Experimental development of the epigenomic library construction method to elucidate the epigenetic diversity and causal relationship between epigenome and transcriptome at a single-cell level

The method of single-cell RNA sequencing has been rapidly developed, and numerous experiments have been conducted over the past decade. Their results allow us to recognize various subpopulations and rare cell states in tissues, tumors, and immune systems that are previously unidentified, and guide us to understand fundamental biological processes that determine cell identity based on single-cell gene expression profiles. However, it is still challenging to understand the principle of comprehensive gene regulation that determines the cell fate only with transcriptome, a consequential output of the gene expression program. To elucidate the mechanisms related to the origin and maintenance of comprehensive single-cell transcriptome, we require a corresponding single-cell epigenome, which is a differentiated information of each cell with an identical genome. This review deals with the current development of single-cell epigenomic library construction methods, including multi-omics tools with crucial factors and additional requirements in the future focusing on DNA methylation, chromatin accessibility, and histone post-translational modifications. The study of cellular differentiation and the disease occurrence at a single-cell level has taken the first step with single-cell transcriptome and is now taking the next step with single-cell epigenome.

Work-Related Musculoskeletal Disorders among Spine Surgeons / 대한정형외과학회잡지

PURPOSE: To investigate the prevalence and risk factors of musculoskeletal disorder (MSD) among spine surgeons. MATERIALS AND METHODS: A modified version of discomfort survey was sent via e-mail to surgeons that belong to the Korean Society of Spine Surgery. The survey questionnaires were composed of demographics, factors relating to spine surgery, and MSD. We investigated the common sites of occurrence of MSD and its risk factors. RESULTS: The survey was sent to a total of 420 subjects; of which, 80 subjects (19.0%) responded. About 78.8% of the respondents had MSD for the past year. The common sites of occurrence included the neck (52.5%), back (46.3%), and shoulder (18.8%). The prevalence of pain in the elbow joint/forearm was higher in the group performing a higher frequency of spine surgeries (p=0.033). Moreover, the prevalence of pain in the wrist/hand (p=0.008) and in the back (p=0.042) was higher in those with greater frequency of major surgeries (>10 case/year) as compared with those with lower frequency of major surgeries. CONCLUSION: As shown, about 78.8% of spine surgeons experienced MSD for the past one year. Its prevalence was higher as compared with the general population. Thus, more attention should be paid to the prevention of MSD among spine surgeons.

The Amputation Rate and Associated Risk Factors within 1 Year after the Diagnosis of Diabetic Foot Ulcer / 대한족부족관절학회지

PURPOSE: This study investigates the amputation rate within 1 year after the diagnosis of diabetic foot ulcer and its associated risk factors. MATERIALS AND METHODS: This study enrolled 60 patients with diabetic foot ulcer. The mean and standard deviation age was 64.4±12.8 years (range, 32~89 years); the mean and standard deviation prevalence period for diabetes mellitus was 21.0±7.5 years (range, 0.5~36 years). The amputation rate was evaluated by dividing the subjects into two groups—the major and minor amputation groups—within 1 year following the initial diagnosis of diabetic foot ulcer. Multivariate Cox proportional hazards regression analysis was used to identify the risk factors for amputation. RESULTS: The total amputation rate of 38.3% (n=23) was comprised of the amputation rate for the major amputation group (10.0%) and rate for the minor amputation group (23.8%). There was a high correlation between peripheral artery disease (toe brachial pressure index <0.7) and amputation (hazard ratio [HR] 5.81, confidence interval [CI] 2.09~16.1, p<0.01). Nephropathy was significantly correlated with the amputation rate (HR 3.53, CI 1.29~9.64, p=0.01). CONCLUSION: Clinicians who treat patients with diabetic foot complications must understand the fact that the amputation rate within 1 year is significant, and that the amputation rate of patients with peripheral artery disease or nephropathy is especially high.