Exercise reduces inhibitory neuroactivity and protects myenteric neurons from age-related neurodegeneration.

The practice of regular exercise is indicated to prevent some motility disturbances in the gastrointestinal tract, such as constipation, during aging. The motility alterations are intimately linked with its innervations. The goal of this study is to determine whether a program of exercise (running on the treadmill), during 6 months, has effects in the myenteric neurons (NADH- and NADPH-diaphorase stained neurons) in the colon of rats during aging. Male Wistar rats 6 months (adult) and 12 months (middle-aged) old were divided into 3 different groups: AS (adult sedentary), MS (middle-aged sedentary) and MT (middle-aged submitted to physical activity). The aging did not cause a decline significant (p>0.05) of the number of NADH-diaphorase stained neurons in sedentary rats (AS vs. MS group). In contrast, a decline of 31% was observed to NADPH-diaphorase stained neurons. Thus, animals that underwent physical activity (AS vs. MT group) rescued neurons from degeneration caused by aging (total number, density and profile of neurons did not change with age--NADH-diaphorase method). On the other hand, physical activity augmented the decline of NADPH-diaphorase positive neurons (total number, density and profile of neurons decreased). Collectively, the results show that exercise inhibits age-related decline of myenteric neurons however, exercise augments the decline of neurons with inhibitory activity (nitric oxide) in the colon of the rats.

Burning mouth syndrome (BMS): sialometric and sialochemical analysis and salivary protein profile.

OBJECTIVE: The aim of the present study was to analyse the characteristics of salivary production and its composition in individuals with burning mouth syndrome (BMS). STUDY DESIGN: Salivary flow rate, concentrations of potassium, iron, chloride, thiocyanate, magnesium, calcium, phosphorus, glucose, total protein and urea, as well as the expression profile of salivary proteins were analysed by SDS-PAGE. RESULTS: The mean salivary flow rate among control patients was lower than that of BMS patients. Chloride, phosphorus and potassium levels were elevated in patients with BMS (p = 0.041, 0.001 and 0.034, respectively). Total salivary protein concentration was reduced in individuals with BMS (p = 0.223). Analysis of the expression of salivary proteins by Coomassie blue SDS-PAGE revealed a lower expression of low molecular weight proteins in individuals with BMS compared to healthy controls. CONCLUSIONS: These results indicate that the identification and characterisation of low molecular weight salivary proteins in BMS may be important in understanding BMS pathogenesis, thus contributing to its diagnosis and treatment.

An emerging peri-urban pattern of infection with Leishmania chagasi, the protozoan causing visceral leishmaniasis in northeast Brazil.

Peri-urban visceral leishmaniasis (VL) caused by Leishmania chagasi is emerging in a new epidemiologic pattern in Brazilian cities. We studied peri-urban VL in endemic neighborhoods surrounding Natal, Brazil, identified through hospitalized individuals with VL. Clinical and environmental information obtained for 1106 members of 216 families living in endemic neighborhoods enabled us to identify 4 groups: VL: individuals with current or prior symptomatic visceral leishmaniasis (n = 135); DTH+: individuals with positive delayed-type hypersensitivity response with no history of VL (n = 390); Ab +: individuals with negative DTH response and seropositive (n = 21); DTH -: individuals with negative DTH and seronegative (n = 560). The mean +/-SD age of VL was 9.3+/-12.3 y. The gender distribution was nearly equal below age 5, but skewed toward males at higher ages. Acutely infected VL subjects had significantly lower hematocrits, neutrophils, and eosinophils than other categories. AB+ subjects also had lower eosinophil counts than others, a possible immune marker of early infection. VL was not associated with ownership of dogs or other animals, raising the question whether the reservoir differs in peri-urban settings. This new pattern of L. chagasi infection enables us to identify epidemiological and host factors underlying this emerging infectious disease.

Changing epidemiology of American cutaneous leishmaniasis (ACL) in Brazil: a disease of the urban-rural interface.

American cutaneous leishmaniasis (ACL) was first reported from the south-western region of the state of Rio Grande do Norte in 1987. São Miguel municipality and adjacent areas have accounted for 90% of the American cutaneous leishmaniasis cases in the region since then. A population survey conducted in São Miguel and adjacent areas was undertaken to identify individuals with a history of ACL. The incidence of ACL, distribution by age and gender, clinical characteristics, family clustering, relationship to animals, association with skin test responses, and development of mucosal lesions were determined. Males and females were equally likely to be infected by Leishmania. Thirty-eight percent of the individuals tested were found to be Montenegro skin test positive. No difference in the Montenegro skin test was observed with gender, but the response increased with age. Among the 140 ACL cases treated in a 4-year period in São Miguel, five (3.6%) developed mucosal involvement. Sandflies capable of transmitting Leishmania were captured inside households and in the areas surrounding them. The high density of sandfly species potentially able to transmit Leishmania species and the age distribution of cases of cutaneous leishmaniasis suggest that transmission of the parasite occurred inside or in close proximity to houses.

Characterization of Leishmania chagasi DNA topoisomerase II: a potential chemotherapeutic target.

DNA topoisomerase II (topo II), an enzyme essential for cellular replication, is an eminent target for antimicrobial therapy against Leishmania chagasi, the major cause of visceral leishmaniasis in Latin America. The complete L. chagasi (Lch) TOP2 gene, encoding L. chagasi topo II, was isolated from genomic DNA using the polymerase chain reaction. The LchTOP2 gene revealed an open reading frame (ORF) of 3,711 base pairs predicting a protein with 1,236 amino acids and an estimated molecular weight of 140 kDA. The L. chagasi topo II sequence had high identity with the L. donovani topo II (98.8%) and L. infantum topo II (98.7%), followed by Crithidia fasciculata topo II (84.4%), Trypanosoma cruzi topo II (67.6%) and Trypanosoma brucei topo II (66.6%). Lch topo II had low identity with the human homologs htopo II alpha (26.3%) and htopo II beta (26.4%). Differences between L. chagasi TOP2 and human TOP2 genes suggest that leishmanial topo II is a potential target for the development of new antileishmanial agents.

Avaliaçäo da resposta glicêmica ao cuscuz, em humanos sadios / Evaluation of the glycemic response to \"cuscuz\" in healthy volunteers

O índice glicêmico é um parâmetro que representa o impacto provocado por um alimento específico na glicemia pós-prandial. O conceito de índice glicêmico tem sido aplicado à diabetes, pesquisas ligadas a perfomance física e do apetite. Avaliou-se a resposta glicêmica ao cuscuz, em seis voluntárias sadias do curso de especializaçäo em bioquímica da nutriçäo, com idade média de 28 anos e índice de massa corporal (IMC) de 21,8 kg/m2. Determinou-se o índice glicêmico, avaliando-se a resposta glicêmica após a ingestäo de 50 g de carboidrato disponível do alimento teste, usando como referencial a glicose, conforme JENKINS, et al., 1981. Foi realizado um teste oral de tolerância à glicose e após 15 dias o de tolerância ao cuscuz. O resultado mostrou que o alimento teste (cuscuz) apresentou um alto índice glicêmico (IG=140,3) quando comparado com o arroz branco rico em amilose (IG=59); por isso, sugere-se que o cuscuz seja indicado para a alimentaçäo do atleta.