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

Patients with leg ulcers caused by venous insufficiency often show evidence of previous deep venous thrombosis. Resistance to activated protein C (APC resistance) is a newly identified, autosomal dominant inherited defect in the anticoagulant system which significantly predisposes affected individuals to develop venous thrombosis. To elucidate the significance of APC resistance in venous leg ulcer patients, APC resistance was determined in plasma samples obtained from 46 unselected, consecutive patients with venous leg ulcers, admitted to hospital during a 6-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 patients with venous leg ulceration and should be considered a risk factor for the development of venous leg ulcer disease.
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PMID:Resistance to activated protein C: a common anticoagulant deficiency in patients with venous leg ulceration. 929 2

Pregnancy and especially delivery and the puerperium are associated with an increased risk of thromboembolic disease. Intravenous high dose heparin is the therapy of choice for manifest thromboembolic disease in pregnancy. However, high-dose heparin fails to prevent postthrombotic chronic venous insufficiency in more than one-third of the cases. Low-dose heparin may be used for antithrombotic prophylaxis during pregnancy. However, low-dose heparin may induce a substantial loss of bone density in up to 30% of cases and may be complicated by heparin-associated thrombopenia in up to 2%. This review discusses strategies to reduce these considerable risks. Prospective studies suggest that the risk of recurrence after prior deep vein thrombosis may be somewhat overestimated. These data suggest new therapeutic options in women with no risk factors other than a personal history of thrombosis. Improved diagnostic techniques may contribute to a better evaluation of the individual risk by assessing possible underlying problems such as resistance to activated protein C or deficiencies of coagulation inhibitors. Also, duration of prophylactic anticoagulation may be reduced by targeting treatment to periods of increased risk such as immobilisation, dehydration, surgery, delivery and the puerperium. Recently, evidence has been provided indicating that the use of low molecular weight heparins may be associated with reduced loss of bone density and a significantly attenuated risk of heparin-associated thrombopenia.
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PMID:[Prevention and treatment of thrombosis in pregnancy]. 876 88

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

Asthma control is a key point in patient management. GINA's most recent report emphasises the need to investigate uncontrolled asthma, of which non-compliance with treatment, COPD, smoking, chronic sinusitis, gastroesophageal reflux disease and obesity are the usual causes. The aim of this work is to evaluate the role of pulmonary thromboembolism (PTE) in cases of difficult- -to-treat asthma. We reviewed the case reports of patients with severe persistent asthma followed in our Asthma Outpatients Clinic between 2004 and 2006. We selected the ones that maintained uncontrolled disease despite an optimal therapeutical approach and investigated the causes. In this group (n=254), 28 (11%) had severe persistent asthma and their mean age was 44 +/- SD18 years old. 86% were females. Of these, 57% (n=16) had uncontrolled disease: 35% (n=6) due to non-compliance with treatment; 29% (n=5) pulmonary thrombombolism (scintigraphic confirmation); 12% (n=2) severe rhinosinusitis; 6% (n=1) hypereosinophilic syndrome; 6% (n=1) persistent allergen exposure and 6% (n=1) are still being investigated. Patients with TPE (mean age 56 +/- SD9 years old; 80% females; 80% Caucasians) were diagnosed with asthma as adults (mean age 37 +/- SD14 years old). The mean time until the diagnosis of TPE was 18 +/- SD12 years. Predisposing factors for TPE were venous insufficiency (40%), hypertension (40%) and deficit of functional protein C and S (20%). All these patients received anticoagulant therapy (80% are still medicated). It should be noted that after the beginning of anticoagulants, 40% of the patients achieved control of their asthma and 40% have partially controlled disease. There were no hospital admissions for asthma exacerbations after the beginning of anticoagulation in this group. This study supports the inclusion of TPE in the group of comorbidities to consider while investigating uncontrolled asthma.
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PMID:[Pulmonary embolism and difficult-to-treat asthma]. 1818 29

Acroangiodermatitis of Mali is a dermatologic condition of kaposiform skin lesions that has been associated with chronic venous insufficiency. Here we report a case of a 28-year-old Chinese man with acroangiodermatitis which co-existed with chronic lower limb deep vein thrombosis. Investigations revealed protein C deficiency and a frame shift mutation, c246_247dupCT, of the PROC gene. Our report lengthens the list of male acroangiodermatitis of Mali cases with a Chinese patient harboring a novel PROC mutation with manifest protein C deficiency.
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PMID:Acroangiodermatitis of Mali in protein C deficiency due to a novel PROC gene mutation. 2244 73

Many factors contribute to the pathogenesis of leg ulcer. Most patients have venous leg ulcer due to chronic venous insufficiency. Less often, patients have arterial leg ulcer resulting from peripheral arterial occlusive disease, the most common cause of which is arteriosclerosis. Leg ulcer may be of a mixed arteriovenous origin. In diabetic patients, distal symmetric neuropathy and peripheral vascular disease are probably the most important etiologic factors in the development of diabetic leg ulcer. Other causes of chronic leg ulcers are hematologic diseases, autoimmune diseases, genetic defects, infectious diseases, primary skin diseases, cutaneous malignant diseases, use of some medications and therapeutic procedures, and numerous exogenous factors. Diagnosis of leg ulcer is based on medical history, inspection, palpation of skin temperature, palpation of arteries, fascia holes, presence and degree of edema, firm painful cords, and functional testing to assess peripheral occlusive arterial disease or identify superficial and deep venous reflux of the legs. Knowledge of differential diagnosis is essential for ensuring treatment success in patients with leg ulcer. There are many possible etiologic factors of leg ulcers and sometimes, clinical findings are similar. Additional testing should be performed, e.g., serologic testing such as blood count, C-reactive protein, HBA1c, erythrocyte sedimentation rate, differential blood count, total proteins, electrolytes, coagulation parameters, circulating immune complex, cryoglobulins, homocysteins, AT, PAI-1, APC resistance, proteins C and S, paraproteins, ANA, ENA, ANCA, dsDNA, antiphospholipid antibodies, urea, creatinine, blood lipids, vitamins and trace elements. Also, biopsy of the lesion for histopathology, direct immunofluorescence, bacteriology and mycology should be included. Other tests are Raynaud (cold stimulation) test and pathergy test. Device-based diagnostic testing should be performed for future clarification. Ankle brachial pressure index, color duplex sonography, plethysmography, MSCT and MR angiography, digital subtraction angiography, phlebography, angiography, x-ray, and capillaroscopy in lupus erythematosus are indicated. Except for bacteriologic analyses of wound biopsies, there is no test to provide specific information on the wound condition.
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PMID:[List of diagnostic tests and procedures in leg ulcer]. 2437 72