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)

Protein C antigen and amidolytic activity were assayed in 38 patients with essential hypertension at the first stage of disease. As compared to 20 normal healthy blood donors no abnormality was found.
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PMID:Protein C and hypertension. 152 96

Protein C is a natural anticoagulant glycoprotein which prevents intravascular clot formation. Protein C functions as an anticoagulant when converted to an active serine protease (activated protein C). Activated protein C is formed at the site of the endothelial injury in response to blood clotting and helps limit the size of blood clots. We tested the hypothesis that by temporarily blocking the activation of intrinsic protein C, we could reduce subsequent surgical blood loss from a microvascular surgical wound. The formation of activated protein C was blocked systemically by intravenous administration of a monoclonal antibody (HPC4) which binds to circulating protein C and prevents its conversion to activated protein C. Domestic pigs were blindly pretreated with intravenous HPC4 or saline then underwent partial-thickness skin graft harvesting to create a reproducible microvascular wound. Blood loss was measured from each wound and the hemostatic effect of protein C blockade was compared to intravenous saline alone as well as to topical thrombin or thromboplastin. We found that blocking the activation of protein C significantly (P = 0.005) reduces surgical blood loss in this model by 27% compared to saline control animals. Intravenous HPC4 performed equally as well as topical thrombin or tissue thromboplastin. In addition, topical thrombin acted synergistically with HPC4 to reduce blood loss an additional 44% (P = 0.01) as compared to intravenous HPC4 or topical thromboplastin alone. Autopsies performed 1 week after HPC4 treatment showed no evidence of systemic thrombosis resulting from the protein C blockade.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Blockade of protein C activation reduces microvascular surgical blood loss. 152 31

Protein C (PC) and protein S (PS) are components of a potent, natural anticoagulant system. A deficiency of one of these two inhibitors is associated with thrombotic events in young people. A significant reduction in functional PS activity has been observed during normal pregnancy, and recurrent fetal loss may occur in women with lupus anticoagulant (LA) inhibitor. We measured functional PS activity and free PS antigen in 16 non pregnant patients with LA inhibitor and in 17 normal women as controls. A significant difference was observed between patients and controls in functional PS activity (65 +/- 23% vs 87 +/- 15%, p = 0.02) but not in free PS antigen (88 +/- 17% vs 93 +/- 17%). Functional PS activity decreased only in six patients (37%). Removal of IgG from plasma reduced the difference in functional PS activity between patients and controls. Immunologic IgG levels did not correlate with anti-phospholipid antibodies (APA) activities, activated partial thromboplastin time/kaolin clotting time (aPTT/KCT) data or functional PS activity.
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PMID:Functional protein S in women with lupus anticoagulant inhibitor. 153 34

To investigate levels of coagulation inhibitors in sera from patients with Clostridium difficile-associated diarrhoea and colitis, commercially available antigen assays were used for immunochemical determination of antithrombin III, protein C and free protein S. Sera from patients with Clostridium difficile-associated diarrhoea and colitis showed significantly lowered levels of all measured inhibitors as compared to controls (Student's t test). Protein C (mean +/- SD): 0.70 +/- 0.30 vs. 1.28 +/- 0.23, t = 6.61, p less than 0.001; antithrombin: 0.70 +/- 0.21 vs. 0.90 +/- 0.17, t = 3.12, p less than 0.01; free protein S: 0.27 +/- 0.06 vs. 0.37 +/- 0.08, t = 3.7, p less than 0.001. Infection with C. difficile may lead to loss of coagulation inhibitors and constitutes a risk for thromboembolic complications.
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PMID:Low levels of coagulation inhibitors in patients with Clostridium difficile infection. 153 51

Protein C and S are important factors in blood coagulation reported in many papers about people who suffered from thromboembolic diseases related to inherited or acquired deficiencies. Homozygous protein C/S deficiency is lethal in most cases without therapy. Heterozygous deficiency is moderate and complications occur between the 20.-50. year of age. Acquired protein C/S deficiency is a strong parameter for liver function. The typical clinical manifestations of protein C/S deficiencies are superficial and deep leg vein thrombosis, thrombosis of the mesenterial, cerebral, renal and axillary veins, portal vein thrombosis and pulmonary embolism. Most of the affected people live disease free over a longer period and develop thromboembolic complications during and after trauma, surgical interventions, pregnancy and puerperium. We report our experience with a 60 years old male who had developed a severe bilateral iliofemoral vein thrombosis with signs of pulmonary embolism after total hip replacement. An extended functional protein C deficiency (type II) was investigated by coagulation tests (Protein C Reagent, coagulometric from Behring Institute). A second female patient developed a descending iliofemoral vein thrombosis during pregnancy. Venous thrombectomy with arteriovenous fistula was performed, but reocclusion occurred after delivery. Redo-surgery was undertaken and a second reocclusion took place 10 days later. Further lysis therapy was not able to reopen the venous system. Whereas immunological and functional protein C levels showed normal ranges, the functional protein S level was markedly reduced (IL-Instrumentation Laboratory Protein S-Test).
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PMID:[The clinical importance of protein C and S deficiency for surgical patients]. 153 92

Protein S (PS) serves as a cofactor for activated Protein C, which has anticoagulative activity. PS deficiency (inherited or acquired) leads to spontaneous, recurrent thromboembolic complications in adulthood. PS level is significantly reduced during pregnancy and puerperium and during use of oral contraceptives. We report on our experience with a 26 year old pregnant woman, who developed a descending iliofemoral venous thrombosis in the 39th week of gestation. She underwent venous thrombectomy with a temporary arteriovenous fistula. Recurrent thrombosis occurred a few days after parturition. Redothrombectomy was performed successfully, but 2nd recurrent thrombosis occurred 10 days later. Further, lysis therapy did not reopen the venous system. Functional PS activity of 34% (IL-Instrumentation Laboratory Protein S-test, normal range 60-140%) was markedly reduced, which was the only pathological finding of coagulation analysis. For 20 years, the patient's mother has been undergoing coumarin therapy because of recurrent thromboembolic complications. We can therefore assume an inherited PS deficiency in the young mother.
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PMID:[Therapy-refractory pelvic vein thrombosis in pregnancy as a sequela of protein S deficiency]. 153 48

Epidermal growth factor (EGF) domains are found in many proteins, particularly those of the coagulation/fibrinolytic system. We and others have demonstrated that tissue plasminogen activator (t-PA) and prourokinase are modified by the attachment of fucose to equivalent threonine residues within their EGF domains. Factor XII and protein C each contain two EGF domains; in both proteins, the EGF domain nearest the N terminus has a threonine residue in a position homologous to that which is fucosylated in t-PA. In protein C, this site is 3 residues from the position of another post-translational modification, beta-hydroxylation of Asp-71. We isolated peptides containing these sites to determine, primarily by mass spectrometric analysis, the presence of O-linked fucose and/or beta-hydroxyaspartate. We found that factor XII is fully fucosylated at Thr-90. Protein C is unmodified at the equivalent site (Thr-68) and is completely beta-hydroxylated at Asp-71. It has been recently reported that the first EGF domain of human factor VII has O-linked fucose at the equivalent position (Ser-60) (Bjoern, S., Foster, D. C., Thim, L., Wiberg, F. C., Christensen, M., Komiyama, Y., Pedersen, A. H., and Kisiel, W. (1991) J. Biol. Chem. 266, 11051-11057), while it is unmodified at Asp-63 despite having the consensus sequence for beta-hydroxylation at the latter site. These observations raise the possibility that O-linked fucosylation and beta-hydroxylation of EGF domains are mutually exclusive post-translational modifications.
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PMID:O-linked fucose is present in the first epidermal growth factor domain of factor XII but not protein C. 154 94

In a study of 20 patients with hypercholesterolemia (type IIa) the effects of lovastatin (20-80 mg/day) on various clotting and thrombosis parameters were monitored for 12 months. On 11 occasions various cholesterol fractions and clotting parameters were determined in each patient. In addition, the clotting inhibitors AT III, protein C, protein S, and C1-esterase inhibitor and the fibrinolysis parameters plasminogen and alpha 2-antiplasmin were examined. Platelet function was monitored on the basis of spontaneous and induced (collagen, ADP, epinephrine, ristocetin) aggregation. Lovastatin in the above dosage brought about a 66 mg/dl (from 320 +/- 12.6 to 254 +/- 12.0 mg/dl) reduction in the total cholesterol level and a 56 mg/dl (from 244 +/- 11.4 to 188 +/- 12.1 mg/dl) reduction in LDL cholesterol at the end of the study. Fibrinogen showed a significance decrease during the study period, whereas PT and aPTT remained unaffected. The initial slopes of the ADP-induced platelet aggregation revealed a significant decrease. C-reactive protein and platelet count remained within the normal range, indicating no significant change. Thrombin clotting time, AT III, C1-esterase inhibitor, plasminogen, and alpha 2-antiplasmin were not modified. Protein C and S behaved in a contradictory way, but remained within the normal range. Long-term treatment with lovastatin was associated with a significant reduction of fibrinogen levels and platelet aggregation induced by ADP in type-IIa hypercholesterolemic patients. These alterations, as well as their role in cardiovascular disease, should be the subject of further investigations.
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PMID:Effects of long-term treatment with lovastatin on the clotting system and blood platelets. 158 7

Protein C together with its plasmatic cofactor protein S and antithrombin III probably represent the most important plasmatic inhibitor in coagulation. Protein C deficiency constitutes a high risk factor for venous thrombosis. Cerebral venous thrombosis is a manifestation which is scarcely referred to in protein C deficiency. The case of a 32 year old patient with protein C deficiency is presented. The patient was admitted for an endocraneal hypertension syndrome. CT and MR demonstrated multiple hemorrhagic cerebral infarctions. Arteriography confirmed vertebral venous thrombosis. Only six cases sufficiently documenting cerebral venous thrombosis due to protein C deficiency were found in the literature. In most cases coadjuvant factors exist predisposing thromboembolic disease. The present clinical case demonstrates the importance of considering protein C deficiency in the diagnosis of cerebral venous thrombosis in young adults.
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PMID:[Cerebral venous thrombosis and hereditary protein C deficiency]. 159 2

Protein C (PC) is a vitamin K-dependent serine protease, a deficiency of which results in thrombus. There is no spontaneously occurring mouse model of the disease. Attempts to create such a model in mice by using anti-sense gene technology requires isolation of a normal mouse PC cDNA. When a mouse liver (BALB/c) cDNA library was screened using a human PC cDNA as a probe, nine overlapping cDNA clones were isolated and sequenced. The cloned mouse PC cDNA comprised 1,512 nucleotides and the open reading frame of the cDNA encoded a polypeptide of 461 amino acids residues including a leader peptide composed of 41 amino acids. Mouse PC exhibited high homology to both human and bovine PCs. Mouse PC also had several structural features common in other PCs; locations of 23 Cys residues, location of putative beta-hydroxy Asp71, possible carbohydrate attachment sites involving Asp residues at amino acid positions 249, 314, and 330, and location of active sites such as His212, Asp258, and Ser361. Northern blot hybridization analysis identified a single species of mouse PC mRNA (2.0 kb in length) in mouse liver.
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PMID:Isolation and characterization of a mouse protein C cDNA. 161 39


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