The effect of age and abstinence time on semen quality: a retrospective study / 亚洲男科学杂志(英文版)

This study analyzed the effects of male age and abstinence time on semen quality and explored the best abstinence time for Chinese males among different age groups. Semen parameters, including sperm kinetics, morphology, and DNA fragmentation index (DFI), were reviewed from 2952 men. Samples were divided into six age groups (≤25 years, 26-30 years, 31-35 years, 36-40 years, 41-45 years, and >45 years) and were divided into six groups according to different abstinence time (2 days, 3 days, 4 days, 5 days, 6 days, and 7 days). The differences in semen quality between the groups were compared, and the effect of age and abstinence time on semen quality was analyzed. Significant differences were observed in semen volume, progressive motility (PR), and DFI among the age groups (all P < 0.05), and no significant differences were observed in sperm morphological parameters (all P > 0.05). There were significant differences in semen volume, PR, and DFI among different abstinence time groups (all P < 0.05) and no significant differences in sperm morphological parameters (all P > 0.05). Pearson analysis showed that male age and abstinence time were both significantly correlated with sperm kinetics and DFI (both P < 0.05), while no significant correlation was found with sperm morphological parameters (all P > 0.05). The box plots and histograms of men's age, abstinence time, and semen quality show that most semen quality parameters differ significantly between the 2 days and 7 days abstinence groups and other groups at different ages. Except for the sperm morphology parameters, sperm kinetic parameters and sperm DFI are linearly related to male age and abstinence time.

Comparison of Clinical Characteristics and Outcomes of Pediatric and Adult Patients with Coronavirus Disease 2019 in Shenzhen, China / 生物医学与环境科学（英文）

Objective@#Here we aimed to investigate the difference in clinical characteristics and outcomes between pediatric and adult patients with COVID-19.@*Methods@#A total of 333 consecutive patients with laboratory-confirmed SARS-CoV-2 infection treated in the departments of Internal medicine of Shenzhen Third People's Hospital from January 11 @*Results@#Compared with adult patients, pediatric patients had a shorter time of symptom onset to hospitalization than adults [median time, 1 ( @*Conclusion@#Pediatric patients with COVID-19 had milder or less clinical symptoms, less evident pulmonary imaging changes, better prognosis, and shorter length of hospital stay.

The clinical significance of nucleotide G1613A and C1653T mutations in the core promoter region of hepatitis B virus / 解放军医学杂志

Objective To evaluate the impact of hepatitis B virus (HBV) genome G1613A and C1653T mutations on disease progression, viral replication capacity, and transcription activity of HBV core promoter (CP). Methods A total of 258 patients were enrolled in the present study, including 65 patients with acute hepatitis B (AHB), 120 with chronic hepatitis B (CHB), and 73 with acute on chronic liver failure (ACLF). Serum HBV DNA was extracted from patients, and full-length HBV genome was amplified by PCR. The incidences of G1613A, C1653T and G1613A+C1653T in different groups were compared, and through functional experiments, the impact of mutants and wild-type virus on viral replication capacity and CP transcription activity was assessed. Results Genotype B, C and D were the three detected genotypes in 285 patients, with detection rates of 22.2%, 76.2% and 1.6%, respectively. The incidences of G1613A, C1653T and G1613A+C1653T mutations increased with the disease exacerbation, and they were 13.70%, 31.80% and 45.20% in AHB patients (P<0.01), 2.30%, 16.30% and 27.40% in CHB patients (P<0.01), and 2.29%, 12.07% and 23.29% in ACLF patients (P<0.05). Compare with wild-type strain, the G1613A mutant strain of HBV increased the viral replication capacity by 6%, reduced HBsAg level and core promoter activity by 15% and 16.2%, and reduced HBeAg to undetectable level; the C1653T mutant strain increased the viral replication capacity, HBsAg level, and core promoter activity by 10%, 55% and 17.1%, respectively, and the HBeAg level was comparable to that of wild-type strain; the G1613A+C1653T mutant strain increased viral replication capacity, HBsAg level and HBeAg level by 7%, 66% and 227%, respectively, while it had no influence on core promoter activity. Conclusion The G1613A and C1653T mutation in CP region may increase HBV replication capacity and alter CP activity and HBV antigens expression, the doublet mutation of G1613A+C1653T shows synergic effect on these changes, suggesting these mutations are associated with liver disease progression.