Search

The paper presents the results of the assessment of the quality of cultural detection and determination of Mycobacterium tuberculosis (MBT) sensitivity at Russia's public health laboratories, which has been made by the Federal System for External Assessment of the Quality of Clinical Laboratory Studies in 2002-2003. The "Bacteriological Detection" Section involved 102 laboratories, of them 57 laboratories also participated in the section "Detection of Drug Resistance". Sixty-three laboratories operated as part of specialized tuberculosis-controlling service facilities and 39 laboratories worked as part of general medical care therapeutic-and-prophylactic institutions. A set of 5 lyophilized samples containing 2.5 x 10(6) M. tuberculosis H37Rv (n = 1); 2.5 x 10(4) M. tuberculosis H37Rv (n = 2); M. fortuitum (n = 1); E. coli in the mixture with autoclaving-killed M. tuberculosis H37Rv (n = 1). 77% of the laboratories could detect in the cultural sample with a high content of M. tuberculosis, by obtaining a correct result; 85% revealed MBT if only in every three MBT-containing samples; 15% of the laboratories could not find MBT in none of the three positive samples. 12% of the laboratories took the growth of microorganisms in the M. fortuitum-containing sample for that of M. tuberculosis. 58% of the laboratories obtained correct results if only in one sample containing M. tuberculosis H37Rv; 42% reported the detection of resistance to one or several antituberculous drugs in the samples containing the drug-sensitive strain H37Rv (a false drug resistance). All the results of determination of drug resistance (DR) in the M. fortium-containing sample were correct. The findings suggest that it is necessary to increase the professional competence of laboratory personnel to the level that ensures the adequate of fulfillment of the standard protocols for detecting MTB and determining DR, which have been introduced by the Ministry of Health of the Russian Federation through its order No. 109 on March 21, 2003.

Three main classes of human serum lipoproteins (LP), very low density lipoproteins (VLDLP), low density lipoproteins (LDLP), and high density lipoproteins (HDLP) were selectively sedimented by heparin and dextran sulfate in the presence of metal ions. These data were used for the development of a method for preparation of fractions of human serum enriched with certain class of LP. Using isolated fractions serums with increased content of total cholesterol, cholesterol of HDLP and triglycerides were prepared. These fractions may be used as control samples for evaluation of corresponding parameters in native samples.

Fractionation of human blood serum, using ammonium sulfate and dextran sulfate, enabled to obtain fractions containing lipoproteins of low and high density as well as lipoproteins of very low density including low density lipoproteins. The fractions obtained could be used for special enrichment of native blood serum with known classes of lipoproteins in order to produce blood serum containing high amount of cholesterol, triglycerides and high density lipoprotein cholesterol, respectively, required for control evaluation of lipid assays.

A procedure is developed for isolation of human blood serum fractions, enriched with lipoproteins of definite classes and meant for production of standard human blood sera. Addition of one of these fractions to native human blood serum enabled to increase distinctly selectively the content of main components of corresponding lipoproteins. Lipoprotein-free blood serum might be used as a diluent for a decrease in concentration of lipoproteins and their components in the initial blood serum, while content of the other components was maintained.