1.Effects of cementless fixation of implant prosthesis: A finite element study
Hyeonjong LEE ; Soyeon PARK ; Kung Rock KWON ; Gunwoo NOH
The Journal of Advanced Prosthodontics 2019;11(6):341-349
PURPOSE: A novel retentive type of implant prosthesis that does not require the use of cement or screw holes has been introduced; however, there are few reports examining the biomechanical aspects of this novel implant. This study aimed to evaluate the biomechanical features of cementless fixation (CLF) implant prostheses.MATERIALS AND METHODS: The test groups of three variations of CLF implant prostheses and a control group of conventional cement-retained (CR) prosthesis were designed three-dimensionally for finite element analysis. The test groups were divided according to the abutment shape and the relining strategy on the inner surface of the implant crown as follows; resin-air hole-full (RAF), resin-air hole (RA), and resin-no air hole (RNA). The von Mises stress and principal stress were used to evaluate the stress values and distributions of the implant components. Contact open values were calculated to analyze the gap formation of the contact surfaces at the abutment-resin and abutment-implant interfaces. The micro-strain values were evaluated for the surrounding bone.RESULTS: Values reflecting the maximum stress on the abutment were as follows (in MPa): RAF, 25.6; RA, 23.4; RNA, 20.0; and CR, 15.8. The value of gap formation was measured from 0.88 to 1.19 µm at the abutmentresin interface and 24.4 to 24.7 µm at the abutment-implant interface. The strain distribution was similar in all cases.CONCLUSION: CLF had no disadvantages in terms of the biomechanical features compared with conventional CR implant prosthesis and could be successfully applied for implant prosthesis.
Crowns
;
Finite Element Analysis
;
Prostheses and Implants
;
RNA
2.Quantitative Evaluation of Hepatic Steatosis Using Advanced Imaging Techniques: Focusing on New Quantitative Ultrasound Techniques
Junghoan PARK ; Jeong Min LEE ; Gunwoo LEE ; Sun Kyung JEON ; Ijin JOO
Korean Journal of Radiology 2022;23(1):13-29
Nonalcoholic fatty liver disease, characterized by excessive accumulation of fat in the liver, is the most common chronic liver disease worldwide. The current standard for the detection of hepatic steatosis is liver biopsy; however, it is limited by invasiveness and sampling errors. Accordingly, MR spectroscopy and proton density fat fraction obtained with MRI have been accepted as non-invasive modalities for quantifying hepatic steatosis. Recently, various quantitative ultrasonography techniques have been developed and validated for the quantification of hepatic steatosis. These techniques measure various acoustic parameters, including attenuation coefficient, backscatter coefficient and speckle statistics, speed of sound, and shear wave elastography metrics. In this article, we introduce several representative quantitative ultrasonography techniques and their diagnostic value for the detection of hepatic steatosis.
3.Papular Mucinosis in a Renal Transplantation Recipient.
Jae Keun PARK ; Mi Yeon YU ; Gunwoo KOO ; Joo Hee KWAK ; Jung Hoon LEE ; In Sub JUNG ; Hyunwoo OH ; Joon Sung PARK
The Journal of the Korean Society for Transplantation 2014;28(4):236-240
Papular mucinosis (PM, scleromyxoedema) is a rare dermatologic disease. It is histologically characterized by a focal dermal deposit of mucin within the skin. Although PM is accepted as an idiopathic disease in most cases, some authors argued that it may be a cutaneous manifestation of a systemic disease. Here, we describe a 68-year-old male kidney transplantation recipient with a complaint of intractable itching sensation on the forehead. We diagnosed the skin lesions as PM, which were improved after cyclosporine dose reduction.
Aged
;
Cyclosporine
;
Forehead
;
Humans
;
Kidney Transplantation*
;
Male
;
Mucins
;
Pruritus
;
Scleromyxedema*
;
Sensation
;
Skin
4.The Effectiveness of Ferritin as a Contrast Agent for Cell Tracking MRI in Mouse Cancer Models.
Chan Wha LEE ; Sun Il CHOI ; Sang Jin LEE ; Young Taek OH ; Gunwoo PARK ; Na Yeon PARK ; Kyoung Ah YOON ; Sunshin KIM ; Daehong KIM ; Yun Hee KIM ; Jin Suck SUH
Yonsei Medical Journal 2017;58(1):51-58
PURPOSE: We aimed to investigate the effectiveness of ferritin as a contrast agent and a potential reporter gene for tracking tumor cells or macrophages in mouse cancer models. MATERIALS AND METHODS: Adenoviral human ferritin heavy chain (Ad-hFTH) was administrated to orthotopic glioma models and subcutaneous colon cancer mouse models using U87MG and HCT116 cells, respectively. Brain MR images were acquired before and daily for up to 6 days after the intracranial injection of Ad-hFTH. In the HCT116 tumor model, MR examinations were performed before and at 6, 24, and 48 h after intratumoral injection of Ad-hFTH, as well as before and every two days after intravenous injection of ferritin-labeled macrophages. The contrast effect of ferritin in vitro was measured by MR imaging of cell pellets. MRI examinations using a 7T MR scanner comprised a T1-weighted (T1w) spin-echo sequence, T2-weighted (T2w) relaxation enhancement sequence, and T2*-weighted (T2*w) fast low angle shot sequence. RESULTS: Cell pellet imaging of Ad-hFTH in vitro showed a strong negatively enhanced contrast in T2w and T2*w images, presenting with darker signal intensity in high concentrations of Fe. T2w images of glioma and subcutaneous HCT116 tumor models showed a dark signal intensity around or within the Ad-hFTH tumor, which was distinct with time and apparent in T2*w images. After injection of ferritin-labeled macrophages, negative contrast enhancement was identified within the tumor. CONCLUSION: Ferritin could be a good candidate as an endogenous MR contrast agent and a potential reporter gene that is capable of maintaining cell labeling stability and cellular safety.
Animals
;
Brain Neoplasms/*diagnostic imaging/pathology
;
Cell Line, Tumor
;
Cell Tracking/*methods
;
Colonic Neoplasms/*diagnostic imaging/pathology
;
*Contrast Media/administration & dosage
;
Disease Models, Animal
;
Female
;
*Ferritins/administration & dosage
;
Genes, Reporter
;
Glioma/*diagnostic imaging/pathology
;
Humans
;
Injections, Intravenous
;
Macrophages
;
Magnetic Resonance Imaging/*methods
;
Male
;
Mice
;
Neoplasm Transplantation
;
Skin Neoplasms/*diagnostic imaging/pathology
;
Time Factors
5.Reversible Posterior Leukoencephalopathy Syndrome in a Patient withSystemic Lupus Erythematosus Treated with Cyclosporine.
Jae Dae SHIN ; Ja Young SON ; Dae Young KIM ; Jin Hong PARK ; Gun Woo KIM ; Eun Joo SONG ; Ji Min KIM ; Kyung Hoon KIM ; Eon Jeong NAM ; Young Mo KANG
The Journal of the Korean Rheumatism Association 2007;14(3):291-296
Reversible posterior leukoencephalopathy syndrome (RPLS) is characterized clinically by headache, seizure, altered mental status and visual impairment. Neuroimaging shows reversible white matter edema predominantly in the parietal and occipital lobes. RPLS has been associated with a variety of conditions, including hypertensive encephalopathy, renal failure, immunosupressive therapy, and autoimmune diseases such as systemic lupus erythematosus (SLE). We report a young woman of SLE presented with headache, generalized tonic-clonic seizure and altered mental status, after taking azathioprine and cyclosporine. The brain magnetic resonance images showed bilateral hyperintensitiy in the posterior parietal, occipital, temporal lobes and cerebellum on T2-weighted images and fluid attenuated inversion recovery images, whereas diffusion-weighted images showed isointensity in the same distribution. The patient was improved clinically and radiologically one week after the control of hypertension and discontinuation of cyclosporine.
Autoimmune Diseases
;
Azathioprine
;
Brain
;
Cerebellum
;
Cyclosporine*
;
Edema
;
Female
;
Headache
;
Humans
;
Hypertension
;
Hypertensive Encephalopathy
;
Lupus Erythematosus, Systemic
;
Neuroimaging
;
Occipital Lobe
;
Posterior Leukoencephalopathy Syndrome*
;
Rabeprazole
;
Renal Insufficiency
;
Seizures
;
Temporal Lobe
;
Vision Disorders
6.Preclinical development of a humanized neutralizing antibody targeting HGF.
Hyori KIM ; Sung Hee HONG ; Jung Yong KIM ; In Chull KIM ; Young Whan PARK ; Song Jae LEE ; Seong Won SONG ; Jung Ju KIM ; Gunwoo PARK ; Tae Min KIM ; Yun Hee KIM ; Jong Bae PARK ; Junho CHUNG ; In Hoo KIM
Experimental & Molecular Medicine 2017;49(3):e309-
Hepatocyte growth factor (HGF) and its receptor, cMET, play critical roles in cell proliferation, angiogenesis and invasion in a wide variety of cancers. We therefore examined the anti-tumor activity of the humanized monoclonal anti-HGF antibody, YYB-101, in nude mice bearing human glioblastoma xenografts as a single agent or in combination with temozolomide. HGF neutralization, The extracellular signal-related kinases 1 and 2 (ERK1/2) phosphorylation, and HGF-induced scattering were assessed in HGF-expressing cell lines treated with YYB-101. To support clinical development, we also evaluated the preclinical pharmacokinetics and toxicokinetics in cynomolgus monkeys, and human and cynomolgus monkey tissue was stained with YYB-101 to test tissue cross-reactivity. We found that YYB-101 inhibited cMET activation in vitro and suppressed tumor growth in the orthotopic mouse model of human glioblastoma. Combination treatment with YYB-101 and temozolomide decreased tumor growth and increased overall survival compared with the effects of either agent alone. Five cancer-related genes (TMEM119, FST, RSPO3, ROS1 and NBL1) were overexpressed in YYB-101-treated mice that showed tumor regrowth. In the tissue cross-reactivity assay, critical cross-reactivity was not observed. The terminal elimination half-life was 21.7 days. Taken together, the in vitro and in vivo data demonstrated the anti-tumor efficacy of YYB-101, which appeared to be mediated by blocking the HGF/cMET interaction. The preclinical pharmacokinetics, toxicokinetics and tissue cross-reactivity data support the clinical development of YYB-101 for advanced cancer.
Animals
;
Antibodies, Neutralizing*
;
Cell Line
;
Cell Proliferation
;
Glioblastoma
;
Half-Life
;
Hepatocyte Growth Factor
;
Heterografts
;
Humans*
;
In Vitro Techniques
;
Macaca fascicularis
;
Mice
;
Mice, Nude
;
Pharmacokinetics
;
Phosphorylation
;
Phosphotransferases
;
Toxicokinetics
7.Fatal Clinical Course of Probable Invasive Pulmonary Aspergillosis with Influenza B Infection in an Immunocompetent Patient.
Dong Won PARK ; Ji Young YHI ; Gunwoo KOO ; Sung Jun JUNG ; Hyun Jung KWAK ; Ji Yong MOON ; Sang Heon KIM ; Tae Hyung KIM ; Jang Won SOHN ; Dong Ho SHIN ; Sung Soo PARK ; Ho Joo YOON
Tuberculosis and Respiratory Diseases 2014;77(3):141-144
Invasive pulmonary aspergillosis (IPA) is rarely reported in patients who have normal immune function. Recently, IPA risk was reported in nonimmunocompromised hosts, such as patients with chronic obstructive pulmonary disease and critically ill patients in intensive care units. Moreover, influenza infection is also believed to be associated with IPA among immunocompetent patients. However, most reports on IPA with influenza A infection, including pandemic influenza H1N1, and IPA associated with influenza B infection were scarcely reported. Here, we report probable IPA with a fatal clinical course in an immunocompetent patient with influenza B infection. We demonstrate IPA as a possible complication in immunocompetent patients with influenza B infection. Early clinical suspicion of IPA and timely antifungal therapy are required for better outcomes in such cases.
Critical Illness
;
Humans
;
Immunocompetence
;
Influenza B virus
;
Influenza, Human*
;
Intensive Care Units
;
Invasive Pulmonary Aspergillosis*
;
Pandemics
;
Pulmonary Disease, Chronic Obstructive
8.Recommendations for the management of patients with systemic rheumatic diseases during the coronavirus disease pandemic
Mi Ryoung SEO ; Ji-Won KIM ; Eun-Jung PARK ; Seung Min JUNG ; Yoon-Kyoung SUNG ; Hyungjin KIM ; Gunwoo KIM ; Hyun-Sook KIM ; Myeung-Su LEE ; Jisoo LEE ; Ji An HUR ; Bum Sik CHIN ; Joong Sik EOM ; Han Joo BAEK ;
The Korean Journal of Internal Medicine 2020;35(6):1317-1332
Patients with systemic rheumatic diseases (SRD) are vulnerable for coronavirus disease (COVID-19). The Korean College of Rheumatology recognized the urgent need to develop recommendations for rheumatologists and other physicians to manage patients with SRD during the COVID-19 pandemic. The working group was organized and was responsible for selecting key health questions, searching and reviewing the available literature, and formulating statements. The appropriateness of the statements was evaluated by voting panels using the modified Delphi method. Four general principles and thirteen individual recommendations were finalized through expert consensus based on the available evidence. The recommendations included preventive measures against COVID-19, medicinal treatment for stable or active SRD patients without COVID-19, medicinal treatment for SRD patients with COVID-19, and patient evaluation and monitoring. Medicinal treatments were categorized according to the status with respect to both COVID-19 and SRD. These recommendations should serve as a reference for individualized treatment for patients with SRD. As new evidence is emerging, an immediate update will be required.
9.Quality Indicators for Evaluating the Health Care of Patients with Rheumatoid Arthritis: a Korean Expert Consensus
Mi Ryoung SEO ; Gunwoo KIM ; Ki Won MOON ; Yoon-Kyoung SUNG ; Jong Jin YOO ; Chong-Hyeon YOON ; Eun Bong LEE ; Jisoo LEE ; Eun Ha KANG ; Hyungjin KIM ; Eun-Jung PARK ; Wan-Sik UHM ; Myeung Su LEE ; Seung-Won LEE ; Byoong Yong CHOI ; Seung-Jae HONG ; Han Joo BAEK
Journal of Korean Medical Science 2021;36(17):e109-
Background:
There is increasing interest in the quality of health care and considerable efforts are being made to improve it. Rheumatoid arthritis (RA) is a disease that can result in favorable outcomes when appropriate diagnosis and treatment are provided. However, several studies have shown that RA is often managed inappropriately. Therefore, the Korean College of Rheumatology aimed to develop quality indicators (QIs) to evaluate and improve the health care of patients with RA.
Methods:
Preliminary QIs were derived based on the existing guidelines and QIs for RA. The final QIs were determined through two separate consensus meetings of experts. The consensus was achieved through a panel of experts who voted using the modified Delphi method.
Results:
Fourteen final QIs were selected among 70 preliminary QIs. These included early referral to and regular follow-up with a rheumatologist, radiographs of the hands and feet, early initiation and maintenance of disease-modifying anti-rheumatic drug (DMARD) therapy, periodic assessment of disease activity, screening for drug safety and comorbidities,including viral hepatitis and tuberculosis before biologic DMARD therapy, periodic laboratory testing, supplementation with folic acid, assessment of the risk for cervical spine instability before general anesthesia, patient education, and specialized nurse.
Conclusion
These QIs can be used to assess and improve the quality of health care for patients with RA.
10.Quality Indicators for Evaluating the Health Care of Patients with Rheumatoid Arthritis: a Korean Expert Consensus
Mi Ryoung SEO ; Gunwoo KIM ; Ki Won MOON ; Yoon-Kyoung SUNG ; Jong Jin YOO ; Chong-Hyeon YOON ; Eun Bong LEE ; Jisoo LEE ; Eun Ha KANG ; Hyungjin KIM ; Eun-Jung PARK ; Wan-Sik UHM ; Myeung Su LEE ; Seung-Won LEE ; Byoong Yong CHOI ; Seung-Jae HONG ; Han Joo BAEK
Journal of Korean Medical Science 2021;36(17):e109-
Background:
There is increasing interest in the quality of health care and considerable efforts are being made to improve it. Rheumatoid arthritis (RA) is a disease that can result in favorable outcomes when appropriate diagnosis and treatment are provided. However, several studies have shown that RA is often managed inappropriately. Therefore, the Korean College of Rheumatology aimed to develop quality indicators (QIs) to evaluate and improve the health care of patients with RA.
Methods:
Preliminary QIs were derived based on the existing guidelines and QIs for RA. The final QIs were determined through two separate consensus meetings of experts. The consensus was achieved through a panel of experts who voted using the modified Delphi method.
Results:
Fourteen final QIs were selected among 70 preliminary QIs. These included early referral to and regular follow-up with a rheumatologist, radiographs of the hands and feet, early initiation and maintenance of disease-modifying anti-rheumatic drug (DMARD) therapy, periodic assessment of disease activity, screening for drug safety and comorbidities,including viral hepatitis and tuberculosis before biologic DMARD therapy, periodic laboratory testing, supplementation with folic acid, assessment of the risk for cervical spine instability before general anesthesia, patient education, and specialized nurse.
Conclusion
These QIs can be used to assess and improve the quality of health care for patients with RA.