Evaluation of a possible styrene-induced damage to the haematopoietic tissues in the rat.

The aim of this study was to determine a possible risk of malignancies in the haematopoietic tissues of rats treated with styrene, either by injection or by inhalation. Two experiments were carried out: in the first (acute treatment), 12 male rats were treated intraperitoneally with different doses of styrene (40 mg/Kg/2 ml/die and 400 mg/Kg/2 ml/die) for 3 consecutive days. A control group (6 rats) was administered corn oil 2 ml/kg/die for the same period of time. In the second experiment (chronic treatment), 12 male rats were exposed to styrene inhalation (300 ppm/6 hour day/5 days a week for 2 weeks) for 3 weeks and sacrificed at the end of the experiment or after 3 weeks. The rats treated with the highest doses of styrene by injection (400 mg/kg, acute treatment) showed a hyperactivity of the erythropoietic series while the granulocytopoietic series was at the normal value. The rats exposed to 300 ppm styrene vapour (chronic treatment) showed a statistically significant increase in erythropoietic cells (basophilic, polychromatophilic and orthochromatic erythroblasts). A temporary block of immature cells of the granulocytopoietic series was also evident. These results indicate an alteration of the erythropoietic series independently of method of administration. However, these findings do not show a possible risk of preleukemic or leukemic disorders in rats exposed or treated with styrene.

Comparison of K(+)-p-nitrophenyl phosphatase activity in the urinary bladder of the frog Rana esculenta during hibernation and active life.

We have studied effects of hibernation on the frog urinary bladder, an organ involved in water and ion transepithelial transport and taking part in osmoregulation. We have demonstrated K(+)-p-nitrophenyl phosphatase activity (an enzyme involved in ion and water transport) both in active and hibernating frogs. Most of the reaction product deposition was found on basolateral membranes of granular cells of the urinary bladder epithelium during all seasons. Therefore, it seems likely that this organ, unlike organs studied previously (skin, kidney and lung), maintains its function in the osmoregulatory process during hibernation.

Styrene-induced alterations in the respiratory tract of rats treated by inhalation or intraperitoneally.

Although exposure to styrene occurs primarily via inhalation, the action of this agent on the respiratory tract has scarcely been investigated. This article describes morphological and biochemical changes occurring in the respiratory tract of rats after either inhalation of styrene vapors (300 ppm, 6 h/d, 5 d/wk, for 2 wk) or systemic (ip) treatment with 40 or 400 mg/kg styrene for 3 consecutive days. Electron microscopy analysis showed diffuse cell damage involving the tracheal, bronchiolar, and alveolar epithelium. In the tracheal epithelium, several cell types were affected. Ciliated cells presented vacuolation, detachment of cilia, blebbing of the apical cytoplasm, and compound cilia. Most secretory cells showed scant secretory granules and blebbings. Dense bodies and fibrillary inclusions were seen in intermediate and basal cells. Styrene also caused alterations of cytoplasmic components in type II pneumocytes and bronchiolar cells as well as thickness of the alveolar wall. These abnormalities were accompanied by depletion of glutathione (GSH) in the lung tissue. Pneumotoxic effects of systemic administration of styrene were dose dependent and tended to be more severe than those seen in the animals exposed for longer periods to styrene by inhalation. Metabolic activation of styrene and subsequent cell damage induced by the reactive metabolite styrene oxide may be involved in the sequence of events culminating in the toxic insult to the respiratory tract.

Establishment and characterization of two cell lines derived from human glioblastoma multiforme.

We established and characterized two cell lines derived from glioblastoma multiforme. Both cell lines exhibited tumor cell morphology and growth kinetics and showed variable expression of glial fibrillary acidic protein (GFAP), S-100, fibronectin and vimentin. Cytofluorimetrical analysis of tumor samples showed a diploid DNA distribution, whereas permanent culture cells evolved to the hyperdiploid DNA content. Karyotype studies revealed cytogenetical abnormalities described in glial tumors including gain of chromosome 7, loss of chromosome 10 and presence of double minutes (DMs). Enhanced expression of Ha-ras and c-myc genes resulted from high p-21 and p-62 levels. The contemporary presence of TGF-alpha and EGF-Rc transcripts suggested an autocrine mechanism in the cell lines growth.

Histochemical demonstration of oxidoreductase activities in the fat body and symbionts of Blattella germanica (Blattodea) following chlortetracycline-treatment.

The metabolic apport of prokaryotic symbionts in the fat body of Blattella germanica was investigated by histoenzymatic methods, using chlortetracycline-treated and normal strains. In the experimental insects, bacteriocytes showed a decreased oxidoreductase activity, whereas the staining intensity of the other cell types was generally unchanged. Electron microscopic observations showed that some bacteria were still present in the bacteriocytes of the treated insects, but exhibited degeneration patterns to a different extent; therefore, they are not likely to carry on any enzymatic activity. Hence, chlortetracycline, an antibiotic that blocks the transovaric transmission of the symbionts, is active also on the endocellular symbionts of the fat body.

Leucine aminopeptidase activity in blood and hemopoietic organs of different vertebrates. A histochemical comparative study.

Leucine aminopeptidase distribution was examined in the cells of peripheral blood and hemopioetic organs of different Vertebrate classes using histoenzymatic methods. Various degrees of staining intensity were observed in leukocytes of the distinct Vertebrates: in particular, leukocytes of fresh water Osteichthyes and Mammals looked strongly positive, whereas leukocytes of Amphibians, Reptiles, and Birds were barely reactive without great differences among species. The observations should be related to enzyme molecular structure and to kinetics and substrate specificity.

Cytochemical study of K+-dependent p-nitrophenyl-phosphatase activity in the urinary bladder of Salamandra salamandra.

The ultrastructural Na+-K+-ATPase localization in the salamander urinary bladder has been studied by the histochemical techniques of Ernst (1972) and Mayahara et al. (1980). Reaction products have been specially found on the basal and lateral membranes of granular and mitochondria-rich cells. The variable presence of artifacts, often accompanying Pb-capture phosphatase cytochemistry, is discussed. Additional data on the active ion transport have been obtained by using electrophysiological techniques.

Tetrahydrofolate dehydrogenase in blood cells and in hematopoietic organs of different vertebrate species.

Some general aspects in cytochemical demonstration of the tetrahydrofolate dehydrogenase, concerning the final reaction product, are studied. Steady and variable factors are detected in a comparative study of Vertebrate hemopoiesis: the enzyme exhibits peculiar features in different cell types. The reactivity progressively decrease in the erythropoietic series, in concomitance with hemoglobin synthesis. Conversely an increase in the intensity of reaction is found in the granulocytopoietic series; the correspondence of positive material with the specific (eosinophil and heterophil) granulations can be discussed. The thrombocytopoietic series is also labelled by this reaction.

The sulfatides and some histochemical correlations of the lachrymal glands involved in salt secretion in Chelonia.

High concentrations of sulfolipids (four fractions having different hexose/sulfate ratio), intense enzyme activity (ATPase, oxoreductases) and evidence of mucines (staining with PAS and Alcian blue) in intercellular spaces were found in the lachrymal glands of Caretta caretta and Malaclemys terrapin adapted to sea water. In addition, the supranuclear region of the gland cells in Malaclemys terrapin is filled with mucin granules. These biochemical and histochemical observations indicate that these glands have a function in salt secretion in both species and are also consistent with a function of mucous secretion exclusively in Malaclemys terrapin. Limited signs of hypotrophy are not accompanied by changes in concentrations of sulfolipids in Malaclemys terrapin adapted to fresh water; only the reactions for enzyme activities are less intense. The mucous secretion is not affected, whereas, in correlation with changes in salt secretion, the change in ATPase activity is mot conspicuous. The correlations between the different components of the gland and salt secretion are compared with salt glands of birds and elasmobranchs.