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Biomedical subjects

O Aalund

Publications and source records attributed to O Aalund.

At least 37 records · Page 2Linked to original sources

Tracing the use of torture: electrically induced calcification of collagen in pig skin.

Reports of the use of electrical torture are usually denied, so that there is an urgent need of diagnostic methods to distinguish the consequences of electrical torture from other superficial injuries. The 'electrical group' of Anti-Torture Research (ATR) has accordingly studied the possibility of distinguishing between the sequelae of electrical and heat injury. Among the reported differences of the two types of injuries is the occurrence in epidermis, vessel walls and sweat glands of vesicular nuclei exclusively in electrically injured skin. On the basis of experiments with anaesthetized pigs, we now report that the late sequelae of electrical injury appear to include the deposition of calcium salts beneath the area of an electrical cathode.

Aggression↗

The effect of direct current, sodium hydroxide and hydrochloric acid on pig epidermis. A light microscopic and electron microscopic study.

Lesions in pig skin were induced by direct current, hydrochloric acid and sodium hydroxide, and the morphology of the lesions was compared in order to establish the influence of electrolysis in the electrical lesions. Both light microscopically and electron microscopically a pronounced similarity was found between cathode lesions and base-induced lesions including the presence of vesicular nuclei in both kinds of lesions. Some features were also common to anode lesions and acid induced lesions, but dissimilarities were present as well. From the results it is concluded that electrolysis in the tissue with the subsequent shift of pH, especially towards the alkaline side, is responsible for the formation of the vesicular nuclei which we repeatedly have found to be characteristic of electrical skin lesions. The shift of pH also induces the cytoplasmic feature called "white necrosis" which therefore is found more regularly in electrical lesions than in heat lesions.

Animals↗

Epidermal changes in heat and electrically injured pig skin. A light microscopic study of the influence of heat energy intensity and electrical current frequency.

Pigs were exposed to heat of low and high temperature and electricity of various frequences. Comparable amounts of energy were transferred in all experiments. In lesions induced by heat of low temperature granularity and/or fibrillarity of the cytoplasm were present in the epidermal cells. Lesions induced by heat of high temperature had a similar appearance, but occasionally "white necrosis", defects in the epithelium and light yellow material in stratum corneum were present. Lesions induced by 100.000 hz alternating current were segmental but otherwise microscopically often indistinguishable from lesions produced via transfer of heat of low temperature. Lesions induced by 8000 hz and 59 hz alternating current were segmental. Vesicular nuclei, "white necrosis" and yellow, clumped keratin were present in most lesions. Anode areas in direct current induced lesions showed a shrunken epidermis. The cytoplasm of the epidermal cells were often eosinophilic and homogeneous, and the nuclei were small with condensed chromatin. Occasionally, "empty" nuclei were noted. Yellow, clumped keratin was presented in all lesions. In cathode areas epidermis was of varying thickness and "white necrosis" and vesicular nuclei were present. The pathogenesis of the individual morphological features is discussed based upon theoretical concepts and the difference in morphology of the various lesions encountered in the present study as well as in other studies in this series of experiments. It is concluded that except for lesions produced via transfer of high frequency alternating current the morphology of electrical lesions is specific. Further, an alleged torture instrument was able to produce lesions similar to those observed in the experimental studies.

Animals↗

Legionella microagglutination test. A serological study of Danish patients.

A microagglutination (MA) test for antibodies to 10 different Legionella antigens was evaluated by comparison with an indirect fluorescent antibody (IFA) test. Sera from 227 patients were investigated. There was good agreement between the two tests, especially when testing sera from patients with a rise in titre. The MA is promising as an easy, quick, cheap and reproducible test for antibodies to Legionella.

Agglutination Tests↗

Epidermal changes in heat and electrically injured pig skin: a light microscopic study of the sequences in morphology.

Biopsies were obtained from heat and electrically exposed pig skin at different at different times after exposure, in order to describe the morphological sequences in heat and electrically injured skin. The work is part of a series of studies in which it is investigated whether morphological methods can be used in disclosing electrical torture. Epidermal changes in heat lesions differed from those of electrical lesions in all experiments. Heat lesions typically showed a detached epidermis with fibrillar or granular cytoplasm. In older lesions the epidermis appeared concrete. Electrical lesions showed an attached epidermis with small defects, a white, homogeneous cytoplasm, vesicular nuclei and curled, clumped keratin. The electrical lesions were rejected at day 4 or 5. The number of characteristic morphological changes in epidermis decreased with the age of the lesions. It is concluded that epidermal electrical lesions differ in morphology from heat lesions and that it is possible to evaluate the age of the lesions.

Animals↗

Paratuberculosis in cattle and free-living exotic deer.

Paratuberculosis was studied among dairy cows and exotic deer that shared grazing areas at Point Reyes National Seashore, California. Of the 10 dairy herds tested, 5 (50%) were infected with Mycobacterium paratuberculosis (based on results of fecal culture). Mycobacterium paratuberculosis was cultured from 9 (8.7%) of the 103 bovine fecal samples and from 4 (3.9%) of the 103 bovine rectal mucosa scapings tested. Of 89 fecal samples from 52 axis deer (Axis axis) and 37 fallow deer (Dama dama), 5 (9.6%) and 3 (8.1%), respectively, contained M paratuberculosis. Culture of intestinal necropsy samples from the same deer indicated that 3 (5.8%) of the axis deer and 2 (5.4%) of the fallow deer were infected with M paratuberculosis. The cows were tested for serum antibodies by the complement-fixation test and by radioimmunoassay. Of 95 sera tested by complement fixation, 15 (15.8%) were positive, as were 15 (14.7%) of 102 sera tested by radioimmunoassay. Culture results and serologic test results were compared on a herd basis.

Animals↗

Bioproduction of [14C]ochratoxin A in submerged culture.

A number of Aspergillus and Penicillium species were tested for production of ochratoxin A (OA) in several media. After 8 days of static incubations of submerged cultures at 28 degrees C, toxin yields of 25 and 30 micrograms/ml were obtained with Aspergillus alliaceus NRRL 4181 in Ferreirás and 2% yeast extract-4% sucrose media, respectively. However, the largest production observed in the preliminary screening was 54 micrograms/ml; this highest level was produced by A. sulphureus NRRL 4077 in a modified Czapek solution. The medium contained the basal salts and sucrose of Czapek plus urea (3%) and corn steep liquor (0.5% solids). A time study of toxin production demonstrated maximum yield of 350 micrograms/ml by the A. sulphureus isolate in the modified Czapek medium after 11 days of static incubation at 28 degrees C. The optimal production conditions were employed in additional tests designed to measure the efficiency of 14C incorporation from sodium [1-14C]-acetate into OA. Samples (20 microCi) of sodium acetate were added to separate culture flasks at 24-h intervals during the initial 9 days of the fermentation. Addition of [14C]acetate on day 4 of incubation provided the maximum yield of labeled OA. The highest specific activity of labeled toxin obtained was 0.07 microCi/mg of OA and the maximum incorporation rate of labeled acetate was 5.3%.

Acetates↗

A retrospective study of respiratory disease in a cohort of bacon pigs. I. Clinico-epidemiological analyses.

Previous studies of respiratory disease problems in pig herds have to a large extent relied on mortality data and slaughterhouse findings. The present report deals with simultaneously recorded clinical data and post mortem information for individual pigs from a large herd. Among other things, the results suggest that the commonly applied treatments of clinical cases have limited effect, that routine meat inspection is a fairly sensitive tool in monitoring the disease status, that productivity is affected relatively more by clinical episodes than by subclinical occurrence, and that respiratory disease and diarrhea are interrelated in more than one way.

Animals↗

Respiratory diseases in calves. An economic analysis.

From a Danish dairy herd comprising 350 milking cows data were obtained on all (1010) single, liveborn calves dropped over a three year period. Deaths incurred before, during, and immediately after delivery were not included in the study. The mortality rate up to the first few hours after birth was 10% leaving 910 calves to be included in the present study. The overall respiratory disease (r.d.) attack rate among calves from birth up to the end of the sixth month was 23%; the r.d. case fatality rate was 40%; the r.d. mortality rate was 9%. The mortality rate due to ailments other than r.d. was 11%, and the overall mortality rate during the first six months of life was 20%. The economic impact of r.d. in the herd was evaluated using a disease model which, in mathemathical terms, conceptualizes the basic patterns of the disorders within the calf population. The economic implications of various changes in the prevailing herd health status with respect to r.d. are outlined and discussed (Table VII, IX, XI). Also the economic expectations under different sales policies were studied (Table VIII and X). The study clearly demonstrates the versality of health models and how these may be applied to prepare economic forecasts during periods with rapidly changing market and production conditions.

Animals↗

Lung lesions at slaughter: associations to factors in the pig herd.

A survey was made of available data files to gain a preliminary insight into the association between environmental factors and the prevalence at slaughter of lung lesions. Herd size was the factor that showed the most predominant association with the prevalence of lung lesions. This was largely independent of the recruitment system for weanlings. There was a moderate trend toward positive association between the prevalence of lung lesions and the prevalence of other lesions. Lung lesions were weakly but significantly associated with the occurrence of infectious diarrhoea in the herd. The investigation demonstrated the feasibility of and the need for continuous epidemiological studies to identify disease determinants. Studies of the nature reported here makes it possible to define essential health factors with an accuracy that could never be achieved through clinical observations in a few herds.

Abattoirs↗