[Obscure gastrointestinal bleeding due to duodenal infiltration of a non-functioning pancreatic neuroendocrine tumor diagnosed by capsule endoscopy: a case report]. / Hemorragia gastrointestinal de origen obscuro secundaria a infiltración duodenal de tumor neuroendocrino pancreático no funcional diagnosticada por cápsula endoscópica; informe de un caso.

Non-functioning pancreatic neuroendocrine tumors (PNETs) are infrequent slow-growing, clinically-silent tumors. They are incidentally detected and some of them may present in advanced stages with local involvement of surrounding structures. The diagnostic accuracy of endoscopio ultrasound (EUS) and fine needle aspiration (FNA) biopsy is significantly lower in neuroendocrine tumors (46.7%) compared with adenocarcinoma (81.4%) and other histologies (75%). Therefore, preoperative diagnosis is very difficult. Exceptionally, hey present with gastrointestinal bleeding. We present a case of a non-functioning PNET initially diagnosed as cystic serous tumor of pancreas with EUS and FNA biopsy. Two years later patient presented obscure gastrointestinal bleeding due to duodenal infiltration. Diagnosis was made by capsule endoscopy.

Comparative genomics of insect juvenile hormone biosynthesis.

The biosynthesis of insect juvenile hormone (JH) and its neuroendocrine control are attractive targets for chemical control of insect pests and vectors of disease. To facilitate the molecular study of JH biosynthesis, we analyzed ESTs from the glands producing JH, the corpora allata (CA) in the cockroach Diploptera punctata, an insect long used as a physiological model species and compared them with ESTs from the CA of the mosquitoes Aedes aegypti and Anopheles albimanus. The predicted genes were analyzed according to their probable functions with the Gene Ontology classification, and compared to Drosophila and Anopheles gambiae genes. A large number of reciprocal matches in the cDNA libraries of cockroach and mosquito CA were found. These matches defined known and suspected enzymes of the JH biosynthetic pathway, but also several proteins associated with signal transduction that might play a role in the modulation of JH synthesis by neuropeptides. The identification in both cockroach and mosquito CA of homologs of the small ligand binding proteins from insects, Takeout/JH binding protein and retinol-binding protein highlights a hitherto unsuspected complexity of metabolite trafficking, perhaps JH precursor trafficking, in these endocrine glands. Furthermore, many reciprocal matches for genes of unknown function may provide a fertile ground for an in-depth study of allatal-specific cell physiology. ESTs are deposited in GenBank under the accession numbers DV 017592-DV 018447 (Diploptera punctata); DR 746432-DV 747949 (Aedes aegypti); and DR 747950-DR 748310 (Anopheles albimanus).

Induction of DNA synthesis in Anopheles albimanus tissue cultures in response to a Saccharomyces cerevisiae challenge.

DNA synthesis was detected by the incorporation of 5-bromo-2' deoxy-uridine (BrdU) in adult Anopheles albimanus organs in culture in response to a challenge with Saccharomyces cerevisiae. Abdomens of mosquitoes inoculated with Roswell Park Memorial Institute medium (RPMI, control) or yeast were cultivated in RPMI plus ConA and BrdU for 5 days. DNA was obtained by phenolic extraction and the incorporated BrdU was quantified by ELISA using anti-BrdU peroxidase-labeled antibodies. Abdomen tissues of mosquitoes inoculated with yeast showed higher DNA synthesis than controls. Organs from untreated mosquitoes cultured in the presence of zymosan also synthesized DNA but at a lower level than tissues from yeast-inoculated mosquitoes. In similar experiments, DNA synthesis was inhibited by the addition of colchicine. DNA synthesis, evidenced by epifluorescence using an anti-BrdU fluorescein-labeled antibody, occurred in fat body, epithelial cells in pleural membranes, and the dorsal vessel. Pleural membranes showed the highest number of labeled cells. These tissues were also labeled with anti-PCNA (proliferating cell nuclear antigen) antibodies, two of which were able to produce polytene chromosomes under yeast stimulation. These results demonstrate that different An. albimanus tissues undergo DNA synthesis in response to foreign particles.