ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Ultrastructure  (49)
  • Springer  (49)
  • American Chemical Society
  • Elsevier
  • 2020-2024
  • 1985-1989  (49)
Collection
Keywords
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    A microscopic investigation of enamel in wombat (Vombatus ursinus) (1985)
    Springer
    Cell & tissue research 242 (1985), S. 349-355 
    Details
    ISSN: 1432-0878
    Keywords: Teeth (Vombatus ursinus) ; Enamel (regions) ; Ultrastructure ; Enamel (mature and developing)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A study of the enamel of continuously growing Vombatus ursinus molars was carried out using the techniques of light microscopy, hardness testing, scanning electron microscopy and transmission electron microscopy. From the erupted end to within 8 mm of the growing end, mature enamel was observed and it was found that between comparable areas there were no significant ultrastructural differences in enamel; however, small (∼12nm diameter), loosely packed needle-like crystals characteristic of developing enamel were observed near the growing end. Mature enamel was found to consist of three optically-translucent regions interleaved with two opaque regions. Opaque enamel was softer than translucent enamel. The opacity and relative softness characteristic of two of the enamel regions was not related to prism pattern or orientation; it was, however, related to the presence of voids (∼28 nm diameter) in these regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214547
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Gonadotropin production and release in female goldfish (Carassius auratus) after administration of pimozide and an LHRH analogue as studied by electron microscopy and radioimmunoassay (1987)
    Springer
    Cell & tissue research 247 (1987), S. 477-482 
    Details
    ISSN: 1432-0878
    Keywords: Gonadotropic cells ; LHRH analogue ; Pimo-zide ; Ultrastructure ; Goldfish ; Carassius auratus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of pimozide and an LHRH-analogue (LHRH-A) on gonadotropic cells of the goldfish pituitary gland were described qualitatively and quantitatively. A scale of four categories was devised to reflect various ultrastructural appearances of the cells. Experimental animals were divided into a control group, a group injected with LHRH-A alone, pimozide alone, and groups receiving these two substances in combination. Fish injected with the single substance were killed 12 h after injection while the groups receiving the combined treatments were killed at 4, 12 and 48 h. Serum levels of gonadotropin measured by radioimmunoassay were used to indicate whether an increase in hormone release had occurred. An immunocytochemical technique, the protein A-gold procedure, assured that the cells studied were gonadotropes. The control group showed variation in the profiles of gonadotropic cells. The single treatment groups showed some increase in secretory inclusions. At 4 h after injection the combined treatment caused a significant increase in hormone granules; at 12 and 48 h there was a gradual decrease in content of secretory products, and an increase in vacuolization. The results indicate that the combined pimozide and LHRH-A treatment stimulated gonadotropin production as well as release.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00215739
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Study of neuropeptide Y-containing nerve fibers in the human penis (1988)
    Springer
    Cell & tissue research 254 (1988), S. 69-74 
    Details
    ISSN: 1432-0878
    Keywords: Neuropeptide Y (NPY) ; Penis erection ; Perivascular nerve fibers immunocytochemistry ; Ultrastructure ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neuropeptide Y 1–36 (IR-NPY) immunoreactive nerve-fiber processes have been observed in tunicae of veins and arteries and in smooth muscles of the human penis taken at autopsy or during surgery by use of light-and electron-microscopic immunohistochemical techniques. Numerous IR-NPY nerve fibers were mostly concentrated in the inner part of the adventitia close to the media of the arterial and venous vessels and among the intracavernous smooth muscle cells. IR-NPY nerve fibers were less abundant in veins than in arteries. Positive somata were not observed in the penises. At the ultrastructural level, IR-NPY were localized exclusively in large, dense granules of nerve terminals by means of the postembedding immunogold technique. In the deep dorsal vein, IR-NPY nerve fibers were also located in the media formed by an outer circular and an inner longitudinal layer. In the intracavernous and dorsal arteries, they showed the highest density in the inner part of the adventitia. In the corpora cavernosa and in the corpus spongiosum, IR-NPY nerve processes were intermingled between the smooth-muscle fibers around the sinusoid spaces. IR-NPY nerve fibers were present in the cavernous nerves close to the central arteries. The urethra did not show any IR-NPY-positive nerve fibers. This peculiar distribution of IR-NPY nerve fibers suggested that they could participate in regulating arterial and venous blood flow and intracavernous smooth-muscle tone. NPY may therefore be of importance in some of the mechanisms of penile erection especially during detumescence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220018
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Effect of brief vascular perfusion on the ultrastructure and activity of mitochondria isolated from the rat heart (1985)
    Springer
    Cell & tissue research 240 (1985), S. 247-249 
    Details
    ISSN: 1432-0878
    Keywords: Heart ; Mitochondria ; Perfusion ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Mitochondria isolated from heart tissue after a 1-min perfusion with Hanks medium were found to have significantly lower rates of State-3 respiration and respiratory control ratios compared to mitochondria isolated from non-perfused hearts. Examination of the mitochondrial preparations by electron microscopy revealed that a large proportion of the mitochondria isolated from perfused heart tissue were swollen and broken compared to mitochondria from non-perfused hearts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217581
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Quantitative analysis of estradiol-17β-induced changes in the ultrastructure of the liver of the male zebrafish, Brachydanio rerio (1985)
    Springer
    Cell & tissue research 242 (1985), S. 377-382 
    Details
    ISSN: 1432-0878
    Keywords: Liver ; Hepatocytes ; Ultrastructure ; Estradiol ; Vitellogenesis ; Teleosts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Hepatocytes of male zebrafish, Brachydanio rerio, were studied by means of light- and electron-microscopy, following a period of maximally 16 days of in-vivo treatment with estradiol-17β. The responsiveness of the male hepatocytes to this female sex steroid was investigated by use of morphometric methods. The results of this investigation show that the responsiveness was most obvious between 2 and 16 days, as revealed by an increase in cell size, accompanied by a proliferation of the granular endoplasmic reticulum and the Golgi complex. In addition, accumulations of glycogen granules, which are characteristic of hepatocytes in untreated males, had disappeared and lipid droplets had accumulated. These experimentally induced changes in the morphology of the male hepatocyte closely resemble those described for the female hepatocyte during the sexual cycle. It is concluded that the hepatocytes of male zebrafish can be stimulated by estradiol-17β to produce vitellogenin and that in female zebrafish this steroid is a key sex hormone responsible for vitellogenin production by the liver during the natural sexual cycle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214551
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Glomerular ultrastructure of the trout, Salmo gairdneri: Effects of angiotensin II and adaptation to seawater (1987)
    Springer
    Cell & tissue research 249 (1987), S. 437-442 
    Details
    ISSN: 1432-0878
    Keywords: Angiotensin II ; Glomerulus ; Salmo gairdneri ; Seawater-adaptation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of angiotensin infusion on the glomerular ultrastructure of freshwater- and seawater-adapted rainbow trout, Salmo gairdneri, has been examined by scanning and transmission electron microscopy. Adaptation of trout to seawater resulted in epithelial podocyte flattening, primary process broadening and apparent loss of foot processes in almost all glomeruli, features which were uncommon in freshwater-adapted trout. Similar changes were induced by infusion of freshwater-adapted animals with angiotensin, suggesting that the renin-angiotensin system plays a role in the modification of glomerular epithelial ultrastructure. Adaptation of trout to seawater also reduced glomerular diameter, but infusion of freshwater-adapted animals with angiotensin did not mirror this effect. Infusion of angiotensin into seawater-adapted animals increased the overall thickness of glomerular basement membrane by increasing the lamina rara interna and lamina densa. This did not occur when freshwater-adapted fish were either infused with angiotensin or adapted to seawater. These findings suggest that other humoral systems are involved in the control of glomerular diameter and basement membrane thickness as part of an integrated response to increased environmental salinity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00215528
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Ultrastructural study ofErwinia amylovora strains: Effect of culture conditions and fixation procedures (1987)
    Springer
    Protoplasma 139 (1987), S. 1-8 
    Details
    ISSN: 1615-6102
    Keywords: Ultrastructure ; Erwinia amylovora ; Outer membrane ; Fixation procedure ; Cold storage ; Virulence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Modifications of the ultrastructure of the plant pathogenic bacteriumErwinia amylovora were analyzed according to growth conditions and fixation procedures. Six bacterial strains with various virulence characteristics were examined. Cultures were grown either in Yeast Peptone Glucose medium (YPG) or in a medium containing asparagine (ASP) supplemented with sorbitol (1% or 5% sorbitol). When grown in ASP + 1% sorbitol or in YPG, the strains, structurally similar to each other in ASP + 5% sorbitol, presented different frequencies of small evaginations which were observed arising from the cell surface mainly after an OsO4 fixation step. There was no correlation between the frequency of evaginations and the virulence of the strain. An overnight storage at 4 °C considerably enhanced the frequency of the evaginations. It was suggested that the OsO4 fixation step visualized differences in the bacterial outer membrane structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01417529
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Morphology ofEntomophthora muscae protoplasts grownin vitro (1988)
    Springer
    Protoplasma 146 (1988), S. 166-173 
    Details
    ISSN: 1615-6102
    Keywords: Entomophthorales ; Entomophthora muscae ; Ultrastructure ; Cytochemistry ; Protoplast ; in vitro growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Entomophthora muscae (C.) Fres. can be grownin vitro as protoplasts. Light and electron microscopical studies of thein vitro developed protoplasts have demonstrated the absence of an organized wall over the protoplasmic Con A-positive membrane at all stages of growth. The cytological organization is typical of the Entomophthorales with condensed chromatin in the interphase nuclei and small eccentric metaphase spindles. Long strands of endoplasmic reticulum, microubules and vesicles surrounding the plasmalemma may be involved in maintaining the precise shape ofE. muscae protoplast. Starvation of the fungus induces the formation of hyphal bodies after deposition of Con A- and WGA-positive wall material at the plasmalemma surface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01405926
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Changes in carbohydrates and ultrastructure in xylem ray cells ofPopulus in response to chilling (1987)
    Springer
    Protoplasma 137 (1987), S. 45-55 
    Details
    ISSN: 1615-6102
    Keywords: Carbohydrates ; Chilling effects ; Populus ; Sugars ; Ultrastructure ; Xylem ray cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructure of xylem ray cells inPopulus was studied in conjunction with their content of individual sugars and of starch. They differ considerably in structure and in carbohydrate content at the three chosen stages,i.e., of starch deposition (August), of starch maximum (November), and of starch dissolution (January). The transition from the summer to winter stage was also induced experimentally by storage of tissue at 0°C. Both in nature and after cold-storage, sucrose and its galactosides raffinose and stachyose were accumulated to a great extent, contributing up to 69.7 and 57.3% of total sugar content, respectively. They originated parallel to the breakdown of starch and to the appearance of abundant vesicular and dilated ER cisternae. Results indicating that they are the specific sites of sucrose accumulation, and/or its galactosides, are discussed. The occurrence of phytoferritin-like crystalloids in amyloplasts and of vacuolar flocculent material, which condenses into electron-dense bodies of suspectedly proteinaceous nature, is described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01281175
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Pre-fertilization degeneration of both synergids in Brassica campestris ovules (1988)
    Springer
    Sexual plant reproduction 1 (1988), S. 208-216 
    Details
    ISSN: 1432-2145
    Keywords: Megagametophyte ; Synergids ; Brassica campestris ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In Brassica campestris, both synergids of the ovule degenerate before the arrival of the pollen tube. Synergid degeneration does not depend on pollination. At the non-degenerated stage, the synergids are completely filled with a complexly organized cytoplasm containing numerous mitochondria with many cristae, a large number of dictyosomes with many associated vesicles, and a very extensive rough endoplasmic reticulum. The degenerative changes that occur in the cytoplasm of the synergids are characterized by a loss of visibility of the membranes of the endoplasmic reticulum and the simultaneous formation of dense deposits on the surrounding membranes of the mitochondria. Locally, the plasma membranes of the synergids disappear, and some ground plasma of the synergids penetrates into the space between the plasma membranes of the egg cell and the central cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00189154
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...