bluuebunny/crossref_metadata_2025 huggingface dataset:
New Method for Assessment of Plasma Von Willebrand Factor
Authors: Sano T. , Motomiya T. , Mashimo N. , Yamazaki H.
Published: May 2019

As much interests have been focused on von Willebrand factor (vWF) in diabetes melitus and atherosclerosis, request to determine vWF has been increasing recently. Two methods for assessment of plasma vWF level, without platelet aggregometer, were devised. 1) Platelet-rich plasma (PRP) sensitivity to ristocetin-induced platelet aggregation (RIPA): PRP was separated without centrifugation from citrated blood. Serially two-fold diluted restocetin (16 to 16x2-10 mg/ml) was prepared in a Cooke Microtiter tray and PRP (25 μl each) was added to each concentration of ristocetin. Then the ristocetin-PRP mixture was agitated for 15 seconds using a Kowa Kizai Micromixer and the minimum effective final concentration of ristocetin to give platelet aggregation was obtained microscopically and this was defined as PRP sensitivity to RIPA. This method is convenient for screening test. 2) vWF assay:Serially two-fold diluted plasma (2 to 1024 times, in Tris-salin pH 7.2 containing 12 mg/ml bovine serum albumin), fixed and washed platelet suspension (6x105 /μl, Macfarlane et al.1975) and 3 mg/ml ristocetin were mixed (25 μl each) in a microtiter tray and agitated for 15 seconds. The maximal plasma dilution to induce platelet aggregation was obtained microscopically and defined as the titer of plasma vWF. In normal subjects, minimum effective ristocetin concentration (PRP sensitivity to RIPA) was around 1 to 0.5 mg/ml and maximal plasma dilution to give platelet aggregation (vWF titer) was around 16 to 32 times. The present methods have a good reproducibility and are performed easily without aggregometer and thought to be useful clinically.
Platelet Antithrombin III in Atherosclerosis
Authors: Aktulga A. Z. , Ulutin O. N.
Published: May 2019

The presence of antithrombin III in the platelets and its secretion from the platelets was shown. In normals the antithrombin III was 13.71 ± 1.5 μg per 109 platelets, but in the cases of atherosclerosis with hypercoagulability this value decreased to 8.43±1.07 pg per 109 platelets.
Antithrombin III and Hypercoagulability in Smokers
Authors: Losito R. , Nathan D. , Gattiker H. , Longpré B.
Published: May 2019

It is known that various coagulation tests such as the thromboplastin generation test (TGT), thrombin generation (TG), levels of factor VIII or antithrombin III have been found to be abnormal in individuals with intravascular coagulation or having an increased tendancy to thrombosis. The aim of this study was to evaluate the role of the TGT, TG, factor VIII and antithrombin III assays in the diagnosis of possible mild intravascular coagulation in patients undergoing cardiac catheterization who had a history of smoking. In addition to these four tests, a routine coagulogram was performed for a total of 13 tests. It appeared that smokers had more abnormal tests (7.3/patient) than the controls (3.3/patient). The greatest association was between TGT and TG (29.6%) and TG and AT-III (25.9%). If by definition, hypercoagulability is present where 3 or more of these 4 mentioned tests were abnormal, then five patients were found to be in this category; all, except one, formed clots. In the patients (50) with a history of smoking, a third were found to have the TGT and the TG abnormal; however, the most striking observation in this group was in the antithrombin III where it was noted to be low in forty-five percent of the patients compared to the controls (patients having catheterization and were non-smokers) whose antithrombin III was found to be decreased in only five percent of the individuals. It is concluded that determination of antithrombin III may be of more importance in assisting the detection of hypercoagulability, especially in the smoking population, than the TGT, TG, or factor VIII.
Treatment of Clotted Brescia-Cimino-Shunts by Thrombolytic Therapy with Streptokinaser
Authors: Koestering H. , Girndt H. , Schnuett K.U. , Guerrero M.A.
Published: May 2019

In patients with chronic renal insufficiency undergoing chronic hemodialysis or heme— filtration, shunts uith great blood flous are always needed. In the past feu years ue have preferred Brescia-Cimino shunts (BCS). As there are only a feu arteries and veins, from uhich shunts are able to be formed, ue aluays try to save clotted shunts. Ide have performed thrombolytic therapy uith StreptokinaseR 24 times. Immediately following the clotting of a BCS ue began hemodialytic treatment for about 10-12 hours. Afterwards, according to the ASTK titres, an initial dose of StreptokinaseR uas applied; this uas folloued by continuous doses of about 100,000 units/hour. If another hemodialytic treatment uas necessary before reopening the shunt, ue started this only after 3 days uith a reduced dose of StreptokinaseR (50% of the original amount). In 22 cases this thrombolytic therapy uas successful uithin 3-120 hours, in 2 cases the shunts remained clotted. In three of the successfully treated patients, the shunts had been clotted for 19, 28 and 40 days. Ide believe that thrombolytic therapy uith StreptokinaseR in patients uith clotted BCS has proven to be successful and dependable.
ADP and Retention of Platelets in Glass Bead Columns
Authors: Dale J.
Published: May 2019

Platelet retention is known to be dependent upon ADP, thought to be derived either from red cells by hemolysis in the glass bead columns or from the platelets themselves. In order to study this, the following experiments were done in blood from 8 healthy subjects and 11 patients with prosthetic heart valves: The whole blood content of adenine nucleotides was measured, the platelet retention in whole blood was determined by Hellem’s modified method, the degree of hemolysis provoked by passage of whole blood and EDTA-anticoagulated blood was estimated, and finally the liberation of adenine, nucleotides from EDTA-blood was measured. The wholeblood content of ADP was similar in the two groups of subjects, as was the degree of hemolysis caused by passage of blood through the columns, while platelet retention was low in blood from the ball-valve patients. The adenine nucleotides were liberated in the same proportions as hemoglobin, and ADP appeared in plasma in mean concentrations of 0.10 juM in both groups of subjects after passage of EDTA-blood through the columns. The results indicate that ADP in amounts necessary to induce platelet retention is derived from red cells. The reduced retention in ball-valve patients in spite of normal ADP-liberation is probably a result of trauma to the platelets inflicted by the prosthetic valve.
Heparin Neutralizing Activity (HNA) in Clinical Practice
Authors: Birk-Jensen A. Hurlet , Moriau M. , Beys C. Col-De , Vanderlinden M. , Masure R.
Published: May 2019

HNA is measured in several pathological conditions by a biological assay.PFP, platelets and serun are compared.

In PFP, HNA/ml is high in thrombocytosis, in acute DIC and in some thrombotic states; it is normal in most cases of thrombocytopenia. When expressed as units/109 platelets, PFP’s HNA is low in thrombocytopenia from hepatic origin.HNA/ml of PFP decreases during treatment with suloctidil; these last results are related to platelet survival time.

Serum HNA, more than platelet HNA, reflects the antiheparin capacity of the blood and could be used to estimate the minimal amount of heparin required in therapy.
Platelets and Massive Transfusion
Authors: McNamara J.J. , Leinberger H. , Suehiro G.
Published: May 2019

Diffuse oozing is a common problem after massive transfusion of stored blood. Coagulation studies usually show depression of all clotting factors, presumably is rarely of sufficient magnitude to cause bleeding. Similarly, platelet counts, which are frequently between 60,000 and 100,000 are still in a range not associated with clinical bleeding. Recent studies have suggested that coagulopathy post transfusion is due primarily to a qualitative defect in platelet function of unknown origin. Five baboons had blood drawn and stored by usual blood banking techniques for 10 days. Platelet rich plasma (PRP) was then prepared and platelets tagged with Cr51. Another five animals had fresh PRP prepared and platelets tagged with Cr51. Survival curves for tagged platelets demonstrated a half life of 13 ± 3 hours for 10-day old platelets and 47 ± 9 hours for fresh platelets. Platelet counts in stored blood averaged 100,000/cmm. Although nearly all 10-day old platelets were cleared by 24 hours, 50% were still present at 13 hours. It is evident then that platelet counts immediately after massive transfusion may be composed in large part of old stored, non-functional platelets.
Contact Activity in Cerebrovascular Disorders
Authors: Takamatsu S. , Satoh K. , Sakuta S. , Takamatsu M. , Mizuno S. , Takekawa H.
Published: May 2019

An Association of contact factor with arteriosclerotic disorders relating to coagulation, fibrinolysis and kinin reíase was investigated by assessment in plasma of cerebrovascular patients. Contact activity was determined in plasma of 89 cerebrovascular patients and of 42 healthy controls following Waaler’s method. Patients’ activity was significantly higher than that of controls. The activity in patients with normal ECG findings was significantly higher compared with abnormal ECG cases. In patients with normal ECG findings, the activity of hypertensives was higher than that of normotensives, in patients elapsed over 4 months after their admisson it was higher than that in one month, in patients with good marks in the test of activities of daily livings (ADL-T) it was higher than that with poor marks. In normotensive patients with abnormal ECG findings, the activity was inversely proportional to serum cholesterol and 3-lipoprotein levels. The high activity in patients with normal ECG findings and few arteriosclerotic changes in contrast to patients with abnormal findings, and the inverse correlations between the activity and two lipids are unreasonable considering only the participation of the coagulation system triggered by contact factor. Therefore, the high activity must be regared as the result of participation of the fibrinolytic system activated by this factor. Although the high activity in patients with normal ECG findings and hypertension may be regarded as the protective effect of the fibrinolytic system to developement of arteriosclerosis induced by hypertension, and may be appreciated as the direct effect of kinin release by this factor in hypertension.
Coagulation Studies in Asian Women on the 50 Microgram Combined Oral Contraceptive Pill
Authors: Tsakok F.H.M. , Koh S. , Ratnam S.S.
Published: May 2019

Few, if any studies of coagulation and fibrinolysis have been performed in Asian women. This was because they seemed to be immune from thromboembolic diseases. Since it has been confirmed that the risk of thromboembolism in Caucasian women on oral contraceptives containing 50 microgram of oestrogen is much increased, and that there are also coagulation changes in them, it was found therefore necessary to do similar studies in Asian women.

The present report is a prospective study of 100 women on the combined pill containing not less than 50 ug oestrogen. A comprehensive number of tests were performed for the overall clotting effect, coagulation factors and inhibitors, fibrinolysis and inhibitors, and platelet function tests.

The overall clotting time seemed to be reduced. Certain coagulation factors were elevated, especially factor VII and factor X. Antithrombin III levels remained the same. There were no significant fibrinolytic changes in the blood. Platelet function tests were not significantly changed. The changes in the blood profile although similar to Caucasian women, have still to be evaluated in its significance to the risk of developing thromboembolic disease.
Thromboembolic Surveillance Using 125 I Labelled Fibrinogen of 1000 Patients who Underwent Traumatologic and Orthopedic Surgery
Authors: Marchai C. , Robert C. , Videgrain M. , Pourcelot L.
Published: May 2019

From 1975 to 1977, 1006 tests using 125 I fibrinogen have been performed on orthopedic and traumatologic patients who were undergoing a thromboembolic treatment either by means of the association of dipyramidole and aspirin administered orally (24%) or by subcutaneous heparin (76%). The 125 I fibrinogen was injected preoperatively or immediately postoperatively. A daily radioactive counting was performed on the inferior members for approximately 6 to 8 days. 102 venous phlebography controls demonstrated an accuracy of 80% for the 125 I fibrinogen test. Of 1006 patients, 15.2% of the fibrinogen tests were positive, 59.7% of which were positive between the first and fifth postoperative day (p<0.02). The isotopic signs of venous thrombosis occurred in 21% of the hip surgery patients, 14.5% of the lumbar spine surgeries, 13% of the knee surgeries, and 11.5% of the patients who underwent surgery for other traumatic lesions. In these 1006 patients, 9 pulmonary emboli occurred of which 2 were fatal. The 125 I fibrinogen test can only be applied to evolutive thrombosis and does not permit one to differentiate between hematomas and thrombosis, nor to detect pelvic thrombosis. However, this test still remains a simple, faithful, and nontraumatic diagnostic tool in the early detection of thrombosis of the inferior members in patients undergoing traumatologic and orthopedic surgery. Moreover, the labelled fibrinogen test is useful in the determination of the efficacy of antithrombotic preventive medication. Our study has manifested the superiority of subcutaneous heparin (18% positive test) over the association of dipyramidole-aspirin (38.6% positive test) in the prevention of thromboembolic accidents in hip patients (p<0.001).
The Combined Effects of 2,3-Diphosphoglycerate and Phospholipase-A on Platelet Aggregation Induced by ADP, Epinephrine, Norepinephrine and Collagen
Authors: Asterita M.F. , Iatridis P.G. , Iatridis S.G. , Torrella R. , Ragatz B.H. , Gadarowski J. , Markidou S.G.
Published: May 2019

It has been shown recently, that under specific conditions, phospholipase-A (Phl-A) or 2,3-diphosphoglycerate (2,3-DPG) can inhibit human platelet aggregation induced by ADP, epinephrine, norepinephrine or collagen. In this report, by using a dual channel Payton Aggregometer, the effects of 2,3-DPG and Phl-A on platelet aggregation were further studied. When 2,3-DPG (2μM) was added in human platelet rich plasma with Phl-A (200μU), 30, 60, 120 or 300 sec. before the addition of ADP (0.5-2.0μM), epinephrine (2-5uM) or norepinephrine (2-5μM) an enhancement of platelet aggregation was observed, whereas the same concentration of 2,3-DPG alone or Phl-A alone, inhibited both the rate and extent of the second phase of platelet aggregation induced by the same aggregating substances. The combined effects of 2,3-DPG and Phl-A on collagen induced platelet aggregation remained inhibitory. Aspirin on the other hand abolished the enhancement of platelet aggregation induced by 2,3-DPG and Phl-A. These combined effects of 2,3-DPG and Phl-A were both a concentration and a time dependent response. The results indicate that the combined effects of 2,3-DPG and Phl-A were probably mediated through prostaglandin formation. Since Phl-A is a physiological platelet enzyme which releases arachidonic acid, then we may postulate that 2,3-DPG probably activates the synthetases and/or cyclooxygenases which are the enzymes necessary for the formation of the important platelet aggregating substances, namely the endoperoxides and thromboxanes. Supported by USPHS HL-15425.
Thromboembolic Prophylaxis and Viscosity Reduction with Ancrod
Authors: Lowe G.D.O. , Forbes C.D. , Prentice C.R.M. , Barbenel J.C.
Published: May 2019

Blood and plasma viscosity were measured at high shear rates in 10 patients receiving intravenous ancrod and 9 patients receiving subcutaneous ancrod. In both groups significant viscosity reduction accompanied fibrinogen depletion and there was no significant fall in haematocrit. Blood and plasma viscosity were also significantly reduced in 28 patients after operation for fractured hip, who were given daily subcutaneous injections of ancrod to reduce the mean plasma fibrinogen to 1G/L. Dose ranging studies suggest a suitable regime to be a total of 560 units ancrod, given in five daily doses starting immediately after surgery. No significant viscosity changes were observed in 14 control patients after hip surgery although the haematocrit fall was similar in both groups. No significant changes occurred in 13 patients receiving intravenous heparin. Viscosity reduction during ancrod therapy does not depend on haematocrit reduction or anticoagulation, and is probably due to depletion of plasma fibrinogen. Subcutaneous ancrod appears feasible and safe, and merits trial as a thromboembolic prophylactic agent.
Therapeutic Ultrasound - An Inducer of Platelet Aggregation in Vitro
Authors: Chater B.V. , Williams A.R. , Sanderson J.H.
Published: May 2019

Exposure of human platelet rich plasma to therapeutic levels of ultrasound, was found to initiate platelet aggregation and release in vitro. The amount of aggregation, as assessed using a modified platelet aggregometer was found to be related to both the intensity and frequency of the ultrasound. Aggregation occurred at a faster rate and was more extensive at lower frequencies (0.75MHz) and higher intensities. The ability to induce aggregation was found to be directly related to platelet sensitivity to ADP, more sensitive platelets responding to lower intensities of ultrasound. Experiments monitoring the release of 3 thromboglobulin, a marker of the release reaction, indicated that ultrasound was inducing release in two distinct ways.

Firstly by the physical disruption of a number of platelets, and secondly by ADP released from the disrupted platelets inducing further release. Release and platelet aggregation was found to parallel the disruption of red cells, as measured by plasma, haemoglobin levels, and this coupled with the greater effect at lower frequencies is thought to indicate that platelet destruction is occurring by cavitation.
Identification of Sources of Inter-Laboratory Variation in Factor VIII Assay
Authors: Kirkwood T.B.L. , Rizza C.R. , Snape T.J. , Rhymes I. , Austen D.E.G.
Published: May 2019

A repeated finding of national and international collaborative studies of standard Factor VIII preparations has been that systematic differences exist between laboratories in their measurement of the relative activities of the same pairs of Factor VIII preparations.

A workshop meeting was held at the Oxford Haemophilia Centre (England) during 23rd-26th November 1976 to investigate which of the possible sources of variation between laboratories were responsible. Participants from 16 British laboratories (9 one-stage, 7 two-stage) performed a total of 273 assays using three freeze-dried preparations of differing purity (a plasma, an intermediate and a high purity concentrate). The results of assays with each participant using their normal system established that, if the participants were a representative cross-section, approximately one-third of one-stage laboratories would show a systematic difference from the overall mean of at least 16%, with a similar figure for the two-stage laboratories of 9%. Various features of the assay systems were then modified in a controlled series of experiments. The results showed conclusively that i) differences between reagents accounted for most of the variation between laboratories and, ii) the two-stage assays were, on average, detecting relatively more activity in the more purified preparations than the one-stage assays. The results also suggested that the use of buffer as opposed to haemophilic plasma for the initial dilution of concentrates did not affect the assay results.
Adenosine Diphosphate Induced Aggregation and Release Reaction in Heparinized Platelet Rich Plasma
Authors: Heptinstall S. , Mulley G.P.
Published: May 2019

Preparations of heparinized platelet rich plasma (PRP) from 54 different volunteers were examined to determine the extent of platelet aggregation and release reaction both in the absence and presence of citrate. Platelet aggregation was studied in fresh untreated samples of PRP using a range of concentrations of ADP. To study release reaction platelets in a portion of each preparation were labelled with 3H-5-hydroxytryptamine. Released radioactivity was measured after stirring with ADP or with ADP and citrate.

Even in the absence of citrate release was considerable in 26 of the preparations. There was a good correlation between extent of aggregation and extent of release reaction. When second phase aggregation occurred release was extensive, when release was low or absent the higher concentrations of ADP were required to bring about “irreversible” aggregation. Whenever citrate was present release reaction was enhanced. Enhanced release reaction was also observed in PRP in which the bulk of plasma calcium had been exchanged for sodium by ion exchange chromatography.

It is concluded that ADP induced release reaction can occur in heparinized PRP but that it is enhanced by reducing the concentration of extracellular ionised calcium.
Plasminogen Activator Release After Venous Occlusion and Infusion of DDAVP
Authors: Åberq M. , Nilsson I.M.
Published: May 2019

Defective release of fibrinolytic activator from the. vessel walls implies an increased risk of thromboembolic disease (Isacson and Nilsson 1972). Therefore methods suitable for determination of the fibrinolytic “capacity” in man have become increasingly interesting. The fibrinolytic activity (FA) in blood after infusion of DDAVP (l-desamino-8-D-argininvasopressin) was determined in 21 normals and 42 patients with recurrent venous thrombosis. The results were compared with those found after venous occlusion (VO) in the same subjects. DDAVP induced a significant but lower increase of the fibrinolytic activity in blood than VO. The correlation was good between the FA immediately after DDAVP and VO both in normals (r = 0.53) and in patients (r = 0.63). Both DDAVP and VO induced a significantly lower FA in patients than in normals. All subjects studied showed an increase of the FA with both methods used. Both DDAVP and VO induced a significant increase of VIII:C and VIIIR:AG. This increase was about the same in the two groups. No side effects were found after infusion of DDAVP which thus seems to be suitable for determination of the fibrinolytic “capacity” in patients with thromboembolic disease.

Isacson, S. and Nilsson, I.M. 1972. Acta chir. scand. 138, 313.
Platelet ADP-Hypersensitivity by Aging and Isometric Exercise in Diabetics and its Prevention by EG-626
Authors: Sano T. , Motomiya T. , Itoh Y. , Mashimo N. , Yamazaki H. , Shimamoto T.
Published: May 2019

The important role of platelet aggregation in the pathophysiology of diabetic vascular disease has been emphasized. The authors devised a new method to assess platelet sensitivity to aggregation performed without centrifugation (Sano et al. Thrombos. Haemostasis April '77 issue, in press). Using this technique, platelet aggregability in diabetics was assessed concerning to age and to. the effect of isometric exercise. The effect of EG-626, a potent cAMP phosphodiesterase inhibiting and thromboxane A2-antagonistic substance, administered prior to exercise was also observed.

In 52 diabetics without macroangiopathy, platelet sensitivity to ADP-aggregation was assessed. The sensitivity was expressed by ‘n’ of the minimum effective concentration of serially two-fold diluted ADP, 2-n mg/ml, to give aggregation. In males, both diabetics and healthy, the sensitivity correlated significantly with age. The regression lines obtained were Y=2.15+0,13X (Y: sensitivity, X:age in years) in the diabetics and Y=6.58+0.04X in the healthy subjects respectively. The value of the slope was significantly higher in the diabetics comparing to the healthy subjects. An enhancement of the platelet sensitivity was disclosed significantly in the diabetics but not in the healthy subjects, after isometric handgrip exercise at 50% maximal voluntary contraction for 2 minutes.. This enhancement was prevented when the patients were treated orally with 300 mg of EG-626, 1.5 hours before exercise. These findings would suggest the thrombotic tendency in diabetics and anti-thrombotic effect of this compound.
Coagulation and Fibrinolytic Findings in Cerebrospinal Fluid of Various Neurological Diseases
Authors: Maruyama I. , Fukuda R. , Kazama M. , Igata A. , Abe T.
Published: May 2019

The coagulation and fibrinolytic factors in cerebrospinal fluid (CSF) of various neurological diseases as well as their inhibitors were examined.

a) CSF of inflammatory diseases in central nervous system (CNS) was proved to have elevated FDP, plasminogen and inhibitors which were rapidly increased at the first stage, showing no obvious relation with those in blood.

b) CSF of neoplasmas showed markedly elevated macromolecular FDP manufactured in CSF, plasminogen and inhibitors which were gradually increased along the courses.

c) In cases of cerebral hemorrhage, almost all the coagulation factors, FDP and inhibitors were found in CSF. These substances seemed to be originated from bled blood and FDP was consisted of smaller molecules, D and E.

d) Subarachnoidal bleeding gave CSF with plenty amount of fibrinogen and other coagulation and fibrinolytic components from blood including F.XIII which was not proved usually in CSF.

The administration of tranexamic acid for prevention of reccurrent attacks might possibly allow fibrin deposition on subarachnoidal membrane and develope normal pressure hydrocephalus with the collaboration of activated F.XIII.

e) CSF with Froin’s sign sometimes shwed markedly elevated fibrinogen and soluble fibrin monomer complex which had no relation to those in blood.
Complications in one Stage Potency Estimation of Factor VIII Due to Traces of Thrombin
Authors: Miller-Andersson M. , Seghatchian M.J.
Published: May 2019

Recent studies have revieled significant differences between potency estimations of F VIII using one stage or two stage assay technique. Especially in highly purified concentrates, two stage assays estimate considerably higher potencies. Because of the complicated nature of the two stage assay reagent it might seem advicably to use one stage for highly purified preparations. With this in mind a study has been performed evaluating the influence of thrombin activation of F VIII concentrates in one stage systems, which seem to be very susceptible to thrombin activation. Theresults of the study showed a dramatic effect of minute amounts of thrombin on the potency estimation of F VIII concentrates with low fibrinogen content. A concentrate containing 5 U F VIII/ml and 1.5 mg fibrinogen/ml was brought to a final thrombin concentration of 10-6 IU/ml. The activity increased and stayed at 25 U/ml for the first 6 h, went down to 10 U/ml after 24 h and reached the level of the reference material (5 U/ml) after 48 h. Thus the activation effect is remarcably stable and might cause false high results. A1(OH)3 adsorption has been recommended to overcome activation problems in F VIII potency estimation. This process, however, adsorbes a lot of both F VIII:c and F VIII:R Ag from the test sample when the total protein content is low, thus introducing another source of error. As there is an increasing demand for highly purified F VIII concentrates for home therapy, it is urgent to indicate the need for a generally recommended assay procedure for these preparations.
In Vivo Microscopic Observations of Vasoactive Drugs and Platelet Aggregation
Authors: Wiedeman Mary P. , Turna Ronald F. , Mayrovitz Harvey N.
Published: May 2019

A survey of the literature concerning the effect of vasoactive drugs on platelet aggregation would support the generalization that, vasoconstrictors enhance platelet aggregation while vasodilators inhibit the action. Some of the information comes from in vitro studies and some from in vivo studies. Using the bat wing as the experimental site, microscopic observation of the effect of intra-arterial injections of vasoconstrictor drugs (epinephrine and serotonin) and vasodilator drugs (dipyridamole and phenoxybenzamine) confirmed the concept. Platelet activity induced by laser beam after administration of vasoconstrictors showed an increased response while vasodilator drugs produced the converse. In addition, denervated vessels showed diminished activity in platelet aggregate formation. Experimental procedures and responses will be shown by cinemicrophotography.
Circulating Platelet Aggregates During Emotional Stress and Cigarette Smoking
Authors: Gensini G.F. , Abbate R. , Prisco D. , Serneri G.G. Neri
Published: May 2019

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.
Thrombokinetic Study to Predict Episodes of Thrombogenesis
Authors: Kuramoto A.
Published: May 2019

To predict thrombosis and to evaluate anti-thrombotic agents, a thrombokinetic study was done on subjects in thrombogenic state with cardio-vascular and hematologic diseases, artificial heart valve replacement, thromboangiitis and thrombocythemia. Platelets were labelled with 51Cr (Thromb. Res. 8, Suppl. 11: 347, 1976).During thrombocytosis (>106/mm3), 2 of 4 cases with primary thrombocythemia and 3 of 4 cases of chronic myelogenous leukemia (2 of whom developed thrombosis) had shortened survival. This increased turnover reflected compensatory production of platelets and increased thrombopoiesis. Fourteen cases with artificial heart valve replacement showed short survival with proportionally higher turnover. Three cases with short survival despite high doses of dipyridamole therapy developed thrombosis.

To evaluate platelet participation in the development of cerebrovascular lesion; cerebral infarction and/or bleeding in animal model, platelet survivals were measured by 75se-methionine incorporation in the spontaneously hypertensive rat-stroke prone strain, (SHR-SP, Okamoto-Yamori), which become hypertensive at age 5-25 weeks. Peak of 75se-methionine in platelets which develop hypertension at age, 5-25 weeks occur on 3rd. day after I.V. injection in SHR-SP and controls (SHR-stroke resistant and normotensive Wistar rat), and was significantly higher in SHR-SP than the controls. Survivals by 75se-methionine and by 51cr labels (16th Int. Congr. Hemat. Sept. 1976, Kyoto, Abstr. Symp. S-12-4, pp. 39) suggested shorter survival of SHR-SP in 10-15 weeks of age than control. Short survival with increased turnover indicated increased consumption due possibly to vascular damage associated with the development of hypertension. Ability to predict strokes in adult rats has been examined.
Factor VIII Related Properties in Platelets of Patients with von Willebrand’s Disease (VWD)
Authors: Ruggeri Z.M. , Bader R. , Barbui T. , Mannucci P.M.
Published: May 2019

In 10 normal subjects washed human platelets (Pl)contained FVIII related antigen(VIIIR:AG) as measured by immunoradiometric assay (iRMA)and electroimmunodif fusion (EID);and ristocetin co-factor (VIIIR:RCo)as assayed by a washed platelet method. The observed values were: AG(IRMA) 0.11-0.24u/mg Pl protein; VIIIR:AG (EID)0.11-0.30u/mg; VIIIR:RCo 0.06-0.21u/mg, In 10pts with seve re homozygous VWD, VIIIR:AG was unmeasurable in 7 and extremely low (1x10-3-0.6x10-3u/mg) in 3 u-sing the very sensitive IRMA; VIII RCo was always unmeasurable. In 12 pts with “classical” dominant VWD characterized by very low plasma levels of VIIIR:AG(0.03-0.09u/ml)and VIIIR:RCo(<0.03u/ml), FVIII related properties were normal in Pl and the mobility of PI VIIIR:AG on bidimensional immunolectrophoresis was not different from that of normal controls. In 7 pts showing a faster mo bility of plasma VIIIR:AG, the same abnormality was found in Pl.Pl VIIIR:AG level was within the normal range when assayed by EID whereas IRMA gave lower values both in plasma and in PI.PI VIII R:RCo was lower than in normal subjects and pts with “classical”VWD without electrophoretic variant. These findings show that severe VWD is the expression of a marked reduction of VIII synthesis fully expressed both in PI and in plasma. In “classical” VWD the plasma defects are not reflected in PI, which show normal levels of FVIII-related properties accompanied by normal electro, phoretic mobility of VTIIR:AG; this suggests a defective transfer from PI to plasma. Patients with abnormal mobility are the expression of a qualitative alteration of the FVIII molecole functionally defective both in Pl and in plasma.
The Problem. How Much is Required?
Authors: Schiff P.
Published: May 2019

Haemophilia is an international health problem, and the supply of adequate amounts of Factor VIII to treat sufferers continues to tax the minds of all sections of the health care industry. Before the scope of the total problem can be defined and solutions proposed, attempts must be made to quantify likely demands at the individual, national and international levels. This paper looks at the known incidence of haemophilia, reviews currently accepted treatment schedules and their effects on Factor VIII requirements, and describes therapeutic materials currently available for the management of bleeding episodes.
Haemophilia Therapy: A View from the Third World
Authors: Páez C.A.
Published: May 2019

Analysis of the problems facing haemophilia therapy in under developed countries shows high cost of imported replacement material, lack of organized blood transfusion services and exploitation of indigenous population by commercial companies as the main drawbacks. The current situation may be largely improved by the creation of national blood transfusion programmes. Economical and political stability and a social security system, already existing in Costa Rica, makes a national blood transfusion programme based on voluntary blood donation an attainable goal.
Surgery in Hemophilia
Authors: Zimbler Seymour
Published: May 2019

The result of followup evaluation on the treatment of 110 Hemophiliacs followed within a comprehensive Hemophilia Clinic through the Tufts New England Medical Center and Memorial Hospital in Worcester, as well as the University of Massachusetts in Worcester, Massachusetts. A larger total of 300 Hemophiliac patients of all types have been followed.40 patients or more have undergone surgical procedures on various joints during the past 7 years. The results of these operations have been reviewed and guidelines are presented regarding their treatment. Breakdown of operative procedures include synovectomy of the knee 7, total knee arthroplasty, 5. Also included are arthrodeses of the knee, ankle, and subtalar joints as well as the elbow. Soft tissue procedures such as heel cord lengthening, decompression of carpal tunnel syndrome, excision of pseudo tumor are also included. Arthroplasty and synovectomy require 3 weeks or more of active treatment with levels of Factor VIII maintained at 50% for the entire treatment period. Those individuals treated by arthrodesis or simpler procedures require infusions for 10 days to 2 weeks. Factor IX deficiency patients require levels of 30-50% for their entire treatment program.
Factor IX Level in Various Conditions
Authors: Veltkamp J.J.
Published: May 2019

In newborns the factor IX level is only 20-60% of that observed in adults. This implies that factor IX levels have to increase with age, as was demonstrated already by Simpson and Biggs (1962). A rapid rise might occur in the first year of life, as is the case for albumen. During life, then, a slow rise continues, as was also demonstrated for factors V and VII (Brozovic 1976, 1974). It is of special interest that for factors VII and IX, both vitamin K dependant clotting factors, not onlyage but also hormones influence the activity level. Both the oestrogen containing contraceptive pill and pregnancy cause a substantial rise in factor IX level, both activity and CRM. 7 Years ago we started to measure factor IX levels every 3 months in 10 children, now at the age of 19, to see whether an abrupt rise would occur during puberty; this was not so. This information was considered relevant for the explanation of the appearance of factor IX activity and CRM in patients with hemophilia B Leyden during puberty. After a rise from <1% to 20% factor IX in the age period from 15 to 20 factor IX continues to rise at a slower rate and may reach 50% in old age. Clinical symptoms disappear. There is no good explanation for this phenomenon that occurs in patients from two probably related kindreds with hemophilia B in The Netherlands.
The Hemophiliac and Knowledge of Their Condition
Authors: Inwood M.J. , Barr J.D. , George R.
Published: May 2019

The Canadian Hemophilia Society (CHS) emphasizes education of the hemophilia and his family. A questionnaire was designed to answer the following. Was the level of knowledge a sample of Canadian hemophiliacs and their parents had of their condition related to the educational objectives of the CHS? Was the standard of treatment they received directly related to this level of knowledge, and in turn did it affect the degree of compliance to physician’s orders? 220 hemophiliacs and parents across Canada were interviewed and 203 (91%) responded. The following results were verified using suitable statistical analysis. Individuals who attended CHS meetings, received CHS literature and Handbook had superior knowledge of their condition compared to those hemophiliacs and parents not receiving these services. Although physicians knew more about hemophilia than the average parent or hemophiliac, if a parent had post secondary education, or if the hemophiliac was severely effected, their knowledge was equal to that of non actively treating physicians. Hemophiliacs had increased knowledge if they were enrolled in a home infusion program and had regular inhibitor and factor assays performed. Only 5 of 167 hemophiliacs and parents were non compilers, and had a lower level of knowledge compared to the compliant group. This suggests that the hemophiliac with superior knowledge is severely affected and enrolled in a home infusion program. He is cared for by a physician actively treating hemophilia, who arranges regular inhibitor and factor level assays. Furthermore he is a member of the CHS, possesses a CHS Handbook and attending regular CHS meetings.
A Multicenter Evaluation of an Activated Partial Thromboplastin Time Test, Cepho-Test
Authors: Collen D. , Godal H.C. , Mannucci P.M. , Nilsson I.M. , Gilhuus-Moe C. , Refsum N.
Published: May 2019

To compare the sensitivity and precision of the Activated Partial Thromboplastin Time (APTT) test Cephotest to that of APTT methods in current use, Cepho-test and current APTT method (Leuven and Milan: Locally modified Thrombofax/kaolin procedures; Malmoe: Automated APTT; Oslo: APTT of human brain/kaolin) were performed in parallel (20 tests) on lyophilized standard plasmas of 4 levels of factors VIII. The mean value (1 standard deviation) of Cephotest on Control Plasma Normal was 36.3 (2.21) s in Leuven, 31.7 (1.13) s in Oslo, 35.0 (1.36) s in Milan and 35.0 (1.16) s in Malmoe. The corresponding values of the local APTT methods were 50.2 (I.58) s, 34.5 (1.27) s, 51.9 (1.17) s and 38.8 (1.23) s, respectively. In Oslo, Milan and Malmoe, the sensitivity of Cephotest was superior to that of the local APTT reagent at all levels of factor VIII. In Leuven, the local APTT method had a higher ratio than Cephotest. There was no statistical significant differences between the standard deviation of Cephotest and the local APTT methods. The study indicates that Cephotest has a high sensitivity, satisfactory precision and is subjected to only minor interlaboratory variations.
The Need to Filter Cryoprecipitate. A Microscopic Assessment of Filter Deposition
Authors: Barr J.D. , Chauvin W.J. , Warren B.A. , Inwood M.J.
Published: May 2019

A number of hemophiliacs, particularly on self infusion programs, avoid the use of a filtration apparatus when transfusing cryoprecipitate because it is thought Factor VIII activity is decreased, ;and it makes the procedure too cumbersome. The purpose of this study was to document that no loss of Factor VIII occurred using conventional filtration, and that blood filters are necessary. Individual and pooled units of cryoprecipitate were passed through standard blood administration sets, cryoprecipitate sets and 40 micron ultrafiltration sets. Factor VIII levels were performed on pre and post transfusion samples. The used filters were examined using conventional light, scanning (SEM), and transmission electron microscopy (TEM). No decrease in Factor VIII (p <.001) was noted when pre versus post filtration assays were compared. Examination of the filters by light microscopy demonstrated a greater than 50% obstruction of the available filter area in 39/60 units examined, and this material appeared to contain fibrin. This was substantiated by SEM and TEM examination which identified the fibrillar structure of fibrin on all filters. Furthermore, the deposits were contaminated by globular and flocculent proteinaceous material, accompanied by cellulose and plastic debris. This material passed through conventional filters, but was successfully removed by a graded 40 micron filter. This study not only demonstrates the necessity for careful filtration of cryoprecipitate prior to administration, but also identifies significant contaminating materials.
Chemical Cross-Linking of Factor VIII Subunits
Authors: Furlan M. , Jakab T. , Beck E.A.
Published: May 2019

Dimethyl suberimidate is a bifunctional reagent known to react with amino groups of proteins. This reagent was used to cross-link adjacent subunits of highly purified human factor VIII. Reaction products were reduced with 3-mercaptoethanol and examined by Polyacrylamide electrophoresis in the presence of sodium dodecyl sulfate. Low concentrations of dimethyl suberimidate (< 0.5 mM) produced dimers of the subunit polypeptide chains and virtually no oligomers of larger size. Treatment with higher concentrations of the cross-linking agent resulted in an almost simultaneous appearance of both trimeric and tetrameric products, suggesting the existence of specific intradimer contacts. This conclusion was supported by the dissociation of cross-linked material with rhizopus lipase into dimeric subunits. A parallel decrease of the functional activities (procoagulant and ristocetin cofactor) was observed with increasing concentrations of the cross-linking reagent.
Elevations in VIII:C, VIIIR:Ag and VIIIR:vW
Authors: Hasiba Ute , Spero Joel A. , Lewis Jessica H.
Published: May 2019

High levels of factor VIII:C and VIIIR:Ag have been described following exercise, in pregnant women and in liver diseases. The objective of the present study was to compare levels of VIII:C to VIIIR:Ag and VIIIR:vW in patients with a variety of disorders. The normal range in this laboratory for each of the VIII components is 0.50 to 1.50U/ml. Following exercise all three components rose. Hemophiliacs, who have had no recent treatment with VIII concentrate, have low VIII:C and, usually, normal VIIIR:Ag and vW. A few have high levels which may relate to liver dysfunction. In twelve hemophiliacs with anti-VIII, VIIIR:Ag was above 2.0 in six and between 1.5 and 1.9U/ml in another three; VIIIR:vW-was elevated in only four of these. In all four patients with acquired anti-VIII, who were tested, VIIIR:Ag and vW were elevated. In the last six months, all patients’ plasma samples in which VIII:C assayed above 2.0U/ml were also assayed for VIIIR:Ag and VIIIR:vW. In seventy-four patients all three components were elevated. Many diseases were represented:liver disease, thrombo-embolism, leukemia and cancer, infection, etc. No common factor was ascertained, although, these are all clinical settings in which disseminated intravascular coagulation (DIC)is found. Twelve of these patients had coexistant laboratory evidence of DIC. In these patients VIIIR:Ag tended to be higher than VIIIR:C. Those studied without DIC generally showed a 1:1 correspondence between the levels of VIIIR:Ag and VIII:C. In seven patients not included in the above group of seventy-four the VIII:C was high, but VIIIR:Ag and vW fell within the normal range, suggesting that some activation may have occurred.
The Natural History of Haemophilic Arthritis
Authors: Handelsman J.E. , Lurie A.L. , Rippey J.J. , Hill R.R. , Sweet M.B.E. , Thonar E.J-M.A.
Published: May 2019

Surgical exploration of eight chronically afflicted haemophilic knee joints in patients aged 6 to 31 years, has revealed a pattern of progressive arthropathy.

Significant synovial changes occurred very early. Cellular overgrowth produced thickening, convolution and increased vascularity. Haemosiderin was deposited heavily in all cell layers. Fibrosis ultimately contracted the synovium.

Chronic inflammation produced epiphyseal overgrowth. Initially, articular cartilage changes resembled chondromalacia, but fissuring soon occurred and ultimately cartilage was totally lost over central weight-bearing areas and in the intercondylar region. Anomalies of matrix, chondrocyte aggregation and death, and subchondral round cell infiltration were features. Haemosiderin staining was sparse, occurring only in some chondrocytes and infiltrating cells.

Biochemical analysis of articular cartilage biopsies revealed a severe depletion of glycosaminoglycans. There was no biochemical evidence of a reaction of repair.

Articular cartilage damage occurred mainly between the ages of 6 and 10 years. This evidence suggests that early surgical synovectomy may arrest the process that produces progressive joint destruction.
Radioiron Uptake in Hemophiliacs Joints by 59FE-Red Cells Radioactivity Surface Counting
Authors: Morfini M. , Sistemi S. , Bernabei P. , Locchi F. , Ferrini P. Rossi , Legnaioli M. , Boncompagni L.
Published: May 2019

Hemosiderin deposits in the synovial membrane has long been recognized in hemophiliac patients and its possible relationship to the arthropaty is very attractive. 59Fe-labelled autologous transferrin has been injected in 10 hemophiliacs and in 5 normal consentient volunteers. Red cells and plasma radioactivity, surface counts on knees, thighs and sacrum has been recorded every 1 hour for the first day and every 6 days over the course of ensuing 60 days. All counts were adjusted for background and decay. The surface counts rate in control group and on the thighs of hemophiliacs parallels the initial rapid clearance and the following incorporation of 59Fe in circulating red cells. In hemophiliacs the surface counts rate on the knees instead shows a progressive increase of radioactivity and at 60th day it is raised to a mean +28,6% value in respect that at 10 min. In the control group this value is equal to –20%, The findings suggest that, beyond hemarthrosis, intra-articular accumulation of iron may take place from small subclinical hemorrage or erythrocytes breakdown by the synovial membrane.