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Biomedical subjects

R Fuller

Publications and source records attributed to R Fuller.

At least 73 records · Page 4Linked to original sources
PubMed1985

Intestinal bacteria--passengers or partners?

The gut of all warm-blooded animals contains a large population of bacteria. The metabolic activities of this diverse collection of bacteria can affect the host animal in a variety of ways, some of which are harmful and some of which are beneficial. The way in which an organism reacts with its host can be affected by diet or by other bacteria present in the gut. The complex inter-relationship between the different bacteria and between the bacteria and the host are discussed.

Animal Nutritional Physiological Phenomena↗
PubMed1984

Bile acid deconjugation and attachment of chicken gut bacteria: their possible role in growth depression.

Bacteria isolated from the chicken gut were tested for their ability to deconjugate bile acids and attach to chicken epithelial cells (crop squamous cells and duodenal brush borders). Clostridium perfringens, streptococci and some of the bifidobacteria and lactobacilli were able to deconjugate all 4 substrates whereas the bacteroides deconjugated only the taurine conjugates and the coliforms were completely inactive. None of the strains of Escherichia coli or streptococci attached to squamous cells, but the anaerogenic coliform, the strain of Klebsiella aerogenes and the lactobacilli did show attachment. Attachment to brush borders was obtained with the anaerogenic coliforms, K. aerogenes, 2 out of 5 of the lactobacilli, and 4 out of 9 of the streptococci, but none of the strains of E. coli.

Adhesiveness↗
PubMed1984

The effect of yoghurt on some components of the gut microflora and on the metabolism of lactose in the rat.

Feeding yoghurt or base milk (from which the yoghurt was prepared by fermentation) to rats increased the counts of coliforms in the gut whereas the counts of lactobacilli were reduced by yoghurt but not by the base milk. Lactobacillus bulgaricus survived in the guts of gnotobiotic and conventional rats when yoghurt was fed continuously. Streptococcus thermophilus also survived in gnotobiotic rats but its ability to survive in conventional rats could not be examined. Both organisms failed to colonise the gut when a small inoculum of yoghurt was administered orally to germfree rats maintained on the stock diet. Streptococcus thermophilus but not Lact. bulgaricus grew in the rat diet when tested in vitro. Two enzyme systems (beta-galactosidase and lactase) were studied using, respectively, o-nitrophenyl-beta-D-galactopyranoside (ONPG) and lactose as the test substrates. Enzyme levels estimated with both substrates increased in the gut contents when rats were fed yoghurt but an increase was only found with ONPG in the intestinal mucosa fraction. The bacterial origin of all this increased activity is discussed. The other lactose-containing diets did not affect enzyme activity to the same degree. Feeding yoghurt changed the lactobacillus flora from one which was predominantly heterofermentative (Lact. reuteri ) to one which was predominantly homofermentative (Lact. salivarius).

Animals↗
PubMed1984

The adhesion of coagulase negative staphylococci to human skin and its relevance to the bacterial flora of milk.

Twenty-eight isolates of coagulase negative staphylococci were obtained from nipple swabs provided by one non-lactating woman and five nursing mothers. All but two of these isolates were shown by scanning electron microscopy to adhere to the surface of human skin. Experiments with frozen sections of human skin confirmed and extended these results by showing that isolates exhibited one of three patterns of adhesion, suggesting that there are three different adhesion receptors on epidermal cells. It is proposed that adhesion of staphylococci to the nipple and areolar epidermis provides a mechanism whereby large numbers of bacteria, nourished by residues of milk and saliva, are maintained on the surface of the skin.

Adhesiveness↗
PubMed1983

Compliance with disulfiram treatment of alcoholism.

One hundred twenty-four men were randomly assigned to receive disulfiram with a riboflavin marker or riboflavin alone. During a one year follow-up urine specimens were collected at each visit and analyzed for riboflavin. There was a strong relationship between excellent attendance and infrequent drinking. For subjects taking disulfiram there was a high correlation between a subject submitting 15 or more positive urines during follow-up and infrequent drinking. For the disulfiram patients there was also a strong relationship between continuous usage of disulfiram and infrequent drinking. However, the correlation between percentage of urine specimens positive for the riboflavin marker and infrequent drinking was slight. This occurred because a person who was drinking tended to return for follow-up only when he was not drinking and thus submitted only a few specimens of which the majority were positive. We conclude that (1) excellent attendance, (2) submission of a large number of positive urines and (3) a period of continuous compliance to the disulfiram regimen were highly associated with infrequent drinking.

Adult↗
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 activities of amylase and a trypsin-like protease in the gut contents of germ-free and conventional chickens.

1. Proteolytic and amylase activities were assayed in the gut contents of germ-free and conventional chickens aged 3 and 14 d. 2. The tendency was for the proteolytic activity to be increased and the amylase activity to be decreased in conventional chicks. These differences were statistically significant in the caecum. 3. All of the additional proteolytic activity detectable in the caecum of conventional chicks was inhibited by soybean trypsin inhibitor. However, the increased activity was not detectable in the small intestine and was, therefore, not due to pancreatic trypsin. 4. Attempts to demonstrate in vitro bacterial production of a trypsin-like enzyme were unsuccessful.

Amylases↗
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

Furosemide kinetics in patients with hepatic cirrhosis with ascites.

Furosemide, 20 mg, was given intravenously as a bolus to seven patients with cirrhotic ascites and a 10-mg intravenous bolus dose was given to three normal subjects. Furosemide concentrations were measured by a specific high-performance liquid chromatographic analytic method. The median plasma elimination half-life (t1/2), volume of distribution at a steady state (VdSS), and VDarea of furosemide were 0.70 hr, 91 ml/kg, and 119 ml/kg in normal subjects. In the cirrhotic patients elimination t1/2 and Vd at steady state doubled and the Vdarea of furosemide was almost double that of the normal. There were no differences in plasma clearance or renal and nonrenal clearance between patients and controls, but five of the seven patients had lower renal clearances than controls. The water and sodium response to furosemide was directly related to the urinary furosemide excretion rate. We identified a subset of cirrhotic patients who responded poorly (125 ml/hr urinary output in the first 4 hr after furosemide compared to 300 ml/hr in the other patients and 400 ml/hr in the controls) to furosemide. These "poor responders" had the lowest renal clearance of furosemide and the lowest urinary furosemide excretion rates. Our data indicate that furosemide kinetics are altered in patients with cirrhotic ascites and lack of response in a subset of these patients is due to lack of delivery of furosemide to the renal site of its action.

Adult↗
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↗
PubMed1981

Attachment of Streptococcus faecium, to the duodenal epithelium of the chicken and its importance in colonization of the small intestine.

The counts of Streptococcus faecium SY1 in the duodenums of gnotobiotic chicks exceeded the counts in their crops, indicating that multiplication was occurring in the anterior small intestine. This growth was related to adhesion to the gut wall which could be demonstrated by viable counts of macerated washed duodenal tissue. Scanning electron microscopy demonstrated that adhesion occurred in restricted areas on the surface of the villus, and transmission studies showed the presence of a thick extracellular layer on the bacterium. Attachment of S. faecium SY1 was confirmed in vitro by using chicken duodenal brush borders. The washings, produced during the preparation of the brush borders, increased the number of S. faecium adhering to the brush borders. This enhancing effect was due to the presence of trypsin in the duodenal washings. However, the effect was not dependent on the enzymatic activity of the trypsin molecule. The initial adhesion was not prevented by pretreatment of the brush borders with soy bean trypsin inhibitor. There were, therefore, two adhesion systems operating, only one of which was dependent on trypsin. Pretreatment of brush borders with trypsin digested them, but they remained intact in the presence of S. faecium SY1, indicating that the enzymatic activity was being inhibited. This effect was specific for the adhering strain of S. faecium SY1; the nonadhering S. faecium strain CRS23 and an adhering strain of Lactobacillus sp. were inactive, as was strain SY1 when adhesion was prevented by including sodium periodate in the test system. The colonizations of the gut by strains of S. faecium of differing adhesive abilities were compared. The nonadhering strain CRS23 showed reduced ability to colonize the duodenum, but the penicillin-resistant mutant of S. faecium SY1, which had reduced adhesive ability but could still attach to a lesser degree, was able to colonize the duodenum as efficiently as the parent strain.

Anaerobiosis↗