Biomedical subjects

D Hanson

Publications and source records attributed to D Hanson.

At least 73 records · Page 4Linked to original sources

PubMed1982

Effect of dietary butylated hydroxyanisole on methylazoxymethanol acetate-induced toxicity in mice.

Administration of butylated hydroxyanisole (BHA), a widely used food additive, has been found to inhibit the carcinogenic and toxic effects of various chemicals in animal models. To study the relationship of dietary BHA to the acute toxicity of methylazoxymethanol (MAM) acetate, a colon-specific carcinogenic compound, groups of female CF1 mice were fed NIN-07 diet containing 0, 300, 1000, 3000 or 6000 ppm BHA or a semipurified diet containing 0 or 6000 ppm BHA for 4 wk, and were injected ip with MAM acetate (20 mg/kg body weight) at the end of the first 2 wk and again 4 days later. At levels of 300-6000 ppm, BHA was found to protect against death caused by MAM acetate. The mortality rates in MAM-treated mice were 80 and 92% in those fed the diets with no BHA and 0 and 1% in those fed 6000 ppm BHA, and were inversely related to the amount of BHA in the diet. The protection was associated with increased levels of hepatic cytochrome P-450 and b5 and with a reduction in necrotic changes in the liver.

Animals↗

PubMed1982

Fecal sterols and bacterial beta-glucuronidase activity: a preliminary metabolic epidemiology study of healthy volunteers from Umea, Sweden, and metropolitan New York.

The dietary pattern, fecal bile acid and neutral sterol concentrations, and the bacterial beta-glucuronidase activity of 2 population groups with a varied risk for colon cancer development (i.e., a high-risk population in the metropolitan New York area and an intermediate-risk population in Umea, Sweden) were investigated. The average daily intake of dietary protein was the same in the 2 groups, but the fat intake was higher in Umea than in New York. The daily total fiber intake was also higher in Umea, as was the daily total stool output. The concentration of fecal secondary bile acids and beta-glucuronidase activity was lower in Umea than in New York, but the total daily excretion of these constituents was the same in both groups. The data suggest that one of the factors contributing to the lower risk of colon cancer in Umea, despite the high dietary fat intake, is the high intake of dietary whole grain and cereal fiber, which leads to an increase in stool bulk, thus diluting and/or binding promoters.

Bacteria↗

PubMed1981

Effect of fat and microflora on hepatic, small intestinal and colonic HMG CoA reductase, cytochrome P450 and cytochrome B5.

High levels of dietary fat caused a significant reduction in HMG CoA reductase activity in the liver of germ-free rats whereas significantly elevated small intestinal enzyme activity was observed. Dietary fat had no significant effect on HMG CoA reductase activity in any tissue studied in the conventional rat. No significant change in colonic HMG CoA reductase activity was observed between any of the experimental groups. Rats fed a high-fat diet tended to exhibit higher cytochrome P450 levels in all tissues studied, regardless of the presence of intestinal microflora.

Animals↗

PubMed1981

Effect of bran and citrus pulp on hepatic, small intestinal and colonic HMG CoA reductase, cytochrome P450 and cytochrome b5 levels in rats.

The effect of dietary wheat bran and citrus pulp on hepatic, small intestinal and colonic HMG-CoA reductase activity, cytochrome P450 and cytochrome b5 levels was studied in F344 rats. Colonic and small intestinal HMG-CoA reductase activity was significantly lower in the wheat bran group than the control group. No differences in hepatic HMG-CoA reductase activity occurred between the wheat bran, citrus pulp and control groups. A direct relationship between hepatic cholesterol levels and hepatic Cytochrome P450 levels was demonstrated. A similar trend was exhibited between fecal cholesterol and colonic cytochrome P450 levels in the colon. These results suggest that the effect of certain types of dietary fiber in small intestinal and colonic cholesterogenesis is mediated through alterations in small intestinal and colonic mixed function oxidase activity.

Animals↗

PubMed1981

Carcinogen binding to various types of dietary fiber.

The percent of the carcinogen 1,2-dimethylhydrazine (DMH) bound to a variety of fibers, such as wheat bran, corn bran, citrus pulp, citrus pectin, and alfalfa, was examined at pH values ranging from 1 to 12. The percent of DMH bound to wheat bran increased from 4% at PH 1 to 55% at pH 2 to 77% at pH 12. A sharp rise in carcinogen binding to corn bran occurred between pH 5% of the DMH was bound and pH 8 where 51% of the DMH was bound. The percent of DMH bound to dehydrated citrus pulp also increased as the pH increased with 10% binding observed at pH 1 and with 57% binding observed at pH 12. Between pH 2 and pH 7, the percent of DMH bound to pectin decreased from 60 to 11%. As the pH became more basic, the percent of DMH bound to pectin increased to 42% at pH 12. The sharpest rise in the percent of DMH bound to alfalfa meal occurred between pH 10.5 and pH 12.0. Results from this experiment showed that the affinity to various types of dietary fibers for the colon carcinogen DMH was differentially affected by pH. These results suggested that the protective effect of certain types of dietary fiber against chemically induced colon cancer my in part be attributed to enhanced carcinogen binding by dietary fiber in the colon.

Cellulose↗

PubMed1980

Effect of high-fat, high-beef diet and of mode of cooking of beef in the diet on fecal bacterial enzymes and fecal bile acids and neutral sterols.

The effect of a high-fat, high-beef diet and of method of preparation of beef in the diet on the fecal bile acids and neutral sterols and on the activities of fecal bacterial beta-glucuronidase, cholesterol dehydrogenase and 7 alpha-dehydroxylase was studied in healthy men and women, 24-41 years old, who were consuming a customary mixed-western diet. The experimental diets were high in fat and beef, which was cooked rare, medium or well-done. The sequence of dietary regimen was selected at random and each diet phase lasted for 4 weeks. Individual 24-hour fecal specimens were collected from each volunteer for the final 3 days during each dietary period, including pre- and post-experimental periods while they were consuming a customary mixed-western diet. The mode of cooking beef in the high-fat, high-beef experimental diets had no influence on the fat and protein content of the diets but the fat content of experimental diets was high compared to customary mixed-western diet. Fecal bacterial beta-glucuronidase activity and fecal secondary bile acid and cholesterol metabolite levels were significantly higher during the experimental diet periods but the fecal bacterial activities of 7 alpha-dehydroxylase and cholesterol dehydrogenase were unaffected. The mode of cooking beef in experimental diets had no influence on the fecal bacterial enzymes and on the excretion of fecal bile acids and cholesterol metabolites.

Adult↗

PubMed1979

Behçet's disease of the oesophagus.

A forty-two-year-old man known to have Behçet's disease (two major and two minor symptoms) (Mason and Baines, 1969) presented with dysphagia, hoarseness and regurgitation of food. This was subsequently found to be due to a tracheo-oesphageal fistula consequent upon an area of Behçet's ulceration in the oesophagus. The fistula was excised, the defects in the trachea and oesophagues repaired, and the patient's recovery was uneventful.

Adult↗

PubMed1979

Vocal cord paralysis in the Shy-Drager syndrome.

Eight out of 12 unselected patients with Shy-Drager syndrome were found to have severe bilateral paresis of vocal cord abduction by fibre-optic laryngoscopy. This commonly presented as increased snoring followed by episodes of inspiratory and expiratory stridor and sometimes by sleep apnoea. Respiratory failure eventually developed in four cases and was reversed by tracheostomy. In another patient tracheostomy relieved severe attacks of sleep apnoea. This complication was not necessarily associated with advanced disease, and it should be considered in all patients with Shy-Drager syndrome as appropriate treatment can lead to a useful extension of life.

Aged↗

PubMed1973