Ubiquitous Presence in Mammalian Cells of Enzymatic Activity Specifically Cleaving 8-Hydroxyguanine-containing DNA

Here we report the finding of enzymatic activity that specifically cleaves DNA containing 8-hydroxyguanine (oh⁸Gua) residues in various mammalian cells. To detect this activity, we used a synthetic double-stranded DNA containing a single oh⁸Gua at a defined position as the substrate, and analyzed the products of enzymatic digestion by polyacrylamide gel electrophoresis. Two cleavage sites near the oh⁸Gua residue were detected with partially purified fractions from cow brain and rat liver, and also with preparations from all mammalian tissues examined. These results suggest that enzymatic activity for the removal of oh⁸Gua from DNA is widely distributed in mammalian cells.     

Ethical Reasoning Among Registered Nurses Experienced in Dementia Care

Abstract. Registered nurses regarded as “experienced and good” in dementia care were interviewed about the feeding of a severely demented patient who showed refusal-like feeding behaviour. Not one of the twenty nurses could see herself using force against her patients. Most interviewees justified their decisions to feed a severely demented patient and answered questions about whether they would change their minds if there were certain circumstances in terms of words that could be interpreted as referring to the ethical principle of beneficence. The nurses stressed the difficulty to understand the meaning of severely demented patients' feeding behaviour and decide when force-feeding occurs. When asked to rank ethical principles of importance for the decision, however, the most common answer was that they would give priority to the ethical principle of autonomy. The nurses did not see the ethical principles as separate entities, that could be applied one by one, but tried to integrate them into a whole. The findings of this study were interpreted as indicating that principled ethics is not an adequate model to describe experienced nurses' ethical reasoning.     

人胎儿雪旺氏细胞的体外培养及其纯化研究

本实验用酶消化法从孕１４～１９周人胎儿周围神经中分离培养雪旺氏细胞，结合差速贴壁和阿糖胞苷处理进行纯化，根据Ｓ－１００蛋白免疫细胞化学染色和形态学特征，分析不同时期雪旺氏细胞的纯化程度。实验结果显示：培养４ｄ，倒置相差显微镜下观察，雪旺氏细胞呈典型的双极或三极形，端对端或旋涡状排列，Ｓ－１００蛋白免疫细胞化学染色呈阳性反应，其比例约占９８％；在２～３周内，雪旺氏细胞的纯度维持在８５％～９０％；培养３５ｄ，雪旺氏细胞约占８０％；单纯采用阿糖胞苷或差速贴壁处理，培养３５ｄ，雪旺氏细胞约占７０％；原代培养９２ｄ，传代１１代细胞生长良好。实验结果表明，多种方法联合使用较单一方法所得的纯度高。本方法快速、简便，能为雪旺氏细胞作为移植材料提供足够的来源。     

中国西部城市和农村开展面粉营养素强化的可行性分析

目的通过对甘肃农产区居民的饮食习惯、营养知识和态度的调查,从需方的角度对开展面粉营养素强化的可行性进行探讨。方法采用定性和定量调查相结合的方法,对4个地区的城市和农村的男性和女性分别进行现状和原因的调查分析。结果被调查地区多数城市(92.7%)和农村(60.7%)家庭日常饮食以面食为主,94.7%的城市家庭购买面粉,而在农村地区,多数家庭自己种植或购买小麦。城市居民较农村对营养和维生素有更多的了解和关注。农村男性对面粉营养素强化持怀疑态度,女性更加关注孩子的营养,认为目前的饮食单一,孩子可能营养不足。结论与农村地区相比,城市地区的社会经济条件和知识基础较利于开展面粉强化工作。     

A Case of Postbulbar Duodenal Ulcer with Jaundice

Abstract: A 63-year-old man was hospitalized because of jaundice and anorexia. An upper gastrointestinal series and hypotonic duodenography revealed circumferential sclerosis and stenosis of the duodenal wall. Endoscopic examination disclosed an ulcer, the upper margin of which was located at the papilla of Vater. The papilla was situated in the base of the ulcer. Endoscopic retrograde cholangiopancreatography disclosed mild dilatation of the common bile, intrahepatic bile and pancreatic ducts, but with neither severe stenosis nor occlusion. Nevertheless, there was some degree of circumferential compression and mild stenosis of the terminal portions of the bile and pancreatic ducts, as potential causes of obstructive jaundice in this patient. Computed tomographic examination of the abdomen revealed a tumorous lesion at the duodenal bulb. Because malignancy in the duodenum could not be ruled out, a pancreatoduodenectomy was performed. Histopathological examination showed a postbulbar duodenal ulcer, associated with inflammation of the papillary orifice and fibrosis of the region near the papilla. There was no evidence of a tumorous lesion. In this case, a postbulbar duodenal ulcer may have caused obstructive jaundice.     

Multiplex PCR assay for rapid identification of oculopathogenic adenoviruses by amplification of the fiber and hexon genes

Eye infections caused by adenovirus (Ad) often result in nosocomial infections and community epidemics with significant rates of morbidity. No antiviral agent effective against Ad is yet available for clinical use. Therefore, early diagnosis is still the mainstay for patient management and the prevention of epidemics. A multiplex PCR assay based on amplification of a combination of the fiber and hexon genes which can identify the six important oculopathogenic serotypes of Ads (Ad serotype 3[Ad3], Ad4, Ad7, Ad8, Ad19, and Ad37) in a single-tube amplification reaction was developed. Ad serotypes could be distinguished by the different amplicon sizes. The assay correctly identified prototype strains as well as isolates in clinical specimens. In comparison with a previously described PCR-restriction fragment polymorphism method, our assay gave unequivocal results for clinical specimens. Our multiplex PCR has the potential to serve as a rapid and cost-effective tool for the typing of important ocular Ads.