Hyperpalatable Diet and Physical Exercise Modulate the Expression of the Glial Monocarboxylate Transporters MCT1 and 4.

Hyperpalatable diets (HP) impair brain metabolism, and regular physical exercise has an apparent opposite effect. Here, we combined a prior long-term exposure to HP diet followed by physical exercise and evaluated the impact on some neuroenergetic components and on cognitive performance. We assessed the extracellular lactate concentration, expression of monocarboxylate transporters (MCTs), pyruvate dehydrogenase (PDH), and mitochondrial function in the hippocampus. Male C57BL/6J mice were fed 4 months with HP or a control diet. Subsequently, they were divided in the following groups: control diet sedentary (CDS), control diet exercise (CDE), HP diet sedentary (HPS), and HP diet exercise (HPE) (n = 15 per group) and were engaged for an additional 30-day period of voluntary exercise and HP diet. Relative to the control situation, exercise increased MCT1, MCT4, and PDH protein levels, while the HP diet increased MCT1 and MCT4 protein levels. The production of hydrogen peroxide (H2O2) and the mitochondrial membrane potential (∆Ñ°m) stimulated by succinate in hippocampal homogenates were not significantly different between groups. ADP phosphorylation and the maximal respiratory rate induced by FCCP showed similar responses between groups, implying a normal mitochondrial function. Also, extracellular brain lactate levels were increased in the HPE group compared to other groups soon after performing the Y-maze task. However, such enhanced lactate levels were not associated with improved memory performance. In summary, hippocampal protein expression levels of MCT1 and 4 were increased by physical exercise and HP diet, whereas PDH was only increased by exercise. These observations indicate that a hippocampal metabolic reprogramming takes place in response to these environmental factors.

Brain Insulin Administration Triggers Distinct Cognitive and Neurotrophic Responses in Young and Aged Rats.

Aging is a major risk factor for cognitive deficits and neurodegenerative disorders, and impaired brain insulin receptor (IR) signaling is mechanistically linked to these abnormalities. The main goal of this study was to investigate whether brain insulin infusions improve spatial memory in aged and young rats. Aged (24 months) and young (4 months) male Wistar rats were intracerebroventricularly injected with insulin (20 mU) or vehicle for five consecutive days. The animals were then assessed for spatial memory using a Morris water maze. Insulin increased memory performance in young rats, but not in aged rats. Thus, we searched for cellular and molecular mechanisms that might account for this distinct memory response. In contrast with our expectation, insulin treatment increased the proliferative activity in aged rats, but not in young rats, implying that neurogenesis-related effects do not explain the lack of insulin effects on memory in aged rats. Furthermore, the expression levels of the IR and downstream signaling proteins such as GSK3-ß, mTOR, and presynaptic protein synaptophysin were increased in aged rats in response to insulin. Interestingly, insulin treatment increased the expression of the brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) receptors in the hippocampus of young rats, but not of aged rats. Our data therefore indicate that aged rats can have normal IR downstream protein expression but failed to mount a BDNF response after challenge in a spatial memory test. In contrast, young rats showed insulin-mediated TrkB/BDNF response, which paralleled with improved memory performance.

Correlação entre infecções genitais e alterações citopatológicas cervicais em pacientes atendidas no sistema de saúde pública de Porto Alegre / Correlation between genital infections and cervical cytopathological changes in patients assisted in Porto Alegre public health system

Introdução: o câncer cervical tem sido apontado como a segunda neoplasia mais comum entre as mulheres, sendo muitas vezes associado a agentes infecciosos (AI) relacionados a doenças sexualmente transmissíveis (DST) ou oportunistas do trato genitourinário. Objetivo: avaliar diferentes variáveis epidemiológicas, assim como a prevalência dos AI encontrados no exame citológico preventivo e correlacioná-las às alterações citológicas cervicais benignas e malignas. Métodos: análise retrospectiva dos laudos de exames citológicos emitidos entre os anos de 2004 e 2009 de pacientes atendidas em 33 Unidades Básicas de Saúde de Porto Alegre. Foram selecionados 850 laudos de diferentes pacientes e analisadas as variáveis: faixa etária, grau de instrução,AI e alterações celulares. Resultados: cerca de 70% das pacientes situam-se na faixa etária entre 14 e 45 anos, predominando o 1o grau incompleto (38,4%).O agente infeccioso que apresentou maior prevalência foi a Gardnerella vaginalis, com 15,6%, seguida de Candida sp. (2,3%) e Trichomonas vaginalis(2,2%). Dentre as alterações celulares cervicais benignas, a que apresentou maior prevalência foi o epitélio inflamatório (67%), sendo a maioria observada na faixa etária mais jovem. Obteve-se correlação estatisticamente significativa entre as alterações celulares cervicais benignas com os agentes infecciosose com a idade, sendo que dos 275 casos de inflamação, 161 (58,5%) apresentavam também algum AI. Em relação às alterações celulares malignas, poucos casos foram detectados, não sendo possível obter qualquer correlação. Conclusão: os resultados observados em nosso estudo sugerem que há correlação dealterações cérvico-vaginais benignas com casos de infecções microbianas concomitantes ou pregressas nas pacientes avaliadas neste estudo.

Introduction: cervical cancer has been considered the second most common malignancy among women, and is often associated with infectious agents (AI) related to sexually transmitted diseases (STDs) or opportunistic of genitourinary tract. Objective: to evaluate the epidemiological variables and correlate them with cytological benign and malignant cervical changes, as well as the prevalence of AI found in cytology preventive exam. Methods: retrospective analysis of cytological reports issued between 2004 and 2009 of patients treated in 33 Basic Health Care Units in Porto Alegre. A total of 850 reports were selected from different patients and the following variables were analyzed: age, education, AI and cellular changes. Results: approximately 70% of women are at the age between 14 and 45 years old, mainly with incomplete primary school (38.4%). The infectious agent that had the highest prevalence wasGardnerella vaginalis with 15.6% followed by Candida sp. (2.3%) and Trichomonas vaginalis (2.2%). Among the benign cervical cell changes with the highest prevalence was inflammatory epithelium (67%), mostly observed in the youngest age group. A statistically significant correlation between the benign cervical cell changes with infectious agents and with age was obtained, and of 275 cases of inflammation, 161 (58.5%) had also some AI. Regarding tomalignant cell changes, few cases were detected; it is not possible to obtain any correlation. Conclusion: the results observed in this study suggest that there is a correlation of cytological changes in cervical-vaginal benign cases with previous or concomitant microbial infections in women evaluated in this study.