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Biomedical subjects

A Marshall

Publications and source records attributed to A Marshall.

At least 109 records · Page 6Linked to original sources
PubMed1982

Improved prognosis in congenital diaphragmatic hernia: experience of 62 cases over 2-year period.

During 1979 and 1980, 62 babies with congenital diaphragmatic hernia were admitted to the Hospitals for Sick Children. All 62 babies underwent surgical closure of the anatomical defect. There were 44 survivors and 18 deaths, a survival rate of 71%. Both the number treated and the overall survival rate were greater than any series reported for a similar period. The number of admissions may reflect earlier diagnosis and improved resuscitation, with safer and more rapid transfer to our units. The improved survival must be mainly attributed to our experience over the past few years which has consolidated understanding and methods of management and led to a close cooperation between surgeon and anaesthetist both in immediate management and in postoperative care.

Female↗
PubMed1980

High-pressure liquid chromatographic determination of ranitidine, a new H2-receptor antagonist, in plasma and urine.

An assay is described for the determination of a new H2-receptor antagonist, ranitidine, and its desmethyl metabolite in human plasma and urine. Alkalinized plasma or urine was extracted with methylene chloride, the organic phase was evaporated, and the reconstituted residue was analyzed by high-pressure liquid chromatography using a reversed-phase column. Two other identified metabolites of ranitidine, the S-oxide and N-oxide, were separated chromtographically from both ranitidine and the desmethyl metabolite. However, these metabolites could not be quantitative due to poor analytical recovery and interference from endogenous components. The sensitivity limits were 5 ng/ml for ranitidine and 15 ng/ml for desmethylranitidine. Plasma samples from two volunteers who were given oral ranitidine (0.1, 0.2, and 0.4 mg/kg) at 1-week intervals were assayed. Peak levels of 30--130 ng/ml were achieved between 40 and 120 min after dosage, followed by an elimination half-life of 2.9-3.9 hr. Plasma levels of ranitidine were still detectable at 8 hr but were below the sensitivity of the assay by 24 hr. Plasma levels of the desmethyl metabolite were seldom above the threshold sensitivity of the assay. Urinary excretion of unmetabolized ranitidine accounted for 77% of the administered dose, whereas only 4% appeared as desmethylranitidine.

Adult↗
PubMed1979

Hypertrichosis due to minoxidil.

A case of hypertrichosis due to the hypotensive drug minoxidil is described. A review of the literature suggests that this complication appears in nearly all patients treated with this drug. The mechanism is unknown, but the similarity to the cases of hypertrichosis due to diazoxide, another potent vasodilator, suggests that increased cutaneous blood flow may be a factor.

Humans↗
PubMed1978

Analysis of the penetrable space within the nucleus.

Radioactive glycogen molecules have been used as passive probes to compare cavity systems within nuclei and isolated chromatin. Isolated chromatin was found to possess a narrow range of microspaces with mean effective diameters between 4.0 and 4.5 nm (40 and 45 A) depending on shape assumptions. Intact nuclei contained a far larger class of free spaces with average diameters in the order of 11.0-15.0 nm. This clearly shows that DNase-I (diam. 4.1 nm) can penetrate and occupy a large proportion of nuclear space even though this enzyme does not readily attack the undisturbed nuclear structure. A structure which simulated the pattern of penetrability and incorporated other known properties of chromatin was used to explain this DNase-I resistance of intact nuclei in terms of an ordered, compact, local structure interspersed by much larger spaces. A system for this local packing is suggested and the functional implications of this type of organization considered.

Animals↗
PubMed1977

Analgesic effects of 3-carboxysalsolinol alone and in combination with morphine.

A biphasic dose-response pattern is generated by the isoquinoline, 3-carboxysalsolinol, in analgesia tests conducted in mice. Carbidopa pretreatment enhances this effect, as well as the morphine-induced analgesic increase by 3-carboxysalsolinol. Naloxone blockade of all of these responses suggests an interaction of the alcohol-based isoquinoline with central opiate receptors.

Analgesia↗
PubMed1977

The effect of tablet formulation on the haemodynamic properties of glyceryl trinitrate.

A non-invasive haemodynamic study was carried out in 13 normal subjects to compare the pharmacodynamics of glyceryl trinitrate when formulated as a moulded tablet ('Nitrostat') rather than as a generic compressed tablet. The glyceryl trinitrate moulded tablet, with a much more rapid and predictable dissolution time, produced an earlier onset of systolic blood pressure fall (p less than 0.01) and a greater maximum percentage change in peripheral blood flow (p less than 0.02). No other significant differences in effect on pulse rate, blood pressure or peripheral blood flow were noted.

Adult↗
PubMed1976

Potentiation of ethanol narcosis by dopamine- and l-DOPA-based isoquinolines.

The isoquinolines, salsolinol and 3-carboxysalsolinol, prolong ethanol-induced narcosis in mice. Pretreatment with carbidopa increases the effect of 3-carboxysalsolinol but not of salsolinol. These results suggest that ethanol sleeping-time potentiation by l-LOPA may involve a partial conversion to the isoquinoline in vivo. A central depressant action of salsolinol or the 3-carboxy analogue is suggested.

Alkaloids↗
PubMed1975

Sensory system involvement in infantile spinal muscular atrophy.

Nine cases of infantile spinal muscular atrophy were studied post-mortem. Their ages at death ranged from 5 months to 10 years. In all cases severe loss of anterior horn cells in the spinal cord and neurogenic muscular atrophy were characteristic of this disease. In 6 cases there was also loss of myelin in the posterior columns particularly affecting the lumbar contribution. Sensory ganglia, especially from the lumbar region, contained nodules of Nageotte, indicating sensory neuron degeneration. These sensory abnormalities were more severe in the longer surviving cases. It seems possible that sensory neuron degeneration occurs more commonly in Werdnig-Hoffmann disease than has previously been supposed but that it is less severe and develops more slowly than motor neuron degeneration.

Anterior Horn Cells↗
PubMed1975

Oestradiol-17 beta and prolactin levels in rat peripheral plasma.

Radioimmunoassay methods for the determination of oestradiol-17 beta and prolactin have been examined for their reliability and applied to the measurement of hormone concentrations in the plasmas from male and female rats. Prolactin was detectable in all samples (greater than 7 ng RP-1 ng/ml) but the concentration of oestradiol-17 beta was below the sensitivity of the method (greater than 0-10 ng/100 ml) in ovariectomized females. Plasma oestradiol-17 beta concentration rose gradually from metoestrus to proestrus and fell to barely detectable levels in oestrus. Plasma prolactin concentration was very variable even for rats in the same stage of the oestrous cycle but values were minimal in the afternoon of diestrus and a surge in secretion occurred in the afternoon of proestrus. In addition to the stage of the oestrous cycle, the prolactin concentration was influenced by mode of blood collection, degree of haemolysis and choice of serum or plasma. There was no correlation between the concentration of prolactin and that of oestradiol-17 beta in the same sample of plasma.

Animals↗