[Method for isolation of enteroviruses from edible mollusca]

A method for recovery of Poliovirus from experimentally inoculated mussels has been evaluated. The method, based on adsorption-elution-acid precipitation of virus particles, allows a recovery of more than 93% of the added virus.

Effects of carbon tetrachloride on isolated rat hepatocytes. Inhibition of protein and lipoprotein secretion

The effects of carbon tetrachloride on protein and lipoprotein secretion, and on lipid peroxidation, have been investigated in isolated rat hepatocytes. It was found that although the free-radical scavenger promethazine completely suppressed the increased peroxidation produced by carbon tetrachloride, it had no effect on the inhibitory action of carbon tetrachloride on lipoprotein secretion. In consequence, the latter effect of carbon tetrachloride does not appear to be mediated through a peroxidative stage.

Effect of an essential fatty acid deficient diet on dimethylnitrosamine demethylation and derangement of liver polyribosomes induced by this drug

Cytochrome P-450 content and dimethylnitrosamine demethylase activity were determined in the liver of male rats fed a polyunsaturated fatty acid deficient diet. The damaging activity of dimethylnitrosamine (DMN) on liver polyribosomes of control and treated rats was estimated. The reduction of DMN demethylase activity did not protect against polysome derangement due to DMN. These data are consistent with the hypothesis that metabolic pathways, other than the P-450 dependent one, are involved in the DMN bioactivation.

A study of bovid herpesvirus 2 infection in calves inoculated intradermally or intranasally

Bovid herpesvirus 2 infection was studied in calves exposed to the virus by intradermal inoculation of the skin of the left cheek or by nasal spray. In either case a localised infection developed and virus replication was shown to occur mostly in the tissues of its primary localisation, i.e. the skin of the left cheek or the nasal mucosa. There were neither secondary lesions, except at the site of virus injection, nor any serious systemic involvement on the part of the animals. The virus was also recovered from some areas of the skin (right cheek, perineum and scrotum) that were free of macroscopic lesions; moreover, intranuclear inclusions were found in several tissues of the nervous system (brain, superior cervical, stellate and Gasserian ganglia) which did not show any signs of inflammatory or degenerative changes. These findings suggest that the skin and the nervous system play an important role in the naturally-occurring disease since they could be the sites where the virus is maintained latently in the host.

Distribution of Bovid herpesvirus 2 in calves inoculated intravenously

The behavior of Bovid herpesvirus 2 in the skin, lymph nodes, and nervous system of calves injected intravenously with the virus was studied. After a latent phase that lasted up to 40 hours after inoculation, the virus produced a systemic infection which was characterized by primary localization of virus in the skin, lymph nodes, and nervous system. Between postinoculation days 7 and 12, the infection tended to persist in the skin only. The finding of intranuclear inclusions in the pyramidal cells of the cerebral cortex and in the neurons of the superior cervical and stellate ganglia supports the hypothesis that the virus might utilize the structures of the nervous system for its replicative cycle in the calf.

Phalloidin poisoning of isolated hepatocytes: inhibition of protein synthesis

Phalloidin added to isolated hepatocytes inhibits amino acid incorporation into protein. Inhibition is very strong with 20 micrograms/ml phalloidin and occurs after a lag period of about 30 min. After this period, poisoned hepatocytes also show morphological changes in their plasma membrane.

Early polyribosomal and lysosomal changes in the liver of rats poisoned with Amanita phalloides or phalloidin

30 min after poisoning with Amanita phalloides extract or phalloidin, rat liver polyribosomes appear strongly dissociated, and a small increase of free phosphatase activity is evident. A cycloheximide pretreatment prevents the polyribosome dissociation, without protecting against the lysosomal change. This indicates that the polysomal derangement is not due to a hydrolytic breakdown of messenger RNA. Phalloidin, added in vitro either to a liver cell-free system, or to isolated hepatocytes, does not inhibit their amino acid incorporating activity. The polysome dissociation, therefore, is dependent on changes induced by phalloidin when the liver cell is "in situ".