182 research outputs found

    The thermal stability of yellow fever vaccines

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    The assessment of yellow fever vaccine thermostability both in lyophilized form and after reconstitution were analyzed. Two commercial yellow fever vaccines were assayed for their thermal stability. Vaccines were exposed to test temperatures in the range of 8 (graus) C to 45 (graus) C. Residual infectivity was measured by a plaque assay using Vero cells. The titre values were used in an accelerated degradation test that follows the Arrhenius equation and the minimum immunizing dose was assumed to be 10 (ao cubo) particles forming unit (pfu)/dose. Some of the most relevant results include that (i) regular culture medium show the same degradation pattern of a reconstituted 17D-204 vaccine; (ii) reconstituted YF-17D-204 showed a predictable half life of more than six days if kept at 0 (graus) C; (iii) there are differences in thermostability between different products that are probably due to both presence of stabilizers in the preparation and the modernization in the vaccine production; (iv) it is important to establish a proper correlation between the mouse infectivity test and the plaque assay since the last appears to be more simple, economical, and practical for small laboratories to assess the potency of the vaccine, and (v) the accelerated degradation test appears to be the best procedure to quantify the thermostability of biological products

    The thermal stability of yellow fever vaccines

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    Extraction of subjective properties in image processing

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    Most of the present digital images processing methods are related with objective characterization of external properties as shape, form or colour. This information concerns objective characteristics of different bodies and is applied to extract details to perform several different tasks. But in some occasions, some other type of information is needed. This is the case when the image processing system is going to be applied to some operation related with living bodies. In this case, some other type of object information may be useful. As a matter of fact, it may give additional knowledge about its subjective properties. Some of these properties are object symmetry, parallelism between lines and the feeling of size. These types of properties concerns more to internal sensations of living beings when they are related with their environment than to the objective information obtained by artificial systems. This paper presents an elemental system able to detect some of the above-mentioned parameters. A first mathematical model to analyze these situations is reported. This theoretical model will give the possibility to implement a simple working system. The basis of this system is the use of optical logic cells, previously employed in optical computing

    Association of Chlamydia trachomatis, C. pneumoniae, and IL-6 and IL-8 Gene Alterations With Heart Diseases

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    Atherosclerosis is a progressive disease characterized by chronic inflammation of the arterial walls, associated with genetic and infectious factors. The present study investigated the involvement of Chlamydia trachomatis and Chlamydia pneumoniae infections and immunological markers (C-reactive protein, CRP, TNF-α, IL-6, IL-8, and IL-10) in the process of atherosclerosis. The evaluation included 159 patients for surgical revascularization (CAD) and 71 patients for surgical heart valve disease (HVD) at three hospitals in Belém, Brazil. The control group (CG) comprised 300 healthy individuals. Blood samples collected before surgery were used for antibodies detection (enzyme immunoassay), CRP (immunoturbidimetry) and IL-6 levels (enzyme immunoassay). Tissue fragments (atheroma plaque, heart valve and ascending aorta) were collected during surgery and subjected to qPCR for detection of bacterial DNA. Promoter region polymorphisms of each marker and relative quantification of TNF-α, IL-8, and IL-10 gene expression were performed. Demography and social information were similar to the general population involved with both diseases. Antibody prevalence to C. trachomatis was 30.6, 20.3, and 36.7% (in the CAD, HVD, and CG, respectively) and to C. pneumoniae was 83.6, 84.5, and 80.3% (in the CAD, HVD, and CG, respectively). C. trachomatis cryptic plasmid DNA was detected in 7.4% of the samples. Frequency of IL6−174G>C polymorphism was higher in CAD and HVD than in CG regardless of previous exposure to Chlamydia. Previous C. trachomatis infection showed involvement in HVD and CAD. Significant association between disease and previous C. pneumoniae infection was found only among HVD. GG genotype of IL6−174G>C is apparently a risk factor for heart disease, whereas AT genotype of IL8−251A>T was mainly involved in valvulopathies, including patients with prior exposure to C. pneumoniae

    Frequência de CHLAMYDIA TRACHOMATIS, CHLAMYDIA PNEUMONIAE E TREPONEMA PALLIDUM em portadores do vírus da imunodeficiência humana 1 (HIV-1), no estado do Pará Frequency of CHLAMYDIA TRACHOMATIS, CHLAMYDIA PNEUMONIAE and TREPONEMA PALLIDUM among virus carr

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    Introdução: A Chlamydia trachomatis e o Treponema pallidum compartilham com o HIV-1 a via sexual como forma de transmissão. Devido ao comprometimento imunológico dos portadores de HIV, a Chlamydia. pneumoniae pode apresentar um papel potencial em infecções respiratórias. Objetivo: Este trabalho objetivou a descrição da soroprevalência destes três agentes em portadores de HIV-1 do Estado do Pará, Brasil. Metodologia: Foram coletadas 430 amostras de portadores de HIV na Unidade de Referência (URE-DIPE) em Belém Pará, que foram submetidas a um ELISA para detecção de anticorpo IgG e IgM anti-Chlamydia e, dentre os positivos, uma amostragem aleatória foi escolhida e submetida à microimunofluorescência para detecção de anticorpos para as espécies. Resultados: Anticorpos anti-T. pallidum foram detectados por RPR e ELISA. A prevalência geral de anticorpos anti-Chlamydia foi 64,2% (51,6% para IgG e 4% para IgM). Houve 100% de prevalência de C. trachomatis (tanto para IgG como IgM), e para C. pneumoniae 73,5% de  IgG e 70,5% de IgM. A prevalência geral de anticorpos contra o T. pallidum foi de 34,9%, sendo que 7,3% apresentaram resultado laboratorial indicativo de sífilis. As variáveis que apresentaram associação com a infecção por Chlamydia e T. pallidum foram: o sexo masculino, mais de um parceiro por semana, sexo anal, homossexualismo/bissexualismo e o uso de droga não-endovenosa. Conclusão: Faz-se necessário tanto a conscientização como o Monitoramento da população, para impedir a transmissão destes agentes e para a melhoria da qualidade de vida dos indivíduos portadores de HIV
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