Pentachlorophenol potentiates benzo[a]pyrene DNA adduct formation in adult but not infant B6C3F1 male mice

The objective of this study is to determine whether pentachlorophenol (PCP) alters benzo[a]pyrene (B[a]P)-induced DNA adduct formation in infant and adult B6C3F1 male mice. Mice were exposed intraperitoneally to 55 microg B[a]P/g body weight (BW) alone and in combination with several doses of PCP in DMSO. The 32P-postlabeling assay was used to analyze for (+/-) anti-7,8-diol-9,10-epoxide-B[a]P-N(2)deoxyguanosine (BPDE-N(2)G) adducts formed in liver and lung DNA. Hepatic DNA also was analyzed for 8-hydroxy-2'-deoxyguanosine (8-OHdG) base damage in mice exposed to PCP. 8-OHdG was not detected at any dose of PCP in infant or adult mice. PCP exhibited an antagonistic effect on BPDE-N(2)G accumulation in infant mice exposed to B[a]P in combination with 50 microg PCP/g BW at both 12 and 24 hr. Comparatively, BPDE-N(2)G adducts were increased in adult mice exposed to binary mixtures at 24 hr in both hepatic and lung DNA (P < 0.05). Multiple comparison analysis between infant and adult mice revealed that adduct levels in infants exposed to B[a]P alone or in combination with PCP were not different from those observed in adult mice exposed to B[a]P. However, a significant increase in adducts was observed in adult mice exposed to a combination of B[a]P and PCP compared to that in all other treatment groups (P < 0.05). These results suggest that PCP alters the metabolism of B[a]P in both infant and adult mice through different mechanisms, and that infants are not susceptible to the potentiating effects of PCP observed in adult mice.     

Latent variable discovery in classification models

The naive Bayes model makes the often unrealistic assumption that the feature variables are mutually independent given the class variable. We interpret a violation of this assumption as an indication of the presence of latent variables, and we show how latent variables can be detected. Latent variable discovery is interesting, especially for medical applications, because it can lead to a better understanding of application domains. It can also improve classification accuracy and boost user confidence in classification models.     

汉坦病毒A9株全长L片段cDNA克隆和核苷酸序列测定

目的克隆我国分离的汉坦病毒A9株L片段全长cDNA,并测定其核苷酸序列.方法用逆转录-聚合酶链反应(RT-PCR)技术分段扩增汉坦病毒A9株全部L片段,用T-A克隆方法进行PCR产物克隆,测定PCR产物的核苷酸序列.通过亚克隆将分段的L片段连接成全长cDNA克隆.结果A9株的基因组L片段长度为6533个核苷酸,腺嘌呤核苷酸和尿嘧啶核苷酸丰富(%A+U=62.47).包含有一个单一的开放读码框架(ORF),编码一个标准的质量为2.46×105的蛋白,含有2151个氨基酸.A9株与76-118、C1-1和C1-2株的同源性最高,达到83.8%.与TULA病毒的关系较远,其核酸序列的同源性为65.8%.将推导的A9株编码的氨基酸序列与其他21种负链RNA病毒的依赖RNA的RNA聚合酶的氨基酸序列以及汉坦病毒几个代表株的L片段氨基酸序列进行比较,显示A9编码的RNA聚合酶也有6个比较保守的区域以及几个极端保守的氨基酸残基.结论汉坦病毒A9株L片段具有和其他汉坦病毒RNA聚合酶相似的核苷酸一级结构,通过对推导的氨基酸分析,该片段具有一些在RNA病毒聚合酶中都存在的保守区域.     

黏着斑激酶酪氨酸磷酸化促大鼠肝纤维化形成及其可能机制

目的探讨在肝纤维化发生中,黏着斑激酶(FAK)酪氨酸磷酸化与肝星状细胞(HSC)增殖的关系,并从细胞周期角度探讨其促HSC增殖的机制。方法采用胆总管结扎(BDL)方法建立大鼠肝纤维化模型;免疫组织化学方法测定α-平滑肌肌动蛋白(α-SMA)表达;Western blot检测p-FAK(Tyr397)、细胞周期蛋白D1(cyclin D1)和细胞周期蛋白依赖激酶4(CDK4)在肝组织中的含量。结果正常大鼠肝组织有少量α-SMA分布,随着肝纤维化发展,α-SMA阳性细胞明显增多;肝组织中p-FAK(Tyr397)、cyclin D1及CDK4蛋白表达逐渐增加,造模4周时达峰值。多元相关分析示α-SMA与p-FAK(Tyr397)正相关(r=0.964,P<0.01);α-SMA与cyclin D1、CDK4正相关(r=0.953,0.906;P<0.01);p-FAK(Tyr397)与cyclin D1、CDK4亦明显正相关(r=0.969,0.893;P<0.01)。结论FAK磷酸化促HSC增殖及肝纤维化形成机制可能与调控细胞周期相关蛋白有关。     

College student attitudes toward forcible date rape: I. Cognitive predictors

Students completed a questionnaire measuring acceptance of forcible date rape, attitudes toward women, sexual knowledge, sexual experience, tolerance of socially unapproved sexual behavior, and religiosity. Findings suggested that persons relatively more accepting of forcible date rape are less sure it really is rape, have more traditional attitudes toward women, are more selfsexually permissive (i.e., more tolerant of their own socially unapproved of sexual behavior, such as premarital and extramarital sex with friends or casual acquaintances), have less accurate sexual knowledge and, though a large majority blame the male, are slightly more inclined than others to blame society or the situation. These predictor variables accounted for 35% of the variance in attitudes toward forcible date rape and identified correctly about two-thirds of the students classified as nonrejectors of forcible date rape, i.e., those who did not consider the male's behavior definitely unacceptable under any one of nine circumstances, including He spent a lot of money on her. In addition to the emotional and personality variables often cited in rapists, the cognitive predictor variables found may be salient to understanding the etiology of rape.This paper was first presented at meetings of the Society for the Scientific Study of Sex, September 1985, in San Diego, California.     

血清生长分化因子15水平与慢性淋巴细胞白血病发生风险的关联研究

目的 采用两样本孟德尔随机化研究方法探讨血清生长分化因子15(GDF15)水平与慢性淋巴细胞白血病(CLL)发生之间的关联。方法 基于欧洲人群血清GDF15和CLL的全基因组关联研究公开数据库,筛选与血清GDF15水平相关的遗传变异位点作为工具变量,采用逆方差加权法评估遗传学预测的血清GDF15浓度与CLL发生的关联,采用最大似然比法进行敏感性分析,采用MR-Egger回归探讨工具变量潜在多效性。结果 研究共纳入3个单核苷酸多态位点作为工具变量,逆方差加权法结果显示,血清GDF15水平与CLL发生风险之间存在负相关,GDF15浓度每升高一个标准差(SD),CLL发生风险降低33%(95%置信区间:2%～54%)(P=0.039)。敏感性分析得到了一致的结果。此外,MR-Egger回归未发现存在多效性。结论 本研究结果提示,在欧洲人群中,血清GDF15水平与CLL发生之间可能存在负相关,仍需大样本人群研究及体内外实验进一步阐明GDF15在CLL发生发展中的作用及其潜在生物学机制。     

Psycho-Behavioural Segmentation in Food and Nutrition: A Systematic Scoping Review of the Literature

Inadequate dietary intakes are a key modifiable risk factor to reduce the risk of developing non-communicable diseases. To encourage healthy eating and behaviour change, innovative public health interventions are required. Social marketing, in particular segmentation, can be used to understand and target specific population groups. However, segmentation often uses demographic factors, ignoring the reasons behind why people behave the way they do. This review aims to explore the food and nutrition related research that has utilised psycho-behavioural segmentation. Six databases from were searched in June 2020. Inclusion criteria were: published 2010 onwards, segmentation by psycho-behavioural variables, outcome related to food or nutrition, and healthy adult population over 18 years. 30 studies were included; most were quantitative (n = 28) and all studies used post-hoc segmentation methods, with the tools used to segment the population varying. None of the segments generated were targeted in future research. Psycho-behavioural factors are key in understanding people’s behaviour. However, when used in post-hoc segmentation, do not allow for effective targeting as there is no prior understanding of behaviours that need to change within each segment. In future, we should move towards hybrid segmentation to assist with the design of interventions that target behaviours such as healthy eating.     

瘦素受体Gln223Arg基因多态性与不同葡萄糖耐量血清瘦素的相关性研究

目的 :研究瘦素受体基因Gln2 2 3Arg等位基因与不同葡萄糖耐量中血清瘦素及其它代谢指标的关系。方法 :运用聚合酶链反应 限制性片段长度多态性 (PCR RFLP)方法测定无亲缘关系 ,不同葡萄糖耐量 198例北京地区汉族人的瘦素受体基因Gln2 2 3Arg等位基因 ,同时分析其与临床资料的相关性。结果 :不同等位基因型的瘦素水平无显著差异 ,而在葡萄糖耐量减低 (IGT)男性 ,Gln2 2 3Arg等位基因有较高的胆固醇水平 [(7 2 6±1 95 )和 (5 31± 1 31)mmol/L ,P =0 0 4]和较高的收缩压 [(18 8± 1 2 )和 (17 2± 1 6 )kPa ,P =0 0 3]。结论 :瘦素受体Gln2 2 3Arg基因多态性与不同葡萄糖耐量的血清瘦素无关 ,但与机体代谢有一定关系     

强制戒毒期海洛因依赖者自测健康的对照分析

目的 探讨强制戒毒期海洛因依赖者自测健康状况。方法 对60名强制戒毒者及60名社区人员采用自测健康评定量表（SRHMS）进行评定。结果 强制戒毒患者的SRHMS总分、生理、心理和社会健康因子分均明显低于社区组,两者之间的差异具有非常显著性意义（P＜0．01）。结论 吸毒严重损害人们的生理、心理及社会健康,提示要采取措施加强对该人群的心理行为干预及监督管理。     

体内外自由基形成的研究及意义

目的研究体内外自由基的形成及意义。方法用TBA-醋酸法检测正常人血清,血浆,胸腹腔渗、漏出液,各细胞提取物及服用西洋参前后的血浆和经过氧化处理后的正常人、糖尿病、高血压、冠心病患者的血清及食用油脂、相应烟雾冷凝油的过氧化脂质(LPO)含量。结果各细胞均有自由基反应,以血小板为最高。血清LPO明显高于血浆(P<0.001),胸腹腔渗出液LPO明显高于漏出液(P<0.001),过氧化处理后的糖尿病、高血压、冠心病患者血清的LPO明显高于过氧化处理后的正常人血清LPO(P<0.001);油脂质量越高,LPO含量越低,相应的烟雾冷凝油的LPO是食用油脂的14.3～35.6倍。结论生物、化学和物理因素均可引起脂质过氧化,不管何种因素所致的脂质过氧化,其反应过程及其产物LPO对生物体都有严重的损害作用。