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Biomedical subjects

G Valentini

Publications and source records attributed to G Valentini.

At least 145 records · Page 8Linked to original sources
PubMed1986

Correction of uremic acid-base imbalance in biofiltration: standardization of the amount of bicarbonate infused.

Beneficial effects of biofiltration on acid-base balance have been described, especially in patients showing poor tolerance to standard hemodialysis. This study was designed to standardize the amounts of bicarbonate to be infused for optimal control of the acid-base balance, without the adverse reactions of symptomatic metabolic alkalosis. In three adult patients (body weight greater than 55 kg) a 300 mEq. bicarbonate infusion achieved normal pre- and post-dialysis plasma levels of bicarbonate and normal pre- dialysis pH. Conversely, in three adolescent patients (body weight less than 40 kg) pre- dialysis plasma bicarbonate levels and pre- dialysis pH could not be adequately corrected in spite of increasingly high doses of bicarbonate infused up to a maximum of 240 mEq per treatment. Larger amounts brought on symptoms of metabolic alkalosis.

Acid-Base Imbalance↗
PubMed1986

Clinical evaluation of biofiltration in uremic patients undergoing chronic hemodialysis.

The clinical efficiency of biofiltration (BF) was evaluated in six hemodialysis patients with poor clinical tolerance for standard hemodialysis. Three were adults (mean age 34 years, mean body weight 67 kg) and three adolescents (mean age 17 years, mean body weight 38 kg). Mean maintenance hemodialysis time was 90.5 months (range 49-132). BF treatments lasted three hours in all cases, for a total of nine hours weekly, with AN69 S membranes and infusion of 3 liters of HCO3 solution (100 mEq/l for the adults, 80 mEq/l for the adolescents). We recorded intra- and inter-dialytic symptoms daily, hematological values and acid-base status monthly. Multimodality evoked potentials were recorded after 3 and 9 months. Biochemical values reached a steady state 9 months from the beginning of the study, metabolic acidosis was corrected more efficiently in both groups at the end of dialysis, but only in the adult patients, were pre-dialysis plasma bicarbonates within normal limits. A clear drop in the number of episodes of intradialytic hypotension was noticed in both groups, but the adolescent patients' tolerance for dialysis did not improve. In conclusion our data show that in adult patients with poor tolerance BF offers a dependable alternative to standard hemodialysis, and the length of treatment can be reduced.

Acid-Base Equilibrium↗
PubMed1985

The anterior segment anomalies in the Warburg syndrome. A study of new cases.

The Warburg syndrome is a primary lethal neurodysplasia recently defined with autosomal recessive inheritance. The clinical diagnosis is based on the association of brain alterations with ocular defects, among which the anterior segment anomalies and the retinal dysplasia appear to be the most significant. The authors report a clinical and histopathological study on personal observations.

Abnormalities, Multiple↗
PubMed1981

Presence of eosinophilia in progressive systemic sclerosis and localized scleroderma.

Recent studies on eosinophilic fasciitis have lead to this investigation of eosinophilia in progressive systemic sclerosis and localized scleroderma. Eosinophilia (eosinophilic count greater than 300/cmm) was found in ten of 63 progressive systemic sclerosis patients (15.8%) and in two of nine localized scleroderma cases (22.2%). In patients with progressive systemic sclerosis eosinophilia was found occasionally in six cases; it was transitory, but frequent in three cases; it was constant and very high in one case. In patients with localized scleroderma eosinophilia was found occasionally in one case and frequent, but not constant, in the other one. The possible influence of drugs could be excluded in five cases: three progressive systemic sclerosis cases and two affected with localized scleroderma. Therefore, it is possible to confirm that eosinophilia is not a distinctive sign of eosinophilic fasciitis in patients suffering from scleroderma-like syndromes. While eosinophilia is related to inflammation in eosinophilic faciitis, eosinophilia and disease activity could not be correlated in our patients with PSS. Recently, it has been suggested that eosinophilia might be an unfavorable prognostic criterion in progressive systemic sclerosis. Our data does not allow confirmation of this assumption.

Adult↗
PubMed1979

Two forms of pyruvate kinase in Escherichia coli. A comparison of chemical and molecular properties.

The two forms of pyruvate kinase (ATP:pyruvate 2-O-phosphotransferase, EC 2.7.1.40) present in Escherichia coli have been purified from the same cultures and crystallized. A modified procedure for the purification of type I pyruvate kinase is described. Molecular weight, subunit structure, amino acid composition, NH2-terminal amino acid, maps of tryptic peptides and conditions for crystallization have been determined for the two forms. A comparison of these data shows that the two forms are different proteins, each being a tetramer of identical subunits.

Amino Acids↗
PubMed1977

Purification and molecular properties of the AMP-activated pyruvate kinase from Escherichia coli.

The AMP-activated pyruvate kinase (ATP:pyruvate 2-O-phosphotransferase, EC 2.7.1.40) from Escherichia coli has been purified 200 times through a three-step procedure which gives a homogeneous preparation with a specific activity of 110. The enzyme appears to be a tetramer of molecular weight 190 000. Subunits (molecular weight 51 000) show a single amino-terminal amino acid (serine) and appear as a single band in polyacrylamide gel electrophoresis in sodium dodecyl sulphate. The enzyme crystallizes in conditions of reduced dielectric constant of the solvent in the pH range 6.5-7.5. Kinetic and regulatory properties of the purified enzyme are similar to those described for crude preparations of the enzyme.

Amino Acids↗