Rederivation of rat colonies seropositive for Bacillus piliformis and the subsequent screening for antibodies.

Latent infection of rats in a breeding colony with Bacillus piliformis detectable by antibodies to the agent in an immunofluorescence assay was eliminated by a combination of traditional rederivation techniques, using animal units not previously used for rat breeding, and the use of specific disinfection procedures. The success rate was apparently correlated with the use of peracetic acid instead of aldehyde products to decontaminate the animal unit.

Impact of bacteria on metabolism of collagen in colonic obstruction in rats.

The influence of bacteria on metabolism of collagen in the colonic wall under normal conditions and after obstruction was evaluated by using germ-free and conventionally bred rats. Under normal conditions, no differences in synthesis and content of collagen or tissue dry weight in the colonic wall were found between germ-free and conventionally bred rats. After obstruction, both groups reacted similarly with an equally increased collagen synthesis. The findings imply that bacteria do not play any major role in the regulation of collagen metabolism in the colonic wall, neither under normal conditions nor in the strained situation with colonic obstruction and fecal impaction.

Diagnosis and monitoring of pregnancy in mice: correlations between maternal weight, fetal and placental mass and the maternal serum levels of progesterone, pregnancy-associated murine protein-2 and alpha-fetoprotein.

Outbred Bom:NMRI mice were weighed daily for 18 days from observation of a vaginal plug. In a separate experiment, fetuses and placentae were weighed on each day of pregnancy. Pregnancy can be determined with 99% certainty on day 12 of gestation by the maternal body weight increase from day 1. The pregnancy-specific proteins alpha-fetoprotein (m-AFP) and pregnancy-associated murine protein-2 (PAMP-2), of fetal and placental origin respectively, were detectable on days 8 and 10 in the maternal circulation. Significant correlations were observed between m-AFP and fetal weight and PAMP-2 and placental weight. These markers may therefore be useful in the monitoring of fetal growth and placental growth respectively.

Pleural effusion disease in rabbits, clinical and post mortem observations.

In Denmark and probably in other countries as well, the infectious agent causing intercurrent death of rabbits by passages of Nichols pathogenic Treponema pallidum has been studied in rabbits in the absence of T. pallidum. This agent can be propagated in rabbits at intervals of 2 to 30 days and, depending on the interval between passages and the number of passages, the mortality may vary from zero to almost 70 per cent. Based on the post mortem findings in fatal cases, the name pleural effusion disease is suggested for this rabbit infection. Iridocyclitis, haematological and biochemical changes are signs of the disease not described previously. The source of the infectious agent is discussed.