Hyperammonemia Is Associated with Increasing Severity of Both Liver Cirrhosis and Hepatic Encephalopathy

Alcoholism and Socioeconomic Status among Patients with Hepatic Encephalopathy in Association with Increased Mortality

Background

Hepatic encephalopathy (HE) is a complex neuropsychiatric disorder indicated by a deterioration in the functioning of hepatocytes. Impaired brain function is observed in advanced alcoholic liver disease particularly manifesting as HE. The pathophysiology of alcohol-related HE remains unclear. Accordingly, this study aimed to assess alcoholism and socioeconomic status of patients with liver disease compared with stages of HE.

Methods

This cross-sectional study was conducted on 62 alcoholic patients who have been consuming alcohol for more than 14 years. Patients were recruited based on the assessment of clinical symptoms and diagnosed according to the MELD and Child-Pugh scoring systems.

Findings

Descriptive statistics including demographic details and clinical features of patients were classified based on alcoholism and socioeconomic status. Patients belonging to the lower- and middle-income classes were more in number with a mean age of 46.66±10.21 and 47.14±6.36 years, respectively compared to upper-middle- and upper-income classes. The amount of alcohol intake was 116.59±45.60 in the middle class and 110.0±62.45 in the upper class.

Conclusion

Increased progression of HE leads to a rise in the mortality rate due to higher consumption of alcohol. HE is a severe complication in alcohol-related liver cirrhosis that contributes to impaired cognitive function in patients.

miRNA-ome plasma analysis unveils changes in blood-brain barrier integrity associated with acute liver failure in rats

BACKGROUND

Hepatic encephalopathy (HE) symptoms associated with liver insufficiency are linked to the neurotoxic effects of ammonia and other toxic metabolites reaching the brain via the blood-brain barrier (BBB), further aggravated by the inflammatory response. Cumulative evidence documents that the non-coding single-stranded RNAs, micro RNAs (miRs) control the BBB functioning. However, miRs' involvement in BBB breakdown in HE is still underexplored. Here, we hypothesized that in rats with acute liver failure (ALF) or rats subjected to hyperammonemia, altered circulating miRs affect BBB composing proteins.

METHODS

Transmission electron microscopy was employed to delineate structural alterations of the BBB in rats with ALF (thioacetamide (TAA) intraperitoneal (ip.) administration) or hyperammonemia (ammonium acetate (OA) ip. administration). The BBB permeability was determined with Evans blue dye and sodium fluorescein assay. Plasma MiRs were profiled by Next Generation Sequencing (NGS), followed by in silico analysis. Selected miRs, verified by qRT-PCR, were examined in cultured rat brain endothelial cells. Targeted protein alterations were elucidated with immunofluorescence, western blotting, and, after selected miR mimics transfection, through an in vitro resistance measurement.

RESULTS

Changes in BBB structure and increased permeability were observed in the prefrontal cortex of TAA rats but not in the brains of OA rats. The NGS results revealed divergently changed miRNA-ome in the plasma of both rat models. The in silico analysis led to the selection of miR-122-5p and miR-183-5p with their target genes occludin and integrin β1, respectively, as potential contributors to BBB alterations. Both proteins were reduced in isolated brain vessels and cortical homogenates in TAA rats. We documented in cultured primary brain endothelial cells that ammonia alone and, in combination with TNFα increases the relative expression of NGS-selected miRs with a less pronounced effect of TNFα when added alone. The in vitro study also confirmed miR-122-5p-dependent decrease in occludin and miR-183-5p-related reduction in integrin β1 expression.

CONCLUSION

This work identified, to our knowledge for the first time, potential functional links between alterations in miRs residing in brain endothelium and BBB dysfunction in ALF.

Novel Serum Biomarkers Associated With Pediatric Hepatic Encephalopathy: A Systematic Review

BACKGROUND

The pathophysiology of pediatric hepatic encephalopathy (HE) is not well understood. Various serum biomarkers associated with HE may provide insight into its pathology, but their use and interpretation in clinical practice for diagnosis and prognostication remain undetermined. We sought to investigate reported correlations of serum biomarkers with presence and degree of HE in children.

METHODS

We conducted a systematic review of studies examining novel serum biomarkers and cytokines in association with HE that included children on PubMed, Embase, Lilacs, and Scopus. We utilized Covidence for abstract and text review by 2 independent reviewers for each study.

RESULTS

We reviewed 2824 unique publications; 15 met criteria for inclusion. Categories of biomarkers reported were inflammatory cytokines, products of amino acid metabolism, trace elements and vitamins, and hepatic and neuro biomarkers. Of 19 individual biomarkers, only 5 were measured in more than 1 study. Elevations in interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) were most commonly reported as associated with HE. Notably, we observed lower average IL-6 and TNF-alpha levels in pediatric-only studies compared to mixed age studies. Overall, high bias and poor applicability to our review question was observed. We encountered low numbers of studies with pediatric focus, and few conducted with low bias study designs.

CONCLUSION

Investigated biomarkers span a large range of categories and suggest potentially useful correlations with HE. Further well-designed prospective biomarker research is necessary to better elucidate the pathogenesis of HE in children and improve early detection and clinical care.

Hepatic Encephalopathy and Melatonin

Hepatic encephalopathy (HE) is a severe metabolic syndrome linked with acute/chronic hepatic disorders. HE is also a pernicious neuropsychiatric complication associated with cognitive decline, coma, and death. Limited therapies are available to treat HE, which is formidable to oversee in the clinic. Thus, determining a novel therapeutic approach is essential. The pathogenesis of HE has not been well established. According to various scientific reports, neuropathological symptoms arise due to excessive accumulation of ammonia, which is transported to the brain via the blood–brain barrier (BBB), triggering oxidative stress and inflammation, and disturbing neuronal-glial functions. The treatment of HE involves eliminating hyperammonemia by enhancing the ammonia scavenging mechanism in systemic blood circulation. Melatonin is the sole endogenous hormone linked with HE. Melatonin as a neurohormone is a potent antioxidant that is primarily synthesized and released by the brain’s pineal gland. Several HE and liver cirrhosis clinical studies have demonstrated impaired synthesis, secretion of melatonin, and circadian patterns. Melatonin can cross the BBB and is involved in various neuroprotective actions on the HE brain. Hence, we aim to elucidate how HE impairs brain functions, and elucidate the precise molecular mechanism of melatonin that reverses the HE effects on the central nervous system.

Predictors of residual hepatic reserve and hepatic decompensation in cirrhotic patients after ablated hepatocellular carcinoma treated by DDAs or systemic therapy

Background

Therapeutic interventions for hepatocellular carcinoma (HCC) particularly in patients with advanced liver disease may lead to more aggravation of clinical and biochemical parameters of liver functions. We aimed to assess the utilization of easily applied variables which evaluate residual hepatic reserve to predict liability for complications and hepatic decompensation in cirrhotic patients with ablated HCC particularly when these patients were exposed to specific medical treatment such as DAAs and systemic therapy for HCC such as sorafenib.

This study included 3 groups with HCC. Group 1: patients with ablated HCC and Child-Turcotte-Pugh (CTP) class A, who received Sofosbuvir (SOF)-based treatment (n = 250), group 2: HCC patients CTP (A), managed with sorafenib after transarterial chemoembolization (TACE) (n = 250) and group 3 as a control group of non-cirrhotic patients (n = 176). Evaluation for all patients was done by routine laboratory investigations including liver and kidney functions, complete blood count, platelet indices and plasma ammonia, upper gastrointestinal (GI) endoscopy and estimation of liver volume by ultrasound and liver stiffness (LS) by Fibroscan.

Results

Unfavorable outcome and increased incidence of complications during DAAs were independently associated with severity of thrombocytopenia (p = 0.001) at a cut-off 78,000/μl, LS > 20 kPa (p = 0.001), liver volume < 500 ml (p = 0.002), and gamma globulin levels > 4 gm/dl (p = 0.004).

In the sorafenib group, unfavorable outcome and complications were independently associated with PDW/MPV ratio > 2.74 (p = 0.001), level of ammonia > 87 μg/dl (p = 0.001), LS > 25 kPa (p = 0.001), and liver volume < 490 ml (p = 0.001).

Conclusion

Non-invasive parameters of residual hepatic reserve are promising tools to guide therapy and avoid further complications in patients with liver cirrhosis and ablated HCC.

Effect of Uncaria rhynchophylla against Thioacetamide-Induced Acute Liver Injury in Rat

Both oxidative stress (OS) and inflammation are two fundamental pathological processes of acute liver injury (ALI). The current work is to investigate the effect and possible mechanism of Uncaria rhynchophylla (UR) on thioacetamide- (TAA-) induced ALI in rats. UR (100 and 200 mg/kg) was orally administrated with TAA (200 mg/kg of bodyweight, intraperitoneal injection) for 3 consecutive days. ALI was confirmed using histological examination and the factors associated with OS and liver function activity measured in serum. Moreover, expressions of inflammation and collagen-related proteins were measured by the Western blot analysis. Myeloperoxidase (MPO), which mediates OS in the ALI control group, was manifested by a significant rise compared with the normal group. UR significantly reduced AST, ALT, and ammonia levels in serum. The nuclear factor-κB (NF-κB) activation induced by TAA led to increase both inflammatory mediators and cytokines. Whereas, UR administration remarkably suppressed such an overexpression. UR supplementation improved matrix metalloproteinases (MMPs) such as MMP-1, -2, and -8. In contrast, tissue inhibitors of metalloproteinases- (TIMP-) 1 level increased significantly by UR treatment. In addition, the histopathological analysis showed that the liver tissue lesions were improved obviously by UR treatment. UR may ameliorate the effects of TAA-induced ALI in rats by suppressing both OS through MPO activation and proinflammatory factors through NF-κB activation. In conclusion, UR exhibited a potent hepatoprotective effect on ALI through the suppression of OS.

Prevalence of and Factors Associated with Sleep-Wake Abnormalities in Patients with Cirrhosis

BACKGROUND & AIMS

Sleep-wake abnormalities [poor nighttime sleep and excessive daytime sleepiness (EDS)] are common in patients with cirrhosis. The aim of this study was to assess the prevalence of sleep-wake abnormalities and clinical factors associated with these abnormalities in a group of patients with cirrhosis.

METHODS

1098 patients with cirrhosis [Child Turcotte Pugh (CTP) class A, 22.2%; CTP class B, 29.2% and CTP class C, 48.6%], with either no ascites or mild ascites controlled on diuretics, and no history of or current overt hepatic encephalopathy were included in the study.

RESULTS

Poor nighttime sleep and EDS were found in 569 (51.8%) and 489 (44.5%) patients respectively. On multivariate analysis, factors associated with poor nighttime sleep were CTP class C (vs. class A), presence of minimal hepatic encephalopathy (MHE), intermediate or evening type of diurnal preference category (vs. morning type), high risk for obstructive sleep apnea (OSA), diuretic use, presence of major depression, and presence of generalized anxiety disorder (GAD). Factors associated with EDS on multivariate analysis were CTP class B and C (vs. class A), intermediate or evening type of diurnal preference category (vs. morning type), high risk for OSA, presence of major depression, and presence of GAD.

CONCLUSIONS

Sleep-wake abnormalities are common in patients with cirrhosis. CTP status, diurnal preference chronotype, risk of OSA, major depression and GAD are associated with both poor nighttime sleep and EDS. MHE and diuretic use are associated with poor nighttime sleep, but not with EDS.

Biogenic Fe(II-III) Hydroxycarbonate Green Rust Enhances Nitrate Removal and Decreases Ammonium Selectivity during Heterotrophic Denitrification

Nitrification-denitrification is the most widely used nitrogen removal process in wastewater treatment. However, this process can lead to undesirable nitrite accumulation and subsequent ammonium production. Biogenic Fe(II-III) hydroxycarbonate green rust has recently emerged as a candidate to reduce nitrite without ammonium production under abiotic conditions. The present study investigated whether biogenic iron(II-III) hydroxycarbonate green rust could also reduce nitrite to gaseous nitrogen during bacterial nitrate reduction. Our results showed that biogenic iron(II-III) hydroxycarbonate green rust could efficiently decrease the selectivity of the reaction towards ammonium during heterotrophic nitrate reduction by native wastewater-denitrifying bacteria and by three different species of Shewanella: S. putrefaciens ATCC 12099, S. putrefaciens ATCC 8071 and S. oneidensis MR-1. Indeed, in the absence of biogenic hydroxycarbonate green rust, bacterial reduction of nitrate converted 11–42% of the initial nitrate into ammonium, but this value dropped to 1–28% in the presence of biogenic hydroxycarbonate green rust. Additionally, nitrite accumulation did not exceed the 2–13% in the presence of biogenic hydroxycarbonate green rust, versus 0–28% in its absence. Based on those results that enhance the extent of denitrification of about 60%, the study proposes a water treatment process that couples the bacterial nitrite production with the abiotic nitrite reduction by biogenic green rust.

DNA-Encoded Glutamine Synthetase Enzyme as Ammonia-Lowering Therapeutic for Hyperammonemia

Hyperammonemia is a dangerous life-threatening metabolic complication characterized by markedly elevated ammonia levels that can lead to irreversible brain damage if not carefully monitored. Current pharmacological treatment strategies available for hyperammonemia patients are suboptimal and associated with major side effects. In this study, we focus on developing and evaluating the in vivo delivery of novel DNA-encoded glutamine synthetase (GS) enzymes for the treatment of hyperammonemia. Direct in vivo delivered DNA-encoded GS enzyme was evaluated in ammonium acetate-induced hyperammonemia and thioacetamide-induced acute liver injury (ALI) models in C57BL/6 mice. In ammonium acetate-induced hyperammonemia model, we achieved a 30.5% decrease in blood ammonia levels 15 min postadministration of ammonium acetate, with DNA-encoded GS-treated group. Significant increase in survival was observed in ALI model with the treated mice. A comparison of the secreted versus intracellular DNA-encoded GS enzyme demonstrated similar increases in survival in the ALI model, with 40% mortality in the secreted enzymes and 30% mortality in the intracellular enzymes, as compared with 90% mortality in the control group. Direct in vivo delivery of DNA-encoded GS demonstrated important ammonia-lowering potential. These results provide the initial steps toward development of delivered DNA as a potential new approach to ammonia-lowering therapeutics.

Gyriform restricted diffusion in adults: looking beyond thrombo-occlusions

Gyriform restricted diffusion (GRD) refers to hyperintense signal involving the cerebral cortex on diffusion-weighted images (DWI) with corresponding hypointensity on apparent diffusion coefficient (ADC) images. These changes are commonly seen following a vascular occlusion, reflecting the limitation of water molecule movement across cell membranes (restricted diffusion) due to the failure of Na⁺/K⁺-ATPase pumps (cytotoxic oedema). However, GRD can occur in several other neurological conditions as well. A thorough understanding of these conditions and their anatomic predilection plays a critical role in identifying and differentiating them from vascular thrombo-occlusion, with impact towards appropriate clinical management. This review highlights the less commonly encountered, non-stroke causes of GRD in adults with case-based examples. A tabulated chart of the patterns of cortical and subcortical involvement associated with these aetiologies is provided for a quick, pattern-based reference for daily radiological reporting.

TLR5 silencing reduced hyperammonaemia-induced liver injury by inhibiting oxidative stress and inflammation responses via inactivating NF-κB and MAPK signals

BACKGROUND

Liver injury is a serious threat for human health and life. Toll-like receptor 5 (TLR5) has reported to be a vital mediator in flagellin or tetrachloride (CCl4)-induced liver injury. However, the roles and etiology of TLR5 in hyperammonaemia (HA)-induced liver injury are poor defined.

METHODS

HA rats were generated by intragastric administration using ammonium chloride solution. Liver status was assessed by haematoxylin and eosin (H&E) staining and measuring serum levels of liver injury markers. Immunohistochemistry (IHC) assay was used to visualize protein expression in tissues. Apoptotic index in tissues was determined by TUNEL assay. RT-qPCR assay was employed to test mRNA expression. Oxidative stress responses was assessed by detecting levels of reactive oxygen species (ROS) and related indicators. NF-κB activity was examined by TransAM NF-κB colorimetric kit.

RESULTS

TLR5 was highly expressed in liver tissues of HA rats. TLR5 knockdown ameliorated HA-induced liver injury by inhibiting liver cell apoptosis. TLR5 depletion inhibited HA-induced pro-inflammatory cytokine expression in liver tissues, but had no effect on the infiltration of T and macrophage cells into liver tissues. TLR5 silencing impaired HA-induced oxidative stress responses in hepatocytes, but not in hepatic stellate cells (HSCs). TLR5 downregulation inhibited HA-induced activation on TLR5/NF-κB and TLR5/MAPK signaling pathways.

CONCLUSION

TLR5 silencing reduced HA-induced liver injury by inhibiting hepatocyte apoptosis, oxidative stress and inflammation responses via inactivating NF-κB and MAPK signals, deepening our understanding on the molecular mechanism of HA-induced liver injury and providing a potential therapeutic target for alleviating liver injury.

Analysis of hepatitis C infection using Raman spectroscopy and proximity based classification in the transformed domain

This work presents a diagnostic system for the hepatitis C infection using Raman spectroscopy and proximity based classification. The proposed method exploits transformed Raman spectra using the proximity based machine learning technique and is denoted as RS-PCA-Prox. First, Raman spectral data is baseline corrected by subtracting noise and low intensity background. After this, a feature transformation of Raman spectra is adopted, not only to reduce the feature's dimensionality but also to learn different deviations in Raman shifts. The proposed RS-PCA-Prox shows significant diagnostic power in terms of accuracy, sensitivity, and specificity as 95%, 0.97 and 0.94 in PCA based transformed domain. The comparison of the RS-PCA-Prox with linear and ensemble based classifiers shows that proximity based classification performs better for the discrimination of HCV infected individuals and is able to differentiate the infected individuals from normal ones on the basis of molecular spectral information. Furthermore, it is observed that characteristic spectral changes are due to variation in the intensity of lectin, chitin, lipids, ammonia and viral protein as a consequence of the HCV infection.

A morphological method for ammonia detection in liver

Hyperammonemia is a metabolic condition characterized by elevated levels of ammonia and a common event in acute liver injury/failure and chronic liver disease. Even though hepatic ammonia levels are potential predictive factors of patient outcome, easy and inexpensive methods aiming at the detection of liver ammonia accumulation in the clinical setting remain unavailable. Thus, herein we have developed a morphological method, based on the utilization of Nessler´s reagent, to accurately and precisely detect the accumulation of ammonia in biological tissue. We have validated our method against a commercially available kit in mouse tissue samples and, by using this modified method, we have confirmed the hepatic accumulation of ammonia in clinical and animal models of acute and chronic advanced liver injury as well as in the progression of fatty liver disease. Overall, we propose a morphological method for ammonia detection in liver that correlates well with the degree of liver disease severity and therefore can be potentially used to predict patient outcome.