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101.
研究背景:通常伴EGFR受体表达的头颈部鳞癌预后较差.西妥昔单抗(C-225)是一种可抑制EGFR的单克隆抗体,并可提高包括顺铂在内的多种细胞毒药物的疗效.  相似文献   
102.

Background and purpose:

α- and β-amyrin are pentacyclic triterpenes found in plants and are known to exhibit pronounced anti-inflammatory effects. Here, we evaluated the effects of a 1:1 mixture of α- and β-amyrin (α,β-amyrin) on an experimental model of colitis in mice.

Experimental approach:

Colitis was induced in Swiss male mice by trinitrobenzene sulphonic acid (TNBS) and followed up to 72 h; animals were treated systemically with α,β-amyrin, dexamethasone or vehicle. Macro- and microscopic damage, myeloperoxidase activity and cytokine levels were assessed in colons. Histological sections were immunostained for cyclooxygenase-2 (COX-2), vascular endothelial growth factor, phospho-p65 nuclear factor-κB (NF-κB) and phospho-cyclic AMP response element-binding protein (CREB)

Key results:

TNBS-induced colitis was associated with tissue damage, neutrophil infiltration and time-dependent increase of inflammatory mediators. Treatment with α,β-amyrin (3 mg·kg−1, i.p.) or dexamethasone (1 mg·kg−1, s.c.) consistently improved tissue damage scores and abolished polymorphonuclear cell infiltration. α,β-Amyrin, like dexamethasone, significantly diminished interleukin (IL)-1β levels and partially restored IL-10 levels in colon tissues 72 h after colitis induction, but only α,β-amyrin reduced vascular endothelial growth factor expression by immunohistochemistry. The colonic expression of COX-2 at 24 h and that of phospho-NF-κB and phospho-CREB (peaking at 6 h) after colitis induction were consistently inhibited by both α,β-amyrin and dexamethasone.

Conclusions and implications:

Systemic administration of α,β-amyrin exerted a marked and rapid inhibition of TNBS-induced colitis, related to the local suppression of inflammatory cytokines and COX-2 levels, possibly via inhibition of NF-κB and CREB-signalling pathways. Taken together, our data suggest a potential use of α,β-amyrin to control inflammatory responses in bowel disease.  相似文献   
103.
薄层色谱溶剂系统的最优化方法   总被引:8,自引:0,他引:8  
班允东  孙毓庆  张敬宝 《药学学报》1989,24(11):841-846
本文以模糊聚类分析法对81种常用溶剂进行分类,并根据最相邻原理从中优选出二十种色谱分析常用溶剂。再据此结果,以均匀设计试验法和最优化方法——单纯形法为手段,进行溶剂系统的最优化设计。并提出一个改良的色谱优化函数。经初步验证,这是一种比较有效与实用的系统化方法,尚未见国内外报道。本法不仅适用于薄层色谱,也适用于纸色谱及柱型液相色谱。  相似文献   
104.
小叶买麻藤中买麻藤甲素的结构研究   总被引:4,自引:0,他引:4  
从小叶买麻藤[Gnetum parvifolium(Warb.)C.Y.Cheng]茎的乙酸乙酯部分得到五个成分,经理化常数测定、光谱(UV,IR,MS,~1HNMR,~(13)CNMR和2D-NMR)分析和衍生物制备,确定买麻藤甲素为一个新的2-苯基苯并呋喃类化合物,结构为2-(3′,5′-二羟基-4′-甲氧基苯基)_-3-甲氧基5-羟基苯并呋喃。另外三个鉴定为异丹叶大黄素、白黎芦醇和β-谷甾醇.还有一个化合物正在鉴定中。  相似文献   
105.
为了寻找抗生育药物,从17β-羟基-7α-甲基-4-雌烯-3-酮经17β-羟基-7α-甲基-4β,5β-环氧雌烷-3-酮合成了七个4-位取代的目标化合物:4,17β-二羟基-7α-甲基-4-雌烯-3-酮及其17-乙酸酯、4-甲氧基-17β-羟基-7α-甲基-4-雌烯-3-酮及其17-乙酸酯、4-氯-17β-羟基-7α-甲基-4-雌烯-3-酮及其17-乙酸酯和4-溴-17β-羟基-7α-甲基-4-雌烯-3-酮。这些化合物均可竞争性地与人蜕膜孕酮受体结合,并能抑制蜕膜细胞的发育,对大鼠具有显著的抗着床活性。  相似文献   
106.
High-dose intravenous gammaglobulin (IVIgG) was given to 12 children and adults with chronic idiopathic thrombocytopenic purpura (ITP) to avoid splenectomy or because they either failed to respond to or required maintenance with high doses of steroids and/or immunosuppressives. The average platelet count increase to initial therapy was 239,500/microliters (range 23,000-790,000). A concomitant IgG Fc receptor blockade, measured by IgG-sensitized 51Cr-labeled autologous erythrocytes, was seen in 11 of 11 patients tested, both splenectomized and not splenectomized, lasting 3-4 wk. Six or more months after treatment, 2 children are in remission, 2 children and 2 adults are stable requiring no therapy with platelet counts of approximately 50,000 and 30,000, respectively, 3 children require maintenance IVIgG therapy at 2-10-wk intervals, and 1 child and 2 adults have become refractory to further IVIgG. Splenectomy was not performed in 4 children. Two adults were able to discontinue daily prednisone. The 3 patients who became unresponsive to Swiss Red Cross gamma-globulin (IgSRK) therapy did so in conjunction with a markedly elevated platelet-associated IgG and IgM. Serum IgM increased an average of 103 mg/dl after the IVIgG infusions. No significant side effects were seen.  相似文献   
107.
108.
109.

Background  

Hospitalization for heart failure (HF) is associated with high-in-hospital and short- and long-term post discharge mortality. Age and gender are important predictors of mortality in hospitalized HF patients. However, studies assessing short- and long-term risk of death stratified by age and gender are scarce.  相似文献   
110.

Background  

Implementation of medical interventions may vary with organization and available capacity. The influence of this source of variability on the cost-effectiveness can be evaluated by computer simulation following a carefully designed experimental design. We used this approach as part of a national implementation study of ultrasonographic infant screening for developmental dysplasia of the hip (DDH).  相似文献   
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