PubMed HealthSearch

Biomedical subjects

W H Weihe

Publications and source records attributed to W H Weihe.

At least 19 recordsLinked to original sources

[Human adaptation to climatic changes].

The causes for the currently predicted change in climate result from behaviours of the rapidly growing human population consuming more natural resources for fulfillment of more natural resources for fulfillment of basic needs and high demands on health and comfort and interfering with homeostasis mechanisms of nature beyond adaptive capacities. Human adaptive potential is considered and strategies for adaptation are outlined aiming at an equilibrium between human and natural systems by behavioural modification, without loss of basic needs for health.

Adaptation, Physiological

[Allergies to laboratory animals. An epidemiological, allergological study in persons exposed to laboratory animals].

The nature, frequency and symptoms of laboratory animal allergies (LAA) were explored in 110 persons having contacts with laboratory animals and working in research laboratories at Zürich University Hospital and institutes. 20.9% of these persons were actually suffering from a laboratory animal allergy, a percentage corresponding to international reports in the literature (12-27%). 82.6% of persons with LAA were atopic subjects. In a group without LAA we found an atopic disposition only in 25.3%. The commonest signs of LAA were a combination of rhinoconjunctivitis with bronchial asthma and with contact urticaria in 43.5% over-all. Rats and mice were the laboratory animals most contacted and they represented the largest number of sensitizations. The interval between the beginning of exposure and onset of the symptoms of LAA ranged between a few months and many years. In general, the time space is much shorter in atopic subjects than in non-atopic persons. Skin tests gave better and more precise results in the detection of a LAA than in vitro examinations. This means that investigations with RAST (PHARMACIA) were less sensitive than the prick multitest (STALLERGENES). The last-mentioned can be recommended as very good for serial allergological examinations. The new Phadiatop-test (PHARMACIA)--in the study we obtained positive results in 38.5%--is a sound and most specific examination for discrimination between atopic and non-atopic disposition. Determination of total IgE was of less value.

Adult

The influence of climatic factors on the nasal mucosa of rats.

The influence of indoor climate on goblet cells and intraepithelial glands of nasal mucosa was analysed. A cold and heat adapted group of twenty rats were compared with a neutral adapted group after eight weeks of climatic exposure. There was a decrease of density of the goblet cells and the intrapeithelial glands in cold adapted rats. It is suggested that the adaptive changes of the mucous membranes of the rats may be correlated with the increased ventilation rate in the cold.

Animals

[Bone replacement using beta-tricalcium phosphate--results of experimental studies and initial clinical case examples].

Beta-Tricalcium phosphate granulates (Ceros 82) implanted in femurs of the rat led to osteoconduction already one week after implantation. Compared to the problems of autologous implants, TCP presents many advantages: No operation on the donor site, no limitation of quantity, clinically negligible resorption, immediate osteoconduction. The results on femoral defects of 26 rats filled up by beta-TCP and our first clinical experiences on juvenile bone cysts are presented.

Animals

Regulation of animal experimentation. The international experience: Switzerland.

The reviewer is head of a Central Animal Laboratory of a Medical Center, where about 140 researchers, chiefly M.D.'s work on 11 species: monkeys, dogs, cats, calves, pigs, sheep, rabbits, guinea pigs, rats, mice and gerbils. In 1984 there were 120 licence projects with 32.000 experiments, 74% were carried out on mice, 24.6% on rats and the rest on the other species. Approximately two third of all animals were used for in vitro studies. Each researcher has to apply for a licence for a limited project by giving the title, a brief description of the method, his reasons for wanting to do the experiment and the value of the expected results, and the exact number of animals required. Details of the planned experiments are discussed with the staff of the Central Animal Laboratory. All information is filled in by the responsible researcher on a nation-wide standardized form. The completed form is signed by the head and forwarded by the secretariat to the Cantonal Veterinary Department. Four copies are submitted of which one goes to the Federal Veterinary Department. All applications for a licence are handled by the cantonal veterinary officer. The decisions are controlled by a Cantonal Commission for animal experiments, consisting of 8 members out of which 4 are animal protectionists. In addition the Department of Education has set up a bioethical commission consisting of 4 members of the university, one from the veterinary faculty, two from the medical faculty and one from the life sciences. This commission can also be called on by a researcher if he needs to clarify points before the application is submitted. The animal protection law requests the cantonal veterinary officer to make a thorough check of the project which often demands one or more letters asking for further information. He has to check whether an animal experiment is necessary at all, whether the experiment is properly designed, whether animals of lower order could be used and whether the demanded number of animals is needed. After a project has been completed or every year for a larger project, the number of animals used in the project has to be reported to the cantonal veterinarian who will prepare statistics on total number of animals used. A division of the experiments into in vivo and in vitro experiments will be prepared and categorization according to the estimated degree of stress and pain is being considered.

Animal Welfare

Use and misuse of an imprecise concept: alternative methods in animal experiments.

The concept of inhumanity of Russell & Burch in 1959 with proposals for human procedures in experiments on animals by way of replacement, reduction and refinement (the 3 R's) and the revival of these by Smyth (1978) as alternatives to animal experiments are presented. Since then under the name 'alternative methods', replacement of in vivo by in vitro methods has found great public attention and promotion. It is argued that alternative methods are a fallacy, because in the progress of research a continual control and reinvestigation of findings on each system level is required until knowledge is complete, which makes in vivo experiments irreplaceable. True alternatives exist only for refinement within a system level. On the level of the organism, refinement would be in the care of animals and experimental procedure through alleviation of stress. The possibilities which refinement offers for animal welfare have been nearly forgotten and need promotion among researchers, animal technicians and attendants.

Animal Testing Alternatives

The haematological and cardiac patterns of adaptation of rabbits to 4,500 m simulated altitude and of readaptation to 400 m.

The haemoglobin (Hb), red blood cell count (RBC) and haematocrit (Hct) of 11 male rabbits were measured at weekly intervals during a 5-week exposure period to hypobaric hypoxia (simulated altitude, 4,500 m) and the following 4 weeks after restoring normoxic conditions in a climatic chamber at constant temperature. RBC showed the slowest response, Hct the fastest during adaptation to hypoxia and readaptation to normoxia. The body weight decreased during the 1st week at hypoxia and remained at a reduced level for 2 weeks after the return to normoxia. In female rabbits exposed up to 43 days to hypoxia the heart ventricle quotient (HVQ) (weights of left ventricle + septum/right ventricle) was determined. There was a gradual decrease of HVQ expressing the development of right heart hypertrophy which was not stabilised within the observation period.

Adaptation, Physiological

[Animal protection and animal experiment from the viewpoint of biomedical research].

Animal protection societies have recently launched strong attacks on the nature and extent of animal experiments in medical research and proposed measures in national parliaments to prohibit all experiments with animals. Scientists engaged in research with animals should examine their own research in the light of these criticisms, and give detailed reasons for the necessity of their investigations. In addition, they should be more concerned with the rectification of false conceptions and statements about the execution and objectives of animal experimentation. This involves explaining the nature and limits of the so-called alternative methods which are requested by animal protectionists as substitutes for experiments with live animals. Improvements in the conditions for research and the upkeep of laboratory animals at the universities during this decade have reached a high level. With the introduction of animal protection laws, uniform regulations have already been achieved in various countries and such regulations will soon be operative in Switzerland. Nevertheless, an open and objective dialogue between animal protectionists and scientists is desirable at this stage of the confrontation, with a view to clarifying their different viewpoints and objectives and searching for solutions.

Animals

Phase maps for particles and microorganisms in animal quarters.

Measurements of fallout of particles and microorganisms were carried out during the light and dark period in animal rooms occupied by rats, rabbits, cats and monkeys. Correlations between both parameters were established. The 24-hour mean was calculated and the percentage deviation of the individual measurements from this mean used for the elaboration of phase maps. For rats there is a high increase of particle and microorganism emission during the night following the activity cycle, while for cats and monkeys emission increases only during the feeding period. In rabbit rooms there is a nearly equal emission during day and night.

Air Microbiology