RESUMO
The physiological balance of juvenile hormone (JH) in insects depends on its biosynthesis and degradation pathway. Three key enzymes namely, juvenile hormone esterase (JHE), juvenile hormone epoxide hydrolase (JHEH) and juvenile hormone diol kinase (JHDK) are required for degradation in insects. Our present results showed that JHE and JHEH exhibited expression in almost all the tissues. This indicated that JHE and JHEH might degrade JH simultaneously. In addition, the highest levels of JHDK were observed in the midgut, with trace level being found in the malpighian tubule and haemocytes. Since the midgut is a digestive organ and not a JH target, it was hypothesized that both JHE and JHEH hydrolyzed JH to JH diol (JHd) which was then transported to midgut and hydrolyzed further by JHDK, to be finally excreted out of the body. Also the expression studies on JH degradation enzymes in different tissues and stages indicated that the activities of the three enzymes are specific and coincident with the JH functions in silkworm, Bombyx mori L.
Assuntos
Bombyx/enzimologia , Bombyx/genética , Regulação Enzimológica da Expressão Gênica , Hormônios Juvenis/metabolismo , Animais , Bombyx/crescimento & desenvolvimento , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Epóxido Hidrolases/genética , Epóxido Hidrolases/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
<p><b>OBJECTIVE</b>To investigate the value of MR imaging in the diagnosis of benign sacrococcygeal teratomas of the infants.</p><p><b>METHODS</b>MR imaging of benign sacrococcygeal teratomas in 6 cases proved by surgery and pathology was retrospectively reviewed. In all patients, a fast imaging sequence, fast spin echo sequence was employed, together with short time inversion recovery sequence and contrast enhancement scanning by intravenous injection of Gd-DTPA.</p><p><b>RESULTS</b>There were 6 benign sacrococcygeal teratomas, which were heterogeneous masses and arose from the distal sacrococcygeal region in the pelvis. The MR imaging appearances of the benign sacrococcygeal teratomas were characteristic, T1- and T2-weighted images demonstrated a large mass containing round, well-defined areas of varying signal intensity representing its cystic, solid, and sometimes fat, calcification within the lesions.</p><p><b>CONCLUSION</b>MR imaging provides definitive information of benign sacrococcygeal teratomas and clearly shows both extra-and intra-pelvic components, and even better anatomic details, which facilitates the surgical planning adequately.</p>
