Objective To examine the association between the insertion/deletion polymorphism in intron 4 of ecNOS gene (ecNOS4b/a) and diabetic nephropathy (DN) in the Han people of Tianjin, China. Methods The genotypes of ecNOS4b/a polymorphism were detected by PCR-minisatellite DNA detection technique. 70 healthy volunteers, 48 patients with type 2 diabetes without DN, 35 patients with type 2 diabetes and DN without chronic renal failure (CRF), 45 patients with DN in type 2 diabetes with CRF, and 58 patients with non-DN CRF were investigated. Results (1) One case (a female DN patient without CRF) with a rare genotype, the heterozygote of 447 bp and 420 bp, was found. (2) The frequency of allele a in type 2 diabetes without DN group was higher than that in control nonsignificantly (x2 = 1. 672, P = 0. 196) . (3) The frequency of allele a in DN group was lower than that in type 2 diabetes without DN group nonsignificantly (x2 = 1. 082, P = 0. 298). (4) The allele frequencies were similar between the DN without CRF group and the DN with CRF group (Continuity correction x2 = 0. 002, P = 0. 967). (5) The frequency of allele a in DN with CRF group was lower than that in non-DN CRF group significantly (x2=4. 360, P = 0. 037). Conclusions (1) Allele a is not a risk factor of DN in the Han people of Tianjin; (2) The frequency of allele a is lower in the Han people of Tianjin than that in Japanese(4. 3% vs 10. 1% , x2 = 4. 898, P = 0. 027); (3)There are different roles of ecNOS in DN-induced CRF and non-DN CRF.

0.05),hints that the tenocyte's function was not disturbed. The DNA index of cells of GDBM group was 0.96 and 2.1% higher than the control group,indicating that the tenocytes grow and proliferate faster when being combine cultured on GDBM. Conclusion GDBM show good biocompatibility combined with tenocytes and they are promising extracellular matrix scaffold for cell transplantation in tendon tissue engineering.