The protein C system is a natural anticoagulant and profibrinolytic system consisting of protein C and protein S and thrombomodulin. Because the increased fibrinolysis and the decreased activities of coagulation factor V and VIII are observed in patients undergoing cardiopulmonary bypass, which are known main effects of achivated protein C, we studied the protein C system in the plasma of patients undergoing operation with extracorporeal circulation(ECC group, 31 patients) and without ECC(control group, 10 patients). The nature of the enhanced blood fibrinolytic activity that evolved during extraacorporeal circulation was charaacterized by significantincrease or fibrin degradation product(FDP) in ECC group(P<0.01) but not in control group. The changes of protein C system also showed only in ECC group. The changes of protein C system were most pronounced in the early phase of cardiopulmonary bypass. The changes of FDP ane protein C system were observed in both bubble and membrane oxygenator-used group, but the pattern and degree of change were quite different (P<0.01), i,e., more severe in membrane oxygenator-used group. These results confirm the disturbance of protein C system by extracorporeal circulation, which is possibly activated by the contact activation between blood and synthetic surface. So measurement of changes of protein C system could be used as a good method in the development of new materials for extracorporeal circulation.
Cardiopulmonary Bypass ; Extracorporeal Circulation ; Factor V ; Fibrin ; Fibrinolysis ; Heart* ; Humans ; Membranes* ; Oxygen* ; Oxygenators* ; Plasma ; Protein C* ; Protein S ; Thoracic Surgery* ; Thrombomodulin

No abstract available.
Acid-Base Equilibrium* ; Acidosis*

No abstract available.
Infarction* ; Retrospective Studies*

PURPOSE: There is increasing consideration about the preemptive transplantation, transplantation without any preceding dialysis, as a one of options of a renal replacement therapy (RRT). This study evaluates a beneficial effect on recipient and allograft survival of preemptive transplantation and compares the outcome to that according to the dialysis modality and duration. METHODS: All patient who had received a kidney transplant from a living donor in the Seoul National University Hospital (SNUH) between January 1990 and October 2004 are included in this retrospective study. Patients were subdivided into three groups; preemptive transplant group (group 1, n=47), hemodialysis group (group 2, n=307) and peritoneal dialysis group (group 3, n=52). RESULTS: The characteristics of each groups were not statistically different except recipient age. Ten-year patient survival was 97.8% in PE group, but is not significantly higher than in HD (89.4%) and in PD (90.7%) groups. However, 10-year graft survival was higher in PE group than in HD group (p<0.05; 100%, 74.7% respectively). The differential effect of pretransplant dialysis duration on graft survival was prominent if the patients had been on the pretransplant dialysis for more than 42 months (p<0.05; 10-year graft survival; PE, 100% and dialysis more than 42 months, 77.9% respectively) Compared with HD group as a pre-transplant dialysis modality, PD group showed better patient and graft survival rate, but not statistically significant. CONCLUSION: Depending on the above results, we may suggest PE or PD being a superior pre-transplant modality than HD. And we should be considerate of choosing treatment modality and duration before transplantation.
Allografts ; Dialysis* ; Graft Survival* ; Humans ; Kidney Transplantation* ; Kidney* ; Living Donors* ; Peritoneal Dialysis ; Renal Dialysis ; Renal Replacement Therapy ; Retrospective Studies ; Seoul ; Transplants*

OBJECTIVES: Urine anion gap(UAG) and urine osmolal gap(UOG) were proposed as indirect measures of urine ammonium(NF4+). While the former is known to have its usefulness limited to hyperchloremic metabolic acidosis, the latter is reported to have its correlation with urine NE4+ in ketoacidosis. This study was undertaken to evaluate the correlation of urine NH with IJOG in high anion gap metabolic acidosis(AGMA) and to compare it with UAG. METHODS: We measured urine NH' by enzymatic determination, UOG(=0.5 X [urine osmolality-{2 X (Na++K+)+urea+glucose)]), and UAG(=Na++K+-Cl-) in 18 patients(serum AG=24.4+/-1.6mmol/L ) with AGMA. RESULTS: When they were grouped into those with acute disorders(n=11) and those with chronic disorder(n=7), urine Nk4+ concentration was higher (p<0.05) in the acute(35.6+/-7.7mmol/L) than in the chronic(3.8+/-0.9mmol/L) group. The UOG was higher (p<0.05) in the acute(73.2+/-18.9mmol/L) than in the chronic(6.3+/-8.7mmol/L) group, but the UAG had no difference between the two groups. When both groups of the patients were considered together, urine NH concentration correlated with the UOG (r=0.90, p<0.01), but not with the UAG. While the patients with lower urine NH4+ excretion(<30mmol/d) had the UOG<40mmol/L, those with higher urine NH' excretion(>40mmol/d) had the UOG>40mmol/L. CONCLUSION: In contrast to the UAG, the UOG has a significant correlation with urine NH4+ in AGMA.
Acid-Base Equilibrium* ; Acidosis* ; Ammonium Compounds* ; Humans ; Ketosis

Mineralocorticoids influences on acid-base homeostasis by the regulation of urine acidification. But its mechanism of acion is not well known in human. This study compared the acid-base status and the indices of urine acidification before and after mineralocorticoid administration in human, and analyzed the effect of mineralocorticoids on human acid-base homeostasis. We administered 9a-fludrocortisone in 6 chronic renal failure patients and 6 normal controls 0.5mg daily for 7 days. The results were as following: 1) After administration of 9a-fludrocortisone in patients group, serum aldosterone level changed from 120.2+/-71.0pg/mL to 44.8+/-32.2pg/mL(mean+/-SD, p< 0.05). Serum HCO- level was not changed. Urine ammonium excretion was incresed from 24.6+/-12.3 mmol/day to 43.7+/-19.0 (p<0.05), but there were no change in urine pH and urine anion gap, Serum potassium level decreased from 5.5+/-0.7mBq/L to 4.1+/-0.5mEq/L (p<0.05), and TTKG increased from 3.9 to 8.9(p<0.05). 2) After administration of 9a-fludrocortisone in control group, serum aldosterone level changed from 99.7+/-44.5pg/mL to 25.1+/-3 mL(p<0.05). Serum HCO- level was not changed. Urine ammonium excretion was incresed from 44.3+/-21.6mmoVday to 76.3+/-19.6(p<0.05), but there were no change in urine pH and urine anion gap. Serum potassium level decreased from 4.8+/-0.5mEq/L to 3.9+/-0.2mHq/L(p< 0.05), but there was no change in TTKG. 3) No patient or control showed any discomfort after 9-fludrocortisone administration, and there was no elevation in diastolic blood pressure, increase in body weight, electrolyte abnormality. In summary, after 9alpha-fludrocortisane administration, urinary ammonium excretion increased in both patients and control group, and this phenomenon occured with correction of hyperkalemia without urine pH change. This result implies urinary ammonium excretion increase by mineralocorticoid. In human increase in renal distal acidification by mineralocorticoid is due to increase in renal ammoniagenesis rather than stimulation on proton excretion.
Acid-Base Equilibrium ; Aldosterone ; Ammonium Compounds* ; Blood Pressure ; Body Weight ; Homeostasis ; Humans ; Hydrogen-Ion Concentration ; Hyperkalemia ; Kidney Failure, Chronic ; Mineralocorticoids ; Potassium* ; Protons

BACKGROUND: The antidiuretic action of oxytocin in human has been controversial. To investigate whether oxytocin directly acts on water balance in human, we evaluated the parameters of urinary concentration in response to administration of oxytocin in ten healthy male volunteers. METHODS: Oxytocin was infused intravenously at a rate of 20 mU/hour for 2.5 hours and urine was collected during the last 2 hours of oxytocin infusion. Changes in urine volume, urine osmolality, excretions of urine electrolytes and free water clearance after the administrartion of oxytocin were compared with the baseline data. RESULTS: The changes in the levels of serum electrolytes and osmolality after the administration of oxytocin were not significant compared with the baseline data. The volume of 2 hours' urine were 446+/-75 mL and 289+/-53 mL in the basal state and after the administration of oxytocin, respectively. The urine osmolality was increased significantly by the infusion of oxytocin(427+/-63 mOsm/kg) compared with that in the basal state(223+/-25 mOsm/kg)(p < 0.05). The free water clearance was 110+/-51 mL/2 hours in the basal state and decreased significantly to -57+/-51 mL/2 hours(p < 0.05). CONCLUSION: We conclude that administration of oxytocin to normal men enhances urinary concentration, evidenced by increased urinary osmolality and decreased free water clearance. In human, oxytocin may play an important role in the regulation of renal water excretion as an antidiuretic hormone.
Electrolytes ; Humans ; Male ; Osmolar Concentration ; Oxytocin* ; Volunteers ; Water

No abstract available.
Glomerulonephritis, Membranous* ; Lower Extremity* ; Small Cell Lung Carcinoma* ; Thrombosis*

BACKGROUND: Darbepoetin alfa is a new erythropoietic agent with a three fold longer terminal half-life than recombinant human erythropoietin (r- HuEPO). The aim of this randomized, open-label study is to determine whether darbepoetin alfa is as effective as r-HuEPO for the treatment of anemia in hemodialysis patients when administered at a reduced dosing frequency. METHODS: A total 74 Korean hemodialysis patients receiving r-HuEPO therapy by either the intravenous (IV) or subcutaneous (SC) route were randomized to continue r-HuEPO or to receive an equivalent dose of darbepoetin alfa at a reduced dosing frequency. Patients receiving r-HuEPO once weekly changed to once every other week darbepoetin alfa, and those receiving r-HuEPO two or three times weekly changed to once-weekly darbepoetin alfa. The initial dose of darbepoetin alfa was based on the r-HuEPO dose at the time of entry into the study, using a formula equating the peptide mass of the two molecules (200 IU r-HuEPO=1 microgram darbepoetin alfa). The doses of r-HuEPO and darbepoetin alfa were titrated to maintain hemoglobin concentrations within -1.0 to +1.5 g/dL of patients' baseline values and within a range of 8.0 to 13.0 g/ dL for up to 20 weeks (16-week dose-titration period followed by a 4-week evaluation period). The primary end point was change in hemoglobin level between baseline and the evaluation period. RESULTS: The mean change in hemoglobin from baseline to the evaluation period was similar in the darbepoetin alfa (-0.03+/-0.19 g/dL) and r-HuEPO (0.27+/-0.20 g/dL) groups, and the difference between the two treatments was -0.30 g/dL (95% CI, -0.84 to 0.23). This was not a statistically significant or clinically relevant difference, despite the reduced frequency of darbepoetin alfa administration. The safety profiles of darbepoetin alfa and r-HuEPO were similar. CONCLUSION: This study suggests that darbepoetin alfa maintains hemoglobin as effectively as r- HuEPO, but with reduced dose frequency.
Anemia* ; Erythropoietin ; Half-Life ; Hemoglobin A ; Humans ; Renal Dialysis* ; Darbepoetin alfa

Oxytocin, like vasopressin, has been known to act in the IMCD by the activation of adenylyl cyclase through V2 receptor, but the exact mechanism of its action remains to be elucidated. To prove whether oxytocin is involved in the activation of adenylyl cyclase in the renal collecting duct, we measured the cAMP production and urinary cAMP excretion rate. After single IMCD segments of Sprague-Dawley rats were microdissected and treated with different con- centrations of vasopressin(10pM, 10nM) and oxytocin (10pM, 10nM), cAMP production was measured. Urinary cAMP excretion rate was measured after dehydration and intraperitoneal injection of vasopressin and oxytocin. The results are as follows. 1) cAMP production in single IMCD was significantly increased in vasopressin group(10pM: 48,9+/-4.7(mean+/-SE), 10nM:94.6+/-5.3fmol/mm) and oxy-tocin group(10pM: 11.3+/-2.9, 10nM: 65.7+/-6.1fmol/mm) compared with that in the control(3.2+/-0.2fmol/ mm). 2) Urine volume was significantly decreased in dehydration group(40+/-7Ml/hour) and vasopressin group(420+/-120Ml/hour), but urine volume of oxytocin group(1,480+/-230Ml/hour) was not different from that of control(1,550+/-120Ml/hour). Urine osmolality was significantly increased in all experimental groups(control: 737.0+/-132.6, dehydration group : 2,463.9+/- 412.5, vasopressin group : 1,702+/-412.5, oxytocin group 1,293.4+/-117.9mOsm/kg). Urinary cAMP excretion rate was significantly increased in dehydration group(4,149.5+/-1,072.3pmol/hour) and oxytocin group(4,843.3+/-2,341.8pmol/hour), but not in vasopressin group(1,358.1+/-690.2pmol/hour), compared with that in control(49+/-10.7pmoVhour). These results suggest that oxytacin has anti-diuretic effect by the activation of adenylyl cyclase through V2 receptor.
Adenylyl Cyclases ; Dehydration ; Injections, Intraperitoneal ; Osmolar Concentration ; Oxytocin* ; Rats, Sprague-Dawley ; Receptors, Vasopressin ; Vasopressins