RESUMO
Anisotropic Magnetoresistive (AMR) sensors shows a new possibility to detect magnetic fields produced by magnetic particles present in the gastrointestinal (GI) tract. A system that uses excitation and detection of magnetic field was developed using AMR sensor. A magnetic flux concentrator was also studied to increase the sensitivity of AMR in this work.
Assuntos
Trato Gastrointestinal , Magnetismo , Imagens de FantasmasRESUMO
Rotaviruses are the single most important etiologic agents of severe diarrhea of infants and young children worldwide. Surveillance of rotavirus serotypes/genotypes (both VP7[G] and VP4[P]) is in progress globally in which polymerase chain reaction (PCR) has been the assay of choice. We investigated polymorphism of the VP7 gene of serotype G9 rotavirus strains and its impact on the determination of VP7 gene genotype by PCR assay. By VP7 gene sequence analysis, we and others have previously shown that the G9 rotavirus strains belong to one of three VP7 gene lineages. By PCR assay using three different sets of commonly used primers specific for G1-4, 8 and 9, 23 Brazilian G9 strains and 5 well-characterized prototype G9 strains which collectively represented all three VP7 gene lineages were typed as: (i) G3; (ii) G4; (iii) G9; (iv) G3 and G9; or (v) G9 and G4 depending on a primer pool employed. This phenomenon appeared to be due to: (i) a VP7 gene lineage-specific polymorphism, more specifically mutation(s) in the primer binding region of the VP7 gene of G9 strain; and (ii) the magnitude of difference in nucleotide homology at respective primer binding site between homotypic (G9) and heterotypic (G3 or G4) primers present in a primer pool employed.
Assuntos
Antígenos Virais , Proteínas do Capsídeo/genética , Polimorfismo Genético , Rotavirus/classificação , Rotavirus/genética , Sequência de Bases , Pré-Escolar , Primers do DNA , Fezes/virologia , Genes Virais , Genótipo , Humanos , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase/métodos , RNA Viral/genética , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rotavirus/isolamento & purificação , Infecções por Rotavirus/virologia , SorotipagemRESUMO
Rotaviruses are the single most important etiologic agents of severe diarrhea of infants and young children worldwide. Surveillance of rotavirus serotypes/genotypes (both VP7[G] and VP4[P]) is in progress globally in which polymerase chain reaction (PCR) has been the assay of choice. We investigated polymorphism of the VP7 gene of serotype G9 rotavirus strains and its impact on the determination of VP7 gene genotype by PCR assay. By VP7 gene sequence analysis, we and others have previously shown that the G9 rotavirus strains belong to one of three VP7 gene lineages. By PCR assay using three different sets of commonly used primers specific for G1-4, 8 and 9, 23 Brazilian G9 strains and 5 well-characterized prototype G9 strains which collectively represented all three VP7 gene lineages were typed as: (i). G3; (ii). G4; (iii). G9; (iv). G3 and G9; or (v). G9 and G4 depending on a primer pool employed. This phenomenon appeared to be due to: (i). a VP7 gene lineage-specific polymorphism, more specifically mutation(s) in the primer binding region of the VP7 gene of G9 strain; and (ii). the magnitude of difference in nucleotide homology at respective primer binding site between homotypic (G9) and heterotypic (G3 or G4) primers present in a primer pool employed.
Assuntos
Antígenos Virais , Proteínas do Capsídeo/genética , Gastroenterite/virologia , Reação em Cadeia da Polimerase/métodos , Polimorfismo Genético/genética , Rotavirus/classificação , Brasil , Pré-Escolar , Primers do DNA , Genótipo , Humanos , Dados de Sequência Molecular , Testes de Neutralização , Filogenia , Rotavirus/genética , Infecções por Rotavirus/virologia , Análise de Sequência de DNA , SorotipagemRESUMO
BACKGROUND: Enteric adenoviruses are related to child diarrhea and appear to be spread worldwide. OBJECTIVES: The aim of the present study was to determine the prevalence of enteric adenovirus infection among children in four Brazilian cities. STUDY DESIGN: stool specimens were collected from children under 5 years of age with acute diarrhea. RESULTS AND CONCLUSIONS: Enteric adenoviruses were detected in 1.55% (n=1420) of the samples analyzed indicating the circulation of these viruses among Brazilian children in association to diarrheal disease. These agents were isolated throughout the year demonstrating no specific seasonal distribution. Also, no pattern of serotype distribution between the cities was observed.
