PubMed Health⌕ Search

Biomedical subjects

R E Flora

Publications and source records attributed to R E Flora.

11 recordsLinked to original sources
PubMed1978

Caffeine elicited withdrawal signs in morphine-dependent rhesus monkeys.

In the dose range of 4.0--32.0 mg/kg s.c., caffeine produced most of the signs which are commonly seen after the administration of naloxone (0.05 mg/kg s.c.) to morphine-dependent monkeys. The signs designated as lying on side or abdomen, avoiding contact, vocalizing, crawling or rolling, restlessness or pacing, tremors, retching, vomiting, coughing, vocalizing when abdomen palpated, rigid abdomen and salivation were noted. A randomized and blind experimental design, which included vehicle and positive (naloxone) controls was used. The significance of the differences between total scores for the whole syndrome was tested by the Mann-Whitney U-test. In preliminary studies in naive monkeys, caffeine was found to elicit some withdrawal signs but the results were equivocal. Na benzoate also elicited some withdrawal signs in morphine-dependent monkeys at 32.0 mg/kg s.c., but few signs were seen in naive monkeys. Caffeine was found to be approximately 10X more active than Na benzoate in inhibiting cAMP phosphodiesterase activity in a neuroblastoma cell whole homogenate assay. These results are consistent with the observations of Collier and Francis that morphine abstinence in rodents is associated with increased brain levels of cAMP.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1977

The effects of naloxone and nalorphine during the development of morphine dependence in rhesus monkeys.

A randomized and blind experimental design was used to study the effects of naloxone and nalorphine on the development of morphine dependence in monkeys. The results suggest: (a) that significant dose-related differences existed for combined numbers of withdrawal symptoms times frequency of occurrences; (b) that naloxone and nalorphine were qualitatively similar; (c) antagonists are more effective as dependence develops; (d) naloxone is approximately 10 times more potent than nalorphine, and (e) vomiting was the only withdrawal sign with which ED50s could be calculated. Dependence on morphine still increases up to 9 months after the commonly accepted 90-day stabilization period as measured by the ED50 for vomiting for naloxone.

Animals↗
PubMed1977

The physiological basis of intracranial pressure change with progressive epidural brain compression. An experimental evaluation in cats.

Sequential cerebrospinal fluid (CSF) pressure-volume studies were carried out in seven cats during the expansion at a constant rate of an epidural balloon. The same studies were performed in three control cats. Beginning after 20 minutes of inflation and continuing to the point of pupillary dilatation there was a progressive increase in the pressure-volume index (volume required to change intracranial pressure (ICP) by tenfold). During the course of balloon inflation, there was also a progressive increase in CSF elastance (instantaneous ICP change per unit change in CSE volume). At the point of pupillary dilatation there was a marked, abrupt increase in the pressure-volume index and an equally dramatic decrease in CSF elastance. The CSF outflow resistance increased to a variable extent during balloon inflation. The plot of the CSF pressure versus balloon volume (the mass lesion pressure-volume curve) was of the classical configuration with an initial relatively flat segment and a final steep segment. A hypothesis is presented that interprets the shape of the mass lesion pressure-volume curve in terms of changes occurring in the elastic properties of the tissues surrounding the CSF space and the volume of the CSF space. It is proposed that this hypothesis will explain most of the commonly observed variations in CSF pressure. Confusion regarding the ICP-volume relationships has arisen because of lack of specificity regarding which anatomical spaces are being perturbed.

Animals↗
PubMed1975

Flow rate maintenance and output of intravenous fluid administration sets.

Seven brands of intravenous fluid administration sets were studied to determine: (1)which set(s) maintained the most consistent flow rates; (2) if the type of fluid container (open, vented or closed, nonvented) affected the flow rates of administration sets; and (3) which set(s) closely approximated the theoretical amounts of fluid to be delivered in one hour at flow rates of 60,100 and 125 ml/hour. Six samples of each brand of administration set were tested in a laboratory setting which approximatedclinical conditions. The type of fluid container had little effect on the performance of the administration sets. The ARDL set was the most accurate in terms of the average volume of fluid delivered in 24 hours. The Burron set required fewer adjustments in 24 hours to maintain a constant flow rate. The U.S. Surgical set recordedthe smallest percent change in flow rate at the end of the first hour. The U.S. Surgical set is rated superior in overall performance. Based on the results of the study,the authors make recommendations to health care personnel, the pharmaceutical industry and the U.S. Pharmacopeial Convention.

Analysis of Variance↗