Effects of anaesthesia and chronic catheterization on circulating levels of prostaglandins (PGE2 and PGF2a in dogs

Summary Chronic catheterization of aorta and inferior vena cava in dogs did not significantly affect circulating levels of prostaglandins (PGE₂ and PGF_2a ). Pentobarbital (30 mg/kg i.v.) anaesthesia produced a significant decrease in PGF_2a .This work was supported by INSERM (grant No. 76.5.183.5).We wish to thank Miss Laure Eloy and Mrs Annick Soubrier for their technical assistance.     

The effects of intraventricular injection of 6-hydroxydopamine on the sleep of kittens during development]

Intraventricular injection of 6-hydroxydopamine does not modify the states of alertness in the Kitten, if it is performed in the first week of postnatal life. At three weeks of age, it induces the same sleep impairments as those observed in the adult Cat. Therefore, in the immediate postnatal period, sleep control is not achieved through the monoaminergic systems.     

Degradation of type I collagen fibrils synthesized by human dental pulp cells in explant culture exposed toActinomyces viscosus. Electron microscope immunotyping

Summary Actinomyces viscosus Be 66, added to pulpal cells in culture, does not cause apparent cellular damage. The extracellular matrix consists of altered collagen fibrils and thin filaments, immunochemically identified as type I collagen. They probably represent the first steps of collagen degradation.This work was supported by INSERM (ATP: 77-85) and CNRS (RCP: 533).     

Bacillus thuringiensis delta-endotoxin: evidence that toxin acts at the surface of susceptible cells

Enzymically activated delta-endotoxin of Bacillus thuringiensis covalently bound to Sephadex beads, has the same effect on insect cells in tissue culture as free toxin. The effect is prevented by antitoxin antibody and heat denaturation and is not due to a nonspecific protein effect, the beads, or toxin released from the beads. The toxin, therefore, probably acts at the cell surface.     

Inclusion of Gross virus cell surface associated antigen in liposomes]

The Gross virus associated cell surface antigen GCSAa was extracted from (C58NT)D cells by solubilization of membranes with detergent and partially purified. This antigen was entraped in liposomes. Absorption experiments of the cytotoxic activity towards EmaleG2 cells of a W/Fu anti (C58NT)D serum showed the presence of the antigen at the surface of sensibilized liposomes.     

What distinguishes cosmopolitan and endemicDrosophila species?

Summary CosmopolitanDrosophila species can survive wide ecological tolerances measured by resistance to desiccation/temperature extremes compared with endemic rain forest species. This, rather than any genetic features, is important in helping to explain the widespread distributions of cosmopolitan species.We thank Dr Lee Ehrman for cultures ofD. paulistorum, and the Australian Research Grants Committee for financial support.     

On the formation of the myotomes in avian embryos. An experimental and scanning electron microscope study

Summary The formation of the myotomes to chick embryos was studied by using experimental and scanning electron microscope techniques. With the aid of the quail-chick marker system, it was demonstrated that the dermatome gives rise to the myotome plate. SEM studies support the conclusion that the myotome cells originate only from the edges of the dermatome.Supported by the Deutsche Forschungsgemeinschaft (Ch 44/2).     

Long-term depression of two primary immune responses induced by a single dose of 5-(3,3-dimethyl-1-triazeno)-imidazole-4-carboxamide (DTIC)

Summary 2 primary immune responses (anti-SRBC antibody response and allograft rejection) have been tested in mice at various time intervals after single doses of either DTIC or cyclophosphamide. The DTIC-induced immunodepression proved to be extremely long-lasting, being still detectable after 2 months.This work was supported by Project NO1-CB 64054 of the U.S.-Italy Cooperative Science Program.