Biomedical subjects
Publications and source records attributed to J D Olsen.
Pleural mesothelioma is a rare neoplasm that is usually highly malignant, but benign mesotheliomas do occur; approximately 400 cases are described in the literature. We report the case of a young woman with a massive benign mesothelioma that filled the entire left hemithorax but was successfully resected with full reexpansion of the lung.
Larkspur (Delphinium spp.) toxicity in cattle seriously impedes the efficient use of productive mountain rangelands. Larkspurs contain complex diterpenoid alkaloids that cause acute intoxication and death from respiratory paralysis. Alkaloids and their concentrations vary among larkspur species, plant parts and phenological growth stages, thus causing great variability in toxicity. Ingestion rate of larkspur by the cow, alkaloid toxicity and concentration in the plant and the kinetics of absorption and excretion interact to determine whether a cow is poisoned. Plant and animal factors influencing consumption and subsequent intoxication must be further elucidated to devise management strategies to reduce liverstock losses.
All calves fed locoweed (green and dry Oxytropis sericea Nutt and dry Astragalus lentiginosus Dougl) at high elevation developed clinical signs, gross and microscopic lesions of congestive right heart failure. Clinical signs and microscopic lesions of locoweed intoxication were also evident. Control calves did not develop the clinical signs, gross or microscopic lesions demonstrated in the locoweed fed calves.
Fiberoptic bronchoscopy and transbronchial needle aspiration were performed on 50 occasions in 47 afebrile patients. The aspirations were followed by endobronchial or transbronchial biopsies in 22 patients, as well as bronchial brushings and washings where appropriate. Blood for cultures was drawn at 5 and 30 minutes following needle aspiration, as well as at the time of any temperature above 38 degrees C during the 24 hours following the procedure. In five (10 percent) of the 50 cases, there was temperature greater than 38 degrees C (100.4 degrees F) in the 24 hours following the bronchoscopy; in no patient were cultures of blood positive, whether done early after the procedure or at the time of fever. We conclude that transbronchial needle aspiration, a new procedure gaining widespread popularity in diagnostic thoracic medicine, is not associated with clinically detectable bacteremia. This procedure should not require antimicrobial prophylaxis in patients susceptible to endocarditis.
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Twelve Hereford heifers were infused with larkspur extract (group 1, n = 4), lithium chloride solution (group 2, n = 4), or sodium chloride solution (group 3, n = 4). After 3 weeks of being fed basal ration (meadow grass hay), all heifers were offered a ration of alfalfa pellets (3,400 g) in a 2-phase, single-day feeding regimen. In phase 1, the amount eaten within 45 minutes was measured by weigh-back of uneaten pellets. In phase 2, cattle that ate greater than 150 g of pellets in phase 1 were offered the balance of uneaten pellets and were infused with their respective designated solution. Five pairings of pellet feedings and appropriate infusions were given at 2- or 3-day intervals to initially induce feed aversion. Heifers in groups 1 and 2 developed a strong aversion to pellets by the 5th feeding. Persistence of aversion was tested twice at weekly intervals. Infusion of cattle with larkspur extract or lithium chloride solution induced a persistent aversion to an otherwise palatable feed.
Seeds of horse chestnut (Aesculus hippocastanum), Ohio buckeye (A glabra), and yellow buckeye (A octandra) were tested for toxicity to 2-week-old Leghorn chicks and adult female Syrian hamsters. The LD50 of the water soluble portion of alcoholic extracts of horse-chestnut seeds (for hamsters and chicks) and of dried, powdered seeds (chicks only) was determined. The LD50 for a single dose of extract from horse-chestnut seeds was 10.6 mg/g of body weight for chicks and 10.7 mg/g of body weight for hamsters. The LD50 for chicks given 2 consecutive daily doses of horse-chestnut seed was 6.5 mg/g. Toxic signs included depression, muscular incoordination, paralysis, coma, and death. Extracts of seeds of Ohio buckeye were nontoxic to chicks and hamsters when fed at 80 mg/g. One of 5 hamsters died after dosing for 5 days with 80 mg/g of extract of seeds of yellow buckeye/g.
Bur buttercup (Ceratocephalus testiculatus) has not been considered to be poisonous, but the sudden death loss of 150 ewes while grazing it prompted study of the plant. It was found that bur buttercup can be highly toxic to sheep, with a lethal dose being as little as 500 g of green plant for a 45-kg sheep. Clinical signs of bur buttercup poisoning are weakness, depression, diarrhea, labored breathing, anorexia, and occasional fever. Postmortem findings include inflammation and edema of the rumen; hemorrhage in the left ventricle of the heart; congestion of the lungs, liver, and kidneys; and excessive fluid in the thoracic and abdominal cavities.
Research with dairy cows was to determine whether dairy cows in confinement are in poor physical condition, if programmed exercise improves physical fitness, and which physiological measures are most useful indicators of physical fitness. If maintenance of physiologic homeostasis when an animal is under a work load is a valid criterion of physical fitness, dairy cows in confinement are in poor physical condition, and physical fitness can be improved by programmed exercise. Walking cows at 4 km/h for a distance of 8 km daily for 5 days per wk for 8 wk prepartum improved their physical fitness. Useful hemic indicators of improved fitness were less increase in erythrocyte numbers and hemoglobin concentration and less decrease in oxygen tension, carbon dioxide, carbonic acid contents, and base excess than in poorly conditioned cattle under work load. Venous blood was satisfactory for these measurements. Also valued were heart and respiratory rates, except these rates being sensitive to extraneous disturbances may be less reliable.
A method was developed for repeated or prolonged infusion of substances into the rumen. A blind rumen fistula was surgically formed so that the unopened rumen compartment was easily accessible immediately beneath the skin. A cardiac catheter was inserted into the rumen and was tied to a canvas patch cemented to the animal's coat. This method has been used in cattle and sheep for continuous infusion periods of one to six weeks. This surgical preparation also has been used to put plant material directly into the rumen and to obtain rumen contents. Thus, a large number of fistulated animals can be maintained over long periods without the disadvantages of maintenance required for animals each having an open fistula fitted with a closure device.
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The effects in sheep of locoweed poisoning on electroencephalograms and on levels of the brain amines serotonin and norepinephrine were measured. Lucoweed-induced EEG changes in sheep were characterized by episodes of high voltage, slow activity (HVSA). There was no effect on brain norephinephrine levels. The mean brain serotonin level of the sheep fed locoweed was approximately 57% higher than the control but was not significant.
That dairy cows housed in confinement might benefit if they were exercised during the dry period prompted development of a facility for exercising dairy cows. Two methhods of the exerciser, which consist of a circular lane and a driving mechanism powered by a variable speed electric motor, are described. A speed of 3.5 k, per h provides a steady but comfortable pace for pregnant dairy cows and heifers. Many animals refused to go at speeds greater than 5.5 km per h.
A technique was developed for estimating the toxicity for rats of an alcoholic extraction product from larkspur (Delphinium barbeyi Huth). The dried residue from alcohol extraction was reconstituted in buffered saline solution and subcutaneously injected into rats. Toxicity was expressed as miligrams of dry plant per gram of body weight. Samples from D barbeyi collected during prebloom and early flower bud stages of growth produced median lethal doses ranging from 5.0 to 6.7 mg/g of body weight. Difference in toxicity of the extract due to age of rats was not significant.
Three-hundred Balb/C mice were used to assess the effect of vasopressin on the response of the gastrointestinal tract to irradiation. Median lethal doses were determined for control and vasopressin treated animals in which the whole abdomen was irradiated. There was a significant difference in LD50/6 (882 +/- 27 for controls vs. 1051 +/- 23 for vasopressin-treated animals). In addition studies demonstrated a significant difference in the survival rate of jejunal crypts at 800 and 1,000 rads.
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Explore the source record for details and available documents.