimal conditions found arep H=9,5, the amount of phenol is 1 250 times the amount of α-naphthylamine.
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  • 5
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    Monatshefte für Chemie 113 (1982), S. 3-14 
    ISSN: 1434-4475
    Keywords: Graphite ; Kinetics ; Reduction ; Thoria ; Thoriumcarbide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Reduktion von Thoriumoxid mit Graphit im Überschuß wurde mittels einer Thermowaage zwischen 1620 und 1920 K im Vakuum untersucht. Ab ThO2:C=1:50 war die Reaktionsgeschwindigkeit vom Mischungsverhältnis unabhängig; das Endprodukt war immer ThC2. Der logarithmische Gewichtsverlust war direkt proportional der Zeit, und dieArrheniusgerade zeigte einen Knickpunkt bei 1710 K: unterhalb dieser Temperatur ergab sich eine Aktivierungsenergie von 440 kJ, oberhalb eine solche von 260 kJ. Die Temperatur des Knickpunkts entspricht der Umwandlungstemperatur von monoklinem in tetragonal raumzentriertes ThC2.
    Notes: Abstract The reduction of thoria with excess graphite was studied with a thermo-balance in vacuum between 1620 and 1920 K. From Th02:C=1:50 the rate of reaction was independent of the ratio of the reactants; the endproduct was always ThC2. The logarithmic weight loss was directly proportional to the time, and theArrhenius plot showed a break at 1710 K: below this temperature the activation energy was found to be 440 kJ, above 260 kJ. The temperature corresponding to the break coincides with the transition temperature of monoclinic to body-centered tetragonal ThC2.
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  • 6
    ISSN: 1434-4475
    Keywords: Kinetics ; Ligand-transfer ; Thallium (III)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The transfer of oxinate ions from thallium (III)oxinate to trivalent Fe(DMF) 6 3+ in propylenecarbonate takes place via rearrangements within a rapidly formed binuclear thallium(III)—iron(III) complex. In a last rapid step this rearranged complex reacts with excess reactants to the final products whose composition accordingly depends on the ratio of the reactant concentrations.
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  • 7
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    Calcified tissue international 34 (1982), S. 273-279 
    ISSN: 1432-0827
    Keywords: Odontogenesis ; Ultrastructure ; Alkaline phosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The ultrastructural localization and gradient of activity of alkaline phosphatase were studied with respect to cell differentiation, matrix synthesis, and matrix mineralization in the incisor and molar teeth of 4-day-old Sprague-Dawley rats. The animals were perfused intracardially at room temperature with 2.5% glutaraldehyde in 0.1M sodium cacodylate (pH 7.4) with 3–4% sucrose. The jaws were dissected, immersion-fixed for 24 h, and the incisor and molar tooth germs removed. These were demineralized in 10% EDTA in NaOH (pH 7.4) with 7% sucrose. After reactivation of the enzyme with 0.1M MgCl in Tris-maleate buffer (pH 7.4) at 4°C, the teeth were incubated for alkaline phosphatase in a medium consisting of 6 ml 3% sodiumβ-glycerophosphate, 4 ml 0.2M Tris-HCl buffer (pH 9.2), 3 ml 1.6% MgSO4, 12 ml 0.5% lead citrate (pH⋍12), and 2.1 g sucrose. The pH was adjusted to 9.2 with 0.2M HCl, the volume made up to 30 ml, and the solution centrifuged for 10 min at 5000 rpm. Control teeth were incubated in medium minus the substrate. Finally, the specimens were routinely post-fixed and embedded for sectioning and examination with a Philips 300 electron microscope. A gradient of alkaline phosphatase activity was mapped along the developing teeth in the cells of the stratum intermedium, the proximal borders of the ameloblasts, the early dentine matrix, the predentine-dentine border, matrix vesicles, and the plasma membranes of odontoblasts and subodontoblast cells. The gradient of alkaline phosphatase activity was evident in the forming tooth from the cervical loop to the crown apex and was related to the cellular events, matrix synthesis, and matrix mineralization occurring during odontogenesis.
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  • 8
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    Calcified tissue international 34 (1982), S. 9-12 
    ISSN: 1432-0827
    Keywords: Parathyroid hormone ; Pregnancy ; Nephrogenous cAMP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Parathyroid hormone (PTH) metabolism in pregnancy has not been clearly defined. Studies have reported either increased or unchanged values of immunoreactive PTH (iPTH). However, iPTH levels do not necessarily correlate with hormonal bioactivity due to the presence of immunoreactive but nonbioactive PTH fragments. In this study we evaluated PTH metabolism in the third trimester of pregnancy by determining iPTH blood levels as well as the biological effects of PTH, assessed by tubular maximum phosphate reabsorption (TmP) and nephrogenous cAMP (ncAMP) excretion, in 10 young, healthy pregnant patients (mean gestational age 35 weeks) and 10 young, healthy age-matched female controls. Pregnancy was associated with a significant increase in creatinine clearance (146±13 vs 106±9 ml/min,P〈0.01), and a significant decrease in total fasting serum calcium (8.4±0.1 vs 9.0±0.1 mg/dl,P〈0.001) and serum albumin (3.6±0.1 vs 4.2±0.1 g/dl,P〈0.001). There was no significant difference in iPTH (3.7±0.4 vs 4.3±0.5 µlEq/ml), serum phosphorus (3.6±0.1 vs 3.8±0.2 mg/dl), TmP (3.61±0.13 vs 3.75±0.25 mg/100 ml GFR), or ncAMP (1.68±0.20 vs 1.88±0.23 nmoles/100 ml GFR) between the two groups. Pregnancy was attended by a significant increase in fasting urinary calcium to creatinine ratio (0.14±0.03 vs 0.06±0.01,P〈0.05), an index of bone resorption. The data suggest that the biological effects of PTH are unchanged in pregnancy, and that reported increments in 1,25(OH)2 vitamin D in pregnancy are not regulated by changes in either PTH, calcium, or phosphate.
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  • 9
    ISSN: 1432-0827
    Keywords: Vitamin D ; Vitamin D deficiency ; Bone ; Pregnancy ; Lactation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The effect of vitamin D on bone changes during the reproductive cycle in female rats has been investigated. One group of female rats was maintained on a vitamin D-deficient diet and another group on a vitamin D-replete diet from weaning. Both groups were mated with normal males and changes in their bones were determined histomorphometrically during pregnancy, lactation, and after weaning. All vitamin D-deficient rats had bone changes typical of rickets. Pregnancy caused significant reductions in mineralized tissue of trabecular and cortical bone in the vitamin D-deficient rats. Lactation caused further significant reductions in mineralized tissues of cortical and trabecular bone in both the vitamin D-deficient and vitamin D-replete animals, with the greatest changes seen at weaning. Some restoration of mineralized tissues occurred following weaning. There was an increase in tetracycline-labeled bone surface in the vitamin D-replete animals during lactation, likely due to an increase in bone formation rates. In the vitamin D-deficient animals during lactation, there was a decrease in tetracyclinelabeled bone surface, likely due to severely depressed bone mineralization. These results indicate that the mobilization of calcium from bone to maintain pregnancy and lactation occurs by a mechanism independent of vitamin D.
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  • 10
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    Calcified tissue international 34 (1982), S. 382-390 
    ISSN: 1432-0827
    Keywords: Avian osteopetrosis ; Avian oncornavirus ; Ultrastructure ; Calcification ; Bone cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Diaphyseal tibial bone of 12.5 – 13-day and 19-day-old embryos and 20-day-old hatched chicks infected with retrovirus MAV.2-O were examined by transmission electron microscopy. The viruses were associated with lining osteoblasts and osteocytes. Whereas the infection of the osteoblast layer seemed to be a transient stage, virus association with osteocytes was a constant and main ultrastructural feature. The viruses were found either in the osteoid or in the periosteocytic space of the bone lacunae. They arose from dense cytoplasmic areas located near the cell plasmalemma via a budding process. The newly budded virus particles often had a large tail or a fine stalk-like process lost in the extracellular space. The viruses underwent calcification by deposition of inorganic material and were incorporated in the bone trabeculae. No production of virus was observed in typical osteoclasts with well-differentiated ruffled borders. The viral-induced avian osteopetrosis seemed to result from increased bone deposition through stimulation of osteoblast and osteocyte activities, whereas osteoclastic bone resorption seemed to be undisturbed.
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  • 11
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    Archives of microbiology 133 (1982), S. 11-19 
    ISSN: 1432-072X
    Keywords: Cyanobacteria ; Ultrastructure ; Mastigocladus laminosus ; Fischerella ; True branching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The morphology and ultrastructure of the thermophilic cyanobacteriumMastigocladus laminosus were examined by scanning and transmission electron microscopy. Mature cultures consisted of relatively old, wide filaments that branched frequently to form younger, thinner filaments. The cells of the younger filaments had a consistently cylindrical morphology, while those of older filaments were rounded and pleomorphic. The internal ultrastructure of the cells depended somewhat on their age. As young cells became larger and wider, their thylakoids underwent slight rearrangement and spread out toward the center of the cytoplasm. Polyphosphate bodies, carboxysomes (polyhedral bodies), and lipid-body-like structures increased in number as the cells aged, but ribosomes and cyanophycin granules were depleted. Cell division involved septum formation followed by ingrowth of the outer membrane and sheath. Cells in older filaments were separated from each other by a complete layer of sheath material. Septum formation in older cells was also seen to occur parallel to the long axis of the filament, thereby confirming that true branching took place.
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  • 12
    ISSN: 1615-6102
    Keywords: Anemia phyllitidis ; Chloroplast ; Gametophyte ; Metronidazole ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Metronidazole inhibits cell division in gametophytes of the fernAnemia phyllitidis without changing morphogenetic patterns. Simultaneously the sensitivity of the prothallia against gibberellins which substitute for the natural sexual pheromone “antheridiogen A”, is increased. The inhibition of cell division is accompanied by a loss of chlorophyll and by severe changes in the ultra-structure of the chloroplasts.
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  • 13
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    Protoplasma 113 (1982), S. 189-192 
    ISSN: 1615-6102
    Keywords: Brassica napus ; Membrane ; Nucleolus ; Nucleus ; Ultrastructure ; Vacuole
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Vacuole-like structures were found in the nuclei of root tip cells ofBrassica napus. The cells containing the unusual nuclear inclusions were found to be adjacent to zones of degenerating cells. Such groups of cells occurred irregularly in the meristematic regions of the young root tips. The possibility that they represent changes which have occurred in old seeds is discussed. The “vacuole-like” structures seen in the cells adjacent to the degenerating zones were bounded by a membranous layer 12 nm thick. This is thicker than most cellular membranes. The “vacuoles” frequently contained inclusions and showed similarities to protein bodies reported elsewhere. The structures are thought to represent rearrangements of cell products which may have accumulated through an imbalance of metabolism in consequence of the imminent cell degeneration.
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  • 14
    ISSN: 1615-6102
    Keywords: Aspergillus nidulans ; Aspergillus giganteus ; Hyphal apex ; Ultrastructure ; Woronin body
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The hyphal tip ultrastructure ofAspergillus nidulans andAspergillus giganteus indicates that their apical organization is very similar to that found in other filamentous fungi. Both species have an area immediately behind the hyphal apex free of all large organelles and containing a high concentration of vesicles. InA. giganteus only one size class of vesicle is clearly evident, with a mean diameter of 72 nm. InA. nidulans two size classes of vesicle were found, with mean diameters of 75 nm and 31 nm. A Spitzenkörper is evident inA. nidulans as an area very close to the tip containing only the smaller vesicles. InA. giganteus one or more apparently mature Woronin bodies were found within the first 1 μm of some hyphal apices. The possible significance of their presence is discussed.
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  • 15
    ISSN: 1615-6102
    Keywords: Meiosis ; Microtubules ; Polarity ; Ultrastructure ; Mosses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary An extensive system of microtubules develops during meiotic prophase in the mossRhynchostegium serrulatum (Hedw.)Jaeg. &Sauerb. Development of the cytoskeleton can be traced to early prophase when the nucleus is acentric and the single plastid divides into four plastids. The cytoskeletal microtubules are associated with equidistant positioning of the four plastids at the distal tetrad poles and with migration of the nucleus to a central position in the sporocyte. The cytoskeleton, which interconnects plastids and encloses the nucleus, contributes to the establishment of moss sporocyte polarity. Just prior to metaphase I evidence of the prophase cytoskeleton is lost as the bipolar metaphase I spindle develops in association with discrete polar organizers located in opposite cleavage furrows between plastids.
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  • 16
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    Protoplasma 113 (1982), S. 10-22 
    ISSN: 1615-6102
    Keywords: Diatom ; Motility ; Mucopolysaccharide ; Secretion ; Staining ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Generation of movement in benthic diatoms is thought to be intimately associated with secretion at the raphe, a slit in the silica cell wall. The presence and distribution of extracellular substances and their source was investigated cytochemically by transmission electron microscopy. Extracellular material, possibly-acid mucopolysaccharide, was observed consistently within the entire length of the raphe of both valves and also as a sheath enveloping the silica frustule. Such quantities of extracellular material are absent in conventionally fixed motile diatoms. Numerous cytoplasmic vesicles, with fibrillar contents, distributed peripherally but concentrated along the raphe and at the cell poles, react strongly with a polysaccharide specific stain; their distribution in the cell and polysaccharide content suggest these may be the source of raphe and sheath material. Results support the most recent theories on the mechanism of locomotion in outline only; the details cannot be clarified. Localization procedures using alcian blue and silver staining of peroxidised sections are discussed briefly.
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  • 17
    ISSN: 1615-6102
    Keywords: Fungi ; Gilbertella persicaria ; Membranes ; Mitochondria ; Organelle isolation ; Plasma membrane ; Ultrastructure ; Vacuoles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Methods are described for isolating and identifying subcellular membranes from walled hyphae ofGilbertella persicaria. Differences in thickness and symmetry of membranes and in contents of vesicles were used to distinguish different types of membranes. Mitochondria, vacuoles, plasma membrane, and vesicles with attached ribosomes from homogenized germlings equilibrated at the 1.2/1.4 M interface in discontinuous sucrose gradients. Accelerated flotation in centrifuged Ficol-sucrose gradients resulted in the additional separation of the mixed membranes into three fractions: one contained predominantly intact mitochondria, another was composed of vacuoles and vesicles coated with ribosomes, and a third was enriched in plasma membranes. Based upon morphometric analysis, these fractions contained 92% mitochondria, 53% vacuoles, and 89% plasma membranes, respectively. The source of vesicles coated with ribosomes was investigated since rapidly growing hyphae ofG. persicaria contained little rough endoplasmic reticulum as compared with other classes of membranes. Reconstruction from electron micrographs of mitochondrial fragmentation and vesiculation suggested that most of the ribosome-coated vesicles originated from disrupted mitochondria rather than from rough endoplasmic reticulum. The study demonstrates the utility of ultrastructural markers to identify membranesin vitro independent of, or as an adjunct to, cytochemical and biochemical markers.
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  • 18
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    Protoplasma 112 (1982), S. 26-36 
    ISSN: 1615-6102
    Keywords: Aneilema ; Commelina ; Cytochemistry ; Evolution ; Papillae ; Pollination ; Secretion ; Stigmas ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The stigmas of species inAneilema andCommelina are trifid and comprise elongate papillae. Progressive degeneration of papular cells is observed in stigmas from open flowers and at anthesis papillae may be moribund and collapsed. Fluid emanating from the hollow style flows onto the surface through ruptures in the cuticle at the interpapillar junctions into the interstices at maturity. This secretion stains positively for protein. Stigmas are of the “wet” type. The cuticle overlying the papillar cells is ridged and at the final stages prior to flowering this cuticle becomes detached from the underlying cellulosic wall. The sub-cuticular space so formed is filled with secretion. InAneilema species detachment of cuticle is at the papillar tip and along the lateral walls. InCommelina species the anticlinal walls of adjacent papillae are strongly attached for much of their length and thus detachment of cuticle is restricted to the papillar tip. The cell wall at the tip in both genera may proliferate forming a rudimentary transfer-cell type wall. The secretion is considered to be produced by the papillar cells. It is PAS positive but fails to stain for protein and in both the light and electron microscopes appears heterogenous. Pollen attachment, hydration, germination and early tube growth are very rapid following self-pollination, the pollen tubes entering the neck of the style within ten minutes of attachment. A unique character combination involving pollen and stigmas in these genera indicates a monophyletic origin.
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  • 19
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    Protoplasma 112 (1982), S. 81-91 
    ISSN: 1615-6102
    Keywords: Didymium iridis ; Microcyst-encystment ; Ultrastructure ; Differentiation ; Myxomycete
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Myxamoebae ofDidymium iridis were removed from the bacterial food source and induced to encyst by transfer to 10 mM phosphate buffer. After 24 hours of induction approximately 90% of the myxamoebae had differentiated into microcysts. The kinetics of encystment were not significantly affected by pH or osmolarity of the encystment medium. Early stages of encystment were distinguished by the appearance of autophagic vacuoles and an extracellular “slime-like” sheath. The outer wall layer, consisting of dense fibrils, was unevenly deposited after 4 hours. An electron-lucent, second wall layer appeared between 5–10 hours followed by a densely packed, third wall layer adjacent to the plasma membrane. Wall formation appeared to involve smooth-membraned vesicles of possible Golgi origin. The vesicle contents and outer wall layer reacted with the periodic acid-silver methenamine stain for polysaccharide. The density of intramembrane particles of the protoplasmic fracture face increased during encystment with a gradual formation of aggregates of particles.
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  • 20
    ISSN: 1615-6102
    Keywords: Discophrya ; Tentacle contraction ; Cations ; Calcium ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Discophrya collini is a suctorian protozoan with contractile tentacles containing a microtubule-lined canal and microfilaments. The effects of a range of cations on tentacle contraction and ultrastructure have been determined. Treatment with 80 mM CaCl2 and 95 mM MgCl2 causes contraction to 28% and 57% of the control length respectively. Re-extension takes over 4 hours in the culture medium, but CaCl2-treated tentacles are re-extended after a 5 minutes treatment with 10−2 M EDTA or 5 × 10−3 M EGTA. CuCl2 causes a significant contraction at 10−5 M (to 77%); LaCl3 at 10−4 M (to 65%); ZnCl2 at 10−2 M (to 65%), but BaCl2, CoCl2, MnCl2, NiCl2, and SrCl2 cause significant changes only at 10−1 M. The cytoplasm of CaCl2-treated cells contains two forms of membraneous structures when viewed in TEM; that of MgCl2-treated cells reveals granular areas of medium electron density. None of these features are seen in control cells. The microtubules of the tentacle canal appear to be intact upon its retraction into the cell with no change occurring in the numbers or relative positions of the microtubules. The tentacle cortex is wrinkled. It is suggested from this and previous work that tentacle contraction may be mediated by a microfilament-based mechanism, and that calcium may be involved.
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  • 21
    ISSN: 1615-6102
    Keywords: Fungus ; Zoospore ; Ultrastructure ; Membranes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Determining how the orientation and association among organelles are maintained within zoospores of theChytridiales is important to understanding the control of zoospore motility. Zoospores of the aquatic fungi,Chytriomyces aureus andC. hyalinus, contain microbody-lipid globule complexes with an elongate microbody adjacent to the portion of a lipid globule facing the cell's interior and a fenestrated cisterna (the rumposome) opposed to the surface of the lipid globule toward the plasma membrane. Mitochondria are intimately associated with the microbody. Electron microscopy of the microbody-lipid globule complex fixed in glutaraldehyde and osmium tetroxide, with or without tannic acid, reveals cross-linking bridges connecting the rumposome to the plasma membrane, to the microbody, and to microtubules of the rootlet extending from the kinetosome. It is concluded that these bridges are responsible, at least in part, for the consistent location of the microbody-lipid globule complex in the zoospore body. The possible role of the rumposome as a receptor organelle is discussed.
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  • 22
    ISSN: 1615-6102
    Keywords: Secretion ; Vesicles ; Ultrastructure ; Cultured cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Callus-derived suspension cultures of oats dramatically increase the viscosity of the culture media after one month in culture. Colorimetric assays for sugars and protein, as well as measurements of viscosity, suggest that the released material is a long-chain polysaccharide, probably a pectinaceous substance. These cells grow slowly in liquid culture, yet despite their low cell density, they are able to increase the viscosity of the media several fold within seven days after media transfer. Ultrastructural observations show that oat cells have features common to actively-secreting cells; especially evident are numerous dictyosomes with hypertrophied cisternae. Using a combination of filtering and centrifugation techniques we were able to recover large numbers of intact secretory vesicles. The interior of the vesicles stain with periodic acid-silver hexamine, and colormetric analysis of the vesicle pellet for total sugars confirms the presence of polysaccharides in this vesicle fraction. Because of the uniformity of these cells, the high rate of secretion, and the accessability of a large vesicle population, this culture system is'a useful model for studying the secretory process in plant cells.
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  • 23
    ISSN: 1573-5036
    Keywords: Ammonification ; Cadmium ; Heavy metals ; Kinetics ; Lead ; Nitrification ; Perfusion incubations ; Polluted soils ; Selection ; Toxicity ; Zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The sensitivity of the mineralization of nitrogen by a range of soils contaminated with heavy metals (up to 340 μg Cd g−1, 7500 μg Pb g−1 and 34000 μg Zn g−1) to the addition of heavy metals in solution were studied using pot incubations (ammonification) and a soil perfusion technique (nitrification). The ammonification of peptone showed little correlation between treatments with Cd, Zn (1000 and 5000 μg g−1) and Pb (10000 and 20000 μg g−1) and origin of the soil. Nitrification was considerably more sensitive to heavy metals than ammonification. All the soils had active, often large, populations of ammonifying and nitrifying organisms which showed substantial similarities between the soils. The rate of nitrifying activity (NO3−N production) was logrithmic in most cases. The presence of tolerant populations of nitrifying organisms in the contaminated soils was demonstrated. Tolerance was also eventually acquired after a longer lag phase, by the non-contaminated soil populations although the rate of activity was often reduced. Metals added in solution were adsorbed by the soil within 4 hours. Differences in toxicity between metal salts (chlorides, sulphates and acetate) were attributed to the amount left in solution. However, in many instances, acetate was found to stimulate all the stages in the mineralisation of nitrogen.
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  • 24
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    Cell & tissue research 225 (1982), S. 235-248 
    ISSN: 1432-0878
    Keywords: Rhinophore ; Larva ; Nudibranch ; Sensory cell ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The rhinophores of the veliger larva of Rostanga pulchra are located in the intravelar field near the base of the velar lobes. Each rhinophore is a cylindrical structure, tapering distally, and covered with a dense meshwork of microvilli. A conspicuous row of ciliary tufts runs along each side of the rhinophore and several stiffer tufts, composed of fewer cilia, are positioned around the tip or at the base. The rhinophoral epithelium consists of supporting cells, ciliated cells (giving rise to the ciliary rows), dendritic terminals (giving rise to the tufts around the apex), and sinuses containing occasional amebocytes. The lumen of the rhinophore is occupied by the rhinophoral ganglion and muscle cells that are oriented in two perpendicular planes. Cell bodies of the dendritic endings are located within the rhinophoral ganglion, which in turn joins into the optic and cerebral ganglia. Rhinophoral ganglionic neurons do not synapse with each other, but numerous neuromuscular synapses are found in the lumen of the rhinophore. Morphological evidence suggests that the dendritic endings are chemoreceptors and the ciliated cells are possibly mechanoreceptors but are not functional at this stage in development. The functional role of the rhinophores is discussed in relation to larval behavior at settlement and metamorphosis.
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  • 25
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    Cell & tissue research 226 (1982), S. 167-175 
    ISSN: 1432-0878
    Keywords: Pineal gland ; Ultrastructure ; Kangaroo rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the pinealocytes of the wild-captured ord kangaroo rat (Dipodomys ordi) was examined. A homogeneous population of pinealocytes was present in the pineal gland of the kangaroo rat. The Golgi apparatus, granular endoplasmic reticulum, mitochondria, lysosomes, dense-core vesicles, vacuoles containing a flocculent material and lipid droplets were consistent components of the pinealocyte cytoplasm, whereas infrequently-observed organelles included centrioles, multivesicular bodies, subsurface cisternae, “synaptic” ribbons and cilia. The number of dense-core vesicles was relatively high and dense-core vesicles and vacuoles containing a flocculent material were present in the same cell. Although it has been recently suggested that two different secretory processes, i.e., neurosecretory-like (Golgi apparatus — dense-core vesicles) and ependymal-like (granular endoplasmic reticulum — vacuoles containing a flocculent material) may be involved in different regulatory mechanisms in the pinealocytes, the definitive answer to this is still far from clear. Therefore, the pineal gland of the kangaroo rat appears to be a good model for the study of the potential relationship between these two secretory processes, especially in respect to seasonal changes.
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  • 26
    ISSN: 1432-0878
    Keywords: Sperm polymorphism ; Ultrastructure ; Mollusca ; Prosobranchia
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    Topics: Biology , Medicine
    Notes: Summary The prosobranch Fusitriton oregonensis exhibits an unusual form of sperm polymorphism. The viable, eupyrene sperm are attached in groups of about fifty to worm-shaped, apyrene, carrier sperm. There is a second apyrene sperm, which is lancet-shaped and has a different internal organization than the carrier, but does not transport eupyrene sperm. The eupyrene sperm are filiform (185 μm long), with a conical acrosome, elongate nucleus and midpiece. They contain large stores of glycogen in the principal piece, together with an unusually high proportion of protein. The latter is due to a complex interconnecting system of fibres that supports the tail internally. A distinct annulus is located, characteristically, at the junction between midpiece and principal piece. The carrier sperm has a core of about 112 axonemes that arise from basal bodies in the anterior end and extend through its entire length of 36 μm. The basal bodies have unstriated rootlets that are embedded in a granular cap. Large membrane-bound “yolk bodies” are arranged along the length of the carrier sperm, on either side of the median axonemal core. Dense bodies, which may be indigestible residues formed from the degeneration of the nucleus, are excreted by exocytosis. Individual carrier sperm are capable of “corkscrew” propulsion, resembling that of spirochaetes. The lancet sperm is three times as long as the carrier. The sixteen or so axonemes, which are arranged peripherally like a cage enclosing the cytoplasm, originate from a dense centriolar plate in the anterior end. The cytoplasm is filled with secretions including small yolk granules, dense bodies (also excreted), clear vesicles, and a membranated granular secretion that resembles mucus. The possible functions of the lancet and carrier sperm are discussed.
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  • 27
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    Cell & tissue research 227 (1982), S. 429-437 
    ISSN: 1432-0878
    Keywords: Smooth muscle ; Arteriole ; Three-dimension ; Ultrastructure ; Laboratory rodents
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    Topics: Biology , Medicine
    Notes: Summary Three-dimensional aspects of smooth muscle cells of the microvas-culature were studied ultrastructurally in laboratory rodents by means of serial thin sections and reconstruction of muscle cell models. It was demonstrated that a muscle cell of an arteriole (luminal diameter (LD) 17 μm) in hamster striated muscle was spindle-shaped, 70 μm long, and wound twice round the vessel axis. The volume of the cell was calculated as 750 μm3 and its surface area as 1330 μm2. A muscle cell in an arteriole (LD 6 μm) in the rat retina was irregular in shape, about 22 μm long, and had branched processes. The cell volume was calculated as 139 μm3 and its surface area as 298 μm2.
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    Cell & tissue research 222 (1982), S. 41-51 
    ISSN: 1432-0878
    Keywords: Ultrastructure ; Interstitial cell ; Myenteric plexus ; Colon ; Rabbit
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    Topics: Biology , Medicine
    Notes: Summary The interstitial cells associated with the myenteric plexus of the rabbit colon were studied by scanning and transmission electron microscopy. It was demonstrated that the interstitial cells were stellate or fusiform in shape and located over the ganglia, over nerve bundles and between muscle cells. They were characterized by many slender processes, and resemble fibroblasts. No basal lamina was observed between the interstitial cells and muscle cells. It was concluded that structural features of the interstitial cells are distinctly different from those of neurons, Schwann cells, or of smooth muscle cells, while they show clear similarities to those of fibroblasts. By scanning electron microscopy the shapes and the relations of these cells could be demonstrated in great detail.
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  • 29
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    Cell & tissue research 222 (1982), S. 359-378 
    ISSN: 1432-0878
    Keywords: Axon terminals ; Substantia gelatinosa ; Spinal cord ; Noradrenaline ; Ultrastructure ; Rat
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    Notes: Summary The noradrenergic terminals in the substantia gelatinosa of the dorsal horn of the cervical spinal cord of the rat were investigated by means of the histofluorescence technique and electron-microscopic cytochemistry using the glyoxylic acid-KMnO4 fixation technique. In accordance with the topographical distribution of fluorescent catecholaminergic fibers, noradrenergic terminals containing small granular vesicles were frequently observed electron microscopically in the outer layer of the substantia gelatinosa. These terminals were most frequently found to appose without showing typical synaptic features, small-caliber dendrites, spine apparatus, and rarely, large caliber dendrites. Only in a few cases, the noradrenergic terminals exhibited typical synaptic contacts with dendritic elements of small size. In addition, noradrenergic terminals apposed non-noradrenergic terminals containing small agranular vesicles. In rats bearing surgical lesions of the dorsal roots, no noradrenergic terminal were found in contact with the degenerated axon terminals in the substantia gelatinosa. These findings suggest that the noradrenergic afferents to the substantia gelatinosa may exert their influence on sensory transmission via dorsal horn cells.
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  • 30
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    Cell & tissue research 222 (1982), S. 695-698 
    ISSN: 1432-0878
    Keywords: Pineal gland ; Ultrastructure ; Dense-core vesicles ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dense-core vesicles, 90–200 nm in diameter, were found in pinealocytes of the cat. They were present both in perikarya and cell processes.
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  • 31
    ISSN: 1432-0878
    Keywords: Immunoelectron microscopy ; Preoptic nucleus ; Goldfish ; Magnocellular neuroendocrine cells ; Ultrastructure
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    Topics: Biology , Medicine
    Notes: Summary We describe the ultrastructural localization of isotocin, vasotocin and neurophysin in the magnocellular preoptic nucleus of the goldfish. With the aid of immunocytochemical techniques, we see staining both in classical neurosecretory granules and in diffuse agranular form throughout somata and processes. Signs of cellular and synaptic interactions between chemically identified neurons include axon terminals which contain vasotocin immunoreactivity and membrane specializations (puncta adhaerentia) between adjacent somata. Our investigations provide an anatomical basis for neuroendocrine and neurotransmitter-like functions of peptidergic neurons in the teleost preoptic nucleus.
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  • 32
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    Cell & tissue research 224 (1982), S. 195-206 
    ISSN: 1432-0878
    Keywords: Pinealocytes ; Nucleolus ; Rat ; Ultrastructure ; Twenty-four-hour changes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An ultrastructural and morphometric analysis was made of the nucleolar components in pinealocytes of 40 male Fischer rats sampled at eight times in an LD 12∶12 photoperiod cycle. Comparisons of results from the eight times showed variation in estimated mean volume of the granular component of ±29%, and of the fibrillar component ±11%, in relation to daily means. Peaks in mean volume of total nucleolus and its granular component occurred at 1 h of light. Near maximal and minimal mean volumes of the fibrillar component both occurred during both light and dark. Fibrillar centers (nucleolar organizer regions) of different sizes were found at all sampling times. It is concluded that temporal patterns in 24-h changes in the nucleolar components are most prominent in the granular component, and are more complex than suggested by changes in total nucleolar size or mean dimensions, and than represented by a simple biphasic circadian rhythm. Examples of different stages in the migration of the granular component, and of possible sites of nucleo-cytoplasmic transfer of nucleolar material, are described.
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  • 33
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    Keywords: GALT (gut-associated lymphoid tissue) ; Urodeles ; Ultrastructure
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    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'ultrastructure du tissu lymphoïde associé au tube digestif (GALT) a été étudiée chez l'amphibien urodèle, Pleurodeles waltlii. Les follicules lymphoïdes se présentent comme de vrais infiltrés entre les éléments conjonctifs de la muqueuse. Ils se trouvent principalement constitués par des plasmocytes mûrs et en développement, des macrophages et des granulocytes. Les cellules lymphoïdes migratrices provoquent une invasion massive de l'épithelium intestinal qui présente des modifications notables comme la disparition de la membrane basale et une diminution du nombre de cellules muqueuses. D'après son organisation et ses composants cellulaires, le GALT de P. waltlii semble représenter un précurseur phylogénétique primitif de la “barrière immunologique intestinale” des mammifères.
    Notes: Summary The ultrastructure of gut-associated lymphoid tissue (GALT) has been studied in the salamander, Pleurodeles waltlii. Lymphoid accumulations appear as true infiltrates scattered throughout the lamina propria cell elements. The most important components of these infiltrates are small and medium sized lymphocytes, and, in lesser amounts, developing and mature plasma cells, macrophages and granulocytes. Migrating lymphoid cells massively invade the intestinal epithelium inducing noticeable modifications, such as the disappearance of the basement membrane and decreased numbers of mucous cells. Thus, in its organization and cell composition, the GALT of P. waltlii appears to represent a primitive phylogenetic precursor of the mammalian “intestinalimmunologic ” barrier.
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    Cell & tissue research 225 (1982), S. 111-127 
    ISSN: 1432-0878
    Keywords: Loops of Henle ; Thin limbs ; Kidney (hamster) ; Ultrastructure
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    Notes: Summary In the kidney of the Syrian hamster the descending thin limbs of both the short and long loops of Henle are not spatially separated from each other and descend between the vascular bundles. Ultrastructurally, five different epithelial types are distinguished in the thin limbs of the short and long loops of Henle. Short loops possess only a descending thin limb with a simply organized epithelium (type 1). Long loops comprise an upper and a lower part of the descending thin limb and the ascending thin limb. The upper part of the long descending thin limb is equipped with a complex and highly interdigitating epithelium with shallow junctions (type 2), which gradually transforms into the simple noninterdigitating type-3 epithelium of the lower part. In a minor portion of long descending thin limbs, however, the upper part begins with an even more complexly organized epithelium (type 2a) than type 2. Type-2a epithelium is conspicuously thicker and possesses a more elaborate mode of cellular interdigitation. Along the descent of this tubular part through the inner stripe of the outer medulla, type-2a epithelium transforms into type-2 epithelium. It is suggested that the long descending thin limbs, which start with type-2a epithelium, belong to the longest loops. The type-4 epithelium of the ascending thin limbs is characterized by flat and extensively interdigitating cells with shallow junctions. The unique pattern of the type-2 a epithelium favors the assumption that solute secretion essentially contributes to the increase in concentration of tubular fluid in long descending thin limbs.
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  • 35
    ISSN: 1432-0878
    Keywords: Opiate peptides ; Pituitary ; Pro-opiomelanocortin cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of acute injections of synthetic opiate peptides into the lateral cerebral ventricle of young adult male rats on cells of the intermediate lobe of the pituitary were studied. Met-enkephalin (100/μg) injected into anesthetized rats, or 20 μg beta-endorphin administered via a previously implanted cannula to unanesthetized animals, will lead to cell degranulation and often to expanded Golgi zones and prominent regions of rough endoplasmic reticulum in secretory cells when tissue is fixed 45–60 min after peptide administration. Treatment of animals with the opiate antagonist naloxone hydrochloride prior to enkephalin injection appeared to prevent the cellular changes elicited with peptide alone. Observations suggest that opiate peptides administered to the cerebrospinal fluid may stimulate release of pro-opiomelanocortin-peptide from pituitary cells.
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  • 36
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    Cell & tissue research 226 (1982), S. 493-510 
    ISSN: 1432-0878
    Keywords: Ovarian cords ; Surface epithelium ; Fetal germ cells ; Mesonephros ; Ultrastructure ; SEM
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    Topics: Biology , Medicine
    Notes: Summary The ovarian surface and associated germ cells have been studied in human fetuses from 12 weeks of age until near term, using light, TEM and SEM techniques. The surface epithelium and related cords proliferate extensively, especially at midterm. The cords in the ovarian cortex appear to be linked with ingrowths from the surface epithelium, and both structures have a common basal lamina. Germ cells are always interspersed among the somatic cells of the surface epithelium and associated cords. These results indicate that both the proliferating cords and surface epithelium may contribute to the formation of early follicles. Furthermore, the occurrence, of elements having some of the features of primitive steroidogenic cells in the regions of cordsurface epithelium continuity, suggests that both structures (surface epithelium and cords) contribute somatic cells, which in addition to becoming granulosa cells, might also contribute to the provision of primitive interstitial cells. Gonocytes tend to migrate through the developing ovarian tissue towards the surface where they become extruded into the peritoneal cavity. This phenomenon might contribute to the reduction in the number of germ cells at birth and parallels the atretic processes within the ovary.
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  • 37
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    Cell & tissue research 226 (1982), S. 541-554 
    ISSN: 1432-0878
    Keywords: Oral epithelium ; Cell differentiation ; Vitamin A ; Ultrastructure ; Stereology
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    Topics: Biology , Medicine
    Notes: Summary The ultrastructural changes induced by the topical application of retinol acetate on hamster cheek pouch epithelium were evaluated using stereological analysis. Electron micrographs were prepared of the basal and superficial regions of the nucleated cell layer of the epithelium obtained from 3 treated and 3 control animals and examined at two levels of magnification. A total of 528 micrographs were analyzed using a coherent double lattice test system. Although the mean thickness of the nucleated cell layer did not change significantly after 10 days of treatment with retinol acetate the formation of keratinized squames was completely inhibited. This was paralleled by significant changes in the volume density of a number of organelles in both the basal and superficial strata. Rough endoplasmic reticulum increased significantly whereas filaments, which maintained a constant diameter of approximately 9 nm, keratohyalin granules and membrane-coating granules decreased in both strata. Desmosomes also showed a significant decrease in numerical area density in the treated tissues. In contrast, no changes were observed in the volume density of the Golgi apparatus, free ribosomes or mitochondria in the treated epithelium. It is concluded that this treatment provides an epithelium lacking all features of keratinization and may be a useful model for examining metabolic activities specifically associated with keratinization.
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  • 38
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    Cell & tissue research 226 (1982), S. 565-578 
    ISSN: 1432-0878
    Keywords: Mechanosensory hair ; Chordotonal organ ; Ultrastructure ; Crustacea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In this study we examine the fine structure of mechanosensory hairs in the antennule of crayfish. The sensory hair is a stiff shaft with feather-like filaments. The hair's base is a large expansion of membrane which allows the hair shaft to deflect. The sensory transducing elements are located far from the hair, but are coupled mechanically with the hair shaft by a fine extracellular chorda. The sensory element is a type of scolopidium which consists of a scolopale cell and three sensory cells with a 9 + 0 type ciliary process. This type of scolopidium is characteristic of the chordotonal organ that has no cuticular structure on the surface of the exoskeleton. In this crustacean hair receptor, the deflection of the cuticular hair is transmitted through the chorda to the scolopidium which is a tension-sensitive transducer. The present study reveals that the mechanosensory hair of decapod crustaceans is a chordotonal organ accompanied by a cuticular hair structure. We also discuss comparative aspects of cuticular and subcuticular chordotonal organs in arthropods.
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  • 39
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    Cell & tissue research 227 (1982), S. 129-137 
    ISSN: 1432-0878
    Keywords: Mitochondria ; Ultrastructure ; Microinjection ; ATP ; ADP ; Amoeba proteus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Microinjection of adenine nucleotides and substrates into the cytoplasm of Amoeba proteus followed by EM examination has been used in an attempt to relate alterations in mitochondrial morphology with functional changes. Contracted mitochondria with dark matrix and wide cristae (Type I), and expanded mitochondria with light matrix and narrower cristae (Type II) coexist in normal active amoebae, but their numbers can be varied according to different cell activity states. Following injection of ATP, the mitochondria of the amoebae showed a time-dependent movement towards a predominately Type II form, whilst injections of ADP produced predominately the Type I form. Injection of succinate or deionised water, even in large amounts, had little effect on the numbers of Type I or Type II forms. The change induced by ATP was of long duration; that induced by ADP was influenced by both concentration injected and the cell's substrate levels. With 3 mM solutions of ADP the mitochondrial population was primarily of Type I organelles; higher ADP concentrations or the simultaneous injection of succinate, however, resulted in a switch with time to increased proportions of Type II mitochondria. The results extend the findings of previous in vivo and in vitro mitochondrial studies and are discussed in the light of these.
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  • 40
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    Cell & tissue research 227 (1982), S. 139-151 
    ISSN: 1432-0878
    Keywords: Migration ; Primordial germ cell ; Teleost ; Oryzias latipes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The primordial germ cells (PGCs) of Oryzias latipes in migration to the gonadal anlage have been investigated by light and electron microscopy. The ultrastructure of the PGCs, which occur in the subendodermal space on the syncytial periblast, differ conspicuously from that of the surrounding endodermal cells. After the PGCs move to the cavity between lateral plate and ectoderm, they are taken into the somatomesodermal layer and transferred to the dorsal mesentery where they form gonadal anlage with mesodermal cells. During their translocation to the dorsal mesentery through the somatic mesoderm, apparently without formation of pseudopods, the PGCs are completely surrounded by mesodermal cells. Since these conditions seem unfavorable to the active translocation of the PGCs to the dorsal mesentery, it is more likely that the PGCs are transferred passively by the morphogenic activity of the lateral-plate mesoderm. Counts of the number of the PGCs revealed that they are mitotically dormant during the migratory period. After the completion of the migration, they regain their proliferative activity. The PGCs in the female proliferate more actively than those in the male, which provides the first morphological indication of sex differentiation in this species of fish.
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  • 41
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    Cell & tissue research 227 (1982), S. 201-211 
    ISSN: 1432-0878
    Keywords: Optic systems ; Axonal growth ; Myelination ; Ultrastructure ; Teleosts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The early differentiation of the optic pathway of the trout was studied by means of autoradiography, silver impregnation and electron microscopy. Ingrowth of optic nerve fibers into the optic tectum was consistently shown by tracer application and Golgi studies to occur at stage 28, about one week before hatching. Fibers being arranged in discrete bundles were rapidly growing through the longitudinal axis of tectum and at stage 33 reached its posterior end. Cross sections of these fiber bundles at different positions revealed myelin ensheatment to be initiated at the end of stage 34 at the anterior pole of the tectum. Since in the optic nerve of the trout the onset of myelination occurred even earlier (stage 33), it is assumed that this differentiation process follows a rostro-caudal gradient during development of the optic pathway.
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  • 42
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    Cell & tissue research 227 (1982), S. 371-386 
    ISSN: 1432-0878
    Keywords: Tentacle sensory input system ; Neuroendocrine control of growth ; Ultrastructure ; L. stagnalis
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    Notes: Summary Several environmental factors influence the growth of the basommatophoran freshwater snail Lymnaea stagnalis. Growth is hormonally controlled by 4 cerebral clusters of ca 50–75 peptidergic, neuroendocrine Light Green Cells (LGC). The present light, transmission, and scanning electron microscopic study shows that the LGC are synaptically contacted by a tentacle sensory system (TSS). The TSS consists of 2 types of primary sensory neurone, viz. ca 150 S1-cells and ca 50–100 S2-cells. A S1-cell has a non-ciliated dendrite and an axon branch that synaptically contacts the soma of a S2-cell. A S2-cell has a branching, ciliated dendrite. Probably, S1- and S2-cells have different sensory modalities and can integrate sensory information by intersensory interaction. The S2-axons run through the tentacular nerves, the cerebral ganglia, and the intercerebral commissure. In each ganglion S2-axons branch and form synaptic contacts on the axons and somata of the LGC and on glial cells that surround the LGC. In an LGC-cluster, 1–3 LGC-somata are particularly strongly innervated. Probably, the TSS is involved in the environmental control of growth in L. stagnalis.
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  • 43
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    Cell & tissue research 221 (1982), S. 551-581 
    ISSN: 1432-0878
    Keywords: Non-adrenergic, non-cholinergic nerves ; Cholinergic nerves ; Ultrastructure ; Nervous transmission
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In order to test the premise that non-adrenergic, non-cholinergic (NANC) autonomic nerves have a distinctive ultrastructural appearance, clearly different from that of cholinergic nerves, a detailed quantitative ultrastructural analysis has been made of the non-adrenergic innervation of 15 tissues thought from pharmacological evidence to be innervated by NANC nerves (rat and rabbit anococcygeus muscles; rabbit hepatic portal vein; extrinsically denervated toad lung); cholinergic nerves (atria of rat, rabbit, guinea-pig and toad); or both (guinea-pig cervical and thoracic trachealis muscle; rabbit rectococcygeus muscle; urinary bladder of rat, rabbit, guinea-pig and toad) in addition to their adrenergic supply. Following fixation with a modified chromaffin procedure allowing identification of adrenergic nerves, large, randomly selected samples of non-adrenergic nerve profiles from each tissue were analysed with respect to numbers, relative proportions, and size frequency distributions of different vesicle classes within the profiles. The neuromuscular relationships within each tissue were also analysed. On the basis of these analyses, it is clear that there are no consistent ultrastructural differences between cholinergic and NANC autonomic nerves: neither proportions nor sizes of the vesicles provide any clue as to the transmitter used by a particular nerve. The great majority of nerve profiles, whether cholinergic or NANC, contain predominantly small clear “synaptic” vesicles. Large filled “peptidergic” vesicles are no more common in most NANC nerves than in most cholinergic ones. It is concluded, on ultrastructural grounds, that the primary transmitter in these NANC autonomie nerves is most likely to be stored in and released from the small clear vesicles.
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  • 44
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    Cell & tissue research 221 (1982), S. 607-615 
    ISSN: 1432-0878
    Keywords: Hemocytes ; Drosophila ; Ultrastructure ; Phagocytosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Hemocytes of Drosophila melanogaster and Drosophila yakuba larvae have been defined in terms of their ultrastructure and functions in “coagulation”, wound healing, encapsulation, phenol-oxydase activity, and phagocytosis. The position of these cells among the classical hemocyte types of insects is determined. We distinguish two plasmatocyte types (macrophage plasmatocytes and lamellocytes) which do not seem to belong to the same lineage, and oenocytoids which are the crystal cells of the literature.
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  • 45
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    Keywords: Melanophores ; Periodic albinism ; Ultrastructure ; Physiology ; Xenopus laevis, tadpoles
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    Notes: Summary Pigment of tail-fin melanophores in periodic albino Xenopus laevis tadpoles is dispersed in response to darkness and to α-MSH in a manner similar to wild-type melanophores. However, periodic albino tadpoles lack the response to different background conditions and the melatonin-induced aggregation in darkness. The tyrosinase activity in cells of the latter type tadpoles is weak compared to the wild-type cells. Ultrastructural examination of melanophores from periodic albino mutants and cells from wild-type tadpoles shows similar organelles at corresponding sites. A morphological difference can be observed in the fine structure of the melanosomes, which in albinos resembles an earlier stage of development. It is postulated that periodic albino Xenopus laevis possess the cellular mechanism to disperse pigment in the melanophores, but that under physiological conditions the release of α-MSH appears to be absent or scarce.
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    Cell & tissue research 222 (1982), S. 143-152 
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    Keywords: Sertoli cells ; Seminiferous tubules ; Irradiated rats ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the seminiferous tubules was studied in rats that had been subjected to whole body irradiation on the 19th day of gestation. The seminiferous tubules from 3 months-old irradiated animals are devoid of germ cells and contain only Sertoli cells. Compared with controls of the same age, the seminiferous tubule basal membrane is thickened and multilayered and several alterations are observed in the Sertoli cells. The most characteristic of these alterations are: (a) an abnormal number of nuclear heterochromatin clumps, (b) the presence of numerous cytoplasmic vacuoles and various sized lipid droplets, (c) elaborate interdigitations and junctions between adjacent cells, and (d) the presence of anomalous ectoplasmic specializations disposed perpendicularly to the Sertoli cell membrane.
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  • 47
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    Cell & tissue research 222 (1982), S. 531-546 
    ISSN: 1432-0878
    Keywords: Pineal gland ; Ultrastructure ; Chinese hamster (Cricetulus griseus)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the pineal parenchymal cells, pinealocytes and glia-like cells, of the Chinese hamster (Cricetulus griseus) is described. Pinealocyte nuclei contain spindle-shaped inclusions consisting of bundles of closely packed parallel filaments of about 8 nm in thickness. Mitochondria contain lamellar and tubular cristae. Smaller and larger mitochondria are usually localized separately in individual pinealocytes. Flattened mitochondria contain two to four closely arranged, unusual lamellar cristae, which lie parallel to the surface of the mitochondria. These cristae exhibit particular structures. Rough endoplasmic reticulum is frequently found in close association with such flattened mitochondria. Tubular expansions of the outer membrane of mitochondria occur frequently. The pinealocyte cytoplasm contains stacks of flattened cisternae, which are continuous with both smooth and rough endoplasmic reticulum. Pinealocyte cell bodies and processes contain granulated vesicles. Although larger granulated vesicles measuring up to 300 nm in diameter occasionally occur, smaller granulated vesicles (about 100 nm in diameter) and larger ones are usually localized separately in individual cells. Vacuoles containing flocculent material are found in groups in close association with rough endoplasmic reticulum. Glia-like cells with darker cytoplasm and nuclei lie surrounding pericapillary or intercellular spaces. The glia-like cells are characterized by the presence of abundant lipid droplets and occasional pigment granules. Bundles of filaments run parallel to the long axis of the processes of the glia-like cells.
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  • 48
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    Cell & tissue research 222 (1982), S. 479-491 
    ISSN: 1432-0878
    Keywords: Gastrin cell ; Secretory granules ; Secretory process ; Peptide hormones ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of gastrin cells in the rat antrum was analyzed with standardized and quantitative planimetric methods. Resting and active cells were compared. The gastrin cells were activated by removal of the acidproducing part of the stomach (fundectomy). As a result the serum gastrin concentrations were greatly elevated. Compared with gastrin cells in fasted control rats the gastrin cells in fundectomized rats were increased in number, contained fewer cytoplasmic granules, increased amount of endoplasmic reticulum, and an enlarged Golgi area. Generally, the secretory granules of the gastrin cell displayed a wide range of electron density from highly electron-dense to electron-lucent. They exhibited certain characteristic features: 1) Electron-dense granules made up a greater proportion of the total granule population in active gastrin cells than in resting cells. 2) Electron-dense granules were more frequent near the Golgi stacks than in the periphery of the cell. 3) Electron-dense granules were smaller in size than the electron-lucent granules; hence, small electron-dense granules probably represent young granules (progranules), while large, electron-lucent granules represent mature (old) granules. 4) Electron-dense granules invariably displayed a more intense immunoreactivity than electron-lucent granules. The gastrins are generated from a large precursor molecule. The posttranslational processing of this precursor is reflected in the gastrin-component pattern. The gastrin-component pattern in antral extracts of fundectomized and normal fasting rats differed in that the proportion of the gastrin-4-like component was reduced, whereas the gastrin-34-like component was increased in the fundectomized rats. The results suggest a greater proportion of small gastrin components in the mature granules than in the newly formed ones, presumably due to more extensive conversion of larger forms into smaller forms with a longer granule half-life. As a result gastrin-17-and gastrin-34-like components make up a larger proportion of total gastrin in active gastrin cells than in resting gastrin cells.
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  • 49
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    Cell & tissue research 223 (1982), S. 201-215 
    ISSN: 1432-0878
    Keywords: Liver ; Endothelial cells ; Primary culture ; Ultrastructure ; Adsorptive endocytosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A new isolation and purification procedure for endothelial cells of the rat liver and the conditions for large scale survival of these cells in maintenance culture are reported. Cells isolated by this new method and cultured with homologous rat serum on a collagen matrix show the restoration of several ultrastructural characteristics typical of rat liver endothelial cells in situ, including the broad cytoplasmic extensions that contain the sieve plates. These fenestrated cytoplasmic projections, which cover the liver sinusoids in vivo, are well preserved and are reformed in a manner reminiscent of the situation in situ. Reformation of specific membrane receptors is indicated by the reappearance of the capacity to take up horseradish peroxidase by adsorptive endocytosis, a characteristic that is lost during the cell isolation procedure. From the results obtained in this study, maintenance culture of rat liver endothelial cells seems to be a promising system for studying the regulation of pore size of the fenestrated sieve plates by alcohol and certain hormones, for studying the interaction of endothelial cells with other liver cells and tumor cells, and for studying the mechanisms of adsorptive endocytosis.
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  • 50
    ISSN: 1432-0878
    Keywords: Uterus ; Epithelial cells ; Tight junctions ; Pregnancy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of tight junctions between uterine luminal epithelial cells of the pregnant rat was studied by the freeze-fracture technique. On day 5 of pregnancy, the day of implantation, the region of tight junctions extended three times as far down the lateral cell membrane as on day 1 of pregnancy, and the strands of the complex interlinked more frequently. These observations suggest that tight junctions on day 5 may be more efficient in preserving the contents of the uterine lumen from dilution or escape than at earlier times of pregnancy.
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  • 51
    ISSN: 1432-0878
    Keywords: Spleen (rat) ; Ultrastructure ; Periarteriolar lymphatic sheath ; Interdigitating cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To obtain more information concerning the origin of interdigitating cells, the postnatal development and morphology of the periarteriolar lymphatic sheath in splenic white pulp of rats was investigated by light- and electron-microscopy. Special attention was paid to the ontogeny of interdigitating cells. The spleens of the animals were studied in the age range from 1 h to 28 days after birth. The splenic white pulp of neonatal rats consists only of a few reticuloblasts, which are concentrically arranged around central arterioles. After 21 h an increase in promonocytes and monocytes was noted. Between the fifth and seventh postnatal day monocytogenic cells with a light and almost translucent cytoplasm appear, which display long cytoplasmic projections between the adjacent cells. Neighbouring lymphocytes often insert finger-like processes into the invaginated cellular membrane of these transitional forms. This intimate cellular contact is supported by zonulae occludentes. These cells represent transitional forms between monocytes and interdigitating cells. From seven days of age onwards typical interdigitating cells were present as in adult animals. After the differentiation into an inner and outer periarteriolar lymphatic sheath, the T-cell-dependent area of splenic white pulp has attained its adult appearance and further changes are not to be expected. On the basis of these findings, it is highly probable that interdigitating cells develop via transformation of monocytes.
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  • 52
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    Cell & tissue research 223 (1982), S. 349-367 
    ISSN: 1432-0878
    Keywords: Teleost scales ; Ultrastructure ; Rapid freeze-fixation ; Mineralization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Resumé Des précisions concernant les aspects ultrastructuraux des dépôts minéraux dans les écailles deCarassius auratus ont été obtenues grâce à l'utilisation de la congélation ultra-rapide suivie d'une cryosubstitution en milieu anhydre. Ces données sont comparées à celles fournies par les méthodes usuelles utilisant des fixateurs aqueux. La couche externe des écailles comprend des fibres collagènes disposées sans ordre apparent. Les dépôts minéraux se produisent surtout dans la substance interfibrillaire où des granules denses semblent représenter des sites actifs au cours de la minéralisation apparentée au type sphéritique. La plaque basale comporte deux catégories de fibres collagènes. Les unes, les plus nombreuses, de plus fort diamètre, sont organisées en lamelles formant une structure en contre-plaqué; les autres appelées “fibres TC”, orientées de la base de l'écaille vers la zone superficielle, jouent un rôle important dans les premières phases de la minéralisation de type inotropique dans cette partie de l'écaille. Dans les deux couches de l'écaille, la phase minérale est surtout trouvée dans la substance interfibrillaire. De ce fait, les écailles élasmoides des Téleostéens peuvent être distinguées des autres écailles dermiques connues de Vertébrés inférieurs.
    Notes: Summary New data on the ultrastructural features of the elasmoid scales ofCarassius auratus have been obtained by use of rapid freezing with subsequent freeze-substitution in anhydrous solvents. These are compared with the results obtained using conventional aqueous fixatives. The external layer of the scales is composed of randomly oriented collagen fibres. In the first stages of mineralization, mineral deposits are located in the interfibrillary substance where dense granules appear to be active sites of mineralization. Spheritic mineralization occurs in this layer. The fibrillary plate is composed of two kinds of collagen fibres. Most of them are organized in lamellae forming the “plywood-like structure”. They are thicker than the so-called “TC fibres”, which are oriented from the basal part towards the superficial layer. These TC fibres are involved in the first stages of mineral deposition in the fibrillary plate where inotropic mineralization occurs. The mineral phase is almost always located in the interfibrillary matrix in both layers of the elasmoid scale. In this respect, teleost scales differ from those described so far in other lower vertebrates.
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  • 53
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    Cell & tissue research 223 (1982), S. 431-443 
    ISSN: 1432-0878
    Keywords: Eye ; Ultrastructure ; Gambusia affinis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the tissue components of the eye ofGambusia affinis, excluding the sensory cells, is described. The cornea consists of two different sections of collagenous layers of different density. The choroid includes an argentea composed ofα- andβ-melanophores, lipopterinophores and a choriocapillaris associated with the rete mirabile of the choroid body. Bruch's membrane, underlying the retinal pigment layer, can develop complex associations with fibroblasts delimiting the choriocapillaris. The outer section (stroma) of the iris includes several cell types that are not found in the inner or vitread section. In adultGambusia the lens capsule is well developed, but in twoweek-oldSarotherodon larvae the lens epithelium is covered only by a glycocalyx.
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  • 54
    ISSN: 1432-0878
    Keywords: Microtubules ; Cattle ; Mammary gland ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural examination of milk secretory cells from lactating bovine mammary gland revealed presence of numerous microtubules in the apical and paranuclear cytoplasm, particularly in the vicinity of Golgi components. Most microtubules were oriented perpendicular to the apical plasma membrane and appeared to form a framework around Golgi dictyosomal elements and secretory vesicles. In comparison, non-secretory cells obtained from involuting glands displayed few microtubules and these were randomly located throughout the cytoplasm with no particular orientation.
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  • 55
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    Cell & tissue research 224 (1982), S. 449-454 
    ISSN: 1432-0878
    Keywords: Gallbladder epithelium ; Brush border ; Apocrine secretion ; Ultrastructure ; Teleosts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The free surface of the epithelial cells in the gallbladder of the rainbow trout (a predatory fish) and the tench (an omnivorous fish) is characterized by well-developed microvilli. They are irregularly arranged in the tench, but form a true brush border consisting of regularly aligned microvilli in the rainbow trout. In both species membrane-bounded cytoplasmic protrusions, up to 5 μm in diameter, extend from the apical surface. These protrusions are free of granules, secretory vesicles or other organelles; only in the tench some of them contain glycogen. Thus, the previously used terms “apocrine and droplet secretion” are not justified; the epithelial protrusions are now to be regarded as droplets of degenerated cytoplasm. Since they resemble the protrusions reported in fetal and postnatal epithelial cells in the gallbladder of higher vertebrates, interspecific differences are discussed. There is no significant correlation between the seasonal activity of the fish and the abundance or structure of the cytoplasmic protrusions.
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  • 56
    ISSN: 1432-0878
    Keywords: Interdigitating cells ; Thymus ; Birds ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Interdigitating cells (IDC) in the thymus of the spotless starling, Sturnus unicolor, were examined by electron microscopy. They occur principally in the thymic medulla and corticomedullary border. They possess an irregular nucleus and a perinuclear area of cytoplasm, containing most of the membranous organelles, surrounded by a peripheral electron-lucent zone. Clusters of smooth Golgi vesicles and complicated labyrinthine membrane-membrane contacts are the most characteristic cytological features. Birbeck granules are absent. Lymphocytes, plasma cells and even myoid cells can be found embedded in the cytoplasm. Immature elements, intermediate between epithelial-reticular cells and interdigitating cells, are tentatively identified as prointerdigitating cells. The functional significance of IDCs, and their phylogenetic significance in the vertebrate immune system, is discussed.
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  • 57
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    Cell & tissue research 226 (1982), S. 27-35 
    ISSN: 1432-0878
    Keywords: Median eminence ; Ultrastructure ; In vitro systems ; Neurosecretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Isolated medio-basal hypothalami of adult rats were continuously superfused in a chamber with controllable inputs and outputs, for periods from 30 to 240 min. The median eminence was prepared for transmission electron microscopy under carefully controlled conditions by immersion fixation with osmium tetroxide. The ultrastructure of superfused median eminence was compared with that of directly fixed, non-superfused median eminence. Even after 4h of superfusion, the median eminence displays remarkably well preserved histological and cytological patterns; cytomembranes, cell organelles, intercellular relationships, and extracellular spaces were remarkably similar in superfused and non-superfused tissues. As a consequence of osmium tetroxide fixation, microtubules were not observable. The ultrastructural information obtained from unstimulated rat median eminence superfused in vitro provides a basis for future morphofunctional correlations in the study of neurosecretion.
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  • 58
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    Cell & tissue research 226 (1982), S. 51-62 
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Ultrastructure ; Ageing ; Hormone-containing vesicles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The neurohypophyses (neural lobes of the pituitary) of young adult (3–6 months) and aged (12–30 months) male rats were studied by means of electron microscopy. Stereomorphometric analyses were performed to determine the size, number and relative volume of the hormone-containing vesicles. The principal observations included: 1) the conspicuous depletion in aged rats of the granular hormone-containing vesicles from the axon terminals and the Herring bodies, with a decrease in the relative volume fraction of the vesicles from 4.8 Vv % in the control animals to 1.1 Vv % in the aged rats; 2) a change in the size-distribution of the hormone vesicles; 3) an increase in the extracellular space around the nerve terminals, axons and capillaries; and 4) lipid accumulations and signs of activation in the pituicytes. The possible physiological significance of the findings is discussed in the light of several regulatory functions known to be altered during the process of ageing.
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  • 59
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    Cell & tissue research 226 (1982), S. 237-240 
    ISSN: 1432-0878
    Keywords: Polychaetes ; Neuroendocrine system ; Nerve endings ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the brain of Ophryotrocha puerilis swollen nerve endings filled with electron-lucent vesicles and aggregates of vesicles were observed. The vesicles do not resemble elementary neurosecretory granules. Tests for biogenic amines were negative; no dense-core vesicles were found. The vesicle type described here cannot be related to any of the types thus far found in nerve cells.
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  • 60
    ISSN: 1432-0878
    Keywords: Exocytosis ; Estrogen ; Ultrastructure ; Canine prostate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Glandular cells in the prostate of the intact, adult dog contain numerous, large secretory granules that are released by exocytosis. Following hypophysectomy or castration, the glandular epithelium atrophies and the secretory granules degenerate and eventually disappear. Pharmacologic doses of estradiol-17β 17-cyclopentylpropionate cause the regressed glandular cells to synthesize a new population of smaller granules that are also released by exocytosis, even though estrogen is known to inhibit fluid secretion by the canine prostate. Thus, the mechanisms involved in prostatic synthesis and exocytosis of secretory granules are independent of those regulating fluid secretion and are operative in the absence of androgen or pituitary hormones.
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  • 61
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    Cell & tissue research 227 (1982), S. 277-290 
    ISSN: 1432-0878
    Keywords: Lymph node (rat) ; Macrophages ; Dendritic reticulum cells ; Immune response to paratyphoid vaccine ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphology and kinetics of macrophages and reticulum cells of rat lymph nodes have been studied in relation to the immune response to a second exposure to antigen. During the first 24 h after stimulation monocyte-like exudate macrophages, including some scattered interdigitating cells (IDC), contain granules similar to those present in epidermal Langerhans cells and lymph-borne veiled cells. In this induction phase these macrophages migrate from the marginal sinus into the paracortex and during the migration they gradually transform into IDC. In the proliferation phase the paracortex is mainly populated by transitional macrophages and there are almost no typical IDC present between the lymphoblasts. In the memory phase the relative number of IDC again rapidly increases. During this period in the paracortex there are often typical IDC which contain partially digested necrotic lymphocytes, thus resembling tingible body macrophages (TBM) of the germinal centre in this respect. It is suggested that the newly arrived macrophages induce the lymphoblast reaction, while mature IDC may have an inhibitory function in the memory phase of the immune response. In this phase the phagocytic potential of IDC is clearly shown.
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  • 62
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    Publication Date: 1982-07-02
    Description: Gastric acid secretion has been thought to depend on histamine stimulation of the parietal cell. However, in the 2-week-old rat neither exogenous histamine nor the H-2 receptor agonist impromidine stimulates acid secretion, whereas pentagastrin and the cholinergic agent bethanechol are potent stimuli. At this age, the effect of pentagastrin in acid secretion is not blocked by the H-2 receptor antagonist cimetidine, nor is it potentiated by impromidine. These data suggest that, in the rat pup, the acid secretory response to pentagastrin and cholinergic agents occurs before the histamine-mediated system is functional and operates independently of the actions of histamine.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ackerman, S H -- K1-MH00077/MH/NIMH NIH HHS/ -- R01-AM-18804/AM/NIADDK NIH HHS/ -- New York, N.Y. -- Science. 1982 Jul 2;217(4554):75-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6211765" target="_blank"〉PubMed〈/a〉
    Keywords: Aging ; Animals ; Bethanechol Compounds/pharmacology ; Gastric Juice/drug effects/*secretion ; Gastric Mucosa/growth & development ; Guanidines/pharmacology ; Histamine/pharmacology ; Imidazoles/pharmacology ; Impromidine ; Pentagastrin/pharmacology ; Rats ; Rats, Inbred Strains ; Receptors, Histamine H2/drug effects
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  • 63
    Publication Date: 1982-11-12
    Description: Female athymic nude mice and their phenotypically normal littermates were exposed transplacentally to ethylnitrosourea. Skin tumors (papillomas and sebaceous adenomas) developed on the nude mice with an almost tenfold greater incidence than on their haired littermates. Skin tumors were also induced on nude mice but not haired controls by direct intraperitoneal treatment with ethylnitrosourea. These results indicate that nude mice have higher than normal susceptibility to carcinogenesis under some circumstances.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Anderson, L M -- Last-Barney, K -- Budinger, J M -- CA 08748/CA/NCI NIH HHS/ -- CA 22498/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 1982 Nov 12;218(4573):682-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7134965" target="_blank"〉PubMed〈/a〉
    Keywords: Adenoma/chemically induced ; Animals ; *Ethylnitrosourea ; Female ; *Maternal-Fetal Exchange ; Mice ; Mice, Nude/*physiology ; Neoplasms, Experimental/chemically induced ; *Nitrosourea Compounds ; Pregnancy ; Sebaceous Gland Neoplasms/chemically induced ; Skin Neoplasms/*chemically induced
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  • 64
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-02-05
    Description: A single identified neuron was repeatedly isolated by axotomy from the central nervous system of the nudibranch mollusk Hermissenda crassicornis. An early voltage-dependent outward K+ current of this neuron was reduced and more rapidly inactivated for animals previously trained with paired but not randomized light and rotation. Since this current change can affect interneuron and motorneuron output via known synaptic pathways, it helps explain a long-lasting behavioral change that shows the defining features of vertebrate associative learning.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Alkon, D L -- Lederhendler, I -- Shoukimas, J J -- New York, N.Y. -- Science. 1982 Feb 5;215(4533):693-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7058334" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Association Learning/*physiology ; Central Nervous System/physiology ; Electric Conductivity ; Learning/*physiology ; Membrane Potentials ; Mollusca ; Neurons/*physiology ; Photoreceptor Cells/physiology ; Potassium/*physiology
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  • 65
    Publication Date: 1982-11-26
    Description: Within 1 day after the removal of one branch of the bifurcated axon of an identified neuron in Aplysia, the cell body reduced its output of transmitter storage vesicles to adjust precisely for the decreased need. This adjustment terminated the initial consequence of the removal, the transport of an inappropriately large number of vesicles to the remaining synapses. The most likely cause of the reduction of transport of transmitter is the loss of information normally provided by the disconnected axon or synapses.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Aletta, J M -- Goldberg, D J -- GM 07182/GM/NIGMS NIH HHS/ -- NS 14711/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1982 Nov 26;218(4575):913-6.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6182616" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Aplysia/physiology ; *Axonal Transport ; Axons/*physiology ; Biological Transport ; Cytoplasmic Granules/metabolism ; Intracellular Membranes/metabolism ; Serotonin/*metabolism
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  • 66
    Publication Date: 1982-10-29
    Description: Exposure of rats to cimetidine during intrauterine life and the immediate neonatal period results in hypoandrogenization in adult life with decreased weights of androgen-dependent tissues and decreased concentrations of testosterone. Moreover, sexual behavior patterns in adult life are disturbed as shown by a lack of sexual motivation and decreased performance.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Anand, S -- Van Thiel, D H -- New York, N.Y. -- Science. 1982 Oct 29;218(4571):493-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7123252" target="_blank"〉PubMed〈/a〉
    Keywords: Abnormalities, Drug-Induced/*etiology ; Animals ; Animals, Suckling ; Cimetidine/metabolism/*toxicity ; Female ; Guanidines/*toxicity ; Male ; Pregnancy ; Pregnancy, Animal/drug effects ; Rats ; Sex Differentiation/*drug effects ; Sexual Behavior, Animal/drug effects
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  • 67
    Publication Date: 1982-07-30
    Description: As shown previously, laying hens given 1,25-dihydroxyvitamin D3 as their sole source of vitamin D produce fertile eggs having normal shells, but only 35 to 55 percent of the embryos are normal. Giving these hens additional 25-hydroxyvitamin D3, 24,25-dihydroxyvitamin D3, or 24,24-difluoro-25-hydroxyvitamin D3 at 1.25 nanomoles per day resulted in 90 to 100 percent normal embryos, and hence, hatchability. Since 24,24-difluoro-25-hydroxyvitamin D3 cannot be 24-hydroxylated, 24-hydroxylation is not required for this function of 25-hydroxyvitamin D3.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ameenuddin, S -- Sunde, M -- DeLuca, H F -- Ikekawa, N -- Kobayashi, Y -- New York, N.Y. -- Science. 1982 Jul 30;217(4558):451-2.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6979782" target="_blank"〉PubMed〈/a〉
    Keywords: 24,25-Dihydroxyvitamin D 3 ; Animal Feed ; Animals ; Calcifediol ; Calcitriol/analogs & derivatives/pharmacology ; Chick Embryo/*growth & development ; Chickens/metabolism ; Dihydroxycholecalciferols/pharmacology ; Female ; Hydroxycholecalciferols/*metabolism/pharmacology ; Hydroxylation
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  • 68
    Publication Date: 1982-12-10
    Description: Rhodamine-123, a cationic laser dye, markedly reduced the clonal growth of carcinoma cells but had little effect on nontumorigenic epithelial cells in vitro. This selective inhibitory effect of Rhodamine-123 on some carcinomas is unusual since known anticancer drugs, such as arabinosyl cytosine and methotrexate, have not been shown to exhibit such selectivity in vitro.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bernal, S D -- Lampidis, T J -- Summerhayes, I C -- Chen, L B -- New York, N.Y. -- Science. 1982 Dec 10;218(4577):1117-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7146897" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Carcinoma/*drug therapy ; Cell Line ; Cell Survival/drug effects ; Mice ; Mitochondria/metabolism ; Neoplasms, Experimental/drug therapy ; Rhodamine 123 ; Rhodamines/metabolism/therapeutic use ; Time Factors ; Urinary Bladder Neoplasms/drug therapy
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  • 69
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-09-24
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Benveniste, R E -- Todaro, G J -- New York, N.Y. -- Science. 1982 Sep 24;217(4566):1202.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7112123" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Cell Physiological Phenomena ; Eukaryotic Cells/*physiology ; Humans ; *Recombination, Genetic ; Retroviridae/genetics
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  • 70
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-04-30
    Description: Vasoactive intestinal peptide caused a prompt, dose-dependent relaxation of isolated gastric smooth muscle cells of the guinea pig and a significant increase in intracellular adenosine 3',5'-monophosphate coincidentally with optimum relaxation. Relaxation was augmented by a threshold concentration of isobutyl methylxanthine. The direct relaxant effect of vasoactive intestinal peptide and the distribution of nerves containing this peptide to circular smooth muscle support the view that vasoactive intestinal peptide is the neuromuscular transmitter of enteric inhibitory nerves.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bitar, K N -- Makhlouf, G M -- AM-15564/AM/NIADDK NIH HHS/ -- AM-28300/AM/NIADDK NIH HHS/ -- New York, N.Y. -- Science. 1982 Apr 30;216(4545):531-3.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6176025" target="_blank"〉PubMed〈/a〉
    Keywords: 1-Methyl-3-isobutylxanthine/pharmacology ; Animals ; Cyclic AMP/physiology ; Gastrointestinal Hormones/*pharmacology ; Guinea Pigs ; In Vitro Techniques ; Muscle Contraction/*drug effects ; Muscle Relaxation/*drug effects ; Muscle, Smooth/*drug effects ; Neurotransmitter Agents/physiology ; Stomach/drug effects/*innervation ; Vasoactive Intestinal Peptide/*pharmacology
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  • 71
    Publication Date: 1982-06-25
    Description: Golden Syrian hamsters were placed individually in cages with three drinking bottles--one empty, one containing water, and the third containing water and ethanol. Control hamsters received water only. After 1 year the experimental hamsters showed a significantly lower concentration of leucine-enkephalin-like immunoreactive substance in the basal ganglia than the control hamsters. This finding indicates that the action of ethanol involves endogenous peptidyl opiates.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Blum, K -- Briggs, A H -- Elston, S F -- DeLallo, L -- Sheridan, P J -- Sar, M -- New York, N.Y. -- Science. 1982 Jun 25;216(4553):1425-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7089531" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Basal Ganglia/*drug effects ; Cricetinae ; Endorphins/*analysis ; Enkephalin, Leucine ; Enkephalins/*analysis/metabolism ; Ethanol/metabolism/*pharmacology ; Mesocricetus ; Time Factors
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  • 72
    Publication Date: 1982-02-19
    Description: As reticulocytes mature into erythrocytes, organelles and many enzymes are lost. Protein degradation during reticulocyte maturation was measured by monitoring the release of tyrosine from cell proteins. Proteolysis in rabbit red blood cells was directly proportional to the number of reticulocytes and was low in erythrocytes. This process was inhibited by blockers of cellular adenosine triphosphate production and by agents, such as o-phenanthroline, N-ethylmaleimide, and hemin, which inhibit the soluble adenosine triphosphate-dependent proteolytic system. The breakdown of endogenous proteins in reticulocyte extracts was also inhibited by these agents and required adenosine triphosphate. Inhibitors of lysosomal function, however, did not affect proteolysis. Thus, the proteolytic system that degrades abnormal proteins also catalyzes the elimination of proteins during red cell development.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Boches, F S -- Goldberg, A L -- New York, N.Y. -- Science. 1982 Feb 19;215(4535):978-80.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7156977" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Triphosphate/*physiology ; Animals ; Blood Proteins/*metabolism ; Cell Differentiation ; Cyclophosphamide/pharmacology ; Deoxyglucose/pharmacology ; Dinitrophenols/pharmacology ; Lysosomes/enzymology ; Rabbits ; Reticulocytes/*physiology ; Tyrosine/analysis
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  • 73
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-07-16
    Description: A method has been developed for the measurement of intracellular free calcium in mammalian cells. The calcium-sensitive photoprotein aequorin can be incorporated into isolated cells by hypo-osmotic treatment without altering the cell viability, permeability, or metabolism. Intracellular calcium activity (Cai2+) was monitored in a perfusion system. In monkey kidney cells (LLC-MK2), Cai2+ is approximately 57 nanomoles per liter. Changes in Cai2+ with time can also be followed: exposure of the cells to anaerobiosis or the calcium ionophore A23187 reversibly increases Cai2+. The method has also been successfully tested in rat hepatocytes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Borle, A B -- Snowdowne, K W -- New York, N.Y. -- Science. 1982 Jul 16;217(4556):252-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6806904" target="_blank"〉PubMed〈/a〉
    Keywords: *Aequorin ; Anaerobiosis ; Animals ; Calcimycin/pharmacology ; Calcium/*metabolism ; Cell Line ; Kidney/drug effects/*metabolism ; Kinetics ; *Luminescent Proteins ; Macaca mulatta
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  • 74
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-08-20
    Description: Mice will replace the tip of a foretoe when it is amputated distal to the last interphalangeal joint. Amputation of the digit more proximal to the joint does not result in regrowth of the foretoe. Though this growth shares certain similarities with the epimorphic regeneration of amphibian limbs, the two processes are not the same. The regrowth reported here in mice is probably similar to the scattered clinical reports of fingertips regeneration in children, and presents a model system with which to explore the controls of wound healing and tissue reconstruction in mammals.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Borgens, R B -- CA 20920/CA/NCI NIH HHS/ -- NS 18456/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1982 Aug 20;217(4561):747-50.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7100922" target="_blank"〉PubMed〈/a〉
    Keywords: Amputation ; Animals ; Child ; Humans ; Mice ; Mice, Inbred C3H ; *Regeneration ; Toe Joint ; Toes/anatomy & histology/*physiology ; Wound Healing
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  • 75
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-05-14
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bowden, D M -- New York, N.Y. -- Science. 1982 May 14;216(4547):682, 684.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7079726" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Animals, Laboratory ; *Research Design
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  • 76
    Publication Date: 1982-06-11
    Description: Receptors that selectively bind micromolar concentrations of benzodiazepines are present in rat brain membrane. These micromolar receptors exhibit saturable, stereospecific binding, and the potency of benzodiazepine binding to these receptors is correlated with the ability of the benzodiazepines to inhibit maximum electric shock-induced convulsions. Benzodiazepine receptors with nanomolar affinity differ from the micromolar receptors in their binding, kinetic, and pharmacologic characteristics. The micromolar receptors also bind phenytoin, a non-benzodiazepine anticonvulsant. These results provide evidence for a distinct class of clinically relevant benzodiazepine receptors that may regulate neuronal excitability and anticonvulsant activity.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bowling, A C -- DeLorenzo, R J -- NS 1352/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1982 Jun 11;216(4551):1247-50.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6281893" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Benzodiazepines/*metabolism/pharmacology ; Benzodiazepinones/metabolism ; Brain/*metabolism ; Calmodulin/antagonists & inhibitors ; Diazepam/metabolism ; Kinetics ; Ligands ; Protein Kinase Inhibitors ; Rats ; Receptors, Drug/*metabolism ; Receptors, GABA-A ; Structure-Activity Relationship
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  • 77
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-12-10
    Description: Development of video-enhanced contrast-differential interference contrast for light microscopy has permitted study of both orthograde and retrograde fast axonal transport of membranous organelles in the squid giant axon. This process was found to continue normally for hours after the axoplasm was extruded from the giant axon and removed from the confines of the axonal plasma membrane. It is now possible to follow the movements of the full range of membranous organelles (30-nanometer vesicles to 5000-nanometer mitochondria) in a preparation that lacks a plasma membrane or other permeability barrier. This observation demonstrates that the plasma membrane is not required for fast axonal transport and suggests that action potentials are not involved in the regulation of fast transport. Furthermore, the absence of a permeability barrier surrounding the axoplasm makes this an important model for biochemical pharmacological, and physical manipulations of membranous organelle transport.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Brady, S T -- Lasek, R J -- Allen, R D -- GM27284/GM/NIGMS NIH HHS/ -- NS07118/NS/NINDS NIH HHS/ -- NS15731/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1982 Dec 10;218(4577):1129-31.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6183745" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Triphosphate/physiology ; Animals ; *Axonal Transport ; Axons/*physiology ; Biological Transport, Active ; Cell-Free System ; Cytoplasmic Granules/physiology ; Cytoskeleton/physiology ; Decapodiformes ; Intracellular Membranes/physiology ; Microscopy/methods ; Microtubules/physiology ; Motion Pictures as Topic
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  • 78
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-08-06
    Description: Spinal cord damage in neonatal cats has different effects on different spinal pathways. Corticospinal projections exhibit anatomical plasticity, forming an aberrant pathway that bypasses the lesion. In contrast, brainstem-spinal pathways undergo massive retrograde degeneration. Neither of these responses occurs in adult cats. Sparing of motor function is found in cats operated on as neonates but not in cats operated on as adults, and appears to depend on the plasticity of the corticospinal tract.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bregman, B S -- Goldberger, M E -- GM06772/GM/NIGMS NIH HHS/ -- NS16629/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1982 Aug 6;217(4559):553-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7089581" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Animals, Newborn/*physiology ; Brain Stem/pathology ; Cats/*physiology ; Horseradish Peroxidase/metabolism ; Motor Activity/physiology ; Motor Cortex/pathology ; Neural Pathways/physiopathology ; *Neuronal Plasticity ; Neurons, Efferent/metabolism ; Retrograde Degeneration ; Spinal Cord Injuries/*physiopathology
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  • 79
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-11-05
    Description: Simple chemical catalysts have been designed to achieve some desirable features of enzymes. These novel catalysts are not proteins, but they may incorporate the typical enzyme catalytic groups and they achieve selectivity in their reactions by use of geometric control, as do enzymes. Catalysts that carry out geometrically controlled chlorinations of aromatic rings and steroids have been constructed. Other catalysts achieve the selective synthesis of amino acids, and still others imitate ribonuclease in detailed mechanism and hydrolyze RNA. Optimization of geometries has led to a rate acceleration of over 10(8) in one instance.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Breslow, R -- New York, N.Y. -- Science. 1982 Nov 5;218(4572):532-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7123255" target="_blank"〉PubMed〈/a〉
    Keywords: Catalysis ; Cyclodextrins ; *Enzymes ; Kinetics ; Models, Chemical ; Ribonucleases ; Structure-Activity Relationship ; Substrate Specificity ; Transaminases
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  • 80
    Publication Date: 1982-01-08
    Description: (+/-)-N-Allylnormetazocine is a benzomorphan opioid with psychotomimetic effects. The pure stereoisomers of this compound, as well as the racemic mixture, were compared to phencyclidine for their behavioral effects on squirrel monkeys and rats trained to discriminate phencyclidine from saline. Dose-response determinations were made for responses to phencyclidine, to a racemic mixture of N-allylnormetazocine, and to the pure levo and dextro isomers of N-allylnormetazocine. In both rats and monkeys, the dextro isomer and the racemic mixture produced dose-dependent responses appropriate for phencyclidine; the levo isomer did not produce the responses appropriate for phencyclidine at any of the doses tested. In both species, the levo isomer was more potent than the dextro isomer in decreasing the rate of responding. Thus racemic N-allylnormetazocine is a mixture of compounds that produce different behavioral effects.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Brady, K T -- Balster, R L -- May, E L -- DA-00490/DA/NIDA NIH HHS/ -- DA-01442/DA/NIDA NIH HHS/ -- New York, N.Y. -- Science. 1982 Jan 8;215(4529):178-80.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6274022" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Behavior, Animal/*drug effects ; Male ; Naloxone/pharmacology ; Phenazocine/*analogs & derivatives/pharmacology ; Phencyclidine/pharmacology ; Rats ; Rats, Inbred Strains ; Receptors, Opioid/drug effects ; Saimiri ; Stereoisomerism ; Structure-Activity Relationship
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  • 81
    Publication Date: 1982-10-08
    Description: Rats whose pregnancies were surgically terminated on day 17 of gestation were injected with morphine, morphine plus naloxone hydrochloride, or saline, and then tested for maternal responsiveness toward foster young. Morphine treatment alone significantly disrupted the rate of onset and quality of maternal responsiveness. Concurrent administration of naloxone to morphine-injected rats reinstated the rapid onset of behavioral responsiveness toward foster young, such that the responsiveness of the rats treated with both morphine and naloxone was indistinguishable from that shown by saline-injected controls. The disruptive effects of morphine did not appear to result from a general reduction in activity levels as measured in an open-field apparatus. These findings suggest that the normal onset and maintenance of maternal behavior in the rat may be regulated by endogenous opiates.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bridges, R S -- Grimm, C T -- New York, N.Y. -- Science. 1982 Oct 8;218(4568):166-8.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7123227" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Behavior, Animal/*drug effects ; Drug Antagonism ; Female ; Morphine/*pharmacology ; Naloxone/*pharmacology ; Pregnancy ; Rats ; Rats, Inbred Strains
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  • 82
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-12-10
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cartmill, M -- New York, N.Y. -- Science. 1982 Dec 10;218(4577):1145.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6983135" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Biological Evolution ; Humans ; Primates/*genetics ; T-Lymphocytes/*immunology
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  • 83
    Publication Date: 1982-07-02
    Description: Instantaneous stiffness of frog skeletal muscle, an indication of the proportion of attached crossbridges, was determined drug the tetanus rise and after a step length change imposed during the tetanus plateau. During the onset of contraction as well as after a step, the ratio of stiffness to force differed from that determined during the tetanus plateau. The data after a step are predicted by the Huxley-Simmons model of muscular contraction, but the results during the rise suggest that a long-lived state may exist between crossbridge attachment and force generation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cecchi, G -- Griffiths, P J -- Taylor, S -- NS 14268/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1982 Jul 2;217(4554):70-2.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6979780" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Mathematics ; *Muscle Contraction ; Muscles/physiology/ultrastructure ; Rana temporaria
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  • 84
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-03-12
    Description: Brief tetanic stimulation of the preganglionic nerves to the superior cervical ganglion enhances the postganglionic response to single preganglionic stimuli for 1 to 3 hours. This long-term potentiation of transmission through the ganglion is apparently not attributable to a persistent muscarinic action of the preganglionic neurotransmitter, acetylcholine, since neither the magnitude nor the time course of the phenomenon is reduced by atropine. The decay of long-term potentiation can be described by a first-order kinetic process with a mean time constant of 80 minutes. We conclude that long-term potentiation, once considered a unique property of the hippocampus, is in fact a more general feature of synaptic function. This form of synaptic memory may significantly influence information processing and control in other regions of the nervous system, including autonomic ganglia.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Brown, T H -- McAfee, D A -- 12116/PHS HHS/ -- NS 16576/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1982 Mar 12;215(4538):1411-3.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6278593" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Ganglia, Sympathetic/*physiology ; Kinetics ; Learning/*physiology ; Neuronal Plasticity ; Rats ; Synapses/*physiology ; *Synaptic Transmission ; Time Factors
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  • 85
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-08-06
    Description: Depletion of glutathione in Chinese hamster ovary cells in vitro by diethyl maleate resulted in enhancement of the effect of x-rays on cell survival under hypoxic conditions but not under oxygenated conditions. Hypoxic EMT6 tumor cells were similarly sensitized in vivo. The action of diethyl maleate is synergistic with the effect of the electron-affinic radiosensitizer misonidazole, suggesting that the effectiveness of misonidazole in cancer radiotherapy may be improved by combining it with drugs that deplete intracellular glutathione.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bump, E A -- Yu, N Y -- Brown, J M -- CA-15201/CA/NCI NIH HHS/ -- CM-87207/CM/NCI NIH HHS/ -- New York, N.Y. -- Science. 1982 Aug 6;217(4559):544-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7089580" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Anoxia ; Cell Survival/drug effects/*radiation effects ; Cells, Cultured ; Cricetinae ; Cricetulus ; Drug Synergism ; Glutathione/*metabolism ; Maleates/administration & dosage ; Mice ; Mice, Inbred BALB C ; Misonidazole/administration & dosage ; Neoplasms, Experimental/metabolism ; *Oxygen Consumption
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  • 86
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-09-03
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cowan, M D -- New York, N.Y. -- Science. 1982 Sep 3;217(4563):884.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7112101" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Carcinogens ; Humans ; Occupational Diseases/chemically induced ; United States ; *United States Occupational Safety and Health Administration
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  • 87
    Publication Date: 1982-07-30
    Description: The messenger RNA for a beta-crystallin polypeptide with a molecular size of 27 kilodaltons, first detected 5 to 10 days after birth in the normal mouse lens and the Nakano mouse cataract, was not detected in the Philly mouse cataract with translation in vitro. The heterozygous Philly lens had intermediate levels of the 27-kilodalton beta-crystallin polypeptide and exhibited delayed onset of the cataract. The deficiency of functional 27-kilodalton beta-crystallin messenger RNA is the earliest lesion reported yet for the Philly lens and points to a transcriptional or posttranscriptional developmental defect in this hereditary cataract.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Carper, D -- New York, N.Y. -- Science. 1982 Jul 30;217(4558):463-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6178163" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Cataract/*genetics ; Cell-Free System ; Crosses, Genetic ; Crystallins/*genetics ; Mice ; Mice, Inbred Strains ; Protein Biosynthesis ; Proteins ; RNA/genetics ; RNA Splicing ; RNA, Messenger/*genetics
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  • 88
    Publication Date: 1982-01-15
    Description: The electrophysiological effects of ethanol in low doses (5 to 20 millimoles per liter or 23 to 92 milligrams per 100 milliliters) were examined intracellularly in CA1 cells of rat hippocampus in vitro. Inhibitory and excitatory postsynaptic potentials were increased when ethanol was applied to the respective synaptic terminal regions. Postsynaptically, ethanol caused a moderate hyperpolarization with increased membrane conductance, even when synaptic transmission was blocked. Ethanol augmented the hyperpolarization that followed repetitive firing or that followed the eliciting of calcium spikes in the presence of tetrodotoxin, but not the rapid afterhyperpolarization in calcium-free medium. Ethanol appears to augment calcium-mediated mechanisms both pre- and postsynaptically.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Carlen, P L -- Gurevich, N -- Durand, D -- R01 NS16660-01/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1982 Jan 15;215(4530):306-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7053581" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Calcium/physiology ; Electric Conductivity ; Ethanol/*pharmacology ; Hippocampus/*drug effects/physiology ; Male ; Membrane Potentials/drug effects ; Potassium/physiology ; Rats ; Rats, Inbred Strains ; Synaptic Membranes/drug effects ; Tetrodotoxin/pharmacology
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  • 89
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-10-01
    Description: Mouse embryos were grown successfully in vitro from the blastocyst stage to the limb bud stage. Mouse blastocysts grown in vitro for 10 days showed blood circulation in the yilk sac, forelimb buds, and the primordia of liver, pancreas, and lungs. These characteristics are indicative of a developmental stage equivalent to one-half of the total gestation period in utero. Improvements in culture conditions from days 7 to 9 have made it feasible to culture mouse blastocysts beyond the early somite stage.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chen, L T -- Hsu, Y C -- AM 19535/AM/NIADDK NIH HHS/ -- AM 28550/AM/NIADDK NIH HHS/ -- New York, N.Y. -- Science. 1982 Oct 1;218(4567):66-8.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7123220" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Blastocyst/*physiology ; Cell Differentiation ; Culture Media ; Culture Techniques ; Embryo, Mammalian/*physiology ; Female ; Fetal Blood ; Humans ; Mice ; Pregnancy ; Yolk Sac/physiology
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  • 90
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-05-07
    Description: The activity of angiotensin-converting enzyme is significantly higher in the intermediate and posterior pituitary lobes of Brattleboro rats than in Long-Evans control rats. The high activity level was reversed by vasopressin treatment. Conversely, angiotensin-converting enzyme activity was significantly lower in the anterior pituitary of Brattleboro rats than in Long-Evans rats, and this activity level was not affected by vasopressin. these findings suggest an inverse relation between vasopressin and angiotensin systems in the posterior and intermediate lobes of the pituitary gland.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chevillard, C -- Saavedra, J M -- New York, N.Y. -- Science. 1982 May 7;216(4546):646-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6280284" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Diabetes Insipidus/*enzymology/genetics ; Disease Models, Animal ; Peptidyl-Dipeptidase A/*metabolism ; Pituitary Gland, Posterior/*enzymology ; Rats ; Rats, Mutant Strains/*physiology ; Vasopressins/*physiology
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  • 91
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-07-02
    Description: The rat hippocampal formation was tested for the presence of factors that would accelerate neurite extension from chick parasympathetic (ciliary ganglion) or sympathetic (lumbar chain) neurons in vitro. Two growth factors were identified in extracts of this brain region. One accelerated neurite extension from sympathetic neurons and was blocked by antiserum to nerve growth factor. The other accelerated neurite extension from parasympathetic neurons but was not affected by the antiserum. These results suggest that specific growth factors account for the specificity of neuronal sprouting.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Crutcher, K A -- Collins, F -- NS 17131/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1982 Jul 2;217(4554):67-8.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7089542" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Axons/physiology ; Cells, Cultured ; Chick Embryo ; Ganglia, Parasympathetic/physiology ; Ganglia, Sympathetic/physiology ; Growth Substances/*physiology ; Hippocampus/*physiology ; Neurons/*physiology
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  • 92
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-12-17
    Description: Localization of the anatomic substrate for anticonvulsant activity mediated by gamma-aminobutyric acid (GABA) was examined using intracerebral injections of GABA agonists. Blockade of tonic hindlimb extension in the maximal electroshock test and blockade of tonic and clonic seizures produced by pentylenetetrazole and bicuculline were obtained by elevating GABA in the ventral midbrain tegmentum. Elevation of GABA in forebrain and hindbrain areas had no effect on convulsant activity. Blockade of tonic and clonic seizures was also obtained after microinjections of the direct GABA receptor agonist, muscimol, into the midbrain. The substantia nigra was identified as the critical midbrain site for GABA-mediated anticonvulsant activity. Local injection of GABA agonists into the midbrain provided seizure protection without a widespread augmentation of GABA-mediated activity throughout the brain and without impairing either alertness or motor function. Synapses in the substantia nigra appear to represent an important control mechanism for inhibiting the propagation of generalized convulsions.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Iadarola, M J -- Gale, K -- DA 02206/DA/NIDA NIH HHS/ -- MH32359/MH/NIMH NIH HHS/ -- New York, N.Y. -- Science. 1982 Dec 17;218(4578):1237-40.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7146907" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Bicuculline/pharmacology ; Brain Mapping ; GABA Antagonists ; Male ; Muscimol/pharmacology ; Pentylenetetrazole/pharmacology ; Rats ; Seizures/*physiopathology ; Substantia Nigra/*physiology ; gamma-Aminobutyric Acid/*physiology
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  • 93
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-04-30
    Description: Calcium ionophore A23187 promotes ooplasmic segregation and orange crescent formation in eggs of the ascidian Boltenia villosa. When eggs were exposed to a gradient A23187 the orange crescent was induced to form in the region corresponding to the highest concentration of ionophore. This result is consistent with the hypothesis that a local increase in intracellular calcium polarizes cytoplasmic localization in the ascidian embryo.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Jeffery, W R -- 232-HDO-7098/HD/NICHD NIH HHS/ -- HD-13970/HD/NICHD NIH HHS/ -- New York, N.Y. -- Science. 1982 Apr 30;216(4545):545-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6803360" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Anti-Bacterial Agents/*pharmacology ; Calcimycin/*pharmacology ; Calcium/*physiology ; Cell Compartmentation/drug effects ; Cytoplasm/ultrastructure ; Dose-Response Relationship, Drug ; Female ; Ovum/*drug effects/ultrastructure ; Urochordata
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  • 94
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-06-11
    Description: Local administration of human growth hormone in vivo to the cartilage growth plate of the proximal tibia of hypophysectomized rats resulted in accelerated longitudinal bone growth. This finding suggests that growth hormone directly stimulates the cells in the growth plate, and does not support the theory that the increase in the plasma concentration of somatomedin that follows growth hormone administration is the cause of this stimulation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Isaksson, O G -- Jansson, J O -- Gause, I A -- New York, N.Y. -- Science. 1982 Jun 11;216(4551):1237-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7079756" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Bone Development/*drug effects ; Bone and Bones/*drug effects ; Growth Hormone/*pharmacology ; Male ; Prolactin/pharmacology ; Rats ; Somatomedins/pharmacology ; Stimulation, Chemical
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  • 95
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-09-24
    Description: Phencyclidine elicits hyperthermia at low doses and hypothermia at high doses in rats. Naloxone antagonizes both effects. Phencyclidine's effects on thermo-regulation are probably mediated by an interaction with a mu opiate receptor.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Glick, S D -- Guido, R A -- DA 02534/DA/NIDA NIH HHS/ -- DA 70082/DA/NIDA NIH HHS/ -- New York, N.Y. -- Science. 1982 Sep 24;217(4566):1272-3.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6287581" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Body Temperature Regulation/*drug effects ; Dose-Response Relationship, Drug ; Female ; Naloxone/pharmacology ; Phencyclidine/antagonists & inhibitors/*pharmacology ; Rats ; Receptors, Opioid/*drug effects
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  • 96
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-04-16
    Description: Exposure of embryonic leeches to 5,7-dihydroxytryptamine a cytotoxic analog of the monoamine neurotransmitter serotonin, results in the selective ablation of serotonin-containing neurons in the ventral nerve cord. Other neurons appear to be unaffected by this treatment, including those that contain another monoamine neurotransmitter, dopamine. Embryos with ablations continue to develop into juvenile leeches, but as juveniles they are unable to make normal swimming movements. However, normal swimming movements can be instated in such leeches by injecting them with serotonin.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Glover, J C -- Kramer, A P -- GM 07048/GM/NIGMS NIH HHS/ -- NS 06456/NS/NINDS NIH HHS/ -- NS 12818/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1982 Apr 16;216(4543):317-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7063890" target="_blank"〉PubMed〈/a〉
    Keywords: 5,7-Dihydroxytryptamine/*pharmacology ; Animals ; Behavior, Animal/drug effects ; Cell Survival/drug effects ; Dihydroxytryptamines/*pharmacology ; Leeches/*drug effects/embryology ; Locomotion/drug effects ; Membrane Potentials/drug effects ; Neurons/*drug effects ; Serotonin/analogs & derivatives/physiology
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  • 97
    Publication Date: 1982-11-05
    Description: Receptors for maleylated or acetylated proteins as well as for alpha-2-macroglobulin-protease complexes on macrophages serve as scavengers by mediating the uptake of macromolecules from the extracellular compartment. Described in this report is a novel function of these receptors on macrophages: regulation of neutral protease secretion. The binding of maleylated bovine serum albumin to macrophages triggered secretion of three neutral proteases: neutral caseinases, plasminogen activator, and cytolytic proteinase. Release of acid phosphatase, however, was not induced. An important biological consequence of protease secretion by macrophages, tumor-cytolysis, was also triggered by engagement of the receptor for maleylated bovine serum albumin. By contrast, the binding of alpha-2-macroglobulin-protease complexes to the macrophages suppressed secretion of all three proteases. Thus two receptors heretofore believed to serve principally as scavengers also regulate secretory functions of macrophages.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Johnson, W J -- Pizzo, S V -- Imber, M J -- Adams, D O -- New York, N.Y. -- Science. 1982 Nov 5;218(4572):574-6.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6289443" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Cells, Cultured ; Glycoproteins/*metabolism ; Macrophages/*enzymology ; *Metalloendopeptidases ; Mice ; Peptide Hydrolases/*secretion ; Plasminogen Activators/secretion ; Receptors, Cell Surface/*physiology
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  • 98
    Publication Date: 1982-10-01
    Description: Studies of isolated islets labeled with radioactive leucine show that glucose at a critical time "marks" islets in such a way as to cause preferential release of newly synthesized insulin. The preferential release of insulin from marked islets is relatively independent of subsequent secretagogues or rates of insulin secretion. Previous kinetic studies have indicated that the critical time at which marking occurs is after proinsulin biosynthesis but before the secretory event. Thus, secretory cells may regulate the diversion of newly synthesized material for immediate release as it is approaching or transiting the Golgi apparatus.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gold, G -- Gishizky, M L -- Grodsky, G M -- AM 01410/AM/NIADDK NIH HHS/ -- New York, N.Y. -- Science. 1982 Oct 1;218(4567):56-8.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6181562" target="_blank"〉PubMed〈/a〉
    Keywords: 1-Methyl-3-isobutylxanthine/pharmacology ; Animals ; Glucose/*pharmacology ; In Vitro Techniques ; Insulin/biosynthesis/*secretion ; Islets of Langerhans/drug effects/*secretion ; Kinetics ; Leucine ; Potassium/pharmacology ; Tolbutamide/pharmacology
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  • 99
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-10-08
    Description: In an eight-arm radial maze, normal rats demonstrated good immediate retention for the order of first items (primacy component of serial position curve) and last items (recency component of serial position curve) of an eight-item (arm) list. In contrast, rats with dorsal hippocampal lesions displayed, on an immediate retention test, disruption of the primacy but not the recency component of the serial position curve. Furthermore, imposing a 10-minute delay before the retention test impaired all components of the serial position curve. These results support correspondence in mnemonic function of the hippocampus in animals and humans.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kesner, R P -- Novak, J M -- RR07092-12/RR/NCRR NIH HHS/ -- New York, N.Y. -- Science. 1982 Oct 8;218(4568):173-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7123228" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Hippocampus/anatomy & histology/*physiology ; Male ; Memory/drug effects ; Rats ; *Serial Learning
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  • 100
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 1982-05-14
    Description: The influx of K+ into swollen mitochondria in the presence of valinomycin results in the synthesis of adenosine triphosphate in which approximately one H+ disappears per adenosine triphosphate synthesized. The synthesis is blocked by atractyloside but is insensitive to oligomycin and relatively insensitive to uncouplers.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kinnally, K W -- Tedeschi, H -- GM27043/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1982 May 14;216(4547):742-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6281882" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Triphosphate/*biosynthesis ; Animals ; Antimycin A/pharmacology ; Atractyloside/pharmacology ; Cyanides/pharmacology ; Ion Channels/physiology ; Mitochondria/*metabolism ; Mitochondrial Swelling ; Phosphorylation ; Potassium/*metabolism ; Rotenone/pharmacology ; Uncoupling Agents/pharmacology ; Valinomycin/pharmacology
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