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Biomedical subjects

L Bruckner

Publications and source records attributed to L Bruckner.

At least 19 recordsLinked to original sources
PubMed2006

Serological responses of adult dogs to revaccination against distemper, parvovirus and rabies.

Serum antibody titres to canine distemper virus (CDV), canine parvovirus (CPV) and rabies were measured in dogs that had not been revaccinated annually and compared with the titres in a control group of regularly vaccinated animals; 83 per cent (171 of 207) of the dogs vaccinated against CDV one or more years earlier had serum neutralising antibody titres equal to or greater than 16; 64 per cent (136 of 213) of the dogs vaccinated against CPV one or more years earlier had haemagglutination inhibiting titres equal to or greater than 80; and 59 per cent (46 of 78) of the dogs vaccinated against rabies two or more years earlier had serum neutralising antibody titres equal to or greater than 0.5 iu/ml. Three weeks after a single booster vaccination the dogs' antibody titres against CDV had increased above the threshold level in 94 per cent of the dogs, against CPV in 68 per cent, and against rabies in 100 per cent.

Animals↗
PubMed2006

DNA vaccines: safety aspect assessment and regulation.

For licensing purposes, besides the immunogenic aspects, deoxyribonucleic acid (DNA) vaccines present safety considerations that must be critically assessed during preclinical or/and clinical safety studies. The major concerns with regard to safety are integration of the plasmid DNA into the host genome, adverse immunopathological effects, the formation of anti-DNA antibodies resulting in auto-immune disease and the use of novel molecular adjuvants. Moreover, for veterinary vaccines intended to be used in husbandry animals, food safety aspects will become an important issue. All new vaccine candidates should therefore be thoroughly tested in target animals, keeping in mind that for food producing animals, the products will be consumed. Finally, a further safety aspect of interest concerns the possible spread of genetic material to the environment, by the potential transformation of the environmental microflora with only a few copies of complete or fragmented plasmid. These are issues that need to be considered in the final scientific decisions underpinning the registration of vaccines. Thus, to establish criteria for guidance and regulations for industry and licensing authorities, a project has been initiated to assess such risks of plasmid DNA vaccinations. Major emphasis will be placed on aspects such as the biodistribution of plasmid in vaccinated animals. This paper is intended as a contribution to the debate on the use of biotechnology in the future and should facilitate further discussions on the various safety aspects of DNA-based immunisations.

Legislation, Drug↗
PubMed2001

Qualitative assessment of the humoral immune status against FMDV in post-vaccination cattle.

Analyses on diluted sera would not measure the complete activity of the natural in-vivo serum environment used by humoral immune responses. Since these humoral defences must react rapidly, serum reactions occurring during 10 and 60 s were analysed. Primo- and multiple-vaccinated, efficiently responsive, and protected animals were differentiated. A variation in the responses, particularly the quality of response, of individual animals was also now discernible. The critical importance of antibody-antigen contact time was demonstrated, wherein natural immunoglobulins and non-immunoglobulin opsonins would influence specific antibody reactivity, through an increased avidity of reaction with antigen. Although not measured directly, the influence of the non-specific serum components would be manifest through increased specific antibody binding. By considering serum as an entity, analysis of all constituent components permits increased qualitative assessment of post-vaccination sera.

Age Factors↗
PubMed2001

The humoral immune response to recombinant nucleocapsid antigen of canine distemper virus in dogs vaccinated with attenuated distemper virus or DNA encoding the nucleocapsid of wild-type virus.

This study compared the humoral immune response against the nucleocapsid-(N) protein of canine distemper virus (CDV) of dogs vaccinated with a multivalent vaccine against parvo-, adeno-, and parainfluenza virus and leptospira combined with either the attenuated CDV Onderstepoort strain (n = 15) or an expression plasmid containing the N-gene of CDV (n = 30). The vaccinations were applied intramuscularly three times at 2-week intervals beginning at the age of 6 weeks. None of the pre-immune sera recognized the recombinant N-protein, confirming the lack of maternal antibodies at this age. Immunization with DNA vaccine for CDV resulted in positive serum N-specific IgG response. However, their IgG (and IgA) titres were lower than those of CDV-vaccinated dogs. Likewise, DNA-vaccinated dogs did not show an IgM peak. There was no increase in N-specific serum IgE titres in either group. Serum titres to the other multivalent vaccine components were similar in both groups.

Animals↗
PubMed2000

DNA vaccine encoding nucleocapsid and surface proteins of wild type canine distemper virus protects its natural host against distemper.

Canine distemper virus (CDV), a member of the genus Morbillivirus induces a highly infectious, frequently lethal disease in dogs and other carnivores. Current vaccines against canine distemper consisting of attenuated viruses have been in use for many years and have greatly reduced the incidence of distemper in the dog population. However, certain strains may not guarantee adequate protection and others can induce post vaccinal encephalitis. We tested a DNA vaccine for its ability to protect dogs, the natural host of CDV, against distemper. We constructed plasmids containing the nucleocapsid, the fusion, and the attachment protein genes of a virulent canine distemper virus strain. Mice inoculated with these plasmids developed humoral and cellular immune responses against CDV antigens. Dogs immunized with the expression plasmids developed virus-neutralizing antibodies. Significantly, vaccinated dogs were protected against challenge with virulent CDV, whereas unvaccinated animals succumbed to distemper.

Animals↗
PubMed2000

[Distribution of antigen types of canine parvovirus in Switzerland, Austria and Germany].

In this study the distribution of the various antigenic types of canine parvovirus in Switzerland, Austria, and Germany was investigated. From 14 samples from Switzerland, 35 samples from Austria, and 82 samples from Germany exclusively the new antigenic types CPV-2a and CPV-2b were isolated. Most of these isolates had a Ser-Val mutation at amino acid 297, which was shown to be prevalent in recent CPV isolates from various parts of the world. These findings are discussed with regard to the use of modified live virus vaccines.

Animals↗
PubMed1999

Use of polymerase chain reaction (PCR) for the detection of vaccine contamination by infectious laryngotracheitis virus.

Quality control of biologicals for veterinary use includes certification of freedom from extraneous agents. Contamination of vaccines may originate from various materials used for production and during manufacturing process. Requirements for avian virus vaccines to demonstrate freedom of adventitious agents are stated in the European Pharmacopoeia and include monitoring for infectious laryngotracheitis virus (ILTV). ILTV is an avian herpesvirus belonging to the alphaherpesvirus subfamily causing acute respiratory disease. To date the methods to detect ILTV contaminating biologicals consist of demonstration of antibody induction in chicken after immunization or virus cultivation in embryonated eggs. These methods are time consuming and laborious. Therefore, a specific, simple and sensitive in vitro polymerase chain reaction (PCR) for the detection of ILTV contamination in avian virus vaccines was developed. Primers were designed to amplify part of the p32 gene. Four different ILTV vaccine strains could be unequivocally detected. The identity of the amplified fragment was confirmed by restriction endonuclease analysis.

Animals↗
PubMed1999

[Molecular and immunodiagnostic studies of bovine neosporosis in Switzerland].

Cyst-forming coccidia may cause significant losses in livestock, primarily due to abortion, loss of young animals and neuromuscular diseases. Rather recently, Neospora caninum has been recognized as one of the major protozoal abortion-inducing parasites in cattle. The present study addressed the performance of different diagnostic tools (in vitro-cultivation; histology; immunohistochemistry; serology; PCR) suitable for the direct or indirect detection of N. caninum. By PCR, Neospora-DNA was detected in 24 brains (29%) from 83 bovine abortion, many of these brains were simultaneously characterized by histopathological findings typical for a protozoal, cerebral parasitosis. The diagnostic methods were furthermore assessed using samples of different tissues and body fluids from three experimentally Neospora-infected pregnant cows and their foetuses. The diaplacental passage of N. caninum to the foetus was successful in two of the three cases. In these two cases, PCR was positive for different foetal organs and, additionally, for the abomasal and amniotic fluid. The successfully infected cows developed anti-Neospora serum antibodies between 10 and 17 days post infection, foetuses remained serologically negative in all cases. The results obtained in the present study demonstrated the usefulness of PCR, complemented by serology, for the specific diagnosis of bovine neosporosis. Such tests may prove suitable to perform epidemiological investigations. Taken together, our data indicated that prenatal neosporosis may be an important cause of infectious bovine abortion in Switzerland.

Abortion, Veterinary↗
PubMed1997

Use of reverse transcriptase polymerase chain reaction for detection of vaccine contamination by avian leukosis virus.

A reverse transcriptase polymerase chain reaction (RT-PCR) for avian leukosis virus (ALV) was developed for the detection of contamination of vaccines produced in embryonated eggs and cell cultures derived from chicken. ALV is highly pathogenic and induces a wide spectrum of disease in infected animals. ALV can be divided into five subgroups (A-E). The envelope glycoprotein (env gp85) is the main antigen determinant and responsible for subgroup classification. Viral RNA of all subgroups (A-E) was isolated and amplified using three sets of primers. Subsequently, restriction endonuclease analysis confirmed the product identity and discriminated between subgroups. In specific pathogen free (SPF) eggs experimentally inoculated with ALV, viral RNA was found in allantoic fluids, as well as in vaccines spiked with different subgroups of ALV. No adventitious virus was detected in commercially available preparations. This system provides a rapid and specific in vitro method for the detection of ALV RNA as an extraneous agent and may be applied for quality control of avian vaccines.

Animals↗
PubMed1996

Detection of extraneous agents in vaccines using the polymerase chain reaction of Newcastle disease virus in poultry biologicals.

Reverse transcription-polymerase chain reaction (RT-PCR) in poultry vaccine was applied to the detection of Newcastle disease virus (NDV), using two primer pairs spanning the cleavage site of the FO fusion protein coding sequence. Amplification of a specific cDNA segment was possible from live and inactivated, oil-adjuvanted NDV vaccines without previous treatment. The RT-PCR was able to detect between 5 x 10(2) EID50 (in live vaccine preparations) and 10(5) EID(50) or 0.056 haemagglutinating units of NDV (in inactivated vaccine preparations). In addition, live vaccine preparations were inactivated with beta-propiolactone (beta-PL). Amplified cDNA was obtained after treatment with 0.1% beta-PL, whereas at a concentration of 1% or 10% no specific bands were visible in the agarose gel. These results demonstrate the applicability of the method for the control of poultry vaccines by ensuring the absence of extraneous agents.

Animal Testing Alternatives↗
PubMed1995

Detection of Newcastle disease virus in poultry vaccines using the polymerase chain reaction and direct sequencing of amplified cDNA.

In order to develop an in vitro method for the control of poultry vaccines for identity and the absence of extraneous agents, reverse transcription-polymerase chain reaction (RT-PCR) was applied for the detection of Newcastle disease virus (NDV). NDV vaccines were employed for the establishment of the method, using two primer pairs spanning the cleavage site of the F0 fusion protein coding sequence. Amplification of a specific cDNA segment was possible from live and inactivated, oil-adjuvanted NDV vaccines without prior treatment. The cDNA was characterized by restriction endonuclease digestion as well as by direct nucleotide sequencing. The RT-PCR was able to detect between 5 x 10(2) EID50 (in live vaccine preparations) and 10(5) EID50 or 0.056 haemagglutinating units of NDV (in inactivated vaccine preparations). In addition, live vaccine preparations were inactivated with beta-propiolactone (beta-PL). Amplified cDNA was obtained after treatment with 0.1% beta-PL, whereas at a concentration of 1% or 10% no specific bands were visible in the agarose gel. These results demonstrate the applicability of the method for the control of poultry vaccines for identity and for the absence of extraneous agents, and additionally allow a rapid characterization of the respective NDV strain.

Animals↗
PubMed1992

Relationship between the anti-FMD virus antibody reaction as measured by different assays, and protection in vivo against challenge infection.

The antibody response of cattle after vaccination against foot-and-mouth disease (FMD) virus was monitored using the serum neutralization test (SNT), the sandwich ELISA, liquid-phase ELISA, sandwich competition ELISA, liquid-phase competition ELISA, and the liquid-phase sandwich competition (blocking) ELISA. The competition ELISAs (in particular the "blocking" ELISA) were the most effective at detecting reactivity in these cattle sera. However, 95% of negative sera also competed in the most sensitive ELISA (the "blocking" ELISA) to titres of 1:32 (4% of the sera competed to a titre of 1:128). Comparisons between the different ELISAs, and between these ELISAs and the SNT, demonstrated that the tests were not measuring exactly the same reaction of antibody with FMD virus. With respect to the capacity of animals to resist FMD virus challenge, neither the SNT nor the competition ELISAs were consistently able to identify such animals. The anti-FMD virus antibody titres obtained could be classified into three zones; the "white zone" wherein antibody titres were high and donor animals likely to be protected; the "black zone" wherein antibody titres were low and donor animals likely to be susceptible to infection; the "grey zone" wherein the antibody titres were intermediary and no interpretation could be made with respect to protection. Assays such as ELISA and SNT cannot and do not measure immunological protection; they are a measure of antibody responses and nothing more, and should be interpreted in terms of the "three zone" phenomenon.

Animals↗
PubMed1992

[Recurrent eyelid tumor in necrotizing panniculitis].

To our knowledge, necrotizing lid tumors occurring in the context of a necrotizing lobular panniculitis have not yet been described in the literature. Our patient, a 75-year-old male, presented with indolent, nonmoveable subcutaneous lumps that were centrally ulcerating. They appeared first on his upper lid, then on his lower lid and thereafter on the neck, back, upper extremity and abdomen, especially in the area of his cholecystectomy scar. A thorough work-up, which included repeated histopathological examinations performed by several laboratories, led to the diagnosis of an idiopathic necrotizing lobular panniculitis. A serum level determination performed later revealed no alpha 1-antitrypsin deficiency. As the eye-lid's subcutaneous tissue lacks fat, the association between the necrotizing lid tumors and the necrotizing panniculitis appears to be a paradox. In spite of the normal alpha 1-antitrypsin serum levels--determined when the patient's lesions had long ago healed--we think in retrospect that the differential diagnosis should have included the possibility of a decreased alpha 1-antitrypsin serum level (e.g. heterozygous MZ-phenotype). An alpha 1-antitrypsin level deficiency--with resulting decreased inhibition of collagenase and elastase--could account for the necrotizing process that also occurred in the eyelid's subcutaneous tissue. In the Van Gieson stain of this patient's eyelid biopsy, fragmentation of all visible collagen and elastic fibers was noted. In our opinion, the differential diagnosis does include lid involvement with secondary panniculitis caused by partially decreased alpha 1-antitrypsin serum levels and--by exclusion--idiopathic necrotizing lobular panniculitis. Therapeutic possibilities are briefly discussed.

Aged↗
PubMed1990

Eradication of infectious bovine rhinotracheitis in Switzerland: review and prospects.

Ten years after the first outbreak of infectious bovine rhinotracheitis (IBR) in Swiss dairy cows, the national cattle herd is almost free from infection with IBR virus (bovine herpesvirus 1, BHV 1). The national programme for the eradication of IBR was divided into four phases: (1) Prevention of transmission of the infection by restrictions on trade of bovines and assessment of the prevalence of cattle with antibodies to BHV 1. (2) Slaughtering animals with antibodies to BHV 1 in order to eradicate BHV 1 from breeding herds. (3) Detection and eradication of further BHV 1 reservoirs (e.g. fattening cattle). (4) Monitoring programme and legal actions in order to maintain the favourable situation. Approximately 50,000 animals were slaughtered in the course of the eradication of IBR. The total costs amounted to approximately SFr. 110,000,000 over 10 years. The costs for maintaining the situation are estimated at approximately SFr. 5,000,000 per annum.

Animals↗
PubMed1989

Effect of strain differences on the potency testing of rabies vaccines in mice.

Antigenic differences between several strains of rabies virus, namely CVS, SAD and Flury (LEP) strains, were studied in cross-challenge experiments or cross-neutralization tests performed on sera of mice immunized with vaccines containing each strain. A typical wild fox virus strain was also included as challenge virus. The strain differences affected the relative potencies of the three vaccines in the European Pharmacopoeia mouse protection test for veterinary rabies vaccines, in that higher antigenic values were obtained when the vaccine strain was homologous to the challenge virus. This observation was confirmed by neutralizing antibody induction in mice.

Animals↗
PubMed1989

Antibodies to foot-and-mouth disease virus infection associated (VIA) antigen: use of a bioengineered VIA protein as antigen in an ELISA.

An enzyme-linked immunosorbent assay (ELISA) to detect antibodies to foot-and-mouth disease (FMD) virus infection associated (VIA) antigen (viral RNA polymerase) in cattle sera, was developed using a bioengineered VIA (BioVIA) protein antigen. Compared with the classical immunodiffusion test, with viral RNA polymerase purified from infected cell cultures as antigen, this ELISA was more sensitive. However, depending on the cattle population examined, sera with antibodies to viral RNA polymerase, probably due to infection with other picornaviruses, were detected. Despite these observations, the ELISA using BioVIA provided a rapid answer as to whether or not FMD virus circulated in a given herd of cattle. The main advantage of this ELISA is its absolute safety, since in no step of the antigen production was infectious or uninfectious FMD virus involved. The test can therefore be performed under normal laboratory conditions and no isolation units are needed as they are for the immunodiffusion test.

Animals↗
PubMed1989

[Serologic and virologic studies of selected cattle with antibodies to bovine herpesviruses].

In order to investigate the specificity of low titer antibodies to BHV 1, twelve cattle were subjected to stress and dexamethasone treatment. They were monitored virologically by inoculating cell cultures with naso-pharyngeal-, ocular- and vaginal- or preputial swabs and serologically by assessing the prevalence and incidence of antibodies to bovine, caprine-, porcine-, and equine herpesviruses and to bovine leukemia virus. Antibodies were classified as specific for BHV 1 if the animals excreted IBR virus, or if the antibodies neutralized BHV 1 and reacted with BHV 1 antigens, or if they reacted additionally with CapHV antigens. Animals whose sera recognized BHV 1 and BHV 2 but not other herpesviruses, were judged to have experienced both infections. Nine of the twelve animals had specific BHV 1 antibodies. With three animals the question for specificity of their antibodies remains open. Two animals experienced several herpesvirus infections. Therefore, the induction of crossreacting antibodies, directed against epitopes common to herpesviruses, could not be ruled out. The sera of one animal reacted with BHV 1 and BHV 4 antigens in ELISA tests. They did, however, not neutralize BHV 1.

Animals↗