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Biomedical subjects

J Moore

Publications and source records attributed to J Moore.

At least 631 records · Page 35Linked to original sources
PubMed1979

A study of the plasma concentrations of lorazepam in mother and neonate.

A standard dose of lorazepam 2.5 mg was given i.v. to two groups of mothers: (a) before surgical induction of labour and (b) at the beginning of the second stage of labour. A group of non-pregnant women was studied as control. Plasma concentrations of lorazepam were measured by gas-liquid chromatography, in the mothers before delivery, and in the mother and neonate at delivery and 24 and 48 h thereafter. Concentrations at delivery in the neonates were similar to those in the mothers in group (a), but significantly less in group (b). Fetal concentration rarely exceeded that in the mother. Measurements after delivery indicated that the neonates were able to metabolize lorazepam at the same rate as the mothers. Of the 22 neonates studied only one had an Apgar score of less than 8 at 5 min and this score was 10 at 10 min.

Adult↗
PubMed1979

Effect of cold submersion on intramuscular temperature of the gastrocnemius muscle.

This study investigated the effect of a 30-minute, 10 degrees C water bath on the intramuscular temperature of a lower leg and the contralateral lower leg. Intramuscular temperature was measured in 10 subjects using hypodermic thermistor probes inserted 25.3 mm into the lateral head of the gastrocnemius muscles of both legs. One lower leg was submersed in a 10 degrees C cold bath with the water level maintained 5 cm above the patella and with the subject in a nonweight-bearing position. Intramuscular temperature significantly decreased in both lower legs during treatment, although the intramuscular temperature of the treatment lower leg was significantly lower than that of the contralateral lower leg. A temperature difference continued for four hours after treatment; however, the temperature of both lower legs was significantly lower after four hours than it was before the cold bath treatment.

Adipose Tissue↗
PubMed1979

Choice and number of reinforcers.

Pigeons were exposed to the concurrent-chains procedure in two experiments designed to investigate the effects of unequal numbers of reinforcers on choice. In Experiment 1, the pigeons were indifferent between long and short durations of access to variable-interval schedules of equal reinforcement density, but preferred a short high-density terminal link over a longer, lower density terminal link, even though in both sets of comparisons there were many more reinforcers per cycle in the longer terminal link. In Experiment 2, the pigeons preferred five reinforcers, the first of which was available after 30 sec, over a single reinforcer available at 30 sec, but only when the local interval between successive reinforcers was short. The pigeons were indifferent when this local interval was sufficiently long. The pigeons' behavior appeared to be under the control of local terminal-link variables, such as the intervals to the first reinforcer and between successive reinforcers, and was not well described in terms of transformed delays of reinforcement or reductions in average delay to reinforcement.

Journal Article↗
PubMed1979

Prlonged bubble production by transient isobaric counter-equilibration of helium against nitrogen.

The production of systemic gas bubbles by isobaric counter-equilibration of helium against 5 atmospheres saturated nitrox (0.3 ATA O2 in both mixes) in awake goats was demonstrated. Sixteen animal exposures (8 dives, 2 animals per dive) to a sudden isobaric gas switch from saturation on N2 to He were conducted; 8 saturations occurred at 132 fsw and 8 at 198 fsw. Central venous bubbles were detected acoustically by means of a Doppler ultrasonic cuff surgically implanted around the inferior vena cava of each animal. Bubbles occurred from 20 to 60 min after the switch in both the 132 fsw and 198 fsw exposures, but were not always present in the 132 fsw exposure, and did not persist for as long. Bubbles or other Doppler events were often detected for the entire isobaric period-12 h-following the gas switch in the 198 fsw exposures. Decompressions were conducted according to the USN saturation tables and were uneventful, with only occasional bubbles. Supersaturation ratios calculated to have occurred for a considerable period after the gas switch were approximately 1.15 (tissue gas tension pi, divided by ambient hydrostatic pressure, P) with maxima at 1.26 for the faster tissues. These values are limiting ones in USN decompression only for the slower tissues. In general, therefore, these results argue for reducing the permissible ascent criteria for the faster tissues-assuming bubbles are to be avoided-and allowing more time at stops for non-saturation decompression. Gas switches from a more soluble to a less soluble and/or more rapidly diffusing gas should therefore be avoided until physiological limits are well worked out.

Animals↗
PubMed1978

(-)-2-Hydroxy-n-cyclopropylmethylmorphinan: radioimmunoassay and phamacokinetic profile.

The pharmacokinetic profile of (-)-2-hydroxy-N-cyclopropylmethylmorphinan (HCMM), a narcotic antagonist and analgesic, has been evaluated in man following administration of 25 to 50 mg of the drug orally and 10 to 15 mg intramuscularly. A specific radioimmunoassay procedure was developed for the determination of HCMM in plasma and urine. The drug had a mean "apparent" elimination half-life in plasma of about 11 hr following both routes of administration. A mean of 47% of the oral dose was excreted in the urine as unconjugated and conjugated HCMM and only 5% of the dose was excreted as intact HCMM. In one subject studied, the plasma levels of conjugated HCMM were as much as 5-fold higher than the levels of unconjugated drug. Although there was considerable intersubject variability following both routes of administration, the overall pharmacokinetic parameters suggest that oral and intramuscular doses are bioequivalent.

Administration, Oral↗
PubMed1978

An improved method for computed tomography of the base of the skull in head scanners that utilize a water bag.

The original EMI Mark I head scanner as well as the Artronix Neuro CAT scanner utilize a water bag surrounding the patient's head. One of the disadvantages of this system is that the patient's head may be displaced out of the scanning beam by the pressure of the water bag, thus making it difficult to obtain good scans of the base of the skull or the posterior fossa. A device that utilizes an adjustable footboard and restraining straps around the legs to hold the patient in position is described. Although designed specifically for the Artronix Neuro CAT scanner, it can readily be adapted to other scanners that utilize a water bag. In our experience it has worked well in restraining caudal movement of patients, thus enabling us to obtain good images of the posterior fossa and base of the skull.

Humans↗
PubMed1978

Attempts to attenuate the cardiostimulatory effects of ketamine.

In an attempt to attenuate the cardiostimulatory effects of ketamine, a number of drugs were given individually, or in combination, to fit adults undergoing body surface operations, either before or aftera ketamine induction of 1 mg kg-1 followed by an infusion of 1 mg ml-1. Of these, practolol, phentolamine, practolol-phentolamine, phentolamine-practolol, promethazine, hexamethonium, procainamide and verapamil were unacceptable. Labetalol, in doses of 0.5 mg kg-1 and 1.0 mg kg-1, proved to be the most promising drug and is worthy of further study.

Adult↗
PubMed1978

Attempted reduction of the cardiostimulatory effects of ketamine by labetalol.

Labetalol, a new antihypertensive agent with alpha and beta-adrenoceptor blocking properties was given to five series of patients anaesthetised with a ketamine infusion. in an attempt to reduce the cardiostimulatory effects of ketamine. It proved very effective in controlling the chronotrophic action of ketamine but was unreliable in controlling the rise in blood pressure. In doses of 1.0 mg kg-1 given with tubocurarine, it was not without side effects.

Adolescent↗
PubMed1978

Ketamine infusions. Observations on technique, dosage and cardiovascular effects.

A continuous infusion of ketamine, following an initial dose of 1 mg/kg, has been used as sole anaesthetic in over 200 adult patients. The pre-operative use of 4 mg lorazepam has made this acceptable with respect to emergence sequelae and dreams. The technique can be used with neuromuscular blocking drugs and controlled ventilation with air, but here pancuronium is best avoided because of excessive tachycardia and hypertension. Hypertonus was the main problem encountered in the non-relaxant cases. The amount of ketamine required for anaesthesia has been analysed in detail and recommendations on dosage are given. The cardiovascular effects have also been analysed in detail. There is a need for a similar investigation to be carried out in circumstances where inhalation agents are not available and where there is a shortage of anaesthetists.

Administration, Oral↗
PubMed1978

Coital cephalgia and ischaemic muscular work of the lower limbs.

A case is reported of a patient who presented with coital cephalgia, and in whom an obstructive lesion of the lower aorta was demonstrated. Bicycle ergometry evoked an abnormal pressor response. The condition was cured by restoration of normal circulation. An abnormal pressor response to treadmill exercise was shown to exist in subjects with intermittent claudication, and in normal subjects with circulation to lower limbs artificially occluded. A pressor response to buttock or leg exercise or both is suggested as the cause of the coital cephalgia.

Adult↗