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Biomedical subjects

C Breen

Publications and source records attributed to C Breen.

27 records · Page 2Linked to original sources
PubMed1989

Ductus arteriosus: involvement of a sarcolemmal cytochrome P-450 in O2 constriction?

Our previous studies implicate a cytochrome P-450-based mechanism in the constrictor response of the ductus arteriosus to oxygen. The present experiments were conducted on saponin-skinned strips of ductal muscle from mature fetal lambs to determine the location, sarcolemmal versus intracellular, of this cytochrome and to obtain a better insight into the sequence of events underlying the action of oxygen. Skinned preparations contracted to free Ca2+ over the range between 0.1 and 5-10 microM (pCa 7 to 5). In contrast, oxygen (PO2, 608-690 Torr; 1 Torr = 133.3 Pa) had no significant effect, both in the absence and presence of 10 microM calcium. Carbon monoxide, tested as pure CO or a CO-O2 mixture (ratio 0.28), did not relax preparations maximally contracted with calcium. These findings indicate that oxygen exerts its effect on the plasma membrane of ductus muscle cells and that a membrane-bound cytochrome P-450 mechanism likely functions as the signal transducer for oxygen in the formation of a constrictor agent.

Animals↗
PubMed1986

Teaching social language to moderately handicapped students.

Three students with moderate handicaps were taught to initiate and expand on conversational topics. The teaching procedure used stimuli generated from actual conversations with nonhandicapped peers. Generalization was assessed by audiotaping conversations between the handicapped students and their peers in natural school contexts without adult supervision. Results indicated that training generalized to natural contexts. These results were socially validated by undergraduate special education students, who rated tapes of two of the students' conversations during training phases as more socially competent than during baseline. Results are discussed in terms of the evaluation of complex social behavior as multioperant behaviors.

Adolescent↗
PubMed1984

The training and generalization of social interaction skills with autistic youth.

Two experiments were conducted to increase the initiations and duration of social interactions between autistic and nonhandicapped youths. Experiment 1 taught two autistic youths to initiate and elaborate social interactions with three age-appropriate and commonly used leisure objects; a radio, a video game, and gum. The students were first taught to use the objects and subsequently instructed in the related social skills. The youths generalized these social responses to other non-handicapped peers in the same leisure setting. A second experiment trained a third autistic youth to emit similar social leisure skills. The use of the leisure objects and the related social skills were taught at the same time. The autistic youth learned these skills and generalized them to other handicapped peers in the same leisure setting. The importance of teaching generalized social responding in particular subenvironments was emphasized.

Adolescent↗
PubMed1974

A comparative study of some commercially available tests for rheumatoid factor.

Seven commercially available screening tests for rheumatoid factor and two quantitative tests have been compared with the standard Rose-Waaler test in a series of 477 sera from patients with various joint diseases. Markedly different results were obtained, and on the basis of our findings suggestions are made as to what we consider to be the most satisfactory currently available tests.

Animals↗