Biomedical subjects

A N Pankrushina

Publications and source records attributed to A N Pankrushina.

5 recordsLinked to original sources

PubMed1996

Cellular signals regulating antibiotic sensitivities of bacteria.

The effects of bacterial masses upon the drug resistance of neighboring bacteria were investigated. The experiments were performed with plastic Petri dishes divided into two identical compartments. A growing mass of Bacillus subtilis (signal emitter cell) in one compartment exerted enhancing effects upon the erythromycin and streptomycin resistance of Bacillus carboniphilus (signal recipient) cells, sparsely seeded in the other compartment, through the plastic wall and the air. These effects of the growing mass of cells are attributed to the emission of "sonic" signals.

Anti-Bacterial Agents↗

PubMed1995

Studies on carbon material requirements for bacterial proliferation and spore germination under stress conditions: a new mechanism involving transmission of physical signals.

The growth of bacteria is often enhanced by addition of carbon materials such as graphite or activated charcoal to the growth medium. In this work, bacterial strains that strictly require such carbon materials under the ordinarily lethal stress caused by high concentrations of salt were isolated. The organisms were gram-positive, spore-forming, sugar-nonfermenting aerobic bacilli and were provisionally designated "Bacillus carbophilus" Kasumi after examination of their phenotypic traits. The growth- and germination-promoting effects of graphite and activated charcoal were demonstrated either quantitatively on agar plates containing fine crystals of the carbon materials mixed with a nonpermissive growth medium or qualitatively on agar plates on nonpermissive growth media half-covered with fine carbon particles. Further experiments demonstrated a novel feature of the phenomenon; i.e., the ability to induce colony formation on the nonpermissive plate was transmissible through the air, as well as through plastic or glass barriers. The mechanism probably involves transmission of physical signals regulating cell growth.

Bacteria↗

PubMed1981

[Biosynthesis of carbohydrate-containing polymers in plants. I. Products formed with enzyme preparation from clover seedlings. Characterization of polyprenylphosphosugars].

Membrane preparations from clover seedlings catalyzed the incorporation of monosaccharide residues from GDPMan, UDPGlc and UDPGal into glycolipids, lipid-oligosaccharides and polymers. The lipid-oligosaccharides were shown to be alpha-dihydropolyprenyl pyrophosphate derivatives. Incorporation of mannose residues into the lipid-oligosaccharides and the polymers was significantly stimulated by addition of UDPGlc, GDPGlc, UDPGal but not by UDPGlcNAc. Exogenic polyprenyl phosphates also stimulated the process; the formation of moraprenyl pyrophosphate oligosaccharides was demonstrated after addition of moraprenyl phosphate. The lipid-oligosaccharides were precursors of the polymers which were shown to be mainly glycoproteins. A solubilized preparation of mannosyl transferase from clover membranes was obtained and some properties of the enzyme were studied.

Glycolipids↗

PubMedDate not supplied

[Changes in ATPase activity in tissues and mitochondria of some steroid-producing rat organs during autolysis].

The activity of Mg(2+)-ATPase was studied in the tissues, homogenates, specimens of rat spermatic and adrenal glands during postmortem autolysis. The initial enzymatic activity was 2-fold higher in adrenal tissue, homogenate and mitochondria than in spermatic ones. As autolysis proceeded in the tissue and homogenate of the adrenal and spermatic glands, and spermatic mitochondria, the ATPase activity was drastically decreased, by disappearing completely at hour 24 of autolysis. At the same time, the enzyme from adrenal mitochondria exhibited a higher stability. Of great importance for this can be rearrangements in the phospholipid profile of the corresponding membranous structures, as well as hormonal factors.

Adrenal Glands↗

PubMedDate not supplied

[An ultramicro method for determining pyrophosphatase using malachite green B].

A modified sensitive micromethod is described for estimation of pyrophosphatase activity both in homogenate and suspensions of nuclear and mitochondrial fractions of rat liver tissue using a kit of reagents containing malachite green B. The analysis may be carried out in the preparation containing only 0.2 mg of biological material; the procedure is reproducible, rapid and allows to the requisite amount of reagents to be decreased. The activity of pyrophosphatase in homogenate, nuclear and mitochondrial fractions of rat liver tissue was higher at acid pH values as compared with that in the neutral medium; the highest enzymatic activity was detected in the nuclear fraction.

Animals↗