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Biomedical subjects

W R Thompson

Publications and source records attributed to W R Thompson.

At least 91 records · Page 5Linked to original sources
PubMed1981

Lumbar epidural morphine as an effective analgesic following cholecystectomy.

Relief of pain with epidural morphine was evaluated in five patient subjects during two consecutive twenty-four periods after cholecystectomy. In one period, each subject received lumbar epidural morphine, first 4-6mg, and twelve hours later, 2-3 mg; in the other period, epidural placebo at the same times. Except for four hours before each injection and twenty minutes thereafter, intramuscular morphine was administered as required throughout. The experiments were double-blind. Epidural morphine, unlike epidural placebo, reduced both a visual pain analogue score (p less than 0.05) and a pain questionnaire score (p less than 0.01) twenty minutes after injection. Epidural morphine compared to placebo reduced by one-half the total amount of narcotic (epidural plus intramuscular) administered over the twenty-four hour period (p less than 0.05). Four of five subjects clearly preferred analgesia with epidural morphine over the effect of placebo plus therapeutic doses of intramuscular morphine. We conclude that epidural morphine, administered in this manner, is effective in relieving pain after cholecystectomy and that it may be preferred by patients over conventional intramuscular morphine.

Adult↗
PubMed1981

Regional analgesic effect of epidural morphine in volunteers.

Limb ischaemia induced by a sub-maximum effort tourniquet technique was used to characterize the analgesic effects of lumbar epidural morphine in volunteers. As an index of pain threshold, we measured the time to perception of pain in and upper an a lower limb before and at intervals up to six hours following epidural injections of morphine 3.5 mg an 7.0 mg, and before and after subcutaneous injections of the same doses. Subcutaneous morphine had no significant effect on the times to perception of pain in either limb. Lumbar epidural morphine did not alter upper limb times, but markedly delayed the onset of pain in the lower limbs. This lower limb analgesic effect was apparent thirty minutes after injection, peaked at about ninety minutes and was still present after six hours. Serum levels of morphine were nearly identical after subcutaneous and epidural injections of the same dose. We conclude that lumbar epidural morphine produces marked analgesia for this type of experimental pain primarily by a "regional" effect rather than as a result of systemic absorption. This regional effect develops slowly and is prolonged.

Analgesics↗
PubMed1981

Epidural morphine causes delayed and prolonged ventilatory depression.

We measured ventilation, PETCO2 and the Ventilatory response to added carbon dioxide before and at intervals up to six hours after epidural morphine 3.5 mg and 7.0 mg, and before and after subcutaneous injections of the same dose in volunteers. Subcutaneous morphine increased PETCO2 slightly, but did not alter the sensitivity of the response to added carbon dioxide. Epidural morphine reduced ventilation and increased PETCO2 progressively with time and, six hours after injection, reduced the ventilatory response to carbon dioxide considerably. In two subjects tested, these ventilatory effects persisted for twenty-four hours. The added effects of epidural morphine were due primarily to reductions in tidal volume and the tidal volume response to added carbon dioxide. We conclude that epidural morphine causes delayed and very prolonged ventilatory depression, which is of a greater magnitude and a different ventilatory pattern than that which follows the same does of morphine given subcutaneously. Ventilatory depression after lumbar epidural morphine develops slowly, as the lower limb analgesic effect is waning.

Adult↗
PubMed1981

Disposable condenser humidifiers in intensive care.

Two disposable condenser humidifiers were evaluated in nine ventilated intensive care patients. The Portex "Humid Vent" delivered end-inspired absolute humidities of 22--26.3 g/m3 at end-inspired temperatures of 27--28.3 degrees C. Corresponding humidities and temperatures with the Servo "Humidifier 150" were higher and were constant, at 27.7--29 g/m3 and 29.3--29.7 degrees C respectively. These disposable devices can be used for humidification in intensive care, but only for patients breathing room air, or on a short term basis.

Adolescent↗
PubMed1981

Toxic shock syndrome -- some new features.

A thirty-year-old female presented with a high fever, conjunctivitis, confusion, vomiting, watery diarrhoea, diffuse erythroderma, shock and oliguric renal failure. Staphylococcus aureus phage 29/52 (Group 1) was isolated from a high vaginal swab. In addition to all the previously reported features which defined toxic shock syndrome, there were pustular skin vesicles, altered red cell morphology, and severe myocardial involvement. Treatment with fluid replacement, cloxacillin, haemodialysis, positive inotropic agents, and supportive measures resulted in a full recovery.

Adult↗
PubMed1980

Pavlovian excitation, internal inhibition, and their interaction with free operant avoidance as a function of age in rats.

The central hypothesis was that, in young as compared with adult rats. Pavlovian excitation is weaker and extinguishes more slowly, whereas internal inhibition is weaker but extinguishes more rapidly. In Experiment I, the suitability of free operant (Sidman) avoidance as a baseline for measuring Pavlovian effects was assessed in 5 age groups between 19 and 98 days of age trained in a shuttle box. Although clear age-related increases were evident in avoidance capacity, efficient "high criterion" avoiders were found in all age groups, indicating that the response was suitable. In Experiment II, groups of 26-, 38-, and 95-day-old rats first received Pavlovian aversive excitatory and differential inhibitory conditioning, or the conditional stimuli and shock randomly, or no treatment. Three days later they received free avoidance training. Prior Pavlovian conditioning facilitated subsequent avoidance learning in young subjects, but depressed it in adults. Among "high criterion" avoiders, such effects were absent. Following the avoidance training phase, 3 age groups of matched "high criterion" avoiders received conditioned stimuli superimposed on the baseline (a conditioning test). These results confirmed the central hypothesis.

Age Factors↗
PubMed1980

Experience with the EEA stapling device.

The EEA stapling instrument was used to perform 48 anastomoses without operative mortality. One of the 29 colorectal anastomoses developed a leak. Two intraabdominal abscesses were noted, one after an intraperitoneal colocolostomy and one after a colorectal anastomosis. No leaks were demonstrated in the 12 esophageal anastomoses. Minor bleeding that occurred in one of the colorectal anastomoses ceased spontaneously without need for transfusion. One esophageal and one colorectal anastomosis became narrowed postoperatively, but both were corrected with dilatation without further problem. In two of the very low colorectal anastomoses, transient fecal soilage occurred for 4 to 5 months postoperatively. On the basis of our experience, we believe that the EEA instruments has a definite place in gastrointestinal surgery. Its greatest virtue is that it provides a means to perform the heretofore technically difficult and frequently insecure colorectal and esophageal anastomoses with greater facility and security.

Colon↗
PubMed1979

Increases in cuff volume and pressure in red rubber endotracheal tubes during anaesthesia.

Increases in endotracheal tube cell volume and pressure during anaesthesia have been reported to be due to the diffusion of nitrous oxide into the cuff. This study compared cuff volume and pressure changes in anaesthetized intubated patients who were ventilated with those allowed to breath spontaneously. The cuffs of Magill red rubber endotracheal tubes were inflated with either air or a nitrous oxide-oxygen mixture. Serial pressure and volume recordings confirmed that both parameters increased when the cuff was inflated with air. The increase in cuff pressure was however, greater during intermittent positive pressure ventilation than for spontaneous respiration. There were no significant changes when the cuff was inflated with the nitrous oxide-oxygen mixture.

Adolescent↗
PubMed1978

Change in the management of adult groin hernia.

Three hundred fifty-seven groin hernia repairs were performed under local anesthesia using a long-lasting local anesthetic agent. An ilioinguinal, iliohypogastric, and twelfth intercostal nerve block was carried out initially, followed by regional infiltration of the agent, using a technic first described by Ponka [8] with several modifications. This technic can be employed suffessfully in the majority of groin hernia repairs. It requires careful attention to detail in the administration of preoperative sedation and analgesia and the use of sharp dissection only and greater gentleness in the handling of tissue. We have observed a significant reduction in postoperative discomfort and the virtual elimination of urinary retention, urinary sepsis, atelectasis, and phlebitis in these cases. All patients are fully ambulatory, without assistance immediately after surgery and the majority are discharged the same day or the following morning. This results in a marked reduction in the total cost of repairing a groin hernia.

Adolescent↗
PubMed1976

Acetylcholine receptor oligomers from electroplax of Torpedo species.

Sedimentation in sucrose gradients of alpha-bungarotoxin-labeled crude and pure acetycholine receptor preparations from Torpedo californica showed two major oligomers. The molecular weights, corrected for the bound Triton X-100 by comparing sedimentation in H2O and in D2O, were 330 000 for the heavy (H) oligomer and 190 000 for the light (L) oligomer. Lesser peaks found in preparations of T. marmorata and purified preparations of T. californica with molecular weights of 500 000 (HH) and 80 000 (LL). These molecular weights are based upon the assumption of globularity, and may require adjustment if the assumption is wrong. The H and L peaks have similar drug sensitivities, but at pH 10 the L peak was stable whereas the H peak dissociated to components sedimenting as LL. Treatments with p-chloromercuribenzoate, which blocks acetylcholine binding partially without affecting alpha-bungarotoxin binding, had no effect upon the pattern of sedimentation. This and other evidence suggested that the heterogeneity of oligomers was unrelated to the heterogeneity of site affinities for acetylcholine and nicotinic drugs.

Acetylcholine↗
PubMed1976

Drugs derived from cannabinoids. 3. Sulfur analogs, thiopyranobenzopyrans and thienobenzopyrans.

Sulfur analogs of cannabinoids corresponding to DMHP (1) were prepared utilizing the Pechmann condensation between the appropriate keto ester and (5-(1,2-dimethylheptyl)resorcinol, followed by Grignard reaction. Compounds of various structural types (2-6), which had different ring size and position of the sulfur atom substituted in the alicyclic ring, were found to be active CNS agents in pharmacological tests in mice, rats, and dogs. They showed profiles qualitatively similar to those of the nitrogen and carbocyclic analogs. Basic esters of the most interesting parent phenols 2 and 4 were also prepared and tested.

Aggression↗
PubMed1972

Flavonols: pigments responsible for ultraviolet absorption in nectar guide of flower.

The petals of the black-eyed susan (Compositae: Rudbeckia hirta) contain three flavonol glucosides (6,7-dimethoxy-3',4',5-trihydroxyflavone-3-O-glucoside, patulitrin, and quercetagetin). These compounds, which show intense spectral absorption at 340 to 380 nanometers, are restricted in distribution to the petal bases, which are ultraviolet absorbing as a result. Such ultraviolet-absorbing petal zones, known as "nectar guides," are invisible to us, but are visible and of orientation value to the pollinating insect that lands on the flower in search for food. This is the first time that ultraviolet absorption in a nectar guide has been interpreted in chemical terms. In view of the widespread occurrence of flavonols in flowers, it is suggested that these pigments serve specifically for demarcation of ultraviolet petal patterns visible and relevant to insects.

Chemical Phenomena↗