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Biomedical subjects

A Gatta

Publications and source records attributed to A Gatta.

At least 109 records · Page 6Linked to original sources
PubMed1991

Hypophosphatemia and renal tubular dysfunction in alcoholics. Are they related to liver function impairment?

The study was designed to evaluate (a) the role of reduced renal phosphate reabsorptive capacity assessed as the ratio of maximum capacity for renal phosphate reabsorption (TmPO4) to glomerular filtration rate (GFR) in the pathogenesis of hypophosphatemia in alcoholics, (b) possible mechanisms leading to reduced TmPO4/GFR, and (c) the effect of liver function impairment on TmPO4/GFR. The TmPO4/GFR, its major extrarenal determinants, ratios of urinary excretion gamma-glutamyl transpeptidase and of alpha-glucosidase to GFR (uGGT/GFR and uAGL/GFR), indices of structural damage of renal tubular cells, and fractional clearance of lysozyme, an index of proximal renal function, were evaluated in 31 alcoholics with alcohol-related liver disease, 24 alcoholics without alcohol-related liver disease, 14 patients with non-alcohol-related liver disease, and 25 control subjects. Hypophosphatemia was found in 35% of alcoholics with alcohol-related liver disease, 29% of alcoholics without alcohol-related liver disease, and no patients with non-alcohol-related liver disease. A reduced TmPO4/GFR was the major determinant of hypophosphatemia in both groups of alcoholics. No difference in extrarenal determinants of TmPO4/GFR was found between alcoholics with and without hypophosphatemia. Alcoholics with and without alcohol-related liver disease had increased uGGT/GFR and normal uAGL/GFR regardless of serum phosphate level. Fractional clearance of lysozyme, instead, was increased only in hypophosphatemic alcoholics with and without alcohol-related liver disease. The TmPO4/GFR correlated inversely with the fractional clearance of lysozyme in both groups of alcoholics (P less than 0.01). The TmPO4/GFR and urinary enzymes were normal in patients with non-alcohol-related liver disease. It was concluded that a reduced TmPO4/GFR is involved in the pathogenesis of hypophosphatemia in alcoholics. A proximal tubular dysfunction seems to be responsible for the reduced TmPO4/GFR. Liver function impairment is not required for the expression of this tubular dysfunction.

Adult↗
PubMed1991

Renal cytochrome P-450-dependent metabolism of arachidonic acid in cirrhotic rats.

Cirrhosis was induced in Wistar-Kyoto rats by intragastric administration of carbon tetrachloride. Microsomes were obtained from the renal cortex and outer medulla and incubated with [14C]arachidonic acid (AA) (0.2-0.4 microCi) in the presence or absence of indomethacin, NADPH, and SKF-525A. Cytochrome P-450-dependent AA metabolites (those whose formation required NADPH, were inhibited by SKF-525A, but not by indomethacin) were separated by thin-layer chromatography and high-pressure liquid chromatography (HPLC). Compared to controls, total synthesis of cytochrome P-450-dependent AA metabolites was reduced in cirrhotic rats (renal cortex: cirrhotics 380 +/- 52 vs. controls 493 +/- 68 pg/mg protein per 30 min; p less than 0.05; renal outer medulla: cirrhotics 304 +/- 57 vs. controls 387 +/- 53 pg/mg protein per 30 min; p less than 0.05). The cytochrome P-450-dependent AA metabolites were composed of three peaks separated by HPLC. Peak I, which had a retention time of 16.3 +/- 0.3 min and comigrated with 11,12-dihydroxyeicosatrienoic acid, and peak II, which had a retention time of 18.7 +/- 0.4 min and comigrated with 19- and 20-hydroxyeicosatetraenoic acid, were not different in cirrhotics and controls. Peak III, which had a retention time of 26.8 +/- 0.3 min, and comigrated with 11,12-epoxyeicosatrienoic acid, was significantly decreased in the renal cortex of cirrhotic rats compared to controls (cirrhotics 316 +/- 40 vs. controls 473 +/- 89 pg/mg protein per 30 min; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Theophylline pharmacokinetics and liver function indexes in chronic liver disease.

Since patients with chronic liver disease present with greatly varying theophylline disposal reductions, in cirrhotics the acute theophylline dose schedule must be guided by an index of liver function that predicts theophylline pharmacokinetics. We therefore studied 26 patients with severe chronic liver disease to ascertain the efficacy of the routinely used clinical and biochemical liver function tests in predicting theophylline pharmacokinetics. The prealbumin plasma level, recently proposed as a valuable index of liver function, was also considered. With respect to 10 controls, theophylline clearance was found to be significantly reduced (30 +/- 2 vs. 75 +/- 11 ml/kg/h, mean +/- SD, p less than 0.01). However, only 7 patients had a reduction great enough to require a reduced intravenous theophylline dose schedule. An analysis of clinical utility, made on the basis of ROC curves, showed that the albumin/globulin ratio was the most effective index for identifying patients requiring lower doses of theophylline. Prealbumin and albumin were also useful, whereas bilirubin, prothrombin time, pseudocholinesterase, the presence of ascites and Pugh-Child's classification of the severity of liver disease were found to be worthless.

Adult↗
PubMed1991

Evaluation of splanchnic angiography as a prognostic index of survival in patients with cirrhosis.

Prognostic evaluation of advanced liver disease is usually made on the basis of the common clinical and biochemical data included in the Child-Turcotte classification. The aim of this study was to evaluate the contribution of data from splanchnic angiography as a guide to prognosis in patients with cirrhosis. Over an 8-year period 219 patients with cirrhosis were investigated by splanchnic angiography and followed up prospectively. At the end of the study 95 patients had died (43.4%). Median survival time was 68 months. In addition to several clinical and biochemical data, hepatic portal venous perfusion and the presence of caudad hepatofugal veins as assessed by angiography were significant predictors of survival. Incorporating all nonangiographic variables in a Cox's multiple regression analysis, a clinicobiochemical set of prognostic covariates (ascites, s-albumin, gammaglobulins, s-alkaline phosphatase, and sex) was selected. When adding to this model each of the angiographic variables, only portal perfusion resulted in an independent predictor of survival. In conclusion, in cirrhotics the angiographic evaluation of portal perfusion improved the prognostic information obtained from clinical and biochemical data.

Adult↗
PubMed1991

A pathophysiological interpretation of unresponsiveness to spironolactone in a stepped-care approach to the diuretic treatment of ascites in nonazotemic cirrhotic patients.

It has been hypothesized that the magnitude of proximal sodium reabsorption affects the response to aldosterone antagonists in nonazotemic cirrhotic patients with ascites. To verify this hypothesis, we evaluated intrarenal sodium handling by lithium clearance in 51 nonazotemic ascitic cirrhotic patients and in 23 controls who were maintained on the same low-sodium diet (80 mmol/day). Seven of 51 cirrhotic patients underwent spontaneous diuresis, whereas 44 required diuretic treatment. Treatment was started with spironolactone at a dose of 150 mg once daily. The dose was increased to 300 mg and then to 500 mg once daily if no response ensued. Cirrhotic patients who did not experience ascites mobilization with 500 mg spironolactone were then treated with a combined diuretic regimen that included spironolactone at a fixed dose (500 mg once daily) and furosemide at an initial dose of 50 mg once daily. The dose was increased to 100, 150 and 200 mg once daily if no response was noticed. Response to diuretic treatment was defined as body weight loss greater than 700 gm every 3 days until ascites became clinically undetectable. Nonresponders (43%) to spironolactone showed lower sodium fractional excretion (0.34% +/- 0.28% vs. 0.80% +/- 0.50%; p less than 0.001) because of a lower fractional sodium delivery to the distal tubule (18.2% +/- 5.8% vs. 23.4% +/- 7.2%; p less than 0.025) than responders.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Comparison of sublingual captopril and nifedipine in immediate treatment of hypertensive emergencies. A randomized, single-blind clinical trial.

Sublingual captopril (25 mg) was compared with sublingual nifedipine (10 mg) to determine their effectiveness and safety in the treatment of hypertensive emergencies. In nine of 10 patients who received sublingual captopril, mean (+/- SD) systolic blood pressure and diastolic blood pressure dropped from 245 +/- 39 to 190 +/- 25 mm Hg (P less than .0025) and from 144 +/- 8 to 115 +/- 8 mm Hg (P less than .001) at 50 minutes, respectively. The hypotensive effect of the drug was maintained for a mean of 4 hours. In six of nine responders to sublingual captopril, blood pressure-lowering effect was associated with a clear improvement of end-organ failure within 60 minutes. There were no side effects, including a dangerous fall in blood pressure or reflex tachycardia. Sublingual nifedipine lowered diastolic blood pressure and systolic blood pressure in eight of 10 patients. The hypotensive effect of nifedipine was more rapid than that of captopril (10 vs 20 minutes for diastolic blood pressure and 20 vs 30 minutes for systolic blood pressure, respectively), but no difference was observed in the time or in the magnitude of peak hypotensive effect between the two treatments, nor was a difference observed in the duration of hypotensive effect. In six of eight responders to nifedipine therapy, a clear improvement of symptoms and signs of end-organ failure was observed within 60 minutes. In three patients, minor side effects were observed. We conclude that sublingual captopril effectively and safely lowers arterial blood pressure in patients with hypertensive emergencies.

Administration, Sublingual↗
PubMed1990

Lack of effect of verapamil and isosorbide dinitrate on the hepatic clearance of indocyanine green in cirrhosis.

1. Vasodilators are currently under investigation as possible therapeutic agents in the treatment of portal hypertension. Among them calcium-channel antagonists and organic nitrates have been of particular interest. Few and conflicting data, however, have been reported on their effect on liver function. 2. Twenty patients with biopsy-proven alcoholic cirrhosis were studied before and 25-35 min following the acute administration of 5 mg verapamil i.v. (eight patients) or 5 mg isosorbide dinitrate sublingually (12 patients). The plasma clearance of indocyanine green (ICG) and its intrinsic hepatic clearance were used as indices of liver function. Seven further patients were investigated before and after a placebo infusion according to the same methodology. 3. No significant change in ICG kinetics was found after verapamil or isosorbide dinitrate.

Adult↗
PubMed1990

Tubular site of renal sodium retention in ascitic liver cirrhosis evaluated by lithium clearance.

Renal tubular sodium handling was evaluated in 27 non-azotemic cirrhotic patients with ascites and positive sodium balance and in 17 controls after at least 5 days of a constant sodium intake using the lithium clearance as an index of fluid delivery to the distal tubule. Plasma renin activity and plasma aldosterone were also evaluated. Sodium fractional excretion, filtered sodium load, absolute sodium distal delivery, lithium fractional excretion and absolute distal sodium reabsorption were significantly lower in cirrhotics than in controls (0.58 +/- 0.11 vs. 1.29 +/- 0.12%, P less than 0.001; 12529 +/- 677 vs. 15707 +/- 796 microEq min-1 1.73 m-2 BSA, P less than 0.005; 2384 +/- 135.2 vs. 3685 +/- 219.3 microEq min-1 1.73 m-2 BSA, P less than 0.001; 19.5 +/- 1.0 vs. 24.2 +/- 1.3%, P less than 0.01; 2299 +/- 127 vs. 3485 +/- 214 microEq min-1 1.73 m-2 BSA, P less than 0.001, respectively). A correlation was found between lithium clearance and sodium clearance only in cirrhotic patients (r = 0.62; P less than 0.01). Distal sodium reabsorption evaluated as a per cent of filtered sodium load was lower in cirrhotics than in controls (19.1 +/- 1.0 vs. 22.4 +/- 1.2%, P less than 0.05) while distal sodium reabsorption evaluated as a per cent of sodium distal delivery was higher in cirrhotics than in controls (96.7 +/- 0.4 vs. 94.4 +/- 0.5%, P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗
PubMed1990

Plasma carnitine levels in liver cirrhosis: relationship with nutritional status and liver damage.

The plasma level of carnitine, a co-factor involved in many metabolic reactions, is high in alcoholic liver cirrhosis, due to an increased amount of esterified carnitine. To determine if this alteration is linked to alcoholic liver disease or to liver cirrhosis per se. total carnitine, free carnitine, total esterified carnitine, short chain acylcarnitine and long chain acylcarnitine were measured in 41 patients suffering from liver cirrhosis of different aetiology and severity. In 19 of these patients, acetylcarnitine was also measured. Moreover, multivariate analysis was performed to assess the association of carnitine plasma levels with nutritional and liver disease indices. Of the nutritional indices (creatinine/height ratio, mid upper arm muscle circumference and triceps skinfold) only triceps skinfold appeared to be weakly correlated with carnitine (with long chain acylcarnitine). Significantly high levels of acetylcarnitine, short chain acylcarnitine, total esterified carnitine and total carnitine were found in cirrhotics independently of the aetiology of cirrhosis, even though a trend towards higher levels of acetylcarnitine was evident in heavy drinkers. Direct correlations of gamma-glutamyltransferase with acetylcarnitine, acetylcarnitine/free carnitine, short chain acylcarnitine/free carnitine and total esterified carnitine/free carnitine were found. Carnitine plasma levels did not differ in the three Pugh-Child's classes; however, a trend towards higher levels of acetylcarnitine was found in Pugh-Child's class C. In conclusion, the high levels of acetylcarnitine, short chain acylcarnitine, total esterified carnitine and total carnitine found in cirrhosis were linked to liver disease. Alcohol abuse seemed only to be an exacerbating factor.

Adult↗
PubMed1990

Pharmacokinetics of iloprost in patients with hepatic dysfunction.

In the present experiment the pharmacokinetics of iloprost was studied in eight hospitalized patients suffering from liver cirrhosis (mean age: 56 years, 3 females, 5 males, child-classification: A [n = 1], B [n = 5], C [n = 2]/mean 14C-aminopyrine breath test: 3.9% dose/2 h). Iloprost was administered as a 1 h-i.v. infusion with 1 ng/kg/min to all the test subjects. Steady state plasma levels of 93 +/- 31 pg/ml were observed at the end of infusion. The terminal half-life of iloprost was 28 +/- 24 min. From AUC values of 126 +/- 60 pg.h/ml a total clearance of 10 +/- 5 ml/min/kg was calculated. The study demonstrated that iloprost clearance was reduced by a factor of 2 in patients suffering from hepatic dysfunction compared with healthy subjects. Individual dose titration is the recommended dose regimen for iloprost therapy in all patients. Therefore, apart from a reduction of the starting dose (of approximately 50%) for titration, special recommendations are not necessary for patients with impaired liver function.

Adult↗
PubMed1989

Indocyanine green intrinsic hepatic clearance as a prognostic index of survival in patients with cirrhosis.

The prognostic value of quantitative liver function tests in patients with cirrhosis is not clearly established. Indocyanine green intrinsic hepatic clearance (ICG-IHC) is a quantitative liver function parameter independent of liver blood flow, which was shown to correlate strictly with the Child-Turcotte-Pugh (CTP) classification of severity of liver disease. Few data are available on its prognostic value. One hundred and five patients with cirrhosis were studied. ICG-IHC was measured according to the 'sinusoidal perfusion' model. Median ICG-IHC in the whole series was 374 ml/min (interquartile range: 214-496 ml/min). During follow-up (mean 31 months; max. 48 months) 38 patients died. The probability of survival was lower in patients with ICG-IHC lower than 300 ml/min (35% at 48 months) than in patients with ICG-IHC between 300 and 1000 ml/min (70%), or with ICG-IHC over 1000 ml/min (80%) (P = 0.02). Also s-albumin (P less than 0.01), ascites (P = 0.001) and CTP class (P less than 0.001) were significant predictors of survival. On incorporation of age, sex, etiology of cirrhosis, ICG-IHC, s-albumin, s-bilirubin, prothrombin index, ascites and encephalopathy, into a multiple regression analysis according to the Cox's model, the results showed only ascites and s-albumin to be independent significant predictors of survival, while ICG-IHC was not among the covariates independently predictive of survival. When CTP class was added to the investigated covariates, the results showed it as the only independent predictor of survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Detection of the early steps of cadmium nephropathy--comparison of light- and electron-microscopical patterns with the urinary enzymes excretion. An experimental study.

Few data are yet available comparing the histological patterns of cadmium nephropathy with the values of urinary enzyme excretions, useful indexes of renal tubular damage. 40 Wistar rats, divided into four groups (A-D), were intoxicated with cadmium chloride (CdCl2) at 16 ppm in drinking water for 4, 16, 40 and 60 weeks, respectively. At the end of each period all the intoxicated rats and 5 controls were assessed for creatinine clearance, fractional excretion of gamma-glutamyltransferase (UfrGGT) and alpha-glucosidase (UfrAGL), indexes of anatomical tubular damage, and for fractional clearance of lysozyme (CfrLys), index of functional tubular damage. Thereafter, the rats were sacrificed and their kidneys examined with light and electron microscopy. Control rats and group A and B rats did not show any histological impairment. A widespread vesiculation of proximal tubular cells with mitochondrial and lysosomal alterations was found in the group C rats and was more evident in group D. The brush border never showed any damage in all groups in accordance with the finding of a normal excretion pattern of UfrGGT, an enzyme situated in this structure. The UfrAGL was increased only in group D rats (p less than 0.025), who showed the most severe anatomical damages. The CfrLys, an index of tubular function, was elevated in group C and D rats (p less than 0.02 and p less than 0.002, respectively). It was possible to detect the initial renal tubular damage.

Animals↗
PubMed1989

Prognostic indicators of survival in patients with cirrhosis and esophageal varices, without previous bleeding.

Sixty-one patients with cirrhosis with varices without previous bleeding were admitted to our Department over a period of 2 yr. Fifty had alcoholic cirrhosis. Child-Turcotte-Pugh class was A in 11 patients, B in 30, and C in 20. Varices were F1 in 18, and F2-F3 in 43. During follow-up of up to 40 months, one patient was lost to follow-up and 22 patients died, seven of gastrointestinal bleeding and 15 of liver failure. The probability of death from any cause was significantly related to Child-Turcotte-Pugh class, ascites, encephalopathy, s-albumin, s-bilirubin, prothrombin index, and galactose elimination capacity. Independent prognostic variables according to Cox's model resulted s-albumin, s-bilirubin, encephalopathy, and varices. Considering only patients who died from liver failure, survival was univariately related to the same determinants, whereas the Cox's model individuated s-bilirubin, s-albumin, ascites, and galactose elimination capacity as independent prognostic indicators. Considering only patients who died from gastrointestinal bleeding no Cox model could be performed due to the small number of deaths. In patients with F1 varices, the probability of death from liver failure was 5 times higher than that from gastrointestinal bleeding; in patients with F2-F3 varices, liver failure and gastrointestinal bleeding each accounted for approximately half of the deaths. These data could become useful when programming a clinical trial of prophylaxis which considers reduction in mortality as the main end-point.

Adult↗
PubMed1988

Long-term effect of nadolol on quantitative liver function tests in patients with cirrhosis.

Nadolol, a non-cardioselective beta adrenoreceptor blocking agent, has been reported to decrease portal pressure without affecting liver function in cirrhotic patients treated for 1 month. There were no data about the long-term effects of nadolol on liver function. In 11 patients with cirrhosis and portal hypertension galactose eliminating capacity, aminopyrine metabolic capacity, ICG clearance and IGC intrinsic hepatic clearance according to the "parallel tube" model were measured before and after 6 months of treatment with nadolol at a dose reducing resting heart rate by approximately 25%. No significant variation in any of these parameters was found. Thus 6 months of continuous oral administration of nadolol did not further impair liver function in cirrhotics.

Adult↗