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Biomedical subjects

A M Hayler

Publications and source records attributed to A M Hayler.

11 recordsLinked to original sources
PubMed1979

Simple gas-liquid chromatographic method for the measurement of mexiletine and lignocaine in blood-plasma or serum.

A simple method has been developed for the measurement of mexiletine and lignocaine in blood-plasma or serum at the concentrations attained during therapy. A relatively small (200 microliter) sample volume is made basic and extracted with 50 microliter of chloroform containing internal standards, and the extract is analysed directly by gas-liquid chromatography with flame-ionisation detection on two separate columns. The instrument calibrations are linear and pass through the origin of the graphs. Neither solvent transfer nor evaporation steps are used in the extraction procedure, which takes less than 3 min to complete, and no interference from either endogenous sample constituents or other drugs has been observed.

Chromatography, Gas↗
PubMed1979

Cardiac consequences and treatment of disopyramide intoxication: experimental evaluation in dogs.

A slow (1.18 mumol.kg-1.mm-1) intravenous infusion of disopyramide (mol.wt 339) was given to 8 adult Beagle dogs. An initial phase of slow decline in cardiac output and broadening of the QRS complex on the ECG, with systolic blood pressure maintained above 13.5 kPa (100 mmHg), was followed by a phase of rapid circulatory failure without a correspondingly dramatic change in ECG appearances. Underventilation and cardiac arrhythmias were observed only in the agonal phase after several minutes of circulatory arrest. They were not therefore the primary cause of death, which was due to failure of myocardial contractility. Three positively inotropic drugs (isoprenaline, dopamine, and glucagon) are shown to be capable of restoring the failing circulation, provided they are given before the phase of complete circulatory standstill. In this respect isoprenaline appears superior to dopamine and glucagon.

Animals↗
PubMed1978

Simple gas-liquid chromatographic method for the measurement of disopyramide in blood-plasma or serum and in urine.

A simple method has been developed for the measurement of disopyramide in blood-plasma or serum at the concentrations attained during therapy. A relatively small (200 microliter) sample volume is made basic and extracted with 50 microliter of chloroform containing an internal standard, and the extract is analysed directly by gas-liquid chromatography with flame-ionization detection. The instrument calibration is linear and passes through the origin of the graph. Neither solvent transfer nor evaporation steps are used in the extraction procedure, which takes less than 3 min to complete, and urine specimens may be analysed by an analogous technique. No interference from either endogenous sample constituents or other drugs has been observed, although a simple back-extraction procedure is described which eliminates potential interference from a small number of basic and neutral drugs.

Chromatography, Gas↗
PubMed1978

Fatal overdosage with disopyramide.

The most common clinical finding in five patients who died after deliberately taking overdoses of disopyramide was an early loss of consciousness after an apnoeic episode. An initial response to resuscitation and antiarrhythmic drugs in four patients was not sustained and these patients deteriorated rapidly with cardiac arrhythmias and loss of spontaneous respiration. At necropsy the appearance of the lungs in four cases was consistent with pulmonary congestion secondary to left ventricular failure.

Adolescent↗
PubMed1976

Penetration of digoxin into cerebrospinal fluid.

The concentration of digoxin in the cerebrospinal fluid (CSF) of ten patients receiving conventional oral doses of this cardiac glycoside has been measured by a radioimmunoassay technique. Digoxin was undetected in eight patients and barely detectable in two, suggesting the presence of a significant blood-CSF barrier for digoxin. The implication of these findings is discussed.

Adult↗