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Biomedical subjects

F Trevisani

Publications and source records attributed to F Trevisani.

At least 37 records · Page 2Linked to original sources
PubMed2000

Starvation impairs antioxidant defense in fatty livers of rats fed a choline-deficient diet.

Although fatty liver (FL) is considered an innocuous condition, the frequent incidence of graft failure when FL are transplanted has renewed interest in the intracellular disorders causative of or consequent to fatty degeneration. Oxidative stress and nutritional status modulate the tolerance to reperfusion injury in control livers (CL), but very little is known in the case of FL. This study was designed to compare the oxidative balance in CL and FL from fed and food-deprived rats. Serum and liver samples were collected from fed and starved (18 h) rats with CL or FL induced by a choline-deficient diet. Hepatic injury was assessed by transaminase activities and histology. The hepatic concentrations of glutathione (GSH), vitamin C, alpha-tocopherol, thiobarbituric acid-reactive substances (TBARS) and protein carbonyls (PC) were measured. Fed rats with FL had significantly greater TBARS and lower alpha-tocopherol and vitamin C levels than those with CL, whereas GSH and PC concentrations were not affected. Starvation impaired the oxidative balance in both groups. However, compared with the other groups, FL from food-deprived rats generally had the lowest hepatic concentrations of alpha-tocopherol, vitamin C and GSH. Unlike in CL, protein oxidation occurred in FL. These data indicate that fatty liver induced by consumption of a choline-deficient diet is associated with a lower level of antioxidants, which results in lipid peroxidation. Starvation further affects these alterations and extends the damage to proteins. In conclusion, steatosis and starvation may act synergistically on the depletion of antioxidants, predisposing fatty livers to a reduced tolerance to oxidative injury.

Animals↗
PubMed1999

Ischemia-reperfusion injury in rat fatty liver: role of nutritional status.

Fatty livers are more sensitive to the deleterious effects of ischemia-reperfusion than normal livers. Nutritional status greatly modulates this injury in normal livers, but its role in the specific setting of fatty liver is unknown. This study aimed to determine the effect of nutritional status on warm ischemia-reperfusion injury in rat fatty livers. Fed and fasted rats with normal or fatty liver induced by a choline deficient diet underwent 1 hour of lobar ischemia and reperfusion. Rat survival was determined for 7 days. Serum transaminases, liver histology and cell ultrastructure were assessed before and after ischemia, and at 30 minutes, 2 hours, 8 hours, and 24 hours after reperfusion. Survival was also determined in fatty fasted rats supplemented with glucose before surgery. The preischemic hepatic glycogen was measured in all groups. Whereas survival was similar in fasted and fed rats with normal liver (90% vs. 100%), fasting dramatically reduced survival in rats with fatty liver (14% vs. 64%, P <.01). Accordingly, fasting and fatty degeneration had a synergistic effect in exacerbating liver injury. Mitochondrial damage was a predominant feature of ultrastructural hepatocyte injury in fasted fatty livers. Glucose supplementation partially prevented the fasting-induced depletion of glycogen and improved the 7-day rat survival to 45%. These data indicate that rat fatty livers exposed to normothermic ischemia-reperfusion injury are much more sensitive to fasting than histologically normal livers. Because glucose supplementation improves both the hepatic glycogen stores and the rat survival, a nutritional repletion procedure may be part of a treatment strategy aimed to prevent ischemia-reperfusion injury in fatty livers.

Alanine Transaminase↗
PubMed1999

Autonomic dysfunction and hyperdynamic circulation in cirrhosis with ascites.

Patients with advanced cirrhosis frequently show hemodynamic abnormalities. Autonomic dysfunction (AD) is also common and, owing to the importance of autonomic function in cardiovascular homeostasis, it may be involved in the pathogenesis of the hyperdynamic circulation. We, therefore, evaluated the hemodynamic status and autonomic function in 30 patients with cirrhosis, most of them with an advanced stage of the disease. Autonomic function was assessed with 7 cardiovascular tests exploring the vagal or sympathetic function. Each test was scored from 1 to 3 (normal, borderline, altered). Cardiac index (CI) was measured by an echocardiogram. Twenty-four (80%) patients showed an AD, this being definite in 14 (47%) patients. A vagal dysfunction (VD) was found in 19 patients (63%), this being definite in 11 patients (37%), and a sympathetic dysfunction (SD) in 7 patients (definite in 3 [10%] patients). The patients with AD showed a faster heart rate (P =.021), lower indicized peripheral vascular resistance (P =.013), and increased CI (P =.004) than patients without AD whereas mean arterial pressure did not differ. Similar results were seen by grouping patients according to the VD. AD score was directly correlated with heart rate (r = 0.53; P =.002) and CI (r = 0.45; P =. 016), and inversely correlated with peripheral vascular resistance (r = 0.46; P =.013). Even closer correlations were found with vagal score. AD (mainly VD) may be involved in the pathogenesis of the hyperdynamic circulatory syndrome of patients with advanced cirrhosis.

Adult↗
PubMed1998

Q-T interval prolongation in cirrhosis: prevalence, relationship with severity, and etiology of the disease and possible pathogenetic factors.

Prolonged Q-T interval predicts severe arrhythmias and sudden death, and has been shown to occur in alcoholic liver disease and cirrhotic patients who are candidates for liver transplantation. This study first evaluated the prevalence of prolonged Q-T interval in a large population of unselected patients with cirrhosis, and assessed the relationship between abnormal Q-T, etiology, and severity of liver disease and mortality of patients. Possible causes of Q-T abnormality were also explored. Ninety-four patients with cirrhosis without overt heart disease and 37 control subjects with mild chronic active hepatitis were enrolled. Rate-corrected Q-T interval (Q-Tc) was assessed along with routine liver tests, Child-Pugh score, serum bile salts, electrolytes and creatinine, plasma renin activity, aldosterone, norepinephrine, atrial natriuretic factor and, gonadal hormones. Q-Tc was longer in patients with cirrhosis than in controls (440.3 +/- 3.2 vs. 393.6 +/- 3.7 ms; P < .001) and prolonged (> 440 ms) in 44 patients (46.8%) and 2 controls (5.4%; P < .001). Q-Tc length was not influenced by the etiology of cirrhosis and correlated with Child-Pugh score (r = .53; P < .001), liver tests such as prothrombin activity, and serum concentrations of albumin and bilirubin, plasma bile salts, and plasma norepinephrine. Multivariate analysis showed that only Child-Pugh score and plasma norepinephrine were independently correlated with Q-Tc duration. Over a median follow-up period of 19 months (range, 2-33 months), patients with Q-Tc longer than 440 ms had a significantly lower survival rate than those with normal Q-Tc. Q-T interval is frequently prolonged in patients with cirrhosis, regardless the etiology of the disease, worsens in parallel with the severity of the disease, and may have an important prognostic meaning. In addition to other undefined factors related to the severity of cirrhosis, sympathoadrenergic hyperactivity may play a pathogenetic role.

Electrocardiography↗
PubMed1998

Effect of ischemia--reperfusion on heat shock protein 70 and 90 gene expression in rat liver: relation to nutritional status.

Heat shock proteins are intracellular proteins associated with a generalized response of cells to stress. The purpose of this study was to assess RNA levels of heat shock protein 70 and 90 in fed or fasted rat livers during ischemia-reperfusion. Northern blot analysis of heat shock proteins was performed. Adenosine triphosphate and glutathione were assessed. In baseline conditions, livers of fasted rats showed a twofold increase in mRNA for both heat shock proteins and 38% and 43% reductions in adenosine triphosphate and glutathione, respectively, when compared with organs from fed rats. After ischemia, livers of fasted rats presented a twofold decrease in heat shock protein mRNA, while no changes were observed in livers of fed rats; reduced glutathione and adenosine triphosphate decreased 55% and 50% in fasted livers and 25% and 20% in fed organs, respectively. After 120 min of reperfusion, heat shock protein mRNA rose threefold in fasted livers, while a slight decrease was observed in the fed group; reduced glutathione and adenosine triphosphate returned to 65% and 70% of baseline values in fasted livers and 85% and 90% in fed organs, respectively. In conclusion, the nutritional status affects heat shock protein expression determined by reperfusion. The reduced antioxidant status leading to increased oxidative stress could be the mechanism underlying the phenomenon.

Adenosine Triphosphate↗
PubMed1997

Rat hepatocytes isolated from alcohol-induced fatty liver have an increased sensitivity to anoxic injury.

The aim of this study was to determine whether rat hepatocytes isolated from steatotic or nonsteatotic livers have different thresholds for injury due to anoxia-reoxygenation. Rats were fed ethanol or control diets for 8 weeks. Histology showed that more than 75% of the hepatocytes in alcohol-fed and less than 3% in control animals contained fatty vacuoles. The glycogen content was significantly reduced in steatotic livers. Isolated hepatocytes were cast in agarose gel threads and perfused with Krebs-Henseleit bicarbonate buffer. Cell viability was determined by Trypan Blue (TB) exclusion; cell injury was determined by lactate dehydrogenase (LDH) release; and superoxide anion (O2.-) was determined by lucigenin-enhanced chemiluminescence (LCL). During the pre-anoxic basal perfusion the following occurred: viability was 86% +/- 1% and 85% +/- 1%; LDH release was 16 +/- 3 and 15 +/- 3 mU/min; and LCL was 4 +/- 1 and 5 +/- 1 nA in steatotic and nonsteatotic hepatocytes, respectively. Cell viability decreased slightly under 4 hours of aerobic perfusion without differences between the two groups. In contrast, fatty hepatocytes died much faster than did control hepatocytes during anoxia; after 3 hours viability was 17% +/- 8% vs. 60% +/- 2% (P < .001), respectively. With reoxygenation following 2 hours of anoxia, the changes in viability, in LDH release, and in LCL were similar in both groups. These results indicate that in hepatocytes isolated from alcohol-fed rats when compared with control hepatocytes: 1) cell viability under aerobic conditions is not influenced; 2) anoxic injury is significantly increased; 3) a reduction in the hepatic glycogen stores, which may contribute to the enhanced sensitivity to anoxia, can be demonstrated; and 4) O2.- generation and cell injury occurring immediately after reoxygenation do not appear to be affected.

Animals↗
PubMed1997

Daily profile of plasma endothelin-1 and -3 in pre-ascitic cirrhosis: relationships with the arterial pressure and renal function.

BACKGROUND/AIMS: Measurements of plasma endothelin-1 and -3 in pre-ascitic cirrhosis have provided controversial results. Similarly, the role of the endothelin system in the pathogenesis of volume and hemodynamic disturbances of cirrhosis is still debated. To provide a further insight into this issue, we assessed the daily fluctuations of plasma endothelins and their relationship with arterial pressure and renal function in pre-ascitic cirrhosis. METHODS: Endothelin-1 and -3, plasma renin activity, atrial natriuretic peptide, noradrenaline and mean arterial pressure were measured at 11 pm, 7 am, 9 am and 6 pm in 10 patients with pre-ascitic cirrhosis and in 10 healthy subjects on normal sodium diet and carrying on their usual activities (supine from 10 pm to 7 am, standing and mobile after 7 am). Glomerular filtration rate and daily renal sodium excretion were assessed during the supine period, and from 7 am to 12 am and from 12 am to 10 pm during the standing period. RESULTS: Endothelin-1 was higher in patients than in control subjects (p=0.000) and did not change during the study. Endothelin-3 was also higher in patients (p=0.002) and showed slight fluctuation in control subjects. The mean daily level of plasma renin activity was lower (p=0.016) and that of atrial natriuretic peptide higher (p=0.000) in patients with cirrhosis. Norepinephrine and mean arterial pressure did not differ significantly between the two groups. No correlations were found between endothelins and either hemodynamic or neuro-hormonal and renal function parameters in the two groups. CONCLUSIONS: Despite the presence of increased effective volemia (as suggested by the reduced plasma renin activity and elevated atrial natriuretic peptide) and normal adrenergic tone, patients with pre-ascitic cirrhosis show elevated levels of endothelin-1 and endothelin-3 throughout the day. In early cirrhosis circulating endothelins, although elevated, do not appear to play a more prominent role in setting arterial pressure than in normal subjects, and endothelin elevation is not detrimental to renal function.

Adult↗
PubMed1996

Clinical and pathologic features of hepatocellular carcinoma in young and older Italian patients.

BACKGROUND: It is not known whether putative etiologic factors and clinical and pathological features of hepatocellular carcinoma (HCC) differ between young adult and older white patients. METHODS: We examined the characteristics of 498 consecutive patients with HCC age < 50 years (Group 1: 54 patients) and age > or = 50 (Group 2: 444 patients), an age beyond which the tumor occurrence rate briskly increases. RESULTS: Demographic characteristics, alcohol and coffee intake, and cigarette smoking did not differ between the two groups. Group 1 had a greater prevalence of the hepatitis B surface antigen (HBsAg) carriers (P = 0.006), while the prevalence of either past hepatitis B virus infection (P = 0.008) or antivirus C antibodies (P = 0.016) was higher in Group 2. The lack of both hepatitis B and C virus serologic markers was more common in Group 1 (P = 0.018). In these patients, HCC was less frequently superimposed on cirrhosis (P = 0.002) and was more advanced at the time of diagnosis. In fact, despite a better histologic differentiation grade (P = 0.019), monofocal (solitary and massive) tumors were larger (P = 0.012), small lesions (< or = 5 cm) less frequent (P = 0.028), and either diffuse (P < 0.001) or massive (P = 0.011) types more common. An elevation of serum alpha-fetoprotein was less frequent in group 1 (P = 0.016), but this difference disappeared when the "diagnostic" cut-off of 400 ng/mL was considered. Albeit the prevalence of presenting symptoms did not significantly differ between the two groups, the clinical stage was more advanced in young patients (P = 0.004). The 9-year cumulative rate of survival was similar in the 2 groups. CONCLUSIONS: An early exposure to the virus and/or an accelerated hepatocarcinogenesis in HBsAg carriers can be inferred. Moreover, in the period of life at low risk for hepatoma: (1) the impact of nonalcoholic chemical carcinogenesis seems to be greater; (2) the tumor occurrence is less dependent on cirrhosis development; (3) although histologically better differentiated, the neoplasm is more advanced at the time of diagnosis; and (4) the long term survival is similar to that of the patients age 50 years or older.

Adolescent↗
PubMed1996

Effect of ethanol on adenosine triphosphate, cytosolic free calcium, and cell injury in rat hepatocytes. Time course and effect of nutritional status.

The events implicated in the early phases of acute ethanol-induced hepatocyte injury and their relation with the nutritional status of the liver are not clearly defined. We aimed to determine the effect of ethanol on ATP and cytosolic free Ca2+ in hepatocytes isolated from fed or fasted rats. Cell injury was assessed by LDH release and trypan blue uptake, ATP by [31P]NMR spectroscopy, and cytosolic free Ca2+ with aequorin. In control conditions, cells from fasted animals had a lower ATP level (-52%) and a higher cytosolic free Ca2+ (+101%) than did those isolated from fed animals. Ethanol caused a dose-dependent cell injury in both groups. At all ethanol doses, greater, damage occurred when using hepatocytes isolated from fasted rats. In both groups, a dose-dependent decrease in ATP content and a rise in cytosolic free Ca2+ were seen. The magnitude of these changes were significantly greater in the fasted group. In conclusion, these data showed that fasting affects the energy status and cytosolic free calcium level in hepatocytes; ethanol causes a dose-dependent cell injury that occurs in association with a fall in ATP and a rise in cytosolic free Ca2+ levels. The nutritional status of an animals is an important determinant of the severity of ethanol-induced damage to liver cells.

Adenosine Triphosphate↗
PubMed1996

Plasma endothelin-1 and -3 in cirrhosis: relationship with systemic hemodynamics, renal function and neurohumoral systems.

BACKGROUND/AIMS: The postural change from upright to supine is a physiological maneuvre which increases central blood volume. This model was used to investigate the effects of changes in effective volemia on plasma endothelin-1 and -3 concentrations in cirrhosis. METHODS: Plasma endothelin concentrations, measured by radio-immunoassay, were determined in 20 patients with cirrhosis, 10 of whom has ascites, and nine healthy control subjects, in the upright posture and 30, 60 and 120 min after the assumption of the supine position. RESULTS: In the upright posture, endothelin-1 was 8.9 +/- 0.4 pg/ml and endothelin-3 3.7 +/- 0.6 (mean +/- SEM) pg/ml in control subjects. Endothelin-1 was increased only in patients with ascites (12.7 +/- 1.4 pg/ml, p < 0.05; patients without ascites: 9.7 +/- 0.7 pg/ml), while endothelin-3 was elevated in both patients with and without ascites (8.0 +/- 1.5 pg/ml, p < 0.01; 5.9 +/- 0.5 pg/ml, p = 0.01, respectively). In the supine position, no significant changes in endothelin-1 or -3 occurred either in patients with ascites or in controls throughout the observation period, while a reduction in endothelin-3 was found in compensated patients after 30 and 60 min. In patients, we found negative correlations between endothelin-3, but not endothelin-1, and mean arterial pressure, both in upright (r = -0.59; p < 0.01) and supine (r = -0.56; p = 0.01) positions, atrial natriuretic factor (r = 0.50; p < 0.05) and plasma renin activity (r = 0.67; p = 0.001) in the supine position alone. In patients with ascites, endothelin-1 was inversely correlated with both glomerular filtration rate (upright: r = -0.62; p = 0.06; supine: r = -0.71, p < 0.05) and renal sodium excretion (upright: r = -0.82; p < 0.01; supine: r = -0.88; p < 0.001). CONCLUSIONS: Plasma endothelin-1 and -3 were increased in cirrhosis with ascites, while, in pre-ascitic cirrhosis, only endothelin-3 was increased in the upright posture. Although increased endothelin-3 was associated with features suggesting a reduced effective volemia, it is likely that other mechanisms than hypovolemia were mainly responsible for high plasma endothelin levels. Increased endothelin production may play a role in circulatory and renal function abnormalities of advanced cirrhosis.

Adult↗
PubMed1996

[Natural course and physiopathology of ascites in the cirrhotic patient].

Ascites formation in cirrhosis results from the interaction of "local" and "systemic" pathogenetic factors. Among local factors, post-sinusoidal portal hypertension plays the most important role, while the main systemic event is renal sodium retention. The latter precedes ascites formation and leads to plasma volume expansion. Many factors are responsible for renal sodium retention, but secondary hyperaldosteronism and reduced renal perfusion prevail. The events promoting the onset of sodium retention are far from being clarified. However, there is evidence that the main afferent mechanism is represented by the "effective" hypovolemia secondary to splanchnic venous vasodilation, due to portal hypertension, and reduced peripheral vascular resistance, which becomes evident in the advanced stage of the disease. Systemic hemodynamic abnormalities are responsible for the progressive reduction of renal perfusion, which ends in the hepatorenal syndrome. The appearance of ascites is a crucial event in the natural history of cirrhosis and has a negative prognostic meaning. In fact, ascites appears when pathogenetic factors, such as liver function abnormalities, portal and systemic hemodynamics, and renal function, have reached a critical threshold severity. Second, ascites itself induces additional complications, closely linked to its presence, such as spontaneous bacterial peritonitis, restrictive respiratory failure, or rupture of abdominal hernias. Finally, ascites implies pharmacological or invasive treatment which can lead to further morbidity or even to death.

Ascites↗
PubMed1995

Etiologic factors and clinical presentation of hepatocellular carcinoma. Differences between cirrhotic and noncirrhotic Italian patients.

BACKGROUND: It is not known whether the prevalence of hepatocarcinogenic factors differs between cirrhotic and noncirrhotic patients with hepatocellular carcinoma (HCC) or whether the clinical presentation of HCC in these two groups differs. METHODS: The prevalence of the putative etiologic factors of HCC and its clinical presentation in 373 patients with cirrhosis and 102 without cirrhosis seen from 1981 to 1992 were evaluated. RESULTS: Hepatitis C virus infection (76 vs. 48%, P = 0.003) and both current (22.5 vs. 10%, P = 0.007) and past (50.5 vs. 34.5%, P = 0.045) hepatitis B virus infections were more common in cirrhotic than in noncirrhotic patients with HCC. The absence of exposure to both viruses was much less frequent in the former (7 vs. 40%, P < 0.001). Heavy alcohol intake prevailed in patients with cirrhosis (30 vs. 16.5%, P = 0.01). Alpha-fetoprotein elevation was more common in cirrhotic patients (63% vs. 31%, P < 0.001); however, the prevalence of diagnostic (> 400 ng/ml) levels did not differ significantly (24 vs. 17%) between the two groups. Extrahepatic extension of HCC was more common in noncirrhotic patients (20.5 vs. 6.5%, P < 0.001) and its independent predictors were poor cancer differentiation and absence of cirrhosis. "Asymptomatic" cancers were more frequently encountered with cirrhosis. Abdominal pain was the most common presenting symptom in both groups. Signs of hepatic decompensation prevailed in cirrhotic patients, whereas a "toxic syndrome" dominated the clinical picture of the noncirrhotic patients. CONCLUSIONS: Hepatitis viruses are associated more with carcinogenesis of the cirrhotic than of the noncirrhotic liver. Alpha-fetoprotein is not a sensitive neoplastic marker, particularly in noncirrhotic patients. In the latter, HCC appears more advanced at diagnosis and symptoms of neoplastic toxicity are prominent.

Abdominal Pain↗
PubMed1995

Hemodynamic and renal effects of ascites apheresis, concentration and reinfusion in advanced cirrhosis.

BACKGROUND/AIMS: We studied the effects of ascites apheresis, concentration and reinfusion, a new form of treatment for tense or refractory ascites, on systemic hemodynamics and renal function. METHODS: Twelve patients with advanced cirrhosis (two belonging to Child-Pugh's class B and the remainder to class C) were monitored. They were evaluated under baseline conditions, just after the treatment, and 24 and 48 h after baseline assessment. In addition to systemic hemodynamics--as evaluated by Doppler echocardiography--and renal function, indirect markers of effective volemia, such as atrial natriuretic factor, plasma renin activity and aldosterone concentration, and plasma norepinephrine were also measured. RESULTS: The technique led to significant changes in systemic hemodynamics, such as an increase in stroke volume and cardiac output. However, due to a striking reduction in peripheral vascular resistance, mean arterial pressure also declined. The hemodynamic changes were associated with a parallel increase in atrial natriuretic factor. Despite the reduction in arterial pressure, plasma renin activity also significantly declined, while plasma norepinephrine did not undergo significant changes. Although an improvement in glomerular filtration rate and renal sodium excretion occurred, neither change reached statistical significance. All the hemodynamic, renal and neuro-humoral changes described above subsided almost entirely after 48 h, when no significant changes with respect to baseline values were any longer detectable with the exception of a slight reduction in mean arterial pressure. CONCLUSIONS: In advanced cirrhosis ascites apheresis, concentration and reinfusion enhance central volemia, but an exaggerated peripheral vasodilation largely wastes the potential favourable effect on arterial volemia. As a result, no significant improvement in renal perfusion and sodium excretion can ensue.

Adult↗