Expression of RNF8 on cochlear apoptosis and aging in mice of different ages.

This study aimed to investigate the role of RNF8 (RING finger protein 8) in DNA damage repair in mice of different ages, and to provide new insight into the pathology and treatment of senile deafness. Sixteen C57BL/6J mice aged 8 weeks, 16 weeks and 32 weeks were obtained by paired reproduction. The mice of three age groups were equally divided into two groups, named experimental group (RNF8 gene knockout) and control group (no knockout). The cochlear hair cells, stria vascularis and spiral ganglion cells were observed by HE (hematoxylin-eosin) staining. The degree of DNA damage and the related expressions were observed by immunofluorescence γ-H2AX staining and 8-OH immunohistochemical staining, and the aging of damaged cells was detected by lipofuscin and ß-galactosidase staining. HE staining showed that the changes of cochlear hair cells, stria vascularis and spiral ganglion cells were obvious in the same group of mice at different ages. Compared with the control group, the aging changes of cochlear hair cells, stria vascularis and spiral ganglion cells were more significant in the experimental group. Immunofluorescence γ-H2AX staining showed H2AX phosphorylation in injured cells. The aging of cochlea in mice changed, and staining of ß-galactosidase in the experimental group suggested that the striae of blood vessels were changed with age at 32 weeks old and staining of lipofuscin showed dark brown staining around the nucleus (P < 0.05). In conclusion, the deletion of RNF8 is an important cause of morphological changes in the cochlea of mice. The deletion of RNF8 accelerates the aging of the cochlea of mice, suggesting that the apoptosis of the cochlea could contribute to aging in RNF8 gene-deficient mice.

[Retinal image quality in northern rural Chinese adult population].

Objective: To assess the retinal image quality of the normal northern rural Chinese adult population. Methods: A normal population-based, cross-sectional study. From Oct, 2012 to Jan 2013, a clustered, random sampling procedure was used to select normal population who visual acuity≤ 0(LogMAR) and 30-69 years old from 2 villages. All eligible subjects were invited to undergo a comprehensive eye examination, and the retinal image quality related index were examined with pupil 4 mm using objective optical quality analysis systemⅡ(OQAS Ⅱ, Visiometrics, Spain), including MTFcutoff, VA20, VA9, PSF50, PSF10, OSI, SR. And describe the retinal image quality of different age group, including 30-39y, 40-49y, 50-59y, 60-69y. Results: Among 1 108 participants (61.9%) that completed examinations in our center, 681 participants (1 362 eyes) were recruited. There were 146, 586, 440 and 190 eyes in each group. The spherical equivalent refraction of each group was (-0.35±0.84), (-0.19±0.50), (-0.03±0.54) and (0.20±0.71) D. The best corrected vision acuity of each group was -0.02±0.04, -0.01±0.03, -0.01±0.02 and -0.00±0.01. The MTFcutoff of each group was (37.06±9.31), (36.69±8.93), (36.52±9.05) and (32.61±10.08) c/deg. Retinal imaging parameters were significantly different(MTFcutoff: MD=4.45, SR:MD=0.03, PSF50: MD=-0.45, PSF10: MD=-2.87, VA20:MD=0.13, A9:MD=0.09, OSI:MD=-0.41, P<0.001)between aged 30-39 group and aged 60-69 group. Objective scattering index (OSI) were significantly different(MD=-0.13, P=0.004)between aged 30-39 group and aged 50-59 group. Retinal imaging parameters were significantly different(MTFcutoff:MD=4.45, SR:MD=0.03, PSF50:MD=-0.45, PSF10:MD=-2.87, VA20:MD=0.13, VA9: MD=0.09, OSI: MD=-0.41, P<0.001)between aged 40-49 group and aged 60-69 group. Retinal imageing parameters were significantly different(MTFcutoff: MD=4.45, SR: MD=0.03, PSF50: MD=-0.45, PSF10: MD=-2.87, VA20:MD=0.13, VA9:MD=0.09, OSI:MD=-0.41,P<0.001)between aged 50-59 group and aged 60-69 group. Conclusion: Retinal image quality was gradually worse over time in the northern rural Chinese adult population. (Chin J Ophthalmol, 2018, 54:593-598).

A study of siliceous pneumoconiosis in a desert area of Sunan County, Gansu Province, China.

Three hundred and ninety five residents in a desert area were examined with chest radiographs and 28 cases with siliceous pneumoconiosis were found. The prevalence of siliceous pneumoconiosis was 7.09%, and that over 40 years of age was 21%. The histological findings of lungs from a camel living in that area for 20 years also confirmed to have siliceous pneumoconiosis.

[A primitive study on the histological changes in the lungs of residents in the wind-sand area of Gansu Province].

395 residents in a wind-sand area were examined with chest radiographs. Silicotic roentgeno- graphic changes were shown in 28 cases. The abnormal finding rate of the > 40 years old age group was 21%. The histological findings of lungs from a camel lived in that area for 20 years also confirmed that the cause of death was silicosis.