Chronic psychological stress exacerbates aortic medial calcification via glucocorticoids / 生理学报

Chronic psychological stress can promote vascular diseases, such as hypertension and atherosclerosis. This study aims to explore the effects and mechanism of chronic psychological stress on aortic medial calcification (AMC). Rat arterial calcification model was established by nicotine gavage in combination with vitamin D3 (VitD3) intramuscular injection, and rat model of chronic psychological stress was induced by humid environment. Aortic calcification in rats was evaluated by using Alizarin red staining, aortic calcium content detection, and alkaline phosphatase (ALP) activity assay. The expression levels of the related proteins, including vascular smooth muscle cells (VSMCs) contractile phenotype marker SM22α, osteoblast-like phenotype marker RUNX2, and endoplasmic reticulum stress (ERS) markers (GRP78 and CHOP), were determined by Western blot. The results showed that chronic psychological stress alone induced AMC in rats, further aggravated AMC induced by nicotine in combination with VitD3, promoted the osteoblast-like phenotype transformation of VSMCs and aortic ERS activation, and significantly increased the plasma cortisol levels. The 11β-hydroxylase inhibitor metyrapone effectively reduced chronic psychological stress-induced plasma cortisol levels and ameliorated AMC and aortic ERS in chronic psychological stress model rats. Conversely, the glucocorticoid receptor agonist dexamethasone induced AMC, promoted AMC induced by nicotine combined with VitD3, and further activated aortic ERS. The above effects of dexamethasone could be inhibited by ERS inhibitor 4-phenylbutyrate. These results suggest that chronic psychological stress can lead to the occurrence and development of AMC by promoting glucocorticoid synthesis, which may provide new strategies and targets for the prevention and control of AMC.

Urinary cotinine in tobacco farmers in Southern Brazil

ABSTRACT OBJECTIVE To describe urinary cotinine levels in tobacco farmers. METHODS A cross-sectional study was conducted in 2,570 tobacco farmers. All participants that reported green tobacco sickness in the week prior to the interview plus a subsample of 492 pesticide applicators were included. We collected urinary samples and information about sociodemographic, behavioral, dietary, occupational characteristics, and pesticide poisoning during their lifetime. Stratification by sex and smoking was performed and the Wilcoxon and Kruskal-Wallis non-parametrical tests were used to analyze cotinine means. RESULTS This study included 582 individuals. There was no difference in urinary cotinine means between green tobacco sickness symptomatic and asymptomatic individuals. Among non-smokers, having picked tobacco in the previous week was associated with higher cotinine means in both genders. Cotinine levels were higher on the first day of symptoms and reduced exponentially with each day in female non-smokers. Male non-smokers had higher levels on the second day and a more gradual reduction. The cotinine level rose up to 15 cigarettes/day of consumption. CONCLUSIONS The urinary cotinine measures exposure to nicotine up to its saturation point; while green tobacco sickness, affected by tolerance, indicates nicotine poisoning. Strategies to reduce nicotine exposure in tobacco production are needed. Mechanization could be an alternative, as long as it overcame the challenge of irregular terrain and did not affect the quality of the leaf. More studies are needed to evaluate the chronic effect of nicotine exposure.

Different levels of brain-derived neurotrophic factor and cortisol in healthy heavy smokers

Studies suggest that brain-derived neurotrophic factor (BDNF) and the hypothalamic-pituitary-adrenal (HPA) axis modulate dopaminergic activity in response to nicotine and that the concentrations of BDNF and cortisol seem to be dependent on the amount and duration of smoking. Therefore, we investigated BDNF and cortisol levels in smokers ranked by daily cigarette consumption. Twenty-seven adult males (13 non-smokers and 14 smokers) participated in the study. The smokers were divided in two groups: light (n=7) and heavy smokers (n=7). Anthropometric parameters and age were paired between the groups, and plasma BDNF and salivary cortisol levels were measured. Saliva samples were collected on awakening, 30 min after awakening, at 10:00 and 12:00 am, 5:00 and 10:00 pm. Additionally, cotinine serum levels were measured in smokers. Heavy smokers had higher mean values of BDNF compared to the control group (P=0.01), whereas no difference was observed in light smokers. Moreover, heavy smokers presented lower cortisol levels in the last collection (10:00 pm) than the control group (P=0.02) and presented statically higher values of cotinine than the light smokers (P=0.002). In conclusion, changes in BDNF and cortisol levels (10:00 pm) appear to be dependent on heavy cigarette smoking and can be involved in activation and in the relationship between the mesolimbic system and the HPA axis.

Análisis de frecuencias alélicas y genotípicas de las variantes CYP2A6*12 y rs16969968 de CHRNA5 y su asociación con el hábito de fumar y el índice de masa corporal (IMC) en sujetos jóvenes del noreste de México / Association between genotype and allele frequencies of CYP2A6*12 and rs16969968 in CHRNA5 variants with smoking and body mass index in young subjects from Northeast Mexico

Background: Several studies have reported that variants rs16969968 G>A of the CHRNA5 gene and CYP2A6*12 of the CYP2A6 gene are associated with smoking and smoking refusal, respectively. In addition, some studies report that a higher cigarette consumption is associated with low body mass index (BMI). Aim: To analyze the allele and genotypic frequencies of these variants and their impact on smoking and BMI. Material and Methods: A blood sample was obtained and a survey about smoking habits was answered by 319 university students aged 18 to 35 years (127 women, 171 smokers), living in Northeastern Mexico. Genetic variants were studied by polymerase chain reaction/restriction fragment length polymorphism and their frequencies were associated with smoking and BMI. Results: No associations were found between the analyzed variants and smoking in the study groups. However, there was an association among non-smoking subjects between the A allele of rs16969968 and high a BMI (p < 0.01). Conclusions: This last variant may be involved in food-addiction disorders.

Washington y Ginebra llegan a Buenos Aires: notas sobre la historia del hábito de fumar y su medicalización / Washington and Geneva arrive in Buenos Aires: notes on the history of the habit of smoking and its medicalization

Durante gran parte del siglo XX tanto los gobiernos civiles como los militares no encontraron en el tabaquismo un tema prioritario. Recién en la última década del siglo el movimiento internacional contra el cigarrillo, liderado por la Organización Mundial de la Salud, organizaciones norteamericanas y académicos, empezó a tener algún impacto en la escena política argentina. Fue en ese contexto que un nuevo grupo profesional logró impulsar la constitución de un amplio bloque político antitabaco. En ese proceso, el voluntarismo centrado en programas individuales para dejar de fumar que había marcado gran parte de las iniciativas del siglo XX, terminó desplazado por políticas públicas destinadas a producir ambientes libres de humo y a combatir la exposición pasiva al humo de tabaco ajeno.

For much of the twentieth century both the civilian and military governments did not consider smoking a priority concern. It was only in the last decade of the twentieth century that the international movement against cigarettes, led by the World Health Organization, US organizations and academics, began to have some impact on Argentina's political scene. It was in this context that a new professional group managed to foment the creation of a broad anti-smoking political bloc. In this process, voluntarism focused on individual programs to quit smoking that had marked much of the initiatives of the twentieth century, ended up being replaced by public policies designed to ensure smoke free environments and combat passive smoking.

Generation of tobacco lines with widely different reduction in nicotine levels via RNA silencing approaches.

Issues related to the nicotine content of tobacco have been public concerns.Several reports have described decreasing nicotine levels by silencing the putrescine N-methyltransferase (PMT) genes, but the reported variations of nicotine levels among transgenic lines are relatively low in general. Here we describe the generation in tobacco (Nicotiana tabacum) lines with widely different, reduced nicotine levels using three kinds of RNA-silencing approaches.The relative efficacies of suppression were compared among the three approaches regarding the aspect of nicotine level in tobacco leaves.By suppressing expression of the PMT genes, over 200 transgenic lines were obtained with nicotine levels reduced by 9.1-96.7%. RNA interference (RNAi) was the most efficient method of reducing the levels of nicotine,whereas cosuppression and antisense methods were less effective. This report gives clues to the efficient generation of plants with a variety of metabolite levels, and the results demonstrate the relative efficiencies of various RNA-silencing methods.

Effect of tobacco smoking on renal function.

Nicotine is one of many substances that may be acquired through active and passive smoking of tobacco. In man, nicotine is commonly consumed via smoking cigarettes, cigars or pipes. The addictive liability and pharmacological effects of smoking are primarily mediated by the major tobacco alkaloid nicotine. High stress jobs favour repeated smoking and further reinforce addictive behaviours. There are elevated serum cadmium and lead levels in smokers resulting in glomerular dysfunction. Nephropathies are accelerated by nicotine with an increased incidence of microalbuminuria progressing to proteinuria, followed by type-1 diabetes mellitus induced renal failure. Cigarette smoke-induced renal damage is due, at least in part, to activation of the sympathetic nervous system resulting in an elevation in blood pressure. Ethanol, nicotine, or concurrent intake significantly increases lipid peroxidation in liver, and decreased superoxide dismutase activity and increased catalase activity in the kidney. This review describes the effects of nicotine, smoking, smoke extracts and other tobacco constituents on renal and cardiovascular functions, and associated effects on the nervous system. Both active and passive smoking is toxic to renal function.

El tabaco daña la salud. Alerta para los tejidos periodontales! / Tobacco damages the health. An alert for periodontal tissues!

En este trabajo de revisión bibliográfica se encontró que diversos autores coinciden acerca del daño que las sustancias tóxicas del tabaco, provocan a los tejidos periodontales. Conocer la influencia de la nicotina sobre dichos tejidos, servirá de motivación para trabajar en prevención, mejorar el diagnóstico, conocer la limitación del tratamiento y orientar el pronóstico de la enfermedad periodontal del fumador

Urinary cotinine in narguila or chicha tobacco smokers

Urinary levels of nicotine metabolites were measured in nonsmokers and of tobacco either as cigarettes or as the middle eastern water pipes [narguila]. Levels of urinary cotinine were similar for the smokers of cigarettes [median 30 cigarettes per day] and narguila [median 2 pipes per day, or around 40 grams of tobacco]. Use of water pipes may remove a small amount of nicotine, but smokers appear to titrate dose to effect. It is unlikely that narguila smoking confers any less risk

Efeitos do cigarro, da nicotina e do monóxido de carbono sobre alguns parâmetros fisiológicos: uma revisäo da literatura / Physiological effects of cigarrete smoking, nicotine and carbon monoxid: a review of the literature

O hábito de fumar seguramente é prejudicial a saúde, influenciando negativamente a capacidade física. A nicotina é a principal substância presente no fumo e, certamente, a mais prejudicial. O monóxido de carbono é outro componente da fumaça do cigarro que também prejudica a performance em atividades aeróbias. A abstinência do tabaco provoca uma série de efeitos no organismo que säo dependentes do hábito e de características individuais. Abster-se do tabaco por pelo menos un dia implica em melhores performances de atividades aeróbicas, principalmente devido a diminuiçäo da concentraçäo da caroxiemoglobina