• Childhood Kidney Diseases
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• v.2 no.2
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• pp.138-144
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• 1998

Purpose : The use of cyclosporine and mitomycin in various immunologic or neoplastic disorders has been known to cause wide-ranged nephrotoxic effects including thrombotic microangiopathy. However, the mechanism of nephrotoxicity of these drugs has not been studied adequately, so that present experimental study has been undertaken to find out whether these drugs can cause direct damage to the kidney and to clarify the pathogenetic mechanism of nephrotoxic effect of these drugs. Materials and methods : Sprague-Dawley rats weighing 250-300 gm were used for experimental animals and unilateral renal perfusion technique, modified from the method described by Hoyer et al was used. Isolation of left kidney from systemic circulation was made by clamping aorta and left renal vein and a hole was punctured in the anterior wall of the left renal vein. Cyclosporine (2.5 mg in 4 ml solution) and mitomycin (1.6 mg in 4ml solution) were infused through left renal artery and normal saline was used in control rats. Forty-eight hours after infusion of the drugs, animals were sacrificed and left kidney removed and processed for histologic examination. Total ischemic time of left kidney was less than 15 minutes: Results : Cyclosporine-perfused group showed severe swelling of glomerular endothelial ceil along with swelling of glomerular epithelial cell and interstitial vascular endothelial cell. Mitomycin-perfused group also showed severe swelling of glomerular endothelial and epithelial cells. And in addition to these findings, they demonstrated platelets aggregation, swelling and degranulation of platelets and fibrin accumulation in some of the capillaries, indicating occurrance of thrombotic microangiopathy. Conclusion : present experiment indicates that cyclosporine and mitomycin can cause direct toxic injury to renal endothelial cell. And this direct toxic damage to endothelial cell seems to be an important initiating event for the development of thrombotic microangiopathy.

• Clinical and Experimental Pediatrics
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• v.51 no.9
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• pp.956-963
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• 2008

Purpose : Indomethacin is widely used for the prophylaxis and treatment of patent ductus arteriosus (PDA); however, it is associated with side effects such as renal failure, intraventricular hemorrhage, and gastrointestinal bleeding. Intravenous ibuprofen has been shown to be as effective as indomethacin in prompting PDA closure. If treatment with oral ibuprofen is as effective as indomethacin, it would have the advantages of greater availability, simpler administration, and lower cost. We conducted this study to compare the efficacy and side effects of indomethacin with those of oral ibuprofen, vis-$\grave{a}$-vis on the pharmacological closure of PDA. Methods : As a randomized double-blind study, 34 preterm infants with respiratory distress syndrome and hemodynamically significant PDA were treated with either intravenous indomethacin or oral ibuprofen. Echocardiography was performed by one cardiologist who was blind to the treatment that any given infant received. The rate of ductal closure, the need for additional drug treatment or surgical ligation, clinical outcome, and the side effects of drug treatment were compared. Results : Ductal closure occurred in 16 of 18 patients (88.9%) from the indomethacin group and in 14 of 16 patients (87.5%) from the ibuprofen group (P>0.05). Three patients in the indomethacin group and four in the ibuprofen group required a second drug treatment (P>0.05). Three patients (i.e., one patient in the indomethacin group and two in the ibuprofen group) underwent surgical ligation (P>0.05). Between the two groups, there was no significant difference vis-$\grave{a}$-vis in side effects or clinical outcome. Conclusion : Compared to indomethacin, oral ibuprofen has the advantages of simpler administration and lower cost, while being as effective; in addition, there are no differences between the two drug treatments with regards to side effects or clinical outcomes. Therefore, the widespread use of oral ibuprofen should be considered in treating PDA in preterm infants.

• Journal of Chest Surgery
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• v.25 no.1
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• pp.105-111
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• 1992

Total atherosclerotic obstruction of the juxtarenal abdominal aorta is a relatively rarely encountered form of atherosclerotic vascsular disease, accounting for less than 5% of all arterial obstrutive disease. We have encountered two patients with such lesions, both of whom were admitted for intermittent claudication of the lower extremities and symptoms of vascular ischemia. Digital subtraction angiography[DSA] was performed on both patients, the results of which revealed total obstruction of the aorta just inferior to the renal arteries without involving the latter. Operative technique involved the use of the sup-raceliac aorta as the site of proximal anastomosis of aortofemoral bypass followed by a fem-orofemoral bypass graft with Smm sized Woven Dacron[Vascutek] through a subcutaneous tunnel within the retroperitoneal space. Both patients experienced restoration of blood flow distal to the obstruction postoperatively without any complications, and OPD follow-up one month postoperatively and postoperative DSA showed evidence of continued graft patency with persistent symptomatic improvement.

• Childhood Kidney Diseases
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• v.7 no.2
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• pp.125-132
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• 2003

Purpose : Lipoprotein(a) is a genetically determined risk factor for atherosclerotic vascular disease and is elevated in patients with renal disease. Especially the patients with nephrotic syndrome exhibit excessively high Lp(a) plasma concentrations. Also the patients with end-stage renal disease have elevated Lp(a) levels. But the mechanism underlying this elevation is unclear. Thus, in this study, by measuring the level of serum Lp(a) in common renal diseases in children, we hoped to see whether there would be a change in Lp(a) in renal diseases other than nephrotic syndrome. Then, we figured out its implications, and looked for the factors that affect the Lp(a) concentrations. Methods : A total of 75 patients(34 patients with hematuria of unknown etiology, 10 with hematuria and hypercalciuria, 8 with IgA nephropathy, 8 with poststreptococcal glomerulone phritis, 3 with $Henoch-Sch\"{o}nlein$ nephritis, 7 with urinary tract infection, and 5 with or- thostatic proteinuria) were studied. The control group included 20 patients without renal and liver disease. Serum Lp(a), total protein, and albumin levels, 24-hour urine protein and calcium excretions, creatinine clearance and the number of RBCs and WBCs in the urinary sediment were evaluated. Data analysis was peformed using the Student t-test and a P-value less than 0.05 was considered to be statistically significant. Results : LP(a) was not correlated with 24-hour urine calcium and creatinine. Lp(a) level had a positive correlation with proteinuria and negative correlation with serum albumin and serum protein. Among the common renal diseases in children, Lp(a) was elevated only in orthostatic proteinuria (P<0.05). Conclusion : Lp(a) is correlated with proteinuria, serum protein, and serum albumin, but not with any kind of specific renal disease. Afterward, Lp(a) needs to be assessed in patients with orthostatic proteinuria and its possible role as a prognostic factor could be confirmed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.973-980
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• 2004

To evaluate the antioxidative effect of rice coated with maengjong-juk extract in vivo system, rice coated with maengjong-juk extract diets were fed to NZW rabbit for 16 weeks and lipid peroxidation, protein oxidation, activities of antioxidative enzymes and total glutathione content in tissues were measured. TBARS contents in liver and spleen were significantly decreased in maengjong-juk extract diet group compared to control group, while those in kidney and heart tissue were not significantly different. Maengjong-juk extract diet suppressed the protein oxidation significantly in liver, spleen, kidney and heart tissues. Hepatic total SOD, Cu$.$Zn-SOD and Mn-SOD activities of maengjong-juk extract diets were significantly higher than those of control diet. GSH-Px and catalase activities of maengjong-juk extract diet were higher than those of control, while GR activities show no significant difference between the two groups. Total hepatic glutathione content was significantly increased by maengjong-juk extract diet. According to this study, many antioxidative materials and phytochemicals in maengjong-juk extracts seems to protect tissues from oxidative stress by stimulating antioxidative systems in atherosclerotic rabbit fed high cholesterol diet.

• Journal of Life Science
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• v.32 no.2
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• pp.175-188
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• 2022

Relaxin has been demonstrated to have regulatory functions on both the smooth muscle and extracellular matrix (ECM) of blood vessels and fibrotic organs. The diverse mechanisms by which relaxin acts on small resistance arteries and fibrotic organs, including the bladder, are reviewed here. Relaxin induces vasodilation by inhibiting the contractility of vascular smooth muscles and by increasing the passive compliance of vessel walls through the reduction of ECM components, such as collagen. The primary cellular mechanism whereby relaxin induces arterial vasodilation is mediated by the endothelium-dependent production of nitric oxide (NO) through the activation of RXFP1/PI3K, Akt phosphorylation, and eNOS. In addition, relaxin triggers different alternative pathways to enhance the vasodilation of renal and mesenteric arteries. In small renal arteries, relaxin stimulates the activation of the endothelial MMPs and EtB receptors and the production of VEGF and PlGF to inhibit myogenic contractility and collagen deposition, thereby bringing about vasodilation. Conversely, in small mesenteric arteries, relaxin augments bradykinin (BK)-evoked relaxation in a time-dependent manner. Whereas the rapid enhancement of the BK-mediated relaxation is dependent on IK_Ca channels and subsequent EDH induction, the sustained relaxation due to BK depends on COX activation and PGI₂. The anti-fibrotic effects of relaxin are mediated by inhibiting the invasion of inflammatory immune cells, the endothelial-to-mesenchymal transition (EndMT), and the differentiation and activation of myofibroblasts. Relaxin also activates the NOS/NO/cGMP/PKG-1 pathways in myofibroblasts to suppress the TGF-β1-induced activation of ERK1/2 and Smad2/3 signaling and deposition of ECM collagen.

• Clinical and Experimental Pediatrics
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• v.46 no.7
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• pp.687-694
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• 2003

Purpose : Regeneration and repair after ischemic renal injury appears to be modulated by circulating or locally produced growth factors. This study examined the changes of serum insulin like growth factor(IGF-I) and renal expression of IGF-I and II, vascular endothelial growth factor(VEGF), transforming growth $factor-{\beta}$($TGF-{\beta}$), and connective tissue growth factor(CTGF) during the active regeneration period after acute ischemic injury. Methods : Sera and kidney tissue samples(whole kidney, cortex, outer medullae and inner medullae) were obtained before and after one, three, five and seven days of 40 minutes bilateral renal pedicle clamping. Acute renal failure was assessed by measuring the concentration of serum creatinine. Serum IGF-I level was measured by radioimmunoassay. The mRNA expression in kidney was measured by RT-PCR. The distribution of IGF-I and CTGF was detected by immunohistochemistry. Resuts : Serum IGF-I concentration after one day following acute ischemic renal injury was significantly decreased compared to preischemic value. The mRNA levels of IGF-I, IGF-II, $TGF-{\beta}1$ and VEGF in whole kidney were temporally decreased on day one of ischemic injury. IGF-I and IGF-II expressions in outer medullae were significantly decreased on day one after ischemic injury. $TGF-{\beta}1$, CTGF and VEGF expressions were markedly decreased in medullae after one day of ischemic injury compared to other kidney sections. IGF-I was markedly decreased in cortical tubules on day one of uremic rat. CTGF was markedly increased on tubule within three days of ischemic injury. Conclusion : These findings suggest that IGFs, $TGF-{\beta}1$ and CTGF may involve in the pathogenesis or the recovery from acute ischemic renal injury.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.5
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• pp.65-70
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• 2004

In this paper, we present a new methodology to analyze the characteristic of artery by using 4 channels photoplethysmograpy. The proposed parameter is a time difference of pulse transit time(PTT) between Pulse waves at finger site and at toe site. To verify the usefulness of the developed system volume pulse waves on 4 sites were measured simultaneously for total 51 normal subjects (male 26 and female 25) aged from 9 to 83 years old. And then correlations between the analysis parameters and age were evaluated by using linear regression analysis method. As the result of experiments, the change of parameter was found according to ages. The result of regression analysis about relationships between the parameter and ages for n=51, the coefficient of correlation of non-normalized data has 0.79770 in left side and 0.80599 in right side and the coefficient of correlation of normalized data by height has 0.81345 in left side and 0.81605 in right side.

• Childhood Kidney Diseases
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• v.6 no.1
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• pp.114-119
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• 2002

Takayasu's arteritis(TA) is a chronic idiopathic vasculitis mainly involving the aorta and its main branches, such as brachiocephalic, carotid, subclavian, vertebral and renal arteries, as well as coronary and pulmonary arteries The clinical features usually reflect limb or organ ischemia resulting from gradual stenosis of involved arteries. We experienced a case of idiopathic Takayasu's arteritis with negative tuberculin test involving multiple main branch arteries at active stage without pulse. We treated this patient with combined therapy of steroid and azathioprine, with remission of disease activity. (J Korean Soc Pediatr Nephrol 2002 ;6 : 114-9)

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.177-177
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• 1993

뇌모세혈관내피세포로 구성된 혈액-뇌관문(BBB)은 tight junction으로 구성되어 있을뿐만 아니라 fenestra가 없는 등 BBB가 가진 특성으로 인해 물질 수송에 장벽역할을 하기 때문에 주로 중추신경계 질환시의 약물요법에 많은 제한이 따른다. 따라서 뇌로의 효율적인 약물 송달방법에 대해 많은 연구가 진행중에 있는데 본 연구에서는 BBB의 hyperosmotic opening법을 이용하여 뇌로 잘 수송되지 않는 약물의 뇌송달 방법에 대해 연구하고자 하였다. 먼저 수용성으로 인해 BBB 에 잘 통과하지 않는 물질로 신장 및 뇌영상 촬영시 사용되는 방사성 의약품이 Tc-DTPA를 이용하여, hyperosmotic opening법에 의한 뇌투과 증가정도를 검토하였으며, 실험방법이 확립됨에 따라 뇌암의 항암요법을 위해 뇌로의 투과가 적은 항암제(5-Fluorouracil, 5-FU)의 뇌송달에 대해 본 방법을 적용하여 검토하였다. 실험동물로는 S.D.계 웅성 랫트를 사용하였으며, 실험방법은 다음과 같이 하였다. 랫트의 좌측 외경동맥(left external carotid artery)에 혈류의 역방향으로 혈관 분지점에서 1-2mm 전까지 PE-50 catheter를 삽입하고, 1.6 molal L－(＋)－ arabinose 고장액(1580mOsm)을 0.12ml/sec의 일정한 속도로 30초간 infusion함으로 BBB를 opening 한 다음, 5분 후에 Tc-DTPA를 대퇴 정맥으로 주사하여 0, 10, 30초, 1, 1.5, 2, 3, 4, 5, 7 및 10분 간격으로 대퇴동맥에 설치한 카테타로부터 혈액을 채취하고 마지막 혈액을 취한 후 즉시 단두하여 뇌를 적출하였다. 채취한 뇌를 액체질소에 담근 후 tissue Tek으로 고정하고 autoradiography를 하기 위한 slice와 농도측정을 위해 필요한 부위를 취한 후 감마카운터로 Tc-DTPA의 brain각 부위별 및 혈장농도를 측정하였다. 뇌조직중 혈액부피의 측정은 Tc-albumin를 이용하여 구하였다. 같은 방법으로 5-FU에 대한 실험도 행하였고, 이때 각 혈장 및 조직중의 5-FU함량은 HPLC로 하였다.