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Biomedical subjects

M J Gibney

Publications and source records attributed to M J Gibney.

At least 19 recordsLinked to original sources

The effects of acute and chronic administration of n-6 and n-3 polyunsaturated fatty acids on ethanol-induced gastric haemorrhage in rats.

Female weanling rats in three equal groups (n 12) were given orally by intubation 1 ml micellar solution of taurocholic acid (10 mM) and either arachidonic acid (20:4 n-6), linoleic acid (18:2 n-6) or eicosapentaenoic acid (20:5 n-3) at a concentration of 120 mM. After 1 h the rats were given intragastrically 2 ml absolute ethanol and were killed 1 h later. Rats given oral 20:4 n-6 showed a significant reduction (P less than 0.05) in the extent (%) of gastric mucosal haemorrhage compared with either the rats given 20:5 n-3 or 18:2 n-6 (8.3 (SD 7.3), 23.2 (SD 10.4) and 21.4 (SD 10.4) respectively. In a second experiment, four equal groups (n 12) of female Wistar rats were fed for 5 weeks on either a control diet of standard laboratory rat food, or the same diet enriched with either maize oil or fish oil or butterfat at a level of 100 g/kg. Following a 24 h fast the rats received an intragastric dose of 2 ml ethanol and were killed 1 h later. Examination of the extent (%) of gastric lesion showed a significant reduction (P less than 0.05) with the feeding of either maize oil or fish oil compared with the controls (12.2 (SD 8.2), 15.3 (SD 13.2) and 29.3 (SD 14.0) respectively). The butterfat diet was not significantly different from the control diet (23.8 (SD 8.1)).

Animals

Mucosal and systemic IgA anti-gliadin antibody in celiac disease. Contrasting patterns of response in serum, saliva, and intestinal secretions.

Serum IgA anti-gliadin antibody estimation is a recognized screening method for celiac disease. However, celiac disease is primarily a small intestinal mucosal disorder, and so we have examined the possibility that secreted, mucosal IgA anti-gliadin antibody might provide a more relevant measure of gluten sensitivity than that obtained from serum tests. Serum IgA anti-gliadin antibody and serum, salivary, and small intestinal aspirate IgA anti-gliadin antibody were measured by enzyme-linked immunosorbent assay. Serum IgA and IgG anti-gliadin antibody were markedly increased in untreated celiacs (N = 31) as compared to normals (N = 20) or disease controls (N = 39) (P less than 0.0001). Levels were lower in treated (N = 30) than untreated celiacs (P less than 0.001). In intestinal aspirates both untreated and treated patients had similar levels of IgA anti-gliadin antibody (P = 0.48), but both were significantly higher than in controls (P less than 0.01). Salivary IgA anti-gliadin antibody, by contrast, was not increased in celiac patients as compared to controls. Serum IgA anti-gliadin antibody was the most sensitive (84%) and specific (95%) test for detecting untreated celiac disease. It was also the most useful in patient follow-up where it provides an early objective indicator of adherence to a gluten-free diet. Mucosal IgA responses to gliadin in celiac disease appear to be compartmentalized, with different portions of the gastrointestinal tract functioning as separate immunological organs. Our results also demonstrate that serum and secretory IgA production are under independent control.

Adult

The effects of dietary levels of inorganic phosphorus, calcium and cholecalciferol on the digestibility of phytate-P by the chick.

Male broiler chicks (1-d-old; Ross one) were given either a control diet containing recommended levels of phosphorus, calcium and cholecalciferol or experimental diets low in P and with variable levels of Ca (normal and low) and cholecalciferol (normal or high). The low-P diet with normal levels of Ca and cholecalciferol induced a hypophosphataemia and a hypercalcaemia which was reflected in reduced tibia length and weight and in reduced Ca, P and magnesium contents of tibia. The phytate digestibility remained normal while the retention of P and Ca fell significantly. The lowering of Ca alone elevated phytate digestibility and restored P and Ca retention. The hypercalcaemia and hypophosphataemia remained and tibia mineralization remained impaired. The raising of cholecalciferol alone dramatically increased phytate digestibility and the retention of Ca and P. While this remedied the hypercalcaemia, the hypophosphataemia persisted as did the diminution of tibia weight. The simultaneous lowering of dietary Ca and elevation of cholecalciferol on low-P diets restored all variables to the levels for the control diet. Circulating levels of 1,25-dihydroxycholecalciferol were significantly elevated by low-P diets, more so with high cholecalciferol intakes. However, Ca did not influence 1,25-dihydroxycholecalciferol levels in plasma.

Animals

Nutrient intakes in long-stay mentally handicapped persons.

A study of the dietary intake of 115 male and 217 female mentally handicapped persons aged 15-64 years in five long-stay institutions was carried out using a semi-weighed technique over 4 d. Nineteen per cent of males and 5% of females were classified as being underweight and 15% of males and 27% of females were classified as being obese. The average daily intakes of nutrients were: energy 8.8 MJ, protein 92 g, carbohydrate 218 g, fat 101 g, dietary fibre 18 g, calcium 1024 mg, iron 12.5 mg, vitamin B6 1.4 mg, vitamin B12 10.8 micrograms, ascorbic acid 68 mg. The distribution of energy between protein, carbohydrate and fat was 18, 39 and 43% respectively. Energy intakes were not related to ambulatory status, degree of mental handicap, the level of drug usage or body mass index. Energy intakes varied significantly between hospitals and between the sexes.

Adolescent

Nutrition in the management of HIV antibody positive patients: a longitudinal study of dietetic out-patient advice.

The efficacy of a dietetic service was evaluated in an AIDS clinic; 17 asymptomatic (CDC II) and 17 symptomatic (CDC IV) patients participated in a 12 week evaluation of out-patient dietetic advice. The symptomatic group, classified as CDC stage IV according to the Centre for Disease Control classification, were significantly lighter (P less than 0.05) and had significantly lower values for usual weight, current body mass index, mid-upper arm and mid-arm muscle circumferences and triceps and subscapular skinfold thicknesses (P less than 0.05) at the outset of the study. There were no significant differences in nutrient intakes between the two groups. After 12 weeks of dietetic intervention which included personalised advice, prescription of food supplements and the provision of a special food allowance as social welfare payments for the unemployed, there were significant increases in the intakes of most nutrients, the effect being greater with the symptomatic CDC IV group. It is concluded that dietetic intervention has a significant role to play in the management of HIV antibody positive patients.

Adult

Dietary intakes and adipose tissue levels of linoleic acid in peptic ulcer disease.

Adipose tissue levels of linoleic acid were determined from biopsies of subcutaneous abdominal fat of normal healthy controls (n 40) and from two patient groups with endoscopically evaluated non-ulcer dyspepsia (n 40) or peptic ulcer disease (n 38). The level (g/100 g) of adipose tissue linoleic acid in the normal healthy controls (15.0 (SD 4.1] was significantly (P less than 0.05) greater than that in patients with non-ulcer dyspepsia (12.8 (SD 3.5] and in patients with peptic ulcer disease (11.7 (SD 2.7]. A dietary history revealed a lower intake of linoleic acid and a significantly (P less than 0.05) lower intake of dietary fibre (g/d) for both the non-ulcer dyspepsia (15.9 (SD 6.2] and peptic ulcer disease (15.2 (SD 7.8] patients compared with normal healthy controls (20.2 (SD 11.2]. Adipose tissue linoleic acid tended to increase with indices of increasing socioeconomic status, although the differences between patient and controls were not confounded by socioeconomic status. Patients with dyspepsia reported more foods causing symptoms (onion, fried foods, alcohol, citrus fruits and spices) and more foods giving relief (milk, bread) compared with control orthopaedic patients.

Adipose Tissue

The Kilkenny Health Project: food and nutrient intakes in randomly selected healthy adults.

1. Sixty healthy subjects aged 35-44 years (thirty men and thirty women) were randomly selected from electoral registers to participate in a dietary survey using the 7 d weighed-intake method during June-August 1985. 2. Energy intake (MJ/d) was 12.5 for men and 8.4 for women. Fat contributed 36.0 and 39.1% of the total energy intake of men and women respectively. When this was adjusted to exclude energy derived from alcoholic beverages, the corresponding values were 38.8 and 39.7% respectively. The major sources of dietary fat (%) were spreadable fats (28), meat (23), milk (12) and biscuits and cakes (11). 3. The subjects were divided into low- and high-fat groups both on the relative intake of fat (less than 35% or greater than 40% dietary energy from fat) and on the absolute intake of fat (greater than or less than 120 g fat/d). By either criterion, high-fat consumers had lower than average intakes of low-fat, high-carbohydrate foods such as potatoes, bread, fruit and table sugar, and higher intakes of milk, butter and confectionery products. Meat intake was higher among high-fat eaters only when a high-fat diet was defined as a percentage of energy.

Adult

Effect of polyunsaturated fatty acids of the n-3 and n-6 series on lipid composition and eicosanoid synthesis of platelets and aorta and on immunological induction of atherosclerosis in rabbits.

The effect of dietary fish oil (rich in n-3 polyunsaturated fatty acids (PUFA], corn oil (rich in n-6 PUFA) and coconut oil (low in n-3 and n-6 PUFA) on the induction of atherosclerosis by serum sickness in rabbits was investigated over a 12-month period. Dietary fish oil led to a significant increase in the level of eicosapentaenoic acid (EPA) in all platelet phospholipid fractions and to a significant reduction in the level of platelet phosphatidylethanolamine arachidonic acid (AA). In aortic total phospholipids, rabbits given fish oil showed a significant reduction in AA and a significant increase in EPA. Rabbits given fish oil showed significantly lower collagen-induced platelet thromboxane A2 release and aortic production of 6-keto-PGF1 alpha. Serum total immune complex levels and anti-horse serum IgG levels were not influenced by diet. There was a significant reduction in total aortic atherosclerosis in fish oil-fed animals compared with coconut oil fed animals.

Animals

Uptake of exogenous and endogenous eicosapentaenoic acid by cultured human mononuclear cells.

1. Peripheral blood mononuclear cells from eight healthy volunteers were cultured, with or without concanavalin A (Con A), in a medium containing (ml/l) 100 normal autologous serum, 100 experimental autologous serum or 100 heterologous (fetal calf) serum. 2. The control and experimental autologous sera were obtained from the volunteers, before and after 15 d supplementation with 15 g fish oil (MaxEPA)/d to provide 1.5 g eicosapentaenoic acid (EPA; 20:5n-3)/d. The sera were frozen at -20 degrees. The level of EPA increased from trace quantities in the control autologous serum to 14.3% w/w free fatty acids and between 6.9 and 8.1% w/w lipoprotein phospholipids in the experimental autologous serum. The heterologous fetal calf serum was enriched with EPA, complexed with bovine serum albumin, to provide a final concentration of 15 micrograms/ml. All culture medium contained 10 ml fresh autologous serum/l and cells were obtained from the volunteers for the culture studies about 60 d after the end of EPA supplementation. 3. Portions of cells were removed from culture at 36, 48 and 72 h for phospholipid fatty acid analysis. 4. The level of EPA in phospholipids of cells cultured with exogenous EPA in fetal calf serum was increased significantly (P less than 0.05) at all sampling times, both with and without Con A. By 48 h the levels had peaked at 15.8 (SE 2.7) and 18.4 (SE 4.5)% w/w respectively. 5. Resting cells, i.e. with no Con A present, failed to accumulate EPA when cultured in the experimental autologous serum containing 8.6% w/w total lipids as endogenous EPA.(ABSTRACT TRUNCATED AT 250 WORDS)

Cells, Cultured

Dietary fibre and blood pressure.

Ninety-four volunteers participated in a three-day weighed dietary survey and had their blood pressures measured once. They were classified according to their fibre intake. Subjects with a high-fibre intake were found to have lower mean blood pressures than those with a low-fibre intake. Forty-two of the volunteers further participated in a group of experiments. Those eating a high-fibre diet decreased their dietary fibre, and those eating a low-fibre diet increased their dietary fibre. The first group (11 subjects) showed increased mean blood pressures after four weeks of eating the experimental diet. The last group (31 subjects) showed decreased mean blood pressures after four weeks of eating the experimental diet. The 11 subjects consuming the low-fibre experimental diet showed a decrease in mean blood pressure when some of the saturated fat in their diet was replaced by polyunsaturated fat. A similar substitution carried out by 14 of the subjects consuming the high-fibre experimental diet also resulted in decreased mean blood pressure, but this was not statistically significant. Twelve more volunteers, with hypertension, were all found to have low-fibre diets. They consumed a high-fibre diet for a six-week experimental period, but their mean blood pressures did not decrease significantly; individual recordings varied substantially during this period.It is suggested that differences in the type and quantity of dietary fibre and fat may be responsible for the lower mean blood pressures of groups of vegetarians compared with similar groups of non-vegetarians.

Adolescent