[COMPUTER TECHNOLOGY FOR ACCOUNTING OF CONFOUNDERS IN THE RISK ASSESSMENT IN COMPARATIVE STUDIES ON THE BASE OF THE METHOD OF STANDARDIZATION].

There was performed an analysis of the accounting of the impact of concomitant variables (confounders), introducing a systematic error in the assessment of the impact of risk factors on the resulting variable. The analysis showed that standardization is an effective method for the reduction of the shift of risk assessment. In the work there is suggested an algorithm implementing the method of standardization based on stratification, providing for the minimization of the difference of distributions of confounders in groups on risk factors. To automate the standardization procedures there was developed a software available on the website of the Institute of Industrial Ecology, UB RAS. With the help of the developed software by numerically modeling there were determined conditions of the applicability of the method of standardization on the basis of stratification for the case of the normal distribution on the response and confounder and linear relationship between them. Comparison ofresults obtained with the help of the standardization with statistical methods (logistic regression and analysis of covariance) in solving the problem of human ecology, has shown that obtaining close results is possible if there will be met exactly conditions for the applicability of statistical methods. Standardization is less sensitive to violations of conditions of applicability.

[Combined subchronic toxicity of nickel and manganese oxides nanoparticles, and its decrease due to bioprotectors complex].

Stable suspensions of NiO and/or Mn304 nanoparticles with average diameter 16,7?8,2 nm and 18,4?5,4 nm respectively, obtained via laser ablation of the metals with 99,99% purification in deionized water, were injected intraperitoneally into rats in dose of 0,5 mg or 0,25 mg three times per week up to 18 times separately or in various dose combinations. A group of rats received combined injections of nanoparticles in the highest dose or merely water with oral <> containing pectin, vitamins A, C and E, glutamate, glycine, N-acetylcysteine, selenium, iodine and polyunsaturated fatty acids of omega-3 class. Intoxication development was assessed through multiple functional parameters and histologic changes in liver, spleen, kidneys and brain. Nickel and manganese accumulation in these organs was measured-via various methods. Both types of metallic oxide nanoparticles appeared to be hazardous for body, but Mn304 caused more harm according to major nonspecific toxicity manifestations. Moreover, they caused more intense injury to caudate nucleus and hippocamp neurons - that can be considered as an experimental model of manganese parkinsonism. Mathematic analysis based on response pattern revealed ambiguity of the combined toxicity type, depending on the effects assessed and on its level. Due to the bioprotector complex, organic and systemic toxicity and genotoxicity of Mn304 and NiO nanoparticles combined were diminished.

Combined subchronic fluoride-lead intoxication and its attenuation with the help of a complex of bioprotectors.

BACKGROUND: Combined toxicity of lead and fluoride has been studied insufficiently, and there is no known information about attempts to inhibit it with any bioprotectors. METHODS: Lead acetate and sodium fluoride, administered separately or in combination, were injected i.p. to rats at isoeffective sublethal doses 3 times a week for 6 weeks. Some of the rats were exposed to the same combination against the background of oral administration of a bioprotector complex (BPC) comprising pectin, glutamate, and multivitamin/multimineral preparations. Following exposure, functional and biochemical indices and histopathological examinations of the femur of exposed and control rats were evaluated for signs of toxicity. RESULTS: We have shown that with regard to a number of effects on the organism level the combined toxicity of lead and fluoride may be evaluated as additive or even superadditive, but lead reduces fluoride accumulation in the bone, and pathological changes in the bone tissue proved to be less marked for combined exposure compared with separate exposures. The BPC has been demonstrated to attenuate a range of the combined harmful effects of lead and fluoride, including those on the bone tissue. CONCLUSIONS: In spite of the fact that fluoride and lead may reciprocally attenuate their harmful effects on the bone tissue in case of combined exposure, they prove to be more toxic for soft tissues just in combination than when administered separately. The development of combined intoxication may be substantially inhibited by means of the tested set of innocuous biologically active agents.

[An effect of ipidacrine (neuromidin) on electroneuromyographic parameters in the conditions of artificial decompression (a clinical/instrumental study)]. / Vliianie ipidakrina (neiromidin) na élektroneiromiograficheskie pokazateli v usloviiakh iskusstvennoi kompressii (kliniko-instrumental'noe issledovanie).

AIM: To study an effect of neuromidin on the changes in electroneuromyographic (ENMG) parameters in patients with carpal tunnel syndrome in the conditions of artificial decompression of a forearm. MATERIAL AND METHODS: Sixty-four 64 patients, 46 women and 18 men, mean age 50,7±4,5years, matched for disease severity were studied. The patients were randomized into neuromidin group and control group. Neuromidin was introduced using subcutaneous local perineural injections. Characteristics of neuromidin effect on the changes in ENMG parameters of the median nerve were studied in a model of additional artificial decompression of the median nerve. RESULTS AND CONCLUSION: There was the significant depression of the nerve function and worsening of ENMG parameters during the additional decompression as well as the aggravation of conduction block along nerve fibers (motor and sensory). In patients treated with ipidacrine, there was an increase in the amplitude of sensory and (to a less extent) of M-response that indicated the activation of axonal transport and reservation of functioning of the compressed nerve.

[Electroneurographic monitoring during the test of artificial compression as a method of early diagnosis of carpal tunnel syndrome]. / Elektroneirograficheskoe monitorirovanie pri provedenii testa iskusstvennoi kompressii kak metod rannei diagnostiki sindroma zapyastnogo kanala.

AIM: To develop the algorithm of early diagnosis of carpal tunnel syndrome (CTS) at the stage of functional neurological disturbances by expanding diagnostic possibilities of electroneuromyography using artificial compression test. MATERIAL AND METHODS: Parameters of conductivity of the median nerve in 54 patients with finger numbness were analyzed during 3 months before and after compression of the forearm (blood pressure was measured for 1 min). RESULTS AND CONCLUSION: An increase in the latency in motor fibers and a decrease in the amplitude of sensory response were identified in patients with CTS signs and normal electroneuromyographical parameters at baseline. The use of additional electroneuromyographical monitoring during the provocative artificial compression test expands the possibilities of this method and improves early diagnosis of CTS.

Changes in the Dose-Response Relationship of One Toxicant Under Simultaneous Exposure to Another Toxicant.

We considered, in general form for a 22 full factorial experiment, linear approximations of the organism's dose-response relationship for some factors operating alone and modification of this relationship by another factor operating in the background. A typological classification of such modifications is suggested. An analysis of the outcomes obtained in a number of subchronic animal experiments on rats in which this response was assessed by changes in a large number of biomedical indices revealed that all theoretically possible variants (types) of the modification under consideration are actually observed depending on a specific index and specific harmful exposure. Statistical significance estimation procedures are formulated for each of them.

Applying theoretical premises of binary toxicity mathematical modeling to combined impacts of chemical plus physical agents (A case study of moderate subchronic exposures to fluoride and static magnetic field).

Sodium fluoride solution was injected i.p. to rats at a dose equivalent to 0.1 LD50 three times a week up to 18 injections. Two thirds of these rats and of the sham-injected ones were exposed to the whole body impact of a 25 mT static magnetic field for 2 or 4 h a day, 5 times a week. For mathematical analysis of the effects they produced in combination, we used a response surface model. This analysis demonstrated that (like in combined toxicity) the combined adverse action of a chemical plus a physical agent was characterized by a diversity of types depending not only on particular effects these types were assessed for but on their level as well. From this point of view, the indices for which at least one statistically significant effect was observed could be classified as identifying (1) single-factor action; (2) additivity; (3) synergism; (4) antagonism (both subadditive unidirectional action and all variants of contradirectional action). Although the classes (2) and (3) taken together encompass a smaller part of the indices, the biological importance of some of them renders the combination of agents studied as posing a higher health risk than that associated with each them acting alone.

[Effect of the contraction of other muscle groups on muscle strength, latency period and endurance]. / Vliianie na myshechnuiu silu, latentnyi period i vynoslivost' sokrashcheniia storonnykh myshechnykh grupp.

The following investigation was undertaken in connection with Sechenov's idea on mutual influence of muscles performing different work. It deals with the influence on test muscle (TM) efficiency of other simultaneously working muscles (SWM). It was shown that tension of SWM or maintenance of complex postures exert a negative influence on the force and latency of the visual-motor reaction and the static effort endurance. The mechanism involved is external inhibition. After its extinction as a result of repeated combinations of both activities the degree of lowering of TM activity grows less and finally its improvement is observed as compared to data obtained in the absence of SWM contractions. It is suggested that when external inhibition is extinguished impulses arising in SWM reinforce and improve according to the law of dominant the functions of nervous centers regulating activities of the TM.

[Changes in the bodies of trained and untrained subjects working to capacity and having different degrees of motivation]. / Izmeneniia v organizme trenirovannykh i netrenirovannykh liudei pri rabote do otkaza v usloviiakh razlichnoi stepeni motivatsii.

In conditions of enhanced motivation trained subjects performed a greater work and untrained ones--a lesser work than under ordinary motivation. The most stable parameters in regard to working to capacity were as follows: heart rate, minute respiratory volume, amount of oxygen consumption, amount of exhaled CO2, energy expenditure, and oxygen pulse. The data obtained show that untrained subjects under ordinary and, particularly, enhanced motivation for working to capacity are able to mobilize a lesser amount of the organism's physiological reserves than trained people.