New Sorbent on the Basis of Covalently Immobilized Lysozyme for Removal of Bacterial Lipopolysaccharide (Endotoxin) from Biological Fluids.

It was demonstrated for the first time that immobilized lysozyme can efficiently remove Escherichia coli and Pseudomonas aeruginosa lipopolysaccharides (endotoxins) from solutions. Experimentally confirmed sorption capacity for the developed sorbent was at least 400 ng of endotoxin per ml sorbent. The new sorbent is compatible with the whole human blood and can be potentially used in extracorporeal therapy in the treatment of sepsis.

Characteristics of Lipoprotein(a)-Containing Circulating Immune Complexes as Markers of Coronary Heart Disease.

We studied the composition of circulating immune complexes precipitated in the presence of various concentrations of polyethylene glycol in patients with coronary heart disease (CHD) and high concentration of lipoprotein(a) - Lp(a). Precipitation of highly purified Lp(a) preparation with polyethylene glycol was evaluated. The contents of Lp(a), autoantibodies to Lp(a), IgG, and IgM in circulating immune complexes isolated from the sera of donors and CHD patients with normal and high levels of Lp(a) were measured. Circulating immune complexes containing Lp(a) were detected in the plasma of CHD patients with high Lp(a) concentrations. The presence of high concentrations of Lp(a), autoantibodies to Lp(a), and circulating immune complexes in CHD patients suggests that immunological factor contributes to high atherothrombogenicity of Lp(a).

[Elevated Lipoprotein(a) Cncentration and Presence of Subfractions of Small Dense Low Density Lipoproteins as Independent Factors of Risk of Ischemic Heart Disease].

AIM: To study relation of lipoproteina - Lp(a) and subfractional composition of apoB containing lipoproteins to the presence of ischemic heart disease (IHD). Manerial and methods. Parameters of lipid spectrum, Lp(a), and subfractions of apoB containing lipoproteins were determined in blood serum of 187 patients with known data of instrumental examination. RESULTS: Lp(a) concentration was not linked to any of risk factors, levels total cholesterol (TC), low and high density lipoprotein CH, and subfractions of lipoproteins. In total group triglyceride (TGG) level correlated with content of small dense LDL (sdLDL) (r=0.445, <0.0001) and mean dimension of LDL particles (r=-0.424, p<0.0001). This correlation was absent in the subgroup with Lp(a) more or equal 30 mg/dl and was strengthered among patients with normal Lp(a) level. In total group presence of IHD was associated with sex (r=0.325, p<0.0001), Lp(a) concentration (r=0.271, p=0.0001), and level of triglycerides (r=0.159, p=0.030). In multiple regression analysis levels of TG, Lp(a) and sdLDL were selected as factors independently associated with presence of IHD. Detection of subfractions sdLDL>2 mg/dl in blood plasma (atherogenic profile B), as well as lowering of concentration of large LDL subfractions significantly increased probability of IHD presence in patients with elevated Lp(a) concentration Lp(a) concentration. CONCLUSION: Lp(a) is an independent factor of risk of coronary atherosclerosis more significant than shifts in subfractional composition of apoB containing lipoproteins. In patients with Lp(a) concentration less or equal 30 mg/dl subfractions of sdLDL were directly related to TG. Level of sdLDL and large lipoproteins of intermediate density are directly related to the presence of IHD. Large LDL correlates with concentration of HDL DL C and probably is cardioprotective. sdLDL content>2 mg/l or hypertriglyceridemia (TG>1.7 mmol/l) significantly increase chances of detection of confirmed IHD in patients with elevated Lp(a).

[The effect of increased concentration of lipoprotein (a) on identification of sub-faction of lipoproteins using native electrophoresis technique].

The quantitative analysis of sub-fractions of lipoproteins acquires growing significance in diagnostic and prognosis of cardiovascular diseases. It is well known that presence of lipoprotein (a) in high concentrations significantly distorts results of biochemical analysis, in particular detection of level of cholesterol of low-density lipoproteins. The lipoprotein (a) is a heterogeneous particle and its mobility in the systems used for analysis of sub-fractions of lipoproteins can have significant variability that will bring inaccuracy into results. The data concerning relationship between lipoprotein (a) and sub-fractions of lipoproteins and also their differentiation in various systems of determination of lipid spectrum are quite numerous. The given study is considered as actual one because it analyses input of lipoprotein (a) into results of detection of sub-fractions using the technique with diagnostic significance. The study was carried out for evaluating possible input of lipoprotein (a) into results of quantitative estimation of sub-fractions of lipoproteins by technique of native electrophoresis in polyacrylamide gel used for diagnostic of cardio-vascular diseases. To detect concentration of lipoprotein (a) in blood serum the technique of enzyme-linked immunosorbent assay was applied. The qualitative valuation of content of sub-fractions of lipoproteins was implemented using system Lipoprint Quantimetrix (USA). The sub-fractions of lipoproteins were detected in samples of serum of healthy donor and normolipidic patients before and after removal of lipoprotein (a) using technique of affine chromatography in vitro. It turned out that after removal of lipoprotein (a) analysis of sub-fractions of lipoproteins in plasma of healthy donor detects significant decreasing of level of lipoproteins of medium density. The samples of serum of patients with atherosclerosis besides removal of sub-fractions of lipoproteins of medium density, decreasing of level of large sub-fractions of low density lipoproteins was observed. The analysis of samples obtained after procedures of therapeutic lipoprotein (a) apheresis using columns "Lp (a) Lipopak" (Russia) demonstrated that along with removal of lipoprotein (a), decreasing of concentration of sub-fraction C lipoproteins of medium density in all samples that substantiates in vitro data. In patients without affection and with multi-vessel lesion of coronary bloodstream reliable differences in concentration of lipoproteins of medium density were established. The received data testify that high level of lipoprotein (a) can contribute significant inaccuracies into results of detection of subfractions of lipoproteins. Therefore, application of system Lipoprint (Quantimetrix USA) provides no opportunity to unequivocally interpret data concerning input of sub-fractions of lipoproteins into risk of development of cardio-vascular diseases in patients with pathological lipid profile and higher concentration of lipoprotein (a).

[Tyramine and tryptamine as ligands for medical and biotechnological affinity sorbents].

A novel technique for preparation affinity sorbent based on tyramine and tryptamine was proposed. It was shown that tryptamine-Sepharose and tyramine-Sepharose effectively bind IgG, IgA, lipoprotein (a) (Lp(a)) and low density lipoproteins (LDL) from blood plasma. The sorption capacity is 4-9 mg of IgG, 2-4 mg IgA, 3-5:mg of Lp(a) and 5-7 mg of LDL per mL of gel. It was found that new sorbents can bind Lp(a) and IgG as themselves or in a complex of Lp(a) with IgG. The existence of this complex may indicate the presence of anti-Lp(a) autoantibodies in the blood of some patients. The advantages of new sorbents are easiness of its synthesis and stability during use and storage. In practice they can be applied for medical and biotechnological purposes where it is necessary to bind Lp(a), LDL, IgG, IgA.

[Affine Haemosorbents Based on Aromatic Peptides for Binding of the Immunoglobulin G].

Affinity haemoadsorbents based on WY, WTY, WNY ligands and polysaccharide matrix were developed for the human immunoglobulin G binding. The characteristics of new sorbents such as the binding of total IgG and binding of IgG subclasses were compared. It was found that all new sorbents well extract the IgG from the blood plasma. It was evidenced that WNY-based sorbent is more effective for binding of IgG subclass 3. The determination of physic-chemical characteristics of IgG binding revealed that desorption constants for IgG are 10 ± 3, 28 ± 4 and 13 ± 3 µM for WY, WTY, WNY based sorbents respectively. Maximum sorption capacities for IgG are 43 ± 2, 45 ± 3 and 46 ± 3 mg IgG per ml of sorbent for WY, WTY, WNY based sorbents respectively. Also it was shown that the new sorbents are compatible with blood and are suitable for the medical purposes.

Comparative analysis of efficiency and specificity of various sorbents for apheresis of low-density lipoproteins.

Efficiency of sorbents for LDL apheresis was compared in vitro. The sorbents based on ion-exchange interaction of the ligand with LDL (Liposorber, DALI) exhibited minimum specificity towards the eliminated component, while immunosorbents (LNP-Lipopak, LDR-TheraSorb) were most efficient. By sorption capacity, the available hemosorbents are inferior to plasmasorbents, which explains low efficiency of the therapy based on single application of hemosorbents especially in patients with consederably increased content of LDL cholesterol.