bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Different Effects Of Aspirin On Experimental Arterial And Venous Thrombus Formation
Authors: Thiessen M , Zimmermann R , Weckesser G , Harenberg J 
Published: July 2018

The influence of aspirin on platelet aggregation has given rise to frequent use as an antithrombotic agent. The knowledge of an unfavorable alteration of the thromboxane/prostacyclin ratio in the vessel wall at high dosage may favor therapy with low dosages of aspirin.In order to obtain further information on the most effective dosage of aspirin the antithrombotic effect of repeated and different doses of aspirin was investigated in a standardized experimental model in 120 rabbits. In a 1. group aspirin 100 mg/kg were given 30 min before producing thrombosis. In two further groups aspirin was administered 12 hours and additionally 30 min before beginning the experiment. These rabbits received repeatedly either 10 mg (2.group) or 100 mg/kg (3. group) two times. In a 4.series aspirin was given at 50 mg/kg per day during three days.A paradoxical thrombogenic effect with an increase of venous and arterial thrombus growth could be seen after a single high dose of 100 mg/kg aspirin but not after an additional one. If applicated two times a thrombus size minor than under repeated low doses of 10 mg/kg aspirin has been observed in the arterial and venous system (p< 0.05).Additionally after repeated treatment with 50 mg/kg an antithrombotic effect could be seen.According to our data the paradoxical effect of only a single or first high dose of aspirin has to be taken into account but cannot be observed after repeated doses. At a low dosage aspirin a paradoxical effect was seen later,after a second dose. Animal thrombosis experiments does not provide sufficient evidence to support antithrombotic therapy with low doses of aspirin.
An Analog Of Thiazole Which Has Potential Antithrombotic Activity With Low Toxicity
Authors: Nishizawa E E , Rynbrandt R H , Mendoza A R , Balqoyen D P , Annis K A 
Published: July 2018

Chemical modification of a compound found active in preventing death in mice following intravenous administration of collagen led to the development of an inhibitor of collagen-induced platelet aggregation which was active at 1 ng/ml in human PRP, namely 4,5-bis(p-methoxyphenyl)-2- (trifluoromethyl)-thiazole (TFT). It did not inhibit ADP, thrombin or PGH2-induced aggregation but inhibited the collagen-induced release of radioactivity from platelets labelled with radioactive serotonin. It was active in many animal species and in the rabbit it had a duration of activity of about 8 hours at 1 mg/kg (p.o.).TFT has cyclooxygenase inhibitory activity, but unlike aspirin (A) or flurbiprofen (F), it showed no incidence of ulcers at 500 mg/kg p.o. in rats. However, again unlike A or F, it had very little anti-inflammatory activity as measured by the carrageenan-induced hind paw edema assay in rats. Its LD50 in mice (i.p.) was greater than 1 gm/kg.Thus TFT appears to be a potential antithrombotic agent with high antiplatelet specificity and a wide therapeutic margin as compared with A or F. The anti platelet action of TFT may be due to its inhibition of cyclooxygenase.
The Influence Of Physiological Parameters On The Plasma Concentration Of β-Thromboglobulin (β-TG) And Platelet Factor 4 (PF-4) In Normal Healthy Subjects
Authors: Duncan A , Didisheim P 
Published: July 2018

The variability of normal ranges in different laboratories and the occurrence of occasional elevated values of β-TG and PF-4 in normal subjects are well established.
We examined the influence of factors such as age, sex, smoking, exercise, oral contraceptives and day-to-day variation in 148 healthy subjects. The β-TG and PF-4 assays were performed by commercial RIA’s modified by utilizing an EDTA- PGE1 -theophylline mixture as anticoagulant.The statistical method used to compare our groups was a student t-test after log transformation of the data. Our baseline control group (N=63) were non smokers and not taking oral contraceptives (O/C) or any medications. There was no difference between sexes or a significant change with increasing age, although the mean β-TG and PF-4 does increase in cohosts of 20 years. [<30 years (21.65±8.35)(SD), 30-50 years (24.32±10.94) >50 years (27.88±14.3)-β-TG data].Women on O/C were significantly different from those not on O/C for β-TG [35.06±22.45 (O/C) and 23.67±9.38 (N)] but not for PF-4 values [3.79±1.77 (O/C) and 3.91±1.63 (N)].Strenuous exercise was the parameter that influenced both β-TG and PF-4 significantly, showing an elevated value after exercise for both β-TG [81.9±31.4 v 26.73±10.91] and PF-4 [7.08±1.71 v 3.73±1.91].Day-to-day variations in β-TG and PF-4 were examined in 10 subjects for 7-10 days. The coefficient of variation (CV) amongst these subjects was 21-51%. In athletes day-today variation was the same unless a change in pattern of exercise occurred [CV-49-132%].Our results confirm that parameters such as above do influence normal values and should be taken into consideration in establishing a normal range.It also indicates the β-TG is a more sensitive parameter for delineating differences in physiological parameters in normal subjects than PF-4, and this may be applicable to clinical studies.
Platelet Factor 4 (PF4) And β-Thromboglobulin (BTG) In Atherosclerosis And Diabetes Mellitus
Authors: Kazmier F J , Bowie E J W , O’Fallon W M , Palumbo P J 
Published: July 2018

Distinguishing between in vitro and in vivo release of platelet specific proteins has led to problems in interpretation of clinical studies with PF4, and with BTG.As part of a prospective study of peripheral occlusive arterial disease in diabetes mellitus PF4 and BTG were measured together by specific radioimmunoassay in four groups of subjects age 50-70 years. Groups included (1) 106 normal subjects (NC); (2) 126 with clinical and objective evidence (transcutaneous doppler ultrasound and treadmill exercise) of peripheral arterial occlusive disease (ASO); (3) 244 with diabetes mellitus without ASO and (4) 101 with both diabetes mellitus and ASO.PF4 did not distinguish among the four groups: NC vs ASO p=. 18, NC vs DM p=.52, NC vs DM+ASO p=.73, NC vs all diabetics p=.61, and NC vs all ASO p=.46. However, BTG did distinguish the groups with vascular disease from NC: NC vs ASO p=.02, NC vs DM+ASO p<.001, NC vs DM p=.32, DM vs DM+ASO p<.01, all ASO vs all nonASO p<.001.Normal range for PF4 is 0-13 ng/ml with a median of 3.0 ng/ml, a mean of 3.0 ng/ml, and SD 1.97. Normal range for BTG is 14-46 ng/ml with a median of 26 ng/ml, a mean of 27.2 ng/ml, and SD 10.3. When PF4 and BTG are correlated (all groups included) r=.41 p<.001.PF4 and BTG levels should be performed together. When done together low PF4 levels support the absence of in vitro platelet release due to sample collection and handling. BTG levels are significantly increased in subjects with peripheral arterial disease, supporting the active role of platelets in thrombotic occlusive arterial disease.
Fibrinopeptide A And Beta-Thromboglobulin Concentrations In Venous And Arterial Disorders
Authors: van Hulsteijn H , Bertina R M , Briët E 
Published: July 2018

The purpose of this study was to assess the relative importance of thrombin generation and platelet activation in venous and arterial disorders. To this end Fibrinopeptide A (FPA) was used as an index of thrombin generation and Beta- thromboglobulin (BTG) as an index of platelet activation.
FPA and BTG were determined by specific radioimmunoassays.In 80 controls (age 19-70, mean 41 yrs) mean FPA concentration was 0.72 ± 0.47 (ng/ml ± SD) and mean BTG concentration 28.2 ± 10.1 (ng/ml ± SD).In 51 patients with the symptoms of deep vein thrombosis (DVT) or pulmonary embolism (PE), in which these disorders were confirmed by phlebography and/or Doppler ultrasound or perfusion lungscanning, mean FPA and BTG concentrations were clearly elevated compared to mean FPA and BTG concentrations in controls and in 25 patients with the symptoms of DVT or PE in which these disorders could be excluded by the above named techniques. Heparin and phenprocoumon lowered FPA concentrations into the normal range, while the BTG concentrations remained elevated.In 20 patients with intermittent claudication, in which peripheral vascular disease (PVD) was confirmed by Doppler ultrasound mean FPA concentration did not differ from that in controls, while the mean BTG concentration was obviously elevated. This picture did not change after 2 months of phenprocoumon therapy.In 33 patients with angina pectoris in which coronary artery disease (CAD) was demonstrated by arteriography mean FPA concentration did not differ from that in 7 patients with angina pectoris in which no coronary lesions were present and in controls contrary to the mean BTG concentration, which was clearly elevated. Results in patients on phenprocoumon or acenocoumarol therapy were not different from those without oral anticoagulant treatment.So far the experimental results indicate that in venous disorders (DVT or PE) fibrin formation plays a more important role than in arterial disorders (PVD or CAD).
Evaluation Of In Vivo Platelet Activation In Sickle Cell Disease
Authors: Watson-Williams E J , Westwick J , Krishnamurthi S , Marks G , White J , Kakkar V V 
Published: July 2018

This study was made to identify indicators of in vivo platelet activation in patients with sickle cell disease. Seven patients, homozygotes for sickle cell haemoglobin and seven age, sex and race matched controls were each studied 2 or 3 times in a six week period of normal health. Venous blood was drawn with minimal use of a tourniquet and, after 5ml was taken for other tests, 2.5ml was collected into ice- cold “Amersham BTG” tubes. The samples were centrifuged at 2,600g for 25 minutes at 4°C and the plasma immediately separated and stored at -20°C until assayed for Betathromboglo- bulin (BTG), platelet factor 4 (PF4), Thromboxane (TXB2) and 6-oxo-PGF1α. Circulating platelet aggregation was measured by the method of Wu and Hoak (1974).BTG was greater than 60ng/ml in 17 of 20 samples from the patients but in only 4 of 17 samples from the controls. This difference remained significant when corrected for the platelet count. In vivo aggregation was above 25% on 8 of 16 occasions in patients and on 3 of 16 occasions in controls. Plasma PF4, TXB2 and 6-oxo-PGF1α levels were not significantly different in the two groups. BTG and in vivo platelet aggregation may be useful parameters with which to assess in vivo platelet activation in patients with homozygous sickle cell disease whilst not in crisis.
Intracellular Localization Of F.VIII R:Ag In Platelet And Endothelial Cells Using Peroxidase Fab Conjugates In Electron Microscopy
Authors: Jeanneau C , Sultan Y 
Published: July 2018

In previous studies (Jeanneau et al Thromb. Haemost.1977, 38, 42) specific rabbit antibodies against human F.VIII R:Ag isolated by immuno absorption on insolubilized polymers from monospecific rabbit antisera against the F.VIII/ VW factor molecule and coupled to peroxidase showed the labelling of platelet and endothelial cell membranes but did not allow to visualize intra cellular localization of this antigen. Preparation of the peroxidase coupled Fab fragments of the same specific antibodies showed the intra cellular localization of F.VIII R:Ag in platelet and endothelial cells. Fab antibody fragments were prepared using papain digestion. Fab and Fc fragments were separated from the non digested antibody by filtration through Sephedex G 100. The Fab fragments were then separated from the Fc using CM 52 carboxymethyl cellulose.In human washed platelets, staining was observed on the plasma membrane, the canalicular system and some granules. After thrombin activation the release of granules containing F.VIII R:Ag better visualized in the canalicular system. In patients with storage pool disease only some platelets showed normal SCS labelling, however no stained granules were observed.Native human endothelial cells were obtained from umbilical cord veins, washed and resuspended in culture medium prior to incubation with peroxidase Fab conjugates. After fixation in glutaraldehyde and exposure to diaminobenzidine, the peroxidase staining was seen on the plasma membrane and in a large number of vacuoles. In some endothelial cells the Golgi apparatus appeared labelled demonstrating evidence of F.VIII R:Ag synthesis by endothelial cells.
Elevation Of Antithrombin III By Sulfinpyrazone Therapy In Chronic Renal Failure
Authors: Bern M , Green J 
Published: July 2018

Sulfinpyrazone can reduce the incidence of thrombosis of A-V shunts in chronic renal failure. The drug is also reported to prevent acute deaths from coronary artery disease. This study was to determine mechanisms for these protective effects.Patients on chronic hemodialysis served as the study models. Six patients on dialysis three times per week for 6 or more months received sulfinpyrazone 200 mgm t.i.d. p.o. for 14 days. Blood samples were obtained before dialysis was begun before and after the 14 days of drug therapy.Results are shown as mean ± standard error of mean.AT III levels rose significantly by functional and immune assays. Functional levels (by von Kaulla technique) rose
24.5 ± 3.1 sec. to 47.3 + 5.5 sec. (P>.005) Plasma protein AT III (by radial immunodiffusion) rose 31.2 ± 2.17 mg/dl to 37.9 ± 2.1 mgm/dl. (P>.01) Platelet factor 4 (by Abbot radioimmunology assay) fell from 46.4 + 13.6 ngm/ml to 9.5 ± 1.1 ngm/ml.(P>.005) The concentration of thrombin-anti-thrombin complex (by R. Rosenberg, Harvard Medical School, Boston) rose from 4.2 ± .09 to 8.4 ± 1.0 (P>.005)Thus it appears that sulfinpyrazone elevates antithrombin concentration and function while simultaneously suppressing platelet release. These two effects may or may not be mutually dependent. The clinical efficacy of sulfinpyrazone may relate in part to the elevation of antithrombin III, probably by inhibiting its consumption, while also inhibiting platelet function.
The Reaction Mechanism Of “Limulus Test”
Authors: Morita T , Tanaka S , Nakamura T , Ohki M , Iwanaga S 
Published: July 2018

The principle of the so-called “Limulus Test” for detection of bacterial endotoxins (LPS) is based on the LPS- induced coagulation reaction, using horseshoe crab amebocyte lysate. To establish the overall molecular events in such a reaction system, we have previously studied on the complete amino acid sequence of a clottable protein, coagulogen, and the enzymatic properties of active clotting enzyme. We also developed a new chromogenic substrate method for assay of LPS, using Limulus amebocyte lysate. During these investigations, we found that proclotting enzyme, which has been characterized as a LPS-sensitive protein, is not sensitive to LPS but that another unknown factor sensitive to LPS is involved in the reaction sequence which mediates the activation of the known proclotting enzyme. The evidences were as follows.When amebocyte lysate prepared from Tachypleus tridentatus (Japanese horseshoe crab) was applied to a column of heparin-Sepharose CL-6B, two components beside coagulogen, all of which are associated with the coagulation system, were separated into the breakthrough fraction (fraction A) and the adsorbed fraction (fraction B). Among them a component eluted in fraction A was identified as the known proclotting enzyme, but this proenzyme did not show any clotting activity even after preincubation with LPS. The other component, tentatively named factor B, eluted in fraction B showed a very weak LPS-dependent amidase activity towards Boc-Leu-Gly-Arg-pNA. However, when a catalytic amount of factor B treated with LPS was added to fraction A, a strong clotting activity appeared, indicating that both components are essential to develop the clotting activity in the presence of LPS. The same experiments as made for the lysate from T. tridentatus were performed using the lysate from Limulus polyphemus. The data was the same as those described above. These results indicate that the LPS- mediated coagulation system in the amebocyte consists of a multi-enzyme system and that this cascade system may provide an extremely high sensitivity of the lysate to endotoxins.
Inhibitory Effect Of Gabexate Mesilate On Experimental Disseminated Intravascular Coagulation
Authors: Ohno H , Chang S W , Kambayashi J , Imaoka S , Kōsaki G 
Published: July 2018

Gabexate mesilate:[Ethyl p-(6-guanidinohexanoyloxy)benzoate]methanesulfonate, which is clinically used as a potent trypsin inhibitor in Japan, inhibits competitively the hydrolytic reactions with synthetic substrates by thrombin and factor Xa. However, its virtual anticoagulant effect in vivo remains to be evaluated, because of its short halflife due to the presence of plasma esterase. In the present study, the inhibitory effect of gabexate mesilate on experimental disseminated intravascular coagulation was investigated in comparison with those of heparin and aprotinin.
125I-Fibrinogen was injected into rats along with t-AMCHA to prevent lysis of fibrin formed. Five minutes after a infusion of gabexate mesilate, heparin, aprotinin or saline, intravascular cogulation was triggered by a continuous infusion of thrombin or tissue thromboplstin. The deposition of fibrin in kidney was continuously monitored by scintillation detector. Platelet count and 125I-fibrinogen in blood were determined. The formation of fibrin induced by thrombin and tissue thromboplastin was completely inhibited by continuous administration of 120 μmol gabexate mesilate/kg/h or 200 U heparin/kg/h. On the other hand, aprotinin failed to prevent the deposition of fibrin even at dose of 50,000 U/kg/h. Also, other parameters corroborated the same aspect. The naturally occuring lysis of the microthrombi previously formed by thrombin was not blocked by the infusion of 120 μmol gabexate mesilate/kg/h or 200 U heparin/kg/h. However, aprotinin, at 5,000 U/kg/h, completely blocked the lysis. Using clotting assay, the biological half life of gabexate mesilate in human plasma was found to be ten times longer than that in rat plasma, suggesting that much lower dose would be effective in human. In conclusion, gabexate mesilate is a relevant compound as an antithrombotic agent.
THe Effect Of The Synthetic Thrombin Inhibitor, No. 805, On An Experimental DIC In Rabbits
Authors: Tamao Y , Hara H , Kikumoto R , Okamoto S 
Published: July 2018

Our studies of synthetic thrombin inhibitors of arginine derivatives yielded very recently No. 805 (MCI-9038 or MD-805) having a specific stereostructure of 4-methyl-2- piperidinecarboxylic acid at its carboxamide portion which showed an extremely potent and selective inhibition of thrombin with a Ki of 0.019 μM.The effect of No. 805 on an experimental DIC was studied. An experimental DIC in rabbits was generated by a constant i.v. infusion of 0.1 M lactic acid and crude bovine placental tissue thromboplastin. A rapid decrease in platelet number and a gradual decrease in fibrinogen content in plasma were observed over the experiment period of 5 hrs. The i.v. infusion of No. 805 suppressed the decrease in platelet number and fibrinogen content dose- dependently from 1.0 to 31.6 μg/kg/min and the suppression of ca. 50% was attained at a dose of 3.16 μg/kg/min showing a plasma level as low as ca. 0.3 μM, while heparin given at a dose of 100 or 1,000 u/kg i.v. (x2) did not show a notable suppression of the platelet number decrease but a significant suppression of the fibrinogen content decrease. Thus, No. 805 was shown to be effective on the experimental DIC at lower plasma level, exhibiting more dominant effects on platelets than heparin. This result was carefully compared with those on other animal thrombosis.
The Amino Acid Sequence Studies On Limulus Polyphemus Coagulogen
Authors: Miyata T , Umezu M , Iwanaga S 
Published: July 2018

Coagulogen, which is a clottable protein found in the amebocyte lysate of Limulus polyphemus, consists of a single basic polypeptide chain having the total of 174 amino acid residues. Upon gelation of this protein, a large peptide, named peptide C, which has 28 amino acid residues, was released, and the resulting gel protein consisted of A and B chains, bridged by two disulfide linkages. This work is to determine the whole sequence of B chain and to compare with the primary structure of Tachypleus tridentatus (Japanese horseshoe crab) coagulogen previously established. The Limulus B chain was digested with trypsin and the resulting fragments were separated into 17 major peptides. For the sequence determination, manual Edman degradation was employed and resulting PTH amino acids were identified by HPLC. These analyses established the sequence of the isolated tryptic peptides, ending with the COOH-terminal serine, and the following whole sequence of Limulus coagulogen was presumed, comparing with that of Tachypleus coagulogen.Tachypleus: NH2-A-D-T-N-A-P-I-C-L-C-D-E-P-G-V-L-G-R-T-Q-I-V- Limulus : NH2-G-D-P-N-V-P-T-C-L-C-E-E-P-T-L-L-G-R-K-V-I-V-
T-T-E-I-K-D-K-I-E-K-A-V-E-A-V-A-Q-E-S-G-V-S-G-R-G-F-S-I-F-S- S-Q-E-T-K-D-K-I-E-E-A-V-Q-A-I-T-B-K-D-E-I-S-G-R⋅G-F-S-I-F-G⋅
H-H-P-V-F-R-E-C-G-K-Y-E-C-R-T-V-R-P-E-H-S-R-C-Y-N-F-P-P-F-T- H-G-P-A-F-K-E-C-G-K⋅Y-E-C-R⋅T-V-T-S-E-D-S-R⋅C-Y-N-F-F-P-F-S⋅
H-F-K-L-E-C-P-V-S-T-R-D-C-E-P-V-F-G-Y-T-V-A-G-E-F-R-V-I-V-Q-
H⋅F⋅H⋅P⋅Z⋅C⋅P⋅T⋅S⋅T⋅S⋅B⋅C⋅Z⋅P⋅V⋅L⋅S⋅Y⋅T⋅V⋅A⋅G⋅Z⋅F⋅R⋅I-I-V-Q-
A-P-R-A-G-F-R-Q-C-V-W-Q-H-K-C-R-F-G-S-N-S-C-G-Y-N-G-R-C-T-Q- A-P-K.A-G-F-R⋅D-L-E(W)V⋅H⋅K⋅C-R⋅A-Y-G-S-N-F-C-Q-S-Z-R⋅C-T-Q-
Q-R-S-V-V-R-L-V-T-Y-N-L-E-K-D-G-F-L-C-E-S-F-R-T-C-C-G-C-P-C- Q-R-S-V-V-R-L-V-T-Y-D-L-E-K⋅ G-V-F-F-C-E-N-V-R-T-C-C-G-C-P-C-
R-S-F-COOH
R-S-C00H
Platelet Function Tests Compared In An Indobufen And Aspirin Study
Authors: O’Brien J R , Etherinoton M D , Shuttleworth R D , Adams Cheryll 
Published: July 2018

To compare the effect of Indobufen with Aspirin, a double blind cross-over study was carried out on 9 controls and 9 arteriopaths with 14 days on each drug. Many tests were carried out twice before and twice during each drug period and once in the wash-out period. The results were analysed using Wallenstein and Fisher’s model.In patients and controls both drugs strongly inhibited malondialdehyde (MDA) and Thromboxane B2 production in thrombin stimulated platelets. Only Indobufen resulted in an increase in the volume of native blood passing through a 5μ Nuclepore filter (“bleeding time” model). No other tests were affected by these drugs.Before treatment the patients (Pts) differed from the controls (Cs) by having a higher fibrinogen (Pts 399 ± 85.5 mg %, Cs 325 ± 45.8, p<0.0l) and low MDA production (Pts 176 ± 86.3 ng/109 plats, Cs 290 ± 111.3 p<0.05).The following correlations were significant for the combined baseline figures: (n = 18, p<0.01 if r > 0.590, p<0.05 if r > 0.468). (l) plat PF4 and plat βTG (r 0.517), (2) plat PF4 and plat 5HT (r 0.518), (3) plasma PF4 and plasma βTG (r 0.582), (4) plat 5HT v plasma 5-hydroxy- indoles (5HIs) (r -0.465), (5) plat 5HT and plat 5HT uptake (r 0.788), (6) Age and plat PF4 (r -0.633) (7) Age and plat 5HT (r -0.644), (8) Age and plasma 5HIs (r 0.770).Conclusions: Indobufen has similar effects to Aspirin and inhibits the platelet prostaglandin/thromboxane pathway. The 9 selected arteriopaths differed from the controls principally in having a high fibrinogen and low MDA production. The many correlations may be relevant to platelet physiology. The contents of both the α granules (PF4, βTG) and the dense bodies (5HT) are, at least under some circumstances, related and both are influenced by age.