Leptospirosis is a neglected zoonosis with worldwide distribution. The causative agents are spirochete bacteria of the Leptospira genus, displaying huge diversity of serovars, the identity of which is critical for effective diagnosis and vaccination purposes. Among many other mammalian species, Leptospira infects cattle, eliciting acute signs in calves, and chronic disease in adult animals often leading to abortions. In South America, and including in Uruguay, beef and dairy export are leading sources of national income. Despite the importance of bovine health, food safety, and bovine-related dissemination of leptospirosis to humans, extremely limited information is available as to the identity of Leptospira species and serovars infecting cattle in Uruguay and the South American subcontinent. Here we report a multicentric 3-year study resulting in the isolation and detailed characterization of 40 strains of Leptospira spp. obtained from infected cattle. Combined serologic and molecular typing identified these isolates as L. interrogans serogroup Pomona serovar Kennewicki (20 strains), L. interrogans serogroup Canicola serovar Canicola (1 strain), L. borgpetersenii serogroup Sejroe serovar Hardjo (10 strains) and L. noguchii (9 strains). The latter showed remarkable phenotypic and genetic variability, belonging to 6 distinct serogroups, including 3 that did not react with a large panel of reference serogrouping antisera. Approximately 20% of cattle sampled in the field were found to be shedding pathogenic Leptospira in their urine, uncovering a threat for public health that is being largely neglected. The two L. interrogans serovars that we isolated from cattle displayed identical genetic signatures to those of human isolates that had previously been obtained from leptospirosis patients. This report of local Leptospira strains shall improve diagnostic tools and the understanding of leptospirosis epidemiology in South America. These strains could also be used as new components within bacterin vaccines to protect against the pathogenic Leptospira strains that are actually circulating, a direct measure to reduce the risk of human leptospirosis.
Aminoacetone (AA) is a threonine and glycine catabolite long known to accumulate in cri-du-chat and threoninemia syndromes and, more recently, implicated as a contributing source of methylglyoxal (MG) in diabetes mellitus. Oxidation of AA to MG, NH(4)(+), and H(2)O(2) has been reported to be catalyzed by a copper-dependent semicarbazide sensitive amine oxidase (SSAO) as well as by Cu(II) ions. We here study the mechanism of AA aerobic oxidation, in the presence and absence of iron ions, and coupled to iron release from ferritin. Aminoacetone (1-7 mM) autoxidizes in Chelex-treated phosphate buffer (pH 7.4) to yield stoichiometric amounts of MG and NH(4)(+). Superoxide radical was shown to propagate this reaction as indicated by strong inhibition of oxygen uptake by superoxide dismutase (SOD) (1-50 units/mL; up to 90%) or semicarbazide (0.5-5 mM; up to 80%) and by EPR spin trapping studies with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), which detected the formation of the DMPO-(*)OH adduct as a decomposition product from the DMPO-O(2)(*)(-) adduct. Accordingly, oxygen uptake by AA is accelerated upon addition of xanthine/xanthine oxidase, a well-known enzymatic source of O(2)(*)(-) radicals. Under Fe(II)EDTA catalysis, SOD (<50 units/mL) had little effect on the oxygen uptake curve or on the EPR spectrum of AA/DMPO, which shows intense signals of the DMPO-(*)OH adduct and of a secondary carbon-centered DMPO adduct, attributable to the AA(*) enoyl radical. In the presence of iron, simultaneous (two) electron transfer from both Fe(II) and AA to O(2), leading directly to H(2)O(2) generation followed by the Fenton reaction is thought to take place. Aminoacetone was also found to induce dose-dependent Fe(II) release from horse spleen ferritin, putatively mediated by both O(2)(*)(-) and AA(*) enoyl radicals, and the co-oxidation of added hemoglobin and myoglobin, which may be viewed as the initial step for potential further iron release. It is thus tempting to propose that AA, accumulated in the blood and other tissues of diabetics, besides being metabolized by SSAO, may release iron and undergo spontaneous and iron-catalyzed oxidation with production of reactive H(2)O(2) and O(2)(*)(-), triggering pathological responses. It is noteworthy that noninsulin-dependent diabetes has been frequently associated with iron overload and oxidative stress.
ResumoO estudo objetivou investigar a produção científica sobre Políticas Públicas de Humanização, disponibilizada em periódicos online, de 2009 a 2012, no campo da Saúde. Trata-se de revisão integrativa da literatura, realizada em bases de dados da Biblioteca Virtual de Saúde: Literatura Latino-americana e do Caribe em Ciências da Saúde (Lilacs) e a Scientific Electronic Library Online (SciELO) e Portal Capes. Os dados foram coletados em julho de 2013. Para tanto, foram empregados os Descritores em Ciências da Saúde (DeCS), a saber: "Humanização da Assistência," "Políticas Públicas," "Política Nacional de Humanização". A amostra foi constituída por 27 artigos acerca da temática investigada. Das publicações selecionadas para a pesquisa, emergiram três categorias temáticas de acordo com os seus respectivos enfoques: Política Nacional de Humanização: trajetória e processos envolvidos em sua implementação; Política Nacional de Humanização: contribuição de profissionais da saúde; e Humanização no processo de cuidar. O estudo possibilitou evidenciar que a Política Nacional de Humanização é um relevante marco de referência na elaboração de práticas de saúde. Por essa razão, é premente a multiplicação de reflexões relacionadas às maneiras de se promover humanização nos serviços saúde.
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