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.

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.

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.

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.

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.

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.

병원 전 심정지가 없는 성인 익수 환자에서 폐렴 발생의 예측 인자 분석

송주현,위정희,박정호,박규남,최승필 대한응급의학회 2015 大韓應急醫學會誌 Vol.26 No.2

Purpose: Pneumonia is a serious and relatively common complication among submersion victims without out-of-hospital cardiac arrest (OHCA). The purpose of this study was to investigate the risk factors of pneumonia among adult submersion victims without OHCA. Methods: All adult submersion victims without OHCA who visited our hospital between 2004 and 2013 were included. This study was conducted retrospectively, with collection of data by review of medical records. Among total submersion victims (310 patients), 191 patients did not suffer OHCA. We investigated the characteristics of the patients and classified them according to two groups based on the presence of pneumonia. We then compared clinical variables between the two groups. Results: A total of 191 adult submersion patients without OHCA; 157 patients did not have pneumonia during their hospital stay; 34 patients had pneumonia. In respective analysis, alert mentality, pH and core temperature showed correlation with pneumonia. However, in logistic regression analysis with these 3 variables, only pH was a risk factor of pneumonia. All patients with pneumonia except one were discharged with full recovery. Conclusion: The risk of pneumonia among adult submersion victims without OHCA is higher when the lower pH is checked. Further studies are needed in order to evaluate the other risk factors of pneumonia for early prediction and proper management.

외상 환자를 위한 변형된 중증 외상 팀 활성화 기준의 적절성 평가

황지현,최승필,위정희,박정호,차경만 대한응급의학회 2015 大韓應急醫學會誌 Vol.26 No.1

Purpose: Rapid multidisciplinary trauma care by trauma team is essential for severely injured patients. Different protocols for trauma team activation are used in each hospital. Correct trauma triage is needed to ensure appropriate use of medical resources. The aim of this study was to evaluate the performance of our modified protocol for trauma team activation. Methods: This is an observational, retrospective cohort study. Injured patients with trauma team activation (TTA) or who had been admitted to a surgical intensive care unit were investigated from 1st March 2010 to 31st May 2012. The TTA protocol was analyzed with respect to sensitivity, positive predictive value (PPV), and overtriage (1-PPV). Undertriage (1-sensitivity) was defined as no TTA despite severe injury (Injury Severity Score (ISS) >15). Results: A total of 229 patients were included. There were 201 patients with TTA and 28 patients without TTA. Of the 201 patients with TTA, 104 were identified as severely injured (ISS>15), yielding sensitivity of 79%, PPV of 51%, and overtriage of 49%. Undertriage was 21% (n=28) when considering all severely injured patients (n=132). Among 12 criteria of our TTA protocol, ‘injury in two or more body regions’ accounted for 85.6% of the overtriage. Of the patients with undertriage, 75% represented isolated head injury and 28.5% from interhospital transfer. Conclusion: The rate of overtriage of TTA protocol in our hospital is appropriate, but the rate of undertriage is relatively high. We believe, to decrease the overtriage of all and undertriage in patients with injury in an isolated specific body region, more research for evaluation of effects of protocol excluding the criteria of ‘injury in two or more body regions’ is needed.

응급의학과 의사들의 급성 막창자꼬리염 진단 시 다중검출 전산화 단층 촬영을 이용한 관상 재구성 영상의 유용성

박정호,윤준성,위정희,김지훈,김영민,최승필,박규남,김한준 대한응급의학회 2008 大韓應急醫學會誌 Vol.19 No.6

Purpose: We compared diagnostic accuracy using transverse scans and combined transverse and coronal reformation images in the MDCT diagnosis of acute appendicitis. Methods: MDCT was performed in 100 patients with acute non-traumatic abdominal pain who visited the emergency department. One half was diagnosed acute appendicitis by radiologic and histologic findings and the other half was not. Transverse scan and combined transverse and coronal reformation images were interpreted by six emergency physicians. Emergency physicians included two board physicians, two senior residents, and two junior residents. For comparison of diagnostic value, the chi-square test and cross tabs test were done. Results: For all emergency physicians except one senior resident, the added coronal reformation images tended to increase the diagnostic accuracy. For board physicians, it increased the diagnostic accuracy from 81.5% to 91% (p=0.003). Senior residents increased from 82.5% to 91.5% (p=0.005), junior residents increased from 75.5% to 87% (p=0.002). The diagnostic accuracy of board physicians and senior residents were higher than junior residents for both image types. Conclusion: Coronal reformation images improve the accuracy of emergency physicians in the MDCT diagnosis of acute appendicitis.

요로결석 의심 환자들에게서 조영증강 다중 검출기 전산화 단층 촬영을 통한 요로 결석 진단과 혈뇨의 진단적 유용성

김태훈,최승필,오상훈,위정희,박정호,김수현 대한응급의학회 2011 大韓應急醫學會誌 Vol.22 No.5

Purpose: Our aim was to determine the efficacy of hematuria testing in suspected urinary stone disease using contrast enhanced multidetector computed tomography (MDCT) as the reference standard. Methods: Records of all patients who presented to the emergency department with suspicion of urinary stone that undergone MDCT during a 2-year period were reviewed. The sensitivity, specificity, positive predictive value, and negative predictive value of the positive hematuria on the urinalysis for renal colic were calculated. The rates of incidence of negative hematuria were obtained. In addition, significant alternative CT findings requiring immediate or deferred treatment were classified. Results: A total of 492 enhanced MDCTs were performed. Urinary stone had been identified in 414(84.1%) of the 492patients, and 78 patients had a negative stone, including 33(6.7%) with clinically significant alternative diagnoses in the latter group. Microscopic urinalysis had a sensitivity, specificity,positive predictive value, and negative predictive value of 89.4%, 41.1, 88.9%, and 42.1%, respectively. The combination of microscopic urinalysis and Urine Dipstick test (UDT) yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 96.9%, 28.2%,87.5%, 62.9%, respectively. The incidence of negative hematuria for microscopic urinalysis, UDT, and the combination were 10.6%, 4.4%, 3.1%, respectively. Conclusion: The presence or absence of blood on urinalysis alone cannot be used to reliably determine which patients actually have urinary stone. Therefore, patients presenting with an episode of clinically suspected urinary stone should undergo CT scanning because it enhances diagnostic certainty by identifying alternative significant diagnoses not suspected on clinical grounds alone.