RESUMO
About half of the human population is infected with Helicobacter pylori, a bacterium causing gastritis, peptic ulcer and progression to gastric cancer. Chemotaxis and flagellar motility are required for colonization and persistence of H. pylori in the gastric mucus layer. It is not completely clear which chemical gradients are used by H. pylori to maintain its position. TlpA, a chemotaxis receptor for arginine/ bicarbonate, has been identified. This study aimed to find out whether tlpA gene expression is required for the chemotactic response to arginine/bicarbonate. Wild-type motile H. pylori ATCC 700392 and H. pylori ATCC 43504, a strain having an interrupted tlpA gene, were used. Also, a tlpA-knockout mutant of H. pylori 700392 (H. pylori 700-tlpA::cat) was produced by homologous recombination. Expression of tlpA was assessed by a Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) assay. Chemotaxis was measured as a Relative Chemotaxis Response (RCR) by a modified capillary assay. H. pylori 700392 presented chemotaxis to arginine and sodium bicarbonate. H. pylori 700-tlpA::cat showed neither tlpA gene expression nor chemotaxis towards arginine and bicarbonate. Besides confirming that TlpA is a chemotactic receptor for arginine/bicarbonate in H. pylori, this study showed that tlpA gene expression is required for arginine/bicarbonate chemotaxis.
Assuntos
Arginina/farmacologia , Proteínas de Bactérias/genética , Bicarbonatos/farmacologia , Quimiotaxia/genética , Helicobacter pylori/genética , Proteínas de Membrana/genética , Expressão Gênica , Helicobacter pylori/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Ureia/metabolismoRESUMO
Probablemente de los problemas hematológicos, los relacionados con los mecanismos de la coagulación sean los que requieren mayor urgencia tanto en establecer un correcto diagnóstico así como la instauración de un manejo apropiado, dada la alta incidencia de complicaciones y secuelas, debido a la presencia de sangre en diferentes órganos y sistemas.
Assuntos
Humanos , Masculino , Criança , Hemorragia/etiologia , Vasculite por IgA/diagnóstico , Vasculite por IgA/fisiopatologiaRESUMO
Se presenta un caso de hernia del cordón umbilical y se describe la patología del cordón umbilical
Assuntos
Recém-Nascido , Humanos , Índice de Apgar , Cordão Umbilical/fisiopatologia , Doenças do Recém-Nascido/diagnóstico , Hérnia Umbilical/fisiopatologia , Umbigo/anormalidadesRESUMO
La enuresis es un problema frecuente en pediatría; su orgien es aún obscuro y su tratamiento se presta a controersias. Obedece generalmente a un retardo en la maduración neurológica del niño; sin embargo en muchos pacientes es posible reconocer un problema orgánico.