川贝母药材分子鉴定方法研究

川贝母基源鉴定对于其临床用药的安全性、有效性非常重要,但基于性状、显微或化学成分的鉴定方法缺乏专属性,因此,建立专属性强的川贝母分子鉴定方法具有重要意义。本研究在本实验室前期研究工作的基础上,建立了一种适用于川贝母商品药材(干鳞茎)的简便可行的聚合酶链反应-限制性酶切图谱(PCR-RFLP)分子鉴定法,即称取贝母干鳞茎20 mg,依次用75%乙醇和灭菌超纯水清洗后,以新型广谱植物基因组DNA快速提取试剂盒提取基因组DNA,以所提取的DNA为模板进行ITS₁区PCR扩增和酶切反应,最后将酶切液进行琼脂糖凝胶电泳,所得图谱显示川贝类核糖体DNA的ITS₁区存在限制性内切酶SmaⅠ的酶切位点,在100～200 bp之间有2条清晰的酶切条带,而非川贝类均不能被酶切,没有这两条特征性条带。该方法应用于12批贝母商品药材的鉴定,可将川贝类药材与非川贝类药材区别开来。     

以浆膜腔积液上清为标本检测ras基因第12密码子突变及其意义

有研究显示, 体液中的游离核酸可直接用于肿瘤的分子诊断, 且效果优于以体液中的脱落细胞为实验材料 [1] 。近年来随着肿瘤发病率的上升, 恶性浆膜腔积液的比例不断升高, 但部分恶性积液的诊断一直困扰人们。     

儿童脊肌萎缩症运动神经元生存基因缺失分析

目的评价聚合酶链反应-限制性片段长度多肽性（PCR-RFLP）分析技术在脊肌萎缩症（SMA）临床诊断中的价值，分析端粒侧运动神经元生存基因（SMNt）表达与SMA临床分型之间的关系。方法对临床拟诊为SMA的23例患儿同时采用临床诊断标准和PCR-RFLP分析技术进行诊断，两种结果对比，分析灵敏度、特异度、Kappa值及P值。结果（1）临床诊断与PCR-RFLP基因诊断结果比较：23例拟诊患儿中临床确诊为SMA者18例，非SMA者5例。PCR-RFLP技术检测结果：5例非SMA者，SMNt基因检测均无缺失；18例确诊SMA者，SMNt基因缺失者15例，无SMNt基因缺失者3例，缺失频率为83．3％。此方法的灵敏度为83．3％，特异度为100％，阳性预测值100％，阴性预测值62．5％，真实性为86．96％，Kappa值为0．685。（2）SMA不同临床分型中SMNt基因7、8号外显子缺失检测结果：Ⅰ型患者以7、8号外显子缺失为主，SMNt基因缺失频率100．0％；Ⅲ型患者以7号外显子缺失为主，SMNt基因缺失频率为66．7％；Ⅰ型患者7、8号外显子联合缺失频率较Ⅲ型高（P〈0．05）。结论（1）PCR-RFLP分析技术简便、快捷、特异性高，敏感性好，适用于临床儿童型SMA的基因诊断，尤其对于SMAI型患者。（2）SMNt基因7、8号外显子联合缺失常常提示病情严重，预后不良；单独缺失提示病情较轻，预后较好。     

急性白血病病人ECR1基因多态性与红细胞免疫功能的关系

目的:探讨急性白血病病人红细胞补体受体Ⅰ型分子(ECR1)基因密度多态性与红细胞免疫黏附功能的相关性。方法:急性白血病46例,正常对照50例,采用PCR-RFLP法测定RBC-CR1基因型。以红细胞黏附花环试验测定RBC-C3b受体花环率(RBC-C3bRR)及免疫复合物花环率(RBC-C ICR)。结果:①与对照组比,急性白血病病人RBC-C3bRR下降,RBC-C ICR上升(P<0.01);②急性白血病病人HH型、HL型LL型分别是60.87%、30.44%、8.69%,突变率是39.13%,与对照组相比无统计学意义(P>0.05);③在急性白血病组内,HL型的RBC-C3bRR为17.23±5.74,低于HH型的26.06±6.21;RBC-C ICR为7.36±2.45,高于HH型的4.63±2.00,其差异有统计学意义(P<0.01)。结论:急性白血病病人RBC免疫功能低下,ECR1基因缺陷对病人的RBC免疫能力下降有一定影响。不同ECR1基因型的人群红细胞免疫功能有差异,HH型的红细胞免疫黏附功能强于HL型。     

A study of point mutation of ras genes in human gastric cancer

Ａｓｔｕｄｙｏｆｐｏｉｎｔｍｕｔａｔｉｏｎｏｆｒａｓｇｅｎｅｓｉｎｈｕｍａｎｇａｓｔｒｉｃｃａｎｃｅｒ￥ＷａｎｇＪｕｎｒｕ（王俊茹）；ＬｉｕＷｅｉｗｅｎ（刘为纹）；ＤｅｎｇＧｕｏｒｅｎ（邓国仁）；ＬｕＹｏｕｙｏｎｇ（吕有勇）；ＷａｎｇＸｉｎ（王欣）（...     

Cystatin C基因5’端-157G/C突变与阿尔茨海默病的相关性研究

目的探讨Cystatin C基因5’端-157G/C突变与中国昆明地区汉族人阿尔茨海默病是否存在关联。方法运用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)分析方法在134例无亲缘关系之中国昆明汉族人(正常对照组73例,阿尔茨海默病患者61例)中对Cystatin C基因变异进行检测。同时检测两组人群血浆Cystatin C之浓度。结果在阿尔茨海默病患者中GG,GC和CC基因型频率分别为16.39%,50.82%和32.79%;正常对照组中分别为26.03%,41.10%和32.87%。G等位基因频率在阿尔茨海默病组中和正常对照组中分别为41.80%和46.58%。基因型频率和等位基因频率在阿尔茨海默病患者与对照组之间无统计学差异。两组人群血浆Cystatin C浓度也无统计学差异。结论在中国昆明汉族人群中存在Cystatin C基因5’端-157G/C变异的多态性,但可能对阿尔茨海默病的发生不起作用。     

Restriction fragment-length polymorphism analysis of 16S rDNA from oral asaccharolytic Eubacterium species amplified by polymerase chain reaction

Restriction fragment-length polymorphism (RFLP) analysis of 16S rDNA amplified by polymerase chain reaction was used to generate restriction profiles of the type strains of oral asaccharolytic Eubacterium species, that is, Eubacterium brachy, Eubacterium exiguum, Eubacterium lentum, Eubacterium minutum, Eubacterium nodatum, Eubacterium saphenum, Eubacterium timidum and 33 asaccharolytic Eubacterium strains isolated from oral sites. The 16S rRNA gene sequences from isolated genomic DNA samples were amplified by polymerase chain reaction (PCR). PCR products were purified and characterized by single digestions with 7 restriction endonucleases. Among the 7 endonucleases, Hpall was found to discriminate the respective reference strains. Twenty-three isolates, out of 33, were assigned to one of the reference species, on the basis of their restriction profiles by digestion with Hpall. The remaining 10 isolates could not be assigned to any of the established species and constituted 4 distinct groups, each of which may be a new species.     

Lewis genotyping by the PCR-RFLP method in a Japanese population and its evaluation in forensic analysis

Lewis phenotyping of red blood cells has many problems such as the influence of many biological conditions, the change during the period from newborn to early childhood and mistyping by non-specific anti-Lewis antibodies. Therefore, it would be useful to determine the Lewis genotype. Recently a method of Le-genotyping by PCR-RFLP was established. We determined the frequencies of Lewis genotypes in a Japanese population and discuss the applicability to paternity tests and other forensic applications. The gene frequencies of Le, le1 and le2 in the Japanese population studied were 0.7032, 0.2358 and 0.0610 respectively. Out of 12 paternity cases where paternity was excluded by other markers, 3 alleged fathers could also be excluded by Lewis genotyping. The genotype from organs of a fetus from a 3-month pregnancy was Le/Le. The determination of Lewis genotypes could play a useful role as a genetic marker in paternity tests and forensic analyses. Received: 9 October 1996 / Received in revised form: 1 April 1997     

Epidemiologic Study of Malassezia Yeasts in Seborrheic Dermatitis Patients by the Analysis of 26S rDNA PCR-RFLP

Background

This case-control study concerns a molecular biological method based on the data gathered from a group of Korean subjects to examine the distribution of Malassezia yeasts in seborrheic dermatitis (SD) patients. Cultures for Malassezia yeasts were taken from the foreheads, cheeks and chests of 60 patients with SD and in 60 healthy controls of equivalent age.

Objective

The purpose of this study is to identify the relationship between certain species of Malassezia and SD. This was done by analyzing the differences in the distribution of Malassezia species in terms of age and body parts of the host with healthy controls.

Methods

26S rDNA PCR-RFLP, a fast and accurate molecular biological method, was used to overcome the limits of morphological and biochemical methods.

Results

The positive Malassezia culture rate was 51.7% in patients with SD, which was lower than that of healthy adults (63.9%). M. restricta was dominant in patients with SD (19.5%). Likewise, M. restricta was identified as a common species (20.5%) in healthy controls. In the ages 31~40, M. restricta was found to be the most common species (31.6%) among SD patients.

Conclusion

According to the results of the study, the most frequently isolated species was M. restricta (19.5%) in patients with SD. There was no statistically significant difference in the distribution of Malassezia species between the SD patients and healthy control groups.