Effects of interferon inducers on chemically-induced mutagenesis and carcinogenesis

The in vitro study on an isolated system of myocardial contractile proteins determined optimal concentrations of the positive inotropic action and biological activity ranges of beta-methyldigoxin (beta-MD), strophanthin K, K-strophantozide, beta-acetyldigoxin (beta-AD), milrinone, and amrinone. Optimal concentrations of the beta-MD and strophanthin K (10(-2) and 10(-6) M, respectively) significantly increased qualitatively and quantitatively the economy and thermodynamic efficiency, altered the energy transformation in the contractile protein system under the isometric contraction, whereas the beta-AD produced only the quantitative effect. However, the beta-MD and strophanthin K at concentrations exceeding the optimal one by one order lost the ability to produce the qualitative effect, retaining only the quantitative one in the actomyosin ensemble. The strophanthin K significantly increased the economy of a single actomyosin ensemble in the force generation phase and the beta-MD in the tension maintenance phase. Unlike the strophanthin K, the beta-MD did not slow down (did not worsen) the relaxation process. This provides grounds to conclude that the beta-MD produces most favorable effect on the energy transformation by myocardial contractile proteins.     

Comparative characteristics of some cultural and toxigenic properties of the Dendrodochium Bonorden and Myrothecium Tode ex Fr. representatives

The comparative study of sporulation intensity, change of medium pH, yield of biomass and ethanol soluble fraction (ESF) of extracellular metabolites as well as antibiotic and toxigenic properties of 106 fungi strains which were the potential producers of macrocyclic trichothecenes has been carried out under the conditions of stationary cultivation. It was shown that all the studied Dendrodochium strains were characterized by moderate growth, variations of biomass were within 3.5-4.5 g/l. Variations of ESF level in different strains were rather essential (from 8 to 241.6 mg/l). High antibiotic activity correlated with high or moderate toxicity (on the basis of rabbit skin test) in most cases. Dendrodochium strains with intensive sporulation were as a rule characterized by high efficiency of toxin production (40% of studied strains) and only 3 strains (5.5%) with low level of sporulation were characterized by high rate of toxin production. The toxigenic activity for Myrothecium cinctum, M. commune and M. ukrainicum has been shown for the first time. The toxigenic activity of the studied strains depending on the source of isolation and possible correlative connections between sporulation, toxin formation and other properties are discussed.     

Optimization of the diagnosis and treatment of anemias under exposure to aromatic-type organic solvents

171 iron-deficient painters and 20 subjects with chronic intoxication with aromatic hydrocarbons were studied in a large aircraft construction factory. After correlative analysis of iron metabolism, ferritin, erythrocytes, diameter and perimeter of reticulocytes, length of service three types of iron-deficiency were identified: typical, with evident toxicity, with a high risk of toxic damage. An important role of lipid peroxidation activity and toxic erythrocyto-membranopathy for pathomorphosis of iron deficiency anemia and progress of toxic anemia is demonstrated. A differential approach to treatment of different anemia variants was used. The treatment included membranoprotectors (alpha-tocopherol, essential, lypostabil) and unspecific detoxication (SUMS-enterosorbent, unitiol).     

Preavoidance hypercapnia and decreased hematocrit in micropigs

Previous studies found that regular confinement of dogs in an experimental environment preceding onset of an avoidance task was associated with increases in blood pressure and decreases in heart rate and respiration rate that were not prevented by adrenergic antagonists. The present study investigated a) whether divergent changes in blood pressure and heart rate also occur in micropigs preceding onset of an avoidance task, and b) the nature of changes in blood gases, plasma pH, plasma bicarbonate, hematocrit, and plasma electrolytes observed under these conditions. Blood pressure increased and heart rate decreased during 2-h preavoidance periods, whereas both blood pressure and heart rate were elevated during 20-min avoidance periods. During preavoidance periods, pO2, plasma pH, and plasma potassium pCO2 were decreased below home kennel levels during early preavoidance, whereas pCO2 and plasma bicarbonate were persistently increased and hematocrit was persistently decreased for the duration of the preavoidance periods. Each of these changes was reversed during the avoidance sessions. These findings suggest that behaviorally induced hypercapnia might participate in blood pressure regulation via increased renal sodium/hydrogen exchange and renal sodium retention.     

Substantiation of physiologic and hygienic requirements of heat-proof properties of winter headgear

Experimental studies conducted in cooling environment assessed the features of heat exchange and thermoregulation of head during physical work varying in hardness and type. The studies determined allowable parameters of heat exchange on head (skin temperature and surface heat outflow), which are necessary for construction and evaluation of headgear. The article presents correlations between main heat-proof parameters of headgear (total heat resistance, thickness of materials and their permeability to air). The data of experimental and industrial trials helped to elaborate physiologic and hygienic requirements for heat-proof headgear in various climate conditions.     

Experimental study of the mutagenic activity of gentamicin sulfate in relation to the causative agent of plague

Gentamicin sulfate was studied with an aim of obtaining mutants of the plague microbe with a changed character of requirements in the growth factors. The antibiotic provided a high yield of auxotrophic mutants and induced streptomycin resistance in some cells. Mutants with single dependence on arginine, leucine, histidine and uracyl were most often. Comparison of the data obtained with gentamicin and those obtained with other chemical mutagens showed that gentamicin by its mutagenic activity was only slightly inferior than the preparations of the group of supermutagens.     

Extinction coefficient of thyroglobulin

The extinction coefficient at 280 nm of the solution (pH 7,2-7,4) of thyroglobulin from normal thyroid and nodular euthyroid goiter was measured with the values of 0,6-0,7 to 0,9 ml.mg-1.cm-1. The value of E1%280 as function of the iodoamino acid content depends on the morphological state of the thyroid gland. A simple method for determination of the E1%280 value by measuring of the protein absorption spectrum is proposed.