Linkage studies of psychiatric disorders

Summary Linkage analysis has been successful in identifying the genetic basis of numerous Mendelian diseases. These successes were due in part to the rapid developments in molecular biology, which have yielded a plethora of informative genetic markers. Although there is strong evidence that the manifestation of schizophrenia and bipolar affective disorders is controlled by genes, no evidence for linkage has been established. For psychiatric disorders, the most important limiting factor is likely to be the lack of single loci with very large effects that occur with any relevant frequency. The difficulties of linkage studies in psychiatric disorders are discussed with reference to non-psychiatric genetic diseases for which linkage to genetic markers has been successful. Recommendations for collecting information to clarify the patterns of transmission of the psychiatric disorders are described.     

Suppurative corneal ulceration in Bangladesh

Suppurative keratitis is an important preventable cause of blindness, particularly in the developing world. This study analyses 142 cases of suppurative keratitis referred to Chittagong Eye Infirmary, Bangladesh. Some 53.5% of cases were bacterial and 35.9% were fungal. The five most common pathogens were: Pseudomonas sp. 24%, Streptococcus pneumoniae 17%, Aspergillus sp. 13%, Fusarium sp. 7% and Curvularia sp. 6%. Gram stain and culture results were consistent in 62.6% of cases. Previous antibiotic treatment was a significant factor for failure of culture isolation and less so for Gram stain failure. On Gram stain, 55.9% of pseudomonal cases were missed, but only 2% of fungal cases were missed. Over all, Gram stain had a sensitivity of 62% and positive predictive value of 84% for bacterial cases, and 98% and 94% for fungal cases, respectively. Fungal ulcers were typically filamentous, but an antecedent history of trauma was not common. The most frequent injury was due to rice grains, but the inoculum appeared to be introduced during eye washing with contaminated water. Pseudomonal ulcers occurred most frequently in the monsoon season, and Fusarium cases were seen only in the hot, dry season.     

Periodontal conditions among the middle-aged and the elderly in Hong Kong

Abstract The aim of this study was to describe the periodontal conditions in 372 35–44-yr-old and 537 noninstitutionalized 65–74-yr-old Hong Kong Chinese who were examined clinically for loss of attachment, recession, probing depth, calculus, and bleeding after probing. Community Periodontal Index (CPI) data and treatment need indications were compiled from index teeth or their substitutes. The prevalence of loss of attachment varied considerably in both cohorts according to the definition of the threshold (≥6, ≥9, and ≥12 mm, respectively). The mean numbers of teeth with loss of attachment at the ≥6-mm threshold and at higher thresholds were small. In both age cohorts, about one-fifth of subjects had probing depths ≥6-mm, while al the ≥9-mm threshold only 2–3% were so affected. Although recession was an important component of loss of attachment in the younger cohort, in the older cohort the prevalence and extent of recession were greater than for probing depths at thresholds ≥4 mm. All subjects had one or more teeth with calculus, bleeding, or both, most teeth being so affected. Eighty-four of the 537 65–74-yr-old subjects were excluded either because of edentulousness or because extractions indicated for the remaining teeth would have rendered the subjects edentulous. The distribution of subjects according to their highest CPI score was remarkably similar for the two cohorts. No subjects in either age group were assessed as “healthy” (CPI code 0) or had “bleeding only” (code 1) as their highest score. While most subjects scored CPI code 2 or 3 us their highest score, only 17% of the younger and 15% of the older cohort scored Community Periodontal Index of Treatment Needs (CPITN) code 4. Differences in the mean number of sextants affected by CPI codes between the two cohorts were mainly due to a greater number of excluded sextants in the older cohort. CPI findings for 35–44-yr-olds differed little from those reported in 1984.     

标化比例死亡比分析在筛检恶性肿瘤高发人群中的应用

在筛检肿瘤高危险人群过程中,应用标化比例死亡比(SPMR)的分析方法,研究了两个工厂全肿瘤和肺癌的发生状况,并用标化死亡比(SMR)的方法验证SPMR的结论。结果表明,两种方法分析结果均一致性显示全肿瘤和肺癌在两工厂中的死亡率显著高于当地居民。由于SPMR分析资料极易获得,分析方法又较SMR简便易行,适用于基层实际工作中对各种疾病死亡状况进行病因学分析。     

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.     

Effects of exposure to air pollution on blood coagulation

BACKGROUND: Consistent evidence has indicated that air pollution increases the risk of cardiovascular diseases. The underlying mechanisms linking air pollutants to increased cardiovascular risk are unclear. OBJECTIVES: We investigated the association between the pollution levels and changes in such global coagulation tests as the prothrombin time (PT) and the activated partial thromboplastin time (APTT) in 1218 normal subjects from the Lombardia Region, Italy. Plasma fibrinogen and naturally occurring anticoagulant proteins were also evaluated. METHODS: Hourly concentrations of particulate (PM10) and gaseous pollutants (CO, NO2, SO2, and O3) were obtained from 53 monitoring sites covering the study area. Generalized additive models were applied to compute standardized regression coefficients controlled for age, gender, body mass index, smoking, alcohol, hormone use, temperature, day of the year, and long-term trends. RESULTS: The PT became shorter with higher ambient air concentrations at the time of the study of PM10 (coefficient = -0.06; P < 0.05), CO (coefficient = -0.11; P < 0.001) and NO2 (coefficient =-0.06; P < 0.05). In the 30 days before blood sampling, the PT was also negatively associated with the average PM(10) (coefficient = -0.08; P < 0.05) and NO2 (coefficient = -0.08; P < 0.05). No association was found between the APTT and air pollutant levels. In addition, no consistent relations with air pollution were found for fibrinogen, antithrombin, protein C and protein S. CONCLUSIONS: This investigation shows that air pollution is associated with changes in the global coagulation function, suggesting a tendency towards hypercoagulability after short-term exposure to air pollution. Whether these changes contribute to trigger cardiovascular events remains to be established.     

密闭液性环境干燥环境下供皮区创面愈合的比较研究

目的比较研究密闭液性环境和干燥环境下供皮区创面的愈合过程. 方法 1996年7月～1997年3月以13例成人断层供皮区创面为研究对象,其中男9例,女4例,年龄20～50岁,创面面积(100～400) cm2,取皮深度中厚,约0.44 mm.同一个创面分为实验组(密闭液性环境)和对照组(干燥环境),采用自身对照法.应用大体、组织学及电镜观察等方法进行观察. 结果密闭液性环境下创面愈合较快,创面组织中成纤维细胞较早活跃、且持续时间较长,再血管化和再上皮化均较早和较快发生. 结论密闭液性环境下创面愈合较快,与组织修复细胞较为活跃、再血管化和再上皮化较快发生有关.     

宣威昆明两地肺癌ras基因表达及突变的比较研究

目的 :比较ras基因在宣威、昆明两地肺癌中遗传变异的差异性 .方法 :采用免疫组化染色和PCR -SSCP -DNA直接测序技术 ,对 4 5例宣威地区肺癌和 4 5例昆明地区肺癌石蜡包埋组织标本中ras蛋白的表达及k -ras基因 12密码子突变进行检测 .结果 :5 5例 (5 5 / 90 )ras蛋白表达阳性 ,其中宣威肺癌组 31例 ,昆明肺癌组 2 4例 ,2 8例 (2 8/ 90 )检测到k -ras基因 12密码子突变 .对ras基因在两组肺癌中的表达及突变进行比较分析表明 :ras蛋白表达及k -ras基因 12密码子突变在宣威肺癌组中高于昆明肺癌组 ,但差异无统计学意义 (P >0 0 5 ) ,ras蛋白在Ⅰ期肺癌病例以及腺癌病例中的表达 ,宣威肺癌组均高于昆明肺癌组 ,差异有统计学意义 (P =0 0 4 5 ,χ2 =4 5 72 ,P =0 0 32 ) .结论 :ras基因的激活是肺癌发生过程中常见的分子生物学事件 ;宣威地区肺癌与昆明地区肺癌相比 ,ras蛋白在Ⅰ期病例以及腺癌病例中的表达存在着差异 .k -ras基因 12密码子在宣威地区肺癌中的突变与昆明地区肺癌相比无明显特异性     

Control of endemic methicillin-resistant Staphylococcus aureus—recent advances and future challenges

Although the exact burden of disease caused by methicillin-resistant Staphylococcus aureus (MRSA) remains largely unknown, most experts agree that MRSA infections are an important clinical and public health problem. Thousands of reports have been published during the last four decades concerning epidemiological and microbiological aspects of MRSA, but uncertainty remains about the best approach to prevent and control this worldwide plague, especially endemic MRSA. Epidemiological methods, e.g., risk scores for targeted screening upon admission, rapid molecular tests and pre-emptive isolation of high-risk patients, new decontamination regimens and restriction of certain antibiotic classes, are all promising approaches that may decrease MRSA cross-transmission; however, further evidence is needed before these strategies can be implemented on a wide scale. Control of community MRSA is an additional challenge for the future, requiring improved surveillance and contact tracing, as well as education and treatment of both infected cases and colonised contacts. This review summarises recent advances and studies that address these issues. Overall, it seems that there is no level of MRSA prevalence for which active control measures are no longer warranted.     

Cultural adaptation is associated with atopy and wheezing among children of Turkish origin living in Germany

BACKGROUND: Turkish children have been found to suffer less from atopic diseases than their German peers. The underlying causes are unknown. OBJECTIVE: To evaluate rates of sensitization and atopic disease among children in Germany with German or Turkish ethnicity and different degrees of cultural adaptation. METHODS: This was a cross-sectional study. The setting was screening for school eligibility in an inner-city district of Berlin/Germany. The participants were preschool children born in Germany with double German or double Turkish parental citizenship. Cultural adaptation of Turkish children was assessed by the language parents used to communicate with their child: only Turkish (n = 60, group A); Turkish and German (n = 269, group B); and only German (n = 103, group C). Group D contained children from German parents (n = 383). The main outcome measures were specific sensitization to common aeroallergens (CAP-System, Pharmacia Phadiatop >or= 0.35 kU/L), and lifetime and 1-year prevalences of allergic disease symptoms (ISAAC questionnaire in German and Turkish, Mantel-Haenszel test for trend). RESULTS: Sensitization rates for groups A, B, C and D were 8.0%, 6.8%, 18.9% and 18.3%, respectively (P = 0.004). The corresponding prevalence rates for wheeze ever were 6.7%, 9.3%, 12.6% and 21.3% (P < 0.001), wheeze in the past year 3.3%, 3.7%, 9.7% and 10.2% (P = 0.001), itchy rash ever 3.3%, 6.3%, 8.7% and 13.7% (P < 0.001), itchy rash in the past year 1.7%, 3.7%, 4.9% and 9.5% (P < 0.001), respectively. No significant differences were found for hay fever symptoms. CONCLUSIONS: Higher cultural adaptation is correlated with higher rates of allergic sensitization and disease among children of Turkish origin living in Berlin. This correlation suggests that environmental rather than genetic differences are responsible for the differences observed.