Microbial community profiling using 16S rRNA amplicon sequencing allows for taxonomic characterization of diverse microorganisms. While amplicon sequence variant (ASV) methods are increasingly favored for their fine-grained resolution of sequence variants, they often discard substantial portions of sequencing reads during quality control, particularly in datasets with large number samples. We present a streamlined pipeline that integrates FastP for read trimming, HmmUFOtu for operational taxonomic units (OTU) clustering, Vsearch for chimera checking, and Kraken2 for taxonomic assignment. To assess the pipeline’s performance, we reprocessed two published stool datasets of normal Korean populations: one with 890 and the other with 1,462 independent samples. In the first dataset, HmmUFOtu retained 93.2% of over 104 million read pairs after quality trimming, discarding chimeric or unclassifiable reads, while DADA2, a commonly used ASV method, retained only 44.6% of the reads. Nonetheless, both methods yielded qualitatively similar β-diversity plots. For the second dataset, HmmUFOtu retained 89.2% of read pairs, while DADA2 retained a mere 18.4% of the reads. HmmUFOtu, being a closed-reference clustering method, facilitates merging separately processed datasets, with shared OTUs between the two datasets exhibiting a correlation coefficient of 0.92 in total abundance (log scale). While the first two dimensions of the β-diversity plot exhibited a cohesive mixture of the two datasets, the third dimension revealed the presence of a batch effect. Our comparative evaluation of ASV and OTU methods within this streamlined pipeline provides valuable insights into their performance when processing large-scale microbial 16S rRNA amplicon sequencing data. The strengths of HmmUFOtu and its potential for dataset merging are highlighted.

A 17-month-old boy was evaluated for a midline mass on his chin. The mass was anchored to the mentalis muscle with a stalk-like structure. The pathological diagnosis of the mass was rhabdomyomatous mesenchymal hamartoma. This is the first report of rhabdomyomatous mesenchymal hamartoma presenting as a midline chin mass in Korean pediatric patients.
Chin* ; Diagnosis ; Hamartoma* ; Head and Neck Neoplasms ; Humans ; Infant ; Male ; Mandibular Neoplasms ; Rhabdomyoma ; Soft Tissue Neoplasms

A 17-month-old boy was evaluated for a midline mass on his chin. The mass was anchored to the mentalis muscle with a stalk-like structure. The pathological diagnosis of the mass was rhabdomyomatous mesenchymal hamartoma. This is the first report of rhabdomyomatous mesenchymal hamartoma presenting as a midline chin mass in Korean pediatric patients.
Chin* ; Diagnosis ; Hamartoma* ; Head and Neck Neoplasms ; Humans ; Infant ; Male ; Mandibular Neoplasms ; Rhabdomyoma ; Soft Tissue Neoplasms

BACKGROUND: This research is to identify the difficulties occuring in the course of managing the adverse events and the adverse event related standard operating procedure in the regulation of each institutional review board. METHODS: In order to identify the issues of the management of adverse events of each institution, this research surveyed the IRB administrators in fifty two university hospitals nation-wide. This survey is conducted among one chairman and one IRB member from the IRB members per each IRB who have experience in reviewing adverse events. The survey also includes investigators and sponsors who engage in reporting adverse events. RESULTS: The result of this survey demonstrates that the objects and the terms of adverse event reports provided by the Standard Operating Procedure and the KGCP of each institution are not very different from each other. However, according to the survey, any cases reported to the IRBs, although they are not specified as the object of reports in the institution, have been reviewed by the IRB members. To sum up the results of the survey, the major issues include ambiguous regulations on adverse event reports and reviews, the use of different report formats for each institution, and the difficulty with evaluating the causal relationship with Investigational Product. CONCLUSION: It is necessary to develop concrete and specified guidelines on the objects and the terms of reports, the standard for the causal relationship and the adequate measures for adverse events after review and to standardize the format of adverse event reporting.
Administrative Personnel ; Ethics Committees, Research ; Hospitals, University ; Humans ; Research Personnel ; Social Control, Formal

Clostridium difficile infection (CDI) after ileostomy reversal is rare, with few reports available in the available literature describing this condition. The diagnosis of CDI after ileostomy reversal is challenging because symptoms such as diarrhea observed in these patients can occur frequently after surgery. However, CDI can be fatal, so early diagnosis and prompt treatment are important. We discuss 2 patients with positive C. difficile toxin assay results on stool cultures performed after ileostomy reversal. Clinical progression differed between these patients: one patient who presented with severe CDI and shock was successfully treated following a prolonged intensive care unit stay for the management of vital signs and underwent hemodialysis, while another patient showed symptoms of mild colitis but we could not confirm whether diarrhea was associated with CDI or with the usual postoperative state. To our knowledge, these represent 2 of just a few cases reported in the literature describing CDI after ileostomy reversal.

Clostridium difficile infection (CDI) after ileostomy reversal is rare, with few reports available in the available literature describing this condition. The diagnosis of CDI after ileostomy reversal is challenging because symptoms such as diarrhea observed in these patients can occur frequently after surgery. However, CDI can be fatal, so early diagnosis and prompt treatment are important. We discuss 2 patients with positive C. difficile toxin assay results on stool cultures performed after ileostomy reversal. Clinical progression differed between these patients: one patient who presented with severe CDI and shock was successfully treated following a prolonged intensive care unit stay for the management of vital signs and underwent hemodialysis, while another patient showed symptoms of mild colitis but we could not confirm whether diarrhea was associated with CDI or with the usual postoperative state. To our knowledge, these represent 2 of just a few cases reported in the literature describing CDI after ileostomy reversal.

Background: Pilomatrixoma is a benign tumor that originates from the hair follicle matrix. It usually presents as a hard, slow growing, solitary mass that can be easily misdiagnosed as other skin masses. The aim of this study was to clinically analyze a case series of pilomatrixoma in pediatric patients from Korea. Methods: A total of 165 pediatric patients from 2011 to 2018 with a histological diagnosis of pilomatrixoma were included. A retrospective review was performed using the electronic medical records, including patient demographics, number and location of the mass, clinical and imaging presentation, and postoperative outcomes. Results: There were 61 male and 104 female patients with 152 solitary and 13 multiple pilomatrixomas. Among solitary pilomatrixomas, the lesion commonly occurred in the head and neck (84.2%), followed by upper limbs (11.2%), lower limbs (3.3%), and trunk (1.3%). The pilomatrixoma lesion presented as the following types based on our clinical classification: mass (56.02%), pigmentation (25.31%), mixed (12.65%), ulceration (4.82%), and keloid-like (1.2%). Ultrasonography showed a high positive predictive value (95.56%). There were no specific complications observed except for two cases of recurrence. Conclusion Pilomatrixoma has various clinical feature presentations and commonly occurs in the head and neck. Ultrasonography is a helpful diagnostic tool. Surgical removal of the lesion is the main treatment method with a low recurrence rate.

Background and Objectives: Recent studies have described direct reprogramming of mouse and human somatic cells into induced neural stem cells (iNSCs) using various combinations of transcription factors. Although iNSC technology holds a great potential for clinical applications, the low conversion efficiency and limited reproducibility of iNSC generation hinder its further translation into the clinic, strongly suggesting the necessity of highly reproducible method for human iNSCs (hiNSCs). Thus, in orderto develop a highly efficient and reproducible protocol for hiNSC generation, we revisited the reprogramming potentials of previously reported hiNSC reprogramming cocktails by comparing the reprogramming efficiency of distinct factor combinations including ours. Methods: We introduced distinct factor combinations, OSKM (OCT4+SOX2+KLF4+C-MYC), OCT4 alone, SOX2 alone, SOX2+HMGA2, BRN4+SKM+SV40LT (BSKMLT), SKLT, SMLT, and SKMLT and performed comparative analysis of reprogramming potentials of distinct factor combinations in hiNSC generation. Results: Here we show that ectopic expression of five reprogramming factors, BSKMLT leads the robust hiNSC generation (>80 folds enhanced efficiency) from human somatic cells compared with previously described factor combinations. With our combination, we were able to observe hiNSC conversion within 7 days of transduction. Throughout further optimization steps, we found that both BRN4 and KLF4 are not essential for hiNSC conversion. Conclusions Our factor combination could robustly and reproducibly generate hiNSCs from human somatic cells with distinct origins. Therefore, our novel reprogramming strategy might serve as a useful tool for hiNSC-based clinical application.

Background: Most of the studies that have examined the association between the sub-factors of occupational stress and depressive symptoms have used cross-sectional data. However, our study has longitudinally measured the occupational stress and depressive symptoms of Korean workers of a semiconductor manufacturing company across six years to intending to investigate the associations between the sub-factors of occupational stress and depressive symptoms using longitudinal data. Methods: Data collected from the workers of a semiconductor manufacturing company.Out of 1,013 recruited workers, 405 (40.0%) completed the survey questionnaires at 3 and 6-year follow-ups. Occupational stress was measured using a shorter version of the Korean Occupational Stress Scale (KOSS), whereas depressive symptoms were assessed using the Korean version of the Center for Epidemiological Studies-Depressive Symptoms Scale (CES-D). The data of male and female participants independently analyzed. Longitudinal associations were analyzed using panel data analysis with fixed effects. Results: In panel data analysis with fixed effects, job insecurity (B = 0.048, p-value = 0.004) was associated with depressive symptoms among male workers. In female workers, inadequate social support (B = 0.080, p-value < 0.001), job insecurity (B = 0.039, p-value = 0.004), lack of reward (B = 0.059, p-value = 0.004) and discomfort in occupational climate (B = 0.074, p-value < 0.001) were associated with depressive symptoms among female workers. Conclusions Temporal changes in the sub-factors of occupational stress were associated with changes in depressive symptoms within the same period. There was a gender difference in occupational stress sub-factors related to depressive symptoms.