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B C Kruijt

Publications and source records attributed to B C Kruijt.

11 recordsLinked to original sources
PubMed1992

Comparative evaluation of the immune status of congenitally athymic and euthymic rat strains bred and maintained at different institutes: 1. Euthymic rats.

We performed a comparative evaluation of the immune status, focused on the T-cell system, of euthymic rat strains in which the nude mutation had been introduced. From 10 institutes, we sampled 12 groups of euthymic rats at ages of 1 1/2-2 months and 1/2 year. We analyzed weight of body, spleen and thymus; antibody response and delayed-type hypersensitivity response to ovalbumin immunization; and (immuno)histopathology of spleen, lymph nodes, and lymphoid tissue along the gastrointestinal tract. In the spleen morphometric analysis was done of the periarteriolar lymphocyte sheath (using the antibody R73 recognizing the alpha beta-T-cell receptor) and of the red pulp (using the antibody ED2 recognizing red pulp macrophages). For almost all parameters tested, statistically significant differences between the groups (origin of the animals) were observed. A cluster analysis on the basis of body weight, spleen weight, and morphometric data of spleen did not yield clusters with a different composition among animals from individual groups. Based on the antibody response to ovalbumin, clustering revealed groups of "fast-and-high", "slow-and-low", and "intermediate" responders. The various groups differed in location within these clusters, i.e. the speed and extent of the immune response depends on the background euthymic strain. Considering the microbiological status assessed by serology, a variation was found both in post-infection state at entrance in the study, and in primo-infection associated with a rise in antibody concentrations during the study. These states showed no negative effect on anti-ovalbumin reactivity. Rather, the response in primo-infection to Rat Corona Virus, Sendai Virus, and Pneumonia Virus of Mice was the highest in animals clustered as "fast-and high" responders to ovalbumin.

Animals↗
PubMed1992

Comparative evaluation of the immune status of congenitally athymic and euthymic rat strains bred and maintained at different institutes: 2. Athymic rats.

We performed a comparative evaluation of the immune status, focused on the T-cell system, in congenitally athymic rat strains. From 11 institutes around the world, we sampled 15 groups of animals at ages of 1 1/2-2 months and 1/2 year. The analysis included weight of body and spleen; antibody response and delayed-type hypersensitivity response after immunization with ovalbumin; and (immuno)histology of spleen, lymph nodes and lymphoid tissue along the gastrointestinal tract. Morphometric analysis was done for alpha beta-T-cell receptor-bearing cells in spleen tissue as a measure of the periarteriolar lymphocyte sheath; it was also done for splenic red pulp using the antibody ED2 recognizing red pulp macrophages. For almost all variables analyzed, statistically significant differences between the groups were observed. The extent of alpha beta-T-cell receptor-bearing cells in the spleen increased with age. The functioning of these cells in immunological responses can be questioned, because an immune response to ovalbumin was invariably absent. But secondary follicles with germinal centers, reflecting T-cell-dependent B-cell reactivity, were observed in lymph nodes and Peyer's patches (up to 40% and 75%, respectively, depending on the group), with a higher prevalence in older animals. A cluster analysis on the basis of body and spleen weight and composition of spleen compartments did not yield clusters with a different profile in regard to the animals' group of origin. The data presented are useful when comparing studies performed with various athymic rat strains at different institutes.

Animals↗
PubMed1989

The 'normalization' of germ-free guineapigs with host-specific caecal microflora.

Hysterectomy-derived germ-free guineapigs were given colonization-resistant caecal flora from mice (mCRF) or microflora obtained from the caecum of an antibiotic-decontaminated conventional guineapig (gpCRF) and compared with guineapigs raised conventionally with the sow. Body weight and the following intestinal parameters were determined for the groups: colonization resistance (CR) to Escherichia coli, relative caecal weight (RCW), beta-aspartylglycine (faeces), volatile fatty acids (caecum) and bile acids (faeces). mCRF guineapigs showed values quite different from control animals for CR and RCW, indicating the unsuitability of mouse CRF for normalizing guineapigs. In gpCRF guineapigs CR and RCW values were comparable with controls, indicating the suitability of the guineapig flora for normalizing guineapigs. mCRF guineapigs housed with gpCRF guineapigs, showed an improvement in CR and RCW, yielding values found in control animals.

Animals↗
PubMed1985

The 'normalization' of germ-free rabbits with host-specific caecal microflora.

Hysterectomy-derived germ-free rabbits were given colonization-resistant caecal flora (CRF) from mice, or microflora obtained from the caecum of an antibiotic-decontaminated conventional rabbit and compared with rabbits conventionally raised with the doe. Bodyweight and the following intestinal parameters were determined for the 3 groups: colonization resistance to E. coli, relative caecal weight, villus:crypt ratio (ileum), beta-aspartylglycine (faeces), volatile fatty acids (caecum), and bile acids (faeces). Germ-free rabbits given mouse CRF-flora showed values quite different from control animals for most parameters, indicating unsuitability of mouse CRF flora to 'normalize' rabbits. In germ-free rabbits given modified (antibiotic-treated) rabbit flora, values for most parameters were intermediate between those found for the other 2 groups. This species-specific caecal flora should be improved to provide full 'normalization' of germ-free rabbits.

Animals↗
PubMed1981

Breeding of Macaca fascicularis for poliovaccine production.

In our Institute Cynomolgus monkeys (M. fascicularis) are mainly used for production and control of poliovaccine. In 1974 a small individual breeding colony was started. Last year the colony was enlarged with 10 harem groups. Based on colony reproduction data, group breeding seems more successful than individual breeding. Owing to developments in the production of poliovaccine, a state of total self supply is within reach. However attention must be paid to factors reducing breeding results, comprising aggressive interactions and disturbed mother-care. Finally replacement of breeding stock might require rearing conditions which are not compatible with those necessary for the establishment of a Foamy virus and Herpes-B virus breeding colony.

Animals↗
PubMed1980

Use of captive-bred monkeys for vaccine production.

Cynomolgus monkeys (Macaca fasicularis) were bred in captivity for the production and control of inactivated poliomyelitis vaccine. Compared to imported wild-caught animals the captive-bred monkeys contracted fewer virus infections, as evidenced by results of serological examination, and yielded remarkably clean cell cultures. These cultures could be grown in series and appear very suitable for the production of viral vaccines.

Animals↗
PubMed1976

[Veterinarians and experimental animals - duties and rights (author's transl)].

Well over one million warm-blooded experimental animals are used in the Netherlands every year. The community is socially responsible for the purposes of research. The team of investigators is responsible for the scientific and technical merits of the experimental study, and this responsibility is based on the special knowledge and skill of those concerned. The future Laboratory Animal Act will not be able to ensure "the rights of animals" by rigid rules. The Act is effective in that it: (a) affords guarantees that experts (including veterinarians having expert knowledge of the care and management of laboratory animals, veterinary inspectors and animal technicians) will assist at experiments on animals and, (b) will make available that data of laboratory animals and types of experiment, which is essential to the proper functioning of social responsibility. The veterinarian having expert knowledge of the care and management of laboratory animals should take steps to ensure that the stress to which animals are exposed in experimental studies is not in excess of the value of the experiment. His attention should therefore be directed to the health and uniformity of the experimental animals, the methods adopted in experimental procedures, the training of animal technicians and medical or biological students, instruction of intending research workers, providing literature on experimental animals and normal values, advice on experimental designs and the choice of an animal model.

Animals↗
PubMed1976

Enteritis in a conventional rabbit colony.

Necrotic typhlitis, often accompanied with necrotic liver foci, was frequently observed in a conventional rabbit colony during the years 1965-1969. Although different serotypes of Escherichia coli could be cultured from the diseased caeca, many cases occurred from which no Escherichia coli could be isolated. Assuming that the disease might be bacteriological in origin, tetracycline was administered, and mortality decreased. The prevalence of tetracycline-resistant Escherichia coli strains makes application of an alternative therapy desirable.

Animals↗