尿中尼古丁代谢产物Cotinine含量的测定

目的：探索一种灵敏准确的测定尿中cotinine的方法。方法：酸水解后直接用HPLC法测定Cotinine。结果：Cotinine的最低检出限在0．32μmol／L，回收率在76．7％-85．4％之间。结论：该实验方法简单，准确度与精密度高，能在日常测定中应用。

主被动吸烟者尿中尼古丁代谢产物cotinine含量的研究

Cotinine是人体吸入烟草烟雾中尼古丁后经肝脏时其吡咯烷环被氧化的主要代谢产物。它的生物半减期较尼古丁相对长,而且不受饮食因素影响,是判定烟草烟雾吸入量比较客观而又特异的实验室指际。而烟草烟雾的吸入量越大,受到的危害通常越大,引起肺癌的危险性增加。大量研究已证明。

An Evaluation of Cotinine as an Index of Exposure to Tabacco Smoke in Children with Recurrent Respiratory Tract Infections Using HPLC Method

The authors evaluated the frequency of exposure to tobacco smoke among children suffering from respiratory tract infections. The investigations comprised 141 children aged from 2 months to 6 years that were treated in the 2nd Department of Pediatric and Allergology of Polish Mother’s Memorial Hospital Research Institute in ?ód? (Poland). 69 of them were exposed to tobacco smoke in their home environment. The remaining 72 children came from non-smoking families. 26 (37.7%) individuals among the passive smokers and 15 (20.83%) among the children from non-smoking families suffered from recurrent respiratory tract infections. Cotinine concentrations were evaluated in the group of 69 children using the HPLC-UV method. The determined average cotinine/creatinine index expressed as median was higher in passive smokers with recurrent respiratory infections than among passive smokers with non-recurrent respiratory infections. Moreover, it was stated that the exposure to cigarette smoke was more often among children of younger and less well educated parents as well as living in poor housing conditions. These studies clearly indicate that there is a need for extensive education on the harmful effects of passive smoking and the recurrence of infections.

A New Molecularly Imprinted Polymer for Solid-phase Extraction of Cotinine from Human Urine

A molecularly imprinted polymer （MIP）, prepared around a cotinine template, has been synthesized. The feasibility of using the polymer for solid-phase extraction （SPE） of cotinine from biological samples has been investigated. The results show that cotinine can be quantitatively retained and eluted from the polymer. Experiments with human urine samples indicate that clean target analyte is obtained for HPLC with UV detection using the protocol.

Association of a Tobacco-specific Nitrosamine Carcinogen with Urinary Cotinine,Urinary Sodium Excretion,and Total Energy Intake in Adolescents and Children

This study investigated the association of a tobacco-specific nitrosamine carcinogen,4-(methylnitrosamino)-1-(3-pyridy1)-I-butanol(NNAL)with urinary cotinine(uCot),urinary sodium(uNa)excretion,systolic blood pressure(sBP),and total energy intake in adolescents and children in relation to the subjects'age.A total of 790 subjects aged 6-19 years were evaluated.NNAL,uCot,corrected NNAL(cNNAL),the NNAL/uCot ratio,uNa,sBP,and nutrient intake were measured.A strong association between uCot and cNNAL was observed in children who were 11 years of age(r=0.881,P<0.001);however,no significant association was noted in adolescents who were 19 years of age.The uNa level was significantly higher(133.9 mmol/L vs.107.8 mmol/L,P<0.001)and sBP was significantly lower(105.3 mmHg vs.110.6 mmHg,P=0.012)in adolescents with elevated NNAL than in those without elevated NNAL.NNAL was significantly higher in subjects with increased uNa excretion than in those without increased uNa excretion.NNAL was positively correlated with uNa(r=0.183,P<0.001)and negatively correlated with sBP(r=0.142,P<0.001).Non-smokers with elevated NNAL/uCot ratios had significantly lower total energy intake than those without elevated NNAL/uCot ratios(1729.0 kcal/day vs.1911.0 kcal/day,P=0.008).The relationship between NNAL and uCot varied according to the subjects'age.NNAL seems to play a role in decreasing sBP by enhancing uNa excretion.Insufficient nutrient intake may contribute to endogenous formation of NNAL in non-smoking adolescents and children.

Development of simple HPLC/UV with a column-switching method for the determination of nicotine and cotinine in hair samples

Nicotine and cotinine in hair are good biomarkers for assessing long-term exposure to smoking. However, analytical devices such as GC/MS are associated with high cost and are not widely used. HPLC/UV is used widely in laboratories, but is unsuitable for measurement of minor constituents, except when using the column-switching method. Thus, we aimed to establish a simple, inexpensive and sensitive method based on HPLC/UV with column switching for measuring nicotine and cotinine in hair. First, we compared the presence and absence of a column selection unit. We then measured amounts of nicotine and cotinine in hair samples collected from the general population, and compared both the corresponding levels and the detection limits with those in previous studies. Finally, initial and running costs of HPLC/UV were compared with other analytical methods. As one of the results, the areas of nicotine and cotinine measured by HPLC/UV with column-switching method were 12.9 and 16.9 times greater, respectively, than those without the column-switching method. The amount of nicotine and cotinine in hair was significantly correlated to number of cigarettes smoked per day (r = 0.228, p = 0.040). In addition, the HPLC/UV method showed similar sensitivity and detection limit (nicotine, 0.10 ng/mg;cotinine, 0.08 ng/mg) as reported in previous studies. The cost of the HPLC/UV method is lower than that of other analytical methods. We were able to establish a low-cost method with good sensitivity for measuring nicotine and cotinine in hair. The HPLC/UV with a column-switching method will be useful as a first step in screening surveys in order to better understand the effects of smoking exposure.

被动吸烟与冠心病和脑卒中风险的关系:通过测量cotinine的前瞻性研究

Objective: To examine the associations between a biomarker of overall p assive exposure to tobacco smoke (serum cotinine concentration) and risk of coronary he art disease and stroke. Design: Prospective population based study in general pr actice (the British regional heart study). Participants 4729 men in 18 towns who provided baseline blood samples (for cotinine assay) and a detailed smoking his tory in 1978-80. Main outcome measure: Major coronary heart disease and stroke events (fatal and non-fatal) during 20 years of follow up. Results: 2105 men wh o said they did not smoke and who had cotinine concentrations < 14.1 ng/ml were divided into four equal sized groups on the basis of cotinine concentrations. Re lative hazards (95%confidence intervals) for coronary heart disease in the seco nd (0.8-1.4 ng/ml), third (1.5-2.7 ng/ml), and fourth (2.8-14.0 ng/ml) quarte rs of cotinine concentration compared with the first (≤0.7 ng/ml) were 1.45 (1. 01 to 2.08), 1.49 (1.03 to 2.14), and 1.57 (1.08 to 2.28), respectively, after a djustment for established risk factors for coronary heart disease. Hazard ratios (for cotinine 0.8-14.0 v ≤0.7 ng/ml) were particularly increased during the f irst (3.73, 1.32 to 10.58) and second five year follow up periods (1.95, 1.09 to 3.48) compared with later periods. There was no consistent association between cotinine concentration and risk of stroke. Conclusion: Studies based on reports of smoking in a partner alone seem to underestimate the risks of exposure to pas sive smoking. Further prospective studies relating biomarkers of passive smoking to risk of coronary heart disease are needed.

三种卷烟的成分及其对健康的影响

本文分析了我国高、中、低三种卷烟的成分、致突变性和对人体健康的影响。结果表明,高焦油卷烟含焦油、BaP和重金属元素均高于中、低焦油的卷烟,其焦油有致突变作用。吸烟者吸三种卷烟后能引起气道阻力、血中COHb％和尿中柯的宁等指标明显升高。吸烟者吸烟时可使其被动吸烟者的COHb％浓度均达有害程度。

A Participant-assigned Interventional Research of Precesarean Internal Iliac Artery Balloon Catheterization for Managing Intraoperative Hemorrhage of Placenta Previa and Placenta Accreta Spectrum Disorders After Cesarean Section

Placenta accreta spectrum disorder (PASD) and placenta previa (PP) are two of the mosthideous obstetric complications which are usually associated with a history of cesarean section(CS). Moreover, women with PASD, PP and/or a cesarean scarred uterus are more likely to haveadverse pregnancy outcomes, including blood transfusion, hysterectomy, pelvic organs damage,postpartum hemorhage, disseminated intravascular coagulation, multi-organ dysfunction syndromeand even maternal or fetal death. This study aimed to investigate the efficacy of precesareaninternal iliac artery balloon catheterization (BC) for managing severe hemorhage caused by PASDand PP with a history of CS. This participant-assigned interventional study was conducted inTongji Hospital. We recruited 128 women with suspected PASD, PP and a history of CS. Womenin the BC group accepted precesarean BC of bilateral internal iliac arteries before the scheduledcesarean delivery. Women in the control group underwent a conventional cesarean delivery.Intraoperative hemorrhage, transfusion volume, radiation dose, exposure time, complicationsand neonatal outcomes were discussed. There were significant differences in calculated bloodloss (CBL) between BC group and control group (1015.0±144.9 vs. 1467.0±171.0 mL, P=0.04).Precesarean BC could reduce intraoperative red blood cell (RBC) transfusion as compared withcontrol group (799.5±136.1 vs. 1286.0±161.6 mL, P=0.02) and lessen the rate of using bloodproducts (57.1% vs. 76.4%, P=0.02). The incidence of hysterectomy was also lower in BC groupthan in control group. Postpartum outcomes showed no significant differences between the twogroups, except that postoperation hospitalization was longer in BC group than in control group(6.7±0.4 vs. 5.8±0.2 days, P=0.03). Precesarean BC of internal iliac artery is an effective methodfor managing severe hemorrhage caused by PASD and PP with a cesarean scarred uterus, as it couldreduce intraoperative blood loss, lessen intraoperative RBC transfusions and potentially decreasehysterectomies.

Misclassification of smoking habits:An updated review of the literature

BACKGROUND Misclassification of smoking habits leads to underestimation of true relationships between diseases and active smoking, and overestimation of true relationships with passive smoking. Information on misclassification rates can be obtained from studies using cotinine as a marker.AIM To estimate overall misclassification rates based on a review and meta-analysis of the available evidence, and to investigate how misclassification rates depend on other factors.METHODS We searched for studies using cotinine as a marker which involved at least 200 participants and which provided information on high cotinine levels in selfreported non-, never, or ex-smokers or on low levels in self-reported smokers. We estimated overall misclassification rates weighted on sample size and investigated heterogeneity by various study characteristics. Misclassification rates were calculated for two cotinine cut points to distinguish smokers and nonsmokers, the higher cut point intended to distinguish regular smoking.RESULTS After avoiding double counting, 226 reports provided 294 results from 205 studies. A total of 115 results were from North America, 128 from Europe, 25 from Asia and 26 from other countries. A study on 6.2 million life insurance applicants was considered separately. Based on the lower cut point, true current smokers represented 4.96%(95% CI 4.32-5.60%) of reported non-smokers, 3.00%(2.45-3.54%) of reported never smokers, and 10.92%(9.23-12.61%) of reported exsmokers. As percentages of true current smokers, non-, never and ex-smokers formed, respectively, 14.50%(12.36-16.65%), 5.70%(3.20-8.20%), and 8.93%(6.57-11.29%). Reported current smokers represented 3.65%(2.84-4.45%) of true non-smokers. There was considerable heterogeneity between misclassification rates.Rates of claiming never smoking were very high in Asian women smokers, the individual studies reporting rates of 12.5%, 22.4%, 33.3%, 54.2% and 66.3%. False claims of quitting were relatively high in pregnant women, in diseased individuals who may recently have been advised to quit, and in studies considering cigarette smoking rather than any smoking. False claims of smoking were higher in younger populations. Misclassification rates were higher in more recently published studies. There was no clear evidence that rates varied by the body fluid used for the cotinine analysis, the assay method used, or whether the respondent was aware their statements would be validated by cotinine-though here many studies did not provide relevant information. There was only limited evidence that rates were lower in studies classified as being of good quality,based on the extent to which other sources of nicotine were accounted for.CONCLUSION It is important for epidemiologists to consider the possibility of bias due to misclassification of smoking habits, especially in circumstances where rates are likely to be high. The evidence of higher rates in more recent studies suggests that the extent of misclassification bias in studies relating passive smoking to smoking-related disease may have been underestimated.

Self-reported cigarette smoking status imprecisely quantifies exposure in pregnancy

Objective: We sought to determine the validity of self-reported smoking activity versus two quantitative measurements of tobacco exposure in pregnancy. We hypothesized that pregnant women would under-report their daily smoking amounts, due to the negative social stigmas associated with such a behavior. Methods: Cigarette-smoking and non-smoking pregnant women were recruited as part of a larger research study. Pregnant women with a singleton baby (>24 weeks) were recruited at a clinical appointment or prior to an elective caesarian section. Self-reported smoking status, including time since last cigarette, was recorded. End-tidal breath carbon monoxide (ETCO) levels and urine cotinine levels were measured and compared. Results: Both normotensive non-smoking (NTN) (n = 44) and normotensive smoking (NTS) (n = 24) pregnant women were recruited. A strong correlation was found between ETCO levels and urine cotinine measurements (r = 0.6566, p 0.05). Conclusion: Self-reported smoking status accurately identifies women who smoke in pregnancy, but not their level of tobacco exposure. Urine cotinine or ETCO are much better quantitative measurements of nicotine and carbon monoxide, respectively, and should be measured for a more precise indicator of smoking activity. These devices will allow for better counseling and monitoring of women who are trying to quit smoking and/or who enter into smoking cessation programs.