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Biomedical subjects

G Castrucci

Publications and source records attributed to G Castrucci.

At least 73 records · Page 4Linked to original sources
PubMed1982

Reactivation in calves of Bovid herpesvirus 2 latent infection.

Seven calves which had recovered from an experimentally induced infection with Bovid herpesvirus 2 (BHV 2) were subjected to a course of dexamethasone (DMS) treatment six months later. BHV 2 was recovered from nasal swabs obtained from each calf 11 days after the start of DMS treatment. The virus was also isolated from the skin, nervous system tissue and lymph nodes of a calf killed 11 days after the start of DMS treatment in which a concurrent piroplasma infection was also, unexpectedly, discovered. It is suggested that the skin and nervous system are possible anatomical sites for the latency of BHV 2 in the host.

Animals↗
PubMed1981

[Persistent infections induced by viral agents in animals].

Several studies have been conducted on persistent infections induced by viruses which are usually lytic for the infected cells. At the onset of these infections at least four mechanisms seem to be involved, i.e., the defective interfering (DI) viral particles, the temperature-sensitive (ts) mutants, the interferon or the presence in the culture of integrated DNA proviral copies of RNA viruses. Actually these systems are very complex and their evolution could depend on several factors such as the type of virus, the growth temperature of the culture or the kind of culture. Beside the systems that have been discussed here there may be other still unknown factors which might be involved in persistent infections, both in vitro and in vivo. The discovery of these factors could eventually represent a realistic basis for a better understanding of the pathogenesis of slow virus diseases and also would offer the possibility to study the long-term reactions of the organism when subjected to vaccination with ts mutants.

Animals↗
PubMed1980

Attempts to reactivate bovid herpesvirus-2 in experimentally infected calves.

A study was carried out to determine whether bovid herpesvirus-2 (BHV-2) is able to induce a recurrent infection in experimentally infected calves. Twelve calves infected with the virus were treated with dexamethasone (DMS) beginning 69 days after the infection, ie, several weeks after the animals had recovered from the disease and were negative for BHV-2. The stress induced by DMS treatment failed to reactivate the clinical condition or to induce shedding of BHV-2. However, treatment with DMS reactivated a latent infectious bovine rhinotracheitis (IBR) virus infection in all calves previously inoculated with BHV-2, and also in 2 noninoculated controls. The reactivation of IBR virus occurred without any clinical evidence of the disease, but the virus was isolated from nasal and pharyngeal swabbings and from the organs. A proliferative ganglionitis of the trigeminal ganglion was also observed. Because of the interference by IBR virus, this study did not resolve the question as to whether BHV-2 can induce a recurrent infection.

Animals↗
PubMed1979

Characterization of furosemide-induced activation of the renal prostaglandin system.

A detailed time course of changes in plasma renin activity (PRA), urinary prostaglandin (PG) E2, PGF2 alpha, thromboxane (TX) B2 and sodium excretion rates following furosemide was obtained in 7 women. PRA increased within the first 15 min and remained elevated all through the experiment. PGE2, PGF2 alpha, TXB2 and sodium increased simultaneously, reached a peak between 15 and 45 min after furosemide and declined thereafter. It is concluded that furosemide induces a generalized activation of the renal PG system temporally related to the increase of renin release and natriuresis.

Adult↗
PubMed1979

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.

Administration, Intranasal↗
PubMed1978

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.

Animals↗
PubMed1976

Preliminary characterization and pathogenicity studies of a virus isolated from ticks (Ornithodoros coriaceus) and from tick-exposed cattle.

Several viral isolates from ticks (Ornithodoros coriaceus) and from the blood of cattle which aborted after exposure to these ticks were found to be identical by reciprocal cross serum-neutralization tests. Characterization studies indicate that the virus is a member of the Togaviridae family, although specific identification is still incomplete. Whether its natural host is the tick or bovine animals is also unknown. Pregnant cows inoculated with the agent by all conventional parenteral routes, including intrafetal, delivered healthy calves at term. It was concluded, therefore, that it was not a bovine pathogen and that the abortions which occurred after tick-exposure were due to a 2nd agent in O coriaceus ticks which also harbor the virus. While several ciruses believed to be tick-borne have been isolated from cattle in various parts of the world, it is believed that the present report describes the first isolation in the Western Hemisphere for a viral agent from Argasid ticks which has been demonstrated to replicate in cattle.

Abortion, Veterinary↗
PubMed1975

A study of immunologic relationships among serologically heterologous strains of bovine viral diarrhea virus by cross immunity tests.

Three serologically heterologous strains of bovine viral diarrhea (BVD) virus were compared in reciprocal cross immunity tests in calves. Each strain was inoculated into five calves. Thirty-eight days later one calf in each group was reinoculated with homologous virus while the immunity of the remaining four was challenged with the serologically heterologous strains of virus, using two calves for each strain. Of the 12 calves in the cross immunity tests, nine were refractory to immunity challenge with the heterologous viral strains while one in each group responded with mild, atypical signs of BVD. On the basis of immunity testing it appears that significant serologic differences among strains of BVD virus are unrelated to the immunologic properties of the strains. It was demonstrated, moreover, that each of the three strains used in the present study evoked the production of antibody to the heterologous as well as to the homologous strain of virus.

Animals↗