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  • Life and Medical Sciences  (2,215)
  • Atomic, Molecular and Optical Physics  (441)
  • 1990-1994  (2,656)
  • 1970-1974
  • 1965-1969
  • 1992  (2,656)
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  • 1990-1994  (2,656)
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  • 1
    ISSN: 0886-1544
    Keywords: activation ; fertilization ; microtubules ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Centrosomes are undetectable in unfertilized sea urchin eggs, and normally the sperm introduces the cell's microtubule-organizing center (MTOC) at fertilization. However, artificial activation or parthenogenesis triggers microtubule assembly in the unfertilized egg, and this study explores the reappearance and behavior of the maternal centrosome. During activation with A23187 or ammonia, microtubules appear first at the cortex; centrosomal antigen is detected diffusely throughout the entire cytoplasm. Later, the centrosome becomes more distinct and organizes a radial microtubule shell, and eventually a compact centrosome at the egg center organizes a monaster. In these activated eggs, centrosomes undergo cycles of compaction and decompaction in synchrony with the chromatin, which also undergoes cycles of condensation and decondensation. Parthenogenetic activation with heavy water (50% D2O) or the microtubule-stabilizing drug taxol (10 μM) induces numerous centrosomal foci in the unfertilized sea urchin egg. Within 15 min after incubation in D2O, numerous fine centrosomal foci are detected, and they organize a connected network of numerous asters which fill the entire egg. Taxol induces over 100 centrosomal foci by 15 min after treatment, which organize a corresponding number of asters. The centrosomal material in either D2O- or taxol-treated eggs aggregates with time to form fewer but denser foci, resulting in fewer and larger asters. Fertilization of eggs pretreated with either D2O or taxol shows that the paternal centrosome is dominant over the maternal centrosome. The centrosomal material gradually becomes associated with the enlarged sperm aster. These experiments demonstrate that maternal centrosomal material is present in the unfertilized egg, likely as dispersed undetectable material, which can be activated without paternal contributions. At fertilization, paternal centrosomes become dominant over the maternal centrosomal material. © 1992 Wiley-Liss, Inc.
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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  • 3
    ISSN: 0886-1544
    Keywords: Chloroplast movement ; phytochrome ; near infrared laser ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cell of the green alga Mougeotia orients its chloroplast by rotation, according to the direction or polarization of incident red light. The mechanics of the rotation is described by the angle of rotation and the angular velocity of the rotator (i.e., the chloroplast). We developed a laser diffractometer to determine the angle of rotation of the chloroplast. The angle of rotation of the chloroplast shifted by a constant angular velocity, and hence, the net torque on the chloroplast was zero. This suggests that the driving torque acting on the chloroplast is always balanced by the viscous torque. The maximal driving force acting on the chloroplast was estimated to be nearly equal to the force generated by an actomyosin system. This is the first measurement of the driving force acting on the chloroplast in Mougeotia. The amplitude of the force supported the anchorage site hypothesis. However, it remains unclear whether or not the angular independence of the force also supports the hypothesis. © 1992 Wiley-Liss, Inc.
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  • 4
    ISSN: 0886-1544
    Keywords: division polarity ; F-actin ; microtubules ; plastids ; preprophase band ; stomata ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Stomatogenesis, the determinate developmental pathway leading to formation of a pair of specialized guard cells, was studied in monoplastidic cells ofSelaginella. Observations of living cells followed by immunofluorescence microscopy of the same cells made it possible to correlate changes in cytoskeletal organization with developmental events. The guard mother cell divides in a plane perpendicular to previous divisions and this shift in polarity is marked by morphogenetic plastid migration, as well as by extensive reorganization of cytoskeletal arrays. The single plastid divides and daughter plastids move to a position opposite each other (incipient spindle poles). The axis defined by the opposing plastids rotates in the cell before becoming fixed in position with polar plastids adjacent to the lateral anticlinal walls. Plastid polarity predicts spindle orientation and the plane of division. Once division polarity is defined by plastid position, which will remain unchanged throughout mitosis and cytokinesis, cortical microtubules become reorganized from radial to longitudinal (relative to the long axis of the leaf). The initially random cortical F-actin also becomes aligned longitudinally. A wide preprophase band of microtubules and F-actin is formed at right angles to the spindle axis. Plastid-based microtubules establish the preprophase spindle and also connect to the preprophase band. The mitotic spindle remains anchored at the polar plastids. After mitosis, a phragmoplast that forms among microtubules emanating from plastids and nuclei develops in the plane marked previously by the preprophase band. Mitosis is completed in 1 h 15 min ± 3 min (mean ± S.E.). © 1992 Wiley-Liss, Inc.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 21 (1992), S. 74-82 
    ISSN: 0886-1544
    Keywords: motion analysis ; sperm activation ; K+inhibition ; Fluo-3 ; eukaryotic flagella ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We investigated the swimming patterns of trout sperm using computer-assisted analyses of video microscopy. Under full activation conditions, in which 80-100% of sperm activate their motility, sperm swim in circular paths for 2-5 sec, followed by 30-60 sec of a more linear swimming, and, finally, cessation of movement, with a straightening of the flagella. Threshold activation, in which 50% of the sperm activate, is characterized by circular patterns of swimming for less than 20 sec, with straightened flagella upon cessation. Full activation and threshold activation are observed in low-K+ solution or in an Mg++ -supplemented K+ solution. Similarities in swimming patterns in low-K+ solution and in a Mg++ -supplemented K+ solution suggest a common underlying mechanism of activation. Initiation of movement in solutions with high Ca++ to K+ ratio is similar to activation in K+ -free solution. However, sperm in Ca++ -supplemented media resume circular swimming within 20-25 sec after activation, and, upon cessation of movement, the flagella are frequently cane shaped or bent. Differences in swimming patterns upon activation by high Ca++ concentration suggest additional effects of Ca++ on regulating swimming patterns. We used the fluorescent Ca++ indicator Fluo-3 to measure changes in intracellular Ca++ concentration upon activation. Intracellular Ca++ concentration transiently increases upon activation, with peak Ca++ concentration coinciding with the period of circular swimming. This transient increase in Ca++ concentration is seen in the absence of external Ca++, providing strong evidence for the released of Ca++ from intracellular stores upon activation.
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 21 (1992), S. 101-110 
    ISSN: 0886-1544
    Keywords: F-actin ; silk gland ; phalloin ; periluminal circumferential actin bundles ; actin-coated vacuoles ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Labeling of silk glands with rhodaminyl-phalloin shows that most F-actin is restricted to parallel bundles that form rings around the gland lumen at the apical cell surface. The bundles are lost when larval feeding stops at moulting, and the F-actin is redistributed through the cytoplasm as coats to vacuoles and, occasionally, in variably oriented strands. After moulting there is a return to the distribution of filamentous actin in the apical periluminal rings of bundles. These events occur at the same time as F-actin in the nuclear shell [Henderson and Locke, submitted] undergoes its own set of changes. In silk gland cells two kinds of f-actin deployment take place concurrently.
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  • 7
    ISSN: 0886-1544
    Keywords: myofibrils ; extracellular matrix ; cytoskeleton ; integrins ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The influence of the extracellular matrix (ECM) on cell behavior, myofibrillogenesis and cytoarchitecture was investigated in neonatal rat cardiac myocytes in vitro. Cell behavior was examined by analyzing cell spreading on different ECM components under a variety of experimental conditions. Area measurements were made on digitized images of cells grown for various time intervals on fibronectin (FN), laminin (LN), collagens I and III (C I + III), plastic, and bovine serum albumin (BSA). The amount of spreading was varied on the different matrices and was maximal on FN 〉 LN 〉 C I+III 〉 plastic 〉 BSA. Addition of anti-β1 integrin antibodies to myocytes cultured on FN, LN and C I+III blocked spreading outward on the substrates and altered normal myofibrillogenesis, especially on LN. Concomitantly, the integrin antibodies induced the formation of giant pseudopodial processes which protruded upward from the substrates. These pseudopods contained actin polygonal networks which exhibited a regular geometrical configuration.Effects of the ECM on cytoarchitecture was examined by analyzing the temporal and spatial patterns of fluorescence and immunogold labeling of cytoskeletal and integrin proteins as myocytes spread in culture. The first indication of sarcomeric patterns was the appearance at 4 hours of striations formed by lateral alignment of α-actinin aggregates into Z bands. At later times, vinculin at 8 hours and β integrin at 22 hours became co-localized with α-actinin at the Z bands and focal adhesions. These data indicate that ECM components influence myocyte spreading and that myofibril assembly and/or stability is associated with ECM-integrin-cytoskeleton associations.
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  • 8
    ISSN: 0886-1544
    Keywords: cardiac muscle ; actin dynamics ; α-actinin ; vinculin ; microinjection ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: When fluorescently labeled contractile proteins are injected into embryonic muscle cells, they become incorporated into the cells' myofibrils. In order to determine if this exchange of proteins is unique to the embryonic stage of development, we isolated adult cardiac myocytes and microinjected them with fluorescently labeled actin, myosin light chains, α-actinin, and vinculin. Each of these proteins was incorporated into the adult cardiomyocytes and was colocalized with the cells'native proteins, despite the fact that the labeled proteins were prepared from noncardiac tissues. Within 10 min of injection, α-actinin was incorporated into Z-bands surrounding the site of injection. Similarly, 30 sec after injection, actin was incorporated into the entire I-bands at the site of injection. Following a 3-h incubation, increased actin fluorescence was noted at the intercalated disc. Vinculin exchange was seen in the intercalated discs, as well as in the Z-bands throug hout the cells. Myosin light chains required 4-6 h after injection to become incorporated into the A-bands of the adult muscle. Nonspecific proteins, such as fluorescent BSA, showed no association with the myofibrils or the former intercalated discs. When adult cells were maintained in culture for 10 days, they retain the ability to incorporate these contractile proteins into their myofibrils. T-tubules and the sarcoplasmic reticulum could be detected in periodic arrays in the freshly isolated cells using the membrane dye WW781 and DiOC3[3], respectively. In conclusion, the myofibrils in adult, as in embryonic, muscle cells are dynamic structures, permitting isoform transitions without dismantling of the myofibrils.
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  • 9
    ISSN: 0886-1544
    Keywords: MAP p15 ; microtubule bundling ; trypanosoma brucei ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A protein of 15 kDa (p15) was isolated from Trypanosoma brucei subpellicular microtubules by tubulin affinity chromatography. The protein bound tubulin specifically both in its native form and after SDS-PAGE in tubulin overlay experiments. p15 promoted both the in vitro polymerization of purified calf brain tubulin and the bundling of preformed mammalian microtubules. Immunolabeling identified p15 at multiple sites along microtubule polymers comprising calf brain tubulin and p15 as well as on the subpellicular microtubules of cryosectioned trypanosomes. Antibodies directed against p15 did not cross react with mammalian microtubules. It is suggested that p15 is a trypanosome-specific microtubule-associated protein (MAP) that contributes to the unique organization of the sub-pellicular microtubules.
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  • 10
    ISSN: 0886-1544
    Keywords: microtubules ; vesicles ; cytoplasmic movement ; monoclonal antibody ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A cytoskeletal apparatus is involved in the movement of vesicles, organelles, and gametes in the pollen tube. The function of microfilaments has been defined quite precisely, but the role of microtubules needs to be further clarified. On the basis of immunological and biochemical investigations, we have identified a polypep-tide showing common properties with kinesin, a microtubule-based motor mainly described in nonplant tissues, in the pollen tube of Nicotiana tabacum. Like mammalian kinesin, the kinesin-immunoreactive homolog from Nicotiana tabacum pollen tubes binds to mammalian microtubules in an AMP-PNP dependent manner. The kinesin-like component is likely to be involved in the movement of vesicular material in the growing pollen tube.
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  • 11
    ISSN: 0886-1544
    Keywords: actin ; acidic vesicles ; Ca2+ ; pH ; motility ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Unfertilized eggs of the sea urchin Arbacia punctulata contain pigment granules distributed throughout their cytoplasm. During the first 15 minutes after fertilization, these vesicles move out to the cortex where they become firmly anchored. We have used time-lapse video differential interference microscopy to analyze the motility of these organelles in unfertilized and fertilized Arbacia eggs. Pigment granules exhibit saltatory movement in both unfertilized and fertilized eggs. Quantitation of vesicle saltations before and after fertilization demonstrates that while there is no significant difference in the speed or pathlength of vesicle movement, there is a dramatic change in the orientation of these saltations. Saltations in the unfertilized egg are very non-radial and are as likely to be directed toward the cortex as away. In contrast, saltations in the fertilized egg are more radially oriented and more likely to be cortically directed. This transition must reflect underlying changes in the cellular structures necessary for pigment granule saltations. The change in the orientation of pigment granule saltations following fertilization requires both a transient increase in the cytoplasmic concentration of Ca2+ and an elevation of cytoplasmic pH. Similarly, the ability of pigment granules to adhere to the cortex requires both the transient elevation of cytoplasmic Ca2+ and the alkalinization of the cytoplasm. As the reorganization of cortical actin at fertilization is regulated by these ionic fluxes, and both movement and adhesion are sensitive to cytochalasins, we hypothesize that the alterations in directed motility and adhesion reflect underlying changes in the actin cytoskeleton.
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  • 12
    ISSN: 0886-1544
    Keywords: bioluminescence ; ATP depletion ; motility ; flagellum ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The initiation of motility and modification of energy metabolism of rat caudal epididymal spermatozoa can be induced by dilution in a saline medium. We have investigated in these cells the relationships between the energy reserve (sperm ATP content measured by bioluminescence) and flagellar movement (high speed videomicrography, 200 frames/sec). A steady state was observed in sperm ATP content, progressive velocity (Vp) and flagellar beat frequence (F) with sperm dilution in a medium with glucose, lactate, pyruvate and acetate substrates after 30 minutes of incubation, without these substrates, changes in metabolic pathways occurred immediately and initially disturbed the relationship between ATP levels and F, suggesting differences in motility initiation when energy is from an endogenous origin via mitochondrial oxidative phosphorylation. This “energy crisis” was reversed by the addition of substrates to the medium.The three-dimensional flagellar movement observed in the presence of substrates quickly became two-dimensional in their absence. The flagellar beat envelope became more splayed, the mean amplitude of lateral head displacement increased and F decreased. The resulting high flagellar beat efficiency can be compared to that observed during hyperactivation which is a physiological event related to a fall in intracellular ATP level. In both media, the displacement of the flagellum in relation to the wave axis varied sinusoidally. The sine period increased with time when the spermatozoa were incubated in the medium without substrates. These results suggest a gradual slowing-down of the velocity of wave formation in the proximal part of the flagellum.
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  • 13
    ISSN: 0886-1544
    Keywords: actin polymerization ; cell elongation ; photoreceptor ; cytoskeleton ; phalloidin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the retinas of teleost fish, rod photoreceptors elongate in response to light. Light-activated elongation is mediated by the myoid of the rod inner segment and is actin-dependent. Inner segment F-actin filaments form bundles running parallel to the cell's long axis. We examined the mechanism of rod elongation using mechanically-detached rod fragments, consisting of the motile inner segment and sensory outer segment (RIS-ROS). When RIS-ROS are isolated from darkadapted green sunfish and cultured in the light, they elongate 15μm at 0.3-0.6μm/min. Elongation was inhibited 65% by 0.1μM Cytochalasin D, suggesting a requirement for actin assembly. To determine the extent of assembly during elongation, we used three approaches to measure the F-actin content in RIS-ROS: detection of pelletable actin by SDS-PAGE after detergent-extraction of RIS-ROS; quantification of fluorescein-phalloidin binding by fluorimetry, fluorescence-activated cell sorting and image analysis; estimation of total F-actin filament length by electron microscopy. All three assays indicated that no net assembly of RIS-ROS F-actin accompanied myoid elongation. An increase in F-actin content within the elongated myoid was counterbalanced by a decrease in F-actin content within the 13 microvillus-like calycal processes located at the end of the inner segment opposite to the growing myoid. O'Connor and Burnside (Journal of Cell Biology 89:517-524, 1981) showed that minus-ends of rod F-actin filaments are oriented towards the elongating myoid while plus-ends are oriented towards the shortening calycal processes. Our observations suggest that RIS-ROS elongation entails actin polymerization at the minus-ends of filaments coupled with depolymerization at the filament plus-ends.
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  • 14
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    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 21 (1992), S. 281-292 
    ISSN: 0886-1544
    Keywords: ATPase ; CTPase ; minus-end-directed microtubule motility ; cytoplasmic dynein ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Extracts of unfertilized sea urchin eggs contain at least two isoforms of cytoplasmic dynein. One exhibits a weak affinity for microtubules and is primarily soluble. The other isoform, HMr-3, binds to microtubules in an ATP-sensitive manner, but is immunologically distinct from the soluble egg dynein (Porter et al.: Journal of Biological Chemistry 263:6759-6771, 1988). We have now further distinguished these egg dynein isoforms based on differences in NTPase activity. HMr-3 copurifies with NTPase activity, but it hydrolyzes CTP at 10 times the rate of ATP. The soluble egg dynein is similar to flagellar dynein in its nucleotide specificity; its MgCTPase activity is ca. 60% of its MgATPase activity. Non-ionic detergents and salt activate the MgATPase activities of both enzymes relative to their MgCTPase activities, but this effect is more pronounced for the soluble egg dynein than for HMr-3. Sucrose gradient-purified HMr-3 promotes an ATP-sensitive microtubule bundling, as seen with darkfield optics. We have also isolated a 20 S microtubule translocating activity by sucrose gradient fractionation of egg extracts, followed by microtubule affinity and ATP release. This 20 S fraction, which contains the HMr-3 isoform, induces a microtubule gliding activity that is distinct from kinesin. Our observations suggest that soluble dynein resembles axonemal dynein, but that HMr-3 is related to the dynein-like enzymes isolated from a variety of cell types and may represent the cytoplasmic dynein of sea urchin eggs.
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  • 15
    ISSN: 0886-1544
    Keywords: cytoskeleton ; globoside ; vimentin ; desmin ; keratin ; glial fibrillary acidic protein ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We reported recently that two glycosphingolipids (GSLs), globoside (Gb4)and ganglioside GM3, colocalized with vimentin intermediate filaments of human umbilical vein endothelial cells. To determine whether this association is unique to endothelial cells or to vimentin, we analyzed a variety of cell types. Doublelabel immunofluorescent staining of fixed, permeabilized cells, with and without colcemid treatment, was performed with antibodies against glycolipids and intermediate filaments. Globoside colocalized with vimentin in human and mouse fibroblasts, with desmin in smooth muscle cells, with keratin in keratinocytes and hepatoma cells, and with glial fibrillary acidic protein (GFAP) in glial cells. Globoside colocalization was detected only with vimentin in MDCK and HeLa cells, which contain separate vimentin and keratin networks. GM3 ganglioside also colocalized with vimentin in human fibroblasts. Association of other GSLs with intermediate filaments was not detected by immunofluorescence, but all cell GSLs were detected in cytoskeletal fractions of metabolically labelled endothelial cells. These observations indicate that globoside colocalizes with vimentin, desmin, keratin and GFAP, with a preference for vimentin in cells that contain both vimentin and keratin networks. The nature of the association is not yet known. Globoside and GM3 may be present in vesicles associated with intermediate filaments (IF), or bound directly to IF or IF associated proteins. The prevalence of this association suggests that colocalization of globoside with the intermediate filament network has functional significance. We are investigating the possibility that intermediate filaments participate in the intracellular transport and sorting of glycosphingolipids.
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  • 16
    ISSN: 0886-1544
    Keywords: nonmuscle myosin ; antibodies ; neurons ; blood vessels ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The distribution of nonmuscle myosin isoforms in brain and aorta was studied by using polyclonal antibodies against two synthetic peptides selected from a region near the carboxyl terminus of bovine brain (peptide IIB) and human macrophage (peptide IIA) myosin. Immunoblots of brain homogenates and purified myosin showed two major bands stained by anti-peptide IIB (MIIB1 and MIIB2) and a minor band stained by anti-peptide IIA (MIIA2). Polyclonal anti-human platelet myosin antibodies did not react with MIIB isoforms. In cryosections from bovine, rat, and mouse brains, anti-peptide IIB stained most neuronal cells. In bovine cryosections, glial staining was also observed. In contrast, anti-peptide IIA and anti-platelet myosin antibodies primarily stained blood vessels. In bovine aorta, the anti-peptide antibodies recognized four bands, MIIB3, MIIB4, MIIA1, and MIIA2. Only MIIA2 was recognized by anti-human platelet myosin antibodies. In bovine aorta cryosections, anti-peptide IIB stained smooth muscle cells in tunica intima and tunica media but did not stain endothelial cells. Anti-peptide IIA stained smooth muscle cells in the tunica media, and endothelial cells of vaso vasorum but not of aorta. Only polyclonal anti-platelet myosin antibodies stained the endothelial cells of aorta tunica intima. These results indicate that multiple isoforms of cellular myosins exist in mammals, that these isoforms are expressed in a cell specific manner, and that the major myosin isoforms isolated from whole brain originate from neurons and, at least in bovine brain, from glia, but not from blood vessels. © 1992 Wiley-Liss, Inc.
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  • 17
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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  • 18
    ISSN: 0886-1544
    Keywords: epidermal keratinocytes ; cytoskeleton ; UV induced reorganization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Indirect immunofluorescence microscopy has been used to investigate the ultraviolet (UV) radiation induced disruption of the organization of microfilaments, keratin intermediate filaments, and microtubules in cultured human epidermal keratinocytes. Following irradiation, concurrent changes in the organization of the three major cytoskeletal components were observed in cells incubated under low Ca2+ (0.15 mM) conditions. UV irradiation induced a dose-dependent condensation of keratin filaments into the perinuclear region. This collapse of the keratin network was accompanied by the reorganization of microfilaments into rings and a restricted distribution of microtubules, responses normally elicited by exposure to high Ca2+ (1.05 mM) medium. The UV induced alteration of the keratin network appears to disrupt the interactions between keratin and actin, permitting the reorganization of actin filaments in the absence of Ca2+ stimulation.In addition to the perinuclear condensation of keratin filaments, UV irradiation inhibits the Ca2+ induced formation of keratin alignments at the membrane of apposed cells if UV treatment precedes exposure to high Ca2+ medium. Incubation of keratinocytes in high Ca2+ medium for 24 hours prior to irradiation results in the stabilization of membrane associated keratin alignments and a reduced susceptibility of cytoplasmic keratin filaments to UV induced disruption. Unlike results from investigations with isogenic skin fibroblasts, no UV induced disassembly of microtubules was discernible in irradiated human keratinocytes. © 1992 Wiley-Liss, Inc.
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  • 19
    ISSN: 0886-1544
    Keywords: spermatozoa ; flagella ; motility ; epididymis ; maturation ; mammal ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Motility and flagellar movement of ram spermatozoa along the epididymis were analysed in vitro. From the caput to the cauda of the epididymis, the percentage of motile and progressive spermatozoa increases. No flagellar bending was observed in spermatozoa from the testis or the epididymal anterior caput. When spermatozoa reached the distal caput of the epididymis, a static curvature, associated with an initiation of the flagellar beating, appeared on the flagella. This curvature normally disappeared during epididymal transit. Its disappearance was associated with an increase in the flagellar beat efficiency. Our results suggest that the initiation of motility is related to two mechanisms involving: (1) the presence of a transient static curvature, and (2) the establishment of a symmetric regular beating of the flagellum. © 1992 Wiley-Liss, Inc.
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  • 20
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Clinical Anatomy 5 (1992), S. 157-158 
    ISSN: 0897-3806
    Keywords: Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 21
    ISSN: 0897-3806
    Keywords: Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 22
    ISSN: 0897-3806
    Keywords: MRI ; abdomen ; liver ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Magnetic resonance imaging (MRI) is an excellent modality for tomographically visualizing abdominal structures, particularly the liver, In an effort to simulate the natural color scheme of the living abdomen using MRI, we have generated color composites from sets of gray tone MR images obtained at corresponding anatomic slice positions from two healthy individuals. Pulse sequences used for our image sets included T1-, T2-, and proton density-weighted spin echo sequences as well as an angiographic FISP gradient echo sequence. A PC/AT-compatible computer with 24-bit graphics display capbilites, along with commerical and customized image-processing software, was used for composite generation. The applied colors were selected based on quantitative characteristics tissue intensity patterns so that tissue contrast could be optimized in the final image. The generated composites were correlated with cadaver sections to evaluate the color scheme of these false-colored images. With our composite generation techniques, it was possible to generated near-natural appearing color images of the abdomen. Color composites may be useful for teaching human cross-sectional anatomy and may also have diagnostic applications in abdominal MRI studies. © 1992 Wiley-Liss, Inc.
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  • 23
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    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Clinical Anatomy 5 (1992), S. 212-224 
    ISSN: 0897-3806
    Keywords: pulmonary valve ; pulmonary trunk ; pulmonary arteries ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: This paper provides a decription and a mini-atlas (with bold labeled anatomic drawings and magnetic resonance images) (MRIs) of the pulmonary arterial system and surrounding structures for the purpose of interpreint MRIs of heart patients examined in sagittal planes. The pulmonary arterial system (right outflow tract) was studied by examination of cadaver sections made in sagittal planes and by examination of corresponding MRIs from two living normal adult males. We propose a nontraditional format for describing the pulmonary arterial system by dividing in into four parts, rather than the customary three parts, adding a Pulmonary valve region between the ending of the conus arteriosus and the beginning of the pulmonary trunk. This region contains the entire pulmonary valve. It is approximately 1.5 cm long and is defined or outlined by the triple-scalloped fibrous annulus of the pulmonary valve as decribed by Zimmerman (Ann R Coll Eng 39:348, 1966). Defining this region as a separate anatomic entity provides for a more precise description of the relationships of the left coronary and anteior interventricular arteries, the left sinus of the aortic valve, and left auricle to the outflow tract than that found in conventional descriptive anatomy. This paper also defines the ending of the pulmonary trunk, and the orifices of the left and right pulmonary arteries in relationship to the carina found in the upper posterior wall of the pulmonary trunk. An explanation for preferential enlargement of the left pulmonary artery in pulmonary valve stenosis is correlated to our study. © 1992 Wiley-Liss, Inc.
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  • 24
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    Clinical Anatomy 5 (1992), S. 249-250 
    ISSN: 0897-3806
    Keywords: Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 25
    ISSN: 0897-3806
    Keywords: Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 26
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    Clinical Anatomy 5 (1992) 
    ISSN: 0897-3806
    Keywords: Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 27
    ISSN: 0897-3806
    Keywords: rib cage ; rib-vertebra angle differences ; idiopathic scoliosis ; etiology ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Rib-vertebra angles (RVAs) were measured (T1-12) on the chest radiographs of 412 children aged 0-17 years attending the hospital with minimal disorders or diseases (boys 193, girls 219). A new method for measuring RVAs is used and the asymmetry of rib-vertebra angles is calculated as rib-vertebra angle differences (RVADs). The data are analysed in three age groups - infancy, childhood, and puberty, after the classification of Karlberg (1989).The findings show the following:(1) RVAs decrease from T1-12, especially so between (T8 and T12.2) Between infancy and childhood, RVAs of the upper ribs incrase, more so in boys than girls. (3) Between childhood and adolescence there is a further elevation of ribs, involving more ribs in boy than girls (boy T1-10, girls T1-8). (4) Between infancy and childhood, the lower ribs droop more in girls than boys (boys T9-10/12, girls T7/8-12). There is no change in the RVAs of the lower ribs between childhood and puberty in either boys or girls. (5) The hypothesis is suggested that RVAs are influenced by the central nervous system through its influence on trunk muscle activity. (6) Ribvertebra angle asymmetries (or differences, RVADs) are related to age and sex; their pattern reflects the common age, sex, and laterality patterns of idiopathic scoliosis. Extremes of such asymmetries may be an etiological factor for both infantile and adolescent idiopathic scoliosis. © 1992 Wiley-Liss, Inc.
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  • 28
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    Clinical Anatomy 5 (1992), S. 321-325 
    ISSN: 0897-3806
    Keywords: dorsalis pedis artery ; plantar arch ; limb salvage ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The Dorsalis Pedis artery (DPA) is an often overlooked but important artery that can be utilized for limb salvage surgery. It is especially useful in the diabetic patient in whom disease at the level of the bifurcation of the popliteal artery is common. The unique anatomic location and communication with the pedal arch makes the DPA a good outflow vessel. Surg. Gynecol. Obstet. 105:401-405 (Verta, 1982, Ascer, 1988 J. Vasc. Surg., 8:434-441; Harris, 1989, Arch Surg., 124:1232-1235). © 1992 Wiley-Liss, Inc.
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  • 29
    ISSN: 0897-3806
    Keywords: Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 30
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    Clinical Anatomy 5 (1992), S. 335-336 
    ISSN: 0897-3806
    Keywords: Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 31
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    Clinical Anatomy 5 (1992), S. 372-387 
    ISSN: 0897-3806
    Keywords: spine anatomy ; biomechanics ; arch model ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A reassessment is presented of the functional anatomy of the spine and associated musculature. Recent detailed anatomical studies of the erector spinae muscle group have shown a complex organization which is not well explained by traditional models of the mechanical behavior of the spine. In an arch-like model for the spine this complexity is required to control the curvature and the compressive thrust along the spine to ensure mechanical stability. This model also assigns a biomechanical function to the erector spinae muscles that is consistent with their anatomical description, unlike previous lever models. Implications are that posture, the many-curved configuration of the spine adopted during maneuvers, is important when assessing spinal function and that the spine forms a dynamic structure in which all the muscles, ligaments, discs, and vertebrae must be considered synergistically. © 1992 Wiley-Liss, Inc.
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  • 32
    ISSN: 0897-3806
    Keywords: spine ; spinal radiographs ; idiopathic scoliosis ; screening ; etiology ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: This paper reports a segmental analysis of the lateral spinal radiographs of 37 children referred to hospital in a school screening study of 4,890 school children aged 12-13 years. On each lateral radiograph a line was drawn along the posterior surface of each vertebral body from T5-L5 and the angle of this line from the vertical was recorded.After measuring the scoliosis curve (Cobb) angle and using conventional criteria for diagnosis, three groups of patients are defined, namely, 1) a control group (average scoliosis curve angle (Cobb) of 5°, n = 14), 2) a group with lumbar curves (average Cobb angle 21°, n = 7), and 3) a group with thoracic curves (average Cobb angle 19 degrees, n = 10). Individual lateral spinal profiles are also analyzed.The findings show: (1) In the control group, there are different degrees of vertical backward tilt (declivity) from T7-L3, with a maximum tilt at T12 (mean 26°). The most vertical vertebrae are T6 and L4, with forward tilting (proclivity) at each of (T5 and L5.2) In the lumbar curve group, the segmental sagittal tilt is not significantly different from that in the control group. The mean declivity at T12 is 25°. (3) In the thoracic curve group, the segmental sagittal tilt is significantly less than that in the control group at each of T10-L1. The mean declivity at T12 is 17°. A more vertical T12 is associated with a larger Cobb angle. (4) The individual sagittal spinal profiles of the thoracic curve group (but no other group) show lordosis in the region of the lateral spinal curve (scoliosis) and a kyphotic angulation at an average of three vertebrae below the apical vertebrae of the scoliosis curve. (5) It is suggested that as a thoracic lordoscoliosis develops, the appearance of a kyphotic angulation in the thoracolumbar and upper lumbar spine is determined by the compressibility of each disc in relation to the length of the articular processes at the corresponding level. Where the combination of disc weakness to facet length is most adverse, forward flexion occurs, as in a spinal fracture, to produce the kyphotic angulation. © 1992 Wiley-Liss, Inc.
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  • 33
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    Clinical Anatomy 5 (1992), S. 409-416 
    ISSN: 0897-3806
    Keywords: Life of Grant ; anatomy teaching ; overspecialization ; imaging ; gross morphology ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: John C. Boileau Grant was one of the most outstanding teachers of anatomy in the 20th century. His life's work is honored by the thirty editions to which, collectively, his three textbooks have run; by the J.C.B. Grant Museum in the Anatomy Department of the University of Toronto; and by the establishment by the Faculty of Medicine of that university of a John C.B. Grant Memorial Award and Lecture. The present article is an abridgement of the first lecture in this new eponymous series. An account and an appraisal are given of Grant's life and contributions. Reference is made to the deleterious impact on anatomy of overspecialization - not of research methods and goals, but of the minds of anatomists. The catalytic and revitalizing effect that an array of new imaging techniques is exerting on the interest in, and emphasis upon, gross human morphology is stressed and the author underlines R. Ger's claim that, thereby, all gross anatomy has become clinical anatomy. © 1992 Wiley-Liss, Inc.
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  • 34
    ISSN: 0897-3806
    Keywords: Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 35
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    Clinical Anatomy 5 (1992), S. 423-424 
    ISSN: 0897-3806
    Keywords: Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 36
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    Clinical Anatomy 5 (1992), S. 441-451 
    ISSN: 0897-3806
    Keywords: venous obstruction ; thrombosis ; inferior vena cava ; venous decompression ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The purpose of this study was to review venous collateralization resulting from inferior vena cava obstruction. The elements responsible for the extent and distribution of venous collaterals in inferior vena cava obstruction and whether or not the obstructive lesion involves tributaries of the inferior vena cava. Common etiologies of inferior vena cava obstruction include extensions of iliofemoral vein thrombi, thrombosis from intraluminal tumors or following trauma, and external compression. The anatomy of the venous collateral systems may be divided into deep and superficial networks, each of which is composed of systems of primary or secondary clinical significance, as defined by the degree of restoration of adequate venous return and the extent of visceral venous decompression.The most common obstructions of the inferior vena cava involve the lower third of the vessel. The azygos-hemiazygos and vertebral venous plexus systems play the most significant roles, while the superficial systems are less prominently involved. In upper level inferior vena cava obstruction, reestablishment of venous circulation is less developed, which usually leads to a poorer clinical outcome. © 1992 Wiley-Liss, Inc.
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  • 37
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    Clinical Anatomy 5 (1992), S. 485-487 
    ISSN: 0897-3806
    Keywords: knee joint ; meniscus ; accessory ligaments ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The case of a 34-year-old man is reported, in whom a ligament was found at arthrotomy connecting the anterior horn of the medial meniscus of the knee joint to the medial aspect of the lateral femoral condyle.It appeared to be an example of a rare accessory meniscal ligament, previous reports of which are reviewed. © 1992 Wiley-Liss, Inc.
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  • 38
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    Clinical Anatomy 5 (1992), S. 490-491 
    ISSN: 0897-3806
    Keywords: Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 39
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    Clinical Anatomy 5 (1992), S. 496-497 
    ISSN: 0897-3806
    Keywords: Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 40
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    Clinical Anatomy 5 (1992), S. 25-33 
    ISSN: 0897-3806
    Keywords: pressure ; silicone gel ; disfigurement ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Over several years, pressure has been used to lessen disfigurement of postoperative and particularly post-traumatic scars and latterly the application of silicone gel topical dressing has been used. Attempts have been made to quantify and elucidate why these forms of treatment are effective.
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  • 41
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    Clinical Anatomy 5 (1992), S. 16-24 
    ISSN: 0897-3806
    Keywords: morphology ; bile duct ; duodenal wall ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The precise morphology of the human sphincter of Oddi was investigated. Anatomic samples, including the terminal portion of the bile duct and main pancreatic ducts, the major duodenal papilla, and the periampullary duodenal wall, were removed from 22 cadavers of various ages of patients who had died without any history of biliary or pancreatic disease.The specimens were fixed and processed by routine techniques and examined by light microscopy; serial sections were stained with haematoxylin-eosin, Masson's trichrome, and Van Gieson methods.The muscular bundles of the human sphincter of Oddi were divided into the following tracts: The X-Y tract, the distance from the papillary opening to the first muscular thickening that showed a circular trend; the Y-Z tract, the thickest portion of the circular muscular bundles (the true sphincter of the hepatopancreatic ampulla( (HPA) (Oddi), reinforced by fibres arising from the duodenal wall and the Z-W tract, the terminal thinner portion of the circular bundles that pass from the duodenal wall to the bile duct. The X′, Y′, Z′, and W′ points were fixed by the same criteria along the wall of the main pancreatic duct.The single tracts were measured, and the data derived therefrom subjected to statistical analysis.
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  • 42
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    Clinical Anatomy 5 (1992), S. 1-15 
    ISSN: 0897-3806
    Keywords: human heart ; cardiac veins ; atrial wall ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The incidence and distribution of landmarks relating to the coronary sinus (c.s.) were evaluated in 240 human hearts. Special attention was directed to the myocardial coat of the c.s., the distribution and pattern of the cardiac veins, and their dimensions. In all specimens the myocardial coat of the c.s. also covered the adjacent 2 to 11 mm of the great cardiac vein. In 15% of cases this myocardial layer was thickened in a sphincter-like fashion, the edge of which was formed obliquely, in a crescent-like manner, or diffusely without a sharp border.In 3% of the hearts the myocardial cover of the c.s. extended over the terminal 10 mm of the middle cardiac vein as a strong fiber cord. In 9%, single isolated belts of fibers fixated the terminal parts of the adjoining cardiac veins to the posterior wall of the left atrium, and in 8% two or three myocardial cords, embedded in the fatty tissue of the left coronary sulcus, did the same.Because the myocardial cover extended leftwards to variable distances over the c.s., the left edge of the myocardial covering cannot serve to define the beginning of the coronary sinus. The location of the ostial valve of the great cardiac vein (valve of Vieussens) was variable as well, being found on the average 2.5 mm proximal to the opening of the oblique vein of the left atrium. Moreover, the valve of the great cardiac vein was found in only 87% of cases; therefore it is inappropriate for defining the beginning of the coronary sinus. Finally, the dot-like ostium of the oblique vein was most constant, and from the viewpoint of embryologic development, it is the logical landmark for determining the beginning of the coronary sinus, a necessary presupposition for cardiologic procedures like reperfusion of cardiac veins.
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  • 43
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    Clinical Anatomy 5 (1992), S. 34-44 
    ISSN: 0897-3806
    Keywords: palatal muscles ; cleft palate ; soft palate ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: In spite of its clinical importance in cleft palate, there are few detailed accounts of the blood supply of the soft palate and palatal muscles. A series of dissections was carried out to investigate the supply of the levator and tensor veli palatini muscles. Ten adult cadavers and 12 fetuses were used, all of which had been previously injected with a variety of media to outline the vascular tree. Conventional dissection was performed on the cadavers, and microsurgical instruments and a dissection microscope were utilized for fetal dissections.In 70% of dissections the m. levator veli palatini had a dual arterial supply, from the ascending palatine and ascending pharyngeal arteries. In the remainining cases the muscle was supplied by a single artery, either the ascending palatine or ascending pharyngeal. In 79% of dissections the tensor muscle had a dual supply from the accessory meningeal artery along with either the ascending palatine, ascending pharyngeal, or, in one case, the lesser palatine arteries.The results suggest that in careful surgical closure of the cleft soft palate the normal dual arterial supply would protect the tensor and levator muscles from vascular damage. In the minority of patients where only a single vessel supplies the levator, a radical intrapalatal dissection may jeopardize its vascularity.
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  • 44
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    Clinical Anatomy 5 (1992), S. 50-56 
    ISSN: 0897-3806
    Keywords: corpus cavernosum ; Peyronie's disease ; fibrosis ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The thickness of the fibrous connective tissue sheath around the corpus cavernosum was measured in a population of 41 men aged 30-90 years. Specimens were obtained from embalmed cadavers and compared with tissue from fresh cadavers. Sections of tissue were stained with hematoxylin and eosin, Masson's trichrome, or VerHoeff-Van Gieson's to show the connective tissue in the best manner. The thickness was correlated with the presence of inflammation and/ or fibrosis and showed an age-dependent thinning after the sixth decade of life. The results are related to the age occurrence of Peyronie's disease and the possibility of men with chronic thickening of the tunica albuginea having a predisposition toward developing the disease.
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  • 45
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    Clinical Anatomy 5 (1992), S. 57-63 
    ISSN: 0897-3806
    Keywords: cortical index ; femur ; second metacarpal ; male ; female ; age ; correlation ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: This study was conducted on X-ray films of the shaft of normal femur and second metacarpal bones of adult male and female Nigerians to compare the percentage cortical thickness relative to the subperiosteal diameter (cortical index) of these bones. Age was correlated with cortical index (CI) using Pearson's product of moment correlation coefficient. Confidence limits of CI were calculated for clinical use. Results obtained were analysed for each sex and compared at P〈0.05 level of significane. CI of the second metacarpal is significantly greater than of the femur in both the male and female. Age maintained significant inverse correlation with CI of the femur and nonsignificant correlation with the second metacarpal in the female. In the male, age had nonsignificant correlation with the femur or with the second metacarpal bone.It is concluded that (i) the amount of percentage relative cortical bone to subperiosteal diameter of the second metacarpal, a nonweight-bearing bone, is greater than that of the femur, a weight-bearing bone, (ii) age of the adult has significant effect on the amount of cortical bone of the femur in the female but not in the male, and (iii) age of the adult does not have significant effect on the amount of cortical bone of the second metacarpal in both sexes.
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  • 46
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    Clinical Anatomy 5 (1992), S. 45-49 
    ISSN: 0897-3806
    Keywords: lower extremity venous hypertension ; vein harvesting ; cephalic ; basilic ; brachial veins ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Vein valve transplantation is a recently described operation to treat the sequelae of lower extremity venous hypertension resulting from valvular dysfunction. The operation involves harvesting a segment of an arm vein contianing a competent valve and transplanting it into a lower extremity vein. To determine the optimal incisions for obtaining a suitable valve-containing segment of vein, 20 cadaver arms were dissected. Cephalic, basilic, and brachial veins were examined for size, distribution of valves, and presence of tandem valves (defined as valves separated by 2 cm or less). Because patency rates are low in vascular grafts 〈 4 mm in diameter, only veins of this size or greater were considered adequate for transplantation. Cephalic veinswere found to have a consistently smaller diameter than basilic or brachial veins (P 〈 0.0001). Incisions for exposure of the basilic and brachial veins were evaluated. When exposure was limited to the middle third of the arm, an adequate vein, either the basilic or one of the brachial veins, was found in all cases. When either the distal or proximal third of the arm was exposed, however, an adequate vein was found in only 70% of the cases (P 〈 0.02). Tandem valves, although potentially useful, were present in only 5%, 25%, and 20%, respectively, of distal, middle, and proximal arm segments. Based on the results of this study, a medial incision along the middle third of the arm, exposing a basilic or brachial vein, is recommended as the optimal approach for vein harvesting in vein valve transplantation.
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  • 47
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    Clinical Anatomy 5 (1992), S. 64-68 
    ISSN: 0897-3806
    Keywords: sensory ; innervation ; palate ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Following the application of a topical anesthetic agent to the tympanic membrane, a number of patients described a sensation of numbness in the mouth. On examination these patients were found to have a significant area of anesthesia on the inferior surface of the ipsilateral soft palate.As a result of auditory tube dysfunction many of the tympanic membranes were atrophic and retracted. In these cases the pars tensa was closely related to the medial wall of the tympanic cavity, and local anesthetic agents applied to the tympanic membrane could easily diffuse through to the promontory and related structures. If the bone over the tympanic plexus or that over the facial nerve were dehiscent these nerves would be exposed to the effect of the anesthetic. We feel that our observation suggests that in some individuals at least, the pathway of sensory innervation of the soft palate may involve either the facial nerve or the tympanic branch of the glossopharyngeal nerve.
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  • 48
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    ISSN: 1040-452X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 49
    ISSN: 1040-452X
    Keywords: Oncogenes ; Development ; Embryo ; Placenta ; Rabbit ; In situ hybridization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A large variety of proto-oncogenes are known to be of key importance in cellular growth and differentiation during embryonic development. Using quantitative during in situ hybridization, we studied in detail the levels of the proto-oncogenes Ha-ras and c-myc mRNA in embryos and extraembryonic tissues (maternal and embryonic placentas, trophoblast, and endometrial epithelium) during prental life of rabbit. cDNA probes encoding for Ha-ras (fragment Kpn 1-BstE II of 883 bp) and c-myc (fragment Pst 1-Pst 1 of 490 bp) were used to detect specific transcripts in fixed cryostat sections. High levels of Ha-ras and c-myc mRNA were detected in the rabbit embryo as well as in the decidua and in the trophoblast as early as day 9 of gestation. At 12 and 15 days of gestation, Ha-ras and c-myc mRNA levels decreased in both embryonic and maternal placenta while in the embryo a significant increase of Ha-ras and c-myc expression was detected with particular evidence in the central nervous system. Finally, at 25 days of gestation the expression of the two proto-oncogenes, Ha-ras and c-myc, was greatly decreased in both the embryo and extraembryonic tissues, and was undetectable by 30 days of gestation. These results show that in rabbit the expression of the two proto-oncogenes Ha-ras and c-myc is localized in the same tissues with similar intensity and follows an unparallel temporal modulation in the embryo and in the extraembryonic tissues during prental development.
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  • 50
    ISSN: 1040-452X
    Keywords: Spermatogenesis ; Spermiogenesis ; Sperm tail antigen ; CHO cells ; Germ cells ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A general mammalian expression vector designated pSV2-EP was reconstructed by inserting an oligonucleotide fragment into pSV2-dhfr. This vector allowed insertion of cDNAs with EcoRI cohesive ends. The pSV2-EP contains a simian virus 40 (SV40) early promoter, origin for DNA replication, SV40 poly-A site, splicing site, an initiator ATG downstream from the promoter and an EcoRI site for the insertion of cDNA fragment screened from Àgt11 expression libraries. A recombinant plasmid (pSVRS-1) was constructed by inserting RSD-1, a cDNA encoding a rabbit sperm tail protein, into the EcoRI site of the pSV2-EP vector. Chinese hamster ovarian (CHO) dhfr-negative cells were contransformed with pSV2-dhfr and pSVRS-1 by the calcium phosphate method. In selective culture medium without thymidine and hypoxanthine, several cell lines were obtained containing mRNA and DNA that hybridized with RSD-1. One of these transformed cell lines stained intensely with anti-rSMP-B antibodies, demonstrating that the RSD-1 was expressed in the transformed CHO cells.
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  • 51
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    ISSN: 1040-452X
    Keywords: Blastocysts ; Serine proteases ; Trophoblast ; Embryonic discs ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The type of plasminogen activator (PA) secreted by bovine embryos was identified. Day 12-14 embryos were collected from estrus-synchronized, superovulated, and naturally mated crossbred beef cows. Embryos were left intact (E) or microdissected into component embryonic discs (ED) and trophoblastic vesicles (TV). Intact embryos, ED, and TV were pre-cultured for 2 days in Minimum Essential Medium Alpha (MEMα) with 10% heat-inactivated fetal calf serum, washed in serum-free MEMα, and cultured individually for 5 days in 50 μl microdrops of MEMα with 15 mg/ml bovine serum albumin. At 24 hr intervals, E, ED, and TV were observed for tissue morphology and transferred to fresh microdrops, and medium was recovered and frozen at -20°C. At the end of culture, blastocoelic fluid (BF) and embryonic tissues were recovered and frozen at -20°C. Plasminogen activator concentrations in medium, tissues, and BF were determined by using a caseinolytic assay. Antibodies to urokinase-type PA (anti-uPA) and tissue-type PA (anti-tPA), and the urokinase inhibitor, amiloride (AMR), were used to identify the type of PA produced by bovine embryonic tissues. Intact embryos and TV released more PA (P 〈 0.05) than ED, and tissues exhibiting expanded blastocoels released less PA (P 〈 0.05) than tissues with collapsed blastocoels. Blastocoelic fluid from TV exhibited more PA (P 〈 0.05) activity than from ED. Treatment with anti-uPA decreased PA activity (P 〈 0.05) in pooled medium and tissues from E compared to treatment with nonspecific immunoglobulins and anti-tPA. Amiloride completely eliminated PA activity (P 〈 0.05) in tissues, medium, and BF. These results suggest that day 12-14 bovine embryos secrete a urokinase-type PA.
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  • 52
    ISSN: 1040-452X
    Keywords: Spermatozoa ; Zona pellucida ; Binding ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The hemizona assay is a diagnostic test used to evaluate the binding potential of spermatozoa to zonae pellucida and has been used to predict fertilization potential in the human. In this study, frozen-thawed gorilla spermatozoa were coincubated with human hemizonae to evaluate tight binding and to assess the use of human zonae in evaluating sperm fertility. Matching hemizonae were incubated with human sperm to serve as a control. For evaluation of binding studies in a homologous system, matching halves of gorilla hemizonae were coincubated with both gorilla and human sperm. Whole, intact zonae of both human and gorilla oocytes were also coincubated with heterologous sperm to determine of penetration into the perivitelline space could occur. This study found that gorilla sperm bound well to both gorilla and human hemizonae, with a mean of 112.5 and 81.0 tightly bound sperm, respectively. Human sperm also bound to gorilla (mean 229.5) and human (mean 236.5) hemizonae. Following incubation with intact gorilla zonae, motile human sperm were found within the perivitelline space. However, gorilla sperm were not visible within the perivitelline space of nonviable human oocytes. These findings demonstrate that the zonae of nonviable human oocytes can be used to assess sperm binding of gorilla sperm. Studies continue for optimizing assay condition and correlation of findings with the fertility potential of gorilla sperm.
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  • 53
    ISSN: 1040-452X
    Keywords: Chromatin organization ; Endogenous nicks ; DHR ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: DNase I-hypersensitivity of rat spermatogenic cells was analyzed (1) to establish overall patterns of hypersensitivity in individual cell types, (2) to correlate these patterns with known changes in chromatin organization and function, and (3) to provide a foundation for further analyses examining DNase I-hypersensitivity and the localization of specific genes during spermatogenesis. Parameters for in situ nick translation, using radioactive and fluorescent probes to visualize DNase I-hypersensitive regions (DHR), were established for fixed and sectioned testicular preparations, permeabilized cells, and isolated germ cell nuclei. As anticipated, the pattern of DHR changed in a cell-type specific manner during the course of spermatogenesis, reflective of known stage-dependent alterations in the composition and structure of both the chromatin and the nuclear lamina/matrix as well as changes in gene expression. DHR in preleptotene spermatocytes were primarily peripheral, while in pachytene spermatocytes they were localized along the condensed chromosomes. The pattern of DHR changed from “checkerboard” in steps 7-8 round spermatid nuclei to “lamellar” in steps 10-11 elongating spermatids. In steps 12-13 elongating spermatids, DHR were localized throughout the nuclei or in a graded manner - increasing from anterior to posterior and mirroring the pattern of chromatin condensation. However, unlike the case in other stages, DNA of steps 12-13 elongating spermatids was exquisitely sensitive to nick translation even in the absence of exogenous DNase I. In contrast to the labeling of earlier stages, steps 16-19 spermatids and mature spermatozoa did not demonstrate DNase I-hypersensitivity under any conditions employed. A variety of agents that interact with topoisomerase II and DNA (teniposide, novobiocin, ethidium bromide, and adenosine triphosphate) were tested to determine the basis for the unique sensitivity to nick translation of steps 12-13 elongating spermatids. None of the agents tested, however, affected this unique labeling. The sensitivity of steps 12-13 elongating spermatids to nick translation in the absence of exogenous nuclease indicates the presence of endogenous nicks, which may relieve torsional stress and aid rearrangement as the chromatin is packaged into a form characteristic of the mature spermatozoon.
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  • 54
    ISSN: 1040-452X
    Keywords: Mouse ; Denuded oocytes ; Purines ; Germinal vesicle breakdown ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The potential action of purines, such as hypoxanthine and adenosine, in meiotic arrest was examined using denuded mouse oocytes. The spontaneous meiotic maturation of denuded oocytes was significantly inhibited by hypoxanthine and/or adenosine in a dose-dependent manner. Germinal vesicle breakdown (GVBD) was inhibited even at a low concentration (1 nM) of hypoxanthine, when hypoxanthine was microinjected into the cytoplasm of denuded oocytes. This inhibitory action was potentiated by co-injection with allopurinol, a metabolic blocker of hypoxanthine that can block a metabolic pathway to uric acid. By contrast, a microinjection of adenosine was no longer effective in inhibiting GVBD. Inhibitory action of purines in meiotic maturation was correlated with sustaining intracellular cAMP levels. GVBD was resumed by econazole, one of the nitroimidazole derivatives which act as inhibitors of catalytic subunit of adenylate cyclase. This compound was effective in counteracting the effect of adenosine, but not the action of 3-isobutyl-1-methylxanthine (IBMX) on GVBD, indicating that adenosine is probably exerted at the level of oocyte plasmalemma. These data suggest that the inhibitory action of hypoxanthine and adenosine in oocyte meiotic maturation may be involved in the regulation of cAMP metabolism in a differential manner.
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  • 55
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    ISSN: 1040-452X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 56
    ISSN: 1040-452X
    Keywords: Acrosome reaction ; Signal transduction ; Pertussis toxin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Mammalian sperm possess a guanine nucleotide-binding regulatory protein (G protein), with properties similar to Gi, that appears to be involved in the signal transduction pathway required for zona pellucida (ZP)-mediated acrosomal exocytosis. Mouse sperm treated with pertussis toxin (PT), a toxin that functionally inactivates Gi proteins, bind to the ZP of mouse eggs but are inhibited from undergoing acrosomal exocytosis. We have measured high-affinity GTPase activity and GTPγ[35S] binding in mouse sperm homogenates incubated in the absence and presence of ZP glycoproteins isolated from either ovulated eggs or from ovarian homogenates to determine whether this extracellular matrix can activate the sperm-associated Gi protein. An increase in GTP hydrolysis (∼50% over basal activity) and GTPγ[35S] binding (∼25-60% over basal activity) is observed when sperm homogenates are incubated in the presence of solubilized ZP glycoproteins, and the increase in GTPase activity is dependent on the concentration of ZP added to the homogenates. Accompanying this increase is a reduction in the ability of PT to catalyze in vitro [32P]ADP-ribosylation of a Mr = 41,000 sperm Gi protein, suggesting that the increase in GTPase activity and GTPγ[35S] binding is associated with the activation of a PT-sensitive sperm G protein(s). The ability of the ZP to stimulate high-affinity GTPase activity in these homogenates appears to be dependent on the capacitation state of the sperm from which the homogenates are prepared. These data suggest that a component(s) of the ZP may function in a manner similar to that of other ligands by binding to a sperm surface-associated receptor and subsequently activating a G protein coupled to an intracellular signal transduction cascade(s) required for induction of acrosomal exocytosis.
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  • 57
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 287-296 
    ISSN: 1040-452X
    Keywords: Phosphorylation ; Protein synthesis ; Pronuclei ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The nuclear restructuring that occurs between insemination and full pronuclear formation in pig eggs is accompanied by posttranslational changes to specific egg proteins. Sperm penetration begins in vitro at 3 hr postinsemination (hpi). By 5 hr, decondensing sperm heads and anaphase II plates are observed in 50% of eggs, and, by 8 hpi, both male and female pronuclei have formed. Three consistent changes to the pattern of newly synthesised proteins are triggered in this period; they affect the 46K, 25K, and 22K polypeptides. Changes are also triggered in the 180-200K polypeptides and in the 14K polypeptides, but these are highly variable. The same changes in the prefertilization pattern were observed when prelabelled eggs were used and new protein synthesis was suppressed. The first and most abrupt change involves the apparent catabolic elimination of a group of 46K unphosphorylated polypeptides (pl 7.3-6.4), whose synthesis was greatest before germinal vesicle breakdown but declined slowly in the final phase of maturation, then declined precipitously after activation. Ageing (beyond maturation) also leads to the disappearance of these polypeptides. The progressive disappearance of a set of 25K polypeptides and the concomitant appearance of a dominant 22K polypeptide is the most characteristic fertilization-induced modification to porcine egg proteins. These modifications begin within 1 hr of sperm penetration or activation, are specific to the pig, and involve heavily phosphorylated polypeptides (25K, pl 6.7-6.0) whose synthesis is begun in the early metaphase I stage. Dual ([35S] and [32P]) labelling, protein blocking experiments, and use of alkaline phosphatase suggest that dephosphorylation selectively affects these 25K polypeptides and is mainly or wholly responsible for converting them (completely within 6 hr) to a single, new (22K, pl 7.6) species that is positively charged. The 25K/22K polypeptide modification has a close temporal relationship with the formation of the male and female pronuclei.
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  • 58
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    ISSN: 1040-452X
    Keywords: Meiotic maturation ; Germinal vesicle breakdown ; Cycloheximide ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The regulation of meiotic events of goat oocytes from prophase I to metaphase II was studied by inhibiting protein synthesis at different times of the transition and by analyzing the changes in the protein synthesis pattern during maturation. Protein synthesis was required for germinal vesicle breakdown (GVBD). Nevertheless, the concomitant event to the rupture of germinal vesicle, i.e., chromosome condensation, took place even in a cycloheximide-containing medium. The transition from metaphase I to metaphase II was also protein synthesis dependent as evidenced by experiments using this protein synthesis inhibitor. The inhibition was partly reversible, i.e., after removal of the drug, oocytes were able to progress until metaphase I but could not proceed beyond this stage. Changes in the protein synthesis pattern were studied by radiolabelling of oocytes with [35S]methionine. These changes were correlated with the nuclear status of the oocyte: At GVBD, a polypeptide of 25 kD disappeared, while one of 27 kD appeared. At the same time, a polypeptide of 33 kD appeared, whereas concomitantly one of 34 kD became barely detectable and finally disappeared as the maturation progressed. During maturation, the synthesis of a 67 kD polypeptide increased and became predominant at the end of the maturation process. The synthesis of actin decreased after 18 hr of culture from a very high to a low level of synthesis. © 1992 Wiley-Liss, Inc.
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  • 59
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    ISSN: 1040-452X
    Keywords: Activation ; Calcium ; Fura-2 ; Electrical pulse ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Electrical stimulation is known to cause activation in mammalian oocytes, possibly by eliciting an elevation in intracellular calcium (Ca2+). This study reports intracellular Ca2+ concentrations in mature rabbit oocytes using the Ca2+ indicator fura-2. Calcium levels were determined prior to, during, and after the administration of an electrical pulse (3.6 kV/cm for 60 μsec). Baseline Ca2+ levels ranged from 30 to 90 nM. The intracellular Ca2+ transient evoked by a pulse, peaked at 11 sec, was highly variable in amplitude (40-300 nM) and returned to prepulse levels within 300 sec. Electrically stimulated oocytes did not exhibit repetitive Ca2+ transients. The size of the cytoplasmic Ca2+ rise was influenced by the duration of the pulse, the field strength and the concentrations of external Ca2+ (P 〈 0.05). Oocytes electrically stimulated in the presence of 100 μM CaCl2, which evoked Ca2+ transients with a mean magnitude of 120 nM, activated at a higher rate (P 〈 0.05) than oocytes stimulated in the presence of either higher or lower levels of external Ca2+. Although oocytes electrically shocked at 16-18 hr after administration of human chorionic gonadotropin (hphCG) activated at a lower rate than oocytes stimulated at 22-24 hphCG (P 〈 0.05), their intracellular Ca2+ response to the pulse was similar (P 〈 0.05). These results indicate that electrical pulse parameters and extracellular Ca2+ concentrations can be used to modulate intracellular Ca2+ levels and optimize oocyte activation rates. Furthermore, the data suggest that as the oocyte ages it becomes more responsive to a given intracellular Ca2+ elevation. © 1992 Wiley-Liss, Inc.
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  • 60
    ISSN: 1040-452X
    Keywords: Sperm-egg interaction ; Glycolipid binding protein ; Capacitation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Sulfolipid-immobilizing protein 1 (SLIP1) is a germ cell plasma membrane protein that binds specifically to sulfogalactosylglycerolipid, a sulfoglycolipid found preferentially in mammalian male germ cells (Lingwood, Can. J. Biochem. Cell. Biol. 63:1077-1085, 1985b). SLIP1 in mouse and rat sperm exists on the periacrosomal membrane, where sperm initially bind to eggs. Using the in vitro mouse sperm-egg binding assay with in vitro-capacitated sperm, we obtained results previously suggesting that sperm SLIP1 is involved in mouse sperm-zona pellucida interaction. In this study, using the in vitro sperm-egg binding assay, we showed that SLIP1 in uterine sperm was similarly engaged in this process. Involvement of mouse sperm SLIP1 was also shown to be important in the vivo fertilization process. Superovulated females inseminated with caudal epidididymal and vas deferens sperm preexposed to anti-SLIP1 lgG yielded only 20% fertilized zygotes, while 80% fertilization was observed in females inseminated with sperm preincubated with preimmune serum lgG. The lower fertilization rate was not due to changes in the sperm capacitation rate as assessed by chlortetracycline staining. © 1992 Wiley-Liss, Inc.
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