Objective To observe the protective effects of melatonin against spinal cord injury from seawater immersion in rabbits.Methods The 120 mature and health New Zealand White rabbits,weight range from 2.6 to 2.9kg,were randomly divided into four groups (30 each):control group,ethanol group,melatonin group (100mg/kg),methylPrednisolone group (30mg/kg).The rabbit model of spinal cord injury were built by modified Allen's method taking the 10th thoracic vertebra as a center,seawater immersion for 60 minutes,and then by grouping to give the appropriate treatment.After each group was given the corresponding treatment,six rabbits in each group were randomly selected at 1,6,12,24 and 48 hours five different time points.The neurological function scores of the rabbits were evaluated by Tarlov method,the spinal cord ofT9 to T.which were obtained from all the groups were used for further study,including immunohistochemical detection of apoptosis proteins:Bax,Bcl-2,neurofilament protein 200 (NF200) and in situ end labeling (TUNEL) method to detect spinal neuronal cell apoptosis.Results Within each observation time point,the Tarlov score was higher in melatonin group and methylprednisolone group compared with control group and ethanol group (P＜0.05),there was no significant difference between melatonin group and methylprednisolone group (P＞0.05).The expressions of Bcl-2 and NF200 were significantly higher in melatonin group and methylprednisolone group compared with control group and ethanol group,while Bax expression was significantly lower (P＜0.05).There were no significant difference between melatonin group and methylprednisolone group in the expression of three proteins (P＞0.05).The TUNEL-positive apoptotic cells were fewer in melatonin group and methylprednisolone group compared with control group and ethanol group (P＜0.05),and there was no significant difference between melatonin group and methylprednisolone group (P＞0.05).Conclusion Melatonin has protective effect against spinal cord injury from seawater immersion in rabbits,no difference in efficacy exists compare with methylprednisolone.

Background Experimental studies have shown that radiofrequency electromagnetic waves emitted by mobile phones can cause adverse effects on male reproductive health, including decreased semen quality and altered sex hormones. However, the results of epidemiological studies on the relationship between mobile phone use and male semen quality are inconsistent. Furthermore, there are few epidemiological studies on the association of mobile phone use with sex hormones. Objective To explore the associations of mobile phone use with male semen quality and sex hormones. Methods A total of 2045 men visited the reproductive medicine center of a hospital in Wuhan and ordered infertility examination were recruited from December 2018 to January 2020. Information on mobile phone use was obtained using a questionnaire. Among them, 1232 and 1694 men were eligible for semen quality analyses and sex hormone analyses, respectively. Multiple linear and logistic regression models were used to analyze the associations of mobile phone use with male semen quality and sex hormones. Results After adjusting for potential confounders, there was no statistically significant associations of mobile phone use with sperm progressive motility, sperm total motility, sperm concentration, sperm count, or serum luteinizing hormone (P>0.05). However, serum total testosterone showed a declined tendency with increasing daily duration of mobile phone use (P_trend=0.08). Compared with men with daily mobile phone use of 0-2 h, men with daily mobile phone use of 2.1-5, 5.1-8, and >8 h showed decreased serum total testosterone concentrations by 6.29% (95%CI: 0.40%-11.84%), 6.01% (95%CI: 0.60%-12.19%), and 7.87% (95%CI: 0.40%-14.79%), respectively. Conclusion Mobile phone use is not associated with male semen quality and serum luteinizing hormone, but increasing daily duration of mobile phone use is potentially associated with a tendency to lower male serum total testosterone.