scholarly journals The Heparin Inhibiting Property of Brain Thromboplastin

1977 ◽  
Author(s):  
E.D. Gomperts ◽  
M. Zucker
Keyword(s):  
Prothrombin Time ◽  
Antithrombin Iii ◽  
Proteinase Inhibitors ◽  
Serine Proteinase ◽  
Weight Fraction ◽  
High Molecular Weight Fraction ◽  
Thrombin Time ◽  
Factor X ◽  
Heparin Resistance

Antithrombin III is one of the serine proteinase inhibitors of the plasma which has been shown to specifically inhibit thrombin as well as Factor X. Heparin acts via antithrombin III, the heparin cofactor, hence it is difficult to explain the relative insensitivity of the prothrombin time to the presence of heparin in plasma as both thrombin, ana Factox Xa are associated functionally with the prothrombin time. This insensitivity becomes more obvious on appreciating the extreme sensitivity to heparin of the activated partial thromboplastin time as well as the thrombin time. This communication reports the demonstration of heparin inhibiting action of brain thromboplastin. The response of the prothrombin time to heparin under various conditions, and the effect of brain thromboplastin obtained from various sources and by different preparative techniques on the action of heparin in vitvo have been studied. The heparin inhibiting activity was shown to parallel the tissue factor activity. It is heat labile, non-dialysable, destroyed by detergent activity and lies in a high molecular weight fraction of the brain thromboplastin preparation (>300,000). In addition to explaining certain in vitro phenomena, these observations may explain the previously observed heparin resistance in the generalised Schwartzman phenomenon.

scholarly journals Effect of Angiography on Blood Coagulation

1977 ◽  
Author(s):  
W. H. Krause ◽  
A. Lang
Keyword(s):  
Contrast Media ◽  
Prothrombin Time ◽  
Antithrombin Iii ◽  
Degradation Products ◽  
Anticoagulant Activity ◽  
Thromboembolic Complication ◽  
Thrombin Time ◽  
Media Concentration

It is known, that angiographic contrast media have an anticoagulant activity in vitro. The purpose of the present study was, to investigate this effect in vivo. The catheter was introduced percutaneously according to Seldinger into the femoral artery. The prothrombin time, activated thromboplastin time (APTT), thrombin time, reptilase time, fibrinogen, plasminogen, antithrombin III, platelets, fibrin/fibrinogen degradation products (FDP), haematocrit and contrast media concentration were studied in a series of 50 patients before and following abdominal aorto-arteriographic procedures up to 6 hours. Thrombin time and reptilase time were prolonged significantly 30 and 60 minutes after angiography. There was a correlation between clotting tiies and contrast media concentrations. Prothrombin time, APTT, and platelet counts remained unchanged. Fibrinogen, plasminogen,and antithrombin III levels showed a significant reduction after 30 minutes. FDP concentrations were increased significantly up to 6 hours, there was no correlation between contrast media concentrations and split products. The results were corrected for contrast media dilution according to the haematocrit. No thromboembolic complication was observed. The results suggest that angiographic procedure may initiate an intravascular coagulation with an activation of the fibrinolytic system. In addition the contrast media showed an inhibition of fibrin polymerization in vivo.

Effects of Heparin Oligosaccharides with High Affinity for Antithrombin III in Experimental Venous Thrombosis

1982 ◽  
Vol 47 (03) ◽  
pp. 244-248 ◽  
Author(s):  
D P Thomas ◽  
Rosemary E Merton ◽  
T W Barrowcliffe ◽  
L Thunberg ◽  
U Lindahl
Keyword(s):  
Antithrombin Iii ◽  
Specific Activity ◽  
High Specific Activity ◽  
Factor Xa ◽  
Blood Levels ◽  
Thrombin Time ◽  
High Affinity ◽  
Very High

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.

scholarly journals Measurement of Novel Dietary Fibers

2004 ◽  
Vol 87 (3) ◽  
pp. 707-717 ◽  
Author(s):  
Barry V McCleary ◽  
Patricia Rossiter
Keyword(s):  
Resistant Starch ◽  
Weight Fraction ◽  
Complete Removal ◽  
High Molecular Weight Fraction ◽  
Interlaboratory Studies ◽  
Human Digestive Tract ◽  
The One ◽  
Good Agreement

Abstract With the recognition that resistant starch (RS) and nondigestible oligosaccharides (NDO) act physiologically as dietary fiber (DF), a need has developed for specific and reliable assay procedures for these components. The ability of AOAC DF methods to accurately measure RS is dependent on the nature of the RS being analyzed. In general, NDO are not measured at all by AOAC DF Methods 985.29 or 991.43, the one exception being the high molecular weight fraction of fructo-oligosaccharides. Values obtained for RS, in general, are not in good agreement with values obtained by in vitro procedures that more closely imitate the in vivo situation in the human digestive tract. Consequently, specific methods for the accurate measurement of RS and NDO have been developed and validated through interlaboratory studies. In this paper, modifications to AOAC fructan Method 999.03 to allow accurate measurement of enzymically produced fructo-oligosaccharides are described. Suggested modifications to AOAC DF methods to ensure complete removal of fructan and RS, and to simplify pH adjustment before amyloglucosidase addition, are also described.

scholarly journals Rapid Purification and Procoagulant and Platelet Aggregating Activities of Rhombeobin: A Thrombin-Like/Gyroxin-Like Enzyme fromLachesis muta rhombeataSnake Venom

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Frank Denis Torres-Huaco ◽  
Cláudio C. Werneck ◽  
Cristina Pontes Vicente ◽  
Talita Vassequi-Silva ◽  
Ana Cláudia Coelho Nery-Diez ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Proteinase Inhibitors ◽  
Ex Vivo ◽  
Serine Proteinase ◽  
Dependent Manner ◽  
Amidolytic Activity ◽  
Venom Component ◽  
Purification Method ◽  
Rapid Purification

We report a rapid purification method using one-step chromatography of SVSP Rhombeobin (LMR-47) fromLachesis muta rhombeatavenom and its procoagulant activities and effects on platelet aggregation. The venom was fractionated by a single chromatographic step in RP-HPLC on a C8 Discovery BIO Wide Pore, showing high degree of molecular homogeneity with molecular mass of 47035.49 Da. Rhombeobin showed amidolytic activity upon BAρNA, with a broad optimum pH (7–10) and was stable in solution up to 60°C. The amidolytic activity was inhibited by serine proteinase inhibitors and reducing agents, but not chelating agents. Rhombeobin showed high coagulant activity on mice plasma and bovine fibrinogen. The deduced amino acid sequence of Rhombeobin showed homology with other SVSPs, especially with LM-TL (L. m. muta) and Gyroxin (C. d. terrificus). Rhombeobin acts,in vitro, as a strong procoagulant enzyme on mice citrated plasma, shortening the APTT and PT tests in adose-dependent manner. The protein showed, “ex vivo”, a strong defibrinogenating effect with 1 µg/animal. Lower doses activated the intrinsic and extrinsic coagulation pathways and impaired the platelet aggregation induced by ADP. Thus, this is the first report of a venom component that produces a venom-induced consumptive coagulopathy (VICC).

scholarly journals An Assessment of the Bioactivity of Coffee Silverskin Melanoidins

Foods ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 68 ◽  
Author(s):  
Silvia Tores de la Cruz ◽  
Amaia Iriondo-DeHond ◽  
Teresa Herrera ◽  
Yolanda Lopez-Tofiño ◽  
Carlos Galvez-Robleño ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Dietary Fiber ◽  
High Molecular Weight ◽  
Research Work ◽  
Weight Fraction ◽  
High Molecular Weight Fraction ◽  
Total Dietary Fiber ◽  
Coffee Silverskin

Melanoidins present in coffee silverskin, the only by-product of the roasting process, are formed via the Maillard reaction. The exact structure, biological properties, and mechanism of action of coffee silverskin melanoidins, remain unknown. This research work aimed to contribute to this novel knowledge. To achieve this goal, melanoidins were obtained from an aqueous extract of Arabica coffee silverskin (WO2013004873A1) and was isolated through ultrafiltration (>10 kDa). The isolation protocol was optimized and the chemical composition of the high molecular weight fraction (>10 kDa) was evaluated, by analyzing the content of protein, caffeine, chlorogenic acid, and the total dietary fiber. In addition, the structural analysis was performed by infrared spectroscopy. Antioxidant properties were studied in vitro and the fiber effect was studied in vivo, in healthy male Wistar rats. Melanoidins were administered to animals in the drinking water at a dose of 1 g/kg. At the fourth week of treatment, gastrointestinal motility was evaluated through non-invasive radiographic means. In conclusion, the isolation process was effective in obtaining a high molecular weight fraction, composed mainly of dietary fiber, including melanoidins, with in vitro antioxidant capacity and in vivo dietary fiber effects.

Evaluation of Five Methods for the Determination of Heparin

1975 ◽  
Author(s):  
A. Teien ◽  
M. Lie
Keyword(s):  
Coefficient Of Variation ◽  
Antithrombin Iii ◽  
Factor Xa ◽  
Thrombin Time ◽  
Heparin Concentration ◽  
Normal Plasma

Heparin was added in vitro to plasma and the heparin content assayed by five clotting methods. The accuracy was lower in pathological than in normal plasma. At a heparin concentration of 0.5 U/ml plasma the coefficient of variation in eleven pathological plasmas was: Polybrene titration 3 per cent, method of Denson and Bonnar 15 per cent, method of Yin et al. 20 per cent, calcium thrombin time 40 per cent. With the APTT method the results ranged from 0.05 U/ml to above 0.6 U/ml (no clotting in five pathological plasmas).At a heparin concentration of 0.05 U/ml plasma, only the calcium thrombin time and the factor Xa methods were sensitive, but the coefficient of variation ranged from 61 to 78 per cent. The influence of the concentration of fibrinogen, antithrombin III and α1-acid glucoprotein was studied. It is concluded that of the methods tested, only polybrene titration gives accurate results in pathological plasmas. This method is, however, laborious and insensitive to heparin concentrations below 0.1 U/ml.

FRACTIONATION OF LIVER SOMATOMEDIN ACTIVITY BY ULTRAFILTRATION

1974 ◽  
Vol 62 (2) ◽  
pp. 355-361 ◽  
Author(s):  
JENNIFER M. DEHNEL ◽  
P. D. McCONAGHEY ◽  
M. J. O. FRANCIS
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Weight Fraction ◽  
Low Molecular Weight ◽  
High Molecular Weight Fraction ◽  
Cartilage Growth ◽  
The Relationship ◽  
Somatomedin Inhibitors

SUMMARY Plasma somatomedin is the intermediary through which growth hormone (GH) exerts its effects on the growing skeleton. Somatomedin activity may be produced in vitro by perfusion of the liver and kidneys of rats with Waymouth's medium containing GH. The relationship between the activity of plasma somatomedin and somatomedin of hepatic and renal origin has yet to be clarified. Somatomedin from plasma can be separated into active fractions of both high and low molecular weight. Similarly, ultrafiltration of medium containing somatomedin of hepatic origin indicates the existence of two active fractions, one of high molecular weight (greater than 50000) and one of low molecular weight (less than 1000). The latter can be attributed to the release of amino acids, such as serine and glutamine, by the perfused tissue. The high molecular weight fraction is believed to represent GH-dependent somatomedin. Fractions that inhibit production of cartilage matrix are present in liver perfusates as well as in plasma. These results provide further evidence that the liver is a source of GH-dependent somatomedin in vivo. Furthermore, cartilage growth may be controlled not only by the GH-stimulated release of somatomedin by the liver, but also by its release of acid-labile somatomedin inhibitors.

scholarly journals Effect of molecular size of 125I-labelled poly(vinylpyrrolidone) on its pinocytosis by rat visceral yolk sacs and rat peritoneal macrophages

1981 ◽  
Vol 196 (1) ◽  
pp. 49-55 ◽  
Author(s):  
R Duncan ◽  
M K Pratten ◽  
H C Cable ◽  
H Ringsdorf ◽  
J B Lloyd
Keyword(s):  
Molecular Weight ◽  
Molecular Size ◽  
Weight Fraction ◽  
Cell Types ◽  
Peritoneal Macrophages ◽  
Yolk Sac ◽  
High Molecular Weight Fraction ◽  
Molecular Weights ◽  
Molecular Weight Distributions

Rates of pinocytosis of different molecular-weight distributions of 125I-labelled poly(vinylpyrrolidone) by rat visceral yolk sacs and rat peritoneal macrophages were measured in vitro. Four preparations of mean molecular weights 50 000, 84 000, 700 000 and 7 000 000, were used. Macrophages captured the highest-molecular-weight preparation more rapidly than the other preparations. In contrast, rate of capture by the yolk sac decreased with increasing molecular weight. Incubations with a very-high-molecular-weight fraction derived from the 7 000 000-average-mol. wt. preparation clearly demonstrated that very large polymer molecules are not accumulated by the yolk sac, but are preferentially captured by macrophages. Analysis of the 125I-labelled poly(vinylpyrrolidone) internalized by the two cell types confirmed that low-molecular-weight material is preferred by the yolk sac, whereas the macrophage is less discriminating.

Involvement of cysteine proteinases in excystment of Paragonimus ohirai metacercariae induced by sodium cholate and A23187

2003 ◽  
Vol 77 (1) ◽  
pp. 21-26 ◽  
Author(s):  
T. Ikeda
Keyword(s):  
Proteinase Inhibitor ◽  
Proteinase Inhibitors ◽  
Cysteine Proteinase ◽  
Serine Proteinase ◽  
Sodium Cholate ◽  
Cysteine Proteinase Inhibitor ◽  
Cysteine Proteinases ◽  
Serine Proteinase Inhibitor ◽  
Similar Activity

AbstractThe involvement of intrinsic proteinases in the excystment of Paragonimus ohirai metacercariae was studied in in vitro excystment induced by sodium (Na) cholate, a bile salt and A23187, a Ca2+ ionophore. The effects of various proteinase inhibitors on the in vitro excystment were examined and similar inhibitory profiles were obtained. Benzyloxycarbonyl-L-leucyl-L-leucinal (Z-Leu-Leu-H), a cysteine proteinase inhibitor and 4-(2-aminoethyl)-benzenesulfonyl fluoride (Pefabloc SC), a serine proteinase inhibitor completely inhibited excystment, while L-3-carboxy-2,3-trans-epoxypropionyl-leucylamido (4-guanidino)-butane (E-64), a cysteine proteinase inhibitor and leupeptin, a cysteine/serine proteinase inhibitor permitted partial excystment at a lower rate, but inhibited it from proceeding from the partial excystment stage. In secretions released from metacercariae during excystment, proteinase activities detected towards various fluorogenic peptidyl substrates were almost completely inhibited by Z-Leu-Leu-H and E-64, but not by Pefabloc SC. Sodium cholate induced a higher secretion of cysteine proteinases and a higher rate of excystment than A23187. Profiles of cysteine proteinase activities towards five peptidyl substrates detected were markedly different among the two secretions and the lysate of newly excysted juveniles. Newly excysted juveniles released cysteine proteinases with similar activity profiles and levels to metacercariae induced by Na cholate-incubation, whereas the release of cysteine proteinases was reduced compared with metacercariae induced by A23187-incubation. These results provide valuable information about the involvement of intrinsic proteinases in metacercarial excystment.

scholarly journals Purification of the 300K intermediate filament-associated protein and its in vitro recombination with intermediate filaments.

1985 ◽  
Vol 101 (3) ◽  
pp. 802-813 ◽  
Author(s):  
N Lieska ◽  
H Y Yang ◽  
R D Goldman
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Intermediate Filament ◽  
Peptide Mapping ◽  
Amorphous Material ◽  
Gel Filtration ◽  
Weight Fraction ◽  
High Molecular Weight Fraction ◽  
In Vitro Recombination

IFAP-300K is a 300,000-mol-wt intermediate filament-associated protein previously identified in the baby hamster kidney fibroblastic cell line (BHK-21) by a monoclonal antibody (Yang H.-Y., N. Lieska, A. E. Goldman, and R. D. Goldman, 1985, J. Cell Biol., 100: 620-631). In the present study, this molecule was purified from the high salt/detergent-insoluble cytoskeletal preparation of these cells. Gel filtration on Sephacryl S-400 in the presence of 7.2 M urea allowed separation of the high molecular weight fraction from the structural intermediate filament (IF) subunits desmin and vimentin, designated 54K and 55K, respectively, and other low molecular weight polypeptides. DE-52 cellulose chromatography of the high molecular weight fraction using a linear NaCl gradient in 8 M urea yielded a pure 300,000-mol-wt species which was confirmed to be IFAP-300K by immunological and peptide mapping criteria. Two-dimensional PAGE of native BHK IF preparations followed by immunoblot analysis demonstrated the inability of the IFAP-300K-immunoreactive material to enter the first dimensional gel except as a 200,000-mol-wt doublet which presumably represented a major proteolytic derivative of IFAP-300K. The molecule's pl of 5.35, as determined by chromatofocusing, and its amino acid composition were extremely similar to those of BHK cell vimentin/desmin despite their non-identity. Ultrastructurally, IFAP-300K preparations in low salt buffers existed as particles composed of one or two elliptical units measuring 16 X 20 nm. In physiological salt buffers, the predominant entities were large, elongated aggregates of the elliptical units, which were able to be decorated by using the immunogold technique with monoclonal anti-IFAP-300K. Compared with the morphology of homopolymer vimentin IF, in vitro recombination studies using column-purified vimentin and IFAP-300K demonstrated the additional presence of aggregates similar in appearance to IFAP-300K at points of contact between IFs. Antibody decoration and immunogold labeling of these recombined preparations using rabbit antidesmin/vimentin and monoclonal anti-IFAP-300K confirmed the identity of the inter-filament, amorphous material as IFAP-300K. The presence of IFAP-300K at many points of intersection and lateral contact between IFs, as well as at apparent inter-filament "bridges," in these recombined specimens was identical to that seen both in situ and in native IF preparations. No such co-sedimentation was found in vitro between actin and IFAP-300K. No effects of IFAP-300K upon the kinetics of IF polymerization were detected by turbidimetric measurements.

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