The Effect of Dialyser Membrane Material on Intradialytic Changes in Platelet Count, Platelet Aggregation, Circulating Platelet Aggregates and Antithrombin III

The authors previously reported an increase in platelet aggregation in the days after coronary angiography, accompanied at times by worrying cardiovascular disorders (ventricular fibrillation in one case, death in two others). In the present study, ten patients received a platelet antiaggregating drug (ticlopidin) 5 days before their coronary angiography. No significant changes were detected in the test for circulating platelet aggregates (CPA test) in these patients.

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Circulating Platelet Aggregates During Emotional Stress and Cigarette Smoking

10.1055/s-0039-1682422 ◽

1977 ◽

Author(s):

G.F. Gensini ◽

R. Abbate ◽

D. Prisco ◽

G.G. Neri Serneri

Keyword(s):

Platelet Aggregation ◽

Medical Students ◽

Cigarette Smoking ◽

Cigarette Smoke ◽

Emotional Stress ◽

Predictive Value ◽

Normal Values ◽

Circulating Platelet Aggregates ◽

Platelet Aggregates ◽

Clinically Significant

Increased platelet aggregation has been observed in various hypercoagulable states, but its predictive value for thrombosis is so far uncertain. We studied the effect of emotional stress and of cigarette smoking on circulating platelets by platelet aggregates ratio (PAR) according to Wu and Hoak (1974.) in medical students aged 20-22 years. The emotional stress was undergoing a University examination.PAR was measured immediately before the examination, at the end and 15 and 30 min after the examination.PAR was significantly lowered in all the subjects at the end (P<0.0l) and after 15 min (P<0.0l) but returned toward normal values after 30 min. The decrease of PAR suggests the production of reversible circulating platelet aggregates. The effect of smo=king a cigarette has been investigated in 8 students. PAR has been determined before smoking, at the end and after 2,5 and 10 min. Smoking lasted 4 min. In 5 subjects we observed a decrease of PAR at 2 min (P< 0. 01), whereas at 5 and 10 min PAR value became normal. Lettuce cigarette smoke did not affect PAR value. Our results indicate that: 1) – Platelet aggregates are very easily produced in circulating blood; 2)- A low value of PAR does not necessarily indicate a platelet hy=peraggregability clinically significant.

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Effect of Indobufen (K 3920) A New Antiplatelet Agent After Oral Administration in Patients with Vascular Diseases

10.1055/s-0039-1684650 ◽

1979 ◽

Author(s):

S. Coccheri ◽

G.C. Fortunato

Keyword(s):

Platelet Aggregation ◽

Antiplatelet Agent ◽

Vascular Diseases ◽

Maximal Amplitude ◽

Marked Inhibition ◽

Lysis Time ◽

Euglobulin Lysis Time ◽

Circulating Platelet Aggregates ◽

Platelet Aggregates ◽

Induced Aggregation

The antiaggregating effect of a new butyric acid derivative, indobufen (K 3920), was investigated in 30 patients with vascular diseases. A between-patient study was performed by administering 50 mg b.i.d. or 100 mg b.i.d. for 14 days to 2 groups of patients. A series of platelet function and clotting parameters were recorded at the end of the treatment period, both 2 and 24 h after the last administration.A marked inhibition of platelet aggregation was observed in both groups, as shown from the significant changes in maximal amplitude, reaction time and slope of ADP- and collagen-induced aggregation wave.Similar results were observed at the Breddin test in both groups of patients and at all experimental times.Platelet adhesiveness was also reduced and circulating platelet aggregates were normalized in all patients who had abnormal basal values.A shortening of euglobulin lysis time was observed 2 h but not 24 h after administration of both doses.Tolerability was excellent.Indobufen appears to be a promising drug for treatment of vascular diseases where platelet aggregation is involved.

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Comparison Of The Thrombogenic Potential Of Two Membranes During Haemodialysis

10.1055/s-0038-1652947 ◽

1981 ◽

Author(s):

S M Rajah ◽

M J Crow ◽

D R Donaldson ◽

N Sreeharan ◽

A M Davison

Keyword(s):

Platelet Count ◽

Platelet Aggregation ◽

Detailed Examination ◽

Polycarbonate Membrane ◽

Dialysis Treatment ◽

Regular Dialysis Treatment ◽

Dialysis Membranes ◽

Platelet Aggregates ◽

Thrombogenic Potential ◽

Sparing Effect

The thrombogenicity of two dialysis membranes was compared by observing the changes in platelet function, heparin sparing effect and scanning electron microscopy (SEM) findings following haemodialysis. Ten patients undergoing regular dialysis treatment using a Meltec Multipoint Kiil board dialyser of 1.5 sq.m, surface area, have been investigated. The two membranes studied were Cuprophane (C) and Polycarbonate (P). All patients entering the study had not received any antiplatelet therapy in the 14 day period prior and the heparin schedule remained unchanged for both membranes. The thrombogenic potential was assessed by chaig- es in platelet count, platelet adhesion, platelet aggregation with collagen, plasma B-Thromboglobulin (B-Tg) during dialysis, changes in heparin concentration post-dialysis and detailed examination of the membranes by SEM at the end of dialysis.There was a significant fall in platelet count (p< 0.001) and platelet aggregation with collagen (p<0.05) with the C membrane, whereas the comparable values for the P membrane were not significant. Plasma B-Tg was very significantly raised with the C membrane (p<p.001) but to a lesser degree with the P membrane (p<0.05). Plasma heparin concentrations were significantly higher at the end of dialysis (p<0.05) with the P membrane compared to the C membrane, indicating a heparin sparing effect. SEM demonstrated consistently less platelet aggregates and fibrin deposition with the P membrane.The results of this study indicate that the polycarbonate membrane has less thrombogenic potential (hence greater overall efficiency) than the Cuprophane membrane.

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Platelet Function Parameters In Diabetic Patients

10.1055/s-0038-1653365 ◽

1981 ◽

Author(s):

A I Woods ◽

S S Meschengieser ◽

N M Sutton ◽

M A Lazzari

Keyword(s):

Platelet Aggregation ◽

Platelet Function ◽

Diabetic Patients ◽

Circulating Platelet Aggregates ◽

Diabetic Population ◽

Platelet Aggregates ◽

Spontaneous Platelet Aggregation ◽

Age Range ◽

Induced Aggregation ◽

Ristocetin Cofactor

Abnormalities in platelet function tests have already been described in diabetic patients reflecting platelet hyperreactivity. An attempt to determine which of the tests seemed to be more affected in the diabetic population was done in a group of 34 diabetic patients (20 men and 14 women, age range 15-76). The tests performed included assay of Ristocetin Cofactor (McFarlane et al.) circulating platelet aggregates (CPA) (Wu-Hoak) and platelet aggregation induced by ADP in low concentration (0.6 x 10-6M) and Bovine Factor VIII (0.001 U/ml). In matched controls only 3.5% had a positive aggregation induced by Bovine F VIII and with ADP (0.6 x 10-6M% ) the extent of maximum aggregation was 30%.In 15 of the 34 patients (44%) aggregation induced by ADP in high dilution was greater than 50% and this was the test more frequently affected. The level of Ristocetin Cofactor was increased (>160%) in 12 of 34 patients (35%) and aggregation induced by BF VIII was positive also in 12 patients (35%). The detection of CPA was positive in 9 patients (26%). Two patients had spontaneous platelet aggregation and in them all the other tests performed were also positive. Three patients had 3 of the tests altered, and 11 patients only had 2 affected tests.The assay more affected was the ADP induced aggregation followed by the Ristocetin Cofactor levels and BF VIII induced aggregation. The test less affected was the CPA. A correlation with clinical data will be mentioned.

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Prevention of in vivo Platelet Aggregation by Indobufen in Angina Patients during Exercise

Journal of International Medical Research ◽

10.1177/030006058100900205 ◽

1981 ◽

Vol 9 (2) ◽

pp. 113-119 ◽

Cited By ~ 1

Author(s):

E M Pogliani ◽

R Fantasia ◽

C Perini ◽

G Corvi

Keyword(s):

Platelet Aggregation ◽

Bicycle Ergometer ◽

Crossover Design ◽

Double Blind ◽

Before And After ◽

Circulating Platelet Aggregates ◽

Platelet Aggregates ◽

Induced Aggregation ◽

Platelet Functions

Platelet aggregation induced by 3 concentrations of ADP and collagen was assessed in thirty patients with stable angina, before and after exercise with a bicycle ergometer. The patients received a single oral 200 mg dose of indobufen and placebo according to a crossover design in double-blind conditions. Platelet sensitivity to both aggregating agents increased when exercise was carried out after placebo, whereas indobufen markedly inhibited ADP- and collagen-induced aggregation. Circulating platelet aggregates increased in some patients during exercise after placebo but not after indobufen. These results suggest that effort may be an important factor in activation of platelet functions and that the use of drugs blocking the arachidonate pathway and the release reaction may be appropriate in patients with angina.

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The Evaluation of a Method for Adenosine Diphosphate Induced Platelet Aggregation in the Guinea Pig

Thrombosis and Haemostasis ◽

10.1055/s-0038-1654277 ◽

1971 ◽

Vol 25 (01) ◽

pp. 030-040 ◽

Cited By ~ 3

Author(s):

R. D Mackenzie ◽

J. G Henderson ◽

J. M Steinbach

Keyword(s):

Platelet Count ◽

Platelet Aggregation ◽

Guinea Pig ◽

Adenosine Diphosphate ◽

Infusion Time ◽

Platelet Response ◽

In Vivo Measurement ◽

Platelet Concentration ◽

Platelet Aggregates

SummaryA method is described for the in vivo measurement of ADP-induced platelet aggregation in the guinea pig. This method uses the property of the lungs to remove platelet aggregates from the circulation. ADP is infused into the jugular vein and blood samples are removed from the carotid artery for determination of platelet concentration.In order to find a practical concentration of ADP and infusion time, the effects of several concentrations and infusion time on platelet count versus time were determined. A dose of 0.2 mg/kg ADP infused over 1 min was found to produce an approximately 50% drop in platelet count with a return to the original level at about 30 min. The analysis of the platelet response to ADP can be made quantitative by measurement of the total response, that is, the total decrease of platelet count from start of infusion to the return to preinfusion values.Prostaglandin E1 was tested and found to inhibit the total aggregation response with this method.

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P-selectin–dependent platelet aggregation and apoptosis may explain the decrease in platelet count during Helicobacter pylori infection

Blood ◽

10.1182/blood-2009-09-241166 ◽

2010 ◽

Vol 115 (21) ◽

pp. 4247-4253 ◽

Cited By ~ 40

Author(s):

Jeng-Jung Yeh ◽

Sharon Tsai ◽

Deng-Chyang Wu ◽

Jeng-Yih Wu ◽

Ta-Chih Liu ◽

...

Keyword(s):

Flow Cytometry ◽

Helicobacter Pylori ◽

Platelet Count ◽

Platelet Aggregation ◽

Thrombocytopenic Purpura ◽

Membrane Blebbing ◽

Significant Release ◽

Platelet Aggregates ◽

H Pylori

P-selectin expression has been shown in Helicobacter pylori–infected persons, an infection that has been clinically associated with platelet-related diseases, such as idiopathic thrombocytopenic purpura. However, the role of P-selectin expression during H pylori infection remains unclear. In this study, we hypothesized that P-selectin expression was associated with platelet aggregation during H pylori infection. Using flow cytometry, we examined the levels of adhesion between H pylori and platelets as well as the levels of P-selectin expression and platelet phosphatidylserine (PS) expression during H pylori infection. Significantly high levels of adhesion between pro-aggregatory bacteria and platelets were observed. We identified that H pylori IgG is required for bacteria to induce P-selectin expression and that a significant release of P-selectin is essential for H pylori to induce aggregation. In addition, cellular apoptotic signs, such as membrane blebbing, were observed in platelet aggregates. PS expression was also detected in platelets during infection with both pro-aggrogatory and nonaggregatory strains of H pylori. These results suggest that the decrease in platelet counts seen during H pylori infection is the result of P-selection–dependent platelet aggregation and PS expression induced by the bacteria.

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Prostacyclin can Replace Heparin for Haemodialysis in Dogs

10.1055/s-0039-1684576 ◽

1979 ◽

Cited By ~ 1

Author(s):

H.F. Woods ◽

M.J. Weston ◽

S. Bunting ◽

S. Moncada ◽

J.R. Vane

Keyword(s):

Platelet Count ◽

Platelet Aggregation ◽

Vascular Endothelium ◽

Potent Inhibitor ◽

Initial Value ◽

Platelet Counts ◽

Filtration Pressure ◽

Platelet Aggregates

Prostacyclin, produced by vascular endothelium, is the most potent inhibitor of platelet aggregation known to man. To assess its effects on platelets during dialysis ten greyhounds were dialysed for 90 minutes with cuprophan coils. At the end of dialysis arterial platelet counts (% of initial value) were significantly higher in the five dogs in which prostacyclin had been infused (115.7 ± 8.6) than in the animals in which heparin alone had been used (77.8 ± 16.8, < 0.05). Prostacyclin reduced the extraction of platelets by the dialyser. The screen filtration pressure, a measurement of platelet aggregates in blood leaving the dialyser, remained unelevated in the prostacyclin treated animals (80 ± 11.3 mm Hg) but rose significantly in those infused with heparin alone (249 ± 57 mm Hg, < 0.02). In another five dogs infused with prostacyclin but no heparin, dialysis did not reduce platelet count, elevate the screen filtration pressure or alter the overall clotting tests.Thus prostacyclin enables haemodialysis to be carried out without the undesired effects on platelets and haemostasis that are associated with the use of heparin.

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