Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.69 (APC)
 16,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fibrin deposition is a common accompaniment of renal allograft rejection, indicating disruption of the normal physiologic balance between procoagulant and anticoagulant pathways. In vitro, tumor necrosis factor (TNF) induces endothelial expression of the procoagulant, tissue factor, and downregulation of thrombomodulin, a key component of the thrombomodulin/protein C (PC)/protein S (PS) pathway, which normally maintains an anticoagulant state by inactivating thrombin, preventing further thrombin formation by degrading factors Va and VIIIa, and decreasing plasminogen activator inhibitor activity. Raised levels of TNF were recently demonstrated within the blood of patients during episodes of renal allograft injection, and may be an early and discriminatory marker of rejection. This led us to investigate prospectively whether monitoring of serum TNF levels was of value clinically, and was associated with effects on circulating PC and PS levels, or alterations in intragraft thrombomodulin expression. Plasma samples (n = 454) were collected three times/week from all patients (n = 25) undergoing renal transplantation during a 9-month consecutive period, and assayed by ELISA and functional assays for TNF, PC, and free PS (FPS). Portions of renal biopsies, taken to evaluate episodes of acute deterioration of renal function, were evaluated by immunoperoxidase labeling for the presence and distribution of TNF, thrombomodulin, PC, PS, thrombin, fibrin, and factors V and VIII. Comparison of 78 plasma samples collected during 26 episodes of biopsy-proven acute cellular rejection with samples collected during periods of stable renal function (n = 349) showed that TNF levels rose significantly (390 +/- 242 pg/ml, p less than 0.01) above background levels 3 days before rising serum creatinine concentrations, and peaked (2,426 +/- 978 pg/ml) on the day of clinical rejection. PC-antigen (Ag) concentrations also decreased 3 days before rejection (68 +/- 13%, p less than 0.05), and were maximally depressed (49% +/- 16%, p less than 0.001) on the day of rejection. FPS levels were normal until the day before rejection (63% +/- 8%, p less than 0.01) and, like PC, were maximally depressed (43 +/- 10%) at rejection. Plasma TNF levels were significantly and inversely correlated with PC-Ag (p less than 0.001) and FPS (p less than 0.005) levels during rejection, regardless of whether such rejection episodes were steroid responsive or required OKT3 monoclonal antibody therapy. TNF, PC, and FPS levels were normal during episodes of cyclosporine toxicity and viral infection.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Tumor necrosis factor production during human renal allograft rejection is associated with depression of plasma protein C and free protein S levels and decreased intragraft thrombomodulin expression. 130 55

Twenty-nine of 54 uremic patients had low levels of protein C measured as anticoagulant activity, contrasting with normal levels measured as amidolytic activity or antigenic concentration. We demonstrate that this discrepancy is due to the presence of a soluble plasma inhibitor that interferes specifically with the anticoagulant activity of activated protein C. The inhibitor does not interfere with other coagulation assays. It is resistant to diisopropylfluorophosphate, high temperatures and repeated freezing and thawing. It can be dissociated from protein C by anti-protein C antibodies or by dialysis in vitro and in vivo. It binds to positively charged resins and can be eluted with high salt concentrations without losing its inhibitory capacity. The inhibitory effect is correlated with plasma creatinine levels and fluctuates with time.
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PMID:Low levels of the anticoagulant activity of protein C in patients with chronic renal insufficiency: an inhibitor of protein C is present in uremic plasma. 179 90

Longitudinal Cohort Study: Electrocardiogram and blood pressure were taken biannually along with history taking, physical examination and other laboratory studies. 6,690 subjects were included in this study in whom at least 7 out of 9 biannual check up examinations were performed. At the end of the study period, their ages ranged from about 40 to 90 years. The incidence of atrial fibrillation was about 0.2% in the forties and early fifties and increased to 0.6% by the late fifties. The incidence of atrial fibrillation was then increased almost linearly up to 2.5% at the end of the eighties. Likewise, incidence of CRBBB and LBBB was also increased with age even after the age of sixty; 1.0% at the fifties to 7.5% at the eighties in CRBBB and 0.05% at the fifties to 1.4% at the eighties in LBBB, respectively. Holter ECG Study: Holter ECG was recorded in 164 healthy subjects aged 14 to 87 years in whom no arrhythmias were found in the routine 12 leads ECG at entry to the study. In 96.9% of the subjects APC was recorded in the 24-hour Holter ECG irrespective of their age. The total number of APCs in 24 hours significantly increased with age, especially after age sixty. The incidence of couplet or short run APCs was 21.4% under age sixty and 74.2% above age sixty. Electrophysiologic Studies in Patients with Paroxysmal Atrial Fibrillation (Paf): Repetitive atrial firing (RAF) elicited by premature atrial stimulation, and prolonged intra-atrial electrogram (PAE) with multiple (more than 7) spikes recorded during sinus rhythm were taken as indicators of atrial vulnerability. RAF and PAE was observed in more than 60% of Paf patients with or without sick sinus syndrome (SSS), but only approximately 25% in the control group (without SSS). It was also noted that in patients with SSS, who were generally of old age, RAF was observed in about 63% even without Paf. These results suggest that the atrial vulnerability might be an expression of the common electrophysiologic properties of the atrial muscle in the elderly with atrial arrhythmias and/or SSS. Syncopal Episodes due to Transient Severe Hyperkalemia in the Elderly: Two patients with mild to moderate chronic renal failure developed transient severe hyperkalemia (9.9, 7.3 mEq/L, respectively), severe sinus bradycardia with sinus arrest and syncopal episodes. These transient findings almost completely improved in a few days by kayexatete and bicarbonate, and temporary back-up atrial pacing. Hyperkalemia was disproportionately severe compared to BUN and serum creatinine.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Arrhythmias in the elderly]. 267 51

Protein C was determined in 42 patients with terminal uremia and 20 healthy controls in three different ways 1) anticoagulant activity 2) amidolytic activity 3) antigen level. Protein C anticoagulant activity was markedly decreased in uremia, but was partly normalized during hemodialysis treatment, whereas the amidolytic activity and antigen level of protein C were normal and without changes during dialysis. The activities and antigen levels of factor II and X were normal before and after hemodialysis. In anticoagulated patients we found a good correlation between prothrombin levels and protein C levels determined with three different assays. We did not find any evidence for a defect carboxylation of protein C as the cause for the defective protein C in uremia. The BaCl2 precipitation in the Protein C anticoagulant assay was incomplete both in uremia and in controls but without differences between the two groups. In vitro addition of urea and creatinine did not decrease protein C activity. The cause of the defective protein C in uremia is still not known but it might contribute to thromboembolic complications.
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PMID:Protein C assays in uremia. 276 69

Activated protein C is a potent, physiologic anticoagulant that inactivates the activated forms of factors V and VIII as well as facilitates in vivo fibrinolysis. We developed a competitive protein-binding enzyme-linked immunoadsorbent assay (ELISA) for protein C that was utilized to investigate if the hypercoagulability of the nephrotic syndrome is related to a deficiency of circulating plasma protein C. Protein C was measured in plasma of 11 patients with nephrotic syndrome (24 hr protein 8.4 +/- 1.6 g, SEM; serum creatinine 4.2 +/- .74 mg/dl, SEM). Ten azotemic nonnephrotic patients were employed as controls (serum creatinine 6.0 +/- 1.25 mg/dl, SEM). No significant reduction of protein C values was observed (mean 108%, range 65-200%) in nephrotic patients when compared with the controls (mean 127%, range 100-200%) even though protein C antigen was present in all nephrotic urine samples tested. Also, no correlation existed between blood levels of urea nitrogen, creatinine, albumin, total protein, or 24-hr urine protein excretion and the observed protein C values. These results suggest that in patients with the nephrotic syndrome, a hypercoagulable state may not be related to a deficiency of protein C and that the level of this zymogen in nephrotic syndrome reflects a dynamic balance between urinary losses and systemic production.
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PMID:Protein C levels in nephrotic syndrome: use of a new enzyme-linked immunoadsorbent assay for protein C antigen. 308 87

It has been suggested that the severity of an attack of acute pancreatitis is related to the presence of intraglandular trypsinogen activation and that disease severity is also reflected by the degree of the acute-phase protein response. In this study we examine the relationships among amylase release, the degree of trypsinogen and prophospholipase A2 activation [as measured by urinary trypsinogen activation peptide (TAP) and prophospholipase A2 activation peptide (PLAP) concentrations], and the serum concentrations of the acute phase-protein C-reactive protein (CRP) and the principal mediator of the acute-phase protein response, interleukin-6 (IL-6). Twenty-four patients (14 mild and 10 severe attacks) were studied. Peak serum amylase concentrations were seen within 12 h and peak urinary TAP/creatinine (Cr) and PLAP/Cr ratios between 12 and 24 h after the onset of symptoms, preceding those of IL-6 and CRP. The integrated TAP/Cr and PLAP/Cr responses were significantly greater in those with severe disease [95% confidence internal (CI) = 106-259.6 pmol/mmol/h, p < 0.0008; and 95.1% CI = 462.2-3887 pmol/mmol/h, p < 0.003, respectively]. The integrated amylase response was not significantly greater in those with severe disease (95.6% CI = -415 to 832 IU/L/h, p < 0.14). There was a strong correlation among the integrated IL-6, TAP/Cr (r = 0.63, p < 0.01), and PLAP/Cr (r = 0.64, p < 0.01) responses but a poor correlation with the integrated amylase response (r = 0.19, NS).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The relationship between pancreatic enzyme release and activation and the acute-phase protein response in patients with acute pancreatitis. 754 Jul 60

The intraglomerular presence of thrombomodulin (TM) was examined in 19 patients with lupus glomerulonephritis (GN). TM is a cell surface glycoprotein found on endothelial cells and plays a key role in the protein C anticoagulant pathway. Renal biopsy specimens of patients with lupus GN and several kinds of renal disease other than lupus GN, i.e., membranous GN, IgA GN, minimal change nephrotic syndrome (MCNS) and hemolytic uremic syndrome (HUS) were examined by indirect immunofluorescence, using three kinds of monoclonal antibodies against human TM: KA-2, KA-3 and KA-4. It has been reported that KA-3 and KA-4 bind to enzyme-digested TM as well as intact TM, while KA-2 recognizes intact TM only. In the glomeruli from both normal subjects and patients with MCNS, only very weak staining of TM was found. Patients with HUS showed negative TM staining in the glomeruli. In contrast, positive to strongly positive staining of KA-2 as well as of KA-3 and KA-4 was observed mainly along the capillary wall of glomeruli from patients with lupus GN. Some patients with non-lupus GN showed positive staining of these monoclonal antibodies, but the staining was far more intense in most patients with lupus GN than in the patients with non-lupus GN. Staining of albumin and transferrin by the indirect method was negative in all cases of lupus GN that showed positive staining of TM. There was no relationship between the intensity of TM staining and the degree of proteinuria, creatinine clearance or histologic types of lupus GN.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Enhanced presence of thrombomodulin in the glomeruli of lupus glomerulonephritis. 802 12

Thrombomodulin (TM) is a thrombin receptor found on endothelial cells. TM acts as a cofactor for the thrombin-catabolized activation of protein C and protects these cells from the formation of thrombi. We hypothesized that the soluble form of TM which reflects the damage of the endothelial cells and that simultaneously, soluble TM will be affected by renal excretion because a significant positive correlation has been found between soluble TM and serum creatinine (sCr) in the renal failure state. However, there have been no reports on the relationship between plasma TM and clinical parameters except for sCr in primary glomerulonephritis (PGN). Plasma TM (pTM) and urinary TM (uTM) were measured in 107 patients with PGN using a one-step sandwich enzyme immunoassay. These values were assessed together with other laboratory and histological findings. We were able to divide all subjects into two groups: an sCr-dependent group whose sCr level was over 1.2 mg/dl and an sCr-independent group whose sCr level was under 1.2 mg/dl. In the sCr-independent group, patients who suffered from nephrotic syndrome (NS) had a much higher pTM level than patients who did not suffer from NS. Histological findings and other parameters were not correlated with pTM or uTM. Therefore, the two patients who suffered from NS with very high pTM levels and normal sCr level at the time of admission exhibited a decrease in their pTM value as their condition improved. We concluded that in our patients, pTM was affected not only by renal excretion of TM, but also by renal damage with heavy proteinuria and may have been associated with an ongoing disease process in PGN.
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PMID:Elevation of plasma thrombomodulin level in primary glomerulonephritis with heavy proteinuria. 874 91

Nephrotic syndrome (NS) is associated with an increased incidence of various thromboembolic complications in adult patients. It was found to be due to elevated factor IX (FIX) F.VII, F.VIII, F.V, fibrinogen, thrombocytosis and increased platelet reactivity. Acquired AT-III deficiency, reduced functional levels of protein S and reduced activity of protein C were also reported. We evaluated 15 children aged 1 to 13 years. Thirteen of these children suffered from nephrotic syndrome and two others had non-nephrotic proteinuria. All patients but one were normotensive. Two patients were not steroid responsive. Serum creatinine was normal for age in 14 patients. Kidney biopsy was carried out only in three children. Haemostatic parameters included protein C and S antigenicity in plasma and urine. Plasma levels of protein C and protein S were within the normal range. Protein C antigenicity in urine was increased in five children out of 14 examined. Protein S in urine was increased in seven out of 12 children examined. No thromboembolic phenomena were documented even though protein C and protein S antigenicity were identified in the urine.
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PMID:Protein C and protein S in pediatric nephrotic patients. 904 58

A case of significant proteinuria occurred as a result of bilateral renal vein thrombosis secondary to dehydration, which resolved after treatment with urokinase. The patient developed nausea and vomiting from viral gastroenteritis with subsequent volume contraction. He later noted the onset of aching lower abdominal and flank pain. On admission, he was noted to have a serum creatinine of 1.7 mg/dL, and 4+ proteinuria on urinalysis. A 24-hour urine collection showed 2.34 g protein. A renal venogram showed bilateral renal vein thrombosis (RVT) without involvement of the inferior vena cava. Therapy was initiated with heparin at 1,000 U/hr, followed by intravenous (IV) urokinase, 4,400 U/kg bolus, followed by 4,400 U/kg/hr with continuous infusion for 12 hours. A repeat renal venogram done at this time showed partial resolution of thrombosis bilaterally. A second 12-hour infusion of urokinase at 5,000 U/kg/hr was performed; at this time, the patient reported resolution of his flank and abdominal pain. A repeat 24-hour urine collection showed 60 mg protein with a normal creatinine clearance. Levels of antithrombin III, protein C, and protein S were all normal. A renal biopsy was performed and showed normal histology on light, immunofluorescent, and electron microscopic evaluation. The patient has done well on no therapy and has had no recurrence of thrombosis or proteinuria after 2.5 years. This is a US government work. There are no restrictions on its use.
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PMID:Resolution of proteinuria secondary to bilateral renal vein thrombosis after treatment with systemic thrombolytic therapy. 910 53


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