bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Glyoxylate on Adenine Nucletodies and Aggregation of Human Platelets
Authors: Holmsen H. , Setkowsky C. A. , Day H. J. 
Published: June 2019

Glyoxylate (G) reduces the ATP/ADP ratio and the adenine nucleotide pool in Ascites tumor cells, probably through inhibition of Krebs cycle and accumulation of citrate (JBC 246, 1607 1971). Incubation of human platelets in plasma or after gelfiltration with G reduced the level of metabolic ATP with a corresponding accumulation of hypoxanthine within the first 10 min after which no changes took place. The decrease in ATP levels is noticeable above 15 mM and is maximal (60–75% decrease) at 45 mM G. Oligomycin, antimycin A (AA), pyruvate, succinate, aspartate or glutamate did not alter the effect of G; 2-deoxyglucose (2-DG) and absence of extracellular glucose enhanced the G-induced reduction in ATP levels. Lactate production was not altered by 45 mM G. The same degree of ATP reduction was observed in the absence and presence of extracellular Na indicating that G did not cause depletion of the adenine nucleotide pool by activating the Na-dependent platelet AMP deaminase through increased Na uptake. The adenylate energy charge (AEC) remained constant (0.89–0.93) despite the large fall in the ATP levels. Primary and secondary platelet aggregation also remained unaffected by G-induced reduction of the ATP levels. Incubation with 2-DG plus AA reduced both ATP levels and AEC, with complete abolishment of secondary and primary aggregation at AEC lower than 0.85 and 0.80, respectively. Although the mechanism whereby G reduces the levels of metabolic ATP remains obscure, these experiments demonstrate clearly that the platelets’ ability to undergo primary and secondary aggregation does not correlate with the level of metabolic ATP, but may correlate with AEC.(Supported by NIH Grant HL 14217–05.)
The Contribution of Individual Protease Inhibitors to Plasma Antiplasmin Activity
Authors: Crawford G. P. M. , Ogston D. , Douglas A. S. 
Published: June 2019

The plasma proteins alpha-1-antitrypsin, alpha-2-macroglobulin, antithrombin III, Cl inhibitor and inter-alpha trypsin inhibitor have been shown to be capable of inhibiting plasmin activity. Whole plasma possesses both ‘rapid’ and ‘progressive’ plasminneutralising activity: the study was intended to assess the contribution of individual protease inhibitors to this plasminneutralising activity.The antiplasmin properties, assessed as ‘rapid’ and ‘progressive’ by the neutralisation of plasmin in a caseinolytic assay, and the levels of the individual protease inhibitors, assayed by single radial immunodiffusion, were measured in the plasma of 35 subjects. Statistical analysis using zero order correlation coefficients and zero order partial correlation coefficients indicated that ‘rapid’ and ‘progressive’ antiplasmin activity correlated with the plasma concentration of alpha-2-macroglobulin and alpha-1-antitrypsin respectively, but not with antithrombin III, Cl inhibitor and interalpha trypsin inhibitor.It is concluded that alpha-2-macroglobulin and alpha-1-antitrypsin are the major plasma inhibitors of plasmin and that immunological determination of these proteins provides a valid assessment of plasma antiplasmin activity.
A new Fibrinolytic Enzyme: the Prolixase. Physicochemical and Biological Properties
Authors: Hamouda Ben M. , Soria J. , Soria G. 
Published: June 2019

A new fibrinolytic enzyme was discovered in hemolymph of rhodnius prolixus. Its isolation was performed and the physicochemical proterties were determined.The activity of this enzyme was measured either by fibrinolysis of fibrin plates and by decrease of fibrinogen level induced by incubation of fibrinogen with the enzyme, or by its esterase activity on synthetic substrates.The nature of fibrinogen degradation products (FDP) were analysed both by Immunoelectrophoresis and by SDS polyacrylamide gel electrophoresis and compared with those obtained by degradation of fibrinogen with plasmin.Furthermore, considering the analysis of FDP after addition of mercapto-ethanol and urea, it was found that the enzyme induces in a first time a lysis of the α (A) chain of the fibrinogen molecule, in a second time a degradation of the β (B) chain and later a degradation of the γ chain. The activity of this enzyme was not inhibited by addition of Kunitz inhibitor. We propose to call this new enzyme: the prolixase.
Reactions of Human Endothelial Cell Cultures Exposed to Adrenalin Concentrations
Authors: Wright Payling H. , Evans M. 
Published: June 2019

Cultures of vascular endothelium obtained from fresh human umbilical veins and grown in vitro in fortified 199 medium for several days have been subjected to differing concentrations of adrenalin for various times. Their reactions to the drug, as seen microscopically, were recorded photographically. The viability of endothelial cells under these cultural conditions gives a measure of the maximal exposure to adrenalin which they are able not only to survive, but also to multiply. Their capacity to mitose was studied autor adiographically.The significance of the findings will be discussed with reference to atherogenesis and particularly the possible link with infection and in “stress”.
Effect of Structural Changes of Collagen on Collagen-platelet Reaction
Authors: Yamanaka M. , Nagai Y. , Kodama M. 
Published: June 2019

Removal of telopeptides from the acid soluble calf skin collagen with proctase did not affect the platelet aggregation. Limited digestion with tadpole collagenase at 20° C maintained the ability of collagen to aggregate platelets, when it was measured at 20°C., although its ability was completely abolished at 37° C. Neither α1 and α2-components of collagen did show the ability to aggregate platelets. Denaturation of the soluble collagen by heating at 45° C for 10 min destroyed its ability to aggregate platelets, although an initial shape change of platelets was observed.These results suggest that there may be different mechanisms in relation to the structure of collagen in the adhesion of platelets and the aggregation of platelets as a sequential reaction and that the tertiary structure of the soluble collagen composed of three polypeptides chains with a some critical length may be necessary for the platelet aggregation.
A Method for the Quantitative Determination of the Antithrombin III (AT III) a Citivity in Plasma and Serum Using the Complex Formation with Heparin
Authors: Karges H. E. , Heimburger N. , Loechelt C. 
Published: June 2019

A prerequisite of most AT III assays is the defibrination of the samples. Defibrination of plasma, however, is generally associated with a loss of AT III. This especially true of heat defibrination. Furthermore, according to our experience, most of the functional determinations don’t correlate well with the immunological ones, and don’t provide reproducible results. Therefore, it was the aim of our investigations to establish a method which omits the defibrination and yields reproducible results.The method reported is based on the identity of AT III and heparin cofactor antithrombin II (AT II) respectively. AT III is converted by heparin from a progressive into an immediate inhibitor, allowing a plasma dilution of 1:50. Due to this high dilution, the defibrination step can be omitted and AT III determined in native plasma. To transform AT III completely into its heparin complex, 5 USP units heparin are used. α2-macro-globulin up to 400% of normal plasma concentration does not influence the assay. When determinations are performed at a certain pH value, good reproducibility is obtained. The mean error of determinations of the same sample does not exeed 4%. Maximal deviations were in the range of 5 to 10%. The results of functional determinations are compared with those obtained by two immunological methods. Deviations scarcely exeed the limits of methodical errors.
ICSH-ISTH International Anticoagulant Control Study III. Implications of the Findings
Authors: Ingram G. I. C. 
Published: June 2019

For general standardization of oral anticoagulant control, the results of tests performed with the present diversity of reagents must be referable to a common scale. To date, most comparative work has been related to the relative sensitivities of different thromboplastins to the anticoagulant defect. A “master” reference thromboplastin, against which working reference materials — thromboplastins and standardized plasmas — could be expertly calibrated, may well provide the backbone of an international scheme. For working-laboratories, anticoagulant treatment could then be controlled by using either a thromboplastin of known sensitivity or standard plasmas with calibrated responses, to refer patients’ clotting times to a common scale.The relative merits of these two schemes will be discussed in the light of the findings of the international study described in the previous two abstracts.
Clinical Thrombosis. A Subunit Study of the Fibrin
Authors: Strachau G. J. L. , Gaffney P. J. 
Published: June 2019

The fibrins in venous and arterial thrombi, obtained by surgical intervention, were examined with respect to their subunit compositions. All the fibrin samples examined were totally crosslinked by the action of Factor XIII, e.g. the α chains were crosslinked as α chain polymers (αP) and the γ chains were crosslinked as γ chain dimers (γ-γ), while the β chains were uncrosslinked. The only difference between the subunits of the in vivo formed fibrins and those of in vitro plasma clots, was the consistent presence of some partly digested fibrin chains (of molecular weight 33,000) which were fragments of the β or γ chains, suggesting that the latter polypeptide chains may be more subject to lysis in vivo than the crosslinked α chains. The α chain polymers may be structural features stabilising the thrombus fibrin in vivo.Brinase (a purified extract of Aspergillus Oryzae) was shown in vitro to rapidly lyse the in vivo formed thrombi, having the unique property of degrading the plasmin resistant crosslinked α chain regions of fibrin. The in vitro lysis of the pulmonary emboli by plasmin resulted in the production of soluble fragments called D dimer and E which are also associated with the lysis of plasma clots made in vitro. These similarities in the formation and lysis of in vitro and in vivo fibrins encourages the use of in vitro systems to help understand the initiation and progression of clinical thrombosis.
Comparative Effects of Platelet Suppressant Drugs on Platelet Survival Time
Authors: Genton E. , Ellis J. , Steele P. 
Published: June 2019

The important role of platelets in thrombosis makes inhibitors of their reactivity potentially useful therapeutically. A number of laboratory tests have been identified which measure platelet reactivity, but it is not clear which test and which drug effect will correlate with thrombosis and thrombosis prevention. Platelet survival (SURV) correlates with thromboembolism in patients with valvular heart disease and is shortened in several other diseases. Therefore, it is of interest to identify drugs which prolong shortened SURV. Patients with arterial and venous thromboembolism and shortened SURV (51Chromium) were treated with platelet suppressants and restudied after 12 weeks. Sulfinpyrazone prolonged SURV(2.4±.04 to 3.1 ±.06 days; p < 0.001; n = 94; average ± SEM; normal, 3.7±.04 days) and 68 (72%) had some prolongation and 39 (42%) had normalization (> 3.3 days). Dipyridamole (100 mg qd) combined with aspirin (1200 mg qd) prolonged SURV (2.6±.11 to 3.2±0.12 days; p < 0.001; n = 13) and 9 of 13 (69%) had prolongation and 6 (46%) had normalization. Clofibrate altered SURV (2.6±.09 to 3.4±.14days;p < 0.001; n = 12) and 10 of 12 (83% ) had prolongation and normalization occurred in 6 (50%). Aspirin (1200 mg qd), cyproheptadine (32 mg qd) and propranolol (160 mg qd) failed to alter SURV.Thus, of drugs which alter in vitro tests of platelet reactivity, only sulfinpyrazone, dipyridamole and clofibrate improve shortened SURV.
Tissue Antithrombogenic Inducing Factor: Experimental evidence and practical applications in the construction of cardiac valves and the artificial heart
Authors: Carpentier A. , Relland J. , Carpentier S. , Lessana A. , Fabiani J. N. , Deloche A. , Chauvaud S. , Schahmaneche L. , Gory G. 
Published: June 2019

Thrombo-embolic complications remain the major problem in human organ support and replacement devices: artificial kidney, artificial heart, cardiac valves. Based on our 7 year experience with heterograft valves which did not present thrombo-embolic problems, we postulated the existence of an anticoagulant factor inherent in tissue valves and in the biopolymers extracted from these valves.
Methods:
- Biopolymers were extracted from cardiac valves according to the method of L. Robert and the various fractions were used for impregnation of a Rhodergon fabric trileaflet valve prosthesis.- Three types of prosthetic valve were implanted in the mitral position in 31 sheep: glutaraldehyde preserved heterograft, valve (4), biopolymer impregnated prosthesis (22), non impregnated trileaflet prosthesis (5).- Anticoagulation was not used in the post-operative period.
Results:
- None of the heterograft valves presented thrombo-embolic complications.- Collagen impregnated prostheses thrombosed 4 to 12 days following implantation.- Proteoglycans and glycoproteins impregnated prostheses did not present any thromboembolic complications.- Non biopolymer impregnated prostheses thrombosed in the first few days.Electron microscopic studies in the heterograft and proteoglycans valve group showed a transitory adhesion of protein and platelets followed after 6 hours by formation of a protein layer preventing further platelet adhesion. These data suggest that a Tissue Antithrombogenic Inducing Factor (T. A. I. F.) may exist in the proteoglycan fraction of heterograft valve tissue. The precise nature of this factor remains to be elucidated.
Prothrombin Binding” to Phospholipid Vesicle Surfaces and Phospholipid Acceleration of Prothrombin Activation
Authors: Jackson Craig M. , Dombrose Frederick A. , Ittyerah T. Roy , Gitel Sanford N. , Esmon Charles T. , Suttie John W. 
Published: June 2019

Prothrombin binds to phospholipid vesicle surfaces via the Fragment 1 region of the prothrombin molecule. The physiological importance of the direct prothrombin binding to phospholipid has been demonstrated recently in comparative studies of the activation of bovine normal and abnormal (dicoumarol “induced”) prothrombins (Esmon, C. T., Suttie, J. W. and Jackson, C. M., In Press). The binding of prothrombin and isolated Fragment 1 to vesicles composed of a variety of different phospholipids has been quantitatively investigated. From these studies it has been shown that prothrombin binding involves 20 ± 2 calcium ions and by comparison with the binding of calcium to prothrombin and Fragment 1 in free solution, this binding is consistent with association via calcium bridges between protein and lipid. Comparison of the ability of phospholipid to accelerate prothrombin activation with the affinity of prothrombin for particular phospholipid surfaces underlines the quantitative importance of the lipid-protein-calcium interaction in the activation process.The in vitro acceleration of prothrombin activation by phospholipid surfaces which can be readily quantitated and related to protein binding to the surface provides a new set of criteria for quantitatively assessing the thrombogenicity of surfaces in general. Although providing a limited definition of and scale for thrombogenicity, the specificity of such assay provides a means by which the multiplicity of factors contributing to surface thrombogenicity may be better understood.(Supported by a grant to Washington University, HL-14147 for a Specialized Center on Research on Thrombosis).
Serum F.D.P. Measurement as a Screening Test for Thrombo-Embolic Disease
Authors: Vasilescu C. , Jones D. R. B. , Webber Anne , Webber R. G. , Allan N. C. , Ruckley C. V. 
Published: June 2019

Serum F.D.P. values are elevated in venous thrombo-embolic disease. In order to define the place of daily serum F.D.P. estimation as a screening test 300 consecutive patients admitted to medical wards and 70 undergoing operation have been studied. All patients were screened for venous thrombosis (D.V.T.) with the 125I-fibrinogen test and if positive they were further investigated by lung scanning and phlebography. All had daily blood sampling for F.D.P. and fibrinogen. F.D.P. were estimated by the Staphylococcal Clumping test to provide rapid results, backed up by the Tanned Red Cell Haemag-glutination Inhibition Immunoassay (Wellcome). The mean F.D.P. in medical patients with no detectable thrombo-embolic disease was 10.5 ug/ml. In patients with positive leg scans the mean was 43.3 ug/ml. In surgical patients with negative leg scans the mean F.D.P. was 15.4 ug/ml and with positive leg scans 38.9 ug/ml. In those with positive lung scans it was 275 ug/ml.We conclude that a finding of elevated serum F.D.P. in hospital patients strongly favours the diagnosis of venous thrombo-embolic disease. Low F.D.P. values do not exclude the condition.
Structural Studies of Fibrinogen by Ultrasound Irradiation
Authors: Albert A. , Ayuso M. R. , Usobiaga P. 
Published: June 2019

Low frequency ultrasound irradiation of purified fibrinogen solutions produces a precipitation of protein and a loose on clottability due to molecular fragmentation, both depending in different ways on the irradiation dose. Precipitation seems to be closely related to free radical formation, the fragmentation being due mainly to the shearing forces appearing during cavitation.The high molecular weight fragments obtained by ultrasound irradiation of fibrinogen have been isolated by gel filtration and studied by disc gel electrophoresis and analytical ultracentrifugation. They show molecular properties similar to those of the fragments obtained by endopeptidase incubation and the protein degradation proceeds in a similar way. All that can be interpreted according to a trinodular model for the fibrinogen molecule, with two elongated fibrous zones more easily cleaved by mechanical forces and less compact parts of the molecule that are mostly constituted by the α-chains.
Sugar-Amine Interactions in the Blood Clotting System and their Effects on Haemostasis
Authors: Mester L. , Kraska B. , Crisba J. , Mester M. 
Published: June 2019

N-Glycosides and l-Desoxy-l-amino-2-keto-sugar derivatives (Amadori compounds) are formed from reducing sugars and amino groups of amino acids, proteins or simple amines in the first step of the Maillard reaction leading to the non enzymic browning of foodstuffs. Very little if any attention has been devoted to this reaction in the blood clotting system. Two examples are given to illustrate the possible role of this reaction in haemostasis.Poly-L-lysine, often considered as a model for collagen, reacts easily with D-glucose or D-galactose to form Amadori compounds with the ε-amino group of poly-L-lysine (mol. w. from 2,000 to 30,000). As a consequence, poly-L-lysine looses its ability to aggregate platelets. Serotonin reacts with D-glucose to form a stable and strongly reducing Amadori type compound. No change in the platelet aggregating ability of this compound has been observed, but other biological properties of the amine are highly affected.
Binding of Anti-Actin Auto-Antibodies to Platelets
Authors: Bouvier C. A. , Gabbiani G. , Majno G. 
Published: June 2019

It was recently shown (Gabbiani & Coll., Am. J. Path. 72, 473-488, 1973) that a natural antibody occurring in patients with chronic hepatitis is specifically directed against smooth and striated muscle actin or, in the case of platelets, Thrombosthenin A. Thus it is proposed to change its name from Smooth Muscle Antibody (SMA) to Anti Actin Antibody (AAA). The possibility that AAA would contain a contaminant directed against cell membranes was ruled out because it does not bind (nor its titer in supernatant decrease) to intact platelets, but only to damaged ones (by freeze-thawing). However AAA binds to a platelet-rich clot, and bright fluorescent staining is obtained both for such clots and bone-marrow megacaryocytes. AAA does not induce platelet aggregation in vitro when added to platelet-rich plasma; it does not inhibit or potentiate ADP, Adrenalin or Collagen induced aggregation, and does not inhibit platelet-rich plasma clot retraction.With aggregation controlled in an aggregometer, the following observations were made : AAA adsorption (and consequent fluorescent staining) begins immediately after addition of the trigger, and becomes maximal when a plateau is reached (so-called irreversible aggregation). However, when liminary amounts of ADP are added, so as to obtain reversible aggregation, a large number of disaggregated platelets do bind with AAA, suggesting that actin-related antigens have become available to antibody. This implies that a major change in membrane permeability to large molecules has occurred. The same holds true when ADP-induced aggregation is prevented by EDTA.
The Role of Membrane Receptors in Pathways of Human Platelet Activation by Endotoxin and other Microbial Products
Authors: Hawiger A. , Hawiger J. , Timmons S. , Steckley S. , Cheng C. 
Published: June 2019

Endotoxin-producing gram-negative rods cause thrombocytopenia and contribute to shock and death of 25% of bacteremic patients. Cellular pathways of clot-promoting activity of endotoxin compared with other microbial products were studied. Membrane receptor for endotoxin was demonstrated using human platelets as target cells separated from plasma proteins by albumin gradient-Sepharose 2B gel filtration. Endotoxin receptor was distinct from thrombin-sensitive protein and from IgG Fc receptor. It was resistant to neuraminidase and trypsin. It was related to membrane hydrophobic region(s) as demonstrated with fluorescent probe. Endotoxin-receptor interaction triggered unmasking of platelet procoagulant (Platelet Factor 3) and selective release of 3H-serotonin. A similar receptor was found for histoplasmin (yeast antigen). In contrast, staphylococcal protein A (cell wall antigen) required IgG Fc fragment and complement for its interaction with platelet membrane.Thus in addition to the well known indirect pathway of activation of human platelets by microbial antigens through receptors for IgG Fc fragment and complement there is a direct pathway of activation due to the existence of specific antigen receptors on human platelets.(Supported by NIH Grants HL 16646 and HL 08399 and VA.)
On the Origin of the Aα Chain Heterogeneity of Human Fibrinogen
Authors: Semeraro N. , Collen D. , Verstraete M. 
Published: June 2019

Human fibrinogen was highly purified with over 95 per cent yield by affinity chromatography on insolubilized fibrin. The chains were separated after reduction and S-carboxy-methylation by CM-cellulose chromatography. The extent of Aα chain degradation was quantitated by SDS-polyacrylamide gel electrophoresis in combination with densitometric scanning. Calibration curves with mixtures of intact Aα chains and Aα chains degraded to variable extents revealed that the reproducibility of the method was better than 10 per cent.Fresh frozen plasma as obtained from the blood bank contained 11.3±3.7 per cent degraded Aα chains (n = 5). Fresh plasma collected on aprotinin (Trasylol) and p-nitrophenyl-p’-guanidinobenzoate, (p-NPGB) and immediately processed at room temperature contained 6.4±2.5 per cent degraded Aα chains (n = 4). Plasma obtained from blood stored for 3 to 6 weeks at 4° C contained between 38 and 61 per cent degraded Aα chains (n = 3).These results indicate that the major portion of the fibrinogen Aα chain heterogeneity demonstrated in outdated human plasma is the result of in vitro degradation which occurs during storage and that the more protective measures one takes the lower the residual Aα chain degradation. The extent to which the residual 6.4 per cent of Aα chain degradation results from incomplete prevention of in vitro proteolysis or from in vivo fibrinogenolysis remains to be established.