Study on influence of cigarette smoking on the mutagenicity of urine. I. Influence of cigarette smoking on the mutagenicity of urine in healthy smokers and bladder cancer patients

We studied the mutagenicity of urine of healthy smokers and smokers with bladder tumors by the Ames test. The 41 healthy smokers studied showed a significant increase in urinary mutagenic activity compared to the 24 passive smokers and the 22 non-smokers, but there was no significant difference between the passive smokers and non-smokers. In the 5 healthy subjects, the urinary mutagenic activity increased in accordance with the increase of tobacco consumption. In the 32 healthy subjects and 22 smokers with bladder tumors, the time-course changes of the mutagenicity of urine after smoking were investigated by testing the urine every 2 hours. In the healthy subjects, urinary mutagenic activity was increased up to 4 hours after cigarette smoking and decreased to the level noted before smoking after the 6th hour. By contrast, in the 22 smokers with bladder tumors, the urinary mutagenic activity remained high even after the 6th hour, and only decreased to the level seen before smoking after the 8th hour. The influence of smoking on the mutagenicity of urine tended to protract in smokers with bladder tumors in comparison to healthy smokers. There was no correlation between urinary mutagenic activity and tumor status and recurrence rate of the bladder tumors.     

Effect of cigarette smoking on experimental microvascular anastomoses

Cigarette smoking has been shown to cause cutaneous vasoconstriction, a decrease in digital blood flow, impaired wound healing, and it was implicated as a cause of failure of microvascular anastomoses in replanted digits. The subject of the following study was to assess the effect of cigarette smoking on experimental microvascular anastomoses. Twenty Sprague-Dawley male rats weighing 200 to 250 grams were divided into groups of ten. Both the experimental and the control groups were acclimatized to a Maddox/ORNL rat smoke inhalation exposure system for six days prior to operation. At this time they were anesthetized and bilateral femoral artery end to end anastomoses were performed by two surgeons, using standard microsurgical techniques. After a recovery period of 24 hours, both groups were started on a smoking/sham-smoking regime for 12 to 13 days. After this time they were anesthetized again, the femoral artery anastomoses were checked for patency in vivo and excised for histological evaluation. Five cm³ of blood was drawn from each animal to be analyzed for the presence of nicotine and its metabolites, and the rats were sacrificed. All the anastomoses in both groups were patent at the time of exploration and no histological difference could be demonstrated between the two groups. The radioimmunoassay of nicotine and cotinine showed large amounts in the smokers, and none in the nonsmokers.     

Histological changes in intervertebral discs after smoking and cessation: experimental study using a rat passive smoking model

Background Passive smoking has been reported to induce intervertebral disc degeneration in rats, and the objective of the present study was to histologically investigate changes in smoking-induced intervertebral disc degeneration after cessation of smoking. Methods Four-week-old rats were subjected to passive smoking for 8 weeks in a smoking box [20 cigarettes a day: one cigarette an hour (inhaled over 3 minutes and followed by ventilation with room air for 5 minutes)] to induce intervertebral disc degeneration. Smoke-free periods of different lengths were then established, and intervertebral discs were histologically analyzed. Results Immediately after 8 weeks of passive smoking, intervertebral discs exhibited cracks, tears, and misalignment of the annulus fibrosus, and increased fibrous tissue was seen in the nucleus pulposus. In addition, the level of interleukin-1β in intervertebral discs was higher in the smoking group than in the non-smoking group. After cessation, progression of degeneration ceased, and the matrix of the nucleus pulposus and annulus fibrosus exhibited increased fibrous connective tissue and proteoglycan. However, there were no changes in annulus fibrosus misalignment. Interleukin-1β levels also remained significantly elevated after 8 weeks of cessation. Conclusions While the annulus fibrosus degeneration caused by smoking was partially irreversible after cessation of smoking, the amount of mucin (proteoglycan) in the nucleus pulposus and annulus fibrosus tended to increase after cessation, thus suggesting the possibility that smoking-induced intervertebral disc degeneration can be repaired to some degree by cessation of smoking.     

The effects of cigarette smoking on anesthesia.

Cigarette smoke contains over 4000 substances, some of which are harmful to the smoker. Some constituents cause cardiovascular problems, increasing the blood pressure, heart rate, and the systemic vascular resistance. Some cause respiratory problems, interfering with oxygen uptake, transport, and delivery. Further, some interfere with respiratory function both during and after anesthesia. Some also interfere with drug metabolism. Various effects on muscle relaxants have been reported. Risk of aspiration is similar to that of nonsmokers, but the incidence of postoperative nausea and vomiting appears to be less in smokers than in nonsmokers. Even passive smoking effects anesthesia. Best is to stop smoking for at least 8 weeks prior to surgery or, if not, at least for 24 hours before surgery. Anxiolytic premedication with smooth, deep anesthesia should prevent most problems. Monitoring may be difficult due to incorrect readings on pulse oximeters and higher arterial to end tidal carbon dioxide differences. In the recovery period, smokers will need oxygen therapy and more analgesics. It is time that anesthesiologists played a stronger role in advising smokers to stop smoking.     

Effects of cigarette smoking on early medial collateral ligament healing in a mouse model.

Cigarette smoking delays the healing process and increases morbidity associated with many common musculoskeletal disorders such as medial collateral ligament (MCL) injury. In the current study, a murine model of MCL healing was used to test the hypothesis that smoking impairs extracellular matrix synthesis after injury. Mice were divided into two groups, a nonsmoking control group and a group exposed to smoke for 2 months prior to surgical MCL injury. Mice were euthanized at 3 and 7 days after surgery. Subsequently, propidium iodine staining was used to quantify cellular density of injured and sham ligaments. Immunohistochemical staining and in situ hybridization to mRNA were used to detect proliferation, apoptosis, and type I collagen gene expression at the site of injury. Cell density increased significantly from baseline to 7 days after injury in control mice. In mice exposed to cigarette smoke, there was a significantly lower cellular density compared to controls at this time point (p=0.01). There was no difference in proliferation between groups at the site of injury, and the low level of proliferation observed was not sufficient to account for the large increase in cell density by day 7. No evidence of apoptosis was observed in any of the groups at the site of injury. Type I collagen gene expression was higher in controls compared to smokers at day 7. Almost all of the cells in the substance of the injured MCL at day 7 were spindle-shaped and expressed type I collagen, suggesting that increased cell density from day 3 to day 7 represented an increase in ligament cells rather than an increased inflammatory response. We conclude that the decreased cellular density and type I collagen expression in the injured ligament of mice exposed to smoke begin to provide a cellular and molecular basis for delayed or deficient early healing in these animals.     

Acute effects of cigarette smoking on microcirculation of the thumb.

The acute effect of smoking on the microcirculation of the skin of the thumb was investigated in healthy volunteers. Twenty-two were smokers and 10 were non-smokers. The flow was assessed by means of laser Doppler flowmetry. The smokers inhaled 2 cigarettes. During smoking of their first and second cigarette respectively, a mean decrease in laser Doppler flow of 23.8% and 29.0% was seen (p = 0.03; p = 0.01). Ten minutes after smoking this decrease was recovered by half. This experiment confirms that one should prohibit smoking of cigarettes pre- and postoperatively for optimal wound healing conditions.     

Effects of passive smoking on the pulmonary function of adults.

The effects of exposure to environmental tobacco smoke (passive smoking) on pulmonary function of non-smoking, healthy Iranian men (n = 167) and women (n = 108) were investigated. There were significant reductions in % predicted FEV1 (5.7%), forced vital capacity (FVC, 4.6%) and forced expiratory flow 25-75% (FEF25-75, 9.9%) among men exposed to cigarette smoke (n = 78). The adverse effect of passive smoking was greatest among men exposed at the workplace (reduction in % predicted FEV1 9.4%, FVC 7.6%, and FEF25-75 15.3%). No significant difference in pulmonary function was found among the 54 women exposed to passive smoke, but only eight women had smoke exposure at work. It is concluded that exposure to environmental tobacco smoke, particularly at the workplace, adversely affects the pulmonary function of adults.     

Impact of cigarette smoking on papaverine-induced erection

Owing to the vasoconstrictive effect of nicotine, smoking may potentially interfere in the results of the drug-induced erection test for papaverine hydrochloride. To investigate the effect of smoking on this test, 12 patients between 22 and 65 years old underwent the following protocol: phase 1--intracavernous injection of 100 mg. papaverine hydrochloride with measurement of intracavernous pressure by puncture with a 19 caliber butterfly needle attached to an aneroid manometer and phase 2--1 week after the initial test the procedure was repeated after the patient smoked 2 cigarettes. In phase 1 all men obtained a full erection, compared to only 4 in phase 2. The average intracavernous pressures were 85.83 and 53.50 mm. Hg, respectively, in phases 1 and 2 (p less than 0.01). We conclude that cigarette smoking, probably through nicotine, interferes with the drug-induced erection test, which might explain some false negative results.     

The effect of cigarette smoking and smoking cessation on spinal fusion

STUDY DESIGN: The effect of cigarette smoking and smoking cessation on spinal fusion was studied in a retrospective review of 357 patients who had undergone instrumented spinal fusion. OBJECTIVE: To document the widely assumed but unreported benefit of cigarette smoking cessation on fusion rate and clinical outcome after spinal fusion surgery. BACKGROUND DATA: Cigarette smoking has been shown to inhibit lumbar spinal fusion and to adversely effect outcome in treatment of lumbar spinal disorders. Prior reports have compared smokers and nonsmokers, as opposed to comparing smokers and quitters. METHODS: This study retrospectively identified 357 patients who underwent a posterior instrumented fusion at either L4-L5 or L4-S1 between 1992 and 1996. Analysis of the medical record and follow-up telephone surveys were conducted. Clinical outcome and fusion status was analyzed in relation to preoperative and postoperative smoking parameters. RESULTS: In this study, the nonunion rate was 14.2% for nonsmokers and 26.5% for patients who continued to smoke after surgery (P < 0.05). Patients who quit smoking after surgery for longer than 6 months had a nonunion rate of 17.1%. The nonunion rate was not significantly affected by either the quantity that a patient smoked before surgery or the duration of preoperative smoking abatement. Return-to-work was achieved in 71% of nonsmokers, 53% of nonquitters, and 75% of patients who quit smoking for more than 6 months after surgery. DISCUSSION: These results validate the hypothetical assumption that postoperative smoking cessation helps to reverse the impact of cigarette smoking on outcome after spinal fusion.     

Effect of cigarette smoking on the specific antibody response in pigeon fanciers.

Titres of circulating IgG antibodies to pigeon gammaglobulin and end expired carbon monoxide concentrations were measured in 86 pigeon fanciers attending the "Show of the Year." Antibody levels were significantly higher in non-smokers and in those with end expired carbon monoxide concentrations below 10 parts per million.     

The effects of cigarette smoking on voice-fundamental frequency

Previous group research has shown that the mean voice-fundamental frequency (F0) for individuals who smoke is lower than that of age- and sex-matched nonsmokers. It is believed that this reduction in F0 is a result of edema of the vocal folds caused by tobacco smoke. This study investigated F0 changes during smoking and no-smoking periods. Data were collected before, during, and after a 40-hour period of no-smoking. Analysis of the voice recordings showed a rise in voice F0 for the two smoking subjects during the 40-hour no-smoking period. Age- and sex-matched control subjects did not show a rise in their F0 during the same tasks. Results suggest that the pitch-lowering effects of cigarette smoking may be reversed after as few as 40 hours of smoking cessation.     

The effect of cigarette smoking on wound healing

To see if there was any difference in the skin healing of smokers as opposed to non-smokers we studied 120 women admitted consecutively for laparotomy sterilisation. The method of skin suture was standardised. We compared width, length, and colour of the scars, and assessed the overall cosmetic result using a scoring system in 69 smokers and 51 non-smokers. When the incision was in the midline the scars in the smokers measured 7.4 mm averagely as compared with 2.7 mm in non-smokers (p less than 0.02). There was a corresponding tendency in transverse incisions. When the colour was compared, 26% of smokers had light coloured scars compared with 12% of non-smokers (p less than 0.05). There were no differences between the groups when dark coloured scars were assessed. Overall, using the scoring system, smokers had significantly worse cosmetic results than non-smokers.     

The effect of cigarette smoking on hindfoot fusions

In a group of 160 patients who had hindfoot fusions (isolated subtalar, talonavicular, and calcaneocuboid fusions and double and triple arthrodeses), smokers had a significantly higher rate of nonunion than did nonsmokers (18.6% vs. 7.1%). The relative risk of developing a nonunion was 2.7 times higher for smokers than non-smokers. With the numbers available, there was a trend for patients who had quit smoking prior to surgery to have a higher rate of nonunion (11.1%) than patients who had never smoked, but not as high as those who continued to smoke. There was no statistical difference in the rate of infection or delayed wound healing among the groups.     

The effect of cigarette smoking on penile erection

Clinical observations suggest that cigarette smoking impairs erectile function in patients with moderate arterial insufficiency. To evaluate the effects of smoking on the physiology of erection, we studied six healthy adult mongrel dogs in which bipolar cuff electrodes were implanted around the cavernous nerves. After threshold stimulation parameters for penile erection were established, cigarette smoke collected in a 60-ml. syringe was released slowly near the dog's mouth, to be inhaled by natural breathing. Stimulation of the cavernous nerve was repeated and blood samples for nicotine, cotinine and blood gases were obtained before and after each cigarette. The systolic and intracorporeal pressure, flow through the internal pudendal artery, and venous flow from the corpora cavernosa were recorded at baseline and with each electrostimulation after smoke inhalation. Five of the six dogs were unable to achieve full erection after inhalation of smoke from two to three cigarettes. Some decrease of flow through the internal pudendal artery occurred and the venous restriction ability was almost completely abolished by smoking. Further, when nicotine was injected intravenously into two additional dogs, the same phenomenon was observed. These findings support the idea that cigarette smoking may contribute to impotence in some patients.     

The acute effect of cigarette smoking on the microcirculation of a replanted digit.

Thirty-one patients who had undergone digital replantation or revascularization volunteered to participate in a study of the acute effect of smoking on the microcirculation of the skin of replanted fingers. Fourteen were smokers and 17 were nonsmokers at the time of the study. Blood flow was assessed by means of the laser Doppler flowmeter under standard conditions. Each smoker inhaled 2 cigarettes. During smoking of the first and second cigarettes a mean decrease in laser Doppler flow of 8% and 19%, respectively, was found, whereas the nonsmokers showed a slight increase of 4% and 4%, respectively. Ten minutes after the last cigarette almost no recovery could be detected. The negative effect of smoking on the microcirculation in replanted digits proved to be more pronounced in the patients operated on more recently. This experiment confirms that smoking after replantation surgery should be prohibited to guarantee optimal circulation.     

Health effects of passive smoking. 9. Parental smoking and spirometric indices in children

BACKGROUND: A systematic quantitative review was conducted of the evidence relating parental smoking to spirometric indices in children. METHODS: An electronic search of the Embase and Medline databases was completed in April 1997 and identified 692 articles from which we included four studies in neonates, 42 cross-sectional studies in school aged children (22 were included in a meta-analysis), and six longitudinal studies of lung function development. RESULTS: In a pooled analyses of 21 surveys of school aged children the percentage reduction in forced expiratory volume in one second (FEV1) in children exposed to parental smoking compared with those not exposed was 1.4% (95% CI 1.0 to 1.9). Effects were greater on mid expiratory flow rates (5.0% reduction, 95% CI 3.3 to 6.6) and end expiratory flow rates (4.3% reduction, 95% CI 3.1 to 5.5). Adjustment for potential confounding variables had little effect on the estimates. A number of studies reported clear evidence of exposure response. Where exposure was explicitly identified it was usually maternal smoking. Two studies in neonates have reported effects of prenatal exposure to maternal smoking. Of five cross sectional studies that compared effects of perinatal exposure (retrospectively assessed) with current exposure to maternal smoking in later childhood, the three largest concluded that the major effect was in utero or neonatal exposure. Longitudinal studies suggest a small effect of current exposure on growth in lung function, but with some heterogeneity between studies. CONCLUSIONS: Maternal smoking is associated with small but statistically significant deficits in FEV1 and other spirometric indices in school aged children. This is almost certainly a causal relationship. Much of the effect may be due to maternal smoking during pregnancy.     

Influence of cigarette smoking on the risk of acid pulmonary aspiration

Twenty-five non-smokers and 35 smokers who had abstained overnight from cigarette smoking and were undergoing minor elective orthopaedic surgery were studied in order to compare gastric volume and pH. There was no significant difference in aspirated volume and pH both just after intubation and prior to extubation between the two groups, thus indicating that habitual smokers undergoing elective surgery in general anaesthesia do not have increased risk of acid pulmonary aspiration compared with non-smokers.