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Biomedical subjects

Y S Yoon

Publications and source records attributed to Y S Yoon.

At least 37 records · Page 2Linked to original sources

Prevention of posttransplant peptic ulcer by misoprostol.

Misoprostol is effective in protecting the gastric mucosa against various injuries (cytoprotection), but its role in preventing peptic ulcer disease (PUD) is controversial. Therefore, this study was designed to evaluate the effect of misoprostol on preventing posttransplant PUD. 87 patients undergoing kidney transplantation (KT) were randomly separated into three groups according to the antiulcer regimen. Group 1 (n = 28) received antacid and ranitidine; group 2 (n = 34) received antacid, ranitidine, and bismuth (De Nol), and group 3 (n = 25) received antacid, ranitidine, and misprostol (prostaglandin E1). Antiulcer drugs started 1 week before KT and were continued after surgery. A pretransplant gastrofibroscopy was performed 1 month before KT, and a follow-up gastroscopy was performed 2-3 weeks after KT. The incidence of peptic ulcer in groups 1 and 2 was 50.0% (14/28) and 35.3% (12/34), respectively (p > 0.05 groups 1 vs. 2). In group 3, 12.0% (3/25) of the patients showed PUD (p < 0.05 when compared with group 1 or 2). The known risk factors of posttransplant PUD were not significantly different in three groups, but the KT recipients of groups 1 and 2 had 7.8 times the risk of PUD when compared with group 3. In conclusion, the antiulcer regimen including misoprostol is more effective than ranitidine or bismuth in preventing posttransplant PUD, and the antiulcer effect of misoprostol seems to be related to the cytoprotective effect of the drug.

Adult↗

Factors on graft survival of living donor kidney transplantation in a single center.

We analyzed the potential factors that could influence the survival of graft, focused on primary graft living-donor kidney transplantation with cyclosporine (CsA) therapy. 680 cases were enrolled in this study. Patients and graft survival rates were calculated by a Kaplan-Meier product limit estimate with a 1-day time interval. The analyzed variables were donor relationship, HLA matching, recipient age and sex, donor age and sex, ABO blood type compatibility, diabetic status, hepatitis virus infection, donor specific or non-specific blood transfusion and acute rejection episode. The results suggested that acute rejection episode was the most prognostic factor in graft survival. An HLA-matched donor and a young male donor, i.e. a greater donor nephron mass for less recipient body mass, will show better long-term survival. Diabetes and hepatitis B infection have some negative effects on the long-term survival of graft kidney, but age of recipient, donor-specific transfusion and donor-recipient relationship have little effect.

ABO Blood-Group System↗

Serum soluble HLA class I antigen levels in hemodialysis patients and following renal transplantation.

We measured the serum levels of soluble HLA class I antigen (sHLA-I) to evaluate the immune status of uremia and following renal transplantation. Twenty-one hemodialysis (HD) patients had serum samples collected for sHLA-I analysis before and after HD and also during the initial posttransplant period. The serum sHLA-I levels in patients undergoing HD were higher than in the normal controls (574.8 +/- 431.1 vs. 415.6 +/- 256.1 ng/ml, p < 0.05). In the HD patients, HD duration was not correlated with serum sHLA-I levels (r = 0.01, p > 0.05), and pre- and post-HD serum sHLA-I levels were not significantly different (574.8 +/- 431.1 vs. 568.3 +/- 398.4 ng/ml, p > 0.05). After successful renal transplantation, the serum sHLA-I levels decreased significantly (574.8 +/- 431.1 vs. 226.7 +/- 202.8 ng/ml, p = 0.0001) but increased significantly during the rejection period as compared to the prerejection period (642.8 +/- 296.1 vs. 305.5 +/- 194.7 ng/ml, p = 0.0002). In conclusion, sHLA-I levels are stable in uremic status and can be used as a parameter for monitoring acute graft rejection in renal transplantation.

Adult↗

Prevalence and clinical course of hepatitis B and hepatitis C liver disease in ciclosporin-treated renal allograft recipients.

We performed this study to evaluate prevalence and clinical course of hepatitis B surface antigen (HBsAg)-positive and anti-hepatitis C virus (HCV)-positive renal transplant recipients. HBsAg positivity was 13.7 and anti-HCV positivity 12.8%. Before transplantation, the HBsAg positivity was observed in in 83.5% of the patients, and 16.4% of the patients acquired HBsAg after renal transplantation. In the HCV group, anti-HCV positivity was observed in 47.1% before transplantation, and 19.6% acquired anti-HCV after renal transplantation. The prevalence of chronic hepatitis in the hepatitis B virus (HBV) and in the HCV groups was not different (25.7 vs. 25.5%). Among those with chronic hepatitis in the HBV group, 4 cases progressed to fulminant hepatic failure, 1 case progressed to the end-stage liver cirrhosis, and 1 case to hepatocellular carcinoma. However, in the HCV group, no case showed progression of chronic hepatitis. The overall mortality in the HBV and HCV groups was 25.3 and 7.8%, respectively (p = 0.001). Among 20 fatal cases in the HBV group 9, cases were liver disease related, but no liver disease related death occurred in the HCV group. In conclusion, HCV as well as HBV infections are quite prevalent and important causes of posttransplant chronic hepatitis, and the clinical course of anti-HCV-positive recipients is less aggressive than that of HBsAg-positive recipients.

Adult↗

Comparison of peritoneal catheter survival with fistula survival in hemodialysis.

OBJECTIVE: To compare continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis (HD) with regard to long-term maintenance of access. DESIGN: Retrospective study of a four- to six-year time period at one center. PATIENTS: One hundred and twenty-two CAPD patients between December 1988 and December 1992, and 172 HD patients between May 1986 and December 1992. MAIN OUTCOME MEASURE: Cumulative survival rate of peritoneal catheters and arteriovenous fistulas (AVF) was the main outcome measure. Variables affecting the survival rate including sex, age, presence or absence of diabetes, and type of AVF (autogenous or prosthetic graft) were assessed. The causes of peritoneal catheter failures were analyzed. RESULTS: The cumulative survival rate of all peritoneal catheters was significantly longer than the AVF survival rate (84% vs 74% at one year; 73% vs 61% at two years; and 63% vs 48% at three years) (p = 0.029). There were no differences in peritoneal catheter survival according to sex, age, or diabetes. Compared with AVF survival, peritoneal catheter survival was significantly longer in male (p = 0.0492), elderly (p = 0.0082), and diabetic (p = 0.0022) patients. Prosthetic graft and old age were risk factors for AVF survival. Of all peritoneal catheter failures, infectious complications were responsible for 75% (33/44) and mechanical complications for 25% (11/44). Peritonitis was the leading infectious complication (21/33) and outflow obstruction was the leading mechanical complication (9/11). CONCLUSION: In terms of long-term maintenance of access, CAPD is superior to HD, especially in the elderly or diabetics. Prevention and proper management of peritonitis may prolong the peritoneal catheter survival.

Adult↗

Acute focal bacterial nephritis presented as acute renal failure and hepatic dysfunction in a renal transplant recipient.

We describe acute focal bacterial nephritis (AFBN) presented as acute renal failure and hepatic dysfunction in a renal transplant recipient. He had received a renal transplantation 5 years previously and maintained good renal function without an episode of acute rejection or any urinary abnormalities. He had been an HBsAg carrier and showed mild elevation of liver enzymes after renal transplantation. For 5 days before admission, the patient suffered from fever, graft kidney swelling, tenderness and oliguria. On admission, renal biopsy was performed and solumedrol pulse therapy was started under the impression of acute rejection. The following laboratory findings revealed acute renal failure and hepatic dysfunction. From the abdomen CT and renal biopsy findings this case was confirmed as AFBN in a grafted kidney. With successive hemodialysis and antibiotic therapy clinical symptoms and renal function improved promptly. In acute hepatic dysfunction we discontinued cyclosporine (CsA) to prevent irreversible fulminant hepatic failure until the normalization of liver function. It should be considered that AFBN must be included in the differential diagnosis of acute rejection, and the early diagnosis and treatment of AFBN is important to save the grafted kidney. In addition, early withdrawal of CsA is essential to prevent irreversible hepatic failure when infection triggers hepatic dysfunction in HBsAg-positive renal transplant recipients.

Acute Kidney Injury↗

Primary aldosteronism detected after renal transplantation.

A 44-year old female was admitted to our hospital for evaluation of uncontrolled hypertension. She received renal transplantation 3 months ago and suffered from a tingling sensation and weakness on both hands. Laboratory findings (low serum potassium, low plasma renin activity and elevated plasma aldosterone level) was consistent with primary aldosteronism. Through the postural study for plasma aldosterone and the adrenal CT finding we diagnosed this case as adrenal adenoma, which was confirmed by surgical removal. A retrospective review of medical records showed that characteristic findings in primary aldosteronism (hypokalemia and low plasma renin activity) were masked by renal failure and became evident after successful renal transplantation. It was suggested that impaired urinary potassium excretion and excess release of renin from the ischemic kidney masked the characteristic findings of primary aldosteronism. To our knowledge, this is the first report documenting the change of renin-angiotensin-aldosterone system after renal transplantation in a case of coexistence of primary aldosteronism and chronic renal failure.

Adrenal Cortex Neoplasms↗

Inhibition of 80 kDa protein phosphorylation by short-wavelength UV light in NIH 3T3 cells.

The exposure of NIH 3T3 fibroblast cells to 254 nm UV radiation resulted in a temporary depression of DNA synthesis and inhibition of 80 kDa protein phosphorylation. This inhibition of protein phosphorylation was correlated with decreased protein kinase C activity in the membrane fractions of UV-damaged cells. The inositol triphosphate contents measured, by the competitive binding assay using bovine adrenal binding protein, showed 80% reduction in the fibroblasts treated with 15 J/m2 of UV light. The intracellular diacylglycerol concentration was also markedly reduced in UV-damaged cells. The results suggest that UV light causes acute reductions of inositol triphosphate and diacylglycerol contents in cells along with decreases in membrane protein kinase C activity, which leads to the inhibition of phosphorylation of an acidic protein of 80 kDa.

3T3 Cells↗

Effect of long-term administration of somatostatin analogue on renal enlargement in uninephrectomized-diabetic rats.

Recent study has demonstrated that the long-acting somatostatin analogue administration effectively prevented initial renal growth in diabetic and uninephrectomized rats. In the present study we examined long-term effect of somatostatin analogue (Sandostatin) on renal enlargement in uninephrectomized-diabetic rat5. Animals were divided into 4 groups: (1) normal control rats (C) (n = 7), (2) uninephrectomized rats (NPX) (n = 7), (3) uninephrectomized-diabetic rats (NPX + DM) (n = 7) and (4) NPX + DM rats treated with Sandostatin (NPX + DM + Tx) (n = 9). All animals had free access to diet (50% protein) and water during the experimental period. To the NPX + DM + Tx rats, 2.5 micrograms of Sandostatin was given subcutaneously twice a day for 8 weeks. Periodic observations were done at 0, 4 and 8 weeks. After 8 weeks. NPX rats (0.540 +/- 0.017 (SEM)) had higher fractional kidney weights (FKW) (wet kidney wt/body wt) compared to C rats (0.410 +/- 0.014) (p < 0.0005), and both NPX + DM rats (0.983 +/- 0.098) and NPX + DM + Tx rats (1.091 +/- 0.042) had higher FKW compared to C rats (p < 0.0001) and NPX rats (p < 0.005), respectively. But no significant change of FKW was observed between NPX + DM rats and NPX + DM + Tx rats. Systolic blood pressure, BUN, serum creatinine, glomerular filtration rate and 24 hour urine protein excretion in NPX + DM rats were not different from those in NPX + DM + Tx rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗