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Biomedical subjects

G Chappuis

Publications and source records attributed to G Chappuis.

At least 55 records · Page 3Linked to original sources
PubMed1984

Biochemical study of the Feline Herpesvirus 1. Identification of glycoproteins by affinity.

Feline Viral Rhinotracheitis herpesvirus (Feline Herpesvirus 1; FHV-1) was purified by rate zonal isopycnic centrifugation. Viral nucleocapsids were isolated from the nuclei and purified. Analysis of the purified and radiolabelled viral polypeptides and glycoproteins by gradient SDS polyacrylamide gel electrophoresis revealed that 23 viral proteins and 6 glycoproteins were present in the whole virus particle. Tween 80-diethylether treatment removed the major glycoproteins. FHV-1 viral glycoproteins were detected using [14C] glucosamine and a lectin binding procedure. The fluorescein isothiocyanate-Concanavalin A (FITC-Con A) specificity was checked by trials on other viruses whose glycoproteins had already been described. The FITC-Con A allows a very simplified procedure for glycoprotein determination after slab acrylamide gel electrophoresis and can be used prior to Coomassie blue staining of proteins.

Animals↗
PubMed1983

Propagation of bovine rotavirus by young dogs.

Ten young dogs were experimentally infected twice with different isolates of bovine rotavirus and 2 uninfected dogs were kept in contact with them. None of the animals developed diarrhoea, but all of them excreted rotavirus in their faeces over a period of up to 10 days after each inoculation, as shown by counterimmunoelectro-osmophoresis and virus isolation. Dogs may thus play a role in the epizootiology of rotavirus diarrhoea in calves. Seroconversion occurred in 6 of the 10 infected dogs but in neither of the 2 contact controls.

Animals↗
PubMed1982

Rabies virus pathogenicity and challenge. Influence of the method of preparation, the route of inoculation, and the species. Comparison of the characteristics of the modified, fixed and wild strains.

The challenge we carried out, which regularly brought about the death of the control animals, led us to study the different factors influencing the pathogenicity of the rabies virus. So, the method of preparation is important. The strain NYC, prepared from the salivary glands is extremely pathogenic for dogs; however, when it is prepared from mouse brains after nine passages have been made, it proves to be already partially modified. One then notices a death-rate which is less severe, even when larger quantities of virus are employed, and also the presence of some aberrant phenomena. (The survival of some of the infected animals and the nature of their inapparent forms of infection were confirmed by serology.) The significance of the route of inoculation in the different species of animals was studied. The injection in the crotaphytes was reserved for dogs, the cervical muscles for cats and the masseters for sheep. Paradoxically, cats prove to be most resistant to the challenge under our conditions. Finally the numerical data, allowing us to compare the different strains, modified, fixed or wild, was established. The data was based on the incubation period and on the differences between the titres obtained via intramuscular routes and intracerebral routes in the mice.

Animals↗
PubMed1982

[Correlation between the NIH test and the seroneutralizing antibodies obtained after vaccination in the dog].

This work reports on two distinct studies on the analysis of correlation of results of potency tests of rabies vaccine intended for dogs. In a first study, the analysis compares the results of the conventional NIH test in mice with seroneutralizing antibodies obtained after 21 days of vaccination in dogs. Arithmetical analysis (109 NIH results, 466 antibody titres) did not reveal significant linear correlation between the results. In a second study, the analysis compares the results of the conventional NIH test and of the NIH test without booster in mice with seroneutralizing antibodies obtained after 21 days of vaccination in dogs. Arithmetical analysis (27 conventional NIH results (without booster), 118 antibody titres) did not reveal any significant linear correlation between the results.

Animals↗
PubMed1982

[Haemagglutination inhibition test: improvements, limits and advantages of the method. Comparison with neutralization test].

In this study, we report some technical improvements which enable us to envisage wider use of the haemagglutination test and haemagglutination inhibition of the rabies virus. Moderated trypsination of sensitive red blood cells and their counting are important parameters. An interesting application of the test was the haemagglutination competition enabling the amount of soluble glycoprotein (obtained during the fractionating of the virus components) to be evaluated. From antibody kinetics of vaccinated dogs, a study of the correlation which exists between the IHA titres, SN mice titres and SN-RFFIT titres was carried out. Satisfactory correlation was obtained between these three techniques.

Animals↗
PubMed1982

[Modalities of production and immunity conferred by an inactivated rabies vaccine originating from cell culture].

Further to guidelines advised by the World Health Organization, an inactivated Rabies vaccine was prepared from virus propagated on cell culture. This vaccine is presented either in the freeze-dried form or in the liquid form together with an immunity adjuvant. The specific and nonspecific immunity of the vaccine is excellent. The potency, tested in laboratory animals and in species for which the vaccine is intended, satisfies recommendations published by the W.H.O. The immunity persistence, evaluated by the titration of serum antibodies and by challenge with a pathogenic virus, proves to be excellent 3 years following primovaccination. Finally, the stability of this vaccine is an interesting factor for its application, especially in the form of a combined vaccine.

Animals↗
PubMed1982

[Feline rhinotracheitis: a purified inactive vaccine and an experimental model].

The medical prophylaxis of feline rhinotracheitis is presently carried out varying success, using three sorts of vaccine: 1. A so-called "attenuated" living virus vaccine, administrable by parental route. 2. A modified living virus vaccine administrable by nasal route. 3. An activated virus vaccine with adjuvant incorporated, administrable by parental route. When this third sort of vaccine was used in contaminated catteries, unfavorable clinical signs were sometimes observed, which resulted in a state of hypersensitivity and even causing excretion of latent virus from convalescent cats which were carriers of Herpes virus. First of all we checked that this was a specific reaction and that it was directly in relation to the viral antigen. Our study was then directed towards the biochemical analysis of the virus and the determination of the sensitizing antigenic fractions and to the immunogenic fraction of the Herpes virus felis. In this paper we report the first results obtained. However, going further than the feline Herpes virus, we think that this is a practical experimental model which could be used in the study of other Herpes virus.

Animals↗
PubMed1982

Propagation of bovine rotavirus by cats and dogs.

SPF cats were experimentally infected orally with bovine rotavirus. All of them excreted virus over a period of at least two weeks after inoculation. Seroconversion was observed after one week for all the animals, but it did not stop viral excretion or prevent further excretion of the same or another rotavirus strain given later. Cats or dogs kept in the same cage as inoculated animals became infected and excreted virus, but seroconversion was not observed in these contact animals. None of the animals developed diarrhoea during the experiment. Cats are thus able to multiply bovine rotavirus, and transmission of this virus occurs between cats or between dogs and cats. Therefore, cats, like dogs, may play a role in the epizootiology of rotavirus infection in calves.

Animals↗
PubMed1981

Experimental rabies in cats: immune response and persistence of immunity.

Experimental rabies was studied in cats under defined conditions. A correlation between the virus dosage and the incubation period was established and results were compared with those published previously by others. the susceptibility of cats to rabies virus appears to be paradoxical. The persistence of the immunity induced by an inactivated rabies vaccine prepared form cell culture-propagated virus used in combination with feline panleukopenia vaccine, with or without adjuvant, was studied through severe virulent virus challenge. Complete protection was observed after more than 3 years following a single vaccination. A proposed vaccination schedule is discussed.

Animals↗
PubMed1979

Immunisation against panleukopenia: early development of immunity.

The time necessary to obtain the immunity of cats against Panleukopenia has been studied by means of a modified live vaccine. This vaccine makes it possible to obtain a very early post-vaccinal immunity: the full immunity is reached 72 hr after the inoculation of the vaccine by the subcutaneous route. Furthermore, we have demonstrated that a sensitive kitten can be admitted in a contaminated environment immediately after vaccination without showing any clinical evidence of the disease.

Animals↗
PubMed1978

[Prevention of animal rabies by an attenuated monovalent or mixed vaccine].

In view of the advantages and disadvantages of the different rabies vaccines, classified according to the production method of the virus and according to their nature - activated or inactivated - the choice of an activated vaccine produced on cell cultures is particularly justified for developing countries. The production of this type of vaccine, as well as the methods and results of the activity and innocuity controls are shown in detail. The interest of combined vaccines for certain developing countries, particularly the combined vaccine rabies/foot-and-mouth disease for ruminants, is stressed. The use of this type of vaccine on a vary large scale (more than 20 million doses up to this date) has given complete satisfaction. It should be noted that the same principles have been successfully applied to the realisation of a vaccine for human use, which can be administered before as well as after contamination.

Animals↗
PubMed1976

[Use of anti-foot-and-mouth disease vaccine in oil adjuvant in young cattle].

A comparative study of the activity of foot-and-mouth disease vaccines, both aqueous- and oil-adjuvanted, was carried out on young bovines from vaccinated mothers. The immunity of these animals against foot-and-mouth disease was controlled after the first vaccination and booster by serology (neutralizing antibody count and immunology virulence testing). After having followed the kinetics of decrease in seroneutralizing antibodies of maternal origin the animals were vaccinated at the age of 11 weeks either with aqueous-adjuvanted or oil-adjuvanted vaccine. A booster dose was given two months later. Blood samples were taken at regular intervals and two virulence tests were made, one 21 days after the first vaccination and the other six months after the booster dose.

Adjuvants, Immunologic↗
PubMed1976

[Production, control and use in swine of anti-foot-and-mouth disease vaccine in oil adjuvant].

A certain number of parameters involved in the manufacture, control and use of an efficacious vaccine against foot-and-mouth disease have been studied. This report considers the problems raised by the standardization of the raw material constituent to the vaccine as well as the different types of innocuity and activity testing carried out on sows, young pigs and bacon pigs. Special attention is given to virulence testing methods, to the criteria allowing evaluation of the quality of the vaccines and to the transmission of maternal immunity of the sows to their piglets and its incidence on the vaccination schedule.

Adjuvants, Immunologic↗