Effects of selegiline (L-deprenyl) during smoking and short-term abstinence

RATIONALE

Changes in dopamine level are thought to play an important role in both smoking reward and withdrawal symptoms during abstinence. Medications that modulate dopamine levels may have beneficial effects on both withdrawal symptom levels and on response to smoking lapses during abstinence.

OBJECTIVES

To examine the effects of the selective MAO-B inhibitor selegiline on withdrawal symptoms, smoking behavior and smoking satisfaction ratings.

METHODS

Fifteen smokers received selegiline (10 mg/day) and placebo (in counterbalanced order) on Monday through Thursday of 2 study weeks, separated by a 2-week washout. During each study week, ad lib smoking sessions were scheduled to assess smoking behavior both before and after a brief period of abstinence. Subjective withdrawal symptoms and mood were measured daily, and a modified Stroop test sensitive to withdrawal was scheduled during the period of abstinence.

RESULTS

Selegiline decreased craving, especially during abstinence, and impaired performance on the modified Stroop test during subjects' attempts to abstain. Medication also reduced number of cigarettes smoked and smoking satisfaction ratings during the smoking sessions both before and after the brief abstinence attempt.

CONCLUSION

These results are consistent with an important role of dopamine in smoking behavior and abstinence. They suggest that pharmacological reduction of MAO-B levels during the early part of a quit attempt may aid in smoking cessation.

Expression of cell cycle proteins in head and neck cancer correlates with tumor site rather than tobacco use

Head and neck squamous cell carcinomas of non-smoking patients may result from specific defects in cell cycle control. Expression of p53, pRb, p16(INK4a) and Cyclin D1 was examined by immunohistochemistry of biopsies obtained from 24 non-smoking and 25 smoking patients, both groups representing similar clinical features (tumor site, stage of disease, gender). Expression of p16(INK4a) was restricted to carcinomas of the tonsils (8/24), P=0.0069. In 6/8 p16(INK4a)-positive cases, expression of pRb was absent or reduced. p16 was the only marker showing a significant correlation with a negative smoking history (P=0.0208). Overexpression of Cyclin D1 was frequent in carcinomas of the tongue (6/14) but rare in tonsillar carcinomas (2/24), P=0.0303. Expression of p53 was independent of the smoking history and the tumor site. Our results implicate that there are factors other than tobacco consumption which may influence the development of head and neck cancers at distinct tumor sites.

Increased expression of nuclear factor-kappaB in bronchial biopsies from smokers and patients with COPD

The expression of nuclear factor (NF)-kappaB is an indicator of cellular activation and of inflammatory mediator production. The aim of the present study was to characterise the expression and localisation of p65, the major subunit of NF-kappaB, in the bronchial mucosa of patients with chronic obstructive pulmonary disease (COPD), and to examine the relationship between p65 expression and disease status. Bronchial biopsies were obtained from 14 smokers with COPD, 17 smokers with normal lung function and 12 nonsmokers with normal lung function. The number of p65 positive (+) cells was quantified by immunohistochemistry and the expression of p65 in bronchial biopsies from the three groups was examined by Western blotting (WB). Smokers with normal lung function and patients with COPD had increased numbers of p65+ cells in the epithelium and increased p65 nuclear expression. In COPD patients the number of epithelial p65+ cells correlated with the degree of airflow limitation. WB analysis showed an increase in p65 in smokers with normal lung function and COPD patients (p<0.05). Bronchial biopsies in smokers with normal lung function and chronic obstructive pulmonary disease patients show increased expression of p65 protein, predominantly in the bronchial epithelium. Disease severity is associated with an increased epithelial expression of nuclear factor-kappaB.

Regional and cellular expression of CYP2D6 in human brain: higher levels in alcoholics

Cytochrome P450 (CYP) 2D6 is expressed in liver, brain and other extrahepatic tissues where it metabolizes a range of centrally acting drugs and toxins. As ethanol can induce CYP2D in rat brain, we hypothesized that CYP2D6 expression is higher in brains of human alcoholics. We examined regional and cellular expression of CYP2D6 mRNA and protein by RT-PCR, Southern blotting, slot blotting, immunoblotting and immunocytochemistry. A significant correlation was found between mean mRNA and CYP2D6 protein levels across 13 brain regions. Higher expression was detected in 13 brain regions of alcoholics (n = 8) compared to nonalcoholics (n = 5) (anovap < 0.0001). In hippocampus this was localized in CA1-3 pyramidal cells and dentate gyrus granular neurons. In cerebellum this was localized in Purkinje cells and their dendrites. Both of these brain regions, and these same cell-types, are known to be susceptible to alcohol damage. For one case, a poor metabolizer (CYP2D6*4/*4), there was no detectable CYP2D6 protein, confirming the specificity of the antibody used. These data suggest that in alcoholics elevated brain CYP2D6 expression may contribute to altered sensitivity to centrally acting drugs and to the mediation of neurotoxic and behavioral effects of alcohol.

Beta-carotene plasma levels and content in oral mucosal epithelium is skin type associated

Beta-carotene is one of the important antioxidants in the defence mechanisms of the body against reactive oxygen species and, in particular, against UV radiation in the skin. The aim of our study was to measure if differences of beta-carotene in the peripheral blood and oral mucosa exist in relation to skin types I-IV (according to Fitzpatrick). One hundred and seventy-four subjects were studied with regard to beta-carotene plasma levels. Out of these, 63 healthy volunteers (24-28 years) with skin type I-IV were studied with regard to plasma levels and content of beta-carotene in the oral mucosa. Ten millilitres of venous blood was obtained and oral mucosa cells (OMCs) were taken by gently brushing the oral cavity without contamination of capillary leak blood. A modified method by Stich et al. was used for preparing cells and measuring beta-carotene in OMCs by HPLC. Plasma levels of skin type I were 0.1565 micromol/l and increased via skin types II with 0.2989 and III with 0.5457 to 1.221 micromol/l in skin type IV. A similar skin type-dependent increase in beta-carotene could be measured in the oral mucosa epithelium (OMC) either when measured in micromoles/litre (0.0056-0.0217) or in nanograms/10(6) cells (0.2090-0.9989). Smokers had significantly lower levels of beta-carotene in plasma and OMC as compared with non-smokers. Non-melanoma and melanoma skin cancer patients also showed lower beta-carotene plasma levels and in the OMCs as well. From our results, we conclude that plasma levels and content of beta-carotene in the cytoplasm of OMCs show marked and significant differences with regard to skin types I-IV. The question arises whether these differences are genetically controlled.

A review of the pharmacological and psychopharmacological aspects of smoking and smoking cessation in psychiatric patients

The data reviewed confirm that mentally ill patients smoke twice as many cigarettes as patients without mental illness. The secretion of neurotransmitters such as noradrenaline, serotonin, dopamine, acetylcholine, gamma-amino-butyric acid and glutamate is increased by the binding of nicotine to central nicotine receptors. There are also data showing that serotonin formation and secretion in patients with mental illness are influenced by chronic smoking. Cigarette smoke inhibits the activity of monoamine oxidase B, which is responsible for the catabolism of several brain neurotransmitters. Patients suffering from major depression show a comorbidity between heavy smoking and the disease. In patients with schizophrenia treated with neuroleptics, increased cigarette smoking reduces adverse reactions to the drug therapy presumably because of an increase in metabolism of the neuroleptics. There is also evidence suggesting that quitting smoking is more difficult for mentally ill patients than patients without psychiatric disease. Several studies have been carried out on smoking cessation in psychiatric patients. The alternative method of harm reduction, e.g. reducing the number of cigarettes smoked using nicotine patches or chewing gum, is necessary in patients not able to quit. The data indicate that strategies such as the coupling of smoking prohibition with administration of nicotine preparations are useful in smoking cessation. A no-smoking policy in psychiatric clinics, even when this leads to withdrawal symptoms in the patients affected, has no negative effect on mental illness. Because patients with mental diseases are particularly vulnerable to the marketing strategies of the tobacco industry, this chronically ill section of the population requires special protection by the law-makers.

Tobacco smoke and formation of N-(2-hydroxyethyl)valine in human hemoglobin

Human exposure to ethylene oxide (EtO) occurs mainly through inhalation of polluted air in occupational workplaces and/or via tobacco smoke. A significant biochemical reaction of EtO converts the terminal valine of hemoglobin into N-(2-hydroxyethyl)valine (HOEtVal). In the present study, the extent of HOEtVal formation in 360 healthy adults who were not occupationally exposed to EtO was measured with a gas chromatograph/mass spectrometer in the electron-capture negative chemical ionization mode. This parameter was correlated with smoking habits and urinary cotinine concentration, exhibiting a positive relationship between HOEtVal and the number of cigarettes smoked (r2 = .4416). Urinary cotinine measurements also correlated with HOEtVal and the number of cigarettes smoked. This positive correlation between urinary cotinine and HOEtVal (r2 = .3893) provides a new perspective on the early stages of carcinogenic processes.

Cigarette smoke condensate activates nuclear transcription factor-kappaB through phosphorylation and degradation of IkappaB(alpha): correlation with induction of cyclooxygenase-2

Cigarette smoke (CS) contains several carcinogens known to initiate and promote tumorigenesis and metastasis. Because various genes that mediate carcinogenesis and tumorigenesis are regulated by nuclear factor-kappaB (NF-kappaB), we postulated that the effects of CS must be mediated through activation of this transcription factor. Therefore, in the present report we investigated whether cigarette smoke condensate (CSC) activates NF-kappaB, and whether the pathway employed for activation is similar to that of TNF, one of the potent activators of NF-kappaB. Our results show that the treatment of human histiocytic lymphoma U-937 cells with CSC activated NF-kappaB in a dose- and time-dependent manner. The kinetics of NF-kappaB activation by CSC was comparable with that of TNF. CSC-induced NF-kappaB activation was not cell type-specific, as it also activated NF-kappaB in T cells (Jurkat), lung cells (H1299), and head and neck squamous cell lines (1483 and 14B). Activation of NF-kappaB by CSC correlated with time-dependent degradation of IkappaB(alpha), an inhibitor of NF-kappaB. Further studies revealed that CSC induced phosphorylation of the serine residue at position 32 in IkappaB(alpha). In vitro immunocomplex kinase assays showed that CSC activated IkappaB(alpha) kinase (IKK). The suppression of CSC-activated NF-kappaB-dependent reporter gene expression by dominant negative form of IkappaB(alpha), TRAF2, NIK and IKK suggests a similarity to the TNF-induced pathway for NF-kappaB. CSC also induced the expression of cyclooxygenase-2, an NF-kappaB regulated gene product. Overall, our results indicate that through phosphorylation and degradation of IkappaB(alpha), CSC can activate NF-kappaB in a wide a variety of cells, and this may play a role in CS-induced carcinogenesis.

4-Hydroxy-2-nonenal, a specific lipid peroxidation product, is elevated in lungs of patients with chronic obstructive pulmonary disease

Cigarette smoking results in oxidative stress and inflammation in the lungs, which are involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). 4-Hydroxy-2-nonenal (4-HNE), a highly reactive diffusible product of lipid peroxidation, is a key mediator of oxidant-induced cell signaling and apoptosis. 4-HNE has a high affinity toward cysteine, histidine, and lysine groups and forms direct protein adducts. We investigated the presence of 4-HNE-modified proteins in lung tissue obtained from subjects with and without COPD. We studied 23 current or ex-smokers with similar smoking histories with COPD (n = 11; FEV(1) < 70% predicted) or without COPD (n = 12; FEV(1) > 84% predicted) who had undergone lung resection. As 4-HNE and transforming growth factor-beta(1) (TGF-beta(1)) can modulate gamma-glutamylcysteine synthetase (gamma-GCS) mRNA levels in lung cells, we assessed the relations between 4-HNE-modified protein levels, FEV(1), gamma-GCS, and TGF-beta(1). 4-HNE-modified protein levels were elevated in airway and alveolar epithelial cells, endothelial cells, and neutrophils in subjects with COPD, compared with the levels in subjects without COPD (p < 0.01). We also observed a significant inverse correlation between the levels of 4-HNE adducts in alveolar epithelium, airway endothelium, and neutrophils and FEV(1) (p < 0.05) and a positive correlation between 4-HNE adducts and TGF-beta(1) protein and mRNA as well as gamma-GCS mRNA levels in airway and alveolar epithelium (p < 0.01). The elevated levels of 4-HNE may play a role in the signaling events in lung inflammation leading to the imbalance of the expression of both proinflammatory mediators and protective antioxidant genes in COPD.

Lung uptake of technetium-99m tetrofosmin in healthy subjects is related to smoking habits

To determine the influence of smoking on lung uptake of technetium-99m tetrofosmin (Tc-TF) during myocardial perfusion imaging, we examined 50 healthy subjects with normal myocardial perfusion single photon emission computed tomography findings, normal coronary angiograms, and no evidence of left ventricular hypertrophy. The 50 healthy subjects were divided into two groups. Group 1: 25 healthy subjects had smoking histories of at least 10 pack-years. Group 2: 25 healthy subjects were nonsmokers. Lung to heart ratios (L/H ratios) calculated from anterior planar images during exercise and rest states of Tc-TF myocardial perfusion imaging were obtained for all of the 50 healthy subjects. L/H ratios calculated from Tc-TF myocardial perfusion imaging in smokers were significantly higher than in nonsmokers during both exercise and rest states. However, no significant difference in L/H ratios was found between exercise and rest states in smokers and nonsmokers. In addition, a positive but nonsignificant correlation was found between smoking pack-years and either rest or exercise L/H ratios. When L/H ratios are used as a clinical diagnostic tool in Tc-TF myocardial perfusion imaging, we must consider that L/H ratios in smokers are higher than in nonsmokers.

Hemoglobin adducts of ethylene oxide, propylene oxide, acrylonitrile and acrylamide-biomarkers in occupational and environmental medicine

In a chemical plant, ethylene oxide (EO) and propylene oxide (PO) were used for the production of surfactants for the textile industry. Within health supervision, we investigated the internal exposure of the workers using hemoglobin adducts as parameters of biochemical effects. The 95th percentile for N-2-hydroxyethylvaline (HEV) was 1280 pmol/g globin (=29.4 microg/l blood) in blood from exposed workers compared with 100 pmol/g globin (or 2.3 microg/l) in controls. N-(R,S)-2-hydroxypropylvaline (HPV) both in workers and controls was below the detection limit (80 pmol/g globin or 2 microg/l). The levels of the adducts of acrylonitrile (ACN) and acrylamide (AA) were also determined, though they were mainly accounted for by smoking and diet. Median values of N-2-cyanoethylvaline (CEV) were below 4 pmol/g globin (or 0.1 microg/l) in non-smokers (n=24) and 131 pmol/g globin (or 3.3 microg/l) in smokers (n=38). Median values of N-2-carbamoylethylvaline (AAV) were 22 pmol/g globin (or 0.6 microg/l) in non-smokers compared with 89 pmol/g globin (or 2.4 microg/l) in smokers. Correlations were found between smoking habits and adduct levels of CEV and AAV.

Maternal smoking during pregnancy and nicotine and cotinine concentrations in maternal and neonatal hair

OBJECTIVE

Conflicting data have been reported in the association between maternal smoking and adverse effects during pregnancy and in neonates. Some studies, conducted on a limited number of patients have evaluated maternal consumption and fetal exposure by measuring nicotine and cotinine in the hair. Our aims were to evaluate the relationship among maternal cigarette consumption, fetal smoking exposure and outcome of pregnancy in a population of pregnant women who smoked.

DESIGN

Mothers smoking during pregnancy were included at their first prenatal visit and followed prospectively. Maternal data (demographic variables, obstetrical history and cigarette consumption), neonatal data and birth indicators (number of weeks of gestation, type of delivery, weight) were collected. Hair samples from the mothers and the babies were collected at birth.

SETTING

The present study was conducted in the Department of Obstetrics of the University Hospital Robert Debré in Paris.

POPULATION

A total of 254 women smokers were included in the study and 182 mother/neonate pairs were analyzed after exclusion of 50 babies whose hair samples were inadequate and 22 for various other reasons.

METHODS

Nicotine and cotinine concentrations in the maternal and neonatal hair were measured at birth by radio-immunoassay.

MAIN OUTCOME MEASURES

Cigarette consumption was based on self reporting and quantified each trimester. It was expressed more precisely during the third trimester by the mean number per cigarette per day. Nicotine and cotinine concentrations in the maternal and neonatal hair at birth were also analysed.

RESULTS

Nicotine and cotinine concentrations in maternal hair were associated with cigarette consumption during the third trimester of pregnancy (P < 0.003 and P < 0.01, respectively). In neonates, only cotinine concentrations were associated to maternal cigarette consumption (P < 0.0001). This association remained significant in a multivariate analysis, which included maternal cotinine hair concentrations and the ethnic group.

CONCLUSIONS

Our results have shown a strong relationship between maternal cigarette consumption and fetal exposure to smoking measured by cotinine concentrations in neonatal hair. Further studies are required to look for associations between fetal exposure and adverse pregnancy outcome.

Determination of SCN- in urine and saliva of smokers and non-smokers by SCN(-)-selective polymeric membrane containing a nickel(II)-azamacrocycle complex coated on a graphite electrode

The construction, performance characteristics, and application of a novel polymeric membrane coated on a graphite electrode with unique selectivity towards SCN- are reported. The electrode was prepared by incorporating Ni(II)-2,2,4,9,9,11-hexamethyltetraazacyclotetradecanediene perchlorate into a plasticized poly(vinyl chloride) membrane. The influences of membrane composition, pH and foreign ions were investigated. The electrode displays a near Nernstian slope (-57.8 mV decade-1) over a wide concentration range of 1 x 10(-7)-1 x 10(-1) M of SCN- ion. The electrode has a detection limit of 4.8 x 10(-8) M (2.8 ng/cm3) SCN- and shows response times of about 15 s and 120 s for low to high and high to low concentration sequences, respectively. The proposed sensor shows high selectivity towards SCN- over several common organic and inorganic anions. The electrode revealed a great enhancement in selectivity coefficients and detection limit for SCN-, in comparison with the previously reported electrodes. It was successfully applied to the direct determination of SCN- in milk and biological samples, and as an indicator electrode in titration of Ag+ ions with thiocyanate.

The interindividual differences in the 3-demthylation of caffeine alias CYP1A2 is determined by both genetic and environmental factors

This study investigated the role of genetic factors (CYP1A2) in caffeine metabolism. The CYP1A2 activity was determined in 378 Danish twins following oral intake of a single dose of 200 mg caffeine and subsequent determination of the caffeine ratio (AFMU+1MU+1MX)/17DMU in a 6-h urine sample. The mean (+/- SD) caffeine ratio was 5.9 +/- 3.4. The caffeine ratio was statistically significantly higher in men compared to women, in smoking men and women compared to non-smoking persons of the same gender and in women not taking oral contraceptives compared with women on oral contraceptives. Thus, we confirmed that CYP1A2 is more active in men than in women, that it is induced by smoking and inhibited by oral contraceptives. In the subsequent analysis of heritability, we included 49 monozygotic twin pairs and 34 same gender dizygotic twin pairs concordant for non-smoking and non-use of oral contraceptives. The intraclass correlation coefficient was 0.798 (95% confidence interval, 0.696-0.900) and 0.394 (95% confidence interval, 0.109-0.680) in the monozygotic and dizygotic twins, respectively. The correlation was statistically significantly higher (P = 0.0015) in the former compared with the latter. A biometrical model for the caffeine ratio including only additive genetic factors and unique environmental factors was the overall best fitting model. Estimates based on this model gave a heritability estimate of 0.725 (95% confidence interval 0.577-0.822). Unique environmental effects seem to account for the remainder 0.275 (95% confidence interval, 0.178-0.423). Our study shows that the CYP1A2 activity is mainly governed by genetic factors.

Effects of cigarette smoking on quinine pharmacokinetics in malaria

OBJECTIVE

Quinine is an important antimalarial drug that is metabolised mainly by the hepatic mixed-function microsomal enzyme cytochrome P(450). Cigarette smoking in healthy volunteers has been reported to enhance quinine clearance. The present study evaluated the effects of smoking on quinine pharmacokinetics in patients with uncomplicated falciparum malaria treated with a 7-day course of oral quinine. Of 22 studied male patients, 10 were regular smokers and 12 were non-smokers.

METHODS

All patients were treated with a 7-day oral regimen of quinine sulfate (10 mg salt/kg three times a day). Serial venous blood samples were taken for quinine levels before and during treatment at 12 h and 24 h and then daily until day 7. Plasma quinine and 3-hydroxyquinine concentrations were assayed using high-performance liquid chromatography. Quinine pharmacokinetics were evaluated using non-compartmental modelling.

RESULTS

All patients recovered, and there were no significant differences in clinical responses or cure rates between the two studied groups ( P> or =0.32). The median (range) fever clearance time was 51 h (4-152 h) and mean (SD) parasite clearance time was 74+/-28 h. The overall median times to maximum concentrations of quinine and its main metabolite 3-hydroxyquinine were 1.5 days and 4.0 days, respectively. The maximum concentrations of quinine were approximately tenfold higher than 3-hydroxyquinine. There were no significant differences in any pharmacokinetic variables for the parent compound or metabolite between the two groups. The median area under the plasma drug concentration-time curve to day 7 (AUC(0-7)) of quinine in non-smokers was 67.0 micro g/ml/day and in smokers was 51.3 micro g/ml/day, and AUC(0-7) values of 3-hydroxyquinine were 6.2 micro g/ml/day and 4.8 micro g/ml/day, respectively.

CONCLUSION

These results indicated that cigarette smoking has no significant effects on quinine pharmacokinetics or the therapeutic response in patients with falciparum malaria.

Therapeutic drug monitoring of racemic venlafaxine and its main metabolites in an everyday clinical setting

When Efexor (venlafaxine) became available in Sweden, a therapeutic drug monitoring (TDM) service was developed in the authors' laboratory. This analytical service was available to all physicians in the country. From March 1996, to November 1997, 797 serum concentration analyses of venlafaxine (VEN) and its main metabolites, O-desmethylvenlafaxine (ODV), N-desmethylvenlafaxine (NDV), and N,O-didesmethylvenlafaxine (DDV) were requested. These samples, each of which was accompanied by clinical information on a specially designed request form, represented 635 inpatients or outpatients, comprising all ages, treated in a naturalistic setting. The first sample per patient, drawn as a trough value in steady state and with documented concomitant medication, was further evaluated pharmacokinetically (n = 187). The doses prescribed were from 37.5 mg/d to 412.5 mg/d. There was a wide interindividual variability of serum concentrations on each dose level, and the mean coefficient of variation of the dose-corrected concentrations (C/D) was 166% for C/D VEN, 60% for C/D ODV, 151% for C/D NDV, and 59% for C/D DDV. The corresponding CV for the ratio ODV/VEN was 110%. However, within patients over time, the C/D VEN and ODV/VEN variation was low, indicating stability in individual metabolizing capacity. Patients over 65 years of age had significantly higher concentrations of C/D VEN and C/D ODV than the younger patients. Women had higher C/D NDV and C/D DDV, and a higher NDV/VEN ratio than men, and smokers showed lower C/D ODV and C/D DDV than nonsmokers. A number of polycombinations of drugs were assessed for interaction screening, and a trend for lowered ODV/VEN ratio was found, predominantly with concomitant medication with CNS-active drug(s) known to inhibit CYP2D6.

Decreased level of vascular endothelial growth factor in bronchoalveolar lavage fluid of normal smokers and patients with pulmonary fibrosis

Vascular endothelial growth factor (VEGF) plays multifunctional roles in both the development of vasculature and the maintenance of vascular function. A decrease in VEGF reduces angiogenesis and induces apoptosis of vascular endothelial cells. Inhibition of the VEGF receptor causes endothelial cell apoptosis and emphysema. We postulated that VEGF concentrations might be reduced in patients with chronic lung diseases. The level of VEGF was evaluated by enzyme-liked immunosorbent assay in bronchoalveolar lavage fluid (BALF) from normal smokers, nonsmoking volunteers, idiopathic pulmonary fibrosis, pulmonary fibrosis associated with a connective tissue disease, and sarcoidosis. The isoforms of VEGF in BALF were determined by high-performance liquid chromatography. VEGF in nonsmoking volunteers was detectable at a high concentration. In contrast, VEGF in most of the normal smokers was below the detectable limit. The VEGF found in nonsmoking volunteers BALF was VEGF165. VEGF was significantly decreased in idiopathic pulmonary fibrosis, pulmonary fibrosis associated with a connective tissue disease, and sarcoidosis compared with nonsmoking volunteers. The smoking patients showed a further decrease in VEGF. These data suggest that the decrease in VEGF in smokers and patients with chronic lung diseases may reduce angiogenesis and induce apoptosis of vascular endothelial cells.

[Nuclear factor-kappa B and intercellular adhesion molecule-1 expression in airway epithelial cells from smoking rats]

OBJECTIVE

To investigate the changes and of nuclear factor-kappa B (NF-kappaB) and intercellular adhesion molecule (ICAM)-1 expression in airway epithelial cells from smoking rats.

METHODS

Wistar rats (n = 39) were randomly divided into a nonsmoking control group and 2 smoking groups-smoking for 1 month and 3 months, with 13 rats in each group. Immunohistochemistry and in situ hybridization staining were used to semiquantitatively analyse the changes of NF-kappaB and ICAM-1 expression in airway epithelial cells.

RESULTS

(1) The percentages of positive cells for NF-kappaB nuclear staining in bronchiolar epithelial cells in 1 month smoking group (63 +/- 4)% and 3 month smoking group [(51 +/- 5)%] were significantly higher than that in the control group [(27 +/- 5)%] (P < 0.01 respectively). (2) ICAM-1 mRNA expression in bronchial and bronchiolar epithelial cells in the 1 month smoking group (0.645 +/- 0.038, 0.747 +/- 0.041) and the 3 month smoking group (0.688 +/- 0.062, 0.809 +/- 0.023) was significantly higher than those in the control group (0.526 +/- 0.023, 0.635 +/- 0.044), (P < 0.01 respectively), and the expression of ICAM-1 mRNA in the 3 month smoking group was higher than that in the 1 month smoking group (P < 0.05 and P < 0.01 respectively). (3) ICAM-1 protein expression in the main bronchial and bronchiolarepithelial cells in the 1 month smoking group (0.73 +/- 0.04, 0.94 +/- 0.05) and the 3 month smoking group (0.77 +/- 0.04, 0.99 +/- 0.03) was significantly higher than those in the control group (0.57 +/- 0.04, 0.83 +/- 0.04) (P < 0.01 respectively), and the expression of ICAM-1 protein in the 3 month smoking group was higher than those in the 1 month smoking group (P < 0.05 respectively). (4) ICAM-1 mRNA and protein expression in bronchioles were significantly higher than those in the bronchi (P < 0.01 respectively) in all groups. (5) The percentage of cells staining positive for nuclear NF-kappaB correlated with ICAM-1 protein expression in bronchioles from the 1 month smoking group (r = 0.462, P < 0.05).

CONCLUSION

NF-kappaB and ICAM-1 may play an important role in smoking-induced airway inflammation.

Therapeutic drug monitoring data on olanzapine and its N-demethyl metabolite in the naturalistic clinical setting

Olanzapine (Zyprexa) was approved for general prescription in Sweden in November 1996, and an HPLC-based therapeutic drug monitoring (TDM) routine for serum olanzapine (OLA) and its major metabolite, N-demethylolanzapine (DMO) was established in February 1997. During 1997 to 1999, a total of 753 TDM requests for a total of 545 Swedish patients was analyzed. Additional patient information on certain clinical variables was collected on specifically designed TDM request forms. After the exclusion process, samples from 194 patients were found to be eligible for further scrutiny. The concentration-to-dose (C/D) ratio for OLA varied 25-fold and that of DMO 22-fold. Women had a higher (P < 0.01) median C/D ratio for OLA than men (median, 7.2 nmol/L/mg vs 5.2 nmol/L/mg). Nonsmokers had a higher (P < 0.001) C/D ratio for OLA than smokers (median, 9.2 nmol/L/mg vs 4.0 nmol/L/mg). Smokers got higher prescribed (P < 0.05) doses of OLA than nonsmokers did. In the group with reported side effects, the median serum OLA concentration was 22% higher (P < 0.05) than in the group without side effects. Patients co-medicated with carbamazepine had a 71% lower median C/D ratio for OLA than patients on OLA monotherapy. The present TDM-based follow-up suggests that the influence of gender, smoking habits, and certain drug interactions may need to be considered for optimal dosage of OLA. TDM may be used for this purpose more readily in the future.

Nitric oxide but not carbon monoxide is continuously released in the human nasal airways

Results from different laboratories indicate that nitric oxide (NO) and carbon monoxide (CO) coexist in the human airways both in health and disease. These gases are present in exhaled human breath and high concentrations of NO as well as CO have been reported in the nasal airways. In addition, exhaled CO and NO are increased in patients with airways inflammation. NO and CO were measured simultaneously in orally exhaled air and in air sampled from the nose in 18 healthy subjects using chemiluminescence (for NO) and infrared (for CO) techniques at different fixed flow rates. The acute effects of smoking on airway release of NO and CO were also studied. Nasal NO was detected in all subjects and the concentrations were highly flow-dependent (mean+/-SEM: 236+/-23 and 527+/-49 parts per billion (ppb), at 2 and 0.5 L x min(-1), respectively). In contrast, no evidence of CO release in the nasal airways regardless of sample flow rate was found. In fact, additional experiments indicated a net absorption of CO when low levels of this gas were flushed through the nasal cavity. Nasal CO also remained undetectable after smoking. Both NO (22+/-2 ppb) and CO (1.1+/-0.1 parts per million) were consistently found in orally exhaled air. CO, but not NO, levels increased acutely after smoking a cigarette. The authors conclude that the patterns of nitric oxide and carbon monoxide release in the airways seem to differ profoundly in healthy subjects. Orally exhaled air contains both nitric oxide and carbon dioxide whereas nasal air contains nitric oxide only.

Increased nitric oxide elimination from the airways after smoking cessation

Smokers have been found to have low exhaled nitric oxide (NO) levels. The aim of the present study was to investigate where in the respiratory system the decrease in NO occurs, and whether this decrease was affected by smoking cessation. Measurements of exhaled NO were carried out in smokers (n=20) and non-smoking control subjects (n=30). In nine of the smokers, exhaled NO was analysed 1, 2 and 4 weeks after smoking cessation. The level of exhaled NO at a flow rate of 0.1 litre/s was significantly lower in smokers (4+/-2 p.p.b.) than in non-smokers (7+/-5 p.p.b.; P=0.007). A calculation of the contributions from different areas of the lung showed that the NO flux from the airways was significantly lower (14+/-10 compared with 36+/-26 nl/min; P=0.0001) and the alveolar fraction was significantly higher (2.1+/-0.8 compared with 1.5+/-0.9 p.p.b.; P=0.006) in smokers than in non-smokers. Nine smoking subjects refrained from smoking for 4 weeks, and this resulted in increased NO flux from the airways of 28+/-17 nl/min, which was no longer significantly different from controls. In conclusion, endogenous production of NO in the airways is decreased in smokers, but can be restored to normal values by 4 weeks after cessation of smoking. Smokers have an increased alveolar fraction of NO, and this might be a diagnostic sign of lung damage. Thus NO monitoring can be used to indicate improvements when a smoker decides to stop smoking.

Effect of smoking on hemoglobin A1c and body mass index in patients with type 2 diabetes mellitus

BACKGROUND

Smoking is associated with a decrease in body weight in patients without diabetes mellitus and an increase in insulin resistance and hemoglobin A1c (HbA1c) levels in patients with type 1 diabetes mellitus. Whether smoking is associated with an increase in HbA1c and/or a decrease in body mass index (BMI) in type 2 diabetes mellitus is unresolved, however. Therefore, the objective of this study was to determine the effect of smoking on HbA1c levels and BMI in a cross-section of outpatients with type 2 diabetes mellitus.

METHODS

A questionnaire was completed by 102 sequential outpatients (32 men, 70 women) with type 2 diabetes mellitus to assess age, sex, duration of diabetes mellitus, medications, exposure to nicotine, medical complications as a result of type 2 diabetes mellitus, and BMI In addition, a urine sample was obtained from each patient to assess the microalbumin-creatinine and cotinine-creatinine ratios. HbA1c level were also obtained from each volunteer as a measure of glucose control.

RESULTS

Smokers had significantly higher cotinine-creatinine ratios than nonsmokers. Smokers and nonsmokers did not differ significantly with regard to HbA1c level, BMI, or duration of diabetes mellitus. Smokers were younger than nonsmokers. Smokers and nonsmokers did not differ significantly in terms of microalbumin-creatinine ratio, amount of diabetic medications, or medical complications.

CONCLUSION

The results of this study suggest that smoking does not have a significant direct effect on BMI or HbA1c in patients with type 2 diabetes mellitus. This conclusion suggests that the relationship between these factors is much more complex than in people without diabetes or in patients with type 1 diabetes mellitus.

Increased levels of the chemokines GROalpha and MCP-1 in sputum samples from patients with COPD

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) have increased numbers of neutrophils and macrophages in their lungs. Growth related oncogene-alpha (GROalpha) attracts neutrophils, whereas monocyte chemoattractant protein-1 (MCP-1) attracts monocytes that can differentiate into macrophages. The aim of this study was to determine the concentration of GROalpha and MCP-1 in bronchoalveolar lavage (BAL) fluid and sputum from non-smokers, healthy smokers and patients with COPD, and to see if there was a correlation between the concentrations of these chemokines, lung function, and numbers of inflammatory cells.

METHODS

BAL fluid and sputum from non-smokers (n=32), healthy smokers (n=36), and patients with COPD (n=40) were analysed for the presence of GROalpha and MCP-1 using ELISA. Cells counts were performed on the samples and correlations between the concentrations of these chemokines, lung function, and inflammatory cells observed.

RESULTS

Median (SE) GROalpha and MCP-1 levels were significantly increased in sputum from patients with COPD compared with non-smokers and healthy smokers (GROalpha: 31 (11) v 2 (2) v 3 (0.8) ng/ml; MCP-1: 0.8 (0.4) v 0.2 (0.1) v 0.1 (0.04) ng/ml, p<0.05), but not in BAL fluid. There were significant negative correlations between both GROalpha and MCP-1 levels in sputum and forced expiratory volume in 1 second (FEV(1)) % predicted (GROalpha: r=-0.5, p<0.001; MCP-1: r=-0.5, p<0.001), together with significant positive correlations between GROalpha and MCP-1 and neutrophil numbers in sputum (GROalpha: r=0.6, p<0.001; MCP-1: r=0.4, p<0.01).

CONCLUSION

These results suggest that GROalpha and MCP-1 are involved in the migration of inflammatory cells, thus contributing to the inflammatory load associated with COPD.

Nicotine addiction: insights from recent animal studies

RATIONALE

Recent preclinical behavioral and neurobiological research has characterized important behavioral features and has identified neurobiological substrates that may underlie nicotine reinforcement and addiction.

OBJECTIVE

To examine recent advances on nicotine exposure in preclinical models, from three perspectives: (a) the chronopharmacokinetics of nicotine, (b) behavioral studies on nicotine reinforcement, withdrawal, and reinstatement/relapse, and (c) effects of nicotine on neurobiological substrates after repeated exposure.

RESULTS

Preclinical studies can be used to operationally model selected aspects of nicotine reinforcement, withdrawal, and reinstatement or relapse. These may be used to investigate the functional in vivo consequences of acute and long-term changes in neuronal acetylcholine receptor populations that follow nicotine exposure. Behavioral studies focusing on distinct stages of nicotine exposure (e.g., active reinforcement vs. cessation or reinstatement) may also be used in parallel with studies on dopaminergic function, a proposed substrate for the reinforcing effects of nicotine, and of opioid receptor function, a possible site of neuroadaptations secondary to nicotine exposure.

CONCLUSIONS

While no single current animal model may capture the experience of human smoking or nicotine addiction, increasingly, separate animal models are capturing the full spectrum of behavioral and neurobiological dimensions of this complex condition.