24 research outputs found
Testing the Efficacy of a Multi-Component DNA-Prime/DNA-Boost Vaccine against Trypanosoma cruzi Infection in Dogs
Immunization of dogs with DNA-prime/DNA-boost vaccine (TcVac1) enhanced the
Trypanosoma cruzi-specific type 1 antibody and
CD8+ T cell responses that resulted in an early control of
acute parasitemia and a moderate decline in pathological symptoms during chronic
phase. Further improvement of vaccine-induced immunity would be required to
achieve clinical and epidemiological benefits and prevent transmission of
parasites from vaccinated/infected dogs to triatomines
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
O plexo pampiniforme na fase crônica da doença de Chagas humana: avaliação histológica The pampiniform plexus of chronic chagasic patients: a histologic evaluation
Pesquisou-se a ocorrência, na parede das veias do plexo pampiniforme de chagásicos crônicos, de acúmulos intracelulares de Trypanosoma cruzi e sinais inflamatórios (flebite). Para tal fim, colheram-se, à necropsia, 23 pares de funículos espermáticos, epidídimos e testículos, sendo 17 de chagásicos crônicos e 6 de controles (não chagásicos). Em cada caso, foram feitos múltiplos cortes das gônadas e dos vasos; fez-se pesquisa de T. cruzi por imuno-histoquímica nos funículos espermáticos de todos os casos. Não se observaram parasitos nas paredes vasculares. Notou-se flebite crônica inespecífica, focal e discreta, em cinco chagásicos (bilateral em três pacientes) e dois controles; havia infiltração mononuclear discreta do interstício funicular em treze chagásicos e cinco controles. A análise estatística dos resultados (chi2) não revelou diferenças significativas. Conclui-se que o ambiente hormonal devido à testosterona não parece favorecer a infecção da parede dos vasos gonadais por Trypanosoma cruzi, embora, segundo a literatura, o referido hormônio pareça ter ações imunodepressoras.<br>The occurrence of Trypanosoma cruzi intracellular clusters and phlebitis was searched for on pampiniform plexus vein walls of chronic chagasic patients. For this purpose, 23 pairs of spermatic cords, epididymides and testes (17 from chagasic patients and 6 from non-chagasic controls) were obtained, at autopsy. Trypanosoma cruzi was investigated by immuno-histochemistry on slides obtained from several sections of the gonads and vessels of each case. Only discrete and focal undetermined chronic phlebitis was observed, with no parasites, in 5 chagasics (bilateral in 3) and 2 controls (chi2: p < 0.10), and discrete mononuclear interstitial infiltration in the funiculi of 13 chagasics and 5 controls (chi2: p < 0.75). In conclusion, on the contrary to that published regarding the supra-renal central veins, it seems that the hormonal environment provided by testosterone does not favor the infection of the gonadal vessel wall