1.NADPH oxidase mediated oxidative stress in hepatic fibrogenesis.
Yong Han PAIK ; David A BRENNER
The Korean Journal of Hepatology 2011;17(4):251-257
NADPH oxidase (NOX) is a multicomponent enzyme complex that generates reactive oxygen species (ROS) in response to a wide range of stimuli. ROS is involved as key secondary messengers in numerous signaling pathways, and NADPH oxidases complex has been increasingly recognized as key elements of intracellular signaling of hepatic fibrogenesis. In the liver, NADPH oxidase is functionally expressed both in the phagocytic form and in the non-phagocytic form. The non-phagocytic NADPH oxidase complex is structurally and functionally similar to the phagocytic NADPH, resulting in reduction of molecular oxygen to generate superoxide. There are six homologous NOX proteins in the non-phagocytic forms of NADPH oxidase. An emerging concept is that both phagocytic and nonphagocytic NADPH oxidase components in hepatic stellate cells (HSCs) mediate hepatic fibrosis, suggesting its potential role as a pharmacological target for anti-fibrotic therapy. The molecular components and signaling pathways of various NADPH oxidase homologues that are critical for the fibrotic activity in HSCs need to be more clearly identified.
Angiotensin II/metabolism
;
Hepatic Stellate Cells/metabolism
;
Humans
;
Liver Cirrhosis/*enzymology/pathology
;
NADPH Oxidase/*metabolism
;
Oxidative Stress
;
Reactive Oxygen Species/metabolism
2.Frontalis Transfer and Closed Silicone Rod Frontalis Suspension.
Yong Jig LEE ; David Dae Hwan PARK
Archives of Aesthetic Plastic Surgery 2016;22(1):3-9
BACKGROUND: Improvements in the degree of marginal reflex distance 1 (MRD1) were compared before and after use of the frontalis transfer (FT) method and closed silicone rod frontalis suspension surgery (SS) for severe blepharoptosis under general or local anesthesia with or without minimal sedation. METHODS: We reviewed the medical records and photographs of 76 patients who had visited our institute between 2006 and 2013 because of severe blepharoptosis with poor levator function and treated by the same senior doctor. RESULTS: In total, 104 eyes (63 patients) were included after applying exclusion criteria; 71 eyes (44 patients) were corrected using FT, and 33 eyes (19 patients) were corrected using the frontalis sling method with a silicone rod. Among the general FT, local FT, general SS, and local SS groups, the mean preoperative MRD1 was not significantly different. Postoperative MRD1 was highest in the local FT group. CONCLUSIONS: Both FT and SS positively increased MRD1, regardless of the anesthesia used; however, the change in MRD1 of the general SS group was the lowest (1.11+/-0.848 mm). Further, general FT, local FT, and local SS groups had an approximate 2 mm or greater increase in the differences between postoperative and preoperative MRD1. Specifically, the local FT group had a definite positive correlation with postoperative MRD1.
Anesthesia
;
Anesthesia, Local
;
Blepharoptosis
;
Eyelids
;
Humans
;
Medical Records
;
Reflex
;
Silicon*
;
Silicones*
3.Activation of Neutrophil Menbrane Phospholipase D by Soluble Proteins: Comparison of Cytosolic Neutrophil 50 kDa Factor , ADP-ribosylation Factor and a Novel Brain Factor.
Yong KIM ; Jong Young KWAK ; Tae Hoon G LEE ; Isabel LOPEZ ; J David LAMETH ; Pann Ghill SHU ; Sung Ho RYU
Korean Journal of Immunology 1999;21(3):183-191
GTPrS-dependent phospholipase D activity in human neutrophils was investigated using exogenous phospholipid as a substrate. Both cytosolic and membrane- associated phospholipase D activities were identified. The previously described 50 kDa cytosolic activating factor was resolved chromatographically from the cytosolic phospholipase D. Using exogenous phospholipid as substrate along with chromatographically resolved 50 kDa factor and recombinant ADP-ribosylation factor 1, plasma membrane was required for activity, indicating that the activity which was previously seen using endogenous phospholipid substrate was due to a phospholipase D located in the plasma membrane. In addition, ADP-ribosylation factor and the 50 kDa factor activated synergistically. Using neutrophil plasma membranes, a third regulator of neutrophil membrane phospholipase D was identified from bovine brain cytosol. This factor was resolved from ADP-ribosylation factor and Rho A by successive column chromatographies. The brain factor showed a synergistic effect with the 50 kDa neutrophil activator but an additive effect with recombinant ADP- ribosylation factor. Whether or not ADP-ribosylation factor or the brain factor were present, high activities were seen only when the 50 kDa factor was present, indicating that the 50 kDa cytosolic factor is a major activating factor for the neutrophil plasma membrane phospholipase D.
ADP-Ribosylation Factor 1
;
ADP-Ribosylation Factors*
;
Brain*
;
Cell Membrane
;
Chromatography
;
Cytosol*
;
Fibrinogen
;
Humans
;
Membranes
;
Neutrophils*
;
Phospholipase D*
;
Phospholipases*
4.Five-year Change in Corneal Endothelial Cell Density after Foldable Iris-fixed Lens Insertion
Myungsik NAM ; David Sung Yong KANG ; Sun Woong KIM
Journal of the Korean Ophthalmological Society 2021;62(4):479-486
Purpose:
To investigate changes in corneal endothelial cell density over 5 years after implantation of Artiflex lenses (Ophtec BV, Groningen, The Netherlands) and to explore the influence of anterior chamber depth and volume on changes in endothelial cell density.
Methods:
This study included 146 eyes of 88 patients implanted with foldable phakic iris-fixation intraocular (Artiflex) lenses for myopia correction from March 2009 to March 2014. To simulate chronological changes in endothelial cell density with age, we collected normal endothelial cell density data from 100 healthy subjects aged 20, 25, or 30 years, and compared the changes among these groups at 5 years after surgery. Changes in corneal endothelial cell density were compared among four groups to which subjects were assigned based on the distance from the intraocular lens to the corneal endothelium, and the volume and depth of the preoperative anterior chamber.
Results:
The mean endothelial cell density, pre-operatively and at 1, 3, and 5 years post-operatively, was 3,038.8 ± 223.2, 2,985.3 ± 235.5, 2,905.1 ± 231.3, and 2,814.9 ± 250.5 cells/mm2, respectively (1.73%, 4.36%, and 7.31% reduction, respectively, vs. pre-operatively, p < 0.001). These differences were greater than those observed among different age groups (2.2% difference between 20- and 25-year-olds, and 1.2% difference between 25- and 30-year-olds, p < 0.001). A shorter distance from the lens to the endothelium and smaller anterior chamber volume were associated with greater decreases in endothelial cell density following surgery.
Conclusions
Corneal endothelial cell density significantly decreased during a 5-year follow-up after Artiflex lens implantation. The distance from the intraocular lens to the corneal endothelium, and the anterior chamber volume, were negatively correlated with the rate at which endothelial cell density decreased over time.
5.Five-year Change in Corneal Endothelial Cell Density after Foldable Iris-fixed Lens Insertion
Myungsik NAM ; David Sung Yong KANG ; Sun Woong KIM
Journal of the Korean Ophthalmological Society 2021;62(4):479-486
Purpose:
To investigate changes in corneal endothelial cell density over 5 years after implantation of Artiflex lenses (Ophtec BV, Groningen, The Netherlands) and to explore the influence of anterior chamber depth and volume on changes in endothelial cell density.
Methods:
This study included 146 eyes of 88 patients implanted with foldable phakic iris-fixation intraocular (Artiflex) lenses for myopia correction from March 2009 to March 2014. To simulate chronological changes in endothelial cell density with age, we collected normal endothelial cell density data from 100 healthy subjects aged 20, 25, or 30 years, and compared the changes among these groups at 5 years after surgery. Changes in corneal endothelial cell density were compared among four groups to which subjects were assigned based on the distance from the intraocular lens to the corneal endothelium, and the volume and depth of the preoperative anterior chamber.
Results:
The mean endothelial cell density, pre-operatively and at 1, 3, and 5 years post-operatively, was 3,038.8 ± 223.2, 2,985.3 ± 235.5, 2,905.1 ± 231.3, and 2,814.9 ± 250.5 cells/mm2, respectively (1.73%, 4.36%, and 7.31% reduction, respectively, vs. pre-operatively, p < 0.001). These differences were greater than those observed among different age groups (2.2% difference between 20- and 25-year-olds, and 1.2% difference between 25- and 30-year-olds, p < 0.001). A shorter distance from the lens to the endothelium and smaller anterior chamber volume were associated with greater decreases in endothelial cell density following surgery.
Conclusions
Corneal endothelial cell density significantly decreased during a 5-year follow-up after Artiflex lens implantation. The distance from the intraocular lens to the corneal endothelium, and the anterior chamber volume, were negatively correlated with the rate at which endothelial cell density decreased over time.
6.Rehabilitation of mandibular edentulous patients with a few unilateral remaining teeth using implant-assisted removable partial denture: A case report.
Bhumgey David LEE ; Yong Sang LEE
The Journal of Korean Academy of Prosthodontics 2019;57(1):42-48
In the case of a patient with a small number of unilateral remaining teeth in the mandible, a restoration with conventional removable partial denture cannot provide sufficient retention and resistance. A harmful stress from the poor stability of denture on remaining teeth occurs due to alveolar bone resorption in edentulous area. Although implant fixed prosthesis can provide multiple benefits over conventional removable partial denture, there are limitations come from anatomic structures and costs. In this case, an implant-assisted removable partial denture (IARPD) with a couple of implants placed in strategic positions can be a treatment modality. The objective of this article is to present a case report of two patients showed satisfactory clinical outcomes during three-year follow-up period describing the fabrication and advantages of removable partial denture assisted by teeth and implants (IARPD) for a patient with a small number of unilateral remaining teeth in mandible using Locator as an implant attachment.
Bone Resorption
;
Denture, Partial, Removable*
;
Dentures
;
Follow-Up Studies
;
Humans
;
Mandible
;
Prostheses and Implants
;
Rehabilitation*
;
Tooth*
7.Teleophthalmology and its evolving role in a COVID-19 pandemic: A scoping review.
Jiamin Charmaine CHONG ; Chai-Hoon Nowel TAN ; David Z CHEN
Annals of the Academy of Medicine, Singapore 2021;50(1):61-76
INTRODUCTION:
Teleophthalmology may assist the healthcare sector in adapting to limitations imposed on clinical practice by a viral pandemic. A scoping review is performed in this study to assess the current applications of teleophthalmology for its suitability to diagnose, monitor or manage ophthalmological conditions with accuracy.
METHODS:
A search of PubMed was conducted for teleophthalmology-related articles published from 1 January 2018 to 4 May 2020. Only articles that focused on the use of teleophthalmology in terms of diagnosis and management, as well as its benefits and detriments, were included. The Mixed Methods Appraisal Tool (MMAT) was used to assess the quality of the included articles.
RESULTS:
A total of 38 articles were assessed at the full-text level. There were 2 qualitative studies and 1 quantitative randomised controlled trial, while the majority were either quantitative descriptive studies (19, 50.0%) or quantitative non-randomised studies (16, 42.1%). Overall, 8 studies described reducing manpower requirements, 4 described reducing direct patient-doctor contact, 17 described storage of medical imaging and clinical data, and 9 described real-time teleconferencing. The MMAT analysis revealed limitations in appropriate sampling strategy in both quantitative non-randomised studies (9 of 16, 56.3%) and quantitative descriptive studies (9 of 19, 47.4%). Cost-effectiveness of teleophthalmology was not performed in any included study.
CONCLUSION
This current review of the various aspects of teleophthalmology describes how it may potentially assist the healthcare sector to cope with the limitations imposed by a viral pandemic through technology. Further research is required to evaluate the cost-effectiveness of the various strategies.
COVID-19/transmission*
;
Humans
;
Ophthalmology/organization & administration*
;
Telemedicine/organization & administration*
8.Impact of Baseline Ischemia on Outcome in Older Patients Undergoing Endovascular Therapy for Acute Ischemic Stroke.
Yang Ha HWANG ; Yong Won KIM ; Dong Hun KANG ; Yong Sun KIM ; David S LIEBESKIND
Journal of Clinical Neurology 2017;13(2):162-169
BACKGROUND AND PURPOSE: The outcome for older stroke patients who undergo endovascular revascularization remains unsatisfactory. We aimed to determine the effect of the extent of baseline ischemia on outcome according to age, testing the hypothesis that the restorative capacity for recovery is only marginal in older patients. METHODS: Two hundred and thirteen patients who underwent endovascular revascularization due to occlusion in the M1 segment of the middle cerebral artery (with or without internal carotid artery occlusions) were selected for analysis. Patients were categorized into three age groups: group A (<66 years), group B (66–75 years), and group C (>75 years). Using pretreatment diffusion-weighted imaging (DWI), the Alberta Stroke Program Early CT Score (ASPECTS) and lesion volume were independently measured and analyzed in relation to a favorable outcome. RESULTS: A favorable outcome was achieved in 111 of 213 patients overall: in 60 of the 94 (63.8%) patients in group A, in 36 of the 70 (51.4%) patients in group B, and in 15 of the 49 (30.6%) patients in group C (p=0.001). In older stroke patients (group C), a DWI ASPECTS ≥9 and lesion volume ≤5 mL were found to predict a favorable outcome, which was more restrictive than the cutoffs for their younger counterparts (groups A and B; DWI ASPECTS ≥8 and lesion volume ≤20 mL). CONCLUSIONS: The age-adjusted pretreatment DWI lesion volume and ASPECTS may represent useful surrogate markers for functional outcome according to age. The use of more-restrictive inclusion criteria for older stroke patients could be warranted, although larger studies are necessary to confirm these findings.
Aging
;
Alberta
;
Biomarkers
;
Carotid Artery, Internal
;
Diffusion
;
Humans
;
Ischemia*
;
Middle Cerebral Artery
;
Reperfusion
;
Stroke*
9.Mutagenic and Anti-Mutagenic Properties of Meju and Other Korean Food Products from Fermented Soybeans.
Neville Sue RAPP ; Yong Chung SEONG ; Hye SHIN ; ln Sun HONG ; Jae Yeon JANG ; David J SEEL
Yonsei Medical Journal 1988;29(2):117-123
ln order to investigate the mutagenic activity of Meju, an important component of the Korean diet, both chemical techniques and the Ames test were used. To determine if antimutagenic activity is present in Meju and other soybean based foods, the Ames Test was done in the presence of aflatoxin B1, benzo(a)pyrene, and other mutagens. Although aflatoxin contamination was found in 6 of 43 samples of Meju tested, the amounts were less than 1 ppb in all but one. Meju had a protective effect against mutations produced by both aflatoxins and benzo(a)pyrene, both of which act via an epoxide, but not against other mutagens tested.
Aflatoxins/analysis/*toxicity
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Fermentation
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Food Contamination/*analysis
;
In Vitro
;
Korea
;
Mutagenicity Tests
;
*Mutation
;
Plant Extracts/toxicity
;
Soybeans/*toxicity
;
Support, Non-U.S. Gov't
10.Korean Standardization of Parent Temperament Questionnaire for Children.
Seong Goo CHOI ; S Peter KIM ; Soyoung LEE ; Yoosook JOUNG ; Sungdo David HONG ; E Yong KIM
Journal of Korean Neuropsychiatric Association 1999;38(1):201-210
OBJECTIVES: One of the factors that obstructs active progress of the temperament study in Korea is lack of the standardized assessment tools. Therefore, this study was designed and conducted for the purpose of Korean standardization of "Parental Temperament Questionnaire(PTQ)", which was developed by Thomas and Chess, to assess the temperament of children between the ages of 3 and 7 years through parental questionnaire. METHOD: The samples consisted of 1,175 children who were attending nurseries nationwide. PTQ was translated into Korean language by the authors and distributed to the parents of these children, along with "Toddler Temperament Scale(TTS)" and "Yale Child Inventory(YCI)" which had been previously standardized by different investigators. The reliability and validity of the Korean version of PTQ were tested. RESULTS: Test-retest reliability, item-category correlations and internal consistency of the Korean version of PTQ were generally satisfactory. Correlations between the perceived temperament and the rated temperament were statistically significant in all temperamental categories except distractibility. The correlation between PTQ and TTS was statistically significant in all categories. The 9 categories of PTQ correlated variously with 11 subscales of preschool behavioral assessment of YCI. CONCLUSIONS:The Korean version of PTQ is a standardized tool to assess the temperament of children between ages 3 and 7 years, which will be a useful basic tool for the study of temperament of Korean children.
Child*
;
Humans
;
Korea
;
Nurseries
;
Parents*
;
Surveys and Questionnaires*
;
Reproducibility of Results
;
Research Personnel
;
Temperament*