Directed migration of neuronal precursors into the ischemic cerebral cortex and striatum

Pathological processes, including cerebral ischemia, can enhance neurogenesis in the adult brain, but the fate of the newborn neurons that are produced and their role in brain repair are obscure. To determine if ischemia-induced neuronal proliferation is associated with migration of nascent neurons toward ischemic lesions, we mapped the migration of cells labeled by cell proliferation markers and antibodies against neuronal marker proteins, for up to 2 weeks after a 90-min episode of focal cerebral ischemia caused by occlusion of the middle cerebral artery. Doublecortin-immunoreactive cells in the rostral subventricular zone, but not the dentate gyrus, migrated into the ischemic penumbra of the adjacent striatum and, via the rostral migratory stream and lateral cortical stream, into the penumbra of ischemic cortex. These results indicate that after cerebral ischemia, new neurons are directed toward sites of brain injury, where they might be in a position to participate in brain repair and functional recovery.     

“雷公炮炙十七法”辩疑

“十七法”在炮制领域占有重要位置,对后世的炮制方法产生过一定影响,亦存在不少疑点。本文就“十七法”的来源、方法的记载、以及有异议的方法作一浅述。     

Human Rad17 is phosphorylated upon DNA damage and also overexpressed in primary non-small cell lung cancer tissues

The spRAD17 gene is an essential component of the DNA damage and replication checkpoints in the fission yeast Schizosaccharomyces pombe. Cloning of the human homologue of spRAD17, hRAD17, indicated that it exhibits structural similarity with the replication accessory protein family, which include subunits of the Replication factor C complex. We have analyzed the phosphorylation status of hRad17 in response to DNA damaging agents. Our results showed that phosphorylation of hRad17 occurred immediately after UV and ionizing radiation treatment and reached peak level at approximately 3 h, suggesting that hRad17 may be a component of the DNA damage checkpoint. When primary tumor samples were analyzed, we observed that the majority (74%) of non-small cell lung carcinoma samples exhibited a significantly higher level of hRad17 expression compared with matched normal tissue controls. In contrast, hRad17 protein levels in a panel of primary colon carcinoma samples did not show an elevated level of expression compared with normal colon tissues. This observation suggests that the function of the hRAD17 gene may be involved in lung cancer development and may serve as a potential tumor marker.     

Lifetime residential and workplace exposure to environmental tobacco smoke and lung cancer in never-smoking women, Canada 1994-97

Although the risk of lung cancer among never-smokers living with a spouse who smokes has been extensively studied, the impact of lifetime residential and workplace environmental tobacco smoke has received less attention. As part of a large population-based case-control study of lung cancer, we collected lifetime residential and occupational passive smoking information from 71 women with lung cancer and 761 healthy control subjects, all of whom reported being lifetime nonsmokers. The adjusted odds ratio (OR) for lung cancer associated with residential passive exposure only was 1.21 (95% confidence interval [CI] 0.5-2.8). Although more years of and more intense residential passive smoke exposure tended to be associated with higher risk estimates, no clear dose-response relationship was evident. The OR for women with passive exposure as a child and as an adult was 1.63 (95% CI 0.8-3.5) and for those only exposed as an adult 1.20 (95%CI 0.5-3.0). Exposure to environmental tobacco smoke only in the workplace was associated with an adjusted OR of 1.27 (95% CI 0.4-4.0). Risks associated with increasing occupational exposure year tertiles were 1.24, 1.71 and 1.71. Total smoker-years of residential and occupational exposure combined resulted in a statistically significant trend (linear test for trend p = 0.05) with ORs for tertiles of exposure of 0.83, 1.54 and 1.82. Our results are consistent with the literature suggesting that long-term, regular exposure to either residential or occupational environmental tobacco smoke is associated with increased lung cancer risk in never-smoking women.     

Identification and initial characterization of 5000 expressed sequenced tags (ESTs) each from adult human normal and osteoarthritic cartilage cDNA libraries

OBJECTIVE: To prepare, sequence and analyse adult human cartilage cDNA libraries to study the gene expression pattern between normal and osteoarthritic cartilage. METHODS: Poly A(+)RNA from adult human normal and osteoarthritic articular cartilage was isolated and used to prepare cDNA libraries. Approximately 5000 ESTs from each library were sequenced and analysed using bioinformatic tools. The expression of select genes was confirmed by Northern blot and in situ hybridization analysis. RESULTS: Multiple gene families including several classical cartilage matrix protein encoding genes were identified. Approximately 28-40% of the genes sequenced from these libraries were novel, while half of the genes encoded known proteins and 4-6% of the genes encoded novel homologs of known proteins. Several known genes, whose expression has not been reported previously in cartilage, were also identified. We have confirmed the cartilage expression of three known (CTGF, CTGF-L and clusterin) and two novel homologs of known genes (PCPE-2 and Gal-Nac transferase) by Northern blot and in situ hybridization analysis. CONCLUSION: This is the first report of the preparation and sequencing of cDNA libraries from adult human normal and osteoarthritic articular cartilage. Further analysis of genes identified from these libraries may provide molecular targets for diagnosis and/or treatment of osteoarthritis (OA).     

Socioeconomic status and lung cancer risk in Canada

BACKGROUND: Several epidemiological studies have found that lung cancer is inversely related to socioeconomic status (SES) and suggest it as a possible risk factor for lung cancer. This study examines SES and lung cancer risk in Canada. METHODS: Mailed questionnaires with telephone follow-up were used to obtain data on 3280 newly diagnosed, histologically confirmed lung cancer cases and 5073 population controls, between 1994 and 1997, in eight Canadian provinces. Measurement included information on SES, smoking habits, alcohol use, diet, residential and occupational histories and both residential and occupational exposure to environmental tobacco smoke (ETS). Odds ratios (OR) and 95% CI were derived from unconditional logistic regression analysis. RESULTS: Compared with high income adequacy, an increased risk was found among low income males and females, with adjusted OR of 1.7 (95% CI : 1.3-2.2) and 1.5 (95% CI : 1.1-2.0), respectively. Compared with < or = 8 years of education, the adjusted OR were 0.6 (95% CI : 0.5-0.7) and 0.6 (95% CI : 0.5-0.8) for > or = 14 years education among males and females, respectively. Lung cancer risk was significantly increased for males of some social classes. The population attributable risk for income adequacy, education and social class was 24%, 25% and 21% among males, respectively, and 14% and 19% for income adequacy and education among females, respectively, in this Canadian population. CONCLUSIONS: A statistically significant association between income adequacy, education social class and lung cancer risk was found.     

新生儿感染性肺炎病原学检测及临床研究

目的 了解昆明地区新生儿感染性肺炎的病原学、流行病学及临床表现特点.方法 选择506例确诊新生儿感染性肺炎住院患儿为观察组及50例非新生儿感染性肺炎住院患儿为对照组,对两组病例取呼吸道分泌物做细菌及病毒病原学检测,将检测结果与临床相关因素进行分析总结.结果 对照组呼吸道病毒病原学检测均为阴性.为非病原菌生长.观察组呼吸道病原学阳性检出率为58.7%,其中细菌培养阳性占35.18%,以大肠埃希菌为主;病毒占23.3%,以呼吸道合胞病毒多见;结核感染占0.2%;病原不明者41.3%.新生儿感染性肺炎以出生后感染居多,占89.33%,而宫内感染性肺炎仅占10.67%.新生儿细菌感染性肺炎患儿咳嗽(X2=10.20,P<0.01),感染中毒症状(X2=8.21,P<0.01)、双肺湿罗音(X2=6.11,P<0.05)及缺氧征(X2=8.21,P<0.05)明显多见于病毒感染;而病毒感染者冬春季明显多于夏秋季.结论 新生儿感染性肺炎58.70%可明确病原,细菌感染多于病毒感染;感染性肺炎以出生后多见;细菌感染与病毒感染各有其临床特点.     

化工厂制冷装置液氨泄漏急性职业中毒定量风险评估

化工厂制冷装置发生液氨泄漏,泄漏后形成毒气云团在空气中扩散,初期多形成重气云团,在扩散过程中随着空气的不断卷吸,重气云的密度会越来越接近空气,从而转变为非重气云团。该文应用重气扩散及高斯公式,建立液氨等有毒液化气的泄漏扩散数学模型,将重气云扩散模型和非重气云的高斯模型有机结合起来,估测液氨泄漏扩散连续变化过程中氨气浓度的分布规律及危害范围。相应的数学扩散模型可为职业病危害事故的风险评估提供科学评价方法;风险分析结果可用于职业病危害事故的预测、预警及应急救援。