AIM: To study the changes of K + channels of outer hair cells in guinea pig cochlea with streptomycin ototoxicity. METHODS: Auditory brainstem responses (ABR) and whole-cell patch clamp techniques were used.RESULTS: (1) The body weight of guinea pigs with streptomycin ototoxicity decreased significantly; (2) The ABR threshold markedly increased in streptomycin group (Ⅱ,Ⅲ);(3)The number of dissociated outer hair cells of guinea pigs (Ⅱ,Ⅲ) was lower than that of control (Ⅰ); (4) Streptomycin decreased the Ca 2+ -sensitive K + currents and delayed outward K + currents distinctly; (5) There was no significant difference of K + currents between Ⅰ and Ⅱ/Ⅲ. CONCLUSION: These results suggest that the inhibition of K + channels is the basis of streptomycin ototoxicity, but not the direct reason for cell death.

BACKGROUND: Insulin like growth factor 2 (IGF2) is an important embryonic mitosis growth promoting factor, whichplays a critical role in the process of maintaining normal cell growth. The gene expression of IGF2 is under epigeneticregulation in the way of genomic imprinting. Imprinting loss of IGF2 is likely to be associated with the abnormaldevelopment of the individual and tumorigenesis.OBJECTIVE: To investigate the effect of imprinting loss of IGF2 gene on the differentiation of mouse embryonic stemcells into islet-like cells.METHODS: Two kinds of mouse embryonic stem cells (SF1-G and SF1-1) were induced to differentiate into islet-likecells in vitro. The expression of Insulin gene was detected by real-time PCR and cell immunofluorescence. Theexpression of IGF2 was detected by the polymerase chain reaction-restriction fragment length polymorphism in the cellsbefore and after induced differentiation. The level of insulin released at terminal differentiation stage was tested by insulinrelease assay in vitro.RESULTS AND CONCLUSION: (1) There was no change in the imprinting state of the two kinds of mouse embryonicstem cells with normal and imprinted IGF-2 gene before and after differentiation. (2) In the induced cells, the expressionlevel of insulin in the SF1-1 group was higher than that in the SF1-G group, although there was no significant differencein the insulin release between the two kinds of cells. (3)The imprinting loss of IGF-2 gene may be related to theup-regulation of insulin mRNA expression in terminal cells during induced differentiation.

Objective To investigate the prevalence and risk factors of chronic kidney disease (CKD) in the adult urban population of Hezhou Guangxi. Methods One thousand and two hundred urban residents (older than 18 years) from Hezhou Guangxi were randomly selected using a random sampling. All the residents were interviewed. Their morning spot urine were tested to determine albumin to ereatinine ratio (abnormal:≥30 mg/g), and renal function [abnomal: eMDRD <60 ml·min-1·(1.73 m2)-1] was assessed. Morning spot urine dipstick of hematuria (abnormal:≥1 +) was confirmed by microscopy (abnormal: 3 red blood cells/HP). The associations among demographic characteristics, health eharacteristies and indicators of kidney damage were examined. Results Eligible data of 1069 subjects were enrolled in the study. The prevalence of albuminuria was 7.5%, hematuria 4.8%, and reduced eGFR 3.6%. The prevalence of kidney disease was 14.4% and the recognition was 1.4%. Age (OR 1.022, 95%CI 1.008-1.035), gender (OR 2.249, 95%CI 1.502-3.367), diabetes mellitus (OR 7.422, 95%CI 3.985-13.825) and hypertension (OR 4.397, 95% CI 2.601-7.432) were independently associated with CKD. Conclusions The prevalence of chronic kidney disease is 14.4% and the recognition is 1.4% in adult urban population of Hezhou Guangxi. Independent risk factors associated with chronic kidney disease are age, gender, diabetes mellitus and hypertension which is similar to those in developed countries and domestic big cities.

Objective To observe the effect of hypoxia on the expression of epithelial growth factor receptor (EGFR) and cell apoptosis of breast and cervical cancer xenografts in nude mouse models.Methods The nude mouse models with MCF-7 and HeLa xenografts were established.The degree of hypoxia and EGFR expression were observed by confocal microscopy.The influence of EGFR expression on cell apoptosis under hypoxia was observed by TUNEL assay.Results EGFR expression was either up-regulated or down-regulated in the MCF-7 and HeLa cells with high degree of hypoxia.Furthermore,the degree of apoptosis was reduced in tumor tissues with high EGFR expression compared with that in those with low expression of EGFR.Conclusion The hypoxia in MCF-7 and HeLa cells exerts heterogeneous effect on EGFR expression.Under hypoxic conditions,EGFR exoression is negatively correlated with cell apoptosis.

In this article,the content of radiation physics in the ICRU report No.89 were interpreted in details,aiming to provide reference in the radiation physics for radiologists performing brachytherapy for cervical cancer patients.

This paper made a detailed interpretation about the radiobiology-related contents in the ICRU report No.89,aiming to provide reference to resolve the problems related to radiobiology for the colleagues occupied in the brachytherapy for cervical cancer.

Radiotherapy is an important part of the postoperative adjuvant therapy of cervical cancer. Along with the persistent development of radiotherapy techniques, the application of brachytherapy has been more and more used as a boost to external beam radiotherapy. In this artical, the indications of postoperative radiotherapy and the application of brachytherapy were reviewed.

Objective:To explore the relationship between the life satisfaction of family caregivers and the de-gree of disability of disabled elderly people in Xinjiang Uygur and Kazak nationality,and the role of family mem-bers'participation in the relationship.Methods:A total of 431 elderly people with disabilities at home and their fam-ily caregivers(247 without family members and 184 with family members)were selected from Xinjiang Uygur and Kazak ethnic groups,and the survey was conducted with the Activity of Daily Living Scale(ADL)and Life Satis-faction Index B(LSIB).Results:The LSIB scores in family caregivers were negatively correlated with the ADL scores in the disabled elderly(r=-0.19,P＜0.01),and the family members'participation in care was positively correlated with the LSIB scores of family caregivers(r=0.52,P＜0.01).Family members'participation in care could moderate the negative effect of the ADL scores in the disabled elderly on the LSIB scores in family caregivers(β=0.08,P＜0.05).Conclusion:The involvement of family members in care has a moderating effect on the life satisfaction of Uyghur and Kazak family caregivers and the degree of disability of disabled elderly people.

ObjectiveTo understand the visual environment sanitation in primary and secondary school classrooms in Minhang District， Shanghai， and to investigate the factors affecting the decline in students’ visual acuity. MethodsIn 2020， among all the primary and secondary schools in Minhang District， according to different types of classroom structures， levels， orientations， unilateral lighting， and bilateral lighting， a total of 20 231 students from 674 classrooms in primary and secondary schools were selected through stratified cluster sampling. Each monitored classroom was regarded as a research unit， and the naked eye vision of students was tested using a standard logarithmic vision chart during the 2020 and 2021 academic years. The change in average visual acuity between the two measurements was taken as the dependent variable， and the visual environment indices were considered as independent variables. The relationship between classroom visual environment indices and the decline in students’ naked eye vision was analyzed. ResultsThe qualification rates for per capita classroom area， window to floor area ratio， average illuminance of the blackboard， uniformity of blackboard illuminance， average illuminance of the desks， uniformity of desk illuminance， lighting coefficient of classroom， blackboard reflection ratio， back wall reflection ratio， and distance between lamps and desks were 79.53%， 88.58%， 46.74%， 70.33%，64.69%， 80.86%， 71.81%， 20.30%， 1.63%， and 97.53%， respectively. The average naked eye vision of primary and secondary school students in the 2020 academic year was 4.75±0.37 （right eye） and 4.76±0.37 （left eye）， while in the 2021 academic year， it was 4.70±0.39 （right eye） and 4.71±0.38 （left eye）. There was a significant decrease in the naked eye vision of primary and secondary school students in the 2021 academic year compared to that of 2020 （P<0.05）. Univariate linear regression analysis showed a significant correlation between grade， average illuminance of the blackboard， average illuminance of the desks， uniformity of desk illuminance， lighting coefficient， and distance between lamps and desks， and the decline of students’ naked eye vision within one academic year （P<0.05）. After adjusting for grade， multiple linear regression analysis revealed a significant correlation between the average illuminance of the blackboard， uniformity of desk illuminance， lighting coefficient， and distance between lamps and desks， and the decline of students’ naked eye vision within one academic year （P<0.05）. Higher average illuminance of the blackboard， uniformity of desk illuminance， lighting coefficient， and distance between lamps and desks were protective factors for naked eye vision. ConclusionThe visual environment of primary and secondary school classrooms in Minhang District is a matter of concern. Average illuminance of the blackboard， uniformity of desk illuminance， lighting coefficient， and distance between lamps and desks are related to the degree of visual impairment in students over a year.