Rhythmicity in the structure-functional changes in hepatocytes following exposure to pesticides]

The processes of dursban biotransformation during the liver perfusion in rats exposed to CCl4 and milbex for 4, 8 and 15 days (microsomal enzyme inhibitor and inducer, respectively) were studied. The ultrastructure of hepatocytes was examined in the animals treated with the mentioned poisons. Three stages of the structural and functional changes were revealed. Reconstruction of the dursban biotransformation ways occurred from the 8th day, i.e. the dialkylation processes were intensified, resulting in production of less toxic metabolites.     

Effect of alcoholic intoxication on the body's natural resistance to exposure to infectious and toxic agents]

The influence of alcoholic intoxication on the resistance of albino mice to bacterial toxins and staphylococcus cultures was investigated. Five-day administration of 40% ethyl alcohol to the animals was accompanied by a significant increase of their resistance to the intoxication caused by C1. perfringens toxins and staphylococcus. Thirty-day alcoholic intoxication promoted a marked reduction of albino mice resistance to the both toxins used and the staphylococcus cultures.     

The enhancement of body resistance to combined exposure to immobilization and cold with thyroid hormones]

In experiments on 123 male rats have been found that the combination of immobilizing and cold (4 degrees C) stresses during 6 hours results in the formation of 4.5 gastric mucosa ulcers in every rat, marked activation of lipoperoxidation and depression of antioxidant activity of myocardium, significant increase of relative mass of adrenal glands, decrease of spleen mass and death of 80% animals accompanied by the reduction of concentration of thyroid hormones in blood serum and hypothermia (to 28 degrees C). The prestress injection of small doses of thyroidine decreased of mucosa defect rate and the number of ulcers to 2.8, made less marked the changes of relative mass of adrenal glands and spleen and the changes of concentration of thyroid hormones in blood serum, significantly limited the activation of lipoperoxidation, depression of power in antioxidant systems of myocardium, hypothermia (to 32.5 degrees C) and significantly increased the survival rate (to 70%).     

The modifying action of Sophora japonica and an antioxidant vitamin complex on acute radiation injury to the body]

In experiments with mongrel male rats exposed to whole-body gamma-radiation (7, 9 and 11 Gy) the radioprotective effect of enterally administered Sophora japonica and its combination with an antioxidant vitamin complex was investigated. The radioprotective agents applied were shown to produce a synergistic effect.     

Antibiotic sensitivity of El Tor Vibrio cholerae after exposure to various pesticides and mineral fertilizers]

The strains of El Tor Vibrio cholerae were exposed to different concentrations of pesticides (fazolone, treflane, prometrine, magnesium chlorate, omait and gardon) and mineral fertilizers (superphosphate, ammophos and carbamide) for 2 to 135 days. The subcultures of various ages were tested for their sensitivity to 16 antibiotics. The whole of 229 cultures were tested. There was a general tendency to lowering of the El Tor vibrio sensitivity to the majority of the antibiotics tested. The vibrio strains resistant to the antibiotics widely used in medical practice i. e. levomycetin, streptomycin, tetracycline, lincomycin, neomycin and kanamycin were isolated.     

Frequency, dynamics, and structure of congenital malformations in populations under long-term exposure to ionizing radiation]

Information on the dynamics, frequency, and structure of congenital malformations (CMs) and chromosomal diseases in two generations of rural populations from the Semipalatinsk region was obtained for the first time. The tests performed in the Semipalatinsk nuclear test site (STS) for many years were demonstrated to deteriorate the genetic health of the populations of the zones of extreme and maximum radiation risks. Mutagenic and teratogenic effects of long-term ionizing irradiation were detected. These were mainly expressed as an increase in the frequencies of strictly registered CMs (SR CMs), including the Down syndrome, multiple malformations (MMs) and microcephaly (1.45 +/- 0.11, 1.39 +/- 0.01, and 0.77 +/- 0.05 per 1000 births, respectively). SR CMs exhibited linear trends toward higher frequencies in two generations of exposed persons after surface nuclear tests in 1949-1963. Their frequency was strongly correlated with the effective population dose of radiation; the main population genetic parameters (inbreeding coefficient, endogamy index, etc.) had less pronounced effects on Cms.     

The mutagenic activity and structure of pesticides

The data on mutagenicity of pesticides as to their chemical structure are summarized and discussed. The results from investigation of cytogenetic action of 55 pesticides and their metabolites in somatic human and animal cells are presented. Some structure fragments of molecule related to genotoxic effects are selected.     

Enzymes protecting the erythrocyte membrane during the combined exposure to an antioxidant complex and acute irradiation]

The data are presented concerning the effect of ionizing radiation on the hemolytic process and the influence of an antioxidant vitamin complex on the pentosephosphate metabolism and glutathione reductase activity after gamma-irradiation. The antioxidant vitamin complex has been shown to produce a favourable effect on the erythrocyte membrane stability in correcting the radiation-induced changes.     

Effects of simulated increases in body weight on the growth of limb bones in hypophysectomized rats

The purpose of this study was to subject groups of hypophysectomized male and female rats each to a simulated specific 10% increase in body weight, to a maximum of a doubling of body weight, in order to study the effects of quantified, increased, intermittent, compressive forces on limb bone growth. Chronic centrifugation was employed. 21-day-old Sprague-Dawley rats were used. After 60 days of centrifugation, the rats were sacrificed. The humerus, radius, ulna, femur and tibia were removed from each animal, cleared of all soft tissues, and the bone lengths measured on Helios calipers with an accuracy of 1/20 mm. The data were corrected for differences due to individual body weight by dividing bone lengths by the cube root of the body weight of the same animal. Tukey's studentized multiple-range test was performed to identify aggregations (sets) of force groups between which there are significant differences. The data suggest that the simulated increases in body weight, within the range used for this study, enhance bone growth in hypophysectomized female and male rats similarly - hypophysectomy being a condition known to inhibit bone growth.     

Interrelationship between the structure, microcirculation and tissue-vascular permeability of the liver after experimental toxic damage]

Biomicroscopic and morphological studies demonstrated that in experimental heliotrine affection of the liver there occurred very early and marked microcirculatory disturbances which preceded the parenchymal damage. With the further progress of the pathomorphological changes and chronization of the pathological process in the liver one of the leading roles was played by the advance of microcirculatory disturbances and of the tissue-vascular permeability leading to hypoxia of the hepatic tissue and derangement of the metabolic processes in the organ.     

Scaling of the limb long bones to body mass in terrestrial mammals

Long‐bone scaling has been analyzed in a large number of terrestrial mammals for which body masses were known. Earlier proposals that geometric or elastic similarity are suitable as explanations for long‐bone scaling across a large size range are not supported. Differential scaling is present, and large mammals on average scale with lower regression slopes than small mammals. Large mammals tend to reduce bending stress during locomotion by having shorter limb bones than predicted rather than by having very thick diaphyses, as is usually assumed. The choice of regression model used to describe data samples in analyses of scaling becomes increasingly important as correlation coefficients decrease, and theoretical models supported by one analysis may not be supported when applying another statistical model to the same data. Differences in limb posture and locomotor performance have profound influence on the amount of stress set up in the appendicular bones during rigorous physical activity and make it unlikely that scaling of long bones across a large size range of terrestrial mammals can be satisfactorily explained by any one power function. J. Morphol. 239:167–190, 1999. © 1999 Wiley‐Liss, Inc.     

The syndromal approach to the diagnosis of toxic food poisonings]

The authors criticize the nosological principle of the diagnosis of toxic infections and believe that in a vast majority of cases such diagnosis must be based on syndromes. The only exceptions are cases of mass outbreaks and hospital infections. The definition of alimentary toxic infection is given, the difficulties of their clinical diagnosis and the ways to overcome these difficulties are indicated.     

The focus of pathological (toxic) action of metals in the human body and the role of galvanic currents in its formation

Chronic influence of metals on the human body differs from their acute toxic effect. In some individuals subjected to a long-term chronic impact of low doses of metals, chronic inflammatory diseases, including oncological diseases, develop against a background of neurological symptoms. Today, the overwhelming majority of the population older than 40–50 years carry metal alloys in the form of dental prostheses and various implants in the body. Because of metal corrosion, an increased concentration of ions is formed in the body of these subjects. Galvanic currents induced in the presence of any metals promote corrosion and the transfer of metal ions in the body. If these currents are sufficiently strong (when the potential difference is more than 150 mV), the development of local inflammatory pathologies due to the concentration of metal ions in their foci is stimulated.     

Effects of simulated increases in body weight from birth on the growth of limb bones in rats

The purpose of this study was to subject groups of newborn male and female Sprague-Dawley rats each to a specific 10% simulated increase in body weight, to a maximum of a doubling of body weight, to study the effects of quantified, increased, intermittent, compressive forces on limb bone growth. Chronic centrifugation was employed. After 90 days of centrifugation the rats were sacrificed. The humerus, radius, ulna, femur, and tibia were removed from each animal, cleared of all soft tissues, measured and weighed. Tukey's Studentized multiple range test was performed to identify aggregations (sets) of force groups between which there are significant differences. The data suggest that newborn male and female rats subjected to simulated increases in body weight, within the range used for this study, undergo enhanced general body growth and limb bone growth.