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Biomedical subjects

I G Shcherbak

Publications and source records attributed to I G Shcherbak.

32 records · Page 2Linked to original sources
PubMedDate not supplied

[The action of karbogal on the complement system under model conditions and in an animal experiment].

The influence of dimethylperfluorocyclohexane (carbogal) on the hemolytic activity of human blood serum complement was studied in vitro. It has been show that different effects of carbogol on the complement depend on the serum lipid composition. Endotracheal administration of carbogal to rats results in a significant reduction of complement activity in the animal's blood. Significant changes in the hemolytic activity of the complement recorded 21 days after the endotracheal administration of the compound are, probably, associated with the complement depletion after its activation by carbogal particles or with disorders in the complement component synthesis by macrophages.

Animals↗
PubMedDate not supplied

[Antitrypsin effects of alpha-2-macroglobulin].

Purified preparations of alpha 2-macroglobulin were preincubated with bovine trypsin at various molar ratios. Effects of the preincubation were measured before and after addition of soybean trypsin inhibitor in excess if N-benz-L-arg-p-nitroanilide was used as a substrate. Two types of interaction between alpha 2-macroglobulin and trypsin were detected. One of them was carried out depending on the "trap" hypothesis, another type of the interaction led to the enzyme loss of both proteolytic activity and its ability to hydrolyze the low molecular substrate. The data obtained suggest that various molecular forms of native alpha 2-macroglobulin were responsible for these types of interaction.

Animals↗
PubMedDate not supplied

[The effect of plasmin on complement in human blood serum].

Plasma exhibited the dose-dependent inactivating effect on human blood serum hemolytic complement both in classic and alternative pathways. Negative correlation (r = -0.8) was found between the rate of complement inactivation and content of C3 component. Plasmin appears to hydrolyze mainly the C3 component of complement as a result of which hemolytic activity of complement is decreased.

Blood↗
PubMedDate not supplied

[Endogenous inhibitor of cysteine proteases from the human kidney].

A thermo- and acid stable inhibitor of cysteine proteinases was isolated from the human kidney by successive procedures--acid fractionation, gel-filtration on Sephadex G-75, affinity chromatography on papain-sepharose. The final purification factor was 650 fold. The inhibitor molecular weight was equal to 12 kDa. The values of Ki measured by different methods are (7.9-9.4) X 10(-4) M for papain and (7.1-8.0) X 10(-10) M for purified human kidney cathepsin B. In experiments with papain, inhibitor kass and kd were 1.1 X 10(6) M-1 s-1 and 9.0 X 10(-4) s-1, respectively. The inhibitor did not influence the trypsin activity, its properties being similar to those of related thermo- and acid-stable inhibitors from other human and animal tissues.

Chromatography, Gel↗
PubMedDate not supplied

[Activity of cathepsin B and serine trypsin-like peptide hydrolases in human kidney extracts].

A potentiality to use the available substrates BAPNA and BAME was studied in estimation of activities of cathepsin B and other trypsin-like hydrolases in extracts of human kidney cortex. In these extracts the BAME-hydrolyzing activity of cathepsin B was difficult if impossible to detect due to high level of attendant non-thiol esterases. At the same time, BAPNA might be used for this purpose as a substrate in estimation of cathepsin B- and trypsin-like peptide hydrolase activities in biopsies of human kidney.

Benzoylarginine-2-Naphthylamide↗
PubMedDate not supplied

[Products of the proteolytic effect of cathepsin on various protein substrates].

Cathepsin B was shown to hydrolyze in calf thymus histones not only the peptide bonds involving alkaline amino acid residues but also the bonds involving aromatic amino acid residues. Thermo- and acid stable inhibitors of cysteine proteinases were found among the products of albumin hydrolysis by means of these enzymes as well as in the products of the enzymes autolysis.

Animals↗
PubMedDate not supplied

[Leukotrienes].

The paper deals with the structure and nomenclature, distribution, metabolism and biological role of leukotrienes, a group of derivatives of eicosanic acids, in the human and animal organism. Leukotrienes can cause contraction of smooth muscles, stimulate the function of leukocytes, and affect the permeability of vessels and arterial pressure. The participation of these substances in the inflammatory processes and allergic reactions is discussed.

Animals↗
PubMedDate not supplied

[Activity of the complement system in blood serum of dogs after treatment of acute necrotic pancreatitis with boiled pancreatic juice].

The investigations were conducted on 14 dogs. To assess the blood serum complement system, the erythrocyte lytic rate of a rabbit (RE) and a sheep (SE), the hemolytic capacity of the complement system against rabbit (RH) and sheep (SH) was measured. In acute necrotic pancreatitis, no changes in SE and SH were revealed either in the control and experimental animals. RH was decreased both in the control and experimental animals. Lower RE was found only in the controls untreated with boiled pancreatic juice. It can be suggested that in the controls the decrease in the parameter RE that characterized the activity of the complement system is associated with the emergence of complement inhibitors, which did not take place when the boiled juice was given. Preventing the complement inhibitors from forming, pancreatic juice is likely to be able to diminish the body's endogenous intoxication which is a cause of death in acute necrotic pancreatitis. This may be suggested by the higher survival of the animals and lower relative extent of pancreatic acinar tissue necrosis after boiled pancreatic juice treatment of acute necrotic pancreatitis.

Animals↗
PubMedDate not supplied

[Gas chromatographic method for determining esterase activity of proteolytic enzymes using continuous gas extraction of the volatile product].

A new procedure was developed for estimating the esterase activity of proteolytic enzymes by using CIS subcomponent of complement and N-alpha-benzoyl-L-arginine ethyl ester as a substrate. In contrast to other methods, which used static variants of gas chromatographic vapour-phase analysis for registration of the volatile reaction product alcohol, the procedure involved steady gas extraction of the volatile product in the gas stream over the incubation mixture. This method enabled to obtain a kinetic curve during one experiment as well as to elevate the accuracy of enzymatic activity estimation.

Arginine↗