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Biomedical subjects

F Brighenti

Publications and source records attributed to F Brighenti.

At least 19 recordsLinked to original sources
PubMed1991

Specific types of colonic fermentation may raise low-density-lipoprotein-cholesterol concentrations.

To assess the effects of increased colonic fermentation on serum lipids, eight healthy volunteers were placed on two identical 2-wk metabolic diets, one of which was supplemented with lactulose (18-25 g/d). Lactulose raised day-long concentrations of breath hydrogen and serum glutamine as indicators of increased colonic fermentation by 78 +/- 13% (P less than 0.001) and 24.7 +/- 9.5% (P less than 0.05), respectively). Unexpectedly, however, fasting serum total and low-density-lipoprotein cholesterol and apolipoprotein B concentrations were higher at 2 wk by 8.9 +/- 1.5% (P less than 0.001), 10.9 +/- 2.2% (P less than 0.005), and 18.9 +/- 5.9% (P less than 0.02), respectively, compared with the control diet. With lactulose, mean free fatty acid concentrations were reduced over the day by 19.5 +/- 5.9% (P less than 0.02), with no change in mean day-long blood glucose, serum insulin, or C-peptide concentrations. We conclude that certain rapidly fermented substrates may raise rather than lower serum lipids, possibly through increasing the amount of acetate absorbed from the colon.

Acetates↗
PubMed1991

Is colonic fermentation minimized by increasing meal frequency?

It has been suggested that, although increasing meal frequency has metabolic advantages in terms of carbohydrate and lipid metabolism, the efficiency of small intestinal absorption may be enhanced, thus reducing the extent of colonic fermentation. Since this may be undesirable, we have tested whether increasing meal frequency reduces the amount of carbohydrate fermented into the colon. Accordingly, seven healthy male volunteers took, in random order, two identical 2-week metabolic diets divided into either seventeen or three meals daily. On day 13 of each period measurements were made throughout the day of breath H2 and serum acetate, as markers of colonic fermentation. Mean levels of both breath H2 and acetate were similar on both diets, being lower on nibbling by 3.2 +/- 0.8 ppm and 25 +/- 9 mumols/l respectively (not significant). This study failed to demonstrate an effect of more efficient carbohydrate absorption with increased meal frequency.

Acetates↗
PubMed1989

Nibbling versus gorging: metabolic advantages of increased meal frequency.

We studied the effect of increasing the frequency of meals on serum lipid concentrations and carbohydrate tolerance in normal subjects. Seven men were assigned in random order to two metabolically identical diets. One diet consisted of 17 snacks per day (the nibbling diet), and the other of three meals per day (the three-meal diet); each diet was followed for two weeks. As compared with the three-meal diet, the nibbling diet reduced fasting serum concentrations of total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B by a mean (+/- SE) of 8.5 +/- 2.5 percent (P less than 0.02), 13.5 +/- 3.4 percent (P less than 0.01), and 15.1 +/- 5.7 percent (P less than 0.05), respectively. Although the mean blood glucose level and serum concentrations of free fatty acids, 3-hydroxybutyrate, and triglyceride were similar during both diets, during the nibbling diet the mean serum insulin level decreased by 27.9 +/- 6.3 percent (P less than 0.01) and the mean 24-hour urinary C-peptide output decreased by 20.2 +/- 5.6 percent (P less than 0.02). In addition, the mean 24-hour urinary cortisol excretion was lower by 17.3 +/- 5.9 percent (P less than 0.05) at the end of the nibbling diet than at the end of the three-meal diet. The blood glucose, serum insulin, and C-peptide responses to a standardized breakfast and the results of an intravenous glucose-tolerance test conducted at the end of each diet were similar. We conclude that in addition to the amount and type of food eaten, the frequency of meals may be an important determinant of fasting serum lipid levels, possibly in relation to changes in insulin secretion.

3-Hydroxybutyric Acid↗
PubMed1989

Effect of rectal infusion of short chain fatty acids in human subjects.

Solutions containing 90 mmol sodium acetate plus 30 mmol sodium propionate (90 mM; isotonic), 180 mmol acetate plus 60 mmol propionate (180 mM; hypertonic) or an equivalent volume of isotonic saline were given over a 30-min period in random order by rectal infusion to six healthy subjects. Peripheral venous blood samples were obtained at 30-min intervals over the next 2 h. After the 90 mM infusion, the serum acetate response reached a peak at 60 min and had fallen to baseline by 120 min. The incremental area under the serum acetate response curve after 180 mM was twice that after 90 mM. Propionate was undetectable in serum at any time. Blood glucose fell after all of the infusions, but there was no significant difference between the saline- and short chain fatty acid (SCFA)-containing infusions. SCFA had no significant effect on serum insulin or c-peptide concentrations. However, compared with the saline control, the 180 mM solution resulted in a significant fall in serum free-fatty acids (FFA) and a significant rise in serum total cholesterol and triglyceride, with no change in beta-hydroxybutyrate levels. The data provide strong evidence that colonic SCFA are absorbed and metabolized in the human subject. The fall in FFA suggests that colonic SCFA have an effect on carbohydrate metabolism. In addition, the data provide indirect evidence for utilization of SCFA for lipid synthesis.

Acetates↗
PubMed1987

Plasma glucose and insulin responses to carbohydrate food (rice) with different thermal processing.

The effects of thermal processing on plasma glucose and insulin responses in healthy subjects were examined. Fourteen volunteers, after being tested with a glucose load, were randomly administered a test meal, consisting of an amount of rice, calculated to yield the same quantity of glucose, used for the glucose tolerance test (70 g). Rice (90 g, raw) was cooked in two different manners: (a) boiled in salted water and (b) baked for 10 min at 160 degrees C after boiling as in the first test. A clear difference in viscosity and in in vitro hydrolytic rates between the two rice items could be established, whereas the plasma glucose and insulin responses in the volunteers differed to a smaller extent. In particular the 60-min incremental area for glucose was significantly lower in the case of baked rice, compared to boiled rice. These findings suggest that thermal processing of complex carbohydrates may differently affect glycemic responses in man.

Adult↗
PubMed1987

Dietary selenium and zinc intake and the medium-term Se and Zn status in obese persons on low-calorie diets.

The Se and Zn content of several foodstuffs collected in Northern Italy was evaluated by Atomic Absorption Spectrometry, these foodstuffs, employed in markedly hypocaloric diets with high fiber content, were utilized in the medium-term treatment of obesity. The plasma and erythrocyte selenium and zinc contents were evaluated in sixteen non-hospitalized obese patients over a 6-week period. Dietary regimens of 700 Kcal/day for 21 days followed by 1050 Kcal/day for 42 days were imposed. In spite of the drastic reduction in calorie intake, significant elevations in plasma (p less than 0.05) and erythrocytes (p less than 0.005) Se were observed after 9 weeks of treatment; plasma Zn, on the contrary, shows a slight but significant reduction (p less than 0.05) at the end of the experimental period. Findings suggest that, from the point of view of the microelement status, the balanced low-calorie diet with high fiber content is a mild, but quite adequate method for the treatment of subjects in good health even for long periods.

Adolescent↗
PubMed1985

[High resolution liquid chromatography (HPLC) analysis of the vitamin A and beta-carotene content of heat-treated precooked food].

Vitamin A and beta-carotene contents in 22 samples of precooked foods were determined before and after the use of various reheating techniques. The method used includes saponification by boiling with etOH and KOH, diethyl ether extraction in the presence of BHT as antioxidant, drying under controlled conditions and detection of the vitamins by HPLC. The results suggest good applicability of the procedure to food analysis and show how reheating processes can have a significant influence on the vitamin content of such foodstuffs.

Carotenoids↗
PubMed1978

[Industrial pollution by solvents with special reference to limited values for mixtures].

The report concerns the AA. experience in the field of pollution due to solvents, particularly in the following industries: shoe manufacturing, graphics and the production and application of paints. The exposure risk in these 3 indutries is quantitatively and qualitatively defined based on data obtained from the gas--chromatographic analysis of 238 work environment samples. The data are evaluated with reference to limit values established by the ACGIH, the Italian Society of Occupational Medicine and the Italian Society of Industrial Hygiene. In additon to the evaluation with respect to the TLV and VLP, the hygiene parameter of TLVs for mixtures is evaluated in the field of industrial hygiene.

Air Pollutants↗
PubMed1978

[Risk of absorption of fluoride in electrode arc welding].

The AA. in order to investigate the risk of fluoride absorption examined two factories in which arc-welding electrodes were used. They measured: a) fluoride content in two most used electrodes; b) airborne fluoride concentrations and dustness in the presumed respiratory area of welders with or without fume and dust capture devices; d) airborne fluoride concentrations and dustness three meters away from the welding place during unprotected work with basic electrodes; e) concentrations of fluoride in urine during a workweek in welders (n = 63) and in a control group (n. = 25). The AA. conclude that, in spite of the high teoretical risk of breathing fluoride, the intake of this compound is very low if welders are protected by easy devices.

Air Pollutants↗
PubMed1978

[Industrial hygiene and improvement of the work environment].

The AA. report a series of practical experiments in the following industries: textiles, ceramics, graphics and heavy industry, in order to demonstrate the necessity and utility of industrial hygiene in which an occupational hazard is not simply identified, but rather an improvement of the work environment is undertaken and the results of such a programme are again controlled and evaluated. The data presented lend themselves to a discussion of a preventive nature since, from a comparison of the data before and after modification, the efficacy of the modification itself is evaluated. The efficacy may vary from simple maintenance of equipment to environmental purification procedures and necessity of applying corrective modifications directly by the raw materials.

Air Pollutants, Occupational↗