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Biomedical subjects

O Siegmann

Publications and source records attributed to O Siegmann.

At least 19 recordsLinked to original sources
PubMed1993

Oxygen concentration and asexual development of Eimeria tenella in cell cultures.

Primary chicken kidney cells in Flexiperm cultures were either inoculated with Eimeria tenella sporozoites or incubated as noninoculated controls. Oxygen concentration was reduced (10 or 15 vol% O2, 5 vol% CO2) or increased (25 or 30 vol% O2, 5 vol% CO2) in a triple gas incubator (Heraeus B 5061 EK/O2) and retained in a CO2-air incubator (20 vol% O2, 5 vol% CO2) 24 hours post inoculation (hpi). Mature second generation schizonts (mS2) were counted microscopically at 120 hpi and numbers were compared either as mS2 or mS2/cm2 confluent cells. Asexual development of Eimeria tenella was neither stimulated nor inhibited by different oxygen concentrations, indicating that higher numbers of schizonts in cultures under reducing conditions reported earlier are probably a result of increased invasion rates of sporozoites.

Animals↗
PubMed1991

Clinical selection criteria for secondary examinations of the health-status of broiler flocks.

Results of post-mortem and laboratory examinations of broilers sampled randomly or selected by clinical symptoms were compared. The male:female-ratio was in all cases nearly equal for randomly sampled and selected birds. Regarding post-mortem findings, differences dependent on selection criteria were observed: in randomly-sampled birds the frequency of breast-blisters and plantar inflammations was higher than in selected broilers, whereas in the latter osteodystrophy and bursal atrophy were seen more frequently. Alterations of joints and tendon-sheaths caused by a reovirus-arthritis in one flock were seen in same frequency in randomly sampled and selected birds, respectively. Parasitological examinations revealed the highest coccidial lesion scores in selected birds with lameness or slightly retarded growth but when dwarfism birds were included into calculations, there was no significant difference among both groups. Results of bacteriological and serological examinations showed no differences between the groups.

Animals↗
PubMed1991

[Diseases and causes of death in native wild birds--a literature review].

Little attention was dedicated to diseases and causes of death of indigenous wild birds compared to poultry until recent decades. The interest of veterinary medicine in the spectrum of causes of morbidity and mortality of wild birds increased with the understanding of the importance of these birds as vectors in the epidemiology of zoonoses and as a biological indicator for the occurrence of substances noxious for the environment. The climate as a natural factor and the influences of civilization as traffic, high voltage lines and oil contamination of the sea lead to a reduction of bird species by starvation, traumata, intoxication and degenerative or proliferative and inflammatory or non inflammatory processes. Many parasitological, bacteriological, mycotic and viral diseases are wide spread among free living birds and make difficulties in keeping and breeding endangered birds.

Animals↗
PubMed1990

[Clinical diagnosis and differential diagnosis in ornamental birds].

Clinical diagnosis in companion birds consists of well established procedures such as case history, clinical observation, physical examination and further special investigations, e.g. radiology, endoscopy or clinical chemistry. Also some peculiarities of the numerous bird species have to be taken into consideration. These are, for example, certain characteristics of the different species, the varieties of husbandry and environment as single caged birds or flocks in zoos and aviaries and, especially, the lack of typical clinical symptoms in most cases. In regard to those aspects, case history concerning aspects such as age, sex, feeding or course of the disease and special investigations in the case of single caged birds and diagnostic dissections and etiological laboratory examinations, e.g. microbiology, parasitology and toxicology, in the case of flock problems are of major significance. Examples of differential diagnosis in single caged birds, e.g. abnormal behaviour ("feather plucking"), gout, intestinal foreign bodies, tumors or pneumomycosis, and flock health problems, e.g. acariasis, canary pox, coccidiosis or bacterial infections complete this paper.

Animals↗
PubMed1989

[Hygiene problems with ornamental birds in the household].

Approximately 8 million pet birds are kept in the Federal Republic of Germany. The number of households where these birds are living is insignificantly lower, and the birds are usually kept as singles. Hygienic problems can arise due to the close contact between humans and birds. In view of the different pet birds species originating from different biotopes, specific knowledge is often lacking regarding adequate housing, nutrition and general management. This can result in a decrease of natural resistance and therefore can lead to diseases of those birds. Therapy, performed by a nonveterinarian, usually does not only affect the birds, but also endangers the owners themselves. Especially, the carrier state of newly purchased birds with pathogens hazardous for human health has to be considered. Psittacosis has to be mentioned as one of the major zooanthroponoses deriving from birds. This requires to reconsider governmental measures to cope with this disease including policies of bird import as one of the major reasons for spreading the disease. Better management conditions can extend the life expectation of birds. This might also lower the fluctuation within the pet bird population and therefore biohazards for humans. Therefore, instruction and advice of pet bird-owners are necessary.

Animals↗
PubMed1989

[The occurrence of paramyxoviruses in game birds: epizootiological aspects, characteristics in vivo and in vitro. A review of the literature].

The recent review is based on recent literature on the epizootiology and on properties of avian paramyxoviruses in vivo and in vitro. Paramyxoviruses are classified according to their pathogenicity (especially serotype 1), in addition to serotyping by means of hemagglutination-inhibition tests and by monoclonal antibody binding assays. Also, neuraminidase-inhibition tests, double-immunodiffusion tests can be performed. Growth properties of the different paramyxovirus-serotypes are accessory techniques to classify paramyxoviruses parallel to the determination of the pathogenicity. Structural polypeptides can be demonstrated in polyacrylamide-electrophoresis, thus leading to a distinction of the different serotypes.

Animals↗
PubMed1989

[Comparative studies of paramyxovirus isolates from wild birds].

As a result of a surveillance programme in North-Germany, paramyxovirus-isolates of serogroup 1 with different pathogenicity were isolated from different species of feral birds (Black-headed gull, mallard, tawny owl, tree sparrow, mute swan). In chick embryo fibroblast monolayers these isolates produced plaques exhibiting different plaque morphology. After cloning the isolates, further physicochemical, serological and pathogenicity testings were performed. On the basis of mean death time and intracerebral pathogenicity index, two of the isolates were found to be avirulent (lentogenic), whereas the others proved to be virulent (velogenic). SDS-Polyacrylamide-gel-electrophoresis showed polypeptide patterns similar to that of the PMV-1 reference strains. Summarizing all relevant findings of these investigations under consideration of the suggestions for the virological description of avian PMV (Alexander, 1987; Alexander et al., 1987; Who-Expert-Committee, 1980), including the recently established serotyping by means of monoclonal antibodies, the following designations of the PMV isolates tested herein are proposed: 1. PMV-1/black-headed gull/Germany/SSP-233/83, lentogenic NDV, monoclonal antibody group G 2. PMV-1/mallard/Germany/SSP-284/83, lentogenic NDV, monoclonal antibody group H 3. PMV-1/tawny owl/Germany/SSP-262/84, velogenic NDV, monoclonal antibody group B 4. PMV-1/tree sparrow nestling/Germany/SSP-352/84, velogenic NDV, monoclonal antibody group B 5. PMV-1/mute swan/Germany/SSP-204/85, velogenic NDV, monoclonal antibody group B.

Animals↗
PubMed1982

Lack of immunostimulatory effect of N-acetyl muramyl-L-alanyl-D-isoglutamine on selected chicken immune functions.

Synthetic N-acetyl muramyl-L-alanyl-D-isoglutamine, syn. muramyl-dipeptide (MDP) was found to be immunostimulatory in several experimental animal species. In order to determine the influence of MDP on the chicken immune response, different doses (0.05-0.2 mg) of this compound were administered to 6-week old chickens, and cellular as well as humoral immune functions were tested. Neither the immune response against sheep red blood cells or Newcastle disease virus (strain Hitchner B 1), nor the ability to reject skin grafts, or to react in the delayed hypersensitivity (tuberculin) test, were affected significantly under the experimental conditions employed. This study reveals little evidence for parallels between the ability of the chicken immune system and the immune system of other animal species examined so far, to develop enhanced immune reactions under the influence of MDP.

Acetylmuramyl-Alanyl-Isoglutamine↗