Systematic Reviews on the Basis of Methodological Criteria

This paper describes a method of systematic reviewing. This method puts much emphasis on the methodological quality of the randomised clinical trials involved. Various items concerning the internal validity, precision and relevance of the studies are scored in such a way that next to the methodological quality the amount of uncertainty about it also becomes visible. These quality assessments are not only useful for systematic reviews, but also have an educational function for researchers with respect to the design and publication of a clinical trial.     

Semiconductor manufacturing: an introduction to processes and hazards

Recent studies suggest that semiconductor workers have an increased incidence of work-related illness. Semiconductor manufacturing is a chemically intensive industry involving many potentially hazardous operations. As this industry moves into new geographic areas, health care professionals will be asked to evaluate medical or workplace conditions associated with unfamiliar and complex production processes. This paper provides an overview of semiconductor manufacturing processes for these health practitioners. Each step of device fabrication is detailed with its attendant chemical and physical hazards. Broader concepts of industrial control technology, clean room ventilation, and ergonomics are explained. The hazards are tabulated to allow rapid assessment of the risks inherent to each processing step. References have been chosen to guide the reader to more indepth information.     

Understanding how Listeria monocytogenes targets and crosses host barriers

Human listeriosis is caused by the Gram-positive bacterium Listeria monocytogenes. In humans, this pathogen has the ability to cross the intestinal, placental and blood-brain barriers, leading to gastroenteritis, maternofetal infections and meningoencephalitis, respectively. The entry of L. monocytogenes into cultured human epithelial cells is mediated by the interaction of an L. monocytogenes surface protein, internalin, with its human receptor, E-cadherin. The internalin-E-cadherin interaction is species-specific, and relies on the nature of a single amino-acid in the E-cadherin molecule, which is proline in permissive species such as humans, and glutamic acid in non-permissive species such as the mouse. In a transgenic mouse model that expresses human E-cadherin in enterocytes, internalin allows L. monocytogenes to cross the intestinal barrier. Epidemiological evidence also supports a role for internalin in human listeriosis, not only for crossing the intestinal barrier, but also for targeting and crossing the placental and blood-brain barriers. Consistent with these epidemiological data, infection with L. monocytogenes of trophoblastic cell lines, primary trophoblast cultures and human placental villous explants demonstrates that bacterial invasion of the syncytiotrophoblast barrier is mediated by the internalin-E-cadherin interaction, leading to histopathological lesions that mimic those seen in the placentas of women with listeriosis. Thus, the internalin-E-cadherin interaction that plays a key role in the crossing of the intestinal barrier in humans is also exploited by L. monocytogenes to target and cross the placental barrier. Further investigations are currently focusing on the molecular mechanisms by which L. monocytogenes targets and crosses the blood-brain barrier.     

"五四"新文学的内倾化形态

这种形态的文学其最为显著的标志是内倾化即自剖，暴露作家的思想观念，心灵情绪直到作家的私生活，包括作家的性心理与性行为等在一般社会眼中视为卑微的东西。作家们弘扬个人的心灵欲望，宣泄“食与色”的双重焦虑与痛苦，其思想内涵无疑带有强烈的反封建色彩。其批判的向度指向内外两个方面，既有对自我心灵严酷的审视，又有对于社会与国家的无情拷问。     

A review of 2975 consecutive operations by one surgeon in an accredited outpatient plastic surgicentre: A Canadian experience

The present paper constitutes a retrospective review of 2975 consecutive operations performed by the author, one of the three owners of the Saskatoon Plastic Surgicentre. The unit opened in 1987; therefore, the study spans 17 years. Patients are not kept overnight, and the Surgicentre is approved and equipped as a level C facility for general anesthesia. Only patients who score 1 or 2 according to the American Association of Anesthesiologists are treated. Only certified anesthesiologists are used. Of the patients with postoperative complications, only two required transfer to a hospital. One developed a pneumothorax, which was treated on arrival at the intensive care unit with no sequelae. The other collapsed following facelift surgery. She was transferred to University of Saskatchewan hospital and died later that evening with a massive pulmonary embolus. In a properly established outpatient centre, a large number of patients can be safely treated with very few complications. However, despite placing patient safety as the first consideration and adhering strictly to the highest standards, death can occur.     

醒脑静注射液治疗缺血性中风急性期随机对照试验的系统评价

目的 系统评价醒脑静注射液治疗缺血性中风急性期的疗效及安全性。方法 集醒脑静注射液治疗缺血性中风急性期随机对照试验文献，筛选合格研究，应用Jadad评分法进行质量评价，运用异质性检验、Meta-分析、漏斗图分析、敏感性分析等方法统计相关数据。结果 项研究符合纳入标准，Jadad评分所有研究得分均低于3分，属低质量文献。Meta-分析结果显示，总有效率比较的相对危险度（RR值）=1．04，99％的可信区间（CI值）为（0．88，1．23）。结论 前尚无充分证据证实醒脑静注射液治疗缺血性中风急性期的疗效及安全性。要进一步验证醒脑静注射液治疗缺血性中风急性期的疗效及安全性，尚需进行设计合理、执行严格、多中心大样本且随访时间足够的随机对照试验。     

Symptoms, diagnosis and endoscopic management of common bile duct stones

Symptomatic BDS commonly cause significant morbidity and attempt at stone removal should be attempted if possible. Complications of CBDS include biliary colic, jaundice, cholangitis and pancreatitis. Investigations aimed to predict the presence of stones within the bile duct include serum bilirubin, AST, ALP, common bile duct diameter and age as independent predictors of choledocholithiasis. TUS is a sensitive test in detecting bile duct dilatation but the sensitivity is reduced in its ability to detect choledocholithiasis. A NIH consensus statement found that ERC, MRC and EUS were comparable in their sensitivities, specificities and accuracy rates for detection of choledocholithiasis. ERC and stone removal using a balloon or basket is often performed following EST. EBD may be performed if patients have uncorrected coagulopathies but the risk of pancreatitis is higher than for EST (although the risk of bleeding complications is lower for EBD). ML is often required in difficult to remove CBDS and using this device, CBDS can be removed in 90–95% of cases. Other forms of lithotripsy including laser lithotripsy and EHL are confined to specialised centres and the evidence for their use is based on small studies. ESWL may clear stones from the bile duct in up to 93% of patients but frequently ERC and stone fragment removal is required post ESWL. The role of medical therapy in difficult to remove CBDS (or in CBDS in patients with severe co-morbid illness preventing ERC + stone removal) is still currently uncertain due to a lack of large randomised control trials.