Molecular biological mechanisms of photodynamic therapy

The biological mechanisms of photodynamic therapy, a new approach to the treatment of malignant lesions, are considered. The data on chemical composition of hematoporphyrin derivative are given, the photophysical and photochemical reactions caused by photosensitizer distribution in organism and cell, as well mechanisms of photodestruction of cells and cell organelles.     

Effects of conditions ofPenicillium funiculosum G-15 cultivation on production of extracellular glucose oxidase

Effects of conditions ofPenicillium funiculosum G-15 cultivation on the production of extracellular glucose oxidase were studied. The data showed that surface and submerged methods of cultivation can be used for obtaining a glucose oxidizing enzyme. The optimum conditions for submerged cultivation (25°C., initial pH 5.0, and aeration of 3 1/1 per min) and surface cultivation (temperature 25°C and initial pH 4.0) providing the maximum levels of glucose oxidase synthesis were determined.     

Transformation of glycyrrhizic acid. Synthesis of glycopeptides of glycyrrhizic acid monomethyl ether, having anti-inflammatory and immunostimulating action

Three triterpene glycopeptides, glycyrrhizic acid monomethly ester derivatives containing peptide fragment of N-acetylmuramoyldipeptide and its analogues, are synthesized. They possess high prednizolone-like antiinflammatory activity and display pronounced stimulative effect on humoral factors of immunity.     

Morphological and ultrastructural characteristics of symbiotic bacteria colonizing the surface of the helminth Triaenophorus nodulosus and the intestine of pike Esox lucius

The microflora inhabiting the intestinal mucosa of the pike and the tegument surface of the intestinal parasite Triaenophorus nodulosus is investigated. By means of electron microscopy, the ultrastructural features of bacteria and pattern of their interaction with the colonized surfaces are estimated. Specific distribution of microorganisms belonging to different morphotypes and subdivided into subpopulations on the colonized surfaces is found. Predominance of gram-negative bacteria in all studied microbiocenoses and abundance of nanobacteria in the “superficial” subpopulations are observed. The bacteria of “a deep population” associated with the basal parts of microtrichiae and microvilli are described. It is concluded that the helminthes, the fish parasites possess the normal microflora characterized by specific composition, by ultrastructural features of cells, and by patterns of interaction with the helminth surface. The obtained data characterize the mechanisms of symbiotic interaction of prokaryotes and eukaryotes in the system parasite-host-symbiotic microflora.     

Multiplication of the late slow fluctuation of induced potential to light under conditions of aminazin administration]

A study was made of the effect of chlorpromazine on the multiplication of late slow component of evoked potential to the flash-light (1 sec.) in experiments on nonanesthetized rabbits with electrodes chronically implanted in different brain structures. Electro-skin pain stimulation of the pore was applied simultaneously in some experiments. Chlorpromazine was found to decrease the multiplication of the late slow component to the flash-light alone, and to double this component in response to light when it was combined with pain stimulation. A supposition was made on the role of adrenergic structures in the formation of the acceptor of the action results of a defensive character, serving as one of the most important mechanisms of the functional system.     

The inhibition of proteolytic enzyme activity by humic acids]

The inhibitory effect of peat humic acids on the hydrolysis of N-acetyl-L-tyrosine ethyl ester and N-benzoyl-L-leucine methyl ester by alpha-chymotrypsin and subtilism has been studied. Samples of humic acids with M(W) approximately 18,000 have been used in experiments. The results of kinetic studies indicates the mixed type of inhibition of proteinase activity by humic acids. The meanings of inhibition constants under the action of humic acids on alpha-chymotrypsin and subtilism have been calculated.     

Antibodies against synthetic peptide fragments of T-cadherin inhibit binding of low density proteins with T-cadherin]

Potential antigenic determinants of the atypical lipoprotein-binding proteins T-cadherin (p105) and its precursor (p130) from cells of human smooth muscles were synthesized by the solid phase method according to the Fmoc-scheme. These corresponded to the 51-61, 140-160, 161-179, 260-271, 340-352, 350-362, and 370-385 sequences of p130 and were chosen on the basis of computer analysis of its antigenic structure. The conjugates of the peptides with horseradish peroxidase were used for the immunization of mice and rabbits. Antisera against the peptides corresponding to the 140-160, 161-179, and 260-271 sequences of p105 were shown by immunoblotting to react with p105, which we isolated from the vascular cells of smooth muscles and earlier identified as T-cadherin. These antisera inhibited the binding of low density lipoproteins with p105 in a dose-dependent manner. These results confirmed the identification of the p105 protein as T-cadherin and demonstrated the fundamental possibility of studying the interaction of this protein with low density lipoproteins by using antipeptide antibodies that inhibit binding.     

Interaction of the uterus and developing eggs in cyclophyllidean cestodes with different fecundity

The interaction of morphological changes of the uterus and fecundity of the strobilae of cestodes has been investigated. It is shown that cestodes with maximal fecundity have different and highly effective ways of supplying eggs with nutrients. It is noted that differences in fecundity of cestodes depend not only on their strategy of reproduction, ecology, and complexity of life cycles but also on the complexity of interactions between the uterus and the developing eggs.