PURPOSE: We retrospectively investigated to find out the equation of calculating the probability of minimal change nephrotic syndrome (MCNS) using clinical parameters. We prospectively investigated to determine the usefulness of the mathematical model. METHODS: We retrospectively examined 56 patients with nephrotic syndrome (NS) (30 MCNS and 26 non-MCNS) diagnosed by kidney biopsy. A mathematical model for calculating the probability of MCNS was obtained through multiple logistic analysis in SAS statistics package. In addition, we prospectively studied 28 patients with NS. Clinical MCNS and non-MCNS were classified according to the probability of 85% in the mathematical model. Kidney biopsy was performed, and serum albumin and urinalysis were measured after 2 weeks of steroid treatment. RESULTS: In the retrospective study, the mathematical model was P=ea/(1+ea), a=17.2507 - 5.5777xON - 4.2256xALB-0.000579x24PROT - 1.2569xUBL+2.1703xUAL. The mode of onset (ON), 24 hours urine protein (24PROT), serum albumin concentration (ALB), the grade of hematuria (UBL) and proteinuria (UAL) were included as clinical parameters. At the probability of 85%, the sensitivity and specificity for predicting MCNS was 73.3% and 100% respectively. In the prospective study, the result of kidney biopsy was consistent with clinical MCNS and non-MCNS according to a mathematical model. All clinical MCNS showed negative proteinuria on urinalysis and a significant increase in serum albumin after 2 weeks treatment (1.85+/-0.30 g/dL to 2.88+/-0.26 g/dL, p<0.05). CONCLUSION: We conclude that the mathematical model for predicting the probability of MCNS may be useful in diagnosis of the MCNS.
Biopsy ; Diagnosis ; Hematuria ; Humans ; Kidney ; Models, Theoretical* ; Nephrosis, Lipoid* ; Nephrotic Syndrome ; Prospective Studies ; Proteinuria ; Retrospective Studies ; Sensitivity and Specificity ; Serum Albumin ; Urinalysis

BACKGROUND: Thiazides have been used in nephrogenic diabetes insipidus (NDI) patients to decrease urine volume, but the mechanism of antidiuretic effect is not known yet. Recently, it has been demonstrated that abundance of aquaporin-2 (AQP2) was decreased in lithium induced NDI. We performed this study to investigate the effect of hydrochlorothiazide (HCTZ) in lithium induced NDI rats and the change of AQP2 expression. METHODS: NDI was induced in 7 male Spraque- Dawley rats by feeding lithium carbonate containing rat chow (40 mmol/kg) for 5 weeks. 4 rats were control group. HCTZ 3.75 mg/day (n=3 among lithium treated; Li+TZ) or vehicle (n=4 among lithium treated and control; Li and Control, respectively) was infused to the rats through osmotic minipump for the last 7 days. Urine volume and urine osmolality were measured. Kidneys were processed for immunohistochemistry and immunoblotting using antibody to AQP2. RESULTS: Li+TZ showed decreased urine volume (46+/-11 mL/day for Li+TZ vs. 127+/-1 mL/day for Li, p<0.05) and higher urine osmolality (557+/-139 mmol/kgH2O for Li+TZ vs. 207+/-9 mmol/kgH2O for Li, p<0.05) comparing to Li. In semi-quantitative immunoblotting using whole kidney homogenate, Li+TZ showed increase in AQP2 expression comparing to Li (39+/-2% for Li+TZ vs. 20+/-9% for Li, p<0.05, % of normal controls). In immunohistochemistry, AQP2 expression in cortex was markedly decreased after lithium treatment. But, AQP2 expression was slightly increased after HCTZ treatment. CONCLUSION: HCTZ treatment partially increased urine concentrating ability and AQP2 expression in rats with lithium induced NDI. We concluded that partial improvement in urine concentrating ability might be associated with upregulation of AQP2.
Animals ; Antidiuretic Agents ; Aquaporin 2* ; Diabetes Insipidus, Nephrogenic* ; Humans ; Hydrochlorothiazide* ; Immunoblotting ; Immunohistochemistry ; Kidney ; Kidney Concentrating Ability ; Lithium Carbonate ; Lithium* ; Male ; Osmolar Concentration ; Rats* ; Thiazides ; Up-Regulation

The resistance to recombinant human erythropoietin (r-HuEPO) in patients with chronic renal failure can develop in conditions such as iron deficiency, chronic bleeding, or chronic inflammatory disease. Recently, there have been several case reports of pure red cell aplasia due to antibody production to r-HuEPO in chronic hemodialysis patients. A 59-year old female undergoing chronic hemodialysis responded well to r-HuEPO for 6 years. But, a rapidly progressive anemia was then noted which was unresponsive to maximal doses of r-HuEPO and the patient became transfusion-dependent. Bone marrow examination showed absence of red cell precursors. A detailed search for the cause of this pure red cell aplasia was unrevealing. We conclude that although very rare, pure red cell aplasia should be considered in evaluating chronic hemodialysis patients with erythropoietin-resistant anemia.
Anemia* ; Antibody Formation ; Bone Marrow Examination ; Erythropoietin ; Female ; Hemorrhage ; Humans ; Iron ; Kidney Failure, Chronic ; Middle Aged ; Red-Cell Aplasia, Pure* ; Renal Dialysis*

We developed a cardiac cell model to explain the phenomenon of mechano-electric feedback (MEF), based on the experimental data with rat atrial myocytes. It incorporated the activity of ion channels, pumps, exchangers, and changes of intracellular ion concentration. Changes in membrane excitability and Ca2+ transients could then be calculated. In the model, the major ion channels responsible for the stretch-induced changes in electrical activity were the stretch-activated channels (SACs). The relationship between the extent of stretch and activation of SACs was formulated based on the experimental findings. Then, the effects of mechanical stretch on the electrical activity were reproduced. The shape of the action potential (AP) was significantly changed by stretch in the model simulation. The duration was decreased at initial fast phase of repolarization (AP duration at 20% repolarization level from 3.7 to 2.5 ms) and increased at late slow phase of repolarization (AP duration at 90% repolarization level from 62 to 178 ms). The resting potential was depolarized from -75 to -61 mV. This mathematical model of SACs may quantitatively predict changes in cardiomyocytes by mechanical stretch.
Action Potentials ; Animals ; Ion Channels ; Membrane Potentials ; Membranes ; Models, Theoretical ; Muscle Cells* ; Myocytes, Cardiac ; Rats*

PURPOSE: Commonly used diuretics such as furosemide and hydrochlorothiazide may cause metabolic alkalosis by increasing proton secretion from distal nephron. We evaluated changes in urinary acidification and abundance of proton-secreting transporters in response to chronic subcutaneous infusion of diuretics. METHODS: Osmotic minipumps were implanted into Sprague-Dawley rats to deliver 12 mg/day furoemide or hydrochlorothiazide 7.5 mg/day for 7 days. All animals were offered tap water and a solution containing 0.8% NaCl and 0.1% KCl as drinking fluid. RESULTS: Compared with vehicle-infused controls, diuretic and natriuretic responses were evident from furosemide or hydrochlorothiazide infusion. However, there were no changes in body weight, serum aldosterone and creatinine clearance between diuretic- infused(n=6) and control(n=6) rats. In both furosemide-infused and hydrochlorothiazide-infused rats, urine pH was significantly lowered compared with controls. Furosemide-infused rats showed significantly larger excretion of urinary ammonium. Semiquantitative immunoblotting was carried out from rat kidneys to investigate abundance of proximal tubule or medullary thick ascending limb Na(+)/H(+) exchanger type 3(NHE3) and collecting duct H(+)- ATPase using specific polyclonal antibodies to NHE3 and H(+)-ATPase B1 subunit, respectively. The abundance of NHE3 from cortical homogenates was not changed by either furosemide or hydrochlorothiazide infusion. However, the abundance of NHE3 from outer medullary homogenates was increased by furosemide infusion. The H(+)-ATPase B1 subunit abundance was increased by furosemide or hydrochlorothiazide infusion in both cortical and outer medullary homogenates. CONCLUSION: These increases in the abundance of proton-secreting transporters may account for the enhanced distal urinary acidification in response to chronic diuretic administration.
Adenosine Triphosphatases ; Aldosterone ; Alkalosis ; Ammonium Compounds ; Animals ; Antibodies ; Body Weight ; Creatinine ; Diuretics ; Drinking ; Extremities ; Furosemide ; Hydrochlorothiazide ; Hydrogen-Ion Concentration ; Immunoblotting ; Infusions, Subcutaneous ; Kidney ; Nephrons ; Proton-Translocating ATPases* ; Protons ; Rats ; Rats, Sprague-Dawley ; Water

Spontaneous renal artery dissection is an uncommon cause of renal infarction. Previous reports of spontaneous renal artery dissection has been associated with hypertension or fibromuscular dysplasia. We report herein the case of a previously healthy, normotensive patient with renal infarction due to spontaneous renal artery dissection who remained normotensive throughout his course without therapy. A previously healthy 31-year-old man with well- documented normotension had a sudden onset of right flank pain and delayed onset of elevation of lactic dehydrogenase, hematuria, and proteinuria. Thin section spiral computerized tomogram shows linear intraluminal filling defect suggesting intimal flap. Angiography shows dissection of main right renal artery. Six months later, he has remained well and normotensive without therapy. To our knowledge, this is the first case of spontaneous renal artery dissection in normotensive patients in Korea.
Adult ; Angiography ; Fibromuscular Dysplasia ; Flank Pain ; Hematuria ; Humans ; Hypertension ; Infarction* ; Korea ; Oxidoreductases ; Proteinuria ; Renal Artery*

BACKGROUND: The efficacy of dialysis on the autonomic and peripheral nerve function has been a subject of considerable debate. In addition, no longitudinal study on the course of uremic neuropathy in end-stage renal disease (ESRD) during dialysis has been reported. We carried out a prospective study to investigate the effect of dialysis on the autonomic and peripheral nerve function during the first 12 months of dialysis. METHODS: Twenty-five patients with ESRD (14 on HD and 11 on CAPD; 11 diabetic and 14 non- diabetic) were enrolled. Autonomic nerve function test and median nerve conduction velocity study were done at the initiation of dialysis and then repeated after 12 months of dialysis. RESULTS: At the initiation of dialysis, sympathetic nerve function and parasympathetic nerve function were abnormal in all HD and CAPD patients. After 12 months of dialysis, no significant changes occurred in autonomic function test. There was no significant difference in autonomic function test between HD and CAPD patients. There was no significant difference in median nerve conduction velocity between HD and CAPD patients after 12 months of dialysis. At the initiation of dialysis, 6 of 11 diabetic and 4 of 14 non-diabetic patients had abnormal median nerve conduction velocity. After 12 months of dialysis, normalization of median nerve conduction velocity occurred only in 3 non-diabetic patients. There was a singinficant difference in median nerve conduction velocity between diabetic and non-diabetic patients after 12 months of dialysis. CONCLUSION: We conclude that dialysis does not significantly alter the autonomic nerve function during the first 12 months of dialysis, but may improve the peripheral nerve function in non-diabetic uremic patients.
Autonomic Pathways ; Dialysis* ; Humans ; Kidney Failure, Chronic* ; Longitudinal Studies ; Median Nerve ; Peripheral Nerves* ; Peritoneal Dialysis, Continuous Ambulatory ; Prospective Studies

Recombinant human erythropoietin(r-HuEPO) is the mainstay of anemia therapy in patient with end stage renal disease(ESRD), but the use of r-HuEPO is primarily limited by its high cost. So, it encourages any strategies that potentially enhance the erythropoietic response. However, studies designed to assess whether androgens would enhance the response to r-HuEPO were inconclusive. While androgens may be less expensive and may improve several nutritional parameters, their potential adverse effects discourage usage. We carried out a prospective study to examine the effect of low-dose androgen in combination with subcutaneous r-HuEPO on anemia and nutritional paramenters in hemodialysis patients. Twenty-four hemodialysis patients with hematocrit <24% or hemoglobin <8.0g/dL were randomly assigned into two groups. Group A(n=12) received 2000U r-HuEPO subcutaneously twice a week for six months. Group B(n=12) received the same dose of r-HuEPO plus nandrolone decanoate 100mg intramuscularly biweekly. Anthropometry, albumin, cholesterol, prealbumin, and transferrin were measured as nutritional parameters. The groups showed no differences in baseline levels of the followings : Hemoglobin, hematocrit; transferrin saturation; serum ferritin; intact serum parathyroid hormon, Kt/V; vitamin B12, folate; nutritional parameters. At the completion of the study, both groups showed significant increase in hematocrit compared with baseline levels(group A 20.7+/-2.2% to 26.0+/-3.8%; group B : 21.5+/-3.5% to 30.1+/-2.8%). The mean hematocrit in group B was significantly higher than in group A after 4 month study period(p<0.05). Ten of 12 patients in group B achieved a target hematocrit of 30%, as compared with four of 12 patients in group A. Both groups didn't show significant changes in any nutritional parameters. No significant side effects of androgen were noted during this short-term study. We conclude that low-dose androgen in combination with subcutaneous r-HuEPO is effetive treatment on anemia in hemodialysis patients, but does not improve nutritional status.
Androgens ; Anemia* ; Anthropometry ; Cholesterol ; Erythropoietin* ; Ferritins ; Folic Acid ; Hematocrit ; Humans* ; Nandrolone ; Nutritional Status ; Prealbumin ; Prospective Studies ; Renal Dialysis* ; Transferrin ; Vitamin B 12

We have experienced two patients who had hypokalemic metabolic alkalosis as well as hypomagnesemia and hypocalciuria with elevated plasma renin activity. We have performed renal clearance study after water loading, administration of furosemide and thiazide in two patients and two normal controls. Maximal free water clearance per 100 mL glomerular filtration rate(CH2O) and distal fractional chloride reabsorption[CH2O/(CH2O+CCl)] in our patients were reduced than the controls. Chloride clearance(CCl) was increased after furosemide administration but not after thiazide administration. Distal fractional chloride reabsorption[CH2O/(CH2O+CCl)] was dramatically decreased by furosemide administration in our patients, whereas thiazide had little effect on it. Fractional excretion of sodium, chloride, magnesium, calcium was increased by furosemide administration, whereas thiazide administration had little effect on this parameters. These findings suggested the presence of a defect in the distal convoluted tubule rather than in the thick ascending loop of Henle. Herein, we report two cases of Gitelman's syndrome diagnosed by renal clearace study after water loading, administration of furosemide and thiazide.
Alkalosis ; Calcium ; Filtration ; Furosemide ; Gitelman Syndrome* ; Humans ; Loop of Henle ; Magnesium Chloride ; Plasma ; Renin ; Sodium ; Water

ATP-sensitive potassium channels (KATP channels) play an important role in insulin secretion from pancreatic beta cells. We have investigated the effect of propofol on KATP channels in cultured single pancreatic beta cells of rats. Channel activity was recorded from membrane patches using the patch-clamp technique. In the inside-out configuration bath-applied propofol inhibited the KATP channel activities in a dose-dependent manner. The half-maximal inhibition dose (ED50) was 48.6+/-8.4 micrometer and the Hill coefficient was 0.73 0.11. Single channel conductance calculated from the slope of the relationship between single channel current and pipette potential (+20~+100 mV) was not significantly altered by propofol (control: 60.0+/-2.7 pS, 0.1 mM propofol: 58.7+/-3.5 pS). However, mean closed time was surely increased. Above results indicate that propofol blocks the KATP channels in the pancreatic beta cells in the range of its blood concentrations during anesthesia, suggesting a possible effect on insulin secretion and blood glucose level.
Anesthesia ; Animals ; Blood Glucose ; Insulin ; Insulin-Secreting Cells ; KATP Channels* ; Membranes ; Patch-Clamp Techniques ; Propofol* ; Rats*