Biomedical subjects

E W Rypka

Publications and source records attributed to E W Rypka.

10 recordsLinked to original sources

PubMed1992

Methods to evaluate and develop the decision process in the selection of tests.

An objective, comprehensive method is described for organizing medical information that determines the most useful and sufficient test sets for separating diseases. The system is purposive, i.e., both its means and ends are known and tests results can be correlated with patient outcomes. The method is based on levels of information, probability and uncertainty and on measurement of comprehension and effectiveness. As the number of diseases in the system increases, the probability of their message sources decreases, which results in an increase in uncertainty. Resolution of uncertainty results in the diagnosis. Methods of reducing computational time are presented in this article.

Clinical Laboratory Techniques↗

PubMed1988

Influence of oxygen tension on the respiratory activity of Mycobacterium phlei.

Growth of Mycobacterium phlei under low oxygen tension resulted in specific activities two to twenty times lower for formate dehydrogenase, malate dehydrogenase, beta-hydroxybutyrate dehydrogenase, lactate oxidase and NADH dehydrogenase than when cultures were grown under high aeration. An increase in fumarate reductase and succinate dehydrogenase occurred with M. phlei grown under low oxygen tension. Malate: vitamin K dehydrogenase and glucose-6-phosphate dehydrogenase activity were not significantly affected by the oxygen tension used to grow the bacteria, and neither culture contained a lactate dehydrogenase. With growth of M. phlei in conditions of low oxygen tension, cytochrome a was not detected, but cytochrome b was prominent in membranes and cytochrome c was present in the soluble fraction.

Aerobiosis↗

PubMed1986

Phenotypic changes in mycobacteria grown in oxygen-limited conditions.

Laboratory strains of Mycobacterium phlei, M. smegmatis, M. fortuitum, M. gordonae, M. kansasi, M. bovis, M. tuberculosis and M. intracellulare were adapted to grow in an anaerobic environment. Concomitant with the transition to anaerobic growth was loss of acid-fastness, loss or modification of colonial pigmentation, and loss of ability to grow on a malachite green-containing medium. The mycobacteria grown anaerobically produced acid from a greater range of carbohydrates than aerobically grown cultures, lost iron-uptake activity, and showed a reduction of urease, catalase and nitratase activity. Back adaption of mycobacteria from an anaerobic to an aerobic environment resulted in the acquisition of acid-fastness, pigmentation, and other characteristics used in the taxonomy of mycobacteria. These results suggest that mycobacterial cultures, if grown in an anaerobic environment, may be erroneously identified in clinical laboratories.

Adaptation, Physiological↗

PubMed1981