New SNP variants of MARVELD2 (DFNB49) associated with non-syndromic hearing loss in Chinese population.

Non-syndromic hearing loss (NSHL) is a common defect in humans. Variants of MARVELD2 at the DFNB49 locus have been shown to cause bilateral, moderate to profound NSHL. However, the role of MARVELD2 in NSHL susceptibility in the Chinese population has not been studied. Here we conducted a case-control study in an eastern Chinese population to profile the spectrum and frequency of MARVELD2 variants, as well as the association of MARVELD2 gene variants with NSHL. Our results showed that variants identified in the Chinese population are significantly different from those reported in Slovak, Hungarian, and Czech Roma, as well as Pakistani families. We identified 11 variants in a cohort of 283 NSHL cases. Through Sanger sequencing and bioinformatics analysis, we found that c.730G>A variant has detrimental effects in the eastern Chinese population, and may have relatively high correlation with NSHL pathogenicity.

PEG and DBBF modified porcine hemoglobin and their oxygen-carrying capacity.

Modifications of proteins with polyethylene glycol (PEG) have been proven to enlarge molecule size of proteins, to prolong their retention time in the circulation as well as blunt immune or allergic reactions. Hemoglobin cross-linked with small molecular modifiers turns out to be more stable and to have better oxygen carrying capacity. In the present study, four derivatives of PEG with different activation groups, and several PEGs with different molecular weights were covalently bound to porcine hemoglobin (pHb). PEG-pHbs exhibited a variety of differences in their properties depending on the molecular weights of the used PEGs, the amounts of bound PEGs and the presence or absence of allosteric cofactors. The optimal modification conditions for bis (3, 5-dibromosalicyl) fumarate (DBBF) as well as the physical features and oxygen carrying capacity of DBBF-modified pHb were evaluated. Furthermore, both PEG and DBBF were used simultaneously to modify pHb. The results indicate that the pHbs modified with PEG and DBBF have more stable tetrameric conformations with a molecular weight of 107 kD. Their oxygen half-saturation pressure (P(50)) is around 3.33 kPa which approximates the physiological P(50) of human red blood cells.