METHODS: Male Sprague Dawley rats were subjected to normal condition, REM sleep deprivation and control wide platform condition for 72 hr. During this procedure, saline or nicotine (1 mg/kg) was given subcutaneously twice a day. Then, Morris water maze (MWM) test was used to assess learning and memory performance of the rats. The rats were sacrificed and the brain was harvested for immunohistochemistry and Western blot analysis.
RESULTS: MWM test found that REM sleep deprivation significantly impaired learning and memory performance without defect in locomotor function associated with a significant increase in hippocampus DREAM protein expression in CA1, CA2, CA3, and DG regions and the mean relative level of DREAM protein compared to other experimental groups. Treatment with acute nicotine significantly prevented these effects and decreased expression of DREAM protein in all the hippocampus regions but only slightly reduce the mean relative level of DREAM protein.
CONCLUSION: This study suggests that changes in DREAM protein expression in CA1, CA2, CA3, and DG regions of rat's hippocampus and mean relative level of DREAM protein may involve in the mechanism of nicotine treatment-prevented REM sleep deprivation-induced learning and memory impairment in rats.
MATERIAL AND METHODS: A) Effects of various doses of nicotine on in vitro embryonic development: Female mice were treated with 1.0, 3.0, or 5.0 mg/kg/day nicotine for 7 consecutive days. Animals were superovulated, cohabited overnight, and sacrificed. Embryos were cultured in vitro. Plasma was assayed. B) Effects of concomitant treatment of nicotine concurrently with various doses of gamma-TCT on in vitro embryonic development: Female mice were treated with nicotine (5.0 mg/kg/day), gavaged gamma-TCT of 30, 60, or 90 mg/kg/day or nicotine concurrently with gamma-TCT of 3 different doses for 7 consecutive days. Animals were superovulated, cohabited overnight, and sacrificed. Embryos were cultured and plasma was assayed.
RESULTS: A) Effects of various doses of nicotine on in vitro embryonic development: Number of hatched blastocysts decreased in 1.0 and 3.0 mg/kg/day nicotine groups. Nicotine at 5.0 mg/kg/day stopped embryo development at morula. MDA concentrations increased following all nicotine doses. B) Effects of concomitant treatment of nicotine concurrently with various doses of gamma-TCT on in vitro embryonic development: Embryo development was completed in all groups. MDA concentration increased only in the group treated with nicotine concurrently with 30 mg/kg/day gamma-TCT.
CONCLUSIONS: Nicotine impairs in vitro embryo development and increases MDA in plasma. The deleterious impact of nicotine on embryo development is reversed by supplementing gamma-TCT concurrently with nicotine.
MATERIAL AND METHODS: The Singapore Mental Health Study (SMHS) is a cross-sectional epidemiological study that was conducted between December 2009 and December 2010. Information on smoking status was assessed using the Composite International Diagnostic Interview version 3.0 (CIDI 3.0) and the Fagerstrom Test for Nicotine Dependence measured nicotine dependence. Socio-demographic information was also collected.
RESULTS: In total, 6616 respondents participated in the SMHS giving a response rate of 75.9%. We found that 16% of the population were current smokers and 4.5% had nicotine dependence. Current smokers were more likely to be younger (18 to 34 years old), males, Malay and have lower education, whilst males had a 4.6 times higher risk of nicotine dependence to that of females. The prevalence of nicotine dependence was also higher in those with alcohol abuse and those experiencing chronic pain.
CONCLUSION: The results from this study highlight the important differences in the prevalence of smoking and nicotine dependence among different age groups, gender and ethnicity in Singapore and are important for developing future health policies and targeted preventive strategies.
Methods: Twelve rats were equally divided into two groups. Group I received normal saline, and group II received 0.6 mg/kg body weight nicotine intraperitoneally for 28 consecutive days. At the end of the experimental period, sperm was collected for sperm characteristic evaluation, and the testes and prostate were isolated for biochemical and morphological analysis. The effects of nicotine on the body and reproductive organ weights of the animals were evaluated.
Results: Chronic nicotine treatment significantly (P < 0.05) altered the sperm count, motility, viability, and morphology, and remarkably increased the malondialdehyde (P < 0.001) and advanced oxidation protein product (P < 0.05) levels in the testes and prostate of nicotine-treated group compared to control group. Moreover, nicotine caused a significant decrease (P < 0.05) in the superoxide dismutase activity of the testes. No significant differences were observed in the reduced glutathione level in both of the testes and prostate of nicotine group compared with control group. Nicotine also induced histopathological alteration in the testes.
Conclusion: A low-dose nicotine exposure at 0.6 mg/kg caused detrimental effects on sperm characteristics and induced oxidative stress in the testes and prostate.
Methods: This comparative cross-sectional study was conducted among healthy women. The cases included those women exposed to SHS, and the controls included those women not exposed to SHS. SHS exposure was defined as being exposed to SHS for at least 15 min for 2 days per week. Venous blood was taken to measure the metabolic markers (high molecular weight adiponectin, insulin level, insulin resistance, and nonesterified fatty acids), oxidative stress markers (oxidized low density lipoprotein cholesterol and 8-isoprostane), and inflammatory markers (high-sensitivity C-reactive protein and interleukin-6). A hair nicotine analysis was also performed. An analysis of covariance and a simple linear regression analysis were conducted.
Results: There were 101 women in the SHS exposure group and 91 women in the non-SHS exposure group. The mean (with standard deviation) of the hair nicotine levels was significantly higher in the SHS exposure group when compared to the non-SHS exposure group [0.22 (0.62) vs. 0.04 (0.11) ng/mg; P = 0.009]. No significant differences were observed in the high molecular weight adiponectin, insulin and insulin resistance, nonesterified fatty acids, 8-isoprostane, oxidized low density lipoprotein cholesterol, interleukin-6, and high-sensitivity C-reactive protein between the two groups. The serum high molecular weight adiponectin was negatively associated with the insulin level and insulin resistance in the women exposed to SHS. However, no significant relationships were seen between the high molecular weight adiponectin and nonesterified fatty acids, 8-isoprostane, oxidized low density lipoprotein cholesterol, high-sensitivity C-reactive protein in the SHS group.
Discussion: There were no significant differences in the metabolic, oxidative stress, and inflammatory markers between the SHS exposure and non-SHS exposure healthy women. A low serum level of high molecular weight adiponectin was associated with an increased insulin level and resistance in the women exposed to SHS.
METHODS: This cross-sectional study conducted in 2016 involving 388 late adolescents from six government colleges in Kelantan, Malaysia, aged 18 to 19 years. They were requested to answer self-directed questionnaires with items on sociodemographic information and types of ATNP used. Other variables obtained include the environmental influence and reasons for using the products. Regression analyses between the dependent and independent variables were conducted using IBM SPSS ver. 20.0 (IBM Corp., Armonk, NY, USA).
RESULTS: The prevalence of ATNP use among late adolescents was 14.4%. The male sex, cigarette smoking status, and peer use were significantly associated with ATNP use. Several reasons for use were not significantly associated with ATNP use: perception of ATNP being less harmful and less addictive compared with cigarettes, curiosity, less expensive than cigarettes, to aid smoking cessation, and pleasurable flavors and taste.
CONCLUSION: The prevalence of ATNP use among late adolescents studying in government colleges in Kelantan is significant. There is higher perception on ATNP being less harmful and addictive than the conventional cigarette among the users compared with non-users. Significant associations are seen for the male sex, peer use, and concurrent cigarette smoking.