The importance of feeding in the larval development of the ghost shrimp Callichirus major (Decapoda: Callianassidae)

O presente estudo investigou se o callianassid Callichirus major apresenta um comportamento lecitotrófico durante o desenvolvimento larval. Dois experimentos foram realizados. No primeiro experimento, larvas foram submetidas a um período inicial de alimentação, enquanto no segundo elas foram submetidas a um período inicial de inanição. No experimento 1, 80% das larvas de C. major mudaram com sucesso para o estágio de juvenil no tratamento com larvas alimentadas diariamente. Nos tratamentos com larvas alimentadas por 1, 2 e 3 dias, houve uma mortalidade total antes de alcançarem o estágio de megalopa. No experimento 2, as larvas zoés mostraram mais resistência quando submetidas a um período inicial de inanição. Nos tratamentos nos quais as larvas estiveram em inanição por 1, 2 e 3 dias, as taxas de sobrevivência foram100%, 60% e 90%, respectivamente. Porém atrasos na duração do desenvolvimento dos estágios de zoés foram observados. Houve mortalidade total para as larvas cultivadas no tratamento com ausência constante de alimento. Os resultados sugerem não existir um comportamento lecitotrófico nas zoés de C. major.

Clinical and pathological importance of vacA allele heterogeneity and cagA status in peptic ulcer disease in patients from North Brazil

We have examined the prevalence of gene cagA and vacA alleles in 129 patients, 69 with gastritis and 60 with peptic ulcer diseases from North Brazil and their relation with histopathological data. vacA and cagA genotype were determined by polymerase chain reaction. Hematoxylin-eosin staining was used for histological diagnosis. 96.6% of the patients were colonized by Helicobacter pylori strains harboring single vacA genotype (nont-mixed infection). Among them, 11.8% had subtype s1a, 67.8% had subtype s1b, and 17% subtype s2. In regard to the middle region analysis, m1 alleles were found in 75.4% and m2 in 21.2% of patients. The cagA gene was detected in 78% patients infected with H. pylori and was associated with the s1-m1 vacA genotype. The H. pylori strains, vacA s1b m1/cagA-positive, were associated with increased risk of peptic ulcer disease and higher amounts of lymphocytic and neutrophilic infiltrates and the presence of intestinal metaplasia. These findings show that cagA and vacA genotyping may have clinical relevance in Brazil.