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Biomedical subjects

G M Wyatt

Publications and source records attributed to G M Wyatt.

18 recordsLinked to original sources
PubMed1990

Enzyme-linked immunosorbent assay for Salmonella typhimurium in food: feasibility of 1-day Salmonella detection.

A microtitration plate, antibody-capture, enzyme-linked immunosorbent assay was developed for detection of Salmonella typhimurium. The assay utilizes a monoclonal detector antibody which shows no cross-reactions with non-Salmonella species and only a slight cross-reaction with one other Salmonella serotype. By using only one cultural stage (in a nonselective, chemically defined medium) prior to the enzyme-linked immunosorbent assay, low numbers of cells in food (10 cells 25 g-1) were detected in 19 h. Non-Salmonella competing organisms did not interfere with detection of S. typhimurium even when present in the ratio of 10(6):1 (non-Salmonella/Salmonella spp.). The assay shows the feasibility of rapid, 1-day testing for Salmonella spp. with antibody technology.

Antibodies, Monoclonal↗
PubMed1988

Flatulence--causes, relation to diet and remedies.

In addition to causing embarrassment and unease, flatulence is linked to a variety of symptoms, some of which may be distressing. This review describes the origins of intestinal gas, its composition and methods which have been developed for its analysis. Emphasis is placed upon the effects of legumes in the diet in producing excessive intestinal gas and, particularly, on the role of raffinose-type oligosaccharides, containing alpha-galactosidic groupings. Suggestions for overcoming the problem are presented, including drug treatment, enzyme treatment, food processing and plant breeding. It is emphasised that removal of all raffinose-oligosaccharides from beans does not remove the problem of flatulence in animals and man; the compounds responsible--though assumed to be polysaccharides (or polysaccharide-derived oligomers formed by processing or cooking)--have yet to be characterised.

Animals↗
PubMed1988

Intestinal microflora and gastrointestinal adaptation in the rat in response to non-digestible dietary polysaccharides.

1. A comparison was made of the effect of a fibre-free diet and diets containing non-digestible polysaccharides on rat caecal and colonic physiology and microflora. 2. All polysaccharide-containing diets led to enlargement of the caecum and colon, associated with increased weight of contents, and of tissue. Carboxymethylcellulose (CMC) had the most marked effect and animals given this also had watery faeces. 3. The density of bacteria in the caecum and colon varied significantly with diet and the proportion of aerobic bacteria in the flora was increased by the CMC diet. 4. In vitro, CMC and hydroxypropylmethylcellulose were poorly fermented. 5. There was a high correlation (caecum r 0.93; colon r 0.94) between tissue weight and wet weight of organ contents but no correlation with bacterial density, number of bacteria per organ, moisture content or short-chain fatty acid content. 6. It is concluded that caecal and colonic enlargement is due to tissue hypertrophy in response to increased bulk of contents, irrespective of the nature of that bulk which varies with diet; it is unlikely that short-chain fatty acids or other microbial metabolites are the stimulus for the trophic response seen when non-digestible dietary polysaccharides are fed to rats.

Adaptation, Physiological↗
PubMed1988

Response of populations of human faecal bacteria to viscosity in vitro.

The effects of viscosity on cultures of human faecal bacteria in vitro were studied. The composition of the microbial populations which developed during in vitro incubation were affected by viscosity. The proportion of Bacteroides species was decreased at high viscosities and it is concluded that the 'viscotolerance' of a bacterial population contributes towards its composition. Viscosity alters the enzyme activity of cultures. Cell-associated total, and specific, beta-galactosidase activities of cultures of human faecal bacteria were decreased at high viscosity.

Bacteria↗
PubMed1987

Comparison of populations of human faecal bacteria before and after in vitro incubation with plant cell wall substrates.

Human faecal slurries were incubated anaerobically with larchwood xylan, oat spelt xylan, wheat bran, apple cell walls or sugar beet pulp as sole carbon sources. The populations which developed during incubation were different from the inoculum, the most marked changes being an increase in the number of Bacteroides species and a decrease in the number of Fusobacterium species for all carbon sources tested. With a water-soluble preparation of larchwood xylan the population was dominated by species able to ferment this substrate, in contrast to the population which developed with the insoluble substrates. The ability to use one plant cell wall substrate appeared to be related to the ability to use others. Strains capable of using plant cell wall substrates included Bacteroides spp., Clostridium clostridiiforme, Bifidobacterium longum, Fusobacterium spp. and Escherichia coli. When incubation with two contrasting substrates (bran and larchwood xylan) was replicated, the populations which developed were reproducibly different from the inoculum and from each other.

Bacteroides↗
PubMed1986

A change in human faecal flora in response to inclusion of gum arabic in the diet.

1. Gum arabic is a water-soluble polysaccharide resistant to human gut enzymes and thus can be described as dietary fibre. 2. Using a most-probable-number technique, estimates were made of total anaerobes and of gum-arabic fermenters in the faeces of a volunteer during a control period and during addition of 10 g gum arabic/d to the diet. Using an enrichment technique, the principal bacteria able to utilize gum arabic as the only carbohydrate source were isolated and characterized. 3. Faecal samples were analysed for undegraded gum arabic and, following acid-hydrolysis, for total sugars. 4. The proportion of the faecal flora able to degrade the gum arabic polymer rose from an initial level of 6.5% to more than 50% during gum-arabic ingestion, and subsequently returned to the control level after ingestion ceased. The principal gum-arabic fermenters were species of Bacteroides and Bifidobacterium. 5. Undegraded gum arabic was not detected in any faecal sample nor were there significant differences in the level of total sugars in acid-hydrolysed faeces between gum arabic and control periods. 6. The results presented indicate a direct and rapid change in faecal flora in response to a specific change in the diet of a human volunteer.

Adult↗
PubMed1986

Intestinal microflora, morphology and enzyme activity in zinc-deficient and Zn-supplemented rats.

1. Immature, male Wistar rats were given a low-zinc diet (2 mg/kg) for 22-24 d. Control groups received a similar diet supplemented with 58 mg Zn/kg either ad lib., or in amounts matched to the consumption of the Zn-deficient group. Food consumption, rate of growth and food conversion efficiency were markedly lower in the Zn-deficient group of rats compared with controls. Appetite, growth rate and food utilization improved dramatically over a subsequent 4 d period of Zn supplementation. 2. Morphological examination of samples of jejunum and ileum confirmed that Zn deficiency in the rat is accompanied by a reduction in villous dimensions and increase in villous density. After a short period of Zn supplementation, villous density and the basal width and maximum height of individual villi in the jejunum returned to normal. Similar changes occurred in the ileum but to a lesser extent. 3. Mucosal alkaline phosphatase (EC 3.1.3.1) activity was significantly lower in the small intestine of Zn-deficient rats compared with Zn-supplemented rats. Disaccharidase activities were lower in the Zn-deficient group, compared with their feed-restricted counterparts, but were similar to values for ad lib.-fed controls. Tissue alkaline phosphatase and disaccharidase activities were consistently higher after a 4 d period of Zn supplementation, compared with non-supplemented animals, but this increase was only significant for alkaline phosphatase. 4. Although there were striking similarities in the mucosal characteristics of gnotobiotic and Zn-deficient rats, there was no indication that even severe dietary Zn depletion reduced the numbers of viable bacteria present in either the small or large intestine.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1979

Renal vein thrombosis: an underdiagnosed complication of multiple renal abnormalities.

Thirty-one cases of renal vein thrombosis (RVT) were reviewed retrospectively for clinical laboratory, and radiographic findings. An underlying renal disorder was present in 28 cases, absent in only 3. This supports other evidence that RVT is usually a complication of renal disease rather than a primary event, and that nephrotic syndrome may be due to renal disease rather than RVT. The findings also confirmed the large spectrum of urographic appearances in RVT, and were used as a basis for developing specific and liberal indications for renal venography.

Humans↗
PubMed1977

Rectus sheath hematoma.

Two patients who developed rectus sheath hematoma while on anticoagulants are presented. Ultrasound was the definitive method of establishing the diagnosis.

Abdominal Muscles↗
PubMed1976

Roentgen findings in aorto-enteric fistulae.

Six cases of aorto-enteric fistulas are discussed. In three patients the aorta ruptured into the duodenum and in three there was rupture into the esophagus. Aorto-enteric fistula is usually caused by atherosclerosis, but may also be due to syphilis or tuberculosis. Following insertion of an aortic graft, fistula is usually the result of breakdown of the anastomosis. Gastrointestinal bleeding usually heralds the problem. The roentgen signs of rupture are pressure on the esophagus or intestine, bleeding into the wall or lumen, and demonstration of the fistula. The abnormal connection may not be demonstrable by aortography. These signs permit early diagnosis and subsequent possible life saving surgical correction.

Aged↗
PubMed1975

Anaesthesia for dwarfs and other patients of pathological small stature.

Sixty-nine anaesthetics were administered to 29 patients of pathological proportionate and disproportionate small stature. The anaesthetic course in most cases was uncomplicated. The few complications noted were similar in type and severity to those found in normal size patients undergoing similar anaesthesia and operative procedures. Achondroplastic dwarfs often develop neurological problems due to their bony deformities. General anaesthesia should be given preferential consideration in these patients. Non-achondroplastic dwarfs may have an associated odontoid dysplasia and if the neck is placed in flexion there is a potential risk of spinal cord damage. Tube size for proportionately small children is best estimated from body weight. No definite recommendations concerning proper tybe size in dwarfs can be given on the basis of the findings in the study.

Achondroplasia↗