[The laboratory animal - measuring device and/or fellow-creature?]. / Das Versuchstier - Messinstrument und/oder Mitgeschöpf?

The Animal Protection Law is oriented anthropocentrically and is trying to preserve human interests in animal utilisation, as well as doing justice to the indisputable responsibility towards the animals. The law is using the term "fellow-creature" but at the same time, it is regulating the objectification and exploitation of the animals. Both views can be derived largely from the Judeo-Christian tradition in the West. Today, the ambivalent attitude towards animals has reached extreme proportions. Large numbers of animals are being valued as man's companion or even as members of the family and, at the same time, are being utilised on a massive scale as industrial products or instruments of research. The conflicts arising out of this ambiguous contact with animals are being dealt with by those concerned, scientists in animal experimentation or animal keepers, in various ways. They are developing individual strategies and, in this, are being supported by the animal protection legislation. The question remains if true fellowship between humans and animals wouldn't be - finally - more beneficial and salutary for mankind, even if animal exploitation certainly has some advantage.

Survival and transmissibility of Pasteurella pneumotropica.

Survival has been determined for Pasteurella pneumotropica on various surfaces found in an animal room at 23+/-1 degrees C and 50+/-10% relative humidity. Longest survival (120 min) was found on mouse hair, shortest (< 30 min) on laboratory coat fabric. Transmission experiments were performed using sentinel animals in order to evaluate the efficiency of their use for the detection of P. pneumotropica in quarantined mice. In sentinels exposed to infected mice by close contact, P. pneumotropica was detected by culture 2 weeks post-exposure and seroconversion 3 weeks after contact. Transfer of soiled bedding from Pasteurella-infected mice did not infect sentinels within a period of 12 weeks as tested by cultivation or serum antibodies.

[The Great Ape Project--human rights for the great anthropoid apes]. / The Great Ape Project--Menschenrechte für die Grobetaen Menschenaffen.

The Great Ape Project (GAP) is an appeal of 36 scientist from different disciplines aiming at the legal equalisation of the non-human great apes (chimpanzees, gorillas and orang-utans) with man. The appeal is expressed by a number of essays stating zoological, genetical, ethological, anthropological, ethical and psychological knowledge and, based on these arguments, demanding the abolition of the species barrier between human beings and great apes. The central point of the initiative is the "Declaration on Great Apes", claiming the inclusion of great apes in the "community of equals" and thus securing three basic rights for all great apes: 1. The Right of Life; 2. The Protection of Individual Liberty; 3. The Prohibition of Torture. Not only experiments with great apes and their capture from the wilderness will be banned, but it is also intended to enfranchise as many great apes as possible from research laboratories and zoos. As a legal basis for the achievement of basic rights most of the authors plead for the idea of conferring the moral status of "persons" on great apes. Criticism of the GAP is due to its anthropocentrism. Rejection is especially expressed by advocates of pathocentric ethics who argue that the species barrier will not be abolished but only shifted, running then between the great apes and the remaining living beings. However, the GAP resulted in a greater retention in the use of great apes for experiments in several industrial countries. Additionally, the popular literature published by ethologists in the passed decades has supported a more responsible attitude of the public towards primates. Despite of all efforts the survival of the great apes is greatly endangered within their native countries.

Notes on technical progress in veterinary public health.

Scientific and technical progress in the field of veterinary public health (VPH) over the last one hundred years has contributed to the protection of consumer health and the environment. This report presents examples of the success achieved in the control of epizootics of tuberculosis, brucellosis, rabies and trichinellosis, which are also zoonotic diseases. The discussion also considers hygiene measures in relation to Listeria in food as well as certain challenges resulting from the spread of latent infections among farm animals. The increasing incidence of Salmonella infections among humans is also considered. Other important VPH tasks include the control of chemical residues of varying origin and of toxic biological substances in foods. Examples are also presented of measures taken and problems which arise in connexion with ensuring that meat is produced under hygienic conditions (meat inspection). The principles involved in efficient controls of establishments and products are outlined. Technical progress in consumer protection is exemplified by the processes of pasteurisation, cooling and freezing, and the limitation of additives. Other important tasks arise in the disposal of animal carcasses and wastes, and in the fields of animal welfare and genetic engineering. Future activities in VPH will depend upon proper education, onward and postgraduate training for veterinarians, and suitable infrastructures for research, examination and surveillance.

A cage for the ferret.

A cage for ferrets is described that consists of a plastic box with a metal sliding-grill top and metal front lattice. It contains a new feeding system using dishes that can be removed without opening the cage. The cages are kept in mobile racks and are commercially available.

Production of timed pregnant mice by utilization of the Whitten effect and a simple cage system.

Pregnant female mice with an impregnation time of 4 hours were achieved by utilizing the Whitten effect and a simple caging system. The cage consisted of a mobile wire-lattice which divided a plastic cage into two compartments to separate the females from the male but still allowed some contact. A synchronization time of 72 hours succeeded in an average copulation rate of 28.1 +/- 5.39% when the procedure was conducted in the forenoon.

Comparative studies on isolated rat hepatocytes and AS-30D hepatoma cells with leucocidin from Pseudomonas aeruginosa.

Leucocidin, one of the cytotoxic principles of Pseudomonas aeruginosa induces potassium loss and swelling in isolated hepatocytes and in AS-30D ascites hepatoma cells in a dose and time dependent manner. Hepatoma cells are more sensitive than normal hepatocytes. As shown by scanning electron microscopy the volume increase of both types of cells is accompanied by disappearance of microvilli. In contrast to phalloidin poisoning no protrusions were formed when the cells were exposed to leucocidin under isotonic conditions.

Cardiovascular reactions induced by leucocidin from Pseudomonas aeruginosa.

Leucocidin from Pseudomonas aeruginosa causes cardiovascular failure in rats and mice. The time between i.v. injection and death depends on the dose. After injection of high doses (500 mug/kg) the arterial blood pressure decreases rapidly and cardiac irregularities and AV block occur within about 5 min. In contrast to endotoxin shock no pulmonary hypertension was observed, whereas portal hypertension was seen in our experiments. Injection of lower doses (less than 200 mug/kg) caused peripheral vascular damage with lung oedema, vascular disturbances in various tissues, exudation and bleeding. Finally cardiac insufficiency predominated. Dexamethasone delayed the symptoms but did not prevent death in either rats or mice. Heparin was ineffective in this type of shock.

Interaction of purified leukocidin from Pseudomonas aeruginosa with Bovine polymorphonuclear leukocytes.

The interaction of purified leukocidin from Pseudomonas aeruginosa, strain 158, with polymorphonuclear leukocytes of cattle (PMLC) was studied by using 125I-labeled toxin. According to the Scatchard plot, PMLC offered two binding sites for leukocidin: one at the surface of the plasma membrane, and a second one that presumably became accessible to the toxin in the course of the cytotoxic action. Toxin once fixed to PMLC at 37 C could not be detached from the cells by either chemical or mechanical treatment. However, active leukocidin was liberated if it was bound to PMLC at 4 C and the temperature of the cell suspension was subsequently increased to 37 C. In the presence of Ca2+, the velocity of toxin fixation was accelerated and the rate of fixation was increased. Preliminary investigations on the identification of the leukocidin-binding material indicated the leukocidin receptor to be an integral protein of the plasma membrane.

Purification and characterization of leucocidin from Pseudomonas aeruginosa.

Leucocidin from Pseudomonas aeruginosa strain 158 was released from bacteria by autolysis and purified 19-fold by ammonium sulphate precipitation (20% saturation) and combined 'tandem' gel filtration on Sephadex G-100 superfine and Bio Gel P-100. The product gave a single band (mol. wt. 27000) after poly-acrylamide gel electrophoresis with sodium dodecyl sulphate (SDS). However, it was separated into two active peaks (pI 5-0 and 5-2) by isoelectric focusing, and into five bands by disc electrophoresis without SDS. All bands contained leucocidic activity of about the same specific activity and retained their homogeneity. The purified toxin was thermolabile and was inactivated by pronase, but not by several other proteases. The ultraviolet light absorbancy was typical of proteins. Antibodies directed against leucocidin were detected by passive haemagglutination and by toxin-neutralization. These antibodies inhibited the cytotoxic action of leucocidin bound to granulocytes. The toxin damaged all tested leucocytes (granulocytes of various animal species and lymphocytes of humans) and a number of tissue cultures, but was ineffective against erythrocytes, thrombocytes and isolated granules from polymorphonuclear leucocytes. The intravenous lethal dose for mice was about 1 mug.

The cytotoxic action of leucocidan from Pseudomonas aeruginosa on human polymorphonuclear leucocytes.

Human polymorphonuclear leucocytes treated in vitro with leucocidin from Pseudomonas aeruginosa underwent characteristic morphological alterations as shown by phase-contrast and scanning electron microscopy. Within a few minutes of exposure to leucocidin the granulocytes became round, and protoplasmic extrusions appeared on the cell membrane, were withdrawn again and put out at another point of the cell. The final stage of the leucocidin-treated leucocyte was an enlarged, rounded vesicle with apparently intact plasma membrane. Omission of calcium ions from the diluting buffer caused certain differences in the morphologic appearance of the damaged leucocytes.

Formation and isolation of leucocidin from Pseudomonas aeruginosa.

A toxic substance, which destroyed leucocytes from man but was inactive against erythrocytes, was demonstrated in cultures of four out of 110 strains of Pseudomonas aeruginosa tested. The toxin, designated 'leucocidin', was cell-bound as a precursor toxin, exhibiting little or no toxicity. It was converted into toxin with maximum activity by various proteases including an endogenous elastase. The production of leucocidin was directly proportional to the number of bacteria and was not influenced by variations in media, iron concentration, pH or temperature. The best method for large-scale production of leucocidin was autolysis of washed bacteria.

Cytotoxic effects of leukocidin from Pseudomonas aeruginosa on polymorphonuclear leukocytes from cattle.

The cytotoxic action of leukocidin from Pseudomonas aeruginosa was studied in vitro by following the release of various intracellular markers from polymorphonuclear leukocytes from cattle (PMLC). Low-molecular markers (K+, 86Rb+, glucose) were lost from PMLC within 1 to 2 min after the addition of leukocytes. The release of high-molecular-weight indicators (51Cr, bound to intracellular protein; lactate dehydrogenase) occurred only after swelling of the cells, leading to an increased permeability of the plasma membrane. Calcium ions stimulated the leakage of granule enzymes but retarded or inhibited the release of cytoplasmic markers. At 4 C, leukocytes were unaffected by the toxin. Leukocidin, bound at 4 C to leukocytes and treated with antiserum against leukocidin, did not damage the cells upon increasing the incubation temperature to 37 C.

Leucocidin from Pseudomonas aeruginosa and membrane functions.

Leucocidin from Pseudomonas aeruginosa (strain 158) induced loss of potassium from isolated hepatocytes. The (Na+-K+) stimulated ATPase activity of isolated rat liver plasma membranes showed dose-dependent activation up to 56%. Electron-spin-resonance (ESR) measurements gave no indication of toxin-induced changes in membrane fluidity. On isolated guinea pig heart auricles the toxin produced an increase in frequency from 180/min to about 300/min, with arrhythmia and transitory flutter. On isolated nerve-diaphragm preparations the toxin caused a contracture and a decline in twitch tension, with a loss of potassium into the bathing solution. The action potential of the electrically stimulated N. ischiadicus of rat or frog was not affected when leucocidin was added to the bathing solution up to a concentration of 10 micrograms/ml.

[Toxicity of culture supernatants from Pseudomonas aeruginosa (author's transl)]. / Toxizitätsuntersuchungen an Kulturüberständen von Pseudomonas aeruginosa

In an effort to learn more about the pathogenicity of Pseudomonas aeruginosa we studied the culture supernatants of 20 strains of this bacterial species. Of these 5 proved to be highly toxic, 9 moderately toxic and 6 nontoxic for mice. The toxic component could not be separated from protease (elastase), neither by gel-filtration on Sephadex G-100 superfine, nor by isoelectric focusing. From this we assumed that the toxicity of the culture supernatants was associated with elastase. Purified elastase from P. aeruginosa, strain 75, elicited cytotoxic effects in cultures of L-, HeLa- and testicular-cells from calves. It apparently did not damage cultures of kidney-cells from rabbits and pigs.

[Effects of an antiserum prepared against purified protease of pseudomonas aeruginosa (authors transl)]. / Wirkungen eines gegen gereinigte Protease von Pseudomonas antiserms hergestellten aeruginosa

Purified protease was obtained from Pseudomonas aeruginosa. It stimulated in rabbits the production of antibodies, which could be demonstrated mainly in an indirect hemagglutination test. Injected intracutaneously into rabbits, the protease caused an increased permeability in the capillaries and in higher doses bleedings. Immunization with the protease reduced the development of these lesions. Similar findings were obtained in experiments with mice. An antiserum prepared in rabbits against purified protease did not protect mice against infection with P. aeruginosa. However, a small protective effect could be observed after active immunization.