Cigarette smoking and periodontal destruction in young adults

The relationship between cigarette smoking and periodontal destruction was assessed in young adults. Eighty-two regular dental attenders (21 current cigarette smokers, 61 non-smokers) aged between 20 and 33 years were examined. The smokers consumed on average 15.4 (+/- 7.3) cigarettes per day and had smoked for an average of 11.8 (+/- 7) years. Cigarette smokers had almost the same levels of plaque as non-smokers but had more proximal surfaces with subgingival calculus (P < 0.01) and which bled on probing (P < 0.05). Smokers had significantly more pockets > or = 4 mm (14.6 +/- 19.9) than non-smokers (5.8 +/- 7.9), P < 0.01. Only 2 (10%) of the smokers and 1 (2%) of the non-smokers had deep pocketing (> or = 6 mm). Smokers had significantly more sites (21.8 +/- 24.9) with periodontal attachment loss of > or = 2 mm than non-smokers (9.3 +/- 12.2), P < 0.01. Severe loss of periodontal attachment (> or = 6 mm) was present in 4 (19%) of smokers compared with 2 (3%) of non smokers. In total 4 (19%) of the smokers had "established periodontitis" compared with 1 (2%) of the non-smokers. The odds ratio for the presence of "established periodontitis" and smoking was 14.1 (confidence interval 1.5 to 132.9). It is concluded that cigarette smoking was a major environmental factor associated with accelerated periodontal destruction in this selected group of young adult regular dental attenders.     

Prospective study of effect of switching from cigarettes to pipes or cigars on mortality from three smoking related diseases

OBJECTIVE: To estimate the extent to which cigarette smokers who switch to cigars or pipes alter their risk of dying of three-smoking related diseases-lung cancer, ischaemic heart disease, and chronic obstructive lung disease. DESIGN: A prospective study of 21520 men aged 35-64 years when recruited in 1975-82 with detailed history of smoking and measurement of carboxyhaemoglobin. MAIN OUTCOME MEASURES: Notification of deaths (to 1993) classified by cause. RESULTS: Pipe and cigar smokers who had switched from cigarettes over 20 years before entry to the study smoked less tobacco than cigarette smokers (8.1 g/day v 20 g/day), but they had the same consumption as pipe and cigar smokers who had never smoked cigarettes (8.1 g) and had higher carboxyhaemoglobin saturations (1.2% v 1.0%, P < 0.001), indicating that they inhaled tobacco smoke to a greater extent. They had a 51% higher risk of dying of the three smoking related diseases than pipe or cigar smokers who had never smoked cigarettes (relative risk 1.51; 95% confidence interval 0.96 to 2.38), a 68% higher risk than lifelong non-smokers (1.68; 1.16 to 2.45), a 57% higher risk than former cigarette smokers who gave up smoking over 20 years before entry (1.57; 1.04 to 2.38), and a 46% lower risk than continuing cigarette smokers (0.54; 0.38 to 0.77). CONCLUSION: Cigarette smokers who have difficulty in giving up smoking altogether are better off changing to cigars or pipes than continuing to smoke cigarettes. Much of the effect is due to the reduction in the quantity of tobacco smoked, and some is due to inhaling less. Men who switch do not, however, achieve the lower risk of pipe and cigar smokers who have never smoked cigarettes. All pipe and cigar smokers have a greater risk of lung cancer than lifelong non-smokers or former smokers.     

Frontopolar ictal epileptiform discharges on scalp electroencephalogram in temporal lobe epilepsy

OBJECTIVE: To determine the prevalence of the smoking habit among Mexican physicians as well as some of their attitudes and information on specific issues concerning smoking. MATERIAL AND METHODS: In 1993, a survey was carried out among 3,568 physicians of the three major official health care institutions in Mexico City. A questionnaire designed for The Mexican National Survey of Addictions (ENA 1993) was used. Prevalence of cigarette smoking, age of onset, number of cigarettes per day; also information and attitudes concerning smoking were assessed. RESULTS: The mean age was 37, 66% were males. Of the 3,488 (98%) surveyed, 26.9% were smokers (62% daily), 20.6% were ex-smokers and 52.5% non-smokers. There were differences related to age and sex (p < 0.05). Of daily smokers, 36% smoked between 1 and 5 cigarettes. There was a significant trend among ex-smokers that linked the time they had ceased smoking with the fear to start smoking again. Physicians were well informed of the relationship between cigarette smoking and lung cancer. Over 80% considered tobacco an addictive drug but only 65% were in favor of banning smoking from their workplaces and over 10% were not aware that it is forbidden to smoke inside health care facilities. CONCLUSIONS: These results differ from other studies that find the prevalence of smoking among physicians lower than in the general population. Our study revealed a greater prevalence of the smoking habit among female physicians and the number of cigarettes smoked per day was greater than in the general population regardless of sex.     

Acetonitrile as a possible marker of current cigarette smoking

Volatile nitriles are present in cigarette smoke. We tested the hypothesis that the presence of any of four nitriles in the blood can serve as a marker of recent cigarette smoking. We determined the sensitivity and specificity of these nitriles as indicators of daily cigarette smoking in 24 smokers (Group A) and 18 non-smokers (Group B), as well as the correlation between intensity of daily smoking and the blood concentration of acetonitrile. A new head space GLC assay method was used. Of the four nitriles, only acetonitrile was present in the blood of any study subject. Acetonitrile was moderately sensitive (67%) and entirely specific (100%) for self-reported daily smoking. There was fair correlation between blood acetonitrile concentration and the average daily number of cigarettes smoked (r2 = 0.39; P = 0.001), and the mean blood acetonitrile concentration was significantly higher (P = 0.03) among subjects with higher (> 10 cigarettes per day) current cigarette exposure (148.3 +/- 18.0 micrograms/l) than among smokers with low or minimal (1-10 cigarettes per day) exposure (43.3 +/- 6.0 micrograms/l). Thus, acetonitrile in blood appears to be highly specific and a moderately sensitive marker of cigarette smoking with a dose-effect relationship. As such, acetonitrile shows promise as a marker of current cigarette exposure.     

Toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to several ecological receptor groups: a short review

The objective of this study was to examine the risks for lung cancer associated with lifestyle characteristics of smoking in a developing country where lung cancer is the first cause of mortality by cancer in men, tobacco propaganda is freely allowed, and there are no restrictions operating for smoking. The design was a case-control and hospital-based study. Two hundred men with lung cancer and 397 hospital controls were interviewed. Odds ratio (OR) for current smokers was 8.5, whereas former smokers displayed an OR of 5.3. The risk increased with duration of smoking and with the number of cigarettes smoked per day. The attributable risk for smoking was 85%. Smokers of black tobacco and more than 24 cigarettes/day showed a risk of 12.9 regarding non-smokers, and of 15.5 for 40 or more years duration of smoking. The proportion of cases diagnosed as adenocarcinoma was higher than the proportion of squamous cell carcinoma.     

Does smoking influence the eradication of Helicobacter pylori and duodenal ulcer healing with different regimens?

To determine the effect of smoking on Helicobacter pylori eradication and ulcer healing, we investigated 232 patients with H. pylori-positive duodenal ulcer. Patients were given one of seven different treatment protocols and divided into three groups according to smoking habits. Group 1 (n = 128) consisted of non-smokers, group 2 (n = 65) of mild smokers (5-20 cigarettes/day) and group 3 (n = 39) of heavy smokers (> 20/day). The eradication of H. pylori and ulcer healing rate was controlled eight weeks later after ceasing the therapy. The overall eradication rate was 66% in all patients and 68%, 66%, 59% in each group, respectively. The eradication rates showed no statistical difference between groups. Complete ulcer healing was achieved in 84% of all patients and ulcer healing rate between groups did not show any significance (85%, 83% and 82% respectively). These results suggest that smoking status does not influence the eradication of H. pylori and duodenal ulcer healing rates at eight weeks in patients on different treatment schedules.     

Notes on the intermediary form of incontinentia pigmenti

In a survey of a representative sample of 900 persons in Switzerland (excluding the Italian speaking parts comprising some 4-5 percent of the population), the smoking habits of the adult population were studied. Smokers were defined as persons smoking at least one cigarette or an equivalent weight of pipe tobacco or cigars per day. 51.8% of men and 29.0% of women over age 15 are smokers. Among male smokers of cigarettes only (42% of all men), over three quarters (77.6%) smoke ten cigarettes or more per day, i.e., a quantity found harmful to health; over one half (55.8%) smoke twenty or more cigarettes per day. Half of all female smokers smoke ten or more cigarettes, more than one in every four female smokers (28.8%) smoke twenty or more cigarettes per day. It is calculated that almost two thirds of all cigarettes sold in Switzerland are smoked by smokers of twenty or more cigarettes per day, and that almost three quarters are smoked by smokers of ten or more cigarettes. Among men, smoking habits are independent of social status, whereas among women, those with higher family incomes show more frequent smoking, but also more widespread cessation of smoking than with lower incomes. Thirty percent of adults having been smokers have given up the habit, so that among men and women above age 15, theree are now some 20% and 14% respectively, of ex-smokers. This corresponds to at least 700,000 former smokers in all of Switzerland. The trend to give up starts already in the group aged 15-24 (over 20% of men and women having ever smoked have given up) and becomes more marked with increasing age. A large part of male and female smokers would like to free themselves of the habit. 30% of male and 34% of female smokers indicate that they had tried seriously to stop smoking during the twelve months preceding the interview. Trying to give up was not significantly associated with intensity of smoking or social status. According to this survey, a majority of the population (57.6%) is in favor of reserving certain parts of restaurants to non-smokers, following the example of non-smokers-compartments in railway trains. In a situation where a non-smoker asks a co-worker in a closed room not to smoke, 78.3% take sides with the non-smoker, either by conceding to him a right to smoke-free air, or by demanding from the smoker to show consideration for the non-smoker. Only 10.9% demand from the non-smoker understanding for the smoker, or concede to the smoker a right to smoke at work. Women show more understanding for cause of the non-smoker than men. This difference is more marked among smokers and former smokers than among non-smokers. Inasmuch as the results of this study are comparable to those of earlier surveys conducted in Switzerland, ther is good agreement. The only exception is a significant increase of the proportion of former smokers in the past years.     

Adverse influence of cigarette smoking on the endothelium

The effect of smoking on the blood vessel intima was examined by comparing indices of endothelial activity in serum from smokers with that from non-smokers. Serum from smokers contained higher levels of von Willebrand factor (p < 0.01), the smoking markers cotinine (p < 0.02) and thiocyanate (p < 0.01), and was more cytotoxic to endothelial cells in vitro (p < 0.02) than serum from non-smokers. The acute effects of smoking two unfiltered medium tar cigarettes was to briefly increase von Willebrand factor (p < 0.001) and cytotoxicity of serum to endothelial cells in vitro (p < 0.005), but lipid peroxides or thiocyanate were not increased by this short exposure to tobacco smoke. Although there were correlations between von Willebrand factor and smokers consumption of cigarettes (r = 0.28, p < 0.02), number of years smoking (r = 0.41, p < 0.001) and cotinine (r = 0.45, p < 0.01), the tissue culture of endothelial cells with physiological levels of thiocyanate or nicotine suggested that these two smoking markers were not cytotoxic. They are therefore unlikely to be directly responsible for increased von Willebrand factor in the serum of smokers. We suggest that smoking exerts a deleterious influence on the endothelium and that the mechanism is complex.     

Human ecology and tropical medicine]

Previous work with the autoradiographic mutant lymphocyte assay has provided information about the time-course of development of hprt mutations and the persistence of detectable mutant cells in human subjects following therapeutic exposures to genotoxic agents. These early studies also revealed elevations in frequencies of mutant cells in pretreatment blood samples from patients who were current tobacco smokers, but no information was available on former smokers. In the present study, blood samples were obtained from 21 healthy former tobacco smokers who had quit smoking at least 1 year before sampling, 42 subjects who had never smoked, and 23 tobacco smokers. Plasma from all samples was tested for cotinine, a metabolite of nicotine. Current smokers were categorized as heavy smokers (> or = 10 cigarettes per day, cotinine > or = 90 ng/ml plasma) and light smokers (< 10/day, cotinine < 90 ng/ml). Lymphocytes from the blood samples were isolated, cryopreserved, and later thawed and assayed with the autoradiographic hprt assay. The 21 former tobacco smokers had a mean variant (mutant) frequency (Vf +/- standard error) of 1.97 (+/-0.13) per million evaluatable cells. The Vf of 42 subjects who had never smoked was 1.74 (+/-0.13) x 10(-6), not significantly different from the former smokers. The smokers had Vfs of 8.09 (+/-0.78) x 10(-6) for 18 heavy smokers and 5.22 (+/-1.02) x 10(-6) for five light smokers. The two categories of smokers had frequencies of mutant cells significantly different from each other, and each was significantly higher than non-smokers and former smokers (P < 0.05). Vfs were significantly correlated with both cotinine concentrations and the number of cigarettes smoked per day, P < 0.001. This study demonstrates the sensitivity of the autoradiographic hprt assay for detecting mutagenic effects related to chronic low-level exposures to genotoxins, and indicates that this assay is more likely to detect the effects of recent rather than past exposures.     

Benign symmetrical lipomatosis: Madelung''s disease

The relationship between smoking and bladder cancer risk was investigated using data from a case-control study conducted between January 1994 and July 1996 in Alexandria, Egypt. Cases were 151 males with incident, histologically confirmed invasive cancer of the bladder, and controls were 157 males admitted to hospital for acute, non-neoplastic, non-urinary tract, non-smoking-related conditions. With reference to never smokers, ex-smokers had a multivariate odds ratio (OR) of 4.4 [95% confidence interval (CI) 1.7-11.7] and current smokers of 6.6 (95% CI 3.1-13.9). The ORs were 5.4 for < 20 and 7.6 for > or = 20 cigarettes per day. After adjustment for cigarette smoking, the ORs were 0.8 for waterpipe and 0.4 for hashish smokers. The risk was significantly related to duration of smoking (OR of 16.5 for > 40 years), and inversely related to age at starting (OR of 8.8 for starting < 20 years), and inversely related to time since quitting smoking. Compared with never smokers who did not report a clinical history of schistosomiasis, the OR was 9.4 for smokers with a history of schistosomiasis, and 10.7 for smokers ever employed in high-risk occupations compared with non-smokers not reporting such a history. Thus, our results, while not giving indications of an increased bladder cancer risk with habits other than cigarette smoking, found a remarkably strong association with various measures of cigarette smoking that could explain 75% of bladder cancer cases among males from Alexandria. The prevalence of smoking was very low among women, and consequently tobacco was not a relevant risk factor for female bladder cancer.     

Morphology and ultrastructure of the antennal chemoreceptors and mechanoreceptors of worker Coptotermes formosanus Shiraki

Data on respiratory symptoms and smoking for 2749 white American high school students from two linked surveys, separated by a one year lapse, are presented. There was a significantly higher likelihood of smoking at second survey among those who had initial symptoms. (There had been no educational efforts linking smoking and respiratory symptoms in the interim.) This difference was almost entirely contributed by those who had been ex-smokers and light (less than or equal to four cigarettes/day) smokers at first survey. Initial ex-smokers and light smokers also had, overall, least fixed smoking habits. Whatever the initial smoking or symptom status, symptoms at second survey were far more likely with current smoking. Controlling for initial symptom and smoking status, the gradient of symptoms between current smokers and non-smokers was over two and a half fold, except among those who had had symptoms and had not been smoking, and whose initial symptoms presumably arose from causes other than current cigarette smoking. Even among that group, symptoms at second survey were half as likely again among those who reported having become smokers (p less than-001). There were also strong linear trends of increased likelihood of symptoms with increased numbers of cigarettes smoked. Symptom rates at second survey of those who had symptoms a year earlier, and who stopped smoking during the year, were not as low as for those who also stopped smoking, but who had not had initial symptoms, suggesting that symptoms associated with smoking were not completely reversible in the time interval of this study. The difference, however, was not significant.     

Factors associated with smoking and the reasons for stopping in Maori and Europeans: a comparative study

AIM: To compare the prevalence of smoking, factors associated with smoking, ex-smokers and reasons for stopping in Maori and Europeans aged 10 years and older. METHODS: Demographic and smoking data were obtained by personal interview using a standard questionnaire and assisted by Maori health carers. Report-back meetings were held. RESULTS: The smoking status in 713 subjects (Maori 52.5%, Europeans 47.5%) was: current smokers (Maori 48.1%, Europeans 19.8%); never smoked (Maori 28.1%, Europeans 47.5%); ex-smokers (Maori 23.8%, Europeans 32.7%). Of Maori smokers, 66.1% were women whereas of European smokers 47.8% were women. Significantly more Maori aged 10 to 29 years smoked than Europeans (p = 0.0002). Nineteen percent of smokers smoked < 5 cigarette equivalents per day, 68.8% smoked 5 to 20, and 12.2% smoked > 20 cigarettes per day. There was no gender difference in cigarette consumption. Maoridom (p = 0.00001), a less skilled occupation (p = 0.0008), lower income (< or = $15,000 p = 0.002) and alcohol consumption (p = 0.00001) were significantly associated with current smoking. Reasons for giving up smoking were health (majority), awareness of risks (Europeans), financial (Maori men), pregnancy (Maori women), social unacceptability (European women), on advice of medical practitioner (minority). CONCLUSIONS: Smoking remains a major problem in New Zealand, particularly in Maori. Stricter anti-tobacco measures than already exist, greater input from medical practitioners and particularly ongoing participation by Maori health carers should lead to a further decline in smoking.     

Smoking and lung function

In a cross-sectional survey of 3 separate communities, we studied the white residents 7 year of age and older in order to determine the relation between cigarette smoking and lung function. We identified 2,817 nonsmokers, 664 ex-smokers, and 1,209 smokers who were further classified as light smokers (1 to 20 cigarettes per day) and heavy smokers (greater than 20 cigarettes per day). Residual lung function (observed-predicted) was examined in these groups for forced expiratory volume in one second (rFEV1) and for maximal expiratory flow rates at 50% and 25% of the vital capacity (rVmax50% and rVmax 25%). Mean residuals by sex, age, and smoking category were compared and revealed an increasing progression of lung function loss with advancing age in males and females in all smoking categories. These age-related trends were due primarily to the amount smoked by persons in each group. The age of onset of these abnormalities was found to be as early as the age group 15 to 24 yr. Abnormalities were greater in smokers than ex-smokers, even when the amount smoked was taken into account. This is suggested improvement in lung function after cessation of smoking. Men and women were found to experience the same relative degree of gain. Also, the contribution of the various smoking habits to lung function loss was assessed using regression analyses and accounted for no more than 15% of the variation of the residual lung function. Combinations of variables were found to explain only slightly more variation than a single variable. The two most important variables were duration of smoking and pack-years. Inhalation and use of filters were not significant. Although the same amount of variation explained by the smoking variables after accounting for age, height, weight, and sex was small, this variation accounted for almost all of the decrease, over age, in residual lung function for smokers and ex-smokers.     

Reliability of the Agitated Behavior Scale

Polycyclic aromatic hydrocarbon-DNA adducts were evaluated in oral cells from 98 healthy volunteers by an immunohistochemical method using a specific antiserum against benzo(a)pyrene-DNA adducts revealed by the immunoperoxidase reaction. Mean adduct content, determined as relative staining intensity by absorbance image analyzer, was significantly higher in the cells from tobacco smokers compared with nonsmokers (330 +/- 98, n = 33 versus 286 +/- 83, n = 64, respectively) with a P = 0.013 obtained by two-sample t test with equal variances. We found that in the smoker group, the PAH-DNA adduct content increases with the number of cigarettes. Thus, the relative staining intensity was 305 +/- 105 in the group smoking 1-10 cigarettes/day (n = 16), 347 +/- 77 in the 11-20 group (n = 14), and 386 +/- 112 in the group smoking more than 20 cigarettes/day (n = 3; P = 0.03 by nonparametric test for trend). No significant association was detected between PAH-DNA adducts in oral cells and variables such as residential area, oral infections, alcohol or vitamin intake, grilled food consumption, and professional activity. This work confirms and extends previous data suggesting that this immunohistochemical method might be used as a valuable dosimeter of genotoxic damage in a carcinogen-exposed population, although further studies are needed to verify the applicability of the test in high-risk populations other than smokers.     

Clinicopathological significance of Fhit protein expression in stage I non-small cell lung carcinoma

Abnormalities in structure and expression of the FHIT gene have been detected in a considerable fraction of primary lung tumors. Previous reports indicated that FHIT gene alterations can be simply detected by immunohistochemical methods. Therefore, we investigated the association of Fhit expression with clinicopathological features and allelic imbalance (AI) at the FHIT locus in 105 stage I non-small cell lung cancers (NSCLC) by the immunohistological method and PCR analysis. Thirty-six of 105 (34%) tumors showed marked reduction of Fhit immunoreactivity. Fhit expression was markedly reduced in most squamous cell carcinomas (24 of 28, 86%), whereas such a reduction was detected only in a small subset of adenocarcinomas (7 of 67, 10%; P < 0.001). A marked reduction of Fhit protein expression was observed more frequently in patients with a smoking history (32 of 80, 40%) than in patients without a smoking history (4 of 25, 16%; P = 0.013). These results indicate that FHIT gene alterations preferentially occur in squamous cell carcinomas and in smokers. Furthermore, a reduction of Fhit protein expression in tumor cells was associated with a poorer survival of patients with stage I NSCLC, irrespective of histological subtypes of tumors (P = 0.005; log-rank test). Fhit expression was reduced preferentially in tumors with AI at the FHIT locus; however, AI at the FHIT locus did not correlate with patients' survival (P = 0.262; log-rank test). These results suggested that Fhit protein expression could be a useful molecular marker for the prognosis of patients with surgically resected stage I NSCLC.     

The influence of smoking on pancreatic function in man

A combination secretin-Lundh test was performed on 14 healthy established smokers to determine if smoking inhibited pancreatic secretion and therefore might contribute to the production of a duodenal ulcer. Seven of the patients studied smoked more than 20 cigarettes per day and were classified "heavy smokers". The remaining seven patients smoked less than 20 cigarettes per day and were classified "light to moderate smokers". The volume and bicarbonate output of the pancreas were lowered in both groups of patients after smoking one cigarette. This apparent side effect of nicotine may possibly play an important role in the production of duodenal ulcers in smokers by producing an acid milieu in the duodenum. Tryptic activity was unaffected by smoking.     

Smoking patterns and cancer of the oral cavity and pharynx: a case-control study in Uruguay

A case-control study of cancer of the oral cavity and pharynx was conducted in Uruguay, between 1992 and 1996. 425 patients microscopically diagnosed with squamous cell carcinoma of the oral cavity and pharynx were frequently matched on age, residence, and urban/rural status with 427 hospitalised controls. The study was restricted to males. Smokers of black tobacco cigarettes were associated with an increased risk of 12.1 (95% confidence interval (CI) 7.6-19.4), when compared with non-smokers after fitting a model which included the matching variables, birthplace, education, and total alcohol consumption. Lifelong smokers of hand-rolled cigarettes displayed an odds ratio (OR) of 8.7 (95% CI 5.6-13.4), compared with non-smokers. When smokers were excluded from the calculations, the OR for smokers of black tobacco cigarettes was 3.0 (95% CI 2.0-4.6), compared with smokers of blond tobacco cigarettes, after controlling for the same variables mentioned above, plus pack-years, years since stopping, and filter use. Hand-rolling appears to be less important than smoking black tobacco in this study (OR 1.6, 95% CI 0.9-2.5). Thus, smoking black tobacco cigarettes appears to be an important habit in oral and pharyngeal carcinogenesis.     

Mortality of iron miners in Lorraine (France): relations between lung function and respiratory symptoms and subsequent mortality

An increased mortality from lung and stomach cancer was found in previous studies on Lorraine iron miners. A detailed analysis, however, was not possible due to the lack of data for survivors. In this study the cohort included 1178 workers selected at random from all the 5300 working miners aged between 35 and 55 at the start of the follow up period, which ranged from 1975 to 1985. Occupational exposures and tobacco consumption, lung function tests, and respiratory symptoms were assessed for each subject in 1975, 1980, and 1985. This study confirmed the excess of lung cancer (standardised mortality ratio (SMR) = 389, p < 0.001) and of stomach cancer (SMR = 273, p < 0.05). There was no excess of lung cancer in non-smokers and moderate smokers (< 20 pack-years) or the miners who worked only at the surface or underground for less than 20 years. A significant excess (SMR = 349, p < 0.001) was found in moderate smokers when they worked underground for between 20 and 29 years. Heavy smokers (over 30 pack-years) or subjects who worked underground for more than 30 years experienced a high risk: SMR = 478 (p < 0.001) for moderate smokers who worked underground for over 30 years; 588 (p < 0.001) for heavy smokers who worked underground for between 20 and 29 years; and 877 (p < 0.001) for heavy smokers who worked underground for over 30 years. This showed an interaction between smoking and occupational exposure. The excess mortality from lung cancer was because there were some subjects who died young (from 45 years old). Comparison with the results of a previous study showed that additional hazards produced by diesel engines and explosives increased the mortality from lung cancer. The SMR was higher than 400 (p < 0.001) from 45 years old instead of from 56 years. A relation was found between a decrease in vital capacity (VC), forced expiratory volume in one second (FEV1) and of FEV1/VC and mortality from all causes and from lung cancer in heavy smokers or men who had worked underground for more than 20 years. Respiratory symptoms were related to mortality from lung cancer among smokers (moderate and heavy) who worked underground for more than 20 years. It is considered that the risk of lung cancer in the Lorraine iron miners was mainly due to dust, diesel engines, and explosives although the role of low exposure to radon daughters could not be totally excluded.     

Genetic analysis of inflammation, cytokine mRNA expression and disease course of relapsing experimental autoimmune encephalomyelitis in DA rats

Past history of major depression is more common in smokers than in non-smokers. We have shown in a previous study that lifetime prevalence of major depression is higher in dependent smokers and they have lower monoamine oxidase-A and -B activities than non-smokers. Because several studies have found an association between MAO-B activity and depression we analysed data of these smokers to assess whether past history of major depression is associated with reduced monoamine oxidase activities (A and B) or not. Further, we tried to characterize smokers with past history of major depression and its effect on withdrawal symptoms. The data of 88 dependent smokers (Fagerstr?m Tolerance Questionnaire score > or = 6 and smoking > or = 20 cigarettes/day) who participated in a smoking cessation study were analysed. Smokers with past history of major depression but without current illness did not differ in demographic and smoking characteristics from smokers without past history of major depression. Smokers with past history of major depression were mainly women and had lower body mass index. Adjusted for gender and body mass index dependent smokers with or without past history of depression had similar MAO-A and MAO-B activities but smokers with past history of major depression had significantly lower resting plasma norepinephrine levels. Smokers with past history of depression had not significantly higher ratings for depression (Montgomery-Asberg Depression Rating Scales) and anxiety (Hamilton Anxiety Scales) and smoking cessation did not exacerbate these ratings (assessed up to 3 months) and none had depressive episode during the postcessation period up to one year. Past history of depression was associated with higher scores on 'expressed sadness' and 'depressive mood'. Abstinent smokers with past history of depression had significantly higher ratings in one of the seven ratings of a 6 months period for craving (day 28), anxiety (day 7) and total withdrawal symptom score (day 7) when compared to those who had no past history of major depression. It is concluded that (i) past history of major depression is more frequent in female smokers; (ii) smokers with past history of depression may have more intense withdrawal symptoms (craving and anxiety) at some time after cessation: and (iii) past history of depression does not affect monoamine oxidase activities, therefore, reduced monoamine oxidase activities found in previous studies are possibly characteristic features of smoking.     

Sister chromatid exchange and micronucleus frequency in human lymphocytes of 1,650 subjects in an Italian population: II. Contribution of sex, age, and lifestyle

Sister chromatid exchange (SCE) and micronuclei (MN) analysis was carried out on 1,650 healthy individuals living in Pisa and in two nearby small cities, Cascina and Navacchio (Ca-Na). The effect of smoking on SCEs was linearly correlated with the number of cigarettes per day, and an increase of 7.3% SCEs was detectable for as few cigarettes as 1-10/day. Ex-smokers showed intermediate mean values of SCEs (8.09 +/- 1.88) in comparison with never smokers (7.54 +/- 1.61) and current smokers (8.45 +/- 1.94). Mean values of SCEs of ex-smokers decreased linearly with time of smoking cessation, reaching the mean values of never smokers within 8 years. The extent of SCE decrease was inversely proportional to the number of cigarettes previously smoked. No interaction between smoking habits and coffee or alcohol drinking on SCEs was observed. A borderline (P = 0.053) increase in mean SCE values in coffee drinkers (more than 3 cups/day) was found. The age effect on SCEs was remarkable in Ca-Na, but not in Pisa donors. Job type was not associated with significant modification of mean values of SCEs. Multiple logistic regression analysis revealed a statistically significant association between the proportion of high frequency cells (HCF) outliers and coffee consumption. Age and sex appeared to be by far the most important variables associated with modifications in MN frequency, which increased by 0.04 per thousand and 0.02 per thousand per year in males and females, respectively. Children and young donors (age < or = 40 years) showed lower MN frequency regardless of sex, whereas sex appeared to determine a significantly higher increase of MN only in females older than 40 years. In contrast, in males the MN rate by age tended to level off after the age of 30-50. MN frequencies of Pisa blue- and white-collar workers were statistically significantly higher than in students (+0.71 and +0.55 per thousand, respectively). Smoking did not determine any increase of MN frequency. A total lack of correlation (P = 0.913) between MN and SCEs was observed.