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Biomedical subjects

G B Eliakov

Publications and source records attributed to G B Eliakov.

18 recordsLinked to original sources

[Immunoenzyme method for detecting microbial producers of palytoxin].

A competitive ELISA using the intact toxin as a coating antigen for detecting palytoxin was developed. This immunoassay allows palytoxin (PTX) to be determined in the range of 6-250 ng/ml. In sensitivity, this determination is comparable with RIA but is three times inferior to ELISA using monoclonal antibodies. Inhibition experiments using some toxins of marine invertebrates proved the serological specificity of the palytoxin binding to antibodies. Both the indirect and competitive ELISA were used to find PTX-producing bacteria among 420 isolates of sea bacteria. It was found that gram-negative bacteria Aeromonas sp. and Vibrio sp. associated with toxic samples of the soft coral Palythoa sp. produced compounds antigenically related to PTX.

Acrylamides↗

[Bioactive compounds from marine actinomycetes].

Studies of the origin of bioactive metabolites of marine actinomycetes are reviewed. Structures and properties of new metabolites from indigenous marine bacteria from Actinomycetales order, such as a benzanthraquinone antibiotic from a strain of the Chainia purpurogena, istamycins, aplasmomycins, altemicidin, new phenazine esters. C13-butanolide, marinone and debromomarinone, palmyromycin, urauchimicins and some others compounds are presented. Prospects of marine biotechnology and microbiology (with considerable emphasis on the development of the basis biology of marine microorganisms in cultures collection) are discussed.

Actinomycetales↗

[Amino acid sequence of neurotoxins IV and V from the sea anemone Radianthus macrodactylus].

Amino acid sequences of neurotoxins RTX-IV and RTX-V isolated from the sea anemone Radianthus macrodactylus were determined by the automated Edman degradation; their polypeptide chains consist of 48 and 47 amino acid residues, respectively. For identification of tryptophan-30 in toxin RTX-IV, its trypsin and chymotrypsin digests were investigated. Amino acid sequences of the above toxins show that they belong to a new structural class and that C-terminal positive charge and tyrosine-25 are important for toxic activity of sea anemone polypeptides.

Amino Acid Sequence↗

[Effect of toxin from the sea anemone Homostichantus duerdemi on the sodium inward current in mammalian neurons].

The effect of toxin from sea anemone Homostichantus duerdemi (HTX-1) on the inward sodium current was studied on the isolated neurons of spinal ganglia of a rat. The experiments were carried out under conditions of voltage clamp and intracellular perfusion at 20 degree C. HTX-1, when added to the extracellular solution, slowed down the inactivation process of sodium channels with no action on activation process. The dependence of the fraction of modified channels upon the concentration of HTX-1 could be described by Langmuir isotherm with the dissociation constant 1.1 +/- 0.1.10(-7) M (at holding potential --100 mV). HTX-1 caused an increase in the peak of early inward current up to 80%. The binding of HTX-1 with sodium channel was strongly potential-dependent. After a short time of application (up to 5 min) the effect of HTX-1 was completely reversible. However, if the action of the toxin exceeded 30 min, the following washing for 90 min did not lead to pronounced removal of the effect.

Animals↗

[Some results and prospects of studies in the area of marine biochemistry and biotechnology].

Recent studies on bioactive metabolites from marine macro- and microorganisms are reviewed with 83 refs. Structures of new sulphated and glycosylated secondary metabolites, which have been reported to have antifungal, immunomodulatory, and cytotoxic properties, are given. Some peculiarities of biosynthesis of natural compounds in marine organisms are revealed. It was shown that some natural products, isolated earlier from sponges, are produced by microbial symbionts. Different physiological activities associated with 8000 marine microbial (mainly symbiotic) strains are discussed as well as some prospects of marine biochemistry and biotechnology development.

Animals↗