Effects of cigarette smoking on lipid peroxidation

We monitored serum malondialdehyde (MDA), an indicator of lipid peroxidation, to determine whether active cigarette smoking causes oxidative damage. The results revealed that the concentration of serum MDA was higher in cigarette smokers than in nonsmoking control subjects. No relation was found between lipid peroxidation and the number of cigarettes smoked by an individual. This finding supports the hypothesis that oxidative damage in smokers is due to the number of hours of active exposure to cigarette smoke.

Reference ranges of copper and zinc and the prevalence of their deficiencies in an Arab population aged 15-80 years

Serum concentrations of copper and zinc were measured by flame atomic absorption spectrophotometry in 560 Kuwaitis aged from 15 to 80 yr who were in apparent good health to establish reference ranges and determine the prevalence of the deficiency of the trace metals. Zinc/copper ratios were derived by calculation. Because the mean +/- SD (microM) for copper in females (24.9 +/- 7) was significantly higher (p<0.0001) than in males (21.0 +/- 5.8) and vice versa for zinc (17.0 +/- 3.5 [males] vs 15.5 +/- 3.4 [females]) and zinc/copper ratios (0.87 +/- 0.28 [males] vs 0.67 +/- 0.27 [females]), gender-specific reference ranges were established in addition to reference ranges for the total population. The reference range for zinc was closer to those reported for other populations than was copper. Body mass index (BMI) and copper values were lower and the zinc/copper ratio was higher in the young (15-24 yr) compared to the older subjects. Copper concentrations were positively associated with BMI values (r=0.302, p<0.0001). Smokers had significantly lower (p=0.011) BMI than nonsmokers. The prevalence of copper and zinc deficiency, 0.36% and 0.53%, respectively, was low. Generally, the values for serum copper and zinc obtained for the Kuwaiti population studied suggest adequate dietary intake of the trace metals.

Monoamine oxidase and cigarette smoking

Current cigarette smokers have reduced monoamine oxidase (MAO) and there is evidence that this is a pharmacological effect of tobacco smoke exposure rather than a biological characteristic of smokers. This article summarizes human and animal studies documenting the inhibitory effects of tobacco smoke on MAO and discusses MAO inhibition in the context of smoking epidemiology, MAO inhibitor compounds in tobacco, reinvestigations of low platelet MAO in psychiatric disorders and smoking cessation.

Immune cells in bronchoalveolar lavage in peripheral lung cancer--analysis of 140 cases

BACKGROUND

Changes in the bronchoalveolar lavage fluid (BALF) cell profile may reflect immunologic reactions of the lung in pulmonary malignancies.

OBJECTIVE

Our aim was to analyse the BALF cell profile in peripheral lung cancer.

METHODS

This study was a retrospective analysis of BALF samples containing tumor cells from patients with confirmed peripheral lung cancer (140 cases). Routine analysis and lymphocyte phenotyping by an immunoperoxidase technique with the monoclonal antibodies CD3, CD20, CD4, CD8, CD57, CD1, CD25, CD71 and HLA-DR were performed. The data were compared with those from healthy persons.

RESULTS

We found a significantly lower proportion of macrophages (60%), and significantly elevated proportions of lymphocytes (24%) and neutrophils (13%) in cases with cancer when compared with controls. The proportion of eosinophils was higher in the cancer patients (2.4%), though not significantly. Regarding the lymphocyte phenotypes, we found a significantly elevated proportion of T cells (86%), a relatively low CD4/CD8 ratio (1.7 +/- 1.3), and a relatively higher percentage of HLA-DR+ lymphocytes (6.6%) in patients with cancer. There were no significant differences between smokers and nonsmokers in the cancer patients. In more than half of the cases, a positive staining for epithelial membrane antigen was found.

CONCLUSION

Our observations confirm the possible participation of lymphocytes (activated and suppressor subtypes) and eosinophils in the response against tumor in peripheral airways.

Population analyses of sustained-release verapamil in patients: effects of sex, race, and smoking

OBJECTIVE

Our objective was to determine the effects of age, sex, and sustained-release formulation on apparent oral clearance of sustained-release racemic verapamil in patient populations.

METHODS

Population pharmacokinetic analyses were performed on data from 186 patients with hypertension, coronary artery disease, or supraventricular arrhythmias who were receiving long-term sustained-release oral racemic verapamil (Covera SR in 105 patients, Calan SR in 67 patients, and other formulations in 14 patients; mean +/- SD dose, 280 +/- 139 mg) for clinical care or as a part of phase III efficacy studies. Of those 186 patients, 135 were men (age, 63 +/- 12 years; ideal body weight, 70.7 +/- 6.6 kg) and 51 were women (age, 60 +/- 17 years; ideal body weight, 53.7 +/- 7.2 kg). Verapamil was measured by HPLC, and population analyses were performed by use of NONMEM software. Sex, age, and formulation were the covariates considered in the population model building. Subgroup analyses of race, smoking, and alcohol consumption were also performed. Significance of covariates was determined by likelihood ratio tests.

RESULTS

Sex significantly affected steady-state clearance of oral sustained-release racemic verapamil. Apparent oral clearance of sustained-release verapamil was 23.8 +/- 2.3 mL/min per kilogram in women compared with 18.6 +/- 3.4 mL/min per kilogram in men. Clearance estimates were faster in black subjects compared with white subjects, as well as in smokers compared with nonsmokers. Effects of age, formulation, and alcohol consumption were not detected.

CONCLUSIONS

In middle-aged and older patients, apparent oral clearance of sustained-release racemic verapamil was affected by sex (faster in women compared with men), race (faster in black subjects compared with white subjects), and smoking (faster in smokers compared with nonsmokers) but not by age, alcohol, or formulation.

Smoking and exposure to environmental tobacco smoke decrease some plasma antioxidants and increase gamma-tocopherol in vivo after adjustment for dietary antioxidant intakes

BACKGROUND

Free radicals in cigarette smoke may cause oxidative damage to macromolecules, contributing to cardiovascular diseases and cancer. Decreased plasma antioxidant concentrations may indicate cigarette smoke-related oxidative stress.

OBJECTIVE

We compared the effects on plasma antioxidant concentrations in cotinine-confirmed active and passive smokers with those in nonsmokers, independent of differences in dietary intakes and other covariates.

DESIGN

Plasma samples from 83 smokers, 40 passive smokers, and 36 nonsmokers were analyzed for total ascorbic acid, alpha- and gamma-tocopherols, 5 carotenoids, retinol, and cotinine. Groups were compared by using analysis of variance with adjustment for sex, age, race, body mass index, alcohol intake, triacylglycerol concentration, fruit and vegetable intakes, and dietary antioxidants.

RESULTS

After adjustment for dietary antioxidant intakes and other covariates, smokers and passive smokers had significantly lower plasma beta-carotene concentrations than did nonsmokers (0.15, 0.17, and 0.24 micro mol/L, respectively) and significantly higher gamma-tocopherol concentrations (7.8, 7.8, and 6.5 micro mol/L, respectively). Smokers had significantly lower plasma ascorbic acid and beta-cryptoxanthin concentrations than did nonsmokers and passive smokers (ascorbic acid: 43.6, 54.5, and 54.6 micro mol/L, respectively; beta-cryptoxanthin: 0.12, 0.16, and 0.16 micro mol/L, respectively) and significantly lower concentrations of lutein and zeaxanthin than did nonsmokers (0.33 compared with 0.41 micro mol/L). The P values for all the differences described above were < 0.05. No significant differences in plasma concentrations of alpha-tocopherol, alpha-carotene, total carotenoids, lycopene, or retinol were observed.

CONCLUSIONS

These results indicate that cigarette smokers and nonsmokers exposed to cigarette smoke have a significantly lower plasma antioxidant status than do unexposed nonsmokers, independent of differences in dietary antioxidant intakes. Further research is required to explain why plasma gamma-tocopherol concentrations were significantly higher in smokers and passive smokers than in nonsmokers.

Effect of maternal smoking on fetal catecholamine concentrations at birth

The aim of this study was to compare catecholamine concentrations in the fetal umbilical artery cord blood from the offspring of smokers versus the offspring of nonsmokers. Pregnant women who were self-identified as smokers (>/=10 cigarettes per day throughout pregnancy) or nonsmokers were recruited for study participation. Maternal blood was collected for cotinine concentrations. Umbilical artery cord blood was collected at delivery for arterial pH and catecholamine concentrations. Cord blood was obtained from 51 subjects, including 21 smokers and 30 nonsmokers. Median epinephrine concentrations [304 pg/mL versus 597 pg/mL (Mann-Whitney U = 170; p = 0.006)] and median norepinephrine concentrations [3148 pg/mL versus 6558 pg/mL (Mann-Whitney U = 191; p = 0.006)] were significantly lower in smokers compared with nonsmokers, respectively. After controlling for gestational age, route of delivery, and arterial pH, log-transformed epinephrine concentrations between smokers and nonsmokers were statistically significant (p = 0.03), with a similar trend for log-transformed norepinephrine concentrations (p = 0.07). Analyses of the data using cotinine <20 ng/mL to classify nonsmokers also showed differences in epinephrine concentrations between groups (p = 0.02). These results are consistent with results from animal studies showing that catecholamine concentrations may be affected by prenatal nicotine exposure. Further studies are needed to validate these findings and to examine the specific mechanism by which these differences may arise.

Effect of smoking and transdermal nicotine on colonic nicotinic acetylcholine receptors in ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a disease largely of non-smokers, in which nicotine is of therapeutic value. The mode of action is unknown, but may involve nicotinic acetylcholine receptors (nAChRs) in the bowel wall.

AIM

To investigate the presence of nAChRs in rectal mucosa, and the effect of smoking and nicotine on their expression.

DESIGN

Prospective case-control study.

METHODS

In situ hybridization (ISH) and immunocytochemistry (ICC) were used to show alpha3 nAChRs in colonic mucosa. Rectal mucosa was examined from controls (n=55) and patients with inactive UC (n=62), both smokers and non-smokers, by ICC, using two antibodies to show the density and distribution of receptors in the mucosa. Non-smokers with UC (n=43) were given transdermal nicotine or placebo patches for 6 months, and rectal biopsies, taken before and after treatment, were examined by ICC to show nAChRs.

RESULTS

In normal colon, ISH and ICC showed alpha3 subunit in a wide variety of cells, including mucosal epithelium. In rectal biopsies, neither smoking nor nicotine influenced the expression of alpha3 immunoreactivity in epithelium, either in controls or UC. However, controls had a significantly greater density of immunodetectable mucosal epithelium alpha3 subunit, compared with UC patients.

DISCUSSION

The presence of nAChRs in colonic epithelium may be pertinent to the beneficial effect of nicotine in UC, but since neither smoking nor nicotine treatment is associated with any change in the expression of epithelial alpha3 nAChRs, the effect may be due to functional changes in the receptor. The decreased number of alpha3 nAChRs in UC compared with controls may be related to an increased cell turnover in UC.

Does the bleomycin sensitivity assay express cancer phenotype?

The bleomycin (BLM) sensitivity assay has been associated with the measuring of increased risk of individual susceptibility to cancer, when chromatid breaks per cell (b/c) induced by an in vitro treatment of lymphocytes with BLM are elevated. The high heritability of BLM sensitivity indicates a genetic background. We wished to clarify whether the test characterizes the head and neck cancer phenotype as compared not only with healthy individuals, but also with alcoholic patients (ALCs) whose exposure to tobacco and alcohol consumption were similar to that of head and neck cancer patients (HNCPs), but whose liver diseases were not cancerous. If the BLM test quantifies merely cancer susceptibility on an inherited basis, the mutagen sensitivity of HNCPs should differ from that of ALCs. Conventional chromosome analysis and the BLM assay were carried out on 156 HNCPs, 51 ALCs, 146 healthy non-smokers and non-drinkers and 149 non-drinking smokers. The spontaneous rates of chromosomal aberrations (CAs) in HNCPs, ALCs and healthy smokers were identical (2.8%), but differed significantly from the non-smoking controls (2.25%). Sporadic CAs were clearly associated with tobacco smoking, but not with health status. Mutagen sensitivity measured by the BLM test showed significantly (P < 0.04) elevated values not only in HNCPs (1.13 b/c), but also in ALCs (1.29 b/c) as compared with the controls (1.01 b/c). The main finding of the study was that a considerable proportion (46%) of Hungarian controls were mutagen sensitive, twice as many as in those populations reported by others so far. Our data suggest that the BLM test does not characterize susceptibility to cancer due to insignificant differences between HNCPs and ALCs (P = 0.12) under our conditions. However, the assay might be used as a biomarker to predict cancer susceptibility under circumstances when aberrant cell frequency is >or=2% and b/c is >or=1.

Protein and mRNA levels of nicotinic receptors in brain of tobacco using controls and patients with Alzheimer's disease

The neuronal nicotinic receptors (nAChRs) are involved in several processes in brain including nicotine dependence and cognitive disorders. While the number of nAChRs in the brain of tobacco smokers is up-regulated, the receptors are reduced in the brain of patients with Alzheimer's disease (AD). The aim of this study was to investigate nAChR mRNA and protein levels in brain of smoking and non-smoking controls and AD patients. Western blotting and RT-PCR techniques were used to quantify different nAChR subunits in autopsy brain. The alpha4 and alpha7 but not the alpha3 nAChR protein levels were significantly increased in the temporal cortex of smoking (SC) compared with non-smoking controls (NSC). The alpha4-protein level was significantly higher in the temporal cortex of smoking AD (SAD) patients compared with non-smoking AD (NSAD). No changes in the alpha3, alpha4 or alpha7 subunits protein level were found in the hippocampus in any of the smoking groups. For both SADs and NSADs the protein levels for the alpha3 and alpha4 in temporal cortex and hippocampus and alpha7 in the hippocampus were significantly lower compared with non-smoking controls. No significant differences in alpha4 and alpha7 mRNA levels were detected in the hippocampus or temporal cortex of smokers compared with non-smokers. In conclusion this study showed an increased level of alpha4 and alpha7 nAChRs subunits in the temporal cortex of SC compared with NSC. This up-regulation was also seen in SAD although the protein levels of nAChR subunits were still lower in smoking AD brain compared with the NSC. The up-regulation of nAChRs in smoking groups and the loss of these receptors in AD patients were not correlated to any changes at the mRNA level suggesting that these changes may reflect post-transcriptional events.

The influence of salivary activity in evaluating adolescent tobacco consumption by determining the level of thiocyanate in saliva

The thiocyanate (SNC) concentration in saliva is a biochemical measure frequently used as an objective indicator of tobacco consumption. However, variations in the volume of saliva can influence SNC levels, making it more difficult to ascertain the relation between tobacco consumption and SNC concentration. The goal of this study was to determine the extent to which salivary activity can influence SNC concentration in saliva among adolescents. We measured the SNC concentration in saliva and the salivary activity (using cotton dental rolls) of 592 students aged 14-17 years. The results of a stepwise regression analysis did not show any significant effect of the salivary activity on SCN levels.

Chronic nicotine and smoking exposure decreases GABA(B1) receptor expression in the rat hippocampus

Nicotine and smoking have long been proved to play an important role in cognition and memory in the hippocampus. This effect is closely related to the gamma-aminobutyric acid (GABA)ergic system. Previous research has focused on functional and pharmacological aspects of nicotine's modulation activity. In this study, the effects of nicotine and different doses of smoking on GABA(B1) expression in the rat hippocampus have been examined using in situ hybridization and RNase protection assay. GABA(B1) receptor mRNAs were intensely expressed in the CA1, CA2, CA3, and dentate gyrus areas of the hippocampus. Nicotine and smoking doses dependently decreased GABA(B1) receptor expression in the hippocampus. These results revealed new aspects of nicotine's modulation on GABA(B) receptor, and on learning and memory.

The interaction of cigarette smoking and antioxidants. Part 2: alpha-tocopherol

It is logical that the requirement for antioxidant nutrients depends on a person's exposure to endogenous and exogenous reactive oxygen species. Since cigarette smoking results in an increased cumulative exposure to reactive oxygen species, it would seem cigarette smokers would have an increased requirement for antioxidant nutrients. This review examines available evidence of alpha-tocopherol supplementation by smokers and its effect clinically and on in vitro biomarkers of oxidative stress.

11Beta-hydroxysteroid dehydrogenase 1 expression in squamous cell carcinomas of the head and neck

11Beta-hydroxysteroid dehydrogenase 1 (11beta-HSD1) has been identified as a major detoxification enzyme of one of the most potent tobacco smoke-derived carcinogens, NNK. If not metabolized by 11beta-HSD1, activation of NNK by cytochrome p450 mono-oxidase 2D6 (CYP2D6) results in an electrophile intermediate responsible for DNA damage. Interindividual variability in the expression of 11beta-HSD1 and CYP2D6 has been found to influence the susceptibility to lung cancer. The aim of this study was to compare 11beta-HSD1 mRNA expression and CYP2D6 metabolizer status in pharyngeal tissues of patients with oropharyngeal carcinoma and controls. In 20 patients with oropharyngeal cancer and 15 non-smoking controls, the 11beta-HSD1 mRNA expression was assessed with RT-PCR. The frequency of genetic polymorphisms of the CYP2D6 gene was assessed using RFLP. It was found that 11beta-HSD1 mRNA is expressed in human pharyngeal mucosa. It is upregulated in mucosa exposed to tobacco smoke. In tumour tissues, 11beta-HSD1 expression was significantly lower than in non-affected mucosa. The frequency distribution of CYP2D6 gene polymorphisms was similar in patients and controls. Chronic tobacco abuse results in 11beta-HSD1 enzyme induction. A reduction of 11beta-HSD1 expression in tumour tissues could be a consequence of malignantly transformed cells. It remains unclear if the lower 11beta-HSD1 expression gives rise to an increased rate of additional mutations.

Domestic aeroallergen levels in Barcelona and Menorca (Spain)

Exposure to common indoor allergens is known to be associated with sensitization and triggers of asthma. Levels of allergens have been barely described in Mediterranean countries. This study reports domestic allergen levels among the general population of two regions of Spain. Dust samples were collected from living rooms and mattresses in homes of infants in Barcelona (n = 366) and Menorca (n = 475) and assayed for house dust mite (Der p 1) and cat allergen (Fel d 1) concentrations by enzyme-linked immunoabsorbent assay (ELISA). Geometric mean values (95% CI) of Der p 1 were 0.77 micro g/g (0.65, 0.92) in living rooms and 0.68 (0.56, 0.82) in children's mattresses in Barcelona, and 9.06 (7.93-10.34) and 3.12 (2.71-3.59) in Menorca, respectively. Fel d 1 levels were 0.37 micro g/g (0.31, 0.45) and 0.14 (0.12, 0.18) in Barcelona, and 0.42 (0.35, 0.50) and 0.20 (0.18, 0.24) in Menorca. Home characteristics were not consistently related to levels of aeroallergens in either location. Differences in Der p 1 levels in the two locations indicate that levels cannot be extrapolated from one part of a country to another with any certainty. Additionally, allergen reduction measures related to indoor sources must be specific to each location.

Microsomal N-glucuronidation of nicotine and cotinine: human hepatic interindividual, human intertissue, and interspecies hepatic variation

Two of the abundant conjugates of human nicotine metabolism result from the N-glucuronidation of S-(-)-nicotine and S-(-)-cotinine, transformations we recently demonstrated in liver microsomes. We further studied these microsomal N-glucuronidation reactions with respect to human hepatic interindividual, human intertissue, and interspecies hepatic variation. The reactivities of microsomes from human liver (n = 12), various human tissues, and liver from eight species toward the N-glucuronidation of S-(-)-nicotine and S-(-)-cotinine, and also R-(+)-nicotine in human liver were examined. Assays with (14)C-labeled substrates involved radiometric high-performance liquid chromatography. For the human liver samples examined there were 13- to 17-fold variations in the catalytic activities observed toward S-(-)-nicotine, R-(+)-nicotine, and S-(-)-cotinine. Gender and smoking effects were studied, and after exclusion of an outlier a decrease in catalytic activity in females was observed. Significant correlations were observed between all three analytes, indicating that the same UDP-glucuronosyltransferase(s) enzyme is likely to be involved in these transformations. Catalytic activities were not observed for human gastrointestinal tract (colon, duodenum, ileum, jejunum, and stomach), kidney, or lung microsomes. For the seven animal species examined, activity was measurable only for monkey, guinea pig, and minipig, and only for S-(-)-nicotine N-glucuronidation and at rates 10- to 40-fold lower than humans. Activity was not measurable in the case of dog, mouse, rabbit, or rat, for the latter under five different treatment conditions for one of the strains. In conclusion, there are large hepatic interindividual variations in N-glucuronidation of S-(-)-nicotine and S-(-)-cotinine, in human extrahepatic metabolism seems limited, and none of the animal strains examined resembled human.

Biomarkers in the assessment of exposure and the biological effects of environmental tobacco smoke

Environmental tobacco smoke is one of the most widespread carcinogenic exposures. Given the substantial numbers daily exposed to this substance and the great amount of scientific data on its association with chronic diseases, accurate measurements of its exposure, intake, and biological effects are needed. In fact, studies exploiting various kinds of biomarkers are crucial in increasing the understanding of the biological processes and mechanisms of the adverse health effects related to exposure, as well as in adding biological plausibility to the existing epidemiologic evidence. This paper summarizes data on known biomarkers currently in use in human population studies for detecting exposure, the biologically effective dose, the biological effects, or the disease processes related to environmental tobacco smoke. Of the biomarkers discussed, cotinine is currently well suited for assessing the exposure and intake of environmental tobacco smoke, while urinary metabolites of tobacco-specific nitrosamines appear to serve as sensitive markers for the uptake and metabolism of carcinogenic constituents of environmental tobacco smoke.

CYP2A6 genetic variation and potential consequences

Human cytochrome P450 2A6 (CYP2A6) has been shown to have large interindividual and interethnic variability in levels of expression and activity. This is thought to be largely due to genetic polymorphisms. In recent years, 13 genetic variants (CYP2A6*1-*11 and the gene duplication, *1 x 2) of CYP2A6 have been identified and a number of these have been shown to result in altered CYP2A6 enzyme activity. For example, there are alleles which result in variants that are in inactive (e.g. due to a gene deletion), have decreased activity (e.g. altered enzyme structure or transcriptional activity) or have increased activity (e.g. due to gene duplications). The resulting interindividual variation in metabolic activity may affect the metabolism of CYP2A6 substrates including nicotine, cotinine (the major metabolite of nicotine), several tobacco-specific procarcinogens, coumarin and many toxins. The frequencies of the CYP2A6 alleles vary considerably among different ethnic populations, which may partially explain the interethnic variability found in CYP2A6-related metabolic activity (e.g. nicotine metabolism), behaviors (i.e. smoking) and disease (i.e. lung cancer). Investigations of the genetic variation of CYP2A6 and its resulting effects on metabolism and health consequences are still fairly early; this review summarizes what is presently known about CYP2A6, its genetic variants and their clinical consequences.

Correlation between a single nucleotide polymorphism in the matrix metalloproteinase-2 promoter and risk of lung cancer

Matrix metalloproteinases (MMPs) play an important role in several steps of cancer development. A single nucleotide polymorphism (-1306C-->T) in the MMP2 promoter sequence disrupts an Sp1 site and thus results in strikingly lower promoter activity. We examined the relationship between this polymorphism and risk for lung cancer in 781 cases and 852 age- and sex-matched controls in a Chinese population. We found that the allele frequency of MMP2-1306C was significantly higher among cases than among controls (0.91 versus 0.83). Subjects with the CC genotype had an overall 2-fold increased risk for developing lung cancer [adjusted odds ratio (OR) 2.18; 95% confidence interval (CI), 1.70-2.79] compared with those with the CT or TT genotype. The elevated risk was observed evenly among different subtypes of this cancer. Stratified analysis indicated an additive interaction between the CC genotype and smoking on the elevated risk. The ORs of lung cancer for the CC genotype, smoking, and both factors combined were 2.38 (95% CI 1.64-3.45), 4.26 (95% CI 2.57-8.44), and 7.64 (95% CI 4.74-12.33), respectively. Furthermore, when the data were stratified by the pack-years smoked, this joint effect was more evident and stronger in heavy smokers (OR 10.25, 95% CI 5.80-18.09) than in light smokers (OR 5.55, 95% CI 3.34-9.22). These results demonstrate a significant association between the MMP2 -1306C/T polymorphism and risk of developing lung cancer solely or in a manner of interaction with carcinogen exposure.

Pi*S and Pi*Z alpha 1 antitrypsin polymorphism and the risk for asbestosis in occupational exposure to asbestos

Alpha 1 antitrypsin is a highly polymorphic anti-elastase enzyme, especially active in the protection of alveoli and liver. Here we studied the distribution of two deficient alleles Pi*Z and Pi* S, in 194 asbestos workers, of whom 100 were asbestosis cases, and 94 were controls without disease (exposed controls, EC). A second group of controls without asbestos exposure (non-exposed controls, NEC; n=122) was also included. Multivariate analysis adjusted by age and smoking habit showed ninefold risk for asbestosis in Pi*Z heterozygous individuals and 5.9-fold risk for Pi*S homozygous although differences were only significant in the first case (cases vs. EC: OR 8.9; p=0.04). Considering both genotypes (Pi*Z heterozygous, Pi*S homozygous) we obtained an OR of 8 (p=0.01). Our results suggest that the alpha 1 antitrypsin polymorphisms, especially Pi*Z, could help to predict asbestosis risk and confirm the high prevalence of the Pi*S allele in Spain.

Effects of smoking cessation or reduction on hormone profiles and bone turnover in postmenopausal women

The purpose of this study was to prospectively evaluate the impact of smoking cessation on hormonal concentrations, sex hormone-binding globulin (SHBG) and markers of bone turnover in postmenopausal women. Sixty-six women who were either users or non-users of estrogen replacement therapy (ERT) were randomly assigned, using a weighted randomization scheme, to smoking cessation (SC) or to smoking cessation after 6 weeks of monitoring (wait-list control group, WLC). We measured hormones [estrone, estradiol, testosterone, parathyroid hormone, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS) and androstenedione] and SHBG, markers of bone turnover [procollagen peptide (PINP), bone alkaline phosphatase (BAP), and osteocalcin (OC), N- and C-terminal collagen cross-links (NTx and CTx)], and cotinine, at baseline and again at 6 weeks in women who reported smoking cessation and in women randomized to the WLC group. Analyses included 20 subjects who quit or significantly reduced their smoking and 18 subjects in the WLC group. After controlling for differences in age and ERT use between groups, we found a significant change in SHBG in the SC vs. the WLC group (-8% vs. +5%, respectively; p = 0.01), and in DHEA (-18% vs. -5%, respectively; p = 0.04), but not in other hormonal concentrations. We also noted a significant change in NTx in the SC vs. WLC group (-5% vs. +56%, respectively, p = 0.01), but not in other markers of bone turnover. Percentage changes in SHBG and NTx were correlated with changes in plasma cotinine (r = 0.48; p = 0.004 and r = 0.36; p = 0.04, respectively). Six weeks of smoking abstinence produces reductions in SHBG and NTx. This may partly explain how smoking contributes to osteoporosis in postmenopausal women.

Specific p53 immunostaining patterns are associated with smoking habits in patients with oral squamous cell carcinomas

AIMS

To identify immunostaining patterns that are predictive for p53 mutations and to investigate whether p53 mutations are associated with established risk factors for oral squamous cell carcinoma (OSCC).

METHODS

Fifty five OSCCs were investigated for p53 protein expression by immunohistochemistry (IHC). Ten of these cases, including five p53 immunopositive and five p53 immunonegative cases, were subjected to microdissection of representative tumour areas followed by sequence analysis for the detection of TP53 mutations.

RESULTS

Paired IHC and sequence analysis revealed that p53 immunoexpression in more than 25% of tumour cells was indicative of TP53 mutations, whereas p53 immunonegativity was not informative. Therefore, for p53 immunohistochemical interpretation, p53 immunonegative cases were excluded from the analysis and the cut off value for p53 immunoexpression was set at 25%. Of the OSCCs showing any p53 immunoexpression, 64% revealed staining in more than 25% of the tumour cells. p53 immunoexpression in more than 25% of the neoplastic cells was significantly associated with smoking but not with alcohol consumption. No significant association with smoking habits was found when OSCCs were dichotomised into p53 immunonegative and p53 immunopositive.

CONCLUSIONS

In OSCCs the following conclusions can be made: (1) p53 immunonegativity is not informative for TP53 mutations; (2) 25% p53 immunopositive cells appears to be a good cut off value to predict TP53 mutations; (3) p53 immunostaining patterns that appeared to be predictive for TP53 mutations were associated with the smoking habits of the patients.