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Biomedical subjects

J H Sanderson

Publications and source records attributed to J H Sanderson.

14 recordsLinked to original sources

Multicentre study of propofol in day case surgery.

An open multicentre study that involved 879 patients was set up after the launch of propofol to examine its use outside of the clinical trial programme and within the context of a routine clinical setting. Propofol was assessed as the main anaesthetic agent for a range of day case surgery that included gynaecological, urogenital, body surface, orthopaedic and dental procedures. For the purposes of the study, supplementary agents were restricted to fentanyl, alfentanil or nitrous oxide; no volatile anaesthetics were allowed. Induction of anaesthesia was smooth; 91.6% of patients experienced no excitatory or other adverse effect. The mean duration of anaesthesia was 12 minutes 12 seconds and the mean dosage of propofol was 10.6 mg/kg/hour. Maintenance was uneventful in the large majority of patients. Pain on injection affected approximately 25% of patients and the incidence was reduced when large veins were used for injection. Recovery was rapid with a short interval of approximately 1 minute between awakening and orientation (time to giving correct date of birth). There was a low incidence of postoperative nausea and vomiting.

Adolescent

Release of beta-thromboglobulin from human platelets by therapeutic intensities of ultrasound.

The effects of therapeutic intensities of ultrasound on human platelets in whole blood were investigated by monitoring the release of the platelet specific protein beta-thromboglobulin (beta-TG). More beta-TG was released as the intensity of the ultrasound was increased and also as the driving frequency was decreased from 3.0 to 0.75 MHz. Some beta-TG was released at spatially-averaged intensities as low as 0.6 W/cm2 at 0.75 MHz, a value significantly lower than that observed for the onset of aggregation of platelet rich plasma (obtained from the same volunteer) in the same exposure system. Liberation of beta-TG by ultrasound was diminished but not abolished in the presence of inhibitors which rendered the platelets functionally inert. Our data suggests that beta-TG is liberated in two ways, firstly as a result of platelet disruption by cavitation, and subsequently by potent aggregating agents, liberated in parallel with beta-TG, inducing the physiological release reaction in adjacent platelets. The low therapeutic intensities and short exposure times (30 s or less) necessary to liberate beta-TG from normal human platelets in vitro, suggests that patients with abnormally sensitive platelets and/or 'hypercoagulable state' could be at risk if subjected to high therapeutic intensities of ultrasound.

Beta-Globulins

A new method of carboxyhaemoglobin determination.

A quick and accurate method of determining the concentration of carboxyhaemoglobin (COHb) in blood has been developed. The method uses a dual wavelength double beam spectrophotometer in the 1st derivative mode, linked to a digital voltmeter (DVM), with the two beams set 3 nm apart around an isobestic point of reduced haemoglobin (Hbred) and carboxyhaemoglobin at 579 nm. The 1st derivative mode measures the slope, and this slope is proportional to the concentration of COHb.

Animals

Pirimicarb induced immune haemolytic anaemia in dogs.

The feeding of pirimicarb (2-dimethylamino-5,6-dimethylpyrimidin-4-yl dimethylcarbamate) to normal beagle dogs resulted in anaemia in a small number of animals. Dosing studies confirmed pirimicarb as the causative agent and the anaemia was characterised as haemolytic. Serological tests revealed the presence of an IgG antibody active only in the presence of pirimicarb. The level of antibody detected was related to the dose of pririmicarb given.

Anemia, Hemolytic

The investigation of collagen induced platelet aggregation by the screen filtration pressure technique.

A modification of the screen filtration pressure technique has been developed to allow platelet response to collagen to be measured. Using a commercial collagen suspension this method has been found to be both simple to perform and to give highly reproducible results. Changes in platelet response to collagen after administration of acetylsalicyclic acid were clearly detected and this suggests that collagen screen filtration pressure may provide a sensitive method for evaluating the effect of platelet release inhibiting drugs.

Aspirin

Biochemical and haematological changes during the induction of labour at term with oxytocin, prostaglandin E-2 and prostaglandin F-2alpha.

A total of 75 patients had labour induced near term using intravenous oxytocin, prostaglandin E-2 or prostaglandin F-2alpha. Biochemical and haematological investigations were performed to assess hepatic, renal and adrenocortical function and changes in platelet adhesiveness. In doses which were similarly effective in inducing labour, both prostaglandins were without the water-retaining effect of oxytocin. Adrenocortical stimulation was greatest with oxytocin. No difference between these agents was observed for the other measurements made.

Alkaline Phosphatase