Biomedical subjects

M Udvardy

Publications and source records attributed to M Udvardy.

At least 37 records · Page 2Linked to original sources

PubMed1999

[Gastric MALT lymphoma, clinical features].

Gastric mucosa associated lymphoma (MALT) can be regarded as a pathogenetic continuum of reactive B lymphocyte accumulation due to Helicobacter pylori infection, which after a series of mutation may presumably transform into a low grade and later on into a high grade MALT lymphoma. If the lymphoma is confined to the mucosa or strictly to the superficial part of gastric wall, a conventional, regular Helicobacter pylori eradication procedure has a good chance to bring about clinical, histological and less frequently molecular biological remission as well.

Amoxicillin↗

PubMed1998

[Hemostatic abnormalities in ischemic stroke].

The authors studied whether haemostatic abnormalities connected with the development of cerebral circulatory disturbances can be demonstrated in young stroke patients in whom Doppler and angiographic examination failed to reveal deviations indicative of stroke. They determined the in vivo activation of the coagulation system (TAT, F 1 + 2), the degree of secondary fibrinolysis (D-dimer), the plasma levels of the markers of fibrinolysis, with special regard to inhibitors: plasminogen activator inhibitor (PAI-1), alpha 2 antiplasmin (alpha 2 AP), alpha 2 macroglobulin (alpha 2 M), the frequency of pathologic serum lipoprotein (a)-Lp(a)-values and the association of PAI-1 and Lp(a) with the fibrinolytic system. They conclude that in the acute phase of the disease, the TAT and F 1 + 2 values were significantly elevated compared to the control, without change in the D-dimer value. The results suggest that in the tested period increased thrombin generation dominated and it significantly surpassed plasmin activity since the D-dimer values of that period did not indicate substantial increase in secondary fibrinolysis. The results of the study were separately analyzed in acute, chronic TIA and stroke groups. In the TIA and acute group the F 1 + 2 values, while in stroke the TAT values were more elevated. The in vitro fibrinolytic capacity of the patients significantly decreased compared to controls, showing significant correlation with the Lp(a) level, but not with the PAI value. Examination of the marker molecules renders possible to assess the degree of hypercoaguability and of endogenous lysis. Their knowledge is held important for judging the progression of the disease and the therapeutic consequences.

Adult↗

PubMed1998

[New possibilities in the management of hemorrhagic diathesis caused by factor deficiency and thrombocytopenia: recombinant active factor VII concentrate].

Recombinant Factor VIIa, a new therapeutic tool to treat severe bleeding caused by inhibitory haemophilia cases, some cases of thrombocytopenia and thrombocytopathy (e.g. severe type III von Willebrand disease) receives growing attention in clinical practice. Exogeneous FVIIa-in a supraphysiological concentration (clearly over 6 U/ml) seems to be able to generate quickly and safely (without thrombotic side effects) thrombin--the final enzyme of clotting--in physiological, or pathological conditions. A concise review about the possible mechanisms of action, indications, monitoring and clinical experience gained sofar with FVIIa is given in this report.

Factor VII↗

PubMed1998

[Current status of the management of upper gastrointestinal hemorrhage at a specialized hospital unit].

The prevalence of bleeding of the gastrointestinal tract is around 100/100,000 adults/year. These events need special diagnostic and therapeutic approach, which previously was located mostly to surgical departments. At the beginning of 1996 a specialized ward ("gastrointestinal bleeding unit, GBU") was created at the 2nd Dept. Medicine of the University Medical School of Debrecen. The authors give an account about their experiences with the first 250 cases, try to establish the optimal and necessary conditions and analyse the consequences of their newly developed "risk-score" system. The overall mortality was 9% during this period and surgical intervention proved to be necessary in only 10 cases. On the basis of the collected experiences, they are convinced that the described and elaborated model can well be used for the proper, up-to-date management of gasrointestinal bleeding disorders. As next they suggest an overall, regional organisation of such units, together with the correct determination and provision of the financial background.

Female↗

PubMed1998

[The role and significance of the most important known cytokines in inflammatory bowel diseases].

Several theories have already been postulated in connection with the pathogenesis of inflammatory bowel diseases, yet none of them has been approved. Recently increasing attention has been payed to different cytokines, playing central role in the development of inflammatory processes. In the intestinal mucosa of patients suffering from inflammatory bowel diseases increasing amounts of interleukin-1 (IL-1), tumor necrosis factor (TNF) and platelet activating factor (PAF) could be measured. On the other hand, antiinflammatory cytokines seem to be ineffective, or being present in insufficient amount (IL-4 and IL-10 respectively). It is therefore probable, that altered ratios of cytokines, or pathologic regulation of their production lead to progression of inflammation in IBD. Influence of cytokine production may open new therapeutic approach, e.g. IL-10 enema proved to be effective in the treatment of some cases of steroid-resistant ulcerative colitis, while intravenous administration was useful in Crohn's disease. A brief, comprehensive review of our present knowledge about cytokines in IBD is given.

Cytokines↗

PubMed1998

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.

Adolescent↗

PubMed1998

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.

Journal Article↗

PubMed1998

Increased in vivo platelet activation and reduced intravascular endothelium-derived relaxing factor and nitrate/nitrite production in patients with insulin-dependent diabetes mellitus.

Limited information seems to be available about the role of reduced endothelial production of endotheliumderived relaxing factor (EDRF)-nitrate/nitrite (NO) in the pathogenesis of diabetic angiopathy in insulindependent diabetes. A report of urinary and serum nitrate/nitrite, glucometabolic parameters, endothelial and in vivo platelet activation markers of 22 insulin dependent diabetics (IDDM) patients are given. Urinary and serum nitrate/nitrite concentrations were reduced in IDDM. This was independent of disease duration, presence of angiopathy and the glucometabolic parameters. A significant and inverse correlation of nitrate/nitrite excretion with endothelial markers (von Willebrand factor, soluble thrombomodulin) was documented. Moreover, reduced nitrate/nitrite excretion was strongly associated with elevated plasmatic beta -thromboglobulin levels. EDRF-NO production is reduced in IDDM and this reduction correlates with endothelial damage. Decreased nitrate/nitrite excretion may also influence in vivo platelet function, which results in increased in vivo platelet activation and suggests that the reduced intravascular production of EDRF-NO might play a role in the pathogenesis of angiopathy in IDDM.

Journal Article↗

PubMed1998

Changes in oncogene expression implicated in evolution of chronic granulocytic leukemia from its chronic phase to acceleration.

Expression of nine oncogenes was investigated in cell samples from fifteen patients with Philadelphia chromosome (Ph)-positive chronic granulocytic leukemia (CGL) both at diagnosis and at the onset of accelerated phase (AP) of the disease. The bcr-abl fusion gene, the H-ras gene and the c-myb gene were universally expressed. In comparison with the chronic phase (CP) of the disease, an increase in the levels of bcr-abl-, c-myb- and H-ras-related transcripts was found in three, two and three AP samples, respectively. Elevation of the bcr-abl-related message was associated with duplication of the Ph chromosome and amplification of the bcr-abl fusion gene in one AP sample. No CP samples were positive for c-myc or c-sis expression. On the contrary, c-myc and c-sis were expressed in three and four AP samples, respectively. The presence of c-myc-related transcript was associated with trisomy 8 with or without amplification of the c-myc oncogene in leukemia cells of two patients with CGL in AP. No changes of oncogene expression were found in four AP samples. However, we observed deletions of chromosome 13 and 17 or i(17q) in three of them, suggesting that tumor suppressor gene alterations may also be responsible for the development of AP of CGL. Our data indicate that heterogeneous alterations in oncogenes and tumor suppressor genes accompany the evolution of CGL-CP to the AP of the disease.

Acute-Phase Reaction↗

PubMed1997

[Pure red cell aplasia, associated with chronic lymphoid leukemia, successfully treated with closorine].

Pure red cell aplasia (PRCA) is a rare disorder, which is characterized by severe anaemia associated with reticulocytopenia and absence of erythroid precursor cell from the bone marrow. Mostly immunological mechanisms have a role in its pathogenesis. Primarily the acquired, idiopathic type occurs in adults, however, it is rarely associated with other disorders (autoimmune-, and lymphoproliferative diseases, etc.). The authors present a patient with B-cell chronic lymphocytic leukemia associated with PRCA, which was successfully treated with cyclosporine. The pathogenesis and the therapy of the PRCA is also summarized.

Cyclosporine↗

PubMed1997

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.

Arginine↗

PubMed1997

[Nitrogen monoxide (NO) in the function of the gastrointestinal tract and the liver].

This review is concerning with the endothel derived relaxing factor (EDRF) discovered in 1980 and identified as NO in 1987 in the function and activities of the gastrointestinal tract and the liver. It is of importance, that NO seems to basic mediator of the so called nonadrenerg-noncholinerg inhibitory innervation of the bowel, and also takes part in the regulation of mucosal blood supply and secretory function. In portal hypertension elevated cGMP is found in the urine, as evidence of increased nitrogen oxide synthase (NOS) activity. NO may act both as hepatoprotective and cytotoxic factor in the free radical reactions of several liver disease.

Digestive System↗

PubMed1997

The association of reduced endothelium derived relaxing factor-NO production with endothelial damage and increased in vivo platelet activation in patients with diabetes mellitus.

The role of reduced endothelial production of EDRF-NO in the pathogenesis of diabetic angiopathy has received much attention, however, most of the rather conflicting data were gained from animal experiments. Limited human experience seems to be available in insulin dependent diabetes, calling attention to decreased EDRF-NO production. Hereby the clinical, as well as laboratory investigation (urinary and serum nitrate/nitrite, lipid peroxidation, glucometabolic parameters, endothelial and in vivo platelet activation markers, etc.) of 35 non-insulin dependent (NIDDM) and 15 insulin dependent diabetics (IDDM) patients are given. Urinary and serum nitrate/nitrite concentrations were proven to be reduced in both patients groups. This change was independent of diabetes duration, presence of macroangiopathy, coronary heart disease and the glucometabolic parameters, however, correlation was registered with lipid peroxidation (total antioxidant status). An inverse correlation of nitrate/nitrite excretion with endothelial markers (von Willebrand factor, soluble thrombomodulin) was documented in NIDDM, this correlation was much stronger in IDDM. Moreover, in IDDM patients reduced nitrate/nitrite excretion was strongly associated with elevated plasmatic beta-thromboglobulin levels. The data presented here support to the hypothesis, that EDRF-NO production is reduced in diabetes and this reduction seems to correlate with endothelial damage. In IDDM the decreased nitrate/nitrite excretion may also lead to increased in vivo platelet activation, which suggests that the reduced amount of EDRF-NO might play a role in the pathogenesis of angiopathy in IDDM.

Adult↗

PubMed1997

[New agents and challenges in the antithrombotic management of arterial diseases].

The past decades have exposed and faced antithrombotic therapy (anticoagulants, antiplatelet agents, and fibrinolytics) to new challenges. The reperfusion treatment modalities of myocardial infarction needed improvement of fibrinolytic agents and adjuvant anticoagulant-antiplatelet therapy. The secondary prevention of stroke, along with the renewal of thrombolytic and anticoagulant therapy seems to be an other major area of new approach to antithrombotic therapy. The reocclusion and restenosis of coronary arteries means the most difficult issue and task for antithrombotic treatment modalities. These requirements accelerated the development of novel antithrombotic agents, the disintegrin family, the monoclonals directed against platelet adhesion and aggregation, the application of hirudin and its analogs and new generation of thrombolytic agents. Combined and sequential administration of different antithrombotic agents receives growing attention and seems also to be promising.

Anticoagulants↗

PubMed1996

[Fibrinolysis and vascular diseases].

A wide array of in vitro fibrinolysis tests had been performed for a long period, suggesting defective fibrinolysis, mainly impaired tPA response and reserve as major, frequent abnormality, predecessor or causative factor of venous thromboembolism. However, these abnormalities were troublesome to reproduce, and more recently fibrinolytic activators and inhibitors received growing attention as rather atherogenic and less thrombogenic risk factors. Even if it is still not settled, lipoprotein(a) may interfere with fibrinolysis, and seems to carry atherogenic risk, too. The genetic polymorphism of fibrinogen, plasminogen, PAI-1 and some other compounds modifying circulating fibrinogen levels are also discussed in this review.

Arteriosclerosis↗

PubMed1996

[Fibrinolysis studied by an in vitro clot lysis test in polycythemia vera].

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.

Adult↗

PubMed1996

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.

Blood Coagulation↗

PubMed1996

Promotion of the crosslinking of fibrin and alpha 2-antiplasmin by platelets.

Factor XIII (FXIII) is of high importance in the regulation of fibrinolysis. It crosslinks alpha 2-antiplasmin (alpha 2AP) and fibrin and by this way protects fibrin from the prompt elimination by plasmin. Although FXIII of platelets has been implicated in this protective mechanism, the role of platelets and platelet FXIII in the crosslinking process is far from being elucidated. As demonstrated by SDS PAGE and by immunoblotting for alpha 2AP, intact normal platelets resuspended in FXIII-free plasma or FXIII-free fibrinogen solution catalyzed the crosslinking of fibrin chains and also the crosslinking of alpha 2AP to fibrin alpha-chains. With FXIII-deficient platelets no crosslinking reaction could be observed indicating that the crosslinking with normal platelets was, indeed, due to platelet FXIII and not to another, putative platelet transglutaminase. However, the crosslinking of alpha 2AP to fibrin induced by the FXIII of intact platelets resuspended in FXIII-free plasma was considerably less extensive than the crosslinking carried out by the FXIII of normal plasma in the presence of FXIII-free platelets. Furthermore, the replacement of FXIII-free platelets by normal platelets in normal FXIII-containing plasma resulted in little, if any, difference in the crosslinking process. When crosslinking was induced by highly purified plasma FXIII the presence of intact FXIII-free platelets significantly accelerated the formation of alpha-chain polymers as well as the incorporation of alpha 2AP-fibrin alpha-chain hetero-dimer into these polymers. The results indicate that, in physiological conditions, platelet FXIII plays only a minor role in the crosslinking of alpha 2AP and fibrin; however, platelets, independently of their FXIII content, promote the crosslinking reaction by providing a catalytic surface on which the formation of highly crosslinked fibrin polymers is accelerated.

Blood Platelets↗