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Biomedical subjects

R Wilson

Publications and source records attributed to R Wilson.

At least 613 records · Page 34Linked to original sources
PubMed1987

Pulmonary vascular obstruction in severe ARDS: angiographic alterations after i.v. fibrinolytic therapy.

IV streptokinase was infused to test the potential reversibility of adult respiratory distress syndrome (ARDS) associated pulmonary vascular thrombosis in five patients suffering from severe ARDS with elevated mean pulmonary artery pressure, increased pulmonary vascular resistance, and angiographically documented pulmonary vascular thrombosis. At 48 hr there was clearance of obstructions in arteries larger than 1 mm in diameter in all patients, increased filling of the microvasculature and small arteries less than 1 mm in diameter in four patients, a fall in pulmonary vascular resistance in all patients, a rise in cardiac output in four patients, improved oxygenation (PAO2/FlO2) in three patients, and variable changes in shunt fraction and ventilator pressures. Expressed as a mean fraction of the preinfusion controls, the postinfusion physiologic values were pulmonary artery pressure = 0.89 mm Hg, pulmonary vascular resistance = 0.68 mm Hg X min/L, cardiac output = 1.36 L/min, central venous pressure = 0.77 cm H2O, pulmonary capillary wedge pressure = 0.92 mm Hg, PAO2/FlO2 = 1.08, and shunt fraction = 0.95. Follow-up angiography showed no evidence of reocclusion. Postmortem studies of the three nonsurvivors confirmed recanalization of thrombosed pulmonary arteries. One documented bleeding episode occurred. We conclude that fibrinolytic infusion can lyse thrombi and possibly improve hemodynamics and oxygenation in ARDS-associated pulmonary vascular thrombosis.

Angiography↗
PubMed1987

Gene amplification: the Chinese hamster glutamine synthetase gene.

The glutamine analogue, methionine sulphoximine, has been used to develop Chinese hamster ovary cell lines which overproduce the enzyme glutamine synthetase. Southern and Northern blot hybridization studies showed that this overproduction is due to gene amplification of a region of DNA containing the glutamine synthesis gene coding sequences, with a corresponding increase in glutamine synthetase mRNA and protein. This amplification has increased the glutamine synthetase gene copy number to approximately 1000 copies per cell. Genomic DNA sequences from the amplified region have been cloned and the structure of the glutamine synthetase gene within this region is being analysed.

Animals↗
PubMed1987

Defending ACC.

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Accidents, Occupational↗
PubMed1987

Biochemistry of hybridoma technology.

The study of the metabolic requirements of cells in vitro requires both a qualitative definition of such nutrients and a quantitative analysis to optimize cell growth. The development of a rapid weaning procedure which allows cells to be cultured in low serum concentrations, facilitates the easy assessment of factors which regulate cell growth and antibody productivity. The novel combination of existing technology; the MTT (tetrazolium) cell ELISA (Mosman, 1983) and the TSP (Transferable solid phase) immuno ELISA provides a method for studying such factors.

Animals↗
PubMed1987

Upper respiratory tract viral infection and mucociliary clearance.

Twenty-six normal volunteers were exposed to rhinovirus or influenza B virus. Measurement of nasal mucociliary clearance, ciliary beat frequency, percent of epithelium ciliated, ciliary ultrastructure and nasal transmucosal potential difference were made before exposure, during viral incubation and at the time of expected overt infection. Ten volunteers failed to become infected, six were subclinically infected and nine were infected with symptoms. There were no significant differences between the results in volunteer groups during the incubation period or between uninfected and subclinical groups at the time of expected symptoms. Six of nine symptomatic infected volunteers had prolonged nasal clearance, and six of the seven biopsied had less than 50% of their epithelium ciliated. However, there was no significant reduction in ciliary beat frequency nor increase in ultrastructural ciliary abnormalities within this group of symptomatic volunteers. Of the two symptomatic infected (influenza B) volunteers tested, both showed significantly reduced transmucosal potential difference.

Adult↗
PubMed1986

Purification and structural analysis of pyocyanin and 1-hydroxyphenazine.

Pyocyanin and related members of the phenazine family are produced by Pseudomonas aeruginosa and have been associated with events of pathophysiological importance. Pyocyanin and its base hydrolysis product 1-hydroxyphenazine were purified to homogeneity by reverse-phase high-pressure liquid chromatography. Their mass spectrometric behaviour was examined with a view to evaluating the use of high-resolution chromatography/mass spectrometry in studying phenazine-mediated effects in man. The molecular mass of naturally derived pyocyanin was determined as 210 Da by thermospray liquid chromatography/mass spectrometry and confirmed by desorption electron-impact mass spectrometry. Mass spectrometric data could not be obtained by fast-atom bombardment or desorption chemical ionisation, techniques commonly used to determine molecular mass of polar or thermally labile species. The thermal lability of underivatised pyocyanin precluded analysis by gas chromatography/mass spectrometry. In contrast to pyocyanin, mass spectrometric data were readily obtained for 1-hydroxyphenazine, using direct probe analysis as well as with gas and liquid chromatography inlet systems.

Chromatography, Gas↗
PubMed1986

Relative importance of antibiotic and improved clearance in topical treatment of chronic mucopurulent rhinosinusitis. A controlled study.

50 patients with chronic mucopurulent rhinosinusitis were randomly allocated to treatment with nasal sprays of dexamethasone, tramazoline, and neomycin, dexamethasone and tramazoline with no antibiotic, or matched placebo (propellant alone) four times daily to both nostrils for 2 weeks. The patients were assessed in a double-blind manner for symptomatic response and improvement in nasal mucociliary clearance, nasal airway resistance, sinus radiographs, and intranasal bacteriology and appearance. Both active preparations (with antibiotic 14 of 20 patients responded; without antibiotic 12 of 20 patients responded) were more effective than the placebo (2 of 10 patients responded). There was no significant difference in response between the active preparations with and without antibiotic. Thus, in treatment of chronic mucopurulent rhinosinusitis, reduction of the inflammatory response and decongestion make topical antibiotic unnecessary, probably by allowing host clearance mechanisms to recover.

Administration, Intranasal↗
PubMed1986

Character of transient ischemia in angina pectoris.

There is growing interest in the possible therapeutic and prognostic significance of silent myocardial ischemia in coronary artery disease (CAD) and its detection by ambulatory electrocardiographic (ECG) monitoring. In 100 apparently healthy normal subjects (20 with angiographically normal coronary arteries), Holter monitoring revealed significant ST-segment depression in only 2 (both over 40 years, one with positive treadmill test, the other with risk factor for CAD). No significant ECG changes were found in those with normal coronary vessels. In 30 patients with documented CAD, significant ST-segment depression during 1,934 episodes over 446 days of monitoring over 18 months was found. Only 24% of the episodes were associated with angina. Asymptomatic and symptomatic episodes were associated with comparable changes in perfusion detected by positron emission tomography. Heart rate increases greater than 10 beats/min preceding the onset of the ST-segment changes occurred in only 23% of the episodes. There was considerable variability in the ST-segment changes in the same patient monitored serially over long periods of time. The data indicate that it is extremely uncommon for patients without CAD to exhibit silent myocardial ischemia, whereas patients with stable angina exhibit frequent, variable and often asymptomatic ECG evidence of myocardial ischemia rarely triggered by increases in heart rate. These findings are likely to be of therapeutic and prognostic significance.

Adult↗