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Biomedical subjects

S Badalamenti

Publications and source records attributed to S Badalamenti.

At least 37 records · Page 2Linked to original sources

High prevalence of silent gallstone disease in dialysis patients.

Gallstone disease was detected in 28% of 119 patients on regular dialysis treatment. The disease was silent in 82% of the patients. Stones were radiolucent in 88% of the cases, radioopaque in 8% and mixed in 4%. Among 49 variables considered, increasing age was the only variable that correlated significantly with increasing prevalence of gallstone disease. Since no relationships were found between gallstones and age or modes of dialysis, it is conceivable that some mechanism(s) linked with the preexisting chronic nephropathy might have been involved in the development of cholelithiasis. End-stage renal disease could be another so far unrecognized risk factor for cholelithiasis.

Adult↗

A pharmacodynamic study of two omeprazole regimens suitable for long-term treatment of duodenal ulcer.

BACKGROUND: The experience with long-term treatment of peptic ulcer with omeprazole is still scant, but the possibility cannot be excluded that its better pharmacodynamic effect on gastric acidity also has a positive result in the relapse rate. Moreover, this drug acts via a mechanism other than receptorial binding, and therefore its efficacy should not dissipate with time. This study was carried out to assess the pharmacodynamic properties and the possible changes with time of two dose regimens of omeprazole that could be suitable for long-term treatment in duodenal ulcer. METHODS: Twenty patients with endoscopically proven duodenal ulcer were studied by means of 24-h gastric pH-metry both in basal conditions and on the 5th day of acute treatment with 40 mg omeprazole in the morning. All the ulcers healed after 4 weeks, and thereafter 10 patients were randomized to receive orally 20 mg omeprazole daily at 0800 h in single-blind fashion (group A) and 10 to receive 20 mg omeprazole every other day (group B) for up to 6 months. At the end of the 1st, 3rd, and 6th month of these maintenance treatments 24-h gastric pH-metry was repeated to assess the antisecretory effect of each regimen over time. In group-B patients the test was performed on 2 consecutive days (without and with medication) at each time interval. The fasting gastrin values were also determined. The patients underwent esophagogastroduodenoscopy every 2 months. RESULTS: Three patients in group B were lost to follow-up for various reasons, and only seven remained eligible for final analysis. The two long-term regimens of omeprazole were able to increase significantly pH values (p < 0.02-0.001) and the times spent at and above pH 3.0 (p < 0.001) over 24 h compared with basal conditions. In group A the 24-h pH value obtained in the 6th month was higher (p < 0.02) than that in the 3rd month of maintenance treatment. In group B the pharmacologic effect tended to decrease on the day without medication compared with the day with medication, but the difference between them was significantly (p < 0.05) only at the 6-month interval. There was no significant difference between the gastrin levels of the two groups in the long-term treatment. No ulcer relapse was detected at any long-term endoscopic control in the two groups of patients. CONCLUSIONS: The two omeprazole regimens we tested are effective in reducing gastric acidity, and their pharmacodynamic action does not decrease with time. They are therefore suitable for maintenance treatment in acid-related disorders.

Adult↗

Hepatorenal syndrome. New perspectives in pathogenesis and treatment.

Hepatorenal syndrome is a life-threatening complication of severe liver disease. It is generally accepted that the syndrome is the final stage of complex hemodynamic derangements associated with portal hypertension, ie, peripheral arterial vasodilation, effective hypovolemia, and hyperkinetic status. In spite of reduced systemic resistances, intrarenal vascular resistances are increased. This is probably the consequence of the activation of systemic vasoactive factors, such as the renin-angiotensin system, the sympathetic nervous system, and vasopressin aimed at restoring arterial filling pressure. Recently, it has been shown that intrarenal vasoconstrictors, such as leukotrienes and endothelins, are activated with the progression of liver disease. The renal vasoconstriction is counterbalanced by the intrarenal hyperproduction of vasodilating prostaglandins and kallikreins. When this balance is lost, for whatever mechanism, the renal vascular resistances dramatically increase and the hepatorenal syndrome develops. In spite of increased knowledge about pathogenesis, the treatment of hepatorenal syndrome remains unresolved. Low-dose dopamine or ornipressin are currently employed in many liver units to avoid further deterioration of renal function in patients with severe liver disease who are waiting for liver transplantation that remains, at present, the only effective treatment for hepatorenal syndrome.

Hepatorenal Syndrome↗

Effects of imidazole-salicylate on renal function and the diuretic action of furosemide in cirrhotic patients with ascites.

Imidazole-salicylate is a non-steroidal anti-inflammatory drug with limited inhibitory effects on prostaglandin synthesis. The renal effects of this drug were investigated by a double-blind cross-over study in 10 patients with cirrhosis and ascites. Two therapeutic doses of imidazole-salicylate (750 mg each) were given at midnight and 08:00 h and 80 mg of furosemide were injected intravenously at 09:00 h. The same procedure was followed on another day but a placebo replaced imidazole-salicylate. Renal function (creatinine clearance, free water and electrolyte excretions) and urinary excretion of prostaglandin E, 6-keto-prostaglandin F1 alpha and thromboxane B2 were evaluated for 8 h after the first dose of the drug and for 2 h after furosemide injection. Platelet thromboxane production was also determined 9 h after the first administration of drug or placebo. Imidazole-salicylate did not affect renal function or inhibit kidney prostanoid production either under basal conditions or after the stimulating effect of furosemide. On the contrary, imidazole-salicylate significantly inhibited platelet thromboxane production (45.8 +/- 9 vs. 69.4 +/- 7.5 ng/ml, P < 0.05). These results suggest that imidazole-salicylate is an anti-inflammatory drug that can be given to patients with decompensated cirrhosis without risk of inhibiting kidney prostaglandin synthesis or the renal response to furosemide.

Adult↗

Abnormal hemodynamics and elevated angiotensin II plasma levels in polydipsic patients on regular hemodialysis treatment.

To investigate the cause and the mechanisms responsible of the compulsive thirst and excessive fluid intake observed in many patients on chronic dialysis treatment, we measured plasma antidiuretic hormone (ADH), angiotensin II (Ang II) and some hemodynamic parameters in seven polydipsic and in six normodipsic patients before hemodialysis, at the end of it and several times during the interdialytic interval. Before dialysis we found that ADH was elevated in both groups (6.9 +/- 1.9 vs. 6.9 +/- 1.3 pg/ml, respectively in polydipsics and controls), whereas Ang II was abnormally high only in polydipsics (51 +/- 12 vs. 11 +/- 3 pg/ml, P < 0.01); these patients also had significantly higher heart rate and cardiac indices and lower total peripheral resistances than control patients. Overall these hemodynamic indices were related with Ang II but not with ADH. Ang II rose markedly in polydipsics after dialysis, reaching a peak at the fourth hour after its termination (136 +/- 12 pg/ml) and remained consistently elevated throughout the interdialytic period, whereas in controls Ang II was practically unchanged with respect to baseline. In contrast, ADH had minor and similar modifications in both groups, in whom also the hemodynamic changes were superimposable. Significant correlations were found between the absolute and percent changes of Ang II and those of plasma volume during the interdialytic interval (P < 0.001 for both), and between the individual values of Ang II measured during the whole study and the interdialytic weight gain (P < 0.05). These results demonstrate that polydipsic patients have abnormally high levels of Ang II before and after the hemodialysis-induced volume depletion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Survival and prognostic factors of cirrhotic patients with ascites: a study of 134 outpatients.

Ascites is a complication of chronic liver disease that is associated with decreased survival. The purpose of the present study was to identify some prognostic factors easily obtainable by the clinician in a large group of cirrhotic patients with ascites, possibly useful for first screening of outpatients as candidates for liver transplantation. We studied 134 ambulatory patients with cirrhosis who came to our outpatient clinic between July 1983 and March 1989 because of an episode of ascites. These patients were then followed up for an average period of 31 +/- 23 months and survival was determined. Thirty-one variables determined at the time of inclusion were analyzed with a Cox proportional hazards model to identify predictors of mortality. Cumulative mortality as of June 30, 1991, was 59%. Factors independently correlated with death were: refractory ascites (relative risk, 4.78), low albumin levels (3.77), high Child-Pugh score (3.31), encephalopathy (2.71), high bilirubin levels (2.03), high gamma-glutamyl-transferase levels (1.87), and old age (1.57). The results show that 1) the occurrence of refractory ascites has a prognostic value superior to those of other variables, and 2) simple clinical and biochemical parameters, most of them components of the Child-Pugh score, are useful for a first screening of ascitic cirrhotic patients as candidates for liver transplantation.

Aged↗

Renal effects in cirrhotic patients with avid sodium retention of atrial natriuretic factor injection during norepinephrine infusion.

The administration of atrial natriuretic factor to patients with cirrhosis, and avid sodium retention causes marked hypotension and blunted kidney responses. To evaluate whether the unresponsiveness of the kidney is caused by a fall in mean blood pressure below a critical value for the renal blood perfusion pressure (80 mm Hg), we studied nine such patients and compared the effects of synthetic atrial natriuretic factor alone (1 micrograms/kg as a bolus) with those of an atrial natriuretic factor combination with infused norepinephrine titrated to raise baseline blood pressure by 15 to 20 mm Hg (182 to 625 ng/kg/min). The administration of atrial natriuretic factor during norepinephrine infusion caused a fall in mean blood pressure to values not less than 80 mm Hg in eight of nine patients, with a slight natriuresis (greater than 5 mumol/min) in five patients but no changes in the other four. The mean urinary sodium output was markedly lower than that previously observed after atrial natriuretic factor injection into normal subjects and into cirrhotic patients without avid sodium retention. Unlike sodium excretion, urine flow rate and free water clearance (which were not affected by atrial natriuretic factor alone) were markedly improved by the coadministration of norepinephrine and atrial natriuretic factor. In four additional patients we studied the urinary electrolyte excretion during a low-dose infusion of atrial natriuretic factor (20 ng/kg/min) to which an infusion of norepinephrine titrated to maintain blood pressure over 80 mm Hg was added. In only one of these four patients urinary sodium output consistently increased during atrial natriuretic factor infusion, and the output increased even more when norepinephrine was added.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Renal insensitivity to atrial natriuretic peptide in patients with cirrhosis and ascites. Effect of increasing systemic arterial pressure.

The IV infusion of pharmacological doses (0.05 microgram.kg-1.min-1) of atrial natriuretic peptide to 16 patients with cirrhosis and ascites induced a significant increase in sodium excretion (65 +/- 23 to 517 +/- 231 mu Eq/min), urine volume (10.7 +/- 2.3 to 15.7 +/- 3.7 mL/min), and glomerular filtration rate (89 +/- 4 to 110 +/- 4 mL/min) in only 5 patients (responders). No significant changes in these parameters (15 +/- 6 to 11 +/- 4 mu Eq/min, 5.5 +/- 1.0 to 4.2 +/- 1.1 mL/min, and 81 +/- 5 to 79 +/- 6 mL/min, respectively) were observed in the remaining patients (nonresponders). Compared with responders, nonresponders had significantly lower baseline sodium excretion (P less than 0.02), urine flow (P less than 0.05), free water clearance (2.5 +/- 0.9 vs. 6.9 +/- 2.1 mL/min; P less than 0.05), and mean arterial pressure (82 +/- 3 vs. 96 +/- 2 mm Hg; P less than 0.01) and significantly higher plasma renin activity (16.3 +/- 4.9 vs. 1.8 +/- 0.2 ng.mL-1.h-1; P less than 0.05) and aldosterone level (99 +/- 24 vs. 13 +/- 2 ng/dL; P less than 0.05). Atrial natriuretic peptide produced a similar reduction of arterial pressure in both groups. To investigate whether the blunted natriuretic response to atrial natriuretic peptide in nonresponders was caused by their lower arterial pressure, atrial natriuretic peptide was infused in 7 of these patients after increasing their arterial pressure to the levels of responders with nonrepinephrine. The increase in arterial pressure (from 81 +/- 5 to 95 +/- 5 mm Hg), which was not associated with significant changes in plasma renin activity and aldosterone concentration, did not reverse the blunted renal response to atrial natriuretic peptide in any of these patients. These results indicate that cirrhotic patients with blunted renal response to atrial natriuretic peptide are characterized by low arterial pressure, marked overactivity of the renin-aldosterone system, and severe sodium and water retention. Correction of hypotension without increasing effective blood volume does not restore renal insensitivity to atrial natriuretic peptide.

Atrial Natriuretic Factor↗

Renal effects of imidazole-2-hydroxybenzoate in patients with compensated liver cirrhosis.

A double-blind crossover study versus placebo of the renal effects of the nonsteroidal anti-inflammatory drug imidazole 2-hydroxybenzoate was conducted in 10 patients with compensated liver cirrhosis. The administration of the drug (750 mg, t.i.d., for three days) did not affect renal plasma flow, glomerular filtration rate, free water clearance nor the urinary excretion of sodium or potassium. Values of plasma renin activity also did not change after drug administration. Direct tubular damage from imidazole 2-hydroxybenzoate was also excluded by normal excretion of beta-2-microglobulin and N-acetyl-beta-D-glucosaminidase. Urinary 6-keto-PGF1 alpha output were comparable during imidazole 2-hydroxybenzoate and placebo administration. These data indicate that this nonsteroidal antiinflammatory drug does not affect the renal function in patients with compensated liver cirrhosis.

6-Ketoprostaglandin F1 alpha↗

Randomized comparative study of hemaccel vs. albumin infusion after total paracentesis in cirrhotic patients with refractory ascites.

Fifty-four cirrhotic patients with refractory ascites were treated with one-session large-volume paracentesis and randomly assigned to two groups. The first group was infused with human albumin, and the second group was infused with hemaccel at doses with comparable oncotic power. The two groups were compared for incidence of complications, recurrence of massive ascites after hospital dismissal and survival rate. The incidence of complications traditionally related to paracentesis, the probability of requiring readmission to the hospital for ascites (p = 0.48) and the probability of survival after entry into the study (p = 0.85) were the same for the two groups. A multivariate analysis of 16 parameters, including treatment modality, identified absolute unresponsiveness to diuretics as the only independent predictor of mortality. These results indicate that hemaccel infusion may safely replace albumin infusion after total paracentesis for cirrhotic patients with refractory ascites.

Aldosterone↗

Effects of intravenous amino acid infusion and dietary proteins on kidney function in cirrhosis.

Acute intravenous amino acid infusion or a high-protein diet increases renal plasma flow and the glomerular filtration rate in healthy subjects. Conversely, a low-protein diet reduces renal plasma flow and glomerular filtration rate. The aim of this study was to investigate the effect of intravenous amino acid infusion and dietary proteins on kidney function in cirrhosis. Protocol 1: renal plasma flow and glomerular filtration rate were measured before and during intravenous administration of a 10% amino acid solution (0.043 ml/kg/min) to eight compensated cirrhotic patients (group 1), nine nonazotemic cirrhotic patients with ascites (group 2) and seven cirrhotic patients with ascites and functional renal failure (group 3). Amino acid administration induced a significant increase in renal plasma flow and glomerular filtration rate in all groups studied. Renal plasma flow and glomerular filtration rate increased by 16% and 14%, respectively, in group 1; 31% and 22% in group 2 and 25% and 21% in group 3. Protocol 2: Renal plasma flow and glomerular filtration rate were measured in nine cirrhotic patients with ascites after 11 days on a low-protein diet (0.5 gm/kg body weight/day) and also after the patients followed for 11 days a moderately high-protein diet (1.5 gm/kg body weight/day). The moderately high-protein diet was associated with a significant increase in renal plasma flow (12%) and glomerular filtration rate (13%) compared with values obtained while the patients followed the low-protein diet. Plasma glucagon levels increased markedly during the intravenous administration of amino acid and the intake of the moderately high-protein diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗

Atrial natriuretic factor in cirrhotic patients with tense ascites. Effect of large-volume paracentesis.

The plasma levels of atrial natriuretic factor in liver cirrhosis can be affected by various factors, such as ascites, renal function, use of diuretics drugs and dietary sodium intake. Moreover, the influence of high intra-abdominal pressure on cardiac atrial natriuretic factor release in patients with tense ascites has not been investigated. The aim of the present study was to evaluate the circulating levels of atrial natriuretic factor and their relationships to plasma renin activity, aldosterone concentration, and urinary sodium excretion in 45 cirrhotic patients divided into 4 groups: (a) cirrhotics without ascites; (b) nonazotemic cirrhotics with ascites; (c) cirrhotics with ascites and functional renal failure; and (d) cirrhotics with ascites taking diuretics. In some patients with tense ascites, atrial natriuretic factor was also measured after rapid abdominal relaxation by large volume paracentesis. Plasma levels of atrial natriuretic factor obtained in 13 healthy control subjects after 5 days on a 40-50 mEq sodium daily intake were 22.8 +/- 3.3 pg/ml. Mean plasma atrial natriuretic factor levels were normal in patients without ascites (35.1 +/- 11.4 pg/ml) and in those with ascites taking diuretics (27 +/- 9.2 pg/ml), but elevated in patients with ascites not taking diuretics (59.6 +/- 12 pg/ml) and in those with ascites and functional renal failure (58.5 +/- 16.6 pg/ml). These data show that plasma atrial natriuretic factor levels are elevated only in cirrhotic patients who are ascitic and not taking diuretics. In these patients atrial natriuretic factor levels were directly correlated with urinary sodium excretion, even though sodium balance was positive. This could be the consequence of the contrasting effects of antinatriuretic factors, as suggested by the inverse relationships between atrial natriuretic factor and urinary sodium on the one hand and plasma renin activity and plasma aldosterone concentration on the other. Twenty-six patients with tense ascites (12 taking diuretics and 14 not) were treated with rapid large-volume paracentesis (6500 +/- 330 ml of ascitic fluid removed in 168 +/- 16 min). At the end of the procedure, plasma atrial natriuretic factor levels had increased in all patients (from 45.5 +/- 10.1 to 100 +/- 17 pg/ml), whereas plasma renin activity and plasma aldosterone concentration had decreased (from 10.3 +/- 1.6 to 7 +/- 1.3 ng/ml/h, and 1160 +/- 197 to 781 +/- 155 pg/ml, respectively).(ABSTRACT TRUNCATED AT 400 WORDS)

Aldosterone↗