Background: A decline in masticatory function may indicate brain dysfunction related to dementia, but the relationship between masticatory function and dementia risk remains unclear. This study aimed to investigate whether masticatory function is associated with the risk of cognitive decline and dementia. Methods: Data were obtained from the nationwide prospective cohort study of randomly sampled community-dwelling Koreans aged ≥ 60 years. The 5,064 non-demented participants, whose number of chewing cycles per bite was assessed by clinical interview, were followed for 8 years with biennial assessments of cognitive performance and clinical diagnoses of all-cause dementia and Alzheimer’s disease (AD). Structural brain magnetic resonance imaging was collected from a subset of cohort participants and their spouses for imaging analyses. Results: Males who chewed ≥ 30 cycles/bite had faster decline in global cognition and memory function and were at higher risk for incident all-cause dementia (hazard ratio [HR], 2.91; 95% confidence interval [CI], 1.18–7.18) and AD (HR, 3.22; 95% CI, 1.14–9.11) compared to males with less than 10 cycles/bite. Additionally, increased chewing cycles in males were associated with reduced brain volume, particularly in regions involved in compensatory cognitive control of mastication. There was no significant association between chewing cycles and the risk of dementia or brain volume in females. Conclusion Older men who frequently chew their meals could be considered a notable population at risk for dementia who should be carefully assessed for their cognitive trajectories.

Objective: The Montreal Cognitive Assessment (MoCA) is recommended for general cognitive evaluation in Parkinson’s disease (PD) patients. However, age- and education-adjusted cutoffs specifically for PD have not been developed or systematically validated across PD cohorts with diverse education levels. Methods: In this retrospective analysis, we utilized data from 1,293 Korean patients with PD whose cognitive diagnoses were determined through comprehensive neuropsychological assessments. Age- and education-adjusted cutoffs were formulated based on 1,202 patients with PD. To identify the optimal machine learning model, clinical parameters and MoCA domain scores from 416 patients with PD were used. Comparative analyses between machine learning methods and different cutoff criteria were conducted on an additional 91 consecutive patients with PD. Results: The cutoffs for cognitive impairment decrease with increasing age within the same education level. Similarly, lower education levels within the same age group correspond to lower cutoffs. For individuals aged 60–80 years, cutoffs were set as follows: 25 or 24 years for those with more than 12 years of education, 23 or 22 years for 10–12 years, and 21 or 20 years for 7–9 years. Comparisons between age- and education-adjusted cutoffs and the machine learning method showed comparable accuracies. The cutoff method resulted in a higher sensitivity (0.8627), whereas machine learning yielded higher specificity (0.8250). Conclusion Both the age- and education-adjusted cutoff methods and machine learning methods demonstrated high effectiveness in detecting cognitive impairment in PD patients. This study highlights the necessity of tailored cutoffs and suggests the potential of machine learning to improve cognitive assessment in PD patients.

Objective: To investigate the relationship between reduced glutathione (GSH), a key molecule of the antioxidant defense system in the blood, and glutathione reductase (GR), which reduces oxidized glutathione (glutathione disulfide [GSSG]) to GSH and maintains the redox balance, with the prevalence of Alzheimer’s dementia and cognitive decline. Methods: In all, 20 participants with Alzheimer’s dementia who completed the third follow-up clinical evaluation over 6 years were selected, and 20 participants with normal cognition were selected after age and sex matching. The GSH and GR concentrations were the independent variables. Clinical diagnosis and neurocognitive test scores were the dependent variables indicating cognitive status. Results: The higher the level of GR, the greater the possibility of having normal cognition than of developing Alzheimer’s dementia. Additionally, the higher the level of GR, the higher the neurocognitive test scores. However, this association was not significant for GSH. After 6 years, the conversion rate from normal cognition to cognitive impairment was significantly higher in the lower 50th percentile of the GR group than in the upper 50th percentile. Conclusion The higher the GR, the lower the prevalence of Alzheimer’s dementia and incidence of cognitive impairment and the higher the cognitive test scores. Therefore, GR is a potential protective biomarker against Alzheimer’s dementia and cognitive decline.

Objective: Biliary decompression through bile drainage is a key treatment for common bile duct obstruction with cholangitis. However, the effectiveness of early interventions has not been studied sufficiently in Korea. This study investigated the effectiveness of fast-track biliary decompression. Methods: A group of patients diagnosed with common bile duct obstruction with cholangitis between January 1, 2014, and December 31, 2019, was reviewed retrospectively. We divided them into two groups: before and after the implementation of fast-track biliary decompression. The following items were analyzed in the two groups: time to intervention, number of hospital days, length of stay in the emergency department, and intensive care unit (ICU) admission. Results: Between January 1, 2014, and December 31, 2019, 418 patients were admitted for common bile duct obstruction, and a total of 369 patients were included in this study. Of these, 168 patients visited the hospital prior to implementation of the treatment, and 201 patients visited after implementation. The time to intervention was 6.1 (4.2-11.0) hours in the fast-track group, which was about 9 hours shorter than the other group (P<0.001). There was no statistical difference in the number of hospital days, emergency department length of stay, and ICU admissions (P=0.535, P=0.034, P=0.322). Conclusion The time to intervention was shortened significantly in the fast-track group. However, we did not observe a significant improvement in patient prognosis. It may be possible that the procedure time may need to be shortened for a better prognosis. This should be investigated in future studies.

Purpose: To retrospectively evaluate the chest computed tomography (CT) findings of coronavirus disease 2019 (COVID-19) in patients with mild clinical symptoms at a single hospital in South Korea. Materials and Methods: CT scans of 87 COVID-19 patients [43 men and 44 women; median age:41 years (interquartile range: 26.1–51.0 years)] with mild clinical symptoms (fever < 38℃ and no dyspnea) were evaluated. Results: CT findings were normal in 39 (44.8%) and abnormal in 48 (55.2%) patients. Among the 48 patients with lung opacities, 17 (35.4%) had unilateral disease and 31 (64.6%) had bilateral disease. One (2.1%) patient showed subpleural distribution, 9 (18.8%) showed peribronchovascular distribution, and 38 (79.2%) showed subpleural and peribronchovascular distributions.Twenty-two (45.8%) patients had pure ground-glass opacities (GGOs) with no consolidation, 17 (35.4%) had mixed opacities dominated by GGOs, and 9 (18.8%) had mixed opacities dominated by consolidation. No patients demonstrated consolidation without GGOs. Conclusion The most common CT finding of COVID-19 in patients with mild clinical symptoms was bilateral multiple GGO-dominant lesions with subpleural and peribronchovascular distribution and lower lung predilection. The initial chest CT of almost half of COVID-19 patients with mild clinical symptoms showed no lung parenchymal lesions. Compared to relatively severe cases, mild cases were more likely to manifest as unilateral disease with pure GGOs or GGOdominant mixed opacities and less likely to show air bronchogram.

Background: This study aimed to determine the parameters for worsening oxygenation in non-severe coronavirus disease 2019 (COVID-19) pneumonia. Methods: This retrospective cohort study included cases of confirmed COVID-19 pneumonia in a public hospital in South Korea. The worsening oxygenation group was defined as that with SpO2 ≤94% or received oxygen or mechanical ventilation (MV) throughout the clinical course versus the non-worsening oxygenation group that did not experience any respiratory event. Parameters were compared, and the extent of viral pneumonia from an initial chest computed tomography (CT) was calculated using artificial intelligence (AI) and measured visually by a radiologist. Results: We included 136 patients, with 32 (23.5%) patients in the worsening oxygenation group; of whom, two needed MV and one died. Initial vital signs and duration of symptoms showed no difference between the two groups; however, univariate logistic regression analysis revealed that a variety of parameters on admission were associated with an increased risk of a desaturation event. A subset of patients was studied to eliminate potential bias, that ferritin ≥280 μg/L (p=0.029), lactate dehydrogenase ≥240 U/L (p=0.029), pneumonia volume (p=0.021), and extent (p=0.030) by AI, and visual severity scores (p=0.042) were the predictive parameters for worsening oxygenation in a sex-, age-, and comorbid illness-matched case-control study using propensity score (n=52). Conclusion Our study suggests that initial CT evaluated by AI or visual severity scoring as well as serum markers of inflammation on admission are significantly associated with worsening oxygenation in this COVID-19 pneumonia cohort.