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1.
双波长紫外分光光度法测定贝母中腺苷和胸苷的含量   总被引:4,自引:0,他引:4  
将4种贝母的甲醇提取物经薄层色谱法粗分离后,直接用双波长紫外分光光度法测定其含量。结果表明,该方法线性关系好,腺苷和胸苷标准曲线的相关系数均为0.9999,同时也发现平贝、炉贝和伊贝中腺苷都占核苷总量60%以上,而浙贝中仅占约40%,提示贝母生药的抗凝血活性可能与贝母中核苷类化合物的种类和含量的差别有关。  相似文献   
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新缩瞳剂包公藤甲素人工合成研究   总被引:11,自引:0,他引:11  
包公藤甲素是从包公藤(Erycibe obtusifolia Benth.)茎中提得的一个新莨菪烷生物碱,具有强烈的缩瞳作用,临床用于治疗青光眼。本文报道用合成的6β-乙酰氧基托品酮为原料,经卤代、水解、还原和N-去甲基化等反应合成包甲素(8)。经光谱测定证实8与天然包甲素的结构完全一致。合成品系外消旋体,其作用机理与天然品相同,而强度则减半。  相似文献   
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This study was conducted on 1359 healthy, non-smoking Turkish children (727M, 632F) with a mean age of 11.7 ± 3.4 (6–17) years, in order to determine the normal values of peak expiratory flow (PEF) in Turkish children and to compare various peak-flow meters (PEFMs). PEF values increased with age and height in boys and girls. The relative increase in boys was significantly higher at puberty (p < 0.01). The values of Turkish children were found to be similar to those of Europeans. The results obtained from the three PEFMs were closely correlated.  相似文献   
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Chemosensitivity of B lymphocytes, obtained from 65 patients with B- cell chronic lymphocytic leukemia (B-CLL), Rai stages 0 through IV, was determined using the MTT assay. The results were expressed by the drug concentration required for 50% inhibition of cell viability (IC50). The cytotoxicity of chlorambucil (CLB) was compared with that of fludarabine and the DNA topoisomerase I inhibitors, camptothecin, 9- aminocamptothecin, 10,11-methylenedioxy-20(S)-camptothecin (10,11-MDC) and 9-amino-10,11-methylenedioxy-20(S)-campthothecin (9-A-10,11-MDC), and topotecan. Considerable heterogeneity in sensitivity to CLB was observed, with a median IC50 of 40.5 mumol/L in untreated patients. B- CLL cells from patients treated with CLB had a significantly higher median IC50 of 86.0 mumol/L (P < .01). Untreated as well as CLB-treated patients were divided into two subsets. For the purpose of this study, B-CLL lymphocytes with an IC50 CLB of less than 61.0 mumol/L were designated as "sensitive" and those with an IC50 CLB of > or = 61.0 mumol/L were designated as "resistant." After baseline assays, 15 untreated patients received CLB; after treatment, the IC50 increased in B-CLL lymphocytes from 13 of 15 patients. The response to CLB treatment, determined by its effect on the absolute lymphocyte count and by the Eastern Cooperative Oncology Group clinical criteria, was significantly better in patients whose lymphocytes had an IC50 CLB of less than 61.0 mumol/L before therapy (P < .01). B-CLL lymphocytes also had a variable degree of sensitivity in vitro to each of the other drugs. There was significant cross-resistance between CLB and fludarabine (P < 0.01). Whereas only 29% of CLB-resistant B-lymphocyte specimens obtained from individual patients were sensitive to fludarabine in vitro, 52% and 67% of CLB-resistant lymphocyte samples were sensitive to 10,11-MDC and 9-A-10,11-MDC, respectively. We have previously reported that p53 gene mutations were associated with aggressive B-CLL and a poor prognosis. B lymphocytes from seven patients with these mutations were resistant to CLB, and five of six were resistant to fludarabine. Lymphocytes from four of seven were resistant to 10,11-MDC, and three of four were resistant to 9-A-10,11- MDC. This study implies that the MTT assay may be useful in identifying subsets of CLL patients resistant to conventional chemotherapy. However, definitive conclusions can not be drawn in view of the small number of patients studied prospectively. In addition, these results suggest the potential of camptothecin-based therapy for patients unresponsive to standard treatment.  相似文献   
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本文在前报的基础上,设计和合成了4-芳杂环取代的氨甲基酚衍生物28个。初步药理试验表明,多数显示不同程度的抗炎活性。用CNDO/2法计算所得数据提示,该类化合物分子中的氨甲基氮和酚羟基氧与受体正电荷中心的结合,可能对抗炎活性起着重要作用。  相似文献   
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Objective: The aim of this study was to evaluate the alterations on plaque index (PI), gingival index (GI), gingival bleeding index (GBI), and gingival crevicular fluid (GCF) volume after use of three different brackets types for 60 days. Setting Participants: The sample comprised 20 patients of both sexes aged 11–15 years (mean age: 13.3 years), with permanent dentition, adequate oral hygiene, and mild tooth crowding, overjet, and overbite. Methods: A conventional metallic bracket Gemini?, and two different brands of self-ligating brackets — In-Ovation®R and SmartClip? — were bonded to the maxillary incisors and canines. PI, GI, GBI scores, and GCF volume were measured before and 30 and 60 days after bonding of the brackets. Data were analysed statistically using non-parametric tests coefficient at a 5% significance level. Results: There was no statistically significant correlation (P?>?0.05) between tooth crowding, overjet, and overbite and the PI, GI, GBI scores, and GCF volume before bonding, indicating no influence of malocclusion on the clinical parameters. Regardless of the bracket design, no statistically significant difference (P?>?0.05) was found for GI, GBI scores. PI and GCF volume showed a significant difference among the brackets in different periods. In pairwise comparisons a significant difference was observed when compared before with 60 days after bonding, for the teeth bonded with SmartClip? self-ligating bracket, (PI P?=?0.009; GCF volume P?=?0.001). Conclusion: There was an increase in PI score and GCF volume 60 days after bonding of SmartClip? self-ligating brackets, indicating the influence of bracket design on these clinical parameters.  相似文献   
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缬昔洛韦的合成   总被引:1,自引:0,他引:1  
目的;对缬昔洛韦的合成进行了研究。方法:以阿昔洛韦和N-苄氧羰基-L-缬氨酸为原料,经酰化,催化氢解反应得到了新型抗疱疹毒药物缬昔洛韦。结果;本品的元素分析,红外,质谱及核磁共振图谱数据与文献报道一致,总收率为45.2%,结论;采用此法合成缬昔洛韦是可行的,适合于工业生产。  相似文献   
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娄超  边惠洁  陈志南 《医学争鸣》2001,22(4):369-371
0 引言 凋亡或细胞程序性死亡是一种不同于细胞坏死的死亡方式 ,是在基因控制下的有序死亡 ,是一个主动性自杀过程 ,常伴有特征性形态学和生化变化 .临床上放射线治疗肿瘤主要应用射线诱导细胞凋亡这一机制 .1 88Re发射 2 110Ke V的 β射线 ,15 5 Ke Vγ射线 ,半衰期 17h,具有良好的核物理性质 .国外 1 88Re的研究主要在 1 88Re标记单克隆抗体对肿瘤的放射免疫治疗 ,并显示具有一定的疗效 ,而国内关于 1 88Re的研究较少 ,经文献检索未见有关于 1 88Re诱导细胞凋亡的报道 .本实验旨在研究 1 88Re-β射线诱导人肝癌细胞系 h HCC(human…  相似文献   
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