Search PubMed⌕ Search

Biomedical subjects

L Morgan

Publications and source records attributed to L Morgan.

At least 163 records · Page 9Linked to original sources
PubMed1981

Viscosity differences between various guar gums.

Guar gum from four industrial sources was investigated. The viscosity of two preparations of hydrated guar gum in the form of powdered flour and one granulate flour was measured at 22 degrees and 32 degrees C and pH 1.0 and pH 4.0. Viscosity measurements on wax-coated guar granules proved impossible but visual assessment indicated an extremely low viscosity in all conditions. These findings were compared with the ability of the equivalent of 5 g guar gum of the various preparations to modify the absorption of a 50 g liquid glucose load. The mean post-prandial blood glucose curve was not significantly different from the control situation after the incorporation of each preparation. Despite the granulate flour attaining a considerably lower viscosity than the powdered flour they were equally effective in significantly reducing the mean post-prandial insulin curve (area under the curve (0-180 min) reduced by 46 and 50% respectively). The wax-coated granules which achieved minimal viscosity caused significantly less reduction of post-prandial insulin levels (area under the curve reduced by 37%). The viscosity of guar gum upon hydration is of importance in assessing the efficacy of a preparation in clinical use.

Adult↗
PubMed1981

Response of circulating immunoreactive somatostatin to nutritional stimuli in normal subjects.

We have previously reported that in normal subjects plasma immunoreactive somatostatin levels rise after a mixed meal. The contribution of individual nutrients to this rise, and the molecular nature of the somatostatin immunoreactivity measured, have now been studied. Six normal healthy subjects received, on separate occasions, isocaloric (520 calories) and isovolumetric (260 ml) quantities of carbohydrate, protein, and fat. The mean fasting plasma somatostatin level was 29 +/- 5 pg/ml. After carbohydrate a peak of 48 +/- 7 pg/ml was reached at 30 min, and after protein and fat there were more sustained rises with peak levels of 74 +/- 8 pg/ml and 80 +/- 9 pg/ml, respectively. Sephadex G50 chromatography of extracts of fasting peripheral plasma showed two main peaks of somatostatin immunoreactivity, one coeluting with cyclic somatostatin and a larger peak of approximately 3500 molecular weight (mol wt). Levels of both 1600 and 35000 mol wt somatostatin were increased 60 min after a mixed meal. Approximately 80% of the 3500 mol wt form of somatostatin could be converted to the 1600 mol wt form by treatment with dithiothreitol (an agent which reduces disulphide bonds). It is concluded that: (a) in normal subjects fat and protein are potent stimuli for somatostatin release; (b) somatostatin in normal peripheral plasma exists in multiple forms, and that both 1600 and 35000 mol w forms of somatostatin immunoreactivity are stimulated by feeding; (c) the 3500 mol wt form could represent a dimer of somatostatin or a somatostatin molecule linked to a second peptide chain by disulphide bonds.

Adult↗
PubMed1980

Metabolism of carprofen, a nonsteroid anti-inflammatory agent, in rats, dogs, and humans.

The metabolic disposition of 14C-labeled carprofen [(+/-)-6-chloro-alpha-methylcarbazole-2-acetic acid] was investigated in rats, dogs, and humans. Carprofen is eliminated predominantly by biotransformation in these three species. In dogs and rats, the direct conjugation of carprofen to form an ester glucuronide and oxidation to the C-7 and the C-8 phenols followed by their conjugation represent the major metabolic pathways. Small amounts of the alpha-hydroxy derivative also are formed by these species and are excreted free in the urine. In dogs, biliary secretion predominates, and 70% of an intravenous dose of carprofen is excreted in the feces while 8--15% of the dose is excreted in the urine. In rats, fecal excretion due to biliary secretion varies from 60 to 75%, and urinary excretion accounts for 20--30% of an intravenous dose. In humans direct conjugation of carprofen represents the only significant pathway of metabolism. Between 65 and 70% of the orally administered carprofen was found to be excreted as the ester glucuronide in the urine, and most of the remaining dose was estimated to be secreted as this metabolite in the bile. Due to enterohepatic circulation, only a fraction of the biliary metabolite was recovered in the feces in humans. Less than 5% of the dose was excreted in human urine as free, intact carprofen. In dogs and humans, plasma levels of carprofen and of total radioactivity exhibit a multiphasic decline. In the three human subjects studied, the terminal component declined with a 13--26 hr half-life; the terminal half-life was approximately 40 hr in dogs.

Adult↗
PubMed1979

Overlooked resources: the place of the library in visual science research.

Effective research should be based on familiarity with what has already been accomplished in the field. The best place to look for this information is a library, since even the most widely read professional may miss much that is relevant. Libraries not only provide access to their own holdings but assist the investigator by means of computerized literature searches and the use of indexes, abstracts, and other forms of printed reference material. Efficient use of library facilities can aid research and facilitate preparation of grant proposals.

Abstracting and Indexing↗
PubMed1978

Hb I alpha16 Lys leads to Glu and Hb Broussais alpha90 Lys leads to Asn in Australian families.

This paper describes the finding of Hb 1 alpha16 Lys leads to Glu and Hb Broussais alpha90 Lys leads to Asn in Australian families. Neither of these variants has been previously described in the Australian population. The variants were detected in an electrophoretic screening of 2500 blood samples. Both variants were clinically silent. The haematological parameters were within normal limits and the peripheral blood morphology was normal.

Adult↗
PubMed1976

Translocation of Y chromosome to an autosome in the Bolivian owl monkey, Aotus.

Karyotypic study of a population sample of twenty-one owl monkeys, Aotus, originating from Bolivia, revealed two sex-specific somatic diploid chromosome numbers: 49 for males and 50 for females. The presence of a trivalent in male meiotic figures and the identification of chromosomes by band pattern analysis confirmed the interpretation of a Y-autosome translocation in the males.

Animals↗
PubMed1975

Y-autosome translocation in the howler monkey, Alouatta palliata.

Two modal diploid chromosome numbers were encountered in a population sample of howler monkeys, Alouatta palliata. The modal diploid number of males was 53, females: 54. Karyotypes prepared by G-band and C-band techniques identified a Y-auto-some translocation in the males.

Alouatta↗