1.Long and Short-Term Effect of mTOR Regulation on Cerebral Organoid Growth and Differentiations
Sung Bum PARK ; Byungho LIM ; Ki Young KIM ; Byumseok KOH
Tissue Engineering and Regenerative Medicine 2024;21(1):159-169
BACKGROUND:
The mammalian target of rapamycin (mTOR) signaling is critical for the maintenance and differentiation of neurogenesis, and conceivably for many other brain developmental processes. However, in vivo studies of mTOR functions in the brain are often hampered due to the essential role of the associated signaling in brain development.
METHODS:
We monitored the long- and short-term effects of mTOR signaling regulation on cerebral organoids growth, differentiation and function using an mTOR inhibitor (everolimus) and an mTOR activator (MHY1485).
RESULTS:
Short-term treatment with MHY1485 induced faster organoid growth and differentiation, while long-term treatment induced the maturation of cerebral organoids.
CONCLUSION
These data suggest that the optimal activity of mTOR is crucial in maintaining normal brain development, and its role is not confined to the early neurogenic phase of brain development.
2.The Comparison of Emergency Medical Service Responses to and Outcomes of Out-of-hospital Cardiac Arrest before and during the COVID-19 Pandemic in an Area of Korea
Daesung LIM ; Song Yi PARK ; Byungho CHOI ; Sun Hyu KIM ; Ji Ho RYU ; Yong Hwan KIM ; Ae Jin SUNG ; Byung Kwan BAE ; Han Byeol KIM
Journal of Korean Medical Science 2021;36(36):e255-
Background:
Since the declaration of the coronavirus disease 2019 (COVID-19) pandemic, COVID-19 has affected the responses of emergency medical service (EMS) systems to cases of out-of-hospital cardiac arrest (OHCA). The purpose of this study was to identify the impact of the COVID-19 pandemic on EMS responses to and outcomes of adult OHCA in an area of South Korea.
Methods:
This was a retrospective observational study of adult OHCA patients attended by EMS providers comparing the EMS responses to and outcomes of adult OHCA during the COVID-19 pandemic to those during the pre-COVID-19 period. Propensity score matching was used to compare the survival rates, and logistic regression analysis was used to assess the impact of the COVID-19 pandemic on the survival of OHCA patients.
Results:
A total of 891 patients in the pre-COVID-19 group and 1,063 patients in the COVID-19 group were included in the final analysis. During the COVID-19 period, the EMS call time was shifted to a later time period (16:00–24:00, P < 0.001), and the presence of an initial shockable rhythm was increased (pre-COVID-19 vs. COVID-19, 7.97% vs. 11.95%, P = 0.004). The number of tracheal intubations decreased (5.27% vs. 1.22%, P < 0.001), and the use of mechanical chest compression devices (30.53% vs. 44.59%, P < 0.001) and EMS response time (median [quartile 1-quartile 3], 7 [5–10] vs. 8 [6–11], P < 0.001) increased. After propensity score matching, the survival at admission rate (22.52% vs. 18.24%, P = 0.025), survival to discharge rate (7.77% vs. 5.52%, P = 0.056), and favorable neurological outcome (5.97% vs. 3.49%, P < 0.001) decreased. In the propensity score matching analysis of the impact of COVID-19, odds ratios of 0.768 (95% confidence interval [CI], 0.592–0.995) for survival at admission and 0.693 (95% CI, 0.446–1.077) for survival to discharge were found.
Conclusion
During the COVID-19 period, there were significant changes in the EMS responses to OHCA. These changes are considered to be partly due to social distancing measures. As a result, the proportion of patients with an initial shockable rhythm in the COVID-19 period was greater than that in the pre-COVID-19 period, but the final survival rate and favorable neurological outcome were lower.
3.The Comparison of Emergency Medical Service Responses to and Outcomes of Out-of-hospital Cardiac Arrest before and during the COVID-19 Pandemic in an Area of Korea
Daesung LIM ; Song Yi PARK ; Byungho CHOI ; Sun Hyu KIM ; Ji Ho RYU ; Yong Hwan KIM ; Ae Jin SUNG ; Byung Kwan BAE ; Han Byeol KIM
Journal of Korean Medical Science 2021;36(36):e255-
Background:
Since the declaration of the coronavirus disease 2019 (COVID-19) pandemic, COVID-19 has affected the responses of emergency medical service (EMS) systems to cases of out-of-hospital cardiac arrest (OHCA). The purpose of this study was to identify the impact of the COVID-19 pandemic on EMS responses to and outcomes of adult OHCA in an area of South Korea.
Methods:
This was a retrospective observational study of adult OHCA patients attended by EMS providers comparing the EMS responses to and outcomes of adult OHCA during the COVID-19 pandemic to those during the pre-COVID-19 period. Propensity score matching was used to compare the survival rates, and logistic regression analysis was used to assess the impact of the COVID-19 pandemic on the survival of OHCA patients.
Results:
A total of 891 patients in the pre-COVID-19 group and 1,063 patients in the COVID-19 group were included in the final analysis. During the COVID-19 period, the EMS call time was shifted to a later time period (16:00–24:00, P < 0.001), and the presence of an initial shockable rhythm was increased (pre-COVID-19 vs. COVID-19, 7.97% vs. 11.95%, P = 0.004). The number of tracheal intubations decreased (5.27% vs. 1.22%, P < 0.001), and the use of mechanical chest compression devices (30.53% vs. 44.59%, P < 0.001) and EMS response time (median [quartile 1-quartile 3], 7 [5–10] vs. 8 [6–11], P < 0.001) increased. After propensity score matching, the survival at admission rate (22.52% vs. 18.24%, P = 0.025), survival to discharge rate (7.77% vs. 5.52%, P = 0.056), and favorable neurological outcome (5.97% vs. 3.49%, P < 0.001) decreased. In the propensity score matching analysis of the impact of COVID-19, odds ratios of 0.768 (95% confidence interval [CI], 0.592–0.995) for survival at admission and 0.693 (95% CI, 0.446–1.077) for survival to discharge were found.
Conclusion
During the COVID-19 period, there were significant changes in the EMS responses to OHCA. These changes are considered to be partly due to social distancing measures. As a result, the proportion of patients with an initial shockable rhythm in the COVID-19 period was greater than that in the pre-COVID-19 period, but the final survival rate and favorable neurological outcome were lower.
4.Concordance between the underlying causes of death on death certificates written by three emergency physicians
Hyeji LEE ; Sun Hyu KIM ; Byungho CHOI ; Minsu OCK ; Eun Ji PARK
Clinical and Experimental Emergency Medicine 2019;6(3):218-225
OBJECTIVE: This study was conducted to evaluate the concordance between the underlying causes of death (UCOD) on the death certificates written by three emergency physicians (EPs). We investigated errors on the death certificates committed by each EP.METHODS: This study included 106 patients issued a death certificate in the emergency department of an academic hospital. Three EPs reviewed the medical records retrospectively and completed 106 death certificates independently. The selection of the UCOD on the death certificates by each EP (EP-UCOD) was based on the general principle or selection rules. The gold standard UCOD (GS-UCOD) was determined for each patient by unanimous consent between three EPs. We also compared between the EP-UCOD and the GS-UCOD. In addition, we compared between UCODs of three EPs. The errors on the death certificates were investigated by each EP.RESULTS: The rates of concordance between EP-UCOD and the GS-UCOD were 86%, 81%, and 67% for EP-A, EP-B, and EP-C, respectively. The concordance rates between EP-A and EP-B were the highest overall percent agreement (0.783), and those between EP-A and EP-C were the lowest overall percent agreement (0.651). Although each EP had differences in the errors they committed, none of them listed the mode of dying as UCOD.CONCLUSION: This study confirmed that each EP wrote death certificates indicating different causes of death for the same decedents; however, the three EPs made fewer errors on the patients’ death certificates compared with those reported in previous studies.
Cause of Death
;
Death Certificates
;
Emergencies
;
Emergency Medicine
;
Emergency Service, Hospital
;
Humans
;
Medical Records
;
Mortality
;
Retrospective Studies
5.An idiopathic delayed maxillary hemorrhage after orthognathic surgery with Le Fort I osteotomy: a case report
Byungho PARK ; Wan Hee JANG ; Bu Kyu LEE
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2019;45(6):364-368
A Le Fort I osteotomy is a common procedure for correcting dental and facial deformities in orthognathic surgery. In rare cases, a delayed hemorrhage can occur as early as several hours or up to 12 weeks, postoperatively. The most frequently involved blood vessels in a delayed hemorrhage are the descending palatine artery, the internal maxillary artery, and the pterygoid venous plexus of veins. Intraoral bleeding accompanied by severe epistaxis in these cases makes it difficult to locate the precise bleeding focus. Eventual uncontrolled bleeding would require Merocel packing or surgical intervention. In general, a severe late postoperative hemorrhage is most effectively managed by angiography and embolization. Herein we describe a delayed hemorrhage case in which the cause was not evident on angiography. We were able to detect the bleeding point through an endoscopic nasal approach and treat it using direct cauterization.
Aneurysm, False
;
Angiography
;
Arteries
;
Blood Vessels
;
Cautery
;
Congenital Abnormalities
;
Epistaxis
;
Hemorrhage
;
Maxillary Artery
;
Orthognathic Surgery
;
Osteotomy
;
Postoperative Complications
;
Postoperative Hemorrhage
;
Veins
6.A Rare Case of Solitary Osteochondroma at the Temporomandibular Joint: A Case Report
Byungho PARK ; Wan Hee JANG ; Tae Jun PARK ; Bu Kyu LEE
Journal of Korean Dental Science 2019;12(2):66-72
Osteochondroma is a bone tumor with cartilaginous growth potential that generally appears near the growth plate of long bones in areas such as hip, knee, and shoulder joints, related to the nature of endochondral ossification and it is known a common benign bone tumor. However, it has been very rare in craniofacial region possibly because craniofacial bone is largely formed by intramembranous ossification. Moreover, reports on the solitary type of osteochondroma in mandibular condyle has been extremely rare. Osteochondroma in mandibular condylar may show various symptoms similar to general temporomandibular joint disorders (TMDs), such as pain in the condylar area during mouth opening, internal derangement, facial asymmetry or posterior open bite. Therefore, it can be disregarded for a long time period without any adequate treatment. Surgical excision has been the treatment option for the solitary osteochondroma with very low recurrence rate reportedly. In this case report, a rare case of solitary osteochondroma developed in unilateral mandibular condyle is presented with emphasis on differential diagnosis with general TMDs.
7.An idiopathic delayed maxillary hemorrhage after orthognathic surgery with Le Fort I osteotomy: a case report
Byungho PARK ; Wan Hee JANG ; Bu Kyu LEE
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2019;45(6):364-368
A Le Fort I osteotomy is a common procedure for correcting dental and facial deformities in orthognathic surgery. In rare cases, a delayed hemorrhage can occur as early as several hours or up to 12 weeks, postoperatively. The most frequently involved blood vessels in a delayed hemorrhage are the descending palatine artery, the internal maxillary artery, and the pterygoid venous plexus of veins. Intraoral bleeding accompanied by severe epistaxis in these cases makes it difficult to locate the precise bleeding focus. Eventual uncontrolled bleeding would require Merocel packing or surgical intervention. In general, a severe late postoperative hemorrhage is most effectively managed by angiography and embolization. Herein we describe a delayed hemorrhage case in which the cause was not evident on angiography. We were able to detect the bleeding point through an endoscopic nasal approach and treat it using direct cauterization.
8.Accuracy of Imputation of Microsatellite Markers from BovineSNP50 and BovineHD BeadChip in Hanwoo Population of Korea.
Aditi SHARMA ; Jong Eun PARK ; Byungho PARK ; Mi Na PARK ; Seung Hee ROH ; Woo Young JUNG ; Seung Hwan LEE ; Han Ha CHAI ; Gul Won CHANG ; Yong Min CHO ; Dajeong LIM
Genomics & Informatics 2018;16(1):10-13
Until now microsatellite (MS) have been a popular choice of markers for parentage verification. Recently many countries have moved or are in process of moving from MS markers to single nucleotide polymorphism (SNP) markers for parentage testing. FAO-ISAG has also come up with a panel of 200 SNPs to replace the use of MS markers in parentage verification. However, in many countries most of the animals were genotyped by MS markers till now and the sudden shift to SNP markers will render the data of those animals useless. As National Institute of Animal Science in South Korea plans to move from standard ISAG recommended MS markers to SNPs, it faces the dilemma of exclusion of old animals that were genotyped by MS markers. Thus to facilitate this shift from MS to SNPs, such that the existing animals with MS data could still be used for parentage verification, this study was performed. In the current study we performed imputation of MS markers from the SNPs in the 500-kb region of the MS marker on either side. This method will provide an easy option for the labs to combine the data from the old and the current set of animals. It will be a cost efficient replacement of genotyping with the additional markers. We used 1,480 Hanwoo animals with both the MS data and SNP data to impute in the validation animals. We also compared the imputation accuracy between BovineSNP50 and BovineHD BeadChip. In our study the genotype concordance of 40% and 43% was observed in the BovineSNP50 and BovineHD BeadChip respectively.
Animals
;
Cattle
;
Genotype
;
Korea*
;
Methods
;
Microsatellite Repeats*
;
Polymorphism, Single Nucleotide
9.Feasibility and Safety of Mild Therapeutic Hypothermia in Poor-Grade Subarachnoid Hemorrhage: Prospective Pilot Study.
Wookjin CHOI ; Soon Chan KWON ; Won Joo LEE ; Young Cheol WEON ; Byungho CHOI ; Hyeji LEE ; Eun Suk PARK ; Ryeok AHN
Journal of Korean Medical Science 2017;32(8):1337-1344
Therapeutic hypothermia (TH) improves the neurological outcome in patients after cardiac arrest and neonatal hypoxic brain injury. We studied the safety and feasibility of mild TH in patients with poor-grade subarachnoid hemorrhage (SAH) after successful treatment. Patients were allocated randomly to either the TH group (34.5°C) or control group after successful clipping or coil embolization. Eleven patients received TH for 48 hours followed by 48 hours of slow rewarming. Vasospasm, delayed cerebral ischemia (DCI), functional outcome, mortality, and safety profiles were compared between groups. We enrolled 22 patients with poor-grade SAH (Hunt & Hess Scale 4, 5 and modified Fisher Scale 3, 4). In the TH group, 10 of 11 (90.9%) patients had a core body temperature of < 36°C for > 95% of the 48-hour treatment period. Fewer patients in the TH than control group (n = 11, each) had symptomatic vasospasms (18.1% vs. 36.4%, respectively) and DCI (36.3% vs. 45.6%, respectively), but these differences were not statistically significant. At 3 months, 54.5% of the TH group had a good-to-moderate functional outcome (0–3 on the modified Rankin Scale [mRS]) compared with 9.0% in the control group (P = 0.089). Mortality at 1 month was 36.3% in the control group compared with 0.0% in the TH group (P = 0.090). Mild TH is feasible and can be safely used in patients with poor-grade SAH. Additionally, it may reduce the risk of vasospasm and DCI, improving the functional outcomes and reducing mortality. A larger randomized controlled trial is warranted.
Aneurysm
;
Body Temperature
;
Brain Injuries
;
Brain Ischemia
;
Embolization, Therapeutic
;
Heart Arrest
;
Humans
;
Hypothermia, Induced*
;
Mortality
;
Pilot Projects*
;
Prospective Studies*
;
Rewarming
;
Subarachnoid Hemorrhage*
;
Vasospasm, Intracranial
10.The Reliability and Validity of the Korean Version of Burden Assessment Scale (K-BAS).
Hyun Jung KWAK ; Byungho LEE ; Jong Hyun JEONG ; Seung Chul HONG ; Jin Hee HAN ; E Jin PARK ; Yang Whan JEON ; Sang Ick HAN ; Ho Jun SEO
Journal of Korean Neuropsychiatric Association 2013;52(4):197-204
OBJECTIVES: This study was conducted for evaluation of the reliability and validity of the Korean version of the Burden Assessment Scale (K-BAS). METHODS: A sample of 256 first-order relatives of schizophrenics completed the K-BAS and the data were analyzed for internal consistency and factor structure. In addition, a subset of participants (n=112) refilled the K-BAS after two weeks for test-retest reliability. To test for validity, the Family Burden Scale (FBS), Korean version of Drug Attitude Inventory-10 (KDAI-10), and Korean version of the Scale to Assess Unawareness of Mental Disorder (SUMD-K) were administered. RESULTS: The Cronbach's alpha coefficient of the K-BAS was high (0.91), which provided evidence for good internal consistency. The test-retest reliability of K-BAS was 0.86 (correlation coefficient, p<0.001). Convergent validity was examined through correlations between the K-BAS and the FBS (r=0.80, p<0.001). Divergent validity was examined through correlations between the K-BAS and KDAI-10 (r=-0.21, p=0.001), and between the K-BAS and SUMD-K (r=-0.02, p=0.796). Results of the factor analysis revealed a three-factor solution: activity limitation, social strain, and feelings of worry and guilt. CONCLUSION: These results suggest that the K-BAS had good psychometric properties and may be a useful instrument for evaluation of burden of families with schizophrenics.
Humans
;
Mental Disorders
;
Psychometrics
;
Reproducibility of Results
;
Sprains and Strains

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