Early onset Alzheimer's disease in a South American pedigree from Argentina

We report the clinical, SPET, immunohistochemical and DNA features of an early-onset familial Alzheimer's disease (FAD) in an Argentine pedigree of South American indian ethnic background. Pedigree spans 5 generations comprising more than 110 biological relatives. Clinical data supported the diagnosis of early onset FAD (mean age at onset 38.9 years) in 10 family members, including 3 with pathological confirmation (mean age at death 48.5). The pattern of transmission suggested autosomal dominant inheritance. Prominent features were mood changes, early language impairment, myoclonus, seizures and cerebellar signs. SPET displayed bilateral frontal, temporo-parietal and cerebellar hypoperfusion in early stages and in an asymptomatic member at risk, suggesting that SPET may have predictive value in this family. Immunohistochemistry showed β amyloid deposits within neuritic plaques and vessel walls and no anti-PrP immunoreactivity. DNA analysis showed no abnormalities in the β amyloid precursor protein gene. The identification of additional genetic defects in well characterized independent FAD pedigrees will contribute to the understanding of the pathogenesis of Alzheimer's disease.     

胃癌D17S261和D17S799位点二核苷酸重复序列不稳定性的意义

目的研究二核苷酸重复序列不稳定性〔ＤＲＳＩ〕在胃癌发生中的作用及其临床意义．方法采用ＰＣＲ方法检测了Ｄ１７Ｓ２６１和Ｄ１７Ｓ７９９位点二核苷酸重复序列不稳定性．结果胃癌总ＤＲＳＩ发生率为３４％（１７／５０），其中高中分化腺癌ＤＲＳＩ阳性率（６６７％，１０／１５）显著高于低分化癌（１９４％，６／３１，Ｐ＜００１）；肠型胃癌ＤＲＳＩ阳性率（５５６％，１０／１８）显著高于胃型胃癌（２０％，６／３０，Ｐ＜００５），ＤＲＳＩ与胃癌部位、大小、浸润、分期、淋巴结转移无显著相关．结论ＤＲＳＩ在胃癌的发生中可能起重要作用．     

Two genes for chloramphenicol resistance common to Staphylococci and streptococci

Southern blot hybridization and pneumococcal transformation were used to study the epidemiology at a molecular level of the genes for chloramphenicol resistance (cat) in streptococci and staphylococci. The cat gene of staphylococcal plasmid pC194 showed homology to the cat genes of the chromosomal elements of 5 different strains of Streptococcus pneumoniae and of Streptococcus agalactiae B109. DNA sequence homology was also detected between the cat gene of staphylococcal plasmid pC221 and the cat gene of broad host range conjugative plasmid pIP501, originally isolated from S. agalactiae. Two different cat genes appear to be present in clinical isolates of both streptococci and staphylococci.     

苯作业工人白细胞降低者的总估校正现患率

选择乡镇工业苯作业工人４次外周血白细胞计数中的间隔半年的两次数据，应用俘获再俘获法，计算其白细胞降低者的总估校正现患率（ＡＣＰＲ）。结果苯接触组为３６．８ｌ％（２９．１４％～４４．４８％），对照组为１２．７１％（７．２０％～１８．２２％）具有显著差异，其相对危险度为２，９。用常规法求得的４次检出率分别是：苯接触组为２６．３７％，１８．７３％，２７．９３％，３６．７６％；对照组为６。８５％，７．３８％，７．９４％，１５．００％。均在其ＡＣＰＲ之９５％可信限内，可见ＡＣＰＲ计算方法简便、结果准确，值得推广。对于稳定的人群，可用其每年一次的健康监护资料计算ＡＣＰＲ。     

The Lewis blood group--a new genetic marker of ischaemic heart disease.

In a cohort of 3383 men aged 53 to 74 in the Copenhagen Male Study we investigated the association between ischaemic heart disease (IHD) and the Lewis blood group, assigned to chromosome 19. Among men with the Le(a-b-) phenotype, 8% had a history of non-fatal myocardial infarction, among others the frequency was 4%. The corresponding odds ratio was (95% confidence interval: CI) 1.9 (1.2-3.0) P < 0.01, men with Le(a-b-) had a risk-factor profile and pattern of disease resembling that of Reaven's syndrome X. In a subsequent prospective study 343 men with arteriosclerotic stigmas were excluded. The men had their morbidity and mortality recorded over the next 4 years. One-hundred-and-one men suffered IHD; 26 dying from IHD. In total 162 men died. Men with Le(a-b-) had an increased risk of death from IHD compared with others. Adjusted for age, relative risk (RR) (95% CI) was: 4.4 (1.9-10.3), P < 0.001, and for all causes of mortality: RR = 1.6 (1.0-2.6), P < 0.05. Men with the Le(a-b-) phenotype had an increased risk of an IHD event compared to men with other phenotypes (RR = 1.6 (0.9-2.8), P = 0.10) and a significantly higher IHD case fatality rate (RR = 2.8 (1.5-5.2), P = 0.01). The finding that the Le(a-b-) phenotype is a genetic marker of IHD risk may have implications in terms of prevention. The Le(a-b-) phenotype may also contribute to providing an explanation for the substantial ethnic differences found in the incidence of IHD. The similar risk-factor profile and pattern of disease found between Le(a-b-) men and individuals with Reaven's syndrome X is hypothesized to be due to a close genetic relationship on chromosome 19.     

中国汉族群体D4S111位点的遗传多态性研究

目的：研究中国汉族群体中α艾杜糖苷酶基因Ｄ４Ｓ１１１位点的遗传多态性。方法：采用扩增片段长度多态性（ＡｍｐＦＬＰ）分析技术，检测了广州地区汉族无血缘关系健康个体９７名。结果：Ｄ４Ｓ１１１位点，在９７名无关个体中发现５个等位基因和９种基因型，等位基因片段长度为８３０～５１０ｂｐ，基因频率为０００５２～０３６０８，ＰＩＣ为０５９６６，杂合性为０７８。结论：中国汉族群体中Ｄ４Ｓ１１１位点具有高度多态性，并与其它种族间存在差异性。     

A highly variable STR at the D12S391 locus

A total of 103 fragments in the STR D12S391 locus were sequenced. 24 different alleles were found which can be grouped into 12 allelic classes based on the total number of repeats. The structure of this compund STR consists of blocks of (AGAT) and (AGAC) repeats with a consensus structure (AGAT)_8–l7 (AGAC)_6–10 (AGAT)_0–1. Whereas shorter alleles only have (AGAT) repeats, > 225 bp alleles are more complex, having two motifs (AGAT) and (AGAC). Population data showed that this to be a highly polymorphic STR with a heterozygosity of 0.9. This fact together with its simple structure make this STR very suitable for forensic and genetic purposes.     

Prevalence of smoking in a diabetic population: the need for action

Smoking habits in insulin-treated diabetics in Nottinghamshire (UK) and clinic-attending diabetics in Nottingham have been analysed. Compared with the general population, the prevalence of current cigarette smoking is significantly less (p less than 0.001) in both diabetic men and women older than 50 years. Fewer diabetic men over 60 years have ever smoked than in the general population (p less than 0.001) but this finding does not apply to diabetic women. While intervention probably plays some part in this lower prevalence, the most likely explanation is the multiplicative effect of both smoking and diabetes to produce high mortality risks. Actuarial analysis of insulin-treated clinic attenders diagnosed after 1970 showed that at most 14% (95% confidence interval [Cl] 9-18%) of the 183 who smoked at diagnosis had given up 5 years later while a minimum of 8% (95% Cl, 6-11%) of the 313 who were non-smokers had started smoking. Information about the patterns of smoking in patients with chronic disease is incomplete and it appears that too little is being done in clinical services which provide long-term management for these patients to either discourage smoking or determine why some patients give up smoking but others do not.     

鼻咽癌高危人群微核特征研究

目的 观察鼻咽癌高危人群的主要细胞遗传学特征。方法 常规培养外周血淋巴细胞，检测鼻咽癌高危人群、鼻咽癌患者、鼻咽炎患者及正常人的微核率。结果 鼻咽癌高危人群及鼻咽癌患者的微核率明显增加，且随病情进展而继续增高。结论 鼻咽癌高危人群存在比较明确的细胞遗传不稳定性。     

Parkinson's disease in Africa: A systematic review of epidemiologic and genetic studies.

Parkinson's disease (PD) occurs worldwide, but little is known about PD in Africa. We systematically reviewed publications on PD in Africa, with emphasis on epidemiologic and genetic studies. Articles published between 1944 and December 2004 were identified using several strategies. The studies emanated from 13 African countries (Kenya, Uganda, Tanzania, Ethiopia, Nigeria, Senegal, Ghana, Togo, Libya, Tunisia, Algeria, Zimbabwe, and South Africa). The publications fell into four categories: clinical series (n = 17), prevalence studies (n = 7), incidence studies (n = 1), and genetic studies (n = 3). The clinical series documented the occurrence of PD in Africa and described its clinical characteristics. The prevalence studies suggested some intracontinental geographic variation in PD prevalence. Overall, the prevalence figures and the incidence rates of PD in Africa appeared lower than those reported for European and North American populations. Few genetic studies of PD have been reported from Africa, and none in blacks. There are no case-control or cohort studies of PD reported from Africa. This review provides a summary of PD research in Africa over the past 60 years and highlights the information gaps and potential areas for future research.