Biomedical subjects

D A Fischer

Publications and source records attributed to D A Fischer.

5 recordsLinked to original sources

PubMed1991

Diagnosis of meniscal and cruciate ligament tears using MRI. Evaluation of two scanning techniques.

The accurate diagnosis of meniscal and cruciate ligament tears is essential for proper management of knee injuries. In recent years, magnetic resonance imaging has been increasingly used to diagnose knee pathology. Several articles have documented the accuracy of MRI, but conflicting results have been reported. We present a series of 50 consecutive patients who underwent both MRI and complete arthroscopy. We tested two different scanning protocols and found the higher-resolution scanning protocol to be more accurate, resulting in fewer discrepancies between the results of MRI and arthroscopy, which we used as the standard for comparing the MRI interpretations. Magnetic resonance imaging is an important diagnostic tool in orthopedic practice. It is available, accurate, and well-accepted by patients. However, as demonstrated by the results of this study, the accuracy of MRI is highly dependent upon the scanning protocol used.

Adolescent↗

PubMed1978

Health effects of ozone exposure in asthmatics.

To investigate whether ambient air quality standards for ozone adequately protect high-risk populations, we assessed pulmonary and biochemical responses of 22 asthmatic volunteers to 2-hour controlled exposures to ozone at concentrations approximating 0.2 ppm, with secondary stresses of heat and intermittent exercise. All subjects had physician-diagnosed asthma; clinically, they covered a range from minimal wheezing to persistent marked abnormality in forced expiratory performance. Control experiments included repeated sham exposures (to purified air with no ozone added) as well as brief exposures to the odor of ozone followed by purified air. No meaningful changes in forced expiratory measures, lung volumes, or single-breath N2 indices were found after ozone exposure relative to control. Symptoms, scored semiquantitatively, increased slightly but not significantly with exposure to ozone. Small but significant (P is less than 0.05) group mean blood biochemical changes occurred with exposure to ozone; these included increased glucose-6-phosphate dehydrogenase and lactate dehydrogenase activities, increased erythrocyte fragility, and decreased concentration of reduced glutathione. Hemoglobin concentration and acetylcholinesterase activity decreased with ozone and decreased to a lesser extent in control studies. Concentrations of ozone readily attainable in smog episodes thus appear to be capable of affecting blood biochemistry in at least some asthmatic persons, in the absence of obvious adverse pulmonary responses. Whether the biochemical effects represent harm to health or a normal response to stress remains to be determined.

Acetylcholinesterase↗

PubMed1978

Osteosarcoma.

Explore the source record for details and available documents.

Adolescent↗

PubMedDate not supplied

Experimental studies on human health effects of air pollutants. IV. Short-term physiological and clinical effects of nitrogen dioxide exposure.

Adult male volunteers were exposed to nitrogen dioxide (NO2) at 1.0 ppm in purified air under conditions simulating ambient photochemical smog exposures (2-hr exposure with intermittent light exercise at 31 degrees C and 35% relative humidity). Sham exposures to purified air alone served as controls. Exposure effects were assessed by pulmonary physiological tests and by a standardized clinical evaluation. No statistically physiological changes attributable to NO2 exposure were found except for a marginal loss in forced vital capacity after exposure on two successive days (1.5% mean decrease, P less than .05). Reported respiratory and other symptoms were slightly increased with exposure as compared to control, but the change was not significant. Short-term toxicity of NO2 at peak ambient concentrations appears to be substantially less than that of ozone in healthy people, but adverse NO2 effects in diseased people or in long-term exposures cannot be ruled out at present.

Adult↗

PubMedDate not supplied

Syndesmotic ankle sprains.

In this study we reviewed ankle sprains in a professional football team over a 6 year period. Fifteen players who sustained syndesmotic ankle sprains were compared with 28 players who sustained significant lateral ankle sprains. Players with syndesmotic sprains missed significantly more games and practices and they received substantially more treatments than players with lateral ankle sprains. Physical examination findings, results of radiographic evaluations, and etiologic factors are discussed. The external rotation stress test, a clinical method for diagnosis of this type of sprain at the time of injury, is described. Results of this study clearly demonstrate a prolonged recovery time for syndesmotic ankle sprains. Physicians and trainers who are aware of this injury can differentially diagnose these two types of sprains in the early postinjury period by the method described.

Ankle Injuries↗