Objective Rho signaling component α-catulin,is a cytoskeletal linker protein and plays an important role in apoptotic and senescence resistance,cytoskeletal reorganization,mobility,invasion and epithelial to mesenchymal transition(EMt)of cancer cells. Methods Here,we ex-amined α-catulin expression in squamous epithelium,dysplasia and cancer of head and neck on tissue microarrays by immunostaining. Its expres-sion was compared with clinicopathological parameters and survival rate of cancers. Results It was found that α-catulin expression level was signifi-cantly higher in primary cancers than that in normal squamous epithelium and dysplasia(P < 0.05),but not significantly correlated with aggressive behaviors or adverse prognosis of HNSCC patients(P > 0.05). Cox′s proportional hazard model indicated that distant metastasis and tNM staging were independent prognostic factors for overall survival of the patients with head and neck squamous carcinoma(HNSCC,P < 0.05). Conclusion these findings suggested that up-regulated expression of α-catulin protein may play an important role in the pathogenesis of HNSCC,which might be employed as a potential marker for tumorgenesis of HNSCCs.

Objective To construct and confirm the JC virus(JCV) T antigen expression plasmid using mouse keratin 19 (K19) promoter specific for the gastric epithelial cells.Methods The Ndel site was mutated by FCR with Bell insertion at both sides.The DNA fragment digested by Bcl Ⅰ was ligated with the plasmid containing K19 promoter via Bam Ⅰ site.The DNA sequence was confirmed by restriction enzyme digestion and direct DNA sequencing.Cytokeratin 19 protein was examined to screen gastric carcinoma cell for transfection of K19-JCV T antigen expression plasmid by immunohistochemistry.The Western blot was employed to detect the JCV T antigen expression in the gastric carcinoma transfectant.Results K19-JCV T antigen expressing plasmid was successfully constructed.The ACS strongly expressed cytokeratin 19 protein and was selected for the transfection of K19-JCV T antigen expressing plasmid.JCV T antigen was positively expressed in the AGS transfectant.Conclusion The synonymous mutation and compatible ligation are useful in the plasmid construction.The methy lation of restriction enzyme should be considered.It is meaning for the transgenic animal model of gastric carcinoma to successfully construct the JC virus T antigen expression plasmid in gastric mucosa.

The Ministry of Health and Welfare of Japan is planning a pooling system for multiple-choice questions (MCQs) for the national examination for medical practitioners. To clarify possible problems of such a system, a field study was performed by 10 medical schools in Japan using 90 MCQs from previous examinations. Nine hundred twenty-four 6th-year students participated in the field test. For each MCQ, the correct-response rates at the originating school and those obtained in the field test were significantly correlated. Thus, the correct-response rates to questions on the field test could be predicted from the rates at the originating schools. However, for each question the correct-response rate was significantly higher for students of the originating school than for students of other schools. In the national examination, care should be taken to prevent differences in scores on the basis of question sources.