生存研究样本量设计表及其使用方法

目的 :本文就两样本生存研究所需样本量用广义渐近正态法设计出 15 30个方案 ,制成设计表供临床使用。方法 :利用C语言编制程序 ,按通用格式打印设计表。结果 :常用方案查表可得。这些与两样本生存率检验相匹配 ,具有还原性 ,摆脱了比例危险的假设 ,在常见临床条件下观测功效符合预定功效。结论 :这些设计表适用于两样本癌症临床研究的设计 ,尤其便于临床医师或有关研究人员使用     

脉冲多普勒超声定量检测狭窄管流中流动指标的方法学探讨

目的　探讨狭窄管流中一系列流动指标的定量检测方法 ,包括 Reynolds数、相对频带展宽度(RSB)、层流剪应力、法向雷诺应力 (RNS)等。方法　采用临床使用的脉冲多普勒血流仪在狭窄前后多个位点进行多时点检测 ,得出流场特征 ,再分别评价各项指标。结果　定性评价见狭窄下游呈现鲜亮的“烛焰形”花色镶嵌湍流流型 ,狭窄后 1.0 cm处得到较大的 RSB、RNS等 ,1/ 2 R取样容积处湍流指标大于相应的轴心处。结论　狭窄后1.0 cm1/ 2 R取样容积处存在最大的湍流度 ;狭窄后各位点的数据离散度大于狭窄前。该研究为进一步在不同流场中开展生物力学的在体研究奠定了前期工作基础     

Self-reported snoring is associated with chronic kidney disease in obese but not in normal-weight Chinese adults

BackgroundThe relationship between sleeping disorders and chronic kidney disease (CKD) has already been reported. Snoring, a common clinical manifestation of obstructive sleep apnea–hypopnea syndrome, is of clinical value in assessing sleeping disorder severity. However, investigations of the connection between snoring and CKD are limited, especially in normal-weight populations. This study assessed the relationship between snoring frequency and CKD in obese and normal-weight people in China.MethodsA community-based retrospective cross-sectional study of 3250 participants was performed. Study participants were divided into three groups – the regularly snoring group, occasionally snoring group, and never snoring group – based on their self-reported snoring frequency. CKD was defined as an estimated glomerular filtration rate of less than 60 mL/min/1.73 m². Multiple logistic regression analysis was used to explore the relevance between snoring frequency and CKD prevalence.ResultsThe CKD prevalence in obese participants was higher than that in normal-weight participants. Frequent snorers had a higher prevalence of CKD than those who were not frequent snorers in the obese group. Snoring frequency was correlated with CKD prevalence in obese participants independent of age, sex, smoking and drinking status, systolic blood pressure, triglyceride level, high-density lipoprotein, and homeostasis model assessment of insulin resistance (odds ratio: 2.66; 95% CI: 1.36–5.19; p=.004), while the same relationships did not exist in normal-weight participants (odds ratio: 0.79; 95% CI: 0.32–1.98; p=.614).ConclusionsSnoring appears to be independently associated with CKD in obese but not in normal-weight Chinese adults.     

显著性概率地形图的一些基础问题探讨——少年组谱参量的正态分布转换问题

本文对41例年龄7—12岁右利健康儿童,头部选取5对(10个)样点,对各样点的功率和相对功率Ⅰ,Ⅱ的四个经典频带(δ,θ,α,β)进行几种数学转换,用正态性D检验法观察各参量转换前后的分布状态。结果,转换前,功率分布状态较差;而相对功率的参量原值近正态分布的情况较好,其中相对功率Ⅰ较相对功率Ⅱ更佳。而相对功率Ⅰ的X、log(X)和log(X/1—X)转换为最佳。就功率而言,log(x)转换最好,但仍不能完全满足各频带统计学的要求。     

Human myeloma light chains with increased molecular weight: high frequency among lambda chains

The discovery of a human myeloma protein comprising a kappa L-chain with an increased mol. wt of 30,000) (Bouvet et. al., 1980) prompted investigations on the incidence of such heavier L-chains among other human myeloma proteins. In 105 samples examined, 34 were found to have L-chains heavier than normal (23,000-24,000), ranging from 25,000 up to 31,000, and five of lighter mol. wt (21,000-22,000). These mol. wt abnormalities were detected by electrophoresis in sodium dodecyl sulfate 10% polyacrylamide gels (SDS-PAGE) after reduction with 2-mercaptoethanol. The mol. wt of three of the heavier kappa or lambda chains was also estimated by filtration through a Sephadex G100 column and by sedimentation equilibrium. All three methods indicated a mol. wt increase of about 15-25% as compared with the usual mol. wt. The distribution of the high mol. wt chains among all L-chains examined was found to be 11 out of 62 kappa chains (17.7%) and 23 out of 43 lambda chains (53%) (P less than 0.001). A preferential association of such L-chains with H-chains producing multiple bands in SDS-PAGE (P less than 0.01) and an association between multiple L-chain and multiple H-chain band (P less than 0.05) were also observed. In contrast, no abnormal L-chain was found in immunoglobulins from normal subjects. Spontaneous degradation of the normal H-chains sometimes yielded fragments of 30,000 mol. wt. These fragments were easily distinguishable from abnormal L-chains. The nature of extra mol. wt in heavy L-chains was investigated for the presence of carbohydrate moiety. Four large and three normal size L-chains were examined for amino-sugar and sialic acid content. A small amount (one residue per molecule) of amino-sugar was detected only in two normal and two heavy L-chains, whereas sialic acid was only found in the heaviest (27,000-30,000) L-chains (Lh) and in small percentage (one or two residues per molecule). Total sugar estimation in one Lh chain indicated a proportion not exceeding three or four residues per L-chain (mol. wt 1,000) and this is insufficient to explain the 15-25% (3,600-6,000) mol. wt increase. It is therefore possible that, at least in some heavy myeloma L-chains, an additional peptide is expressed. Whatever the nature of the increase it would be of interest to elucidate whether this is a marker of malignant process or of an intermediate step of normal Ig synthesis.     

不同年龄组正常人群影响最大胸椎后凸角的相关因素分析

目的：本研究通过对不同年龄组正常人群矢状位参数进行分析,旨在报道正常人群脊柱骨盆参数参考值范围,并探索不同年龄段引起最大胸椎后凸角改变的影响因素。 方法：本研究纳入自2015年1月至2018年月于两所医院健康体检中心的正常人群,收集人口统计学参数以及矢状位影像学参数。通过将人群分为≤40岁组与＞40岁组,对比分析不同年龄组人群的矢状位参数,并对不同年龄组影响最大胸椎后凸角max TK的因素进行相关性分析。结果：本研究共计纳入191例正常人群,其中≤40岁组94人,平均年龄为28.5±6.4岁;＞40岁组97人,平均年龄为53.9±8.3岁。不同年龄组人群在胸1椎体矢状位倾斜角T1 Tilt（18.6±6.5 vs. 20.6±5.5, P=0.023）, 胸椎后凸下端椎倾斜角TVA（15.3±5.3 vs. 17.5±6.6, P=0.013）,max TK（33.9±8.3 vs. 38.0±9.4, P<0.001）,max LL- max TK（14.9±8.9 vs. 12.3±9.4, P=0.048）及矢状面躯干偏移SVA（-2.5±21.8 vs. 6.1±20.9, P=0.006）上存在显著差异。在年龄≤40岁的人群中,T1 Tilt、TVA、max LL及骶骨倾斜角SS与max TK显著相关,而在年龄＞40岁的人群中,年龄、T1 Tilt、TVA、max LL及骨盆入射角PI与max TK显著相关。结论：max TK随着年龄增长呈现上下均匀增长趋势,在＞40岁的人群中,max TK与年龄呈现正相关关系。此外,不同年龄阶段,骨盆对于max TK改变的代偿呈现出不同的模式。     

抗肌萎缩蛋白基因51号外显子的精确定位

抗肌萎缩蛋白基因是迄今发现的人类最大基因,长约2300 kb,含有75个外显子。对该巨大基因的研究是近年来医学分子生物学研究的一个热点。虽然抗肌萎缩蛋白基因HindⅢ片段排序后就知道第51号外显子位于3.lkb的第40号HlndⅢ片段中,由于抗肌萎缩蛋白基因组DNA至今未被克隆,233bP的第51号外显子在3.lkp HindⅢ片段中的部位并不知道,也不知道它两侧的DNA结构。51号外显子     

非甲至非戊型肝炎患者TTV检测和部分基因序列分析

目的：研究新近报道的一种与输血后肝炎有关的病毒在中国郑州地区正常人群、HBsAg阳性者、非甲至非戊型肝炎患者中的感染和基因序列变异情况。方法：采用TTV基因组ORF1区的套式聚合酶链反应(nested-PCR)方法对血清标本进行检测,并对非甲至非戊型肝炎患者中的TTV分离株进行序列测定。结果：TTV DNA在非甲至非戊型肝炎患者中检出率为45％(18／40);在正常体检者中检出率为17．7％(17／96);在HBsAg阳性者(ALT≤34 IU／L)中检出率22．7％(10／44)。TTV分离株序列与日本株(CLON22)相对应位置的核苷酸同源性为．1％。结论：TTV在非甲至非戊型肝炎患者TTV的感染率明显高于其他人群,可能是非甲至非戊型肝炎的主要致病因子。     

正常人尿中单羟酚类物质含量的测定研究

目的：确定正常人尿中单羟酚衍生物（ＭＨＰ）含量范围。方法：采用可见分光光度法,定量测定１８～６０岁各类正常人及ＨＢｓＡｇ阳性携带尿液中单羟酚类物质。结果：ＭＨＰ含量与年龄、性别有一定的,１９９４例健康人尿中ＭＨＰ含量为正态分布,第９５百分位数的ＯＤ值上限为０．３,对应酷氨酸含量是２．４６ｍｍｏｌ／Ｌ,而ＨＢｓＡｇ阳性携带者尿液ＭＨＰ与正常人无显著性差异。结论：此实验结果在运用ＭＨＰ进行肿瘤筛查时,