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Biomedical subjects

C J Morgan

Publications and source records attributed to C J Morgan.

At least 73 records · Page 4Linked to original sources
PubMed1990

Pulmonary function testing in the intensive care unit.

A number of tests of pulmonary function have been successfully developed for use in the intensive care unit. When performed in the ICU on critically ill patients, many of the traditional laboratory-based tests will have different clinical implications than when performed in ambulatory patients, for example vital capacity measurement. Also, the clinical questions posed in the ICU are often different, such that estimates of lung water may be clinically more useful than more traditional measures, such as the flow-volume loop. There is a need for further research to identify the clinical utility of these measurements. As the understanding of ARDS and MOF improves, new therapies may be developed which will require sensitive methods in order that they can be evaluated accurately. Similarly, the potential for new methods of respiratory support such as jet ventilation, extracorporeal techniques and lung transplantation reinforce the need for the pulmonary physician to be able to make an accurate assessment of respiratory function on the intensive care unit.

Extravascular Lung Water↗
PubMed1990

The use of caesium iodide mini scintillation counters for dual isotope pulmonary capillary permeability studies.

A commercially available system of caesium iodide crystal mini-detectors (Oakfield Instruments, Oxon, UK) was modified so that it was suitable for dual isotopic measurement of the plasma protein accumulation index (PPA)- a measure of pulmonary endothelial permeability. Using this modified system the mean PPA x 10(-3) min-1 +/- (S.E.M.) recorded in 11 normal subjects (22 lungs) was 0.18 (0.08) and in 6 patients (9 lungs) with the adult respiratory distress syndrome was 2.88 (0.63) (P less than 0.02). These values for PPA concur with those found by other groups using larger sodium iodide detectors. We conclude that with simple modification caesium iodide mini-detectors may be used successfully for the measurement of PPA in the intensive care setting.

Capillary Permeability↗
PubMed1989

Liver tryptophan pyrrolase. A major determinant of the lower brain 5-hydroxytryptamine concentration in alcohol-preferring C57BL mice.

The lower brain 5-hydroxytryptamine concentration in alcohol-preferring C57BL, compared with -non-preferring CBA, mice is caused by a decrease in circulating tryptophan availability to the brain secondarily to a higher liver tryptophan pyrrolase activity associated with a higher circulating corticosterone concentration. Activity or expression of liver tryptophan pyrrolase and/or their induction by glucocorticoids may be important biological determinants of predisposition to alcohol consumption.

Alcoholism↗
PubMed1989

Effects of acute ethanol administration on rat liver 5-aminolaevulinate synthase activity.

1. Liver 5-aminolaevulinate (ALA) synthase activity of 24 h-starved rats is maximally increased at 4 h after intraperitoneal administration of a 1.6 g/kg body wt. dose of ethanol. Larger doses cause a dose-dependent decrease in the extent of this stimulation, exhibiting a reciprocal relationship with an elevation of hepatic haem concentration, as suggested by the simultaneous increase in the haem saturation of tryptophan pyrrolase. 2. ALA synthase induction by ethanol is abolished if the above increase in pyrrolase saturation with haem is enhanced by theophylline, but is potentiated when the increase in the haem saturation is inhibited by anti-lipolytic agents. 3. ALA synthase induction by ethanol is also inhibited by inhibitors of alcohol dehydrogenase and aldehyde dehydrogenase. Acetaldehyde and acetate are, however, not responsible; they both decrease ALA synthase activity and increase the haem saturation of tryptophan pyrrolase. These latter effects of acetaldehyde are not mediated by acetate. 4. ALA synthase activity is also stimulated by succinate, which, however, also increases the haem saturation of tryptophan pyrrolase. 5. Ethanol does not influence the rate of ALA synthase degradation. 6. It is suggested that ethanol increases rat liver ALA synthase activity as a result of its own metabolism by the alcohol dehydrogenase-dependent pathway by a mechanism not involving decreased degradation of the former enzyme or the participation of the metabolites acetaldehyde and acetate.

5-Aminolevulinate Synthetase↗
PubMed1989

Cell cycle dependent growth factor regulation of gene expression.

The expression of the proto-oncogenes c-fos and c-myc is a rapid response of G0-arrested fibroblasts to serum and peptide growth factors; however, the role of the c-fos and c-myc gene products in subsequent cell cycle transit is not understood. We examined the expression of c-fos and c-myc mRNA in Balb/c 3T3 murine fibroblasts in response to platelet-derived growth factor (PDGF) and platelet-poor plasma, using arrest points associated with density dependent growth inhibition or metabolic inhibition to synchronize cells in S phase of the cell cycle. The expression of c-fos and c-myc mRNA in Balb/c 3T3 cells was differentially regulated with respect to growth factor dependence and cell cycle dependence. c-fos expression was induced in the presence of PDGF and was unaffected by plasma. The induction of c-fos expression in response to PDGF was cell cycle independent, occurring in cells transiting S phase and G2 as well as in G0 arrest. In contrast, c-myc expression was both growth factor and cell cycle dependent. In G0 arrested cells, c-myc expression was PDGF-dependent and plasma-independent, and PDGF was required for maintenance of elevated c-myc levels during G1 transit. In cells transiting S phase, c-myc mRNA was induced in response to PDGF, but was also plasma-dependent in S phase cells that had been "primed" by exposure to PDGF during S phase.

Animals↗
PubMed1989

The management of adult respiratory distress syndrome: 1.

Since its description 20 years ago, the mortality from ARDS has remained largely unchanged despite improved intensive care techniques. This article reviews the rationale underlying the current management of ARDS. In part 2 of this article some of the more recent and novel therapies that are being applied in the treatment of this condition will be described.

Adult↗
PubMed1987

Effects of the haem precursor 5-aminolaevulinate on tryptophan metabolism and disposition in the rat.

5-Aminolaevulinate administration to rats inhibits cerebral 5-hydroxytryptamine synthesis by decreasing tryptophan availability to the brain secondarily to activation of hepatic tryptophan pyrrolase. The results show that tryptophan metabolism and disposition can be influenced by changes in liver haem concentration, and are discussed briefly in relation to mood disorders in the hepatic porphyrias.

Aminolevulinic Acid↗
PubMed1986

Infective endocarditis affecting the eustachian valve.

A previously fit 44 year old man presented with acute staphylococcal pneumonia. Despite appropriate antibiotics he showed signs of continuing sepsis and eventually died. At necropsy endocarditis of the eustachian valve was found.

Adult↗