Prevalencia de intento de suicidio adolescente y factores de riesgo asociados en una comuna rural de la provincia de Concepción / Suicide attempts among Chilean adolescents

Background: Suicide mortality rates are increasing among teenagers. Aim: To study the prevalence and predictive factors of suicide attempts among Chilean adolescents. Material and Methods: A random sample of 195 teenagers aged 16 ± 1 years (53% males) answered an anonymous survey about their demographic features, substance abuse, the Osaka suicidal ideation questionnaire, Smilksten familial Apgar. Beck hopelessness scale, Beck depression scale and Coppersmith self-esteem inventory. Results: Twenty five percent of respondents had attempted suicide at least in one occasion during their lives. These attempts were significantly associated with female gender, absent parents, family dysfunction, drug abuse, smoking, low self-esteem, hopelessness, depression and recent suicidal ideation. A logistic regression analysis accepted female gender, smoking and recent suicidal ideation as significant independent predictors of suicide attempt. Conclusions: Suicide attempted is common among teenagers and its predictors are female sex, smoking and previous suicidal ideation.

Análisis de la interacción entre el polimorfismo Rs671 del gen ALDH2 y consumo de alcohol en individuos chilenos / Interaction between Rs671 polymorphism of the ALDH2 gene and alcohol consumption in Chilean individuals

El alcoholismo es un importante problema de salud pública. En los últimos años ha causado interés el metabolismo del alcohol, puesto que ha sido considerado un posible determinante biológico en la conducta de consumo. Variados estudios se han orientado a la búsqueda y comprensión de la influencia de polimorfismos, en genes que codifican para los principales sistemas enzimáticos que intervienen en el metabolismo hepático. El polimorfismo rs671 del gen que codifica la enzima ALDH2 ha sido asociado a un menor consumo de alcohol debido a la acumulación de acetaldehído en sangre. Diversos estudios indican que este polimorfismo es frecuente en países asiáticos y se considera un factor protector en los individuos que lo portan. Se incluyeron 207 individuos adultos no relacionados, a los cuales se les aplicó un cuestionario sobre consumo de alcohol. El polimorfismo rs671 fue analizado por la reacción de la polimerasa en cadena (PCR) seguida de restricción enzimática. Además, se determinaron los biomarcadores clásicos indirectos de consumo de alcohol, mediante técnicas enzimáticas y hematológicas. La frecuencia del genotipo homocigoto mutado AA para el polimorfismo rs671 fue 3,0% en sujetos consumidores de alcohol y 2,8% en el grupo no consumidor. La distribución de genotipos y las frecuencias alélicas para esta variante fueron semejantes entre los sujetos estudiados (p>0,05). Estos hallazgos sugieren que la variante rs671 del gen ALDH2 no está asociada al oconsumo de alcohol en los individuos estudiados.

Alcoholism is an important public health problem. In recent years, alcohol metabolism caused interest, since it has been considered a possible biological determinant of alcohol consumption behavior. Several studies have focused on finding and understanding the influence of polymorphisms affecting genes that encode for enzymatic systems involved in the hepatic metabolism. The rs671 polymorphism of the gene encoding ALDH2 has been associated with lower alcohol consumption by leading to acetaldehyde accumulation in blood. This genetic variant is frequently found in Asian population and has been considered as protector factor of alcoholism in these individuals. In the present study, 207 unrelated-adult individuals were included. Alcohol consumption was recorded using a structured questionnaire. The rs671 polymorphism was analyzed using polymerase chain reaction followed by enzymatic digestion. Furthermore, classical biomarkers for alcohol consumption were assessed using enzymatic and hematological techniques. The frequency of homozygote genotype for the A allele (AA) was 3 and 2.8% in those subjects defined as alcohol drinkers and non-alcohol drinkers respectively. The genotypes distribution and allelic frequencies were similar among the studied subject (p>0.05). These data suggest that rs671 ALDH2 gene polymorphism is not associated to alcohol consumption in the studied population.

Expression of aldehyde dehydrogenase after neoadjuvant chemotherapy is associated with expression of hypoxia-inducible factors 1 and 2 alpha and predicts prognosis in locally advanced breast cancer

OBJECTIVE: To analyze the expression of hypoxia-inducible factors (hypoxia-inducible factor 1A and hypoxia-inducible factor 2A) and aldehyde dehydrogenase proteins in patients with locally advanced breast carcinoma who were subjected to neoadjuvant chemotherapy. METHODS: We included 90 patients with histologically confirmed stage II and III breast carcinoma who were treated with neoadjuvant chemotherapy between 2000 and 2005. Immunohistochemistry for aldehyde dehydrogenase, hypoxia-inducible factor 1A, and hypoxia-inducible factor 2A was performed before and after neoadjuvant chemotherapy. We analyzed the influence of clinical and pathological features on clinical and pathological response, disease-free survival, and overall survival. RESULTS: An objective clinical response to neoadjuvant chemotherapy was observed in 80% of patients, with 12% showing a complete pathological response. Among all clinical and pathological parameters, only the expression of hypoxia-inducible factor 1A was associated with a pathological response. A positive association was found between expression of aldehyde dehydrogenase and that of hypoxia-inducible factor 1A before and after chemotherapy. Aldehyde dehydrogenase expression was associated with expression of hypoxia inducible-factor 2A in tumors after neoadjuvant treatment. In a univariate analysis, prognosis was influenced by age, pathological response, metastasis to axillary lymph nodes after neoadjuvant chemotherapy, overexpression of hypoxia-inducible factor 2, and the presence of aldehyde dehydrogenase-positive cells within the primary tumor after neoadjuvant chemotherapy. In a multivariate analysis, only age and the presence of aldehyde dehydrogenase-positive cells after chemotherapy were associated with reduced overall survival. CONCLUSION: The presence of aldehyde dehydrogenase-positive cells within the residual tumor after neoadjuvant chemotherapy is associated with an increase in the expression ...

Enzymology of ethanol and acetaldehyde metabolism in mammals

Ehtanol or wthyl alcohol is a molecule that, in mammals, is naturally present at low concentrations due to its production by gastrointestinal flora fermentation activity. However, it is remarkable that this metabolite, with a clearly minor role in regular vertebrate metabolism, can be oxidized into acetaldehyde through several ensymatic and non-enzymatic mechanisms, which comprise the activity of more than ten ensymes and isozymes, many of them broadly distributed in different specie and tissues. In correspondence, acetaldehyde can also be oxidized into acetate through several enzymatic pathways that involve about ten enzymes and isozymes which also have a broad distribution In this article, a complete review of the aforementioned metabolic pathways is elaborated. From this group, the participation and wide distribution of alcohol dehydrogenase and aldehyde dehydrogenase systems are emphasized. The mechanism of reaction, kinetic characteristics and physiological relevance are described, and finally, the possible physiological role of these enzymatic systems as responsible to synthesize or catabolize several endogenous metabolites that regulate growth, metabolism, differentiation and neuroendocrine function in mammals are discussed