Smoking delays chondrogenesis in a mouse model of closed tibial fracture healing.

Smoking delays the healing process and increases morbidity associated with many common musculoskeletal disorders, including long bone fracture. In the current study, a murine model of tibial fracture healing was used to test the hypothesis that smoking delays chondrogenesis after fracture. Mice were divided into two groups, a nonsmoking control group and a group exposed to cigarette smoke for 1 month prior to surgical tibial fracture. Mice were euthanized at 7, 14, and 28 days after surgery. The outcomes measured were immunohistochemical staining for type II collagen protein expression as a marker of cartilage matrix and proliferating cell nuclear antigen (PCNA) staining to measure proliferation at the site of injury. Toluidine blue staining and histomorphometry were used to quantify areas of cartilaginous and noncartilaginous fracture callus. Radiographs were analyzed for evidence of remodeling after injury. At day 7 after injury, mice exposed to cigarette smoke had a smaller fracture callus with less cartilage matrix compared to controls. Proliferation was present at high levels in both groups at this time point, but proliferating cells had a more immature morphology in the smoking group. At day 14, chondrogenesis was more active in smokers compared to controls, while a higher percentage of bone was present in the control animals. At day 28, X-ray analysis revealed a larger fracture callus remaining in the smoking animals. Together, these findings show that the chondrogenic phase of tibial fracture healing is delayed by smoking. This study represents, to our knowledge, the first analysis of molecular and cellular mechanisms of healing in a smoking mouse fracture model.     

同济医科大学控烟活动及效果评价

我校自1993年开展控烟工作，1995年9月开始创办无吸烟大学校园，采取了卫生宣教和行政干预等综合措施，并进行了效果评价。高强度干预措施实施前期（1995年3月）和中期（1996年10月）相比，男医学生和男女学生平均吸烟率分别从16.3％和11．4％下降到9．6％和5．94％；男教工和男女教工平均吸烟率分别从28．6％和13．8％下降到13．9％和8．86％。     

Lack of effect of cimetidine on cigarette smoking

Summary The efficacy of cimetidine as a treatment that could reduce smoking in heavily dependent smokers has been determined. In a randomised, double-blind, double-crossover experiment, 43 heavy smokers were divided into two groups, one receiving cimetidine 400 mg orally three times a day, and the other receiving placebo for two weeks followed by the alternative treatment (placebo or cimetidine).No significant difference in the mean alveolar carbon monoxide, nicotine or cotinine levels was found between the two treatment groups compared to baseline. Since the alveolar carbon monoxide level reflects the intensity of smoking behaviour, the results suggest that no change in smoking behaviour occurred in the subjects.Contrary to our previous findings that cimetidine decreased the total body clearance of nicotine by 30% in a population of non-smokers, in the heavily dependent smokers, cimetidine did not appear to alter nicotine elimination. One possible explanation for the discrepancy is that tobacco smoking is known to induce nicotine metabolism and the induction might have offset any effect of cimetidine on nicotine elimination.Cimetidine does not appear to be a useful treatment leading to a reduction or cessation of cigarette smoking.     

Positive Outcome Expectancies and Smoking Behavior: The Role of Expectancy Accessibility

This study examined the association between smoking outcome expectancy accessibility and smoking behavior. Daily smokers completed a smoking expectancy accessibility task in which they made timed judgments to a series of positive consequences of smoking either after 6 hr deprivation or within 10 min of smoking. Participants then completed a questionnaire battery that contained assessments of smoking behavior and smoking outcome expectancies. Results of hierarchical regression analyses showed that expectancy accessibility was associated with the number of cigarettes smoked per day even when controlling for corresponding questionnaire measures of smoking expectancies. Moreover, smoking expectancy accessibility predicted urge to smoke ratings following exposure to a smoking cue after controlling for the effects of deprivation. Findings suggest that smoking expectancy accessibility may play a central role in smoking behavior and that individual differences in this attribute may be assessed directly through reaction time assessment.     

主动吸入药物烟对大鼠一氧化氮的影响

目的　探讨主动吸入药物烟对大鼠NO的影响。方法　制备大鼠主动吸烟模型 ,采用硝酸还原酶法测定各组大鼠血清、肺、心肌及脑组织的NO含量。结果　非药物烟组大鼠血清、肺、心肌及脑组织中NO含量明显低于非给烟对照组 ,药物烟高、中剂量组NO含量明显高于非药物烟组 ,接近非给烟对照组。结论　吸烟对大鼠血液、肺、心肌及脑组织有不同程度的损伤作用 ,使NO含量降低 ;药物烟具有一定的保护和防止NO含量降低的作用。     

残杀威对舰艇蜚蠊的抗性调查与防制研究

目的：观察残杀威对德国小蠊的药效。方法：采用果酱瓶药膜法和现场试验评价效果。结果残杀威对德国小蠊敏感品系的平均KT50为13．86min，现场品系8个调查点的KT50为11．25—38．02min，对抗氯菊酯品系KT50为16．06-23．37min，72h死亡率均为100％；现场试验，4周后的杀灭率仍达90．58％。结论：残杀威对德国小蠊现场品系为一般击倒；对抗氯菊酯品系尚未形成交互抗性，其水乳剂防制舰艇蜚蠊效果满意。     

Control accuracy and response time in multiple-state myoelectric control of upper-limb prostheses. Initial results in nondisabled volunteers

In myoelectrically operated prosthetic systems control performance decreases with an increasing number of possible movements. A test has been designed that allows quantification of two related qualities of performance. A predefined amount of training was given to 40 nondisabled volunteers without previous prosthetic experience. After training they attempted the test. The two parameters measured were the response time and the control accuracy corresponding to the different movements. It is concluded that even with a very limited amount of training fairly complex control systems can be operated with acceptable performance.     

Case-control study of silicosis, silica exposure, and lung cancer in white South African gold miners

A case-control study was undertaken to assess the association between lung cancer and silicosis or silica dust exposure in white South African gold miners. Cases and controls were identified from deaths reported to the Gold Miners Provident Fund for the period January, 1979-October, 1983. Two controls were matched to each case by year of birth (+/- 2 years) and by smoking (+/- 5 cigarettes or equivalents per day) assessed 10 years (+/- 2 years) prior to death. One hundred thirty-three matched triplets were identified. The results showed no overall association between lung cancer and radiological silicosis (OR = 1.08, p = 0.92). Autopsy data indicated no overall associations between lung cancer and silicosis of the lung parenchyma (OR = 1.49, p = 0.11), the pleura (OR = 0.72, p = 0.30), or the hilar glands (OR = 0.85, p = 0.72). A trend toward increased severity of silicosis of the parenchyma was evident; however, this was not statistically significant (p = 0.08). Odds ratios for lung cancer and silicosis were higher at lower levels of cumulative silica dust exposure (ORs = 2.43, 1.72, 1.35 and 0.62 for lung cancer and autopsy silicosis of the parenchyma for the lowest, second, third, and highest quartiles of dust exposure, respectively; all p greater than 0.05). Cases did not differ from controls for total silica dust exposure, length of exposure, weighted average intensity of exposure, or number of shifts at high dust (all p greater than 0.20). The data do not support the hypothesis of a carcinogenic role for silica dust and no statistically significant associations were found between lung cancer and silicosis.(ABSTRACT TRUNCATED AT 250 WORDS)     

被动吸烟与婴幼儿呼吸系统疾病及生长发育关系的研究

目的 探讨被动吸烟对婴幼儿乎吸系统疾病发病及对生长发育的影响。方法 将我院保健科负责保健的0～3岁的婴幼儿400名，以家长是否吸烟分为被动吸烟组和对照组，每组200名，定期询问患病史，同时翻身高、体重对其进行评价，追踪观察，经统计学处理后进行分析。结果 婴幼儿乎吸系统疾病的发病与被动吸烟密切相关，被动吸烟影响婴幼儿的生长发育，与国内外的相关报道基本一致。结论 被动吸烟对婴幼儿健康速成严重损害，如不加以保护，有演变为严重社会问题的危险。