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Biomedical subjects

A Pietri

Publications and source records attributed to A Pietri.

13 recordsLinked to original sources
PubMed2001

Ineffectiveness of activated carbon in reducing the alteration of sphingolipid metabolism in rats exposed to fumonisin-contaminated diets.

Sphinganine/sphingosine (SA/SO) ratio, a biomarker of fumonisin exposure, has been measured in urine, kidney and liver of male Wistar rats exposed to fumonisin-contaminated diet with and without the addition of activated carbon (AC). The latter was previously shown to adsorb fumonisin B(1) in vitro. Rats were fed either control diet or fumonisin-contaminated diet (4 microg FB(1+)FB(2)/g) or fumonisin-contaminated diet mixed with 20 mg AC/g diet for 1 week. In rats fed fumonisin-contaminated diet, the SA concentration and SA/SO ratio increased significantly and reversibly in kidney, while urine and liver did not show a significant increase of SA/SO ratio. The addition of AC to the fumonisin-contaminated diet did not alter the change of SA/SO biomarker for fumonisin exposure. This provides indications that the use of AC to reduce the toxicity of fumonisins is unlikely to be effective in vivo.

Animal Feed↗
PubMed2001

Occurrence of ochratoxin A in Italian wines.

A total of 96 red wines and 15 white dessert wines produced mostly in the years 1995-97 in 19 Italian regions were analysed for ochratoxin A (OTA). The amount of OTA ranged from < 1 to 3856 ng/l the median (mean) was found to be 90 (419) ng/l for the red wines and 8 (736) ng/l for the white dessert wines. Our survey shows that the geographic region of origin has a strong influence on OTA contamination, both for red and for dessert wines: in fact, wines produced in southern Italy were markedly more contaminated. The overall median (mean) OTA concentration in the red wines produced in the four Italian areas (northwest, northeast, centre and south) was 2 (11), 90 (81), 134 (295) and 1264 (1233) ng/l. The same trend was observed for the white dessert wines: OTA concentrations of over 1000 ng/l were found in four out of five samples from southern Italy (1185, 2454, 3477, 3856 ng/l), while central and northern samples showed very low contamination. The contribution of wine to mean daily OTA intake can be considered negligible in the case of people drinking wine manufactured in northern and central Italy; this is not true if a medium drinker constantly consumes red wine produced in southern Italy in this case wine alone could supply the diet with an amount of OTA equal to or even above the tolerable daily intake of 5 ng/kg body weight recommended by the Scientific Committee on Food of the European Commission.

Chromatography, Affinity↗
PubMed1999

Evaluation of a fluorodensitometric method for analysis of ergosterol as a fungal marker in compound feeds.

Ergosterol is the principal sterol of fungi and plays an essential role as a component of the cell membrane and other cell constituents. This molecule is considered a good marker of fungal contamination in foods and feeds. This paper reports a rapid and sensitive method to test ergosterol content in compound feeds based on fluorodensitometry after thin-layer chromatography (TLC) separation. This method involves a thermal treatment of TLC plates that leads to the formation of a highly fluorescent ergosterol derivative. Such a dosage allows ergosterol testing in any naturally contaminated samples (limit of detection: 1 ppm of ergosterol) and gives results in close agreement with high-pressure liquid chromatography determination. Moreover, values obtained on mixed feeds for animals at different steps of fungal contamination are linked to quantitative development of storage fungi, evaluated by mycological technique, reinforcing the interest of a rapid method for measuring this fungal marker.

Animal Feed↗
PubMed1998

Activated carbons: in vitro affinity for ochratoxin A and deoxynivalenol and relation of adsorption ability to physicochemical parameters.

In vitro affinity tests were conducted to test the effectiveness of 19 activated carbons (ACs), hydrates sodium calcium aluminosilicate (HSCAS) and sepiolite (S) in binding ochratoxin A (OA) and deoxynivalenol (DON) from solution. Relationships between adsorption ability and physicochemical parameters of ACs (surface area, iodine number, methylene blue index) were tested. When 5 ml of a 4-micrograms/ml aqueous solution of OA was treated with 2 mg of AC, the ACs adsorbed 0.80 to 99.86% of the OA. HSCAS and S were not effective in binding OA. In two saturation tests carried out with increased amounts of OA (5 ml of 10-and 50-micrograms/ml aqueous solutions of OA, respectively) three ACs also showed high adsorption ability (adsorbing 92.23 to 96.57% of the OA). When 5 ml of a 4-micrograms/ml aqueous solution of DON was treated with 10 mg of AC, ACs adsored 1.83 to 98.93% of the DON. HSCAS and S were not effective in binding DON. An overall relation of adsorption ability to the physicochemical parameters of ACs was observed. The methylene blue index was more reliable than iodine number and surface area in predicting ability of ACs to adsorb OA and DON. Based on the data observed on the xxxxx eh present study as well as on aflatoxin B1 and fumonisin B1 from previous studies, it is concluded that ACs have high in vitro affinity for chemically different mycotoxins, and can be considered as potential multi-mycotoxin-sequestering agents. However, the ability to bind the main mycotoxins singly or in combination should be confirmed by in vivo investigations. Moreover, information on the amounts of AC to be added to feeds, and on the possible long-term effect on absorption of essential nutrients are needed.

Adsorption↗
PubMed1981

Plasma lipid and lipoprotein levels with continuous subcutaneous insulin infusion in type I diabetes mellitus.

Plasma lipid and lipoprotein-cholesterol levels were measured in 10 insulin-dependent (Type I) diabetics taking their usual dose of conventionally administered insulin during 6 months of a continuous subcutaneous insulin infusion delivered with a small, portable, battery-powered pump. With this insulin delivery system we were able to provide near normal glucoregulation 24 hours a day for the entire study. This improved glucoregulation resulted in significant reductions in total plasma cholesterol and triglyceride, and very low density and low density lipoprotein-cholesterol levels within 2 to 4 weeks of treatment. These changes persisted for the entire 6 months of observation. High density lipoprotein-cholesterol levels rose significantly after 2 months of treatment and continued to increase during the 6-month study. These changes in plasma lipid and lipoprotein-cholesterol levels in response to treatment with continuous subcutaneous insulin infusion would favorably alter the predicted risk for the development of premature atherosclerosis in these patients.

Adolescent↗
PubMed1980

The effect of improved diabetic control on plasma lipid and lipoprotein levels: a comparison of conventional therapy and continuous subcutaneous insulin infusion.

We studied short-term changes in plasma lipid levels in type I diabetics treated with either a conventional insulin regimen or continuous subcutaneous insulin infusion. Mean plasma glucose dropped from 260 +/- 18 to 134 +/- 8 mg/dl when conventional treatment was used and from 194 +/- 18 to 108 +/- 8 mg/dl with CSII. Both forms of therapy were associated with a significant fall in plasma triglyceride levels. However, only CSII treatment produced significant changes in total plasma cholesterol and LDL cholesterol levels. Total cholesterol fell from 195 +/- 17 mg/dl to 161 +/- 11 mg/dl and LDL cholesterol fell from 129 +/- 13 mg/dl to 102 +/- 9 mg/dl. We conclude that improved diabetic control by any method is effective in lowering plasma triglyceride levels, but it requires almost perfect metabolic control to affect plasma cholesterol and LDL cholesterol levels. The changes in plasma lipid and lipoprotein achieved with CSII may favorably alter the prediction for the development of premature atherosclerosis in our patients.

Adult↗
PubMed1980

Changes in nerve conduction velocity after six weeks of glucoregulation with portable insulin infusion pumps.

Near normal glucoregulation was maintained in 10 patients with insulin-dependent (type I) diabetes mellitus for 6 wk with preprogrammed continuous subcutaneous insulin infusion using a portable battery-powered infusion pump (CSII). This form of therapy resulted in a statistically significant increase in motor nerve conduction velocity in the median and peroneal nerves compared with baseline values. There was no significant change in the motor nerve conduction velocity in the ulnar nerve or in the sensory nerve conduction studies. No changes occurred in five additional patients studied in similar fashion while on a conventional insulin regimen. These results suggest that the prevention of sustained hyperglycemia with CSII could theoretically result in the prevention of diabetic neuropathy. However, only long-term studies of CSII will provide the information necessary to determine the clinical relevance of the findings.

Artificial Organs↗
PubMed1979

Pancreatic and gastric release of somatostatinlike immunoreactivity during intestinal phase of a meal.

The present study was designed to examine pancreatic and gastric D-cell function during the intestinal phase of a liver meal. The intraduodenal instillation of a 20% liver meal (5 ml/min) elicited a significant rise in the plasma levels of somatostatinlike immunoreactivity (SLI) in the pancreatic vein and inferior vena cava, together with the rise in glucagon and insulin levels. The rise in pancreatic vein SLI was not reduced after truncal vagotomy or during atropine infusion. In the stomach, the intestinal liver meal elicited a significant rise in antral but not fundic vein SLI levels. The rise in antral vein SLI was augmented after truncal vagotomy and abolished during atropine infusion, as was the rise in inferior vena caval SLI. In contrast to the protein meal, intravenous infusion of an amino acid mixture elicited a rise in pancreatic vein SLI but not antral or fundic vein SLI. It is concluded that during the intestinal phase of a protein meal, pancreatic and antral but not fundic SLI release is stimulated. The effects of truncal vagotomy and atropine infusion on these responses suggest a close interaction between the vagus and muscarinic cholinergic mechanisms and the D cells of the stomach and pancreas.

Animals↗
PubMed1979

Changes in glucagon levels after four to five weeks of glucoregulation by portable insulin infusion pumps.

Near-normal glucoregulation was maintained in five patients with juvenile-onset diabetes mellitus for 4--5 wk with a preprogrammed, continuous, subcutaneous insulin infusion using a portable battery-powered infusion pump. This form of therapy significantly lowered immunoreactive glucagon (IRG) levels below those observed while on conventional insulin treatment at several times during the 24-h profile. The maximum IRG levels were also reduced in all five subjects. Thus, a flexible system of insulin delivery, as is provided by certain open-loop pump systems, can overcome inappropriate glucagon secretion that occurs with conventional insulin therapy.

Adolescent↗
PubMedDate not supplied

Aflatoxin M1 occurrence in dairy products marketed in Italy.

In 1984, 313 samples of imported liquid milk and 159 samples of imported cheese were checked for aflatoxin M1; 225 of the milk samples came from FR Germany and 88 from France, while 82 of the cheese samples came from France, 34 from FR Germany and 43 from the Netherlands. The number of positive samples was small both for German (13.8%) and for French (12.5%) milks, and the contamination levels were very low (maximum 23 ng/l). As regards the cheeses, aflatoxin M1 was detected in 19.5, 26.5 and 53.5% of the French, German and Dutch samples respectively, but only 2 French samples exceeded 250 ng/kg, the limit set by Swiss law. In 1985, two surveys were carried out on 276 milk samples mostly obtained from individual farms and on 416 cheese samples taken from all parts of the country. As regards the milk samples, 70 (25.3%) contained aflatoxin M1, but generally at very low levels; in fact only 7 (2.5%) of the samples exceeded 50 ng/l. Aflatoxin M1 was found in 130 (31.3%) of the cheese samples, but here again only 9 (2.2%) exceeded 250 ng/kg. There was no significant difference in aflatoxin M1 levels between Italian, German and French cheese samples but these were significantly lower (P less than 0.01) than in Dutch samples.

Aflatoxin M1↗
PubMedDate not supplied

Cutaneous complications of chronic continuous subcutaneous insulin infusion therapy.

The cutaneous complications that can develop with continuous subcutaneous insulin infusion constitutes a significant concern when using this innovative and highly effective form of treatment for type I diabetes. These complications are twofold, the first being infection with abscess formation at the infusion needle site. Proper hygiene and frequent changing of the infusion site are helpful and effective measures. The second complication is the development of local allergic skin reactions, again at the infusion needle site, even with highly purified pork insulin. These may subside after several weeks on their own but switching insulin preparations also may be helpful.

Adolescent↗
PubMedDate not supplied

The effect of continuous subcutaneous insulin infusion on endogenous insulin secretion in type I diabetes.

In an attempt to elucidate possible mechanisms for the success of continuous subcutaneous insulin infusion (CSII), we evaluated the C-peptide response to a standard breakfast in seven type I diabetic patients while they were on conventional insulin treatment and again after 4 wk of near-normal glycemia achieved with CSII. While on conventional therapy their 24-h mean blood glucose level was 211 +/- 12 mg/dl and their glycosylated hemoglobin level was 10.6 +/- 0.6%. After 4 wk of CSII their 24-h mean blood glucose level fell to 95 +/- 7 mg/dl and their glycosylated hemoglobin level fell to 6.5 +/- 0.4%. Plasma C-peptide levels were undetectable in all seven patients both while on conventional therapy and after 4 wk of CSII. We conclude that the success of CSII is related to an improved method of insulin delivery and not to either the selection of type I diabetic patients who have some residual insulin secretory capacity or to some change in endogenous insulin secretion produced by the treatment itself.

Adolescent↗