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The synthesis and localization of alternatively spliced fibronectin EIIIB in resting and thrombin-treated megakaryocytes 总被引:1,自引:1,他引:0
There are several species of alternatively spliced fibronectin (FN). One of these, FN EIIIB, is primarily present in embryonic and in proliferating and migrating cells and is believed to be important for cell maturation. We have studied the synthesis, localization, and secretion of this FN isoform in isolated guinea pig megakaryocytes, nonmegakaryocytic bone marrow cells, and platelets. There was 7.5 times more general FN in megakaryocytes than in nonmegakaryocytic cells based on the analysis of equivalent amounts of protein. FN EIIIB was detected by Western blotting in megakaryocytes but not in nonmegakaryocytic cells present in bone marrow. Neither megakaryocytes nor platelets secreted FN EIIIB, while megakaryocytes secreted 25.3% +/- 4.6% general FN and platelets secreted about 61% general FN in response to thrombin. Analysis of immunostained cells by confocal microscopy revealed that FN EIIIB had been redistributed to the surface of megakaryocytes in response to thrombin. Synthesis was studied by metabolic labeling, and megakaryocytes were shown to synthesize FN and FN EIIIB. Thus, megakaryocytes and platelets are among a small number of adult cells and tissues that synthesize and contain FN EIIIB. The expression of FN EIIIB on the megakaryocyte surface may influence migration and maturation. 相似文献
14.
Intestinal schistosomiasis japonica: CT-pathologic correlation 总被引:1,自引:0,他引:1
Lee RC; Chiang JH; Chou YH; Rubesin SE; Wu HP; Jeng WC; Hsu CC; Tiu CM; Chang T 《Radiology》1994,193(2):539
15.
Pulmonary oxidative stress response in young children with cystic fibrosis 总被引:4,自引:3,他引:1
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BACKGROUND: It has been suggested that oxidative stress contributes to lung injury in cystic fibrosis. There is, however, no direct evidence of increased pulmonary oxidative stress in cystic fibrosis nor of the effects of inflammation on the major pulmonary antioxidant, glutathione. A study was undertaken to measure these parameters in infants and young children in the presence or absence of pulmonary inflammation. METHODS: Thirty two infants and young children with cystic fibrosis of mean (SD) age 21.4 (15.3) months (range 2-54) and seven non-cystic fibrosis control subjects of mean (SD) age 21.0 (21.2) months (range 2-54) were studied using bronchoalveolar lavage (BAL). On the basis of the BAL findings the cystic fibrosis group was divided into those with (CF-I) and those without pulmonary inflammation (CF- NI). Levels of lipid hydroperoxide, total glutathione, and gamma- glutamyl transpeptidase (gamma-GT) were then measured in the BAL fluid. RESULTS: The concentrations of lipid hydroperoxide and gamma-GT in the epithelial lining fluid were significantly increased in the CF-I group compared with the control and CF-NI groups, each of which had similar values for these parameters (ratio of geometric means for CF-I group versus control for lipid hydroperoxide 5.4 (95% confidence interval (CI) 1.8 to 15.8) and for gamma-GT 5.2 (95% CI 1.4 to 19.4)). The glutathione concentration tended to be lower in the CF-I subjects but the difference did not reach statistical significance. CONCLUSIONS: These results demonstrate that the airways in patients with cystic fibrosis are exposed to increased oxidative stress which appears to be a consequence of pulmonary inflammation rather than part of the primary cystic fibrosis defect. The increase in gamma-GT in the CF-I group suggests a mechanism by which extracellular glutathione could be utilised by airway epithelial cells.
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16.
B. J. Young R. O’Regan F. Kinsella A. Benedict-Smith M. McDermott M. Hillery L. M. T. Collum M. Hickey-Dwyer P. Mullaney J. Blake M. Hope-Ross S. Travers D. Mooney P. S. Phelan P. E. Cleary D. F. P. Larkin D. Roden P. Eustace H. N. O’Donoghue J. D. McAdoo J. G. Madden J. P. Burke M. O’Keefe R. Bowell M. O’Sullivan P. T. McLister D. J. Wilson J. Walsh 《Irish journal of medical science》1988,157(3):91-94
17.
Lesley Barclay RN CM BA MEd Louise Everitt RN CM Post Grad Dip-Comm Health Frances Rogan RN CM B App S M Com Nurs Virginia Schmied RN CM BA MA Hons Aileen Wyllie RN CM BA MHPEd 《Journal of advanced nursing》1997,25(4):719-728
This paper presents the results of a qualitative study conducted by midwife researchers into women's experience of new motherhood. Data were collected using focus groups involving 55 first-time mothers and analysed using grounded theory method. The analysis produced six categories: 'realizing', 'unready', 'drained', 'aloneness', 'loss' and 'working it out'. The core category, 'becoming a mother', integrates all other categories and encapsulates the process of change experienced by women. Also explained are factors mediating the often distressing experience of becoming a mother. The analysis provides a conceptualization of early motherhood enabling the development of strategies for midwives, nurses and others helping women negotiate this challenge. 相似文献
18.
Summary— Experiments were designed to determine whether or not indapamide, an antihypertensive agent with vasodilator properties, inhibits endothelium-dependent contractions. Rings of aortae with and without endothelium from spontaneously hypertensive rats (SHR) were suspended in conventional organ chambers for the measurement of isometric force. Acetylcholine and adenosine diphosphate-β-S in the presence of a nitric oxide synthase inhibitor, caused endothelium-dependent contractions, which were inhibited by indapamide. The compound (10−4 M) also slightly reduced the contractions of rings without endothelium evoked by U-46,619, which activates thromboxane-endoperoxide receptors. These results demonstrate that indapamide inhibits endothelium-dependent contractions in the SHR aorta, and suggest that the inhibition is due, at least in part, to the action of the drug on the hypertensive vascular smooth muscle. 相似文献
19.
Targeted gene disruption of murine CD7 总被引:2,自引:0,他引:2
CD7 is a 40 kDa type I transmembrane glycoprotein member of the Ig
superfamily. CD7 is a marker of mature human T cells and NK cells, and is
expressed early in their development. Cross-linking CD7 positively
modulates T cell and NK cell activity as measured by calcium fluxes,
expression of adhesion molecules, cytokine secretion and proliferation. CD7
associates directly with phosphoinositol 3'-kinase, and CD7 ligation
induces production of D-3 phosphoinositides and tyrosine phosphorylation.
Severe combined immunodeficiency has been associated with a lack of
lymphocyte surface CD7. The CD7 ligand is unknown. The murine CD7 homolog
is encoded by a single gene on chromosome 11. In order to characterize the
role of CD7 in lymphocyte development and function we have eliminated the
CD7 gene by targeted disruption. CD7- deficient mice display normal
histology of thymus and spleen, normal lymphocyte populations in primary
and secondary lymphoid tissues, and normal serum Ig levels. Specific
antibody responses after immunization with T-dependent and T-independent
antigens are equivalent in wild-type and CD7 knockout mice. CD7-deficient
lymphocytes respond normally to T cell mitogenic and allogeneic stimuli,
and display normal NK cell cytotoxicity.
相似文献
20.
The effects of antioxidant supplementation during Percoll preparation on human sperm DNA integrity 总被引:20,自引:6,他引:20
Hughes CM; Lewis SE; McKelvey-Martin VJ; Thompson W 《Human reproduction (Oxford, England)》1998,13(5):1240-1247
The integrity of sperm DNA is crucial for the maintenance of genetic
health. A major source of damage is reactive oxygen species (ROS)
generation; therefore, antioxidants may afford protection to sperm DNA. The
objectives of the study were, first, to measure the effects of antioxidant
supplementation in vitro on endogenous DNA damage in spermatozoa using the
single cell gel electrophoresis (comet) assay and, second, to assess the
effect of antioxidant supplementation given prior to X-ray irradiation on
induced DNA damage. Spermatozoa from 150 patients were prepared by Percoll
centrifugation in the presence of ascorbic acid (300, 600 microM), alpha
tocopherol (30, 60 microM), urate (200, 400 microM), or acetyl cysteine (5,
10 microM). DNA damage was induced by 30 Gy X-irradiation. DNA strand
breakage was measured using the comet assay. Sperm DNA was protected from
DNA damage by ascorbic acid (600 microM), alpha tocopherol (30 and 60
microM) and urate (400 microM). These antioxidants provided protection from
subsequent DNA damage by X-ray irradiation. In contrast, acetyl cysteine or
ascorbate and alpha tocopherol together induced further DNA damage.
Supplementation in vitro with the antioxidants ascorbate, urate and alpha
tocopherol separately has beneficial effects for sperm DNA integrity.
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