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Biomedical subjects

M Porrini

Publications and source records attributed to M Porrini.

At least 37 records · Page 2Linked to original sources
PubMed1994

Plasma amino acids changes in obese patients on very low-calorie diets.

The reduced feeling of hunger alleged by obese patients on very low-calorie diets (VLCD) could be supposed due to restoration to a normal level of plasma TRP:LNAA ratio, previously found lowered in these subjects. We tested this hypothesis measuring weekly the changes of plasma amino acid concentration in obese individuals who followed a 5 week slimming regimen consisting in a powdered formula diet (500 kcal/d). A decrease in plasma TRP:LNAA ratio was seen, since tryptophan decreased, whereas valine and isoleucine increased over time. An increase in plasma lysine, threonine, glycine and aminobutyrate was also observed. The early decrease shown by alanine and glutamate was followed by an increase in the last weeks of the study. Our hypothesis was not confirmed, since VLCD failed to carry back the plasma TRP:LNAA ratio to a normal level.

Adult↗
PubMed1993

Effect of alcohol intake on lipids and fat-soluble vitamins in blood.

Several investigators have observed that a moderate intake of alcohol can have a positive effect on health (lowering the risk of cardiovascular disease, gall-stones, etc.). Our objective was to investigate how some blood constituents are affected by the consumption of different levels of alcohol. Erythrocyte phospholipids and fatty acids composition and plasma fat-soluble vitamins were determined in 28 volunteers who were divided into three groups according to their alcohol intake: non-drinkers, moderate drinkers--consumption of 20-60 g/day, and heavy drinkers--more than 60 g/day. A relation was seen between alcohol consumption and vitamin status; furthermore alpha-tocopherol and beta-carotene were significantly lower in heavy drinkers. The erythrocyte phospholipid compositions of the non- and moderate drinkers showed no significant differences whereas a definite relation was noted when the alcohol intake was higher than 60 g/day. In conclusion it is possible to say that a moderate alcohol intake does not have any significant effect on the phospholipid and fatty acid composition; only the vitamin status is significantly influenced, but to confirm our results it is essential to evaluate other variables involved in this problem such as the lifestyle, physical activity and the eating habits of the subjects tested.

Adult↗
PubMed1992

Effect of vegetarian soy diet on hyperlipidaemia in nephrotic syndrome.

Nephrotic patients with persistent proteinuria also have various lipid abnormalities that may promote atherosclerosis and more rapid progression of renal disease. We aimed to find out whether dietary manipulation can correct the hyperlipidaemia found in these patients. After a baseline control period of 8 weeks on their usual diets, 20 untreated patients with chronic glomerular diseases, stable long-lasting severe proteinuria (5.9 [SD 3.4] g/24 h) and hyperlipidaemia (mean serum cholesterol 8.69 [3.34] mmol/l) ate a vegetarian soy diet for 8 weeks. The diet was low in fat (28% of total calories) and protein (0.71 [0.36] g/kg ideal body weight daily), cholesterol free, and rich in monounsaturated and polyunsaturated fatty acids (polyunsaturated/saturated ratio 2.5) and in fibre (40 g/day). After the diet period the patients resumed their usual diets for 8 weeks (washout period). During the soy-diet period there were significant falls in serum cholesterol (total, low-density lipoprotein, and high-density lipoprotein) and apolipoproteins A and B, but serum triglyceride concentrations did not change. Urinary protein excretion fell significantly. The concentrations of all lipid fractions and the amount of proteinuria tended to return towards baseline values during the washout period. We do not know whether the favourable effect of this dietary manipulation on proteinuria was due to the qualitative or quantitative modifications of dietary protein intake or was a direct consequence of the manipulation of dietary lipid intake.

Adolescent↗
PubMed1992

[Nutrients, anthropometric characteristics and osteoporosis in women in the recent and late postmenopausal period].

Bone mineral content (BMC) at two different radial sites (mid-diaphysis and ultra-distal epiphysis), anthropometric measurements (Body Mass Index, Lipidic Area, and Muscular Area) and nutrients intake were measured in two populations of women selected on the basis of early (< 9 years) or remote (> 15 years) menopause. The results show the presence of positive relationships between BMC, and protein and lipid intakes in the population of women in early menopause; in the other population no relationships were found. Glucid, fibre and calcium intakes were not related to the BMC of both populations. The positive relationships between BMC, and protein and lipid intakes in the population of women in early menopause is likely mediated by anthropometric characteristics as Body Mass Index and Muscular Area.

Adult↗
PubMed1992

Differential effect of unsaturated oils and butter on blood glucose and insulin response to carbohydrate in normal volunteers.

Plasma glucose and insulin responses were monitored in normal volunteers after a standard carbohydrate meal with unsaturated oils (olive and corn oil, in identical volumes) or butter. Both unsaturated oils almost totally blunted the glycaemic response; butter, instead, only delayed the plasma glucose rise, without significantly changing the area under the curve. The insulin rise was essentially unaffected by the three experimental meals, only a slight delay in the peak being observed with no differences between unsaturated oils and butter. These findings support previous data indicating reduced glucose levels after prolonged administration of olive oil, and reduced glycaemic response, in the absence of clear-cut insulin changes, differentiates unsaturated oils from indigestible fibres; it may be linked to an altered polysaccharide handling at the intestinal level.

Adult↗
PubMed1991

Relation between diet composition and coronary heart disease risk factors.

STUDY OBJECTIVE: The aim was to evaluate dietary intakes and their correlation to some risk factors for coronary heart disease. DESIGN: The study was a population based survey with random sample selection stratified by age and sex. PARTICIPANTS: 352 adults living in a small town in Northern Italy took part in the study. Response rate was 46% among females and 48% among males. Refusal to take part was mainly due to the large number of tests involved. MEASUREMENTS AND MAIN RESULTS: Diets were high in protein (animal/vegetable ratio 1.7 in women and 1.4 in men) and in fat and low in carbohydrates. The hypercholesterolaemic and atherogenic potential of the diet, evaluated by the cholesterol/saturated fat index, was high in about 50% of the population. The thiamin and riboflavin intakes were lower than the Italian recommended allowances in more than 60% of the people tested, whereas the vitamin A intake was more than adequate in about 70%. A positive association was found in the younger groups (men and women 20-39 years old) between some nutrient components (energy, alcohol, total and saturated fats) and some blood lipids. In the older people blood lipids were correlated with body mass index. CONCLUSIONS: The overall data indicate that a correlation exists between dietary intake and some risk factors for coronary heart disease; dietary intervention, at least in young adults, is suggested.

Adult↗
PubMed1990

Availability of selenium in dough and biscuit in comparison to wheat meal.

We studied the availability of selenium in processed foods and whole wheat diets for restoring the Se content and glutathione peroxidase (GSHPx) activity in the blood and liver of selenium-depleted rats. The Se content in the rat diets ranged from 225 to 342 micrograms Se/kg diet. Different selenium sources and different Se amounts had little influence on the Se levels in the blood and liver of repleted rats. Se from processed foods did not completely restore the GSHPx activity in whole blood and liver as happened with Se coming from wheat. These results indicate that it is the milling processes of the flour production, and not the cooking, which decrease the availability of Se for GSHPx synthesis in rats.

Animals↗
PubMed1989

Effects of durum wheat dietary selenium on glutathione peroxidase activity and Se content in long-term-fed rats.

A 120-day assay was made of Se concentration and glutathione peroxidase Se-dependent (GSHpx) activity in plasma, erythrocytes and liver of female Sprague-Dawley rats fed either a Torula diet (low Se content) or a durum wheat diet providing 28-405 micrograms of Se/kg diet. For all groups there was a strong increase for the first 20 days in plasma and liver Se; for the remaining period the increase was lower; erythrocyte Se increased, as before, in the first 60 days for groups fed 28-200 micrograms/kg diet, after this period it decreased in the groups fed high-Se diet. Plasma GSHpx activity was extremely sensitive to dietary Se levels and increased for up to 40 days of repletion, after which the trend was to plateau; liver and erythrocyte GSHpx activity increased continuously for up to 60 days of supplementation, it then remained constant. The correlation between Se in plasma, liver and erythrocytes and its GSHpx activity was statistically significant (p less than 0.001). These results suggested that in long-term-fed rats, a diet with levels of 100-400 micrograms/kg was sufficient to satisfy the rat's needs; there was no evidence of toxicity and, moreover, in all tissues, an amount of Se, probably bound to proteins with unknown functions, was present.

Animals↗
PubMed1989

Thiamin, riboflavin and pyridoxine status in chronic renal insufficiency.

The restricted diets of patients with chronic renal insufficiency (CRI) can lead to inadequate intake of some vitamins. We studied thiamin, riboflavin and pyridoxine nutritional status of CRI subjects on unrestricted or low-protein diet. Results show that riboflavin status is inadequate even before the beginning of the follow up and worsens with time for both groups, while thiamin and pyridoxine status becomes inadequate in some patients after a long period on the low-protein diet. Water-soluble vitamin supplements could improve the nutritional status of CRI patients on protein-restricted diet.

Dietary Proteins↗
PubMed1989

[The measurement of ultradistal radial bone minerals in women in the menopause].

An anthropometric, radiomorphometric and absorptiometric study was carried out to check whether or not reliable information about the mineral content of trabecular bone could be acquired from the ultradistal epiphysis of the human radius. The results indicate that a radius scan 1.2 to 1.6 cm proximal to the ulnar styloid tip gives reproducible information as to the mineral content of a bone which is mainly trabecular in nature. In the ultradistal radial region the bone mineral analyzer (Norland 2780) was always able to automatically find bone edges. The measurement error was 4%, and BMC values were not significantly different in the various subjects; BMC values were positively correlated with body mass and muscular area in postmenopausal women. Conversely, in no subject a direct correlation was found between BMC and BW values at sequential scan sites; BMC/BW ratios were more than 10% variable, and the differences were statistically significant (p less than 0.01). Finally, the comparison of age-related changes in the BMC of ultradistal and mediodiaphyseal radii demonstrated that the former expresses the specific metabolic reactivity of the trabecular bone.

Absorptiometry, Photon↗
PubMed1988

Vitamin nutrition in patients with chronic renal failure and dietary manipulation.

(1) Vitamin abnormalities in patients with CRF are frequent and appear early even with mild renal failure; (2) early supplementation with water-soluble vitamins should be given to patients on low-protein diets--the amount of the supplementation, however, remains to be determined; (3) fat-soluble vitamin supplements (A and E) should be avoided and their dietary intake limited, and (4) it is obvious that vitamin nutrition in patients with CRF requires further investigation.

Dietary Proteins↗
PubMed1987

Vitamin A, E and C nutriture of elderly people in North Italy.

The vitamin A, E and C nutritional status of 313 non institutionalized elderly people living in a small town and in an agricultural village of North Italy has been evaluated. From results obtained it is possible to say that all the population tested is at low risk for vitamin A deficiency, while 10-20% of people over 70 living in the small town have low levels of vitamin E. On the contrary, the nutritional status of ascorbic acid, where the levels are inadequate in more than 50% of the population, is worrying.

Aged↗
PubMed1987

Nutritional status of non institutionalized elderly people in north Italy.

The nutritional status of some elderly people - 313 non institutionalized and 37 assisted by public organization - was investigated. As regards weight, muscle and fat area, BMI and fat %, lower values were found for assisted people. The mean daily nutrient intakes in assisted people are below the recommended values for all nutrients, except fats; free living people have higher intakes of protein and fat, and lower intakes of thiamin and retinol equivalents. About 10% and 15% of non institutionalized people showed respectively an inadequate thiamin and riboflavin nutritional status (determined by alpha ETK and TPP levels and by alpha EGR and FAD levels); a worse situation was found for assisted people. Vitamin B6 levels appear adequate for all the population tested.

Aged↗