[Plasma amino acid concentrations in aggressive dogs].

Following the hypothesis that metabolic screens may be useful tools in the diagnosis of canine aggression we have investigated the blood plasma amino acid levels of dogs which have been found aggressive (N = 10) against dogs or men in comparison to non-aggressive dogs (N = 10). In summary, the aggressive dogs showed elevated plasma concentrations of the neurophysiological active aromatic amino acids tryptophan (46/171 micromol/l, p < 0,001), tyrosine (38/67 micromol/l, p < 0.01) and histidine (74/91 micromol/l, p < 0.

[Zinc metabolism--a factor in canine aggression?].

In order to test the hypothesis of zinc-deficiency as a factor in canine aggression, we examined sera of dangerously aggressive dogs and of behaviourally normal (non-aggressive) dogs for their zinc-contents. The results showed distinctly higher zinc-concentrations (mean +/- SD) in aggressive dogs (1.69 +/- 0.

Development of a special catheterbag to enable artificial organ evaluation in conscious, unrestrained pigs: technical note.

Pigs are widely used as models for a variety of human diseases, because many of their physiological functions closely resemble those of humans. However, information on instrumentation techniques is still scarce. In particular, experiments in conscious pigs focused on extracorporeal circuits are connected to a variety of methodical problems with respect to the handling of the animals.

Dose dependency of fermentation and the extent of renal excretion of palatinit (isomalt) in rats with respect to its energy value.

The impact of dose-dependent caloric salvage by microbial fermentation processes in the lower gut and the extent of renal excretion for the overall energetic availability of the alternative bulk sweetener Palatinit were investigated in rats. To evaluate the extent of dose-dependent fermentation a conventional and a germ-free rat model were used and fecal excretions of Palatinit after intragastric application were compared. Because of the lack of bacterial colonization in the gastrointestinal tract in germ-free rat the difference in fecal excretion of Palatinit between germ-free and conventional rat is mainly due to bacterial fermentation.

A method for estimating the available energy of incompletely digested carbohydrates in rats.

We developed a method to estimate the available energy from carbohydrates that are unavailable or partially unavailable through direct digestion and absorption. Radiolabeled bacterial and plant cellulose and polydextrose were administered orally to germfree and conventional rats. Label in breath, feces, intestinal contents and carcass were determined with excellent total recovery of the administered label.

Prevention of catheter-related infections by a new, catheter-restricted antibiotic filling technique.

Catheter-related infections pose a hazard to both humans and laboratory animals. The aim of this study was to develop a technique preventing bacterial colonization of intravascular catheters. In 27 dogs a total of 70 catheters were implanted.

[A simple method for 14CO2 measurement in metabolic experiments].

The determination of the fate of a compound following administration can be performed using the disposition method with 14C-labeled substances, which also allow the measurement of metabolism with CO2 as an expired end product. To substitute the laborious CO2-collection in washing bottles as carbonate a simple instrumentation was built for continuous 14CO2-measurement. The air from the metabolic cage is led in thin layer through a chamber fitted to a foot-monitor, the output of which is online for computation.

[Modification of the teratogenesis of actinomycin D and cyclophosphamide by a Mycoplasma pulmonis infection in rats].

In the present investigation experiments have been made on the modification of the teratogenesis by a Mycoplasma pulmonis infection in rats. Substances with known teratogenic effects (Actinomycin D, Cyclophosphamide) were used. Groups of artificially infected pregnant rats were compared with pregnant rats from the SPF unit.

[Leukocyte agglutination test for the determination of microbial burden].

Transfer of laboratory animals from the breeder to the experimental unit includes in most cases a change of the microbial environment even under SPF-conditions. Many experimental treatments may also disturb the balance between host and microbial load and provoke infections. With the aim to detect such undesired effects in the course of the experiment the suitability of the leukergy test was investigated.

[Metabolism of 14C-labeled urea in conventional and bacteria-free guinea pigs].

This report deals with the utilization of 14C-labeled urea in antibiotically decontaminated, bacteria-free guinea pigs using intragastric resp. intraperitoneal administration route. With conventional animals 52% of the intragastrically administered 14C dose can be demonstrated in the exhaled air, 1.

Intestinal accumulation of urea in germ-free animals--a factor in caecal enlargement.

To examine the connection between caecal size and urea concentration in the caecal contents urease inhibition was tested in conventional animals and urea and urease were administered to germ-free rats and mice. Administration of alloxan and barbituric acid and immunization with urease led to slightly larger caeca in conventional animals. Neomycin treatment caused a clear enlargement of the caecum.

[Sterilization of drinking water using peracetic acid].

The efficiency of peracetic acid on drinking-water conservation and sterilization was investigated. It was determined in watering experiments that a starting concentration of 0.01-0.