Objective: To investigate the changes of brain gray matter volume in patients with occupational noise-induced hearing loss by voxel based morphometry (VBM) . Methods: 16 age-and education-matched healthy controls and 42 patients with occupational noise induced hearing loss, including 27 in mild group and 15 in severe group, received MRI 3D-FSPGR sequence T1WI sagittal scan, and then underwent VBM of brain gray matter volume data analysis. Results: The brain gray matter volume of the left occipitotemporal lateral gyrus, the anterior cingulate gyrus, the bilateral angular gyrus, the precuneus and the near midline area of cerebellum differed between experimental group and control group (P<0.01) . Conclusion The volume of gray matter in specific brain areas of patients with occupational noise-induced hearing loss was changed, and the effect of noise on brain structure was revealed from the perspective of imaging.

Ranpirnase (onconase, ONC) is a new drug, with weak RNase activity and strong cytotoxicity to various tumor cells in vitro and in vivo. This study is to obtain recombination onconase (rONC) with high bioactivity. Based on the codon preference of Pichia pastoris, we designed and synthesized the gene according to cDNA sequences of ONC and the α mating factor's prepeptide. We screened positive clones after transforming the recombination plasmids into P. pastoris X-33, GSS115 and SMD1168. We screened the best combination of seven different vectors and host strains. Moreover, we optimized culture condition in shake flasks and 10 L bioreactor, and purified rONC from the supernatant after inducing it with 0.25% methanol by aqueous two-phase extraction coupling G50 molecular exclusion method. The highest rONC production was 13 mg/L in pPICZα-A/X-33/ONC combination under the condition of pH 5.5 and 23 degrees C in shake flasks for 7 d; and that the highest rONC production was 180 mg/L when the induction is performed in the lower basic salt medium with pH 5.5 in the 10 L bioreactor for 7 d. The yield of rONC is more than 90% at a purity of above 95%. rONC can kill various tumor cells in vitro. The expression and purification of rONC would be useful for further investigation of this new drug.
Antineoplastic Agents ; metabolism ; Bioreactors ; Cell Line, Tumor ; Codon ; DNA, Complementary ; Genetic Vectors ; Humans ; Pichia ; metabolism ; Recombinant Proteins ; biosynthesis ; Ribonucleases ; biosynthesis