Quality Control in Laboratory Hemostasis and Thrombosis

<正>laboratory equipment,akey to success is not only high quality,complete,technician knowledge,skills,and experiment a clear purpose,select the project has specificity     

Association of passive smoking with increased coronary heart disease risk is not explained by elevation of leucocyte count

The increased risk of coronary heart disease in cigarette smokersmay be due at least partly to an elevation of the leucocytecount Chronic passive smoking has also been found to be associatedwith an increased risk of coronary heart disease, but its effecton the leucocyte count has not been reported. In this study250 male factory employees aged 20–64 years were interviewedon smoking behaviour and exposure to environmental tobacco smoke,and blood counts were determined. Urinary cotinine was measureby radio-immunoassay and corrected for urinary creatinine concentrations.Mean leucocyte count was significantly higher among smokerscompared with non-smokers (8,666 compared to 6, 900; p<0.001).On the basis of smoking history, passive smokers had leucocytecounts similar to non-smokers. These findings were confirmedwhen leucocyte counts were compared with urine cotinine to creatinineratios. The association of haematocrlt and haemoglobin withsmoking was similar to that of leucocyte count These findingssuggest that any association of passive smoking with coronaryheart disease is not through an elevation of leucocyte count.     

Recurrent wheezing in relation to environmental risk factors in infancy

Clinical course and environmental factors were recorded in a prospective study of 276 unselected infants followed from birth to the age of 18 months. The study was performed with a questionnaire at the age of 6 and 12 months and a physical examination at 18 months. Fifty-nine (21%) of the children had greater than or equal to 2 episodes of wheezing before they were 18 months old. A total of 58 (21%) of the children belonged to the lowest social class V, 182 (66%) were daily exposed to passive tobacco smoking at home and/or in daycare, 164 (59%) were breastfed greater than or equal to 3 months, 192 (70%) were in daycare, 62 (22%) lived in flats and 167 (61%) were in daily contact with furred pets at home and/or in daycare. In social class V a preponderance of children were exposed to passive tobacco smoking, a majority were living in flats and a minority were breastfed greater than or equal to 3 months. Linear logistic regression analysis was used for the purpose of assessing the causal effect of environmental risk factors on the risk of recurrent episodes of wheezing before the age of 18 months. The study demonstrated that male sex and daily exposure to passive tobacco smoking were significant risk factors with estimated odds ratios 1.9 and 2.4, respectively. Maternal tobacco smoking seemed to be associated with the highest risk. There was a tendency--though not significant--indicating that breastfeeding greater than or equal to 3 months had a protective effect.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of environmental and clinical factors on lung function and respiratory symptoms in adolescents with α1-antitrypsin deficiency

Individuals identified in the Swedish neonatal α₁-antitrypsin (AAT) screening study were followed prospectively from their first to their eighteenth year of life. The aim of this study was to analyse the effect of environmental factors, i.e. active and passive smoking, and of clinical factors on lung function and the occurrence of respiratory symptoms in AAT-deficient adolescents. The study group consisted of 88 protease inhibitor (Pi)ZZ and 40 PiSZ adolescents. Medical history including respiratory symptoms, and active and passive smoking were recorded at each follow-up up to the age of 18 y. Lung function tests were performed at the present check-up. At the age of 18 y, both forced expiratory volume in one second (FEV₁) and FEV₁/vital capacity (VC) were significantly lower in the smoking than in the non-smoking subgroup, and significantly more smokers than non-smokers reported the presence of phlegm. The mean FEV₁/VC ratio was lower for those presently exposed to parental smoking. Multiple linear regression analysis indicated that clinical liver disease in early life, active smoking and parental smoking were independent determinants of FEV₁/VC. The results suggest that marginal deviations in lung function and the symptom of phlegm among AAT-deficient adolescents occur characteristically early in the subgroup of smokers. Parental smoking may contribute to decreased lung function     

内蒙古赤峰地区鼠疫现状和流行趋势预测及控制措施的研究

赤峰地区于１９４８￣１９９６年发现了１６６３２．２ｋｍ＾２鼠疫自然疫源地，分布于１１个旗（县、区）。目前达到控制鼠疫面积１３９１７．８ｋｍ＾２，占疫源地总面积的８３．６８％。选取与疫源地相关的１２种量经因子进行聚类分析，结果可分为：１．疫源性长存区；２．动物鼠疫间断流行区；３．鼠疫动物病控制区；４．疫源性基本消除区。同时对措施进行了探讨。     

Perioperative respiratory events in smokers and nonsmokers undergoing general anaesthesia

Background: The prevalence of respiratory diseases in smokers and nonsmokers and the incidence of perioperative respiratory events (PREs) were investigated for patients undergoing general anaesthesia. The aim was to quantify well-known problems and to identify possible new associations between smoking and PREs.
Methods: From July 1992 to December 1994, risk factors, demographic data, and PREs were documented by an automatically readable anaesthetic record (ARAR). PREs were used as defined by the German Society of Anaesthesiology and Intensive Care.
Results: Of 26 961 subsequent anaesthesias in adults, 7122 (26.4%) were performed in smokers with a prevalence of chronic bronchitis of 23.3% (4.8% in nonsmokers). 1573 PREs occurred in 1397 (5.2%) of all anaesthetics. 459 events concerned intubation problems and problems in technical airway management. 1114 specific respiratory events (SPREs) like re-intubation, laryngospasm, bronchospasm, aspiration, hy-poventilation/hypoxaemia and others had a total incidence of 5.5% in smokers and 3.1% in nonsmokers. The relative risk (RR) of SPREs was 1.8 in all smokers, 2.3 in young (16–39 years) smokers, and 6.3 in obese young smokers. The RR of perioperative bronchospasm was 25.7 in young smokers with chronic bronchitis.
Conclusion: The impact of smoking on perioperative respiratory problems should make anaesthetists take this widespread preoperative condition seriously, particularly in young adults. The presented method of incident reporting (based on a national classification) could contribute to future research in anaesthetic epidemiology.     

革兰氏阴性杆菌发生过程控制的研究

本研究选择奇异变形杆菌和绿肿杆菌等作为实验体系，从群体发生发展过程的宏观表现上探讨了生物控制的时空表达及非线性问题。结果表明，杆菌发生过程的时相周期性可以表现为空间的波形靶图样，并具有分形的特征。实验结果表明，菌群在生长过程中的代谢产物是富含生物信息的控制中介机制。我们认为，生物系统局部存在着准平衡和准封闭的微生态环境，生物液晶的存在和相变是细菌群体发生过程的重要协同中介因素。     

Up-regulation of nicotinic acetylcholine receptors following chronic exposure of rats to mainstream cigarette smoke or α4β2 receptors to nicotine

Smokers are reported to have a higher density of central nicotinic acetylcholine receptors (nAChRs) that non-smokers at autopsy. Whether this increased receptor density is a response to smoking or a result of genetic variability is not known. While sub-chronic treatment of rats and mice with nicotine results in upregulation of central nAChRs, changes in receptor density in response to cigarette smoke have not been studied previously. In this study, male Sprague-Dawley rats were exposed nose-only for 13 weeks to mainstream cigarette smoke followed by assessment of [³H]nicotine binding in five brain regions of smoke- and sham-exposed animals. In smoke-exposed animals, there was a significant increase in nAChR density in the cortex, striatum, and cerebellum (35, 25, and 31% increases, respectively), while there was no significant change in receptor density in the thalamus and hippocampus. Smoke exposure did not alter markedly the affinity of the receptor for nicotine in these brain regions. Furthermore, up-regulation of nAChRs did not alter the biphasic binding properties by which nicotine binds to its receptor. There were no changes in the association (fast phase) or isomerization (slow phase) rate constants, and the percent contribution of slow and fast phase binding to nAChRs was not altered in the up-regulated receptor population compared with control. Similar results were observed following chronic nicotine exposure of cultured cortical cells from fetal rat brain or cells transfected with the α4β2 nAChR subtype. These results show that the up-regulation following smoke exposure in the rat is phenomenologically similar to that observed in vitro. These data provide preliminary evidence for a relationship between cigarette smoking and nAChR up-regulation in vivo and suggest that similar mechanisms of upregulation may underlie chronic smoke exposure of live animals and nicotine exposure of artificially expressed α4β2 receptors in vitro.     

Clinical response to local delivery of tetracycline in relation to overall and local periodontal conditions

Abstract The purpose of this study was to determine the clinical response to local delivery of tetracycline in relation to clinical and microbiological conditions of the other teeth. 4 deep pockets were monitored in 19 subjects with multiple deep periodontal lesions and high counts of P. gingivalis. In 9 patients (XT) only 2 of the selected lesions were treated by placement of tetracycline fibers (Actisite®). while the rest of the dentition was left untreated. In the other 10 patients, all teeth were supragingivally scaled and then treated by application of polymeric tetracycline HCl containing fibers, the whole dentition was subject to full mouth scaling and root planing, and the patients rinsed with 0.2% chlorhexidine (FT). A significant reduction in mean PPD was observed in all treated sites after two months. This reduction was maintained over the following 4 months. The magnitude of the effect was significantly greater in the FT group (1.74 mm) than in the LT group (0.88 mm). The mean attachment level changes were similar after 2 months in locally and fully treated subjects. A tendency of relapse was noted for treated sites in LT patients from month 2 to 6. A level of statistical significance was not reached for this effect. Data from measurements recorded at 6 sites around all teeth in the full mouth treated patients were analyzed using multiple linear regression. This analysis showed local changes in PPD and AL were significantly and strongly correlated with the baseline value of the respective parameter at the same site. In addition, more pocket depth reduction was noted if a site was not bleeding on probing at 6 months, if the location of a site was not approximal and if the tooth was not a second molar. Sites located on second molars showed also less AL gain than sites located on other teeth. Smokers showed significantly less reduction in PPD and significantly less AL gain. Furthermore, if subjects had a high % of pockets deeper than 4 mm at baseline they showed significantly less attachment gain.     

EFFECT OF CIGARETTE SMOKING ON THE FREQUENCY OF VENTRICULAR PREMATURE COMPLEXES IN NORMAL SUBJECTS

1. Ambulatory ECG monitoring was undertaken in healthy cigarette smokers (33) and non-smokers (20) of similar age (21-66 years). 2. The frequency of ventricular premature complexes (VPC) was less in habitual smokers (P less than 0.05; Mann-Whitney rank test) and an average of more than 1 VPC per hour occurred in a higher proportion of non-smokers than smokers: eight of 20 (40%) vs two of 33 (6%) (P less than 0.01; Chi-square test).