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  • 1990-1994  (15)
  • 1955-1959
  • Life and Medical Sciences  (12)
  • Females  (3)
  • 1
    Digitale Medien
    Digitale Medien
    Agonistic relationships between female mountain gorillas (Gorilla gorilla beringei) (1994)
    Springer
    Behavioral ecology and sociobiology 34 (1994), S. 347-358 
    Details
    ISSN: 1432-0762
    Schlagwort(e): Gorillas ; Females ; Aggression ; Agonistic hierarchies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Females in some mountain gorilla groups can be ranked on the basis of decided, non-aggressive approach-retreat interactions. However, data on four gorilla groups show that females do not form clear agonistic dominance hierarchies. Most aggressive interactions between females were undecided, and most dyads had undecided dominance relationships (Fig. 2). Females ignored aggression or responded to it aggressively more often than they responded submissively (Fig. 3). Moreover, directional inconsistency in aggression (including escalated contests) was high, and in some groups females showed significant bidirectionality in initiation of aggression (i.e., the more often they received aggression from partners, the more often they directed aggression at those partners; Fig. 4). Assigning ranks on the basis of aggressive interactions has limited power to explain variation in rates of initiating aggression and in responses and outcomes to aggression. Aggression was most common during feeding, but usually did not interrupt feeding bouts. It was proportionately more common in contexts that seem to involve competition for access to males (Figs 5, 6). This is consistent with the argument that females depend crucially on male services. As predicted by current models of female primate social relationships, agonistic relationships between gorilla females are unlike those typical in cercopithecine primates. They resemble those of some other primates and some equids in which contest competition for food is relatively unimportant and ecological costs of female transfer are low.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01209781
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  • 2
    Digitale Medien
    Digitale Medien
    Agonistic relationships between female mountain gorillas (Gorilla gorilla beringei) (1994)
    Springer
    Behavioral ecology and sociobiology 34 (1994), S. 347-358 
    Details
    ISSN: 1432-0762
    Schlagwort(e): Key words: Gorillas ; Females ; Aggression ; Agonistic hierarchies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract. Females in some mountain gorilla groups can be ranked on the basis of decided, non-aggressive approach-retreat interactions. However, data on four gorilla groups show that females do not form clear agonistic dominance hierarchies. Most aggressive interactions between females were undecided, and most dyads had undecided dominance relationships (Fig. 2). Females ignored aggression or responded to it aggressively more often than they responded submissively (Fig. 3). Moreover, directional inconsistency in aggression (including escalated contests) was high, and in some groups females showed significant bidirectionality in initiation of aggression (i.e., the more often they received aggression from partners, the more often they directed aggression at those partners; Fig. 4). Assigning ranks on the basis of aggressive interactions has limited power to explain variation in rates of initiating aggression and in responses and outcomes to aggression. Aggression was most common during feeding, but usually did not interrupt feeding bouts. It was proportionately more common in contexts that seem to involve competition for access to males (Figs 5, 6). This is consistent with the argument that females depend crucially on male services. As predicted by current models of female primate social relationships, agonistic relationships between gorilla females are unlike those typical in cercopithecine primates. They resemble those of some other primates and some equids in which contest competition for food is relatively unimportant and ecological costs of female transfer are low.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01209781
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  • 3
    Digitale Medien
    Digitale Medien
    Agonistic relationships between female mountain gorillas (Gorilla gorilla beringei) (1994)
    Springer
    Behavioral ecology and sociobiology 34 (1994), S. 347-358 
    Details
    ISSN: 1432-0762
    Schlagwort(e): Gorillas ; Females ; Aggression ; Agonistic hierarchies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Females in some mountain gorilla groups can be ranked on the basis of decided, non-aggressive approach-retreat interactions. However, data on four gorilla groups show that females do not form clear agonistic dominance hierarchies. Most aggressive interactions between females were undecided, and most dyads had undecided dominance relationships (Fig. 2). Females ignored aggression or responded to it aggressively more often than they responded submissively (Fig. 3). Moreover, directional inconsistency in aggression (including escalated contests) was high, and in some groups females showed significant bidirectionality in initiation of aggression (i.e., the more often they received aggression from partners, the more often they directed aggression at those partners; Fig. 4). Assigning ranks on the basis of aggressive interactions has limited power to explain variation in rates of initiating aggression and in responses and outcomes to aggression. Aggression was most common during feeding, but usually did not interrupt feeding bouts. It was proportionately more common in contexts that seem to involve competition for access to males (Figs 5, 6). This is consistent with the argument that females depend crucially on male services. As predicted by current models of female primate social relationships, agonistic relationships between gorilla females are unlike those typical in cercopithecine primates. They resemble those of some other primates and some equids in which contest competition for food is relatively unimportant and ecological costs of female transfer are low.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00197005
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  • 4
    Digitale Medien
    Digitale Medien
    A multiplanar anatomic study of the cervical proximal nerve roots and spinal nerves (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Clinical Anatomy 5 (1992), S. 433-440 
    Details
    ISSN: 0897-3806
    Schlagwort(e): anatomy ; spine ; sheath ; Life and Medical Sciences ; Miscellaneous Medical
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: An anatomic study focused on the proximal cervical spinal nerves has not been reported. Therefore, we dissected the cervical spinal nerves of three cadavers and examined stained sections in parasagittal and axial planes through the proximal cervical spinal nerves and root sheaths. These studies documented distinct segments of the spinal nerve which had not been completely described in the previous anatomic studies. The sheath originates from the dural sac as a common sleeve, divides into two sleeves, one containing the ventral root and one the dorsal root, and then distal to the dorsal root ganglion fuses again into one sleeve. A space, the interradicular cleft, separates the dorsal and ventral portions of the sleeve. The proximal segment of the spinal nerve proper distal to the dorsal root ganglion is composed of multiple small fascicles surrounded by a dense epineurium. The presence of an interradicular cleft in the cervical nerve root sheath and of fascicles in the cervical spinal nerve has significance for imaging of the cervical spinal nerves and for the pathogenesis of symptoms in cases of partial compression. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/ca.980050603
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  • 5
    Digitale Medien
    Digitale Medien
    Dihydropyridine calcium antagonist modulates cholesterol metabolism and eicosanoid biosynthesis in vascular cells (1992)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 48 (1992), S. 393-400 
    Details
    ISSN: 0730-2312
    Schlagwort(e): calcium channel blocker ; atherosclerosis ; LDL ; LDL-receptor ; vascular smooth muscle ; PGI2 ; cyclic AMP ; cyclooxygenase ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Recent clinical studies have shown that calcium channel blockers can retard and possibly reduce the angiographic progression of coronary artery disease. Calcium channel blockers also inhibit dietary-induced atherosclerosis in animal models of this disease. In this study, we delineate potential cellular and molecular mechanisms by which nicardipine, a dihydropyridine calcium antagonist, may alter lipoprotein and cholesterol trafficking, affect the regulatory signal transduction pathways involved in accelerating cholesteryl ester (CE) catabolism in vascular smooth muscle cells, and modulate cell-cell interactions of vascular and inflammatory cells. We demonstrate in arterial smooth muscle cells that nicardipine increases (1) LDL binding, uptake, and degradation, (2) RNA transcript levels for the LDL receptor, (3) CE catabolic activity, (4) PGI2 release, and (5) RNA transcript levels for cyclooxygenase. Furthermore, nicardipine blocked cytokine-induced monocyte adhesion to endothelial cells and smooth muscle cells. Taken together, these findings support the hypothesis that nicardipine may function as an anti-atherosclerotic agent by promoting CE catabolism and cholesterol clearance and by reducing monocyte adhesion to the activated endothelium.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jcb.240480408
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  • 6
    Digitale Medien
    Digitale Medien
    The p53 protein detected by immunohistochemical staining is not always mutant (1993)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 53 (1993), S. 248-248 
    Details
    ISSN: 0730-2312
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: In human mammary carcinoma, positive immunohistochemical staining for p53 protein is not always indicative of mutation in the p53 gene. Although positive staining is seen in excess of 50% of tumours, mutations have been found in only some 20% of cases. In this presentation, positive p53 staining in mammary carcinomas will be related to the presence and absence of mutation and other possible underlying mechanisms.In some positively stained tumours a mutation has been found. In others, no mutation has been demonstrated and apart from possible stabilisation by a protein such as MDM2, there are alternative underlying mechanisms for this discrepancy. Wild type p53 is elevated in response to DNA damage. This effect can be seen in patients given pre-operative chemotherapy and in cell lines irradiated with UV light and with x-rays. Strong positive staining in scattered nuclei has been found in cell lines with activated ras and myc genes. We postulate that this may also be the reason for similar patterns observed in human tumours.Comparable mechanisms may be active in inherited cancers. Although positive p53 staining in some Li-Fraumeni syndrome patients is associated with mutation, in other Li-Fraumeni-like families, no mutation has been found despite positive staining in tumour and normal tissues.Whatever the mechanism underlying the stabilisation of the protein, increased expression of p53 protein in the majority of tumour cells appears to be associated with poor prognosis in breast carcinoma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jcb.240531147
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  • 7
    Digitale Medien
    Digitale Medien
    Temporally and spatially restricted expression of apolipoprotein J in the developing heart defines discrete stages of valve morphogenesis (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Developmental Dynamics 201 (1994), S. 290-296 
    Details
    ISSN: 1058-8388
    Schlagwort(e): ApoJ/clusterin ; Heart ; Cardiac development ; Cardiac valves ; Endocardial cushions ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: During cardiac valve morphogenesis, a series of interactions between the mesodermal-derived myocardium and the overlying endothelium lead to condensed leaflet structure formation. At the atrioventricular (AV) canal, endocardial cells are transformed by specialized underlying myocardial cells into endocardial cushions, and then remodeled into mitral and tricuspid valves. Aortic and pulmonary valves develop by a similar mechanism in the primitive outflow tract. Few genes exhibit restricted spatiotemporal expression in these critical embryonic structures, thus limiting the clues to the sequence of molecular events necessary for valvulogenesis. Apolipoprotein J (ApoJ), a secreted glycoprotein expressed in a variety of cell types at tissue interfaces, exhibits a highly restricted and dynamic expression pattern in the developing heart. ApoJ transcripts were detected in mice at day 9.0 of gestation in the wall of the developing truncus arteriosus. By day 10, intense signal occurred in a thin layer of myocardial cells adjacent to developing endocardial cushions of both atrioventricular canal and truncus arteriosus. No apoJ mRNA was present in the overlying endocardial cushions until day 13.5 when prevalvular condensation begins. Intense expression occurred in the stromal connective tissue throughout leaflet formation. The highly restricted spatiotemporal expression pattern of apoJ in the developing heart implicates its role in the morphogenesis of the AV canal and outflow tract into cardiac valves. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/aja.1002010311
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  • 8
    Digitale Medien
    Digitale Medien
    Functional organization of the main olfactory bulb (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 24 (1993), S. 142-156 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Sensory processing ; Olfactory coding ; Olfaction ; Odor stimulation ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Complete understanding of the role of the mammalian main olfactory bulb in sensory processing has remained elusive despite many detailed studies on its anatomy and physiology. Several lines of recent evidence viewed in the context of earlier knowledge have provided new insights into the bulbar mechanisms of olfactory coding. The output cells of the olfactory bulb receive a localized olfactory nerve input and interneuronal input via dendrodendritic synapses on distinct sets of dendrites. The spatial arrangement of granule cell contacts on output cell basal dendrites suggests that lateral inhibitory interactions may occur between neighboring output cells. The input from olfactory receptor cell axons to the bulb also has spatial order, but does not represent a precise map of the receptor surface. Recent studies with antibodies and lectins suggest that different groups of axons from chemically similar receptor cells collect into certain glomeruli, even if the axons originate from cells that are not contiguous in the mucosa. Electrophysiological studies have begun to explore the participation of spatially organized circuits in olfactory processing. The degree to which neighboring output cells respond similarly to odor stimulation, for example, depends on the distance between the cells, with those further apart showing complementary responses. Also, a single output cell can show 2 or more different temporal response patterns when different odors are presented. Intracellular recordings indicate that these responses are shaped by IPSPs. Electrical stimulation during such recordings shows that some mitral cells are excited by nerve inputs close to their glomerular tufts, while they are inhibited by nerve inputs to other parts of the bulb. Finally, recordings from granule and periglomerular cells indicate their potential in mediating components of output cell odor responses. These considerations suggest that the olfactory bulb performs a spatially based analysis on the information coming from the receptor cells. While the spatial organization of the olfactory bulb is probably not faithfully represented in the projections to the olfactory cortex, bulbocortical projections are not random. The fact that spatial factors exist at each of these levels in the olfactory system must be considered in developing models of central olfactory processing. © 1993 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070240206
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  • 9
    Digitale Medien
    Digitale Medien
    Multifactorial regulation of IGF-I gene expression (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 35 (1993), S. 358-364 
    Details
    ISSN: 1040-452X
    Schlagwort(e): Gene transcription ; Growth factor ; Growth hormone ; Development ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Insulin-like growth factor-I (IGF-I) is a highly conserved 70-residue circulating peptide with diverse biological effects. In mammals IGF-I is an essential mediator of normal postnatal growth and its expression is influenced by hormonal, nutritional, tissue-specific, and developmental factors. Recent studies have demonstrated that the IGF-I gene is more complicated than might have been predicted from its simple protein sequence. In rats and in humans the single-copy six-exon gene is transcribed by adjacent promoters into nascent RNAs with different 5′ leader sequences that undergo both alternative RNA splicing and differential polyadenylation to yield multiple mature transcripts. These observations suggest that trophic agents may modulate expression of IGF-I at any of several nodal points. In this report we review several of the mechanisms responsible for regulating production of IGF-I in the rat. During neonatal development IGF-I gene transcription is progressively activated leading to a rise in both hepatic IGF-I mRNA and in serum IGF-I. The induction of IGF-I expression is limited to mRNAs directed by promoter 1, the more 5′ of two rat IGF-I gene promoters, and precedes the ontogenic appearance of liver growth hormone (GH) receptors, indicating that mechanisms independent of GH activate IGF-I expression during early postnatal life. By contrast, in adult GH-deficient rats, a single intraperitoneal injection of GH causes a prompt rise in IGF-I gene transcription that is mediated equivalently by promoters 1 and 2. Transcriptional induction occurs within 30 min of GH treatment and is associated with a transiently appearing DNase I hypersensitive site in the second IGF-I intron. These two physiological models show that IGF-I expression is mediated by at least two distinct transcriptional mechanisms. A challenge for the future will be to define the transcription factors and delineate the critical steps in the regulation of a growth factor that is essential for normal growth and maturation. © 1993 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mrd.1080350407
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  • 10
    Digitale Medien
    Digitale Medien
    Cyclical binding, processing, and functional interactions of neutrophils with leukotriene B4 (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 142 (1990), S. 299-308 
    Details
    ISSN: 0021-9541
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Leukotrene (LT) B4 activates human polymorphonuclear neutrophils. (PMN) by binding to plasmalemmal receptors. It stimulates PMN to raise cytosolic calcium and degranulate. Both responses end within 15-30 sec. However, in 〈 15 sec, LTB4-treated PMN lose the ability to respond further to LTB4; decrease the affinity and number of high affinity receptors available for binding LTB4 sequester LTB4 in plasmalemma-associated sites that are inaccessible to a releasing buffei regi i men; and begin internalizing LTB4. Over the next 90 min, the cells increasingly internalize LTB4 and convert it to less potent metabolites; release the metabolites; recover LTB4 binding sites; and become fully sensitive to LTB4. Contrastingly, during the entire 90 min incubation with LTB4. PMN retained the capacity to bind and respond normally to a second stimulus platelet-activating factor. We therefore suggest the following model. LTB4 receptors, when ligand-bound, initiate function but rapidly lose this capacity as they lower their ligand binding affinity and sequester, internalize, or otherwise uncouple from transducing elements. These LTB4 receptor changes contribute to terminating PMN responses and producing a stimulus-selective state of desensitization. During the desensitization period, PMN progressively process and metabolize LTB4. This removes LTB4 from the environment, thereby allowing PMN to recover functional receptors for and sensitivity to the ligand.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jcp.1041420212
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