1.A study on stress distribution in IMZ implant with a plastic or a titanium IME using finite element analysis.
Chi Yang HA ; Boo Byung CHOI ; Yi Hyung WOO
The Journal of Korean Academy of Prosthodontics 1993;31(4):625-642
No abstract available.
Finite Element Analysis*
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Plastics*
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Titanium*
2.Detection of Hepatic Metastases from Colorectal Cancer: A Comparative Study between the SPIO-enhanced MR and Intraoperative Ultrasound.
Seong Jin PARK ; Boem Ha YI ; Hea Kyung LEE ; Chong Woo CHU
Journal of the Korean Radiological Society 2008;58(3):269-275
PURPOSE: To investigate the efficacy of SPIO (superparamagnetic iron oxide) enhanced MR imaging for the detection of colorectal liver metastasis, compared to the intraoperative ultrasound (IOUS). MATERIALS AND METHODS: Thirteen patients who underwent IOUS during surgery for colorectal liver metastasis as well as a liver MR before and after administration of SPIO. The mean patient age was 57 years (age range: 43-77). Two observers reviewed the SPIO-enhanced MR via a double blind test. We evaluated the efficacy of the SPIO-enhanced MR compared to the results of IOUS. RESULTS: Following IOUS, 55 lesions were found, including 32 metastases, 20 cysts, 2 calcifications, and 1 coagulation necrosis. The interobserver correlation of the SPIO-enhanced MR is significant, with a kappa index of 0.839. Radiologist 1 and 2 missed three lesions in three patients. Two of the patients had multiple liver lesions (six and eight, respectively), whereas the other patient had tumor recurrence following hepatic surgery for liver metastasis. In the other nine patients, MR detected all lesions. The sensitivity and positive predictive value of the SPIO-enhanced MR was 94.5%, and 100%, respectively. CONCLUSION: The SPIO-enhanced liver MR shows a good correlation to IOUS, especially in the case of patients who had fewer than three lesions. Therefore, the SPIO-enhanced MR may help to plan a surgical resection of colorectal liver metastasis.
Contrast Media
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Humans
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Iron
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Liver
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Liver Neoplasms
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Necrosis
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Neoplasm Metastasis
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Recurrence
3.Internal Lens Signal Measured by Dual Scheimpflug Anterior Segment Analyzer.
Jin Woo RO ; Ka Young YI ; Ha Kyung KIM ; Joon Young HYON ; Won Ryang WEE ; Young Joo SHIN
Journal of the Korean Ophthalmological Society 2015;56(5):702-708
PURPOSE: To investigate the clinical significance of the internal lens signal measured using dual Scheimpflug anterior segment analyzer (Galilei(TM), Ziemer, Switzerland) in patients receiving cataract surgery. METHODS: The present study included 151 eyes of 148 patients who received surgery for senile cataracts from February 2012 to January 2013. Preoperative internal lens signals were measured preoperatively. The depth of anterior chamber and anterior angles were measured using dual Scheimpflug anterior segment analyzer preoperatively and 1 month postoperatively. Preoperative and postoperative best-corrected visual acuities (BCVAs) were measured. The relationships between preoperative internal lens signal and the changes in BCVA or anterior angles were evaluated. RESULTS: Internal lens signal and preoperative BCVA (log MAR) or preoperative anterior chamber depth were highly correlated (r = 0.287, p = 0.001 and r = -0.271, p = 0.004, respectively). Anterior angles increased 1 month after surgery compared with the preoperative values (p < 0.001). The amount of change between preoperative and postoperative anterior angles correlated with preoperative anterior angles (p < 0.001). However, no statistically significant correlation was observed between internal lens signal and preoperative anterior angles or postoperative BCVA. Internal lens signal correlated with changes in postoperative anterior angles (p < 0.001). CONCLUSIONS: Internal lens signal correlated with preoperative visual acuity and may help evaluate the cataract severity quantitatively and objectively. Internal lens signal may aid in understanding the structure of anterior segments by predicting the lens volume. Knowing the effect of visual impairment due to cataracts and predicting visual improvement after cataract surgery is necessary.
Anterior Chamber
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Cataract
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Humans
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Vision Disorders
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Visual Acuity
4.The Number of Cases, Cause and Treatment of Avellino Corneal Dystrophy Exacerbated After LASIK.
Jeong Ho YI ; Byoung Jin HA ; Sang Woo KIM ; Tae im KIM ; Eung Kweon KIM
Journal of the Korean Ophthalmological Society 2008;49(9):1415-1424
PURPOSE: To present a case report of fungal keratitis related to prolonged overnight use of orthokeratology contact lenses. METHODS: A 13 year-old girl presented with a corneal ulcer in her left eye refractory to antibacterial medication. She had a history of wearing orthokeratology contact lenses overnight for seven months. RESULTS: The organism Aspergillus was isolated by corneal scraping, the contact lens itself, and from the storage case. The patient was treated with topical fluconazole and Natamycin pimaricin in addition to oral itraconazole, resulting in a resolution of the ocular lesion. CONCLUSIONS: The risk of fungal infection as a potential complication of the use of overnight orthkeratology contact lenses should be considered when using these lenses.
Aspergillus
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Contact Lenses
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Corneal Dystrophies, Hereditary
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Corneal Ulcer
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Eye
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Fluconazole
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Humans
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Itraconazole
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Keratitis
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Keratomileusis, Laser In Situ
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Natamycin
5.Standardization of Korean Version of Frenchay Aphasia Screening Test in Normal Adults.
Sung Bom PYUN ; Yu Mi HWANG ; Ji Wan HA ; Hoyoung YI ; Kun Woo PARK ; Kichun NAM
Journal of the Korean Academy of Rehabilitation Medicine 2009;33(4):436-440
OBJECTIVE: To develop Korean version of Frenchay Aphasia Screening Test (K-FAST) and to standardize K-FAST in normal adult population in Korea. METHOD: The 'river scene' of stimulus set in original version of FAST was adapted for K-FAST. English version of the test instructions and scoring methods were translated into Korean and reverse-translation was performed by English- Korean bilinguals. The test structures and language domains (comprehension, expression, reading, and writing) were unchanged and possible maximum score was 30 points. We standardized K-FAST in 240 normal adult populations (male 102, female 138) whose ages were above 44. Basic personal information was collected through an interview and we performed Edinburgh handedness inventory (EHI), K- MMSE and K-FAST. Subjects who had history of brain disease, cognitive communicative disorders, or K-MMSE scores less than 2 percentile of same age group were excluded. K-FAST scores were analyzed according to the age and education groups. RESULTS: Mean EHI, K-MMSE, and K-FAST scores in total subjects were 9.4+/-1.2, 25.9+/-2.8, 25.4+/-3.3 points, respectively. Post-hoc analysis of K-FAST scores according to age groups classified into 3 age groups, 45~64, 65~74, and > or =74 years and education groups into 0, 1~9, > or =10 years of total education. K-FAST scores decreased significantly as increase of age (r=-0.441, p=0.000) and decrease of total years of education (r=0.580, p=0.000). CONCLUSION: Newly adapted K-FAST can be used for screening of aphasia in Korea and the standardized data according to age and education levels may provide useful reference values for interpretation of the results of K-FAST.
Adult
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Aphasia
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Brain Diseases
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Communication Disorders
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Female
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Functional Laterality
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Humans
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Korea
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Mass Screening
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Reference Values
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Research Design
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Stroke
6.Nurse Wage Structure and Its Determinants in Hospital Industry
Jin Hyun KIM ; Sang Keun HA ; Young Woo PARK ; Yeon Hee KIM ; Sun Mi YI ; Hyun Jeong KWON
Journal of Korean Clinical Nursing Research 2019;25(3):294-302
PURPOSE:
The purpose of this study was to investigate the wage structure of hospital nurses in Korea and to analyze the factors that determine the level of nurses' wages.
METHODS:
First, a mobile survey on nurses' wages was conducted with a total of 3,742 nurses working in hospitals. A literature review was also done. Second, a regression model was applied to analyze the determinants of nurses' wages.
RESULTS:
The average monthly wage of 3,742 nurses based on the survey was KRW 3,588,000 and the standardized monthly income of 3,742 nurses was estimated to be KRW 3,364,000 as of the end of 2018. The results of regression analysis(R2=61.7%) showed that gender, nursing experience, designated night duty, ownership, and number of beds were statistically significant variables for nurses' wages at 1% significance level. The monthly wage of nurses working in total nursing care wards was not significantly different from those working in other wards at 5% significance level.
CONCLUSION
The substantial difference in nurses' wages according to job career, hospital size, region, etc may result in the low proportion of nurses with more than three to five years of service experience and the high turnover of less-experienced workers. Consideration should be given to adjust the gap in wage level and a standard nurse wage system could be effective measures.
7.Nursing Salary Guideline for Korean Hospitals
Jin Hyun KIM ; Sang Keun HA ; Young Woo PARK ; Yeon Hee KIM ; Sun Mi YI ; Hyun Jeong KWON
Journal of Korean Clinical Nursing Research 2020;26(1):75-85
Purpose:
The purpose of this study is to develop a nursing salary guideline for Korean hospitals.
Methods:
Literature review and a mobile survey were conducted regarding staff nurses’ salary. Regression analysis and simulation model were applied to develop the nurses’ salary guideline.
Results:
The United Kingdom, Australia, and Germany have standard salary guidelines which demonstrated the standard salary of nurses. These were determined mainly by nursing experience and expertise. The results of the mobile survey indicated that the maximum to minimum ratio of the salary was as high as 4.5 among staff nurses working in Korean hospitals. Two models (exponential and linear) for a standard nursing salary guideline were developed and the simulation results demonstrated an improved salary structure for staff nurses.
Conclusion
This developed salary guideline for staff nurses is recommended to be applied in Korean hospitals which provide total nursing care services.
8.Assessment of nephrotoxicity of herbal medicine containing aristolochic acid in mice
Yi QUAN ; Long JIN ; Kang LUO ; Jian JIN ; Sun Woo LIM ; Yoo Jin SHIN ; Eun Jeong KO ; Byung Ha CHUNG ; Chul Woo YANG
The Korean Journal of Internal Medicine 2020;35(2):400-407
Background/Aims:
It is undetermined if herbal medicines (HM) containing aristolochic acid (AA)-containing have similar nephrotoxicity to AA itself.
Methods:
We administered HM containing a high concentration of AA for 5 days (short-term study) or a low concentration of AA for 30 days (long-term study) to C57BL/6 mice; for comparison, same dose of AA compound was used as controls.
Results:
The nephrotoxicity in the HM- and AA-treated mice was compared in terms of renal function, histopathology, oxidative stress, apoptotic cell death, and mitochondrial damage. Short-term HM treatment resulted in acute kidney injury (marked renal dysfunction, acute tubular necrosis, and neutrophil gelatinase-associated lipocalin [NGAL] expression) in which the severity of renal dysfunction and histopathology was comparable with that induced by the administration of AA alone. Long-term HM treatment resulted in features of chronic kidney disease (CKD, mild renal dysfunction and tubular atrophy and dilatation). No significant differences in these parameters were observed between the HM- and AA-treated mice. HM-induced oxidative stress (8-hydroxy-2’-deoxyguanosine and manganese- dependent superoxide dismutase expression) and apoptotic cell death (terminal deoxynucleotidyl transferase dUTP nick end labelling [TUNEL]-positive cells and active caspase-3 expression) were similar in HM- and AA-treated mice in the short-term and long-term studies. Mitochondrial injury, evaluated by electron microscopy, was also similar in HM- and AA-treated mice in the short-term and long-term studies.
Conclusions
The nephrotoxic potential of HM containing AA was similar to that of AA itself.
9.The therapeutic efficacy of water-soluble coenzyme Q10 in an experimental model of tacrolimus-induced diabetes mellitus
Yi QUAN ; Kang LUO ; Sheng CUI ; Sun Woo LIM ; Yoo Jin SHIN ; Eun Jeong KO ; Ju Hwan KIM ; Sang J. CHUNG ; Soo Kyung BAE ; Byung Ha CHUNG ; Chul Woo YANG
The Korean Journal of Internal Medicine 2020;35(6):1443-1456
Background/Aims:
Coenzyme Q10 (CoQ10) has antioxidant effects and is commercially available and marketed extensively. However, due to its low bioavailability, its effects are still controversial. We developed a water-soluble CoQ10-based micelle formulation (CoQ10-W) and tested it in an experimental model of tacrolimus (TAC)-induced diabetes mellitus (DM).
Methods:
We developed CoQ10-W from a glycyrrhizic-carnitine mixed layer CoQ10 micelle preparation based on acyltransferases. TAC-induced DM rats were treated with either lipid-soluble CoQ10 (CoQ10-L) or CoQ10-W for 4 weeks. Their plasma and pancreatic CoQ10 concentrations were measured using liquid chromatography- tandem mass spectrometry. The therapeutic efficacies of CoQ10-W and CoQ10-L on TAC-induced DM were compared using functional and morphological parameters and their effects on cell viability and reactive oxygen species (ROS) production were also evaluated in cultured rat insulinoma cells.
Results:
The plasma CoQ10 level was significantly increased in the CoQ10-W group compared to that in the CoQ10-L group. Intraperitoneal glucose tolerance tests and glucose-stimulated insulin secretion revealed that CoQ10-W controlled hyperglycemia and restored insulin secretion significantly better than CoQ10-L. The TAC-mediated decrease in pancreatic islet size was significantly attenuated by CoQ10-W but not by CoQ10-L. TAC-induced oxidative stress and apoptosis were significantly more reduced by CoQ10-W than CoQ10-L. Electron microscopy revealed that CoQ10-W restored TAC-induced attenuation in the number of insulin granules and the average mitochondrial area, unlike CoQ10-L. In vitro studies showed that CoQ10-L and CoQ10-W both improved cell viability and reduced ROS production in TAC-treated islet cells to a similar extent.
Conclusions
CoQ10-W has better therapeutic efficacy than CoQ10-L in TAC-induced DM.
10.Alleviation of renal ischemia/reperfusion injury by exosomes from induced pluripotent stem cell-derived mesenchymal stem cells
Sun Woo LIM ; Kyung Woon KIM ; Bo Mi KIM ; Yoo Jin SHIN ; Kang LUO ; Yi QUAN ; Sheng CUI ; Eun Jeong KO ; Byung Ha CHUNG ; Chul Woo YANG
The Korean Journal of Internal Medicine 2022;37(2):411-424
Background/Aims:
Renal ischemia followed by reperfusion (I/R) is a leading cause of acute kidney injury (AKI), which is closely associated with high morbidity and mortality. Studies have shown that induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (iMSCs) exert powerful therapeutic effects in renal ischemia. However, the efficacy of iMSC-derived exosomes (iExo) on I/R injuries remains largely unknown.
Methods:
Human iPSCs were differentiated into iMSCs using a modified one-step method. Ultrafiltration, combined with purification, was used to isolate iExo from iMSCs. iExo was administered following I/R injury in a mouse model. The effect of iExo on I/R injury was assessed through changes in renal function, histology, and expression of oxidative stress, inflammation, and apoptosis markers. Further, we evaluated its association with the extracellular signal-regulated kinase (ERK) 1/2 signaling pathway.
Results:
Mice subjected to I/R injury exhibited typical AKI patterns; serum creatinine level, tubular necrosis, apoptosis, inflammatory cytokine production, and oxidative stress were markedly increased compared to sham mice. However, treatment with iExo attenuated these changes, significantly improving renal function and tissue damage, similar to the renoprotective effects of iMSCs on I/R injury. Significant induction of activated ERK 1/2 signaling molecules was observed in mice treated with iExo compared to those in the I/R injury group.
Conclusions
The present study demonstrates that iExo administration ameliorated renal damage following I/R, suggesting that iMSC-derived exosomes may provide a novel therapeutic approach for AKI treatment.