Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 20
Filter
1.
Neuroimage ; 61(4): 1165-75, 2012 Jul 16.
Article in English | MEDLINE | ID: mdl-22465844

ABSTRACT

Little attention has been paid to cortical integrity in patients with minimal hepatic encephalopathy (MHE), although cognitive functions affected in early stages of liver disease are mainly allocated in different neocortical structures. Here we used cortical surface-based analysis techniques to investigate if patterns of cortical thinning accompany the mildest form of HE. To aim this goal, cortical thickness obtained from high-resolution 3T magnetic resonance imaging (MRI) was measured in patients with no MHE (NMHE), MHE, and healthy controls. Further correlation analyses were performed to examine whether scores in the critical flicker frequency (CFF) test, and blood ammonia levels accounted for the loss of cortical integrity in different stages of liver disease. Finally, we assessed group differences in volume of different subcortical regions and their potential relationships with CFF scores/blood ammonia levels. Results showed a focal thinning of the superior temporal cortex and precuneus in MHE patients when compared with NMHE and controls. Relationships between blood ammonia levels and cortical thickness of the calcarine sulcus accounted for impaired visual judgment in patients with MHE when compared to NMHE. Regression analyses between cortical thickness and CFF predicted differences between controls and the two groups of HE patients, but failed to discriminate between patients with NMHE and MHE. Taking together, these findings provide the first report of cortical thinning in MHE patients, and they yield novel insights into the neurobiological basis of cognitive impairment associated with early stages of liver diseases.


Subject(s)
Cerebral Cortex/pathology , Cognition Disorders/pathology , Early Diagnosis , Hepatic Encephalopathy/pathology , Cognition Disorders/etiology , Female , Hepatic Encephalopathy/complications , Humans , Image Interpretation, Computer-Assisted , Magnetic Resonance Imaging , Male , Middle Aged , Neuropsychological Tests
2.
Hepatology ; 55(2): 530-9, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21953369

ABSTRACT

UNLABELLED: Attention deficit is an early event in the cognitive impairment of patients with minimal hepatic encephalopathy (MHE). The underlying mechanisms remain unclear. Mismatch negativity (MMN) is an auditory event-related potential that reflects an attentional trigger. Patients with schizophrenia show impaired attention and cognitive function, which are reflected in altered MMN. We hypothesized that patients with MHE, similarly to those with schizophrenia, should show MMN alterations related with attention deficits. The aims of this work were to assess whether (1) MMN is altered in cirrhotic patients with MHE, compared to those without MHE, (2) MMN changes in parallel with performance in attention tests and/or MHE in a longitudinal study, and (3) MMN predicts performance in attention tests and/or in the Psychometric Hepatic Encephalopathy Score (PHES). We performed MMN analysis as well as attention and coordination tests in 34 control subjects and in 37 patients with liver cirrhosis without MHE and 23 with MHE. Patients with MHE show reduced performance in selective and sustained attention tests and in visuomotor and bimanual coordination tests. The MMN wave area was reduced in patients with MHE, but not in those without MHE. In the longitudinal study, MMN area improved in parallel with performance in attention tests and PHES in 4 patients and worsened in parallel in another 4. Logistic regression analyses showed that MMN area predicts performance in attention tests and in PHES, but not in other tests or critical flicker frequency. Receiver operating characteristic curve analyses showed that MMN area predicts attention deficits in the number connection tests A and B, Stroop tasks, and MHE, with sensitivities of 75%-90% and specificities of 76%-83%. CONCLUSION: MMN area is useful to diagnose attention deficits and MHE in patients with liver cirrhosis.


Subject(s)
Attention , Evoked Potentials, Auditory , Hepatic Encephalopathy/physiopathology , Hepatic Encephalopathy/psychology , Adult , Case-Control Studies , Female , Humans , Longitudinal Studies , Male , Middle Aged , Psychometrics , Stroop Test
3.
Am J Gastroenterol ; 106(9): 1629-37, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21483460

ABSTRACT

OBJECTIVES: Between 30 and 50% of the cirrhotic patients who do not show symptoms of clinical hepatic encephalopathy (HE) present minimal hepatic encephalopathy (MHE), with mild cognitive impairment. MHE impairs the quality of life, increases the risk of suffering accidents, predicts the appearance of clinical HE, and is associated with shortened lifespan. Early detection of MHE would be very useful. The "gold standard" for MHE diagnosis is the psychometric hepatic encephalopathy score (PHES). However, it is time consuming and needs adjusting for age and educational level. It would be very useful to have some blood biomarker reflecting the presence of MHE in cirrhotic patients. The aim of this work was to identify serum molecules useful as biomarkers for MHE. METHODS: We measured in 63 controls, 43 cirrhotic patients without MHE, and 44 patients with MHE, from Hospital Clinico de Valencia, serum levels of different amino acids, cyclic guanosine monophosphate (cGMP), nitrites+nitrates, and 3-nitrotyrosine. We analyzed for each parameter its diagnostic accuracy as an indicator of MHE, as assessed using the PHES. RESULTS: These studies supported that 3-nitro-tyrosine is a good marker for MHE. To validate its utility as a biomarker for MHE, we analyzed in a second cohort of 44 cirrhotic patients without MHE and 18 patients with MHE, from Hospital Arnau de Vilanova, serum levels of 3-nitro-tyrosine, methionine, and citrulline. Citrulline (173±17%), methionine (173±16%), and 3-nitro-tyrosine (857±92%) were increased in sera from patients with MHE when compared with those without MHE. The receiver operating characteristic (ROC) curve analysis of 3-nitro-tyrosine for the diagnosis of MHE in the first cohort showed an area under the curve (AUC) value of 0.96 (95% confidence interval 0.93-0.99). At the cutoff of 14 nM, the specificity was 93%, sensitivity 89%, and positive and negative predictive values were both 91%. When the same cutoff was applied to the second cohort, the specificity was 83% and sensitivity was 94%. The positive and negative predictive values were 70 and 97%, respectively. CONCLUSIONS: This pilot study, to be validated in a larger cohort, shows that determination of 3-nitro-tyrosine in serum, which is easy and not time consuming, is useful to identify patients with MHE, with good sensitivity, specificity, and positive and negative predictive values.


Subject(s)
Hepatic Encephalopathy/blood , Hepatic Encephalopathy/diagnosis , Liver Cirrhosis/blood , Tyrosine/analogs & derivatives , Adult , Aged , Area Under Curve , Biomarkers/blood , Citrulline/blood , Early Diagnosis , Hepatic Encephalopathy/complications , Hepatic Encephalopathy/psychology , Humans , Liver Cirrhosis/complications , Methionine/blood , Middle Aged , Pilot Projects , Predictive Value of Tests , Prospective Studies , Psychometrics , ROC Curve , Tyrosine/blood
4.
J Proteome Res ; 9(10): 5180-7, 2010 Oct 01.
Article in English | MEDLINE | ID: mdl-20690770

ABSTRACT

Minimal hepatic encephalopathy (MHE) reduces quality of life of cirrhotic patients, predicts overt hepatic encephalopathy, and is associated with poor prognosis. We hypothesized that MHE arises once metabolic alterations derived from the liver reach a particular threshold. Our aim was to assess whether metabolic profiling of serum samples by high-field (1)H-nuclear magnetic resonance spectroscopy ((1)H NMR) and subsequent multivariate analyses would be useful to characterize metabolic perturbations associated with MHE and to identify potential metabolic biomarkers. Metabolic serum profiles from controls (n = 69) and cirrhotic patients without MHE (n = 62) and with MHE (n = 39) were acquired using high field NMR. Supervised modeling of the data provided perfect discrimination between healthy controls and cirrhotic patients and allowed the generation of a predictive model displaying strong discrimination between patients with and without MHE (R(2)Y = 0.68, Q(2)Y = 0.63). MHE patients displayed increased serum concentrations of glucose, lactate, methionine, TMAO, and glycerol, as well as decreased levels of choline, branch amino acids, alanine, glycine, acetoacetate, NAC, and lipid moieties. Serum metabonomics by (1)H NMR offers a useful approach for characterizing underlying metabolic differences between patients with and without MHE. This procedure shows great potential as a diagnostic tool of MHE as it objectively reflects measurable biochemical differences between the patient groups and may facilitate monitoring of both disease progression and effects of therapeutic treatments.


Subject(s)
Hepatic Encephalopathy/metabolism , Magnetic Resonance Spectroscopy/methods , Metabolome , Metabolomics/methods , Adult , Aged , Amino Acids/blood , Blood Glucose/metabolism , Female , Hepatic Encephalopathy/blood , Hepatic Encephalopathy/complications , Humans , Lactates/blood , Liver Cirrhosis/blood , Liver Cirrhosis/complications , Liver Cirrhosis/metabolism , Male , Middle Aged , Multivariate Analysis , Prognosis
5.
Scand J Gastroenterol ; 44(2): 224-8, 2009.
Article in English | MEDLINE | ID: mdl-18951278

ABSTRACT

OBJECTIVE: Previous studies have shown that asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA) and nitric oxide (NO) play a prominent role in liver dysfunction. The objective of this study was to determine whether plasma levels of ADMA, SDMA and NO are altered in patients with chronic hepatitis C. MATERIAL AND METHODS: Plasma levels of ADMA, SDMA and NO (nitrite plus nitrate) were measured in 22 patients with chronic hepatitis C and 24 patients with sustained virologic response after treatment with peginterferon plus ribavirin. Seven healthy volunteers served as controls. RESULTS: Plasma levels of ADMA, SDMA and NO were not significantly different between groups: chronic hepatitis C, ADMA 0.55+/-0.06, SDMA 0.22+/-0.03, NO 36.3+/-5.9 micromol/l; treated patients, ADMA 0.60+/-0.15, SDMA 0.31+/-0.05, NO 36.1+/-5.5 micromol/l; controls, ADMA 0.65+/-0.08, SDMA 0.28+/-0.05, NO 40.7+/-8.9 micromol/l). CONCLUSIONS: Our results show that plasma NO, ADMA and SDMA concentrations are not changed in patients with chronic hepatitis C without superimposed signs of acute inflammatory activity. Furthermore, no significant differences in plasma values of NO and dimethylarginines were observed between the group of untreated patients and the group of patients treated with interferon plus ribavirin.


Subject(s)
Arginine/analogs & derivatives , Hepatitis C, Chronic/blood , Nitric Oxide/blood , Adult , Antiviral Agents/therapeutic use , Arginine/blood , Case-Control Studies , Female , Hepatitis C, Chronic/drug therapy , Humans , Interferon alpha-2 , Interferon-alpha/therapeutic use , Male , Middle Aged , Polyethylene Glycols , Recombinant Proteins , Ribavirin/therapeutic use
6.
J Clin Gastroenterol ; 43(3): 272-9, 2009 Mar.
Article in English | MEDLINE | ID: mdl-18562979

ABSTRACT

BACKGROUND AND AIMS: Patients with liver cirrhosis may present minimal hepatic encephalopathy (MHE) that can be unveiled using specific neuropsychologic examination. Evaluation of MHE in cirrhotic patients might have prognostic value. The psychometric HE score (PHES) has been recommended as the "gold standard" in the diagnosis of MHE. It has been proposed that critical flicker frequency (CFF) analysis would be useful for easier detection of MHE. It would also be useful to have some peripheral parameter that could reflect the presence of MHE. It has been recently proposed that inflammation-associated alterations and hyperammonemia may cooperate in the induction of hepatic encephalopathy. The aim of the present work was to assess whether there is a correlation between the alterations in parameters reflecting inflammation, hyperammonemia, and the presence of MHE. METHODS: We have studied in 55 patients with liver cirrhosis and 26 controls the performance in the PHES battery and the CFF, ammonia, and some interleukins (ILs) as inflammatory markers. RESULTS: IL-6 and IL-18 were significantly higher (2.5-fold and 2.2-fold, respectively) in patients with MHE than in those without MHE. There were significant correlations between IL-6 or IL-18 levels and PHES score and CFF. Moreover, all patients with MHE had IL-6 levels higher than 11 ng/mL, whereas all patients without MHE had IL-6 levels lower than 11 ng/mL. CONCLUSIONS: Inflammatory alterations related with IL-6 and IL-18 may contribute to MHE. Serum concentration of IL-6 and IL-18 may be useful to discriminate cirrhotic patients with and without MHE.


Subject(s)
Hepatic Encephalopathy/diagnosis , Interleukin-18/blood , Interleukin-6/blood , Liver Cirrhosis/blood , Adult , Aged , Biomarkers/blood , Case-Control Studies , Diagnosis, Differential , Female , Flicker Fusion , Hepatic Encephalopathy/blood , Hepatic Encephalopathy/etiology , Humans , Hyperammonemia/blood , Hyperammonemia/diagnosis , Liver Cirrhosis/complications , Male , Middle Aged , Neuropsychological Tests , Prognosis
7.
J Gastroenterol Hepatol ; 23(6): 861-6, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18422960

ABSTRACT

BACKGROUND AND AIM: We assessed whether the two regimens of pegylated alpha-interferon-2b (PEG-IFN-alpha2b) plus ribavirin and pegylated alpha-interferon-2a (PEG-IFN-alpha2a) plus ribavirin showed differences in terms of sustained virological response, withdrawal due to side-effects and dose adjustment requirements in the treatment of naive chronic hepatitis C virus (HCV) patients. METHODS: A prospective non-randomized, open-label comparison was made of naive HCV-infected patients undergoing standard 24- or 48-week treatment with two PEG-IFN combined with weight-based dosing regimen of ribavirin (PEG-IFN-alpha2a/ribavirin, n = 91; PEG-IFN-alpha2b/ribavirin, n = 92). RESULTS: Sustained virological response was similar in PEG-IFN-alpha2a and PEG-IFN-alpha2b (65.9% vs 62%, P = 0.64), without differences according to genotype. In 117 patients with HCV genotype 1, the corresponding rates were 50.8% versus 46.6% (P = 0.713). Rapid virological response at 4 weeks, early virological response at 12 weeks and transient virological response were also similar. In the multivariate analysis, HCV genotype (odds ratio [OR] = 0.076, 95% confidence interval [CI] 0.029-0.198, P = 0.000) and presence of steatosis in the liver biopsy (OR = 2.799, 95% CI 1.362-5.755, P = 0.005) were significantly associated with response to antiviral therapy. The rate of withdrawals due to treatment-related adverse events was 13.2% in the group of PEG-IFN-alpha2a and 10.9% in the group of PEG-IFN-alpha2b. Dose modification of PEG-IFN was necessary in eight patients given PEG-IFN-alpha2a and in seven given PEG-IFN-alpha2b. CONCLUSION: The two PEG-IFN plus ribavirin have comparable anti-HCV activity as shown by similar percentages of patients with sustained virological response.


Subject(s)
Antiviral Agents/therapeutic use , Hepacivirus/drug effects , Hepatitis C, Chronic/drug therapy , Interferon-alpha/therapeutic use , Polyethylene Glycols/therapeutic use , Ribavirin/therapeutic use , Adult , Drug Therapy, Combination , Female , Hepatitis C, Chronic/genetics , Humans , Interferon alpha-2 , Male , Middle Aged , Prospective Studies , Recombinant Proteins , Treatment Outcome , Viral Load
8.
Hepatology ; 45(4): 879-85, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17393525

ABSTRACT

UNLABELLED: Minimal hepatic encephalopathy (MHE) is mainly diagnosed using psychometric tests such as the psychometric hepatic encephalopathy score (PHES). Despite the clinical and social relevance of MHE, psychometric testing is not widespread in routine clinical care. We assessed the usefulness of the critical flicker frequency (CFF), for the diagnosis of MHE and for the prediction of the development of overt episodes of HE. The normal range of PHES in the Spanish population was evaluated in a control group. Subsequently, 114 patients with cirrhosis and 103 healthy controls underwent both PHES and CFF tests. A diagnosis of MHE was made when the PHES was lower than -4 points. Patients were followed-up every 6 months for a total of 1 year. CFF did not correlate with age, education, or sex in the control group. The mean CFF was significantly lower in patients with MHE versus non-MHE or controls. Mean CFF correlated with individual psychometric tests as well as PHES (r = 0.54; P < 0.001). CFF <38 Hz was predictive of further bouts of overt HE (log-rank: 14.2; P < 0.001). There was a weak correlation between mean CFF and Child-Pugh score but not with model for end-stage liver disease score. In multivariate analysis using Cox regression, CFF together with Child-Pugh score was independently associated with the development of overt HE. CONCLUSION: CFF is a simple, reliable, and accurate method for the diagnosis of MHE. It is not influenced by age or education and could predict the development of overt HE.


Subject(s)
Flicker Fusion , Hepatic Encephalopathy/diagnosis , Liver Cirrhosis/complications , Neuropsychological Tests , Aged , Female , Hepatic Encephalopathy/epidemiology , Hepatic Encephalopathy/etiology , Humans , Male , Middle Aged , Prevalence , Risk
9.
Am J Physiol Gastrointest Liver Physiol ; 292(1): G305-14, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17215436

ABSTRACT

Hepatic encephalopathy in patients with liver disease is associated with poor prognosis. This could be due to the induction by the transient episode of hepatic encephalopathy of long-lasting alterations making patients more susceptible. We show that a single transient episode of hyperammonemia induces long-lasting alterations in signal transduction. The content of the regulatory subunit of the protein kinase dependent on cAMP (PKA-RI) is increased in erythrocytes from cirrhotic patients. This increase is reproduced in rats with portacaval anastomosis and in rats with hyperammonemia without liver failure, suggesting that hyperammonemia is responsible for increased PKA-RI in patients. We analyzed whether there is a correlation between ammonia levels and PKA-RI content in patients. All cirrhotic patients had increased content of PKA-RI. Some of them showed normal ammonia levels but had suffered previous hyperammonemia episodes. This suggested that a single transient episode of hyperammonemia could induce the long-lasting increase in PKA-RI. To assess this, we injected normal rats with ammonia and blood was taken at different times. Ammonia returned to basal levels at 2 h. However, PKA-RI was significantly increased in blood cells from rats injected with ammonia 3 wk after injection. In conclusion, it is shown that a single transient episode of hyperammonemia induces long-lasting alterations in signal transduction both in blood and brain. These alterations may contribute to the poor prognosis of patients suffering hepatic encephalopathy.


Subject(s)
Cyclic AMP-Dependent Protein Kinases/metabolism , Hyperammonemia/enzymology , Hyperammonemia/physiopathology , Liver Cirrhosis/complications , Adult , Aged , Animals , Ascites/complications , Chronic Disease , Cyclic AMP-Dependent Protein Kinases/blood , Disease Models, Animal , Erythrocyte Membrane/enzymology , Erythrocytes/enzymology , Female , Hepatitis/complications , Humans , Hyperammonemia/etiology , Liver Failure/blood , Liver Failure/complications , Liver Function Tests , Male , Middle Aged , Rats , Rats, Wistar , Reference Values
10.
J Mol Med (Berl) ; 85(3): 237-45, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17216205

ABSTRACT

Patients with liver cirrhosis with normal neurological and mental status examination may present minimal forms of hepatic encephalopathy, showing intellectual function impairment that cannot be detected through general clinical examination but can be unveiled using specific neuropsychological or neurophysiological examination. Evaluation of minimal hepatic encephalopathy (MHE) in cirrhotic patients would have prognostic value. The psychometric hepatic encephalopathy score (PHES) has been recommended as the "gold standard" in the diagnosis of MHE. Altered modulation of cyclic GMP (cGMP) levels in the brain seems to be responsible for the impairment of some types of cognitive function in liver disease. In animal models of liver disease, some of the alterations in modulation of cGMP levels in the brain are reproduced in lymphocytes. The aim of the present work was to assess whether there is a correlation between the alterations in different parameters involved in modulation of cGMP levels and the presence of MHE in patients with liver disease. We studied in 46 patients with liver cirrhosis and 26 controls the performance in the PHES battery of psychometric tests and the critical flicker frequency (CFF), the concentration of cGMP in plasma and lymphocytes, activation of guanylate cyclase by nitric oxide (NO) in lymphocytes, and several parameters likely involved in altered cGMP homeostasis in liver disease such as ammonia, NO metabolites, and atrial natriuretic peptide (ANP). Activation of guanylate cyclase by NO in lymphocytes and cGMP in plasma were higher and CFF lower in patients with MHE than in patients without MHE. Ammonia, ANP, and metabolites of NO were higher in patients than in controls but were no different in patients with or without MHE. Alteration in activation of guanylate cyclase by NO in lymphocytes correlates with PHES performance, CFF, and ammonia levels. This suggests that altered modulation of guanylate cyclase by NO in lymphocytes would reflect a parallel alteration in the brain occurring in patients with MHE that would be involved in their cognitive impairment.


Subject(s)
Guanylate Cyclase/metabolism , Hepatic Encephalopathy/complications , Hepatic Encephalopathy/enzymology , Liver Cirrhosis/complications , Lymphocytes/enzymology , Nitric Oxide/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Adult , Aged , Case-Control Studies , Cyclic GMP/blood , Enzyme Activation/drug effects , Female , Hepatic Encephalopathy/blood , Humans , Liver Cirrhosis/enzymology , Liver Cirrhosis/metabolism , Liver Failure/complications , Lymphocytes/metabolism , Male , Middle Aged , Nitric Oxide/biosynthesis , Nitric Oxide Donors/pharmacology , Penicillamine/analogs & derivatives , Penicillamine/pharmacology , Soluble Guanylyl Cyclase
11.
J Gastroenterol Hepatol ; 21(6): 982-7, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16724982

ABSTRACT

BACKGROUND: Diagnostic and preventive measures have contributed to a change in the epidemiology of acute hepatitis. The purpose of the present paper was to assess the changing prevalence of acute hepatitis from 1982 to 2003. METHODS: Trends in the epidemiology, clinical findings, and outcome of acute viral hepatitis from 1982 to 2003 were examined. A total of 548 episodes of acute hepatitis diagnosed between 1982 and 2003, the clinical course of which was monitored up to the year 2003, were included. Annual changes as well as for the intervals 1982-1992 and 1993-2003 were compared. RESULTS: Severe infections occurred in 1.3% of cases, with a mortality of 0.6%, with progression into chronicity in 25.1%. The annual incidences of acute hepatitis and the comparative intervals 1982-1992 and 1993-2003 showed a decline of parenterally -B, delta and C virus- transmitted infections, unchanged number of cases of acute hepatitis A, an increase in the number of cases of drug-induced hepatitis, increase in median ages, and a decrease in the proportion of hepatitis in injecting drug users. Ages of patients with hepatitis A tended to increase. CONCLUSIONS: A decline of parenterally transmitted acute hepatitis was documented throughout a 22-year period, while the number of cases of hepatitis A was unchanged and that of drug-induced hepatitis increased. Evaluation of the current targeted hepatitis A vaccination approach and adequate pharmacovigilance measures are required in the near future.


Subject(s)
Hepatitis/diagnosis , Hepatitis/epidemiology , Acute Disease , Adolescent , Adult , Female , Humans , Male , Middle Aged , Prevalence , Spain/epidemiology
12.
Exp Biol Med (Maywood) ; 231(1): 70-5, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16380646

ABSTRACT

In patients with cirrhosis, nitric oxide (NO), asymmetric dimethylarginine (ADMA), and possibly symmetric dimethylarginine (SDMA) have been linked to the severity of the disease. We investigated whether plasma levels of dimethylarginines and NO are elevated in patients with hepatorenal syndrome (HRS), compared with patients with cirrhosis without renal failure (no-HRS). Plasma levels of NO, ADMA, SDMA, and l-arginine were measured in 11 patients with HRS, seven patients with no-HRS, and six healthy volunteers. SDMA concentration in HRS was higher than in no-HRS and healthy subjects (1.47 +/- 0.25 vs. 0.38 +/- 0.06 and 0.29 +/- 0.04 microM, respectively; P < 0.05). ADMA and NOx concentrations were higher in HRS and no-HRS patients than in healthy subjects (ADMA, 1.20 +/- 0.26, 1.11 +/- 0.1, and 0.53 +/- 0.06 microM, respectively; P < 0.05; NOx, 94 +/- 9.1, 95.5 +/- 9.54, and 37.67 +/- 4.62 microM, respectively; P < 0.05). In patients with HRS there was a positive correlation between serum creatinine and plasma SDMA (r2 =0.765, P < 0.001) but not between serum creatinine and ADMA or NOx. The results suggest that renal dysfunction is a main determinant of elevated SDMA concentration in HRS. Accumulation of ADMA as a result of impaired hepatic removal may be the causative factor initiating renal vasoconstriction and SDMA retention in the kidney.


Subject(s)
Arginine/analogs & derivatives , Fibrosis/blood , Hepatorenal Syndrome/blood , Renal Insufficiency/blood , Arginine/blood , Case-Control Studies , Creatinine/blood , Fibrosis/pathology , Hepatorenal Syndrome/pathology , Humans , Kidney/metabolism , Liver/metabolism , Male , Middle Aged , Nitric Oxide/blood , Renal Insufficiency/pathology
13.
Liver Int ; 25(4): 787-95, 2005 Aug.
Article in English | MEDLINE | ID: mdl-15998430

ABSTRACT

BACKGROUND: Cyclic GMP (cGMP) concentration is increased in plasma of patients with liver cirrhosis. Three possible mechanisms may contribute: increased cGMP synthesis by soluble (activated by nitric oxide), or particulate (activated by atrial natriuretic peptide (ANP)) guanylate cyclase or increased release from cells. AIM: The aim of this work was to analyze the possible contributors to increased plasma cGMP and to assess whether changes in the parameters of the system vary with the degree of liver disease (Child Pugh score) or by the presence of ascites. METHODS: We measured cGMP in plasma and lymphocytes, soluble guanylate cyclase activation by nitric oxide in lymphocytes, nitrates and nitrites and ANPs (activator of particulate guanylate cyclase) in plasma. We analyzed the correlation between changes in different parameters to discern which parameters contribute to increased plasma cGMP. RESULTS: The plasma content of nitrates+nitrites, ANP and cGMP are increased. Activation of soluble guanylate cyclase by nitric oxide is increased in patients while basal cGMP in lymphocytes is decreased. CONCLUSIONS: Both increased ANP and increased activation of soluble guanylate cyclase by nitric oxide contribute to increased plasma cGMP in patients. The concentrations of ANP and cGMP in plasma increase with the degree of disease and are higher in patients with ascites.


Subject(s)
Atrial Natriuretic Factor/blood , Cyclic GMP/blood , Liver Cirrhosis/blood , Nitric Oxide/blood , Adult , Aged , Ascites/blood , Ascites/etiology , Ascites/pathology , Cells, Cultured , Guanylate Cyclase/biosynthesis , Humans , Liver Cirrhosis/complications , Liver Cirrhosis/pathology , Lymphocytes/drug effects , Lymphocytes/enzymology , Male , Middle Aged , Nitrates/blood , Nitrites/blood , Penicillamine/analogs & derivatives , Penicillamine/pharmacology
14.
Neurochem Int ; 45(6): 947-53, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15312989

ABSTRACT

Hyperammonemia is the main responsible for the neurological alterations in hepatic encephalopathy in patients with liver failure. We studied the function of the glutamate-nitric oxide (NO)-cGMP pathway in brain in animal models of hyperammonemia and liver failure and in patients died with liver cirrhosis. Activation of glutamate receptors increases intracellular calcium that binds to calmodulin and activates neuronal nitric oxide synthase, increasing nitric oxide, which activates soluble guanylate cyclase (sGC), increasing cGMP. This glutamate-NO-cGMP pathway modulates cerebral processes such as circadian rhythms, the sleep-waking cycle, and some forms of learning and memory. These processes are impaired in patients with hepatic encephalopathy. Activation of sGC by NO is significantly increased in cerebral cortex and significantly reduced in cerebellum from cirrhotic patients died in hepatic coma. Portacaval anastomosis in rats, an animal model of liver failure, reproduces the effects of liver failure on modulation of sGC by NO both in cerebral cortex and cerebellum. In vivo brain microdialisis studies showed that sGC activation by NO is also reduced in vivo in cerebellum in hyperammonemic rats with or without liver failure. The content of alpha but not beta subunits of sGC are increased both in frontal cortex and cerebellum from patients died due to liver disease and from rats with portacaval anastomosis. We assessed whether determination of activation of sGC by NO-generating agent SNAP in lymphocytes could serve as a peripheral marker for the impairment of sGC activation by NO in brain. Chronic hyperammonemia and liver failure also alter sGC activation by NO in lymphocytes from rats or patients. These findings show that the content and modulation by NO of sGC are strongly altered in brain of patients with liver disease. These alterations could be responsible for some of the neurological alterations in hepatic encephalopathy such as sleep disturbances and cognitive impairment.


Subject(s)
Liver Diseases/enzymology , Nitric Oxide/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Animals , Brain/enzymology , Guanylate Cyclase , Hepatic Encephalopathy/enzymology , Hepatic Encephalopathy/metabolism , Humans , Hyperammonemia/enzymology , Hyperammonemia/physiopathology , Liver Cirrhosis/enzymology , Liver Cirrhosis/metabolism , Liver Diseases/metabolism , Liver Diseases/physiopathology , Liver Failure/enzymology , Liver Failure/metabolism , Nitric Oxide/physiology , Rats , Receptors, Cytoplasmic and Nuclear/physiology , Soluble Guanylyl Cyclase
15.
J Hepatol ; 41(1): 55-9, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15246208

ABSTRACT

BACKGROUND/AIMS: The liver plays a prominent role in the metabolism of asymmetric dimethyl-l-arginine (ADMA), an endogenous inhibitor of nitric oxide (NO) synthase. This study was designed to determine whether plasma levels of ADMA and NO production are altered in patients with compensated and decompensated alcoholic cirrhosis. METHODS: Plasma levels of l-arginine, ADMA, symmetric dimethylarginine (SDMA) and NO (nitrite plus nitrate, NOx) were measured in nine patients with compensated alcoholic cirrhosis (Child-Pugh A) and 11 patients with advanced cirrhosis (Child-Pugh B-C). Seven healthy volunteers served as controls. RESULTS: ADMA and NOx concentrations in decompensated cirrhosis were higher than in the compensated group and control group (ADMA: 1.12+/-0.08 vs. 0.58+/-0.05 and 0.58+/-0.07micromol/l, respectively; P<0.05; NOx 97.90+/-10.27 vs. 37.42+/-3.91 and 40.43+/-5.30micromol/l, respectively; P<0.05). There was a positive correlation between the clinical score of the patients and concentrations of ADMA (r(2)=0.547, P<0.01) and NOx (r(2)=0.689, P<0.01). SDMA and l-arginine levels were not significantly different between the three groups. CONCLUSIONS: The results suggest that hepatocellular damage is a main determinant of elevated ADMA concentration in advanced alcoholic cirrhosis. By inhibiting NO release from vascular endothelium, ADMA might oppose the peripheral vasodilation caused by excessive NO production in severe cirrhosis.


Subject(s)
Arginine/analogs & derivatives , Arginine/blood , Liver Cirrhosis, Alcoholic/blood , Nitric Oxide/blood , Endothelium, Vascular/metabolism , Female , Humans , Liver Cirrhosis, Alcoholic/physiopathology , Male , Middle Aged , Nitrates/blood , Nitrites/blood , Vasodilation/physiology
16.
J Hepatol ; 40(5): 766-73, 2004 May.
Article in English | MEDLINE | ID: mdl-15094223

ABSTRACT

BACKGROUND/AIMS: Patients with liver disease show increased plasma cGMP and decreased intracellular cGMP in lymphocytes. The initial aim of this work was to assess whether decreased intracellular cGMP and increased plasma cGMP may be due to increased ATP-dependent release of cGMP from cells. The results obtained led to a new aim: to identify and quantify a protein responsible for the increased cGMP binding found in erythrocyte membranes from patients with liver disease. METHODS: ATP-dependent cGMP transport was determined in inside-out vesicles from erythrocyte membranes. cGMP-binding proteins were isolated from the membranes and identified by MALDI-TOF peptide mass fingerprint. Protein kinase A was quantified by immunoblotting. RESULTS: ATP-independent cGMP binding is increased in erythrocyte membranes from patients. There is a significant increase in the membrane content of a cGMP-binding protein with Mr 48,000, which was identified as the regulatory subunit of protein kinase A. CONCLUSIONS: The content of the regulatory subunit of protein kinase A is significantly increased (twice) in erythrocyte membranes from patients with liver cirrhosis. This protein binds cGMP strongly and may be responsible for the decrease in intracellular cGMP in liver disease.


Subject(s)
Cyclic AMP-Dependent Protein Kinases/blood , Cyclic GMP/blood , Erythrocyte Membrane/metabolism , Liver Cirrhosis/blood , Adult , Aged , Biological Transport, Active , Case-Control Studies , Cyclic AMP-Dependent Protein Kinases/chemistry , Female , Humans , In Vitro Techniques , Kinetics , Liver Cirrhosis/enzymology , Male , Middle Aged , Molecular Weight , Protein Subunits , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
17.
World J Surg ; 27(6): 647-52, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12732995

ABSTRACT

Cirrhosis of the liver appears to have an unfavorable prognosis in the surgical patient. The aim of this study was to determine risk factors for morbidity and mortality in patients with cirrhosis undergoing nonhepatic surgery. We studied 135 patients with liver cirrhosis undergoing nonhepatic procedures and 86 controls matched by age, sex, and preoperative diagnosis. Preoperative, intraoperative, and postoperative variables associated with 30-day mortality and morbidity were assessed by univariate and multivariate analyses. Patients with cirrhosis showed higher blood transfusion requirements, longer length of hospital stay, and a higher number of complications than controls. The mortality rate was 16.3% in cirrhotics and 3.5% in controls. By univariate analysis, the need for transfusions, prothrombin time, and Child-Pugh score were significantly associated with postoperative liver decompensation, whereas duration of surgery, prothrombin time, Child-Pugh score, cirrhosis-related complications, and general complications were significantly associated with mortality. In the multivariate analysis, Child-Pugh score (odds ratio [OR] 24.4; 95% confidence interval [CI] 5.5 to 106); duration of surgery (OR 5; 95% CI 1.2 to 15.6), and postoperative general complications (OR 3.7; 95% CI 3.4 to 6.4) were independent predictors of mortality. Patients with cirrhosis undergoing nonhepatic operations are at significant risk of perioperative complications leading to death. Independent variables associated with perioperative mortality include preoperative Child-Pugh score, the duration of surgery, and the presence of postoperative general complications.


Subject(s)
Blood Transfusion/statistics & numerical data , Liver Cirrhosis/epidemiology , Aged , Comorbidity , Female , Hospital Mortality , Humans , Male , Middle Aged , Multivariate Analysis , Outcome Assessment, Health Care , Risk Factors , Surgical Procedures, Operative , Surgical Wound Infection/epidemiology
18.
J Clin Gastroenterol ; 36(2): 170-4, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12544203

ABSTRACT

GOALS: We assessed the effect of HCV infection and abstinence from alcohol on survival in a cohort of patients with alcoholic cirrhosis. BACKGROUND: Hepatitis C virus (HCV) infection may be an important cofactor for liver disease in chronic alcoholics. STUDY: The study population consisted of 213 patients with the diagnosis of alcoholic cirrhosis, 72 of these patients were infected by HCV. Complete alcohol abstinence after diagnosis of alcoholic cirrhosis was recorded in 86 patients. The reference group consisted of 89 patients with anti-HCV positivity who had never consumed alcohol. Survival was analyzed by the Kaplan and Meier method and predictors of survival by the Cox's multiple regression model. RESULTS: HCV infection was not a determinant factor for survival in alcoholic cirrhosis. Age and Child-Pugh grade at the time of diagnosis of cirrhosis and persistence of alcohol consumption after diagnosis were independent predictors of poor outcome. The cumulative survival curve in abstinent alcoholics was significantly different from that of alcoholics who maintained the same pattern of alcohol consumption (log-rank = 4.30, p = 0.0381). Moreover, the cumulative survival in patients with anti-HCV-positive cirrhosis who stopped drinking after diagnosis was similar to that in patients with HCV-positive cirrhosis who had never consumed alcohol (log-rank 0.26, p = 0.61). CONCLUSIONS: Cumulative survival in alcoholic cirrhosis does not seem to be influenced by the presence or absence of markers of HCV infection. Once liver cirrhosis has been diagnosed in the alcoholic patient, complete alcohol abstinence should be strongly recommended.


Subject(s)
Anti-Infective Agents, Local/adverse effects , Ethanol/adverse effects , Hepacivirus , Hepatitis C/etiology , Hepatitis C/mortality , Liver Cirrhosis, Alcoholic/mortality , Liver Cirrhosis, Alcoholic/virology , Adult , Age Factors , Aged , Carcinoma, Hepatocellular/etiology , Carcinoma, Hepatocellular/mortality , Cohort Studies , Female , Follow-Up Studies , Hepatitis C/diagnosis , Hepatitis C Antibodies , Humans , Liver Cirrhosis, Alcoholic/diagnosis , Liver Neoplasms/etiology , Liver Neoplasms/mortality , Male , Middle Aged , Predictive Value of Tests , Proportional Hazards Models , Risk Factors , Survival Analysis , Time Factors
19.
Hepatology ; 35(5): 1205-14, 2002 May.
Article in English | MEDLINE | ID: mdl-11981771

ABSTRACT

Apoptosis plays an important role in the progression of alcohol-induced liver disease to cirrhosis. Oxidative stress is an early event in the development of apoptosis. The major aim of this study was to study the conditions in which oxidative stress occurs in chronic alcoholism and its relationship with apoptosis of hepatocytes. We have found that oxidative stress is associated with chronic ethanol consumption in humans and in rats, in the former independently of the existence of alcohol-induced liver disease. Ethanol or acetaldehyde induces apoptosis in hepatocytes isolated from alcoholic rats, but not in those from control rats. Inhibition of aldehyde dehydrogenase, but not of cytochrome P450 2E1, prevents ethanol-induced cell death. Ethanol-induced apoptosis is caused by increased reactive oxygen species (ROS) driven by increased availability of the reduced form of nicotinamide-adenine dinucleotide (NADH) owing to mitochondrial acetaldehyde metabolism and it is prevented by blocking the opening of mitochondrial permeability transition (MPT) pores with cyclosporine A. Inhibition of nitric oxide (NO) synthase or addition of antioxidant vitamins C and E completely prevented ethanol-induced apoptosis. Mitochondrial oxidative stress, which occurs during chronic alcoholism, renders hepatocytes susceptible to apoptosis. On the other hand, the CD95 ligand expression was up-regulated by acetaldehyde. In conclusion, ethanol induces apoptosis via 2 different pathways: MPT and up-regulation of the expression of CD95-Fas ligand. The overproduction of ROS by mitochondria, driven by acetaldehyde metabolism, is a common trigger of both mechanisms.


Subject(s)
Alcoholism/metabolism , Apoptosis/physiology , Hepatocytes/pathology , Liver Cirrhosis, Alcoholic/metabolism , Membrane Glycoproteins/metabolism , Acetaldehyde/pharmacology , Alcoholism/pathology , Aldehyde Dehydrogenase/metabolism , Animals , Cells, Cultured , Central Nervous System Depressants/pharmacology , Cytochrome P-450 CYP2E1/metabolism , Ethanol/pharmacology , Fas Ligand Protein , Fasting/physiology , Glutathione Disulfide/blood , Hepatocytes/metabolism , Humans , Liver Cirrhosis, Alcoholic/pathology , Male , Mitochondria/metabolism , NAD/metabolism , Nitric Oxide/metabolism , Oxidative Stress/physiology , Peroxides/metabolism , Rats , Rats, Wistar , Reactive Oxygen Species/metabolism , Up-Regulation/drug effects
20.
J Mol Med (Berl) ; 80(2): 117-23, 2002 Feb.
Article in English | MEDLINE | ID: mdl-11907648

ABSTRACT

Studies of animal models suggest that the activation of soluble guanylate cyclase by nitric oxide is altered in liver disease. We studied 77 patients with liver disease and 17 controls, to investigate whether the activation of soluble guanylate cyclase is altered in lymphocytes from patients with liver disease. The basal content of guanosine 3',5'-cyclic monophosphate (cGMP) in lymphocytes was decreased both in patients with liver cirrhosis (by 52%) and in patients with chronic hepatitis (by 62%). Activation of soluble guanylate cyclase by nitric oxide was higher in lymphocytes from patients with cirrhosis (3100+/-1000% of basal) or with hepatitis (5200+/-2500% of basal) than in lymphocytes from controls (1200+/-500% of basal). cGMP in plasma was increased in patients with liver disease. Successful (but not unsuccessful) treatment with interferon of patients with hepatitis due to virus C reversed all the above alterations. Altered modulation of soluble guanylate cyclase by nitric oxide in liver disease may play a role in the hemodynamic alterations found in these patients.


Subject(s)
Guanylate Cyclase/metabolism , Liver Diseases/enzymology , Lymphocytes/enzymology , Adult , Aged , Cyclic AMP/blood , Enzyme Activation/physiology , Female , Hepatic Encephalopathy/blood , Hepatic Encephalopathy/enzymology , Hepatic Encephalopathy/pathology , Humans , Hyperammonemia/blood , Hyperammonemia/enzymology , Hyperammonemia/pathology , Liver Diseases/blood , Liver Diseases/pathology , Lymphocytes/pathology , Male , Middle Aged , Nitric Oxide/physiology , Solubility
SELECTION OF CITATIONS
SEARCH DETAIL
...