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Biomedical subjects

M I Gurr

Publications and source records attributed to M I Gurr.

At least 19 recordsLinked to original sources
PubMed1990

Effects of lactulose and lactitol on protein digestion and metabolism in conventional and germ free animal models: relevance of the results to their use in the treatment of portosystemic encephalopathy.

Protein digestion and metabolism have been studied in laboratory rats and miniature pigs to investigate the mechanisms of action of lactulose and lactitol when used in the treatment of patients with portosystemic encephalopathy. Lactulose (beta-D-galactopyranosyl-(1----4)-beta-D-fructofuranose) and lactitol (beta-D-galactopyranosyl-(1----4)-D-glucitol) increased the excretion of nitrogenous material in the faeces and decreased nitrogen excretion in the urine in a similar degree to that reported for human patients. In studies with germ free rats given lactulose no such effect was observed, suggesting that, for lactulose at least, these effects are mediated by the gut flora. Measurement of the alpha-, epsilon-diaminopimelic acid content of the faeces confirmed that the enhancement of faecal nitrogen was due to an increased contribution from bacteria. The similarity in the results for lactulose and lactitol suggests that, from the perspective of protein metabolism, lactitol acts in a similar way to lactulose in the treatment of portosystemic encephalopathy.

Animals↗
PubMed1989

Studies on calcium absorption from milk using a double-label stable isotope technique.

Calcium absorption was measured in ten male volunteers from skimmed milk, Ca-enriched skimmed milk or watercress (Nasturtium officinale) soup. The foods were labelled extrinsically with 30 mg 44Ca. Shortly after consuming the labelled meal, each subject was given an intravenous injection of 3 mg 42Ca. Fractional absorption from the oral dose was determined from plasma and urine samples collected 24-72 h later, using fast atom bombardment mass spectrometry to measure isotope ratios. The values for urine and plasma were in good agreement. Mean percentage absorption was 45.5 (SEM 1.9)% from the skimmed milk, 35.7 (SEM 4.7)% from the Ca-enriched milk and 27.4 (SEM 1.9)% from the watercress soup. The effect of consuming 568 ml (1 pint) Ca-enriched milk each day for 4 weeks on the efficiency of absorption of Ca was studied. Although there was no statistically significant difference between Ca absorption before and after the supplementation period, the results were considered to be somewhat inconclusive due to the small number of subjects and wide individual variation in Ca absorption.

Absorption↗
PubMed1979

Studies on the body composition, fat distribution and fat cell size and number of 'Ad', a new obese mutant mouse.

1. Studies have been performed on the body composition, the fat distribution, the fat cell size, and the 'observable' fat cell number of a new obese mutant, the Adipose (Ad) mouse. The serum glucose and insulin concentrations have also been investigated. All studies were undertaken with animals aged 6 months. 2. The obese animals weighed over 50% more than the lean, but there was no difference in the body or tail lengths. 3. The obese animals had an increase in the weight of the liver, but the increase was only proportional to the increase in the total body-weight. 4. The carcasses of the obese mice contained more water as well as more fat than those of the lean. In the males the fat content was 3.9 times greater, while in the females it was increased by 5.5 times. 5. The nitrogen content of the defatted dry carcass was the same in both lean and obese animals but the total body protein was higher in the obese. 6. Fat was dissected from four major depots, gonadal, abdominal, hind subcutaneous and interscapular subcutaneous (including brown adipose tissue), and each was substantially larger in the obese animals. This indicated that the additional fat of the Ad mouse was not localized to any particular site. 7. In Ad males there was no over-all increase in the observed number of adipocytes, all the extra fat being accommodated by an increase in fat cell size (3.8 times). However, in Ad females there was a 3.3 fold increase in the number of observable fat cells as well as a 2.2-fold increase in fat cell size. 8. Non-fasted obese animals were not hyperglycaemic, but there was a 5.3-fold increase in the concentration of serum insulin. Hyperinsulinemia in the presence of normoglycaemia suggested that the obese animals were insulin resistant.

Adipose Tissue↗