Stem cell laden nano and micro collagen/PLGA bimodal fibrous patches for myocardial regeneration

위정희,Yoo Ki-Dong,Sim Sung Bo,Kim Hyun Joo,김한준,Park Kyu Nam,Kim Gee-Hee,문미형,You Su Jung,Ha Mi Yeon,양대혁,Chun Heung Jae,Ko Jae Hoon,Kim Chun Ho 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background: Although the use of cardiac patches is still controversial, cardiac patch has the significance in the field of the tissue engineered cardiac regeneration because it overcomes several shortcomings of intra-myocardial injection by providing a template for cells to form a cohesive sheet. So far, fibrous scaffolds fabricated using electrospinning technique have been increasingly explored for preparation of cardiac patches. One of the problems with the use of electrospinning is that nanofibrous structures hardly allow the infiltration of cells for development of 3D tissue construct. In this respect, we have prepared novel bi-modal electrospun scaffolds as a feasible strategy to address the challenges in cardiac tissue engineering . Methods: Nano/micro bimodal composite fibrous patch composed of collagen and poly (D, L-lactic-co-glycolic acid) (Col/PLGA) was fabricated using an independent nozzle control multi-electrospinning apparatus, and its feasibility as the stem cell laden cardiac patch was systemically investigated. Results: Nano/micro bimodal distributions of Col/PLGA patches without beaded fibers were obtained in the range of the 4-6% collagen concentration. The poor mechanical properties of collagen and the hydrophobic property of PLGA were improved by co-electrospinning. In vitro experiments using bone marrow-derived mesenchymal stem cells (BMSCs) revealed that Col/PLGA showed improved cyto-compatibility and proliferation capacity compared to PLGA, and their extent increased with increase in collagen content. The results of tracing nanoparticle-labeled as well as GFP transfected BMSCs strongly support that Col/PLGA possesses the long-term stem cells retention capability, thereby allowing stem cells to directly function as myocardial and vascular endothelial cells or to secrete the recovery factors, which in turn leads to improved heart function proved by histological and echocardiographic findings. Conclusion: Col/PLGA bimodal cardiac patch could significantly attenuate cardiac remodeling and fully recover the cardiac function, as a consequence of their potent long term stem cell engraftment capability.

Outcomes of Pre-hospital ROSC Who received Therapeutic Hypothermia: a multicenter retrospective cohort study

위정희,최승필,박정호,박규남 대한응급의학회 2015 대한응급의학회 학술대회초록집 Vol.2015 No.2

Due to the quality improvement of EMS, some cardiac arrest patients get ROSC in prehospital area. However, patients who are comatose after ROSC are recommended to receive TTM. We aimed to investigate the effect of TTM in prehospital ROSC patients using multicenter registry. Multicenter retrospective registry-based study was used from the period of 2007 to 2012. This registry contains only patients who got TTM after cardiac arrest. We included patients who got ROSC before ED arrival and whose arrest was only cardiac origin. Thirty-two patients were enrolled in this study. Twenty-eight patients (87.5%) were male, age was 48.0±14.5 years and only 4 patients (12.5%) were over 65 years. Twenty (62.5%) were healthy and only 3 had coronary heart disease, previously. VF/VT was in 27 (84.4%), witness arrest was in 30 (93.8%), and bystander BLS was performed in 20 (62.5%). After ROSC, 26 (81.3%) recovered self-respiration, lactate level was 7.3±3.7 mmol/L, 10 (31.3%) showed STEMI, and 1 showed myoclonus. The target temperature was 33~34℃, and during TTM no serious complication was observed. Thirty-one (96.9%) showed good neurologic outcome and 1 (3.1%) showed bad outcome. During TTM, patients who got prehospital ROSC showed no serious adverse effects. They were almost shockable rhythm, witness arrest and showed good neurologic outcome.

중증 익수환자의 초기 사망원인에 대한 분석

위정희,이미진,최승필,박규남 대한응급의학회 2007 대한응급의학회지 Vol.18 No.3

Purpose: Historically, acute respiratory failure is the most common cause of death in drowning patients. However, there are an increasing number of severe drowning cases where patients die of circulatory failure or cardiovascular collapse. The aim of this study was to analyze the causes of death in severe drowning patients and evaluate the data in terms of survival curves in order to propose a treatment plan for severe drowning patients in the future. Methods: The subjects were 58 patients that visited St. Mary’s Hospital from January 2000 to September 2006 who had drowned and required CPR and mechanical ventilation. Univariate analysis was performed to evaluate factors known to be predictive of severity. Survival analysis was done to determine the degrees of correlation with acute respiratory distress syndrome (ARDS) and refractory shock. Results: Thirty-nine out of 58 severely drowning patients expired in all, with most deaths occurring in the early stages - 45% expired on the first day, 55% on the second day, and 60% on the third day. Cause of death analysis yielded the following results: the correlation coefficient for the existence of ARDS was 2.96 (p=0.086), which did not achieve statistical significance, but, the coefficient for refractory shock was 9.23 (p=0.002) and was statistically significant. Conclusion: Most severe drowning patients expired in the first three days after drowning, and refractory shock was a more significant contributor to patients death than ARDS. This result underscores the need for treatment protocols that includes active management of hemodynamic instability combined with mechanical ventilatory management in the initial stages of treatment.

Abdominal pain in the elderly

위정희 대한응급의학회 2017 대한응급의학회 학술대회초록집 Vol.2017 No.1

Acute Abdominal Pain in the Elderly

위정희 대한응급의학회 2013 대한응급의학회 학술대회초록집 Vol.2013 No.2

마라톤 경기 중 발생하는 열사병에서의 임상 경과 고찰

마범석,위정희,윤준성,김수현,박정호,박규남,최승필 대한응급의학회 2012 대한응급의학회지 Vol.23 No.3

Purpose: Due to an increased interest in health, there have been many types of marathon races for athletes and the general population. Marathon is an extremely difficult sport,therefore, many running injuries can occur. In this study, we aimed at characterization of injuries and clinical courses resulting from marathon induced heat stroke. Based on our findings, we provide suggestions for proper management of patients with marathon induced heat stroke. Methods: We performed a retrospective study of 24patients who visited the emergency department (ED) at Yeouido St. Mary's hospital between January 2000 and August 2011 with symptoms of heat stroke resulting from participation in a marathon race. We reviewed the medical records, which showed clinical presentation and laboratory findings. Results: Of the 24 patients, 20(83.3%) were men. Their average age was 38.1±8.4 years old and their average initial rectal temperature was 39.9±1.3 C. Seventeen (70.8%) patients came to the ED complaining of syncope and seven(29.2%) came because of mental change. In follow-up laboratory tests, ten patients showed an increased level of serum Creatine phosphokinase (CPK) to over 1,000IU/L, six showed serum Aspartate aminotransferase (AST)/Alanine aminotransferase (ALT) to over 300 IU/L,four showed serum creatinine to over 2.0 mg/dL, and two showed an increase in serum troponin-I and MB fraction of creatine kinase. Results of initial laboratory tests showed normal AST/ALT levels, however, they started to rise between 12 to 24 hours, and reached the highest record after 2~3 days of hospitalization. Conclusion: Marathon induced heat stroke can cause various complications, such as rhabdomyolysis, acute hepatic injury, acute renal failure, and metabolic acidosis. Therefore, we recommend follow-up and observation for patients with marathon induced heat stroke.

구연18-5 : 노인 익수 환자의 임상적 특징

이두효,위정희,서민구,김세훈 대한응급의학회 2016 대한응급의학회 학술대회초록집 Vol.2016 No.2

Assessment of serum biomarkers and coagulation/fibrinolysis markers for prediction of neurological outcomes of out of cardiac arrest patients treated with therapeutic hypothermia

박정호,위정희,최승필,오재훈,Shin Cheol 대한응급의학회 2019 Clinical and Experimental Emergency Medicine Vol.6 No.1

Objective Despite increased survival in patients with cardiac arrest, it remains difficult to determine patient prognosis at the early stage. This study evaluated the prognosis of cardiac arrest patients using brain injury, inflammation, cardiovascular ischemic events, and coagulation/fibrinolysis markers collected 24, 48, and 72 hours after return of spontaneous circulation (ROSC). Methods From January 2011 to December 2016, we retrospectively observed patients who underwent therapeutic hypothermia. Blood samples were collected immediately and 24, 48, and 72 hours after ROSC. Neuron-specific enolase (NSE), S100-B protein, procalcitonin, troponin I, creatine kinase-MB, pro-brain natriuretic protein, D-dimer, fibrin degradation product, antithrombin-III, fibrinogen, and lactate levels were measured. Prognosis was evaluated using Glasgow-Pittsburgh cerebral performance categories and the predictive accuracy of each marker was evaluated. The secondary outcome was whether the presence of multiple markers improved prediction accuracy. Results A total of 102 patients were included in the study: 39 with good neurologic outcomes and 63 with poor neurologic outcomes. The mean NSE level of good outcomes measured 72 hours after ROSC was 18.50 ng/mL. The area under the curve calculated on receiver operating characteristic analysis was 0.92, which showed the best predictive power among all markers included in the study analysis. The relative integrated discrimination improvement and category-free net reclassification improvement models showed no improvement in prognostic value when combined with all other markers and NSE (72 hours). Conclusion Although biomarker combinations did not improve prognostic accuracy, NSE (72 hours) showed the best predictive power for neurological prognosis in patients who received therapeutic hypothermia.

Therapeutic Hypothermia Following Emergent Coronary Artery Bypass Grafting After Failed Percutaneous Coronary Intervention in a Comatose Post-Cardiac Arrest Patient

최승필,위정희,박정호,박규남,홍성진,이선희 대한의학회 2013 Journal of Korean medical science Vol.28 No.8

We report the case of 60-yr-old female in which therapeutic hypothermia (TH) was successfully induced maintaining the target temperature of 34°C for 12 hr despite a risk of hypothermia-induced coagulation abnormalities following an emergent coronary artery bypass grafting (CABG) due to failed percutaneous coronary intervention, who suffered a cardiac arrest. Emergent CABG may be a relative contraindication for TH in post-cardiac arrest patients because hypothermia may increase the risk of infection and bleeding. However, the possibility of an improved neurologic outcome outweighs the risk of bleeding, although major surgery may be a relative contraindication for TH.

응급의료센터에 내원한 당뇨 기왕력이 없는 환자의 무작위 혈장 당 농도와 당화혈 색소와의 상관관계

김태홍,위정희,김동희,오지선,김수현,박규남 대한응급의학회 2011 大韓應急醫學會誌 Vol.22 No.1

Purpose: Diabetes is underdiagnosed. Higher-risk populations,such as emergency department (ED) patients, may provide an opportunity for identification of undiagnosed diabetes. Prior studies have indicated that hemoglobin A1c (HbA1c) is effective in the screening detection of diabetes. The objective of this study was to evaluate the correlation between random plasma glucose and HbA1c in Korean ED patients with unknown diabetes status and to determine the value of ED glucose level as a screening tool for diabetes. Methods: This was a prospective nonconsecutive case series of adults aged ≥18-years-of-age presenting to the ED with acute illness that involved acquisition of a a plasma glucose sample for clinical management. From June 1-June 30, 2009, consenting patients with no prior history of diabetes underwent additional testing for HbA1c level. ED glucose results were stratified based on outpatient American Diabetes Association Fasting Plasma Glucose classifications. Two HbA1c cut-off points (6.1% and 6.5%)were selected as the optimum cut-offs for identifying diabetes based on International Expert Committee. Results: There were 423 patients enrolled. The ED glucose levels were correlated with the HbA1c levels (r=0.488,p<0.001). There were few patients (n=10) with a glucose level ≥200 mg/dL, but most (90%) had an elevated HbA1c level. Conclusion: Based on the frequencies of elevated HbA1c levels among patients with elevated ED glucose values, a clinically relevant portion of hyperglycemic patients may have undiagnosed diabetes. ED patients with hyperglycemia may warrant referral for confirmatory diabetes testing.