• Childhood Kidney Diseases
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• v.22 no.2
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• pp.52-57
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• 2018

Purpose: Rhabdomyolysis is a metabolic disorder in which the content of damaged muscle cells is released into plasma. Its manifestations include asymptomatic, myalgia, gross hematuria, and complications of acute kidney injury. Because of limited data on rhabdomyolysis in children, we performed this study to determine clinical characteristics of rhabdomyolysis in children. Methods: We retrospectively reviewed the records of patients with rhabdomyolysis who were treated at the Pusan National University Children's hospital from January 2011 to July 2016. The diagnostic criteria were serum myoglobin level of ${\geq}80ng/mL$, exclusive of acute myocardial injury, cardiac arrest, and brain damage. Results: Forty-five patients were enrolled; mean age, $116{\pm}68$ months. Of these, 35 were boys and 10 were girls. Twenty-six patients experienced myalgia and 12 patients showed gross hematuria. Among these, seven patients initially had both myalgia and gross hematuria. The most common causes of rhabdomyolysis were infection, physical exertion, prolonged seizures, metabolic abnormalities, and drug addiction. Acute kidney injury (AKI) was the most common complication, followed by disseminated intravascular coagulation. Thirty-seven patients improved with sufficient fluid supply but two patients underwent hemodialysis due to deterioration of kidney function. Gross hematuria, positive occult blood test, and positive urine protein were more common in patients with AKI than in those without AKI. Conclusions: In children, infection was the most common cause of rhabdomyolysis. Most patients recovered by sufficient fluid therapy. However, in severe cases, especially in patients with underlying kidney disease, hemodialysis may be necessary in the present study.

• Journal of the Korean Society for Railway
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• v.20 no.2
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• pp.210-222
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• 2017

Railway turnout systems play a key role in railway systems that change train directions. The turnout systems are one of the weakest systems in railway systems, and consecutive maintenance is required. A turnout diagnostic system can automatically measure the turnout status and its deterioration. To diagnose the turnout systems, we follow conventional maintenance procedures and need to identify their physical characteristics to coincide the procedures and the characteristics. According to the physical characteristics, we should choose and install adequate sensors on the turnout systems to measure their physical characteristics. We studied the phenomenon of the turnout system responses for point moving and train running on the turnout systems. We installed sensors on the turnout system in a revenue line to measure the identified physical quantities and to reveal the robustness of the sensors under the turnout system environment.

• Journal of Korean Neurosurgical Society
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• v.49 no.3
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• pp.157-162
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• 2011

Objective : Vasospasm of cerebral vessels remains a major source of morbidity and mortality after an aneurysmal subarachnoid hemorrhage (SAH). The purpose of this study was to evaluate the safety and efficacy of transluminal balloon angioplasty (TBA) for SAH-induced vasospasm. Methods : Eleven patients with an angiographically confirmed significant vasospasm (>50% vessel narrowing and clinical deterioration) were studied. A total of 54 vessel segments with significant vasospasm were treated by TBA. Digital subtraction angiography was used to confirm the presence of vasospasm, and TBA was performed to dilate vasospastic arteries. Medical and angiographic reports were reviewed to determine technical efficacy and for procedural complications. Results : TBA using Hyper-Glide or Hyper-Form balloons (MicroTherapeutics, Irvine, CA) was successfully accomplished in 88.9% vasospastic segments (48 of 54), namely, in the distal internal carotid artery (100%, n=7), the middle cerebral artery (100%), including the M1 (n=10), M2 (n=10), and M3 segments (n=4), in the vertebral artery (100%, n=2), basilar artery (100%, n=1), and in the anterior cerebral artery (ACA), including the A1 (66%), A2 (66%), and A3 segments (100%). Vessel diameters significantly increased after TBA. There were no cases of vessel rupture or thromboembolic complications. GCS at one day after TBA showed an improvement in all patients except one. Conclusion : This study suggests that TBA using Hyper-Glide or Hyper-Form balloons is a safe and effective treatment for subarachnoid hemorrhage-induced cerebral vasospasm.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.1
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• pp.96-101
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• 2014

Wind power is the fastest growing renewable energy source in the world and it is expected to remain so for some times. Recently, there is a constant need for the reduction of Operational and Maintenance(O&M) costs of Wind Energy Conversion Systems(WECS). The most efficient way of reducing O&M cost would be to utilize CMS(Condition Monitoring System) of WECS. CMS allows for early detection of the deterioration of the wind generator's health, facilitating a proactive action, minimizing downtime, and finally maximizing productivity. There are two types of faults such as mass unbalance and aerodynamic asymmetry which are related to wind turbine's rotor faults. Generally, these faults tend to generate various vibrations. Therefore, in this work a simple fault detection algorithm based on spectrums of vibration signals and simple max-min decision logic is proposed. Furthermore, in order to verify its feasibility, several simulation studies are carried out by using GH-bladed software.

• Journal of The Korean Dental Society of Anesthesiology
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• v.11 no.2
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• pp.146-152
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• 2011

Background: Elderly patients with progressive dementia including Alzheimer's disease (AD) are more and more often scheduled to undergo general anesthesia for various pathologies including dental problem. But, there is high risk of deterioration of underlying mental diseases and other co-morbidities. So it is important to implement preventive strategies and take adequate measures to minimize negative perioperative events in these patients. Methods: We reviewed the 17 cases of 11 patients with AD who underwent ambulatory general anesthesia for dental treatment at the clinic for the disabled in Seoul National University Dental Hospital. Results: The mean age was 68 (57-81) years. All of them were diagnosed with AD and some had hypertsnsion, bronchiectasis, urinary incontinence. For anesthesia induction, 3 cases (1 patient) was needed physical restraint, but others showed good or moderate cooperation. Drugs used for anesthesia induction was thiopental (11 cases), propofol (3 cases) and sevoflurane (3 cases). All patients received nasotracheal intubation without difficulties. Mean total anesthetic time was 3 hour 44 min ${\pm}$ 60 min and staying time at PACU was 83 ${\pm}$ 34 min. All the patients except one who showed hypertension discharged without any complication. There was no death or long term hospitalization because of severe complications. Conclusions: If general anesthesia is needed, pertinent diagnostic tests and workup about other medical problems, and appropriate anesthetic planning are essential for safety.

• Journal of Veterinary Clinics
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• v.32 no.4
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• pp.334-337
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• 2015

A 9-month-old castrated male French Bulldog (13 kg of body weight) was presented with the primary complaint of loud heart murmur and exercise intolerance. Diagnostic imaging studies found severe pulmonic stenosis (peak velocity > 5 m/s) with right ventricular hypertrophy. Because of higher pressure gradient between right ventricle and right ventricular outflow tract (> 100 mmHg), the dog was underwent balloon valvuloplasty through femoral vein. After procedure, the peak pulmonic velocity was reduced to 2.1 m/s (PG = 18 mmHg). Further follow-up study found no further deterioration, for 6 months to date. This is the first case report of pulmonic stenosis treated by transvenous balloon valvuloplasty through femoral vein in Korea.

• Journal of Genetic Medicine
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• v.19 no.1
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• pp.22-26
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• 2022

Cerebrotendinous xanthomatosis (CTX) is a rare genetic disease caused by a deficiency of enzymes for the synthesis of bile acid, resulting in the accumulation of cholestanol with reduced chenodeoxycholic acid (CDCA) production and causing various symptoms such as chronic diarrhea in infancy, juvenile cataracts in childhood, tendon xanthomas in adolescence and young adulthood, and progressive neurologic dysfunction in adulthood. Because oral CDCA replacement therapy can effectively prevent disease progression, early diagnosis and treatment are critical in CTX. This study reports the case of CTX in a 10-year-old male who presented with Achilles tendon xanthoma and mild intellectual disability. Biochemical testing showed normal cholesterol and sitosterol levels but elevated cholestanol levels. Genetic testing showed compound heterozygous variants of CYP27A1, c.379C>T (p.Arg127Trp), and c.1214G>A (p.Arg405Gln), which confirmed the diagnosis of CTX. The patient had neither cataracts nor other focal neurologic deficits and showed no abnormalities on brain imaging. The patient received oral CDCA replacement therapy without any adverse effects; thereafter, the cholestanol level decreased and no disease progression was noted. The diagnostic possibility of CTX should be considered in patients with tendon xanthoma and normolipidemic conditions to prevent neurological deterioration.

• The Korean Journal of Medicine
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• v.99 no.2
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• pp.116-121
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• 2024

Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis predominantly involving medium- or small-sized arteries, typically of the kidneys and other internal organs. Given the rarity of PAN and the variable clinical presentation, diagnosis is challenging and, to date, no definitive diagnostic marker has been identified. A patient diagnosed with immunoglobulin A nephropathy was observed to exhibit deterioration in renal function. To determine whether new structural abnormalities had developed, computed tomography scans of the kidneys, ureters, and bladder were obtained. Both kidneys exhibited multiple cortical defects, and a renal angiogram was performed to determine the cause. Angiography revealed partial obliteration of the left distal renal artery branches and multifocal extensive infarctions in both kidneys, and the patient was diagnosed with renal-limited PAN. Following steroid monotherapy, an improvement in renal function was observed. We believe that this case report may be helpful to physicians who assess and treat patients with suspected renal-limited PAN.

• Journal of the Korean Physical Society
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• v.80
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• pp.640-646
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• 2022

Hybrid PET/MRI is a useful imaging system that can improve diagnostic accuracy by providing both functional and anatomical information. However, the combination of PET and MRI can lead to mutual interference, which can degrade the performances of both imaging systems. One of the methods that is capable of preserving the performance of both modalities is to apply RF shielding to PET detectors and electronics. The purpose of this study was to propose a new RF shielding method using Au-plated conductive fabric (PCF) tape that could not only minimize RF interference and eddy current, but that could also be applied to complex PET gantry and detector module structures more easily than thin Cu foils, which have been widely used as a shielding material for hybrid PET/MRI systems. To evaluate the performance of the proposed new RF shielding method, the effects of the two RF shield materials (Cu and Au) on the B1 + field generated by the RF head coil were estimated using a computer simulation method. The effects of the Au PCF tape and Cu foil on the homogeneity and SNR of the MR image were also experimentally evaluated using a commercial 3-T MRI. The uniformity of the B1 + field map was slightly decreased by the use of Cu and Au RF shields. The deterioration in the MR image quality caused by the Au PCF tape was less than that caused by Cu foil. The simulation and experimental results indicate that Au PCF tape can serve as an alternative shielding material that reduces RF interference and eddy current for hybrid PET/MRI systems.

• Tuberculosis and Respiratory Diseases
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• v.47 no.3
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• pp.321-330
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• 1999

Background : Early diagnosis and proper antibiotic treatment are very important in the management of ventilator-associated pneumonia (VAP) because of its high mortality. Bronchoscopy with a protected specimen brush (PSB) has been considered the standard method to isolate the causative organisms of VAP. However, this method burdens consumer economically to purchase a PSB. Another useful method for the diagnosis of VAP is quantitative cultures of aspirated specimens through bronchoscopic bronchoalveolar lavage (BAL), for which the infusion of more than 120 m1 of saline has been recommended for adequate sampling of a pulmonary segment. However, occasionally it leads to deterioration of the patient's condition. We studied the diagnostic efficacy of minibronchoalveolar lavage (miniBAL), which retrieves only 25 ml of BAL fluid, in the isolation of causative organisms of VAP. Methods: We included 38 consecutive patients (41 cases) suspected of having VAP on the basis of clinical evidence, who had received antibiotics before the bronchoscopy. The two diagnostic techniques of PSB and miniBAL, which were performed one after another at the same pulmonary segment, 'were compared prospectively. The cut-off values for quantitative cultures to define causative bacteria of VAP were more than $10^3$ colony-forming units (cfu)/ml for PSB and more than $10^4$ cfu/ml for BAL. Results: The amount of instilled normal saline required to retrieve 25 ml of BAL fluid was $93{\pm}32 ml$ (mean${\pm}$SD). The detection rate of causative agents was 46.3% (19/41) with PSB and 43.9% (18/41) with miniBAL. The concordance rate of PSB and miniBAL in the bacterial culture was 85.4% (35/41). Although arterial blood oxygen saturation dropped significantly (p<0.05) during ($92{\pm}10%$) and 10 min after ($95{\pm}3%$) miniBAL compared with the baseline ($97{\pm}3%$), all except 3 cases were within normal ranges. The significantly elevated heart rate during ($l25{\pm}24$/min, p<0.05) miniBAL compared with the baseline ($1l1{\pm}22$/min) recovered again in 10 min after ($111{\pm}26$/min) miniBAL. Transient hypotension was developed during the procedure in two cases. The procedure was stopped in one case due to atrial flutter. Conclusion: MiniBAL is a safe and effective technique to detect the causative organisms of VAP.