Detection of aberrant DNA methylation patterns in sperm of male recurrent spontaneous abortion patients.

Aberrant DNA methylation patterns in sperm are a cause of embryonic failure and infertility, and could be a critical factor contributing to male recurrent spontaneous abortion (RSA). The purpose of this study was to reveal the potential effects of sperm DNA methylation levels in patients with male RSA. We compared sperm samples collected from fertile men and oligoasthenospermia patients. Differentially methylated sequences were identified by reduced representation bisulfite sequencing (RRBS) methods. The DNA methylation levels of the two groups were compared and qRT-PCR was used to validate the expression of genes showing differential methylation. The results indicated that no difference in base distribution was observed between the normal group and the patient group. However, the chromosome methylation in these two groups was markedly different. One site was located on chromosome 8 and measured 150 bp, while the other sites were on chromosomes 9, 10, and X and measured 135 bp, 68 bp, and 136 bp, respectively. In particular, two genes were found to be hypermethylated in these patients, one gene was DYDC2 (placed in the differential methylation region of chromosome 10), and the other gene was NXF3 (located on chromosome X). Expression levels of DYDC2 and NXF3 in the RSA group were significantly lower than those in the normal group (P < 0.05). Collectively, these results demonstrated that changes in DNA methylation might be related to male RSA. Our findings provide important information regarding the potential role of sperm DNA methylation in human development.

Comparison of Sleep Disturbances Between Older Nursing Home Residents in High- and Low-Altitude Areas.

BACKGROUND AND OBJECTIVE: This study compared sleep disturbances between older adults living in nursing home located in high- and low-altitude areas and explored the association between sleep disturbances and quality of life (QoL). METHOD: In total, 207 participants living in a high-altitude area and 437 participants in a low-altitude area were included. Sleep disturbances (ie, difficulty in initiating sleep, difficulty in maintaining sleep, and early morning awakening) were measured using standardized questions. The independent demographic and clinical correlates of sleep disturbances in high-altitude area were examined using multiple logistic regression analyses. Each type of sleep disturbance was entered as the dependent variable separately, while those with significant group differences in the univariate analyses (ie, male gender, married status, age and depressive symptoms) were entered as independent variables. RESULTS: The prevalence of any type of sleep disturbances in the whole sample was 26.09%, with 41.54% in the high-altitude area and 18.76% in the low-altitude area. Physical, psychological, social, and environmental QoL domains were negatively associated with sleep disturbances in high-altitude area. Multiple logistic regression analyses revealed that male gender and married status were less likely to have sleep disturbances, while those with more severe depressive symptoms were more likely to have sleep disturbances in high-altitude area. CONCLUSION: Sleep disturbance is common among older nursing home residents in high-altitude areas. Considering the negative impact of sleep disturbance on QoL, regular screening and treatment strategies need to be developed directly for this population.