BACKGROUND: The rate of nicotine metabolism described the presence of nicotine metabolites, which are the negative impact of cigarette smoke. CYP2A13 is one of the main enzymes responsible for nicotine metabolism and xenobiotic activity in tobacco smoking-related lung cancer.AIM: This study aims to analyze the correlation between CYP2A13 and nicotine metabolism in male smokers in Indonesia.METHODS: This was a cross-sectional study with consecutive sampling to 100 male smokers aged between 20 and 65 years old meeting inclusion and exclusion criteria. The CYP2A13 polymorphism was examined by restriction fragment length polymorphism (RFLP) PCR through venous blood extraction. The levels of nicotine metabolites in the urine samples were assessed by high-performance liquid chromatography (HPLC). The associations between nicotine metabolism and genetic polymorphism of the CYP2A13 gene in male smokers in Indonesia was determined by logistics regression test using Epi Info-7 software.RESULTS: There were 100 participants involved in this study, in which 78 subjects were with the first stage of CYP2A13 polymorphism. There was no significant correlation between CYP2A13 genotype and nicotine metabolism (p value > 0.05). The CC genotype was more frequently found in the population in this study. Most research subjects had rapid metabolizers.CONCLUSION: There is no significant relationship between CYP2A13 polymorphism and nicotine metabolism in male smokers in Indonesia. Therefore, it is important to carry out further studies to investigate genetic polymorphisms and nicotine metabolism in different population.

Background: Pneumo-mediastinum is a rare disease associated with barotrauma and uncommonly occurs in viral pneumonia. Although the underlying mechanism of the incidence of pneumo-mediastinum in COVID-19 patients is not fully understood, barotrauma is the most probable cause.   Case Report: We reported a case of a 27-years-old woman with the chief complaint was shortness of breath and diagnosed with COVID19 based on RT-PCR examination. On the sixth day after being admitted to the hospital, suddenly, the intensity of dyspnea was increased with the decrease of oxygen saturation. CT of the chest confirmed pneumomediastinum and pneumonia COVID -19. There was no improvement of symptoms after oxygen and steroid administration. Emergency thoracotomy was not performed yet, and the patient has died.  Conclusions: Although pneumomediastinum is benign disease and self-limited disease, the presents of pneumomediastinum may relate to worse outcomes in COVID19 infections.