bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human Basement Membrane Collagens do not Elicit Platelet Aggregation
Authors: Trelstad R. L. , Carvalho A. C. 
Published: May 2019

The immediate subendothelial connective tissue matrix consists of the basement membrane, a collagenous felt-like cell surface coat. The collagen from basement membranes has been isolated from human lung, skin, and kidney using a new fractionation method which separates native forms of collagen Types I, II, III, and IV. The Type IV collagens from the basement membranes have been characterized in respect to amino acid and carbohydrate composition, molecular size, charge and native structure. Antibodies prepared against the Type IV collagen reacted with both epithelial and vascular basement membranes as judged by immunofluorescence. Platelet-rich plasma (250,000/μl) from 5 normal subjects were tested for aggregation and 14C-serotonin release with human collagen Types I, II, III, and IV. Complete aggregation (100%) and 14C-serotonin release (80–100%) was obtained when Types I, II, and III were used. Human kidney, lung, and skin collagen Type IV (10–100μg/ml) did not aggregate platelets nor cause release of their contents. Pre-incubation of platelets and human collagen Type IV for periods of 30 minutes did not result in inhibition of platelet aggregation by Types I, II, or III.These data indicate that the collagenous component of the basement membrane, the first extra-vascular collagen to which a platelet is exposed, does not elicit aggregation as do the fibrillar collagens in the perivascular matrix.
Heterogeneity of Factor IX in Therapeutic Concentrates
Authors: Ménaché D. , Aronson D. 
Published: May 2019

In vivo and in vitro experience shows that factor IX concentrates are partially activated. A rabbit antibody to human factor IX was used to investigate the factor IX antigenic content and electrophoretic mobility of commercial products as well as experimental “activated products”.“Rocket” Immunoelectrophoresis of all concentrates showed a 1.5–3 fold increased antigenic content/unit factor IX clotting activity when compared to plasma. Two dimensional crossed Immunoelectrophoresis of standard factor IX preparation produced a single sharp peak whether electrophoresed in Ca or EDTA containing buffer. “Activated” preparations produced a dome shaped precipitin arc. The addition of plasma to factor IX concentrates yielded a marked shoulder only when the electrophoresis was done in EDTA. This effect could not be reproduced by the addition of antithrombin III (AT-III). The addition of plasma to the activated IX (IXa) revealed an even more pronounced heterogeneity whether in Ca or EDTA. The addition of AT-III produced a second precipitin peak when activated IX was electrophoresed in the presence of Ca++.These results indicate that at least three forms of factor IX exist in factor IX preparations. The absence of detectable AT-III reacting material in the regular IX preparations is a priori evidence of the absence of major amounts of IXa, whereas the presence of AT-III reacting material in the “activated” complex is evidence of biologically active material.
Factor Xa Like Enzyme in Snake “Habu” Venom
Authors: Maruyama I. , Kinoshita T. , Kazama M. , Igata A. , Abe T. 
Published: May 2019

The snake “HABU” venom was divided into subfractions and their influence on both platelet and coagulation were studied. Four fractions were obtained by gel exclusion chromatography on Sephadex G75 of which molecular weight ranged from 100,000 to 5,000. The fraction of the largest molecular weight was further divided into four subfractions; I–1, I–2, I–3 and I–4 by DEAE cellulose chromatography. The subfraction I–1 showed no activity to induce platelet aggregation but suppressed ADP, collagen and ristocetin-induced aggregation. The subfraction I–2 and I–3 equally induced the aggregation of plasma platelet and gel filtrated platelet suspension. The subfraction I–4 had the same effect on the platelet aggregation except for the specific suppressive effect on the restocetin aggregation. The subfraction I–3 was found to have Xa like activity which was revealed using chromogenic substance (S–2222). This activity was not inhibited by purified human antithrombin III, α2-macroglobulin or α1-antitrypsin. The relationship between activites of these fractions on platelet and coagulation suggested that they are different from any known coagulation factor.HABU--- Trimeresurus flavoviridis Hallowell
Isolation of Some Platelet Membrane Glycoproteins
Authors: Clemetson K.J. , Pfueller S.L. , Sturk A. , Lüscher E.F. , Jenkins C.S.P. 
Published: May 2019

The platelet is surrounded by a pronounced glycocalix formed by carbohydrate moieties of the membrane glycoproteins. The number of glycoproteins of the outer platelet membrane is greater in number than had previously been reported : when solubilized membranes are analyzed by SDS-polyacrylamide gel electrophoresis the number of separated carbohydrate entities was found not only to be dependant on the concentration of acrylamide and of bisacrylamide used but also on the buffer system employed.The major platelet membrane glycoproteins have been solubilized and subjected to affinity chromatography on the lectins from Lens culinaris, wheat germ and Abrus precatorius. SDS-polyacrylamide gel electrophoresis in the presence and absence of a reducing agent together with the differential binding of the lectins to the glycoproteins permitted the distinction of at least seven glycoprotein entities. Using combinations of lectin columns, two platelet membrane glycoproteins have been isolated and others have been greatly purified.
Thrombosis: A Function of Surface Charge and/or Chemistry of Collagen
Authors: Sawyer P. , Stanczewskl B. , Stillman R. , Kirschenbaum D. , Sivakoff S. , Lucas T. 
Published: May 2019

Examination of porcine prosthesis and bovine heterografts using histologic, SEM and physical examination revealed that ; (1) they have a measurable half life in terms of function; (2) the areas of failure are predictable; (3) the structure of the observed thrombus is unusual.A number of collagen and human umbilical cord prostheses were prepared by bonding a variety of aliphatic acids to the helical polypetide collagen side chains to produce a repeating surface chemistry. The control (fresh or ficin digested collagen) was compared to (i) glutaraldehyde tanned (GT)(-) charged, (ii) GT plus (+) charged and (iii) GT neutral surface. These resulting tubular grafts were implanted in dog carotid and femoral arteries.The results indicate the most important factor in long term patency and function is a coval-ently bonded, GT (-) surface.Histologic examination reveals that manipulation of the surface charge of collagen results in bizarre thrombus formation with aggregation of a singie cell type or protein element.The (-) charged grafts were free from thrombus. Control collagen grafts contained classical fibrinogen and cellular thrombus. The (+) charged grafts had a pseudo-thrombus i.e. increased fibrinogen fragments (& B) monomers plus trapped cell deposition. The neutral grafts had a less dense, branched fibrinogen deposit with some celluiar elements.In summary, the structural, chemical and surface charge configuration of collagen can be manipulated to produce a biological cardiovascular prosthesis with improved performance.
Actin and Myosin from Platelets and Muscle are Substrates for Fibrinoligase
Authors: Cohen Isaac , Bruner-Lorand Joyce , Blankenberg Tikoes A. , Lorand Laszlo 
Published: May 2019

Fibrinoligase (thrombin and calcium activated factor XIII) from human plasma catalyzes the incorporation of dansylcadaverine and 14C-putrescine into myosin and actin prepared from either human platelets or rabbit skeletal muscle. An average of 3 to 4 moles of amine are incorporated per mole of myosin of either type when the enzyme is used under saturating conditions. The rate of incorporation is 1.4 to 2 fold faster for filamentous than for soluble myosin.Electrophoretic analysis on Polyacrylamide and agarose gels in the presence of sodium dodecyl sulfate and 2-mercaptoethanol was used for locating the acceptor sites and for the detection of possible cross-links. Both heavy and light chains of platelet as well as muscle myosin incorporate dansylcadaverine and 14C-putrescine. However, in quantitative terms, the incorporation into the light chains of either type is only a small fraction of that incorporated into the heavy chains. Fibrinoligase also catalyzes the formation of highly cross-linked polymers in both myosin and actin (platelet or muscle) indicating the presence of acceptor and donor sites in the two contractile proteins.
Ultrastructural Studies on the Surface Coat of Human Platelets Aggregated by Polylysine and Dextran
Authors: Taketomi Y. , Kuramoto A. 
Published: May 2019

The surface coat of human platelets was stained with positive charged colloidal Thorotrast particles and ruthenium red to elucidate the mechanism of platelet aggregation by macromolecules.Positive charged macromolecule, polylysine (Mw.l5,000; 23,000; 180,000) could induce the aggregation in low concentration but high concentration was needed in the case of neutral macromolecule, dextran (Mw.40,000; 250,000; 2000,000). The larger molecules of polylysine and dextran were more effective in inducing platelet aggregation. In the dextran induced aggregation, Thorotrast particles on the cell surface did not decrease significantly. On the other hand, the surface membranes of platelets treated with neuraminidase and aggregated by polylysine were essentially devoid of bound particles. These findings suggested that polylysine induced aggregation more effectively than dextran by reducing the negative surface charge and giving stronger adsorption force on cell surface.In washed platelet suspension, polylysine induced aggregation without release reaction of 14C-serotonin, but average distance between plasma membranes of aggregated platelets did not vary with the degrees of polymerization. In this respect, it seems probable that after forming macromolecular bridging of cell surface, another interaction may follow between cell surfaces.
Production of a High-Titred Sheep Antiserum Against Human Factor IX and Immunological Demonstration of Factor IX Aggregates
Authors: Ørstavik K.H. , Vennerød A.M. 
Published: May 2019

Plasma factor IX was purified from a factor IX concentrate by a five step procedure including absorption onto aluminium hydroxide, affinity chromatography on heparin-coupled Sepharose 4B, preparative disc gel electrophoresis, affinity chromatography on an immunosorbent column with rabbit antiserum against factor X and chromatography on DE-52 cellulose. The pooled fractions had a specific activity of approximately 250 U/mg protein. A sheep was immunized with pooled and concentrated fractions. An antiserum was produced which gave one main precipitin band and occasionally an additional weak band against normal plasma in double immunodiffusion. At a dilution of 1/100-1/200 the antiserum neutralized 90% of the factor IX activity in an equal volume of normal plasma.Polyacrylamide disc gel electrophoresis of the fractions from DE-52 cellulose revealed one major and three minor bands with lower electrophoretic mobility and intensity. The three minor bands disappeared on disc gel electrophoresis in the presence of 10 M urea. When the disc electrophoresis gel was submitted to electrophoresis into anagarose gel containing the sheep antiserum or a previously characterized rabbit antiserum against factor IX, four precipitin arcs corresponding to the four bands were seen. A reaction of identity was seen between the four arcs. This study demonstrates that a highly potent antiserum may be produced against factor IX in sheep.
Kinetic Studies of Soluble Fibrin Complexes in Vivo
Authors: Schönbach F. , Mahn I. , Müller-Berghaus G. 
Published: May 2019

Soluble fibrin complexes may occur in vivo in a variety of coagulation disorders. The aim of this investigation was to elucidate the in vivo behaviour of fibrin-fibrinogen complexes prepared in vitro in a ratio of 1 part fibrin to 20 parts fibrinogen. 12 rabbits (group A) were injected with soluble fibrin complexes containing homologeous I-131-fibrin and I-125-fibrinogen. Another group of 12 rabbits served as control (group B) and received I-131-fibrin solubilized in urea and I-125-fibrinogen separately from each other. Studies were performed over a period of 6 days.The mean distribution volume of fibrin as well as of fibrinogen did not significantly differ between both groups. The elimination characteristics of I-131-fibrin of the soluble fibrin complexes (group A) as well as of the solubilized fibrin (group B) were similiar. The fibrinogen elimination did not differ significantly between the groups: a mean T 1/2 of 47.8 h in group A and a T 1/2 of 46.7 h in group B was calculated.The experiments demonstrate that non-crosslinked soluble fibrin complexes distribute homogeneously in the circulation and dissociate into its subunits. Fibrin is eliminated from the circulating blood without influencing the normal catabolism of fibrinogen.
Thrombocytopenia in Septicemia: ? The Role of Disseminated Intravascular Coagulation
Authors: Neame Peter B. , Hirsh Jack , Nossel Hymie L. 
Published: May 2019

Thrombocytopenia is frequently seen in septicemia but its mechanism is uncertain. We have carried out detailed studies in 18 septicemic patients who had associated thrombocytopenia to determine whether this was associated with coagulation abnormalities indicative of disseminated intravascular coagulation (DIC) or whether it was more frequently an isolated event.Tests performed as indicators of DIC included fibrinogen degradation products (FDP), protamine sulfate test (PS), T½ I125 fibrinogen survival and in some patients fibrinopeptide A assay (FPA). Two distinct patterns of results emerged. In one, made up of patients with mild to moderate thrombocytopenia (platelet count 48,000-135,000/μl), there was no evidence of DIC on the basis of FDP, PS and FPA assays. In the second group, in which there was more severe thrombocytopenia (platelet count 2,000-39,000,/μl), there was definite evidence of DIC on the basis of FDP and protamine sulfate assays. The levels of fibrinogen, Factor VIII and Factor V were significantly lower in group 2 than in group 1.It is concluded that thrombocytopenia can occur in septicemia without evidence of associated DIC, but in those cases with severe thrombocytopenia the fall in platelet count is usually accompanied by consumption of fibrinogen.
Platelet Prostaglandin Endoperoxides Formation in Hyperlipidemias
Authors: Bizios R. , Wong L.K. , Vaillancourt R. , Lees R.S. , Carvalho A.C. 
Published: May 2019

To evaluate the role of prostaglandin endoperoxide formation in the mechanism(s) of platelet hypersensitivity in hyperlipoproteinemias, a study was undertaken in 8 type II patients, 3 type IV, and 8 normal volunteers. Platelet aggregation and release were studied in all subjects. Simultaneously, EDTA-platelets were washed by centrifugation and suspended in modified Ringer’s solution. One ml suspensions (0.8-1x106/μl) were added to 4.5μg of 14C-Arachidonic Acid (AA; sp. act. 50 mCi/mmol) and incubated for 30 sec and 5 min at 37°C. The methylated reaction products were separated by thin layer chromatography. AA, PGE2, PGF2α, and thromboxane B2 (PHD) (Upjohn) were used to identify and locate the respective bands. The products were analyzed by mass spectrometry. TLC-plates were both scanned and scraped for radioactive counting. The chromatograms displayed a pattern similar to that reported by Samuelsson et al. Compared with normal, hypersensitive platelets of type II patients generated 25% more thromboxane A2 (TXA2) after 30 sec incubation with AA, while at 5 min PHD was increased by 30% and TXA2 was still elevated by a factor of 2. The behavior of type IV platelets was similar to normal.Aspirin-treated platelets produced one product (HETE). Among the AA derivatives studied, only eluted TXA2 induced platelet release.Our data suggest that platelet hyperreactivity in type II patients may be mediated by the increased production and long survival of thromboxane A2.
Human Endothelial Cell Injury Mechanisms in Vitro
Authors: Wall R.T. , Harker L.A. , Striker G. , Quadracci L. 
Published: May 2019

Since endothelial cell desquamation constitutes the initial event leading to acute and chronic vascular diseases, we have developed an in vitro system for studying injury mechanisms using cultured cells. The system involves the incubation of test material with confluent, 51Cr-labeled, cultured human umbilical vein endothelial cells in 100% pooled human serum; injury was measured as% endothelial cell 51Cr release (ECR) into the supernatant media. Baseline spontaneous ECR was 6.0% ± 1.5 while specific rabbit antihuman endothelial cell antibody (1:64 dilution) in the presence of fresh complement released 90% ± 3 of the total releasable 51Cr activity. Consistent with in vivo predictions, homocysteine in concentrations of 0.5-40 mM iduced dose response ECR up to 20%. Neither methionine nor homocystine increased ECR over controls. Also as expected from experimental work endotoxin (S. enteritidis) caused dose response ECR, i.e., 24% ± 2 at 10 ug/ml. Control studies with cultured human smooth muscle cells (SMC) demonstrated no ECR with homocysteine but significant release occurred with endotoxin.Specific complement dependent cytotoxic anti-endothelial cell antibody was demonstrated in the secum of two thrombotic thrombocytopenic purpura (TTP) patients at a 1:1 dilution, inducing ECR of 23.1% ± 1.4 and 21.0% ± 0.25. The antibody was also demonstrated by immunoflourescent techniques and was absorbed from the serum using human endothelial cells. One disease-free, six month survivor showed no cytotoxic activity. Serum from a patient with adult hemolytic-uremic syndrome demonstrated antibody dependent cell mediated cytotoxicity with release of 22% ± 1.1 when normal non-immune lymphocytes were added to heat inactivated seriun. Control studies with SMC showed no ECR with TTP sera. We conclude that assays of endothelial cell 51Cr release are stable, reproducible and useful in the characterization of injury mechanisms.
The Functional Significance of Platelet Macromolecules
Authors: Lüscher E.F. 
Published: May 2019

Besides the equipment of enzymes, substrates and structural proteins common to all living cells, the platelet contains a variety of macromolecules which are directly involved in its specific biological functions. Although any selection may be arbitrary, the following functions primarily involve macro-molecules:- contractility based on cytoplasmic and membrane linked actomyosin (AM), responsible not only for active contraction of pseudopodes and clot retraction, but also for shape change. Disputed is the participation of AM in the release reaction.- upkeep of distinct shape, mediated by the microtubular (MT) system. The activation of AM leading to shape change is incompatible with intact MT, suggesting a subtle interplay between both systems.- influence on extracellular activities by means of released macromolecules.- membrane function, involving adhesivity, aggregability, as well as the presence of receptors for external stimulators of platelet activity and the capacity to react upon stimulation in such a way that a signal for the induction of sequential reactions is created. Examples of such secondary reactions of membrane constituents will be discussed and compared with other cells.
Aspirin Prophylaxis Against Thromboembolic Disease
Authors: Harris W.H. 
Published: May 2019

The efficacy and safety of aspirin prophylaxis in preventing deep vein thrombosis is now scientifically established. This was done in a prospective, randomized, simultaneously controlled, double-blind, placebo study using objective diagnostic methods in 98 patients over age 40 undergoing total hip replacement surgery. All patients had fibrinogen uptake tests, cuff impedance phlebography, and radiographic phlebography. The one patient with postoperative pulmonary signs or symptoms had Q/V pulmonary scans and selective pulmonary angiography. Twenty-three of fifty-one patients in the control group developed thromboembolic disease, compared to eleven of forty-seven in the aspirin group (P < 0.02, Fisher Exact Test). The embolus occurred in the control group. There were no deaths. Aspirin was given as 1.2 grams daily starting preoperatively.To study the efficacy of this prophylaxis without the use of early surveillance diagnostic methods, four hundred ninety-eight consecutive patients over 40 years of age undergoing total hip replacement had aspirin prophylaxis but only clinical diagnosis was used. No fatal pulmonary emboli occurred. The only fatality was shown at postmortum not to be caused by an embolus. All patients with pulmonary signs or symptoms had perfusion pulmonary scans. Only seven patients had objectively demonstrated, nonfatal, pulmonary emboli (1.4%).
Hematologic Changes Following Burns
Authors: Caprini J.A. , Lipp V. , Zuckerman L. , Vagher J.P. , Winchester D.P. 
Published: May 2019

Forty-five burn victims were studied at 48 hours and weekly with hematocrit, platelet count (PC), fibrinogen level, prothrombin, and activated partial thromboplastin time, fibrin split products (FSP), plasminogen (PL), complement C'3, C'4, and C'H 50, baseline, and 1 and 5 minute Kallikrein activity (K). Prognostic index was used for grouping blood data. Group I (GI) had a prognostic index under 20% survival and 8 of 12 died. Group II (GII) had a prognostic index of 20-80% survival and 4 of 11 died. Group III (GIII) prognostic index was over 80% survival and all 22 survived. At 48 hours GI had significantly elevated FSP compared to GII (32±6 vs 12±4*) and 5'K of 22±7 vs 50±5*µMoles/hr/ml. At one week PC and C'3 between GI and GII were 157,000±49,000/mm3 vs 326,000±59,000/mm3* and 61±5 vs 113±11 mg/ml, respectively. Also in the first week, PL and 5'K in GI were 6.9±1.0 mg/ml and 5.2±3.2μM/hr/ml compared to GUI 13.5±1.8 mg/ml** and 37.1±4.0μM/hr/ml*, respectively. C'3 in GI was low compared to GII or GIII for two weeks**. Summarizing, severe burns had statistically significant depression of PL, 5'K, C'3, PC, and elevated FSP. These results show activation of coagulation, fibrinolytic, complement, and kinin pathways after thermal injury and at least one measurement from each of these systems shows statistically significant alterations that correlate with the prognostic index. The results strongly support the concept of intravascular contamination with multiple systems activation following thermal injury.* P<.05** P<.01
Formation of Prostaglandin Cyclo-Peroxides and Prostaglandins by Phospholipase A2 in Platelets of Normal and Essential Fatty Acid Deficient Rats
Authors: Vincent J.E. , Zijlstra F.J. 
Published: May 2019

Phospholipase A2 has a biphasic action upon rat platelet aggregation, enhancing after shorter and inhibiting after longer incubation periods. The first effect is inhibited by indomethacin.Cycloperoxides and thromboxane-like substances and prostaglandins are formed on incubation with the enzyme in the same amounts whether aggregation is induced or not. Formation of cycloperoxides and thromboxanes is not leading to aggregation. Phospholipase A2 enhances the aggregation of the platelets of essential fatty acid deficient rats. Only very small amounts of cycloperoxides and thromboxane-like substances are formed. It is concluded that cycloperoxides and thromboxanes can enhance, but not induce aggregation in rat platelets.