Polymorphisms of glycoprotein Ib affect the inhibition by aurintricarboxylic acid of the von Willebrand factor dependent platelet aggregation.

Two polymorphisms of platelet glycoprotein Ib, VNTR and Thr/Met(145), regarded as the possible inherited risks factors for thromboembolic complications, have been suggested to underlie platelet response to activating stimuli. This study examined the functional significance of these polymorphisms in platelet reactivity and sensitivity to aurintricarboxylic acid (the antagonist of von Willebrand factor, vWF). To evaluate platelet function at low and high flow conditions we monitored the ristocetin-induced and vWF-mediated aggregation of isolated platelets and the platelet function analyzer collagen/ADP closure time (PFA-100 CT(CADP)), which reflects platelets' ability to adhere and aggregate in whole blood. Aurintricarboxylic acid significantly reduced ristocetin-induced platelet agglutination in a dose-dependent manner (IC(50)=3.5+/-1.9 microM). At the concentration of 100 microM it also markedly prolonged PFA-100 CT(CADP) (up to 147+/-32 s vs. 94+/-17 s in control). The efficacy of this antagonist in the inhibition of vWF-mediated platelet agglutination was approximately 1.5-fold higher in the VNTR B/Met145(+) carriers than in VNTR B/Met145(-) carriers ( P<0.05). Otherwise, no significant differences occurred between VNTR B/Met(145)-positive and B/Met(145)-negative individuals in the prolongation of closure time by ATA. These findings indicate that under certain experimental conditions VNTR-B and Met(145) alleles may contribute to the increased platelet sensitivity to some antagonists of platelet natural ligands.

[Von Willebrand factor in hemodialysed patients with chronic renal failure]. / Czynnik von Willebranda u chorych hemodializowanych z powodu przewleklej niewydolnosci nerek.

The aim of the work was to evaluate the von Willebrand factor antigen (vWF Ag) concentration in the blood plasma of hemodialysed patients with chronic renal failure. The study was performed in the group of 43 patients (means aged 42.8 years) with chronic renal failure dialysed means 4 hours 3 times a week. The blood was obtained before and after hemodialyze and in 11 patients additionally after 1 year of systematic hemodialyze. The control group consisted of 51 healthy volunteers means aged 35.6 years. In the citric blood plasma concentration of vWF Ag was determined using immunosorbed enzyme-linked assay (ELISA). In the blood plasma of patients with chronic renal failure significantly higher concentration of vWF Ag than in controls was observed. 4-hours and 1-year dialyze did not influence the level of vWF Ag in patients with chronic renal failure.

Thrombomodulin--endothelial thrombin receptor in blood of patients with unstable angina pectoris.

BACKGROUND: Thrombomodulin (TM) a membrane receptor for thrombin generated in blood in vivo, is present on the surface of vascular endothelium cells. The aim of our work was the determination of thrombomodulin in the blood of patients with unstable angina pectoris. MATERIAL AND METHODS: In the study took part 87 patients with unstable angina pectoris (40 women and 47 men) at age 41-79 years. Thrombomodulin was determined in citrated blood plasma with the use of enzyme immunoassay ELISA with the diagnostic kit manufactured by American Diagnostica. RESULTS: Statistically significant higher thrombomodulin concentration (sTM) was found in the patients when compared with the values recorded in control group. Elevated sTM levels depended on patients age and they were significantly higher in patients over 50 years old. There were no statistically significant differences with respect to patients gender and coexistent risk factors such as arterial hypertension, diabetes or smoking, but significantly higher sTM concentration was observed in patients with high serum cholesterol level. CONCLUSION: Elevated sTM concentrations result from the damage to vascular endothelium cells by the atheromatous process manifested in unstable angina pectoris.

[The influence of ozone therapy on endothelial damage markers in patients with atherosclerosis of lower extremities]. / Wplyw ozonoterapii na wskazniki uszkodzenia sródblonka naczyniowego u chorych na miazdzyce zarostowa.

The aim of study was to evaluate the influence of the treatment with oxygen-ozone mixture on the blood plasma antigen concentration of tissue plasminogen activator (t-PA) and von Willebrand factor (vWF) in patients suffering from atherosclerotic disease of lower extremities. The study was performed in the group of 28 (M/F 22/6) patients means aged 64.1 years with atherosclerotic diseases of lower extremities, in whom 2 weeks therapy with oxygen-ozone mixture was used. The control group consisted of 30 healthy volunteers in mean age 51.0 years. In the blood plasma obtained from the patients before and after treatment with oxygen-ozone mixture and from the control group determinations of t-PA and vWF antigen using ELISA were done. Both parameters were significantly increased in the patients before the treatment in comparison to the healthy controls. The treatment with oxygen-ozone therapy caused in patients slight statistically not significant raise of t-PA and vWF antigen showing the endothelial stimulation but not the destruction of vascular endothelium.

[Markers of endothelial stimulation in hyperthyroidism]. / Wskazniki pobudzenia sródblonka naczyniowego w nadczynnosci tarczycy.

The aim of the study was to evaluate function of endothelial cells in the patients with hyperthyrosis before thyrostatic treatment on the base of known markers of endothelial disturbances: von Willebrand factor and tissue plasminogen activator. The study was performed in the 36 patients aged 20-60 (means 36.7) years suffering from Graves disease and in 17 patients with hyperthyrotic goitre aged 30-59 (means 45.8). The control group consisted of 40 healthy volunteers. In the blood plasma concentration of tissue plasminogen activator (t-PA) and von Willebrand factor (vWF) antigen were determined with enzyme-linked immunoassay (ELISA). In patients with hyperthyroidism significantly increased antigen concentration of both studied parameters were observed. It seems that increased concentration of t-PA and vWF antigen in the blood of hyperthyrotic patients was the result of the release of them from injured thyroid gland by disease or of stimulating effect of thyroid hormones on the t-PA and vWF synthesis in the endothelial cells.

[Von Willebrand factor in plasma of patients with rheumatoid arthritis and lupus erythematosus]. / Czynnik von Willebranda w osoczu chorych na reumatoidalne zapalenie stawów i toczen rumieniowaty ukladowy.

The plasma levels of von Willebrand factor antigen (vWf:Ag) were evaluated for groups of 31 patients with rheumatoid arthritis and 34 patients with lupus erythematosus. The control group consisted of 34 healthy volunteers. In both groups the levels of vWf:Ag were increased to 243% and 240% respectively. The levels of vWf:Ag were also analysed statistically for the correlation with age of patients, time of the duration of disease and fibrinogen levels. No correlations were found. Obtained results suggest that measurements of vWf:Ag concentrations may be useful as potential marker of endothelial injury.

[Sorption properties of Polish sorbents of the 2nd generation in relation to phenobarbital]. / Wlasciwosci sorpcyjne Polskich sorbentów polimerowych II generacji wobec fenobarbitalu.

Two polymers sorbents of the 2nd generation Vinylsorb SS and Vinylsorb S (modified) were compared with commercial sorbent Amberlite XAD-4 to present their abilities to bond phenobarbital (Luminalum-Polfa). In the tests on perfusion of whole blood it was noticed that all three sorbents have similar ability to eliminate phenobarbital from the blood. About 80% of phenobarbital was adsorbated from the blood after 90 minutes of tests. Sorption properties of the sorbents were kept until 240 minutes of the experiment.