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101.
A quantitative analysis of nuclear factor I/DNA interactions.   总被引:19,自引:8,他引:11       下载免费PDF全文
Nuclear factor I (NFI) was purified to homogeneity from porcine liver by DNA-affinity chromatography and displays a single band with a molecular weight of 36 kDa in SDS-polyacrylamide gels. The purified protein was used to determine absolute equilibrium binding constants by gel retardation techniques for a variety of DNA fragments with genuine or mutated NFI binding sites and a number of DNA fragments derived from various eukaryotic promoters carrying the CCAAT-box as a half-site for NFI binding. We present a model which allows prediction of the functional significance of mutated NFI binding-sites from sequence data. The data suggest that the single molecular species of NFI from porcine liver may not be able to recognize and activate the -CCAAT- promoter element in vivo without additional interactions, e.g. with other proteins.  相似文献   
102.
An "external," nomothetic perspective that has been formulated by some historians of science (e.g., Kuhn 1968) is used to examine the history of anthropology in the United States. Regularities that characterize the growth of the physical sciences and the production and use of literature associated with them are shown to be characteristic of anthropology as well. Implications for the way anthropology will be done in the future are discussed . [anthropology, future of, growth of, history of]  相似文献   
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INTRODUCTIONAsearlyasin1948wehavefr8CtionatedisolatednucleifromnormalandtumorcellsbyextractionwithiMNaCIanddilutealkali[1].Thenuclearresiduewasthenstudiedmorethoroughly[2,3].Lateron,sillillarproteinousnuclearresidueswereisolatedbyotherworkers[46]andasstud…  相似文献   
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Background

Pneumonia is a major risk factor of death after acute stroke. In a mouse model, preventive antibacterial therapy with moxifloxacin not only prevents the development of post-stroke infections, it also reduces mortality, and improves neurological outcome significantly. In this study we investigate whether this approach is effective in stroke patients.

Methods

Preventive ANtibacterial THERapy in acute Ischemic Stroke (PANTHERIS) is a randomized, double-blind, placebo-controlled trial in 80 patients with severe, non-lacunar, ischemic stroke (NIHSS>11) in the middle cerebral artery (MCA) territory. Patients received either intravenous moxifloxacin (400 mg daily) or placebo for 5 days starting within 36 hours after stroke onset. Primary endpoint was infection within 11 days. Secondary endpoints included neurological outcome, survival, development of stroke-induced immunodepression, and induction of bacterial resistance.

Findings

On intention-to treat analysis (79 patients), the infection rate at day 11 in the moxifloxacin treated group was 15.4% compared to 32.5% in the placebo treated group (p = 0.114). On per protocol analysis (n = 66), moxifloxacin significantly reduced infection rate from 41.9% to 17.1% (p = 0.032). Stroke associated infections were associated with a lower survival rate. In this study, neurological outcome and survival were not significantly influenced by treatment with moxifloxacin. Frequency of fluoroquinolone resistance in both treatment groups did not differ. On logistic regression analysis, treatment arm as well as the interaction between treatment arm and monocytic HLA-DR expression (a marker for immunodepression) at day 1 after stroke onset was independently and highly predictive for post-stroke infections.

Interpretation

PANTHERIS suggests that preventive administration of moxifloxacin is superior in reducing infections after severe non-lacunar ischemic stroke compared to placebo. In addition, the results emphasize the pivotal role of immunodepression in developing post-stroke infections.

Trial Registration

Controlled-Trials.com ISRCTN74386719  相似文献   
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Secretion Pores in Human Endothelial Cells during Acute Hypoxia   总被引:6,自引:0,他引:6  
Weibel-Palade bodies (WPB) are endothelial vesicles that store von Willebrand factor (vWF), involved in the early phase of hemostasis. In the present study we investigated the morphodynamics of single WPB plasma membrane fusion events upon hypoxic stimulation by using atomic force microscopy (AFM). Simultaneously, we measured vWF release from endothelial cells to functionally confirm WPB exocytosis. Exposing human endothelial cells to hypoxia (pO2 = 5 mm Hg) we found an acute (within minutes) release of vWF. Despite acute vWF release, potential cellular modulators of secretion, such as intracellular pH and cell volume, remained unchanged. We only detected a slight instantaneous increase of cytosolic Ca2+ concentration. Although overall cell morphology remained virtually unchanged, high resolution AFM images of hypoxic endothelial cells disclosed secretion pores, most likely the loci of WPB exocytosis on luminal plasma membrane. We conclude that short-term hypoxia barely alters overall cell morphology and intracellular milieu. However, at nanometer scale, hypoxia instantaneously switches the smooth luminal plasma membrane to a rough activated cell surface, covered with secretion pores that release vWF to the luminal cell surface.  相似文献   
110.
The main objective of this study was to investigate the effectiveness of certain progestagen-gonadotrophin treatments on synchronization of estrus in sheep. In Experiment I, 30 Chios ewes were treated at the beginning of the breeding season with medroxyprogesterone acetate (MAP) intravaginal sponges for 12 days and a single i.m. treatment of either FSH (Group 1,10 IU, n = 8; Group 2, 5 IU, n = 8; Group 3, 2.5 IU, n = 8) or eCG (Group 4, 400 IU, n = 6) at the time of sponge removal. Ten days after sponge removal laparotomy was performed to record ovarian response. Clinical estrus was observed in more (though not at a significant level) FSH treated than eCG treated sheep (62.5% versus 33.3%). Administration of 400 IU eCG resulted in the highest mean number of CL perewe ovulating (2.8 +/- 0.2), with administration of 10 IU FSH producing the next best results (2.1 +/- 0.3). Statistically significant differences in the mean number of CL per ewe ovulating were found only between ewes in Group 3 (1.7 +/- 0.4) and Group 4 (2.8 +/- 0.2) (P < 0.05). In Experiment II, 53 Chios and 30 Berrichon ewes were treated during the mid-breeding season with MAP intravaginal sponges for 12 days and a single i.m. treatment of either 10 IU FSH (27 Chios and 16 Berrichon ewes) or 400 IU eCG (26 Chios and 14 Berrichon ewes), at the time of sponge removal. Ewes that were in estrus on Days 2-4 and 19-23 after sponge removal were mated to fertile rams. No significant differences were recorded between treatment or breed groups in the proportions of ewes observed in estrus after treatment. In the Berrichon breed, FSH administration resulted in higher lambing rates (93.8% versus 57.1%, P < 0.05) and higher mean number of lambs born per ewe exposed to rams (1.4 +/- 0.2 versus 0.8 +/- 0.2, P < 0.05) than that of eCG. After treatment with eCG, the mean number of lambs born per ewe exposed to rams was higher in the Chios than the Berrichon breed (1.4 +/- 0.2 versus 0.8 +/- 0.2, P < 0.05). After treatment with FSH, the lambing rate was higher in the Berrichon than the Chios breed (93.8% versus 63.0%, P < 0.05). In conclusion, a single FSH treatment (5 or 10 IU) at the end of progestagen treatment appears to be more effective than eCG for the induction of synchronized estrus in sheep at the beginning of the breeding season, with no cases of abnormal ovarian response observed. During the mid-breeding season FSH (10 IU) appears to be equally as effective as eCG (400 IU) in respect of lambing rate and mean number of lambs born per ewe.  相似文献   
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