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.     

HindII and SduI digests of heat-shock protein 70 PCR for Leishmania typing

Restriction fragment length polymorphisms of the heat-shock protein 70 gene have been used for discriminating Leishmania species. Here, we validated HindII as a much cheaper alternative to EcoRII and SduI for discriminating Leishmania (Viannia) braziliensis from Leishmania (Viannia) naiffi and an atypical Leishmania (V.) braziliensis group, which was previously not possible.     

脱落细胞线粒体基因A1555G突变在诊断线粒体耳聋中的应用

目的用PCR-RFLP技术检测脱落细胞(尿液沉渣细胞和颊黏膜细胞)线粒体基因A1555G突变,探讨脱落细胞用于诊断线粒体基因突变相关耳聋的可行性。方法收集福建省某特殊教育学校126名聋哑学生和1个线粒体基因A1555G突变的遗传性耳聋家系6例患者外周血及尿液沉渣细胞和颊黏膜细胞,用PCR-RFLP技术筛查患者是否携带线粒体DNA A1555G突变,并与测序法进行比较。结果尿液沉渣细胞检测线粒体DNA A1555G突变的检出率最高(9/132),颊黏膜细胞和外周血细胞均为7/132。PCR-RFLP筛查结果与直接测序法基本相符。结论脱落细胞适用于耳聋相关线粒体DNA A1555G突变检测。     

胃癌组织H-ras基因点突变与预后的关系

目的:胃癌发生发展的分子基础仍不甚明了,为了明确H—ras点突变在胃癌发生发展中的作用,本研究对胃癌组织H—ras点突变进行检测。方法:采用多聚酶链延伸反应—限制性片段长度多态性分析法(PCR—RFLP)对88例福尔马林液固定、石蜡包埋胃癌组织H—ras第12位和61位密码子点突变作了检测,并对点突变与肿瘤生物学行为及预后的关系进行分析。结果:H—ras总突变率为14.8％(13/88),点突变的发生与肿瘤将膜浸润,淋巴结转移、临床分期及术后生存期密切相关。结论:检测胃癌组织H—ras基因点突变有助于判断胃癌患者的预后。     

Chronological difference in walking impairment among Japanese group A xeroderma pigmentosum (XP-A) patients with various combinations of mutation sites

Almost all Japanese group A xeroderma pigmentosum (XP-A) patients have nonsense and/or nonsense codon-leading mutations in the XP group A (XPA) gene, and develop neurological abnormalities. Walking ability is one of the most important neuromuscular functions of the patients, because it determines their daily activities. We studied the correlation between the various combinations of mutations found by PCR-RFLP in Japanese XP-A patients and their chronological walking impairment. We classified these patients into six groups. Group I: A patient who was homozygous for the mutation at codon 116 in exon 3 (Type 1 mutation) could never walk unaided. Group III: Typical patients who were homozygous for the mutation at intron 3 (Type 2 mutation) could walk unaided till 7–16 years of age. Group V: Patients who were compound heterozygous for Type 2 mutation and for the mutation at codon 228 in exon 6 (Type 3 mutation) began to develop some walking difficulty at 5–13 years of age and became unable to walk at 25–28 years of age. Group VI: A patient who was homozygous for Type 3 mutation could walk unaided without any difficulty till the age of 21. The walking ability of group II and IV patients is not known yet.     

Apolipoprotein E gene polymorphism in cerebrovascular disease: a case-control study

The association between apolipoprotein E (apo E) polymorphism and stroke has been controversial. So far there are no studies reported on the polymorphism of apolipoprotein E in cerebrovascular diseases in the Asian Indians. A blinded case-control study was therefore undertaken and the apo E genotypes and lipid profile of a total of 120 subjects (63 stroke patients and 57 healthy controls) were done. The frequency distribution of apo E alleles and genotypes were assessed and their relation with the occurrence of stroke in Asian Indian subjects was determined. A significantly high frequency of apo epsilon4 allele (30%) was observed in the stroke patients than the controls (11%) (p < 0.005), and patients with epsilon4 allele had a fourfold higher odds to develop stroke OR (95%CI) 4.2 (1.8-10.1) (p < 0.005). On multivariate analysis, after adjusting for age, triglycerides and hypertension, the association of epsilon4 allele with stroke was found to be no longer statistically significant, OR (95%CI) 1.2 (0.4-4.5) (p = NS). On multiple logistic regression analysis age, OR (95%CI) 1.1 (1.1-1.2) (p < 0.001), and hypertension OR (95%CI) 15.1 (2.6-89.1) (p < 0.005) were found to be independent risk factors for development of stroke. This is the first report to have examined the association of apo E gene polymorphism with stroke in the Asian Indians. This study suggests that apo epsilon4 allele, triglycerides, age and hypertension are the predictors for stroke development.