An improved closed procedure for testing multiple hypotheses.

Clinical trials routinely involve multiple hypothesis testing. The closed testing procedure (CTP) is a fundamental principle in testing multiple hypotheses. This article presents an improved CTP in which intersection hypotheses can be tested at a level greater than α such that the control of the familywise error rate at level α remains. Consequently, our method uniformly improves the power of discovering false hypotheses over the original CTP. We illustrate that an improvement by our method exists for many commonly used tests. An empirical study on the effectiveness of a glucose-lowering drug is provided.

[Use of allogenic acellular dermal matrix combined with autologous epidermal cells for the repair of tissue defect].

OBJECTIVE: To investigate a method for the repair of tissue defect. METHODS: Allogenic acellular dermal matrixes (ADM) were implanted to full-thickness skin defects made on the dorsa of rats. Two weeks later, autologous suspended epidermal cells were transplanted on to the surface of vascularized ADM. Respectively, neoepidermis was macroscopically observed 2, 3, 5 weeks after grafting, and samples were taken to make routine paraffin sections for microscopical examination, and immunohistochemical staining for type IV collagen was also performed. RESULTS: The vascularized ADM could support proliferation and differentiation of epidermal cells, and also could promote the formation of dermal-epidermal junction. Suspended epidermal cells in an artificial culture system in vivo could develop into mature epidermis. The reconstructed skin not only looked like the normal one in appearance in which hair was removed, but also revealed a better function. CONCLUSIONS: Full-thickness skin defect can be repaired by transplanting autologous epidermal cell suspension on to vascularized ADM.

[Synergism of c-myc and p16 in oral squamous cell carcinoma].

BACKGROUND & OBJECTIVE: The study on the protein expression of c-myc and p16 in oral squamous cell carcinoma (OSCC) has been reported, and a few researches involved in their gene amplification and mRNA expression in OSCC, however, the synergism of c-myc and p16 in OSCC in multiple levels is still unclear. This study aims to probe the synergism of c-myc and p16 in OSCC in gene amplification, mRNA expression, and protein expression levels. METHODS: The gene amplification, expression of mRNA, and protein of c-myc and p16 in 30 cases of OSCC were determined by in situ hybridization and immunohistochemical techniques. RESULTS: The amplification rate of c-myc was 63.3%, but no amplification of p16 was found in OSCC. The mRNA expression rates of c-myc and p16 were 83.3% and 93.3%, and their protein expression rates were 60.0% and 86.7%, respectively. The correlation analysis showed that there was significant correlativity between p16 and c-myc both in mRNA expression (r=0.676 5, P=4.055 6E-05) and in protein expression (r=0.564 2, P=0.001 2). CONCLUSION: The gene amplification and overexpression of c-myc plays an important role in the tumorigenesis and development of OSCC. There is certain internal relationship between p16 and c-myc expression in OSCC.