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This study was designed to assess the effect of paraquat on the rat kidney. The experimental animals used were Wistar rats, a strain selected and maintained at the Institut d'hygiène alimentaire. Their diet was well defined and their state of health monitored. Female animals with mean weight of 200 g were used in this study. Doses of 20, 30 and 50 mg/kg were administered via the gastrointestinal route. In this experimentation, performed on 12 rats plus 3 controls, the dose considered to be sublethal was 30 mg/kg administered by gavage. These animals were sacrificed after 24 h, 48 h, 4, 8, 15, 30 and 60 day, selecting those animals with the most severely altered state, at each time. Tubular lesions started to appear by the 24th hour; the proximal tubule was the most sensitive. Lesions of the distal tubule were observed slightly later, from the 48th hour. Lesions became more intense from the 4th day onwards and reached a maximum on the 8th day. The first signs of repair of the proximal tubule and distal tubule were observed on the 15th day, but were less marked for the proximal tubule. This repair was slow and progressive. Persistent lesions of the proximal or distal tubules were still observed after two months. The glomeruli presented several alterations, which were always only moderate. Overall, paraquat induces serious life-threatening lesions of acute tubular necrosis in the absence of adequate intensive care.

It is possible through investigation under the electronic microscope to determine the location and nature of lesions with accuracy. These lesions are mainly found on the epithelium of proximal and distal convoluted tubules. However, the extent of lesions together with the deterioration process of the cell-constituents vary from one structure to the other and even from cell to cell. On the other hand, while blood capillary vessels pertaining to tubules may also show moderate lesions, glomerular and interstitial deterioration is rare. Kidney deterioration which may either result directly from one of the poison effects or from related phenomena, is under discussion.

Endothelial cell alterations are considered to be a primary event in thrombosis and atherosclerosis. The adhesion of red cells from diabetic patients or patients with sickle cell anemia was measured using endothelial cell culture and a radiometric technique. The adhesion was significantly increased (P less than 0.001). Ultrastructure observation of red cells adhering to endothelial cells showed endothelial cell deformations, membrane modifications and formation of an anchoring device. Morphological changes support the hypothesis of an endothelial cell stimulation or damage during adhesion already suggested by the increased prostacyclin release during red cell adhesion.

Lindane or HCH is gamma-hexachlorocyclohexane, still used as an agricultural insecticide. Tests were carried out using primary cultures of chicken embryo hepatocytes at the 11th day of incubation, for a fixed period of 40 hours, using different concentrations of the substance. From 0.5 to 10 mumol/l, acid phosphatase fell significantly, without any other consequences being observed. From 25 to 50 mumol/l, there was a tendency to hypertrophy of the mitochondria, to hyperplasia of the granular and smooth endoplasmic reticulum, and of the Golgi system. Growth was unchanged and acid phosphatase decreased. From 75 to 125 mumol/l, these changes were accompanied by signs of cellular damage and there was marked autophagia. Growth was reduced and acid phosphatase greatly decreased. From 150 to 175 mumol/l, the lesions were markedly polymorphous and some indicative of impending cytolysis, in particular spiral tearing of the hyaloplasm. Growth was markedly impaired, whilst there was a paradoxal increase in acid phosphatase. In increasing concentration, L first had the effect of a metabolisable foreign substance, of the "phenobarbital" type, then a definite toxic action. Sensitivity of the individual hepatocytes differed.

Case report of occupational intoxication, with moderate anemia and hypogranulocytosis, in the course of which occurs a hairy cell leukemia. Cytological data are significative in photonic and electronic microscopy: microvilli and granulo-lamellar complexes. Discussion of benzen, as toxic factor in etiology of this leukemia.

Principle of the method. Description of the techniques used to obtain the cultures, light and electron microscopic study, biochemical determination of proteins, of DNA, of the incorporation of H3-thymidine, of total and lysosomal acid phosphatase activity. Detailed description of hepatocytes developed in unicellular layer: shape and distribution of the cells, junctions, cellular apparatuses and organelles, cytoplasmic inclusions. Comparison of the hepatocyte in vitro and in vivo. The most obvious differences are related to experimental conditions of geometry and nutrition. Particular note should be taken of the microvillous appendices of the free surface and the underlying explasmic layer. Specific physiological activities are evident, including glycogenogenesis. Discussion of multiplication, growth and cellular differentiation phenomena. Vitality tests. In culture, there may develop a tendency to hypertrophy of the mitochondria, of the dictyosomes, to hyperplasia of the granular or smooth endoplasmic reticulum and above all to increased autophagia.

Lindane, in contact with cultured foetal chicken liver cells over a period of 40 hours, has a biphasic action on the lysosomal system of the cells. For the concentrations between 1 micronM and 25 micronM not affecting the cellular growth, the decrease of the acid phosphatase activity and the absence of any reaction in the Golgi saccules might indicate a reduction in the synthesis of the lysosomal enzyme. For the concentrations above 25 micronM slowing down cellular growth, acid phosphatase activity is partialrogeneous content and an increase in the relative acid phosphatase activity in the soluble extralysosomal fraction, for doses over 150 micronM, might indicate the development of the phenomenon of autophagocytosis.