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2 edition of Studies on the development of standardised thromboplastin reagents found in the catalog.

Studies on the development of standardised thromboplastin reagents

Kenneth Johnston Stevenson

Studies on the development of standardised thromboplastin reagents

by Kenneth Johnston Stevenson

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  • 4 Currently reading

Published by Leicester Polytechnic in Leicester .
Written in English


Edition Notes

Thesis (Ph.D) - Leicester Polytechnic, Leicester, 1990.

StatementKenneth Johnston Stevenson.
ContributionsLeicester Polytechnic.
ID Numbers
Open LibraryOL18570723M

The reagent (known as thromboplastin) used for the PT test is derived from various sources and varies in responsiveness to a reduction of the vitamin K-dependent coagulation factors (i.e. factors II, VII, IX, and X). A patient with stable anticoagulation may have completely different PT results depending on the type and lot of thromboplastin Size: 13KB. Activated partial thromboplastin time test (Dacie and Lewis, ) Specimen was centrifuged to obtain platelet poor plasma. ml of plasma was pipetted into test tube; ml of kaolin/platelet substitute was added to it. The contents of the tube were mixed quickly and placed in a C water bath for 5 minutes.

The ISIs of the thromboplastin reagents ranged from to as compared with the WHO reagent using the manual technique. The coefficient of variations between the thromboplastin reagents comparing the orthogonal and the ordinary regression analysis were versus % (Kolle–Hook method, P = ) and versus % (KC10 method, P. The UAB Coagulation Service is dedicated to meeting the coagulation medicine needs of the Southeast. We unify the collective knowledge of Pathology, Internal Medicine, Hematology, Oncology, and Laboratory Medicine in a university-based medical center to advise on the diagnosis and management of both hemorrhagic and thrombotic disorders.

in ratios of the thromboplastins tested versus the reference reagent was either a straight or curved line. The International Sensitivity Index (ISI) was estimated for each of the test thromboplastins and these ranged from to Some ISIs stated by manufacturers were different from our results. Thromboplastins with a high ISI showed a loss of sensitivity in assessing the level of.   In the PT test a thromboplastin (TF and calcium) is added to a citrated patient plasma sample. The time is recorded for fibrin formation The clinical significance of mixing studies: Definition. It is independent of the reagents and methods. It is determined from the PT and reported on patients for monitoring anticoagulant therapy.


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Studies on the development of standardised thromboplastin reagents by Kenneth Johnston Stevenson Download PDF EPUB FB2

Thromboplastin (TPL) or thrombokinase is a mixture of both phospholipids and tissue factor found in plasma aiding blood coagulation through catalyzing the conversion of prothrombin to is a complex enzyme that is found in brain, lung, and other tissues and especially in blood platelets and that functions in the conversion of prothrombin to thrombin in the clotting of blood.

Standardization of Prothrombin and Activated Partial Thromboplastin Time Reagents and Controls Billie B. Patterson, B.S., M.T. (ASCP) Department of Pathology, St. John’s Hospital, Tuba, Oklahoma The Unwarranted Use of Replicate Analysis in Routine Coagulation by: 5.

Anne M. Winkler MD, in Transfusion Medicine and Hemostasis (Third Edition), Variability in Responsiveness to Thromboplastin Reagents. Thromboplastin reagents vary in responsiveness to reduction of the vitamin K–dependent coagulation factors, phospholipid content, and preparation.

More specifically, responsive thromboplastin reagents produce greater prolongation of the PT. Cell injury or death as with cancer, infection and intravascular hemolysis --> releases of thromboplastin-like material --> activation of extrinsic coagulation system --> deletion of coagulation factors especially I, V, VIII, and platelets --> increased FSPs --> inhibition of fibrin formation --> bleeding.

Performed by adding tissue thromboplastin to patient's plasma Will start extrinsic pathway in test cup Timed to see how long it takes for clot to form Specimen & reagents must be warmed to 37C uL of patient's plasma is added to uL of thromboplastin reagent (contains calcium*) Timed until clot is formed.

ACTIVATED PARTIAL THROMBOPLASTIN TIME. Principle. Platelet-poor plasma is added to an equal volume of partial thromboplastin reagent and warmed to 37°C for an exact incubation time.

Pre-warmed (37°C) calcium chloride reagent (M) is added to this mixture to activate the coagulation cascade. The time required for clot formation is recorded. Cloning and expression of recombinant human tissue factor (TF) has enabled production of a new generation of thromboplastin reagents whose performance and utility are under active investigation.

The purpose of this study was to determine the feasibility of producing a sensitive human thromboplastin reagent from a non-recombinant source Cited by: 1. Br J Biomed Sci. Jun;50(2) Activated partial thromboplastin time reagents: an evaluation. Howarth S(1). Author information: (1)Department of Pathology, King Edward Memorial Hospital for Women, Subiaco, Perth, Western Australia.

Nine automated, activated partial thromboplastin time (APTT) reagents were evaluated on an automated coagulometer, in Cited by: 4.

Different aPTT reagents missed different proportions of mild factor VIII and factor IX deficiency (,and % for reagents A, B, C and D, respectively) and showed abnormal results.

Kenneth Johnston Stevenson has written: 'Studies on the development of standardised thromboplastin reagents' Asked in Men's Health, Medical Terminology What does PTT stand for. Rabbit Brain Acetone Powder For Low ISI Thromboplastin PT. Biocontinental rabbit brain powder for low ISI is the main product for your high sensitive thromboplastin reagent in any form either lyophilized or liquid ready-to-use.

It’s suitable for the production of routine reagents in vials for manual or semi-automatic coagulometer analyzers and also frequently used for bulks in. The dilute tissue thromboplastin inhibition (DTTI) test (Schleider et al, ) is a sensitive but non-specific test for lupus anticoagulant (LA).

HUMANBLOOD THROMBOPLASTIN 91 Factor VIIis a substance in the globulin fraction of normal serum; it can be adsorbed byAl(OH)3; it is probably formed during clotting from a precursor in the plasma.

It is the purpose of this communication to demonstrate that blood thromboplastin is formed from the three components, platelets, anti- haemophilic globulin anda Cited by:   T1 - Discrepant sensitivity of thromboplastin reagents to clotting factor levels explored by the prothrombin time in patients on stable oral anticoagulant treatment.

T2 - Impact on the international normalized ratio system. AU - Testa, Sophie. AU - Morstabilini, Giampietro. AU - Fattorini, Annalisa. AU - Galli, Laura. AU - Denti, NadiaCited by: Many thromboplastin manufacturers now provide instrument-specific ISI values for their reagents.

Calibration of a thromboplastin is, in general, more precise when comparisons are made between similar preparations of the same species or the same type.

For this reason, the WHO has established international reference preparations for human. thromboplastin [throm″bo-plas´tin] tissue thromboplastin. tissue thromboplastin factor III, a coagulation factor derived from several different sources in the body, such as brain and lung; it is important in the formation of extrinsic prothrombin converting principle in the extrinsic pathway of coagulation.

Called also tissue factor. See also. Detect acquired or congenital disorders affecting the extrinsic and common pathways with Thermo Scientific™ Pacific Hemostasis™ Prothrombin Time (PT) Reagents. Widely accepted as a means of monitoring patients on oral anticoagulant therapy such as Warfarin/Coumadin, reagents are manufactured with up to three years extended shelf life and.

The activated partial thromboplastin time (aPTT) is widely used as a screening coagulation test and for monitoring unfractionated heparin therapy. Various commercial reagents are available, with different performance characteristics, particularly responsiveness to the lupus anticoagulant (LA).Cited by: In preparation for these studies, CBER scientists are currently evaluating possible impacts of an assay reagent corn trypsin inhibitor and an immune globulin impurity apolipoprotein H on the candidate thrombogenicity assays.

The results of CBER studies will support development of a standardized Immune Globulin Thrombogenicity Testing. Quarter 2. Partial Thromboplastin Time (PTT) Coverage Indications, Limitations, and/or Medical Necessity Basic plasma coagulation function is readily assessed with a few simple laboratory tests: The Partial Thromboplastin Time (PTT), Prothrombin Time (PT), Thrombin Time (TT), or a quantitative fibrinogen determination.

The PTT test is an in vitro File Size: KB. The phospholipid content of different activated partial thromboplastin time (APTT) reagents was determined and compared to heparin sensitivity. The seven reagents included were those most widely used amongst participants of the U.K.

National External Quality Assessment Scheme (NEQAS) at the time of study.Standardization of blood coagulation tests. What has been achieved? Ton van den Besselaar. Department of Thrombosis and Hemostasis. reagents (thromboplastin) and instruments.

• PT reference method: International Standard for thromboplastin + manual method (Tilt-tube).File Size: KB.Identify acquired or congenital disorders to the intrinsic and common pathways with Thermo Scientific™ Pacific Hemostasis™ Activated Partial Thromboplastin Time (APTT) Reagents.

Widely accepted as a means of monitoring patients on oral anticoagulant therapy such as Heparin, reagents are manufactured with up to two years extended shelf life.