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  • Light and electron microscopy  (10)
  • Springer  (10)
  • Cambridge University Press
  • Springer Nature
  • 2020-2024
  • 1970-1974  (10)
  • 1940-1944
Collection
Publisher
  • Springer  (10)
  • Cambridge University Press
  • Springer Nature
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 138 (1973), S. 1-22 
    ISSN: 1432-0878
    Keywords: Mosquitoes-Aedes ; Rectum ; Fine structure, function, comparison ; Salt-adaptation, osmoregulation ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A comparison of rectal morphology and ultrastructure is made between a freshwater (A. aegypti) and salt water (A. campestris) species of mosquito larvae, and between A. campestris larvae producing hyper- and hyposmotic urine. The epithelium of A. aegypti contains one cell type characterized by infolding of both the apical and basal membranes, straight lateral borders, and evenly distributed mitochondria. The rectum of A. campestris contains distinct anterior and posterior regions, each made up of a single cell type. These two regions can be distinguished on the basis of cell thickness, depth of apical infolding and distribution of mitochondria. The anterior region is similar to the rectum of A. aegypti, while the posterior region is considered unique to the salt-water species and hence probably is associated with the formation of hyperosmotic urine. In A. campestris, the apical (rather than lateral or basal) membranes are probably the site of hyperosmotic urine production. Two possible mechanisms for this process are discussed.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 154 (1974), S. 135-150 
    ISSN: 1432-0878
    Keywords: Parotid glands (Rat) ; Secretion ; Sympathetic ; Autonomic innervation ; Cervical sympathectomy ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Rats starved for 40 hours showed similar appearances in both parotid glands despite the fact that cervical sympathectomy had been performed on one side 24 hours before the tissues were removed. The acini of both glands of each animal were loaded with secretory granules and amylase estimations on both sides were similar. Rats starved for 40 hours and then fed chow for 1 1/2–2 1/2 hours showed variable depletion of secretory granules from their parotid acinar cells and corresponding alterations of amylase concentration. There was marked asynchrony in both granule depletion and the phase of resynthesis of individual cells. Rats starved during 40 hours and having had unilateral cervical sympathectomy 24 hours prior to a terminal eating phase of 1 1/2–2 1/2 hours showed big differences between the parotid glands on the different sides of each animal. The sympathectomised gland showed little or no depletion of secretory granules whereas the normally innervated gland showed a variable loss of granules, which was always greater than on the denervated side. Amylase estimations were also lower on the normally innervated side. It is concluded that normal reflex secretion of acinar granules in parotid glands of rats on eating requires intact sympathetic nerve pathways.
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  • 3
    ISSN: 1432-0878
    Keywords: Skin ; Anurans ; Regional differences in grafts ; Neuroepithelial relationships ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Recent investigations have suggested specific differences in back and belly skin in anurans which appear to influence the quality of reflex responses obtained from various areas of the animals body. The present investigation represents a comparative morphological study of back and belly skin in control and skin-graftedRana pipiens, with special regard to the neuroepithelial relationships. A distinct difference in pigmentation of back and belly skin was observed. Intra-epithelial Merkel cells were present in all skin samples studied. The origins of the numerous unclassifiable cells in the Merkel cell region are discussed in relation to a presumed coordinating function of the Merkel cell during epithelial differentiation. Epitheliomesenchymal interactions were observed in the richly innvervated dermal regions. Two types of morphologically different intra-epithelial nerve endings were observed. These observations are discussed in relation to earlier observations on vertebrate skin and in relation to misdirected reflex responses obtained in skin-grafted anurans.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 142 (1973), S. 1-12 
    ISSN: 1432-0878
    Keywords: Harderian gland ; Hamster ; Sexual dimorphism ; Alveolar cells ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The lobules of the Harderian glands of young male and female hamsters are widely separated by connective tissue and are made up of alveolar cells containing small vacuoles. There is considerable increase in the size of the lobules by 12 days. Based on size distribution of vacuoles two types of alveolar cells can be recognized in the male hamsters 4 weeks and older. The Harderian glands of 2-week animals of both sexes contain a black-brown pigment. The appearance of pigment is accompanied by a proliferation of membranes. In the female the amount of pigment increases with increasing age until 4 weeks of age and then remains at a relatively stable level. In the male no pigment was found after 4 weeks of age. Membrane-bounded juxtanuclear structures are present in the alveolar cells of both sexes until 3 weeks of age. These structures appear to play different roles in the male and female hamsters. The differentiation of the alveolar cells into light and dark types must take place during the 3rd week of postnatal development. A possible relationship between the levels of gonadal hormones and the occurrence of pigment at different ages in both sexes is also discussed.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 147 (1973), S. 127-148 
    ISSN: 1432-0878
    Keywords: Melanophores (Teleost) ; Pigment migration, microtubules ; Colchicine, vinblastine ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The antimitotic drugs colchicine and vinblastine were applied to the melanophores of isolated scales of Pterophyllum scalare. The time course of inhibition of pigment migrations was studied quantitatively with the photoelectric method. Within one hour of treatment with 5 mM colchicine, a partial and reversible inhibition of pigment movements is obtained. During this time, the number of microtubules per cell process does not differ significantly from controls when pigment is dispersed. However, their number increases concomitantly with the decrease in rate of aggregation induced by KCl up to about the same value as in dispersed pigment cells. This indicates a close connection between pigment movements and the microtubule turnover known to occur in angelfish melanophores. When applied in a concentration of 0,2 mM, vinblastine has a total and irreversible effect on pigment movements, with an especially rapid and profound inhibition of pigment dispersion. The fine structure of vinblastine-treated melanophores is characterized by an almost complete loss of microtubules and the appearance of crystalloid bodies, which differ in fine structure from vinblastine-induced crystals of all other cell types so far examined. Possibly their peculiar structure is related to special properties of melanophore microtubules, such as rapid turnover and relatively high resistance to colchicine.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 153 (1974), S. 399-413 
    ISSN: 1432-0878
    Keywords: Spinal ganglia (Rat) ; Cell division ; Autoradiography ; Neurone morphogenesis ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pulse labelling with tritiated thymidine was used to determine the time of the final division of the neuroblasts which subsequently form rat lumbar dorsal root ganglion neurones. The final division occurred during a 4 day period, the maximum frequency being on day 12 of gestation. Separation of the ganglion cells into large light neurones and small dark neurones showed that the large light neurones were formed earlier than the small dark neurones. In both cases the final divisions occurred over a period of 3–4 days, but the peak rate of formation of large neurones was on day 12, and that of the small neurones was on day 13. Low power electron micrographs were used to measure mean cell diameter throughout development from day 11 of gestation until a postnatal age of 225 days. A marked increase in cell diameter occurred on day 15–15.5, about 3 days after the final cell divisions of the majority of the cells. The rate of growth increased just before birth, but no increase in mean cell diameter was found between day 21 of gestation and the third day postnatal. The growth was again rapid after this period until a plateau in cell diameter was reached about 33 days after birth.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 138 (1973), S. 113-132 
    ISSN: 1432-0878
    Keywords: Eggs ; Insects (Triatoma infestans) ; Embryogenesis ; Envelopes, Permeability ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The thick rigid chorion of the egg of Triatoma secreted by the follicle cells shows two porous layers: an aerial layer in the exochorion, an alveolar one in the endochorion. The anterior part of the eggshell is closed up by an operculum which is heaved up by the hatching larva. The operculum has no alveolar layer. The air enters through the numerous holes of the shell surface into the aerial layer and through the micropyles into the alveolar layer. The egg has no respiratory plastron. The follicle cells produce also a vitelline envelope whose structure shows a rapid condensation at fertilization time. During its development the embryo secretes two layers: serosal and embryonic cuticle. At high humidities, at low temperatures the egg is able to increase its weight during the early stages of embryogenesis, and this increase stops when the serosal cuticle is secreted. In a dry atmosphere the egg loses water but can develop if the temperature is higher than 20°C. The little permeability of the egg is related to the structure of its envelopes. The chorion and the vitelline envelope prevent the water from getting out of the egg. The serosal cuticle seems to be opposed to the penetration of the water into the egg. The role of the embryonic cuticle is probably limited in the transit of water.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-0878
    Keywords: Iris ; Muscle, Nerves ; Light and electron microscopy ; Acetylcholinesterase ; 6-Hydroxydopamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The adrenergic and cholinergic innervation to the rat iris has been studied at a light and electron microscopic level. Catecholamine fluorescence histochemistry showed adrenergic nerves to be present in both the dilatator and the constrictor pupillae regions. At a fine structural level the terminal innervation of the iris was studied and criteria for the differentiation between presumptive adrenergic and presumptive cholinergic axon terminals were examined. To aid this examination presumptive adrenergic axons were either labelled with the “false” adrenergic transmitter, 5-hydroxydopamine, or chemical sympathectomy performed using 6-hydroxydopamine. The value of using acetylcholinesterase staining as a marker for cholinergic nerve terminals was also studied. Results showed a mixed adrenergic/cholinergic innervation to the dilatator pupillae. In the constrictor pupillae an exclusively cholinergic innervation was found although adrenergic and cholinergic nerves were found supplying the blood vessels and at the dilatator-constrictor interface. These findings are discussed with regard to innervation-function relationships in the iris.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 146 (1973), S. 45-67 
    ISSN: 1432-0878
    Keywords: Cerebellum (rat) ; Growth in Tissue culture ; Cell types ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The outgrowth of newborn rat cerebellum cultivated in the Maximow assembly was studied from the time of explanation until the end of the 1st week “in vitro”. Dynamic characteristics of migrating cells were investigated with time lapse microcinematography and with phase and interference contrast. Three types of cells were identified: bipolar fusiform cells, fibroblasts and macrophages. The ultrastructure of these cells as seen with scanning and transmission electron microscopes is described. Bipolar cells display the same characteristics as those of migrating granule cells “in vivo”. Differentiation of these cells towards neuronal types becomes evident at the end of the first week “in vitro”. Axonal as well as dendritic growth cones were examined, and their ultrastructural characteristics described. Attention is focussed into the abundance of smooth endoplasmic reticulum, which in supposed active growth has the form of thin cisternae, and, at rest or in retraction takes the form of large vesicles. In the latter case, filopodia disappear, and the tips of their processes acquire a bulbous shape.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 146 (1973), S. 297-307 
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Prostaglandins E1 and E2 ; Fine structure ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Histological and fine structural studies of adrenal cortices were performed on male Sprague-Dawley rats which had been given intravenous injections of prostaglandin E1 or E2. It was found that there were increased numbers of intracellular lipid droplets, free ribonucleoprotein particles, cholesterol ester clefts and coated vesicles of both the small and large varieties. A reorganization of the internal mitochondrial membranes and the appearance of protrusions of parenchymal cytoplasm into the sinusoidal lumina accompanied by vasodilation were also observed. These alterations are not typical of those observed following exogenous ACTH administration and are therefore considered to be prostaglandin-induced.
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