• Journal of Biomedical Engineering Research
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• v.35 no.4
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• pp.95-98
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• 2014

The baroreflex is one kind of homeostatic mechanisms to regulate acute blood pressure (BP) changes by controlling heartbeat interval (HBI). To quantify the effect of baroreflex, we suggested a new approach of analyzing Granger causality between systolic BP (SBP) and HBI. The index defined as baroreflex effectiveness (BRE) was generated by the hypothesis that more effectual baroreflex would be related to more effective Granger causal influence of SBP on HBI. Six obstructive sleep apnea (OSA) patients (apnea-hypopnea index, AHI ${\geq}5$ events/hr) and six normal subjects participated in the study. Their SBP and HBI during nocturnal sleep were obtained from a non-invasive continuous BP measurement device. While the BRE ($mean{\pm}SD$) of normal subjects was $47.0{\pm}4.0%$, OSA patients exhibited the BRE of $34.0{\pm}3.8%$. The impaired baroreflex function of OSA patients can be explained by the physiological mechanism associated with recurrent hypoxic episodes during sleep. Thus, the significantly lower BRE in OSA patients verified the availability of Granger causality analysis to evaluate baroreflex during sleep. Furthermore, the range of BRE obtained from normal subjects was not overlapped with that obtained from OSA patients. It suggests the potential of BRE as a new helpful tool for diagnosing OSA.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.449-454
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• 1996

Functional upper airway obstruction due to vocal cord dysfunction is being increasingly recognized and has been variously described as "Munchausen's stridor", "Emotional laryngeal wheezing", "Nervous asthma". It's features are symptoms of acute reversible recurrent dyspnea associated with an inspiratory stridor, normal anatomy of the upper airway, demonstration of variable severe exthrathoracic upper airways obstruction with pathologic adduction of the vocal cord at bronchoscopy. The patients with this condition are frequently misdiagnosed as asthma and the diagnosis is often delayed. So they can present a serious medical problem and are exposed to the complication of treatment and investigation. We report a case of functional upper airway obstruction due to vocal cord dysfunction who showed paradoxical vocal cord motion at bronchoscopy and typical features of variable exthrathoracic obstruction on Flow-volume loop during a symptomatic period.

• Korean Journal of Bronchoesophagology
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• v.10 no.1 s.19
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• pp.41-45
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• 2004

Tracheostomy and endotracheal intubation are often performed in patients with acute and chronic respiratory failure. Recently, the incidence of iatrogenic tracheal stenosis has increased. Tracheal resection and end-to-end anastomosis would be one of the most physiologic treatment options for severe tracheal stenosis. Also, this treatment can be applied to the management of trachea invaded by thyroid cancer and tracheal neoplasm. The authors aimed to analyze the outcomes of end-to-end anastomosis of trachea following segmental resection in tracheal stenosis and tracheal invasion of cancer that we have recently experienced. Materials and methods Authors retrospectively studied 19 cases treated by tracheal resection with end-to-end anastomosis between Feburuary 1996 and January 2003. 12 patients had tracheal stenosis, 6 patients had tracheal invasion by thryroid cancer and 1 patient had tracheal cancer. We analyzed the direct causes of tracheal stenosis, preoperative vocal cord function, operation technique, early and delayed postoperative complications, and the outcome of end-to-end anastomois. Result Decannulation without significant aspiration was achieved in 16 cases($89.5\%$). A 27 year-old man could not be decannulated because of restenosis. A 62 year-old woman could not be decannulated because of bilateral vocal cord palsy. Conclusion End-to-end anastomosis is a safe and effective surgical method for tracheal stenosis. Case selection for end-to-end anastomosis and preservation of recurrent laryngeal nerve during operation is very important.

• Journal of Veterinary Science
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• v.22 no.4
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• pp.48.1-48.15
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• 2021

Background: Porcine epidemic diarrhea virus (PEDV) is a swine enteropathogenic coronavirus that has devastated the swine industry in South Korea over the last 30 years. The lack of an effective method to control the endemics has led to a surge in PEDV recurrences in affected farms throughout the country. Objectives: In the first step toward establishing systematic monitoring of and active control measures over the swine populations, we constructed an assessment model that evaluates the status of (1) biosecurity, (2) herd immunity, and (3) virus circulation in each of the PEDV-infected farms. Methods: A total of 13 farrow-to-finish pig farms with a history of acute PEDV infection on Jeju Island were chosen for this study. The potential risk of the recurrence in these farms was estimated through on-site data collection and laboratory examination. Results: Overall, the data indicated that a considerable number of the PEDV-infected farms had lax biosecurity, achieved incomplete protective immunity in the sows despite multi-dose vaccination, and served as incubators of the circulating virus; thus, they face an increased risk of recurrent outbreaks. Intriguingly, our results suggest that after an outbreak, a farm requires proactive tasks, including reinforcing biosecurity, conducting serological and virus monitoring to check the sows' immunity and to identify the animals exposed to PEDV, and improving the vaccination scheme and disinfection practices if needed. Conclusions: The present study highlights the significance of coordinated PEDV management in infected farms to reduce the risk of recurrence and further contribute towards the national eradication of PEDV.

• Korean Journal of Transplantation
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• v.31 no.4
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• pp.157-169
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• 2017

Regulatory T cells (Treg) naturally rein in immune attacks, and they can inhibit rejection of transplanted organs and even reverse the progression of autoimmune diseases in mice. The initial safety trials of Treg against graft-versus-host disease (GVHD) provided evidence that the adoptive transfer of Treg is safe and capable of limiting disease progression. Supported by such evidence, numerous clinical trials have been actively investigating the efficacy of Treg targeting autoimmune diseases, type I diabetes, and organ transplant rejection, including kidney and liver. The limited quantity of Treg cells harvested from peripheral blood and subsequent in vitro culture have posed a great challenge to large-scale clinical application of Treg; nevertheless, the concept of CAR (chimeric antigen receptor)-Treg has emerged as a potential resolution to the problem. Recently, two CAR-T therapies, tisagenlecleucel and axicabtagene ciloleucel, were approved by the US FDA for the treatment of refractory or recurrent acute lymhoblastic leukemia. This approval could serve as a guideline for the production protocols for other genetically engineered T cells for clinical use as well. The phase I and II clinical trials of these agents has demonstrated that genetically engineered and antigen-targeting T cells are safe and efficacious in humans. In conclusion, both the promising results of Treg cell therapy from the clinical studies and the recent FDA approval of CAR-T therapies are paving the way for CAR-Treg therapy in clinical use.

• Journal of the Korean Society of Radiology
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• v.85 no.1
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• pp.124-137
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• 2024

Malrotation and midgut volvulus are surgical emergencies that commonly occur within the first month of life. The classic symptom is acute bilious vomiting, while nonspecific symptoms such as recurrent abdominal pain may be present in older children. Malrotation can be associated with duodenal obstruction caused by an abnormal peritoneal fibrous band or congenital anomalies, such as an annular pancreas or a preduodenal portal vein. Volvulus can lead to bowel ischemia and a life-threatening condition, thus prompt and accurate diagnosis is crucial. Diagnosis can be made through upper gastrointestinal series, ultrasonography, and CT, with ultrasonography being preferred as a screening tool due to its rapid and accurate diagnosis, without radiation exposure, in children. This pictorial essay discusses the key imaging findings and diagnostic approaches for malrotation and midgut volvulus, as well as diagnostic pitfalls based on actual cases.

• Journal of Chest Surgery
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• v.30 no.2
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• pp.172-178
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• 1997

We present a etrospective analysis of arterial embolectomies performed at the Inje University Seoul Paik Hospital. During the period of March 1987 Feburary 1996 twenty-six patients underwent embolectomies, eighteen patients were male and eight patients were female, mean age of patients was 56.8 years. Rest pain was the chief complaint in 24 patients, the remaining two patients complained of long term history of claudication after recovery of acute symtoms. But only 10 patients had sensBrylmotor symtoms. Heart was the most common source of embolization and frequent predisposing factor of embolism was ischemic heart disease in 8 cases and valvular heart disease in 11 cases. The sites of embolization were upper extremities artery in 6 cases, saddle embolism in 2 cases, lower extremities artery in 18 cases and the most common site of embolism was femoral artery in 1 1 cases. Preoperative angiography was taken in the diagnosis and planning of the embolectomy in 1) patients while in the other patient p eoperative angiography was not taken. Only two cases were operated within the golden period of 6 hours and other cases were operated in more than 6 hours after embolization. In all patients, the Fogarty embolectomy catheter was used without bypass surgery via bachial ateriotomy in the embolism of upper extremities artery, bilateral groin approaches in the saddle embolism and transfemoral approach in the embolism of lower extremities artery. However 3 patients were re-operated via transpopliteal approach in the distal poplitiotibial embolism. Eighteen patients received perioperative anticoagulation therapy by heparin or fraxiparine and wafarin was used in 17 patients at the time of discharge and the indication of anticogulation was patients of valvular heat disease andfor atrial fibrillation, peripheral artery atherosclerosis and recurrent embolism. Postoperative results of the embolectomy were as follows: fouteen pateints had excellent results, five cases had symtom improvement after re-operation, B. K. amputation in 1 case who had severe atherosclerosis of lower extremities, recurrent embolism in 1 case and death in 2 cases the cause of death were acute renal failure and cerebral artery embolism, respectively. The complications of the embolectomy were reperfusion syndrome, pseudoaneurysm and intimal dissection in one case each. Conclusively the problems of embolism is delayed diagnosis and increasing number of old aged patient who had suffered from ischemic heart diease. Preoperative angiography was not always needed for embol ectomy. Selective anticoagulation therapy can decrease incidence of re-embolism. In the distal poplitiotibial embolism, embolectomy of tibial artery was difficult.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.19 no.1
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• pp.20-25
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• 2019

Very-long-chain acyl-CoA dehydrogenase (VLCAD) deficiency (OMIM#201475) is an autosomal recessively inherited metabolic disorder of mitochondrial long-chain fatty acid oxidation. The clinical features of VLCAD deficiency is classified by three clinical forms according to the severity. Here, we report a case of later-onset episodic myopathic form of VLCAD deficiency whose diagnosis was confirmed by plasma acylcarnitine analysis and" multigene panel multigene panel sequencing. A 34-year old female patient visited genetics clinic for genetic evaluation for history of recurrent myopathy with intermittent rhabdomyolysis. She suffered first episode of rhabdomyolysis with acute renal failure requiring hemodialysis at twelve years old. After then, she suffered several times of recurrent rhabdomyolysis provoked by prolonged exercise or fasting. Physical and neurologic exam was normal. Serum AST/ALT and creatinine kinase (CK) levels were mildly elevated. However, according to her previous medical records, her AST/ALT, CK were highly elevated when she had rhabdomyolysis. In suspicion of fatty acid oxidation disorder, multigene panel sequencing and plasma acylcarnitine analysis were performed in non-fasting, asymptomatic condition for the differential diagnosis. Plasma acylcarnitine analysis revealed elevated levels of C14:1 ($1.453{\mu}mol/L$; reference, 0.044-0.285), and C14:2 ($0.323{\mu}mol/L$; 0.032-0.301) and upper normal level of C14 ($0.841{\mu}mol/L$; 0.065 -0.920). Two heterozygous mutation in ACADVL were detected by multigene panel sequencing and confirmed by Sanger sequencing: c.[1202G>A(;) 1349G>A] (p.[(Ser 401Asn)(;)(Arg450His)]). Diagnosis of VLCAD deficiency was confirmed and frequent meal with low-fat diet was educated for preventing acute metabolic derangement. Fatty acid oxidation disorders have diagnostic challenges due to their intermittent clinical and laboratorial presentations, especially in milder late-onset forms. We suggest that multigene panel sequencing could be a useful diagnostic tool for the genetically and clinically heterogeneous fatty acid oxidation disorders.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.13 no.1
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• pp.58-65
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• 2010

Purpose: Since there are few studies involving acute pancreatitis in children, we reviewed our experience with this medical condition to describe the clinical features. Methods: A retrospective analysis was conducted by reviewing the medical records of 41 patients with AP who were admitted to the Department of Pediatrics of Pusan National University Hospital between January 1996 and June 2007. Results: Twenty males and 21 females (mean age, 8.7${\pm}$4.5 years) were included. In 22 patients (53.7%), no definitive causes were found. The most common etiologies were choledochal cysts (22.0%). Necrotizing pancreatitis was diagnosed in 5 patients (12.2%), and recurrent acute pancreatitis in 4 patients (9.8%). CT findings included pancreatic swelling (43.9%), peripancreatic fluid collection (29.3%), ascites (24.4%), and peripancreatic fat necrosis (12.2%). Serum amylase and lipase levels at diagnosis were 535.3${\pm}$553.2 and 766.2${\pm}$723.6 U/L, respectively, and were normalized within 1 week in 22 and 14 patients, respectively. On the basis of the Balthazar scale, 2 patients were diagnosed with severe AP. In 4 patients (9.8%), a surgical procedure was indicated. Major complications included ascites (32.3%), sepsis (16.1%), and pseudocyst and renal impairments (12.9%). Two patients died from multi-organ failure. Conclusion: The etiologies of AP in children are varied. Most children have a single episode and a self-limited course. However, AP of childhood still carries significant morbidity and mortality. Early diagnosis, appropriate treatment according to disease severity, and management of complications are important.

• Tuberculosis and Respiratory Diseases
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• v.61 no.3
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• pp.265-272
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• 2006

Background: Chest wall deformities such as kyphoscoliosis, thoracoplasty, and fibrothorax cause ventilatory insufficiency that can lead to chronic respiratory failure, with recurrent fatal acute respiratory failure(ARF). This study evaluated the frequency and outcome of ARF, the physiologic status, and the long-term prognosis of these patients. Methods: Twenty-nine patients with chest wall disorders, who experienced the first requirement of ventilatory support from ARF were examined. The mortality and recurrence rate of ARF, the pulmonary functions with arterial blood gas analysis, the efficacy of home oxygen therapy, and the long-term survival rate were investigated. Results: 1) The mortality of the first ARF was 24.1%. ARF recurred more than once in 72.7% of the remaining 22 patients, and overall rate of successful weaning was 73.2%. 2) Twenty-two patients who recovered from the first ARF showed a restrictive ventilatory impairment with a mean FVC and TLC of 37.2% and 62.4 % of predicted value, respectively, and a mean $PaCO_{2}$ of 57mmHg. Among the parameters of pulmonaty functions. the FVC(p=0.01) and VC(p=0.02) showed a significant correlation with the $PaCO_{2}$ level. 3) There were no significant differences between the patients treated with conservative medical treatment only and those with additional home oxygen therapy due to significant hypoxemia in the patients with recurrent ARF and the mortality. 4) The 1, 3, 5-year survival rates were 75%, 66%, and 57%, respectively, in the 20 patients who had recovered from the first ARF, excluding the two patients managed by non-invasive nocturnal ventilatory support. Conclusion: These results suggest that active ventilatory support should be provided to patients with ARF and chest wall disorders. However, considering recurrent ARF and weak effect of home oxygen therapy, non-invasive domiciliary ventilation is recommended in those patients with these conditions to achieve a better long-term prognosis.