The avirulence of the cultivated Y strain of Trypanosoma cruzi: IV. The effect of immunosuppressive agents in mice

Drogas imunossupressoras (Azathioprina e Methotrexato) que se mostraram capazes de agravar infecções experimentais por Trypanosoma cruzi virulento (cepa Y), em camundongos, não conseguiram favorecer o aparecimento de qualquer sinal de infecção em animais vacinados com a cepa avirulenta PF do mesmo tripanosoma. Vinblastine, quando dado 3 dias antes da vacina, não favoreceu parasitemias positivas nem mortalidade significativamente aumentada, mas induziu o aparecimento de hemoculturas positivas. Os tripanosomas dessas culturas foram incapazes de infectar camundongos jovens. Quando o Vinblastine foi usado 15 dias após a vacinação dos animais, todos os testes foram negativos, inclusive as hemoculturas

Seroprevalence and risk factors for canine visceral leishmaniasis in the endemic area of Dias D'Ávila, State of Bahia, Brazil

INTRODUCTION: Visceral leishmaniasis (VL) is an important zoonosis in relation to public health systems. Dogs are the main domestic reservoir. This study aimed to investigate occurrences of canine VL in Dias D'Ávila, State of Bahia, Brazil. METHODS: The prevalence was evaluated by means of clinical and laboratory tests on a population of 312 domestic dogs from 23 localities in this municipality, using indirect immunofluorescence and immunoenzymatic assays. RESULTS: Among the animals examined, 3.2% and 6.7% showed signs of VL, confirmed by indirect immunofluorescence and immunoenzymatic assays, respectively, with a distribution of 29.9% (24 dogs) in the rural zone and 4.9% (288 dogs) in the urban zone (p = 0.001). The clinical evaluation on seropositive dogs showed both asymptomatic animals (2.4%) and symptomatic animals (47.6%), along with other abnormalities (e.g. normocytic and normochromic anemia, with leukocytosis and thrombocytopenia). Observations relating to phenotypic characteristics (e.g. sex, age, breed and hair) did not present statistical significance, although high seropositivity among male, short-haired and mixed-breed dogs was observed. CONCLUSIONS: The findings showed that VL was a predominantly rural zoonosis and that close contact between poultry and domestic dogs significantly increased the risk of canine infection in this region.

Prevalence of hypovitaminosis D and its association with oral lesions in HIV-infected Brazilian adults

Abstract: INTRODUCTION: This study assessed the prevalence of hypovitaminosis D and its association with oral candidiasis and clinical parameters of periodontitis (CPP) in HIV-infected patients. METHODS: Periodontal examinations for the 113 HIV-infected patients were recorded using the Community Periodontal Index. A cytological smear from the lateral borders of the tongue was performed to evaluate candidiasis. RESULTS: The frequency of hypovitaminosis D was 23.9%. In multivariate analysis, only the duration of exposure to HIV was associated with CPP [OR 4.72 (95% CI: 0.97-23.00)]. CONCLUSIONS: The prevalence of hypovitaminosis D was 23.9% and was not related with oral candidiasis or CPP.

An account of the Crustacea of Norway, with short descriptions and figures of all the species. By G.O. Sars ...

v.5 Copepoda-Harpacticoida

An account of the Crustacea of Norway, with short descriptions and figures of all the species. By G.O. Sars ...

v.1 Amphipoda (text)

An account of the Crustacea of Norway, with short descriptions and figures of all the species. By G.O. Sars ...

v.2 Isopoda

An account of the Crustacea of Norway, with short descriptions and figures of all the species. By G.O. Sars ...

v.3 Cumaceae

An account of the Crustacea of Norway, with short descriptions and figures of all the species. By G.O. Sars ...

v.6 Copepoda-Cyclopoida

An account of the Crustacea of Norway, with short descriptions and figures of all the species. By G.O. Sars ...

v.4 Copepoda-Calanoida

An account of the Crustacea of Norway, with short descriptions and figures of all the species. By G.O. Sars ...

v.7 Copepoda-Supplement

An account of the Crustacea of Norway, with short descriptions and figures of all the species. By G.O. Sars ...

v.8 Copepoda-Monstrilloida & Notodelphyoida

Endogeneizing know-how flows through the nature of R&D investments

In this paper we carefully link knowledge flows to and from a firms innovation process with this firms investment decisions. Three types of investments are considered: investments in applied research, investments in basic research, and investments in intellectual property protection. Only when basic research is performed, can the firm effectively access incoming knowledge flows and these incoming spillovers serve to increase the efficiency of own applied research.. The firm can at the same time influence outgoing knowledge flows, improving appropriability of its innovations, by investing in protection. Our results indicate that firms with small budgets for innovation will not invest in basic research. This occurs in the short run, when the budget for know-how creation is restricted, or in the long-run, when market opportunities are low, when legal protection is not very important, or, when the pool of accessible and relevant external know-how is limited. The ratio! of basic to applied research is non-decreasing in the size of the pool of accessible external know-how, the size and opportunity of the market, and, the effectiveness of intellectual property rights protection. This indicates the existence of economies of scale in basic research due to external market related factors. Empirical evidence from a sample of innovative manufacturing firms in Belgium confirms the economies of scale in basic research as a consequence of the firms capacity to access external knowledge flows and to protect intellectual property, as well as the complementarity between legal and strategic investments.

Studies on Trypanosoma rangeli Tejera 1920. IV - A reconsideration of its systematic position

The systematic positon of Trypanosoma rangeli is reconsidered and the creation of a new subgenus. Tejeraia, is proposed to remove this trypanosome from the subgenus Herptosoma of the section Stercoraria. The characteristics described for the proposed subgenus indicate that it must be located in the section Salivaria rather than in the Stercoraria. The evidence supporting this proposition is discussed in the text.

Effect of vitamin D on Epstein-Barr (EBV)-specific CD8+T cells in patients with early multiple sclerosis (MS)

Background: Infection with EBV and a lack in vitamin D may be important environmental triggers of MS. 1,25-(OH)2D3 mediates a shift of antigen presenting cells (APC) and CD4+ T cells to a less inflammatory profile. Although CD8+ T cells do express the vitamin D receptor, a direct effect of 1,25(OH)2D3 on these cells has not been demonstrated until now. Since CD8+ T cells are important immune mediators of the inflammatory response in MS, we examined whether vitamin D directly affects the CD8+ T cell response, and more specifically if it modulates the EBV-specific CD8+ T cell response. Material and Methods: To explore whether the vitamin D status may influence the pattern of the EBV-specific CD8+ T cell response, PBMC of 10 patients with early MS and 10 healthy controls (HC) were stimulated with a pool of immunodominant 8-10 mer peptide epitopes known to elicit CD8+ T cell responses. PBMC were stimulated with this EBV CD8 peptide pool, medium (negative control) or anti- CD3/anti-CD28 beads (positive control). The following assays were performed: ELISPOT to assess the secretion of IFN-gamma by T cells in general; cytometric beads array (CBA) and ELISA to determine whichcytokines were released by EBV-specific CD8+ T cells after six days of culture; and intracellular cytokine staining assay to determine by which subtype of T cells secreted given cytokines. To examine whether vitamin D could directly modulate CD8+ T cell immune responses, we depleted CD4+ T cells using negative selection. Results: We found that pre-treatment of vitamin D had an antiinflammatory action on both EBV-specific CD8+ T cells and on CD3/ CD28-stimulated T cells: secretion of pro-inflammatory cytokines (IFNgamma and TNF-alpha) was decreased, whereas secretion of antiinflammatory cytokines (IL-5 and TGF-beta) was increased. At baseline, CD8+ T cells of early MS patients showed a higher secretion of TNFalpha and lower secretion of IL-5. Addition of vitamin D did not restore the same levels of both cytokines as compared to HC. Vitamin D-pretreated CD8+T cells exhibited a decreased secretion of IFN-gamma and TNF-alpha, even after depletion of CD4+ T cells from culture. Conclusion: Vitamin D has a direct anti-inflammatory effect on CD8+ T cells independently from CD4+ T cells. CD8+ T cells of patients with earlyMS are less responsive to the inflammatory effect of vitamin D than HC, pointing toward an intrinsic dysregulation of CD8+ T cells. The modulation of EBV-specific CD8+T cells by vitaminDsuggests that there may be interplay between these twomajor environmental factors of MS. This study was supported by a grant from the Swiss National Foundation (PP00P3-124893), and by an unrestricted research grant from Bayer to RDP.