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Biomedical subjects

L Bush

Publications and source records attributed to L Bush.

43 records · Page 3Linked to original sources
PubMed1983

Differences in myocardial alpha- and beta-adrenergic receptor numbers in different species.

In the present study, we tested the hypotheses that 1) different species have different myocardial adrenergic receptor numbers and 2) selected "slow-channel" calcium antagonists compete with alpha-adrenergic antagonists for binding to varying degrees in different species. The data obtained in the present study demonstrate that there is a markedly decreased number of alpha 1-adrenergic and increased number of beta-adrenergic receptors in canine compared with rabbit and rat myocardium. The differences in adrenergic receptor numbers exist without major differences in alpha 1-adrenergic receptor affinity in the species studied. There was no significant difference in left ventricular or plasma catecholamine content between the rat and dog. Selected slow-channel calcium antagonists compete for alpha 1-adrenergic receptor binding in rabbit, rat, and canine myocardium. However, only in rabbit myocardium does verapamil antagonize alpha 1-adrenergic receptor binding at moderate concentrations, whereas verapamil in canine and rat myocardium and 1) 600 in all three species antagonize alpha 1-adrenergic receptor binding only at relatively high concentrations. Nifedipine, a dihydropyridine-type slow-channel calcium antagonist, had no effect on prazosin binding to rat, rabbit, and dog myocardial membranes.

Animals↗
PubMed1980

Millimeter wave absorption spectra of biological samples.

A solid-state computer-controlled system has been used to make swept-frequency measurements of absorption of biological specimens from 26.5 to 90.0 GHz. A wide range of samples was used, including solutions of DNA and RNA, and suspensions of BHK-21/C13 cells, Candida albicans, C krusei, and Escherichia coli. Sharp spectra reported by other workers were not observed. The strong absorbance of water (10--30 dB/mm) caused the absorbance of all aqueous preparations that we examined to have a water-like dependence on frequency. Reduction of incident power (to below 1.0 microW), elimination of modulation, and control of temperature to assure cell viability were not found to significantly alter the water-dominated absorbance. Frozen samples of BHK-21/C13 cells tested at dry ice and liquid nitrogen temperatures were found to have average insertion loss reduced to 0.2 dB/cm but still showed no reproducible peaks that could be attributed to absorption spectra. It is concluded that the special resonances reported by others are likely to be in error.

Absorption↗
PubMedDate not supplied

Topics of conflict between parents and young adolescents.

ISSUES AND PURPOSE: Parents often examine and question interactions with their young teen and may ask the advice of healthcare professionals. Topics, frequency, and intensity of conflicts between young adolescents and parents were therefore examined. DESIGN AND METHODS: A descriptive survey using the 44-item Issues Checklist (Robin, 1975) with 163 parent and young adolescent (ages 11-14) dyads. RESULTS: Parents and teens were congruent about their reports of the topics, frequency, and intensity of conflict. Discussion of the topics generally was not angry. Mothers reported the greatest quantity of issues. Potentially sensitive topics such as substance use, dating, and sex were rarely approached by either parent or young adolescent. Sociodemographic characteristics did not distinguish or were not associated with IC scores. PRACTICE IMPLICATIONS: Conflict is a common component of the parent-young adolescent relationship. Families with children entering adolescence can expect conflict about issues that recur but usually are not that "hot". Anticipating topics may put conflict in perspective. Nurses help families resolve conflicts associated with day-to-day conflicts as a first step toward opening up larger, potentially sensitive topics.

Adolescent↗