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  • Life and Medical Sciences  (126)
  • ASTROPHYSICS
  • Humans
  • Wiley-Blackwell  (126)
  • 1990-1994
  • 1985-1989  (126)
  • 1987  (126)
  • 1
    Electronic Resource
    Electronic Resource
    Functional mechanisms and histologic composition of the lingual appendage in the alligator snapping turtle, Macroclemys temmincki (Troost) (Testudines: Chelydridae) (1987)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 194 (1987), S. 287-301 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Gross and microscopic examination of the lingual appendages of juvenile and adult alligator snapping turtles, Macroclemys temmincki, shows that it is divided into an anterior horn, a body, and a posterior horn. Lingual appendages of adults usually are more darkly pigmented than those of juveniles and melanocyte distribution is variable, resulting in a mottled appearance. The musculoskeletal components of the hyoid apparatus, presumably responsible for most of the motion displayed by the appendage, are described here. The lingual appendage is innervated by the lingual nerve which divides into three branches, two coursing rostrally into the anterior horn and one running caudally into the posterior horn. These branches ramify and end in numerous terminals within the lamina epithelialis and lamina propria. The lamina epithelialis of the distal three-fourths of the horns of the lingual appendage contain structures similar to taste buds described in other species of turtles. Goblet cells, containing acid mucopolysaccharides, are located in the stratified squamous epithelium. Blood is transported to the appendage via the lingual artery, which is a terminal branch of the external carotid artery. Numerous venous sinuses lie among the predominant bundles of connective tissue and account for approximately one-fifth of the total volume of the appendage. An engorged appendage is swollen and pinker in color.The coloration, enlargement, and wiggling movement combined with its buoyancy in water make the appendage imitate a small worm or an insect larva. The increase in melanin during ontogeny may produce a more variable pattern and may increase the number of organisms attracted by the appendage. The acid mucopolysaccharides of the globlet cells presumably may condition the nonkeratinized, stratified squamous epithelial surface of the appendage. The flexibility of the pseudoerect, active appendage keep it from being injured.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051940308
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  • 2
    Electronic Resource
    Electronic Resource
    Calcium mobilization in permeabilized fibroblasts: Effects of inositol trisphosphate, orthovanadate, mitogens, phorbol ester, and guanosine triphosphate (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 130 (1987), S. 29-36 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Utilizing a digitonin-permeabilized cell system, we have studied the release of calcium from a non-mitochondrial intracellular compartment in cultured human fibroblasts (HSWP cells). Addition of 1 mM MgATP to a monolayer of permeabilized cells in a cytosolic media buffered to 150 nM Ca with EGTA rapidly stimulates 45Ca uptake, and the subsequent addition of the putative intracellular messenger inositol trisphosphate (InsP3) induces rapid release of 85% (±6% n = 6) of the 45Ca taken up in response to ATP. Mitogenic peptides (bradykinin, vasopressin, epidermal growth factor [EGF], and insulin) and orthovanadate, which are effective in mobilizing intracellular Ca in intact cells, have little or no effect when added alone to permeabilized cells. However, in the presence of GTP these agents stimulate accumulation of inositol phosphates and release Ca from the InsP3-sensitive pool. These data suggest that a GTP binding protein is involved in receptor mediated activation of phospholipase C, which leads to release of inositol phosphates. The GTP-dependent release of InsP3 and the mobilization of 45Ca from the intracellular compartment are inhibited by pretreatment of cells, prior to permeabilization, with the protrein kinase C activator 12-O-tetradecanoyl-phorbol-13-acetate (TPA). TPA pretreatment does not affect the InsP3 stimulated Ca release. These results suggest that protein kinase C is involved in down-regulation or inhibition of phospholipase C, or the GTP binding protein responsible for relaying the mitogenic signal from the cell surface receptor to the phospholipase C activity.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041300106
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  • 3
    Electronic Resource
    Electronic Resource
    Growth of a human carcinoma (HEp3) in nude mice: Rapid and efficient metastasis (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 133 (1987), S. 288-296 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Our aim was to identify conditions which would permit the development of spontaneous metastasis of a human tumor in nude mice in a rapid and predictable manner and to explore ways to quantitate metastasis. Using a human squamous carcinoma-HEp3-we determined that invasiveness and metastasis were influenced by the host. HEp3 cells grew very rapidly and without a significant lag period in Balb/c and NIH(S)-II nude mice kept in aseptic conditions; a much longer lag period was observed in NIH-Swiss mice kept in conventional conditions. The HEp3 tumor displayed a highly invasive behavior in N-NIH(S)-II mice, in which it invaded the body wall, gaining access to the peritoneal cavity. Microinvasion was noted in all strains of mice inoculated with HEp3 cells. To prolong survival of the mice until metastases became evident, primary tumors were excised when they weighed 1-2 gm. N-NIH(S)-II and Balb/c nude mice, maintained in germ-free conditions, were most receptive to the development of metastases-lung metastases developed in 80% of these mice. Over 60% of all metastases were present within 4 weeks following the removal of the primary. Only 26% of tumor bearing NIH-Swiss developed lung metastases. Lung metastases were observed in some mice in the absence of local microinvasion, local tumor recurrence, and regardless of the presence of lymph node involvement. They were also noted in mice from which primary tumors were not excised. We compared three methods of lung metastasis detection: histology, detection of tumor cells in the cultures of lung minces, and the measurement of the levels of human urokinase-type plasminogen activator directly in the lysates of lungs. The detection of tumor cells in cultures of lung minces appeared to be the most sensitive of these methods and the determination of enzyme in lung lysates seemed to hold most promise for a quantitative approach. These data indicate that, the type of tumor, as well as the genetic background and the maintenance conditions of the host, have to be carefully selected to ensure the successful outcome of the particular tumor-host interaction being studied. Adherence to these guidelines allowed us, in the case of the HEp3 tumor, to develop a rapid, predictable, and efficient model in which to study factors affecting metastasis of this human tumor.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041330212
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  • 4
    Electronic Resource
    Electronic Resource
    Verapamil inhibits serotonin uptake of endothelial cells in culture by a mechanism unrelated to Ca2+ channel blockade (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 132 (1987), S. 178-182 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Verapamil inhibited Na+-dependent uptake of serotonin (5-HT) by bovine pulmonary artery endothelial cells in culture both exposed to room air and stimulated by prior exposure to anoxia. The effect of verapamil occurred even in the absence of Ca2+ from the assay medium. Although absence of Ca2+ from the medium moderately reduced 5-HT uptake, stimulation of uptake was nevertheless observed for cells previously exposed to anoxia. Verapamil altered the Km, but not the Vmax, of 5-HT uptake. There was no change in 45Ca2+ uptake or release by cells previously exposed to anoxia as compared to those exposed to room air and verapamil did not influence 45Ca2+ fluxes by either set of cells. It is concluded that verapamil inhibits 5-HT uptake by endothelial cells through a mechanism other than Ca2+ channel blockade; the results are consistent with competitive inhibition of a 5-HT carrier. The stimulatory effect of anoxia on 5-HT uptake does not occur through a change in Ca2+ fluxes.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041320126
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  • 5
    Electronic Resource
    Electronic Resource
    Free sterol metabolism and low density lipoprotein receptor expression as differentiation markers of cultured human keratinocytes (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 132 (1987), S. 428-440 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In contrast to most tissues, epidermis and its derivatives appear to lack low density lipoprotein (LDL) receptors and exhibit sterologenesis rates unaffected by circulating lipoprotein (LP) cholesterol content. Since LDL receptors have been demonstrated in both cultured squamous cell carcinoma cells and human foreskin keratinocytes, when maintained in low-calcium media, LDL receptor expression may be related to keratinocyte differentiation. We compared receptor binding and internalization of LDL-gold in normal keratinocytes at different stages of growth at physiological calcium concentrations (early, 3-5 days; preconfluent, 6-10 days; postconfluent, 12-17 days), and correlated receptor expression with sterologenesis in LP-replete vs.-depleted media. Whereas in early cultures about 60% of sterologenesis was LP dependent, this fraction declined in preconfluent and confluent cultures despite continued culture growth and little decline in total sterologenesis. Accordingly, LDL receptors were most evident in early cultures, declining in preconfluent cultures in parallel with the decrease in LP-dependent sterol synthesis. In contrast, sterologenesis in human foreskin fibroblasts was profoundly influenced by exogenous LP at all stages of confluence; total and LP-dependent sterologenesis declined in parallel with growth cessation. These studies represent the first demonstration that normal keratinocytes express functional LDL receptors at physiologic calcium concentrations. Moreover, they demonstrate that LDL receptor expression in keratinocytes, in contrast to fibroblasts, can only in part be attributed to growth requirements. Instead, loss of LDL receptor expression serves as a distinctive marker of keratinocyte differentiation and may reflect the specific functional requirements of the epidermis in vivo.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041320305
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  • 6
    Electronic Resource
    Electronic Resource
    Ornithine decarboxylase activity during rat spermatogenesis in vivo and in vitro: Selective effect of hormones and growth factors (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 133 (1987), S. 305-312 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have established the patterns of ornithine decarboxylase activity (an enzyme related to cell growth, differentiation, and proliferation) during rat testicular development and studied the effect of epidermal growth factor (EGF), platelet-derived growth factor (PDGF), transforming growth factor-type β (TGF-β), and a serum-free, hormone/growth factor-supplemented medium (TKM) on ornithine decarboxylase (ODC) activity in Sertoli-spermatogenic cell cocultures and cultured seminiferous peritubular cells prepared from sexually immature rats (20-22 days old). Results were correlated with timing of ODC activities during rat testicular development. We have found that: (1) although EGF, alone or combined with PDGF and TGF-β, and TKM stimulated ODC activity in Sertoli-spermatogenic cell cocultures after 6 and 24 h of stimulation, PDGF exerted an inhibitory effect, and (2) cultured peritubular cells stimulated with EGF, PDGF, TGF-β (and their combinations), and TKM displayed an increase in ODC activity after 6 h of stimulation, but ODC activities for most of these treatments declined considerably 24 h after stimulation. Light microscopic autoradiographic studies of [3H]thymidine labeled samples demonstrated that (1) clones of spermatogenic cells traverse S phase synchronously, (2) Sertoli cells are not significantly radiolabeled, probably because of contact inhibition achieved by high cell plating density, and (3) peritubular cells are significantly [3H]thymidine labeled in the presence of TKM, a culture medium that facilitates spermatogenic cell long-term viability and differentiation. We conclude that TKM and EGF have stimulatory effects on the biochemical pathway that precedes synchronous DNA synthesis in spermatogonia and preleptotene spermatocytes, and that ODC activity is a sensitive marker for monitoring these events.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041330214
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  • 7
    Electronic Resource
    Electronic Resource
    Regulation of amino acid transport in isolated rat hepatocytes during development (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 130 (1987), S. 103-110 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The effect of amino acid depletion or supplementation and the effect of glucagon and insulin on the amino acid transport mediated by system A were investigated by determining the uptake of either 2-amino [1-14C]isobutyric acid (AIB) or N-methyl 2-amino [1-14C]isobutyric acid (MeAIB) in rat hepatocytes, freshly isolated at different stages of pre- and postnatal development. The data obtained show that the Na+-dependent uptake was higher at the earliest developmental stages, and steadily decreased until the adult level. The hormones increased AIB and MeAIB uptake enhancing the Vmax, while the Km was unchanged. This effect was evident in cells from adult and 18-20-day-old fetuses, while no response was present before the 18th day of fetal life and in the perinatal period. Actinomycin D or cycloheximide abolished this hormone-dependent increase. A decrease in AIB and MeAIB transport after incubation in an amino acid-rich medium was demonstrated at all ages tested, but was particularly evident in the prenatal life. The increase in the activity of the system following amino acid starvation was shown to be mostly dependent from de novo protein synthesis in the fetal life; on the contrary in the adult the increase appeared to be more linked to the releas from transinhibition of the transport.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041300115
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  • 8
    Electronic Resource
    Electronic Resource
    Receptor binding and mitogenic effects of insulin and insulinlike growth factors I and II for human myeloid leukemic cells (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 133 (1987), S. 219-227 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Insulin and insulinlike growth factors I and II (IGF-I and IGF-II) influence mesodermal cell proliferation and differentiation. As multiple growth factors are involved in hemopoietic cell proliferation and differentiation, we assessed the receptor binding and mitogenic effects of these peptides on a panel of mesodermally derived human myeloid leukemic cell lines. The promyelocytic cell line HL60 had the highest level of specific binding for these 125I-labeled ligands, with lower binding to the less differentiated myeloblast cell line KG1 and undifferentiated blast variants of these cell lines (HL60blast, KG1a). Insulin binding affinity and receptor numbers were reduced significantly by chemically induced granulocytic differentiation of HL60 cells and was unchanged following induced monocytic differentiation. No substantial alteration in IGF-I or -II binding occurred with induced HL60 cell differentiation. Insulin and IGF-I demonstrated cross competition for receptor binding and down-regulated their homologous receptors without detectable cross modulation of the heterologous receptors on HL60 cells. IGF-I and insulin increased HL60 cell proliferation, as assessed by 3H-thymidine uptake, IGF-I〉 insulin. IGF-I binding and mitogenic effects were blocked by the monoclonal anti-IGF-I receptor antibody IR3, indicating that IGF-I-induced proliferative effects were mediated via its homologous receptor. In contrast, insulin binding and mitogenesis displayed blocking by both anti-IGI-I and anti-insulin receptor antibodies, indicating mediation of its activity through both receptors. These data demonstrate specific binding and mitogenic interactions between insulin, IGFs, and hemopoietic cells which are associated with their state of differentiation.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041330204
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  • 9
    Electronic Resource
    Electronic Resource
    Identification of a male-specific histocompatibility protein on preimplantation porcine embryos (1987)
    New York, NY : Wiley-Blackwell
    Gamete Research 17 (1987), S. 107-113 
    Details
    ISSN: 0148-7280
    Keywords: immunofluorescence ; early development ; gene expression ; H-Y antigen ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: An indirect immunofluorescence assay was used to detect the presence of male-specific protein(s) on various stages of preimplantation porcine embryos. Embryos were collected at slaughter from the reproductive tracts of day-2.5, -4, -5, -6, and -8 (day 0 = first day of estrus) sows and gilts. Embryos were placed in medium containing an anti-male primary antibody, washed, and transferred to culture drops containing a fluorescein isothiocyanate (FITC)-labeled secondary antibody. Embryos were classified as either fluorescent (H-Y positive) or nonfluorescent (H-Y negative), transferred to coded drops, and karyotyped to examine sex chromosomes. A total of 91 eight-cell to blastocyst stage embryos were evaluated; of these, 46% were classified as fluorescent and 54% as nonfluorescent. Of readable metaphase spreads (65%) from these embryos, 81% (48 of 59, P 〈 0.005) were correctly sexed by immunological detection of the male-specific antigen. Although 13 % (2/15)of four-cell embryos evaluated were classified as fluorescent, the accuracy with which embryos at this stage were sexed by detection of H-Y antigen was not different from 50%. Fifty percent of eight-cell embryos were classified as H-Y positive with 78% of embryos correctly sexed. It was concluded that the eight-cell embryo is the earliest stage of development for which there is evidence for expression of H-Y antigen. Detection of the male-specific protein was difficult at the expanded blastocyst stage.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120170203
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  • 10
    Electronic Resource
    Electronic Resource
    Diversification and progression of malignant tumors (1987)
    New York, NY : Wiley-Blackwell
    BioEssays 6 (1987), S. 204-208 
    Details
    ISSN: 0265-9247
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Tumor-cell diversification mechanisms insure that malignant neoplasms contain diversified tumor-cell subpopulations. Because of the instability of tumor cell phenotypes, some malignant cells will evolve with the most favorable properties for their progression to highly metastatic cells. The rates of cellular phenotypic diversification vary greatly among different tumors, and they are probably modulated, in part, by genetic and chromosome defects and by epigenetic events that may vary widely depending upon the nature of the tumor cells and their microenvironments. As tumor diversification and selection proceed, the most malignant cell subpopulations may eventually become dominant and gradually lose their microenvironmental responsiveness. Tumor-cell diversification mechanisms may be similar or identical to normal, developmentally regulated diversification mechanisms that are used during embryonic cell diversification and differentiation.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bies.950060503
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