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排序方式: 共有749条查询结果,搜索用时 15 毫秒
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Normal and diseased isolated lungs: high-resolution CT 总被引:8,自引:0,他引:8
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The adhesion of hematopoietic progenitor cells to bone marrow stromal cells is critical to hematopoiesis and involves multiple effector molecules. Stromal cell molecules that participate in this interaction were sought by analyzing the detergent-soluble membrane proteins of GBI/6 stromal cells that could be adsorbed by intact FDCP-1 progenitor cells. A single-chain protein from GBI/6 cells having an apparent molecular weight of 37 Kd was selectively adsorbed by FDCP-1 cells. This protein, designated p37, could be surface-radiolabeled and thus appeared to be exposed on the cell membrane. An apparently identical 37- Kd protein was expressed by three stromal cell lines, by Swiss 3T3 fibroblastic cells, and by FDCP-1 and FDCP-2 progenitor cells. p37 was selectively adsorbed from membrane lysates by a variety of murine hematopoietic cells, including erythrocytes, but not by human erythrocytes. Binding of p37 to cells was calcium-dependent, and was not affected by inhibitors of the hematopoietic homing receptor or the cell-binding or heparin-binding functions of fibronectin. It is proposed that p37 may be a novel adhesive molecule expressed on the surface of a variety of hematopoietic cells that could participate in both homotypic and heterotypic interactions of stromal and progenitor cells. 相似文献
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Jonathan G Zaroff Wayne D Babcock Stephen C Shiboski 《The Journal of heart and lung transplantation》2003,22(3):334-337
BACKGROUND: Because of the shortage of heart donors in the United States, efforts are necessary to maximize the yield of donor screening. The purpose of this study was to quantify the effects of left ventricular (LV) systolic dysfunction on heart donor use. METHODS: Using the California Transplant Donor Network database, the records of all potential organ donors screened between January 1997 and June 1998 were reviewed. After excluding subjects for whom family consent could not be obtained and subjects <13 or >or=60 years old, a study group of 223 potential heart donors was analyzed. The number of hearts not used because of LV dysfunction, coronary artery disease (CAD), valvular disease, and LV hypertrophy were quantified. A logistic regression model was developed to quantify the independent effect of LV dysfunction on donor use rates after adjustment for age, weight, and cause of death. RESULTS: Ninety-nine (44%) of the 223 potential donor hearts were not transplanted. Thirty-six of these hearts were not transplanted because of cardiac causes, primarily LV dysfunction (26 cases) and CAD (8 cases). The multivariable analysis showed that after adjusting for other donor variables, ejection fraction was the most significant predictor of non-use, with an odds ratio of 1.48 per 5-point decrease in ejection fraction. CONCLUSIONS: Left ventricular dysfunction is an important cause of failure to transplant adult donor hearts. Efforts to improve the yield of heart donor screening should focus on prevention or reversal of LV dysfunction. 相似文献
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The effects of co-culture with human fibroblasts on human embryo development in vitro and implantation 总被引:5,自引:0,他引:5
Wetzels AM; Bastiaans BA; Hendriks JC; Goverde HJ; Punt-van der Zalm AP; Verbeet JG; Braat DD 《Human reproduction (Oxford, England)》1998,13(5):1325-1330
In a human in-vitro fertilization (IVF) programme, the effect of co-
culture of embryos with human fibroblasts was evaluated with respect to
pregnancy rate and embryo development. Patients were included in the study
after giving informed written consent. The IVF treatments were randomly
assigned by stratification of both age (<36 versus > or =36 years)
and previous IVF attempts (yes versus no). After fertilization was
established, the zygotes were transferred to a 4-well dish with or without
fibroblasts and cultured for 2 days. On the third day after ovum pick-up
(OPU), cell number and quality [5 (good) to 1 (poor)] of the embryos were
scored and a maximum of three embryos was transferred. Supernumerary
embryos of good quality were cryopreserved. The design of this study was a
group sequential trial with the objective of detecting differences between
pregnancy rates following IVF with conventional incubation or incubation in
co-culture with fibroblasts. This design included one evaluation at
half-way data collection. In the study, 148 patients had an OPU, of whom 77
were allocated to the co-culture group. There was no statistically
significant difference in pregnancy rate, cell number and embryo quality
between the two groups. The ongoing pregnancy rate per embryo transfer was
27% in co-culture and 30% in the conventional culture group. The
implantation rates per transferred embryo were 17 and 18% respectively.
Using a multivariate logistic regression model for the probability of
ongoing pregnancies, the odds ratio of co-culture, adjusted for age and
previous IVF attempts, was not statistically significant. In conclusion,
co-culture with human fibroblasts does not contribute to an improvement of
embryo quality nor to a higher pregnancy rate after IVF in an unselected
group of patients.
相似文献