1.Development of an Instrument for Slit-lamp Examination of Donor Corneas in Preservation Medium
Ga Hee NAM ; Da Ran KIM ; Young Chae YOON ; Soon Won YANG ; Woong Joo WHANG ; Yong-Soo BYUN ; Hyung Bin HWANG ; Kyung Sun NA ; Hyun Soo LEE ; So Hyang CHUNG ; Eun Chul KIM ; Yang Kyung CHO ; Hyun Seung KIM ; Ho Sik HWANG
Journal of the Korean Ophthalmological Society 2024;65(2):108-116
Purpose:
To evaluate the effectiveness of an instrument devised for slit-lamp examination of donor corneas suspended in preservation medium.
Methods:
The study examined two donor corneas received at Yeouido St. Mary's Hospital in February 2023 and March 2023. The instrument has three main components: a plastic holder to hold the preservation medium bottle, a cube with a mirror for reflecting the slit beam, and a stand to attach the device to the slit-lamp. Using the instrument, the donor corneas were examined via slit-lamp: microscopy with the endothelium facing upward and downward. Specular microscopy and anterior segment optical coherence tomography (OCT) were also performed on the preserved donor corneas.
Results:
Slit-lamp examination of donor corneas in preservation medium using the instrument showed overall corneal buttoning and optical sections of the donor cornea. Using specular reflection and retroillumination, the endothelial layer was partially visible. However, specular microscopy and anterior segment OCT could not examine the donor cornea in preservation medium using the instrument.
Conclusions
The devised instrument facilitates slit-lamp examination of donor corneas in preservation medium, enabling a qualitative assessment of donor corneas before corneal transplantation surgery.
2.Usefulness of Stool Multiplex Polymerase Chain Reaction Assays in Patients with Acute Diarrhea
Seo Hyun KIM ; You Sun KIM ; Seung Hyuk KIM ; Won Eui YOON ; Hee Jun MYUNG ; Jeong Seop MOON ; Dong Hee WHANG
The Korean Journal of Gastroenterology 2022;79(3):118-125
Background/Aims:
There is a recent increase in the use of stool multiplex PCR assay-based diagnostic tests in patients with acute diarrhea. We used multiplex PCR assays to analyze the distribution of diarrhea-causing bacteria and viruses, as well as the clinical features of patients with acute diarrhea.
Methods:
We retrospectively reviewed stool specimens of inpatients complaining of acute diarrhea from October 2018 to July 2020.The stool specimens had been tested for bacteria and viruses using multiplex PCR assays.
Results:
A total of 414 stool specimens from 346 patients were tested, and 152 pathogens were detected in 131 stool samples (131/414, 31.6%). Co-infection was detected in 20 patients (20/346, 5.8%). The common pathogens detected as causes of acute diarrhea, including co-infection, were Clostridium perfringens (34.9%), Clostridioides difficile (19.7%), and Campylobacter spp. (18.4%). The average age of patients with multiplex PCR-positive tests was lower than those with multiplex PCR-negative tests (p=0.001). In patients with suspected C. difficile infection (CDI), the RT-PCR for toxin gene assay was performed in 370 stool samples, 35 of which were positive (9.5%). Furthermore, 16 of the 35 samples were positive on the multiplex PCR assay (45.7%).
Conclusions
The multiplex PCR assay revealed that C. perfringens was the most common diarrhea-causing pathogen. In addition, in patients with suspected CDI, the multiplex PCR assay alone was insufficiently sensitive to detect pathogens and a conventional CDI test was additionally required.
3.Rapid and accurate diagnosis of Clostridium difficile infection by real-time polymerase chain reaction
Pil Hun SONG ; Jung Hwa MIN ; You Sun KIM ; Soo Yeon JO ; Eun Jin KIM ; Kyung Jin LEE ; Jeonghun LEE ; Hyun SUNG ; Jeong Seop MOON ; Dong Hee WHANG
Intestinal Research 2018;16(1):109-115
BACKGROUND/AIMS: The incidence and severity of Clostridium difficile infection (CDI) have increased worldwide, resulting in a need for rapid and accurate diagnostic methods. METHODS: A retrospective study was conducted to compare CDI diagnosis methods between January 2014 and December 2014. The stool samples, which were obtained in presumptive CDI patients, were compared for their diagnostic accuracy and rapidity, including real-time polymerase chain reaction (PCR) of toxin genes, C. difficile toxin assay, and culture for C. difficile. RESULTS: A total of 207 cases from 116 patients were enrolled in this study and 117 cases (56.5%) were diagnosed as having CDI. Among the 117 cases, the sensitivities of real-time PCR, C. difficile toxin assay, and culture for C. difficile were 87.2% (102 cases; 95% CI, 80.7%–92.8%), 48.7% (57 cases; 95% CI, 41.0%–59.8%), and 65.0% (76 cases; 95% CI, 60.2%–78.5%), respectively (P < 0.005). Notably, 34 cases (29.0%) were diagnosed with CDI by real-time PCR only. The time required to obtain results was 2.27 hours (136.62±82.51 minutes) for real-time PCR, 83.67 hours (5,020.66±3,816.38 minutes) for toxin assay, and 105.79 hours (6,347.68±3,331.46 minutes) for culture (P < 0.005), respectively. CONCLUSIONS: We confirmed that real-time PCR of toxin genes is the most effective diagnostic method for accurate and early diagnosis of CDI. It also helps to diagnose hypervirulent CDI, such as ribotype 027 infection.
Clostridium difficile
;
Clostridium
;
Diagnosis
;
Early Diagnosis
;
Humans
;
Incidence
;
Methods
;
Polymerase Chain Reaction
;
Real-Time Polymerase Chain Reaction
;
Retrospective Studies
;
Ribotyping
4.A Case of Cast Related Green Foot Syndrome.
Sul Hee LEE ; Sun Bum KWON ; Moon Kyun CHO ; Young Lip PARK ; Sung Yul LEE ; Kyu Uang WHANG
Korean Journal of Dermatology 2017;55(8):544-545
No abstract available.
Cross Infection
;
Foot*
;
Pseudomonas aeruginosa
5.Antimicrobial Susceptibility of Stenotrophomonas maltophilia Isolates from Korea, and the Activity of Antimicrobial Combinations against the Isolates.
Hae Sun CHUNG ; Seong Geun HONG ; Young Ree KIM ; Kyeong Seob SHIN ; Dong Hee WHANG ; Jee Young AHN ; Yeon Joon PARK ; Young UH ; Chulhun L CHANG ; Jong Hee SHIN ; Hye Soo LEE ; Kyungwon LEE ; Yunsop CHONG
Journal of Korean Medical Science 2013;28(1):62-66
The aim of this study was to determine antimicrobial susceptibility of recent clinical Stenotrophomonas maltophilia isolates from Korea, and to compare the activity levels of several combinations of antimicrobials. A total of 206 non-duplicate clinical isolates of S. maltophilia was collected in 2010 from 11 university hospitals. Antimicrobial susceptibility testing was performed using the Clinical Laboratory Standards Institute agar dilution method. In vitro activity of antimicrobial combinations was tested using the checkerboard method. The susceptibility rates to trimethoprim-sulfamethoxazole and minocycline were 96% and 99%, respectively. The susceptibility rate to levofloxacin was 64%. All of four antimicrobial combinations showed synergy against many S. maltophilia isolates. A combination of trimethoprim-sulfamethoxazole plus ticarcillin-clavulanate was most synergistic among the combinations. None of the combinations showed antagonistic activity. Therefore, some of the combinations may be more useful than individual drugs in the treatment of S. maltophilia infection. Further clinical studies are warranted to validate our in vitro test results.
Anti-Infective Agents/*pharmacology
;
Gram-Negative Bacterial Infections/microbiology
;
Hospitals, University
;
Humans
;
Microbial Sensitivity Tests
;
Minocycline/pharmacology
;
Ofloxacin/pharmacology
;
Republic of Korea
;
Stenotrophomonas maltophilia/*drug effects/isolation & purification
;
Trimethoprim-Sulfamethoxazole Combination/pharmacology
6.Differentiation of human labia minora dermis-derived fibroblasts into insulin-producing cells.
Bona KIM ; Byung Sun YOON ; Jai Hee MOON ; Jonggun KIM ; Eun Kyoung JUN ; Jung Han LEE ; Jun Sung KIM ; Cheong Soon BAIK ; Aeree KIM ; Kwang Youn WHANG ; Seungkwon YOU
Experimental & Molecular Medicine 2012;44(1):26-35
Recent evidence has suggested that human skin fibroblasts may represent a novel source of therapeutic stem cells. In this study, we report a 3-stage method to induce the differentiation of skin fibroblasts into insulin-producing cells (IPCs). In stage 1, we establish the isolation, expansion and characterization of mesenchymal stem cells from human labia minora dermis-derived fibroblasts (hLMDFs) (stage 1: MSC expansion). hLMDFs express the typical mesenchymal stem cell marker proteins and can differentiate into adipocytes, osteoblasts, chondrocytes or muscle cells. In stage 2, DMEM/F12 serum-free medium with ITS mix (insulin, transferrin, and selenite) is used to induce differentiation of hLMDFs into endoderm-like cells, as determined by the expression of the endoderm markers Sox17, Foxa2, and PDX1 (stage 2: mesenchymal-endoderm transition). In stage 3, cells in the mesenchymal-endoderm transition stage are treated with nicotinamide in order to further differentiate into self-assembled, 3-dimensional islet cell-like clusters that express multiple genes related to pancreatic beta-cell development and function (stage 3: IPC). We also found that the transplantation of IPCs can normalize blood glucose levels and rescue glucose homeostasis in streptozotocin-induced diabetic mice. These results indicate that hLMDFs have the capacity to differentiate into functionally competent IPCs and represent a potential cell-based treatment for diabetes mellitus.
Animals
;
Biological Markers/metabolism
;
*Cell Culture Techniques
;
*Cell Differentiation
;
Cell Proliferation/drug effects
;
Cell Separation
;
Cells, Cultured
;
Dermis/*cytology/drug effects
;
Diabetes Mellitus, Experimental/*surgery
;
Female
;
Fibroblasts/*cytology/drug effects
;
Genitalia, Female/*cytology
;
Glucose/metabolism
;
Hepatocyte Nuclear Factor 3-beta/metabolism
;
Homeodomain Proteins/metabolism
;
Humans
;
Insulin/pharmacology/secretion
;
Insulin-Secreting Cells/*cytology/metabolism
;
*Islets of Langerhans Transplantation
;
Mesenchymal Stem Cells/*cytology/drug effects/metabolism
;
Mice
;
Mice, Nude
;
Niacinamide/pharmacology
;
Recovery of Function
;
SOXF Transcription Factors/metabolism
;
Sodium Selenite/pharmacology
;
Trans-Activators/metabolism
;
Transferrin/pharmacology
7.Use of Nafamostat Mesilate as an Anticoagulant during Extracorporeal Membrane Oxygenation.
Sang Jin HAN ; Hyoung Soo KIM ; Kun Il KIM ; Sung Mi WHANG ; Kyung Soon HONG ; Won Ki LEE ; Sun Hee LEE
Journal of Korean Medical Science 2011;26(7):945-950
Although the incidence of bleeding complications during extracorporeal membrane oxygenator (ECMO) support has decreased in various trials, bleeding is still the most fatal complication. We investigated the ideal dosage and efficacy of nafamostat mesilate for use with ECMO in patients with acute cardiac or respiratory failure. We assessed 73 consecutive patients who received ECMO due to acute cardiac or respiratory failure between January 2006 and December 2009. To evaluate the efficacy of nafamostat mesilate, we divided the patients into 2 groups according to the anticoagulants used during ECMO support. All patients of nafamostat mesilate group were male with a mean age of 49.2 yr. Six, 3, 5, and 3 patients were diagnosed with acute myocardial infarction, cardiac arrest, septic shock, and acute respiratory distress syndrome, respectively. The mean dosage of nafamostat mesilate was 0.64 mg/kg/hr, and the mean duration of ECMO was 270.7 hr. The daily volume of transfused packed red blood cells, fresh frozen plasma, and cryoprecipitate and the number of complications related to hemorrhage and thrombosis was lower in the nafamostat mesilate group than in the heparin group. Nafamostat mesilate should be considered as an alternative anticoagulant to heparin to reduce bleeding complications during ECMO.
Acute Disease
;
Anticoagulants/*administration & dosage
;
Dose-Response Relationship, Drug
;
*Extracorporeal Membrane Oxygenation
;
Female
;
Guanidines/*administration & dosage
;
Heart Failure/diagnosis/mortality/therapy
;
Heparin/administration & dosage
;
Humans
;
Male
;
Middle Aged
;
Myocardial Infarction/diagnosis/mortality/therapy
;
Respiratory Distress Syndrome, Adult/diagnosis/mortality/therapy
;
Retrospective Studies
;
Shock, Septic/diagnosis/mortality/therapy
;
Survival Analysis
8.The Incidence and Clinical Features of Clostridium difficile Infection; Single Center Study.
Jin Ho LEE ; Su Yeon LEE ; You Sun KIM ; Sun Wook PARK ; Sung Won PARK ; So Young JO ; Soo Hyung RYU ; Jung Hwan LEE ; Jeong Seop MOON ; Dong Hee WHANG ; Bo Moon SHIN
The Korean Journal of Gastroenterology 2010;55(3):175-182
BACKGROUND/AIMS: Clostridium difficile is the predominant cause of nosocomial diarrhea. Recently, the incidence of Clostridium difficile infection (CDI) increases in Europe and North America. A retrospective study was performed to evaluate the change of incidence and clinical features of CDI in Korea. METHODS: From January 2003 to December 2008, inpatients diagnosed with CDI in Seoul Paik hospital were enrolled. The diagnosis of CDI was made when patients complained diarrhea with any positive results in C. difficile toxin assay, stool culture, or endoscopy. The incidence, recurrence rate, and clinical features were compared between early period (2003-2005) and late period (2006-2008). RESULTS: The incidence of CDI was 21.73 cases per 10,000 admitted patients in early period group, and significantly increased to 71.71 cases per 10,000 admitted patients in late period group (p<0.01). The hospital stay duration at the time of CDI diagnosis was shorter in late period group. Cephalosporin had the highest ratio as the causative antibiotics of CDI. However, there was no difference in recurrence rate between early and late period groups. Recurrence associated clinical factor was serum albumin level. CONCLUSIONS: The incidence of CDI showed increasing tendency during recent 6 years. The awareness of increasing disease burden is the first step in control of CDI.
Aged
;
Anti-Bacterial Agents/therapeutic use
;
Cephalosporins/therapeutic use
;
*Clostridium difficile
;
Enterocolitis, Pseudomembranous/diagnosis/drug therapy/*epidemiology
;
Female
;
Humans
;
Incidence
;
Male
;
Middle Aged
;
Recurrence
;
Retrospective Studies
;
Risk Factors
;
Serum Albumin/analysis
9.Trichuris trichiura Infection Diagnosed by Colonoscopy: Case Reports and Review of Literature.
Kyung Sun OK ; You Sun KIM ; Jung Hoon SONG ; Jin Ho LEE ; Soo Hyung RYU ; Jung Hwan LEE ; Jeong Seop MOON ; Dong Hee WHANG ; Hye Kyung LEE
The Korean Journal of Parasitology 2009;47(3):275-280
Trichuris trichiura, commonly referred to as a whipworm, has a worldwide distribution, particularly among countries with warm, humid climates. In Korea, trichuriasis was a highly prevalent soil-transmitted helminthiasis until the 1970s. However, the nationwide prevalence decreased to 0.02% in 2004 as a result of national control activities and improvement in the socioeconomic status of Koreans. Most infected individuals have no distinct symptoms, if lightly infected. The diagnosis is typically confirmed by detection of T. trichiura eggs on examination of a stool sample; few reports have described detection of the parasite during colonoscopy. Recently, we managed 4 patients with trichuriasis who were diagnosed by detection of the parasite on colonoscopy, and we reviewed the literature on the colonoscopic diagnosis of T. trichiura in Korea. We suggest that colonoscopy might be a useful diagnostic tool, especially when infected by only a few male worms with no eggs in the stool.
Adult
;
Aged
;
Animals
;
Colonoscopy
;
Female
;
Humans
;
Korea
;
Male
;
Middle Aged
;
Trichuriasis/*diagnosis/parasitology
;
Trichuris/*cytology
10.Allele and Haplotype Frequencies of Human Leukocyte Antigen-A, -B, and -DR Loci in Koreans: DNA Typing of 1,500 Cord Blood Units.
Dong Hee WHANG ; Yun Sun YANG ; Hye Kyung HONG
The Korean Journal of Laboratory Medicine 2008;28(6):465-474
BACKGROUND: The HLA system is known to be the most polymorphic genetic system in human, and HLA allele and haplotype distribution varies widely among different ethnic groups. This study was performed to examine the frequencies of HLA alleles and haplotypes in Koreans. METHODS: We examined HLA-A, -B, and -DR alleles at the serologic level in 1,500 cord blood units obtained from Koreans using the PCR-sequence specific oligonucleotide (SSO) method. Allele and haplotype frequencies were estimated by the maximum likelihood method using the computer program developed for the 11th International Histocompatibility Workshop. RESULTS: HLA alleles found in Koreans were 12 in A, 31 in B, and 13 in DR loci. Most frequent alleles with frequencies > or =10% in each locus in decreasing order of frequency were: A2, A24, A33, A11; B62; DR4, DR15, DR9, and DR13. Two-locus haplotypes with frequencies > or =0.1% were 104 A-B and 115 B-DR haplotypes, among which those with frequencies > or =1.0% showing significant positive linkage disequilibrium (P< or =0.001) were 21 A-B and 20 B-DR haplotypes. A total of 169 A-B-DR haplotypes with frequencies > or =0.1% were identified. The results were similar to those of a previous study in 1,600 Koreans, although some differences were noted in the distribution of some less frequent alleles or haplotypes with frequencies < or =0.5%. CONCLUSIONS: We provided the allele and haplotype frequencies of HLA-A, -B, and -DR in cord blood units of Korean ethnicity defined by a DNA typing method, which can be used as basic data on Koreans for organ transplantation and disease association studies.
Fetal Blood
;
*Gene Frequency
;
HLA-A Antigens/classification/*genetics
;
HLA-B Antigens/classification/*genetics
;
HLA-DR Antigens/classification/*genetics
;
*Haplotypes
;
Histocompatibility Testing
;
Humans
;
Korea
;
Polymerase Chain Reaction

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