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Biomedical subjects

A Mayr

Publications and source records attributed to A Mayr.

At least 91 records · Page 5Linked to original sources
PubMed1990

[Comparative studies of the paraspecific immunostimulation (paramunization) by bacterial lysates in bacterial infection models and in the cytotoxicity test].

Bacterial lysates of different bacterial strains (E. coli, B. bronchiseptica, P. haemolytica) were prepared by heating, acid- and alkaline-hydrolysis. Lysates were tested for their immunostimulating effect in bacterial infection models and with chromium 51 test demonstrating spontaneous (natural) cytotoxicity. Lysate production was standardized by protein- and Lps-determination. The alkaline-hydrolysis reduced toxicity of Lps and increased the content of soluble bacterial protein. Heating and acid-hydrolysis did not alter bacterial suspensions with respect to Lps-toxicity and protein-content. Mice infected with P. aeruginosa, P. multocida, E. coli and L. monocytogenes (5-10 LD50) had a significantly longer survival time after prophylactic immunostimulation with bacterial lysates than control animals. No protection was observed in immunostimulated mice infected with Erysipelothrix rhusiopathiae. In the Pseudomonas infection model, bacterial lysates prepared by alkaline-hydrolysis had a 10 times higher immunostimulating effect than lysates prepared by acid-hydrolysis or heating. Bacterial lysates stimulated spontaneous cytotoxicity of natural mouse peritoneal killer cells after intraperitoneal application. Whole bacterial lysates had a higher NK-activity as their corresponding purified lipopolysaccharide portion.

Adjuvants, Immunologic↗
PubMed1989

[The economic value of a protective vaccination against enzootic bronchopneumonia of cattle].

The bovine enzootic bronchopneumonia is a multi-causal determined and by several factors triggered general factor-disease. Since therapy is mostly disappointing, prophylaxis is the most advantageous way to curb the disease. Vaccination with combined vaccines has been very promising. A cost-benefit-analysis shows that the decrease in morbidity from 72% to 7.3% and in mortality from 5.1 to 0.9% results in a benefit-cost-relation between 5 to 1 and 7 to 1. That means preventive vaccination against crowding associated enzootic bronchopneumonia saves approximately 180,- DM per animal and 250,- DM per animal in case of seasonal enzootic bronchopneumonia.

Animals↗
PubMed1989

Current problems in zoonosis research.

New developments in the field of Zoonosis research are discussed. They include: 1. New emerging viral zoonosis 2. Multicausal zoonoses 3. Genetic aspects of the origin of new zoonoses 4. Transmission of zoonoses to man through foodstuffs of animal origin 5. The environment and zoonoses. Continuous zoonosis research with new molecular biological techniques is a necessity. In the final analysis, there are no true limits in the field of infectiology. Such research requires cooperation between ecologists, zoologists, botanists, molecular biologists, physicians and veterinarians.

Animals↗
PubMed1989

[Experimental detection of the paraspecific effects of purified and inactivated poxviruses].

The paraspecific effect of pox viruses i.e. stimulation of the nonspecific part of the complex immune system, was demonstrated in vitro and in vivo for 3 different types of virus (vaccinia virus, avipox virus, parapox virus). By means of purification, concentration and inactivation, it was possible to prove that the paraspecific effect is brought about by the pox virus particle per se. The effect is induced by certain epitopes in the complex structure of the virus and is independent of virus multiplication. Both purified pox viruses and inactivated, purified pox viruses stimulate NK cell activity, the CSA and the formation of interferon, and reach higher efficacy indices in a challenge test with baby mice using stomatitis vesicularis virus than non-purified and non-inactivated cell culture material. The degree of purity of the pox virus preparations was established using the electron microscope and monoclonal antibodies. The purified and concentrated pox virus preparations proved to be pyrogen-free; they were not toxic to baby mice in vivo. An endotoxin-induced effect could be ruled out. The broad paraspecific effect of pox viruses and their structural components lends itself to use as paramunity inducers in prophylaxis and therapy.

Animals↗
PubMed1989

[Infections which humans in the household transmit to dogs and cats].

An overview of the most important infections which can be transmitted from humans to pet dogs and cats is presented. Two quite different sources of infection stand diametrically opposite each other: 1. The transmission of active human infections to dogs and cats and 2. the transmission of infectious agents by feeding raw meat, offal, unsterilized milk products, kitchen scraps and contaminated feedstuffs. Humans can be the source of the following infections: 1. Zoonoses with reciprocal modes of transmission, e.g. Campylobacter and E. coli infections, trichophyton and microsporum infections, reo-, parainfluenza-, adeno, rota- and corona infections. 2. Zoonoses in which the main direction of infection is human----animal, e.g. tuberculosis and influenza A. 3. Infections originally pathogenic to humans which meet an impasse in dogs and cats (blind alley hosts), e.g. herpes simplex, varicella-zoster, measles and Corynebacterium diphtheriae. Listeria, salmonella, campylobacteria, toxoplasma, fungi, yeasts and viruses are transmitted via feed. The most dangerous virus infection to be transmitted to cats and dogs via raw pork leftovers is Aujeszky's disease. The dog or cat, which is the last link in the infection chain, suffers an agonizing death. The other infections originating from feed must be assessed quite differently. They are links in infection chains, which spread pathogens and endanger the health of man and animal in turn. A typical example is toxoplasmosis. Man becomes infected via sporulated oocysts from feces. Pet cats mainly become infected via raw pork containing cysts.

Animals↗
PubMed1989

[The detection and identification of poxvirus in domestic cats].

Two cases in Southern Germany of pox in cats could be diagnosed virologically. A cowpox-like virus was isolated, its biological and serological characteristics defined. The source of infection could not be traced. The contraindication of treatment with corticosteroids and the pathogenicity of the orthopoxvirus demonstrated here for humans is pointed out.

Animals↗
PubMed1989

[Unexpected effects of a whole body irradiation on the mortality rate of baby mice after an experimental infection with the vesicular stomatitis virus (VSV)].

The effect of total body irradiation of baby mice or their pregnant mothers with surface doses of 3.9 Gy on the mortality rate after infection of the baby mice with VSV has been studied. Irradiation of the newborns had no influence on the mortality rate of the infected animals. Irradiation of the pregnant animals--and the foetuses in utero--caused an astonishing decrease of the mortality rate of the infected baby mice for about 50% in compare to the non irradiated controls.

Animals↗
PubMed1989

[Parvovirus infections in dogs and cats: problems of immunization].

The general problems of immunization against parvoviroses are only understandable when knowing the basic principles of epidemiology, pathogenesis and immunology of those virus infections. The main difficulties with regard to vaccinations are 1. efficacy of homologous respectively heterologous vaccines, 2. indications for live resp. inactivated vaccines, 3. combination with other vaccines, 4. bridging of the "immunological gap" (refractory phase) of puppies, 5. mode of application and timing of vaccinations (schedule of vaccinations), 6. failure in vaccinated animals, 7. complications originating from vaccinations, 8. passive immunization.

Animals↗
PubMed1989

[Borna disease].

Using Borna disease as a model, the consequences of persistent virus infections of the central nervous system, in particular of "slow virus diseases", are briefly described. Both latent and active forms of the disease have much in common with chronically progressive diseases of the central nervous system in animals and man which have until now remained unexplained. Virologically and serologically there exist simple laboratory procedures to examine the pathogenesis and immunology of the disease, in addition to suitable laboratory animals and a variety of cell cultures.

Animals↗
PubMed1988

[The control of kennel cough].

Kennel cough is an infectious factorial disease with a multicausal genesis. The conventional methods (hygiene, management, chemotherapy, symptomatic therapy) are often insufficient in control of the disease. New methods were developed in collaboration with "problem kennels" (animal homes, dealer kennels etc.), which reduce the morbidity significantly. A so-called "synergistic combined vaccine" ("Candiflu", Behringwerke Marburg), which contains the basic viruses (reovirus, human influenza-A-virus, parainfluenza-2-virus), is recommended for prophylaxis. In problem kennels with a permanent changing of dogs the vaccination has to be supported by paramunization. Therapeutical success depends on the combination of conventional methods and the stimulation of the paraspecific immune system (paramunization). This new concept has been very successful in West Germany during the last years.

Animals↗
PubMed1987

[Respiratory infectious diseases in horses].

Among all infectious diseases affecting horses, respiratory disease pose the greatest threat to horses kept in stables, horses used for breeding and race horses. Here a distinction should be made between the so-called monocausal infectious diseases (so-called Henle-Koch postulates) and multicausal infectious diseases which are the result of the synergistic interaction of different processes, that alone do not lead to disease. There is no clearcut distinction between the two groups. The most important monocausal respiratory infections of horses are caused by equine influenza virus (subtypes 1 and 2), equine rhinopneumonitis virus (equine herpes-virus type 1), equine arteritis virus and partially by Reoviruses. In addition, streptococcus equi (strangles, adenitis equorum, coryza contagiosa equorum) and mycobacteria tuberculosis can cause monocausal diseases. In multicausal infections, the first step usually is a virus infection. This is the basis for secondary infection by widespread, opportunistic agents such as bacteria, mycoplasms or fungi which lead to clinical disease. The method of choice for controlling monocausal respiratory infections of horses is prophylactic vaccination and chemotherapy. Measures to control multicausal infections include: vaccination with functional-synergistic combined vaccines; the use of herd-specific vaccines; medical stimulation of the non-specific part of immunity (immunmodulation, paramunization). Paramunization is a new concept in the prophylaxis and therapy of respiratory infections of horses and can be combined with prophylactic vaccination as well as with chemotherapy. In severe cases of respiratory disease paramunization can also be combined with corticosteroids.

Animals↗
PubMed1987

[Cowpox virus infection in a young girl].

An genuine cowpox virus was isolated in a 6-year-old girl with a circumscribed skin lesion between the thumb and forefinger. In the beginning, the lesion was a proliferating skin change, which later became ulcerative with central hemorrhagic necrosis (umbilicated pock). Electron microscopy as well as histological, biological (cell and host range) and serological methods were used to characterize the virus. Cats and rodents are discussed as potential virus carriers. Voluntary vaccination against orthopox should be provided for persons at risk of infection.

Child↗
PubMed1986

Tests on protection against viral diseases.

Despite many attempts to find reliable in vitro criteria for the efficacy of Biological Response Modifiers--BRMs (immunomodulators, paramunity inducers) animal challenge models are still the only way to demonstrate the totality of interlocking defense mechanisms. Challenge models with mouse pathogenic viruses provide an excellent possibility to study protective effects of BRMs against acute or chronic forms of viral diseases. For comparative studies two completely different virus challenge models--Pseudorabies PR and Stomatitis Vesicularis VSV--were developed with adult and baby NMRI mice respectively. The potency of BRMs in preventing lethal disease reveals significant differences depending upon the sort of BRM, the route of application and the time of pretreatment. Defense mechanisms important for the control of Pseudorabies virus infection in adult NMRI mice were tested in vitro (ex vivo) and correlated well with the degree of protection in vivo. Comparison of BRM efficacy in selective viral challenge models combined with screening of a variety of antiviral defense functions in infected animals in vitro provide reliable methods in demonstrating the potency of BRMs against viral infections.

Acute Disease↗