METHODS: The National Health and Morbidity Survey (NHMS) 2017 (n = 8230) was used for analyses. It was a nationwide survey conducted in Malaysia. The dependent variables were measured by three risk behaviors (cigarette smoking, alcohol drinking and use of illicit drugs). Probit regressions were utilized to examine the effect of mental health on the probability of smoking, drinking and using illicit drugs. Demographic and lifestyle factors were used as the control variables. Truancy was identified as a mediating variable.
RESULTS: Anxiety, depression and suicidal ideation affected cigarette smoking, alcohol drinking and use of illicit drugs through mediation of truancy. After controlling for demographic and lifestyle factors, students with anxiety, depression and suicidal ideation were more likely to smoke, drink and use illicit drugs compared with their peers without any mental health disorders. Furthermore, the likelihood of consuming cigarettes, alcohol and illicit drugs was found to be higher among students who played truant than those who did not.
CONCLUSION: Mental health plays an important role in determining participation in risk behaviors among ethnic minority students in Malaysia. Public health administrators and schools have to be aware that students who suffer from mental health disorders are likely to indulge in risk behaviors.
PURPOSE: We adopted a combinatorial approach with the joint application of γ-tocotrienol and jerantinine A at lower concentrations in order to minimize toxicity towards non-cancerous cells while improving the potency on brain cancer cells.
METHODS: The antiproliferative potency of individual γ-tocotrienol and jerantinine A as well as combined in low-concentration was firstly evaluated on U87MG cancer and MRC5 normal cells. Morphological changes, DNA damage patterns, cell cycle arrests and the effects of individual and combined low-concentration compounds on microtubules were then investigated. Finally, the potential roles of caspase enzymes and apoptosis-related proteins in mediating the apoptotic mechanisms were investigated using apoptosis antibody array, ELISA and Western blotting analysis.
RESULTS: Combinatorial study between γ-tocotrienol at a concentration range (0-24µg/ml) and fixed IC20 concentration of jerantinine A (0.16µg/ml) induced a potent antiproliferative effect on U87MG cells and led to a reduction on the new half maximal inhibitory concentration of γ-tocotrienol (i.e.tIC50=1.29µg/ml) as compared to that of individual γ-tocotrienol (i.e. IC50=3.17µg/ml). A reduction on undesirable toxicity to MRC5 normal cells was also observed. G0/G1 cell cycle arrest was evident on U87MG cells receiving IC50 of individual γ-tocotrienol and combined low-concentration compounds (1.29µg/ml γ-tocotrienol + 0.16µg/ml jerantinine A), whereas, a profound G2/M arrest was evident on cells treated with IC50 of individual jerantinine A. Additionally, individual jerantinine A and combined compounds (except individual γ-tocotrienol) caused a disruption of microtubule networks triggering Fas- and p53-induced apoptosis mediated via the death receptor and mitochondrial pathways.
CONCLUSIONS: These findings demonstrated that the combined use of lower concentrations of γ-tocotrienol and jerantinine A induced potent cytotoxic effects on U87MG cancer cells resulting in a reduction on the required individual concentrations and thereby minimizing toxicity of jerantinine A towards non-cancerous MRC5 cells as well as probably overcoming the high-dose limiting application of γ-tocotrienol. The multi-targeted mechanisms of action of the combination approach have shown a therapeutic potential against brain cancer in vitro and therefore, further in vivo investigations using a suitable animal model should be the way forward.
AIMS AND METHODS: The present study aimed to examine the changes in mean daily cigarette consumption among random samples of the Malaysian current smoker population over 20 years using an age-period-cohort (APC) approach. We conducted APC analysis using a multilevel hierarchical age-period-cohort model and data from four nationally representative, repeated cross-sectional surveys (National Health and Morbidity Survey) conducted in 1996, 2006, 2011, and 2015 among individuals aged 18 to 80 years. Analyses were also stratified by gender and ethnicity.
RESULTS: Overall, mean daily cigarette consumption (smoking intensity) among current smokers increased with age until 60, after which a drop was observed. There were increases in daily cigarette consumption across birth cohorts. Age and cohort trends did not vary by gender but by ethnicity. The decreasing cigarette consumption after age 60 among the current smoker population was consistent with those observed among the Chinese and Indians, a trend that was not observed in Malays and other aborigines. In contrast, the increasing cohort trend was consistent with those observed among the Malays and other bumiputras.
CONCLUSIONS: The present study highlighted important ethnic-specific trends for mean daily cigarette consumption among the current smoker population in Malaysia. These findings are essential in guiding the formulation of interventional strategies or implementation of national tobacco control policies and help achieve the Ministry of Health Malaysia's 2025 and 2045 targets for smoking prevalence.
IMPLICATIONS: This is the first APC study on smoking intensity among current smokers in a multiracial, middle-income nation. Very few studies had performed gender- and ethnic-stratified APC analyses. The ethnic-stratified APC analyses provide useful insights into the overall age and cohort trends observed among the current smoker population in Malaysia. Therefore, the present study could add evidence to the existing literature on the APC trends of smoking intensity. The APC trends are also important in guiding the government to develop, implement, and evaluate antismoking strategies.