• Journal of Biomedical Engineering Research
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• v.28 no.4
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• pp.569-576
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• 2007

Ventricular Assist Device(VAD) has switched its goal from a short-tenn use for bridge-to-transplantation to a long-tenn use for destination therapy, With this goal, the importance of long-tenn reliability gets more interests and importances, H-VAD is an portable extracorporeal biventricular assist device, and adopts an electro-pneumatic driving mechanism. The pneumatic pressure to pump out blood is generated with compression of bellows, and is transmitted in a closed pneumatic circuit through a pneumatic line. The existing pneumatic VAD adopts a air compressor which can generate stable pressures but has defects such as a noise and a size problem. Thus, it is not suitable for being used as a portable device, These problems are covered with adopting a closed pneumatic circuit mechanism with a bellows which has a small size and small noise generation, but it has defects that improper pneumatic setting causes a failure of adequate flow generation. In this study, the pneumatic pressure regulation system is developed to cover these defects of a bellows-type pneumatic VAD. The optimal pneumatic pressure conditions according to various afterload conditions for an optimal flow rate were investigated and the afterload estimation algorithm was developed, The final pneumatic regulation system estimates a current afterload and regulate the pneumatic pressure to the optimal point at a given afterload condition. The afterload estimation algorithm showed a sufficient performance that the standard deviation of error is 8.8 mmHg, The pneumatic pressure regulation system showed a sufficient performance that the flow rate was stably governed to various afterload conditions. In a further study, if a additional sensor such as ultrasonic sensor is developed to monitor the direct movement of diaphragm in a blood pump part, the reliability would be greatly increased. Moreover, if the afterload estimation algorithm gets more accuracy, it would be also helpful to monitor the hemodynamic condition of patients.

• Korean Journal of Clinical Pharmacy
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• v.22 no.3
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• pp.220-227
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• 2012

Kidney and liver are the major organs of metabolism and excretion of drugs. Renal and Hepatic impairment may affect the pharmacokinetics/pharmacodynamics and the safety of drugs. Adjusting the dosage based on organ function is the essential role of pharmacists. However, differences have been noted on the recommended dosage among the literatures. We compared and analyzed the recommendations of 4 literature sources which are commonly used for dosage adjustment. From April, 2011 to August, 2011, we selected data on recommendations for dosage adjustment for impaired renal and hepatic function of 100 drugs through a protocol. We analyzed the definition terms of renal and hepatic impairment, recommendations for dosage adjustment, evidenced references in four literature sources: Korean National Formulary (KNF), American Hospital Formulary System Drug Information (AHFS), Micromedex (MM) and Drug Prescribing of Renal Failure (DPRF). We further examined the data homogeneity by comparing how drugs that required no adjustment according to one source were categorized by the other. Sources use different definition terms among themselves except DRPF. Presence or absence of evidenced references about renal/hepatic functional states are KNF (0%/0%), AHFS (78%/62.6%), MM (87.5%/65.6%) and DPRF (93.2%/no recommendation) respectively. Recommendations of specific dosage and dosing interval are KNF (24%/13%), AHFS (39.6%/12.1%), MM (50%/17.7%), and DPRF (55.4%/no recommendation) respectively. Regarding the data homogeneity, the differences were remarkable. Drugs with no adjustment according to AHFS were categorized to be adjusted/ contraindicated by KNF, MM, DPRF and the values were (44%/5.6%), (22%/0%), and (36%/0%) in renal function, (39%/6.5%), (19%/3.2%), and (no recommendation/no recommendation) in hepatic function respectively. Our study shows remarkable definite variation in definitions and recommendations about definition terms, information of dosage and interval, presence or absence of evidenced references. Especially for KNF, quantitative recommendations on dosages and dosing intervals should be made in the near future. To maximize the drug effect and safety and to minimize the heterogeneity of the literature sources, reviewing at least two sources are suggested when recommending the proper dosage adjustment based on organ function.

• Childhood Kidney Diseases
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• v.14 no.2
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• pp.132-142
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• 2010

Hypokalemia usually reflects total body potassium deficiency, but less commonly results from transcellular potassium redistribution with normal body potassium stores. The differential diagnosis of hypokalemia includes pseudohypokalemia, cellular potassium redistribution, inadequate potassium intake, excessive cutaneous or gastrointestinal potassium loss, and renal potassium wasting. To discriminate excessive renal from extrarenal potassium losses as a cause for hypokalemia, urine potassium concentration or TTKG should be measured. Decreased values are indicative of extrarenal losses or inadequate intake. In contrast, excessive renal potassium losses are expected with increased values. Renal potassium wasting with normal or low blood pressure suggests hypokalemia associated with acidosis, vomiting, tubular disorders or increased renal potassium secretion. In hypokalemia associated with hypertension, plasam renin and aldosterone should be measured to differentiated among hyperreninemic hyperaldosteronism, primary hyperaldosteronism, and mineralocorticoid excess other than aldosterone or target organ activation. Hypokalemia may manifest as weakness, seizure, myalgia, rhabdomyolysis, constipation, ileus, arrhythmia, paresthesias, etc. Therapy for hypokalemia consists of treatment of underlying disease and potassium supplementation. The evaluation of hyperkalemia is also a multistep process. The differential diagnosis of hyperkalemia includes pseudohypokalemia, redistribution, and true hyperkalemia. True hyperkalemia associated with decreased glomerular filtration rate is associated with renal failure or increased body potassium contents. When glomerular filtration rate is above 15 mL/min/$1.73m^2$, plasma renin and aldosterone must be measured to differentiate hyporeninemic hypoaldosteronism, primary aldosteronism, disturbance of aldosterone action or target organ dysfunction. Hyperkalemia can cause arrhythmia, paresthesias, fatigue, etc. Therapy for hyperkalemia consists of administration of calcium gluconate, insulin, beta2 agonist, bicarbonate, furosemide, resin and dialysis. Potassium intake must be restricted and associated drugs should be withdrawn.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.3
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• pp.209-216
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• 2013

Soybean polyunsaturated phosphatidylcholine (PC) is thought to exert anti-inflammatory activities and has potent effects in attenuating acute renal failure and liver dysfunction. The aim of this study was to investigate the effects of PC in protecting multiple organ injury (MOI) from lipopolysaccharide (LPS). Six groups of rats (N=8) were used in this study. Three groups acted as controls and received only saline, hydrocortisone (HC, 6 mg/kg, i.v.) or PC (600 mg/kg, i.p.) without LPS (15 mg/kg, i.p.) injections. Other 3 groups, as the test groups, were administered saline, HC or PC in the presence of LPS. Six hours after the LPS injection, blood and organs (lung, liver and kidney) were collected from each group to measure inflammatory cytokines and perform histopathology and myeloperoxidase (MPO) assessment. Serum cytokines (TNF-${\alpha}$, IL-6 and IL-10) and MPO activities were significantly increased, and significant histopathological changes in the organs were observed by LPS challenge. These findings were significantly attenuated by PC or HC. The treatment with PC or HC resulted in a significant attenuation on the increase in serum levels of TNF-${\alpha}$ and IL-6, pro-inflammatory cytokines, while neither PC nor HC significantly attenuated serum levels of IL-10, anti-inflammatory cytokine. In the organs, the enhanced infiltration of neutrophils and expression of ED2 positive macrophage were attenuated by PC or HC. Inductions of MPO activity were also significantly attenuated by PC or HC. From the findings, we suggest that PC may be a functional material for its use as an anti-inflammatory agent.

• Clinical and Experimental Pediatrics
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• v.46 no.1
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• pp.42-50
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• 2003

Purpose : The acute respiratory distress syndrome(ARDS), an acute form of severe alveolar-capillary injury evolving after a direct or indirect lung insult is thought to be a common cause of respiratory failure though not many clinical studies on the subject have been made yet. Methods : Between January 1992 and December 2001, we conducted a retrospective study on 33 children who fulfilled the definition of the ARDS recommended by the American-European Consensus Conference in 1994. Results : A total of 33 patients(20 boys and 13 girls) were selected. Their age ranged from 4 months to 12 years with seven children younger than 1 year. The overall mortality rate was 78.8% and no significant difference was noted based on age or sex. Concerning seasonal variation, incidence of the ARDS increased in spring, especially in May(21.2%). Pneumonia(66.7%) was found to be the most common risk factor of the ARDS followed by sepsis(24.2%) and aspiration(3.0%). In immune compromised children(six cases), including a recipient of bone marrow transplantation, the mortality rate was 100%. Compared with children with multiple organ failure recording a 83.3% mortality rate, those with isolated respiratory failure, showed a lower mortality rate of 33.3%, although stastistically insignificant. Between survivor and non-survivor groups, significant differences were shown in hematocrit, $PaO_2$, $PaCO_2$, PEEP, and $PaO_2/FiO_2$ on the seventh day after the onset of the ARDS. Conclusion : According to our study, respiratory failure proved to have a great effect on mortality rate in the ARDS. More aggressive intervention and further studies on this subject should be done to improve the survival rate.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3843-3846
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• 2013

Objective: The purpose of this study was to assess prognosis after resection of giant tumors (including lobectomy or pneumonectomy) in the mediastinum. Materials and Methods: Patients with resection of a giant tumor in the mediastinum of the thoracic cavity received ICU treatment including dynamic monitoring of vital signs, arterial blood pressure and CVP detection, determination of hemorrhage, pulmonary function and blood gas assay, treatment of relevant complications, examination and treatment with fiber optic bronchoscopy, transfusion and hemostasis as well as postoperative removal of ventilators by invasive and non-invasive sequential mechanical ventilation technologies. Results: Six patients were rehabilitated successfully after ICU treatment with controlled postoperative errhysis and pulmonary infection by examination and treatment with fiber optic bronchoscopy without second application of ventilators and tubes after sequential mechanical ventilation technology. One patient died from multiple organ failure under ICU treatment due to postoperative active hemorrhage after second operative hemostasis. Conclusions: During peri-operative period of resection of giant tumor (including lobectomy or pneumonectomy) in mediastinum ofthe thoracic cavity, the ICU plays an important role in dynamic monitoring of vital signs, treatment of postoperative stress state, postoperative hemostasis and successful removal of ventilators after sequential mechanical ventilation.

• Journal of Chest Surgery
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• v.51 no.2
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• pp.109-113
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• 2018

Background: Low cardiac output syndrome (LCOS) after cardiac surgery usually requires inotropes. In this setting, critical illness-related corticosteroid insufficiency (CIRCI) may develop. We aimed to investigate the clinical features of CIRCI in the presence of LCOS and to assess the efficacy of steroid treatment. Methods: We reviewed 28 patients who underwent a rapid adrenocorticotropic hormone (ACTH) test due to the suspicion of CIRCI between February 2010 and September 2014. CIRCI was diagnosed by a change in serum cortisol of <$9{\mu}g/dL$ after the ACTH test or a random cortisol level of <$10{\mu}g/dL$. Results: Twenty of the 28 patients met the diagnostic criteria. The patients with CIRCI showed higher Sequential Organ Failure Assessment (SOFA) scores than those without CIRCI ($16.1{\pm}2.3$ vs. $11.4{\pm}3.5$, p=0.001). Six of the patients with CIRCI (30%) received glucocorticoids. With an average elevation of the mean blood pressure by $22.2{\pm}8.7mm\;Hg$ after steroid therapy, the duration of inotropic support was shorter in the steroid group than in the non-steroid group ($14.1{\pm}2.3days$ versus $30{\pm}22.8days$, p=0.001). Three infections (15%) developed in the non-steroid group, but this was not a significant between-group difference. Conclusion: CIRCI should be suspected in patients with LCOS after cardiac surgery, especially in patients with a high SOFA score. Glucocorticoid replacement therapy may be considered to reduce the use of inotropes without posing an additional risk of infection.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.7
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• pp.912-918
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• 2011

Newly born lambs have to face challenges in a new environment totally different from that of the uterus. Adaptation to extra-uterine life involves functional changes with almost each organ and system in the body undergoing a series of metabolic and anatomical modifications. Failure to adapt the extra-uterine environment can not only lead to homeostatic disturbances but also lead to the death of the affected lambs. Hematological parameters of newly born lambs show variability that differs between breeds of lambs. The purpose of present study was to determine homeostatic responses and physiological reference values in Kajli breed lambs occurring in the neonatal period through changes in blood profile, respiratory rate, heart rate, live weight and rectal, scrotal and skin temperatures. For this purpose, sixteen clinically fit lambs (males = 10 and females = 6) with a mean body weight $6.92{\pm}0.46$ kg were selected. Physiological data of selected parameters of each Kajli lamb was recorded at three day intervals and hematological parameters at five days for a period of 30 days. In general, statistical analysis showed a significant effect of time (p<0.001) on all the studied physiological and hematological parameters except platelets counts, white blood cells and hemoglobin concentration. The results documented in the current study are an addition to existing knowledge of the physiology of Kajli sheep breed should be helpful in developing feeding, disease diagnoses and treatment protocols for newborn Kajli stock.

• KSBB Journal
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• v.16 no.1
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• pp.24-29
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• 2001

Recently hepatocyte-based bioartificial liver (BAL) and hepatocyte transplantation have been actively investigated to treat acute hepatic failure. The BAL acts as a bridge to provide patients with more time until a donor organ becomes available for transplantation or until their own liver can be regenerated. In this study, we manufactured a polyurethane foam (PUF) using 15% NCO-prepolymer with a pore opening that allows it to be used as a hepatocyte immobilizing material. Cubes of PUF (3 mm dim.) were seeded with rat primary hepatocytes at a density of 5.5$\pm$1.1$\times$ $10^6$ cells/$cm^3$ PUF by centrifuging them together. The cell laden PUF cubes were packed into a prototype reactor and perfused with a hormonally defined medium for a week. Hepatocytes in the pores of the PUF formed spheroids that showed stable ammonia removal and urea synthesis activities. The albumin production level was comparable to other BAL systems. The PUF packed hepatocyte bioreactor has the potential to be used as a BAL.

• Biomolecules & Therapeutics
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• v.24 no.4
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• pp.387-394
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• 2016

Sepsis, a serious clinical problem, is characterized by a systemic inflammatory response to infection and leads to organ failure. Toll-like receptor (TLR) signaling is intimately implicated in hyper-inflammatory responses and tissue injury during sepsis. Histone deacetylase (HDAC) inhibitors have been reported to exhibit anti-inflammatory properties. The aim of this study was to investigate the hepatoprotective mechanisms of trichostatin A (TSA), a HDAC inhibitor, associated with TLR signaling pathway during sepsis. The anti-inflammatory properties of TSA were assayed in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Polymicrobial sepsis was induced in mice by cecal ligation and puncture (CLP), a clinically relevant model of sepsis. The mice were intraperitoneally received TSA (1, 2 or 5 mg/kg) 30 min before CLP. The serum and liver samples were collected 6 and 24-h after CLP. TSA inhibited the increased production of tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-6 in LPS-stimulated RAW264.7 cells. TSA improved sepsis-induced mortality, attenuated liver injury and decreased serum TNF-${\alpha}$ and IL-6 levels. CLP increased the levels of TLR4, TLR2 and myeloid differentiation primary response protein 88 (MyD88) protein expression and association of MyD88 with TLR4 and TLR2, which were attenuated by TSA. CLP increased nuclear translocation of nuclear factor kappa B and decreased cytosolic inhibitor of kappa B ($I{\kappa}B$) protein expression, which were attenuated by TSA. Moreover, CLP decreased acetylation of $I{\kappa}B$ kinase (IKK) and increased association of IKK with $I{\kappa}B$ and TSA attenuated these alterations. Our findings suggest that TSA attenuates liver injury by inhibiting TLR-mediated inflammatory response during sepsis.