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F S Dioguardi

Publications and source records attributed to F S Dioguardi.

9 recordsLinked to original sources
PubMed1999

Batch effects, water content and aqueous/organic solvent reactivity of microcrystalline cellulose samples.

The structural, morphological and surface features on two MCC powders of the same commercial type (Avicel PH 102), but coming from different countries (The Netherlands and Hong Kong) and vendors (DMV International and Mingtai Chemical Co., Ltd., respectively), have been investigated and compared, by means of the X-ray diffraction, SEM and BET and polymerization degree determination. TGA and water sorption from saturated vapor experiments have been applied to characterize and compare the MCC/water interactions of the two samples. The results were integrated by studies of preferential sorption from binary aqueous/organic solvents.

Acetonitriles↗
PubMed1990

Long-term oral branched-chain amino acid treatment in chronic hepatic encephalopathy. A randomized double-blind casein-controlled trial. The Italian Multicenter Study Group.

In a double blind randomized study, branched-chain amino acids and placebo (casein) were compared as a treatment for chronic hepatic encephalopathy in cirrhosis. After a 15-day run-in period with controlled diet (45-65 g protein), the patients were administered, in addition to their diet, branched-chain amino acids (0.24 g/kg, 30 patients) or an equinitrogenous amount of casein (34 patients). One patient on branched-chain amino acids and two on casein were lost to the study. After 3 months, the index of portal-systemic encephalopathy significantly improved in patients on active treatment (from 40 [S.D. 14]% to 21 [17]), but was not in subjects receiving casein (from 37 [13]% to 36 [12]). Two or more parameters of the index improved in 24 patients treated with amino acids (80%; confidence limits, 61-92%), and only in 12 receiving casein (35%; confidence limits, 20-54%; p less than 0.001). Patients who did not improve were given an alternative treatment for 3 more months. Casein-treated patients given branched-chain amino acids rapidly improved. The changes in neuropsychologic function were associated with an improvement in semiquantitative nitrogen balance, which became consistently positive in amino acid-treated subjects; there was also a mild improvement in nutritional parameters and in liver function tests. The supplementation of oral branched-chain amino acids to the diet is superior to casein as a treatment for providing adequate nitrogen supply and improving the mental state of cirrhotic patients with chronic encephalopathy.

Adult↗
PubMed1990

Effects of chronic oral branched-chain amino acid supplementation in a subpopulation of cirrhotics.

Liver cirrhosis is characterized by low plasma levels of branched chain amino acids (BCAA) and high concentrations of aromatic amino acids (AAA), and this imbalance has been implicated in the pathogenesis of hepatic encephalopathy by the synthesis of altered neurotransmitters. Contrasting results on intravenous or oral BCAA efficacy and metabolic impact have already been reported, but studies reported in the literature were never longer than a few weeks. After oral administration of BCAA and a standard diet to 28 cirrhotic patients for 1 year, no modifications in plasma concentrations of BCAA could be observed up to 3 months of therapy. Our data and an accurate analysis of the current literature lead us to propose the hypothesis that in the impaired nitrogen metabolism following cirrhosis there are neither single metabolic presentations nor many perturbations, but numerous 'subpopulations' of patients who present a homogeneous pattern of alterations that may distinguish them in terms of therapeutic approach.

Adult↗
PubMed1981

Plasma amino acid patterns in experimental acute hepatic failure: comparison between hepatectomy and liver devascularization in pigs.

To clarify the physiopathologic mechanism leading to a marked increase in aromatic amino acids (AAA) in acute hepatic failure (AHF), we compared two experimental models of AHF. Ten pigs were submitted to one-stage hepatic devascularization (group A); in eight other pigs total hepatectomy was performed (group B). The animals were maintained under constant glucose infusion. The mean survival time in group A was 23 +/- 2 hours; after hepatectomy it was 30 +/- 4 hours. Hepatic coma progressively deepened from 8 +/- 3 hours in Group A animals and was delayed until 17 +/- 5 hours in the anhepatic pigs. AAA, methionine, and tryptophan immediately increased markedly in pigs with liver ischemia. In group B animals, AAA showed a slight increase only 18 hours after hepatectomy, whereas there were no significant differences in methionine and tryptophan. The different amino acid patterns in the two groups of animals demonstrate that hepatocyte necrosis is a major source of plasma amino acids after liver devascularization. The slight increase in AAA after total hepatectomy suggests that a release mechanism from muscular mass is involved in the later stages of the experiment. The onset of coma is related to the increase in AAA rather than to alterations in blood ammonia that did not differ in either group of animals.

Amino Acids↗
PubMedDate not supplied

Nutritional and hemodynamic implications of large volumes paracentesis in cirrhotics.

Large volume paracentesis is a safe and widely diffused treatment of tense ascites in decompensated liver cirrhosis. Hemodynamic changes induced by this practice have been repeatedly indagated, but although some authors referred the lack of substantial modifications of plasma volumes after paracentesis, the administration of albumin or other plasma expanders is universally recommended to prevent complications as hyponatremia or renal insufficiency. On the other hand, hypoalbuminemia is one of the main features of nitrogen metabolism disturbances. Drawing ascites subtracts to the body an unknown amount of nitrogen because of its content in amino acids, which has never been documented. Because plasma amino acids imbalances have been involved in hepatic encephalopathy pathogenesis, which is a serious complications of cirrhosis potentially precipitated by paracentesis, our purpose was to document the amount of amino acids subtracted and to evaluate the possible modifications induced by paracentesis analyzing amino acidic patterns either in ascite or in plasma at the beginning and at the end of a large volume paracentesis (4 liters) in 20 ascitic patients. Paracentesis confirmed to be a safe practice, because it subtracts to body nitrogen no more than an amount of 3g of amino acids, and this is not followed by any modification of plasma patterns and ratios. In turn, these data allow a mathematical analysis of the relationship among osmolar and oncotic pressures in relationship to ascites and plasma volumes modifications.

Amino Acids↗