Parallel shift of DNA methylation and gene expression toward the mean in mouse spleen with aging.

Age-associated DNA-methylation drift (AMD) manifests itself in two ways in mammals: global decrease (hypomethylation) and local increase of DNA methylation (hypermethylation). To comprehend the principle behind this bidirectional AMD, we studied methylation states of spatially clustered CpG dinucleotides in mouse splenic DNA using reduced-representation-bisulfite-sequencing (RRBS). The mean methylation levels of whole CpGs declined with age. Promoter-resident CpGs, generally weakly methylated (<5%) in young mice, became hypermethylated in old mice, whereas CpGs in gene-body and intergenic regions, initially moderately (~33%) and extensively (>80%) methylated, respectively, were hypomethylated in the old. Chromosome-wise analysis of methylation revealed that inter-individual heterogeneities increase with age. The density of nearby CpGs was used to classify individual CpGs, which found hypermethylation in CpG-rich regions and hypomethylation in CpG-poor regions. When genomic regions were grouped by methylation level, high-methylation regions tended to become hypomethylated whereas low-methylation regions tended to become hypermethylated, regardless of genomic structure/function. Data analysis revealed that while methylation level and CpG density were interdependent, methylation level was a better predictor of the AMD pattern representing a shift toward the mean. Further analysis of gene-expression data showed a decrease in the expression of highly-expressed genes and an increase in the expression of lowly-expressed genes with age. This shift towards the mean in gene-expression changes was correlated with that of methylation changes, indicating a potential link between the two age-associated changes. Our findings suggest that age-associated hyper- and hypomethylation events are stochastic and attributed to malfunctioning intrinsic mechanisms for methylation maintenance in low- and high-methylation regions, respectively.

Factors Influencing Preventive Behavior of COVID-19 among Nursing Students in South Korea.

We aimed to identify factors influencing the preventive behavior of COVID-19 among nursing students. A survey was conducted through an online questionnaire in December 2021 for students in the department of nursing at a university located in C city. An online questionnaire was distributed to 189 nursing students who voluntarily agreed to participate in the study, and data from 179 of them were used for the final analysis. The research tools used were COVID-19 stress scale for Korean people, COVID-19 risk-perception scale, self-efficacy scale, and COVID-19 prevention behavior scale. Data were analyzed by descriptive statistics, t-test, analysis of variance, Mann-Whitney and Kruskal-Wallis test, as well as Spearman correlation coefficient and multiple linear regression with SPSS 23.0 program. Factors significantly influencing the preventive behavior of COVID-19 were self-efficacy (ß = 0.53, p < 0.001) and COVID-19 stress (ß = 0.25, p = 0.001). The explanatory power of related variables was 45.0%. We found that self-efficacy and COVID-19 stress had a significant effect on the preventive behavior of nursing students. Therefore, to promote the preventive behavior of COVID-19, it is necessary to improve the self-efficacy of nursing students and manage COVID-19 stress well.

[Do depression, fatigue, and body esteem influence premenstrual symptoms in nursing students?] / 간간호대학생의 우울, 피로, ì‹ ì²´ì¡´ì¤‘ê°ì€ ì›”ê²½ì „ 증상에 영향을 미치는가?

Purpose: The purpose of this study was to investigate factors affecting premenstrual symptoms among nursing students, focusing on depression, fatigue, and body esteem. Methods: The participants were 145 nursing students at a university located in Changwon, Korea. Data were collected from November 2 to November 30, 2019 using self-reported structured questionnaires, and analyzed using descriptive statistics, independent t-test, analysis of variance, Pearson correlation coefficients, and multiple regression analysis. Results: The mean item score for premenstrual symptoms was 2.52±0.92, indicating a low level. The mean score for depression was 16.05±7.72, and 15.2% of participants were found to be moderately depressed and 9.7% severely depressed. The mean item score for fatigue was 4.84±0.84, indicating a moderate level, and body esteem was 2.94±0.44, indicating a moderate level. The premenstrual symptoms of nursing students showed a statistically significant correlation with depression (r=-.58, p<.001), fatigue (r=.33, p<.001), and body esteem (r=-.28, p<.001). Factors impacting premenstrual symptoms of nursing students were depression (ß=.47, p<.001), dysmenorrhea (ß=-.18, p=.009), menstrual cycle irregularity (ß=.17, p=.013), and body esteem (ß=-.14, p=.038). The total explanatory power of these variables was 41.0%. Conclusion: Findings from this sample of nursing students suggest that intervention programs to relieve premenstrual symptoms should focus on depression, menstrual cycle regularity, dysmenorrhea, and body esteem.

Predicting Posttraumatic Growth among Firefighters: The Role of Deliberate Rumination and Problem-Focused Coping.

Exposure to work-related traumatic incidents in firefighters may result in positive psychological changes which are termed "posttraumatic growth". This study aimed to construct structure equation modeling based on the model of posttraumatic growth in firefighters. Methods: A total of 226 firefighters who had experienced a work-related traumatic incident participated. The participants from three municipal fire departments and seven fire stations completed an anonymous survey asking about extraversion, optimism, calling in the workplace, problem-focused coping, deliberate rumination, and posttraumatic growth. The model fit indices were suitable for the recommended level. Seven of the 11 paths established in the initial hypothetical model were identified. The variables of deliberate rumination, problem-focused coping, and extraversion had a significant effect on the posttraumatic growth of firefighters, with an explanatory power of 38.7%. The findings show that it is important to develop strategies to enhance deliberate rumination and problem-focused coping for firefighters after work-related traumatic events.

Exploring the Relationships between Posttraumatic Growth, Wisdom, and Quality of Life in Older Cancer Survivors.

Objective: The number of older cancer survivors is steadily rising with a growing aging population, and a great interest in evaluating the quality of life is emerged. Although understanding how to improve the quality of life in older cancer survivors is critical as the number of older survivors continues to grow in communities, little is known about empirical evidence regarding predictors of the quality of life in older cancer survivors. This study aimed to examine relationships between posttraumatic growth, wisdom, and quality of life in older cancer survivors. Methods: A convenience sample of older cancer survivors after completing cancer treatments (n=121) participated from one public health center, and they filled out self-report questionnaires on measures of posttraumatic growth, wisdom, and quality of life. Results: As results of multiple regression analysis, the most significant factor on each domain of the quality of life has shown that higher levels of subjective economic status were associated with significant improvement of four domains of quality of life, and wisdom and posttraumatic growth were associated with significant improvement in social/family well-being. Conclusion: This study highlights predictors of each domain of quality of life that subjective economic status, posttraumatic growth and wisdom significantly affected the quality of life in older cancer survivors. Findings indicate that psychological interventions need to be developed and implemented for older cancer survivors to prevent long-term effects of cancer and to increase their quality of life. For improving their quality of life, primary care providers or community health professionals need to develop tailored interventions, such as home-based cancer survivorship programs.

Structure and expression of the zebrafish mest gene, an ortholog of mammalian imprinted gene PEG1/MEST.

PEG1/MEST is a paternally expressed gene in placental mammals. Here, we report identification of zebrafish (Danio rerio) gene mest, an ortholog of mammalian PEG1/MEST. Zebrafish mest encodes a polypeptide of 344 amino acids and shows a significant similarity to mammalian orthologs. Zebrafish mest is present as a single copy in the zebrafish genome and is closely linked to copg2 as in mammals. It is notable that 10 of 11 intron positions in mest are conserved among mammalian PEG1/MEST genes, indicating that the genomic organization and linkage between mest and copg2 loci was established in ancient vertebrates. Zebrafish mest is expressed in blastula, segmentation, and larval stages, exhibiting gradually increased expression as the development proceeds. Allelic expression analysis in hybrid larvae shows that both parental alleles are transcribed. We also observed one-codon alternative splicing involving an alternative usage of the two consecutive splice acceptors of intron 1, generating two protein isoforms with different lengths of a single amino acid.