RESUMO
This work presents bibliographic data on the role and function of microbial diversity. The increasing use of probiotics and prebiotics foods has led to the studies on their actual functions in the human body. It is known that in the environment, microorganisms are extremely important in recycling of nutrients, balance of trophic chains, vital physiological activities in the plants and animals, as well as the conservation of natural habitats. In human food, these microscopic organisms contribute from flavoring products to the synthesis of antimicrobial substances and vitamins essential to living beings.
RESUMO
Plant expression of the entomopathogenic bacteria Bacillus thuringiensis cry gene has reduced the damage created by insect pests in several economically important cultures. For this study, we have conducted genetic transformation of the indica rice "IRGA 424", via Agrobacterium tumefaciens, using the B. thuringiensis cry1Aa and cry1B genes, with the objective of obtaining rice plants resistant to the insect pests from this culture. The gene constructions harbor the promoters maize proteinase inhibitor and ubiquitin. The results showed that high concentration of the hormone 2,4-dichlorophenoxyacetic acid and agarose as the gelling agent helped the production of embryogenic calli for the analyzed cultivar. More than 80% of the obtained transformed plants revealed the integration, using polymerase chain reaction, of the cry1Aa and cry1B genes. Analysis of the expression of the heterologous protein by Western blotting revealed the expression of the Cry1B delta-endotoxin in IRGA 424 plants transformed with the ubiquitin promoter. Data showed the production and dissemination of a high number of embryogenic calli in addition to obtaining plants transformed with the cry1Aa and cry1B genes until the reproductive phase. The feed bioassays with the transformed plants and Spodoptera frugiperda (JE Smith) larvae indicated high rates of mortality to the insect target. The highest corrected mortality rate achieved under laboratory conditions with Bt-rice plants transformed with the cry1B and cry1Aa genes was 94 and 84%, respectively. Thus, our results demonstrated the great potential of transformed Bt-rice plants in controlling the damage caused by these insect pests in rice paddy fields.
Assuntos
Proteínas de Bactérias/genética , Endotoxinas/genética , Proteínas Hemolisinas/genética , Herbivoria , Oryza/genética , Controle Biológico de Vetores , Plantas Geneticamente Modificadas/genética , Spodoptera/fisiologia , Agrobacterium/genética , Animais , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/metabolismo , Western Blotting , Endotoxinas/metabolismo , Proteínas Hemolisinas/metabolismo , Larva/crescimento & desenvolvimento , Larva/fisiologia , Oryza/metabolismo , Reação em Cadeia da Polimerase , Spodoptera/crescimento & desenvolvimentoRESUMO
This study evaluated the effects of soy protein containing isoflavones on the lipid profile of women. A meta-analysis including 13 eligible randomized controlled trials was carried out. The literature was systematically searched for randomized controlled trials on the effects of soy protein containing isoflavones on the serum lipids of adult women. The main searched databases were PubMed, Cochrane Library, MedLine, Lilacs and Web of Science. Randomized controlled trials were included if they met the following criteria: published from 1966 to 2005, the study population consisted of women only, had either a crossover or a parallel design and the amounts of soy protein and isoflavones consumed were provided. Weighted mean effect sizes were calculated for net changes in serum lipid concentrations using fixed-effects and random-effects models. Prespecified subgroup analyses were performed to explore the influence of covariates on net lipid change. Soy protein with isoflavones was associated with a significant decrease in total serum cholesterol (by 5.34mg/dL, or 2.4 percent, p=0.03). No significant associations were detected for low density lipoprotein-cholesterol, triacylglycerols and high density lipoprotein-cholesterol. Amounts of soy protein greater than 40g decreased total cholesterol by 6.56mg/dL (95 percent CI: -12.35 to -0.39, p=0.04). Soy protein supplementation had small statistically significant effects on the total serum cholesterol of women, but they were clinically insignificant. Furthermore, there were no statistically significant effects on serum low density lipoprotein-cholesterol, high density lipoprotein-cholesterol or triglycerides.
Avaliar o efeito da proteína de soja isolada contendo isoflavonas sobre os níveis de lipídeos séricos em mulheres adultas através de uma metanálise. Realizou-se uma busca sistemática de artigos nos bancos de dados Cochrane Library, MedLine e Web of Science databases. Foram selecionados somente ensaios clínicos randomizados que apresentavam os seguintes critérios: desenho do estudo paralelo ou crossover, publicados entre 1966 e 2005, sujeitos do sexo feminino, especificação da quantidade administrada de proteína de soja isolada contendo isoflavonas. Após criteriosa seleção e análise da qualidade dos estudos, conduziu-se uma metanálise incluindo 13 ensaios clínicos randomizados. O efeito do consumo de proteína de soja isolada sobre os níveis de lipídeos séricos foi calculado utilizando-se os modelos de efeito fixo e efeitos aleatórios. Realizou-se análise em subgrupos para avaliar a influência de covariáveis sobre alterações dos níveis de lipídeos sanguíneos. A metanálise mostrou que o consumo de proteína de soja isolada está associado à diminuição do colesterol-total (-5,34mg/dL, ou 2.4 por cento, p=0,03). Não se encontraram alterações significativas ao avaliar o lipoproteina de baixa densidade-colesterol, os triglicerídeos e o lipoproteina de alta densidade-colesterol. O consumo de proteína de soja isolada, em quantidades maiores ou iguais a 40g/dia, reduziu os níveis de colesterol-total em 6,56mg/dl (95 por cento IC: -12,35 a 0,39, p=0,04). Os achados sugerem efeitos estatisticamente significativos de pequena magnitude sobre os níveis de lipídeos séricos em mulheres, mas clinicamente insignificativos. Além disso, não foram encontrados efeitos estatisticamente significativos sobre a concentração sérica de lipoproteina de baixa densidade-colesterol, lipoproteina de alta densidade-colesterol ou triglicerídios.
Assuntos
Humanos , Feminino , Adulto , Anticolesterolemiantes/análise , Proteínas de Soja/metabolismo , Proteínas de Soja/uso terapêuticoRESUMO
The ketogenic diet (KD), characterized by high fat and low carbohydrate and protein contents, has been proposed to be beneficial in children with epilepsy disorders not helped by conventional anti-epileptic drug treatment. Weight loss and inadequate growth is an important drawback of this diet and metabolic causes are not well characterized. The aim of this study was to examine body weight variation during KD feeding for 6 wk of Wistar rats; fat mass and adipocyte cytosolic phosphoenolpyruvate carboxykinase (PEPCK) activity were also observed. PEPCK activity was determined based on the [H(14)CO(3) (-)]-oxaloacetate exchange reaction. KD-fed rats gained weight at a less rapid rate than normal-fed rats, but with a significant increment in fat mass. The fat mass/body weight ratio already differed between ketogenic and control rats after the first week of treatment, and was 2.4 x higher in ketogenic rats. The visceral lipogenesis was supported by an increment in adipocyte PEPCK, aiming to provide glycerol 3-phosphate to triacylglycerol synthesis and this fat accumulation was accompanied by glucose intolerance. These data contribute to our understanding of the metabolic effects of the KD in adipose tissue and liver and suggest some potential risks of this diet, particularly visceral fat accumulation.
Assuntos
Tecido Adiposo/anatomia & histologia , Dieta Cetogênica/estatística & dados numéricos , Fosfoenolpiruvato Carboxiquinase (ATP)/metabolismo , Redução de Peso/fisiologia , Tecido Adiposo/efeitos dos fármacos , Animais , Criança , Colesterol/sangue , Epilepsia/prevenção & controle , Humanos , Masculino , Ratos , Ratos Wistar , Triglicerídeos/sangue , Redução de Peso/efeitos dos fármacosRESUMO
OBJETIVO: Identificar a prevalência e os fatores de risco para sobrepeso e obesidade nas mulheres de São Leopoldo, RS, Brasil. MÉTODOS: Foi realizado um estudo transversal com base populacional incluindo 981 mulheres de 20 a 60 anos de idade. O sobrepeso foi definido pelo índice de massa corporal entre 25 a 29,9 Kg/m² e a obesidade foi considerada como IMC > 30 Kg/m². As medidas de efeito brutas e ajustadas foram calculadas pela Regressão de Poisson. RESULTADOS: A prevalência de sobrepeso foi de 31,7 por cento (IC95 por cento 28,9 - 34,7) e 18 por cento (IC95 por cento 15,8 - 20,6) das mulheres estavam obesas. Após o ajuste no modelo multivariado, o risco de obesidade foi maior nas mulheres de 50 a 60 anos, inseridas nas classes econômicas mais baixas (D e E), com 5 ou mais filhos, com história familiar de obesidade e que relataram fazer as refeições de forma rápida. A idade da menarca mostrou-se inversamente associada com obesidade. O risco de sobrepeso aumentou com a idade, o número de filhos, estado civil e história familiar de obesidade. A única variável socioeconômica associada com sobrepeso foi escolaridade. DISCUSSÃO: Foram percebidos diferenciais entre a determinação de obesidade e de sobrepeso. O estudo comprovou que o direcionamento das ações no sentido do aumento da escolaridade pode influir positivamente nos indicadores de sobrepeso e, consequentemente, de obesidade.
OBJECTIVE: To find the prevalence and associated risk factors for overweight and obesity in women living in São Leopoldo, RS, Brazil. METHODS: A cross-sectional population-based study of 981 women from 20 to 60 years of age was carried out. Overweight was defined as Body Mass Index (BMI) between 25 and 29.9 Kg/m² and obesity as BMI e"30 Kg/m². Adjusted and crude measures of association were calculated using Poisson Regression. RESULTS: A total of 31.7 percent (CI95 percent 28.9 - 34.7) of women were overweight and 18 percent (CI95 percent 15.8 - 20.6) were obese. After adjustments in the multivariate model, risk of obesity was higher in women aged 50 to 60 years, belonging to lower economic classes (D and E), having 5 or more children, parental background of obesity and in those who reported eating fast. Menarch age was shown to have an inverse association with obesity. The risk of overweight increased with age, with the number of children, with marital status and parental background of obesity. The only socioeconomic variable associated with overweight referred to years of schooling. DISCUSSION: There were differences in obesity and overweight determinants. Results confirmed that actions directed toward increasing level of education could have a positive effect on overweight indicators, and indirectly on obesity indicators.
Assuntos
Feminino , Humanos , Obesidade , Aumento de Peso , Mulheres , Prevalência , Fatores de RiscoRESUMO
Ketogenic diets have been used to treat epilepsy in children for almost 80 years. However, there are only few studies concerning behavioral effects of these diets, besides their efficacy in treating seizure disorders induced by kainic acid or pentylenetetrazol in rats. Here, rats were fed with a ketogenic diet and locomotion, anxiety and nociception were investigated after 10 weeks. Male Wistar rats were weight matched and divided into two groups: control rats, that received regular laboratory ration, and KD rats, that received ketogenic diet (70% fat, 24% protein and no carbohydrate). Behavioral tests were applied after 10-12 weeks of treatment, and included tests to evaluate exploration (habituation to the open field), anxiety (plus-maze), and nociception (tail-flick measurement). Performance of the animals in the open field revealed a significant difference in the number of crossings, suggesting a higher locomotor activity in animals fed with a ketogenic diet. No differences in anxiety were observed, as evaluated by the plus-maze test. Nociception was measured by the latency in the tail-flick test, and ketogenic rats presented a hypernociceptive response. Yet, these animals responded to a stressor with the classic analgesia, similarly to the controls. The response of ketogenic diet fed rats to the stressor, however, was more prolonged. Exposure to a ketogenic diet may induce higher locomotor activity, together with a hypernociceptive state in the animals, possibly as a result of some alteration in the neural systems involved in the modulation of these behaviors.
Assuntos
Nível de Alerta , Gorduras na Dieta/administração & dosagem , Proteínas Alimentares/administração & dosagem , Corpos Cetônicos/sangue , Aprendizagem em Labirinto , Atividade Motora , Limiar da Dor , Animais , Nível de Alerta/fisiologia , Masculino , Aprendizagem em Labirinto/fisiologia , Atividade Motora/fisiologia , Limiar da Dor/fisiologia , Ratos , Tempo de Reação/fisiologia , Estresse Psicológico/complicaçõesRESUMO
Ketogenic diets have been used to treat seizure disorders of children resistant to conventional anti-epileptic drug treatment. The mechanism of action of this diet, however, is unknown. Gliosis is a very common characteristic in tissues associated with epileptogenesis and glial cytokines may be involved in the pathology of seizure disorders. We investigate herein, whether ketogenic diet fed rats demonstrate changes in the immunocontent of S100B, an astrocyte-derived cytokine elevated in the temporal lobe of refractory epilepsy. Lower levels of S100B were observed in cerebrospinal fluid with no significant changes in S100B and GFAP content in brain tissue. Ketogenic fed rats presented a lower seizure severity induced by pentylenetetrazole and no change in cerebrospinal fluid S100B after pentylenetetrazole administration. These results support the concept that the ketogenic diet is neuroprotective in seizure disorders. Since S100B has an extracellular activity in neuronal excitability and synaptic plasticity, it would be reasonable to conceive that a decrease in the S100B could be involved in the mechanism of action of the ketogenic diet. However, it is not possible to establish a direct link between reduced CSF S100B and decreased severity of PTZ-induced attacks at present moment. Regardless of this, CSF S100B could be proposed as an index of efficacy of ketogenic diet for seizure disorders.
Assuntos
Epilepsia/líquido cefalorraquidiano , Epilepsia/terapia , Alimentos Formulados , Gliose/líquido cefalorraquidiano , Corpos Cetônicos/metabolismo , Proteínas S100/líquido cefalorraquidiano , Animais , Astrócitos/metabolismo , Biomarcadores , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Convulsivantes , Modelos Animais de Doenças , Regulação para Baixo/fisiologia , Epilepsia/prevenção & controle , Proteína Glial Fibrilar Ácida/metabolismo , Masculino , Fatores de Crescimento Neural , Pentilenotetrazol , Ratos , Ratos Wistar , Subunidade beta da Proteína Ligante de Cálcio S100 , Resultado do TratamentoRESUMO
Ketogenic diets have been used in the treatment of refractory childhood epilepsy for almost 80 years; however, we know little about the underlying biochemical basis of their action. In this study, we evaluate oxidative stress in different brain regions from Wistar rats fed a ketogenic diet. Cerebral cortex appears to have not been affected by this diet, and cerebellum presented a decrease in antioxidant capacity measured by a luminol oxidation assay without changes in antioxidant enzyme activities--glutathione peroxidase, catalase, and superoxide dismutase. In the hippocampus, however, we observed an increase in antioxidant activity accompanied by an increase of glutathione peroxidase (about 4 times) and no changes in lipoperoxidation levels. We suggest that the higher activity of this enzyme induced by ketogenic diet in hippocampus might contribute to protect this structure from neurodegenerative sequelae of convulsive disorders.
Assuntos
Dieta , Glutationa Peroxidase/metabolismo , Hipocampo/enzimologia , Cetonas/metabolismo , Animais , Masculino , Ratos , Ratos Wistar , Substâncias Reativas com Ácido TiobarbitúricoRESUMO
Ketogenic diets have been used to treat seizure disorders of children and recently it was shown to increase the drug-induced seizure threshold in rats. Protein phosphorylation is a major regulatory mechanism of signal transduction that has been implicated in modulating neuronal excitability. We investigated the basal protein phosphorylation in microslices from different brain regions (hippocampus, cerebral cortex and cerebellum) of young rats fed a ketogenic diet, and we evaluated the effect of this diet on weight development and health of these rats based on serum biochemistry. Thirty-day-old rats consumed ad libitum ketogenic (high fat) or control diets for 8 wk. Rats consuming the high fat diet had ketonemia without signs of undernutrition or illness. Microslices were incubated in media containing (32)P-phosphate, and (32)P-phosphoprotein content was analyzed by one- or two-dimensional electrophoresis followed by autoradiography. Basal protein phosphorylation was greater in brain slices from ketogenic rats. Different increments of synapsin I, GAP-43 and GFAP phosphorylation were observed in two-dimensional autoradiography. A ketogenic diet induced metabolic changes affecting the basal status of protein phosphorylation. This change could affect the mechanisms of signal transduction in neural cells involved in the increase in the seizure threshold.