RESUMEN
Clinical practice is a key step that seven-year clinic student take to become doctors.Take the First Affiliated Hospital of Xi'an Jiaotong University as an example,in the medical practice of seven-year clinic students,there still exist some problems such as students' being unable to transform from probationers to doctors,not good at treating with interpersonal relationship in the department and having no perseverant practice attitude.So training before practice should be perfected and supervision should be strengthened to make the seven-year clinic students better.
RESUMEN
<p><b>OBJECTIVE</b>To identify the differentially expressed microRNAs (miRNAs) between esophageal squamous carcinoma (ESC) and adjacent non-tumorous tissue (NT).</p><p><b>METHODS</b>The expression levels of the miRNAs were detected in 3 fresh ESC and NT samples by hybridization with miRNAs microarray chip. Real-time quantitative RT-PCR was performed to confirm the results of the microarray analysis. The expressions of hsa-miR-126 and hsa-miR-518b in ESC were validated by real-time quantitative RT-PCR in another independent 15 matched samples.</p><p><b>RESULTS</b>A total of 11 miRNAs exhibited differential expressions in ESC samples as compared to their expressions in the NT samples, including a 1 up-regulated miRNA and 10 down-regulated miRNAs. Compared with normal esophageal samples, the ESC tissues showed up-regulated hsa-miR-126 and down-regulated hsa-miR-518b expression.</p><p><b>CONCLUSION</b>hsa-miR-126 and hsa-miR-518b are differentially expressed in ESC, and they might play important roles in the carcinogenesis and progression of ESC.</p>
Asunto(s)
Humanos , Biomarcadores de Tumor , Metabolismo , Carcinoma de Células Escamosas , Genética , Patología , Neoplasias Esofágicas , Genética , Patología , Perfilación de la Expresión Génica , Métodos , Regulación Neoplásica de la Expresión Génica , MicroARNs , Genética , Células Tumorales CultivadasRESUMEN
<p><b>OBJECTIVE</b>To examine the effect of fractioned ionizing radiation on the expression of hypoxia inducible factor-1alpha (HIF-1alpha) and multidrug resistance (MDR1) in human esophageal cancer cells.</p><p><b>METHODS</b>The mRNA and protein levels of HIF-1alpha and MDR1 in esophageal caner EC9706 cells incubated in the presence of 150 micromol/L CoCl(2) were measured before and after the irradiation by quantitative RT-PCR and Western blotting, respectively. The chemosensitivity and radiosensitivity of the cells were analyzed by MTT assay and clone formation assay.</p><p><b>RESULTS</b>MDR1 and HIF1alpha expressions were significantly up-regulated in the cells following hypoxia or irradiation (P<0.05). The surviving cell fraction in the exclusive irradiation group was significantly lower than that irradiation+hypoxia group (P<0.05). Compared with exclusive hypoxia group, MDR1 and HIF1alpha expressions were decreased significantly in irradiation+hypoxia group (P<0.05). HIF1alpha expression showed a positive correlation to MDR1 expression (P<0.01).</p><p><b>CONCLUSION</b>Hypoxia is an important factor to induce resistance to chemo- and radiotherapy. Low-dose fractioned irradiation can lower MDR1 and HIF1alpha expressions in esophageal cancer cells, which should be considered when combining radiotherapy chemotherapy for esophageal cancer patients.</p>
Asunto(s)
Humanos , Subfamilia B de Transportador de Casetes de Unión a ATP , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP , Genética , Metabolismo , Carcinoma de Células Escamosas , Patología , Radioterapia , Línea Celular Tumoral , Fraccionamiento de la Dosis de Radiación , Neoplasias Esofágicas , Patología , Radioterapia , Subunidad alfa del Factor 1 Inducible por Hipoxia , Genética , Metabolismo , ARN Mensajero , Genética , Metabolismo , Radiación IonizanteRESUMEN
<p><b>OBJECTIVE</b>To construct a prokaryotic expression vector for apoptin and prepare polyclonal antibody of apoptin.</p><p><b>METHODS</b>Apoptin gene amplified from pGEM-T/Apoptin plasmid by PCR was cloned into pET-28a (+). E.coli BL21 (DE3) was transformed by the recombinant plasmid, and apoptin protein expression induced by IPTG was analyzed by SDS-PAGE. BALB/c mice were immunized with the protein and the titer of the antibody was determined using indirect enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>Apoptin gene was successfully cloned into pET-28a (+), and the expression of a protein with relative molecular mass of about 17 000 was identified by SDA-PAGE. After 5 immunizations of the mice with the protein, the blood antibody titer reached 1:5x10(5).</p><p><b>CONCLUSION</b>The prokaryotic expression vector for apoptin is successfully constructed and the polyclonal antibody of apoptin is obtained, which allows further functional study of apoptin.</p>