The Journal “Toksikologicheskiy vestnik” (Toxicological Review)
The paper deals with factors of the current chemical burden of human population, including food and epidemiological disinfectants, and their potential toxicological impact. Methods of chemical exposure assessment in animal experiments are discussed on the basis of establishing thresholds of its severity. It was suggested that at the sub-threshold exposure, temporarily hidden health effects can also occur, which may only manifest in the form of relevant pathologies at population level. Not only individual but also collective (population) toxic exposure doses should be taken into account when evaluating chemical burden of human population; therefore it is reasonable to develop medical population toxicology as a special area within the toxicology science based both on epidemiological principles in general and on prognosticated advances in epidemiology of non-communicable diseases, in particular.
Keywords: toxicology, epidemiology, disinfectants, hygiene methods, risk assessment, population doses and effects, epidemiologic process monitoring
Nickel(II) oxide and multiple manganese species [manganese(II,III) oxide included], may be jointly present in welding fumes submicron fraction. Using laser ablation of 99.99% pure metallic plates in deionized water, suspensions of NiO and Mn3O4 nanoparticles with mean (± ) diameters 30±12 nm and 32±10 nm respectively were created. Both suspensions were instilled intratracheally to rats, one immediately after another in alternating sequence or separately (another instillation being with water). The broncho alveolar lavage fluid (BALF) was obtained 24 h after. The increase in total BALF cells, alveolar macrophages (AM) and neutrophil leukocytes (NL) counts and especially in the NL/AM ratio (which is a reliable сomparison index of instilled particles cytotoxicity) was significantly higher at exposure to NiO than to Mn3O4. Semi-contact atomic force microscopy of cell surface topography demonstrated active endocytosis of NiO and Mn3O4 nanoparticles by pulmonary phagocytes. The higher pulmonary cytotoxicity of NiO as compared with Mn3O4 nanoparticles was also shown by increase in some lysosomal enzyme activities. Mathematical analysis revealed a sub-additive combined action of NiO and Mn3O4, judging by cellular indices, while judging by different biochemical indices additivity, sub-additivity or synergism were shown. In rats fed glutamate, glycine, acetyl cysteine, iodide and a Se-containing multivitamin preparation orally during 4 weeks before exposure to NiO+Mn3O4 (0.25 mg each), the latter evoked a significantly weaker NL recruitment than in rats so exposed without pretreatment.
Keywords: nanoparticles, nickel oxide, manganese oxide, bronchoalveolar lavage, pulmonary cytotoxicity, combined action, bioprotectors
A comparative assessment of efficacy of peptides Semax, Selank, KK-1, Bestim and Moleksan is presented at highly severe acute intoxication with ethanol, based on daily survival , neurological status, state of the organism certain vital functions. An extremely severe degree of alcoholic poisoning was modelled with intragastric administration of ethanol 40% solution at 12g/kg dose (1.5 LD50). Semax was administrated intra-nasally at dose of 3 mg/kg; Selank- intranasal dose of 3 mg/kg; KK-1 – intranasal dose of 40 μg/kg, Bestim – intranasal dose of 3 mg/kg; Moliksan intra-abdominal dose of 30 mg/kg. The preparations efficacy was evaluated by using the following application schemes: preventive one ( one- time an hour before ethanol administration); therapeutic and preventive ( an hour before and immediately after ethanol administration), early therapeutic ( immediately after ethanol administration and then once a day during 2 consecutive days) and postponed therapeutic ( 30 min. after ethanol administration and then once a day during two consecutive days). It was found out that in case of intoxication caused by 1,5 LD50 ethanol administration, preparation KK-1 was found to be the most efficacious under all schemes applied. The administration of this preparation prevented the nosogeny of coma and death of most poisoned animals. A preventive application of Moliksan significantly lowered the severity of poisoning., reduced 4.9-fold the number of animals in the state of terminal coma, increased by 66% survival in rats. Under the therapeutic and preventive application, Semax and Moliksan showed the greatest efficacy, providing 83% survival in poisoned rats. When applied for early therapeutic treatment, Moliksan appeared to be the most effective based on survival indicators and intoxication clinical picture. Under the postponed scheme of application, the therapeutic action of peptides was low effective.
Keywords: intoxication, ethanol, therapy, peptides, survival, breathing rhythm, body temperature
Expression and polymorphism of encoding the Gaba-receptors of genes, which determine the severity of the depressing effect of ethanol in white outbred rats were studied. In the course of the experiment, genotyping of animals was made using 16 single-nucleotide replacements in genes encoding the GABA. The genetic diversity of allelic variants was revealed, based on 11 polymorphisms. It was found out that in rats with the genotype homozygous variant TT (rs 197587817) the expression level of gene Gabra l ( in brain 8 h after administration of ethanol) was authentically lower ( 2-fold) as compared to the heterozygous genotype CT. An authentic association of the gene Gabrb1 expression level ( p<0.05) with the severity degree of the ethanol depressing effect on the nervous system in rats 8 h after administration of the toxicant was demonstrated.
Keywords: the GABA-receptors, genetic polymorphism, gene expression, ethanol
It was found out that the exposure of rats to asymmetric dimethylhydrazine in a dose of 100 mg/kg leads to acute functional disorders of the central nervous system, toxic lesion of a number of vitally important organs during the two first hours .During the first 4 hours of intoxication, the survival of rats in control groups was 10% to 60%, a day after it did not exceed 20% and in some cases 100% lethality was already observed in the first hours of intoxication. The preventive exposure to electromagnetic radiation modulated by the preparation with the tissue of the brain pituitary-hypothalamic part in newborn infant rat (P1-4) over 4 days with a total exposition of 270 min. increased the rat resistance to the toxic action of asymmetric dimethylhydrazine. In that case the survival of rats over the first 4 hours of intoxication was of 80-90% and a day after lowered up to 40-70%. The corrective action of the given type of radiation with a total exposure time of 150 min. also increased the rat resistance to toxic effect of asymmetric dimethylhydrazine in the indicated dose. In that case the survival in the first 4 hours of intoxication was 80%-90% and 50%-80%. during the first days of intoxication.
Keywords: asymmetric dimethylhydrazine, acute toxicity, electromagnetic radiation, super low exposures, vitamin B6
The content of the total protein and metallothioneins in peripheral blood lymphocytes of sheep which received lead nitrate with the diet in concentration of 5;25 and 150 mg/kg fodder was examined. Blood samples were taken from the sheep jugular vein before feeding on 7, 14, 28, 42, 70 and 90 days of investigation. The chronic intake of lead with the diet by the sheep organism is characterized by an increased level of metallothioneins in peripheral blood lymphocytes with simultaneous decrease of animals viability. At the same time, the amount of the total protein in the initial period of intoxication raises and in the subsequent periods decreases. Based on results obtained, it is suggested to use the determination of the metallothioneins content in peripheral blood lymphocytes as informative parameter to estimate mammalians exposure to lead.
Keywords: sheeps, limphocytes, peripheral blood, metallothionein, lead
The herb golden pert (Gratiola Officinalis ) was used as starting material in the study. Magnitudes of the median lethal concentration (LC50) and accumulation character determined in larvae Chironomus riparius were taken as toxicity indicators on the organismal level. Results of the extract toxicity obtained with larvae were compared with those obtained with laboratory mice in terms of median lethal dose ( LD50). A possibility of using Chironomid larvae Ch.riparius as a new test object in pre-clinical safety assessment of pharmacological substances was proved. A semi-lethal concentration (LC50) of the bio flavonoid extract in which double-wing insects larvae Chironomid Ch.riparius were put was 2280mg/l. A semi-lethal dose ( LD50) determined in laboratory mice at intra-abdominal administration was equal to 2375 mg/l. According to the toxicity classification of substances, the extract refers to the class of practically non- toxic substances. The herb golden pert extract has a weak ability of accumulation (TL50 <12).
Keywords: Chironomus riparius Mg, Gratiola officinalis L., acute toxicity, toxicity class
The article presents information about studies that had been performed to assess the effectiveness of personal respiratory protection (RPD) in the workplace environment for the last 45 years. These data necessitate a revision of fundamental provisions of the respirators selection depending on a known degree of air pollution in the breathing zone.
Keywords: respirator, RPD (Respiratory Protection Devices), the protection factor, personal sampler, harmful gases and aerosols