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J P Koopman

Publications and source records attributed to J P Koopman.

At least 73 records · Page 4Linked to original sources
PubMed1983

Some aspects of the gastrointestinal microflora of germfree mice associated with cultured microfloras.

Attempts are described to 'normalize' germfree mice by association with 3, 21 and 71 different intestinal bacterial cultures isolated from mice with an SPF flora. Germfree mice associated naturally with an SPF flora served as controls. Vital bacterial counts were determined by aerobic and anaerobic culture. Stomach and small intestine contained fewer bacteria per gram than caecum and large intestine. Aerobic vital counts from caecum and large intestine were higher in the experimental groups than in control mice. The aerobic and anaerobic flora in stomach and small intestine comprised mainly Gram-positive non-fusiform shaped rods. In the caecum and colon Gram-positive cocci predominated in the aerobic culture while in the anaerobic culture fusiform-shaped rods were prominent. Scanning electron microscopy of oesophagus, ileum, caecum and faeces demonstrated colonization of the oesophageal epithelium only after association with 71 bacterial strains; the filamentous bacteria present in the ileum of SPF mice were not found in the experimental groups and caecum and faeces contained mainly fusiform-shaped bacteria. Non-bacterial matter decreased in the caecum and faeces with increase in the complexity of the flora.

Aerobiosis↗
PubMed1982

[Animal models (author's transl)].

Animal models are frequently used in medico-biological studies. The why and wherefore of animal models, the question of the requirements which have to be satisfied by an animal model, the pros and cons of animal models, the question of alternatives, the types of animal models available, the choice that has to be made and the manner in which an animal model is used, are discussed in succession. In addition, the animal models and techniques in use in the Central Animal Laboratory of the University of Nijmegen are reviewed.

Animals↗
PubMed1982

Association of germfree mice with intestinal microfloras obtained from "normal" mice.

A cultured microflora obtained from the caecum of a "normal" mouse was given to 4 groups of germfree mice and was supplied 1x, 2x, 3x and 4x respectively at 5-day intervals. Another group received a 10(-7) dilution of the caecal flora while a group associated with an 'SPF' flora served as control. The difference (measured by 8 parameters) between mice supplied with the cultured flora or with a 10(-7) dilution, both given once only, was small. Supplying the flora 3x resulted in more 'normal' mice compared with mice which received the flora once or twice. The caeca of specified-pathogen-free mice contained more bacteria per gram (microscopic bacterial count), less aerobic and anaerobic bacteria per gram (viable counts), while the yield as percentage of the microscopic bacterial count was lower as compared with the group to which a cultured flora was supplied 4 times.

Animals↗
PubMed1982

The influence of media on the recovery of bacteria from the normal mouse caecum.

3 diluting fluids and 6 agar media were compared for the culture of caecal microflora of mice. The efficiency of the media in the growth of caecal bacteria was determined by comparing the quantitative recovery (expressed as percentage of the total microscopic count) from the specimens. Of the diluting fluids saline resulted in a low yield (11.47%). Addition of potassium salts increased the yield (23.25%). A broth medium resulted in the highest recovery (44.44%). The influence of storing the caecal microflora in 3 different diluting fluids on the yield was studied. In all diluents the viable count of caecal bacteria decreased with time, but did so least in broth medium. 6 solid agar media were tested. When saline was used as the diluting fluid, no significant differences in yields were found with all 6 media. When broth medium was used as diluting fluid and yields up to 60% were obtained, no significant differences were shown between the results with 5 media but one medium resulted in a lower yield (32.59%).

Anaerobiosis↗
PubMed1981

[Intestinal flora of mice (author's transl)].

The literature on the build-up of the intestinal flora of mice in the course of time is reviewed. The intestine of the germ-free animal is colonized by large numbers of bacteria as rapidly as within a few days after birth. The ingestion of solid food and weaning are found to be times at which new species appear and others diminish. In addition, the relationship between microflora and host is discussed. Three types of relationship are described. The morphological forms present at various sites in the intestine are illustrated on the basis of personal scanning electron-microscopy. Finally, the effects of the presence of the intestinal flora on the host are briefly discussed.

Animals↗
PubMed1980

Biochemical effects on germ-free mice of association with several strains of anaerobic bacteria.

The effects of the following changes throughout the association of germ-free mice with increasing numbers of anaerobic bacteria were studied: (i) elution patterns obtained by gel-filtration chromatography of caecal diffusates; (ii) concentration of beta-aspartylglycine in caecal and faecal contents; (iii) polypeptide patterns obtained by sodium dodecyl sulphate-polyacrylamide gel electrophoresis of caecal supernatants; (iv) free amino acid content of caecal supernatants; (v) faecal bile acids, analysed by gas-liquid chromatography; (vi) colonization-resistance. The results indicate that monitoring the normalization (association) process can be accomplished in several ways, but the level of colonization-resistance is most easily measured by high-voltage paper electrophoresis of faecal supernatants to determine the concentration of beta-aspartylglycine. During association, the concentration of beta-aspartylglycine decreased and became undetectable after association with 40 to 50 different strains of bacteria. There was a good negative correlation between the level of colonization-resistance and the concentration of beta-aspartylglycine.

Amino Acids↗