DNA damage and repair capacity by comet assay in lymphocytes of white-collar active smokers and passive smokers (non- and ex-smokers) at workplace

The comet assay has been widely used to quantify DNA damage in isolated lymphocytes from subjects exposed to several environmental or occupational substances, especially for estimation of oxidative damage in the DNA, which is well-known to be induced by tobacco smoke. Passive smoking or environmental tobacco smoke (ETS) has been included among those substances that cause cancer with sufficient evidence in humans. In this study, we analyzed, by the alkaline version of comet assay, the lymphocyte DNA damage of white-collar active smokers and non- and ex-smokers exposed to ETS at the workplace. We investigated basal DNA damage, DNA oxidation by formamidopyrimidine glycosylase (Fpg), the repair capacity H2O2-induced DNA damage by kinetics studies and lymphocyte GSH levels, the major intracellular defense against exogenous oxidative stress imposed by cigarette smoking. Our results indicated high basal DNA damage with clear significant correlations with urinary nicotine and cotinine, number of cigarettes/day, and an inverse significant correlation with GSH cellular content in active smokers. Significant Fpg-sensitive sites were found in smokers (> 85%), considerably high but not significant in passive non- and ex-smokers (> 51% and 37%, respectively). The DNA repair capacity had seriously decreased in non-smokers > smokers > ex-smokers, while the same damage was repaired in a short time in never smokers.

Specific detection of anabasine, nicotine, and nicotine metabolites in urine by liquid chromatography-tandem mass spectrometry

The sensitive and specific detection of nicotine, its metabolites, and the tobacco alkaloid, anabasine, is useful in evaluating the success of smoking cessation treatments and detecting tobacco use, passive exposure, and nontobacco nicotine exposure in potential transplant recipients, insurance clients, and elective surgical patients. Rapid sample preparation and extended high-performance liquid chromatographic separation of tobacco alkaloids and metabolites was interfaced with tandem mass spectrometry. By using deuterated internal standards and appropriate confirmatory ion mass transitions, direct injection of centrifugally clarified urine was possible. The method had excellent precision, limit of quantitation, and linearity. The rigorous separation method revealed an interferent of nicotine that had coeluted with anabasine in more rapid chromatography and that may result in tobacco use misclassification. The method provides more specific detection of tobacco exposure and illustrates the potential of centrifugal clarification for sample preparation in the detection of multiple analytes in urine.

[Nicotine and cotinine levels in body fluids of habitual smokers who committed suicide]

Suicide is a serious social problem because over 30,000 people commit suicide every year since 1998 in Japan. Cigarette smoking is associated with a higher risk for suicide and attempted suicide. We determined nicotine and cotinine levels in blood and urine of 104 deceased individuals (21 suicides and 83 non-suicides). Of the 21 suicides, 16 (76.2%) were smokers; the smoking rate in non-suicides was 41.0% (34 persons). Average levels of nicotine and cotinine in blood were significantly higher in the suicide smokers than in the non-suicide smokers (nicotine: 95.6 +/- 43.9 ng/ml vs. 28.0 +/- 15.2 ng/ml, p < 0.0001; and cotinine: 385 +/- 220 ng/ml vs. 229 +/- 181 ng/ml, p < 0.02). Average levels of nicotine and cotinine in urine also significantly higher in the suicide smokers than in the non-suicide smokers. There were eight patients with psychiatric diseases such as schizophrenia, depression and alcohol dependence. Of the eight patients, four were suicide smokers; only a person used antipsychotics. Thirty-one alcohol-intoxicated decedents consisted of 8 suicides (8 smokers) and 23 non-suicides (17 smokers). Our data demonstrate that there is a marked increase in cigarette smoking in habitual smokers with psychiatric disorders before committing suicide. Quantitatively monitoring the severity of stress using blood nicotine level may enable physicians more objectively to find out nicotine dependents who are in the state of an imminent suicide attempt and timely to administer medical treatment for preventing suicide.

4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronides in the urine of infants exposed to environmental tobacco smoke

Biomarkers of carcinogen uptake could provide important information pertinent to the question of exposure to environmental tobacco smoke (ETS) in childhood and cancer development later in life. Previous studies have focused on exposures before birth and during childhood, but carcinogen uptake from ETS in infants has not been reported. Exposures in infants could be higher than in children or adults because of their proximity to parents who smoke. Therefore, we quantified 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronides (total NNAL) in the urine of 144 infants, ages 3 to 12 months, who lived in homes with parents who smoked. Total NNAL is an accepted biomarker of uptake of the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. Cotinine and its glucuronide (total cotinine) and nicotine and its glucuronide (total nicotine) were also quantified. Total NNAL was detectable in 67 of 144 infants (46.5%). Mean levels of total NNAL in the 144 infants were 0.083 +/- 0.200 pmol/mL, whereas those of total cotinine and total nicotine were 0.133 +/- 0.190 and 0.069 +/- 0.102 nmol/mL, respectively. The number of cigarettes smoked per week in the home or car by any family member when the infant was present was significantly higher (P < 0.0001) when NNAL was detected than when it was not (76.0 +/- 88.1 versus 27.1 +/- 38.2). The mean level of NNAL detected in the urine of these infants was higher than in most other field studies of ETS exposure. The results of this study show substantial uptake of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in infants exposed to ETS and support the concept that persistent ETS exposure in childhood could be related to cancer later in life.

Smoking hygiene: reducing infant exposure to tobacco

The American Academy of Pediatrics recently removed nicotine from the list of drugs contraindicated during breastfeeding. The objective of this study was to evaluate the feasibility of determining the effect of a smoking hygiene intervention on infants of breastfeeding mothers who smoke cigarettes. An experimental design with repeated measures was used. A convenience sample of 35 mother-infant dyads from seven sites was recruited and randomly assigned to the intervention or control group. Of the 27 dyads completing the study, 16 were in the experimental group and 11 were in the control group. Smoking hygiene was introduced when infants were 2 weeks old and reinforced when they were 3 and 5 weeks old. At these three data points, infant health and urinary nicotine and cotinine levels were measured, as well as the mothers' breast-milk nicotine and cotinine levels and smoking hygiene behaviors. Recruiting and retaining a sample of breastfeeding mothers who smoke proved difficult. Only 27% of women in the intervention group implemented all aspects of the smoking hygiene intervention behaviors. Repeated-measures ANOVA revealed no difference in a) infant urinary nicotine and cotinine levels or b) breast-milk nicotine and cotinine levels between the two groups. The McNemar test for related samples revealed no difference between frequency of respiratory symptoms in either the control or intervention groups when Week 2 levels were compared with levels at Weeks 3 and 5. Mothers were not successful in adhering to the smoking hygiene intervention. To adequately test interventions, strategies must be developed to help women incorporate health-promoting behaviors into their lives.

Biomarkers of exposure and potential harm in adult smokers of 3-7 mg tar yield (Federal Trade Commission) cigarettes and in adult non-smokers

The paper reports levels of 24-h urine nicotine and five of its major metabolites (expressed as nicotine-equivalents) and blood carboxyhaemoglobin as biomarkers of exposure to particulate- and gas-phase cigarette smoke, respectively, from an exploratory pilot study of adult smokers of 3.0-6.9 mg tar delivery (Federal Trade Commission (FTC) method) cigarettes. On multiple occasions over 6 weeks, blood high-sensitivity C-reactive protein (hs-CRP), fibrinogen, HDL- and LDL-cholesterol, and 24-h urine 8-epi-prostaglandin F2alpha (8-epi-PGF2alpha) and 11-dehydro-thromboxane B2 (11-dehydro-TxB2) were also evaluated as biomarkers of potential harm. All the biomarkers examined, except for LDL-cholesterol, discriminated with high sensitivity and specificity between adult smokers and non-smokers overall. Except for HDL-cholesterol, all biomarker medians were greater in adult smokers than in non-smokers: urine nicotine-equivalents 64.514 versus < 0.034 nmol mg-1 creatinine (p<0.001), carboxyhaemoglobin 4.0 versus 0.4% saturation (p<0.001), hs-CRP 0.27 versus 0.12 mg dl-1 (p=0.05), fibrinogen 292 versus 248 mg dl-1 (p<0.001), HDL-cholesterol 46 versus 53 mg dl-1 (p=0.003), LDL-cholesterol 119 versus 109 mg dl-1 (p=0.18), urine 8-epi-PGF2alpha 1935 versus 1034 pg mg-1 creatinine (p<0.001) and urine 11-dehydro-TxB2 973 versus 710 pg mg-1 creatinine (p<0.001). All the biomarkers of exposure and most of the biomarkers of potential harm showed no time of sampling (by visit week) effect.

Urinary nicotine and its metabolites as a biomarker of exposure to environmental tobacco smoke

The validity of urinary nicotine and its metabolites as a biomarker of exposure to environmental tobacco smoke (ETS) has been investigated. After exposure to ETS, urine samples were collected from 10 subjects for the analyses of nicotine, cotinine and 3'-hydroxycotinine. The former two chemicals were detected in the urine of all subjects, and 3'-hydroxycotinine was detected in the urine of 9 subjects out of 10, indicating these three chemicals can be used as a biomarker of ETS exposure. 3'-Hydroxycotinine was not detected in the urine of one subject, suggesting that this subject may be a poor metabolizer of nicotine. In 9 subjects with 3'-hydroxycotinine excreted, the amounts of nicotine and cotinine started to increase after exposure, reached the peak at the end of the second exposure and decreased gradually. 3'-Hydroxycotinine started to be excreted into urine from 3 hours after exposure and kept the same level until 72 hours after exposure. In the urine of 72 hours after exposure, the amount of 3'-hydroxycotinine was the highest among these three chemicals.

Environmental Tobacco Smoke and Risk of Spontaneous Abortion

BACKGROUND

Studies of exposure to environmental tobacco smoke (ETS) and risk of spontaneous abortion are limited to a few studies of self-reported exposure, and the results have been inconsistent. The aim of this study was to investigate risk of early spontaneous abortion related to ETS and active smoking as defined by plasma cotinine levels.

METHODS

We conducted a population-based case-control study in Uppsala County, Sweden, between January 1996 and December 1998. Cases were 463 women with spontaneous abortion at 6 to 12 completed weeks of gestation, and controls were 864 pregnant women matched to cases according to the week of gestation. Exposure status was defined by plasma cotinine concentrations: nonexposed, <0.1 ng/mL; ETS-exposed, 0.1-15 ng/mL; and exposed to active smoking, >15 ng/mL. Multivariable analysis was used to estimate the relative risk of spontaneous abortion associated with exposure to ETS and active smoking.

RESULTS

Nineteen percent of controls and 24% of cases were classified as having been exposed to ETS. Compared with nonexposed women, risk of spontaneous abortion was increased among both ETS-exposed women (adjusted odds ratio = 1.67; 95% confidence interval = 1.17-2.38) and active smokers (2.11; 1.36-3.27). We could not show a differential effect of exposure to ETS or active smoking between normal and abnormal fetal karyotype abortions.

CONCLUSIONS

Nonsmoking pregnant women exposed to ETS may be at increased risk of spontaneous abortion. Given the high prevalence of ETS exposure, the public health consequences of passive smoking regarding early fetal loss may be substantial.

Chronic nose-only inhalation study in rats, comparing room-aged sidestream cigarette smoke and diesel engine exhaust

Nose-only exposure of male and female Wistar rats to a surrogate for environmental tobacco smoke, termed room-aged sidestream smoke (RASS), to diesel engine exhaust (DEE), or to filtered, fresh air (sham) was performed 6 hours/day, 7 days/week for 2 years, followed by a 6-month post-exposure period. The particulate concentrations were 3 and 10 mg/m3. Markers of inflammation in bronchoalveolar lavage showed that DEE (but not RASS) produced a dose-related and persistent inflammatory response. Lung weights were increased markedly in the DEE (but not RASS) groups and did not decrease during the 6-month post-exposure period. Bulky lung DNA adducts increased in the RASS groups, but not in the DEE groups. Cell proliferation in the lungs was unaffected by either experimental treatment. Histopathological responses in the RASS groups were minimal and almost completely reversible; lung tumors were similar in number to those seen in the sham-exposed groups. Rats exposed to DEE showed a panoply of dose-related histopathological responses: largely irreversible and in some cases progressive. Malignant and multiple tumors were seen only in the DEE groups; after 30 months, the tumor incidence (predominantly bronchiolo-alveolar adenomas) was 2% in the sham-exposed groups, 5%in the high RASS groups, and 46% in the high DEE groups (sexes combined). Our results suggest that in rats exposed to DEE, but not to RASS, the following series of events occurs: particle deposition in lungs --> lung "overload" --> pulmonary inflammation --> tumorigenesis, without a significant modifying role of cell proliferation or DNA adduct formation.

Comparative analysis of the effects of hubble-bubble (Sheesha) and cigarette smoking on respiratory and metabolic parameters in hubble-bubble and cigarette smokers

OBJECTIVES AND BACKGROUND

Hazard of smoking tobacco is believed to be minimized by smoking hubble-bubble (HB) instead of cigarettes. Our aims were to (i) develop an assay for estimating nicotine and cotinine; and (ii) evaluate the effect of smoking on respiratory and metabolic parameters in cigarette and HB smokers.

METHODS

Urine samples were collected from 152 volunteer smokers (75 cigarette and 77 HB) as well as from 16 healthy controls. We optimized an HPLC method for the determination of nicotine and cotinine. Subjects were asked to complete a chronic respiratory symptoms questionnaire and to undergo spirometry. Fasting blood samples were collected for the determination of their lipid profile.

RESULTS

The intra-assay coefficients of variation for nicotine and cotinine were 16.6% and 6.6%, respectively. The mean of cotinine in cigarette smokers (1321.4 ng/mL) was significantly (P = 0.008) higher than the mean cotinine (677.6 ng/mL) in HB smokers. The mean nicotine level in cigarette smokers (1487.3 ng/mL) was significantly (P < 0.0001) higher than the mean nicotine (440.5 ng/mL) in HB smoker. The urinary cotinine and nicotine levels of the control subjects were lower than the detection levels of the assay. The mean high-density lipoprotein cholesterol was lower in cigarette smokers (0.99 mmol/L) compared with HB smoker smokers (1.02 mmol/L) but this was not significant (P = 0.28). Spirometric values were comparable among the three groups but the chronic respiratory symptoms in the smoking groups appeared at an earlier age in the HB smokers compared with the cigarettes smokers (P < 0.05).

CONCLUSION

Smoking HB does not reduce the risk of tobacco exposure and it's potentially harmful metabolites on health.

A high-performance thin-layer chromatographic technique to screen cocaine in urine samples

Qualitative identification of cocaine and its metabolites in urine samples is generally carried out by an immunoassay technique followed by a gas chromatographic/mass spectrometric confirmation of presumptive positives. Nevertheless, other chromatographic techniques such as thin-layer chromatography or gas chromatography could also be used to screen several types of drugs of abuse especially for forensic and legal purposes. In the present work, the capability of high performance thin-layer chromatography (HPTLC) to detect cocaine in urine samples and discriminate it from interfering substances (local anaesthetic, caffeine and nicotine) was studied. Twenty urine samples of drug addicts were submitted to the HPTLC method. Unaltered cocaine present in the urine samples and cocaine obtained after methylation of benzoylecgonine (main cocaine metabolite) with diazomethane were detected in all tested samples. In conclusion, the proposed HPTLC method showed to be useful to detect cocaine in biological matrices.

Nicotine metabolism in healthy smokers and patients with cardiovascular diseases

In this study, we measured the excretion rate of nicotine and its two major metabolites, cotinine and trans-3'-hydroxycotinine (THOC), in the urine of 25 healthy smokers and 15 smokers who underwent a coronary artery bypass surgery or coronary angioplasty. After 1 day of smoking cessation, urine samples were collected in the morning, before smoking two cigarettes, and then three times after smoking, approximately 4 h apart. The results show that (i) in healthy smokers, nicotine and its two major metabolites were present at high concentration in the first urine sample after smoking, (ii) in smokers with cardiovascular disease nicotine and cotinine were less excreted whereas THOC was more excreted, mainly in the second urine sample. We conclude that this shift in nicotine metabolism may contribute to smoking-induced cardiovascular disease.

Biochemical markers of cardiovascular damage from tobacco smoke

There is growing evidence that several biochemical constituents of cigarette smoking play a significant role in the development and progression of heart and blood vessel damage, especially atherosclerotic lesions. Some biochemical markers of tobacco smoke may be determined in blood and urine samples. They are also the main responsible factors of cardiovascular harm. Nicotine and its major metabolite, cotinine, carbon monoxide, and thiocyanate seem to be specific markers. Ischaemic heart disease, cardiac arrhythmias, and endothelial dysfunction are the most common evidence of both active and passive smoking exposure. Dosage of cotinine in urine is of easier determination than that of other metabolites in assessing exposure to smoking, although carboxyhaemoglobin levels seem to be a qualitative, but not quantitative factor to estimate either the degree of cardiovascular damage or the level of exposure. Cigarette smoking is addictive because of nicotine, and it is nicotine withdrawal that causes many side effects of quitting smoking as well as the nicotine itself may exacerbate cardiac lesions. Also haematologic changes are a consequence of cigarette smoking exposure. Increased white blood cells, platelet aggregation and adhesiveness, fibrinogen level, and changes in serum lipids characterise the response to smoking. Anatomical and ultrastructural alterations of the heart and blood vessels are also described as a consequence of negative effects of biochemical markers of cigarette smoking. These alterations are known as "Smoke cardiomyopathy" in experimental pathology.

Smoking and Wound Healing Problems in Reduction Mammaplasty

We sought to prove a significant relationship between cigarette smoking and wound healing problems in reduction mammaplasty patients, to show the effect of stopping smoking before the procedure, and to justify the implementation of urine nicotine testing preoperatively. One hundred and seventy-three consecutive patients aged 16 to 67 years underwent bilateral reduction mammaplasty in our institution over 26 months. Patients were advised to stop smoking at least 4 weeks prior to surgery. Records were reviewed and smoking habits reconfirmed via telephone. Wound problems were registered when intervention was necessary. Smokers made up 38.5% of the cases. Wound healing problems showed statistical significance (P < 0.05) between smokers (55.4%) and nonsmokers (33.7%). More than 75% of smokers admitted denying smoking within 4 weeks of surgery. Trend analysis revealed a significant association of wound healing problems for those who stopped longer than 4 weeks (33.3%), those who stopped less than 4 weeks (52.6%), and those who persisted until the operation (67.7%). Smoking increased wound healing problems after bilateral reduction mammaplasty. The introduction of compulsory urine nicotine testing at the preadmission clinic and prior to the operation will provide objective verification of patients' smoking history, minimize morbidity, and enable healthcare cost savings.

[Evaluation of infants and younger children passive smoking at home and prevalence of their lower respiratory tract infectious]

The nicotine's metabolites were determined in urine of 92 children--59 children of smoking parents (SP) and 33 of non-smoking parents (NSP). The level of metabolites of nicotine and the ratio of the nicotine's metabolites to creatinine concentration were analyzed in infants (older than 5 months) and children 2-4 years old. Moreover the frequency of bronchitis and pneumonia in children was estimated on the basis of the interview with their parents. The nicotine's metabolites concentration was significantly higher in urine of children of SP than in urine of NSP children, as well in the group of infants as in children aged 2 to 4 years. Respiratory tract infections were frequent in 69.4% of SP children and in 21.1% of NSP children. In addition, the mean and the highest level of metabolites of nicotine in urine of SP children were multiple higher in comparison to the levels found in the group of NSP children suffering from the respiratory tract infections with equal frequency.

[Effect of tobacco smoke on permeability of capillary of pregnant and non-pregnant rats]

From among 4200 chemical compounds contained in the tobacco smoke, nicotine and carbon monoxide are responsible for changes in the heart-vessel system to the greatest extent. Additionally, other toxic compounds, including the carcinogenic ones, have a significant impact on the biological activity in the tissues of blood vessels. A particularly complex picture of the detrimental impact of the tobacco smoke is presented in case of pregnant women, fetuses and newborns. The aim of the research was to assess the impact of tobacco smoke on the permeability of capillaries in different tissues of rats (lungs, brain, liver, kidneys) and testing of the potentially protective impact of rutine (3-rutinozide of quercetin). The research on the permeability of capillaries has been carried out applying Evans blue. The animals were divided into 8 research groups: pregnant animals--"control", "rutine", "tobacco smoke", "rutine+tobacco smoke", and non-pregnant animals--"control", "rutine", "tobacco smoke", "rutine+tobacco smoke". In the first stage of research (pregnant, non-pregnant-- groups: "rutine" and "rutine+tobacco smoke"), the water rutine solution in a dose of 40 mg/kg of body weight was administered. The non-pregnant and pregnant animals from groups "tobacco smoke" and "rutine+tobacco smoke" were exposed to tobacco smoke via inhalation (1500 mg CO/m3 of air) for 21 days. All the animals were injected with the water Evans blue solution in a dose of 30 mg/kg of body weight. After 30 minutes, the animals were killed by cutting the abdominal aorta, and lungs, brain, liver and kidneys were taken for further testing. The cotinine in the urine was determined by the HPLC method, using norephedrine as the internal standard, after the preceding extraction by means of the liquid-liquid technique. The concentration of cotinine in case of non-pregnant and pregnant females was respectively 11.8 +/- 1.9 pg/ml of urine and 12.0 +/- 2.5 microg/ml of urine. In case of the rats, which received the rutine, the concentration of rutine in the group of non-pregnant females was 9.3 +/- 1.0 microg/ml of urine, and in the group of the pregnant ones 8.5 +/- 1.1 microg/ml of urine. In the lungs of non-pregnant animals exposed to tobacco smoke, the decreased permeability of vessels for the albumin-Evans blue complex was proven. The administration of rutine to non-pregnant and pregnant animals did not exert influence on the permeability of vessels in lungs. A similar result was obtained for the lungs of rats receiving the rutine, as well as those exposed to tobacco smoke. In the brain tissue of non-pregnant and pregnant animals, a slight decrease in the content of Evans blue was declared as a consequence of tobacco smoke impact. In the groups receiving the rutine, this flavonoid was declared to influence the blood supply of the brain tissue, and the permeability of the vascular walls. In the liver tissue of animals inhaling the tobacco smoke, the permeability of vascular walls for albumin-Evans blue complex was increased. The rutine did not affect significantly the permeability of vessels, whereas the exposure of pregnant females, which received rutine, to smoke decreased the content of Evans blue in the liver tissue. In the tissues of all tested females, no significant differences between the control groups and groups exposed to tobacco smoke as well as rutine+tobacco smoke were detected. The obtained results do not indicate, however, that in case of chronic exposure to tobacco smoke, the rutine has insignificant protective meaning.

[The assessment of urinary nicotine metabolites concentration in children and teenagers with oesophagitis]

Tobacco smoke is important pathogenetic agent of stomach digestive and duodenum ulcers, oesophagitis as well as gastro-oesophageal reflux disease. The aim of work was the assessment of urinary nicotine metabolites concentration in children and teenagers diagnosed and treated in Paediatrics Chair of Medical University of Silesia by chronic stomach pains, or oesophagitis and gastrooesophageal reflux disease symptoms. Urine was sampled from 54 persons before gastrofiberoscopy, in which the main nicotine metabolites concentration was determined by ELISA method and given per creatinine concentration. It was shown, that 30% of examined population was intensively exposed to tobacco smoke (actively or passively smoking), but 37% passively exposed to nicotine. Significant higher nicotine metabolites concentration was stated in the currently H. pylori infected sick, however without differences of these biomarkers concentrations between group with oesophagis in endoscopy as well as histopathologic examination and group without these features.

Urinary metabolites of a tobacco-specific lung carcinogen in nonsmoking hospitality workers

Exposure of nonsmokers to environmental tobacco smoke results in increased risk for cancer and other diseases. In spite of this finding, some restaurants and bars continue to permit smoking. This study examined the uptake of nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a potent lung carcinogen, in nonsmokers who work in restaurants and bars that permitted smoking. Urine samples were collected for 24 hours on working and nonworking days and were analysed for total NNAL [the sum of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its glucuronides (NNAL-Glucs)], metabolites of NNK. In addition, urine samples were analysed for total nicotine (nicotine plus nicotine glucuronide), and total cotinine (cotinine plus cotinine-N-glucuronide). The results showed significant increases in urinary levels of total NNAL, total nicotine, and total cotinine on working days compared with nonworking days. The results of this study show that smoke exposure in bars and restaurants may have important health effects on nonsmoking employees, elicited by the increase in carcinogen levels.

Secondhand tobacco smoke impairs neurogenic and endothelium-dependent relaxation of rabbit corpus cavernosum smooth muscle: improvement with chronic oral administration of L-arginine

The first goal of this study was to examine the effect of secondhand smoking on neurogenic, endothelium- and cGMP-dependent relaxant responses of rabbit corpus cavernosum smooth muscle. Our second goal was to determine whether such an effect can be prevented by oral administration of L-arginine. Male New Zealand rabbits were divided into control, chronic passive cigarette smoking and L-arginine treatment groups. Relaxant or contractile responses in isolated corpus cavernosum smooth muscle strips were determined by using in vitro muscle technique. There was no significant difference in the relaxant response of the strips to papaverine, sodium nitroprusside and contractile response to KCl among the groups. Relaxant responses to acetylcholine and electrical field stimulation and contractile response to phenylephrine were significantly decreased in the strips of the smoking group than that of the control group. The impaired relaxations of strips were markedly improved by treatment of L-arginine, but the contractile responses to phenylephrine were not affected. These data indicate that secondhand smoking may impair both neurogenic and endothelium-dependent relaxation of corpus cavernosum smooth muscle, and may contribute to the etiology of impotence. Chronic dietary supplementation with L-arginine offsets the impairment of neurogenic and endothelial relaxation. Therefore, we suggest that secondhand smoking exposure to cigarette produces selective impairment of neurogenic and endothelium-dependent relaxation of corpus cavernosum smooth muscle via a mechanism related to the decreased production and/or availability of nitric oxide.

Biomarkers of exposure to passive smoking of school children: frequency and determinants

This study aims to assess the extent of children' exposure to ETS and quantify potential determinants. A total of 2767 children aged 5-14 years participated in an environmental survey in East Germany in 1998-1999 (participation rate 75.9%). A subgroup of 979 children between the ages of 11 and 14 years with complete data on nicotine and cotinine in urine were selected for this analysis. This study population consisted of 73 self-reported smokers (7.5%), 793 non-smokers (81%) and 113 children with missing data on smoking status (11.5%). Nicotine and cotinine concentrations in spontaneous urine sample were determined by high-performance liquid chromatography methods with ultraviolet-detection and corrected for creatinine. Approximately 40% of self-reported non-smokers were exposed to environmental tobacco smoke (ETS) at home. Non-smoking children exposed to parental tobacco smoke at home compared with not exposed showed in average higher nicotine and cotinine concentration (geometric mean 4.7 microg/l vs. 1.4 microg/l and 8.1 microg/l vs. 2.7 microg/l) and the adjusted odds ratio (OR) for detectable biomarkers ranged between 17 and 22. There were increased rates of detectable biomarkers in urine with increasing numbers of smoked cigarettes in the household (adjusted OR increased from 8 to 54). Maternal smoking showed a stronger effect than paternal smoking. Furthermore, low parental education, cold season, height of dwelling (<or=2.40), urine collected on Monday were statistically significant associated with high nicotine and cotinine excretion levels. Children exposed to parental smoke showed much higher biomarker levels than the non-smoking spouse of an adult smoker. Therefore, children need specifically protection from ETS at home.

PRACTICAL IMPLICATIONS

As children showed a higher internal exposure compared with adults the health hazards association with passive smoking might have a more serious effect in children. Children are unable to complain and unable to remove themselves from tobacco smoke exposure. Thus, parents should make sure that their children live in a smoke free environment. Each country should take all necessary legislative and regulatory measures which forbids smoking in public places and the home environment even if it requires sacrifices by the parents.

Validation and application of a method for the determination of nicotine and five major metabolites in smokers' urine by solid-phase extraction and liquid chromatography-tandem mass spectrometry

An SPE-LC-MS/MS method was developed, validated and applied to the determination of nicotine and five major metabolites in human urine: cotinine, trans-3'-hydroxycotinine, nicotine-N-glucuronide, cotinine-N-glucuronide and trans-3'-hydroxycotinine-O-glucuronide. A 500 microL urine sample was pH-adjusted with phosphate buffer (1.5 mL) containing nicotine-methyl-d3, cotinine-methyl-d3 and trans-3'-hydroxycotinine-methyl-d3 internal standards. For the unconjugated metabolites, an aliquot (800 microL) of the buffered solution was applied to a 30 mg Oasis HLB-SPE column, rinsed with 2% NH4OH/H2O (3.0 mL) and H2O (3.0 mL) and eluted with methanol (500 microL). The eluate was analyzed isocratically (100% methanol) by LC-MS/MS on a diol column (50 x 2.1 mm). For the total metabolites, a beta-glucuronidase/buffer preparation (100 microL) was added to the remaining buffered solution and incubated at 37 degrees C (20 h). An aliquot (800 microL) of the enzymatically treated buffered solution was extracted and analyzed in the same manner. The conjugated metabolites were determined indirectly by subtraction. The quantitation range of the method (ng/mL) was 14-10,320 for nicotine, 15-9800 for cotinine and 32-19,220 for trans-3'-hydroxycotinine. The validated method was used to observe diurnal variations from a smoker's spot urine samples, elimination half-lives from a smoker's 24 h urine samples and metabolite distribution profiles in the spot and 24 h urine samples.

[Urinary cotinine and nicotine metabolites measurement]

According to the recent regulations (Circulaire DGS/DH du 3 avril 2000), tobacco dependence must be determined by the measurement of urine nicotine metabolites. Various assay methods are presently available. They were tested in order to evaluate their analytical performances and to determine how they can be used for the clinical management of smoking cessation.

MATERIAL AND METHODS

Urine samples from a single void (n = 97) were obtained from active and abstinent smokers (with or without nicotine substitutive therapy). They were all analyzed by the various methods. Cotinine concentration was measured in six laboratories, using HPLC combined with UV detection according to a standardized procedure (Ann Biol Clin 2002 : 60 : 263-72). Immunoassay methods were also tested and the values obtained from urine samples were compared to urine cotinine measured by HPLC-UV.

RESULTS

HPLC-UV: Urinary cotinine varied in a range from undetectable to 4 mg/L. An interlaboratory comparison was performed according to the Valtec procedure (calculation of equation of Deming, chart of differences). There was a good accordance between laboratories. Cotinine concentration was only slightly influenced by fluid intake, as shown by a poorly significant correlation between cotinine and creatinine (r = 0.23, p = 0.05). Homogeneous immunoassays: The two homogeneous immunoassays (Cotinine) from Thermo Electron and Cotinine Enzyme Immunoassay commercialized by Microgenics were highly correlated (r = 0.97). The correlation was not so strong with HPLC-UV (r = 0.86). Firstly, values were found higher with immunoassays because antibodies crossreact with 3-hydroxycotinine. Secondly, the ratio of immunoassays values to HPLC-UV values varied according to urine specimens. Finally, there was a highly significant correlation with urine creatinine (r = 0.40, p = 0.0001), thus indicating the influence of fluid intake. Heterogeneous immunoassay: The kit Metabolites of Nicotine commercialized by DPC France was tested on the analyzer Immulite, using a procedure specifically established for urine. Antibodies revealed a large spectrum of nicotine metabolites. Therefore, the values were much higher than those observed for the same urine samples with homogeneous immunoassays.

CONCLUSION

HPLC-UV can be recommended for the measurement of urinary cotinine, as it was shown a good accordance between laboratories. The low detection limit is of interest for the diagnosis of Environmental Tobacco Smoking. Homogeneous immunoassays can be easily used for routine analysis as they can be performed directly on urine specimen. The results must be interpreted according to cut-off values specifically established according to homogeneous or heterogeneous immunoassays. Variability induced by fluid intake must be taken into account. The interest of the heterogeneous immunoassay needs to be confirmed for the diagnosis of Environmental Tobacco Smoking.

Real-life environmental tobacco exposure does not affect exhaled nitric oxide levels in asthmatic children

Serial measurement of exhaled nitric oxide (eNO) has been shown to be a good noninvasive marker of asthma control. Active smoking decreases eNO levels. The effect of real-life environmental exposure to tobacco smoke (ETS) on eNO levels is not known. Our objective was to study the impact of environmental tobacco exposure on eNO levels in asthmatic and non-asthmatic children. Single breath off-line collection of eNO was performed in asthmatic and non-asthmatic children with and without ETS. Urine was collected for cotinine/nicotine analysis. Fifty-seven children were enrolled, of which 25 were asthmatic and 32 had smoke exposure. One active smoker was excluded from the data analysis. The mean eNO was 11.1 ppb (n = 31; SD = 18.5) in those passively exposed vs. 11.1 ppb (n = 25; SD = 19.9) among the unexposed (not statistically significant). The mean eNO was 6.1 (n = 32; SD = 4.4) among the non-asthmatics and 17.8 (n = 24; SD = 27.4) among the asthmatics (p = 0.02; CI: 1.9-21.6). Real-life environmental tobacco exposure does not appear to decrease eNO levels in asthmatic children. Off-line collection of exhaled nitric oxide with a Mylar collection device helps differentiate asthmatics from non-asthmatics.

Metabolic profile of nicotine in subjects whose CYP2A6 gene is deleted

Generally, 70-80% of absorbed nicotine is mainly metabolized to cotinine by cytochrome P450 (CYP) 2A6. There is genetic polymorphism in the human CYP2A6 gene. Among several mutated alleles, CYP2A6*4 allele is a whole deleted type. The purpose of the present study was to clarify the metabolic profile of nicotine in subjects whose CYP2A6 gene is deleted. We developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for nicotine and its nine metabolites. Excretion levels of nicotine and its metabolites in 24 h accumulated urine after the chewing of one piece of nicotine gum were evaluated in five Japanese subjects whose CYP2A6 genotype was determined. In three subjects with CYP2A6*1A/CYP2A6*1A, CYP2A6*1A/CYP2A6*1B, and CYP2A6*1A/CYP2A6*4 (group I), nicotine was mainly excreted as cotinine, trans-3'-hydroxycotinine, and their glucuronide (approximately 60%). In contrast, in two subjects with CYP2A6*4/CYP2A6*4 (group II), trace levels of cotinine, cotinine N-glucuronide, and cotinine 1'-N-oxide were detected. Trans-3'-hydroxycotinine and its O-glucuronide were not detected. The excretion levels of nicotine itself, nicotine N-glucuronide, and nicotine 1'-N-oxide were higher than those in the other three subjects. The total excretion levels of these three compounds were approximately 95% in group II versus 35% in group I. However, the sum of the excretion levels of nicotine and all metabolites was similar among these five subjects. This is the first report of the metabolic profile of nicotine in subjects whose CYP2A6 gene is deleted.