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Biomedical subjects

I Rossi

Publications and source records attributed to I Rossi.

At least 55 records · Page 3Linked to original sources
PubMed1995

Enhanced endothelium-dependent vasodilation in patients with cirrhosis.

Experimental evidence indicates that an increased production of nitric oxide could play a role in the peripheral vasodilation of portal hypertension. To test this hypothesis in humans, we studied basal serum NO(2-) + NO3- levels and the response of forearm resistance vessels to increasing concentrations of methacholine chloride, sodium nitroprusside, and phenylephrine infused into the brachial artery of 12 cirrhotic patients and 10 controls. Forearm vascular resistance (FVR) was calculated from mean arterial pressure and forearm blood flow (FBF). Cirrhotics showed higher NO(2-) + NO3- levels (P < 0.05), higher FBF (P < 0.01), and lower FVR (P < 0.01) than controls. The reduction of FVR in response to every dose of methacholine was greater in cirrhotics than in controls; this was significant (P < 0.05) at the 3 and 10 micrograms/min doses. This response to methacholine was not modified by blockade of vascular prostacyclin. The response to nitroprusside was similar in both groups. The increase in FVR in response to every dose of phenylephrine was significantly (P < 0.01) lower in cirrhotics than in controls. In cirrhotics, a significant correlation (r = -0.81, P < 0.01) was found between the FVR response to the highest doses of methacholine and phenylephrine. In conclusion, cirrhotic patients show an enhanced endothelium-mediated vasodilation, which suggests an increased synthesis of nitric oxide. This defect may mediate the peripheral vasodilation and hyporeactivity to vasopressors of these patients.

Adult↗
PubMed1994

[Perception of anxiety in patients requesting anonymous HIV testing].

To determine the manifestations of anxiety in subjects seeking anonymous HIV testing and the aptitude of professionals to perceive it, we administered a semi-structured questionnaire to 481 persons, 281 before and 200 after instructing the practitioners to better decode anxiety during the consultation. The perception of anxiety by the care-givers was analyzed using the Covi scale. The results show that subjects requesting an HIV test often report stressful relational events. Their anxiety its often underestimated by the care-givers, and aptitude to recognise the patient's emotions can be improved. Prevention and quality of counselling depend on correct perception of the emotions which prompt the subject to request a test.

AIDS Serodiagnosis↗
PubMed1994

Octreotide prevents postprandial splanchnic hyperemia in patients with portal hypertension.

An increase in splanchnic blood flow is a physiological response to food intake. In patients with cirrhosis whose hepatic vascular resistance is already high, this increase in flow leads to marked increases in portal pressure. This study investigates whether octreotide prevents the increases in hepatic flow and portal pressure that follow the ingestion of a meal in patients with cirrhosis. Twenty-two patients with cirrhosis and portal hypertension were randomized to receive a mixed liquid meal (520 kcal) plus a single subcutaneous injection of either placebo or octreotide (200 micrograms). In the placebo group the ingestion of a meal was followed by an increase in the hepatic venous pressure gradient (+ 19.4 +/- 4.3%, p < 0.01) and hepatic blood flow (+ 38.2 +/- 14.6%, p < 0.05) at 30 min. In contrast, in the octreotide group eating caused no significant change in the hepatic venous pressure gradient (-2.8 +/- 3.6%, NS), while hepatic flow was decreased (-6.08 +/- 5.4%, p < 0.05). Octreotide blunted the postprandial increase in serum insulin and glucagon levels observed in the placebo group. In conclusion, in patients with cirrhosis and portal hypertension, octreotide prevents the postprandial increase in hepatic blood flow, and consequently also in portal pressure. These findings suggest that this drug could play a role in the long-term management of portal hypertension.

Blood Glucose↗
PubMed1994

Hemodynamic effects of alpha-adrenergic blockade with prazosin in cirrhotic patients with portal hypertension.

This study was aimed at investigating whether the blockade of alpha 1-adrenergic receptors could reduce portal pressure in cirrhosis. Splanchnic and systemic hemodynamics were measured in 12 cirrhotic patients with esophageal varices at baseline and 1 hr after oral administration of 2 mg of prazosin (acute study). Measurements were repeated in 10 of these 12 patients after a 3-mo course of 5 mg/12 hr of prazosin (long-term study). Short-term prazosin significantly lowered the hepatic venous pressure gradient from 20.1 +/- 1.3 to 14.4 +/- 0.9 mm Hg (-25.7%) (p < 0.01), and chronic prazosin reduced it to 16.5 +/- 1.3 mm Hg (-19.1%) (p < 0.01). Hepatic blood flow was increased, thus changes in the hepatic venous pressure gradient resulted from a reduction in the estimated hepatic vascular resistance. Reductions in hepatic venous pressure gradient achieved after short-term and long-term prazosin were not significantly different. Reductions in mean arterial pressure and systemic vascular resistance were significantly greater after short-term than after long-term prazosin. Long-term prazosin was associated with significant increases in hepatic and intrinsic hepatic clearances of indocyanine green. This therapy also led to an increase in pulmonary capillary pressure (+ 28.6%, p < 0.05) and body weight (+ 3.06%, p < 0.01) and a decrease in hematocrit (-6.1%, p < 0.05) and urinary sodium excretion (-22.6%, p < 0.05). In contrast, there were no hemodynamic changes in a group of six cirrhotic patients receiving placebo. In cirrhotic patients, short-term prazosin lowers portal pressure by decreasing hepatic vascular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Antagonists↗
PubMed1992

Oral administration of clonidine in patients with alcoholic cirrhosis. Hemodynamic and liver function effects.

The effects of long-term oral clonidine treatment on hepatic and systemic hemodynamics and on quantitative liver function tests were investigated in 15 patients with alcoholic cirrhosis. Clonidine was administered at a mean dose of 0.33 +/- 0.1 mg/day (mean +/- SD) for a mean period of 64 +/- 10 days. Oral clonidine induced a significant reduction in the hepatic venous pressure gradient from 18.8 +/- 3.0 mm Hg to 15.9 +/- 3.4 mm Hg (P less than 0.001), which was the result of an increase in the free hepatic venous pressure from 5.1 +/- 4.2 mm Hg to 8.7 +/- 3.8 mm Hg (P less than 0.05). In 10 of the 15 patients (67%), the reduction in the hepatic venous pressure gradient was greater than 10% of baseline values. Hepatic blood flow did not change significantly after clonidine treatment. Additionally, treatment with clonidine decreased mean arterial pressure by 15.5% +/- 6% (P less than 0.001), heart rate by 17.7% +/- 7% (P less than 0.001), and cardiac output by 14.6% +/- 7% (P less than 0.001). However, systemic vascular resistance did not change significantly. There were no adverse effects on liver function, as shown by the nonsignificant changes in galactose-elimination capacity (149 +/- 59 vs. 170 +/- 58 mg/min), hepatic clearance of indocyanine green (0.19 +/- 0.10 vs. 0.17 +/- 0.07 L/min), and hepatic intrinsic clearance of indocyanine green (0.23 +/- 0.14 vs. 0.21 +/- 0.1 L/min) before and after clonidine treatment, respectively. In none of the patients was the drug withdrawn because of side effects, although 12 subjects complained of dry mouths. This study suggests that in patients with alcoholic cirrhosis, long-term oral clonidine administration achieves a reduction in the hepatic venous pressure gradient without adverse effects on hepatic blood flow and liver function.

Administration, Oral↗
PubMed1992

Fructose 2,6-bisphosphate levels and modulation of glycolysis by histamine, cholecystokinin, and forskolin in isolated rabbit gastric glands.

In isolated rabbit gastric glands incubated in the presence of 1 mmol/L glucose, the content of fructose 2,6-bisphosphate (F-2,6-P2) was 5.7 +/- 0.5 pmol/mg dry weight. This value was progressively incremented by increasing glucose concentration in the incubation medium, and was almost doubled at 10 mmol/L glucose. Under these conditions, a close correlation could be established between the levels of F-2,6-P2 and the rate of L-lactate formation (r = .98; P less than .05). Both histamine (0.1 mmol/L) and cholecystokinin octapeptide (CCK-OCT; 0.1 mumol/L) increased L-lactate production, without significant changes in either F-2,6-P2 concentration or the amount of 6-phosphofructo-2-kinase in active form. In contrast, forskolin, which markedly increased the glandular content of cyclic adenosine monophosphate (cAMP), partially blocked glucose consumption and caused a significant reduction in both F-2,6-P2 levels and the proportion of 6-phosphofructo-2-kinase in active form. Furthermore, forskolin partially blocked the rate of glucose uptake by isolated gastric glands. Our results suggest a regulatory role of F-2,6-P2 in the control of the glycolytic flux in response to glucose, but not in its response to histamine or CCK-OCT.

3-O-Methylglucose↗
PubMed1991

[Surveillance of renal function by scintigraphy with 99m Tc-DMSA after a trans-ileal cutaneous ureterostomy].

The renal function of sixty one adult patients was monitored by 99mTc-DMSA renal scan after cystectomy for a malignant tumour followed by ileal conduit urinary diversion. The postoperative follow-up period was 10 years. The stenosis rate of the uretero-ileal anastomosis was 12.8% and the incidence of pyelonephritis was 8% The mean value for overall renal function and for the function of each kidney did not deteriorate significantly (p = 0.1 and p = 0.7, respectively) over time. However, 26% of kidneys evaluated at 1 year and at 5 years showed a markedly decreased uptake on the renogram. In 70% of cases, this decreased uptake was related to the development of stenosis of the uretero-ileal anastomosis or pyelonephritis. Renal function remained stable at 5 years in group A, corresponding to patients with good initial renal function (n = 22, p = 0.07), and in group B, corresponding to patients with poor initial renal function (n = 7, p = 0.9). Similarly, the function of solitary kidneys did not deteriorate over the 5-year postoperative follow-up period (n = 7, p = 0.5). The functional value of the kidneys was therefore not globally altered after ileal conduit urinary diversion. The existence of a mechanical or infectious complication should be systematically investigated in the presence of a deterioration in renal function. DMSA isotope renal scan is a complete, qualitative and quantitative, follow-up examination after this type of urinary diversion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Effect of streptozotocin diabetes on the glycolytic flux and on fructose 2,6-bisphosphate levels in isolated rat enterocytes.

In epithelial cells isolated from rat small intestine and incubated in the presence of 1 mM glucose, streptozotocin-induced diabetes reduced, by 46 and 29%, respectively, the rates of both glucose utilization and L-lactate formation. These effects were accompanied by a significant decrease of enterocyte fructose 2,6-bisphosphate concentration (about 50%) and of the glycolytic flux through the reaction catalyzed by 6-phosphofructo 1-kinase. The diminution of enterocyte fructose 2,6-bisphosphate levels caused by diabetes occurred in spite of an increase of hexose 6-phosphate concentration, and was associated with a reduction in the amount of active form of 6-phosphofructo 2-kinase; total activity of this enzyme was not significantly modified. Diabetes also caused an acceleration in the rate of 3-O-methyl-D-(14C) glucose uptake and increased hexokinase activity in enterocytes. Lactate dehydrogenase, pyruvate kinase and 6-phosphofructo 1-kinase activities were not found to be significantly different in epithelial cells isolated from control or diabetic animals. Our results indicate that a reduction of the glycolytic flux in enterocytes could collaborate to increase intestinal glucose absorption in the diabetic state.

Animals↗
PubMed1990

Grouping students for instruction: effects of learning style on achievement and attitudes.

The present study examined the effects of matching and mismatching American middle-school students with a preference for learning alone or learning with peers with selected instructional treatments in order to determine the impact upon their attitudes and achievement in social studies. Analysis revealed that the learning-alone preference performed significantly better in the learning-alone condition and that the learning-with-peers preference performed significantly better in the learning-with-peers condition. However, no-preference students also performed significantly better in the learning-alone condition than with peers. In addition, data revealed that the learning-alone and the learning-with-peers students had significantly more positive attitudes when matched with their preferred learning style; the nopreference students had more positive attitudes in the learning-alone condition.

Achievement↗
PubMed1990

Different HCl and pepsinogen I secretion patterns in anatomically defined gastric ulcer subsets.

Anatomically, functionally, and clinically, peptic ulcer patients are a heterogeneous group of subjects. These patients can be classified according to the anatomic localization of the niche. The functional state of the gastric mucosa was studied in 30 gastric ulcer patients, 25 duodenal ulcer patients, and 10 normal controls. The classification of the first group was based on Johnson's criteria, with the following results: 10 individuals were type I, 10 were type II, and 10 were type III. Pepsinogen I levels and gastric acid secretion were measured in all 65 subjects under basal conditions and after subcutaneous pentagastrin stimulation. Both basal and stimulated serum pepsinogen I values were significantly higher (p less than 0.05) in gastric ulcer type III patients than in the other four groups. These values in gastric ulcer type I were similar to those of the controls. Gastric ulcer type II patients showed an intermediate functional state similar to that of duodenal ulcer patients. In both gastric ulcer type II and duodenal ulcer patients, the basal and stimulated pepsinogen I levels were significantly higher (p less than 0.05) than those found in controls, whereas the basal serum gastrin levels were similar in the five groups. In conclusion, different HCl and pepsinogen I secretory patterns, with functional heterogenicity of the gastric mucosa, are shown here for the anatomically defined gastric ulcer subsets.

Adult↗
PubMed1989

Short-term regulation of glycolysis by vasoactive intestinal peptide in epithelial cells isolated from rat small intestine.

In epithelial cells isolated from rat small intestine, we have studied the influence of vasoactive intestinal peptide (VIP), a neurotransmitter which markedly increases enterocyte cyclic AMP, and of two cyclic AMP analogues (8-bromo cyclic AMP and N6,2'-O-dibutyryl cyclic AMP) on the rate of glycolysis, fructose 2,6-bisphosphate concentration and 6-phosphofructo-2-kinase activity, as well as on the rate of 3-O-methyl-D-[14C]glucose uptake. Our results show that, without affecting the rate of 3-O-methyl-D-[14C]glucose accumulation, VIP and cyclic AMP analogues were able to inhibit glucose consumption and L-lactate formation by isolated rat enterocytes. These effects occurred parallel to a significant decrease in the cellular concentration of fructose 2,6-bisphosphate and to a partial inactivation of 6-phosphofructo-2-kinase. These findings support the hypothesis that VIP inhibits glycolysis in rat enterocytes through a cyclic AMP-dependent mechanism.

3-O-Methylglucose↗
PubMed1988

Study of the secretion of pepsinogen I in cirrhotic humans with and without portacaval shunt.

Thirty-nine subjects have been studied: 14 with hepatic cirrhosis who had not been subjected to surgery, 13 cirrhotic patients in whom portacaval shunt had been performed, and 12 normal controls. In all of them, we performed serum determinations of pepsinogen I, both basal and after pentagastrin stimulation, and of basal gastrin levels, as well as analyses of basal and stimulated gastric acid secretion (basal acid output and maximal acid output). The values for pepsinogen I, basal or post-stimulation, were higher (p less than 0.001) in patients with cirrhosis who had not undergone surgical shunt than in those in the control group. However, there were no statistically significant differences when these two groups were compared with the patients who had been subjected to portacaval shunt. In this last group of patients, seven had levels similar to those of the controls, and six presented higher values. Likewise, the values for gastric acid secretion were similar in the three groups of patients, and the basal gastrin level was lower (p less than 0.001) among patients with liver cirrhosis, whether or not they had undergone surgery, than among the control population. In conclusion, the functional alterations of the gastric mucosa in patients with hepatic cirrhosis are not significantly different from those found in cirrhotic patients with portacaval shunt.

Adult↗
PubMed1982

Effect of colistin on reduction of biliary flow induced by endotoxin in E. coli.

In order to evaluate whether an antiendotoxin agent can inhibit the action of endotoxin of Escherichia coli on biliary flow, we used 18 models of isolated perfused pig liver divided into four groups: (A) five perfused livers (control), (B) five perfused livers with 2 mg/100 ml of endotoxin added, (C) five perfused livers with 2 mg/100 ml of endotoxin added and treated with 1,500,000 IU of colistin, and (D) three perfused livers with 1,500,000 IU of colistin with no endotoxin. The livers were isolated and perfused according to a technique previously described by our laboratory. The viability of the perfusions was controlled by means of the mitochondrial respiration test. Transaminase and LDH levels were measured in the perfused circuit. A significant reduction of the biliary flow was found in the group with endotoxin of Escherichia coli (P less than 0.002). There was no reduction of biliary flow after addition of 1,500,000 IU of colistin (P less than 0.001). No significant changes were observed in the other parameters measured, and no increase of the bile flow was observed in the colistin group. From our results we conclude that colistin is an inhibitor in vitro of the diminished biliary flow induced by endotoxin of Escherichia coli.

Alkaline Phosphatase↗