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A Colantoni

Publications and source records attributed to A Colantoni.

At least 55 records · Page 3Linked to original sources
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

Association between reactive oxygen species and disease activity in chronic hepatitis C.

Reactive Oxygen Species (ROS) may be involved in the damage occurring in the course of chronic HCV infection. Individuals with chronic hepatitis C present increased hepatic levels of malondialdehyde (MDA) and reduced levels of glutathione. To determine whether these observations are associated with serological evidence for ROS injury, MDA and protein carbonyl content (PCC) of serum was determined in 20 HCV positive patients (14 chronic active hepatitis -- CAH and 6 cirrhosis) and 20 controls. Compared to controls, HCV positive subjects had increased levels of MDA (13.33 +/- 0.21 SE ng/ml vs. 9.90 +/- 0.65 P < .05) and PCC (4.74 +/- 0.21 mmol/mg vs 3.68 +/- 0.21, p < .02). Patients with CAH had higher levels than did cirrhotics. Both MDA and PCC correlated with serum ALT levels (r = .792 and r = .818 respectively, p < .001). A common origin for MDA and PCC found in patients with chronic hepatitis C was suggested by the correlation between the two measures (r = .741, p < .001). No correlation were found between MDA or PCC and the hepatic iron content. These data demonstrate that: (1) lipid and protein oxidation occur in chronic hepatitis C, (2) oxidative damage can be demonstrated as increased serum levels of MDA and PCC, and (3) both MDA and PCC levels correlate with disease activity.

Adult↗
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

Liver transplantation in virus-induced chronic liver disease.

The current status of liver transplantation (OLTx) for chronic viral hepatitis is reviewed. The major issues addressed include the rate of recurrence of disease, its severity and natural history, and the potential for therapy. These issues vary markedly for each type of viral hepatitis. The development of new antiviral agents for clinical use may change the current restriction on liver transplantation for hepatitis B virus (HBV)-related liver disease such that it begins to challenge hepatitis C virus (HCV) as the principal indication for OLTx world-wide.

Hepatitis B↗
PubMed1996

Interferon-alpha 2b improves short-term survival in patients transplanted for chronic liver failure caused by hepatitis B.

Liver transplantation for cirrhosis caused by hepatitis B virus (HBV) has a poor prognosis. This is primarily a consequence of the near universal reinfection of the allograft, subsequent accelerated hepatic disease while receiving immunosuppression, and a reduced long-term survival. Because interferon-alpha has been shown to have an antiviral effect on HBV, a study was initiated in 1986 to assess the effect of interferon-alpha therapy on the course of liver transplantation in HBV-positive recipients. Twenty-eight patients with decompensated endstage liver disease caused by HBV were treated with 5, 2.5 or 1.25 million units (MU) of human recombinant interferon-alpha 2b (r-IFN-alpha 2b) daily for a minimum of 14 days prior to transplantation and continuing for 42 days post-transplantation. HBV antigens, HBV antibodies, HBV DNA and serum transaminase levels were measured throughout the treatment and post-treatment period. HBV DNA was eliminated in 10 of 19 patients, who survived 3 months or more post-transplantation, and was associated with a significant flare of hepatitis as detected by symptoms and transaminase levels (P < 0.05). Patients who cleared HBV DNA had lower HBV DNA levels (P < 0.05) at entry compared with those who did not. While four of 10 patients with hepatitis B e antigen (HBeAg) converted to hepatitis B e antibody (HBeAb), no surviving patient cleared hepatitis B surface antigen (HBsAg) on a long-term basis. Nonetheless, post-transplant survival was significantly better (P < 0.0001, median follow-up 42 months) in the IFN-alpha treated patients as compared with historical controls, and was similar to that of patients transplanted for all causes of parenchymal liver disease other than HBV cancer. Hence IFN-alpha therapy in the perioperative liver transplantation period improves short-term survival but does not prevent HBV infection of the allograft.

DNA, Viral↗
PubMed1996

Neuropsychological impairment in a patient with a normal liver and long-standing portacaval anastomosis: studies obtained before and after liver transplantation.

A case report of the neuropsychiatric consequence of long-standing portal caval shunting in a man without intrinsic liver disease is described. Because of his neuropsychiatric status he underwent liver transplantation. Over the succeeding 8 months he had progressive improvement in his neuropsychiatric performance. These data document the adverse effects of portal caval shunting on neuropsychiatric performance in the absence of intrinsic liver disease as well as their reversibility with shunt closure.

Humans↗
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

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↗
PubMed1995

Hyperdynamic circulation of advanced cirrhosis: a re-appraisal based on posture-induced changes in hemodynamics.

Little is known about the effect of posture on the circulatory abnormalities of advanced cirrhosis. We evaluated the systemic hemodynamics, measured by Doppler-echocardiography, atrial natriuretic factor, plasma renin activity and plasma norepinephrine, in 10 patients with cirrhosis and ascites and 10 healthy controls, after 2 h of standing and during lying down for a further 2 h. Standing hemodynamic patterns of controls and patients with cirrhosis did not differ significantly. The latter, however, showed higher plasma renin activity, norepinephrine and atrial natriuretic factor. The assumption of the supine position led to greater increases in cardiac index and atrial natriuretic factor, and reduction in systemic vascular resistance in patients with cirrhosis. Norepinephrine and plasma renin activity declined in both groups to a similar extent, while heart rate only slowed in controls. Thus, after 2 h in the supine position, patients with cirrhosis showed hyperdynamic circulation with increased cardiac index and heart rate and reduced systemic vascular resistance. Norepinephrine, plasma renin activity and atrial natriuretic factor were also elevated. The hyperdynamic circulation in advanced cirrhosis appears during or is enhanced by lying down. This finding suggests that this syndrome is, at least in part, attributable to excessive blood volume translocation towards the central area. However, the persistent activation of renin-angiotensin and sympathoadrenergic systems suggests that a concomitant reduced vascular sensitivity to vasoconstrictors concurs in its development.

Adult↗
PubMed1995

High plasma levels of atrial natriuretic peptide in preascitic cirrhosis: indirect evidence of reduced natriuretic effectiveness of the peptide.

Controversial results come from spot measurements of plasma atrial natriuretic peptide (ANP) in compensated cirrhotic patients. Moreover, either blunted or exaggerated natriuresis has been described after maneuvers increasing plasma ANP. This does not make it possible to delineate the ANP effectiveness. Plasma ANP, renin activity (PRA) and aldosterone and hematocrit were serially measured (7 AM, 9 AM, 6 PM, and 11 PM) in nine preascitic cirrhotic outpatients and in nine healthy subjects on normal sodium diet (150 mmol/day) and carrying on their usual activities (mobile from 7 AM to 10 PM). Daily natriuresis was monitored the day before and during the study. In both groups, ANP peaked at the end of the recumbence period (7 AM) and declined on the assumption of the upright position, so that both ANP values of the standing period were significantly lower than the mean daily level. These fluctuations were reciprocal to PRA and hematocrit changes. Patients showed steadily elevated plasma ANP and reduced PRA (ANP mean daily level: 33.3 +/- 3.8 vs. 15.5 +/- 3.2 pg/mL, P = .004; PRA: 0.76 +/- 0.23 vs. 1.66 +/- 0.21 ng/mL/hr, P = .003). Aldosterone fluctuations and mean daily level were similar in the two groups (mean daily level: 122 +/- 11 vs. 119 +/- 9 pg/mL). Natriuresis was well adapted to the sodium intake and similar in healthy subjects (day 1: 152 +/- 11 mmol; day 2: 138 +/- 12.5 mmol) and patients (143 +/- 15 mmol; 148 +/- 29 mmol). Preascitic cirrhotic patients on a normal salt intake and carrying on their usual activities develop a new steady state requiring increased ANP levels to maintain a sodium balance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Prognostic indicators in patients with cirrhosis and hepatocellular carcinoma undergoing surgical resection.

A retrospective study was performed in order to identify factors significantly associated with operative mortality and post-operative complications in 114 patients with liver cirrhosis who underwent resection surgery for single hepatocarcinoma nodules (diameter < or = 7 cm) from 1980 to 1992. Vascular thrombosis, extrahepatic spread of the tumor, ascites, advanced cirrhosis, severe cardio-pulmonary disease, and renal failure were exclusion criteria. Forty-one pre-operative (demographic, clinical, laboratory, and histopathological features) and two peri-operative variables (amount of blood transfused and duration of operation) were cross tabulated using chi 2 test with operative mortality and post-operative complications, which were taken as end-point variables. Stepwise logistic regression analysis was then employed in order to define factors independently associated with end-point variables. Only partial thromboplastin time abnormality was significantly (P = 0.003) and independently associated with operative mortality. The length of the operation and the period during which surgery was carried out (1980-1986 and 1987-1992) were significantly (P < 0.001) and independently associated with the occurrence of at least one post-operative complication. The results suggest that the use of more restrictive selection criteria do not make it possible to lower operative mortality, although the coagulative status should be better assessed. Minimizing surgical stress and optimizing post-operative medical care are crucial for preventing post-operative complications.

Adult↗
PubMed1992

Characterisation of a human glioblastoma cell line (LI) expressing hypothalamic and pituitary hormones.

The human glioblastoma cell line LI showed morphological features typical of its neuroectodermal origin. Cells were positive by immunofluorescence to GFAP, MHC class II, and L1 determinants. Cytogenetic analysis showed the presence of a modal chromosome number of 63, ranging from 58 to 69 chromosomes (DNA index was 1.6). Northern blot analysis demonstrated the presence of mRNA transcripts specific for transglutaminase C (type II or "tissue"), growth-hormone releasing-hormone (GHRH), insulin-like growth factor II (IGF-II), and proopiomelanocortin (POMC). The GHRH mRNA was present in two different sizes, one similar to the normal hypothalamic species of 0.75 kb, whilst the second species was a large transcript of approximately 10 kb size. Treatment with 5 microM retinoic acid or 5 mM alpha-difluoromethylornithine for 5 days sharply reduced the growth rate and also induced modulation of the ultrastructure and antigenic profile. This cell line may be useful to study glial differentiation and the relationship of GHRH, IGF-II and POMC expression with differentiation in neuroectodermal tumours.

Blotting, Northern↗
PubMed1990

Ibopamine in the treatment of mild chronic heart failure in elderly patients. A double-blind, placebo-controlled study.

This double-blind, randomized, multicenter clinical study assessed the efficacy and safety of ibopamine 100 mg t.i.d. as monotherapy vs. placebo in 52 patients with mild chronic heart failure aged over 60 years during a 12-week treatment period. Ibopamine produced a statistically significant increase in exercise tolerance and reduction in fatigue during effort compared to placebo. A trend towards decreased requirement of concomitant diuretic therapy was noted in the ibopamine-treated group. Ibopamine was well tolerated throughout the study. This study indicated that ibopamine is an effective and safe agent as monotherapy in the treatment of mild chronic heart failure in elderly patients.

Aged↗
PubMed1986

Expression of T cell receptors by thymocytes: in situ staining and biochemical analysis.

We have examined the in situ expression of T cell receptor (TCR) V beta 8 protein in murine thymus during ontogeny using the monoclonal antibody F23.1. Positive cells were first detected at day 15 of gestation (0.6%). By day 16 the frequency of positive cells increased dramatically (4.18%). From day 16 to day 17 positive cells doubled (8.17%). The first clusters of F23.1 positive cells were seen at day 17. In the cortex, positive cells decreased from 14% in the newborn mice to 9.8% in 8-week-old mice, whereas in the medulla the frequency remained unchanged at 20%. The antibody F23.1, as well as an antiserum raised against the constant region of the beta chain, immunoprecipitated receptor dimers from highly purified Lyt2+, L3T4+ thymocytes and from two thymic lymphomas of cortical phenotype which express full size alpha and beta mRNA. The receptor dimer could not be precipitated from Lyt2-, L3T4- thymocytes. The results are discussed with regard to intrathymic T cell repertoire selection.

Aging↗