T-Cell Memory Responses Elicited by Yellow Fever Vaccine are Targeted to Overlapping Epitopes Containing Multiple HLA-I and -II Binding Motifs

The yellow fever vaccines (YF-17D-204 and 17DD) are considered to be among the safest vaccines and the presence of neutralizing antibodies is correlated with protection, although other immune effector mechanisms are known to be involved. T-cell responses are known to play an important role modulating antibody production and the killing of infected cells. However, little is known about the repertoire of T-cell responses elicited by the YF-17DD vaccine in humans. In this report, a library of 653 partially overlapping 15-mer peptides covering the envelope (Env) and nonstructural (NS) proteins 1 to 5 of the vaccine was utilized to perform a comprehensive analysis of the virus-specific CD4+ and CD8+ T-cell responses. The T-cell responses were screened ex-vivo by IFN-γ ELISPOT assays using blood samples from 220 YF-17DD vaccinees collected two months to four years after immunization. Each peptide was tested in 75 to 208 separate individuals of the cohort. The screening identified sixteen immunodominant antigens that elicited activation of circulating memory T-cells in 10% to 33% of the individuals. Biochemical in-vitro binding assays and immunogenetic and immunogenicity studies indicated that each of the sixteen immunogenic 15-mer peptides contained two or more partially overlapping epitopes that could bind with high affinity to molecules of different HLAs. The prevalence of the immunogenicity of a peptide in the cohort was correlated with the diversity of HLA-II alleles that they could bind. These findings suggest that overlapping of HLA binding motifs within a peptide enhances its T-cell immunogenicity and the prevalence of the response in the population. In summary, the results suggests that in addition to factors of the innate immunity, "promiscuous" T-cell antigens might contribute to the high efficacy of the yellow fever vaccines. © 2013 de Melo et al

Positive nasal culture of methicillin-resistant Staphylococcus aureus (MRSA) is a risk factor for surgical site infection in orthopedics

Background Although nasal carriage of MRSA has been identified as one of the risk factors for surgical site infection (SSI) with MRSA, there have been no reports of this in the orthopedics field

Physical and sports activity after hip arthroplasty

A artroplastia é utilizada para reconstrução da articulação do quadril, visando minimizar a dor e possibilitar o retorno às atividades de vida diária, esportivas e de lazer. O objetivo deste artigo é analisar na literatura as indicações e contraindicações referentes à prática de atividade física, esportiva e lazer após a artroplastia de quadril. Essa revisão aborda estudos publicados entre os anos de 1980 e 2009, obtidos por buscas em bancos de dados eletrônicos Medline, Scielo, Ovid, Infomaworld, Sciencedirect, Springerlink, Interscience, Sportdiscuss, Bireme, Informglobal, Opas, Ovid, Diseasedex, Eric, que totalizaram 39 artigos. Os artigos analisados apontam para a utilização de atividade física, esportiva e de lazer de baixo impacto. como a caminhada, natação, boliche, ciclismo, dentre outras. Outra indicação constatada na literatura é a utilização da atividade física e esportiva visando à manutenção do condicionamento físico, qualidade óssea e controle do peso corporal. Há ressalvas na literatura sobre a utilização de atividades de alto impacto, esporte com giro como o basquete e futebol ou com grande intensidade como tênis e a corrida, bem como os esportes de luta. As atividades físicas, esportivas e de lazer mais indicadas após uma atroplastia de quadril são as de baixo impacto como a hidroginástica, natação, caminhada, dentre outras. O início dessas atividades deve aguardar a liberação do médico, mas em média iniciam 60 dias após a cirurgia.Hip arthroplasty is used for reconstruction of the hip joint to reduce pain and to make the return to daily life, physical, sports and leisure activities possible. The objective of this article was to analyze in the literature the indications and counter-indications referring to practice of physical, sportive and leisure activities after hip arthroplasty. This revision approaches studies published between 1980 and 2009, obtained in searches in the Medline, Scielo, Ovid, Infomaworld, Sciencedirect, Springerlink, Interscience, Sportdiscuss, Bireme, Informglobal, Opas, Ovid, Diseasedex and Erics electronic databases with a total of 39 articles. The analyzed articles point to the use of physical, leisure and sports of low impact activities such as walking, swimming, bowling, cycling and others. Another indication evidenced in the literature is the use of physical and sportive activity aiming at the maintenance of physical fitness, bone quality and body weight control. The literature shows concerns with the use of activities of high impact or with great intensity like tennis and jogging, as well as fights