Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033036 (APC)
 10,214 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 30-year-old woman is described with both a cerebral venous thrombosis and a deep vein thrombosis of her leg in association with an exacerbation of her ulcerative colitis. Laboratory investigations revealed a transient functional APC resistance, without Factor V mutation, and a mild hyperhomocysteinaemia. After colectomy the APC ratio was normal. These findings may form a partial explanation of the thrombophilia seen in some patients with active ulcerative colitis.
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PMID:Two thrombotic complications in a patient with active ulcerative colitis. 905 Mar 37

Patients with venous leg ulcers often show evidence of previous deep venous thrombosis. Resistance to activated protein C (APC-resistance) is an autosomal dominant inherited defect in the anticoagulant system which is a significant risk factor for development of venous thrombosis. APC-resistance was determined in plasma samples obtained from 46 unselected, consecutively admitted patients with venous leg ulcers, included during a six-month period. Twelve of the 46 patients (26%) (95% confidence limits: 14%-41%) had APC-resistance. APC-resistance is thus a common anticoagulant deficiency among venous leg ulcer patients and should be considered a risk factor for development of venous leg ulcer disease.
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PMID:[Activated protein C resistance in patients with venous leg ulcer]. 914 35

APC-resistance is the most common hereditary condition associated with venous thrombosis. It is in a majority of cases due to a single point mutation in the factor V gene (FVR506Q). Currently used functional APC-resistance tests have 85-90% sensitivity and specificity for the FVR506Q mutation. A modified test which includes predilution of patient plasma in factor V depleted plasma has increased the sensitivity and specificity for the factor V mutation. However, neither the original nor the modified APC-resistance test have been evaluated in patients with acute thrombotic events. We have therefore used the original and the modified APC-resistance tests in 220 patients with clinically suspected acute deep venous thrombosis and in 278 healthy controls. The FVR506Q mutation was determined in all patients. The patients were classified as either DVT (deep venous thrombosis)-negative or DVT-positive depending on the outcome of contrast phlebography. In individuals with normal factor V genotype, the original APC-resistance test gave significantly lower APC-ratio values both in DVT-positive and DVT-negative patients than in healthy controls. The specificity of the original APC-resistance test for the FVR506Q mutation in controls and in DVT-negative and DVT-positive patients were 85%, 54% and 28%, respectively, when a cut off APC-ratio of 3.2 which insured 100% sensitivity was used. Using the modified APC-resistance test, essentially no difference in APC-ratios between patients with normal factor V genotype and healthy controls with normal factor V genotype was observed. The modified APC-resistance test had a specificity for the FVR506Q mutation of 98.8% at an APC-ratio cut off of 2.1 which ensured 100% sensitivity. The original APC-resistance test gave lower APC-ratios in women than in men and in patients with acute thrombosis as compared to controls. In conclusion, the modified APC-resistance test is highly sensitive and specific for the FVR506Q mutation. This test can be used in clinical practice as an easy to perform screening test for the FVR506Q allele. Moreover, the test performs equally well in patients with acute suspected venous thrombosis as in healthy controls.
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PMID:Evaluation of original and modified APC-resistance tests in unselected outpatients with clinically suspected thrombosis and in healthy controls. 915 92

A dimorphism in the 3'-untranslated region of the prothrombin gene (G to A transition at position 20210) has recently been reported to be associated with increases in plasma prothrombin levels and in the risk of venous thrombosis. We have examined the prothrombin dimorphism among 99 unselected outpatients with phlebography verified deep venous thrombosis, and in 282 healthy controls. The prevalence of the 20210 A allele was 7.1% (7/99) in the patient group, and 1.8% (5/282) in the healthy control group (p = 0.0095). The relative risk of venous thrombosis was calculated to be 4.2 (95% CI, 1.3 to 13.6), and was still significant when adjustment was made for age, sex and the factor V:R506Q mutation causing APC resistance [odds ratio 3.8 (95% CI, 1.1 to 13.2)]. As previously reported, 28% of the patients were carriers of the factor V:R506Q mutation. Thus, 34% (one patient carried both traits) of unselected patients with deep venous thrombosis were carriers of an inherited prothrombotic disorder. To sum up, our results confirm the 20210 A allele of the prothrombin gene to be an important risk factor for venous thrombosis.
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PMID:The 20210 A allele of the prothrombin gene is a common risk factor among Swedish outpatients with verified deep venous thrombosis. 949 5

Venous valves are more frequent in distal veins and venulae, providing a protecting action against blood skin reflux. Structurally simple, collagen and endothelium, they allow a cavity to be formed by distension, when occlusion occurs. Venous angioscopy can distinguish bicuspid floating valves, reinforced, reinforcing valves with free edges and seat valves as well as the presence of apertures of small collateral vessels in the sinus, of which they play a role in the filling up. Valves are inefficient in supine and in standing among 20% of the adult population. Sinuses allow vortices to be created, low recirculating zones, where blood flow move slowly in niches, at a low shear rate, independently from the main stream. A deep vortex is located in sinus, usually empty, but likely to receive red cell aggregates and leukocytes in the condition of stasis and hyperviscosity. Such a vortex is hypoxic, cause of endothelial activation. In such areas fibrin-leucocytic nidus are created, histologically recognized, of which sub-endothelium has become thick and thrombogenic. Two stages characterized its progression: stage I: a few alteration in the valves, little thrombin generation, taken over by the coagulation inhibitors: AT III, APC and TFPI. Stage II: damaged valves, local consumption of the inhibitors and extended generation of thrombin over the platelets, through factor IXa. Hereditary inhibitor deficits increase the risk (frequent factor Leyden V). When the coagulation cascade is considered, VIIa-tissue factor complex appears to be the thrombotic pathway, leading first to wall linked thrombin, uneasily reached by AT III and facteur IXa non inhibited by TFPI, therefore explaining the platelet extension. Monocytes, which can bear tissue factor, may be "lodged" inside the niches. Besides this important role in deep venous thrombosis, incompetent venous valves are responsible for the skin venous hypertension, a subsequent ground for ulcers. Their role in chronic venous insufficiency is uncertain. In the near future, venous angioscopy will bring about new findings about the pathophysiology of venous valves.
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PMID:[Venous valves in the legs: hemodynamic and biological problems and relationship to physiopathology]. 948 Mar 31

Congenital deficiency in coagulation inhibitors is a cause of hereditary thrombotic disease. The severity of symptoms is variable and depends on the type of deficit. In this paper, 44 children suffering from deep venous thrombosis, with a mean age of 5 years, were studied. A search for Lupus anticoagulant (LA) and coagulation inhibitor deficiency showed: 3/44 cases (6.8%) had protein S deficiency, 2/44 cases (4.5%) had protein C deficiency, 1/44 cases (2.3%) had deficiencies in both protein C and S; no cases of AT III deficiency and LA was positive in 2/44 cases (4.5%). Only 1 case of APC resistance out of 13 studied was found. Four family studies were performed and confirmed the congenital origin of the disorder.
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PMID:Thrombosis in congenital deficiencies of AT III, protein C or protein S: a study of 44 children. 949 88

Resistance to activated protein C (APC resistance) is the most common cause of thrombophilia and linked to a single point mutation in the factor V gene (G-->A transition at nucleotide 1691). In the past, several PCR based methods have been proposed to determine the allelostatus of individual patients from small amounts of blood DNA including PCR followed by restriction fragment length polymorphism detection (PCR-RFLP), PCR using sequence-specific primers (PCR-SSP) and oligonucleotide ligation assay (OLA). Here, we present a novel approach based on the method of peptide nucleic acid(PNA)-mediated PCR clamping which is extremely sensitive to base pair mismatches. If PNAs specific for the two allelic variants are applied separately in each case a clear discrimination between a heterozygous or homozygous normal or homozygous Factor V Leiden status is possible and no further confirmation step is required. In a prospective study, 60 patients with suspected venous thrombosis events were tested and compared to the conventional PCR-RFLP technique. The concordance between both methods was 100%. PNA-based factor V genotyping, therefore, should be considered for large scale screening of those patients considered to be at risk for deep venous thrombosis.
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PMID:Simple and reliable factor V genotyping by PNA-mediated PCR clamping. 956 91

In order to evaluate the actual incidence and clinical repercussion of activated protein C resistance (APCR) in our area, we performed a coagulation and thrombophillic study on 65 young patients diagnosed with deep vein thrombosis and 53 controls. Family and genetic study was carried out in APC-resistant patients. We found APCR in 26.15% of patients and the 77.7% of these and their relative were heterozygous for factor V Leiden. There's a clear relationship between phenotype APCR and thrombosis, and also between factor V Leiden and thrombosis.
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PMID:Incidence and clinical manifestations of activated protein C resistance and factor V Leiden in young patients with venous thromboembolic disease in Spain. 959 91

The factor V (Arg506-->Gln) mutation confers an increased risk of deep vein thrombosis, whereas its role in saphenous vein graft closure after coronary artery bypass grafting (CABG) remains unclear. This study examined the anticoagulant response to activated protein C (APC ratio) in relation to the surgical trauma and the significance of the factor V Leiden mutation in determining postoperative thrombin generation and fibrin formation and the risk of early vein graft occlusion. A total of 108 men undergoing elective CABG for exertional angina pectoris (mean age 61.1 +/- 8.7 years) were examined. The patency of saphenous vein grafts was studied at routine reangiography three months after CABG. Of 100 patients who underwent reangiography, 23 had one or more occluded vein grafts at reangiography. Heterozygosity for the factor V (Arg506-->Gln) mutation tended to be associated with early saphenous vein graft occlusion (5/11 carriers vs. 18/89 non-carriers with graft occlusion, chi2 = 3.52, p = 0.06), whereas pre- and postoperative APC ratios did not. Pre- and postoperative determinations of prothrombin fragment 1+2, thrombin-antithrombin complexes and soluble fibrin levels did not differ between patients with and without the mutation. Early saphenous vein graft occlusion after CABG could tentatively be added to deep vein thrombosis as a vascular complication that can be attributed to the factor V (Arg506-->Gln) mutation.
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PMID:Coagulation factor V (Arg506-->Gln) mutation and early saphenous vein graft occlusion after coronary artery bypass grafting. 971 41

Resistance to activated protein C (R-APC) is an inherited, autosomal dominant, coagulation abnormality that is increasingly recognized as an important etiology for thromboembolic disease and stroke in young adults. This report describes the case of a 27-year-old woman taking oral contraceptives who experienced an acute thrombotic right hemispheric stroke. Three days after rehabilitation admission (33 days after stroke) she developed a left femoral deep venous thrombosis (DVT) despite appropriate prophylaxis. Further diagnostic workup for the stroke and DVT identified R-APC, possibly exacerbated by oral contraceptives, as the etiology. Hematology consultation recommended lifetime anticoagulation with warfarin. The patient's family history revealed that a 19-year-old cousin had died of a stroke several years earlier. Several months after discharge, an acute DVT occurred in the patient's 28-year-old brother, who tested positive for factor V Leiden, a genetic abnormality closely associated with R-APC. A thrombotic stroke occurred in her grandfather a few months later, but he was not tested. Her father demonstrated a "borderline" positive R-APC test and probably represents the genetic link. Indications for patient and family screening regarding R-APC and other forms of hereditary thrombophilia and implications for rehabilitation medicine physicians are discussed.
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PMID:Resistance to activated protein C as an etiology for stroke in a young adult: a case report. 1008 46


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