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41.
目的:研究蛇毒Ⅱ类磷脂酶A2(PLA2)中D49 PLA2和K49 PLA2的功能分化及其功能分化决定位点的鉴定。方法:运用序列比较分析,进化树构建和DIVERGE v1.04软件计算研究D49 PLA2和K49 PLA2的功能分化情况及其分化位点。结果:序列比较分析,进化树构建和DIVERGE v1.04软件计算结果表明蛇毒Ⅱ类PLA2中D49 PLA2和K49 PLA2的确发生了功能分化,对于K49 PLA2来说,1S,7K,11Q,E12,R34,T56,N88,L92,E108,K116,K128可能为功能分化决定位点。对于D49 PLA2,L2,G33,G35,F46和Y118可能为功能分化决定位点。结论:我们首次通过序列比较分析,进化树构建和DIVERGE v1.04软件计算鉴定出蛇毒Ⅱ类PLA2中D49 PLA2和K49 PLA2可能的功能分化位点,为今后通过基因重组和定点突变方法研究蛇毒Ⅱ类PLA2结构功能关系提供了线索。  相似文献   
42.
BACKGROUND: The mucosal mast cell (MMC) granule-specific beta-chymase, mouse mast cell protease-1 (mMCP-1), is released systemically into the bloodstream early in nematode infection before parasite-specific IgE responses develop and TGF-beta1 induces constitutive release of mMCP-1 by homologues of MMC in vitro. Intraepithelial MMC may also express the chemokine CCL2 (monocyte chemotactic protein-1) during nematode infection but the expression of this chemokine by MMC homologues has not been investigated. OBJECTIVE: To investigate the expression and to compare the mechanisms of constitutive release of the chymase, mMCP-1, and the chemokine, CCL2. METHODS: MMC homologues were generated by culturing bone marrow cells in the presence of TGF-beta1, IL-3, IL-9 and stem cell factor (SCF). The intracellular distribution of mMCP-1 and CCL2 was examined by confocal microscopy. The involvement of the Golgi complex and of protein synthesis in the constitutive release of mMCP-1 and CCL2 was investigated using the Golgi-disrupting agent brefeldin A and cycloheximide to block protein synthesis. Secreted analytes were quantified by ELISA. RESULTS: mMCP-1 colocalized with Golgi matrix protein 130 but was most abundant in the granules, whereas CCL2 was not found in the granules but appeared to be located uniquely in the Golgi complex. Extracellular release of mMCP-1 was significantly inhibited ( approximately 40%) by cycloheximide and by the Golgi-disrupting agent brefeldin A, indicating both continuous protein synthesis and transportation via the Golgi complex are required for optimal mMCP-1 secretion. A similar but more marked inhibitory effect with both compounds was demonstrated on the constitutive secretion of CCL2. CONCLUSION: The culture conditions that promote mMCP-1 expression and release by MMC homologues also promote the expression and release of CCL2. Constitutive release involves de novo protein synthesis and requires a functional Golgi complex, suggesting that similar mechanisms of extracellular secretion operate for both mediators.  相似文献   
43.
高效液相色谱法测定石杉碱甲片的含量   总被引:2,自引:0,他引:2  
采用高效液相色谱法测定石杉碱甲片的含量。固定相为μBondapak C18,流动相为乙腈-0.02mol/L磷酸二氢钾溶液(12:88),以对乙酰氨基酚为内标,石杉碱甲浓度在10 ̄50mg/L范围内与峰面积呈良好的线性关系,平均回收率为99.93%,RSD为0.41%(n=9)。  相似文献   
44.
观察硒和维生素A(VA)对支原体肺炎的治疗效果.方法 采用双盲随机对照2×2析因实验设计,选择100例住院支原体肺炎患儿,分为补硒组26例,补VA组23例,补硒和VA组30例以及病例对照组21例,正常组21例.一次补硒量为1mg亚硒酸钠和/或15万单位VA,对照病例组给予常规治疗.结果 与对照组比,治疗后3个补充组的症状和体征缓解天数均有不同程度缩短(P<0.05),补硒组白细胞硒和谷胱甘肽过氧化物酶水平显著上升(P<0.05),补VA、补硒组血清VA水平上升(P<0.01),细胞免疫功能有所改善.结论 硒和VA有协同作用,补充硒或同时加VA,作为辅助治疗支原体肺炎的方法,安全、有效.  相似文献   
45.
The renin-angiotensin system is involved in control of blood pressure and salt and fluid homeostasis. Genes for components of this system have been of major focus in research on the causation of the common, complex, polygenic trait, essential hypertension (HT). Association of an A→C variant at nucleotide 1166 of the angiotensin II type 1 receptor (AT1R) gene with HT, but an absence of linkage of this locus with this disease, has been reported recently. Since confirmation in a different setting is imperative, we performed a cross-sectional case-control study of the A1166C variant in a well-characterized group of 108 Caucasian HT subjects with a strong family history (two affected parents) and early onset disease. Genotyping was by mismatch polymerase chain reaction/ Bfr I restriction fragment length polymorphism analysis. Frequency of the C1166allele was 0.40 in HTs and 0.29 in normotensives. The difference in genotype (χ2= 13, P = 0.0015) and allele (χ2= 5.3, P = 0.02) frequencies between the two groups was significant (odds ratio for CC vs AA+AC = 7.3 [95% CI, 1.9–31.9). The present results implicate the AT1R gene, or a locus in linkage disequilibrium with the variant tested, in the causation of essential HT.  相似文献   
46.
Summary.  The Haemophilia Utilization Group Study (HUGS) was created 10 years ago to examine the annual utilization and cost of haemophilia-related healthcare services. Retrospective chart reviews for 336 patients with haemophilia A receiving treatment in one of five comprehensive haemophilia treatment centres (HTCs) during 1995 were completed through interview of the provider. This method provided adequate collection of data from patient charts without the abstractor having direct access to patient health information. Utilization data were used to impute the costs of different components of care (e.g. physician visits, factor VIII concentrate, emergency room, hospitalization). The total annual cost of care was $139 102 (SD $304 033). Factor VIII concentrate costs comprised the largest proportion of these costs; mean factor VIII concentrate use was 128 517 units per patient per year. Unbilled physician utilization accounted for 7.8% of the mean total physician costs per annum, while mean allied healthcare costs accounted for 33.5% of the total annual allied healthcare costs per patient. In the ordinary least-squares regression model, higher costs were associated with severe factor VIII deficiency, arthropathy, more comorbid conditions, an inhibitor to factor VIII concentrate, infusing through a port and prophylaxis. Although factor VIII concentrate is the most costly component, the treatment of haemophilia uses many healthcare resources. HUGS has demonstrated that patient clinical characteristics and physician practices predominantly drive the costs of haemophilia care. Specifically, patients with more severe arthropathy had greater healthcare costs. As future funding decisions are made, it is important to provide for all components of care.  相似文献   
47.
Invasion of the reconstituted extracellular matrix composite, Matrigel, by eight human glioma–derived cell lines and human fetal brain cells was assessed in vitro using 8 um polycarbonate filters in a modified Boyden migration chamber. With the exception of one low grade glioma derived cell line, all lines studied proved to be invasive while normal fetal brain cells failed to invade. This invasive potential was independent of the histological grade of the tumour from which the cell lines originated. In addition, the expression of the metastasis–associated gene 18A2lmts1 as well as the tissue inhibitor of metalloproteinases–2 (TIMP–2) was analysed in each of the glioma–derived cell lines. The 18A2/mtsl was expressed in all the cells studied with the exception of fetal brain cells and the low grade non–invasive glioma derived IPRK–7 cell line. The 18A2/mtsl related genes coding for the S100 subfamily of calcium binding proteins were found to be differentially and overexpressed in invasive cell lines. TIMP–2 was expressed only in noninvasive cell lines. These results suggest that the 18A2/ mtsl and TIMP–2 genes could play an important role in the invasive behaviour of human glioma cells in vitro. .  相似文献   
48.
Reports of the human teratogenicity of retinoids have raised concern about the potential human teratogenicity of high doses of vitamin A. Nevertheless, there are few human case reports of excess intake of vitamin A during pregnancy and defective outcomes. No epidemiological studies have been carried out on this subject. Here we present the results of an epidemiological study of prenatal exposure to high doses of vitamin A in Spain, using data from the Spanish hospital-based, case-control registry. Although it is difficult to reach conclusions with such a very low exposure level (1.3 per 1,000 livebirths), our results suggest that a teratogenic effect might exist for exposures to high doses of vitamin A (OR = 0.5, p = 0.15 for less than 40,000 FU and OR = 2.7, p = 0.06 for 40,000 1U or more). As we might expect, this effect also seems to be related to the organogenetic status (OR = 5.4, p = 0.1 for 1st –2nd month, OR = 1.8, p = 0.4 for 3rd onwards) at the time of exposure.  相似文献   
49.
Large granular lymphocytic (LGL) leukaemia and chronic natural killer cell lymphocytosis (CNKL) are chronic indolent disorders often associated with neutropenia and constitutional symptoms. Severe anaemia occurs in about 20% of patients and is currently treated with corticosteroids followed by oral cyclophosphamide in non-responders. 30% of patients fail initial measures, and salvage therapy is inadequate. We describe three transfusion-dependent patients (two with T-LGL leukaemia, one with CNKL) refractory to corticosteroids, cyclophosphamide, and in one case fludarabine. Cyclosporine A (CSA) initiation resulted in prompt transfusion-independence and was well tolerated in all patients, making it an attractive alternative therapy for this disorder.  相似文献   
50.
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