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N F Paradise

Publications and source records attributed to N F Paradise.

23 records · Page 2Linked to original sources
PubMed1976

Effect of nitroglycerin with and without systemic hypotension on canine regional myocardial tritiated water deposition.

A marked alteration in the transmural distribution of left ventricular blood flow, with a relative increase in subendocardial and mid-wall flows, but with no change in the distribution of the relative blood flow to the two ventricles occurred when nitroglycerin was administered and the systemic arterial blood pressure in the upper body maintained near control levels in anaesthetized, open-chested dogs. The relative increase in subendocardial and mid-wall flows may have resulted from a direct action of nitroglycerin on the coronary vasculature. On the other hand, the intravenous administration of nitroglycerin, when followed by the hypotension which it produces, did not alter the transmural distribution of blood flow in the left ventricle of the dog. Blood flow to the right ventricle relative to flow to the left ventricle increased in this situation.

Animals↗
PubMed1975

Localization of rapidly exchangeable calcium in mammalian heart muscle.

Two new methods were used to calculate net labeled Ca++ compartmental influx into rabbit myocardium: 1) continuous measurements of arteriovenous differences in 45Ca levels are corrected for longitudinal mixing and for varying transit times by a double-isotope technique with the relatively impermeant 131I-labeled albumin as the referent substance; 21 tritiated sucrose and 45Ca contents were measured in ventricular muscle after perfusion with the doubly labeled perfusate and washout of aqueous perfusate with fluorocarbon 80. Both methods yielded similar results. Only 52% of the Ca++ efflux from the vascular bed during the rapid flux period can be accounted for as Ca++ in interstitial water under control perfusion conditions. Contracture induced by substituting K+ for Na+ in the perfusate brings the fraction not accounted for as Ca++ in interstitial water from 48 to 60% of the total in 5 min. When irreversible contracture is induced by return to normal [Ca++] after short periods of excitation-contraction uncoupling due to zero [Ca++] perfusion, the fraction not accounted for as Ca++ in interstitial water is 68% in 5 min.

Animals↗
PubMed1975

K+ and Mg-2+ net fluxes in relation to zero [Ca-2+] perfusion and subsequent cardiac contracture.

Following within 45 sec after the development of contracture induced by restoring normal ionic composition perfusion conditions after a 12 min period of mechanical arrest in the rabbit heart caused by zero [Ca-2+] perfusion, there is an explosive efflux of K+ and Mg-2+. After shorter periods of Ca-2+-lack arrest, the restoration of [Ca-2+] to normal causes recovery of rhythmic contraction and no K+ efflux. The K+ and Mg-2+ effuxes are ascribed to the effects of the contracture itself and not simply to the loss of Ca-2+ during zero [Ca-2+] arrest nor to the restoration of normal perfusate [Ca-2+], except insofar as the latter operates to induce the contracture. It is suggested that cell membrane permeability progressively increases during zero [Ca-2+] arrest and that an abnormally large influx of Ca-2+ after restoration of normal perfusate [Ca-2+] induces the contracture.

Animals↗
PubMedDate not supplied

Bystander Trauma Care training in Iowa.

OBJECTIVE: The Iowa Bystander Trauma Care program trained citizens to provide initial care at the scene of a motor vehicle crash. The development, implementation, and evaluation of the program are described. METHODS: The National Highway Traffic Safety Administration's curriculum was used as the basis for developing the Iowa Bystander Trauma Care program. Emergency medical technicians (EMTs) were trained to be instructors in a two-hour course offered at each of four community colleges. The EMTs, in turn, provided instructions to the general populace. Five hundred participants were given a questionnaire before the one-hour Bystander Trauma Care training session, immediately after the training and six months later. The questionnaire obtained background data and assessed attitudes regarding willingness to stop and assist, and knowledge obtained. RESULTS: One hundred twenty EMT instructors trained more than 2,000 citizen bystanders in a 17-county area in central Iowa. Immediately after the training program, participants were more likely to provide assistance (p < 0.001), and understand the sequence of actions to be performed at the scene of a crash and how to prioritize the information provided to 911 (p < 0.05). There was also evidence of retention of the knowledge six months after training. CONCLUSIONS: Citizens readily volunteered for the Bystander Trauma Care training program. Results of the questionnaire suggest citizens can be successfully trained to recognize the needs of, and provide initial care for, acutely injured persons, and the positive effects of such training are maintained over time.

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