[Obtaining active extracts for use in production of soluble thromboplastin]. / Poluchenie aktivnykh ékstraktov dlia prigotovleniia tromboplastina rastvorimogo.

Methods of obtaining (from cadaveric human brain) the highly-active extracts to be used later as raw-materials for thromboplastin manufacturing, which is applied to determine the prothrombin (thromboplastin) time of human plasma or blood, are described in the paper. The study resulted in defining the optimal requirements to choosing the raw-materials, storing regime, centrifuging and extraction. The thus elaborated technology of soluble thromboplastin manufacturing ensures the production of a reagent with a high sensitivity to a changing level of factors VII and X and to a reducing activity of the prothrombin complex, which is achieved through the impact of indirect anticoagulants.

[Effect of activators for activated partial thromboplastin time test on its results in the tube and automated test versions]. / Vliianie aktivatorov, primeniaemykh v teste AChTV, na ego rezul'taty v probirochnom i apparatnom ispolnenii.

Effects of activators used in combination with partial thromboplastin (PT), manufactured by the Kirov Institute of Hematology and Blood Transfusion, on the results of the activated partial thromboplastin time (APTT) test and its sensitivity to heparin were studied. Kaolin manufactured in Russia and by Aldrich firm and silica from Sigma were used. The method was reproduced in tubes and on Organon Teknika photooptic coagulometers: semiautomatic Coag-A-Mate XM and automated Coag-A-Mate RA-4. The concentration and optical density of the activator affected the results of APTT test, which prompts the use of kits calibrated for the PT/activator combination but not separate reagents. Combination of PT manufactured by the Kirov Institute and suspension of Russian kaolin ensured high sensitivity of the method to heparin content in the plasma and good reproducibility of the method both in tubes and on Organon Teknika coagulometers: coefficient of variation of APTT in all variants of the tube test were no higher than 10% and in the automated variant 2.6-6.2%.

[The quality indices of the Quick method using thromboplastin reagents performed manually and instrumentally]. / Pokazateli kachestva metoda Kvika pri ispol'zovanii tromboplastinovykh reagentov v ruchnom i apparatnom ispolnenii.

The reproduction and results of Quick's method with tissue thromboplastin (Kirov Institute of Hematology and Blood Transfusion--KIHBT) and Excel and Excel S simplastins (Organon Teknika, Netherlands) in the tube and automated versions were compared. Semiautomated coagulometer COAG-A-MATE XM and automated COAG-A-MATE RA-4 of the same firm were used. Three Verifi plasmas (Organon Teknika) with different activities of factors II, VII, IX, and X were used. Tests with thromboplastin manufactured by KIHBT were well reproduced both in the tube and automated modifications (CV < 10%). This thromboplastin can be used for monitoring the efficiency of therapy by indirect anticoagulants. For evaluating the correlation between results, plasma samples from 21 donors and 12 patients treated by indirect anticoagulants with the prothrombin index (PI) lower than 75% were analyzed. The PI of the tube and automated modifications were in good correlation. Tests with the Russian thromboplastin showed high coefficients of correlation between the two modifications of Quick's test, which recommends the use of these device-reagent combinations for evaluation of PI.

[The evaluation of lyophilized plasma as a reference standard for the prothrombin complex]. / Otsenka liofilizirovannoi plazmy v kachestve standarta dlia protrombinovogo kompleksa.

Analysis of a number of parameters of a lyophilized donor plasma reference sample to be used for the assessment of the prothrombin complex factors has shown the stability of this sample over the course of 14 months (a follow-up period). The sample may be used as a reference one in estimation of plasma prothrombin complex factor activities, and of PPSB activity. The reference sample activity should be estimated from the fresh donor plasma native pool, whose procoagulant activity is conventionally estimated as 100% or 1 U/ml. Use of a lyophilized reference sample helps obtain objective results compatible within this country, particularly so if all biologic reagents included in the test systems are standardized.

[A lyophilized reagent for standardization of the activated partial thromboplastin time]. / Liofilizirovannyi reagent dlia standartizatsii aktivirovannogo partsial'nogo tromboplastinovogo vremeni.

Native partial thromboplastin, prepared from cadaver brain thromboplastin (a reagent), is a cephalin analog used to detect disorders in the first phase of coagulation. It was lyophilized with the aim of its stabilization, potential commercial manufacture, and introduction into practical clinical laboratories. Native emulsion was distributed into 0.2 ml penicillin flasks and lyophilized for 18-20 hrs in IZ-9 (CSR) or similar equipment at the maximum temperature of the product 5 degrees C. Lyophilized reagent is a white or slightly cream-colored powder. It retains its activity for at least a year as evidenced by the activated partial thromboplastin time test. The range of activities within one lot is less if commercial lyophilized donor reference plasma is used in the test. The reagent is stored in a refrigerator at 4-8 degrees C.

[Evaluation of single-stage methods of studying the activity of factor VIII]. / Otsenka odnostadiinykh metodov issledovaniia aktivnosti faktora VIII.

Accurate diagnosis of coagulopathies related to changed factor VIII activity, studies of specific activities of antihemophilic cryoprecipitate globulin used for hemostatic correction in patients, and monitoring of therapy efficacy are impossible without a reproducible, sensitive, standard, and available method. The authors have compared two single-stage methods developed by Soviet scientists: that by V. P. Baluda et al. and that by L. P. Papayan and P. V. Khrolova. Both methods have proved sufficiently sensitive and capable to detect factor VIII deep deficiency, but L. P. Papayan and P. V. Khrolova's modification was found higher reproducible, and therefore chosen for further investigation in order to standardize it. Besides the conditions of reproducing the method, reference plasma, substrate plasma deficient for factor VIII, and partial thromboplastin are to be standardized.