Study of the interaction between novel ruthenium(II)-polypyridyl complexes and calf thymus DNA

Four new complexes L2RuL'2+, where L = 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen), L' are Schiff bases or phenylhydrazones derived from 4,5-diazafluoren-9-one (AFO), were prepared. They were characterized by elemental analyses, absorption, IR, and emission spectra. The binding of these complexes to calf thymus DNA has been investigated by absorption, circular dichroism spectroscopy, and viscosity measurement. The experimental results show that the complexes bind to calf thymus DNA by three kinds of binding modes, respectively-electrostatic mode, nonintercalative binding mode, and intercalative binding mode.

[HLA-DQ gene and susceptibility of insulin dependent diabetes mellitus in Chinese population]

Trans-racial analysis of disease association has improved mapping of MHC-linked susceptibility to insulin dependent diabetes mellitus (IDDM). In this study, the contribution of the HLA class II DQA1 and DQB1 genes was investigated. Nine DQA1 and 10 DQB1 sequence-specific oligonucleotide gene probing in 49 IDDM and 48 control subjects from Beijing showed that DQA1-A4 alleles was positively associated with the disease (RR = 11.7, Pc < 0.02) as was the Asp57 negative homozygotes of DQB1 gene (P < 0.01, RR = 5.3), and that Asp57 positive homozygote of DQB1 gene conferred protection against IDDM (P < 0.025, RR = 0.38). Compared with trans-racial study, the decrease of Asp57 negative homozygote frequence and increase of Asp57 positive homozygote frequence in Chinese population may contribute to the low incidence of IDDM.