苯DNA加合物研究进展(综述)

苯ＤＮＡ加合物研究进展（综述）李桂兰，常平综述徐伯洪审校（中国预防医学科学院劳动卫生与职业病研究所，北京１０００５０）我国职业接触苯的工人约有５０万，长期接触苯可引起白血病。苯与其它实质性肿瘤的问题也有报道［１，２］。世界癌症研究机构（ＩＡＲＣ）１９...     

豫北地区现代护理事业的起步

直至20世纪20年代，河南豫北地区现代护理事业才开始真正起步。随着先进护理理念的引入，加拿大护理人员先后到来，现代化专业性质的医院开始建立，专门的护理学校建成，中国第一批专业护理人员毕业，这些都标志着现代护理事业在豫北扎下根基。究其原因，既有中国社会不断向现代化转变的宏观历史因素，它促使中国人主动接纳西方的、现代的医学；也有许多具体的原因，其中外国护理人员高尚的奉献精神、精湛的专业素养，起到了关键作用。     

Regional drought-induced reduction in the biomass carbon sink of Canada's boreal forests

The boreal forests, identified as a critical "tipping element" of the Earth's climate system, play a critical role in the global carbon budget. Recent findings have suggested that terrestrial carbon sinks in northern high-latitude regions are weakening, but there has been little observational evidence to support the idea of a reduction of carbon sinks in northern terrestrial ecosystems. Here, we estimated changes in the biomass carbon sink of natural stands throughout Canada's boreal forests using data from long-term forest permanent sampling plots. We found that in recent decades, the rate of biomass change decreased significantly in western Canada (Alberta, Saskatchewan, and Manitoba), but there was no significant trend for eastern Canada (Ontario and Quebec). Our results revealed that recent climate change, and especially drought-induced water stress, is the dominant cause of the observed reduction in the biomass carbon sink, suggesting that western Canada's boreal forests may become net carbon sources if the climate change-induced droughts continue to intensify.     

Sleeping sickness in West Africa (1906-2006): changes in spatial repartition and lessons from the past

Objective To review the geography and history of sleeping sickness (Human African trypanosomiasis; HAT) over the past 100 years in West Africa, to identify priority areas for sleeping sickness surveillance and areas where HAT no longer seems active. Method History and geography of HAT were summarized based on a review of old reports and recent publications and on recent results obtained from medical surveys conducted in West Africa up to 2006. Results/conclusions Active HAT foci seem to have moved from the North to the South. Endemic HAT presently appears to be limited to areas where annual rainfall exceeds 1200 mm, although the reasons for this remain unknown. There has also been a shift towards the south of the isohyets and of the northern distribution limit of tsetse. Currently, the most severely affected countries are Guinea and Ivory Coast, whereas the northern countries seem less affected. However, many parts of West Africa still lack information on HAT and remain to be investigated. Of particular interest are the consequences of the recent political crisis in Ivory Coast and the resulting massive population movements, given the possible consequences on HAT in neighbouring countries.     

Expression of hepatic thrombopoietin mRNA in primary cultured hepatocytes and in rats with acute liver injury or bone marrow suppression with or without cirrhosis

BACKGROUND AND AIMS: The main causes of thrombocytopenia in cirrhosis are thought to be platelet destruction and the reduction of thrombopoietin (TPO) expression in the liver. The mechanisms by which levels of TPO mRNA are regulated in cirrhosis have not been elucidated. In this study, we investigated some possible mechanisms. METHODS: We used three experimental models: bone marrow suppression, acute liver injury and primary cultured hepatocytes. We used northern blots to assess the kinetics of TPO mRNA expression in the livers of irradiated rats (with and without cirrhosis) in acute liver injury and in primary cultured hepatocytes treated with hepatotoxin or cytokines. RESULTS: Although the bone marrow was hypocellular, there was no apparent enhancement of TPO mRNA expression in the irradiated rats with cirrhotic livers compared with the unirradiated rats with cirrhotic livers. There were no conspicuous changes in hepatic TPO mRNA expression between the livers of the control rats and the three models of acute liver injury. There were no conspicuous changes in the levels of TPO mRNA between control hepatocytes and hepatocytes treated with hepatotoxin or cytokines. CONCLUSIONS: Our results suggest that bone marrow is not a regulator of hepatic TPO production in cirrhosis. The reduced TPO mRNA expression found in cirrhotic rats may not result merely from serious cellular damage; it may be associated with cirrhosis-specific regulatory mechanisms for the expression of the TPO gene. Further studies are needed to search for other factors that may induce reduced TPO expression.     

Low awareness of intestinal schistosomiasis in northern Senegal after 7 years of health education as part of intense control and research activities

We evaluated the awareness of and knowledge about intestinal schistosomiasis in a highly infected rural community of northern Senegal where a variety of health information and education activities had taken place for 7 years as a component of different research and control programmes. As the infection had been introduced only recently, an initial 'zero' knowledge can be assumed. Most of the health education activities had been performed with adapted messages through local health and community workers. By a questionnaire, 566 individuals were asked simple questions on symptoms, mode of transmission, the sources of information and health-seeking behaviour. About 86% of the respondents stated that they knew what schistosomiasis was, and 92% that in case of illness they would seek treatment at the health centre. However, only half of the people accurately quoted symptoms associated with intestinal schistosomiasis: diarrhoea, abdominal pain and bloody stools. The majority of respondents realized that the disease was somehow linked with water and (lack of) hygiene, but only 44% of respondents reported water contact as the source of infection. Ultimately, only 30% of the respondents gave adequate answers about both symptoms and mode of transmission. We conclude that even intense and long-lasting education efforts for a specific and straightforward problem as schistosomiasis are not enough to have profound impact on the knowledge of rural traditional communities.     

Northern印迹法检测喉鳞状细胞癌中表皮生长因子受体mRNA的表达

目的 :探讨喉部鳞状细胞癌的发病机制。方法 :采用Northern印迹法检测喉部鳞状细胞癌中表皮生长因子受体mRNA的表达。结果 :在喉部鳞状细胞癌中可见 5 80 0mRNA异常表达。结论 :喉部鳞状细胞癌的生物学行为与其 5 80 0mRNA介导异常表达密切相关。