RESUMO
This study focuses on gene expression during crucial biological phenomena of the dimorphic fungal human pathogen Paracoccidioides brasiliensis, the conidia-to-yeast (C-Y) transition and the conidia-to-mycelia (C-M) germination. We studied 10 genes involved in different cellular functions: oxidative stress response (alternative oxidase (AOX), superoxide dismutase (SOD), flavodoxin, conserved hypothetical protein (Y20)); cell metabolism (glyceraldehyde-3-phosphate dehydrogenase (GADPH), cholestenol Delta-isomerase (ChDI), glycine dehydrogenase (GDh)) and heat shock response (Heat shock protein 90 (HSP90)), and cell synthesis and wall structure (glucan synthase-1 (GS-1), α-1,3-glucan synthase (αGS), and mannosyltransferase (MT)). Gene expression was measured during the first 72 h and 96 h of C-Y and C-M, respectively, previously shown to be a fundamental time frame for the consolidation of these cellular processes. The gene expression of AOX, GAPDH, HSP90, MT, αGS, and GDh was significantly increased during the C-Y transition, while SOD, ChDI, GAPDH, MT, GDh, and GS-1 were increased during C-M germination. Additionally, some were highly expressed in each process: AOX, HSP90, and αGS during C-Y; SOD, ChDI, and GS-1 during C-M. Altogether, these data add new information regarding gene expression during the C-Y and C-M processes. Future research will be targeted to further characterize the true relevance of the studied genes during the morphological transition, either during adaptation to the environment or to the infected host.
Assuntos
Regulação Fúngica da Expressão Gênica , Paracoccidioides/crescimento & desenvolvimento , Esporos Fúngicos/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Micélio/genética , Micélio/crescimento & desenvolvimento , Micélio/metabolismo , Paracoccidioides/genética , Paracoccidioides/metabolismo , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/metabolismoRESUMO
OBJECTIVE: To determine the prevalence of tobacco consumption among the active insured population of the Mexican Social Security Institute. MATERIAL AND METHODS: A cross-sectional study in which the active insured population from the 36 political delegations was interviewed by means of a structured and self-applicable questionnaire on tobacco consumption, age of initiation, amount of cigarettes consumed and suspension. RESULTS: The sample consisted of 45 117 subjects, of which approximately half were men and half women. Smoking prevalence in men was 40% and in women, 17.6%. Prevalence was highest in the north of the country. There is an effect of age on tobacco consumption and more than half started smoking during adolescence. CONCLUSIONS: Smoking prevalence was found to be high, however, the average number of cigarettes is low. Suspension index is low. Public health measures are necessary to diminish this addiction.
Assuntos
Fumar/epidemiologia , Previdência Social , Adolescente , Adulto , Distribuição por Idade , Idoso , Feminino , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Prevalência , Distribuição por Sexo , Abandono do Hábito de Fumar/estatística & dados numéricos , Previdência Social/estatística & dados numéricos , Inquéritos e QuestionáriosAssuntos
Gravidez , Lactente , Cricetinae , Humanos , Animais , Feminino , Neoplasias Pulmonares/etiologia , Nitrosaminas/metabolismo , Tabagismo/complicações , Carcinógenos/efeitos adversos , Dimetilnitrosamina/metabolismo , DNA/metabolismo , Neoplasias Laríngeas , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/etiologia , Menopausa/efeitos dos fármacos , Nitrosaminas/efeitos adversos , Neoplasias Ovarianas/etiologia , Neoplasias Ovarianas/metabolismo , Ovário/enzimologia , Ovário/metabolismo , Placenta/efeitos adversos , Fumar/história , Nicotiana , Poluição por Fumaça de Tabaco/efeitos adversos , Neoplasias da LínguaAssuntos
Gravidez , Lactente , Cricetinae , Humanos , Animais , Feminino , Tabagismo/complicações , Neoplasias Pulmonares/etiologia , Nitrosaminas/metabolismo , Nitrosaminas/efeitos adversos , Tabagismo/história , Poluição por Fumaça de Tabaco/efeitos adversos , Nicotiana , Dimetilnitrosamina/metabolismo , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/etiologia , Neoplasias da Língua , Neoplasias Laríngeas , Ovário/metabolismo , Ovário/enzimologia , Carcinógenos/efeitos adversos , DNA/metabolismo , Menopausa/efeitos dos fármacos , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/etiologia , Placenta/efeitos adversosRESUMO
N-Nitrosodimethylamine (NDMA) was metabolized by ovarian slices of noninbred Sprague-Dawley rats (200-250 g body wt, to CO2 and to reactive metabolites that bind covalently to nucleic acids. That ability was about 10 or 5 times smaller than the one observed in liver slices, respectively. Both ovarian microsomes and mitochondria were able to biotransform NDMA to formaldehyde and to reactive metabolites that bind covalently to proteins. Formaldehyde formation by microsomes was significantly higher than that by ovarian mitochondria but of the same order of magnitude. Ability to lead to covalent binding to proteins in microsomes was not significantly different from that in the respective mitochondrial fraction. DNA isolated from ovarian slices activating NDMA revealed the presence of the altered bases 7-methylguanine (7-MeGua) and O6-methylguanine (O6-MeGua) resulting from NDMA reactive metabolites' attack. Results suggest potential, mutagenic, carcinogenic and reproductive risks derived from women's exposure to NDMA present in tobacco smoke, food, beverages, workplace or other environmental sources.
Assuntos
DNA/metabolismo , Dimetilnitrosamina/metabolismo , Ovário/metabolismo , Animais , Sistema Enzimático do Citocromo P-450/fisiologia , Dimetilnitrosamina/toxicidade , Feminino , Formaldeído/metabolismo , Ovário/efeitos dos fármacos , Ligação Proteica , Ratos , Ratos EndogâmicosRESUMO
Outbreaks of liver necrosis and liver hemangiosarcoma were detected in a mink breeding colony in Argentina. Analysis of the Minks' food revealed the presence of 2.6 ppm dimethylnitrosamine (NDMA) in it, apparently as a result of the addition of nitrite as preservative. Previous studies gave evidence of the particular susceptibility of minks to NDMA and other hepatic insults. We have determined several biochemical parameters known to correlate with NDMA hepatotoxic effects and compared them with those in rat liver. NDMA administration to both species resulted in the formation of reactive metabolites able to interact with liver DNA to give N7-methylguanine and O6-methylguanine adducts. Biotransformation of NDMA by liver slices to CO2 was significantly lower in the mink than in the rat, whereas the covalent binding (CB) to nucleic acids was slightly lower than in in the rat. Aminopyrine N-demethylase activity was also significantly less in mink than in rat liver. The CB of NDMA reactive metabolites to microsomal proteins was not significantly lower in mink as compared to the rat, and the same holds true for the biotransformation of NDMA to formaldehyde by microsomal preparations. Results suggest that the high susceptibility of minks to NDMA might be partially due to a decreased ability to detoxicate NDMA but also to a higher intrinsic susceptibility of their liver cells to a given chemical insult.