[Assessment of thromboplastins according to the WHO guidelines and the results of external quality control].

The study was undertaken to assess commercial thromboplastins for compliance to the WHO guidelines and to substantiate the validity of the results of a prothrombin test carried out using these thromboplastins. The test thromboplastins were shown to meet the WHO guidelines for assessment of thromboplastins. Over 5-8 years of the authors'participation in two external quality control programs (Federal External Quality Control System, Russia; 72 trials; NEQAS, United Kingdom; 60 trials), the international normalized ratio derived through the use of assessed thromboplastins did not differ from that established due to the interlaboratory consensus value of both external quality control systems. It is concluded that correct thromboplastin assessment provide accurate results of determination of prothrombin time.

[Fibrinogen determination by the Clauss method. Reagents and analyzers].

The Clauss method was recommended by the WHO to measure plasma fibrinogen levels. The purpose of this study was to assess the application of test systems made by the RENAM Research-and-Production Association (Moscow) on different types of clinical laboratory analyzers to measure fibrinogen by the Clauss method. The calibration line is shown to be of major value in obtaining correct results on each coagulometer. The findings suggest the accuracy and reproducibility of the determination of fibrinogen concentrations by the Clauss when the REHAM test systems are used to measure fibrinogen concentrations on various analyzers if accurate calibration lines are obtained.

[Analysis of lupus anticoagulant. International external quality control].

The paper describes a reagent kit and standardized methods for lupus anticoagulant (LA) laboratory diagnosis. LA could be determined on the basis of screen/confirm assays and the reagents produced by RENAM, Moscow. The external quality control by ECAT Foundation proved the correctness of the authors' LA determining procedure. A pilot clinical study has shown that the developed approach has a high LA specificity for differential approach in thrombophilic patients.

[Modified capillary blood prothrombin-time test for the calculation of an international normalized ratio].

Prothrombin time (PT) is usually measured in citrated venous blood. This test is undesirable in pediatric practice and in patients taking anticoagulants due to frequent venepunctures. Capillary blood PT test has no adverse impact. The authors have developed a standardized modified method for PT measurement in capillary blood. The adequacy of the test is due to the fact that analyzed test packed cell volumes are kept in mind. The modified test has shown that the values of normal plasma PT may be used to calculate an international normalized ratio (INR). It makes it possible to determine capillary blood PT in the range of packed cell volumes from 0.15 to 0.7 in the examinees and to monitor anticoagulant therapy. The results of the modified test closely correlated with those when determining PT and INR in venous plasma (r = 0.99) and applying the CoaguChek test (r = 0.97).

[Stable thrombin preparations for the Klauss method of determination of thrombin time and fibrinogen level]. / Stabil'nye preparaty trombina dlia opredeleniia trombinovogo vremeni i kontsentratsii fibrinogena po Klaussu.

A method was elaborated enabling an isolation of a stable and highly active thrombin to be used in determining the thrombin time and fibrinogen concentration in plasma. The stability of the thus obtained preparations was studied, which showed no changes in the activity of their liquid variations for as long as 28 days at 2-8 degrees C.

[Use of domestic thromboplastins with attested international indices of sensitivity in the treatment of thrombophilia]. / Opyt primeneniia otechestvennykh tromboplastinov s attestovannym mezhdunarodnym indeksom chuvstvitel'nosti pri lechenii trombophilii.

Clinical evaluation of thromboplastins manufactured by RENAM (Moscow) with international index of sensitivity (IIS) 1.1-1.5 and comparison of the results with the data obtained in the same patients with foreign thromboplastins (Dade, USA; Behring, Germany; Diamed, Switzerland) and Mediolab thromboplastins (Russia) manufactured from different raw materials (rabbit brain and human placenta) showed that by sensitivity to indirect anticoagulants, Russian thromboplastins made by RENAM and Mediolab firms are not inferior to the best foreign analogs.

[Screening test on protein C]. / Skriningovyi test na protein C.

A method for obtaining protein C (PrC) activator from Agkistrodon contortrix contortrix venom, based on ion exchange chromatography, has been developed specificity and sensitivity of a reagent based on ellagic acid and soybean phosphatides to disorders in PrC system has been studied. A simple and convenient screening test for analysis of PrC system has been developed.

[Study of thromboplastin sensitivity]. / Issledovanie chuvstvitel'nosti tromboplastinov.

Comparative analysis of foreign and Russian thromboplastins demonstrated differences in the notions "activity" and "sensitivity" and the significance of low value of International Index of Sensitivity (IIS). Sensitivity of thromboplastin manufactured by RENAM Firm, Russia (IIS = 1.5) to deficiency of prothrombin factors II, VII, X has been demonstrated, which means that this thromboplastin can be used for diagnosis of deficiency of each of these factors. The authors consider that testing of thromboplastin sensitivity to factor VII is the main criterion of its fitness for monitoring anticoagulant therapy.

[Test for detection of activated partial thromboplastin time using ellagic acid]. / Test AChTV s éllagovoi kislotoi.

A simple and sensitive method for estimation of activated partial thromboplastin time (APTT) is developed, making use a complex reagent containing the activator (plant phospholipids) and contact factor (ellagic acid). The test requires additionally only 0.025 M CaCl2. The test is more sensitive to the presence of heparin in the blood and to insufficiency of blood clotting factors VIII and IX than the reagents containing insoluble substances (kaolin and animal phosphatides). Addition of soluble ellagic acid into reagent for APTT estimation allows studies on optic coagulometers.

[Modern principles of standardization in detection of factor VIII activity in human plasma]. / Sovremennye printsipy standartizatsii pri opredelenii aktivnosti faktora VIII v plazme krovi cheloveka.

The authors propose a modified single-stage method for measuring the activity of factor VIII in human plasma, consisting in the utilization of modern philosophy of standardization of coagulological studies, accepted at the National Reference Institute of Great Britain. The authors draw attention to plotting the line of tested plasma titration, which is to be parallel to the calibration curve.