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Biomedical subjects

M Tolomelli

Publications and source records attributed to M Tolomelli.

5 recordsLinked to original sources

Lipid peroxidation and antioxidant status in adults receiving lipid-based home parenteral nutrition.

BACKGROUND: Infusion of lipid emulsions rich in polyunsaturated fatty acids (PUFAs) may increase lipid peroxidation, which is counteracted mainly by superoxide dismutase (SOD) (a zinc-, copper-, and manganese-dependent enzyme), selenium-dependent glutathione peroxidase (Se-GSHPx), and alpha-tocopherol. OBJECTIVE: We investigated lipid peroxidation and antioxidant status in patients receiving home parenteral nutrition (HPN) providing variable amounts of a lipid emulsion rich in PUFAs, and alpha-tocopherol, zinc, copper, and manganese as recommended by the American Medical Association, and no selenium. DESIGN: Serum malondialdehyde, plasma alpha-tocopherol, selenium, Se-GSHPx, PUFAs, and red blood cell Se-GSHPx and SOD were evaluated in 12 patients and in 25 healthy control subjects. Malondialdehyde was also assessed in a group of 40 healthy control subjects. RESULTS: Patients had significantly higher concentrations of malondialdehyde and SOD and lower alpha-tocopherol concentrations and selenium nutritional status. Linear regression analysis showed that malondialdehyde was associated with the daily PUFA load (r=0.69, P< 0.03) and with plasma alpha-tocopherol (r=-0.59, P< 0.05), but stepwise multiple regression analysis confirmed only the association between malondialdehyde and alpha-tocopherol; plasma alpha-tocopherol was associated with the daily PUFA load (r=-0.65, P< 0.04) and with the duration of HPN (r=-0.74, P< 0.02). CONCLUSIONS: In HPN patients, the peroxidative stress due to lipid emulsions rich in PUFAs is counteracted primarily by alpha-tocopherol. The dosages of alpha-tocopherol, zinc, copper, and manganese recommended by the American Medical Association appear sufficient to sustain SOD activity but inadequate to maintain alpha-tocopherol nutritional status. HPN formulations should be supplemented with selenium.

Adolescent↗

Urinary zinc excretion in Crohn's disease.

In order to study the reliability of urinary zinc levels as an index of zinc metabolism and status in Crohn's disease, we evaluated plasma and urinary zinc concentrations, urinary 3-methylhistidine excretion, and Crohn's disease activity index (CDAI) in 42 patients affected by Crohn's disease. Plasma zinc correlated directly with albuminemia (P = 0.01) and inversely with CDAI (P = 0.001). Urinary zinc excretion correlated with urinary 3-methylhistidine (P = 0.001) and plasma zinc levels (P = 0.01), and inversely with CDAI (P = 0.05). However, from multiple regression analysis, it was found that zincemia is influenced by CDAI and not by albumin, whereas zincuria is related to urinary 3-methylhistidine and plasma zinc, and not to CDAI. Our conclusion is that, in Crohn's disease, zincuria can be an index of zinc status when used together with measurements of lean body mass and turnover and factors influencing plasma ultrafiltrable zinc fraction.

Adolescent↗

[A Study of the enzymes of the alkaline phosphatase in commercial sera (author's transl)].

We have examined alkaline phosphatase in five commercial sera employing three analyzers. Alkaline phosphatase in three samples is underestimated or overestimated according to the analyzers used. Therefore we have studied the isoenzymatic fractions employing the fractionation of alkaline phosphatase on celluloseacetate. Alkaline phosphatase isoenzymes have physical and biochemical marks different from human sera. In human sera on the contrary have not noticed any difference according to the analyser used.

Adult↗

[Neuropsychological follow-up of children with phenylketonuria treated early].

We evaluated, yearly, the neuro-psychological development in 16 out of the 27 children with phenylketonuria detected via neonatal screening in the years 1980-90. 14 children had the classical form, while 2 had "variant" type of phenylketonuria. Development quotients always were slightly lower in patients than in controls, but the greatest difference was seen at 1 year of age (92.5 +/- 6.7 vs 101.6 +/- 2.2). At age 6 years, 4 children out of 11 had a IQ equal or below 90.2 of them had neonatal asphyxia, while the others showed, after age 2-4, constantly elevated phenylalanine levels. Four children had a bad metabolic control, as from the age of 2-4 year, and only 1 of them showed a normal IQ at 6 years of age. Regression analyses were used to determine the best predictors of IQ. Parents' social level stood out as the best predictor of IQ at 6 years of age. If this parameter was excluded, phenylalanine level, especially at age 4, best predicted IQ. The following variables had no influence: age at start of diet (they were all begun on diet within the first month of life), pre-diet phenylalanine levels and phenylalanine levels at 1 year of age (all children were, at this age, on good control), DQ (Development Quotient) at age 1. A high percentage (10 out 14) of hyperactive and psychologically instable children was also found, but with no correlations with IQ levels.

Age Factors↗