Association Between Nap and Reported Cognitive Function and Role of Sleep Debt: A Population-Based Study

Background and PurposeThe relationship between napping and cognition remains controversial. This study aimed to investigate the association between napping and cognition according to sleep debt in the Korean adult population.MethodsA population-based nationwide cross-sectional survey was conducted in 2018. A two-stage stratified random sample of Koreans aged ≥19 years was selected and evaluated using questionnaires by trained interviewers. Cognitive function was assessed using the Mail-In Cognitive Function Screening Instrument (MCFSI). Sleep habits on weekdays and weekends, napping, and subjective sleep requirements were assessed using the questionnaires. Accumulated sleep debt was calculated by subtracting the weekly average sleep duration from subjective sleep requirements. Sleep quality, daytime sleepiness, insomnia, depression, demographics, and comorbidities were assessed. Participants were grouped into those with sleep debt ≤60 min and those with sleep debt >60 min. Multiple linear regression was used to estimate the independent association between the factors and cognition.ResultsIn total, 2,501 participants were included in the analysis. Naps were reported in 726 (29.0%) participants (nappers). The mean MCFSI score was higher in nappers (3.4±3.6) than in non-nappers (2.3±3.0) (p<0.001). Multiple linear regression controlling for age, alcohol, smoking, depression, insomnia, daytime sleepiness, sleep quality, and education revealed that 30 to 60 min of napping was associated with worse cognitive function in participants with sleep debts ≤60 min, while >60 min of napping was associated with better cognitive function in participants with sleep debts >60 min.ConclusionsIn general, naps are associated with worse cognitive function in the Korean adult population. However, for those with sleep debt of >60 min, naps for >60 min were associated with better cognitive function.     

Spleen stiffness-spleen size-to-platelet ratio risk score as noninvasive predictors of esophageal varices in patients with hepatitis B virus-related cirrhosis

This study was conducted to evaluate the predictive value of spleen stiffness-spleen size-to-platelet ratio risk score (SSPS) as a noninvasive predictor of esophageal varices (EVs) and to compare it with others.In this retrospective study, from April 2017 to October 2018, a total of 65 patients with hepatitis B virus-related cirrhosis who underwent the liver and spleen stiffness (LS, and SS) measurements by 2 dimensional-shear wave elastography and endoscopic evaluation for EVs were enrolled. Liver stiffness-spleen size-to-platelet ratio risk score (LSPS) and SSPS were calculated. The prognostic values were assessed by the area under the receiver operating characteristic curve (AUC).Twenty-six patients had no EV on endoscopy. Among 39 patients who had EVs, 12 patients had high risk EVs. The AUCs of the LS value, SS value, LSPS, and SSPS for predicting EVs were 0.72, 0.77, 0.80, and 0.85, respectively. The AUCs of the LS value, SS value, LSPS, and SSPS for predicting high-risk EVs were 0.55, 0.78, 0.67, and 0.80, respectively. SSPS had the highest specificity, at 96.15%, for predicting EVs.SSPS may be beneficial to exclude from having EVs and it is expected that the frequency of performing endoscopies for screening EVs can be reduced.     

Immunogenicity and Reactogenicity of Ad26.COV2.S in Korean Adults: A Prospective Cohort Study

BackgroundAs the coronavirus disease 2019 (COVID-19) pandemic continues, there are concerns regarding waning immunity and the emergence of viral variants. The immunogenicity of Ad26.COV2.S against wild-type (WT) and variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) needs to be evaluated.MethodThis prospective cohort study was conducted between June 2021 and January 2022 at two university hospitals in South Korea. Healthy adults who were scheduled to be vaccinated with Ad26.COV2.S were enrolled in this study. The main outcomes included anti-spike (S) IgG antibody and neutralizing antibody responses, S-specific T-cell responses (interferon-γ enzyme-linked immunospot assay), solicited adverse events (AEs), and serious AEs.ResultsFifty participants aged ≥ 19 years were included in the study. Geometric mean titers (GMTs) of anti-S IgG were 0.4 U/mL at baseline, 5.2 ± 3.0 U/mL at 3–4 weeks, 55.7 ± 2.4 U/mL at 5–8 weeks, and 81.3 ± 2.5 U/mL at 10–12 weeks after vaccination. GMTs of 50% neutralizing dilution (ND50) against WT SARS-CoV-2 were 164.6 ± 4.6 at 3-4 weeks, 313.9 ± 3.6 at 5–8 weeks, and 124.4 ± 2.6 at 10–12 weeks after vaccination. As for the S-specific T-cell responses, the median number of spot-forming units/10⁶ peripheral blood mononuclear cell was 25.0 (5.0–29.2) at baseline, 60.0 (23.3–178.3) at 5-8 weeks, and 35.0 (13.3–71.7) at 10–12 weeks after vaccination. Compared to WT SARS-CoV-2, ND50 against Delta and Omicron variants was attenuated by 3.6-fold and 8.2-fold, respectively. The most frequent AE was injection site pain (82%), followed by myalgia (80%), fatigue (70%), and fever (50%). Most AEs were grade 1–2, and resolved within two days.ConclusionSingle-dose Ad26.COV2.S was safe and immunogenic. NAb titer and S-specific T-cell immunity peak at 5–8 weeks and rather decrease at 10–12 weeks after vaccination. Cross-reactive neutralizing activity against the Omicron variant was negligible.     

Objective Interpretation of the Rapid Urease Test for Helicobacter pylori Infection Using Colorimetry

BackgroundThe rapid urease test (RUT) is a major diagnostic tool for detecting Helicobacter pylori infection. This study aimed to establish an objective method for measuring the color changes in the RUT kit to improve the test’s diagnostic accuracy.MethodsA UV-visible spectrophotometer was selected as the colorimeter; experiments were conducted in three stages to objectively identify the color changes in the RUT kit.ResultsFirst, the urea broth solution showed an identifiable color change from yellow to red as the pH increased by 0.2. The largest transmittance difference detected using the UV-visible spectrophotometer was observed at a 590-nm wavelength. Second, the commercialized RUT kit also showed a gradual color change according to the pH change detected using the UV-visible spectrophotometer. Third, 13 cases of negative RUT results with a biopsy specimen and 16 of positive RUT results were collected. The transmittance detected using the UV-visible spectrophotometer showed a clear division between the positive and negative RUT groups; the largest difference was observed at a 559-nm wavelength. The lowest transmittance in the negative RUT group was 64, while the highest in the positive RUT group was 56, at the 559-nm wavelength. The UV-visible spectrophotometry reading showed a consistency of 92.7% compared with that of manual reading.ConclusionA transmittance of 60 at a 559-nm wavelength detected using UV-visible spectrophotometer can be used as a cutoff value for interpreting RUT results; this will help develop an automatic RUT kit reader with a high accuracy.     

Stilbenes and oligostilbenes from leaf and stem of <Emphasis Type="Italic">Vitis amurensis</Emphasis> and their cytotoxic activity

Chromatographic separation of the EtOAc fraction from the leaf and stem of Vitis amurensis led to the isolation of six oligostilbenoids (i.e., r-2-viniferin (1), trans-amurensin B (2), trans-ɛ-viniferin (3), gnetin H (4), amurensin G (5), (+)-ampelopsin A (8)) and four stilbenoids (i.e., trans-resveratrol (6), (+)-ampelopsin F (7), piceatannol (9), and trans-piceid (10)). The structures have been identified on the basis of spectroscopic evidence and physicochemical properties. The isolates were investigated for cytotoxic activity against three cancer cell lines in vitro using the MTT assay method. Amurensin G (5) and trans-resveratrol (6) showed significant cytotoxic activity against L1210, K562 and HTC116 cancer cell lines with IC₅₀ values ranging from 15.7 ± 2.1 to 30.9 ± 1.8 μM. (+)-Ampelopsin A (8) and trans-piceid (10) exhibited considerable cytotoxic activity against L1210 (IC₅₀ values of 30.6 ± 4.1 and 28.7 ± 2.81 μM, respectively) and K562 (IC₅₀ values of 38.6 ± 0.82 and 24.6 ± 0.76 μM, respectively). Gnetin H (4) showed only weak cytotoxic activity against L1210 with an IC₅₀ value of 40.1 ± 4.23 μM. On the other hand, r-2-viniverin (1), trans-amurensin B (2), trans-ɛ-viniferin (3), (+)-ampelopsin F (7), and piceatannol (9) exhibited no activity on three cancer cell lines.     

Enhanced protection of Ins-1 β cells from apoptosis under hypoxia by delivery of DNA encoding secretion signal peptide-linked exendin-4

In this study, we developed an expression system of exendin-4, a glucagon-like peptide (GLP-1) analog, using a secretion signal peptide (SP) to facilitate exendin-4 secretion. For delivery of the exendin-4 expression system, high-molecular-weight polyethylenimine (25 kDa, PEI25k), low-molecular-weight polyethylenimine (2 kDa, PEI2k), and polyamidoamine (PAMAM) dendrimers were evaluated as gene carriers to Ins-1 β cells. As a result, PEI25k showed the highest transfection efficiency. For the construction of the exendin-4 expression vector, DNA coding the SP sequence was inserted upstream of the exendin-4 cDNA, resulting in the construction of pβ-SP-Ex-4. Transfection assay showed that the secretion level of exendin-4 increased in the pβ-SP-Ex-4 transfected cells, compared with the pβ-Ex-4 transfected cells. To identify the β-cell protection effect of pβ-SP-Ex-4 delivery, the Ins-1 β cells were transfected with pβ-SP-Ex-4 or pβ-Ex-4 and incubated under normoxia or hypoxia. An MTT assay showed that the pβ-SP-Ex-4 transfected cells had higher β-cell viability than the pβ-Ex-4 transfected cells under hypoxia. In addition, the pβ-SP-Ex-4 transfected cells exhibited lower caspase-3 activity than the pβ-Ex-4 transfected cells. Therefore, PEI25k/pβ-SP-Ex-4 complex may be useful to protect isolated β cells from apoptosis during transplantation.     

Voice outcomes of polyacrylamide hydrogel injection laryngoplasty

OBJECTIVES: Polyacrylamide hydrogel (PAAG, Aquamid) is widely used as permanent facial tissue filler during facial plastic surgery. In this study, we examined the long-term effects and safety aspects of PAAG as a vocal fold augmentation material for patients with permanent unilateral vocal cord paralysis. STUDY DESIGN: Prospective clinical trials. METHODS: PAAG injection laryngoplasty was performed in 34 consecutive patients with permanent unilateral vocal cord paralysis. Percutaneous injection was performed under local anesthesia into the vocalis muscle using disposable 25 gauge long needles. Of the 34 patients, 16 completed acoustic, perceptual, stroboscopic, and subjective evaluations prior to the injection and at 6 and 12 months after the injection. RESULTS: Acoustic and perceptual parameters (GRBAS [Overall grade of dysphonia, Roughness, Breathiness, Aesthenia, Strain], Maximal phonation time [MPT], jitter, and shimmer) were significantly improved (P < .05) after injection and remained stable over 12 months. The grades of mucosal waves and glottic closure were also significantly improved (P < .01). The voice handicap index (VHI), as well as the visual analogue scale (VAS) of hoarseness and aspiration significantly improved over 12 months. No adverse effects were observed except for a decrease in the mucosal wave of one patient, after injection into a superficial area of the vocal fold. CONCLUSION: Based on the preliminary results of this trial, PAAG appears to be a long-lasting and safe injection material that is suitable for the treatment of glottal insufficiency caused by permanent unilateral vocal cord paralysis.     

Effects of Wollastonite Fiber and Styrene–Butadiene Latex Polymer on the Long-Term Durability of Cement-Based Repair Materials

Concrete structures are constructed in various geographical environments and climates, and frequently fail to fulfill their original functions over time due to issues such as aging and damage. Research on concrete structure repair materials is being conducted to solve these problems. This study evaluated the durability of a repair material composed of ultra-rapid hardening cement, styrene–butadiene (SB) latex polymer, and wollastonite mineral fiber. The performance targets were as follows: compressive strength of 20 MPa at 1 day of age and 45 MPa at 28 days of age, chloride ion charge passed of less than 1000 Coulombs, carbonation depth of 20 mm or less, and resistance to repeated freezing and thawing (relative dynamic modulus of elasticity) of 80% or more. The ultra-rapid hardening cement:silica sand ratio of 1:1.5 was the experimental variable, and the unit weight of each material in the mix proportion was determined to satisfy the flow requirement of 200 ± 5 mm. This flow ensured sufficient fluidity for spraying, which is the most widely used method for applying repair material. Wollastonite mineral fiber and SB latex polymer were added at 3% and 5% of the unit weight of the binder, respectively. The mechanical property of the repair material was evaluated through compressive strength, and durability was evaluated through chloride ion penetration, alkali resistance, resistance to carbonation, water absorption, and repeated freezing and thawing tests. The compressive strength satisfied both target values, regardless of the addition of SB latex polymer and wollastonite mineral fiber. The chloride ion penetration test, which was used as an indicator of durability, showed that mixtures without SB latex and wollastonite mineral fiber were not satisfied the target charge passed of 1000 Coulombs, while mixtures with latex and mineral fiber reached the target value. Notably, the co-addition of latex and wollastonite fiber showed the highest resistance to chloride ion penetration, alkali ion, carbonation, repeated freezing and thawing, and the least absorption. The results confirmed that the durability of the repair material based on ultra-rapid hardening cement was most effectively improved by the co-addition of SB latex polymer and wollastonite mineral fiber.