Plasma leptin concentrations and lipid profiles during nicotine abstinence.

BACKGROUND: Weight gain is a frequent consequence of smoking cessation. Leptin, the protein product of the obese gene, seems to regulate appetite and body fat stores. The purpose of this study was to assess changes in circulating leptin levels and lipid metabolism during nicotine abstinence (NA) and their role in postcessation weight gain. METHODS: Six sedentary, weight-stable, nonobese adult smokers were studied before and after 7 days of NA while following a weight-maintenance diet of standard composition. All subjects refrained from smoking overnight (as assessed by breath CO) and were instructed to chew nicotine polacrilex gum (4 mg) hourly from 7:00 AM to 8:00 PM [nicotine intake (NI) day]. Venous blood samples were collected at 7:00 AM (after an overnight fast) and 5:00 PM (pre-supper) on NI day and again after 7 days of NA. RESULTS: Body weight did not change after 7 days of NA (72.0 +/- 2.8 versus 71.8 +/- 2.7 kg). Serum cotinine levels declined from 207 +/- 40 ng/mL during NI to undetectable levels during NA (P < 0.01). Fasting plasma leptin was similar during NI and NA (5.7 +/- 1.4 versus 6.4 +/- 1.9 ng/mL; P = NS). Moreover, plasma concentrations of glucose, insulin, and free fatty acids were unaffected by 7 days of NA. Although plasma triglycerides, total cholesterol, and low-density lipoprotein cholesterol were similar during NI and NA, high-density lipoprotein cholesterol increased by 15% after 7 days of NA (P < 0.05). CONCLUSIONS: In this group of nonobese, adult smokers consuming an isocaloric diet, NA for 7 days did not affect body weight or circulating concentrations of leptin, glucose, insulin, or free fatty acids. In contrast, HDL cholesterol increased significantly after NA. These results indicate that under controlled dietary conditions, changes in leptin expression do not contribute to the weight gain that commonly accompanies smoking cessation.

Smoking cessation in military personnel.

Tobacco use is the single most important preventable cause of death in military personnel. The purpose of this randomized clinical trial was to evaluate the effectiveness of two behavioral interventions when added to nicotine-replacement therapy on smoking cessation. The sample of 512 included 52% active duty military, 29% family, 11% retirees, and 8% Department of Defense civilians. There was a main effect of compliance at the end of the program (EOP); 69% of those who attended 75% of the classes were abstinent from tobacco; regression analysis found the more intensive program to be twice as effective at EOP and at 3 months, an outcome not continued at 6 months. The longer, more intensive Vanderbilt University Medical Center program was significantly more effective at helping the civilian portion of the population (85% versus 60% in the American Cancer Society program) but not the active duty participants.

[Expression of cytokeratins during embryogenesis and in pathologic epithelia]. / Expression des cytokératines au cours de l'embryogénèse et dans les épithéliums pathologiques.

Epithelial cell intermediate filaments, or cytokeratins, are excellent markers for cell differentiation. During embryogenesis, cytokeratins specific of a stage of differentiation step always become detectable before corresponding morphologic changes: for instance, cytokeratins 5 and 14 are found around the eight week, shortly before stratification of the epithelium occurs, and cytokeratins 1 and 10 are produced before morphologic evidence of keratinization becomes detectable. Among potential diagnostic applications, analysis of cytokeratin patterns of epidermal cells desquamated in the amniotic fluid may provide earlier and less invasive diagnosis than fetoscopic biopsies. Similarly, a review of cytokeratins expressed in a variety of epithelial diseases (involving the epidermis, digestive tract, respiratory tract, urogenital tract, or breast) demonstrated persistence of the original tissue pattern in some instances (this was the case for the majority of simple epithelia) but not in others (complex epithelia). This suggests that cytokeratins may prove valuable as markers for specific tumor stages or types and may provide earlier information than morphologic studies.

Changes in cytokeratin expression in gingiva during inflammation.

Cytokeratins represent specific markers of certain pathways of epithelial differentiation. The purpose of this study was to describe the alterations of cytokeratin pattern and topographical distribution of individual cytokeratins in inflamed gingiva. Five healthy and 15 inflammatory samples of human gingiva were studied. From each biopsy, cryostat sections allowed histological staining, immunofluorescence microscopy using a battery of monoclonal antibodies to cytokeratins, and gel electrophoresis. The results show marked differences in cytokeratin expression by healthy epithelia as compared with inflamed gingiva: in suprabasal cell layers there were reductions or disappearance of cytokeratins 1, 2 and 10, 11--specific for terminal differentiation--and increased expression of cytokeratins 4 and 13, as well as--in basal and parabasal cell layers--expression of cytokeratin 19. These alterations might represent an adaptation of involved epithelia to the alterations brought about by the inflammatory process.