RESUMO
In order to elucidate the toxin composition of the freshwater puffer in Bangladesh, about 230 specimens of Tetraodon sp. were collected from 1997 to 1999 and extracted. After partitioning the toxins between an aqueous layer and a 1-butanol layer, the toxin in the aqueous layer was characterized as paralytic shellfish poison (PSP) (data not shown), while the toxin in the 1-butanol layer was identified as palytoxin (PTX) or PTX-like substance based on the delayed haemolytic activity which was inhibited by an anti-PTX antibody and ouabain (g-strophanthin). This is the first report on the occurrence of PTX or PTX-like substance(s) in puffer fish.
Assuntos
Acrilamidas/isolamento & purificação , Acrilamidas/toxicidade , Venenos de Peixe/toxicidade , Hemólise/efeitos dos fármacos , Tetrodotoxina/toxicidade , Acrilamidas/antagonistas & inibidores , Animais , Bangladesh , Cromatografia Líquida de Alta Pressão , Venenos de Cnidários , Inibidores Enzimáticos/farmacologia , Peixes Venenosos , Humanos , Camundongos , Ouabaína/farmacologia , Tetrodotoxina/antagonistas & inibidoresRESUMO
Gonadotropin-releasing hormone (GnRH) is a possible secretagogue of growth hormone (GH) and somatolactin (SL) in teleosts. Effects of GnRH on the levels of pituitary mRNAs encoding GH, prolactin (PRL), and SL were therefore examined in prespawning sockeye salmon (Oncorhynchus nerka). A capsule of GnRH analog (GnRHa) was implanted into the dorsal muscle of maturing sockeye salmon for 3 weeks. The levels of hormonal mRNAs were then determined by a quantitative dot blot analysis using single-stranded sense DNA of the same sequence of mRNA as the standard. Further, we analyzed effects of GnRHa on expression of the genes encoding pituitary-specific transcription factor (Pit-1/GHF-1). Relative levels of Pit-1/GHF-1 mRNAs were estimated by Northern blot analysis, which showed specific 2- and 3-kb bands of mRNAs. GnRHa significantly increased the level of SL mRNA in the males, but not in the females, compared to the control fish. It did not induce significant increases in the levels of GH and PRL mRNAs in both the males and the females. The levels of Pit-1/GHF-1 mRNAs in the control males tended to be higher than those in the initial controls, so that GnRHa might not be effective in enhancing expression of Pit-1/GHF-1 gene, except for the level of 3-kb Pit-1/GHF-1 mRNA in the females treated with 150 microg GnRHa. The pattern of changes in the levels of Pit-1/GHF-1 mRNAs were similar to those of GH and PRL mRNAs in both the males and the females and to that of SL mRNA in the females. These results indicate that, in prespawning sockeye salmon, GnRH can stimulate SL gene expression, but probably not through the Pit-1/GHF-1-dependent system.
Assuntos
Proteínas de Ligação a DNA/genética , Expressão Gênica/efeitos dos fármacos , Hormônio Liberador de Gonadotropina/farmacologia , Hipófise/metabolismo , Hormônios Hipofisários/genética , Salmão/fisiologia , Fatores de Transcrição/genética , Animais , Implantes de Medicamento , Feminino , Proteínas de Peixes , Glicoproteínas/genética , Hormônio Liberador de Gonadotropina/administração & dosagem , Hormônio do Crescimento/genética , Masculino , Hibridização de Ácido Nucleico , Prolactina/genética , RNA Mensageiro/análise , Fator de Transcrição Pit-1RESUMO
Changes in the levels of pituitary mRNAs encoding GH, prolactin (PRL) and somatolactin (SL) were determined in pre-spawning chum salmon (Oncorhynchus keta) caught at a few key points along their homing pathway in 1994 and 1995. Furthermore, we analyzed relationships between expression of pituitary-specific POU homeodomain transcription factor (Pit-1/GHF-1) and GH/PRL/SL family genes. In 1994, seawater (SW) fish and matured fresh-water (FW) fish were sequentially captured at two points along their homing pathway, the coast and the hatchery. In addition to these two points, maturing FW fish were captured at the intermediate of the two points in 1995. The levels of hormonal mRNAs were determined by a quantitative dot blot analysis using single-stranded sense DNA as the standard. Relative levels of Pit-1/GHF-1 mRNAs were estimated by Northern blot analysis. In 1994, the levels of GH/PRL/SL family mRNAs except for PRL mRNA in the male FW fish were 1.8-4 times higher than those in the SW fish. In 1995, the level of PRL mRNA was somewhat sharply elevated in the maturing FW fish soon after entry into the FW environment, while that of SL mRNA was gradually increased during upstream migration from the coast to the hatchery. The levels of 3 kb Pit-1/GHF-1 mRNA in the FW fish were higher than those in the SW fish in both 1994 and 1995. The present results indicate that expression of genes for the GH/PRL/SL family and Pit-1/GHF-1 is coincidentally enhanced in homing chum salmon. Moreover, the present study suggests that expression of the SL gene is elevated with sexual maturation, whereas that of PRL gene is elevated with osmotic change during the final stages of spawning migration.
Assuntos
Proteínas de Ligação a DNA/genética , Glicoproteínas/genética , Hormônio do Crescimento/genética , Hipófise/metabolismo , Hormônios Hipofisários/genética , Prolactina/genética , RNA Mensageiro/metabolismo , Fatores de Transcrição/genética , Animais , Sequência de Bases , Northern Blotting , Primers do DNA , Sondas de DNA , DNA Complementar , Proteínas de Peixes , Oncorhynchus keta/genética , Oncorhynchus keta/fisiologia , RNA Mensageiro/genética , Reprodutibilidade dos Testes , Reprodução , Fator de Transcrição Pit-1RESUMO
The ultrasonographic examination was applied for the purpose of volume estimation of rectal cancer. We have performed 15 cases of echographic volume estimation compared with that of resected specimen (control group) and mean volume estimation error rate was 14.6% between two methods. And we also performed 17 preoperative irradiation cases of rectal cancer. Each tumor volume of pre- and post-irradiation was estimated echogenically and was compared with that of resected specimen. In the case when irradiation effect was remarkable, estimated volume by ultrasonography was much smaller in post-irradiation compared with that of pre-irradiation. Same tendency was also recognized in the study of resected specimen. Histopathological irradiation effect was also highly recognized in the case when echographic diminished rate was prominent. This method will useful for the judgement of preoperative irradiation effect in rectal cancer.
Assuntos
Neoplasias Retais/diagnóstico por imagem , Adulto , Idoso , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Cuidados Pré-Operatórios , Neoplasias Retais/radioterapia , Neoplasias Retais/cirurgia , Ultrassonografia/instrumentação , Ultrassonografia/métodosRESUMO
We studied an effect of preoperative radiation upon the change of tumor volume in rectal carcinoma. As a preliminary study, tumor volume of 15 cases of rectal carcinoma with no preoperative irradiation was estimated preoperatively using the transrectal ultrasonography, and were compared with those determined by resected specimens after operation. As a result, there was a parallel relationship between the two values, and mean estimation error rate was 14.6%. Next, the same method was applied to 15 patients with rectal carcinoma who underwent preoperative radiation in order to detect the reduction rate of tumor volume after radiation therapy (42.6 Gy). As a consequence, 80% of cases exhibited the reduction rate more than 50% with an average of 61.7%. It was suggested that the determination of pre- and postoperative tumor volume would be beneficial to evaluation of preoperative radiation therapy as well as decision of the optimal dose of radiation in rectal carcinoma.
