A novel HLA allele, HLA-DRB1*13:204, detected in a Brazilian unrelated hematopoietic stem cell donor.

The HLA-DRB1*13:204 allele differs from HLA*13:64 by two nucleotide substitutions at positions 181 and 189 in the exon 2.

Moderate physical exercise protects myenteric metabolically more active neurons in mice infected with Trypanosoma cruzi.

BACKGROUND: Trypanosoma cruzi causes neuronal myenteric depopulation compromising intestinal function. AIM: The purpose of this study was to evaluate the influence of moderate physical exercise on NADH diaphorase (NADH-d)-positive neurons in the myenteric plexus and intestinal wall of the colon in mice infected with T. cruzi. MATERIALS AND METHODS: Forty 30-day-old male Swiss mice were divided into the following groups: trained infected (TI), sedentary infected (SI), trained control (TC), and sedentary control. The TC and TI groups were subjected to a moderate physical exercise program on a treadmill for 8 weeks. Three days after finishing physical exercise, the TI and SI groups were intraperitoneally inoculated with 1,300 blood trypomastigotes of the Y strain of Trypanosoma cruzi. Parasitemia was evaluated from days 4 to 61 after inoculation. On day 75 of infection, myenteric neurons in the colon were quantified (NADH-d), and inflammatory foci were counted. Tumor necrosis factor-α (TNF-α) and transforming growth factor-ß (TGF-ß) levels were evaluated in plasma. The results were compared using analysis of variance and the Kruskal-Wallis test at a 5 % significance level. RESULTS: Moderate physical exercise reduced the parasite peak on day 8 of infection (p = 0.0132) and total parasitemia (p = 0.0307). It also prevented neuronal depopulation (p < 0.01), caused hypertrophy of these cells (p < 0.05), prevented the formation of inflammatory foci (p < 0.01), and increased the synthesis of TNF-α (p < 0.01) and TGF-ß (p > 0.05). CONCLUSION: These results reinforce the therapeutic benefits of moderate physical exercise for T. cruzi infection.

Role of omega-3 polyunsaturated fatty acids in the production of prostaglandin E2 and nitric oxide during experimental murine paracoccidioidomycosis.

There has recently been increased interest in the potential health effects of omega-3 polyunsaturated fatty acids on the immune system. Paracoccidioidomycosis is the most important endemic mycosis in Latin America. Macrophages have a fundamental role and act as first line of organism defense. The purpose of this study was to analyze the effect of n-3 fatty acids on the production of PGE2 and NO by mice infected with Pb18 and fed a diet enriched with LNA for 8 weeks. To study the effect of omega-3 fatty acids on macrophage activity during experimental paracoccidioidomycosis, mice were infected with Pb18 and fed a diet supplemented with LNA. PGE2 in the serum of animals was analyzed and NO in the supernatants of macrophages cultured and challenged in vitro with Pb18 was measured. Omega-3 fatty acids seemed to decrease the production of PGE2 in vivo in the infected group fed an LNA-supplemented diet during the 4th and 8th weeks of the experiment. At the same time, we observed an increase in synthesis of NO by peritoneal macrophages in this group. Omega-3 fatty acids thus appear to have an immunomodulatory effect in paracoccidioidomycosis.

Radiotherapy effect on frequency of Candida spp. and on virulence of C. albicans isolated from the oral cavity of head and neck cancer patients

The aim of this study was to investigate the diversity and prevalence of yeasts, and the virulence of C.albicans found in the oral cavity during the course of ionizing radiation treatment of patients with head and neck tumor (HNTP). Samples from 21 HNTP and 24 healthy controls were isolated and identified. C. albicans isolated from two patients during radiotherapy were analyzed for virulence factors. Radiotherapy induced a higher level of both yeast colonization (81% vs 33%) and non-albicans Candida (NAC) colonization (52.4% vs 4.0%) in HNTP than the control group. Patients were colonized by 5 different NAC species: C. glabrata, C. tropicalis, C. parapsilosis, C. krusei and C. kefir. On the other hand, C. albicans colonization was similar in patients and controls (6/21, 28.6% vs 7/24, 29.2%, respectively). Also, of the 11 patients assessed before and during radiotherapy, 5 (45.5%) were colonized before the start of treatment and another 5 (45.5%) during treatment. All of the latter were colonized by NAC species alone. Moreover, we observed a significant and continuous enhancement of C. albicans virulence as the radiotherapy progressed, in the two patients involved in this test. Thus, it is concluded that radiotherapy is an important predisposing factor for the oral candidiasis, including NAC species. Also, it may facilitate the development of more virulent C. albicans strains.

O objetivo deste estudo foi avaliar a diversidade e a prevalência de Cândida, bem como a virulência de Cândida albicans, isoladas da cavidade bucal no decurso de tratamento por radiações ionizantes de pacientes acometidos por tumores de cabeça e pescoço (PTCP). Amostras de 21 pacientes e 24 controles foram analisadas. C. albicans isoladas de dois pacientes ao longo do tratamento radioterápico foram avaliadas para fatores de virulência. A radioterapia induziu um grande aumento da colonização de Cândida como um todo (81% vs 33%) e Cândida não albicans (CNA) em particular (52.4% vs 4.0%) em PTCP quando comparado com controles não irradiados. Cinco espécies diferentes de CNA foram encontradas nos pacientes: C. glabrata, C. tropicalis, C. parapsilosis, C. krusei and C. kefir. Por outro lado, a colonização por C. albicans nestes pacientes e controles foi similar (6/21, 28.6% vs 7/24, 29.2%, respectivamente). Além disso, dos 11 pacientes que foram avaliados antes e durante o tratamento radioterápico, 5 pacientes (45,5%) foram colonizados antes do início da radioterapia e outros 5 (45,5%) durante o tratamento radioterápico. Destes últimos, todos foram colonizados apenas com espécies CNA. Observou-se, ainda, um aumento contínuo e significante da virulência de C. albicans com o progresso da radioterapia nos dois pacientes estudados. Conclui-se que o tratamento radioterápico é um importante fator de desenvolvimento de candidíase oral, incluindo candidíase por espécies não albicans, em pacientes portadores de tumor de cabeça e pescoço. A radioterapia pode, ainda, facilitar o desenvolvimento de cepas mais virulentas de C.albicans.