1.Pure additive contribution of genetic variants to a risk prediction model using propensity score matching: application to type 2 diabetes
Chanwoo PARK ; Nan JIANG ; Taesung PARK
Genomics & Informatics 2019;17(4):e47-
The achievements of genome-wide association studies have suggested ways to predict diseases, such as type 2 diabetes (T2D), using single-nucleotide polymorphisms (SNPs). Most T2D risk prediction models have used SNPs in combination with demographic variables. However, it is difficult to evaluate the pure additive contribution of genetic variants to classically used demographic models. Since prediction models include some heritable traits, such as body mass index, the contribution of SNPs using unmatched case-control samples may be underestimated. In this article, we propose a method that uses propensity score matching to avoid underestimation by matching case and control samples, thereby determining the pure additive contribution of SNPs. To illustrate the proposed propensity score matching method, we used SNP data from the Korea Association Resources project and reported SNPs from the genome-wide association study catalog. We selected various SNP sets via stepwise logistic regression (SLR), least absolute shrinkage and selection operator (LASSO), and the elastic-net (EN) algorithm. Using these SNP sets, we made predictions using SLR, LASSO, and EN as logistic regression modeling techniques. The accuracy of the predictions was compared in terms of area under the receiver operating characteristic curve (AUC). The contribution of SNPs to T2D was evaluated by the difference in the AUC between models using only demographic variables and models that included the SNPs. The largest difference among our models showed that the AUC of the model using genetic variants with demographic variables could be 0.107 higher than that of the corresponding model using only demographic variables.
2.Pure additive contribution of genetic variants to a risk prediction model using propensity score matching: application to type 2 diabetes
Chanwoo PARK ; Nan JIANG ; Taesung PARK
Genomics & Informatics 2019;17(4):47-
The achievements of genome-wide association studies have suggested ways to predict diseases, such as type 2 diabetes (T2D), using single-nucleotide polymorphisms (SNPs). Most T2D risk prediction models have used SNPs in combination with demographic variables. However, it is difficult to evaluate the pure additive contribution of genetic variants to classically used demographic models. Since prediction models include some heritable traits, such as body mass index, the contribution of SNPs using unmatched case-control samples may be underestimated. In this article, we propose a method that uses propensity score matching to avoid underestimation by matching case and control samples, thereby determining the pure additive contribution of SNPs. To illustrate the proposed propensity score matching method, we used SNP data from the Korea Association Resources project and reported SNPs from the genome-wide association study catalog. We selected various SNP sets via stepwise logistic regression (SLR), least absolute shrinkage and selection operator (LASSO), and the elastic-net (EN) algorithm. Using these SNP sets, we made predictions using SLR, LASSO, and EN as logistic regression modeling techniques. The accuracy of the predictions was compared in terms of area under the receiver operating characteristic curve (AUC). The contribution of SNPs to T2D was evaluated by the difference in the AUC between models using only demographic variables and models that included the SNPs. The largest difference among our models showed that the AUC of the model using genetic variants with demographic variables could be 0.107 higher than that of the corresponding model using only demographic variables.
Area Under Curve
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Body Mass Index
;
Case-Control Studies
;
Genome-Wide Association Study
;
Korea
;
Logistic Models
;
Methods
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Polymorphism, Single Nucleotide
;
Propensity Score
;
ROC Curve
3.Simultaneous Non-transcolumellar Incisioned Rhinoplasty in Nasal Bone Fracture : Analysis of 121 Cases.
Chanwoo KIM ; Sang Soon PARK ; Yongjig LEE
Archives of Aesthetic Plastic Surgery 2011;17(3):165-172
The traditional treatment of nasal bone fracture is closed manual reduction. Disadvantage of the method arises from frequent recurrence and inaccurate correction because open method is nonused in anatomical result. In addition, since the interest about cosmetic problems rapidly rises, people who want aesthetic correction during reduction surgery are increasing. From June 2007 to June 2009, This study includes 121 patients who had been performed by correction of nasal bone fracture in our center. 98 out of 121 patients, were undergone with nasal tip plasty, septoplasty was done in 51 patients. Cartilage graft for augmentation rhinoplasty was performed in 36 patients. Average period of follow-up was 6 months and existence of complications such as nasal deviation, nasal obstruction, infection and etc were investigated. Reoperation was done in one patient who showed nasal obstruction, and patients who complained about other complications, such as nasal deviation, were observed. There is the need of more accurate reduction method than traditional non-invasive reduction maneuver, in order to reduce the occurrence of secondary deformation after nasal bone fracture. Hence the authors operated precise reduction by extended endonasal approach without columellar scar, and aesthetic correction rather than anatomical correction was done with variable cartilage if needed.
Cartilage
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Cicatrix
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Cosmetics
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Follow-Up Studies
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Humans
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Morinda
;
Nasal Bone
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Nasal Obstruction
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Recurrence
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Reoperation
;
Rhinoplasty
;
Transplants
4.A Simple Evaluation Method Using a "Sun-Wukong's Headband" Wire for Positional Plagiocephaly Correction after Cranial Remodeling Helmet Therapy.
Chanwoo KIM ; Young Bae LEE ; Dae Hwan PARK
Journal of the Korean Cleft Palate-Craniofacial Association 2011;12(1):28-32
PURPOSE: A cranioremodeling helmet for correcting plagiocephaly was recently developed. However, no discrete objective methods to evaluate how the deformity is being corrected have been developed. We have established an easy and cost-effective method that can be used not only to show the correction process, but can also be used by physicians to assess the degree of plagiocephaly two-dimensionally. METHODS: For two-dimensional evaluation, a length of malleable memory wire (2 mm in diameter) resembling "Sun-Wukong's headband" was placed on the patient's head. The wire around the patient's head was positioned on a plane including points 1 cm above the eyebrow and 1 cm above the auricle. The wire was placed on a sheet of paper and the outline was marked using pens of various colors during each visit. The degree of plagiocephaly correction could then be shown to the patient's parents at every consultation. RESULTS: The method established by the present study easily shows the horizontal cross-section transformation of the head, illustrates plagiocephaly correction by the helmet, and shows the degree of correction in a two-dimensional manner. CONCLUSION: A soft-shell helmet is widely used for correcting plagiocephaly. However, evaluating the effectiveness of the helmet has been determined in a subjective manner, and a more objective method is now in demanded. Our study found that a "Sun-Wukong's headband" wire can accurately measure two-dimensional changes. Future studies will be required to identify landmarks needed for assessing plagiocephaly correction.
Congenital Abnormalities
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Eyebrows
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Head
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Head Protective Devices
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Humans
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Memory
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Parents
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Plagiocephaly
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Plagiocephaly, Nonsynostotic
5.A Minimally Invasive Lumbar Spine Surgery Technique Using a Modified Thoracoport: Proposal of a New Tubular Retractor.
Kwang Woo PARK ; Chan Woo PARK ; Jin Soo PARK ; Sang Gu LEE
Journal of Korean Neurosurgical Society 2006;40(4):296-299
Recently the trend of surgical procedure for treatment of lumbar benign disease is a minimally invasive surgery due to small incision, minimal blood loss, and a short hospital day. By using a microscope or an endoscope, and other surgical equipment, a delicate manipulation in a narrow space became feasible, consequently, to secure a wider view with small incision, appropriate retractors are required. But the various tubular retractor systems are expensive and have some problems. We modified Thoracoport (Auto Suture Co., Norwalk, CT) by making a window at the distal end of trocar and used it as a tubular retractor in surgical procedure for treatment of lumbar benign disease. This modified tubular retractor is docked closely on the curved lamina and provides a wider view. We used it as a tubular retractor also in lumbar bilateral decompression involving a unilateral approach. But this trocar has the limited sizes (diameter and length), and also it is difficult to fix the retractor or change the direction of retractor. And then, we propose a more modified Thoracoport with various sizes and attaching the settling holders to the head of tubular retractor to be able to fix the retractor.
Decompression
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Endoscopes
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Head
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Spine*
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Surgical Equipment
;
Surgical Instruments
;
Surgical Procedures, Minimally Invasive
;
Sutures
6.Correction of Closed Outer Table Fracture of Frontal Sinus using Upper Eyelid Incision and Autogenous Bone Graft.
Yongjig LEE ; Sanguk PARK ; Peter Chanwoo KIM ; Youngbae LEE ; Daehwan PARK
Archives of Aesthetic Plastic Surgery 2012;18(1):45-50
PURPOSE: The bicoronal incision, traditional procedure to correct the frontal sinus fracture, could remain a long scar, alopecia etc. Hence, the authors introduce the procedure to fix the outer table fracture of the frontal sinus through the upper eyelid incision as a concealed scar. MATERIAL & METHODS: From November, 2007 to December, 2010, five patients who suffered from outer table fracture of frontal sinus fracture underwent operation to correct the depressed contour of forehead. Instead of the reduction of depressed outer wall, autogenous bone was grafted trough the upper eyelid incision. The result of operation was evaluated with VAS score system(score arrange 0 to 5). VAS score was taken from patients as well as 4 plastic surgeons. RESULTS: Both patients and surgeons were satisfied about result of operation. The overall average score from plastic surgeon was 4.2. Especially to the scar of upper eyelid incision, the score was 4.7. Average score from the patients was 4.1. And there were no other complications as follow-up periods. CONCLUSION: This technique could be one of good options to correct the depression after the outer table fracture of the frontal sinus. And this technique has some benefits to overcome the disadvantage of previous introduced methods.
Alopecia
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Bone Transplantation
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Cicatrix
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Depression
;
Eyelids
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Follow-Up Studies
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Forehead
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Fractures, Closed
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Frontal Sinus
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Humans
;
Transplants
7.Ventricular Tachycardia in Rhinoplasty: A Report of Two Cases.
Sang Soon PARK ; Chanwoo KIM ; Dae Hwan PARK
Archives of Aesthetic Plastic Surgery 2011;17(2):137-140
Local infiltration(lidocain and epinephrine) has been used to control bleeding in local or general anesthesia in plastic surgery field. However epinephrine also has various side effects, such as tarchycardia, arrhythmia, pulmonary edema, cardiac arrest, etc. We experienced two cases of ventricular tachycardia after local infiltration in rhinoplasty. The first case was a 21 year-old female and the second case was a 40 year-old male. None of them had previous history of cardiac disease. We performed cardiac massage and cardioversion several times immediately after ECG changed to Ventricular tachycardia in operation room until ECG turned to normal sinus rhythm. Patients were transferred to intensive care unit. The condition of patients improved rapidly in a few days and additional complications were not detected except pulmonary edema following cardiac massage. Conclusion: We experienced ventricular tachycardia unexpectedly after local infiltration during the surgical procedure. We report these cases with literature.
Anesthesia, General
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Anesthetics, Local
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Arrhythmias, Cardiac
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Electric Countershock
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Electrocardiography
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Epinephrine
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Female
;
Heart Arrest
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Heart Diseases
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Heart Massage
;
Hemorrhage
;
Humans
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Intensive Care Units
;
Male
;
Pulmonary Edema
;
Rhinoplasty
;
Surgery, Plastic
;
Tachycardia, Ventricular
8.Severe Paradoxical Reaction Requiring Tracheostomy in a Human Immunodeficiency Virus (HIV)-negative Patient with Cervical Lymph Node Tuberculosis.
In Suh PARK ; Dongwook SON ; Chanwoo LEE ; Jae Eun PARK ; Jin Soo LEE ; Moon Hyun CHEONG ; Young Mo KIM
Yonsei Medical Journal 2008;49(5):853-856
During drug treatment of tuberculous lymphadenitis, paradoxical response (PR) may occasionally occur. Continued treatment or lymph node aspiration improves PR without severe sequelae. However, we report a case of severe PR in a patient with cervical lymph node tuberculosis causing airway obstruction due to retropharyngeal lymph node swelling during antituberculous treatment. Tracheostomy and drainage of the node were performed to secure the airway. Possible airway obstruction due to PR must be suspected when cervical lymph node tuberculosis involves the retropharyngeal lymph node.
Adult
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Female
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*HIV Seronegativity
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Humans
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Tomography, X-Ray Computed
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*Tracheostomy
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Tuberculosis, Lymph Node/*complications/radiography/surgery
9.Using of a Straw as Liposuction Protector at the Treatment of Osmidrosis.
Soo Ho PARK ; Peter Chanwoo KIM ; Dae Hwan PARK
Journal of the Korean Society of Aesthetic Plastic Surgery 2007;13(2):164-166
Osmidrosis could have not cured completely with non-surgical treatment. Surgical methods are most effective but they usually make visible scar and complications. So less-invasive methods as liposuction assisted operation are performing broadly. However, contact burn had occurred by frictional stress of liposuction cannula. Several manufactures are commercialized for skin protection but they makes visible scar due to their large size. Therefore we had designed a device for skin protection using a straw. Regarding the method we have used, the end of sterilized straw into 4 strips for fixation to skin was divided. And skin incision about 7mm was performed and the straw was inserted through it. Fixation suture was done to each 4 strips by nylon 4-0. During liposuction, the cannula was inserted through the straw. After operation, straw was removed and subcutaneous suture is done by PDS 5-0, skin closure is done by Dermabond(R) (Ethicon, USA). Remarkably lesser scar had ranged from 7mm to 10mm had developed. And most patients had been satisfied with invisible scar. Using this device at the treatment of osmidrosis by liposuction, it is not only effective for skin protection but reduces length of incision scar.
Burns
;
Catheters
;
Cicatrix
;
Friction
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Humans
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Lipectomy*
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Nylons
;
Skin
;
Sutures
10.Two Cases of Monosegmental Pedicle Screw Fixation for Thoraco-lumbar Fracture(Three-column Injury), and a Review of the Literature.
Ji Hoon LEE ; Chan Woo PARK ; Chan Jong YOO ; Sang Gu LEE ; Woo Kyung KIM
Korean Journal of Spine 2009;6(3):201-204
The management of thoraco-lumbar fractures remains controversial. Different authors have advocated immobilization, external bracing or internal fixation by either anterior or posterior approaches. To stabilize the fracture and avoid an unne cessary fixation of an uninjured segment, posterior monosegmental fixation was performed in Type B1 fractures according to the classification of Magerl et al, with nearly intact vertebral body for load support. Two patients underwent fixation with 4 titanium pedicle screws, one level above and directly into the fractured vertebra body. Patients had a stable fixation at 6 months following surgery. No patients experienced neurological deficit or had developed a delayed kyphotic deformity. Single level fixation for selected cases of thoracolumbar fracture(Type B1 fractures) may be considered as an effective procedure to obtain fixation and fusion. But it is necessary to get a further follow-up period, further cases and especially biomechanical support.
Braces
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Congenital Abnormalities
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Humans
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Immobilization
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Spine
;
Titanium