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Biomedical subjects

C R Olsen

Publications and source records attributed to C R Olsen.

At least 19 recordsLinked to original sources
PubMed1993

Chronic selenosis in horses fed locally produced alfalfa hay.

Chronic selenosis (alkali disease) was diagnosed in horses of western Iowa, a region associated with marginal to adequate soil selenium. Two locally produced alfalfa hays (Medicago sativa L) were identified as the primary source. Difficulty in selecting diagnostic specimens to evaluate potential chronic selenosis cases is complicated by the wide range of tissue concentrations reported in previous cases, conflicting correlation of sample selenium concentrations in the literature, and different recommendations on specimen selection and diagnostic value. These problems arise form the similarity in clinical signs for mild and severe chronic selenosis cases, and inability to establish the disease time course. Therefore, collection of multiple samples to confirm high selenium concentration in various tissues and identify selenium sources is recommended. Value of samples believed to reflect historical exposure vs current status may be questionable. Interpretation of results by practitioners and diagnosticians should consider selenium exposure level and duration, antagonistic or ameliorating factors, and postexposure excretion.

Animal Feed↗
PubMed1988

Life-threatening hemorrhage due to uterine vascular abnormality.

A case is reported of a 25-year-old woman stricken with prolonged and life-threatening menorrhagia from abnormal uterine vessels resembling hemangioma cavernosum. The condition was suspected at ultrasonic investigation. Hysterectomy was performed as an emergency operation.

Adult↗
PubMed1976

Man-made radionuclides and sedimentation in the Hudson River estuary.

Recently deposited fine-grained sediments in the Hudson River estuary contain radionuclides from global fallout produced by atmospheric bomb tests as well as from low-level releases of a local nuclear reactor. Accumulation rates of these nuclides are dependent on rates of sediment deposition and vary with location in the estuary by more than two orders of magnitude. Within the Hudson estuary, New York harbor is currently the zone of most rapid deposition of sediments containing radionuclides, some of which were released from a nuclear reactor about 60 kilometers upstream of the harbor.

Cesium Radioisotopes↗
PubMed1972

Correction for mechanical dead space in the calculation of physiological dead space.

When physiological dead space (Vd(p)) is calculated for a patient who has alveolar dead space, e.g., after pulmonary vascular occlusion, less than the full volume of attached mechanical dead space (Vd(m)) appears in the measured dead space (Vd(n)). Under these conditions the traditional subtraction of Vd(m) from Vd(n) leads to underestimation of Vd(p) and can give a falsely small ratio of Vd(p) to tidal volume (Vt) when, in fact, an abnormally large Vd(p)/Vt exists. To make the proper correction for Vd(m), two equations have been derived and validated with seven subjects having Vd(p)/Vt from 0.29 to 0.87, using Vd(m)'s from 120 to 322 ml. With only a small modification, these equations are suitable for routine clinical use and give Vd(p)/Vt within 0.02 of that by the validated equations (32 of 33 comparisons). The fraction of Vd(m) subtracted from Vd(n) is the square of the ratio of effective alveolar to total alveolar ventilation and is never > 1. This fraction is (Pa(CO2)/Pa(CO2))(2), where Pa(CO2) and Pa(CO2) are the mean partial pressures of expired alveolar and of arterial CO(2); in the other equation this fraction is [Pe(CO2)/Pa(CO2) (Vt - Vd(an) - Vd(m))](2) where Pe(CO2) is mixed expired Pco(2) and Vd(an) is anatomical dead space. The second equation requires an estimated Vd(an) and is applicable when Pa(CO2) is not measured or does not plateau (as in exercise).

Adult↗
PubMed1969

"Blow" of the pilot whale.

A captive pilot whale emptied as much as 88 percent of lung gas passively, without the aid of expiratory muscles. Level or decreasing pressures in the esophagus during expiration, and in the blowhole at the onset of expiration, revealed the driving force of expiration to be solely elastic recoil. Active muscular reexpansion of the lungs ensued immediately. Expiration and inspiration were completed in about I second.

Animals↗