Effect of antibiotics on fecal excretion of various products of microbial metabolism of aromatic amino acids

The model experiments on intact albino rats and those exposed to lincomycin, ampicillin and rifampicin showed that intragastric administration of the three antibiotics to the laboratory animals in therapeutic doses for 8 days induced statistically significant changes in the fecal excretion of n-cresol, indole and skatole, microbial metabolites of aromatic amino acids in the gastrointestinal tract of a macroorganism. The results are in favour of using biochemical tests for rapid diagnosis of the intestinal microflora response to antimicrobial agents.     

Determination of the penicillin acylase activity of E. coli cultures using a method of gas-liquid chromatography]

Penicillinacylase activity was determined in E. coli by the product of benzylpenicillin destruction, i.e. phenylacetic acid formed under the effect of the enzyme. The determination was performed on a chromatograph. The immobile phase consisted of 10 per cent of ethylenglycol edipate on chromosorb A, modified with 2 per cent H3PO4. Nitrogen was used as the gaseous carrier. The method is rapid and handy for mass testing of the cultures with a purpose of detecting penicillinacylase-producing strains. It provided reliable determination of penicillinacylase in the cultures producing simultaneously beta-lactamase, another penicillin-destroying enzyme.     

Effect of antibiotics on excretion of various microbial metabolites with feces

Concentrations of volatile fatty acids, free amino acids, ammonia, protein, carbohydrates, carboxylic acids and some cations were determined in feces of intact animals (rats) chromatographically and spectroscopically. Oral administration of 8 chemotherapeutic drugs in the therapeutic doses to the animals resulted in changing excretion of the majority of the above compounds associated with vital activity of the large intestine microflora which depended on the drug type. Investigation of metabolic activity of normal microflora of the gastrointestinal tract is shown promising for estimation of intestinal microbial biocenosis.     

Isolation of the new antibiotic variamycin B from the biosynthetic products of a Streptomyces olivovariabilis sp. nov. culture

Variamycin B, a new antitumor antibiotic was isolated from metabolic products of Streptomyces olivovariabilis sp. nov. The empirical formula of variamycin B is C52H76O24, the melting point is 163-165 degrees C (dec.), (alpha)20D--30 +/- 2 degrees (C 0.5, alcohol), the UV-spectrum: lambda max 230, 279, 317, 330, 415 (lg E 4.27, 4.6, 3.83, 3.75, 3.95), IR-spectrum: 1080, 1170, 1380, 1570, 1640, 1720, 3400 cm-1. Variamycin B is classified as belonging to the group of antibiotic analogs of aureolic acid. Chromomycinone, tetrazide and residues of two 2,6-didesoxysugars, i.e. olivose and variose were obtained as a result of complete and partial acid degradation of variamycin B. It was shown with the data of quantitative analysis of the hydrolysates obtained on complete hydrolysis of variamycin B that the ratio between the residues of variose and olivose in the antibiotic molecule was 1 : 4. Oxidation of variamycin B with Fremi salt resulted in formation of chinone having chromomycinone-chinone, 2 residues of olivose and 1 residue of variose in its composition. Investigation of the products of partial hydrolysis provided isolation of a substance having aglicone-chromomycenone and 4 residues of olivose in its composition. A partial structure of variamycin B is proposed.     

Spontaneous mutagenesis in bone marrow cells in the CBA and CBA/H-T6 mouse strains

Comparative analysis of cytogenetic characteristics in bone marrow cells of the mouse lines CBA and CBA/H-T6 has been carried out. It was shown that translocation T6 effects the apparatus of cell division and can cause additional cytogenetic abnormalities.     

The effect of hexadecylphosphocholine on the degradation of mitochondrial phospholipids

Hexadecylphosphocholine (HePC) is known as antitumor agent but the mechanism has not yet been understood. In rat liver mitochondria its effect on phospholipid transformation has been studied by quantitative HPTLC and phosphorus determination. From the results it can be concluded that HePC influences the activities of phospholipase A₂, phospholipase C, phospholipase D, and lysophospholipase A. The phospholipid transformation as well as the influence of HePC are affected by exogenous calcium ions. In the presence of calcium HePC has been found to inhibit enzyme activities, whereas in the absence of exogenous calcium ions enzymatic phospholipid transformations are activated or inhibited depending on HePC concentrations.     

The role of membrane structure in activation of mitochondrial phospholipases. 2. Mechanism of crambin action on the activities of mitochondrial membrane phospholipases and microviscosity

Effects of crambin on the phospholipase activity, lipid peroxidation and structure of mitochondrial membranes have been investigated. Crambin has been shown to inhibit lipid peroxidation and phospholipase activity induced by Ca2+ and freezing-thawing of mitochondria. As shown by ESR studies, these effects are based on the ability of crambin to cause changes in mitochondrial membrane structure.     

Somaticoautonomic functions of rabbits exposed to an ultrahigh-frequency electromagnetic field at acupuncture points

The action of electromagnetic field of ultrahigh frequency with power from 1 to 1000 mwt and acupuncture on the functional state of rabbits under the tooth pulp irritation conditions has been investigated. The action on the points has been established to be accompanied by decrease of the rythm breathing irregularity and motion of animals jaws. The most effectiveness during the action of the field has been registered with power 1-20 mwt that corresponds to the effectiveness of acupuncture. However during the action of the field the frequency of breathing does not change while during acupuncture it increases. This fact points out the differences of the mechanism of normalized effect of these species influence on acupuncture points. The point of view concerning the invariable information action of fields upon the points and the system of points as constantly acting communication channel between an organism and the environment is under discussion.