The most severe forms of Perthes' disease associated with the homozygous Factor V Leiden mutation.

It has recently been postulated that thrombophilia may have a role in the aetiology of Perthes' disease. The published reports, however, remain conflicting. In this study a retrospective analysis of the coagulation parameters was made in 47 patients with Perthes' disease and the results compared with the clinical data. Five patients with Factor V Leiden mutation were found (10.6%) and surprisingly four of them had a homozygous pattern. These four patients showed the most severe form of the disease, Catterall group IV, with flattening of the entire epiphysis, involvement of the metaphysis, shortening and broadening of the femoral neck, trochanteric overgrowth and developed mushroom-shaped aspherical laterally displaced femoral heads in dysplastic acetabula. We would like to suggest that the homozygous form of Factor V Leiden mutation has some role in the clinical course of Perthes' disease and particularly its most severe form.

[Porphyria cutanea tarda and hepatitis C virus]. / Porphyria cutanea tarda és hepatitis C-vírus.

The development of clinically overt porphyria cutanea tarda (PCT) can be attributed to joint effects of genetic predisposition and environmental factors. Regarding exogen factors, studies from several countries published in the last years gave an account of significantly higher frequency of chronic hepatitis C virus (HCV) infection in PCT patients compared to the normal population. At the Department of Dermatology of University of Debrecen the prevalence of positive anti-HCV antibodies has been found in approximately 55% of PCT patients diagnosed from 1990 to 1999, which is comparable to the average prevalence rate seen in Southern-European countries. The majority of male patients were anti-HCV positive and consumed regularly alcohol, whereas every female patient had taken contraceptives. Liver enzymes were only slightly elevated in the majority of the patients and liver biopsy had to be performed only in three patients duo to chronic hepatitis. Our findings emphasise how important the screening of PCT patients for anti-HCV antibody considering that it might be important quo ad vitam for young men.

[Hemostasis in liver diseases]. / Májbetegségek és haemostasis.

Liver plays central role in the synthesis and metabolism of the pro- and anticoagulant enzymes of blood coagulation. Acute or chronic liver failure frequently result in different bleeding phenomena. Thrombocytopenia due to hypersplenism and lack of haemopoietic factors seems to be common, but in spite of thrombocytopenia and more or less platelet malfunction thrombocytopenic bleeding is usually less prominent feature. Bleeding esophageal varices, clotting abnormalities with peritonejugular shunts may pose many difficulties in clinical practice. Transjugular intrahepatic shunt (TIPS) has been a major step forward treating refractory esophageal bleeding or ascites, however to keep the stent patent seems to be still unresolved. Along with the bleeding tendency or symptoms concommittant venous thromboembolic events are may not be considered as rare events in cirrhosis. Special problems are also coupled with ascites, which contains an almost full inventory of coagulation proteins, also with the medical and interventional therapy of Budd-Chiari syndrome, and other veno-occlusive conditions with or without transplantation.

Reduced in vitro clot lysis and release of more active platelet PAI-1 in polycythemia vera and essential thrombocythemia.

Because platelets interact with fibrinolysis in a complex manner, it can be expected that with abnormal platelet numbers and quality this interference can be even more profound. The aim of this work was to study the lysis-resistance of platelet-rich clots in diseases with high platelet counts: polycythemia vera (PV), essential thrombocythemia (ET) and to make comparison with polyglobulia (PG). Platelet-rich plasma (PRP) and platelet-poor plasma (PPP) were analyzed by an in vitro clot lysis test. Plasminogen activator inhibitor-1 (PAI-1) activity was measured in plasma and in the supernatants of the washed and gel-filtered platelets after activation by thrombin. The lysis showed decreased speed of PPP-clots in PV and ET. This phenomenon was even more marked in PRP-clots from PV and ET, but further increased lysis resistance after retraction was not observed in PV and ET, most likely due to abnormal platelet functions. Our results suggest that the fibrinolytic activity is reduced in PV and ET, and may play a role both in the increased aptitude for venous thrombosis and in the arterial complications. These are partly caused by higher plasmatic PAI-1 activity as well as by more active platelet PAI-1. The PAI-1 activity was significantly higher in the supernatants of the washed and gel-filtered platelets of PV after activation by thrombin compared with controls. Other factors might have influenced the reduced fibrinolysis.

Increased platelet activation and decreased fibrinolysis in the pathogenesis of aseptic necrosis of the femoral head.

Thrombotic events, increased tendency toward intravascular thrombosis and decreased fibrinolysis seem to be possible pathologic causes for aseptic necrosis of the femoral head (ANFH) in adults. This project was to study whether either increased platelet activation or decreased fibrinolytic activity and/or any other thrombogenic factor may be implicated in the evolvement of ANFH. The speed of the in vitro lysis was significantly lower in patients (both in primary and in secondary cases) compared with healthy controls. The platelet activation (measuring with beta TG) proved to be significantly higher in the primary group as well as in the secondary group compared with healthy controls. Lp(a) levels were elevated in primary and secondary cases. This alteration was more characteristic in the primary cases. Fibrinogen levels were also elevated in the primary group, but the difference was not significant. The data shown here may further support that hypofibrinolysis and increased thrombogenesis are major causes of ANFH. Early diagnosis of ANFH increases the chances of modifying the course of this disabling disease.

Effect of L-arginine on in vitro plasmin-generation and fibrinogenolysis.

L-arginine ahs received much attention in numerous aspects of the regulation of vascular tone and haemostasis. L-arginine seems to be capable to bind to plasminogen, too. The aim of the present paper is to investigate the action of L-arginine on in vitro plasmin generation and fibrino(geno)lysis by chromogenic, kinetic plasmin generation assay and electrophoretic analysis. The acceleration of tPA-induced plasmin generation in the presence of low concentration of L-arginine, along with augmentation of in vitro fibrinogenolysis have been documented. L-arginine may have a role in the modification of fibrinogenolysis, and this role should be considered if arginine is used as an element of some novel antithrombotic agents.

Coumarin-induced skin necrosis following heparin-induced thrombocytopenia and thrombosis. A case report.

A severe thrombotic thrombocytopenic status, induced by heparin in a sixty-nine-year-old woman undergoing total hip joint arthroplasty, was treated by switching the anticoagulant therapy to coumarin, which induced skin necrosis. There appeared to be a possible causal relation between the severe immune reaction to heparin and the condition that predisposed to skin necrosis in the presence of coumarin. In patients who express a strong immune response to heparin, a different anticoagulant approach other than use of coumarin congeners appears to be justified.

New pentamidine related substances which simultaneously inhibit platelet aggregation and accelerate plasmin generation and in vitro clot lysis.

Pentamidine, a highly toxic drug, possesses RGD-peptide (Arg-Gly-Asp)-like antiplatelet actions. The objective of this investigation was to study the anticipated profibrinolytic and antiplatelet actions of pentamidine and of pentamidine (bearing guanidino-like groups)-related synthetic peptidomimetic compounds. Platelet aggregation inhibition was assessed using ADP, thrombin, collagen, arachidonic acid and epinephrine as inducers, by aggregometry. In vitro chromogenic plasmin generation tests and clot lysis assays were also performed. Two (assigned as D-2 and D-3) of the synthetic pentamidine-guanidino related molecules were able to inhibit platelet aggregation and simultaneously accelerate in vitro plasmin generation and clot-lysis in the nM range. These dual action antithrombotic agents now need to be tested further to assess their antithrombotic actions in vivo.

[Fibrinolysis studied by an in vitro clot lysis test in polycythemia vera]. / A fibrinolysis vizsgálata in vitro alvadékoldási teszt segítségével polycythaemia verában.

Results obtained by a simple in vitro clot lysis test in polycythemia vera, polyglobulia, essential thrombocythemia and chronic immun thrombocytopenic purpura are reported. Increased lysis resistance of the platelet-rich clots was demonstrated in polycythemia and essential thrombocythemia, ostensibly caused by the high plasma level of plasminogen activator inhibitor-1. Following retraction of platelet-rich clots no further increase of lysis-resistance occurred in polycythemia and essential thrombocythemia. This phenomenon is most likely due to abnormal platelet function. The well known thromboembolic complications may at least partly result from the impaired fibrinolysis in diseases with high platelet counts.

RGDFAP: platelet aggregation inhibitory and profibrinolytic hybrid peptide (RGDF coupled with the carboxy terminal part of alpha 2-antiplasmin) enhances plasminogen binding to platelets.

As published in a recent issue of Blood Coagulation and Fibrinolysis, the hybrid peptide RGDFAP, composed of RGDF (Arg-Gly-Asp-Phe) coupled to a synthetic peptide residue of the carboxy terminal part of antiplasmin (AP26) inhibited platelet activation and augmented plasmin generation and in vitro fibrin clot lysis. This peptide contains an RGD motif which provides linkage to platelet GP IIb-IIIa. The antiplasmin part of the molecule may attach free plasminogen, which in turn increases the amount of platelet surface bound plasminogen, probably yielding enhanced lytic action at the site of thrombus formation. This hypothesis was investigated and confirmed by the results of platelet-plasminogen binding assays, using FITC-labelled antiplasmin antibodies and radioligand binding analysis. Increased platelet-linked plasminogen was detected by a chromogenic method, along with the acceleration of in vitro lysis of platelet-rich clots in the presence of RGDFAP peptide.

Altered lysis resistance of platelet-rich clots in patients with insulin-dependent diabetes mellitus.

The fibrinolytic resistance of platelet-rich arterial thrombi received much attention. Clot lysis method was used to assess the in vitro fibrinolytic properties in diabetes mellitus. Platelet rich (PRP) clots were formed by addition of thrombin, and lysis was induced by tissue-plasminogen-activator. The coagulation and lysis was followed by the light scattering properties. A special pattern of good initial lysis followed by a second clotting phase was observed in more than half of insulin dependent diabetic patients, while a similar pattern of clot-lysis was only occasionally found in non-insulin dependent diabetes mellitus or in the healthy control group. Following the thrombin activation of washed, gel-filtered platelets, the supernatants possessed an inhibitory action on in vitro lysis of PPP-clots. This suppression was remarkably stronger in IDDM, along with the highest PAI-1 activity concentration ratio of the platelet lysates, compared to plasmatic levels. The relation of this special type of PRP clot-lysis resistance to diabetic vascular complications needs further clarifying and investigations.

[Syncumar-induced necrosis following heparin-induced thrombocytopenia and thrombosis]. / Heparin indukálta thrombocytopeniát és thrombosist követö syncumar-necrosis esete.

The authors describe the combined occurrence of heparin-induced thrombocytopenia and cumarin-induced skin necrosis, a rare condition that has not yet been reported in Hungary. The 69-year-old woman had received prophylactic heparin treatment prior to total hip arthroplasty. The first complication that the anticoagulant therapy brought about was serious thrombocytopenia paradoxically associated not with bleeding but with deep vein thrombosis. The latter necessitated coumarin therapy which resulted in severe skin necrosis.

[Fibrinolysis in chronic liver diseases studied by in vitro blood coagulation tests]. / A fibrinolysis vizsgálata krónikus májbetegségekben in vitro alvadékoldási próba segítségével.

A simple and easily reproducible in vitro clot lysis test less frequently indicated increased rate of fibrinolysis in chronic hepatic disease than expected. In hepatic cirrhosis clot lysis slows down as the condition deteriorates or as the plasma concentration of von Willebrand factor increases, thus the test may have certain prognostic value. The present observations suggest that the occasional acceleration of fibrinolysis in cirrhosis may be related to either increased production or decreased clearance of tPA, and is not due to impaired fibrinolysis inhibitor system.

Metabolic actions of a single atenolol and metoprolol dose.

Atenolol (CAS 29122-68-7) and metoprolol (CAS 37350-58-6) are beta 1-selective adrenoceptor antagonists without intrinsic sympathomimetic activity. beta-Receptor blockers influence carbohydrate- and lipid metabolism. Liver is a central organ of these processes. The metabolic fate of a single oral atenolol and metoprolol dose and their actions on carbohydrate- and lipid parameters have been investigated. Healthy male rats received a dose reducing heart beat/min by 25% (atenolol: 6 mg/kg; metoprolol: 10 mg/kg). About 9% of atenolol is metabolized by cytochrome P-450 (P-450). P-450-dependent functions (aminopyrine-N-demethylase, hexobarbital biotransformation time) were not inhibited. Serum bilirubin was normal. Triglyceride (TG), total cholesterol and HDL-cholesterol levels of the plasma were not affected. Transient blood glucose increase was measured returning to initial value at 120 min. Metoprolol is metabolized by hepatic monooxygenases. P-450-dependent functions were inhibited correlating to the lowered P-450-content of the microsomes. High TG level and decreased HDL-cholesterol content were measured. Blood glucose was significantly high. The liposoluble metroprolol affected the hepatic functions more than the hydrophilic atenolol. The monitoring of blood glucose during beta-receptor antagonist treatment may be suggested.

[Diabetes mellitus and fibrinolysis (experience with an in vitro clot lysis test)]. / Diabetes mellitus és fibrinolysis (tapasztalatok in vitro alvadék oldási próbával).

After a concise review on fibrinolysis in diabetes mellitus, special attention is given to the observations suggesting impaired fibrinolysis in non-insulin dependent diabetes mellitus and in hyperinsulinaemia. This fibrinolytic defect, based mainly upon indirect data, may contribute to the development of macroangiopathy. The results discussed here, gained by a simple in vitro clot lysis assay revealed decreased fibrinolytic properties in some of the non-insulin dependent diabetic patients, however the mean value did not differ significantly from the control. The potential profibrinolytic effect of different antidiabetic treatment profibrinolytic effect of different antidiabetic treatment modalities also received attention. The clinical significance of the apparent alteration of fibrinolysis in diabetes mellitus should be evaluated appropriately as a part of a complex disturbance of haemostatic balance in diabetes mellitus. Further studies and improved fibrinolytic methods seems to be required to ascertain a causal relationship between altered fibrinolysis and diabetic vascular complications.

[Correlation between adhesive factors of primary hemostasis and liver fibrogenesis in alcoholic live cirrhosis]. / A primer haemostasis adhezív tényezöi és a máj fibrogenesis kapcsolata alkoholos májcirrhosisban.

Colchicine administration is able to reduce collagen production and the fibrogenetic process in alcoholic liver diseases in the same time. The decrease of the serum lipid peroxidation capacity along with type III procollagen propeptide level was associated with the simultaneous reduction of plasmatic von Willebrand factor, fibronectin and beta-thromboglobulin levels. This observation suggest a connection between the regulation of primary haemostasis and liver fibrogenesis.

[Correlation between thrombocytes and fibrinolysis]. / A thrombocyták és a fibrinolysis kapcsolata.

After a concise review of the fibrinolysis modifying effect of platelets, a simple, reliable and reproducible in vitro microplate clot-lysis method is described which is able to demonstrate the lytic resistance of platelet rich clots. The same method proved to be suitable to show the enhanced lysis in platelet rich lytic environment, caused probably by plasminogen attached to platelet surface. The results discussed here suggest that these effects need the presence of intact platelets.

Possible role for platelet insulin receptors in modulating platelet function in health and diabetes mellitus.

Binding studies have shown that human platelets contain binding sites for insulin with a surface density similar to that described for other cells.(1) Evidence for a reduced number and affinity of human platelet membrane insulin binding sites in non-insulin dependent diabetes mellitus (NIDDM) has been provided.(2) However, the influence of insulin and insulin receptors on platelet function has not been completely investigated and clarified. Falcon et al(3) reported phosphorylation of a subunit of the insulin receptor on platelets in response to insulin, but no alterations were detected in cAMP formation or degradation, inositol phosphate formation or phosphorylation of proteins other than the receptor itself. On the other hand Trovati et al(4) found reduced platelet aggregation responses to ADP, PAF, epinephrine, collagen and arachidonate in the presence of 40 µU/ml insulin. Their experience with an euglycemic-hyperinsulinemic clamp provided some further in vivo evidence to support the above mentioned findings. Platelet thromboxane A(2) formation was not altered in the presence of the hormone.

Insulin resistance in obese boys with acanthosis nigricans.

Insulin resistance was investigated in three obese boys with acanthosis nigricans and their results were compared to those obtained in non-acanthotic obese patients. Blood glucose immune reactive serum insulin and C-peptide during oral glucose tolerance test and 125I-insulin binding investigated. Obese patients with acanthosis nigricans were more insulin resistant than simple obese controls. Insulin binding studies performed in two acanthotic patients suggested that one of them had insulin resistance type A, and the second patient had insulin resistance type B. According to the results acanthosis nigricans can serve as a marker for severe insulin resistance in obesity.