38 research outputs found

    Rebleeding rate after interventional therapy directed by capsule endoscopy in patients with obscure gastrointestinal bleeding

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    <p>Abstract</p> <p>Background</p> <p>The precise role of capsule endoscopy in the diagnostic algorithm of obscure gastrointestinal bleeding has yet to be determined. Despite the higher diagnostic yield of capsule endoscopy, the actual impact on clinical outcome remains poorly defined. The aim of this study was to evaluate the follow-up results of patients with obscure gastrointestinal bleeding to determine which management strategies after capsule endoscopy reduced rebleeding.</p> <p>Methods</p> <p>All patients in whom the cause of obscure gastrointestinal bleeding was investigated between May 2004 and March 2007 were studied retrospectively. We evaluated the clinical outcome of patients with obscure gastrointestinal bleeding after capsule endoscopy using the rebleeding rate as the primary outcome.</p> <p>Results</p> <p>Seventy-seven patients with obscure gastrointestinal bleeding underwent capsule endoscopy. Capsule endoscopy identified clinically significant findings that were thought to be the sources of obscure gastrointestinal bleeding in 58.4% of the patients. The overall rebleeding rate was 36.4%. The rebleeding rate was significantly higher among patients with insignificant findings than among those with significant findings (<it>p </it>= 0.036). Among the patients in whom capsule endoscopy produced significant findings, the rebleeding rate of the patients who underwent therapeutic interventions was significantly lower than that in those who did not undergo intervention (9.5% vs 40.0%, <it>p </it>= 0.046).</p> <p>Conclusion</p> <p>Follow-up and further aggressive interventions are necessary for patients with obscure gastrointestinal bleeding and significant capsule endoscopy findings to reduce the chance of rebleeding.</p

    Spermiogenesis and spermatozoa ultrastructure in the Serrasalminae (Ostariophysi: Characiformes) with further evidence on the relationships of the piranhas and pacus

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    A ultraestrutura dos espermatozoides e espermiogênese foram estudadas nas espécies Piaractus mesopotamicus, Mylossoma duriventre, Serrasalmus maculatus e Metynnis mola de Serrasalminae, sendo dois padrões distintos reconhecidos: um comum a Mylossoma, Serrasalmus e Metynnis, e o segundo característico de Piaractus. Este último é mais similar ao observado em Salminus e Brycon. Por outro lado, o espermatozoide dos serrasalmíneos compartilha algumas características com espécies da superfamília Anostomoidea. O significado filogenético destes caracteres é discutido.Spermatozoa and spermiogenesis ultrastructure were studied in the serrasalmine species Piaractus mesopotamicus, Mylossoma duriventre, Serrasalmus maculatus, and Metynnis mola and two distinct patterns may be recognized: the first common to Mylossoma, Serrasalmus and Metynnis, and the other, characteristic of Piaractus. The latter pattern is more similar to the conditions found in Salminus and Brycon. On the other hand, serrasalmine spermatozoa also share characteristics with the spermatozoa of species of the superfamily Anostomoidea. The phylogenetic significance of these characters is discussed

    Spermiogenesis and biflagellate spermatozzoon of the teleost fish Lampanyctus crocodilus (Myctophiformes, Myctophidae): ultrastructure and characterization of its sperm basic nuclear proteins

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    We undertook an ultrastructural study of the spermiogenesis of the lanternfish Lampanyctus crocodilus (Myctophiformes, Myctophidae) with special emphasis on the condensation of chromatin and the biochemical characterisation of its sperm nuclear basic proteins (SNBPs). The round head of the early spermatid of L. crocodilus develops into a curved conical-shaped head in the spermatozoon. Two flagella, present even in the spermatid, are inserted laterally at the convex side of the sperm head. Both flagella possess an axoneme with a 9 + 0 instead of the typical 9 + 2 axonemal structure. Mitochondria undergo a characteristic redistribution during spermiogenesis. A reduced number of them are present lying away from the centrioles at both ends of the concave side of the sperm head. During the chromatin condensation stages in spermiogenesis, fibrogranular structures with granules of 25 ± 5 and 50 ± 5 nm can be observed in the early spermatid and develop into larger granules of about 150 ± 50 nm in the middle spermatid. The latter granules coalesce during the transition to the advanced spermatid and spermatozoon giving rise to highly condensed chromatin in the sperm cell. Protamines are the main SNBPs associated with this chromatin; however, they are unusually large and correspond to the largest protamines described in fish to date. Small stoichiometric amounts of histones and other basic proteins coexist with these protamines in the spermatozoon
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