1.Novel Variant of FDXR as a Molecular Etiology of Postlingual Post-synaptic Auditory Neuropathy Spectrum Disorder via Mitochondrial Dysfunction: Reiteration of the Correlation between Genotype and Cochlear Implantation Outcomes
Bong Jik KIM ; Yujin KIM ; Ju Ang KIM ; Jin Hee HAN ; Min Young KIM ; Hee Kyung YANG ; Chae-Seo RHEE ; Young Cheol KANG ; Chun-Hyung KIM ; Byung Yoon CHOI
Clinical and Experimental Otorhinolaryngology 2024;17(3):206-216
Objectives:
. FDXR encodes mitochondrial ferredoxin reductase, which is associated with auditory neuropathy spectrum disorder (ANSD) and optic atrophy. To date, only two studies have described FDXR-related hearing loss. The auditory rehabilitation outcomes of this disease entity have not been investigated, and the pathophysiological mechanisms remain incompletely understood. Here we report a hearing-impaired individual with co-segregation of the FDXR variant and post-synaptic type ANSD, who underwent cochlear implantation (CI) with favorable outcomes. We suggest a possible pathophysiological mechanism of adult-onset ANSD involving mitochondrial dysfunction.
Methods:
. A 35-year-old woman was ascertained to have ANSD. Exome sequencing identified the genetic cause of hearing loss, and a functional study measuring mitochondrial activity was performed to provide molecular evidence of pathophysiology. Expression of FDXR in the mouse cochlea was evaluated by immunohistochemistry. Intraoperatively, electrically evoked compound action potential (ECAP) responses were measured, and the mapping parameters were adjusted accordingly. Audiological outcomes were monitored for over 1 year.
Results:
. In lymphoblastoid cell lines (LCLs) carrying a novel FDXR variant, decreased ATP levels, reduced mitochondrial membrane potential, and increased reactive oxygen species levels were observed compared to control LCLs. These dysfunctions were restored by administering mitochondria isolated from umbilical cord mesenchymal stem cells, confirming the pathogenic potential of this variant via mitochondrial dysfunction. Partial ECAP responses during CI and FDXR expression in the mouse cochlea indicate that FDXR-related ANSD is post-synaptic. As a result of increasing the pulse width during mapping, the patient’s CI outcomes showed significant improvement over 1-year post-CI.
Conclusion
. A novel FDXR variant associated with mitochondrial dysfunction and post-synaptic ANSD was first identified in a Korean individual. Additionally, 1-year post-CI outcomes were reported for the first time in the literature. Excellent audiologic results were obtained, and our results reiterate the correlation between genotype and CI outcomes in ANSD.
2.Performance Evaluation of VITEK MS for the Identification of a Wide Spectrum of Clinically Relevant Filamentous Fungi Using a Korean Collection
Ju Hyeon SHIN ; Soo Hyun KIM ; Dain LEE ; Seung Yeob LEE ; Sejong CHUN ; Jun Hyung LEE ; Eun Jeong WON ; Hyun Jung CHOI ; Hyun Woo CHOI ; Seung Jung KEE ; Myung Geun SHIN ; Jong Hee SHIN
Annals of Laboratory Medicine 2021;41(2):214-220
The correct identification of filamentous fungi is challenging. We evaluated the performance of the VITEK MS v3.0 system (bioMérieux, Marcy-l’Étoile, France) for the identification of a wide spectrum of clinically relevant filamentous fungi using a Korean collection. Strains that were added to the upgraded v3.2 database were additionally identified by the VITEK MS v3.2 system. Of the 105 tested isolates, including 37 Aspergillus (nine species), 41 dermatophytes (seven species), and 27 other molds (17 species), 43 (41.0%) showed “no identification” or “multiple species identification” results at the initial VITEK MS testing; these isolates were retested using the same method. Compared with sequence-based identification, the correct identification rate using VITEK MS for Aspergillus, dermatophytes, other molds, and total mold isolates was 67.6%, 56.1%, 48.1%, and 58.1% at the initial testing and 94.6%, 78.0%, 55.6%, and 78.1% with retesting, respectively. Following retesting, 19 (18.1%) and two (1.9%) isolates showed “no identification” and “misidentification” results, respectively. VITEK MS reliably identified various filamentous fungi recovered in Korea, with a very low rate of misidentification
3.Main epidemiological characteristics and natural history of pediatric allergic rhinitis
Minji KIM ; Hyun Hee KIM ; Hyo-Bin KIM ; Yeong-Ho RHA ; Yang PARK ; Myongsoon SUNG ; Youn Ho SHIN ; Hye Yung YUM ; Kyung Suk LEE ; Yong Ju LEE ; Yoon Hong CHUN ; Hye Mi JEE ; Bong Seok CHOI ; Sun Hee CHOI ; Yong Mean PARK ;
Allergy, Asthma & Respiratory Disease 2021;9(4):203-207
Allergic rhinitis (AR) is one of the most common allergic diseases characterized by stuffy nose, rhinorrhea, sneezing, and itching. Researchers have indicated an increase in the prevalence of AR and younger-age onset during the last few decades. The increasing burden of AR has caused many researchers to investigate time trends of the prevalence of AR and to identify its risk factors. The most commonly used epidemiological studies are cross-sectional ones such as the International Study of Asthma and Allergies in Childhood study and big data from National Health Insurance Service or National Health and Nutrition Examination Survey. However, these studies have many limitations including recall bias, selection bias, and deficit of objective evaluation. Furthermore, crosssectional studies cannot reflect new risk factors associated with the development of AR. New epidemiological studies will be needed to cover genetic factors, environmental changes, microbiomes, and lifestyles that are known to be risk factors for AR. Further studies will be needed to determine the prevalence, natural history, and risk factors of AR in order to advance our understanding of the pathophysiology, prevention, and management of comorbidities of AR.
4.Resting heart rate control and prognosis in coronary artery disease patients with hypertension previously treated with bisoprolol: a sub-group analysis of the BISO-CAD study.
Yun-Dai CHEN ; Xin-Chun YANG ; Vinh Nguyen PHAM ; Shi-An HUANG ; Guo-Sheng FU ; Xiao-Ping CHEN ; Binh Quang TRUONG ; Yu YANG ; Shao-Wen LIU ; Tian-Rong MA ; Dong-Soo KIM ; Tae-Hoon KIM
Chinese Medical Journal 2020;133(10):1155-1165
BACKGROUND:
Resting heart rate (RHR) is considered as a strong predictor of total mortality and hospitalization due to heart failure in hypertension patients. Bisoprolol fumarate, a second-generation beta-adrenoreceptor blockers (β-blocker) is commonly prescribed drug to manage hypertension. The present study was to retrospectively evaluate changes in the average RHR and its association with cardiovascular outcomes in bisoprolol-treated coronary artery disease (CAD) patients from the CAD treated with bisoprolol (BISO-CAD) study who had comorbid hypertension.
METHODS:
We performed ad-hoc analysis for hypertension sub-group of the BISO-CAD study (n = 866), which was a phase IV, multination, multi-center, single-arm, observational study carried out from October 2011 to July 2015 across China, South Korea, and Vietnam. Multivariate regression analysis was used to identify factors associated with incidence of composite cardiac clinical outcome (CCCO), the results were presented as adjusted odds ratio (OR) along with 95% confidence interval (CI) and adjusted P value.
RESULTS:
A total of 681 patients (mean age: 64.77 ± 10.33 years) with hypertension from BISO-CAD study were included in the analysis. Bisoprolol improved CCCOs in CAD patients with comorbid hypertension, with RHR <65 and <70 beats/min compared with RHR ≥65 and ≥75 beats/min, respectively, in the efficacy analysis (EA) set. In addition, it lowered RHR in both intent-to-treat (ITT) and EA groups after 6, 12, and 18 months of treatment. Further, RHR 70 to 74 beats/min resulted in significantly higher risk of CCCOs EA set of patients (adjusted OR: 4.34; 95% CI: 1.19-15.89; P = 0.03). Also, events of hospitalization due to acute coronary syndrome were higher when RHR 69 to 74 beats/min compared to RHR <69 beats/min in ITT patients.
CONCLUSION
Bisoprolol can effectively reduce RHR in Asian CAD patients with comorbid hypertension and hence, improve CCCO without affecting their blood pressure.
5.Survey on the Preparation Status of Medical Institutions Regarding the Full Revision of the Korean Blood Inventory Monitoring System
Sejong CHUN ; Ji Seon CHOI ; Yung Zoon JUNG ; Jeong Won SHIN ; Kyeong Eun JEONG ; Jin A OH ; Jun Nyun KIM ; Young Ae LIM
Korean Journal of Blood Transfusion 2020;31(3):211-221
Background:
The current Korean Blood Inventory Monitoring System (BMS) has several drawbacks. It does not provide real-time data and only monitors 211 of the more than 2500 institutes that performed blood transfusions.This survey study investigated the status of BMS use and the preparation status of the data input system of medical institutions to help in the revision of BMS in preparation for the full surveillance of BMS.
Methods:
A survey questionnaire was given to 200 hospitals participating in the current BMS, along with another set of questionnaires to 150 non-participating hospitals. The questionnaire consisted of the method of data registry to BMS, the current status of electronic medical records (EMR) and order communication system (OCS), perception, and readiness of adaptation of an open application programming interface system (API).
Results:
Two hundred and one BMS participating hospitals responded to the survey. Approximately 75% entered data with a comma-separated value (CSV) or Excel spreadsheet (xls) files, and approximately half had an in-house developed EMR and OCS. The majority showed enthusiasm for the introduction to an open API. Among the non-participating hospitals, 138 responded. Approximately 70% counted the blood inventory daily, but approximately half did not use electronic methods for this process. The response to the introduction to an open API was positive, but the readiness for a prompt introduction was low at 15.9%.
Conclusion
These results will help revise the current BMS. On the other hand, full surveillance of BMS is anticipated to be hindered by the ready state of each medical institute. Moreover, the encouragement of participation would require supportive government administrative measures.
6.Survey on the Preparation Status of Medical Institutions Regarding the Full Revision of the Korean Blood Inventory Monitoring System
Sejong CHUN ; Ji Seon CHOI ; Yung Zoon JUNG ; Jeong Won SHIN ; Kyeong Eun JEONG ; Jin A OH ; Jun Nyun KIM ; Young Ae LIM
Korean Journal of Blood Transfusion 2020;31(3):211-221
Background:
The current Korean Blood Inventory Monitoring System (BMS) has several drawbacks. It does not provide real-time data and only monitors 211 of the more than 2500 institutes that performed blood transfusions.This survey study investigated the status of BMS use and the preparation status of the data input system of medical institutions to help in the revision of BMS in preparation for the full surveillance of BMS.
Methods:
A survey questionnaire was given to 200 hospitals participating in the current BMS, along with another set of questionnaires to 150 non-participating hospitals. The questionnaire consisted of the method of data registry to BMS, the current status of electronic medical records (EMR) and order communication system (OCS), perception, and readiness of adaptation of an open application programming interface system (API).
Results:
Two hundred and one BMS participating hospitals responded to the survey. Approximately 75% entered data with a comma-separated value (CSV) or Excel spreadsheet (xls) files, and approximately half had an in-house developed EMR and OCS. The majority showed enthusiasm for the introduction to an open API. Among the non-participating hospitals, 138 responded. Approximately 70% counted the blood inventory daily, but approximately half did not use electronic methods for this process. The response to the introduction to an open API was positive, but the readiness for a prompt introduction was low at 15.9%.
Conclusion
These results will help revise the current BMS. On the other hand, full surveillance of BMS is anticipated to be hindered by the ready state of each medical institute. Moreover, the encouragement of participation would require supportive government administrative measures.
7.Planned Transfusion of D-Positive Blood Components in an Asia Type DEL Patient: Proposed Modification of the Korean National Guidelines for Blood Transfusion.
Sooin CHOI ; Sejong CHUN ; Ji Young SEO ; Ji Hyuk YANG ; Duck CHO
Annals of Laboratory Medicine 2019;39(1):102-104
No abstract available.
Asia*
;
Blood Transfusion*
;
Humans
8.Red Blood Cell Alloimmunization in Korean Patients With Myelodysplastic Syndrome and Liver Cirrhosis
Hyun Young KIM ; Eun Jung CHO ; Sejong CHUN ; Kyeong Hee KIM ; Duck CHO
Annals of Laboratory Medicine 2019;39(2):218-222
Red blood cell (RBC) alloimmunization varies across human populations and ethnic groups. We evaluated the characteristics of RBC alloimmunization and compared the risk of alloimmunization in Korean patients with myelodysplastic syndrome (MDS) and liver cirrhosis (LC), two representative diseases in which chronic transfusion is required. In total, 115 MDS patients and 202 LC patients transfused with RBCs between 2013 and 2015 were retrospectively included. Twenty patients (6.3%) were newly alloimmunized (five MDS patients, 4.3%; 15 LC patients, 7.4%). The median number of RBC units transfused in alloimmunized patients was nine (interquartile range, 4–15 units). As the number of transfused RBC units increased, the cumulative risk of alloimmunization was higher in LC than in MDS patients (P=0.001). The most common alloantibody detected in patients was anti-E (45%), followed by anti-c (17%), anti-e (10%), anti-C (7%), anti-Fyb (7%), and anti-Jka (7%). The present data indicate the need for matching of extended RBC antigens (Rh, Duffy, and Kidd systems) for chronically transfused patients with MDS and LC in Korea.
Erythrocytes
;
Ethnic Groups
;
Humans
;
Korea
;
Liver Cirrhosis
;
Liver
;
Myelodysplastic Syndromes
;
Retrospective Studies
9.Hemolytic uremic syndrome caused by Escherichia fergusonii infection
Seung Don BAEK ; Chinhak CHUN ; Kyoung Sup HONG
Kidney Research and Clinical Practice 2019;38(2):253-255
No abstract available.
Escherichia
;
Hemolytic-Uremic Syndrome
10.Case of D-Variant from a Frameshift Mutation RHD 711delC
Taeo MA ; Hongbi YU ; Suhak JEON ; Duck CHO ; Sejong CHUN ; Myung Geun SHIN
Korean Journal of Blood Transfusion 2019;30(2):168-173
D antigens are clinically significant, and routine tests on the D antigen requires the inclusion of weak D testing, which is performed using indirect antihuman immunoglobulin methods. On the other hand, exact typing of the D type of an individual can be done more precisely with RHD genotyping, which is a useful tool in cases where the RHD gene is intact. The majority of weak-D or partial-D cases are from single nucleotide changes or hybridization of RHD and RHCE genes. Nevertheless, frameshift mutations can also result in weak or partial-D. The characteristics of a frameshift mutation is typically a change in protein product after a problematic mutation and early termination of transcription, leading into truncated protein products. This paper reports a D-variant case with RHD 711delC along with a review of the relevant literature. In addition, the results of software analysis are reported.
Frameshift Mutation
;
Genotype
;
Hand
;
Immunoglobulins

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