Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Livedoid vasculitis, a hyalinizing vasculopathy, is characterized by extensive formation of microthrombi and deposition of fibrin in the middermal vessels, which result in epidermal infarction, ulceration, and formation of stellate scars. In a prospective study of nonhealing ulcers in patients with livedoid vasculitis, we found a high incidence of anticardiolipin antibodies, lupus anticoagulants, increased levels of plasminogen activator inhibitor, and low levels of endogenous tissue plasminogen activator (t-PA) activity. This procoagulant tendency and decreased fibrinolysis may provide an explanation for the occlusive vasculopathy often noted in biopsy specimens from these patients. On the basis of these findings, we proposed that fibrinolysis with recombinant t-PA would lyse microvascular thrombi, restore circulation, and promote wound healing. In six patients who had nonhealing ulcers caused by livedoid vasculitis and in whom numerous conventional therapies had failed, low-dose t-PA (10 mg) was administered intravenously during a 4-hour period daily for 14 days. Five of the six patients had dramatic improvement; almost complete healing of the ulcers occurred during hospitalization, and tissue oxygenation, as measured by transcutaneous oximetry, increased. The one treatment failure was due to rethrombosis of the microvasculature; this patient was subsequently re-treated but with concurrent anticoagulation, and her leg ulcers healed. We conclude that daily administration of a low dose of t-PA is safe and effective treatment for nonhealing ulcers due to occlusive vasculopathy.
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PMID:Tissue plasminogen activator for treatment of livedoid vasculitis. 143 47

Three patients with karyotype XYY who had presented with deep vein thrombosis and leg ulcers (plus pulmonary embolism in two of them) were investigated for: (1) androgens (plasma testosterone measurement, testosterone oestradiol binding globulin (TeBG) assay, GnRH 50 micrograms test), and (2) haemostasis by fibrinolysis tests (euglobulin lysis time and area, antigenic plasminogen activator assay before and after 10 min venostasis). Full evaluation of haemostasis failed to demonstrate the presence of circulating anticoagulant or of antithrombin III, protein C and protein S deficiencies. One patient had neither hormonal nor fibrinolytic abnormality. The other two patients shared some clinical features with male hypogonadism (gynoid morphotype in both, hypotrophy of the testes in one, gynaecomastia in the other). They also had hormonal disorders ("over-response" to the GnRH test in one case, elevated TeGB in the other case) and abnormalities of fibrinolysis (poor response to venostasis, high baseline level of plasminogen activator). Response to venostasis became normal after 3 months of treatment with percutaneous dihydrosterone 125 mg per day in the two patients with initially poor response. The mechanism of venous pathology in XYY subjects is discussed. A genetic defect not involving the fibrinolysis system is possible since fibrinolysis was normal in one patient; however, abnormal fibrinolysis may have been responsible for the venous pathology in the other 2 patients. The role played by abnormalities of fibrinolysis in the pathogenesis of deep vein thrombosis and leg ulcers is recalled, and the possible implication of these abnormalities in patients with XYY karyotype is emphasized.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Post-phlebitic leg ulcers and XYY karyotype: fibrinolysis and androgenic function tests. Apropos of 3 cases]. 343 47

Urokinase plasminogen activator (uPA) and tissue plasminogen activator (tPA) were assayed in biopsies from the base, edge and adjacent skin of ischaemic and venous ulcers using a functional bioimmunoassay and a standard immunoassay. Two series of 14 biopsies were examined: from seven venous and seven ischaemic ulcers in the first series, eight venous and six ischaemic in the second. It was found that tPA was detected in only four samples of ulcer edge using the bioimmunoassay and in no sample by the standard immunoassay. By contrast, uPA was detected in all but one ulcer edge biopsy and at a significantly lower median concentration in the adjacent skin (16.9 units/g) than the ulcer edge (26.1 units/g) or base (32.3 units/g) (both P < 0.01). Levels of uPA were greater in the edge and base of venous compared with ischaemic ulcers. The predominant plasminogen activator in chronic leg ulcers is uPA; this activator may play an important role in wound healing.
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PMID:Tissue and urokinase plasminogen activators in the environs of venous and ischaemic leg ulcers. 851 96

The plasminogen activator/plasmin system is known to initiate a proteolytic cascade resulting in the activation of matrix metalloproteinases in vitro leading to the degradation of extracellular matrix. To investigate whether or not this cascade is present during delayed wound healing and contributes to the pathophysiological basis of impaired healing we examined the temporal expression of urokinase plasminogen activator, plasminogen activator inhibitor-1 and gelatinase-B in fluid collected from chronic venous leg ulcers compared to acute surgical mastectomy wounds. Using a chromogenic substrate assay, levels of active urokinase plasminogen activator in chronic wounds were found to be about five fold higher compared to sera and two fold higher compared to mastectomy wounds. Levels of active plasminogen activator inhibitor-1 in chronic wounds were four times higher than those found in sera and two times higher than those found in mastectomy wound fluid. Using a fibrin overlay system and reverse zymography, we found that when the wound was not healing, the expression of urokinase plasminogen activator in chronic wound fluid was initially detected in the active forms (50 and 33 kDa), but that as the wound healed and decreased in size, was detected as an inhibitor- bound urokinase plasminogen activator-plasminogen activator inhibitor-1 complex ( congruent with 80-116 kDa). When the expression of active urokinase plasminogen activator was highest, no plasminogen activator inhibitor-1 was detectable. In contrast, urokinase plasminogen activator was always detected in the inhibitor bound form as a urokinase plasminogen activator-plasminogen activator inhibitor-1 complex in blood- and plasma-derived serum and mastectomy wound fluid. Plasminogen activator inhibitor-1 was detected in blood-derived serum and mastectomy wound fluid but not in plasma derived serum. Expression of matrix metalloproteinase-9 in chronic wound fluids, analyzed by gelatin zymography, showed that when urokinase plasminogen activator was detected in the active forms, matrix metalloproteinase-9 was overexpressed by approximately twice that found in mastectomy wounds and approximately 30 times that detected in blood-derived sera. When urokinase plasminogen activator appeared almost entirely as an enzyme- inhibitor complex, the level of expression of matrix metalloproteinase-9 was similar to that seen in mastectomy wound fluid. We conclude that the switch in urokinase plasminogen activator expression from an active to inhibitor bound form correlates with the decrease seen in matrix metalloproteinase-9 expression suggesting the presence of a proteolytic cascade initiated by the plasminogen activator/plasmin system during wound healing leading to the activation of matrix metalloproteinase-9. In addition, expression of urokinase plasminogen activator and matrix metalloproteinase-9 appear to be useful biomarkers to determine clinical wound healing status.
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PMID:Temporal expression of urokinase plasminogen activator, plasminogen activator inhibitor and gelatinase-B in chronic wound fluid switches from a chronic to acute wound profile with progression to healing. 1041 51

The effect of wound fluids collected from acute well-healing wounds and chronic nonhealing venous leg ulcers on the plasminogen activation system of keratinocyte and fibroblast cell cultures was studied in a simplified wound-healing model. Acute wound fluid was collected from donor sites of split skin grafts at different time points representing the progressive healing of the wound. Urokinase-type plasminogen activator, tissue-type plasminogen activator, urokinase-type plasminogen activator receptor, and plasminogen activator inhibitor 1 expression were studied. The methods used were immunocapture assay and immunocytochemistry. The results indicated that the later the acute wound fluid was collected, the greater the urokinase-type plasminogen activator and the lower the plasminogen inhibitor-1 level in treated cells. In contrast, the level of urokinase-type plasminogen activator receptor remained stable irrespective of wound fluid treatment. Immunostaining for urokinase-type plasminogen activator of acute wound fluid-treated cells showed a disseminated punctate pattern over the cell surface, but with chronic wound fluid, urokinase-type plasminogen activator was localized to focal contacts. Our findings support the view that in the acute wound environment the plasminogen activator system is proteolytically active and that in chronic leg ulcers urokinase-type plasminogen activator and urokinase-type plasminogen activator receptor may also be organized for cell adhesion and migration.
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PMID:Differential effects of acute and chronic wound fluids on urokinase-type plasminogen activator, urokinase-type plasminogen activator receptor, and tissue-type plasminogen activator in cultured human keratinocytes and fibroblasts. 1167 40