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Biomedical subjects

M E Coates

Publications and source records attributed to M E Coates.

At least 37 records · Page 2Linked to original sources
PubMed1983

Trace-nutrient-binding proteins in milk and the growth of bacteria in the gut of infant rabbits.

1. The influence of trace-nutrient-binding proteins on the growth of coliforms, streptococci and lactobacilli in the gastrointestinal tract was examined in neonatal rabbits delivered germ-free and dosed with an artificial flora (ESL), or born conventionally and dosed with ESL or rabbit faeces. 2. In the stomach and small intestine of both gnotobiotic and conventional animals the counts of coliforms were usually atypically high and those of streptococci were always low. In the colon the counts of coliforms and streptococci were high. Lactobacilli usually became established in the gut of the gnotobiotic animals but were not found in the conventional rabbits. 3. Sterilization (freeze-drying followed by gamma-irradiation) of the milk decreased its capacity to bind added iron by 45% and vitamin B12 by 30%. When compared with raw milk, feeding of radiation-sterilized milk did not affect the viable count of coliforms and streptococci in the gut of gnotobiotic animals. 4. Saturating the nutrient-feeding proteins in milk with Fe, folic acid and vitamin B12 had no effect on the numbers of coliforms, streptococci and lactobacilli recovered from the intestine.

Animals↗
PubMed1983

The influence of the gut microflora on protein synthesis in liver and jejunal mucosa in chicks.

Protein synthesis in liver and jejunal mucosa was measured in 19-d-old germ-free (GF) and conventional (CV) chicks fed on a semi-purified casein-gelatin (SCG) diet using a massive-dose single injection of [U-14C]phenylalanine. The effect of subsequent feeding for 9 d either a nitrogen-free (NF) diet or an NF diet supplemented with L-methionine (5 g/kg) and L-arginine hydrochloride (2 g/kg) (MA diet) was investigated in both types of chick. In the liver, apart from the amount of DNA, the values for wet weight, protein, RNA, fractional synthesis rate (FSR) and the amount of protein synthesized were reduced after feeding the NF diet and, to a lesser extent, the MA diet. Except that the total amount of liver DNA was higher in the CV chicks than in their GF counterparts (P less than 0.01), no environmental effect was significant. When expressed on a unit body-weight basis, liver weight, protein, RNA and DNA were significantly higher in the CV than in the GF chicks. In the jejunal mucosa, the values for wet weight, protein and RNA tended to be reduced after the NF treatment but increased after the MA treatment. Mucosal DNA and the amount of protein synthesized (microgram/mm per d) were significantly reduced after the NF diet but were less affected after the MA diet. Mucosal protein FSR and the amount of protein synthesized per mg RNA were significantly reduced after both dietary treatments. No difference was found among dietary treatments in the amount of protein synthesized per mg DNA in jejunal mucosa. Mucosal DNA was significantly higher in the CV chicks and the reverse was true for mucosal protein: DNA. It was suggested that the increased protein synthesis in jejunal mucosa and possibly in liver on supplementation of an NF diet with methionine and arginine would partly, if not completely, account for the N-sparing effect of these amino acids. Although the protein: DNA value was smaller in CV chicks, the FSR and the amount of protein synthesized tended to be higher than in their GF counterparts irrespective of nutritional status. This might imply that protein degradation rate is greater in the CV state.

Animals↗
PubMed1982

The availability to the chick of pantothenic acid in foods.

1. The content of total pantothenic acid (PaA) in two foodstuffs of microbial origin was measured by standard microbiological and chick biological assays. 2. Substantially and consistently higher values were found by the chick assay than by the microbiological determination, indicating that PaA-containing compounds were present that were not utilized by the test micro-organisms but were available for chicks. Attempts to identify these compounds did not explain the source of excess PaA activity for the chick. 3. It is suggested that forms for PaA that are undetected by standard methods of microbiological assay differ from one food to another and require different treatments to make the vitamin available to the assay organism.

Animal Feed↗
PubMed1982

The uptake of nutrients from the small intestine of gnotobiotic and conventional chicks.

1. Uptake of L-[2(n)-3H]methionine and 3-O-methyl[14C]-D-glucose (3MG) from jejunal loops in vivo was investigated in germ-free (GF), gnotobiotic (GN) and conventional (CV) chicks aged between 2 and 4 weeks. 2. Body-weight gain was less, and intestine weight per unit length greater, in CV and GN birds than in corresponding GF birds. 3. Uptake of both nutrients was less in CV and GN birds when calculated per g intestinal tissue, but no difference was found between any of the groups when uptake was expressed per unit length of intestine. 4. Concentration of methionine in mesenteric and cardiac blood was higher, and amounts in the intestinal wall lower, in CV chicks than in corresponding samples from GF birds. 5. Concentration of 3MG in mesenteric blood was similar in both environments but it was higher in cardiac blood and lower in the gut wall of CV birds. 6. It was concluded that uptake of methionine and glucose is not impaired by the presence of micro-organisms in the gut.

3-O-Methylglucose↗
PubMed1982

THe effects of the gut microflora and dietary fibre on energy utilization by the chick.

1. Groups of adult colostimized chickens were given diets with and without dietary fibre in the form of bagasse or wheat straw. The fibrous materials were analysed for their contents of cellulose, hemicellulose and lignin. The digestible energies (DE) and metabolizable energies (ME) of these diets were measured by a balance method. 2. Groups of germ-free and conventional chicks aged 4 weeks were given diets with and without penicillin or with and without graded levels of wheat straw as a source of fibre and the ME of these diets were determined. 3. The incorporation of the forms of dietary fibre tested reduced the DE and the ME of the diets in adult conventional chickens and the ME in young germ-free and conventional chicks. Both DE and ME were reduced in proportions that suggested that the dietary fibre present was acting largely as an inactive diluent of the dietary energy and was not affecting the absorption of other nutrients. In the young germ-free and conventional chicks, there was a linear relationship between the proportion of wheat straw in one diet and the reduction ME. 4. Dietary penicillin did not alter the ME of the diet in either the germ-free or the conventional environments. 5. The reduction of ME with incorporation of wheat straw was less in conventional than in germ-free chicks. It is suggested that this may be due to the ability of chicks with a gut flora to obtain a small amount of energy from wheat straw.

Animals↗
PubMed1982

The metabolism of maltitol in the rat.

Conventional (CV) rats were given a single oral dose of 1 or 2 g maltitol. Urine and faeces were collected during the following 24 h and their contents of maltitol and sorbitol were measured. 2. Very little of either substance appeared in the faeces but appreciable amounts of sorbitol found in the urine indicated that the maltitol had been hydrolysed. 3. Excretion of maltitol and sorbitol was compared in germ-free and CV rats given an oral dose of 2 g maltitol. Significantly less of both substances was recovered in the faeces of CV rats, but urinary excretion was similar in both environments. 4. Maltitol injected intravenously gave rise to only traces of sorbitol in the excreta. A dose of 250 mg was cleared almost completely from the circulation within 1 h. 5. It is concluded that maltitol is hydrolysed by animal tissues, either in the gut lumen before absorption or in the gut wall during absorption. Maltitol and sorbitol are also degraded by gut bacteria, mostly in sites distal to the main absorptive area. The contribution to the host's nutrition would depend on the extent to which the end-products of fermentation are absorbed from the colon.

Animals↗
PubMed1982

Influence of dietary lactose on the gut flora of chicks.

1. The gut microflora of chicks fed on a purified diet containing 300 g lactose plus 300 g starch/kg was compared with that of control birds receiving a diet containing 600 g starch/kg. 2. In 14-d-old conventional chicks, lactose in the diet decreased the incidence of lactobacilli and clostridia in the caecal contents, although when presenting lactose-fed chicks the counts of lactobacilli exceeded those of control chicks. 3. High counts of Proteus sp. were present in the caeca of control birds but they were completely suppressed in conventional birds fed on the lactose diet. In vitro tests showed that this inhibition was partially due to Escherichia coli and Streptococcus faecalis. 4. The growth of Lactobacillus acidophilus was inhibited by lactose when gnotobiotic chicks were monoassociated but not when polyassociated. The protective effect was shown in vitro to be due to L. salivarius. 5. The pH was markedly lowered in the caecum of conventional and polyassociated chicks receiving dietary lactose. Of the strains used in gnotobiotic experiments E. coli, S. faecalis and L. salivarius produced the lowest pH values in the caeca.

Animals↗
PubMed1981

The effects of high dietary supplements of copper sulphate on pantothenic acid metabolism in the chick.

1. The effects of incorporation of copper sulphate supplying 250 mg copper/kg semi-purified diet with graded amounts of calcium pantothenate (CaPa) were studied in chicks. 2. When the doses of CaPa were marginally adequate or less the Cu supplementation induced severe signs of pantothenic acid (PaA) deficiency. 3. Livers of the Cu-treated birds given low doses of PaA had lower concentrations of total and bound PaA than those of the corresponding control birds. The bound:total PaA value was also reduced. 4. The amount and concentration of coenzyme A (CoA) were significantly less in the livers of Cu-treated chicks. Fatty acid synthetase activity was not reduced. 5. It is suggested that high dietary supplements of CuSO4 induce PaA deficiency through interference in the biosynthesis of CoA.

Animals↗
PubMed1981

The influence of microorganisms and of stress on the chick's requirement for pantothenic acid.

1. The responses of germ-free (GF) and conventional (CV) chicks to suboptimal amounts of dietary calcium pantothenate (CaPa) were compared. At the lower levels of supplementation the signs of deficiency were more severe in the CV chicks. 2. Calculations based on mean body-weights of chicks given graded dietary supplements of calcium pantothenate (CaPa) in both environments showed that, to achieve the same body-weight and freedom from signs of deficiency, the GF birds required only approximately two-thirds the amount of CaPa as was needed by corresponding CV birds. 3. Increasing the dietary supplement of CaPa resulted in increased contents of PaA in the livers. GF birds had more PaA per liver than their CV counterparts. In both instances the effect was due to the larger liver size. Concentration of PaA in the liver was not affected by dietary supplement nor by the environment. 4. CV birds were deemed to be under greater stress than GF birds because their adrenal glands were heavier and contained less cholesterol. 5. CV chicks deliberately stressed by injections of adrenocorticotrophic hormone had heavier adrenals with lower cholesterol contents than unstressed controls, but the condition was not altered by increasing the dietary supply of CaPa.

Adrenal Glands↗
PubMed1981

The gut microflora and the uptake of glucose from the small intestine of the chick.

1. Chicks whose growth rate had been depressed either by a fully conventional flora or by association with a bile acid deconjugating strain of Streptococcus faecium and/or a filterable agent from chicken droppings showed no significant reduction in uptake of 3-0-methyl-alpha-D-glucopyranose compared with germ-free birds. 2. Association with a microflora increased the weight of the gut per unit length.

Animals↗
PubMed1978

The influence of the gut microflora and of dietary fibre on epithelial cell migration in the chick intestine.

1. The renewal of the intestinal mucosal epithelium has been investigated in germ-free and conventional chicks given a practical chick diet and a low- and high-fibre diet, using tritiated thymidine to label the nuclei of mucosal cells undergoing division. 2. Villus height, crypt depth and number of mitoses in the crypt were generally, although not always significantly, greater for conventional chicks than for germ-free chicks at all sites investigated in the intestine, and all became progressively lower from the upper intestine to the lower intestine. 3. There was a linear relationship between the height of the radioactively labelled mucosal cells on the villus and the period after injection, and the rates of epithelial cell migration were higher for conventional than for germ-free chicks, the relative differences being greater in the lower intestine than the upper intestine. 4. The inclusion of wheat bran as a source of dietary fibre had no effect on the rate of epithelial renewal, either in germ-free or conventional birds.

Animals↗