The influence of unicellular eukaryotic microorganisms on human gut health and disease is largely unexplored. Blastocystis species commonly colonize the gut, but their clinical significance and ecological role are unclear. We evaluated the effect of Blastocystis colonization on the fecal microbiota of Koreans. In total, 39 Blastocystis-positive and -negative fecal samples were analyzed. The fecal microbiome was assessed by targeting the V3–V4 region of the bacterial 16S ribosomal gene. Bacterial diversity was greater in the Blastocystis-positive than in the Blastocystis-negative group. The bacterial community structure and phylogenetic diversity differed according to the presence of Blastocystis. The mean proportions of Faecalibacterium species and Ruminococcaceae were larger in the Blastocystis-positive group, and that of Enterococcus species was larger in the Blastocystis-negative group. Linear discriminant analysis showed that Faecalibacterium, Prevotella 9, Ruminococcaceae UCG-002, Muribaculaceae, Rikenellaceae, Acidaminococcaceae, Phascolarctobacterium, and Ruminococcaceae UCG-005 were highly enriched in the Blastocystis-positive group, whereas Enterococcus hirae, Enterococcus faecalis, Enterococcus durans, Enterococcaceae, Lactobacillales, and Bacilli were highly abundant in the Blastocystis-negative group. Overall, our results enlighten the notion that Blastocystis colonization is associated with a healthy gut microbiota.

The molecular profile of cholangiocarcinoma (CC) remains elusive. The prognostic value of isocitrate dehydrogenase (IDH) mutations in CC is controversial, and there have been few relevant studies in Asian populations. In the present study, we investigated the frequency and prognostic significance of IDH mutations in Korean patients with CC. CC specimens were collected from patients who underwent surgical liver resection between 2004 and 2019. Clinical and pathological data were retrospectively reviewed from medical records. Mutational IDH profiling was performed by peptide nucleic acid-mediated PCR clamping in 206 surgical specimens; IDH-mutant samples were confirmed by next-generation sequencing (NGS). Of the 195 patients with CC, six (3.13%) were found to exhibit IDH1 (n = 5) or IDH2 (n = 1) mutations. Among patients with IDH1 mutations, four had R132C (c.394C>T) and one had R132G (c.394C>G) mutations. One patient had R172W (c.514A>T) mutations in IDH2. All IDH-mutant samples were of intrahepatic origin, and patients with IDH mutations had physiological to low serum levels of carbohydrate antigen 19-9 (CA19-9). No association between IDH mutation status and long-term survival outcomes was observed. The frequency of IDH mutations was considerably lower than the 10-20% reported in previous studies. The frequency and pattern of IDH mutations in CC are likely to vary among patients with different ethnicities. These findings suggest that characterization of the oncogenic mutation profile in different populations is of high clinical importance.

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Background and Objective Tramadol has been reported to cause hyponatremia but the evidence is conflicting. The risk of hyponatremia resulting from combination oral tramadol/acetaminophen (TA) therapy is thus unknown. This study examined whether, compared with acetaminophen (AA), TA use is associated with an increased risk of hyponatremia. Methods Hospital data compatible with the Observational Medical Outcomes Partnership–Common Data Model (OMOP–CDM; version 5.3) for 30,999 patients taking TA or AA from 2011 through 2020 were analyzed. New-onset hyponatremia was defined as a serum sodium level < 135 mEq/L within 10 days after drug initiation. The incidence rate ratio was calculated based on crude and 1:1 propensity-score-matched models. Subgroup analyses compared patients taking TA extended-release (TA–ER) and TA immediate-release (TA–IR) formulations. Results Among the 30,999 patients, 12,122 (39.1%) were aged > 65 years and 16,654 (53.7%) were male. Hyponatremia within 10 days developed in 1613 (8.4%) of the 19,149 patients in the TA group; the incidence rate was higher than in the AA group (4.2%; 493 out of 11,850 cases). In the propensity-score-matched model, the incidence rate of hyponatremia in the TA group was 6.8 per 1000 person-days (PD), which was 1.57-fold (1.31, 1.89) higher than that in the AA group (4.3 per 1000 PD). In both the crude and propensity-score-matched models, the incidence rate of hyponatremia was significantly higher in the TA–ER than TA–IR subgroup. Conclusion In this real-world study, hyponatremia was more frequently observed in the TA than AA group, and in the TA–ER than TA–IR subgroup. Therefore, it is imperative to prescribe tramadol cautiously and closely monitor electrolyte levels. Supplementary Information The online version contains supplementary material available at 10.1007/s40268-023-00436-4.

Annual proficiency surveys were conducted three times a year (2020-2021) by the Korean Association of External Quality Assessment Services. In addition to the image samples (MPI-20-01-MPI-20-04 and MPI-21-01-MPI-21-05), the pre-made slide samples (MPS-20-01-MPS-20-05 and MPS-21-01, MPS-21-02) and the formalin samples (MPF-21-01 and MPF-21-02) were included. Even though the image samples were not usually found recently, they were prepared to target parasites that were clinically or epidemiologically important in Korea. The overall agreement rates were 97.7% in 2020 (participant laboratories numbers 214-216) and 98.2% in 2021 (participant laboratories numbers 211-213). The agreement rates were significantly lower for the MPS samples than for the MPI samples (MPS 96.6% vs. MPI 99.1%, P=0.0002) in 2020. The agreement rates were significantly lower for the MPF samples than for the MPI or MPS samples (MPF 96.0% vs. MPI 98.9% or MPS 98.6%; P=0.0007 or P=0.0207, respectively) in 2021. Based on our in-depth survey of clinical parasitology, it should be accompanied by continuous education about different parasitic infections, which could aid in overcoming the lack of experience in clinical laboratory inspections.