Incidence of childhood diabetes mellitus in Yorkshire, northern England, is associated with nitrate in drinking water: an ecological analysis

Summary The relationship between the incidence of childhood-onset insulin-dependent diabetes mellitus and levels of nitrate in drinking water in the former Yorkshire Regional Health Authority was investigated by means of an ecological analysis. A population-based register contributed 1797 0–16-year-olds diagnosed with diabetes between 1978 and 1994. Nitrate data were based on 9330 samples of drinking water tested between 1990 and 1995 in 148 water supply zones, for which 1991 census small area statistics were taken on population density, ethnicity and socio-economic status. Diabetes incidence was positively associated with raised mean nitrate levels with a standardised incidence ratio of 115 in zones with greater than 14.85 mg · l^–1 (χ² = 26.81, 1 df, p < 0.001). Significant negative trends were found between standardised incidence ratios and proportion of non-whites in the population (χ² = 33.57, 1 df, p < 0.001), childhood population density (χ² = 30.81, 1 df, p < 0.001) and the Townsend deprivation score (χ² = 33.89, 1 df, p < 0.001). Poisson regression modelling, adjusting for the other factors, showed a significant increase in relative incidence rate ratio from a baseline of 1 at nitrate levels below 3.22 mg · l^–1 to 1.27 (95 % confidence interval 1.09,1.48) for mean nitrate levels above 14.85 mg · l^–1. An association between higher nitrate levels in domestic drinking water and incidence of childhood diabetes has been demonstrated. This was not explained by the ethnic composition of the population, population density or socioeconomic status. Nitrate in drinking water may be a precursor of chemicals which are toxic to the pancreas. [Diabetologia (1997) 40: 550–556] Received: 24 October 1996 and in revised form: 20 December 1996     

新型饮水对小鼠繁殖及抗氧化酶活性的影响

目的　探讨新型饮水对健康的影响及其保健作用。方法　将矿溶生态水、活化水、纯净水、矿泉水、碱性离子水等 5种新型饮水作为唯一水源分别喂饲亲代及子代小鼠 3个月 ,对照给予天然水。观察它们对小鼠体重、繁殖及抗氧化酶活性的影响。结果　与天然水比较 ,活化水、矿溶生态水促进亲代雄性小鼠体重增长 (P <0 0 5) ;矿溶生态水使子代小鼠、矿泉水和碱性离子水使子代雄性小鼠体重增长缓慢 (P <0 0 5) ;纯净水使新生仔鼠体重减轻 (P <0 0 5) ,活化水、矿溶生态水使小鼠窝产仔数增多 (P <0 0 5) ,5种水对小鼠受孕率、妊娠率、出生存活率无影响 ;矿溶生态水、活化水、纯净水、矿泉水使小鼠肝组织SOD活力升高 (P <0 0 5) ,碱性离子水使肝组织SOD活力降低 (P <0 0 5)。结论　 5种新型饮水对小鼠体重有影响 ,对受孕率、妊娠率、出生存活率无影响 ;矿溶生态水、活化水、纯净水、矿泉水有提高SOD活力作用     

Spatial Learning Deficits in Mice with a Targeted Glucocorticoid Receptor Gene Disruption

Previous studies in rats using the Morris water maze suggested that the processing of spatial information is modulated by corticosteroid hormones through mineralocorticoid and glucocorticoid receptors in the hippocampus. Mineralocorticoid receptors appear to be involved in the modulation of explorative behaviour, while additional activation of glucocorticoid receptors facilitates the storage of information. In the present study we used the water maze task to examine spatial learning and memory in mice homozygous and heterozygous for a targeted disruption of the glucocorticoid receptor gene. Compared with wild-type controls, homozygous and heterozygous mice were impaired in the processing of spatial but not visual information. Homozygous mutants performed variably during training, without specific platform-directed search strategies. The spatial learning disability was partly compensated for by increased motor activity. The deficits were indicative of a dysfunction of glucocorticoid receptors as well as of mineralocorticoid receptors. Although the heterozygous mice performed similarly to wild-type mice with respect to latency to find the platform, their strategy was more similar to that of the homozygous mice. Glucocorticoid receptor-related long-term spatial memory was impaired. The increased behavioural reactivity of the heterozygous mice in the open field points to a more prominent mineralocorticoid receptor-mediated function. The findings indicate that (i) the glucocorticoid receptor is of critical importance for the control of spatial behavioural functions, and (ii) mineralocorticoid receptor-mediated effects on this behaviour require interaction with functional glucocorticoid receptors. Until the development of site-specific, inducible glucocorticoid receptor mutants, glucocorticoid receptor-knockout mice present the only animal model for the study of corticosteroid-mediated effects in the complete absence of a functional receptor.     

枸杞地黄汤改善老年小鼠记忆障碍和自由基、免疫系统异常改变

目的：研究枸杞地黄汤对老年小鼠学习记忆、自由基及免疫系统的影响。方法：采用水迷宫行为实验检测枸杞地黄汤对老年小鼠学习记忆的影响，通过测定皮层、海马中MDA和SOD水平检测药物对老年小鼠自由基系统异常改变的影响，通过测定老年小鼠免疫器官指数变化检测药物对老年免疫系统异常改变的影响。结果：5、10、20g／kg的枸杞地黄汤不同程度减小老年小鼠学习记忆障碍，降低皮层、海马中MDA水平，增加SOD活性，提高胸腺、脾指数。结论：枸杞地黄汤能够改善老年小鼠学习记忆障碍．调节不正常自由基系统和免疫系统。     

江油市粮食中霉菌污染调查

对江油市胡豆，黄豆，玉米，大米，麦子，碗豆共３７５件样品进行霉菌污染调查。调查表明：粮食中霉菌平均侵染率８７．８％，其中黄豆，碗豆污染较轻，其侵浸率明显低于小麦，大米，胡豆。胡豆，碗豆，黄豆以曲霉菌属为主；小麦以交链孢霉为主，大米以青霉菌属为主；玉米以预     

Cytogenetic damage in operation theatre personnel

The study in a group of 24 (11 anaesthetists and 13 support staff) was planned to ascertain the cytogenetic risk in a group of theatre personnel who worked in various city hospitals. Their exposure in terms of duration of service vary from 3-30 years. The control group (n = 24) consisted of people with different occupations matched for possible confounding variables. Cytogenetic risk was assessed in terms of chromosome aberration and sister chromatid exchange in 72-hour lymphocyte cultures. A significant increase in the percentage of chromosome aberration was observed. The sister chromatid exchange was double that of the baseline value in 20% of the exposed individuals. These findings indicate the possible risk of cytogenetic damage for staff working in unscavenged rooms.     

天然矿泉水淡水藻类污染检验方法研究

采用天然矿泉水淡水藻类的检验方法，在采自福建省各地区的２０２份样品中检出４２份阳性，共１５属藻类。这些藻在自然界淡水中常见。该方法独特之处是将浓缩培养基直接加入水样瓶中。然后，在培养过程中保持散射光照低于５０００Ｌｘ。瓶中样品的静置，有助于藻类从水处理造成的损伤中恢复。５～１０天后，绿色或蓝绿色的藻细胞将形成明显的斑点或沉淀。经镜检分类，检出了绿藻、蓝藻等１５个属。比较了５种培养基，以改良克诺普液使用效果最好。此培养基容易配制和应用，藻类生长快，观察方便。     

一项新的水质检验——可同化有机碳测定

可同化有机碳(AOC)是一项新的水质检测指标,通过它可以评估供水系统的水中是否有足够的营养物质可使微生物再生长。由于目前尚无可行的化学方法检测 AOC,因此主要是用各种生物方法加以检测。本文介绍用荧光假单胞菌 P—17菌株和螺菌属 NOX 菌株作为测试菌,通过定量观察其在水样中的生长,如从接种到生长至最大数量,以考察其利用水中营养物质的情况,进而推算出水中 AOC 的浓度。     

Group Similarities in Beliefs Concerning the Causes of Alcohol Problems and the Effectiveness of Means of Overcoming Problem Alcohol Use

Four hundred and eight respondents, who did or did not know persons close to themselves with alcohol problems, from four different racial/ethnic groups (with one group, Filipinos, categorized in terms of whether they were born in the Philippines or in the US.) rated the importance of 19 different causes of problem alcohol use and 22 different means of overcoming problem alcohol use. Rank-order correlations across sexes, persons differing in exposure to problem drinkers, and ethnic groups were nearly all in the 0.90's regarding causation. Correlations of Caucasians' ratings with those of other groups were high, but only in the 0.60's and 0.70'9, chiefly because Caucasians were more prone to regard problem alcohol use as hereditary and as a disease, and less likely to believe problem use to result from social factors. All across-group correlations concerning beliefs about the effectiveness of means of overcoming problems were in the 0.90's. Some of the means of treatment regarded most highly by all groups have not been demonstrated to be effective.