Predictors of longitudinal changes in pulmonary function among swine confinement workers

OBJECTIVE

To determine predictors of longitudinal changes in pulmonary function in swine confinement workers.

DESIGN

Longitudinal study conducted from November 1989 to June 1991 and January 1994 to May 1995.

SETTING

Swine confinement workers in Saskatchewan.

PARTICIPANTS

Forty-two swine confinement workers who were studied in 1989/90 and studied again in 1994/95.

RESULTS

Of 98 male swine confinement workers (mean age SD 36.3 11.1 years) studied at baseline, 42 were studied again five years following. Complete information on baseline across-shift pulmonary function (preshift forced expiratory volume in 1 s [FEV1], forced vital capacity [FVC], and every 2 h FEV1 and FVC during the shift), and five-year follow-up pulmonary function (with FEV1 and FVC) were available on all 42 subjects. Mean across-shift changes (preshift measurement to last measurement of the day) at baseline were -159. 8 61.7 mL in FEV1 and -35.3 65.6 mL in FVC. Mean annual rate change between baseline and follow-up for FEV1 was -53.9 61.7 mL/year and for FVC -48.9 71.6 mL/year. After adjusting for age, height, smoking and hours spent in the barn, the baseline across-shift change in FEV1 and FVC was a significant predictor of annual rate change in FEV1 (P=0.01) and FVC (P=0.02), respectively. To determine the effects of indoor air quality on longitudinal lung function decline, indoor air environmental measurements were analysed. Complete information on respiratory health and indoor air quality was available on 34 of the 42 subjects. Assessment of indoor environment of swine barns included a summer and winter measurement for airborne dust, gases and endotoxin levels. After adjusting for age, height, smoking, ammonia and hours spent in the barn, the endotoxin level (Eu/mg)was a significant predictor of annual rate change for FEV1 but not FVC.

CONCLUSIONS

These results suggest that shift change is an important predictor of longitudinal changes in lung function in swine confinement workers and that endotoxin exposures may mediate annual decline in FEV1 in these workers.

[Effect of smoking on the long-term course of ulcerative colitis]

OBJECTIVE

To evaluate the effects of smoking on the long term clinical course in patients with ulcerative colitis.

METHODS

The medical charts of 556 patients with ulcerative colitis were reviewed retrospectively. Patients were classified as smokers (n = 85) or nonsmokers (n = 471) according to their smoking status during the course of the disease. Extent of colonic lesions, complications, medical requirements, and actuarial rate of colectomy were compared in smokers and nonsmokers.

RESULTS

Mean follow-up (+/- SD) was longer in smokers than in nonsmokers (116 +/- 107 mo, vs 87 +/- 94 mo.). Less smokers than nonsmokers required oral steroids (52 vs 63%, P = 0.05). No difference between the groups was observed regarding the use of salicylates, the need for intravenous steroids, for immunosuppressive drugs, for colectomy, and the occurrence of complications. The actuarial rate of colectomy was less in smokers than in nonsmokers (32 +/- 12% and 42 +/- 6% at 10 years respectively. P = 0.04). Initial and cumulative extent of the disease process did not differ between the groups. However, in the subgroup of patients with limited disease at onset, development of pancolitis was less frequent in smokers than in nonsmokers (14 and 26%, respectively, P = 0.04).

CONCLUSION

The lesser need for oral steroids and the lower actuarial rate of colectomy in smokers suggest that ulcerative colitis in smokers is characterized by a less severe clinical presentation and a better long term prognosis than in nonsmokers.

Evaluation of nasal patency: comparison of patient and clinician assessments with rhinomanometry

The correlation between the objective measurement of nasal resistance and nasal airflow sensation is usually regarded as poor. The aim of the study was to assess the relation between objective indices of nasal patency, as assessed by the occlusion method (RN) and the Youlten peak nasal inspiratory flow meter (PNIF), with subjective sensations of nasal blockade by either the patient or the clinician in groups of patients with rhinitis, asthma, rhinitis and asthma, nasal septal deformity and ill normal controls. We studied nasal airway patency in 254 subjects (37 women, 217 men), mean age 21 years (range 14-78) by RN and PNIF. Nasal resistance was also measured by the application of Ohm's law for parallel resistors (NRO) by estimating the unilateral resistance separately. Subjective sensation of nasal blockade was assessed either by the patient on a 10-point Borg scale (SUB), or the clinician (CLN) on a 6-point scale (3 for each side of the nose). The latter was done in a controlled fashion with the aid of reference sensations. Adjusting for age, height, smoking status and airway calibre, we found good correlation between RN and CLN (r=0.57, p=10(-4)), whereas the association between RN and SUB was moderate and of borderline significance (r=0.42. p=0.05). By logistic regression analysis, we found that the only independent predictors of abnormal nasal resistance at a cut-off value of 0.30 kPa/l/s were the nasal scores as assessed by the clinician (r-=0.26, odds=2.45). We conclude that PNIF measurement and SUB scores are of limited use as indices of nasal patency, although the latter showed an improved association in comparison to older studies. As there is a necessity for some sort of objective measurement to assess nasal patency, the described clinician evaluation may be clinically useful in place of PNIF, but due to its somewhat subjective nature and its inability to detect milder levels of nasal obstruction it cannot be recommended as an alternative to rhinomanometry.

Effect of environmental and clinical factors on lung function and respiratory symptoms in adolescents with alpha1-antitrypsin deficiency

Individuals identified in the Swedish neonatal alpha1-antitrypsin (AAT) screening study were followed prospectively from their first to their eighteenth year of life. The aim of this study was to analyse the effect of environmental factors, i.e. active and passive smoking, and of clinical factors on lung function and the occurrence of respiratory symptoms in AAT-deficient adolescents. The study group consisted of 88 protease inhibitor (Pi)ZZ and 40 PiSZ adolescents. Medical history including respiratory symptoms, and active and passive smoking were recorded at each follow-up up to the age of 18 y. Lung function tests were performed at the present check-up. At the age of 18 y, both forced expiratory volume in one second (FEV ) and FEV1/vital capacity (VC) were significantly lower in the smoking than in the non-smoking subgroup, and significantly more smokers than non-smokers reported the presence of phlegm. The mean FEV1/VC ratio was lower for those presently exposed to parental smoking. Multiple linear regression analysis indicated that clinical liver disease in early life, active smoking and parental smoking were independent determinants of FEV1/VC. The results suggest that marginal deviations in lung function and the symptom of phlegm among AAT-deficient adolescents occur characteristically early in the subgroup of smokers. Parental smoking may contribute to decreased lung function.

The effects of nicotine on spatial and non-spatial expectancies in a covert orienting task

The present study examined how nicotine influences shifts of visuo spatial attention in casual smokers at each of three delays after smoking one cigarette: immediately, 1 h and 24 h. Informative peripheral cues were used to exogenously orient attention to the location where an increase or decrease in the size of a peripheral object was most likely to occur. One size change was more likely to occur than the other and the task was choice (expansion/contraction) reaction time. The performance decrement obtained when the target appeared at an uncued location was smallest in sessions run immediately after smoking (when nicotine levels were highest), suggesting that nicotine may increase the ease with which attention can be disengaged from a cued location. This finding confirms previous research which suggests a specific role for the basal forebrain cholinergic system in visual orienting. In contrast, nicotine was not found to affect non-spatial expectancies based on stimulus-response (expansion/contraction) probability. These findings, together with recent converging evidence, strongly support the proposition that different attentional operations are mediated by different neural subsystems.

Cough during emergence from isoflurane anesthesia

We evaluated the effects of smoking history and albuterol treatment on the amplitude and frequency of cough during emergence from anesthesia. Before induction of anesthesia, 68 patients were randomized to receive two puffs of a placebo or two puffs of albuterol via a metered dose inhaler. Anesthesia was then induced with thiopental, fentanyl, and succinylcholine. The patients' tracheas were intubated with an 8.0 mm-endotracheal tube, and isoflurane administration was initiated. At the end of surgery, isoflurane was discontinued, and the pressure in the endotracheal tube cuff was monitored via the pilot balloon while the end-tidal isoflurane concentration was recorded. Of the 68 patients, 52 coughed before responding to command, but the incidence did not differ between smokers and nonsmokers (33 of 43 vs 19 of 25), nor did it differ between albuterol-treated and untreated patients. There was no difference in the frequency or amplitude of coughs between smokers and nonsmokers, nor did albuterol affect either variable. The mean end-tidal concentration at which cough first occurred was 0.30%+/-0.02%, and only 5% of patients coughed at values >0.6%. We conclude that 1) cough is frequent during emergence; 2) smoking does not affect emergence cough; 3) albuterol treatment does not affect emergence cough; and 4) patients are unlikely to cough at end-tidal values of isoflurane >0.6%.

IMPLICATIONS

Most patients cough as they awaken from general anesthesia given via an endotracheal tube. In our study population, cough was frequent but generally did not occur until the end-tidal concentration of isoflurane was <0.6%. Smokers were no more likely to cough than nonsmokers, and the beta-adrenergic agonist albuterol did not prevent cough.

The effect of the prone position on pulmonary mechanics is frame-dependent

By compressing the abdomen and restricting chest wall movement, the prone position compromises pulmonary compliance. For spine surgery, placing the anesthetized patient into the prone position increases the risk of improper ventilation. In this study, we tested the hypothesis that the compromise in pulmonary compliance is related to the patient's body habitus and the surgical frame used to support the patient while in the prone position. Seventy-seven adult patients were divided into three groups according to body mass index: normal (n = 36) < or = 27 kg/m2, heavy (n = 21) 28-31 kg/m2, and obese (n = 20) > or = 32 kg/m2. Patients were placed in the prone position supported by chest rolls, a Wilson frame, or the Jackson spinal surgery table (Jackson table) according to the surgeon's preferences. Peak airway pressure (at the proximal endotracheal tube), pleural pressure (esophageal balloon), and mean arterial pressure were recorded in the supine position and prone position within 15 min of the turn. Dynamic mean (+/- SD) pulmonary compliance (mL/cm H2O) decreased when turning from the supine to the prone position in all three body mass groups when using chest rolls (normal 37+/-5 to 29+/-6; heavy 43+/-2 to 34+/-4; obese 42+/-8 to 32+/-6) or the Wilson frame (normal 39+/-6 to 32+/-7; heavy 43+/-16 to 34+/-10; obese 36+/-11 to 28+/-9). The dynamic pulmonary compliance was not altered in patients positioned on the Jackson table. Regardless of body habitus, using the Jackson table for prone positioning was not associated with a significant alteration in pulmonary or hemodynamic variables. We conclude that moving patients from the supine to the prone position during anesthesia results in a decrease in pulmonary compliance that is frame-dependent but that is not affected by body habitus.

IMPLICATIONS

We hypothesized that compromise in pulmonary compliance in the prone position is related to the patient's body mass index and the surgical frame used. In this study, we demonstrated that prone positioning during anesthesia results in a decrease in pulmonary compliance that is frame-dependent but that is not affected by body mass index.

Effect of cigarette smoking on muscle strength of flexibility of athletes

Kraus-Webber test which indicates muscle strength and flexibility of certain group of muscles showed significant decrease in cigarette smoking athletes in the age group of 19-30 years compared to nonsmoking athletes. The results indicate tobacco smoke inhalation affects muscle flexibility and strength required for athletes.

A 15-year follow-up study of ventilatory function in adults with asthma

BACKGROUND

Although the prevalence of asthma and morbidity related to asthma are increasing, little is known about the natural history of lung function in adults with this disease.

METHODS

We used data from a longitudinal epidemiologic study of the general population in a Danish city, the Copenhagen City Heart Study, to analyze changes over time in the forced expiratory volume in one second (FEV1) in adults with self-reported asthma and adults without asthma. The study was conducted between 1976 and 1994; for each patient, three measurements of lung function were obtained over a 15-year period. The final data set consisted of measurements from 17,506 subjects (8136 men and 9370 women), of whom 1095 had asthma.

RESULTS

Among subjects who participated in all three evaluations, the unadjusted decline in FEV1 among subjects with asthma was 38 ml per year, as compared with 22 ml per year in those without asthma. The decline in FEV1 normalized for height (FEV1 divided by the square of the height in meters) was greater among the subjects with asthma than among those without the disease (P<0.001). Among both men and women, and among both smokers and nonsmokers, subjects with asthma had greater declines in FEV1 over time than those without asthma (P<0.001). At the age of 60 years, a 175-cm-tall nonsmoking man without asthma had an average FEV1 of 3.05 liters, as compared with 1.99 liters for a man of similar age and height who smoked and had asthma.

CONCLUSIONS

In a sample of the general population, people who identified themselves as having asthma had substantially greater declines in FEV1 over time than those who did not.

Effect of smoking cessation on exercise performance in female smokers participating in exercise training

We evaluated in a randomized prospective trial the possible effect of smoking cessation on exercise performance in middle-aged female smokers who underwent vigorous exercise training as an adjunct to a cognitive-behavioral smoking cessation treatment program. A total of 109 subjects met the criteria for this substudy; of these, 51 were in the contact control (nonexercising) group and 58 were in the exercise training group. Both groups had a graded maximal exercise stress test performed on a bicycle ergometer before and after 12 weeks of treatment. All subjects participated in a 12-session, group-based, cognitive-behavioral treatment program for nicotine dependence. Subjects in the contact condition participated in 3 supervised health education lectures per week but did not engage in regular exercise. Subjects in the exercise group trained 3 times a week, averaging 83% of maximum heart rate achieved on their baseline exercise test. On the 12-week exercise stress test, the exercise group did significantly better than control in all aspects of exercise performance. Those who quit showed a further increase in their exercise test duration (p <0.001) and had a greater increase in calculated peak oxygen consumption expressed as fat-free weight (p = 0.031). In conclusion, women who undergo a vigorous exercise training program and quit smoking demonstrate improved exercise performance over those who continue to smoke.

Severity of airflow limitation is associated with severity of airway inflammation in smokers

To investigate the relationship between airflow limitation and airway inflammation in smokers, we examined paraffin-embedded bronchial biopsies obtained from 30 smokers: 10 with severe airflow limitation, eight with mild/moderate airflow limitation, and 12 control smokers with normal lung function. Histochemical and immunohistochemical methods were performed to assess the number of inflammatory cells in the subepithelium and the expression of CC chemokines macrophage inflammatory protein (MIP)-1alpha and -1beta in the bronchial mucosa. Compared with control smokers, smokers with severe airflow limitation had an increased number of neutrophils (p < 0.02), macrophages (p < 0.03), and NK lymphocytes (p < 0.03) in the subepithelium, and an increased number of MIP-1alpha+ epithelial cells (p < 0.02). When all smokers were considered together, the value of FEV1 was inversely correlated with the number of neutrophils (r = -0.59, p < 0.002), macrophages (r = -047, p < 0. 012), NK-lymphocytes (r = -0.51, p < 0.006) in the subepithelium, and with the number of MIP-1alpha+ epithelial cells (r = -0.61, p < 0.003). We conclude that in smokers the severity of airflow limitation is correlated with the severity of airway inflammation and that severe airflow limitation is associated with an increased number of neutrophils, macrophages, NK lymphocytes, and MIP-1alpha+ cells in the bronchial mucosa.

Effect of chronic and acute cigarette smoking on the pharyngo-upper oesophageal sphincter contractile reflex and reflexive pharyngeal swallow

BACKGROUND

Cigarette smoking is known to affect adversely the defence mechanisms against gastro-oesophageal reflux. The effect of smoking on the supraoesophageal reflexes that prevent aspiration of gastric contents has not been previously studied.

AIMS

To elucidate the effect of cigarette smoking on two of the supraoesophageal reflexes: the pharyngo-upper oesophageal sphincter (UOS) contractile reflex; and the reflexive pharyngeal swallow.

METHODS

Ten chronic smokers and 10 non-smokers were studied, before and 10 minutes after real or simulated smoking, respectively. UOS pressure and threshold volume for the reflexes were determined using a UOS sleeve assembly. Two modes of fluid delivery into the pharynx were tested: rapid injection and slow injection.

RESULTS

For both rapid and slow injections, the threshold volume for triggering the pharyngo-UOS contractile reflex was significantly higher in smokers than in non-smokers (rapid: smokers 0.42 (SE 0.07) ml, non-smokers 0.16 (0. 04) ml; slow: smokers 0.86 (0.06) ml, non-smokers 0.38 (0.1) ml; p<0. 05). During rapid injection, the threshold volume for reflexive pharyngeal swallow was higher in smokers (smokers 0.94 (0.09) ml, non-smokers 0.46 (0.05) ml; p<0.05). Acute smoking further increased the threshold volume for the pharyngo-UOS contractile reflex and reflexive pharyngeal swallow during rapid injection.

CONCLUSIONS

Smoking adversely affects stimulation of the pharyngo-UOS contractile reflex and pharyngeal reflexive swallow. These findings may have implications in the development of reflux related respiratory complications among smokers.

Peak expiratory flow rate in flour mill workers

The current cross-sectional study with a comparison group was undertaken to investigate peak expiratory flow rate (PEFR) in flour mill workers and to study relationship between reduction in PEFR and age, smoking, exposure to grain dust and respiratory morbidity. The study included 286 flour mill workers and equal number of neighbourhood controls group-matched for age. PEFR was measured by using Wright's Peak Flow Meter. PEFR was significantly reduced in flour mill workers as compared to comparison group. The decline in PEFR was significantly associated with grain dust exposure, duration of exposure, tobacco smoking and presence of respiratory morbidity.

Usefulness of a national registry of alpha-1-antitrypsin deficiency. The Spanish experience

Severe alpha-1-antitrypsin (AAT) deficiency, phenotype Pi ZZ, is a rare condition with an estimated prevalence of 1/4500 individuals in Spain. Given this low prevalence, it seems useful to accumulate all the information derived from the care of these patients. In this context, the Spanish Registry of patients with AAT deficiency was founded in 1993; its main objectives were to establish guidelines adapted to our country for the treatment and management of AAT-deficient patients, offer expert support to physicians all over the country treating these patients, and provide technical support on the determination of Pi phenotyping and genotyping of individuals suspected of being AAT-deficient. From 1993 to January 1998 the number of enrollees increased from 48 to 223, of which 216 were Pi ZZ. Seventy-three per cent were male and only 31.5% were never smokers, mean age was 46 years (SD = 13 years) and mean FEV1 53% predicted (SD = 31%). 83% were index cases who, compared with non-index cases, were older (49 +/- 11 vs. 35 +/- 13 years, P < 0.001), more likely to have a smoking history (85% vs. 47%, P < 0.01) and displayed more severe impairment in pulmonary function (FEV1% = 40% +/- 19% vs. 96% +/- 23%, P < 0.001). Augmentation therapy was administered to 129 patients (58%). Treated patients had more severe impairment in pulmonary function than the untreated (FEV1% = 40% +/- 21% vs. 72% +/- 32%, P < 0.001) and were more likely to be index cases (81% vs. 43%, P < 0.001). Characteristics of the patients included are similar to those described for other Registries. The Registry has extended knowledge of the disease throughout the country and has established local guidelines for treatment and follow-up. It may be a valid database for future co-operation in international initiatives.

Peripheral vascular reactions to smoking--profound vasoconstriction by atherosclerosis

Analyses of direct effects of smoking on peripheral arteries were done using thermography, blood fluorometry and echography on 97 habitual smoker-diabetics without triopathy. There were found to be four types of thermographic changes following smoking, which varied according to the degree of atherosclerosis of the artery. The smoking-stimulated thermographic pattern in the control group of healthy volunteers was a small wavy pattern, fluctuating along the base line every few minutes within a temperature range of 1.0-1.5 degrees C (N type). In diabetics, four types of thermographic patterns were produced: normal (N) type as control, increasing (I) type (increasing in skin temperature), decreasing (D) type (decreasing in temperature), and F type (no changes in temperature). The most significant finding was the decreasing pattern which closely connected to clinical and echographic aspects of macroangiopathic changes. The increasing type was characterized by a paradoxical increase in temperature after smoking in order diabetics with good blood glucose control and who were less atherosclerotic. Blood flow was correlated to the skin temperature at the base state and changes after smoking. Moreover, blood flow changes measured by fluorometry suggest that vasoconstriction or vasodilatation following smoking took place. These results suggest that this smoking test might be a good tool for diagnosing for the degree of atherosclerosis and for its following up.

Tobacco smoke induces both apoptosis and necrosis in mammalian cells: differential effects of HSP70

Tobacco smoke (TS) has been implicated as a major risk factor in human pulmonary diseases including cancer. In this study, we used TS as a model of oxidative stress. TS-mediated oxidative stress has been shown to induce protein oxidation, DNA damage, and cell death. Here we investigated, in human and rodent cell lines, whether TS induces cell death by apoptosis or by necrosis. As described for classic oxidants, TS induced apoptosis at low concentrations and necrosis at higher concentrations. We have previously described the induction of heat shock (HS) protein (HSP) (in particular, HSP70) in human monocytes exposed to TS. HSP70 is implicated in the regulation of cell injury and cell death and, in particular, modulates apoptosis, as does the antiapoptotic oncoprotein Bcl-2. At both apoptotic and necrotic concentrations, TS induced a dose-dependent HSP70 expression, whereas Bcl-2 was induced only at necrotic concentrations. TS- or HS-induced HSP had no protective effects either on apoptosis or on necrosis, but HSP70 overexpression prevented TS-induced necrosis and consequently led to increased apoptosis. These results might reconcile the apparently contradictory data previously reported on the effects of HSP on apoptosis.

Prospective study on the effect of smoking and nicotine substitution on leucocyte blood counts and relation between blood leucocytes and lung function

BACKGROUND

The influence of smoking and of nicotine substitution on the counts of total blood leucocytes and leucocyte subsets and the relations between the counts and lung function was investigated.

METHODS

The study was a combined cross sectional and prospective study of 298 smokers and 136 non-smokers. Forced expiratory volume in one second (FEV1) was measured in all participants at baseline and six months after quitting smoking in 160 ex-smokers (quitters) and 138 persons with smoking relapse. Blood samples were obtained from all participants at baseline and from 160 quitters and 30 continuing smokers two, six, 12, and 26 weeks after smoking cessation and from 92 quitters one year after the cessation of smoking.

RESULTS

Blood leucocyte counts and leucocyte subsets were all higher in smokers than in non-smokers. In cigarette smokers total leucocyte, neutrophil, and lymphocyte blood counts showed a dose dependent relationship with the daily cigarette consumption and pack years consumption. In smokers the neutrophil blood count was independently associated negatively with FEV1 residuals. After quitting smoking total leucocyte, neutrophil, and lymphocyte blood counts decreased during the first 26 weeks and after one year lymphocyte blood counts were higher than in non-smokers. In quitters substituted with nicotine chewing gum (2 mg) the accumulated number of pieces of chewing gum used in the 12 weeks had an inverse relationship with the decrease in the total lymphocyte blood count at 12 weeks after smoking cessation.

CONCLUSIONS

Leucocyte blood counts are raised in smokers and decrease after smoking cessation. Neutrophil blood counts had an inverse relationship with lung function and nicotine may increase lymphocyte blood counts in smokers.

Evaluation of side effects after nicotine nasal spray in patients with chronic rhinitis

Thirty-three subjects with chronic rhinitis used nicotine nasal spray in an open study as an aid in smoking cessation. Thirty-eight percent of them were completely abstinent at 12 weeks, whereas 35% were completely abstinent at 20 weeks. The nasal spray was associated with irritant nasal side effects, which occurred most often in the early stages of treatment. Clinical nasal examinations could not observe any significant impairment in nasal conditions following spray use. In conclusion, this study confirms the short-term safety of the nicotine nasal spray as an aid in smoking cessation.

Tracking of lung function parameters and the longitudinal relationship with lifestyle

The purpose of this study was to analyse tracking (i.e. relative stability over time/predictability of future values by early measurements) of lung function parameters and their longitudinal relationship with lifestyle (smoking, alcohol consumption, daily physical activity, neuromotor and cardiopulmonary fitness, and dietary intake of retinol and polyunsaturated fatty acids (PUFA)). Data were obtained from the observational Amsterdam Growth and Health Study, a longitudinal study with six repeated measurements between ages 13-27 yrs (n=167). The statistical analyses were carried out with generalized estimating equations. The following "stability" coefficients were found: for forced vital capacity (FVC) in males 0.66 (95% confidence interval (CI): 0.54-0.77) and in females 0.51 (95% CI: 0.43-0.60); for forced expiratory volume in one second (FEV1) in males 0.65 (95% CI: 0.50-0.80), in females 0.53 (95% CI 0.46-0.60); for peak expiratory flow (PEF) in both males and females 0.41 (95% CI: 0.31-0.51). Positive relationships were found between alcohol consumption and FVC and FEV1 and between neuromotor fitness and PEF and (only for males) with FVC and FEV1. Physical activity was inversely related to PEF and the intake of PUFA positively related to FVC and FEV1. Smoking was related to a decrease in FVC and FEV1; changes in physical activity positively correlated to changes in FVC. In conclusion, high to moderate stability/tracking was observed for forced vital capacity and forced expiratory volume in one second; for peak expiratory flow it was slightly lower. Preventive strategies regarding improvements of lung function should focus on smoking cessation and improving daily physical activity.

How dentition status and masticatory function affect nutrient intake

The authors examined nutrient intake in relation to the number of teeth, denture type and masticatory function among 638 men in the U.S. Department of Veterans Affairs Dental Longitudinal Study. They found that calorie-adjusted nutrient intakes decreased with progressively impaired dentition status, independently of age, smoking status and alcohol use. Intakes of fiber and most vitamins and minerals were inversely correlated with masticatory function. The findings suggest that prevention of tooth loss and prosthodontic replacement of missing teeth could improve diets of older adults.

Endothelial dysfunction in human hand veins is rapidly reversible after smoking cessation

Cigarette smoking has been shown to impair endothelium-dependent dilation in arteries. We tested the hypothesis that cigarette smoking also impairs endothelium-dependent venodilation and evaluated changes in this response after smoking cessation in a time-course study using the dorsal hand vein technique. Dose-response curves were constructed in smokers and nonsmokers by infusing bradykinin (1-278 ng/min), an endothelium-dependent vasodilator, and nitroglycerin (0.006-1,583 ng/min), an endothelium-independent vasodilator, into hand veins preconstricted with the selective alpha1-adrenergic agonist phenylephrine. The maximal venodilation induced by bradykinin was 89 +/- 5% in controls (n = 16) and 61 +/- 7% in smokers (n = 18; P = 0.02). No difference in nitroglycerin-induced venodilation was observed between the two groups. Coinfusion of L-arginine (0.33 mg/min) markedly improved the bradykinin-induced venodilation in smokers (52 +/- 7 to 90 +/- 9%; P < 0.01). After acute smoking cessation (n = 7), restoration to normal bradykinin-induced venodilation was observed within 24 h, whereas no change in the response to a maximally effective dose of nitroglycerin (1,583 ng/min) was detected. In a human vein model appropriate for testing vascular functional alterations, this study demonstrates that smoking impairs endothelium-dependent venodilation in heavy smokers. Moreover, this endothelial dysfunction appears to be rapidly reversible after smoking cessation. This model may be useful in studies evaluating mechanisms of endothelial dysfunction and interventions to modify it.

Cigarette smoke increases amosite asbestos fiber binding to the surface of tracheal epithelial cells

Binding of asbestos fibers to the cell surface appears to be important in the initiation of intracellular signaling events as well as in initiation of particle uptake by the cell. We have previously shown that cigarette smoke increases the uptake of asbestos fibers by tracheal epithelial cells in explant culture. Whether smoke acts by increasing surface binding of fibers is not known. In this study, we exposed rat tracheal explants to air or cigarette smoke and then to a suspension of amosite asbestos. Explants were harvested after 1 or 24 h of dust exposure and washed by repeated dips in culture medium to remove loosely bound fibers, and the number of fibers adhering to the apical cell surfaces was determined by scanning electron microscopy. Smoke-exposed explants retained significantly more surface fibers than air-exposed explants. After four washes, binding levels were similar at 1 and 24 h. The smoke effect was still present when incubations were carried out at 4 degrees C, but binding was decreased approximately 25%. Preincubation of the asbestos fibers with iron chloride to increase surface iron increased fiber binding in both air- and smoke-exposed explants, whereas preincubation of the fibers with the iron chelator deferoxamine decreased binding after air exposure and completely eliminated the smoke effect. Inclusion of mannitol or catalase in the medium or preincubation of the explants with GSH produced decreases in binding of 10-25% in air-exposed explants and generally greater decreases in smoke-exposed explants. We conclude that 1) amosite binding is a very rapid process that does not require active cellular metabolism, 2) cigarette smoke increases adhesion of fibers to the epithelial surfaces, and 3) iron on the asbestos fiber appears to play an important role in binding, probably through an active oxygen species-mediated process.