Contribution of DNA sequence and CAG size to mutation frequencies of intermediate alleles for Huntington disease: evidence from single sperm analyses

New mutations for Huntington disease (HD) arise from intermediate alleles (IAs) with between 29 and 35 CAG repeats that expand on transmission through the paternal germline to 36 CAGs or greater. Using single sperm analysis, we have assessed CAG mutation frequencies for four IAs in families with sporadic HD (IANM) and IAs ascertained from the general population (IAGP) by analyzing 1161 single sperm from three persons. We show that IANM are more unstable than IAGP with identical size and sequence. Furthermore, comparison of different sized IAs and IAs with different sequences between the CAG and the adjacent CCG tracts indicates that DNA sequence is a major influence on CAG stability. These studies provide estimates of the likelihood of expansion of IANM and IAGP to > or = 36 CAG repeats for these individuals. For an IA with a CAG of 35 in this family with sporadic HD, the likelihood for siblings to inherit a recurrent mutation > or = 36 CAG is approximately 10%. For IAGP of a similar size, the risk of inheriting an expanded allele of > or = 36 CAG through the paternal germline is approximately 6%. These risk estimates are higher than previously reported and provide additional information for counselling in these families. Further studies on persons with IAs will be needed to determine whether these results can be generalized to other families.      

紫外分光光度法测定背景未知的复方制剂组分

本文利用目标转换因子分析中具有使纯组分光谱可向自身逼近的性质,提出了一种迭代目标转换因子分析算法,用于寻找未知背景光谱.通过在复方扑热息痛注射液分析中的应用,扑热息痛和安替比林的平均回收率均为100.0%,变异系数分别为1.1%和1.0%。结果表明本法为含有未知背景的多组分体系的紫外分光光度分析提供了可行的途径。     

外周血造血干细胞移植治疗实体瘤的临床护理

0　引言　化疗是治疗恶性肿瘤的有效方法 [1 ,2 ] ,但化疗药物的骨髓毒性限制了药物剂量的提高 .自体造血干细胞移植(PBSCT)能迅速重建造血免疫功能 ,在治疗恶性肿瘤方面前景良好 ,护理在 PBSCT中起重要作用 .我科 2 0 0 0 - 12 / 2 0 0 1-0 4共对 6例恶性实体瘤患者采取了 PBSCT疗法 ,取得了满意疗效 ,其护理如下 .1　对象和方法　本组患者 6 (男 2 ,女 4)例 ,年龄 35～ 6 0 (平均年龄 46 )岁 .其中转移性乳腺癌 3例 ,转移性卵巢癌 2例 ,非霍奇金淋巴瘤 1例 . 1自体外周血干细胞的动员 :采用大剂量化疗加 HGF,常选用泰素 2 40 mg,2…     

Proton chemical shift imaging: an evaluation of its clinical potential using an in vivo fatty liver model

The potential laboratory and clinical utility of proton chemical shift imaging (PCSI) was evaluated by studying fatty liver change in rats, which offered a simple animal model for tissue lipid buildup. There was excellent correlation between lipid group signal intensities from in vivo PCSI studies and liver triglyceride levels obtained from in vitro measurements (R = 0.97). The in vivo T1 relaxation time measurements in fatty liver tissue demonstrated two distinct populations of nonexchanging protons. We explain the reason for the lack of sensitivity in conventional magnetic resonance (MR) imaging studies of fatty liver change and discuss the implications of our findings for MR imaging studies of other tissues. PCSI promises improved diagnostic sensitivity and specificity in studying a wide range of human pathologic conditions.