Concurrent assessment of calpain and caspase3 activities in brains of mice with acetaminophen-induced acute hepatic encephalopathy.

To develop pharmacological therapy for acute hepatic encephalopathy (AHE), understanding the molecular basis for cell injury is essential. Excitotoxic neural cell injury mediated by calpain as a post- receptor mechanism has been proposed as a player in neuronal injury in AHE. Concurrent assessment of Calpain and Caspase3 activities in the brain of AHE mice in acetaminophen- induced mourine model was performed. After induction of AHE by acetaminophen in mice, the model was confirmed by histopathological, biochemical and behavioural studies. The brains were removed, western blot analysis was done and the relative activity of calpain and caspase was estimated and compared to control group calpain but not caspase 3 activity was significantly increased in the AHE group compared to the control brains. Experimentally, this finding is the first to report. Increased calpain activity in liver has been previously reported. To translate both finding it can be suggested that calpain inhibition can be an investigational intervention in saving lives in AHE. To confirm the results, besides more advanced toxicodynamic studies on acetaminophen, the results should be confirmed in other models of AHE in future.

Viability assessment of magnetic resonance spectroscopy for the detection of minimal hepatic encephalopathy severity.

OBJECTIVE: To evaluate regional cerebral metabolic changes in minimal hepatic encephalopathy (MHE) patients using magnetic resonance spectroscopy (MRS) in 3T scanner. MATERIALS AND METHODS: This study comprised 30 cirrhotic patients with MHE, 29 cirrhotic patients without MHE and 30 healthy volunteers. Single-voxel proton MRS data in the anterior cingulate cortex (ACC) and basal ganglia were acquired using a 3-T scanner. The concentrations of N-acetylaspartate (NAA), mI (myo-inositol), glutamate (Glu), glutamine (Gln) and creatine (Cr) were obtained by LC-model software. Statistical analysis was performed to evaluate the differences between the three groups. RESULTS: There was a significant increase in Glu for the cirrhotic patients, particularly the MHE patients. There was an elevation of Gln in the cirrhotic patients, but not in all cirrhotic patients or controls. There was a significant decrease in mI for the cirrhotic patients, but no significant difference between the two cirrhosis groups. There was no significant difference in NAA between the three groups. CONCLUSIONS: MRS using a 3-T MR scanner could detect cerebral metabolic changes in cirrhotic patients with MHE. Glu levels were elevated in cirrhotic patients with MHE; Glu levels could be used as a sensitive indicator to evaluate the severity of MHE in patients with cirrhosis.

The role of fecal calprotectin in assessment of hepatic encephalopathy in patients with liver cirrhosis.

INTRODUCTION: Calprotectin is a cytoplasmatic protein of neutrophilic granulocytes and it is an established marker for the assessment of localized intestinal inflammation. AIM: To explore correlation between values of fecal calprotectin and degree of liver cirrhosis and hepatic encephalopathy. METHODS: We included 60 patients with liver cirrhosis and 37 healthy patients as controls. Patients revealing other causes of abnormal calprotectin results (gastrointestinal bleeding or inflammatory bowel disease) were excluded. The degree of liver insufficiency was assessed according to the Child-Pugh classification and Model of End Stage Liver Disease (MELD), and degree of hepatic enceph- alopathy by West-Haven criteria, serum concentration of ammonium ion and the number connection test. RESULTS: The mean value of fecal calprotectin in patients with liver cirrhosis was 189.1 ± 168.0 µg/g, and 35.0 ± 26.0 µg/g in the control group, respectively. We have confirmed significantly higher fecal calprotectin in patients with cirrhosis (p < 0.001). There were no significant differences in values of fecal calprotectin between the patients with different stages of liver cirrhosis according to Child-Pugh classification and MELD score (p > 0.05). We observed statistically significant difference comparing fecal calprotectin by West-Haven criteria of hepatic encephalopathy (p < 0.001), while there were no correlation with the number connection test and serum concentration of ammonium ion (p > 0.05). CONCLUSION: We confirmed significantly higher values of fecal calprotectin in patients with liver cirrhosis, especially in hepatic encephalopathy according to West-Haven criteria.

Serial evaluation of children with ALF with advanced MRI, serum proinflammatory cytokines, thiamine, and cognition assessment.

OBJECTIVES: This prospective, sequential study was done to understand changes in cerebral edema (CE) on magnetic resonance imaging and magnetic resonance spectroscopy, liver functions, and neurocognitive testing (NCT) in children with acute liver failure (ALF). METHODS: A total of 11 ALF and 8 healthy controls were evaluated with advanced magnetic resonance (MR) imaging, blood proinflammatory cytokines (PCs), thiamine levels, liver functions, and NCT. Reevaluation was done at 43.5 ±â€Š26.9 days (first follow-up, n = 8) and 157.3 ±â€Š52.3 days (second follow-up, n = 6) after discharge. RESULTS: At diagnosis, patients with ALF had vasogenic and cytotoxic CE, raised brain glutamine (23.2 ±â€Š3.4 vs. 15.3 ±â€Š2.7), and serum PCs (tumor necrosis factor [TNF]-α 40.1 ±â€Š8.9 vs. 7.2 ±â€Š2.7  pg/mL, interleukin [IL]-6 29.2 ±â€Š14.4 vs. 4.7 ±â€Š1.2  pg/mL). The mammillary bodies (MBs) were smaller, and brain choline (1.9 ±â€Š0.36 vs. 2.6 ±â€Š0.6) and blood thiamine (55.2 ±â€Š6.7 vs. 81.8 ±â€Š10.2  nmol/L) were lower than controls. At first follow-up, the brain glutamine and CE recovered. Brain choline and MBs volume showed improvement and thiamine levels normalized. Significant reduction in TNF-α and IL-6 was seen. The patients performed poorly on NCT, which normalized at second follow-up. Liver biochemistry and thiamine levels were normal and TNF-α and IL-6 showed further reduction at second follow-up. CONCLUSIONS: Patients with ALF have CE contributed by raised brain glutamine and PCs. MBs are small because of thiamine deficiency and show recovery in follow-up. CE and brain glutamine recover earlier than normalization of NCT and liver functions. Persistence of raised cytokines up to 6 months after insult suggests possible contribution from liver regeneration.

Breath-ammonia testing of healthy subjects and patients with cirrhosis.

BACKGROUND: Hepatic encephalopathy (HE) is a serious neuropsychiatric complication in both acute and chronic liver disease. AIMS: To establish the utility of a portable noninvasive method to measure ammonia in the breath of healthy subjects and patients with HE. METHODS: The study included 106 subjects: 44 women and 62 men, 51 healthy and 55 cirrhotic. The breath ammonia was measured with an electrochemical sensor and expressed in parts/billion (ppb). RESULTS: The breath ammonia in healthy subjects had an average value of 151.4 ppb (95% confidence interval [CI]: 149.4-153.4) and the average value in cirrhotic patients was 169.9 ppb (95% CI: 163.5-176.2) (P < 0.0001). In cirrhotic patients with and without HE, the corresponding values were 184.1 ppb (95% CI: 167.7-200.6) and 162.9 ppb (95% CI: 158.8-167.0), respectively (P = 0.0011). Ammonia levels ≥ 165 ppb permitted a differentiation between healthy and cirrhotic subjects; the area under the receiver operating characteristic (ROC) curve for the ammonia-level values in cirrhotic versus control patients was 0.86 (95% CI: 0.79-0.93). In cirrhotic patients, ammonia levels ≥ 175 ppb permitted the distinction between patients with and without HE; the area under the ROC curve in cirrhotic patients with versus without HE was 0.83 (95% CI: 0.73-0.94). CONCLUSION: A portable sensor for measuring breath ammonia can be developed. If the results of the present study are confirmed, breath-ammonia determinations could produce a significant impact on the care of patients with cirrhosis and could even include the possibility of self-monitoring.

Assessment of glutamate and glutamine contribution to in vivo N-acetylaspartate quantification in human brain by (1)H-magnetic resonance spectroscopy.

N-Acetylaspartate (NAA) is one of the most important metabolites detectable by brain (1)H-MRS being considered an index of neuronal integrity. At the low magnetic field used in most clinical settings beta,gamma-glutamate/glutamine (Glx) resonances are very close and partially overlap the methyl-NAA resonance interfering with NAA quantification especially at low TE and in the presence of increased Glx signals. NAA overestimation due to Glx on a set of model solutions containing NAA, glutamate, and glutamine in variable amounts was evaluated and the result tested in vivo in six healthy controls and five age- and sex-matched patients with hepatic encephalopathy (HE), the latter having an increased Glx content. A method to assess in vivo the NAA overestimation caused by Glx is proposed. A perfect match was obtained between the assessment of Glx contamination on the NAA of healthy controls and that obtained on the model solutions. However, a substantial difference in NAA overestimation was found between controls and HE patients that cannot be explained by our model. An interpretative hypothesis is provided.

Energy expenditure in acetaminophen-induced fulminant hepatic failure.

OBJECTIVE: To determine energy expenditure in critically ill patients suffering from acetaminophen-induced fulminant hepatic failure and compare it with values obtained in matched, healthy control subjects and in patients studied during the anhepatic period of elective liver transplantation. DESIGN: Prospective, controlled, observational study. SETTING: A ten-bed intensive therapy unit and a liver transplant unit at a University teaching hospital. PATIENTS AND SUBJECTS: Sixteen patients suffering from acetaminophen-induced fulminant hepatic failure who were sedated, paralyzed, and mechanically ventilated; 16 age-, gender-, and weight-matched, awake, healthy control subjects; and 16 patients with chronic liver disease, undergoing elective liver transplantation, who were studied during the anhepatic period of surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The mean energy expenditure was calculated in each case for a 30-min period, using indirect calorimetry. In the patients undergoing liver transplantation, measurements were performed after clamping the hepatic veins and recipient hepatectomy. Energy expenditure was markedly increased in the fulminant hepatic failure group (mean energy expenditure, 4.05 [SD 0.52] kJ x kg(-1) x hr(-1)), in comparison with healthy control subjects (mean, 3.44 [0.27] kJ x kg(-1) x hr(-1); mean difference, 18%; p < .001) and in comparison with patients during the anhepatic period of liver transplantation (mean, 3.15 [0.61] kJ x kg(-1) x hr(-1); mean difference, 29%; p < .001). These differences were even more pronounced when a correction factor for differences in core temperature was included in the calculation. Harris-Benedict predictions of energy expenditure were unreliable in the patients with acute liver failure. No correlations were found among energy expenditure and hemodynamic variables, the requirement for vasoconstrictors, or the presence of renal failure. CONCLUSIONS: Despite the loss of functioning liver cell mass, the metabolic rate is substantially increased in patients with acetaminophen-induced fulminant hepatic failure. This finding is consistent with the marked systemic inflammatory response, which accompanies acute hepatic failure. The Harris-Benedict equation is unreliable when an estimation of energy expenditure is required in patients with this condition.