[Comparison of DNA adducts between oral, pharyngeal and larynx cancer]

The results concerning examination of DNA adducts in oral (23 patients), pharyngeal (23 patients) and larynx cancer (10 patients) subjects are presented. DNA adduct levels were compared in respect to anatomical structure (primary tumour location), number of cigarettes smoked, TNM stage, and age of patients. DNA was isolated from removed tissue (tumour and non-tumour surrounding tissue) using detergent/phenol extraction. 32P-postlabelling assay including nuclease P1-enhancement modification was applied. Aromatic DNA adducts were found in all studied tissues. Total DNA adduct levels (tumour and non-tumour tissues) was lowest in larynx cancer, higher in oral cancer and highest in pharyngeal cancer. There were no influence of age into formation of DNA adducts. The higher level of DNA adducts was found in tumour tissue of oral cancer in the group of smokers with metastasis into lymph nodes.

Smoking affects collagen synthesis and extracellular matrix turnover in human skin

BACKGROUND

Smoking is associated with premature facial wrinkling and aberrant wound healing, but the underlying mechanisms of skin injury are poorly understood.

OBJECTIVES

To compare the in vivo collagen synthesis and degradation in the skin of smokers and non-smokers.

METHODS

The study population consisted of 47 current smokers and 51 individuals who had never smoked from northern Finland. Suction blisters were induced in the sun-protected upper inner arm of the study subjects, after which suction blister fluid (SBF) was collected for analyses of the levels of aminoterminal procollagen propeptides of type I and III collagens (PINP and PIIINP, respectively), matrix metalloproteinase (MMP)-8 and tissue inhibitor of MMP (TIMP)-1. PINP, PIIINP and TIMP-1 were also determined from serum samples. The levels of active and pro MMP-1 were assessed from deep-frozen skin biopsies by Western blotting.

RESULTS

The synthesis rates of type I and III collagens were lower by 18% and 22%, respectively, in the SBF of the smokers compared with the non-smokers. The levels of MMP-8 were higher by 100% in the SBF of the smokers. The levels of MMP-1 in the skin biopsies did not differ significantly between the groups. The levels of TIMP-1 in SBF were 14% lower in the smokers than in the non-smokers, whereas the serum concentrations of TIMP-1 did not differ between the groups.

CONCLUSIONS

Smoking decreases the synthesis rates of type I and III collagens in skin in vivo and alters the balance of extracellular matrix turnover in skin.

Variation in coumarin 7-hydroxylase activity associated with genetic polymorphism of cytochrome P450 2A6 and the body status of iron stores in adult Thai males and females

The relationships between catalytic activity of cytochrome P450 2A6 (CYP2A6), polymorphism of CYP2A6 gene, gender and levels of body iron stores were analysed in a sample group of 202 apparently healthy Thais, aged 19-47 years. Eleven individuals were found to have high activity of CYP2A6, judged by the relatively large amounts (11.2-14.6 mg) of 7-hydroyxcoumarin (7-OHC) excreted 3 h following administration of 15 mg of coumarin. Ten individuals, however, did not excrete any 7-OHC. Of these 10, four were found to have no CYP2A6 gene (whole gene deletion; CYP2A6*4 allele). The frequency of the CYP2A6 alleles; *1A, *1B and *4 in the whole sample group was 52, 40 and 8% while the frequency of the CYP2A6 gene types; *1A/*1A, *1A/*1B, *1B/*1B, *1A/*4, *1B/*4, *4/*4 was 29, 41, 16, 7, 5 and 2%. Subjects having CYP2A6*1A/*1B gene-type group were found to have higher rates of coumarin 7-hydroxylation compared with those of the CYP2A6*1B/*1B and CYP2A6*1A/*4 gene types. The inter-individual variability in CYP2A6 catalytic activity was therefore attributed in part to the CYP2A6 genetic polymorphism. Variation in CYP2A6 activity in this sample group was not associated with gender but, interestingly, it did show an inverse association with plasma ferritin; an indicator of body iron stores. Higher rates of coumarin 7-hydroxylation were found in individuals with low body iron stores (plasma ferritin < 20 microg/l) compared with subjects having normal body iron store status. Subjects (n = 16) with iron overload (plasma ferritin > 300 microg/l) also tended to have elevated rates of coumarin 7-hydroxylation. These results suggest an increased CYP2A6 expression in subjects who have excessive body iron stores. Further investigations into the underlying factors that may lead to increased expression of CYP2A6 in association with abnormal body iron stores are currently in progress in our laboratory.

Biochemical changes of saliva in tobacco chewers tobacco smokers, alcohol consumers, leukoplakia and oral cancer patients

Normal salivary function is considered to be critical for the maintenance of healthy oral mucosa. Oral fluids provide an easily available non-invasive for the diagnosis of a wide range of diseases and clinical situations. The present study evaluated the variations in the biochemical constituents of saliva of leukoplakia and oral cancer patients when compared with that of the control group. 90 individuals were grouped into 6 categories with 15 individuals in each group. The groups included individuals without tobacco or alcohol habits, tobacco smokers, tobacco chewers, alcohol consumers, leukoplakia and oral cancer patients. There was significant alteration in the salivary biochemical composition of leukoplakia and oral cancer patients which could be attributed to the impairment of salivary gland function caused by tobacco and alcohol usage or by the disease process itself.

Automated homogeneous immunoassay analysis of cotinine in urine

A study was conducted to evaluate the performance comparison of a homogeneous enzyme immunoassay (EIA) designed to detect cotinine in urine and carbon monoxide (CO) breath measurements to determine smoking status. The clinical comparison was done using urine and breath specimens from 218 volunteers. Urine samples were analyzed by immunoassay and confirmed by gas chromatography-mass spectrometry (GC-MS). Breath carbon monoxide was determined by a commercial analyzer. Using cutoffs of 10 ppm for CO and 500 ng/mL for urinary cotinine, the relative sensitivity/specificity was 93.6%/74.0%. The positive predictive value was 86.8%, and the negative predictive value was 86.5%. However, comparison of the EIA to GC-MS showed a sensitivity/specificity of 96.2%/98.4% and a positive predictive value of 99.3%. The EIA was also evaluated non-clinically for precision, stability, recovery, and interferences. In addition, the non-clinical evaluation demonstrated coefficients of variation from 0.37 to 1.09% across cotinine concentrations ranging from 0 to 5000 ng/mL. The assay was found to be highly specific for cotinine and cross-reacted to a limited degree with 3-hydroxycotinine. Finally, multiple freeze-thaw cycles of urines containing cotinine showed no degradation of the drug in the specimen when tested in the EIA. Thus, the EIA tested is a rapid, lab-based test that can reliably determine cotinine levels and their relation to smoking status.

Modified immunoenriched (32)P-HPLC assay for the detection of O(4)-ethylthymidine in human biomonitoring studies

Increased excretion of ethylated DNA bases has been reported in the urine of cigarette smokers. To study DNA ethylation in the target organs of smokers, an immunoenriched (32)P-postlabeling assay for O(4)-ethylthymidine (O(4)-etT) was developed. O(4)-etT-3'-monophosphate (O(4)-etT-3'P) was synthesized, purified, and characterized by LC-MS, ESI-MS, and NMR. DNA was enzymatically digested to 2'-deoxynucleoside-3'-monophosphate followed by immunoprecipitation of O(4)-etT-3'P using specific monoclonal antibodies. The immunoconjugate was washed by filtration, and O(4)-etT-3'P was recovered by ethanol treatment. The enriched O(4)-etT-3'P was labeled with [gamma-(32)P]ATP in the presence of T4-polynucleotide kinase at pH 6.8 to yield its 5'-labeled monophosphate and was subsequently resolved on RP-HPLC and detected with online detection of radioactivity. Adduct recovery was >80%, and the detection limit was approximately 500 amol. To further validate the method, O(4)-etT levels were determined in calf thymus DNA treated with N-ethyl-N-nitrosourea, and a dose-dependent formation of O(4)-etT was observed. Furthermore, O(4)-etT was found to be present in the cells obtained from the lower respiratory tract by sputum induction of two out of four smokers but not in three nonsmokers. O(4)-etT is a poorly repaired promutagenic DNA lesion; thus, it could be of potential use for biomonitoring smoking-related DNA damage. Our improved assay was found to be sufficiently sensitive and specific to detect O(4)-etT in surrogate cells from cigarette smoke exposed humans.

Albumin adducts of benzene oxide and 1,4-benzoquinone as measures of human benzene metabolism

Albumin adducts of benzene oxide (BO-Alb) and 1,4-benzoquinone (1,4-BQ-Alb) were investigated among 134 workers exposed to benzene and 51 unexposed controls in Tianjin, China. Concentrations of both adducts increased with benzene exposure [range = 0.07-46.6 parts/million (ppm); median = 3.55 ppm] and with urinary cotinine. Adduct levels were less than proportional to benzene exposure, suggesting saturable CYP 2E1 metabolism of benzene. Because the transition from linear to saturable metabolism began at approximately 1 ppm, the common assumption of linear kinetics at much higher benzene exposures could lead to substantial underestimation of leukemia risks. Adduct levels were generally lower in older workers, indicating that CYP 2E1 metabolism diminished with age, at approximately 2%/year of life. The ratio of 1,4-BQ-Alb:BO-Alb decreased with age and coexposure to toluene, and increased with alcohol consumption. This indicates that factors affecting CYP 2E1 metabolism exerted a greater role on production of 1,4-BQ than BO, presumably because of the second oxidation step from phenol to hydroquinone. The adduct ratio was also positively associated with urinary cotinine, suggesting that both benzene and hydroquinone from cigarette smoke affected adduct levels. Results of a limited time course study of 11 subjects indicated moderate chemical instability of 1,4-BQ-Alb (half life = 13.5 days compared with 21 days for normal Alb turnover), whereas no evidence of instability of BO-Alb was observed. This study illustrates that Alb adducts can be used to investigate the dispositions of reactive metabolites of procarcinogens in humans, provided that exposures are adequately characterized in the month preceding blood collection.

Real time analysis of breath volatiles using SIFT-MS in cigarette smoking

The selected ion flow tube mass spectrometry (SIFT-MS) technique enables real time analysis of trace volatiles at ppb levels without preconcentration steps or chemical derivatization. Most previous studies of trace compounds on the breath were analyzed using gas chromatography where enhanced detection sensitivity was achieved by concentrating the breath using cryogenic or adsorption trapping techniques. In this paper, we have examined volatile organic substances, isoprene, acetone, ammonia and ethanol in breath before and after smoking a cigarette. It is interesting that isoprene levels increased in all the subjects after smoking one cigarette with a mean increase of 70%. The mean increase for acetone was found to be 22%. In contrast to isoprene, a decreasing ethanol level was observed in all the subjects except one with the negative mean decrease of 28%. Further SIFT-MS studies also have high-lighted some organic substances produced even by unburned cigarettes, US and New Zealand products. Certain US brands have shown much higher levels of volatile species than cigarettes produced in New Zealand.

Associations between human liver and kidney cadmium content and immunochemically detected CYP4A11 apoprotein

This present study was undertaken to assess potential effects of cadmium on CYP4A11 apoprotein in human liver and kidney as detected by Western blotting using a highly specific anti-peptide antibody. Liver and kidney cortex samples were autopsy specimens of 37 individuals (26 males and 11 females) whose ages ranged from 3 to 89 years. All were Caucasians who had not been exposed to cadmium in the workplace. Reduced CYP4A11 apoprotein levels were found in chronic hepatitis samples and in liver samples showing fatty changes. In contrast, increased CYP4A11 apoprotein levels were found in liver samples having higher cadmium content compared to the lower cadmium content samples. Increased CYP4A11 levels were also found in liver samples from female donors, compared to male donors; the difference being attributable to higher female liver cadmium burden. In distinction to liver, lowered CYP4A11 levels were seen in the kidney cortex samples which have high cadmium content. It is proposed here that the difference between the absolute cadmium burden of the liver and kidney samples may be responsible for the different patterns of expression of CYP4A11 in these two tissues. Further, since cadmium exposure may be associated with derangement in blood pressure control, it is interesting to note the possible relationship between altered CYP4A11-dependent production of arachidonic acid hydroxy and epoxy metabolites in kidney cortex and altered control of blood pressure. Our findings provide a possible link between these observations.

Expression of protease activated receptor-2 (PAR-2) in central airways of smokers and non-smokers

BACKGROUND

Protease activated receptor-2 (PAR-2) is a transmembrane G protein coupled receptor preferentially activated by trypsin and tryptase. The protease activated receptors play an important role in most components of injury responses including cell proliferation, migration, matrix remodelling, and inflammation. Cigarette smoking causes an inflammatory process in the central airways, peripheral airways, lung parenchyma, and adventitia of pulmonary arteries.

METHODS

To quantify the expression of PAR-2 in the central airways of smokers and non-smokers, surgical specimens obtained from 30 subjects undergoing lung resection for localised pulmonary lesions (24 with a history of cigarette smoking and six non-smoking control subjects) were examined. Central airways were immunostained with an antiserum specific for PAR-2 and PAR-2 expression was quantified using light microscopy and image analysis.

RESULTS

PAR-2 expression was found in bronchial smooth muscle, epithelium, glands, and in the endothelium and smooth muscle of bronchial vessels. PAR-2 expression was similar in the central airways of smokers and non-smokers. When smokers were divided according to the presence of symptoms of chronic bronchitis and chronic airflow limitation, PAR-2 expression was increased in smooth muscle (median 3.8 (interquartile range 2.9-5.8) and 1.4 (1.07-3.4) respectively); glands (33.3 (18.2-43.8) and 16.2 (11.5-22.2), respectively); and bronchial vessels (54.2 (48.7-56.8) and 40.0 (36-40.4), respectively) of smokers with symptoms of chronic bronchitis with normal lung function compared with smokers with chronic airflow limitation (COPD), but the increase was statistically significant (p<0.005) only for bronchial vessels.

CONCLUSIONS

PAR-2 is present in bronchial smooth muscle, glands, and bronchial vessels of both smokers and non-smokers. An increased expression of PAR-2 was found in bronchial vessels of patients with bronchitis compared with those with COPD.

Genetic variation in CYP2A6-mediated nicotine metabolism alters smoking behavior

Approximately 50% of the initiation of tobacco dependence is genetically influenced, whereas maintenance of dependent smoking behavior and amount smoked have approximately 70% genetic contribution (1-5). Determining the variation in nicotine's inactivation is important because of nicotine's role in producing tobacco dependence and regulating smoking patterns (6-11). The genetically polymorphic CYP2A6 enzyme is responsible for the majority of the metabolic inactivation of nicotine to cotinine (12-14). Both in vitro and in vivo studies have demonstrated considerable interindividual variation in CYP2A6 activity (15-17). CYP2A6 is genetically polymorphic, individuals carrying inactive CYP2A6 alleles have decreased nicotine metabolism, are less likely to become smokers and if they do, they smoke fewer cigarettes per day (13,18,19). The decrease in smoking behavior was confirmed by measuring carbon monoxide (CO, a measure of smoke inhalation) levels, plasma and urine nicotine and cotinine levels, and cigarette counts (13,18,19). A duplication variant in the CYP2A6 gene locus has been identified which increases nicotine inactivation and increases smoking (19). CYP2A6 can also activate tobacco smoke procarcinogens (e.g. NNK, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone); current studies are investigating the role of CYP2A6 in risk for lung cancer. Based on these epidemiologic data it was postulated that inhibition of CYP2A6 activity might be useful in a therapeutic context. Kinetic studies in humans indicated that selective CYP2A6 inhibitors decrease the metabolic removal of nicotine. It was also shown that inhibiting CYP2A6 in vivo (phenocopying, or mimicking the genetic defect) in smokers results in decreased smoking, making nicotine orally bioavailable, and the rerouting of procarcinogens to detoxifying pathways (20-22).

Effects of oral administration of N-acetyl-L-cysteine: a multi-biomarker study in smokers

N-Acetyl-L-cysteine (NAC) has been shown to exert cancer-protective mechanisms and effects in experimental models. We report here the results of a randomized, double-blind, placebo-controlled, Phase II chemoprevention trial with NAC in healthy smoking volunteers. The subjects were supplemented daily with 2 x 600 mg of oral tablets of NAC (n = 20) or placebo (n = 21) for a period of 6 months, and internal dose markers [plasma and bronchoalveolar lavage (BAL) fluid cotinine, urine mutagenicity], biologically effective dose markers [smoking-related DNA adducts and hemoglobin (Hb) adducts], and biological response markers (micronuclei frequency and antioxidants scavenging capacity) were assessed at both pre- and postsupplementation times (T(0) and T(1), respectively). Overall, the internal dose markers remained unchanged at T(1) as compared with T(0) in both NAC and placebo groups. When quantifying the biologically effective dose markers, we observed an inhibitory effect of NAC toward the formation of lipophilic-DNA adducts (5.18 +/- 0.73 versus 4.08 +/- 1.03/10(8) nucleotides; mean +/- SE; P = 0.05) as well as of 7,8-dihydro-8-oxo-2'-deoxyguanosine adducts in BAL cells (3.9 +/- 0.6 versus 2.3 +/- 0.2/10(5) nucleotides; P = 0.003). There was no effect of NAC on the formation of lipophilic-DNA adducts in peripheral blood lymphocytes or polycyclic aromatic hydrocarbon-DNA adducts in mouth floor/buccal mucosa cells or 4-aminobiphenyl-Hb adducts. Likewise, quantification of the biological response markers showed an inhibitory effect of NAC on the frequency of micronuclei in mouth floor and in soft palate cells (1.3 +/- 0.2 versus 0.9 +/- 0.2; P = 0.001) and a stimulating effect of NAC on plasma antioxidant scavenging capacity (393 +/- 14 versus 473 +/- 19 microM Trolox; P = 0.1) but not on BAL fluid antioxidant scavenging capacity. We conclude that NAC has the potential to impact upon tobacco smoke carcinogenicity in humans because it can modulate certain cancer-associated biomarkers in specific organs.

Cigarette smoke extracts delay wound healing in the stomach: involvement of polyamine synthesis

The association between cigarette smoking and peptic ulcer diseases has been well established. Ornithine decarboxylase (ODC) is crucial for the gastroprotective and mucosal growth promoting effects in gastric ulcer healing. The aim of this study is to elucidate the possible mechanism of how inhibition of ODC activity is involved in the delay of ulcer healing, if any, by cigarette smoke extracts (CSE). CSE were fractionated into chloroform extract (CE) and ethanol extract (EE). In in vivo study, rats with acetic acid-induced ulcers were given CE or EE intragastrically (2.5 or 5 mg/kg) once daily for 3 days. Ulcer sizes were significantly larger after CE or EE administration, followed by an increase in myeloperoxidase activity and a reduction in cell proliferation. However, both CSE stimulated the number of microvessels following the increase of basic fibroblast growth factor. In in vitro studies, the effect of CE or EE (10, 40, or 100 microg/ml) on cell migration and cell proliferation were measured using an in vitro wound model and [(3)H]-thymidine incorporation assay, respectively. Both CSE delayed cell migration and decreased cell proliferation, which were accompanied with a reduction in ODC activity. Exogenous spermidine (5 or 10 microM) could reverse the inhibitory action on cell proliferation and ODC activity induced by CSE. In conclusion, both CSE significantly delayed ulcer healing as a result of reduction in cell proliferation and cell migration. All these effects are, in part, related to the reduction of polyamine synthesis.

Protein carbonylation and glycation in human lenses

It has been observed protein carbonylation and glycation in the lens epithelial cell fractions of lenses in people with mature cataract. We used lenses of diabetic patients, weak and strong cigarette smokers and people who had senile cataract. The protein glycation is the highest in a diabetic senile cataract patients and the lowest in non-diabetic senile cataract patients. The protein carbonylation is extremely high in mitochondrial epithelial cells of the strong cigarette smokers. These results show that the glycation and carbonylation of the human lens proteins are the part of the cataract development in people. Specific factors, such as high glucose in diabetes and the tobacco smoke (in cigarette smokers), can change the lens structure, thus stimulating cataract development.

Senile cataract and the absorption activity of cytochrome C oxidase

The aim of the study was to determine the activity of cytochrome c oxidase in mitochondrial fractions of cataractogenic epithelial cells of lenses of 60 patients (34 females and 26 males). According to clinical criteria patients were divided into three groups: group 1--patients with senile cataract, group 2--active smokers with senile cataract, and group 3--diabetic patients with cataract as diabetic complication. In the extracted lenses we determined the absorption activity of mitochondrial enzyme cytochrome c oxidase. Biochemical researches using the method of Yonetani and Ray were applied. We also applied the statistical Student t-test (p < 0.05) and the variance analysis (R. Fisher) with three parameters and Snedecor F distribution (s = p < 0.001). The activity of cytochrome c oxidase in mitochondrial fraction of lens epithelial cells is twice as low in patients who are active smokers than in the non-smoking patients with senile cataract. We measured a significantly different activity of cytochrome c oxidase between active smokers and the non-smoking patients with senile diabetic cataract (tp < 0.05, sp < 0.001). Cigarette smoke decreases the activity of cytochrome c oxidase in mitochondrial fraction of lens epithelial cells. This enzyme is a terminal oxidase in the synthesis of ATPs. We suggest that smoking decreases the synthesis of energy in the lens of cigarette smokers. This emphasizes the significance of giving up smoking in order to preserve the structure and function of the lens.

Slower metabolism and reduced intake of nicotine from cigarette smoking in Chinese-Americans

BACKGROUND

Lung cancer rates are lower in Asians and Latinos than in whites. Ethnic differences in nicotine metabolism might explain, in part, ethnic differences in cigarette consumption and/or nicotine intake per cigarette and resultant tobacco-related cancer risk. We compared the rate of nicotine metabolism and the intake of nicotine per cigarette smoked among smokers of different ethnicities.

METHODS

Healthy volunteer smokers, including 37 Chinese-Americans, 40 Latinos, and 54 whites, received simultaneous infusions of deuterium-labeled nicotine and cotinine, a metabolite of nicotine. From blood and urine measurements, the disposition kinetics and daily intake of nicotine from smoking were determined. All statistical tests were two-sided.

RESULTS

Total and nonrenal clearance of nicotine and cotinine and metabolic clearance of nicotine via the cotinine pathway were similar in Latinos and whites and statistically significantly lower in Chinese-Americans. Intake of nicotine per cigarette by Chinese-Americans (0.73 mg; 95% confidence interval [CI] = 0.53 to 0.94 mg) was statistically significantly lower than that by Latinos (1.05 mg; 95% CI = 0.85 to 1.25 mg) or whites (1.10 mg; 95% CI = 0.91 to 1.30 mg; P =.039). Among all of the participants, there was a statistically significant positive correlation between nicotine clearance and daily intake of nicotine from cigarette smoking and between nicotine clearance and nicotine intake per cigarette (r =.41 and r =.39, respectively) (P<.001 for both).

CONCLUSIONS

The lower nicotine (and, therefore, tobacco smoke) intake per cigarette and the fewer cigarettes smoked per day, which may result, in part, from slower clearance of nicotine, may explain lower lung cancer rates in Chinese-Americans. Lower lung cancer rates among Latinos compared with whites, given their similar nicotine intake per cigarette, are probably due to smoking fewer cigarettes. The results with Chinese-Americans may have implications for dosing with nicotine medications to aid smoking cessation in Chinese- American smokers and perhaps in other Asian smokers.

Maternal cigarette smoking, metabolic gene polymorphism, and infant birth weight

CONTEXT

Little is known about genetic susceptibility to cigarette smoke in relation to adverse pregnancy outcomes.

OBJECTIVE

To investigate whether the association between maternal cigarette smoking and infant birth weight differs by polymorphisms of 2 maternal metabolic genes: CYP1A1 and GSTT1.

DESIGN, SETTING, AND PARTICIPANTS

Case-control study conducted in 1998-2000 among 741 mothers (174 ever smokers and 567 never smokers) who delivered singleton live births at Boston Medical Center. A total of 207 cases were preterm or low-birth-weight infants and 534 were non-low-birth-weight, full-term infants (control).

MAIN OUTCOME MEASURE

Birth weight, gestation, fetal growth by smoking status and CYP1A1 MspI (AA vs Aa and aa, where Aa and aa were combined because of small numbers of aa and similar results), and GSTT1 (present vs absent) genotypes.

RESULTS

Without consideration of genotype, continuous maternal smoking during pregnancy was associated with a mean reduction of 377 g (SE, 89 g) in birth weight (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.2-3.7). When CYP1A1 genotype was considered, the estimated reduction in birth weight was 252 g (SE, 111 g) for the AA genotype group (n = 75; OR, 1.3; 95% CI, 0.6-2.6), but was 520 g (SE, 124 g) for the Aa/aa genotype group (n = 43 for Aa, n = 6 for aa; OR, 3.2; 95% CI, 1.6-6.4). When GSTT1 genotype was considered, the estimated reduction in birth weight was 285 g (SE, 99 g) (OR, 1.7; 95% CI, 0.9-3.2) and 642 g (SE, 154 g) (OR, 3.5; 95% CI, 1.5-8.3) for the present and absent genotype groups, respectively. When both CYP1A1 and GSTT1 genotypes were considered, the greatest reduction in birth weight was found among smoking mothers with the CYP1A1 Aa/aa and GSTT1 absent genotypes (-1285 g; SE, 234 g; P<.001). Among never smokers, genotype did not independently confer an adverse effect. A similar pattern emerged in analyses stratified by maternal ethnicity and in analyses for gestation.

CONCLUSIONS

In our study, maternal CYP1A1 and GSTT1 genotypes modified the association between maternal cigarette smoking and infant birth weight, suggesting an interaction between metabolic genes and cigarette smoking.

Lipid peroxidation and glutathione peroxidase activity in chronic obstructive pulmonary disease exacerbation: prognostic value of malondialdehyde

Results of recent studies have indicated that during exacerbation of chronic obstructive pulmonary disease (COPD), antioxidant capacity is lower and the levels of lipid peroxidation products are higher than those in age-matched healthy subjects. The aim of this study was to assess the time course of changes in oxidant stress during the treatment of exacerbation of COPD. For this purpose, we measured erythrocyte glutathione peroxidase (GPx) activity and serum levels of the lipid peroxidation product malondialdehyde (MDA) in 18 male patients with acute exacerbation of COPD. Fifteen healthy non-smokers having no history of lung disease served as control subjects. Mean erythrocyte GPx values of patients were 45.54 +/- 9.04 u/gHb on admission and had increased to 72.77 +/- 9.68 by the tenth day of treatment, but still remained lower than those of healthy subjects (83.13 +/- 10.91) (p=0.007). Serum MDA values in patients were Vol. 12, No. 1, 2001 significantly higher (2.68 +/- 1.28 nmol/ml) than those in control subjects (1.04 +/- 0.36 nmol/ml) (p=0.000) and returned to normal values by the tenth day of treatment (1.08 +/- 0.36 nmol/ml) (p=0.766). Erythrocyte GPx values in patients who were current smokers (39.87 +/- 3.82 u/gHb) were lower than those in ex-smokers (49.15 +/- 9.67 u/gHb) (p=0.021). Moreover, serum MDA values in patients who were current smokers (3.32 +/- 1.18 nmol/ml) were higher than those in ex-smokers (1.66 +/- 0.60 nmol/ml) (p=0.007). The results show that oxidative stress in patients with acute exacerbation of COPD is related to higher MDA levels that return to normal conditions during the course of treatment. In conclusion, the results suggest that MDA levels can serve as a marker of prognosis and of the success of treatment of the exacerbation of COPD.

Extended NO analysis applied to patients with COPD, allergic asthma and allergic rhinitis

The recommended method to measure exhaled nitric oxide (NO) cannot reveal the source of NO production. We applied a model based on the classical Fick's first law of diffusion to partition NO in the lungs. The aim was to develop a simple and robust solution algorithm with a data quality control feature, and apply it to patients with known alterations in exhaled NO. Subjects with allergic rhinitis, allergic asthma, chronic obstructive pulmonary disease (COPD) smokers and controls were investigated. NO was measured at three expiratory flow rates. An iteration method was developed to partition NO. The airway tissue content of NO was increased in asthma, 144 +/- 80 ppb (P = 0.04) and decreased in smokers, 56 +/- 36 ppb (P = 0.02). There was no difference between subjects with rhinitis, 98 +/- 40 ppb and controls, 98 +/- 44 ppb. The airway transfer rate was increased in allergic asthma and allergic rhinitis, 12 +/- 4 vs. 12 +/- 5 ml sec(-1), compared to controls, 8 +/- 2 ml sec(-1) (P < 0.001). The alveolar levels were no different from controls, 2 +/- 1 ppb. In COPD the alveolar levels were increased, 4 +/- 2 ppb (P < 0.001). Extended NO analysis reveals from where in the respiratory system NO is generated. Hence, this new test can be added to the tools the physician has for the diagnosis and treatment of patients with respiratory disorders.

Mechanism of cigarette smoke condensate-induced acute inflammatory response in human bronchial epithelial cells

BACKGROUND

To demonstrate the involvement of tobacco smoking in the pathophysiology of lung disease, the responses of pulmonary epithelial cells to cigarette smoke condensate (CSC) - the particulate fraction of tobacco smoke - were examined.

METHODS

The human alveolar epithelial cell line A549 and normal human bronchial epithelial cells (NHBEs) were exposed to 0.4 microg/ml CSC, a concentration that resulted in >90% cell survival and <5% apoptosis. Changes in gene expression and signaling responses were determined by RT-PCR, western blotting and immunocytofluorescence.

RESULTS

NHBEs exposed to CSC showed increased expression of the inflammatory mediators sICAM-1, IL-1beta, IL-8 and GM-CSF, as determined by RT-PCR. CSC-induced IL-1beta expression was reduced by PD98059, a blocker of mitogen-actived protein kinase (MAPK) kinase (MEK), and by PDTC, a NFkappaB inhibitor. Analysis of intracellular signaling pathways, using antibodies specific for phosphorylated MAPKs (extracellular signal-regulated kinase [ERK]-1/2), demonstrated an increased level of phosphorylated ERK1/2 with increasing CSC concentration. Nuclear localization of phosphorylated ERK1/2 was seen within 30 min of CSC exposure and was inhibited by PD98059. Increased phosphorylation and nuclear translocation of IkappaB was also seen after CSC exposure. A549 cells transfected with a luciferase reporter plasmid containing a NFkappaB-inducible promoter sequence and exposed to CSC (0.4 microg/ml) or TNF-alpha (50 ng/ml) had an increased reporter activity of approximately 2-fold for CSC and 3.5-fold for TNF-alpha relative to untreated controls.

CONCLUSION

The acute phase response of NHBEs to cigarette smoke involves activation of both MAPK and NFkappaB.

Effects of aldehyde dehydrogenase-2 genetic polymorphisms on metabolism of structurally different aldehydes in human liver

Genotype analysis of the aldehyde dehydrogenase (ALDH)-2 gene was performed using an improved simplified method, and effects of the genotype on the metabolism of a variety of aldehydes in different fractions of human liver cells were investigated. The effects of sex, aging, smoking, drinking alcohol, liver function, and various drugs on ALDH activity were also analyzed. Of the 39 subjects, eight were heterozygotes of the wild (ALDH2*1) and mutant (ALDH2*2) alleles, and the others were homozygotes of the wild allele. ALDH activity toward acetaldehyde in liver mitochondria from subjects with a mutant allele was less than 10% of that with two alleles of wild-type, and the activities toward formaldehyde, propionaldehyde, n-butyraldehyde, capronaldehyde, and heptaldehyde were also significantly lower in the ALDH2*1/*2 rather than ALDH2*1/*1 group. However, the metabolism of octylaldehyde, decylaldehyde, retinaldehyde, benzaldehyde, 3-hydroxybenzaldehyde, and 2,5-dihydroxybenzaldehyde was similar in the two genotypes. Changes in activity in the cytosolic fraction were similar to those in mitochondria. There was no significant difference in ALDH activity in microsomes between the two groups. Total activities of ALDH toward acetaldehyde and other short-chain aliphatic aldehydes in supernatant fractions of homogenized liver were affected in a manner similar to that in mitochondria. Our results suggest that the single nucleotide polymorphisms of the ALDH2 gene only alter the metabolism of aldehydes with a short aliphatic chain. Furthermore, sex, drinking alcohol, and smoking had little effect on ALDH activity, although the activity in elderly individuals tended to be lower albeit statistically insignificant.