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Biomedical subjects

M Thomson

Publications and source records attributed to M Thomson.

36 records · Page 2Linked to original sources
PubMed1989

Comparative biochemical and pharmacological properties of epidermal secretions from Ariid catfish of the Arabian Gulf.

1. Comparative biochemical and pharmacological studies on epidermal secretions from three species of Ariid catfish were carried out to determine whether they share common properties. 2. Protein compositions are generally similar, but show some differences in size and numbers of proteins. 3. Lipids also differ. However, seasonal and dietary changes in lipid compositions exceed the differences among species. 4. Enzymes in the secretions appear common to each fish species, though some differences are noted in relative activities. 5. Toxicity responses of rabbits to injections with secretions from each of the catfish species indicated that two were lethal, with similar lethal dose levels when injected intravenously. 6. Secretions from all three catfish induced changes in plasma enzyme levels indicative of heart and liver damage, and also induced changes in blood glucose and cholesterol levels.

Animals↗
PubMed1989

Pressor effects of the alpha 2-adrenoceptor agonist B-HT 933 in anaesthetized and haemorrhagic rats: comparison with the haemodynamic effects of amidephrine.

1. Blood pressure responses to single and multiple bolus doses of the alpha 2-adrenoceptor agonist B-HT 933 were analysed in intact anaesthetized rats which were either normotensive or hypotensive as a result of haemorrhage. Single bolus doses of B-HT 933 in normotensive rats induced a fall in blood pressure, whilst further doses induced dose-dependent pressor responses which were inhibited by the alpha 2-adrenoceptor antagonist yohimbine and unaffected by the alpha 1-adrenoceptor agonist prazosin. In the haemorrhagic, hypotensive animals, single bolus doses of B-HT 933 induced immediate dose-dependent pressor responses; the maximum pressor responses to the bolus of B-HT 933 and its ED50 values were the same in both the normotensive and hypotensive, haemorrhagic animals. 2. Cardiac output, its distribution and tissue blood flows were determined with tracer microspheres in intact anaesthetized normotensive and haemorrhagic, hypotensive rats during depressor (normotensive) and pressor (normotensive and hypotensive) responses to B-HT 933. Haemodynamics were also determined during pressor responses to the alpha 1-adrenoceptor agonist amidephrine. 3. In control normotensive rats, a single dose of B-HT 933 (1 mg kg-1) reduced blood pressure by reducing cardiac output (through a decrease in heart rate). It increased the fractional distribution of cardiac output to the spleen and stomach, reduced it to the heart and liver and reduced cardiac and hepatic blood flow. A further dose of B-HT 933 (1 mg kg-1 bolus followed by 100 micrograms min-1 infusion) increased blood pressure by increasing total peripheral resistance, which was accompanied by decreased proportions of cardiac output passing to the heart, liver and testes. There was also increased fractional distribution of cardiac output to the lungs, spleen, kidneys and stomach but blood flows through the liver and testes were reduced. Amidephrine (6 micrograms kg-1 bolus followed by 0.5 micrograms min-1 infusion) increased blood pressure by increasing cardiac output through an increased stroke volume. It increased cardiac output distribution to the kidneys and brain, increasing blood flow through the heart, lungs, brain, testes, epididimides, skin and large intestine. 4. Haemorrhage caused a fall in blood pressure which resulted from decreased total peripheral resistance and cardiac output (the latter due to decreases in both heart rate and stroke volume). It reduced the proportion of cardiac output distributed to the lungs, spleen, kidneys, testes and pancreas/mesentery and decreased blood flow through these organs as well as through the heart, liver, brain, epididimides, skin and the gastrointestinal tract.4

Adrenergic alpha-Agonists↗
PubMed1989

The effects of enalapril on hypertension and quality of life. A large multicenter study in Belgium.

Belgian general practitioners studied the effect of enalapril over a period of 6 months on hypertension and quality of life in 4988 patients, whose hypertensive condition remained uncontrolled by previous treatments and/or in whom this previous drug regimen was not tolerated. Blood pressure was reduced from an average of 170/101 mm Hg at the onset of the trial to 145/85.5 mm Hg after 24 weeks. The treatment with enalapril was well tolerated and tolerance improved remarkably in the patients, whose previous treatment had caused intolerance. Quality of life, determined by means of the Nottingham Health Profile questionnaire, was favourably influenced in the patients participating in this study.

Adult↗
PubMed1989

Linoleic acid and coronary heart disease.

Low tissue concentrations of the essential fatty acid, linoleic acid, occur in communities with high rates of coronary disease and in patients with angina and myocardial infarction. This relationship is independent of lipids and blood pressure, but in smokers linoleic acid is particularly low because they eat less linoleic acid-containing foods.

Coronary Disease↗
PubMed1976

The role of copper in preventing gastrointestinal damage by acidic anti-inflammatory drugs.

The ability of several non-steroidal acidic anti-inflammatory drugs to cause ulceration when given as copper complexes has been examined. The damage caused by clopirac, niflumic acid and aspirin was virtually abolished when they were given as copper complexes whereas the damage caused by indomethacin, ketoprofen and (+)-naproxen was unaltered. The lack of ulceration with three of these preparations appeared to be correlated with a much reduced ability to inhibit prostaglandin synthesis as determined using an in vitro enzyme system.

Acetates↗
PubMedDate not supplied

Aerosol inhalation and depth of deposition in the human lung. The effect of airway obstruction and tidal volume inhaled.

Ten patients with chronic bronchitis, whose FEV1.0 varied between 0.48 and 3.00 1, inhaled uniform 5-micronm particles tagged with technetium-99 in tidal volumes (VT) varying between 750 and 1830 ml. Their chests were scanned after inhalation to ascertain depth of deposition of the particles, and clearance from the lungs was monitored for 5 hr by serial whole-lung gamma counting. A significant inverse relationship (P less than .05) was found between depth of deposition after inhalation (D), measured horizontally across the lung as percentage per inch, and rate of clearance of the particles (5-hr retention [%] = 100- % cleared at 5 hr=69.12-3.02D). This confirmed previous findings. The depth of deposition depended directly on the FEV1.0 and VT (5-hr retention [%] = 0.026VT + 12.67FEV1.0-4.13); this resulted in a 14%-75% range for 5-hr retention. Regression slopes for VT and FEV1.0 were independently significant (P less than .05). The findings suggest that, as commonly administered at present, the therapeutic efficiency of most drugs given be aerosol will be reduced in proportion to the degree of airway obstruction as measured by the FEV1.0. The efficiency can be enhanced by increasing the depth of inspiration of the aerosol.

Aerosols↗
PubMedDate not supplied

Heavy birthweight in Native Indians of British Columbia.

An unexpected finding of heavy birthweight in one group of Native Indians in Ontario led to this analysis of the occurrence of heavy birthweight in Natives of British Columbia. Canadian Native Indians have high rates of perinatal mortality, usually directly related to low, not high birthweight. Birth statistics of all singleton livebirths during 1982 to 1986 were examined. Heavy birthweight was 50% more frequent among Natives than non-Natives (relative risk 1.47, 95% confidence limits 1.35 and 1.59), after stratification by week of gestation. Stratification was necessary because pre-term births were twice as frequent among Natives as non-Natives (11.4% vs 5.7%). Fetal and neonatal mortality were 40% more frequent in Natives. To explain these findings, a hypothesis is advanced of high rates of glucose intolerance during pregnancy in Natives.

Birth Weight↗