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Biomedical subjects

M Gracey

Publications and source records attributed to M Gracey.

At least 163 records · Page 9Linked to original sources
PubMed1977

Effect of enteric micro-organisms on intestinal sugar and fatty acid absorption.

The effect of micro-organisms contaminating the upper intestinal contents of malnourished children on intestinal absorption of 3-0 methyl-alpha-D-glucopyranose (3-M.G.) and oleic acid was studied in rats in vivo. Oleci acid absorption was unaffected by non-pathogenic E. coli but decreased by E. coli 0111, Salmonella paratyphi B., Shigella sonnei and Candida sp. This effect was probably explained by intestinal secretion diluting the test solution leading to a decreased diffusion gradient for solubilised fatty acid. Inhibition of sugar absorption occurred with bacterial suspensions of Staphylococcus aureus, Streptococcus faecalis, E. coli and Candida sp. and cell-free preparations of Staphylococcus aureus, Streptococcus faecalis, a non-pathogenic E. coli, Proteus sp., Klebsiella sp., Pseudomonas sp. and Candida sp. These effects were not explained by dilution of the test solution. This indicates that numerous micro-organisms and, in some instances, their cell-free preparations can interfere with intestinal active sugar transport. These findings may be relevant to the production of malabsorption in malnourished children who have a wide variety of micro-organisms contaminating their upper intestinal contents.

Animals↗
PubMed1977

Effects of biliary diversion on intestinal microflora in the rat.

Certain bile acids inhibit the growth in vitro of organisms commonly found in the intestine and, in particular, anaerobic bacteria. As the importance of this effect in vivo has not been demonstrated, we investigated changes in intestinal flora in the rat after diversion of bile to the urinary bladder. Five days after operation there was an increase in numbers of Proteus sp. in the stomach, mid-jejunum and caecum and of coliform bacilli in the stomach and mid-jejunum. Lacto-bacilli were increased in the stomach. There was no change in numbers of anaerobic organisms. Similar changes in bacterial flora followed 5 days of pair feeding in control rats. Our results do not suggest a specific antibacterial effect of bile salts in the rat in vivo. The changes found are probably related to semi-starvation, because the food intake of the rats after operation was about half that of control rats having an unrestricted diet.

Anaerobiosis↗
PubMed1977

Use of a simple duodenal capsule to study upper intestinal microflora.

The upper intestinal microflora was studied in 10 malnourished Indonesian children using the paediatric Enterotest Capsules. Trophozoites of Giardia lamblia were found in 2 specimens, profuse fungal mycelia in 3, and ascaris worms and eggs in 1. In 9 patients an abnormally profuse small intestinal bacterial flora was found. Provided precautions are taken to exclude artefactual contamination of the line on its withdrawal, this is a safe and simple method for studying the upper gut flora which could be applied to field conditions since it does not require radiological facilities.

Child↗
PubMed1977

Diet and serum cholesterol. An Australian family study.

Dietary intake patterns were studied in families in Busselton, Western Australia, known to have mothers and children with high, median, or low serum cholesterol values. There were no significant differences in the percentage contributions to total daily calories by protein, fat, or carbohydrate in mothers, children, or their families from these three groups. The results support the view that diet, per se, does not account for differences in observed serum cholesterol levels within a culturally homogeneous community.

Adolescent↗
PubMed1977

The stomach in malnutrition.

Basal gastric acid output was reduced in 9 out of 14 infants and young children with malnutrition compared with 21 age-matched controls. In all the patients the response of the gastric mucosa to stimulation by pentagastrin was impaired, and gastritis of variable severity was present in 8 out of the 9 patients in who biopsies were performed. Impaired gastric acid secretion probably contributes towards bacterial overgrowth and diarrhoeal diseases in malnourished children.

Child, Preschool↗
PubMed1976

Inhibition of intestinal uptake of amino acids by unconjugated bile salt.

The unconjugated bile salt, sodium deoxycholate, at a concentration of 0.5 mM was shown to inhibit the intestinal uptake of the amino acids L-glycine, L-leucine, L-proline, L-lysine and L-tyrosine in rats in vitro. This effect was acutely reversible except for the basis amino acid L-lysine and is therefore not simply due to tissue damage. These results, and the recent finding that sodium deoxycholate inhibits intestinal absorption of amino acids in vivo, suggest that impaired intestinal amino acid transport may contribute to hypoproteinaemia in patients with bacterial overgrowth in the upper small intestine in whom deoxycholate is present in the small intestinal lumen in excessive concentrations.

Amino Acids↗
PubMed1976

Serum and small intestinal immunoglobulin levels in undernourished children.

Intestinal immunoglobulin levels were quantitated in undernourished Indonesian children with enteric infections and normally nourished Indonesians with and without enteric infections. These were compared to the same parameters in Australian Aboriginal children (also suffering undernutrition) and normal Caucasian children. Children with enteric infections displayed equally elevated levels of intestinal immunoglobulin irrespective of their nutritional status. Intestinal infections appeared to elevate IgG levels more than secretory IgA levels in the age group examined. However, it appeared likely that some of the EgG was serum-derived whereas the IgA appeared to be locally produced. There was no apparent deficiency in the capacity of undernourished children to manufacture and secrete immunoglobulin in the gut.

Asian People↗
PubMed1975

Effect of microorganisms isolated from the upper gut of malnourished children on intestinal sugar absorption in vivo.

The effect of microorganisms isolated from the upper gastrointestinal tract of malnourished children on intestinal sugar absorption was studied in rats in vivo. Pure cultures of organisms were grown overnight in a nutrient broth and the resultant supernatant fluid which contained microorganisms in similar numbers to those found in the patients was used as the basic solution for jejunal perfusions which were done in anesthetized adult Wistar rats. The substrate used was arbutin (p-hydroxphenyl-beta-glucoside), a recognized marker of intestinal active sugar transport. Of the gram-positive cocci studied, only the saprophyte, Staphylococcus saprophyticus, did not adversely affect the intestinal absorption of arbutin. The only gram-positive rod studied, a lactobacillus, also significantly inhibited arbutin absorption. Of the Enterobacteriaciae studied, Salmonella paratyphi B, a Shigella and Proteus sp. did not affect arbutin absorption. All the species of Escherichia coli studied, including a nonpathogenic variety, inhibited absorption. Klebsiella sp. and Pseudomonas sp. were also effective. Of the Candida sp., C. albicans and C. parapsilosis were inhibitory while C. tropicalis was not. These results suggest that microorganisms not generally considered enteropathogenic may adversely affect intestinal function when present in the lumen of the gut in excessive numbers and contribute to the production of diarrhea in children with malnutrition.

Animals↗
PubMed1975

Inhibition of intestinal amino acid absorption by unconjugated bile salt in vivo.

The intestinal absorption of five amino acids studied (L-lysine, L-glycine, L-leucine and L-tyrosine) and one dipeptide (glycylglycine) was significantly inhibited by the deconjugated bile salt, sodium deoxycholate, in rats in vivo. It is suggested that inhibition of absorption of amino acids and dipeptides by unconjugated bile salts may contribute to hypoproteinaemia in patients with the contaminated small-bowel syndrome.

Amino Acids↗
PubMed1975

Effect of stasis on intestinal enzyme activities.

Activities of the small intestinal mucosal enzymes lactase, sucrase, maltase, alkaline phosphatase and N-acetyl-beta-glucosaminidase were studied in rats with surgically-induced upper intestinal stasis and in control animals. The first four are brush border enzymes, the latter a lysosomal enzyme. There was a reduction in the activities of all enzymes in the operated animals. The change lining was significant and most marked in mucosa the blind loop and gut distal to it; areas in which there is gross bacterial overgrowth and excessive levels of intraluminal deconjugated bile salts. The significance of these findings in relation to malabsorption consequent on bacterial contamination of the upper gut is uncertain and requires further study.

Acetylglucosaminidase↗
PubMed1975

Deoxycholate depresses small-intestinal enzyme activity.

Feeding sodium deoxycholate orally to rats for four days caused depression of the activity of the small intestinal enzymes lactase, sucrase, maltase, alkaline phosphatase, and N-acetyl-beta-glucosaminidase. The first four are brush border enzymes, the last a lysosomal enzyme. Alkaline phosphatase activity recovered very rapidly and rebounded to above the normal level within 24 hours. The activity of the three disaccharidases returned to normal within seven days while no recovery was observed within 96 hours of the activity of the lysosomal enzyme, N-acetyl-beta-glucosaminidase, after removing the bile salt from the diet.

Administration, Oral↗