RESUMO
The mammalian target of rapamycin (mTOR) is involved in the regulation of learning and memory. Recently, rapamycin has been shown to be neuroprotective in models for Alzheimer's disease in an autophagy-dependent manner. Here we show that rapamycin exerts neuroprotection via a novel mechanism that involves presynaptic activation. Rapamycin increases the frequency of miniature excitatory postsynaptic currents and calcium transients of rat hippocampal primary neurons by a mechanism that involves the up regulation of SV2, a presynaptic vesicular protein linked to neurotransmitter release. Under these conditions, rapamycin-treated hippocampal neurons are resistant to the synaptotoxic effect induced by Aß oligomers, suggesting that enhancers of presynaptic activity can be therapeutic agents for Alzheimer's disease.
Assuntos
Peptídeos beta-Amiloides/toxicidade , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Hipocampo/metabolismo , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Sirolimo/farmacologia , Transmissão Sináptica/fisiologia , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Cálcio/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Imunofluorescência , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Imunossupressores/farmacologia , Masculino , Neurônios/efeitos dos fármacos , Neurônios/patologia , Ratos , Ratos Sprague-Dawley , Transmissão Sináptica/efeitos dos fármacosRESUMO
1. The objective of this study was to determine a metabolisable energy (ME) requirement model for broiler breeder hens. The influence of temperature on ME requirements for maintenance was determined in experiments conducted in three environmental rooms with temperatures kept constant at 13, 21 and 30 degrees C using a comparative slaughter technique. The energy requirements for weight gain were determined based upon body energy content and efficiency of energy utilisation for weight gain. The energy requirements for egg production were determined on the basis of egg energy content and efficiency of energy deposition in the eggs. 2. The following model was developed using these results: ME = kgW0.75(806.53-26.45T + 0.50T2) + 31.90G + 10.04EM, where kgW0.75 is body weight (kg) raised to the power 0.75, T is temperature ( degrees C), G is weight gain (g) and EM is egg mass (g). 3. A feeding trial was conducted using 400 Hubbard Hi-Yield broiler breeder hens and 40 Peterson males from 31 to 46 weeks of age in order to compare use of the model with a recommended feeding programme for this strain of bird. The application of the model in breeder hens provided good productive and reproductive performance and better results in feed and energy conversion than in hens fed according to strain recommendation. In conclusion, the model evaluated predicted an ME intake which matched breeder hens' requirements.
Assuntos
Galinhas/fisiologia , Metabolismo Energético/fisiologia , Modelos Biológicos , Animais , Dieta/veterinária , Ovos/análise , Feminino , Abrigo para Animais , Oviposição/fisiologia , Temperatura , Aumento de Peso/fisiologiaRESUMO
The objective of this study was to determine models for ME requirements for broiler breeder pullets using the factorial method. The influence of the temperature on maintenance ME requirements was determined by experiments conducted in three environmental rooms with temperature kept constant at 15,22, and 30 degrees C, using the comparative slaughter technique. The energy requirements for weight gain were determined based on the body energy content and efficiency of energy utilization for weight gain. Two ME requirement models for each age were developed using the coefficients for maintenance and weight gain. The models for 3 to 8 wk were ME = W(0.75) (186.52 - 1.94T) + 2.47WG, and ME = W(0.75) (174 - 1.88T) + 2.83WG; for 9 to 14 wk, ME = W(0.75) (186.52 - 1.94T) + 2.69WG, and ME = W(0.75) (174 - 1.88T) + 2.50WG; and 15 to 20 wk, ME = W(0.75) (186.52 - 1.94T) + 2.76WG, and ME = W(0.75) (174 - 1.88T) + 3.24WG. In these equations, W is BW (kg), T is temperature (degrees C), and WG is daily weight gain (g). These models were compared to the breeder's recommendations in a feeding trial from 5 to 20 wk of age. Models 1 and 2 provided energy intakes that promoted BW smaller than the breeder's recommendation. However, all breeder pullets had weights above the standard recommendation. Model 2 gave the smallest ME intake and BW close to the standard recommendation and provided the best prediction of ME requirements.
Assuntos
Galinhas/metabolismo , Metabolismo Energético , Modelos Biológicos , Fenômenos Fisiológicos da Nutrição Animal , Animais , Galinhas/crescimento & desenvolvimento , Ingestão de Energia , Feminino , Necessidades Nutricionais , Temperatura , Aumento de PesoAssuntos
Tuberculose Pulmonar/prevenção & controle , Adolescente , Vacina BCG , Criança , Pré-Escolar , Humanos , Lactente , MéxicoAssuntos
Tuberculose Pulmonar , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História Antiga , História Medieval , Humanos , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/história , Tuberculose Pulmonar/prevenção & controleAssuntos
Mycobacterium tuberculosis , Tuberculose/história , Antituberculosos/uso terapêutico , Bacteriologia/história , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História Antiga , História Medieval , Humanos , México , Mycobacterium tuberculosis/isolamento & purificação , Programas Nacionais de Saúde , Meio Social , Tuberculose/microbiologia , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/históriaAssuntos
Programas Nacionais de Saúde , Tuberculose/prevenção & controle , Adolescente , Criança , Pré-Escolar , Humanos , MéxicoAssuntos
Influenza Humana/epidemiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Surtos de Doenças/epidemiologia , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História Moderna 1601- , Humanos , Lactente , Recém-Nascido , Influenza Humana/história , Influenza Humana/microbiologia , México , Pessoa de Meia-Idade , Orthomyxoviridae/isolamento & purificação , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologiaAssuntos
Agonistas Adrenérgicos beta/farmacologia , Brônquios/efeitos dos fármacos , Broncodilatadores/farmacologia , Receptores Adrenérgicos beta/efeitos dos fármacos , Receptores Adrenérgicos/efeitos dos fármacos , Agonistas Adrenérgicos beta/uso terapêutico , Broncopatias/tratamento farmacológico , Broncodilatadores/uso terapêutico , HumanosAssuntos
Influenza Humana/epidemiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Surtos de Doenças/epidemiologia , Europa (Continente) , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , Humanos , Lactente , Recém-Nascido , Vacinas contra Influenza , Influenza Humana/história , Influenza Humana/microbiologia , México , Pessoa de Meia-Idade , OrthomyxoviridaeAssuntos
Tuberculose/epidemiologia , Adolescente , Adulto , Humanos , México , Tuberculose/prevenção & controle , Tuberculose/terapiaRESUMO
Se mencionan algunos antecedentes historicos de la influenza. Se decriben sus caracteristicas epidemiologicas y clinicas.Se senalan diferencias entre los virus A, B y C se menciona la importancia de la inmunoprofilaxis
