RESUMEN
We report here the production of transgenic quails using a replication-defective pantropic retroviral vector based on Moloney murine leukemia virus (MoMLV) pseudotyped with vesicular stomatitis virus G protein (VSV-G). The retroviral vector was injected into laid quail embryos at the blastodermal stage, and the embryos were incubated to hatch to produce G(0) transgenic quails. Among 134 embryos subjected to viral injection, 37 hatched. The viral vector sequence was detected in the tissues of all G(0) quails. The germ-line transmission efficiency of G(0) quails mated with nontransgenic quails was more than 80% on average. Southern blot analysis revealed that the G(1) transgenic progeny had one to three copies of the transgene. The expression of vector-encoded neomycin-resistance gene under the control of the Rous sarcoma virus (RSV) promoter was observed in several tissues including heart and muscle of both G(1) and G(2) transgenic offspring. Due to the high frequency of germ-line transmission, this method may markedly facilitate the production of transgenic avian.
Asunto(s)
Animales Modificados Genéticamente/genética , Mutación de Línea Germinal , Glicoproteínas de Membrana , Codorniz/genética , Proteínas del Envoltorio Viral/genética , Animales , Southern Blotting , Metilación de ADN , Virus Defectuosos/genética , Femenino , Dosificación de Gen , Genes Reporteros , Vectores Genéticos , Masculino , Virus de la Leucemia Murina de Moloney/genética , Codorniz/metabolismo , ARN Mensajero/biosíntesis , Distribución Tisular , TransgenesRESUMEN
BACKGROUND: Thymic neuroendocrine carcinoma (carcinoid) is rare. Here we present four cases of this unusual neoplasm to provide more clinical, radiologic, and prognostic data. MATERIALS AND METHODS: Four male patients with an average age of 44 years (range 27-63) were identified as having thymic neuroendocrine carcinoma and were reviewed retrospectively. RESULTS: One patient had Cushing's syndrome with elevated serum ACTH. Three others were asymptomatic with normal laboratory findings, one case was associated with MEN type 1. All underwent complete resection along with invaded adjacent structures. Local recurrence developed in two patients at 45 and 98 months after the initial excision. Both patients died at 90 and 105 months, respectively. The other two patients are alive and have been disease-free for 27 and 120 months, respectively. CONCLUSIONS: Thymic neuroendocrine carcinomas have a rather poor prognosis based on their tendency to recur and metastasize many years after the initial operation. Therefore, prolonged follow-up is essential for these tumors.