Library

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
  • Cell & Developmental Biology  (61)
  • Engineering General  (7)
  • Computational Chemistry and Molecular Modeling  (6)
  • 1
    Electronic Resource
    Electronic Resource
    Biochemical characterization and epididymal localization of the maturation-dependent ram sperm surface antigen ESA152 (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 35 (1993), S. 293-301 
    Details
    ISSN: 1040-452X
    Keywords: Plasma membrane ; Proteolipid ; Epididymis ; Spermatozoa (ram) ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We examine here the biochemical properties and epididymal localization of a maturation dependent ram sperm surface antigen. A monoclonal antibody, ESA152, identifies an antigen that is present on the surface of ejaculated sperm, but is absent from testicular sperm. Crosslinking of the ESA152 antigen with bivalent antibodies induces the acrosome reaction, redistributing the antigen into the anterior region of the sperm head where it associates with the fusion product of the plasma membrane and the outer acrosomal membrane. The ESA152 antigen appears as a polypeptide of 18 kDa on immunoblots of SDS-polyacrylamide gels. The ESA152 epitope includes the sialic acid termini of N-linked oligosaccharides, as shown by its sensitivity to neuraminidase and endoglycosidase F. The ESA152 antigen is a highly hydrophobic integral membrane protein that resists aqueous extraction, partitions into the detergent phase of Triton-X-114, and solubilizes in chloroform-methanol mixtures. The anchoring of ESA152 is unaffected by phosphtidylinositol specific phospholipase C. The antigen is absent from extracts of caput and corpus epididymidis but appears abruptly in the first segment of the cauda. Immunofluorescence reveals that the ESA152 epitope first appears in clusters of cells in the luminal epithelium of the proximal cauda, prior to or concurrent with its appearance on sperm. © 1993 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080350312
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Cellular invasion and collagen type IX in the primary corneal stroma in vitro (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Developmental Dynamics 201 (1994), S. 206-215 
    Details
    ISSN: 1058-8388
    Keywords: Type IX collagen ; Mesenchymal cell migration ; Corneal stroma ; TIMP ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: During different stages in the development of the avian cornea, various collagen types have been shown to participate in matrix formation and have been implicated in morphogenesis. One of these is the fibril-associated collagen type IX. This molecule is present when the primary corneal stroma is in a compact state, but rapidly disappears just prior to stromal swelling and its invasion by mesenchymal cells. The temporospatial pattern of the disappearance of type IX collagen in the developing cornea suggests that this molecule may be involved in stabilizing the primary corneal stromal matrix by interacting either with other type IX collagen molecules or with other matrix components. To explore further whether the removal of type IX collagen is involved in stromal swelling, we have employed an in vitro culture system in which swelling of the primary stroma and mesenchymal cell invasion can be experimentally manipulated by culturing chick corneal explants on a Nuclepore filter support in the presence or absence of an associated lens. We have also examined the effect of exogenously added human recombinant tissue inhibitor of metalloproteinases (TIMP-1) on the presence of type IX collagen and cellular invasion. When stage 25 - 26+ corneal explants were cultured with an associated lens, the primary stroma did not swell; immunohistochemically detectable type IX collagen was still present, and mesenchymal cell invasion failed to occur. Conversely, when the same stages of corneal explants were cultured without an associated lens, the primary stroma swelled; type IX collagen disappeared, and mesenchymal cell migration occurred. Under both conditions, however, the type II collagen of the stroma, which is known to be a component of the striated fibrils, remained clearly detectable and with time even seemed to increase in amount. This result is consistent with the proposition that type IX collagen is one factor involved in maintaining the primary stroma as a compact matrix, possibly by functioning as a bridging/stabilizing factor. When TIMP was added to cultures of corneal explants, type IX collagen remained detectable in focal regions, suggesting that one or more metalloproteinases are involved in the removal of the type IX collagen. In addition, some of these type IX-containing regions contained mesenchymal cells, suggesting that in addition to type IX collagen other factors are likely to be involved in regulating mesenchymal cell migration. © 1994 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1002010304
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Ejaculate-hormonal traits in the leopard cat (Felis bengalensis) and sperm function as measured by in vitro penetration of zona-free hamster ova and zona-intact domestic cat oocytes (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 26 (1990), S. 163-174 
    Details
    ISSN: 1040-452X
    Keywords: FSH ; LH ; Testosterone ; Sperm morphology ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Electroejaculate traits and circulating follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone concentrations were analyzed in adult leopard cats (Felis bengalensis), a rare felid species indigenous to east Asia. The ability of leopard cat sperm to bind and penetrate zona-free hamster ova and zonaintact domestic cat oocytes in vitro was examined as a means of testing sperm function. The influence of culture media [Biggers, Whitten, Whittingham (BWW) vs. modified Krebs Ringer bicarbonate (mKRB)], seminal plasma removal, and swim-up separation on sperm motility, sperm morphology, and oocyte penetration also were assessed. Sperm treatments included dilution of raw semen (DR), ejaculate centrifugation, and either resuspension (NS) or swim-up processing (SU). The percentage of oocytes penetrated (penetration rate) and the number of penetrated sperm/oocyte (penetration index) were determined. Ejaculates from each male consisted of at least a 50% sperm motility rating, and hormone concentrations in individual males were unrelated to any ejaculate trait measured concurrently on the same day. The SU technique improved (P 〈 0.05) percent sperm motility and the proportion of structurally normal sperm compared to DR and NS treatments. Leopard cat spermatozoa were capable of binding to and penetrating hamster ova and domestic cat oocytes; however, penetration was influenced by culture medium and seminal processing. In the hamster assay, a higher (P 〈 0.05) penetration rate and penetration index were achieved when mKRB was used for gamete incubation instead of BWW. NS processing also increased (P 〈 0.05) overall penetration compared to DR and SU. In the cat oocyte assay, zona penetration rate was similar (P 〈 0.05) in the DR, NS, and SU aliquots; however, the zona penetration index was increased (P 〈 0.05) by the NS compared to the DR and SU treatments. This study (1) provides baseline ejaculate and endocrine norms for the leopard cat, (2) demonstrates that leopard cat sperm undergo nuclear decondensation in hamster ova and penetrate zona-intact domestic cat oocytes, (3) indicates that seminal plasma removal enhances leopard cat sperm fertilizing ability and ovam penetration, and (4) suggests that heterologous oocyte penetration is effective for assessing factors influencing fertilization and sperm function in this nondomestic felid.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080260211
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Dynamics and organization of MAP kinase signal pathways (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 42 (1995), S. 477-485 
    Details
    ISSN: 1040-452X
    Keywords: MAP kinase activation pathways ; Inter-pathway signal coordination ; MEK specificity ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In the budding yeast, Saccharomyces cerevisiae, four separate but structurally related mitogen-activated protein kinase (MAPK) activation pathways are known. The best understood of these regulates mating. Pheromone binding to receptor informs cells of the proximity of a mating partner and induces differentiation to a mating competent state. The MARK activation cascade mediating this signal is made up of Ste 11 (a MEK kinase [MEKK]), Ste7 (a MAPK/ERK kinase [MEK]), and the redundant MAPK-related Fus3 and Kss1 enzymes. Another MAPK activation pathway is important for cell integrity and regulates cell wall construction. This cascade consists of Bck1 (a MEKK), the redundant Mkk1 and Mkk2 enzymes (MEKs), and Mpk1 (a MAPK). We exploited these two pathways to learn about the coordination and signal transmission fidelity of MAPK activation cascades.Two lines of evidence suggest that the activities of the mating and cell integrity pathways are coordinated during mating differentiation. First, cells deficient in Mpk1 are susceptible to lysis when they make a mating projection in response to pheromone. Second, Mpk1 activation during pheromone induction coincides with projection formation. The mechanism underlying this coordination is still unknown to us. Our working model is that projection formation generates a mobile second messenger for activation of the cell integrity pathway.Analysis of a STE7 mutation gave us some unanticipated but important insights into parameters important for fidelity of signal transmission. The Ste7 variant has a serine to proline substitution at position 368. Ste7-P368 has higher basal activity than the wild-type enzyme but still requires Ste 11 for its function. Additionally, the proline substitution enables the variant to transmit the signal from mammalian Raf expressed in yeast. This novel activity suggests that Ste7-P368 is inherently more permissive than Ste7 in its interactions with MEKKs. Yet, Ste7-P368 cross function in the cell integrity pathway occurs only when it is highly overproduced or when Ste5 is missing. This behavior suggests that Ste5, which has been proposed to be a tether for the kinases in the mating pathway, contributes to Ste7 specificity and fidelity of signal transmission. © 1995 wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080420416
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Estimates of mRNA abundance in the mouse blastocyst based on cDNA library analysis (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 1 (1989), S. 233-241 
    Details
    ISSN: 1040-452X
    Keywords: Preimplantation ; Gene expression ; RNA quantity ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Studies of gene expression during blastocyst formation in mouse preimplantation development have been limited by the amount of RNA available per embryo. Our present approach to this problem has been to construct a large, representative, blastocyst cDNA library in λgtll. Random hexadeoxynucleotides were used as primers with total blastocyst RNA serving as template. RNA collected from 4,100 32-64 cell embryos was used to generate a library with an initial size of 30 × 106 recombinants. By using clone frequency as a measure of relative mRNA abundance, our data support previous work on the relative and absolute amounts of actin, histone H2a, and intracisternal A particle. Furthermore, we provide estimates for the abundance of cytokeratin endo A, cytokeratin endo B, and β-tubulin from clone frequency data. Insert sizes for isolated clones range from 200 bp to 3.6 kb with full-length or near-full-length insert sizes for selected clones, indicating that random primer methods generate cDNAs which can represent a significant portion of the mRNA. We have so far characterized products whose abundance is equal to or greater than 0.002% of total RNA. This library offers the potential for the analyses of presumptive regulatory gene products in the mouse preimplantation embryo which are represented as low abundance (〈1% of mRNA) RNAs.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080010403
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Cross-linking a maturation-dependent ram sperm plasma membrane antigen induces the acrosome reaction (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 29 (1991), S. 200-207 
    Details
    ISSN: 1040-452X
    Keywords: Fertilization ; Proteolipid ; Exocytosis ; Capping ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: ESA152 is a highly hydrophobic 18 kDa sialoglycoprotein, which becomes expressed on ram sperm in the proximal cauda epididymis. ESA 152 is expressed on all regions of the sperm surface, most strongly on the posterior region of the head, most weakly on the anterior region of the head. In this paper, we show that induction of the acrosome reaction with Ca2+ ionophore causes ESA152 to be redistributed from the posterior to the anterior region of the head plasma membrane. Cross-linking ESA152 with bivalent antibody causes similar redistribution and induces the acrosome reaction, Induction of the acrosome reaction with ESA152 antibody requires Ca2+ but is insensitive to (10 ng/ml) pertussis toxin.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080290216
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Collagen fibrillogenesis in situ: Fibril segments undergo post-depositional modifications resulting in linear and lateral growth during matrix development (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Developmental Dynamics 202 (1995), S. 229-243 
    Details
    ISSN: 1058-8388
    Keywords: Collagen ; Fibril growth ; Fibrillogenesis ; Tendon ; Decorin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Elucidating how collagen fibril growth is regulated is important in determining how tissues are assembled. Fibrils are deposited as segments. The growth of these segments is an important determinant of tissue architecture, stability, and mechanical attributes. Fibril segments were isolated from developing tendons and their structure characterized. The post-depositional changes leading to linear and lateral growth of fibrils also were examined. Segments extracted from 14-day chicken embryo tendons had a mean length of 29 μm. The segments were asymmetric, having a short and a long tapered end. Most of the segments were centrosymmetric with respect to molecular packing. Segments extracted from 12-to 16-day tendons had the same structure, but mean segment length increased incrementally due to the addition of an increasingly large population of longer segments. At 17 days of development there was a precipitous increase in segment length. The morphological data indicate that the increase in length was the result of lateral associations among adjacent segments. Analysis demonstrated that this fibril growth was associated with a significant decrease in fibril associated decorin. Using immunoelectron microscopy, decorin was seen to decrease significantly at 18 days of development. When decorin content was biochemically determined, a decrease also was observed. Decorin mRNA also decreased relative to fibrillar collagen mRNA during the same period. These data support the hypothesis that a decrease in fibril-associated decorin is necessary for fibril growth associated with tissue maturation. Growth through post-depositional fusion allows for appositional and intercalary growth and would be essential for normal development, growth, and repair. © 1995 Wiley-Liss, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1002020303
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Limitations of monastral blue as a vascular label: Rapid rate of clearance is age-dependent, and interactions with anesthetics depress arterial blood pressure in rats (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 219-224 
    Details
    ISSN: 1059-910X
    Keywords: Inflammation ; Venule ; Evans blue ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Monastral blue (MB) has been described as an inexpensive, nontoxic vascular label. Discrepancies as to its rate of removal from circulation and physiological side effects prompted this study in which retention time of MB in the vascular system and effects of MB upon arterial blood pressure with different anesthetics (halothane, isoflurane, and pentobarbital) were measured in rats. Arterial pressure was monitored during intravenous infusion of MB with or without Evans blue, an albumin label. Localized areas of leakage were created by injecting 30 μL of 10-4 M histamine into abdominal dermis at -2, 0, 5, 7, 10, and 15 minutes from infusion of MB. Mean arterial pressure decreased by 25-30% after MB infusion when halothane or isoflurane was used, but not with pentobarbital. Sites which leaked at 10 and 15 minutes did not usefully label with MB, although Evans blue-labelled albumin appeared in the interstitium. Younger, lighter rats (125-200 vs. 200-250 gm) retained MB longer in circulation, and had a shorter duration of MB-induced hypotension. Spectrophotometric analysis of rat serum showed rapid elimination of MB from the vascular system, with a half-life of 3.5 ± 1.9 minutes. While MB remains a useful vascular label, its rapid removal from the circulation and its hypotensive effect must be recognized. © 1992 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070230304
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Functional anatomy of the heart of the harbor porpoise, Phocaena phocaena (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 479-493 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Thirty-six harbor porpoises, Phocaena phocaena, were caught off the coast of Southern New Brunswick and Nova Scotia as part of a study of the biology and ecology of these animals. The formalin-preserved heart was examined first in situ, then measured and studied in detail. If the weight of the thick layer of blubber is discounted, the heart is heavy relative to the total body weight as may be expected in an animal capable of fast swimming, great agility and frequent emergence from the water to breathe. The shape of the heart, the relative size of atria and atrial appendages, the morphology of the ventricular septum, the thickness of the walls of the sinus and conus of the right ventricle and the anatomy of the pulmonary veins were found to be constant for this animal and unlike that of non-cetaceans. It is suggested that the absence of respiratory movements during diving may lead to these modifications of cardiac structure in an animal that is particularly well adapted to a totally aquatic existence.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051460405
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Ultrastructure of pericytes in early stages of histamine-induced inflammation (1990)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 206 (1990), S. 333-342 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Physiological and ultrastructural assessment of changes in the walls of venules in the rat cremaster muscle after administration of histamine indicates that pericytes have essential roles in the normal functioning of venules during inflammation. Fluorescein-labelled albumin was used to quantitate macromolecular leakage and to select suitable venules for ultrastructural analysis 4 and 7 minutes after addition of histamine. Pericytes were concentrated over endothelial cell junctions and gaps. At 4 minutes, when albumin leakage was becoming detectable, gaps between endothelial cells were observed in the venule wall. In 24 serially sectioned gaps, pericytes formed covers, with contact points to the endothelial cells along the sides of the gaps. At 7 minutes, when albumin leakage was maximal, gaps with pericyte covers were still evident, but more commonly observed were pericyte covers over closed endothelial cell junctions. Spaces between the innermost pericytes and endothelial cells were enlarged by an order of magnitude, from 95 nm in controls to 872 nm at 4 minutes and 958 nm at 7 minutes. Pericytes formed coverings or bridges over inclusions of extravasated cells, fluid, proteins, and the vascular label monastral blue. The data indicate that pericytes protect the endothelial lining of venules during histamine-induced inflammation by forming a cohesive covering across gaps.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052060310
    Library Location Call Number Volume/Issue/Year 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...