[Neurotoxic effect of toluene on background of prenatal hypoxic brain damage to white rats].

Comparative study covered influence of toluene on behavioral parameters, cognitive abilities and brain bioelectric activity in white rats with normal embryonic development or with prenatal hypoxia. Prenatal hypoxia was simulated by subcutaneous injection of 50 mg/kg sodium nitrite into female white rats on day 13-14 of gestation. The offspring at the age of 2, 5-3 months was exposed to toluene (concentration of 560 mg/m3, 4 hours per day, 5 days per week, over 4 weeks). After the exposure, the animals were estimated for individual and intraspecific behaviour in "open fields and "resident-intruder" tests, for cognitive abilities in "radial maze" training, EEG with visual and auditory evoked potentials. Acute hypoxia at early stages of organogenesis appeared to be burdening factor and to influence consequences of toluene intoxication.

[Dynamics of morphofunctional state of central nervous system in white rates exposed to vibration].

The authors presented results of experimental studies assessing influence of vibration on white rats. Dynamics of morphologic changes development in brain of experimental animals exposed to vibration were shown. Exposure to vibration in white rats daily during 4 hours over 15 days causes astrogliosis--compensation process in response to brain injury; over 1 month--causes morphologic brain changes (vacuoles formation in neuropile, decrease in astroglia cells number); over 2 months--causes lower plasticity of brain neurons, preserved astrogliosis; over 4 months--causes perivascular edema. Changes in brain bioelectric activity indicate stages of pathologic process in central nervous system. Increase in vibration exposure duration leads to more severe diffuse pathologic changes in brain and local cortical and diencephalic disorders. Exposure to vibration in white rats causes increase in general mobility, nonspecific activation of behaviour, intense emotional exertion, negative emotional state, but less severe effects of vibration were seen in orientative-trying reactions that are inborn, inherited forms of behaviour.

[Dynamics of hormonal parameters changes in workers affected by noise nuisance].

The dynamics of hormonal parameters changes in workers of noise dangerous occupations was studied over 5 year period. It was shown that with extension of length of service the content of hormones in peripheral blood of patients with sensorineural deafness has not changed significantly.

[Hormonal mechanisms of peripheral neuropathy in vibration disease].

Studies of peripheral limb nerves through stimulation electroneuromyography, evaluation of hormonal levels via radioimmune assay were performed in 59 patients having vibration disease caused by local vibration. Findings are obligatory signs of peripheral neuropathy and hypothyroid state without thyroid disease manifestations. Statistic analysis revealed reliable dependence between degree of motor axons functional deficit and level of serum triiodothyronine and thyroxin decrease--that could point to participation of thyroid hormones in peripheral neuropathy progression in vibration disease.

[Pathogenetic role of immune reactivity disorders in mechanisms underlying relations between hypothalamus-hypophysis-adrenals and thyroid systems in vibration disease].

Studies of immune and hormonal state in patients with vibration disease caused by general and local vibration helped to evaluate pathogenetic role of immune reactivity disorders in mechanisms underlying relations between hypothalamus-hypophysis-adrenals and thyroid systems, to specify principal scheme of interactions between neuroendocrine and immune systems in such disorders.

[Disorders of main stress effector parameters under effects of local vibration]. / Narushenie osnovnykh parametrov stress-realizuiushchei sistemy pri deistvii na organizm lokal'noi vibratsii.

The authors studied some parameters of hormonal, immune and cytokine state in workers exposed to vibration. Considering local vibration as a chronic stressful factor, the authors analyzed changes in the studied interplaying neuroendocrine and immune parameters in human response to physical stress.