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Biomedical subjects

J H Sanderson

Publications and source records attributed to J H Sanderson.

At least 19 recordsLinked to original sources
PubMed2002

Suppression of multiple ionization of atomic ions in intense ultrafast laser pulses.

The interaction of an intense laser field with a beam of atomic ions has been investigated experimentally for the first time. The ionization dynamics of Ar+ ions and Ar neutrals in a 60 fs, 790 nm laser pulse have been compared and contrasted at intensities up to 10(16) W cm-2. Our results show that nonsequential ionization from an Ar+ target is strongly suppressed compared with that from the corresponding neutral target. We have also observed for the first time the strong field ionization of high lying target metastable levels in the Ar+ beam.

Journal Article↗
PubMed1997

Withdrawal reactions with selective serotonin re-uptake inhibitors as reported to the WHO system.

OBJECTIVE: The present study was performed both to investigate whether there might be a difference between the selective serotonin re-uptake inhibitors, (SSRIs) with regard to the incidence of withdrawal reactions, and to describe the associated symptoms. From the WHO database, therefore, all case reports from the year of introduction for each of the SSRIs, fluoxetine, paroxetine and sertraline, were retrieved. Sales figures were obtained from Intercontinental Medical Statistics International. The reporting rates were calculated as the number of reports per million defined daily doses (DDDs) sold per year. RESULTS: The reporting rate of withdrawal reactions for paroxetine was found to be higher than that for sertraline and fluoxetine in each of the countries selected for detailed analyses (US, UK and Australia), as well as for all 16 countries combined. Moreover, using the WHO system of organ classification, the ratio of central nervous system to psychiatric withdrawal symptoms was 1.9 and 2.1 for paroxetine and sertraline, respectively, whereas that for fluoxetine was 0.48, indicating a possible qualitative difference between the SSRIs with respect to the nature of the withdrawal syndrome.

1-Naphthylamine↗
PubMed1997

How does cystitis affect a comparative risk profile of tiaprofenic acid with other non-steroidal antiinflammatory drugs? An international study based on spontaneous reports and drug usage data. ADR Signals Analysis Project (ASAP) Team.

Series of well-documented case reports strongly suggest a causal association between tiaprofenic acid and a form of aseptic cystitis, which can cause serious and long-term morbidity if the drug is not withdrawn promptly. These findings are supported in the Australian and UK spontaneous reporting data-bases. Using sales data as the denominator, a comparison of NSAIDs in the WHO drug monitoring data-base indicates that the reaction is specific to tiaprofenic acid and cannot be accounted for by changes in reporting patterns in certain countries or years. Delayed recognition is an important feature of this reaction and possible reasons for this are discussed. Comparison of the risk profiles of seven NSAIDs indicated that tiaprofenic acid had the poorest risk profile, compared with NSAIDs of similar efficacy, when cystitis reports were included. The results suggest that combining spontaneous reports, classified according to severity, with sales data may enhance the ability of drug monitoring data-bases to contribute to risk benefit appraisals.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1988

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↗
PubMed1981

The use of beta-thromboglobulin to detect platelet damage by therapeutic ultrasound in vivo.

Three sequential blood samples were drawn from arms of adult human volunteers by means of a cannula technique, and the plasma levels of beta-thromboglobulin (beta-TG an index of platelet damage) were measured. Ultrasound (0.75 MHz, continuous wave; spatially averaged intensity 0.34 to 0.5 W/cm-2) was applied to the blood vessels while the second sample of each series was being taken. No elevation of beta-TG was detected, indicating that under these conditions ultrasonic irradiation had not damaged an appreciable number of platelets. There was, however, an indication of decreased platelet sensitivity following insonation; and it is postulated that this may be the result of either increased production or secretion of the potent endothelial platelet inhibitor, prostacyclin, or both.

Adult↗
PubMed1978

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↗
PubMed1978

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↗
PubMed1977

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↗
PubMed1977

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↗
PubMed1975

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↗