Background: Coronavirus disease 2019 (COVID-19) vaccination is effective in preventing the disease transmission and progression. However, the relatively mild disease course of the omicron variant and the decrease in antibodies over time after vaccination raise questions about the effectiveness of vaccination, especially in young people. We compared the prevalence of pneumonia and chest X-ray severity score according to vaccination status among patients < 50 years old with COVID-19. Methods: From January 17 to March 17, 2022, 579 patients with COVID-19, who were < 50 years old and had a known vaccination history in our institution, were all included in this study. All patients underwent initial chest radiography, and follow-up chest radiographs were obtained every two days until discharge. Pneumonia was scored from the radiographs using the Brixia scoring system. The scores of the six lung zones were added for a total score ranging from 0 to 18. Patients were divided into four groups according to 10-year age intervals. Differences between groups were analyzed using the χ2 or Fisher’s exact tests for categorical variables and the Kruskal–Wallis test or analysis of variance for continuous variables. Results: Among patients aged 12–19 years, the prevalence of pneumonia did not differ depending on vaccination status (non-vaccinated vs. vaccinated, 1/47 [2.1%] vs. 1/18 [5.6%]; P = 0.577).Among patients in their 20s, the prevalence of pneumonia was significantly higher among nonvaccinated patients than among vaccinated patients (8/28, 28.6% vs. 7/138, 5.1%, P < 0.001), similar to patients in their 40s (32/52 [61.5%] vs. 18/138 [13.0%]; P < 0.001). The chest X-ray severity score was also significantly higher in non-vaccinated patients than that in vaccinated patients in their 20s to their 40s (P < 0.001), but not among patients aged 12–19 years (P = 0.678). Conclusion In patients aged 20–49 years, vaccinated patients had a significantly lower prevalence of pneumonia and chest X-ray severity score than non-vaccinated patients.

Background/Aims: The clinical characteristics of patients with masked uncontrolled hypertension (MUCH) have been poorly defined, and few studies have investigated the clinical predictors of MUCH. We investigated the demographic, clinical, and blood pressure (BP) characteristics of patients with MUCH and proposed a prediction model for MUCH in patients with hypertension. Methods: We analyzed 1,986 subjects who were enrolled in the Korean Ambulatory Blood Pressure Monitoring (Kor-ABP) Registry and taking antihypertensive drugs, and classified them into the controlled hypertension (n = 465) and MUCH (n = 389) groups. MUCH was defined as the presence of a 24-hour ambulatory mean systolic BP ≥ 130 mmHg and/or diastolic BP ≥ 80 mmHg in patients treated with antihypertensive drugs, having normal office BP. Results: Patients in the MUCH group had significantly worse metabolic profiles and higher office BP, and took significantly fewer antihypertensive drugs compared to those in the controlled hypertension group. Multivariate logistic regression analyses identified high office systolic BP and diastolic BP, prior stroke, dyslipidemia, left ventricular hypertrophy (LVH, ≥ 116 g/m2 for men, and ≥ 96 g/m2 for women), high heart rate (≥ 75 beats/min), and single antihypertensive drug use as independent predictors of MUCH. A prediction model using these predictors showed a high diagnostic accuracy (C-index of 0.839) and goodness-of-fit for the presence of MUCH. Conclusions MUCH is associated with a high-normal increase in office BP and underuse of antihypertensive drugs, as well as dyslipidemia, prior stroke, and LVH, which could underscore achieving optimal BP control. The proposed model accurately predicts MUCH in patients with controlled office BP.

Objectives: . To compare the surgical outcomes of externally monitored and conventional buried flaps with the goal of determining the usefulness of external monitoring of buried flaps. Methods: . In this case-control study with propensity score matching, 30 patients were evenly divided into externally monitored buried flap and conventional buried flap groups. The total operative time for free flap reconstruction, the flap survival rate, the length of hospital stay, the initial time of a reliable visual assessment, complications, the final diet achieved, and the duration until diet initiation were compared between the groups. Results: . The mean operative time for reconstruction was 115 minutes (interquartile range, 85–150 minutes) and 142 minutes (interquartile range, 95–180 minutes) in the externally monitored and conventional groups, respectively (P= 0.245). The median length of hospital stay was 24 days (interquartile range, 18–30 days) and 27 days (interquartile range, 20–41 days) in the externally monitored and conventional groups, respectively (P=0.298). The median duration until diet initiation was 15 days (interquartile range, 15–21 days) and 18 days (interquartile range, 15–34 days) in the externally monitored and conventional groups, respectively (P=0.466). The final diet, initial time of a reliable visual assessment, and complications were comparable between the groups, but the external skin paddle provided an excellent visual assessment immediately postoperatively in all cases. Conclusion . The outcomes were comparable between the groups, indicating that externalization of the cutaneous component of a buried flap may be a straightforward and useful technique for monitoring a buried anterolateral thigh free flap in laryngopharyngeal reconstructions. The salvage and false-positive rates of compromised flaps should be compared in large subject groups in future studies to prove that the use of an external skin paddle improves flap monitoring.

Background/Aims: The clinical characteristics of patients with masked uncontrolled hypertension (MUCH) have been poorly defined, and few studies have investigated the clinical predictors of MUCH. We investigated the demographic, clinical, and blood pressure (BP) characteristics of patients with MUCH and proposed a prediction model for MUCH in patients with hypertension. Methods: We analyzed 1,986 subjects who were enrolled in the Korean Ambulatory Blood Pressure Monitoring (Kor-ABP) Registry and taking antihypertensive drugs, and classified them into the controlled hypertension (n = 465) and MUCH (n = 389) groups. MUCH was defined as the presence of a 24-hour ambulatory mean systolic BP ≥ 130 mmHg and/or diastolic BP ≥ 80 mmHg in patients treated with antihypertensive drugs, having normal office BP. Results: Patients in the MUCH group had significantly worse metabolic profiles and higher office BP, and took significantly fewer antihypertensive drugs compared to those in the controlled hypertension group. Multivariate logistic regression analyses identified high office systolic BP and diastolic BP, prior stroke, dyslipidemia, left ventricular hypertrophy (LVH, ≥ 116 g/m2 for men, and ≥ 96 g/m2 for women), high heart rate (≥ 75 beats/min), and single antihypertensive drug use as independent predictors of MUCH. A prediction model using these predictors showed a high diagnostic accuracy (C-index of 0.839) and goodness-of-fit for the presence of MUCH. Conclusions MUCH is associated with a high-normal increase in office BP and underuse of antihypertensive drugs, as well as dyslipidemia, prior stroke, and LVH, which could underscore achieving optimal BP control. The proposed model accurately predicts MUCH in patients with controlled office BP.

BACKGROUND: Because conventional echocardiographic parameters have several limitations, strain echocardiography has often been introduced in clinical practice. However, there are also obstacles in using it in clinical practice. Therefore, we wanted to find the current status of awareness on using strain echocardiography in Korea. METHODS: We conducted a nationwide survey to evaluate current use and awareness of strain echocardiography from the members of the Korean Society of Echocardiography. RESULTS: We gathered total 321 questionnaires from 25 cardiology centers in Korea. All participants were able to perform or interpret echocardiographic examinations. All participating institutions performed strain echocardiography. Most of our study participants (97%) were aware of speckle tracking echocardiography and 185 (58%) performed it for clinical and research purposes. Two-dimensional strain echocardiography was the most commonly used modality and left ventricle (LV) was the most commonly used cardiac chamber (99%) for clinical purposes. Most of the participants (89%) did not think LV strain can replace LV ejection fraction (LVEF) in their clinical practice. The common reasons for not performing routine use of strain echocardiography was diversity of strain measurements and lack of normal reference value. Many participants had a favorable view of the future of strain echocardiography. CONCLUSION: Most of our study participants were aware of strain echocardiography, and all institutions performed strain echocardiography for clinical and research purposes. However, they did not think the LV strain values could replace LVEF. The diversity of strain measurements and lack of normal reference values were common reasons for not using strain echocardiography in clinical practice.
Cardiology ; Echocardiography* ; Heart Ventricles ; Korea* ; Reference Values

BACKGROUND: The purposes of the present study were to compare implant stabilities of mandibular block bone graft and bovine bone graft and to evaluate influencing factors for implant stability in mandibular block bone (MBB) graft. METHODS: This retrospective study investigated 1224 cases and 389 patients treated by one surgeon in the Department of Oral and Maxillofacial Surgery of Pusan National University Dental Hospital (Yangsan, Korea) between January 2010 and December 2014. Proportions that MBB graft cases constitute in all implant restoration cases and in all bone graft cases were measured. Implant stability quotient (ISQ) values were achieved by the same surgeon before loading. The average ISQ values of the experimental groups were compared. In addition, ISQ values of influencing factors, such as age, sex, implant size, and implant placement site, were compared within the MBB group using OsstellTM Mentor (Osstell®, Göteborg, Sweden). Paired t test and ANOVA were conducted for statistical analysis with a significance level of 0.05. RESULTS: Fifty-five percent of all implant restoration cases performed bone graft while MBB cases constituted 34% of all implant restoration cases and 61% of all bone graft cases. Comparing ISQ values according to bone graft materials, the MBB group manifested sufficient implant stability by presenting comparable ISQ value to that of the experimental group without bone graft. Among the reviewed factors, females, mandibular molar regions, and implants in larger diameter displayed greater implant stabilities. CONCLUSIONS: Satisfactory implant stability was accomplished upon administration of MBB graft. Within the limitation of this study, gender, implant site, and implant diameter were speculated to influence on implant stability in MBB graft.
Busan ; Female ; Humans ; Mentors ; Molar ; Retrospective Studies ; Surgery, Oral ; Transplants*

BACKGROUND: It is important to understand the distribution of 2-dimensional strain values in normal population. We performed a multicenter trial to measure normal echocardiographic values in the Korean population. METHODS: This was a substudy of the Normal echOcardiogRaphic Measurements in KoreAn popuLation (NORMAL) study. Echocardiographic specialists measured frequently used echocardiographic indices in healthy people according to a standardized method at 23 different university hospitals. The strain values were analyzed from digitally stored images. RESULTS: Of a total of 1003 healthy participants in NORMAL study, 2-dimensional strain values were measured in 501 subjects (265 females, mean age 47 ± 15 years old) with echocardiographic images only by GE echocardiographic machines. Interventricular septal thickness, left ventricular (LV) posterior wall thickness, systolic and diastolic LV dimensions, and LV ejection fraction were 7.5 ± 1.0 mm, 7.4 ± 1.0 mm, 29.9 ± 2.8 mm, 48.9 ± 3.6 mm, and 62 ± 4%, respectively. LV longitudinal systolic strain (LS) values of apical 4-chamber (A4C) view, apical 3-chamber (A3C) view, apical 2-chamber (A2C) view, and LV global LS (LVGLS) were −20.1 ± 2.3, −19.9 ± 2.7, −21.2 ± 2.6, and −20.4 ± 2.2%, respectively. LV longitudinal systolic strain rate (LVLSR) values of the A4C view, A3C view, A2C view, and LV global LSR (LVGLSR) were −1.18 ± 0.18, −1.20 ± 0.21, −1.25 ± 0.21, and −1.21 ± 0.21(−s), respectively. Females had lower LVGLS (−21.2 ± 2.2% vs. −19.5 ± 1.9%, p < 0.001) and LVGLSR (−1.25 ± 0.18(−s) vs. −1.17 ± 0.15(−s), p < 0.001) values than males. CONCLUSION: We measured LV longitudinal strain and strain rate values in the normal Korean population. Since considerable gender differences were observed, normal echocardiographic cutoff values should be differentially applied based on sex.
Echocardiography* ; Female ; Healthy Volunteers ; Heart Ventricles* ; Hospitals, University ; Humans ; Male ; Methods ; Multicenter Studies as Topic ; Reference Values ; Specialization

BACKGROUND: Kojic acid was used for decades in the cosmetic industry as an antimelanogenic agent. However, there are two major drawbacks of Kojic acid, one is cytotoxicity and second are instability on storage. These limitations led the scientist to synthesize the active Kojic acid peptides. OBJECTIVE: In the present study, we synthesize and investigate the effect of five Kojic acid peptides to overcome the limitation of Kojic acid. METHODS: The peptide was analyzed and purified by high-performance liquid chromatography and matrix-assisted laser desorption ionization time of flight mass spectroscopy. Further, the tyrosinase activities of the Kojic acid and Kojic acid peptides were compared. The toxicity was measured and the melanin content is recorded in B16F10 mouse melanoma cells. RESULTS: Maximum tyrosinase activity was measured by Kojic acid peptides. Therefore, Kojic acid peptides were subjected to melanin assay and cytotoxicity assay and finally the stability of the Kojic acid peptide was measured. CONCLUSION: It was observed that this newly synthesized Kojic acid peptide is stable and potent to inhibit the tyrosinase activity and melanin content of B16F10 mouse melanoma cells without exhibiting cell toxicity. Together, these preliminary results suggest that a further exploration is being needed to establish Kojic acid peptide as antimelanogenic agent.
Animals ; Chromatography, Liquid ; Mass Spectrometry ; Melanins ; Melanoma ; Mice ; Monophenol Monooxygenase ; Peptides

BACKGROUND: Mutations in calreticulin (CALR) have been reported to be key markers in the molecular diagnosis of myeloid proliferative neoplasms. In most previous reports, CALR mutations were analyzed by using Sanger sequencing. Here, we report a new, rapid, and convenient system for screening CALR mutations without sequencing. METHODS: Eighty-three bone marrow samples were obtained from 81 patients with thrombocytosis. PCR primers were designed to detect wild-type CALR (product: 357 bp) and CALR with type 1 (product: 302 bp) and type 2 mutations (product: 272 bp) in one reaction. The results were confirmed by Sanger sequencing and compared with results from fragment analysis. RESULTS: The minimum detection limit of the screening PCR was 10 ng for type 1, 1 ng for type 2, and 0.1 ng for cases with both mutations. CALR type 1 and type 2 mutants were detected with screening PCR with a maximal analytical sensitivity of 3.2% and <0.8%, respectively. The screening PCR detected 94.1% (16/17) of mutation cases and showed concordant results with sequencing in the cases of type 1 and type 2 mutations. Sanger sequencing identified one novel mutation (c.1123_1132delinsTGC). Compared with sequencing, the screening PCR showed 94.1% sensitivity, 100.0% specificity, 100.0% positive predictive value, and 98.5% negative predictive value. Compared with fragment analysis, the screening PCR presented 88.9% sensitivity and 100.0% specificity. CONCLUSIONS: This screening PCR is a rapid, sensitive, and cost-effective method for the detection of major CALR mutations.
Adult ; Aged ; Base Sequence ; Bone Marrow/metabolism ; Calreticulin/chemistry/*genetics/metabolism ; DNA Mutational Analysis ; Female ; Follow-Up Studies ; Genotype ; Humans ; Janus Kinase 2/chemistry/genetics/metabolism ; Male ; Middle Aged ; Mutation ; Myeloproliferative Disorders/complications/*diagnosis/genetics ; Polymerase Chain Reaction ; Thrombocytosis/complications/*diagnosis

BACKGROUND: Hemodynamic and functional evaluation with Doppler and tissue Doppler study as a part of comprehensive echocardiography is essential but normal reference values have never been reported from Korean normal population especially according to age and sex. METHODS: Using Normal echOcaRdiographic Measurements in a KoreAn popuLation study subjects, we obtained normal reference values for Doppler and tissue Doppler echocardiography including tricuspid annular velocities according to current guidelines and compared values according to gender and age groups. RESULTS: Mitral early diastolic (E) and late diastolic (A) velocity as well as E/A ratio were significantly higher in women compared to those in men. Conversely, mitral peak systolic and late diastolic annular velocity in both septal and lateral mitral annulus were significantly lower in women compared to those in men. However, there were no significant differences in both septal and lateral mitral early diastolic annular (e') velocity between men and women. In both men and women, mitral E velocity and its deceleration time as well as both E/A and E/e' ratio considerably increased with age. There were no significant differences in tricuspid inflow velocities and tricuspid lateral annular velocities between men and women except e' velocity, which was significantly higher in women compared to that in men. However, changes in both tricuspid inflow and lateral annular velocities according to age were similar to those in mitral velocities. CONCLUSION: Since there were significant differences in Doppler and tissue Doppler echocardiographic variables between men and women and changes according to age were even more considerable in both gender groups, normal Doppler echocardiographic values should be differentially applied based on age and sex.
Deceleration ; Echocardiography* ; Echocardiography, Doppler ; Female ; Hemodynamics ; Humans ; Male ; Reference Values