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991.
Transplanted oligodendrocyte progenitor cells expressing a dominant-negative FGF receptor transgene fail to migrate in vivo 总被引:1,自引:0,他引:1
DJ Osterhout S Ebner J Xu DM Ornitz GA Zazanis RD McKinnon 《Canadian Metallurgical Quarterly》1997,17(23):9122-9132
The proliferation, migration, survival, and differentiation of oligodendrocyte progenitor cells, precursors to myelin-forming oligodendrocytes in the CNS, are controlled by a number of polypeptide growth factors in vitro. The requirement and roles for individual factors in vivo, however, are primarily unknown. We have used a cell transplantation approach to examine the role of fibroblast growth factor (FGF) in oligodendrocyte development in vivo. A dominant-negative version of the FGF receptor-1 transgene was introduced into oligodendrocyte progenitors in vitro, generating cells that were nonresponsive to FGF but responsive to other mitogens. When transplanted into the brains of neonatal rats, mutant cells were unable to migrate and remained within the ventricles. These results suggest a role for FGF signaling in establishing a motile phenotype for oligodendrocyte progenitor cell migration in vivo and illustrate the utility of a somatic cell mutagenesis approach for the study of gene function during CNS development in vivo. 相似文献
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HM Sehdev DM Stamilio GA Macones E Graham MA Morgan 《Canadian Metallurgical Quarterly》1997,177(5):1030-1034
OBJECTIVE: Fewer than 50% of neonates with an umbilical arterial pH < 7.00 have neonatal complications. Our objective was to identify clinical predictive factors for adverse outcomes in this group of neonates. STUDY DESIGN: In this case-control study both cases and controls had an umbilical arterial cord pH < 7.00. Cases were defined as those neonates who had seizures, grade 3 to 4 intraventricular hemorrhage, gastrointestinal dysfunction, respiratory distress syndrome requiring intubation, sepsis, or death. Controls had an umbilical arterial cord pH < 7.00 and no complications. A multivariable prediction model was created, with variables having an association with adverse outcome by bivariate analyses, attempting to predict which neonates in this umbilical arterial pH range are at greatest risk for adverse outcomes. RESULTS: We identified 73 of 10,705 neonates born between July 1992 and October 1996 with an umbilical arterial cord pH < 7.00. Thirty-five neonates met our case definition, and the remaining 38 composed the control group. Cases had significantly lower arterial pH values and 1- and 5-minute Apgar scores, greater arterial base deficit values, and a higher incidence of abruptio placentae and maternal cocaine use. More cases were delivered before 34 weeks. There were three neonatal deaths, two cases of grade 3 or 4 intraventricular hemorrhage, five cases of gastrointestinal dysfunction, and four cases of neonatal seizures. In our predictive model for adverse neonatal outcome, an arterial base deficit > or = 16 mmol/L and a 5-minute Apgar score < 7 had a sensitivity and a specificity of 79% and 80.8%, respectively. CONCLUSION: Neonatal morbidity in neonates with an umbilical arterial cord pH < 7.00 can be predicted by a high arterial base deficit value and low 5-minute Apgar score. 相似文献
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Fiber-optic biosensors that are selective for nitric oxide and do not respond to most potential interferents have been prepared with cytochromes c'. Both micro- and nanosensors have been prepared, and their response is fast (< 1 s), reversible, and linear up to 1 mM nitric oxide. The detection limit is 20 microM, making the sensor useful for some biological samples, such as the macrophages studied here. While sensors have been prepared based on the fluorescence of the cytochromes c', optodes with greatly enhanced signal-to-noise ratios have been made by labeling the cytochrome c' with a fluorescent dye. Comparisons of cytochromes c' from three species of bacteria as well as of two matrixes were performed and the optimum sensor configuration is described. 相似文献
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IP Dudanov GA Sharshavitski? AM Mezhenin GP Chekulaeva EM Libiia?nen IuV Andreev AA Bogdanets OD Morozov 《Canadian Metallurgical Quarterly》1998,157(3):67-69
The authors dealt with treatment of 112 patients aged 27-70 years with the Mallory-Weiss syndrome. The diagnosis was confirmed by esophagogastroduodenoscopy. Diathermocoagulation was used in order to arrest bleeding. In profuse bleeding the margins of the mucosa fissures were first infiltrated with a solution of adrenaline. The Blakemore [correction of Bleikmorr] probe compression method was also used. Organ-saving operations were performed for continuing and recurrent bleedings. Two elderly patients with severe coexistent disease died. The authors consider that patients with the Mallory-Weiss syndrome must be treated by conservative methods. Operations for disruptions of the esophagus mucosa and acute blood loss will entail great risk. 相似文献
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BACKGROUND: The purpose of this study was to determine cost of care for leg ulcers in sickle cell patients and suggest an improved modality in ulcer care. STUDY DESIGN: We performed a retrospective study of a group of sickle cell disease patients with leg ulcers. RESULTS: Eighteen patients with a leg ulcer (duration: mean, 53.7 months), sickle cell disease, and a mean of 20.7 years of age had various modalities of treatment with the only consistency in healing being a commercial moist-wound dressing. CONCLUSIONS: There is no consistency in the treatment of the sickle cell patient with a leg ulcer. Treatment with a moist dressing had the best results. 相似文献
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CE Swanson GA Day CE Yelland JR Broome L Massey HR Richardson K Dimitri A Marsh 《Canadian Metallurgical Quarterly》1998,169(10):515-518
Retroperitoneal fibrosis is an uncommon collagen vascular disease. Back pain with no specific radiation pattern is a common finding. Evaluation usually begins with an abdominal CT scan or MRI. The finding of fibrous periaortic tissue in conjunction with an elevated erythrocyte sedimentation rate supports the diagnosis. A biopsy is necessary to confirm the diagnosis and exclude malignancy. Sometimes retroperitoneal fibrosis can progress to the point of causing bilateral ureteral obstruction leading to acute renal failure. Corticosteroids, in conjunction with surgery when needed, are the mainstay of therapy. 相似文献