Protection by conventional and new antiepileptic drugs against lindane-induced seizures and lethal effects in mice.

Toxic effects caused by the organochlorine xenobiotic lindane may result from too excessive antiscabicidal treatment and in cases of accidental or intentional poisoning. Predominant symptoms of lindane intoxication concern the central nervous system, e.g.

Ethosuximide and valproate display high efficacy against lindane-induced seizures in mice.

Both lindane (gamma-hexachlorocyclohexane), an organochlorine ectoparasiticide and pentylenetetrazol, used as a model of experimental epilepsy, produce convulsive seizures resulting from the blockade of the gamma-aminobutyric acid (GABAA) receptor. In the present study we established the protective effects of ethosuximide and valproate against seizures induced by lindane and compared them with the well-known protective effects of these drugs against pentylenetetrazol-induced seizures in mice. Both ethosuximide and valproate afforded complete and dose-dependent protection against seizures induced by lindane.

Studies of toxicity of dermally-absorbed nurelle D 550 EC preparations.

The aim of the study was the evaluation of the toxic effect of a two-component, preparation Nurelle D 550 EC (500 g of chlorpyrifos and 50 g cypermethrin per 1 l), administrated dermally. Toxicity was evaluated from histological and ultrastructural studies of the internal organs and immunotoxic effects (evaluation of phagocytical and bactericidal activity of neutrophils). The preparation for dermal application was applied in 2 concentrations (200 mg/kg/day of chlorpyrifos plus 20 mg/kg/day of cypermethrin or 1000 mg/kg/day of chlorpyrifos, plus 100 mg/kg/day of cypermethrin).

Toxicity of dermally applied alpha-cypermethrin in rats.

The aim of the study was to assess the immunotoxic effect of dermally applied alpha-cypermethrin in rats based on phagocytic and bactericidal activity of neutrophils of peripheral blood, and the general toxic effect based on histological and ultrastructural examination of internal organs. The preparation was dermally applied in doses of 50 mg/kg and 250 mg/kg. It was administered to the tail skin of female Wistar rats, 4 hours daily for 28 days.

Toxicity of dermally absorbed dichlorvos in rats.

Toxicity of dermally absorbed dichlorvos was studied in rats, based on its effects on internal organs, and on phagocytic and bactericidal activity of the neutrophile system. The studies were conducted on 30 female rats of Wistar strain. The animals were divided into three groups, two of which were experimentally exposed to dermal absorption of dichlorvos (37.

Does moxonidine increase cytotoxic activity of ethanol in rats? Preliminary report on the base of the ultrastructural study.

Combined effects of moxonidine and ethanol on ultrastructure of selected Wistar-Kyoto rat organs (kidney, liver, heart) were investigated. In cells of the animals, which received moxonidine alone, no morphological changes were found. In the group of rats which received alcohol, several typical submicroscopical changes were found, especially related to the mitochondria.

Chlorfenvinphos Dermal Absorption in Rats: Histological and Ultrastructural Changes in the Skin and Internal Organs.

We studied the effect of chlorfenvinphos dermal absorption on the morphological picture of blood, on the histological and fine structure of tail skin, and on the histological structure of internal organs (lungs, heart, liver, spleen, and kidney) of rats. This study was conducted on 25 white Wistar rats, the tail skin of which was-or was not-hydrated before exposure. Rat tails were soaked in 0.

[Morphological studies of bone marrow neutrophilic and acidophilic granulocytes of white rate during stimulated leukopoiesis].

The neutrophils and eosinophils of rat bone marrow were studied after stimulating bone marrow with leucogen administered in therapeutic doses. The morphological examinations of these cells were carried out under electron microscope analysing the activity of myeloperoxidase. Disturbances were observed in the formation of primary and secondary granules in the neutrophils.

[Ultrastructural studies and neutrophil myeloperoxidase determination in rats with acute 2,4-dichlorphenoxyacetic acid poisoning].

The aim of the work was to study changes in the ultrastructure and activity of different developing forms of cells in the neutrophil series in rat bone marrow during acute poisoning with 2,4-dichlorphenoxyacetic acid. The results of the study enabled determination of the influence of this herbicide on the process of granulogenesis in the neutrophils to be achieved. Disturbances of granulogenesis appeared in some cells of the experimental group II (160 mg of 2,4-D-acid/kg of body weight) and in most cells in the experimental group III (400 mg of 2,4-D-acid/kg).

Ultrastructural and cytochemical observation of calcium ion localization in the black-beetle pleural muscles.

The authors examined the infrastructure and distribution of calcium ions in the plexural muscles of a black-beetle (Blatta orientalis L.) after being fixed in a solution of osmiumtetroxide buffered with a cacodylate buffer (pH = 7.4) and according to the method of Carasso-Favard (1966).

Ultrastructural and cytochemical localization of calcium in a rat cardiac muscle in normal and experimental conditions.

The experiment carried out by us on the, stimulated by adrenaline, cardiac muscle allowed the activation of calcium localized mainly in the mitochondria, MA and FA of the intercalated discs and SR to be translocated in the direction of the sarcomere myofilaments and this especially to the thin actin filaments. The authors' experimental proves, that during the contraction--relaxation function of the cardiac muscle there exists a circulation rythm or a oscillatory functional flow of calcium ions between the mitochondria, intercalated discs and SR and the contractile fibrillae of the sarcomere.

An electron microscope cytochemical study of calcium ion localization in the honey-bee flight muscle.

The authors studied the sarcomere ultrastructure and distribution of calcium ions in the cross striated flight muscles (longitudinal-dorsal and tergosternal) of the honey bee after being fixed in osmium tetraoxide and buffered to 7.4 pH and also according to the method of Carasso and Favard (1966). they ascertained an intensive and constant reaction to the presence of calcium on the level of myofilaments within the periphery of the sarcomeres and light and dark mitochondria.

Some observations on the intercalated disc of a rat cardiac muscle.

During the experimental investigations special attention was paid to the orthomorphology of the ultrastructure of cardiac muscle intercalated disc in a rat. The contact junction between the cellular membranes of adjacent cells and intercellular spaces are typical for the cardiac muscle intercalated disc. Attention was paid to the three zone system of the junctions, namely: 1.