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Biomedical subjects

D S Thompson

Publications and source records attributed to D S Thompson.

At least 55 records · Page 3Linked to original sources
PubMed1981

Cord blood lymphocyte in vitro responses to influenza A antigens after an epidemic of influenza A/Port Chalmers/73 (H3N2).

Samples of cord blood from 46 deliveries were collected between 2 and 8 mo after an epidemic of influenza caused by A/Port Chalmers/73 (H3H2) virus. Of 10 samples with HAI antibody titers against A/Port Chalmers of 1:16 or greater, one had 2-mercaptoethanol-sensitive IgM class antibodies against the virus. Lymphocyte proliferative responses with the use of A/Port Chalmers antigens were increased in six of 46 samples. These results provide immunologic evidence that certain neonates have IgM antibodies and lymphocytes sensitized for influenza A virus. Our results suggest, but do not prove definitively, that influenza A/Port Chalmers virus infected the fetus prior to delivery.

Antibodies, Viral↗
PubMed1981

Computerized tomography in the diagnosis of central and extrapontine myelinolysis.

In two patients the diagnosis of central pontine myelinolysis (CPM), suspected on clinical grounds, was supported by computerized tomographic (CT) sections made perpendicular to the pons, and confirmed on postmortem examination. Extrapontine myelinolysis was suggested on CT scans in both cases, and confirmed in one. Computerized tomography may prove to be a sensitive and accurate diagnostic test for CPM, and may aid in the detection of associated extrapontine lesions.

Adult↗
PubMed1980

Haemodynamic and metabolic effects of atenolol in patients with angina pectoris.

Myocardial substrate extraction, coronary sinus flow, left ventricular pressure, and cardiac output were measured in 11 patients with angina pectoris at three pacing rates before and after atenolol (0.2 mg/kg). Left ventricular pressures, and the product of systolic pressure time index and heart rate did not change, but max dP/dt and KV max fell after atenolol. Only at the lowest pacing rate did the drug reduce cardiac output. Coronary sinus blood flow and myocardial oxygen uptake did not change after atenolol. At the highest pacing rate before atenolol four patients developed angina, accompanied by a rise in end-diastolic pressure. After atenolol angina was abolished in three, but the end-diastolic pressure still rose at the highest pacing rate. Myocardial lactate extraction ratio fell as heart rate increased, and was lower in the patients who developed angina. After atenolol, lactate extraction ratio increased significantly at the highest and lowest pacing rates. Myocardial pyruvate extraction rose after the drug. Arterial concentrations of hydroxybutyrate and acetoacetate fell after atenolol, but the decrease in their extraction was not significant. Myocardial extraction of free fatty acids was related to arterial concentration, which fell after atenolol. The changes in lactate and pyruvate extraction after atenolol were related inversely to changes in arterial free fatty acid concentration suggesting that the improvement in myocardial metabolism could have been secondary to reduced peripheral lipolysis. The increase in lactate extraction was associated with relief of angina, but did not abolish the rise in end-diastolic pressure induced by pacing.

Adult↗
PubMed1980

Effects of propranolol on myocardial oxygen consumption, substrate extraction, and haemodynamics in hypertrophic obstructive cardiomyopathy.

Myocardial substrate extraction, coronary sinus flow, cardiac output, and left ventricular pressure were measured at increasing pacing rates before and after propranolol (0.2 mg/kg) in 13 patients with hypertrophic obstructive cardiomyopathy (HOCM) during diagnostic cardiac catheterisation. At the lowest pacing rate myocardial oxygen consumption varied considerably between patients and very high values were found in several individuals (range 10.1 to 57.5 ml/min). These large differences between patients were not explicable by differences in cardiac work; consequently, cardiac efficiency, estimated from the oxygen cost of external work, varied between patients and was lower than normal in all but two. The pattern of substrate extraction at the lowest pacing rate was similar to results reported for the normal heart, and measured oxygen consumption could be accounted for by complete oxidation of the substrates extracted; thus there was no evidence of a gross abnormality of oxidative metabolism, suggesting that low efficiency lay in the utilisation rather than in the production of energy. Each of the four patients with the highest myocardial oxygen consumption and lowest values of efficiency sustained progressive reductions in lactate and pyruvate extraction as heart rate increased, and at the highest pacing rate had low (< 3%) or negative lactate extraction ratios. In three of these four, coronary sinus flow did not increase progressively with each increment in heart rate. One patient with low oxygen consumption and normal efficiency also failed to increase coronary flow with the final increment in heart rate, and produced lactate at the highest pacing rate. Thus the five patients in whom pacing provoked biochemical evidence of ischaemia all had excessive myocardial oxygen demand and/or limited capacity to increase coronary flow. Propranolol did not change lactate extraction significantly at any pacing rate in either the ischaemic or non-ischaemic groups. In only one patient was ischaemia at the highest pacing rate abolished after propranolol, and this was associated with a 30 per cent reduction in oxygen consumption. These results do not demonstrate a direct effect of propranolol upon myocardial metabolism in patients with HOCM, but emphasise the potential value of beta-blockade in protecting these patients from excessive increases in heart rate.

Adolescent↗
PubMed1979

Pharmacokinetic model for procaine in humans during and following intravenous infusion.

A multicompartment pharmacokinetic model is presented to describe procaine distribution in humans during and following intravenous infusion. The model, based on a general perfusion model, relates individual characteristics such as sex, age, weight, height, infusion rate and duration, and hematocrit to general parameters such as drug metabolism, protein binding, ion-trapping effects, and tissue-plasma distribution coefficients to provide an individualized distribution prediction. Experimentally observed kinetics of blood procaine levels collected during intravenous procaine infusion as an adjunct to surgical anesthesia and blood lidocaine levels obtained from the literature compared very well with the model simulation.

Humans↗
PubMed1979

Reappraisal of intravenous procaine as a short-acting anesthetic adjuvant.

Our data in 74 patients demonstrate that procaine hydrochloride is a safe anesthetic adjuvant in doses of 1 mg/kg/min even when total doses are 5 to 7 g. Blood pressure, heart rate, electrocardiographic variables, and blood gases were not adversely affected. Patients had no nausea or untoward postanesthesia symptoms. Emergence from anesthesia was rapid, within less than 15 minutes in all patients, and most were fully awake before leaving the operating room. In two patients in whom blood levels were studied the drug disappeared within 40 minutes. Procaine is inexpensive, $1.16 for 10 g, and it is not a known liver or kidney toxin. Until studies on cardiovascular dynamics and analgesic effects as in whom a low plasma cholinesterase activity is present or suspected. The clinical appraisal in 56 patients indicates its usefulness in suppressing premature venticular contractions and cough reflexes during endoscopic procedures in the respiratory tract. Procaine can be used to advantage in supplementing general anesthesia in outpatient surgery because of its brief action. For these reasons, the drug merits further study.

Adolescent↗
PubMed1979

Haemodynamic effects of disopyramide in patients after open-heart surgery.

Disopyramide phosphate was administered intravenously in a dose of 1.2 mg/kg body weight over one minute to nine patients after open-heart surgery and coronary artery bypass grafting. The haemodynamic changes were studied during and for 30 minutes after drug administration. Heart rate was unchanged throughout the study. During infusion the only significant changes were an increase in systemic blood pressure and systolic impedance signifying a direct increase in peripheral arterial resistance. Systemic blood pressure remained significantly higher for 10 minutes and systolic impedance for 30 minutes. Immediately after infusion max. dPower/dT, a measure of ventricular contractility, was significantly depressed for 15 minutes. Both cardiac output and aortic flow were significantly depressed for 30 minutes. DPTI/TTI, an estimate of subendocardial supply/demand ratio, showed an insignificant increase throughout the study. This study shows that intravenous disopyramide starts acting within 45 seconds of the start of infusion, directly increases peripheral arterial resistance, has a breif negative inotropic action, and does not reduce subendocardial blood flow.

Adult↗
PubMed1979

Assessment of thrombocytopenic patients for splenectomy.

Platelet survival and splenic sequestration patterns were studied in 32 patients with thrombocytopenia using donor platelets labelled with chromium-51. A shorter mean platelet lifespan was observed in immune thrombocytopenia (ITP) (mean 12 hours) than in hypersplenism (mean 56 hours) or marrow hypoplasia (mean 102 hours). There was no such correlation between diagnosis and splenic sequestration. A biphasic survival curve was seen in nine of 22 patients with ITP. Thirteen patients underwent splenectomy with complete (9) or partial (4) response, but no consistent pattern of results was manifest. It is concluded that in vivo isotope studies are of little value in predicting the benefit of splenectomy in thrombocytopenic patients, although they may demonstrate the mechanism of the thrombocytopenia, in particular the biphasic survival curve revealing separate 'immune' and 'hypersplenic' components of platelet destruction in ITP.

Adolescent↗
PubMed1978

Use of supine pressor test to prevent gestational hypertension in primigravid women.

The supine pressor (roll-over) test was performed on 62 nulliparous patients under 20 years of age at conception. The 28 patients (45%) with positive tests were treated to prevent the development of gestational hypertension. Four of those with a positive test and two of those with a negative test developed gestational hypertension. Compared with a composite of other reported studies of this test in which the patients were not treated, our results indicated a statistically significant reduction in the incidence of gestational hypertension. The supine pressor test appears to be useful clinically in young nulliparous women.

Adult↗
PubMed1978

Preoperative oral antacid therapy for patients requiring emergency surgery.

Preoperative oral antacid therapy has been used effectively to reduce the number of emergency obstetric patients "at risk" of developing acid-aspiration syndrome. Thirty-three nonobstetric adult patients requiring emergency surgery were selected to determine whether the protective effects of antacid therapy could also be derived in this high-risk group. Maalox-treated patients had a mean gastric pH of 6.46 +/- 0.5 and gastric volume 21.5 +/- 3.6 ml, with none at risk, whereas control patients had mean pH of 3.71 +/- 0.43, gastric volume 71.5 +/- 16.5 ml, and 42.1% at risk. This report suggests that preoperative antacid therapy should reduce the incidence of acid aspiration and subsequent morbidity and mortality in patients requiring emergency surgery.

Administration, Oral↗
PubMed1978

Intravenous procaine for general anesthesia in dogs: a new look at an old technic.

New anesthetics have been introduced during the last 25 years which are not without inherent disadvantages. They are expensive, and some produce nephrotoxicity and possibly hepatotoxicity. Although the use of procaine intravenously as an anesthetic has been discarded, probably because of a convulsive effect, it is believed this disadvantage can be controlled by concomitant use of other drugs. Hence procaine, preceded by thiamylal, was administered to dogs to test its anesthetic capability, reversibility, and effects on the cardiovascular and central nervous systems. Blood levels of procaine were measured and correlated with these physiologic responses. Convulsive doses were ten times those producing anesthesia. There were no detrimental effects which would preclude a reevaluation in humans. Intravenous procaine produces definite general anesthesia, and it has the additional advantages of being rapidly hydrolyzed and providing antiarrhythmic effects. It may prove useful in modern anesthesia.

Anesthesia, General↗
PubMed1978

Changes in liver enzyme values after halothane and enflurane for surgical anesthesia.

For over a decade there has been concern about hepatitis related to halothane anesthesia. No dose relationship or other direct cause has ever been established, and jaundice has been found to occur after other anesthetics for surgical operations. Enflurane is a newer halogenated compound with a remarkable record of safety, yet a few cases of hepatitis are reported to be associated with its administration. We have compared effects on the liver of the two anesthetics by testing hepatic serum enzymes and sulfobromophthalein in 12 patients who received halothane and 12 who received enflurane. No significant differences between the two groups were found. Both had similar but minimal elevations of the hepatic serum enzymes and retention of sulfobromophthalein. More than half the patients had enzyme increases over normal levels but reasons for this were not obvious. Since hepatic change may take place in many postoperative patients, it is not surprising to have an occasional one develop hepatitis. The exact cause is unknown and therefore it is impossible to predict the patient who will develop the disease, regardless of the anesthetic.

Adult↗