Development and Practical Use of the New Quantitative Bleeding Time Test Apparatus

1998 ◽  
Vol 80 (07) ◽  
pp. 181-185 ◽  
Author(s):  
Hideki Takami ◽  
Rieko Nakahata ◽  
Yuka Nakui ◽  
Tomoaki Akagi ◽  
Akihiro Munakata ◽  
...  
Keyword(s):  
Bleeding Time ◽  
Normal Subjects ◽  
Total Blood ◽  
Bleeding Rate ◽  
Primary Hemostasis ◽  
Before And After ◽  
New Apparatus ◽  
Time Test ◽  
Time Determination ◽  
Computerized System

SummaryWe have developed a new computerized system for measurement of quantitative bleeding time (QBT) to detect subtle abnormalities of primary hemostasis that are difficult to detect with the standard bleeding time determination. This new apparatus can simultaneously measure the bleeding time (BT; sec), amount of total blood loss (Tv; μl), maximum bleeding rate (Rmax; μl/sec) and bleeding pattern from the bleeding time incision. We have also developed a new holder for the Simplate that enables more consistent incisions and thus improves the reproducibility of the BT test.In this study, the newly developed QBT test was performed in 137 normal healthy volunteers and 10 patients having defined abnormalities of either primary or secondary hemostasis. Comparisons of the standard BT test and our QBT were made in 5 normal subjects and 7 thrombocytopenic patients. Additionally, 6 normal subjects were examined with both tests before and after administration of aspirin. Those results show that our QBT appears to be a more sensitive indicator of primary hemostasis than the standard BT method.

scholarly journals DDAVP enhances platelet adherence and platelet aggregate growth on human artery subendothelium

Blood ◽  
1984 ◽  
Vol 64 (1) ◽  
pp. 229-236 ◽  
Author(s):  
KS Sakariassen ◽  
M Cattaneo ◽  
A v.d. Berg ◽  
ZM Ruggeri ◽  
PM Mannucci ◽  
...  
Keyword(s):  
Bleeding Time ◽  
Close Association ◽  
Aggregate Formation ◽  
Human Artery ◽  
Primary Hemostasis ◽  
Platelet Adherence ◽  
Normal Individuals ◽  
Before And After ◽  
Platelet Aggregate ◽  
Aggregate Growth

Abstract The effect of intravenous 1-deamino (8-D-arginine)vasopressin (DDAVP) administration on platelet interaction with human artery subendothelium was investigated with flowing blood from five normal individuals and 12 patients with von Willebrand's disease (vWD). Three of the patients were diagnosed as vWD subtype I, four as subtype IIa, and five as subtype IIb. DDAVP administration to normals enhanced platelet adherence, in parallel with increasing plasma levels of factor VIII- related antigen ( FVIIIR :Ag) and ristocetin cofactor activity ( FVIIIR :RCF). Platelet aggregate formation was transiently increased within 90 minutes. Platelet adherence in patient blood before DDAVP infusion was subnormal. In patients with subtype I, administration of DDAVP normalized the bleeding time, enhanced the platelet adherence, and transiently improved the platelet aggregate formation. The platelet adherence was more corrected than would have been expected on the basis of the FVIIIR :Ag and FVIIIR :RCF levels. In patients with subtype IIa, infusion of DDAVP increased the FVIIIR :Ag levels approximately threefold, without affecting the FVIIIR :RCF levels, and in only two of four patients was a transiently enhanced platelet adherence with a corresponding shortening of the bleeding time observed. In patients with subtype IIb, administration of DDAVP increased the FVIIIR :Ag levels about threefold and the FVIIIR :RCF levels five to tenfold, but decreased the platelet adherence significantly. The bleeding time values were not normalized. A close association between the bleeding time values and corresponding platelet adherence values before and after DDAVP infusion was observed. Normalization of the bleeding time was paralleled with normalization of platelet adherence. We conclude that DDAVP improves the primary hemostasis by causing enhanced FVIII- vWF-mediated platelet adherence. DDAVP has little or no effect on the bleeding time in patients with subtype IIa and subtype IIb, because the platelet adherence is not normalized.

scholarly journals DDAVP enhances platelet adherence and platelet aggregate growth on human artery subendothelium

Blood ◽  
1984 ◽  
Vol 64 (1) ◽  
pp. 229-236 ◽  
Author(s):  
KS Sakariassen ◽  
M Cattaneo ◽  
A v.d. Berg ◽  
ZM Ruggeri ◽  
PM Mannucci ◽  
...  
Keyword(s):  
Bleeding Time ◽  
Close Association ◽  
Aggregate Formation ◽  
Human Artery ◽  
Primary Hemostasis ◽  
Platelet Adherence ◽  
Normal Individuals ◽  
Before And After ◽  
Platelet Aggregate ◽  
Aggregate Growth

The effect of intravenous 1-deamino (8-D-arginine)vasopressin (DDAVP) administration on platelet interaction with human artery subendothelium was investigated with flowing blood from five normal individuals and 12 patients with von Willebrand's disease (vWD). Three of the patients were diagnosed as vWD subtype I, four as subtype IIa, and five as subtype IIb. DDAVP administration to normals enhanced platelet adherence, in parallel with increasing plasma levels of factor VIII- related antigen ( FVIIIR :Ag) and ristocetin cofactor activity ( FVIIIR :RCF). Platelet aggregate formation was transiently increased within 90 minutes. Platelet adherence in patient blood before DDAVP infusion was subnormal. In patients with subtype I, administration of DDAVP normalized the bleeding time, enhanced the platelet adherence, and transiently improved the platelet aggregate formation. The platelet adherence was more corrected than would have been expected on the basis of the FVIIIR :Ag and FVIIIR :RCF levels. In patients with subtype IIa, infusion of DDAVP increased the FVIIIR :Ag levels approximately threefold, without affecting the FVIIIR :RCF levels, and in only two of four patients was a transiently enhanced platelet adherence with a corresponding shortening of the bleeding time observed. In patients with subtype IIb, administration of DDAVP increased the FVIIIR :Ag levels about threefold and the FVIIIR :RCF levels five to tenfold, but decreased the platelet adherence significantly. The bleeding time values were not normalized. A close association between the bleeding time values and corresponding platelet adherence values before and after DDAVP infusion was observed. Normalization of the bleeding time was paralleled with normalization of platelet adherence. We conclude that DDAVP improves the primary hemostasis by causing enhanced FVIII- vWF-mediated platelet adherence. DDAVP has little or no effect on the bleeding time in patients with subtype IIa and subtype IIb, because the platelet adherence is not normalized.

Intrasplenic blood cell kinetics in man before and after brief maximal exercise

1992 ◽  
Vol 83 (1) ◽  
pp. 47-54 ◽  
Author(s):  
P. Allsop ◽  
A. M. Peters ◽  
R. N. Arnot ◽  
A. W. J. Stuttle ◽  
M. Deenmamode ◽  
...  
Keyword(s):  
Blood Cell ◽  
Peripheral Blood ◽  
Time Course ◽  
Maximal Exercise ◽  
Normal Subjects ◽  
Cell Type ◽  
Total Blood ◽  
Cell Counts ◽  
Before And After ◽  
Time Courses

1. After a 4 min period of maximal exercise in 10 normal subjects (14 studies), there was a consistent decrease in total blood volume and a consistent increase in erythrocyte indices, which were maximal immediately after exercise. Peripheral platelet and leucocyte counts increased, but did not reach maximal values until 5–10 min after the end of exercise. 2. The distributions of 99mTc-Iabelled erythrocytes (five studies), 111In-labelled platelets (five studies) and 111In-labelled granulocytes (four studies) were monitored with a γ-camera immediately after injection and before and after maximal exercise performed 60 min after injection. 3. Labelled erythrocytes equilibrated rapidly between the spleen and circulating blood after injection, whereas labelled platelets and granulocytes equilibrated more slowly. After exercise, each cell type was released from the spleen with a time course that was the reciprocal of the time course of the corresponding cell count in peripheral blood. Thus, whereas the radioactivity of 99mTc-labelled erythrocytes in the spleen, which fell to 0.46 (SD 0.09) of the pre-exercise value, increased towards its baseline value as soon as exercise was completed, the radioactivities of 111In-labelled platelets and 111In-labelled granulocytes decreased, to respective minimum values of 0.61 (0.09) and 0.63 (0.09) of the pre-exercise levels, 5–10 min after the end of exercise. The exercise-induced changes in lung radioactivity for each cell type, and their time courses, broadly reflected those in the corresponding cell counts in peripheral blood. Liver radioactivity tended to decrease for each cell type. 4. Because of the dissociation of the time courses of splenic expulsion of erythrocytes (intrasplenic transit time about 1 min) from those of platelets and granulocytes (intrasplenic transit times both of 8–10 min), we conclude that blood cell expulsion from the spleen in man is not the result of active splenic contraction but probably the passive result of a decrease in splenic blood flow.

The Effect of Stapedectomy on the Loudness of One’s Own Voice

1965 ◽  
Vol 8 (3) ◽  
pp. 223-234 ◽  
Author(s):  
William Melnick
Keyword(s):  
Middle Ear ◽  
Normal Subjects ◽  
Sound Energy ◽  
Loudness Function ◽  
Before And After ◽  
Increased Sensitivity

Five subjects with normal middle ear mechanisms, and otosclerotic patients, before and after stapedectomy, matched the loudness of their voices to the loudness of a 125-cps-sawtooth noise. The results showed loudness matching functions with gradual slopes, less than 1.00, for the normal subjects and the patients prior to stapedectomy. Post-surgically, the loudness function for the patients increased in steepness to considerably more than 1.00. These results are explained, most logically, in terms of increased sensitivity of the altered middle ear to sound energy generated by the listener’s own voice.

In Vitro Incorporation of Sodium Acetate-l-C14 into Leukocyte Lipids of Normal and Leukaemic Subjects as a Function of Incubation Time

1962 ◽  
Vol 02 (02) ◽  
pp. 165-172
Author(s):  
C Miras ◽  
G Lewis ◽  
J Mantzos
Keyword(s):  
Sodium Acetate ◽  
Linear Part ◽  
Lipid Synthesis ◽  
Normal Subjects ◽  
Cytostatic Agents ◽  
Time Intervals ◽  
Total Blood ◽  
Effect Of Treatment ◽  
Product Relation

Summary1. Separated leukocytes or total blood from normal subjects, untreated leukaemic patients and from leukaemic patients treated with cytostatic agents were incubated with CH3COONa-l-C14. Radioactivity of mixed lipids was measured at standard time intervals.2. The time incorporation curve observed with leukocytes from treated leukaemic patients showed after an initial linear part, a more rapid levelling off than the curves observed with leukocytes from untreated and normal subjects.3. Therefore, an indirect effect of treatment on leukocyte lipid synthesis seems to be present.4. Phospholipid and neutral lipid synthesis by leukaemic leukocytes was also studied. The results give no evidence that these fractions as a whole have any precursor-product relation.

Observations on Cardiac Output and ”Pulmonary Blood Volume” in Normal Man by External Recording of the Intracardiac Flow of 131I Labelled Albumin

1961 ◽  
Vol 1 (04) ◽  
pp. 353-379
Author(s):  
Jacques Lammerant ◽  
Norman Veall ◽  
Michel De Visscher
Keyword(s):  
Cardiac Output ◽  
Blood Volume ◽  
Normal Subjects ◽  
Published Data ◽  
Total Blood Volume ◽  
Total Blood ◽  
Pulmonary Blood Volume ◽  
Intracardiac Flow ◽  
Normal Man ◽  
Mean Circulation

Summary1. The technique for the measurement of cardiac output by external recording of the intracardiac flow of 131I labelled human serum albumin has been extended to provide a measure of the mean circulation time from right to left heart and hence a new approach to the estimation of the pulmonary blood volume.2. Values for the basal cardiac output in normal subjects and its variations with age are in good agreement with the previously published data of other workers.3. The pulmonary blood volume in normal man in the basal state was found to be 28.2 ± 0.6% of the total blood volume.4. There was no correlation between cardiac output and pulmonary blood volume in a series of normal subjects in the basal state.5. The increase in cardiac output during digestion was associated with a decrease in pulmonary blood volume equal to 6.3 ± 1.2% of the total blood volume, that is, about 280 ml.6. The increase in cardiac output during exercise was associated with a decrease in pulmonary blood volume equal to 4.5 ± 1.0% of the total blood volume, that is, about 200 ml.7. The increase in cardiac output attributed to alarm is not associated with a decrease in pulmonary blood volume, the latter may in fact be increased.8. The total blood volume is advocated as a standard of reference for studies of this type in normal subjects in preference to body weight or surface area.9. The significance of these results and the validity of the method are discussed.

Comparative Arterial Antithrombotic Activity of Clopidogrel and Acetyl Salicylic Acid in the Pig

1992 ◽  
Vol 68 (05) ◽  
pp. 500-505 ◽  
Author(s):  
Ch M Samama ◽  
Ph Bonnin ◽  
M Bonneau ◽  
G Pignaud ◽  
E Mazoyer ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Femoral Artery ◽  
Bleeding Time ◽  
Ex Vivo ◽  
Flow Reduction ◽  
Cyclic Flow ◽  
Left Femoral Artery ◽  
Before And After ◽  
The Right ◽  
Induced Aggregation

SummaryWe investigated the comparative antithrombotic properties of clopidogrel, an analogue of ticlopidine, and aspirin, using the Folts' model on femoral arteries in 22 pigs. On each animal, clopidogrel or aspirin were used to treat the thrombotic process on the left femoral artery and to prevent this process on the right femoral artery. Sequentially: an injury and stenosis were carried out on the left femoral artery; the thrombotic process was monitored with a Doppler during a 30-min observation period for cyclic flow reductions or permanent cessation of flow; after the first cyclic flow reduction occurred, clopidogrel (5 mg kg-1) or aspirin (2.5, 5, 100 mg kg-1) were injected intravenously; if cyclic flow reductions were abolished, epinephrine (0.4 µg kg-1 min-1) was injected to try to restore cyclic flow reductions and/or permanent cessation of flow; then injury and stenosis were applied on the right femoral artery. Before and after injection of clopidogrel or aspirin, ear immersion bleeding times and ex-vivo platelet aggregation were performed. Clopidogrel (n = 7) abolished cyclic flow reductions in all animals and epinephrine did not restore any cyclic flow reduction. On the right femoral artery, cyclic flow reductions were efficiently prevented, even for two injuries. Basal bleeding time (5 min 28) was lengthened (>15 min, 30 min after clopidogrel and remained prolonged even after 24 h). ADP-induced platelet aggregation was inhibited (more than 78%). Comparatively, aspirin had a moderate and no dose-dependent effect. Aspirin 2.5 mg kg-1 (n = 6) abolished cyclic flow reductions in 2 animals, CFR reoccurred spontaneously in one animal and epinephrine restored it in a second animal. Aspirin 5 mg kg-1 (n = 6) abolished cyclic flow reductions in only 3 animals and epinephrine always restored it. Aspirin 100 mg kg-1 (n = 3) was unable to abolish cyclic flow reductions. On the right femoral artery, aspirin did not significantly prevent cyclic flow reductions which occurred in all animals after one (n = 14) or two injuries (n = 1), except for one animal. Basal bleeding time was lengthened but it shortened rapidly, reaching its basal value after 24 h. ADP-induced aggregation was not significantly inhibited, whereas arachidonic acid induced aggregation was always inhibited. Clopidogrel appears as a more potent antithrombotic drug than aspirin in this model, in treating and preventing spontaneous or epinephrine-induced cyclic flow reductions and lengthening bleeding time.

Benefit/Risk Profile of Combined Antiplatelet Therapy with Ticlopidine and Aspirin

1991 ◽  
Vol 65 (05) ◽  
pp. 504-510 ◽  
Author(s):  
Raffaele De Caterina ◽  
Rosa Sicari ◽  
Walter Bernini ◽  
Guido Lazzerini ◽  
Giuliana Buti Strata ◽  
...  
Keyword(s):  
Platelet Function ◽  
Low Dose ◽  
Bleeding Time ◽  
Ex Vivo ◽  
Stable Coronary Artery Disease ◽  
High Dose ◽  
Single Drug ◽  
Before And After ◽  
Serum Thromboxane ◽  
Artery Disease

SummaryTiclopidine (T) and aspirin (ASA) are two antiplatelet drugs both capable of prolonging bleeding time (BT), with a different mechanism of action. A synergism in BT prolongation has been reported and is currently considered an argument for not recommending their combination. However, a profound suppression of platelet function might be a desirable counterpart of a marked prolongation of BT, with a possible use in selected clinical situations. We therefore studied ex vivo platelet function (aggregation by ADP 0.5-1-2.5 μM; adrenaline 0.75-2.5 μM; collagen 1.5-150 μg/ml; arachidonic acid 1 mM; PAF 1 μM; adrenaline 0.17 μM + ADP 0.62 μM; serum thromboxane ([TX]B2 generation) and BT (Mielke) in 6 patients with stable coronary artery disease receiving such combination. Patients underwent sequential laboratory evaluations at baseline, after 7 days of T 250 mg b.i.d., before and after the intravenous administration of ASA 500 mg, respectively, and, finally, after a minimum of 7 days of sole ASA oral administration (50 mg/day). The experimental design, therefore, allowed a comparison of T and ASA effects (2nd and 4th evaluation), and an assessment of the combination effect (3rd evaluation). Platelet aggregation in response to all doses of ADP was depressed more by T than by ASA. Conversely, responses to adrenaline, and arachidonate were affected more by ASA than by T. For all other agents, differences were not significant. T + ASA combination was more effective (p <0.05) than either treatment alone in depressing responses to high-dose collagen (% over control, mean ± SEM: T: 95 ± 3; ASA: 96 ± 5; T + ASA: 89 ± 4). Serum TXB2 (basal, ng/ml: 380 ± 54) did not change with T (372 ± 36), dropped to <1 ng/ml on ASA injection and slightly re-increased to 9.1 ± 3.1 ng/ml on oral low-dose ASA. BT (basal 7.4 ± 0.6 min) was affected similarly by T (9.2 ± 0.8) or ASA (9.7 ± 0.9) alone, but increased to 15.0 ± 0.7 min on combination treatment (106% increase over control). Thus, the strong synergism in BT prolongation by ASA-T combination has a counterpart in the inhibition of platelet function in response to strong stimuli such as high-dose collagen, not otherwise affected significantly by single-drug treatment. This effect is a possible rationale for the clinical evaluation of T + ASA combination.

Hemostatic Disorder of Uremia: The Platelet Defect, Main Determinant of the Prolonged Bleeding Time, Is Correlated with Indices of Activation of Coagulation and Fibrinolysis

1996 ◽  
Vol 76 (03) ◽  
pp. 312-321 ◽  
Author(s):  
Diego Mezzano ◽  
Rodrigo Tagle ◽  
Olga Panes ◽  
Marcos Pérez ◽  
Patricio Downey ◽  
...  
Keyword(s):  
Renal Failure ◽  
Bleeding Time ◽  
Degradation Products ◽  
Plasminogen Activator Inhibitor ◽  
Primary Hemostasis ◽  
Prolonged Bleeding Time ◽  
Fibrin Degradation Products ◽  
Von Willebrand ◽  
Pai 1 ◽  
Coagulation And Fibrinolysis

SummarySeveral parameters of primary hemostasis and markers of activation of coagulation and fibrinolysis were measured in 48 patients with severe (creatinine clearance <20 ml/min) chronic renal failure (CRF) without dialysis and diseases or drugs affecting hemostasis. Bleeding time (BT) was prolonged in 25/48 patients, and was correlated with age of patients, severity of renal failure, hematocrit, impairment in platelet aggregation-secretion and decrease in platelet ATP content. Defects in von Willebrand factor played no role in the prolongation of the BT. Multivariate analysis showed that only platelet dysfunction and severity of renal disease were independent predictors of the BT in uremia. The platelet functional disorder was significantly correlated with a reduction in platelet ATP and ADP.High levels of plasma thrombin-antithrombin complexes (TAT), prothrombin fragment F1+2, fibrinogen and factor VIIc were observed in patients with CRF, as described in prethrombotic states. Plasmin-antiplasmin complexes (PAP), fibrinogen and fibrin degradation products (FgDP, FnDP) were significantly increased, and the activity of plasminogen activator inhibitor (PAI-1) was slightly reduced, denoting an activation of fibrinolysis.A negative correlation was found between platelet levels of ATP and ADP with plasma TAT, F1+2 and PAP. Furthermore, plasma PAI-1 activity was negatively correlated with the BT and was lower in patients with prolonged BT as compared with controls and patients with normal BT. These links between primary hemostasis and activation of coagulation and fibrinolysis suggest that increased intravascular generation of thrombin and/or plasmin is an important mediator of the defects in primary hemostasis, prolongation of the BT and, probably, bleeding in CRF.

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