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Biomedical subjects

T A Smirnova

Publications and source records attributed to T A Smirnova.

At least 91 records · Page 5Linked to original sources
PubMedDate not supplied

[Effect of the antioxidant ionol on proteolytic apparatus of aging coleoptiles of wheat seedlings grown in light].

The dynamics of changes in total proteolytic activity and activities of various groups of proteases in the coleoptiles of 3- to 12-day-old wheat seedlings grown in light with and without antioxidant BHT (2,6-di-tert-butyl-4-methylphenol) was studied. It was established that the specialized proteases that easily hydrolyze specific synthetic substrates and the enzymes actively hydrolyzing histone H1 dominate in young coleoptiles of 3- to 4-day-old seedlings. Proteases that degrade equally well the majority of the studied substrates are accumulated in the cells of old coleoptiles of 11- to 12-day-old seedlings. Under the effect of BHT, the plants grown in light (in comparison with etiolated seedlings) demonstrated a somewhat changed dynamics of proteolytic activity in young coleoptiles and the disappearance of proteases active toward histone H1. An inhibitory analysis revealed a relative domination of cysteine proteases in young coleoptiles at the initial development stage of seedlings, whereas the fraction of serine proteases markedly increased in old coleoptiles. We presume that the revealed quantitative and qualitative changes in the proteolytic apparatus of the coleoptile cells induced by BHT may be largely responsible for the retardant and geroprotective effect of this antioxidant in plants.

Antioxidants↗
PubMedDate not supplied

[Stucture of PhiKZ bacteriophage particles].

The structure of the particle of a new bacteriophage Pseudomonas phiKZ was studied. The particle of phiKZ bacteriophage was shown to have some features distinguishing this phage from all those known heretofore: a large size of the head and DNA and the presence in the head of a special structural formation named the central body. The central has a cylindrical shape and may be isolated from the head of the phage by repeated freezing-thawing the phage preparation. The structure of the central body is complicated. Possible functions of the central body are discussed.

Bacteriophages↗
PubMedDate not supplied

[Proteolytic preparation from the culture of Bacillus polymyxa str. 13-13].

A proteolytic preparation has been isolated from the culture fluid filtrate Bacillus polymyxa str. 13-13 by salting out with (NH4)2SO4 (0.7 of complete saturation). The data characterizing the amino acid composition and the enzymic system of the resultant preparation are given. It has been shown that the proteolytic activity depends on the enzyme containing metal ion, i. e. metal enzyme.

Amino Acids↗
PubMedDate not supplied

[Biofilm formation by different strains of Salmonella typhimurium in artificial systems].

The ability of 14 different strains of Salmonella typhimurium to biofilm formation depending on genotype and culture conditions was investigated in artificial systems: in 96-well plastic microtitre plates, plastic and glass tubes, plastic Petri dishes and on microscope glasses. Quantitative biofilm growth was monitored by using an assay based on crystal violet staining, while planctonic growth in the same cultures was monitored by absorbance in iEMS Reader MF, and qualitatively--by digital photo and visually. Optimal rate between growth and biofilm indications for all strains was determined at initial cell concentration 10(6-7) KOE/ml and culture incubation at t degrees 28 degrees C. The nutrient content of the medium significantly influenced the quantity of produced biofilm. The nutrient broth LB without NaCl was more effective in promoting biofilm formation, than LB itself. The least quantity of biofilm was formed in water. The genotype of the strains also critically influenced the quantity of produced biofilm. Nonmotile mutants cells had reduced ability to form biofilm. RpoS mutant cells produced significantly less biofilm as compared with cells of isogenic parent strains. The chemical content of plastic and glass also influenced biofilm formation.

Bacterial Proteins↗
PubMedDate not supplied

[Formation of biofilms as an example of the social behavior of bacteria].

This paper is a brief review of data on bacterial biofilms that occur inside and outside of host organisms. Such biofilms are of great ecological and clinical importance. The role of interspecies communications in the development of bacterial biofilms and infectious diseases is particularly emphasized. Considerable attention is given to the electron microscopic study of biofilms formed by Salmonella typhimurium cells incubated as a broth culture in microtubes without aeration. Bacterial samples taken from the biofilm and planktonic culture grown in the same microtube were comparatively investigated by transmission electron microscopy.

Bacteria↗
PubMedDate not supplied

[The forensic psychiatric evaluation of mental disorders in diabetic patients].

The article deals with the results of investigation of psychic disturbances in 7 patients with diabetes mellitus. Psychic dysfunctions which are important for forensic psychiatric practice (depressions, transitory psychotic episodes at the background of hyperglycemia and pathologic states with consciousness disturbance, psychomotor excitement and incorrect behaviour in hypoglycemic states) were analysed. Characteristics were noted which contributed to diagnosing in patients with diabetes mellitus, the states of temporary morbid mental disorder and choosing correct expert conclusion in relation to persons who committed indictable actions.

Adult↗
PubMedDate not supplied

[The effect of baclofen on the nociceptive reactions of the blood pressure in waking rats].

The effect of baclophen (5-10 mg/kg) on the background arterial blood pressure (AP), amplitude of nociceptive AP reactions under electrostimulation of the tail's proximal part and the time of AP normalization after the nociceptive action was studied in the experiments of awaking rats with implanted arterial catheters. Baclophen in the range of analgesic doses causes persistent hypertension depending on the drug dose and the level of emotional reactivity of the rats. Simultaneously with the above mentioned effects the amplitude and the duration of the nociceptive AP reactions are decreased. The blockade of the alpha-adrenoreceptors (phenoxybenzamine, 5 mg/kg) abolishes the hypertensive effect of baclophen but increases its inhibitory effect on the nociceptive AP changes.

Animals↗
PubMedDate not supplied

[Effect of triathlon competition on the content of various hormones and the energy substrate of the blood].

The effect of triathlon (3.8 km swimming, 180 km biking, 42 km running) and of its short variant (1.5 km swimming, 42 km biking, 14 km running) was studied in 7 and 14 well-trained men, respectively. The level of plasma glucose, total cholesterol, HDL, LDL did not change significantly during the competition. FFA concentration increased significantly (by 439 and 61%, respectively). Triglycerides concentration decreased during the prolonged variant. Both variants of triathlon caused a pronounced rise in the cortisol level and moderate increase in somatotropin and progesterone levels. Testosterone concentration increased during a short variant and decreased during a prolonged one. Insulin and C-peptide levels decreased. All those changes in hormones concentration are consistent with an increased lipolytic activity and, may be, with increased glycolytic activity (maintenance of the normal glucose concentration in blood). The rise in the aldosterone level reflects the homeostatic activity in maintaining electrolyte balance.

Adult↗
PubMedDate not supplied

[Relation between changes in the blood levels of beta-endorphin and various hormones during physical exercise].

Dynamics of beta-endorphin, corticotropin, cortisol, somatotropin, insulin and triiodothyronine content were studied using bicycle ergometer in blood of 22 persons during 2 hrs exercises. After an initial increase the beta-endorphin content was subsequently decreased. At the same time, the decrease in the neuropeptide content was accompanied by repeated elevation within the second hr of the exercise, mainly in persons exhibiting high working capacity, while in other persons the hormone concentration decreased below the initial level at the end of the exercise. These alterations in the content of beta-endorphin correlated distinctly with dynamics of pituitary-adrenocortical hormones variation. In untrained persons the initial increase in beta-endorphin content was especially distinctly related to the elevation in somatotropin and to a decrease in insulin content in blood. Concentration of triiodothyronine in blood was altered independently of the alterations of other hormones.

Adolescent↗