Background/Aims: This study investigated the clinical efficacy of low-dose mepolizumab (100 mg) in controlling severe eosinophilic asthma, aiming to induce eosinophilic granulomatosis with polyangiitis (EGPA) remission and reduce systemic steroid usage. Additionally, we constructed a basic frame for our longitudinal EGPA cohort by collecting serial blood samples before, during, and after mepolizumab treatment in EGPA patients. Methods: We conducted a 2-year prospective observational cohort study in patients with uncontrolled severe eosinophilic asthma and refractory EGPA who used systemic steroids (≥ 7.5 mg/day of prednisolone) or other immunosuppressant drugs for at least 6 months. All patients were treated with 100 mg of mepolizumab every 4 weeks for 1 year to control severe eosinophilic asthma and then were followed for an additional 1 year to monitor their disease course. We analyzed total systemic steroid use and EGPA remission/relapse during the study period. Results: Three EGPA patients were included in this study and completed 16 study visits over a 2-year period. After 1 year of treatment with mepolizumab (100 mg monthly), all 3 patients were able to reduce their maintenance dose of systemic steroids, with 2 patients completely discontinuing use. These 2 patients achieved EGPA remission during mepolizumab treatment, and their remission status remained stable for 1 year after they stopped receiving the medication. Conclusions Low-dose mepolizumab treatment demonstrated clinical efficacy in reducing the maintenance dose of systemic steroids required for severe refractory EGPA. While not all patients achieved EGPA remission with low-dose mepolizumab, some did, and their remission persisted even after treatment discontinuation.

Background: Perfluoroalkyl substances (PFAS) are used in various products, and PFAS have been detected in outdoor clothing. PFAS can be absorbed into the human body via oral ingestion, inhalation, and dermal contact. In this study, we examined the association between the frequency of using outdoor clothing and serum PFAS concentrations in the Korean population using data from cycle 4 (2018–2020) of the Korean National Environmental Health Survey. Methods: Data from 2,993 adult participants were analyzed. The participants were classified into low-concentration and high-concentration groups based on the 75th percentile concentration of serum PFAS. The use of outdoor clothing was categorized into three groups: non-use, <4 times a week, and ≥4 times a week. The odds ratio (OR) for serum PFAS levels associated with use of outdoor clothing was determined through logistic regression analysis, adjusted for demographic characteristics, health-related factors, PFAS-treated items, dietary factors, and ventilation time. Results: ORs for high serum PFAS were higher in groups using outdoor clothing compared to the non-user group. In males, the adjusted ORs for the < 4 times a week and ≥ 4 times a week outdoor clothing usage group were as follows: perfluorooctanoic acid (PFOA), 1.26 (95% confidence interval [CI]: 1.10–1.44) and 1.70 (1.40–2.07); perfluorohexanesulfonic acid (PFHxS), 1.49 (1.16–1.92) and 1.70 (1.22–2.37); and perfluorononanoic acid (PFNA), 1.34 (1.19–1.51) and 1.68 (1.38–2.05), respectively. In females, the respective ORs were as follows: PFOA 1.32 (95% CI: 1.19–1.46) and 1.53 (1.01–2.32); PFHxS, 1.46 (1.08–1.96) and 2.63 (2.10–3.29); PFNA, 1.38 (1.22–1.55) and 1.45 (1.07–1.96). Conclusions In adults, elevated serum PFAS levels were associated with increased frequency of using outdoor clothing.

Although histone deacetylase 6 (HDAC6) is considered a therapeutic target for Alzheimer’s disease (AD), its role in cholinergic dysfunction in AD patients remains unclear. This study investigated the effects of (E)-3-(2-(4-fluorostyryl)thiazol-4-yl)-N-hydroxypropanamide (4-FHA), a new synthetic HDAC6 inhibitor, on cognitive and memory impairments in a scopolamine-induced-AD mouse model. Behaviorally, 4-FHA improved scopolamine-induced memory impairments in the Y-maze, passive avoidance, and Morris water maze tests. In addition, 4-FHA ameliorated scopolamine-induced cognitive impairments in the novel object recognition and place recognition tests. Furthermore, 4-FHA increased acetylation of α-tubulin (a major HDAC6 substrate); the expression of BDNF; and the phosphorylation of ERK 1/2, CREB, and ChAT in the hippocampus of scopolamine-treated mice. In summary, according to our data 4-FHA, an HDAC6 inhibitor, improved the cognitive and memory deficits of the AD mouse model by normalizing BDNF signaling and synaptic transmission, suggesting that 4-FHA might be a potential therapeutic candidate for AD.

Although histone deacetylase 6 (HDAC6) is considered a therapeutic target for Alzheimer’s disease (AD), its role in cholinergic dysfunction in AD patients remains unclear. This study investigated the effects of (E)-3-(2-(4-fluorostyryl)thiazol-4-yl)-N-hydroxypropanamide (4-FHA), a new synthetic HDAC6 inhibitor, on cognitive and memory impairments in a scopolamine-induced-AD mouse model. Behaviorally, 4-FHA improved scopolamine-induced memory impairments in the Y-maze, passive avoidance, and Morris water maze tests. In addition, 4-FHA ameliorated scopolamine-induced cognitive impairments in the novel object recognition and place recognition tests. Furthermore, 4-FHA increased acetylation of α-tubulin (a major HDAC6 substrate); the expression of BDNF; and the phosphorylation of ERK 1/2, CREB, and ChAT in the hippocampus of scopolamine-treated mice. In summary, according to our data 4-FHA, an HDAC6 inhibitor, improved the cognitive and memory deficits of the AD mouse model by normalizing BDNF signaling and synaptic transmission, suggesting that 4-FHA might be a potential therapeutic candidate for AD.

Although histone deacetylase 6 (HDAC6) is considered a therapeutic target for Alzheimer’s disease (AD), its role in cholinergic dysfunction in AD patients remains unclear. This study investigated the effects of (E)-3-(2-(4-fluorostyryl)thiazol-4-yl)-N-hydroxypropanamide (4-FHA), a new synthetic HDAC6 inhibitor, on cognitive and memory impairments in a scopolamine-induced-AD mouse model. Behaviorally, 4-FHA improved scopolamine-induced memory impairments in the Y-maze, passive avoidance, and Morris water maze tests. In addition, 4-FHA ameliorated scopolamine-induced cognitive impairments in the novel object recognition and place recognition tests. Furthermore, 4-FHA increased acetylation of α-tubulin (a major HDAC6 substrate); the expression of BDNF; and the phosphorylation of ERK 1/2, CREB, and ChAT in the hippocampus of scopolamine-treated mice. In summary, according to our data 4-FHA, an HDAC6 inhibitor, improved the cognitive and memory deficits of the AD mouse model by normalizing BDNF signaling and synaptic transmission, suggesting that 4-FHA might be a potential therapeutic candidate for AD.

Hypoglossal nerve palsy is a rare complication related to airway management during general anesthesia. Its diagnosis can be delayed when postoperative tongue swelling mimics a neoplasm. This paper reports a case of isolated hypoglossal nerve palsy after endotracheal intubation. A 65-year-old woman developed dysphagia and impaired tongue protrusion after orbital floor fracture surgery. Fiberoptic endoscopic evaluation revealed a 3-mm mass-like lesion at the tongue base, and magnetic resonance imaging showed asymmetric swelling of the left tongue and oropharyngeal wall. The tongue strength measured using the Iowa Oral Performance Instrument (IOPI) at six days post-onset was 10 kPa, which was markedly lower than the age norms. Electromyography revealed the fibrillation potentials and positive sharp waves in the left tongue muscle, confirming isolated hypoglossal nerve palsy. Oral methylprednisolone was administered for five days, followed by a five-day taper, with concurrent tongue-strengthening rehabilitation. One month later, the tongue strength improved, reaching a maximal pressure of 24 kPa. The mass-like lesion had resolved on follow-up and was interpreted as a pseudotumor caused by edema and mechanical compression. Complete recovery was achieved by the six-month follow-up. This case highlights the utility of IOPI for early quantitative assessment of tongue weakness and highlights that early diagnosis and steroid treatment can facilitate recovery.

Human pluripotent stem cells (hPSCs) can be used to investigate hematopoietic development and have the potential to advance cell-based therapies and to facilitate developmental biology studies. However, efficient ex vivo differentiation into hematopoietic lineages, including red blood cells (RBCs) of the erythroid lineage and immune cells such as macrophages of the myeloid lineage, is hampered by the need for precise temporal regulation of cytokines and growth factors.In this study, we developed an optimized protocol for hematopoietic lineage specification from hPSCs by fine-tuning the temporal dynamics of cytokine and growth factor applications. Prolonged mesodermal specification in the absence of hemogenic cytokines significantly enhanced the generation of hematopoietic progenitors (CD34＋ CD45＋ ) with robust functional potential. Early administration of interleukin (IL)-3 during hematopoietic specification promoted progenitor expansion and maturation. Supplementation of bone morphogenetic protein 4 at the hematopoietic maturation stage enhanced the differentiation efficiency and preferentially drove myeloid lineage commitment toward macrophages at the expense of erythroid differentiation. The timing of erythropoietin administration was important in erythroid lineage commitment, and delayed treatment (day 10) enhanced erythroblast expansion and RBC production. By contrast, the timing of IL-6, GM-CSF, and M-CSF exposure did not significantly affect macrophage differentiation efficiency, suggesting that myeloid lineage specification follows a default pathway under optimized differentiation conditions. These findings suggest a refined, time-controlled strategy for directing hematopoietic differentiation from hPSCs, and provide insight into therapeutic blood cell production, regenerative medicine, and ex vivo modeling of hematopoietic disorders.

Background: The survival impact of bisphosphonates (BPs) remains uncertain, particularly in East Asian populations, where new-user analyses have been limited. Methods: This was a retrospective, new-user cohort study using the Korean National Health Insurance Service–National Sample Cohort (2002–2011). We identified new users of BPs (N=41,854), and a 1:1 age-matched control group (N=41,854) among women aged ≥ 50 years. Participants were followed for all-cause mortality for up to 10 years. Multivariable Cox proportional hazards models were used to calculate hazard ratios (HRs), adjusting for age and the Charlson Comorbidity Index. Results: A total of 83,708 women were included. Compared with the control group, the risk of all-cause mortality was lower in BP group. BP users showed adjusted HR of 0.47 (95% confidence interval, 0.44–0.49; P<0.001) compared to controls. Conclusions In this large, nationwide Korean cohort, initiating BPs was associated with a reduced risk of all-cause mortality in women aged 50 and older. These findings suggest that BPs may have survival benefits beyond fracture prevention.

A 74-year-old woman presented with a progressive pattern of dysphagia and odynophagia over one month.Magnetic resonance imaging of the neck revealed diffuse swelling from the tongue base and velum extending to the posterior pharyngeal wall. Instrumental evaluation of swallowing showed decreased peristalsis in the esophageal phase, accompanied by severe swelling of the hypopharynx, which limited laryngeal elevation and subsequently led to decreased bolus clearance and impaired airway protection. Laboratory studies revealed a 61% increase in eosinophil count. An endoscopic biopsy of the esophagus confirmed the diagnosis of eosinophilic esophagitis. The patient was administered intravenous dexamethasone at a total dosage of 45 mg/day for 7 days. The eosinophil count dropped to the normal range, correlating with the improvement in dysphagia and aspiration. Eosinophilic esophagitis often presents in children and rarely involves the oropharyngeal structures. Due to its specific involvement of the esophagus, it seldom leads to aspiration. By contrast, the extension of eosinophilic inflammation from the esophagus to the oropharynx in this case resulted in atypical symptoms such as odynophagia and aspiration. The therapeutic approach can be challenging due to the difficulty in administering topical steroids, which are often the treatment of choice. However, the condition showed an excellent response to intravenous steroid therapy.

Benzophenone-3 is a type of ketone with 2 benzene rings attached to a carbonyl group (C=O) and one benzene ring attached to a hydroxyl group (-OH). As an endocrine-disrupting chemical, benzophenone-3 is known to be associated with reproductive, developmental, thyroid, and endocrine toxicities. Benzophenone-3 is commonly used in hair products, cosmetics, and ultraviolet (UV) filters because of its characteristic property to absorb UV light. This study aims to investigate the association between the use of hair products and urine benzophenone-3 using the data from the Korean National Environmental Health Survey (KoNEHS) cycle 4 (2018–2020), which represents the Korean population.