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Biomedical subjects

A E Jennings

Publications and source records attributed to A E Jennings.

4 recordsLinked to original sources

Effects of altitude and two decongestant-antihistamine preparations on physiological functions and performance.

Fourteen men were studied to determine the combined effects of two altitudes--388 and 3,810 m or 1,274 and 12,500 ft--and three preparations--lactose placebo, Compound A (Actified, and Compound B (Dristan). Subjects reported least attentiveness with A and greatest with placebo. Fatigue increased significantly with time while energy, interest, and attentiveness decreased. The Multiple Task Performance Battery (MTPB) showed no effects of altitude, drugs, or time on overall performance; however, performance declined with time in several tasks, while problem solving improved. Subjects enjoyed the problem-solving tasks and may have given them preference as levels of interest declined. Though the MTPB overall composite scores did not change significantly, physiological parameters and subjective evaluations indicate that type of compound and time after ingestion are important. Declines in energy and attentiveness 2.5 h after ingestion could result in neglect of important--although routine--tasks. Hypoxia might enhance this effect and consequences might be worse in subjects whose medical conditions require these drugs.

17-Ketosteroids

Measurement and scaling of workload in complex performance.

Two groups of paid male volunteers (Groups I, N = 51, tested with identical schedules on two successive days; Group II, N = 43, tested on one day only) performed over nine intervals on various combinations of the six tasks of the CAMI Multiple Task Performance Battery. Two of the tasks involved monitoring static (lights) and dynamic (meters) processes, and four more-active tasks involved mental arithmetic, elementary problem solving, pattern identification, two-dimensional compensatory tracking. Five of the nine intervals provided different complex tasks consisting of concurrent monitoring tasks and two of the active tasks. Other trials provided data on the single active tasks as well as the combined monitoring tasks. The results indicated that all performance measures--a total of 12 for the six tasks--varied significantly as a function of the different task-combination conditions. A standard psychological scaling technique (Thurstone Case V) was applied to the monitoring data (response times for green and red lights, and for meter monitoring) to develop an index of workload for the five complex task combinations. Since better performance was presumed to indicate a lower workload, workload was inferred to increase as performance declined across conditions. The best performances, which were assigned scale values of 0, were found to be associated with single-task performances, as expected. Scale values for the complex task-combination conditions were found to be consistent between groups and between the two days of testing of Group I (r's of 0.947 to 0.993). Although the scale values are specific to the task and task-combination conditions employed, the scaling-procedure application shows promise for cases in which quantitative measures of performance can be acquired with moderately large samples of subjects (N's greater than 50).

Adolescent

Factors influencing susceptibility of Nocardia species to trimethoprim-sulfamethoxazole.

Demonstration of synergism between trimethoprim and sulfamethoxazole against 10 Nocardia isolates was found to be critically dependent upon the isolate, the duration of incubation, and the trimethoprim-sulfamethoxazole ratio. Inoculum effect was not significant. The trimethoprim-sulfamethoxazole ratio in the commercial, fixed-dose combination was found to contain too little trimethoprim to be optimal for Nocardia.

Drug Combinations

Disseminated infection by Fusarium moniliforme during treatment for malignant lymphoma.

Disseminated infection caused by Fusarium moniliforme is described in a 32-year-old granulocytopenic man with malignant lymphoma being treated with cytotoxic drugs and corticosteroids. Infected skin denuded by antecedent severe varicella-zoster infection was the probable source of fungemia. F. moniliforme grows rapidly on common mycological media as a lavender- to violet-colored mold at 25 to 37 degrees C. Its aerial hyphae produce fusoid macroconidia and characteristic fusiform microconidia in chains. The morphology of hyphae in tissue closely resembles species of Aspergillus and is not diagnostically specific. Morphological characteristics which distinguish cultures of F. moniliforme from other medically important species of Fusarium are discussed.

Adult