Ammonia and the neutrophil in the pathogenesis of hepatic encephalopathy in cirrhosis

Genetically Modified Hepatocytes Targeting Bilirubin and Ammonia Metabolism for the Construction of Bioartificial Liver System

Acute liver failure (ALF) is a complex syndrome that impairs the liver's function to detoxify bilirubin, ammonia, and other toxic metabolites. Bioartificial liver (BAL) aims to help ALF patients to pass through the urgent period by temporarily undertaking the liver's detoxification functions and promoting the recovery of the injured liver. We genetically modified the hepatocellular cell line HepG2 by stably overexpressing genes encoding UGT1A1, OATP1B1, OTC, ARG1, and CPS1. The resulting SynHeps-II cell line, encapsulated by Cytopore microcarriers, dramatically reduced the serum levels of bilirubin and ammonia, as demonstrated both in vitro using patient plasma and in vivo using ALF animal models. More importantly, we have also completed the 3-dimensional (3D) culturing of cells to meet the demands for industrialized rapid and mass production, and subsequently assembled the plasma-cell contacting BAL (PCC-BAL) system to fulfill the requirements of preclinical experiments. Extracorporeal blood purification of ALF rabbits with SynHeps-II-embedded PCC-BAL saved more than 80% of the animals from rapid death. Mechanistically, SynHeps-II therapy ameliorated liver and brain inflammation caused by high levels of bilirubin and ammonia and promoted liver regeneration by modulating the nuclear factor κB (NF-κB) and signal transducer and activator of transcription 3 (STAT3) pathways. Also, SynHeps-II treatment reduced cerebral infiltration of neutrophils, reduced reactive oxygen species (ROS) levels, and mitigated hepatic encephalopathy. Taken together, SynHeps-II cell-based BAL was promising for the treatment of ALF patients and warrants clinical trials.

Hepatic encephalopathy: From novel pathogenesis mechanism to emerging treatments

Hepatic encephalopathy (HE) is one of the major complications of liver disease and significantly affects the quality of life (QOL) of patients. HE is common and frequently relapses in cirrhotic patients. The management of HE is supportive, and precipitating conditions should be eliminated. Most drugs used to treat HE are conventional and include nonabsorbable disaccharides such as lactulose, and antibiotics such as rifaximin. However, their therapeutic efficacy is still suboptimal, and novel therapeutic agents are urgently needed. In addition, the optimal management and diagnosis of minimal HE/covert HE are under debate. In this review, we focus on novel pathogenetic mechanisms such as central nervous system clearance, and emerging therapeutic targets of HE, such as fecal material transplantation. We also discuss different classifications and etiologies of HE.

Use of bee venom in preventive medicine: An experimental hepatic encephalopathy study in rats

OBJECTIVES

Bee venom is used for medicinal purposes, including the treatment of neurological and liver diseases, but its use as a primary health care approach for preventive purposes requires further exploration. The aim of this study was to provide the first investigation into the possible protective effects of bee venom against hepatic encephalopathy, a serious neurodegenerative disease.

MATERIALS AND METHODS

An experimental animal study was conducted in which healthy albino Sprague-Dawley rats were randomized into three groups: healthy, control and bee venom groups. All rats were tested for locomotor activity at the beginning and end of the study. No intervention was made in the healthy group, whereas hepatic encephalopathy was induced in the control and bee venom groups by the administration of thioacetamide (TAA) (200 mg/kg/day). The bee venom group also received bee venom (5 mg/kg/day) subcutaneously every day for 14 days prior to the TAA administration.

RESULTS

The results for the final locomotor activity tests were statistically better in the bee venom group than in the control group, supporting a beneficial effect of prophylactic bee venom application. Blood ammonia levels and liver weights, determined as indicators of inflammation, were lower in the bee venom group than in the control group and were close to levels in the healthy group, but not statistically significant.

CONCLUSIONS

Bee venom administration has protective effects against the development of hepatic encephalopathy and offers a promising therapeutic opportunity in preventive medicine.

Post-Transjugular Intrahepatic Portosystemic Shunt (TIPS) Hepatic Encephalopathy-A Review of the Past Decade's Literature Focusing on Incidence, Risk Factors, and Prophylaxis

Transjugular intrahepatic portosystemic shunt (TIPS) is an established treatment for portal hypertension and its' complications in liver cirrhosis, yet the development of hepatic encephalopathy (HE) remains a significant concern. This review covers the reported incidence, risk factors, and management strategies for post-TIPS HE over the past decade. Incidence varies widely (7-61%), with factors like age, liver function, hyponatremia, and spontaneous portosystemic shunts influencing risk. Procedural aspects, including TIPS timing, indication, and stent characteristics, also contribute. Pharmacological prophylaxis with lactulose and rifaximin shows promise, but current evidence is inconclusive. Procedural preventive measures, such as shunt embolization and monitoring portal pressure gradients, are explored. Treatment involves pharmacological options like lactulose and rifaximin, and procedural interventions like stent diameter reduction. Ongoing studies on novel predictive markers and emerging treatments, such as faecal microbiota transplant, reflect the evolving landscape in post-TIPS HE management. This concise review provides clinicians with insights into the multifaceted nature of post-TIPS HE, aiding in improved risk assessment, prophylaxis, and management for patients undergoing TIPS procedures.

The contributions of bacteria metabolites to the development of hepatic encephalopathy

Over 20% of mortality during acute liver failure is associated with the development of hepatic encephalopathy (HE). Thus, HE is a complication of acute liver failure with a broad spectrum of neuropsychiatric abnormalities ranging from subclinical alterations to coma. HE is caused by the diversion of portal blood into systemic circulation through portosystemic collateral vessels. Thus, the brain is exposed to intestinal-derived toxic substances. Moreover, the strategies to prevent advancement and improve the prognosis of such a liver-brain disease rely on intestinal microbial modulation. This is supported by the findings that antibiotics such as rifaximin and laxative lactulose can alleviate hepatic cirrhosis and/or prevent HE. Together, the significance of the gut-liver-brain axis in human health warrants attention. This review paper focuses on the roles of bacteria metabolites, mainly ammonia and bile acids (BAs) as well as BA receptors in HE. The literature search conducted for this review included searches for phrases such as BA receptors, BAs, ammonia, farnesoid X receptor (FXR), G protein-coupled bile acid receptor 1 (GPBAR1 or TGR5), sphingosine-1-phosphate receptor 2 (S1PR2), and cirrhosis in conjunction with the phrase hepatic encephalopathy and portosystemic encephalopathy. PubMed, as well as Google Scholar, was the search engines used to find relevant publications.

Machine Learning Insights: Predicting Hepatic Encephalopathy After TIPS Placement

PURPOSE

To develop and assess machine learning (ML) models' ability to predict post-procedural hepatic encephalopathy (HE) following transjugular intrahepatic portosystemic shunt (TIPS) placement.

MATERIALS AND METHODS

In this retrospective study, 327 patients who underwent TIPS for hepatic cirrhosis between 2005 and 2019 were analyzed. Thirty features (8 clinical, 10 laboratory, 12 procedural) were collected, and HE development regardless of severity was recorded one month follow-up. Univariate statistical analysis was performed with numeric and categoric data, as appropriate. Feature selection is used with a sequential feature selection model with fivefold cross-validation (CV). Three ML models were developed using support vector machine (SVM), logistic regression (LR) and CatBoost, algorithms. Performances were evaluated with nested fivefold-CV technique.

RESULTS

Post-procedural HE was observed in 105 (32%) patients. Patients with variceal bleeding (p = 0.008) and high post-porto-systemic pressure gradient (p = 0.004) had a significantly increased likelihood of developing HE. Also, patients having only one indication of bleeding or ascites were significantly unlikely to develop HE as well as Budd-Chiari disease (p = 0.03). The feature selection algorithm selected 7 features. Accuracy ratios for the SVM, LR and CatBoost, models were 74%, 75%, and 73%, with area under the curve (AUC) values of 0.82, 0.83, and 0.83, respectively.

CONCLUSION

ML models can aid identifying patients at risk of developing HE after TIPS placement, providing an additional tool for patient selection and management.

Biological Role of Zinc in Liver Cirrhosis: An Updated Review

Liver cirrhosis is a complication usually due to the consequence of persistent chronic liver disease. It is associated with different mechanisms, including hypoalbuminemia, impaired amino acid turnover, and micronutrient deficiencies. Consequently, cirrhotic patients can develop progressive complications like ascites, hepatic encephalopathy, and hepatocellular carcinoma. The liver is a vital organ that regulates the different metabolic pathways and transportation of trace elements. Zn is an indispensable micronutrient trace element involved in its crucial functions in cellular metabolic activity. Zn mediates its action by binding to a wide range of proteins; therefore, it imparts numerous biological effects, including cellular division, differentiation, and growth. It is also involved in critical processes for the biosynthesis of structural proteins and regulation of transcription factors and acts as a co-factor for the various enzymatic processes. As the liver is a significant regulator of Zn metabolism, its abnormalities lead to Zn deficiency, which has consequences on cellular, endocrine, immune, sensory, and skin dysfunctions. Conversely, Zn deficiency may modify the functions of hepatocytes and immune responses (acute phase protein production) in inflammatory liver diseases. This review has concisely stated the evolving indication of the critical role of Zn in biological processes and complications associated with liver cirrhosis pathogenesis due to Zn deficiency.

A Review of Skin-Wearable Sensors for Non-Invasive Health Monitoring Applications

The early detection of fatal diseases is crucial for medical diagnostics and treatment, both of which benefit the individual and society. Portable devices, such as thermometers and blood pressure monitors, and large instruments, such as computed tomography (CT) and X-ray scanners, have already been implemented to collect health-related information. However, collecting health information using conventional medical equipment at home or in a hospital can be inefficient and can potentially affect the timeliness of treatment. Therefore, on-time vital signal collection via healthcare monitoring has received increasing attention. As the largest organ of the human body, skin delivers significant signals reflecting our health condition; thus, receiving vital signals directly from the skin offers the opportunity for accessible and versatile non-invasive monitoring. In particular, emerging flexible and stretchable electronics demonstrate the capability of skin-like devices for on-time and continuous long-term health monitoring. Compared to traditional electronic devices, this type of device has better mechanical properties, such as skin conformal attachment, and maintains compatible detectability. This review divides the health information that can be obtained from skin using the sensor aspect's input energy forms into five categories: thermoelectrical signals, neural electrical signals, photoelectrical signals, electrochemical signals, and mechanical pressure signals. We then summarize current skin-wearable health monitoring devices and provide outlooks on future development.

The Management of Postoperative Cognitive Dysfunction in Cirrhotic Patients: An Overview of the Literature

Background and objectives: Postoperative cognitive dysfunction (POCD) represents a decreased cognitive performance in patients undergoing general anesthesia for major surgery. Since liver cirrhosis is associated with high mortality and morbidity rates, cirrhotic patients also assemble many risk factors for POCD. Therefore, preserving cognition after major surgery is a priority, especially in this group of patients. The purpose of this review is to summarize the current knowledge regarding the effectiveness of perioperative therapeutic strategies in terms of cognitive dysfunction reduction. Data Collection: Using medical search engines such as PubMed, Google Scholar, and Cochrane library, we analyzed articles on topics such as: POCD, perioperative management in patients with cirrhosis, hepatic encephalopathy, general anesthesia in patients with liver cirrhosis, depth of anesthesia, virtual reality in perioperative settings. We included 115 relevant original articles, reviews and meta-analyses, and other article types such as case reports, guidelines, editorials, and medical books. Results: According to the reviewed literature, the predictive capacity of the common clinical tools used to quantify cognitive dysfunction in cirrhotic settings is reduced in perioperative settings; however, novel neuropsychological tools could manage to better identify the subclinical forms of perioperative cognitive impairments in cirrhotic patients. Moreover, patients with preoperative hepatic encephalopathy could benefit from specific preventive strategies aimed to reduce the risk of further neurocognitive deterioration. Intraoperatively, the adequate monitoring of the anesthesia depth, appropriate anesthetics use, and an opioid-sparing technique have shown favorable results in terms of POCD. Early recovery after surgery (ERAS) protocols should be implemented in the postoperative setting. Other pharmacological strategies provided conflicting results in reducing POCD in cirrhotic patients. Conclusions: The perioperative management of the cognitive function of cirrhotic patients is challenging for anesthesia providers, with specific and targeted therapies for POCD still sparse. Therefore, the implementation of preventive strategies appears to remain the optimal attitude. Further research is needed for a better understanding of POCD, especially in cirrhotic patients.

The shaping of gut immunity in cirrhosis

Cirrhosis is the common end-stage of chronic liver diseases of different etiology. The altered bile acids metabolism in the cirrhotic liver and the increase in the blood-brain barrier permeability, along with the progressive dysbiosis of intestinal microbiota, contribute to gut immunity changes, from compromised antimicrobial host defense to pro-inflammatory adaptive responses. In turn, these changes elicit a disruption in the epithelial and gut vascular barriers, promoting the increased access of potential pathogenic microbial antigens to portal circulation, further aggravating liver disease. After summarizing the key aspects of gut immunity during homeostasis, this review is intended to update the contribution of liver and brain metabolites in shaping the intestinal immune status and, in turn, to understand how the loss of homeostasis in the gut-associated lymphoid tissue, as present in cirrhosis, cooperates in the advanced chronic liver disease progression. Finally, several therapeutic approaches targeting the intestinal homeostasis in cirrhosis are discussed.

Green Tea Catechin EGCG Ameliorates Thioacetamide-Induced Hepatic Encephalopathy in Rats via Modulation of the Microbiota-Gut-Liver Axis

SCOPE

Existing research suggests that (-)-epigallocatechin-3-gallate (EGCG), which is a natural tea catechin active substance, can protect against liver injury. However, its mechanism for hepatic encephalopathy (HE) treatment is still unclear. In this study, the role of EGCG in the amelioration of HE rats and the effect on the microbiota-gut-liver axis are mainly analyzed.

METHODS AND RESULTS

Thioacetamide (TAA) is employed to induce the HE model in rats. The results of open field test show that EGCG restores locomotor activity and exploratory behavior. Histological and biochemical results demonstrate that EGCG ameliorates brain and liver damage, decreases the expression of pro-inflammatory cytokines, and increases the activity of antioxidant enzymes. Meanwhile, EGCG modulates the Nrf2 pathway and TLR4/NF-κB pathway to mitigate TAA-induced oxidative stress and inflammatory responses. Immunohistochemistry reveals protection of the intestinal barrier by EGCG upregulating the expression of occludin and zonula occludens-1. Furthermore, serum levels of ammonia and LPS are reduced. 16S rRNA analysis shows that EGCG treatment increases the abundance of beneficial bacteria (e.g., Bifidobacterium, Lactobacillus, and Limosilactobacillus).

CONCLUSION

The above results reveal that EGCG has anti-oxidative stress and anti-inflammatory effects, and ameliorates the condition through the microbiota-gut-liver axis, with potential for the treatment of HE.

Ammonium quantification in human plasma by proton nuclear magnetic resonance for staging of liver fibrosis in alcohol-related liver disease and nonalcoholic fatty liver disease

Liver fibrosis staging is a key element driving the prognosis of patients with chronic liver disease. Currently, biopsy is the only technique capable of diagnosing liver fibrosis in patients with alcohol-related liver disease (ArLD) and nonalcoholic fatty liver disease (NAFLD) unequivocally. Noninvasive (e.g. plasma-based) biomarker assays are attractive tools to diagnose and stage disease, yet must prove that they are reliable and sensitive to be used clinically. Here, we demonstrate proton nuclear magnetic resonance as a method to rapidly quantify the endogenous concentration of ammonium ions from human plasma extracts and show their ability to report upon early and advanced stages of ArLD and NAFLD. We show that, irrespective of the disease etiology, ammonium concentration is a more robust and informative marker of fibrosis stage than current clinically assessed blood hepatic biomarkers. Subject to validation in larger cohorts, the study indicates that the method can provide accurate and rapid staging of ArLD and NAFLD without the need for an invasive biopsy.

Abnormal brain oxygen homeostasis in an animal model of liver disease

Background & Aims

Increased plasma ammonia concentration and consequent disruption of brain energy metabolism could underpin the pathogenesis of hepatic encephalopathy (HE). Brain energy homeostasis relies on effective maintenance of brain oxygenation, and dysregulation impairs neuronal function leading to cognitive impairment. We hypothesised that HE is associated with reduced brain oxygenation and we explored the potential role of ammonia as an underlying pathophysiological factor.

Methods

In a rat model of chronic liver disease with minimal HE (mHE; bile duct ligation [BDL]), brain tissue oxygen measurement, and proton magnetic resonance spectroscopy were used to investigate how hyperammonaemia impacts oxygenation and metabolic substrate availability in the central nervous system. Ornithine phenylacetate (OP, OCR-002; Ocera Therapeutics, CA, USA) was used as an experimental treatment to reduce plasma ammonia concentration.

Results

In BDL animals, glucose, lactate, and tissue oxygen concentration in the cerebral cortex were significantly lower than those in sham-operated controls. OP treatment corrected the hyperammonaemia and restored brain tissue oxygen. Although BDL animals were hypotensive, cortical tissue oxygen concentration was significantly improved by treatments that increased arterial blood pressure. Cerebrovascular reactivity to exogenously applied CO2 was found to be normal in BDL animals.

Conclusions

These data suggest that hyperammonaemia significantly decreases cortical oxygenation, potentially compromising brain energy metabolism. These findings have potential clinical implications for the treatment of patients with mHE.

Lay summary

Brain dysfunction is a serious complication of cirrhosis and affects approximately 30% of these patients; however, its treatment continues to be an unmet clinical need. This study shows that oxygen concentration in the brain of an animal model of cirrhosis is markedly reduced. Low arterial blood pressure and increased ammonia (a neurotoxin that accumulates in patients with liver failure) are shown to be the main underlying causes. Experimental correction of these abnormalities restored oxygen concentration in the brain, suggesting potential therapeutic avenues to explore.

Risk factors of elevated blood ammonia level in epilepsy patients treated with lamotrigine

AbstractThe aim of this study was to explore the effect of lamotrigine (LTG) on blood ammonia level in patients with epilepsy and identify risk factors affecting blood ammonia level. This study included 91 epilepsy patients who were treated with LTG at Department of Neurology, Zhongshan Hospital, Xiamen University from January 2011 to April 2016, and were followed up for 3 years. Blood samples were taken during the interictal state and analyzed for blood LTG and ammonia levels. Total of 46.1% of the samples exceeded the median blood ammonia level, and 2.1% of patients had hyperammonemia. Blood ammonia level was positively correlated with LTG blood concentration. LTG combined with valproic acid therapy, seizure within 1 year, and elevated neutrophils affected blood ammonia level. Blood ammonia level was significantly correlated with plasma concentration of LTG. LTG combined with valproic acid therapy, seizure within 1 year, and elevated neutrophils may be risk factors for elevated blood ammonia level in epilepsy patients treated with LTG.

Overt hepatic encephalopathy is an independent risk factor for de novo infection in cirrhotic patients with acute decompensation

BACKGROUND

The occurrence of overt hepatic encephalopathy (OHE) is associated with increased mortality. HE is commonly precipitated by infection, but whether HE predisposes to new infection is unclear. This study aimed to test if OHE predisposes to de novo infection during hospitalisation and its association with short-term mortality.

AIMS AND METHODS

Seven hundred and fifty-nine consecutive patients were identified at two institutions from prospectively maintained clinical databases of cirrhotic patients admitted with acute decompensation (AD). Infection and HE data were collected on the day of admission, and the occurrence of de novo infections was assessed for 28 days after admission. EASL-CLIF organ failure criteria were used to determine the presence of organ failures. Multivariable analysis using the logistic regression model was used to assess predictors of 28-day mortality and de novo infection.

RESULTS

Patients were divided into four groups; no baseline OHE or infection (n = 352); OHE with no baseline Infection (n = 221); no OHE but baseline infection (n = 100) and OHE with baseline infection (n = 86). On multivariate analyses, OHE (OR, 1.532 [95% CI, 1.061-2.300, P = 0.024]), and admission to ITU (OR, 2.303 [95% CI, 1.508-3.517, P < 0.001]) were independent risk factors for de novo infection. 28-day mortality was 25.3%, 60.2%, 55.0% and 72.1% in the 4-groups respectively. Age, INR and creatinine were independently predictive of mortality. The presence of overt HE, infection, coagulation, kidney, circulatory, respiratory and liver failures were significantly associated with higher mortality.

CONCLUSION

OHE is an independent risk factor for de novo infection in cirrhotic patients with AD.

Hepatic Encephalopathy After TIPS Placement: Predictive Factors, Prevention Strategies, and Management

Hepatic encephalopathy (HE) is a challenging complication after transjugular intrahepatic portosystemic shunt (TIPS) placement. Despite recent advances, much is still uncertain regarding risk factors, preventative measures, and the management of HE after TIPS placement. Appropriate patient selection and pre-procedural risk stratification remain areas of focus. In this manuscript, we discuss the current state of research related to HE after TIPS placement, including information regarding risk stratification, complication prevention, and treatment options.

Wearable Sweat Loss Measuring Devices: From the Role of Sweat Loss to Advanced Mechanisms and Designs

Wearable sweat sensors have received significant research interest and have become popular as sweat contains considerable health information about physiological and psychological states. However, measured biomarker concentrations vary with sweat rates, which has a significant effect on the accuracy and reliability of sweat biosensors. Wearable sweat loss measuring devices (SLMDs) have recently been proposed to overcome the limitations of biomarker tracking and reduce inter- and intraindividual variability. In addition, they offer substantial potential for monitoring human body homeostasis, because sweat loss plays an indispensable role in thermoregulation and skin hydration. Previous studies have not carried out a comprehensive and systematic review of the principles, importance, and development of wearable SLMDs. This paper reviews wearable SLMDs with a new health perspective from the role of sweat loss to advanced mechanisms and designs. Two types of sweat and their measurement significance for practical applications are highlighted. Then, a comprehensive review of advances in different wearable SLMDs based on hygrometers, absorbent materials, and microfluidics is presented by describing their respective device architectures, present situations, and future directions. Finally, concluding remarks on opportunities for future application fields and challenges for future sweat sensing are presented.

Central nervous system and systemic oxidative stress interplay with inflammation in a bile duct ligation rat model of type C hepatic encephalopathy

The role and coexistence of oxidative stress (OS) and inflammation in type C hepatic encephalopathy (C HE) is a subject of intense debate. Under normal conditions the physiological levels of intracellular reactive oxygen species are controlled by the counteracting antioxidant response to maintain redox homeostasis. Our previous in-vivo¹H-MRS studies revealed the longitudinal impairment of the antioxidant system (ascorbate) in a bile-duct ligation (BDL) rat model of type C HE. Therefore, the aim of this work was to examine the course of central nervous system (CNS) OS and systemic OS, as well as to check for their co-existence with inflammation in the BDL rat model of type C HE. To this end, we implemented a multidisciplinary approach, including ex-vivo and in-vitro electron paramagnetic resonance spectroscopy (EPR) spin-trapping, which was combined with UV-Vis spectroscopy, and histological assessments. We hypothesized that OS and inflammation act synergistically in the pathophysiology of type C HE. Our findings point to an increased CNS- and systemic-OS and inflammation over the course of type C HE progression. In particular, an increase in the CNS OS was observed as early as 2-weeks post-BDL, while the systemic OS became significant at week 6 post-BDL. The CNS EPR measurements were further validated by a substantial accumulation of 8-Oxo-2'-deoxyguanosine (Oxo-8-dG), a marker of oxidative DNA/RNA modifications on immunohistochemistry (IHC). Using IHC, we also detected increased synthesis of antioxidants, glutathione peroxidase 1 (GPX-1) and superoxide dismutases (i.e.Cu/ZnSOD (SOD1) and MnSOD (SOD2)), along with proinflammatory cytokine interleukin-6 (IL-6) in the brains of BDL rats. The presence of systemic inflammation was observed already at 2-weeks post-surgery. Thus, these results suggest that CNS OS is an early event in type C HE rat model, which seems to precede systemic OS. Finally, our results suggest that the increase in CNS OS is due to enhanced formation of intra- and extra-cellular ROS rather than due to reduced antioxidant capacity, and that OS in parallel with inflammation plays a significant role in type C HE.

Albumin Substitution in Decompensated Liver Cirrhosis: Don't Forget Zinc

Decompensated liver cirrhosis has a dismal prognosis, with patients surviving on average for 2-4 years after the first diagnosis of ascites. Albumin is an important tool in the therapy of cirrhotic ascites. By virtue of its oncotic properties, it reduces the risk of cardiovascular dysfunction after paracentesis. Treatment with albumin also counteracts the development of hepatorenal syndrome and spontaneous bacterial peritonitis. More recently, the positive impact of long-term albumin supplementation in liver disease, based on its pleiotropic non-oncotic activities, has been recognized. These include transport of endo- and exogenous substances, anti-inflammatory, antioxidant and immunomodulatory activities, and stabilizing effects on the endothelium. Besides the growing recognition that effective albumin therapy requires adjustment of the plasma level to normal physiological values, the search for substances with adjuvant activities is becoming increasingly important. More than 75% of patients with decompensated liver cirrhosis do not only present with hypoalbuminemia but also with zinc deficiency. There is a close relationship between albumin and the essential trace element zinc. First and foremost, albumin is the main carrier of zinc in plasma, and is hence critical for systemic distribution of zinc. In this review, we discuss important functions of albumin in the context of metabolic, immunological, oxidative, transport, and distribution processes, alongside crucial functions and effects of zinc and their mutual dependencies. In particular, we focus on the major role of chronic inflammatory processes in pathogenesis and progression of liver cirrhosis and how albumin therapy and zinc supplementation may affect these processes.

Therapeutic Applications of Resveratrol in Hepatic Encephalopathy through Its Regulation of the Microbiota, Brain Edema, and Inflammation

Hepatic encephalopathy is a common complication in patients with liver cirrhosis and portosystemic shunting. Patients with hepatic encephalopathy present a variety of clinical features, including neuropsychiatric manifestations, cognitive dysfunction, impaired gut barrier function, hyperammonemia, and chronic neuroinflammation. These pathogeneses have been linked to various factors, including ammonia-induced oxidative stress, neuronal cell death, alterations in the gut microbiome, astrocyte swelling, and blood-brain barrier disruptions. Many researchers have focused on identifying novel therapeutics and prebiotics in the hope of improving the treatment of these conditions. Resveratrol is a natural polyphenic compound and is known to exert several pharmacological effects, including antioxidant, anti-inflammatory, and neuroprotective activities. Recent studies suggest that resveratrol contributes to improving the neuropathogenic effects of liver failure. Here, we review the current evidence describing resveratrol's effects in neuropathogenesis and its impact on the gut-liver axis relating to hepatic encephalopathy. We highlight the hypothesis that resveratrol exerts diverse effects in hepatic encephalopathy and suggest that these effects are likely mediated by changes to the gut microbiota, brain edema, and neuroinflammation.

Thioacetamide-induced acute hepatic encephalopathy: central vs peripheral effect of Allicin

Hepatic encephalopathy (HE) is a debilitating and life-threatening disease. Results from acute or chronic liver failure and is characterized by abnormal cerebral and neurological alterations. This study aimed at investigating the effect of allicin, the major functional component in freshly crushed garlic extract, on thioacetamide (TAA)-induced HE in rats. Induction of HE by a single dose of TAA (300 mg/kg; I.P.) was associated with a marked elevation in the serum levels of alanine aminotransferase, aspartate aminotransferase, bilirubin, albumin, total protein, blood urea nitrogen and serum ammonia besides reduction in the serum level of albumin. Moreover, it was accompanied with an increase in the hepatic and brain levels of inflammatory mediators; TNF-α and IL-1β as well as elevation of the hepatic and brain levels of oxidative stress biomarkers; reduced glutathione and lipid peroxidation evidenced by malondialdeyde. Oral administration of allicin (50, 100 and 200 mg/kg; P.O.) for 6 days prior to TAA injection restored the serum liver function, hepatic and brain levels of inflammatory mediators as well as oxidative stress biomarkers in a dose-dependent manner. From our results, it can be concluded that allicin has a protective effect on TAA-induced HE in rats in a dose-dependent manner due to its powerful antioxidant and anti-inflammatory properties.

Hyperammonemia in azotemic cats

OBJECTIVES

Hyperammonemia occurs in cats with hepatobiliary and nutritional (cobalamin and arginine deficiency) disorders, and has also been documented in four cats with renal azotemia. We hypothesized that in cats with renal azotemia, fasting hyperammonemia would correlate with indices of worsening kidney function, and would be independent of cobalamin, potassium, systemic inflammation or urinary tract infection (UTI) with urease-producing bacteria.

METHODS

A fasted blood sample was prospectively collected for ammonia and cobalamin analysis from 18 client-owned cats with renal azotemia (creatinine [Cr] ⩾1.6 mg/dl, urine specific gravity <1.030 or documentation of historical chronic kidney disease [CKD]). Correlations between blood ammonia and selected biochemical parameters were analyzed using Pearson's correlation coefficient.

RESULTS

Seven castrated males and 11 spayed females with a median age of 12 years (range 4-19 years) were enrolled. Ten of 18 (56%) cats presented for acute kidney injury (AKI) or acute on chronic kidney disease (AoCKD), and 8/18 (44%) presented for progressive CKD. The median Cr was 5.9 mg/dl (range 1.9-24.7 mg/dl). Hyperammonemia was documented in 4/18 (22%) cats, with a median of 95 µmol/dl (range 85-98 µmol/dl), and all four of these cats were classified as AKI/AoCKD. Blood ammonia concentrations had a significant moderate positive correlation between blood urea nitrogen (BUN) (r = 0.645, P = 0.003), Cr (r = 0.578, P = 0.012) and serum phosphorus (r = 0.714, P = 0.0009) but not with cobalamin, potassium or white blood cell count. No cats had UTIs with urease-producing bacteria.

CONCLUSIONS AND RELEVANCE

A correlation exists between blood ammonia and BUN, Cr and phosphorus in cats with renal azotemia. Future studies are warranted in a larger population of cats to determine the true prevalence, etiology and potential therapeutic effect of medical management of hyperammonemia on long-term prognosis in cats with kidney disease.

The Association between Hepatic Encephalopathy and Diabetic Encephalopathy: The Brain-Liver Axis

Hepatic encephalopathy (HE) is one of the main consequences of liver disease and is observed in severe liver failure and cirrhosis. Recent studies have provided significant evidence that HE shows several neurological symptoms including depressive mood, cognitive dysfunction, impaired circadian rhythm, and attention deficits as well as motor disturbance. Liver disease is also a risk factor for the development of diabetes mellitus. Diabetic encephalopathy (DE) is characterized by cognitive dysfunction and motor impairment. Recent research investigated the relationship between metabolic changes and the pathogenesis of neurological disease, indicating the importance between metabolic organs and the brain. Given that a diverse number of metabolites and changes in the brain contribute to neurologic dysfunction, HE and DE are emerging types of neurologic disease. Here, we review significant evidence of the association between HE and DE, and summarise the common risk factors. This review may provide promising therapeutic information and help to design a future metabolic organ-related study in relation to HE and DE.

Recent Progress in Wearable Biosensors: From Healthcare Monitoring to Sports Analytics

Recent advances in lab-on-a-chip technology establish solid foundations for wearable biosensors. These newly emerging wearable biosensors are capable of non-invasive, continuous monitoring by miniaturization of electronics and integration with microfluidics. The advent of flexible electronics, biochemical sensors, soft microfluidics, and pain-free microneedles have created new generations of wearable biosensors that explore brand-new avenues to interface with the human epidermis for monitoring physiological status. However, these devices are relatively underexplored for sports monitoring and analytics, which may be largely facilitated by the recent emergence of wearable biosensors characterized by real-time, non-invasive, and non-irritating sensing capacities. Here, we present a systematic review of wearable biosensing technologies with a focus on materials and fabrication strategies, sampling modalities, sensing modalities, as well as key analytes and wearable biosensing platforms for healthcare and sports monitoring with an emphasis on sweat and interstitial fluid biosensing. This review concludes with a summary of unresolved challenges and opportunities for future researchers interested in these technologies. With an in-depth understanding of the state-of-the-art wearable biosensing technologies, wearable biosensors for sports analytics would have a significant impact on the rapidly growing field-microfluidics for biosensing.

The Potential Neuroprotective Role of Citicoline in Hepatic Encephalopathy

Purpose

Hepatic encephalopathy (HE) is described as impaired brain function induced by liver failure. Ammonia is the most suspected chemical involved in brain injury during HE. Although the precise mechanism of HE is not clear, several studies mentioned the role of oxidative stress in ammonia neurotoxicity. In animal models, the use of some compounds with antioxidant properties was reported to reduce the neurotoxic effects of ammonia, improve energy metabolism, and ameliorate the HE symptoms. Citicoline is a principal intermediate in the biosynthesis pathway of phosphatidylcholine that acts as neurovascular protection and repair effects. Various studies mentioned the neuroprotective and antioxidative effects of citicoline in the central nervous system. This study aims to investigate the potential protective effects of citicoline therapeutic in an animal model of HE.

Materials and Methods

Mice received acetaminophen (APAP,1g/kg, i. p.) and then treated with citicoline (500 mg/kg, i.p) one and two hours after APAP. Animals were monitored for locomotor activity and blood and brain ammonia levels. Moreover, markers of oxidative stress were assessed in the brain tissue.

Results

The result of the study revealed that plasma and brain ammonia and the liver injury markers increased, and locomotor activity impaired in the APAP-treated animals. Besides, an increase in markers of oxidative stress was evident in the brain of the APAP-treated mice. It was found that citicoline supplementation enhanced the animal’s locomotor activity and improved brain tissue markers of oxidative stress.

Conclusion

These data propose citicoline as a potential protective agent in HE. The effects of citicoline on oxidative stress markers could play a fundamental role in its neuroprotective properties during HE.

New anthropometric and biochemical models for estimating appendicular skeletal muscle mass in male patients with cirrhosis

OBJECTIVES

The use of easily accessible methods to estimate skeletal muscle mass (SMM) in patients with cirrhosis is often limited by the presence of edema and ascites, precluding a reliable diagnosis of sarcopenia. The aim of this study was to design predictive models using variables derived from anthropometric and/or biochemical measures to estimate SMM; and to validate their applicability in diagnosing sarcopenia in patients with cirrhosis.

METHODS

Anthropometric and biochemical data were obtained from 124 male patients (18-76 y of age) with cirrhosis who also underwent dual-energy x-ray absorptiometry (DXA) and handgrip strength (HGS) assessments to identify low SMM and diagnose sarcopenia using reference cutoff values. Univariate analyses for variable selection were applied to generate predictive decision tree models for low SMM. Model accuracy for the prediction of low SMM and sarcopenia (when associated with HGS) was tested by comparison with reference cutoff values (appendicular SMM index, obtained by DXA) and clinical sarcopenia diagnoses. The prognostic value of the models for the prediction of sarcopenia and mortality at 104 wk of follow up was further tested using Kaplan-Meier graphics and Cox models.

RESULTS

The models with anthropometric variables, alone and combined with biochemical variables, showed good accuracy (0.89 [0.83; 0.94] and 0.90 [0.84; 0.95], respectively) and sensitivity (0.72 [0.56; 0.85] and 0.74 [0.59; 0.86], respectively) and excellent specificity (0.96 [0.90; 0.99] and 0.97 [0.92; 0.99], respectively) in predicting SMM. Both models showed excellent accuracy (0.94 [0.89; 0.98], good sensitivity (0.68 [0.45; 0.86]), and excellent specificity (1.00 [0.96; 1.00]) in predicting sarcopenia. The models predicted mortality in patients with sarcopenia, with the likelihood of death sixfold greater relative to patients not predicted to have sarcopenia.

CONCLUSIONS

Our simple and inexpensive models provided a practical and safe approach to diagnosing sarcopenia patients with cirrhosis along with an estimate of their mortality risk when other reference methods are unavailable.

Is there a link between bacteriuria and a reversible encephalopathy in dogs and cats?

Bacteriuria has been associated with abnormal neurological status in humans, especially geriatric patients. In this report, we review 11 cases (seven dogs and four cats) that suggest an association between bacteriuria and abnormal neurological status in veterinary medicine. These cases showed diffuse forebrain signs with or without brainstem signs, but primary brain disease was excluded by MRI and cerebrospinal fluid analysis. Bacteriological culture of urine was positive in each animal and neurological deficits improved or resolved with initiation of antibiosis ± fluid therapy and levetiracetam. While further studies are needed to definitively confirm or refute the link between bacteriuria and a reversible encephalopathy, urine bacteriological culture should be considered in veterinary patients presented with acute onset forebrain neuro-anatomical localisation, even in the absence of clinical signs of lower urinary tract inflammation.

Brain MR Spectroscopy Markers of Encephalopathy Due to Nonalcoholic Steatohepatitis

BACKGROUND AND PURPOSE

In hepatic encephalopathy (HE), osmotic stressors promoting brain edema result in a compensatory drop in the astrocyte metabolite myo-inositol (mI). Identifying differences between nonalcoholic steatohepatitis (NASH) with and without HE and healthy controls using proton magnetic resonance spectroscopy (MRS) and evaluating hypoalbuminemia and hyperammonemia as osmotic stressors that predict the reduction of mI allow further understanding of mechanisms that promote brain edema in HE. The aim of this study was to assess brain edema in HE using characteristic MRS markers and serum albumin.

METHODS

We evaluated between group differences among 19 NASH cirrhosis without HE (Crhs-HE) (age = 63 ± 8.7), 9 NASH cirrhosis with HE (Crhs+HE) (age = 63 ± 9.2), and 16 controls (age = 57.8 ± 11.7) using ¹ H MRS. Glutamine (Gln/tCr) and serum albumin were evaluated as predictors of myo-inositol (mI/tCr) using linear regression. Statistical significance was set at P < .05 with adjustment for multiple comparisons.

RESULTS

Brain mI/tCr was decreased, and Gln/tCr increased in Crhs+HE compared to Crhs-HE and controls in both brain regions (P < .001 for all). Evaluated together as joint predictors, serum albumin but not Gln/tCr significantly predicted mI/tCr in GM (P = .02 and P = .2, respectively) and PWM (P = .01 and P = .1, respectively).

CONCLUSION

Low mI/tCr and increased Gln/tCr were characteristics of Crhs+HE. Low serum albumin was the strongest predictor of brain osmotic stress indicated by reduced mI/tCr, with no residual independent association seen for brain Gln/tCr concentration. This suggests that hypoalbuminemia in chronic liver disease may promote brain edema in HE.

High-mobility group protein B1: A predictive biomarker for hepatic encephalopathy after transjugular intrahepatic portosystemic shunt

BACKGROUND

The aim of the present study was to investigate whether portal level of high-mobility group protein B1 (HMGB1) is associated with hepatic encephalopathy (HE) after transjugular intrahepatic portosystemic shunt (TIPS).

METHODS

We enrolled 127 consecutive patients who underwent TIPS and collected portal and peripheral blood samples in our department from December 2017 to May 2019. HMGB1 levels were determined using enzyme-linked immunosorbent assay kits. HMGB1 and other HE related parameters were estimated by competing risk analysis, receiver operating characteristic (ROC) analysis and Kaplan-Meier analysis.

RESULTS

Patients with HE after TIPS were older (P = .019) and had higher portal HMGB1 level (P = .038) than those without. Univariate competing risk analysis: age (sHR 1.025, P = .026), hepatorenal syndrome (sHR 3.149, P = .010), model for end-of-stage liver disease (MELD) score (sHR 1.055, P = .024), prior HE (sHR 4.029, P = .0005), portal HMGB1 before TIPS (sHR 1.177, P = .001) reached statistical significance. Multivariate analysis: age (sHR 1.025, P = .037), MELD score (sHR 1.062, P = .011), prior HE (sHR 2.492, P = .030) and portal HMGB1 level before TIPS (sHR 1.217, P = .0002) were significantly different. ROC analyses and Kaplan-Meier curve showed portal HMGB1 level changes before and after TIPS (ΔHMGB1) had good predictive value in the cut-off 0.012 ng/mL (AUC = 0.748, P < .001, Sensitivity = 0.743, Specificity = 0.655).

CONCLUSIONS

Portal HMGB1 may be a therapeutic target for post-TIPS HE.

Important Unresolved Questions in the Management of Hepatic Encephalopathy: An ISHEN Consensus

Management of hepatic encephalopathy (HE) remains challenging from a medical and psychosocial perspective. Members of the International Society for Hepatic Encephalopathy and Nitrogen Metabolism recognized 5 key unresolved questions in HE management focused on (i) driving, (ii) ammonia levels in clinical practice, (iii) testing strategies for covert or minimal HE, (iv) therapeutic options, and (v) nutrition and patient-reported outcomes. The consensus document addresses these topical issues with a succinct review of the literature and statements that critically evaluate the current science and practice, laying the groundwork for future investigations.

Astrocyte swelling in hepatic encephalopathy: molecular perspective of cytotoxic edema

Hepatic encephalopathy (HE) may occur in patients with liver failure. The most critical pathophysiologic mechanism of HE is cerebral edema following systemic hyperammonemia. The dysfunctional liver cannot eliminate circulatory ammonia, so its plasma and brain levels rise sharply. Astrocytes, the only cells that are responsible for ammonia detoxification in the brain, are dynamic cells with unique phenotypic properties that enable them to respond to small changes in their environment. Any pathological changes in astrocytes may cause neurological disturbances such as HE. Astrocyte swelling is the leading cause of cerebral edema, which may cause brain herniation and death by increasing intracranial pressure. Various factors may have a role in astrocyte swelling. However, the exact molecular mechanism of astrocyte swelling is not fully understood. This article discusses the possible mechanisms of astrocyte swelling which related to hyperammonia, including the possible roles of molecules like glutamine, lactate, aquaporin-4 water channel, 18 KDa translocator protein, glial fibrillary acidic protein, alanine, glutathione, toll-like receptor 4, epidermal growth factor receptor, glutamate, and manganese, as well as inflammation, oxidative stress, mitochondrial permeability transition, ATP depletion, and astrocyte senescence. All these agents and factors may be targeted in therapeutic approaches to HE.

Research Note: Comparative gastrointestinal, tibia, and plasma attributes in 48-day-old fast- and slow-growing broiler chicken strains

Emerging market differentiation for broiler meat from strains exhibiting a range of growth rates is necessitating comparative research on various physiological and production aspects of these strains. The objective of the present study was to compare select gastrointestinal, tibial, and plasma attributes in a sample of 48-day-old (50 male and 50 female) broilers obtained from fast-and slow-growing flocks maintained under similar feed and management regimens. Eight birds were randomly selected from a fast (B; representative of modern commercial strains) and each of the 4 slow-growing strains (SG; D, H, M, and E). The strains differed by estimated time to reach 2.2 kg bodyweight corresponding to 36, 50, 42, 44, and 50 D for B, D, H, M, and E, respectively. Blood samples were collected to determine plasma metabolites, and birds were subsequently euthanized, weighed, and necropsied for gizzard and small intestine weight, jejunal tissue for histomorphology, ceca digesta samples for concentration of short-chain fatty acids (SCFA) and left tibia for ash content. Gizzard was heavier (P < 0.01) for D, H, and M than that for B and E, whereas the small intestine was lighter (P < 0.01) for B, D, and H than for M and E. There were no (P > 0.05) strain differences on SCFA, jejunal villus height and crypt depth, plasma proteins, and electrolytes. Strains D, H, and M exhibited higher (P = 0.01) tibia ash concentration than B; E was intermediate and not different (P > 0.05) from any strain. Specifically, the tibia ash for B, D, H, SG 3, and E were 1.24, 1.44, 1.43, 1.49, and 1.39 g/kg BW, respectively. The B birds showed higher (P < 0.01) plasma concentrations of aspartate transaminase, creatine kinase, lactate dehydrogenase, and creatinine than SG strains. In conclusion, although B and some SG strains had lighter gastrointestinal tract indicative of energy efficiency, higher circulating plasma enzymes in B birds suggested impaired hepatic function. Moreover, lower tibia ash in B suggested disproportionate body mass relative to skeletal support.

Neutrophilia is associated with a poorer clinical outcome in dogs with chronic hepatitis

BACKGROUND

Liver disease is a common cause of morbidity and mortality in dogs. Currently, it is challenging to prognosticate in these cases. The aim of this study was to evaluate the utility of the haematological variables in dogs with chronic hepatitis.

METHODS

Dogs with chronic hepatitis confirmed on histopathology had presenting haematological values retrospectively obtained and evaluated against survival time. Eighty-two dogs met the inclusion criteria and their data analysed.

RESULTS

Neutrophilic patients, with a count greater than 12×10⁹/l, controlled for sex and age, had a shorter survival time (P≤0.01). In dogs, neutrophilia at presentation predicted a poor outcome, whereas the other haematological parameters were not prognostically informative. When the dogs were split into even quarters on the basis of their neutrophil count, those within the higher quartiles had poorer survival times. Neutrophilia was associated with a poorer survival time in comparison to those patients with a lower count.

CONCLUSION

The relationship between neutrophils, inflammation and clinical outcome is deserving of future study in dogs with chronic hepatitis.

A Systematic Review and Meta-Analysis Examining the Impact of Sleep Disturbance on Postoperative Delirium

OBJECTIVES

Basic science and clinical studies suggest that sleep disturbance may be a modifiable risk factor for postoperative delirium. We aimed to assess the association between preoperative sleep disturbance and postoperative delirium.

DATA SOURCES

We searched PubMed, Embase, CINAHL, Web of Science, and Cochrane from inception until May 31, 2017.

STUDY SELECTION

We performed a systematic search of the literature for all studies that reported on sleep disruption and postoperative delirium excluding cross-sectional studies, case reports, and studies not reported in English language.

DATA EXTRACTION

Two authors independently performed study selection and data extraction. We calculated pooled effects estimates with a random-effects model constructed in Stata and evaluated the risk of bias by formal testing (Stata Corp V.14, College Station, TX), DATA SYNTHESIS:: We included 12 studies, from 1,238 citations that met our inclusion criteria. The pooled odds ratio for the association between sleep disturbance and postoperative delirium was 5.24 (95% CI, 3.61-7.60; p < 0.001 and I = 0.0%; p = 0.76). The pooled risk ratio for the association between sleep disturbance and postoperative delirium in prospective studies (n = 6) was 2.90 (95% CI, 2.28-3.69; p < 0.001 and I = 0.0%; p = 0.89). The odds ratio associated with obstructive sleep apnea and unspecified types of sleep disorder were 4.75 (95% CI, 2.65-8.54; p < 0.001 and I = 0.0%; p = 0.85) and 5.60 (95% CI, 3.46-9.07; p < 0.001 and I = 0.0%; p = 0.41), respectively. We performed Begg's and Egger's tests for publication bias and confirmed a null result for publication bias (p = 0.371 and 0.103, respectively).

CONCLUSIONS

Preexisting sleep disturbances are likely associated with postoperative delirium. Whether system-level initiatives targeting patients with preoperative sleep disturbance may help reduce the prevalence, morbidity, and healthcare costs associated with postoperative delirium remains to be determined.

Predicting Overt Hepatic Encephalopathy for the Population With Cirrhosis

Hepatic encephalopathy (HE) is associated with poor quality of life, sharply increased mortality, repeated hospitalizations, falls, and motor vehicle accidents. HE manifests with a dynamic spectrum of severity. Overt HE is clinically obvious disorientation, even coma. Although multiple strategies are available to characterize early-stage HE, data are limited that validate these methods in predicting overt HE, many are impractical in clinical practice, and test cutoffs relevant to the average patient clinicians manage are lacking. To accurately and efficiently classify the risk of overt HE in the population with cirrhosis, novel strategies may be needed. Herein, we review the potential competing strategies for the prediction of overt HE. Conclusion: We propose refining diagnostic cutoffs for tests that are designed to define early HE, using overt HE as a gold standard and expanding prediction tools by using measures of components from the risk pathway for HE.

Hepatic Encephalopathy in the Hospitalized Patient: A Review for Hospitalists

Hepatic encephalopathy is a well-recognized complication of decompensated cirrhosis. It is a reversible state of neurocognitive decline, the etiology of which is multifactorial. Diagnosis is predominantly clinical and usually a diagnosis of exclusion. The identification of precipitating factors and their correction is an essential part of the management along with medical therapies such as lactulose and rifaxmin.

Dietary approach and gut microbiota modulation for chronic hepatic encephalopathy in cirrhosis

Hepatic encephalopathy (HE) is a common and serious neuropsychiatric complication of cirrhosis, acute liver failure, and porto-systemic shunting. HE largely contributes to the morbidity of patients with liver disease, severely affecting the quality of life of both patients and their relatives and being associated with poor prognosis. Its presentation is largely variable, manifesting with a broad spectrum of cognitive abnormalities ranging from subtle cognitive impairment to coma. The pathogenesis of HE is complex and has historically been linked with hyperammonemia. However, in the last years, it has become evident that the interplay of multiple actors, such as intestinal dysbiosis, gut hyperpermeability, and neuroinflammation, is of crucial importance in its genesis. Therefore, HE can be considered a result of a dysregulated gut-liver-brain axis function, where cognitive impairment can be reversed or prevented by the beneficial effects induced by "gut-centric" therapies, such as non-absorbable disaccharides, non-absorbable antibiotics, probiotics, prebiotics, and fecal microbiota transplantation. In this context dietary modifications, by modulating the intestinal milieu, can also provide significant benefit to cirrhotic patients with HE. This review will provide a comprehensive insight into the mechanisms responsible for gut-liver-brain axis dysregulation leading to HE in cirrhosis. Furthermore, it will explore the currently available therapies and the most promising future treatments for the management of patients with HE, with a special focus on the dietary approach.

Proline supplementation mitigates the early stage of liver injury in bile duct ligated rats

Background Proline is a proteinogenic amino acid with multiple biological functions. Several investigations have been supposed that cellular proline accumulation is a stress response mechanism. This amino acid acts as an osmoregulator, scavenges free radical species, boosts cellular antioxidant defense mechanisms, protects mitochondria, and promotes energy production. The current study was designed to investigate the effect of proline treatment on the liver in bile duct ligated (BDL) rats as an animal model of cholestasis/cirrhosis. Methods BDL rats were supplemented with proline-containing drinking water (0.25% and 0.5% w:v), and samples were collected at scheduled time intervals (3, 7, 14, 28, and 42 days after BDL surgery). Results Drastic elevation in the serum level of liver injury biomarkers and significant tissue histopathological changes were evident in BDL rats. Markers of oxidative stress were also higher in the liver of BDL animals. It was found that proline supplementation attenuated BDL-induced alteration in serum biomarkers of liver injury, mitigated liver histopathological changes, and alleviated markers of oxidative stress at the early stage of BDL operation (3, 7, and 14 days after BDL surgery). Conclusions The hepatoprotection provided by proline in BDL animals might be associated with its ability to attenuate oxidative stress and its consequences.

Proton pump inhibitor use increases hepatic encephalopathy risk: A systematic review and meta-analysis

BACKGROUND

Several studies have been conducted to explore the association between the use of proton pump inhibitors (PPIs) and hepatic encephalopathy (HE) risk in patients with liver cirrhosis. However, their results are controversial.

AIM

To perform a systematic review and meta-analysis to evaluate the HE risk among PPI users.

METHODS

A systematic search on PubMed, Web of Science, EMBase, and ScienceDirect databases was conducted up to December 31, 2018 for eligible studies involving PPI use and HE risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using the fixed or random effects model. Publication bias was evaluated using Begg’s test, Egger’s test, and trim-and-fill method.

RESULTS

Seven studies with 4574 patients were included in the present meta-analysis. The meta-analysis results indicated a significant association between the PPI use and HE risk (OR = 1.50; 95%CI: 1.25-1.75) with low heterogeneity (I² = 14.2%, P = 0.321). Although publication bias existed when Egger’s tests were used (P = 0.005), the trim-and-fill method verified the stability of the pooled result. Sensitivity analyses suggested that the results of this meta-analysis were robust.

CONCLUSION

The current evidence indicates that PPI use increases HE risk in patients with liver cirrhosis. Further studies with a large data set and well-designed models are needed to validate our findings.

Review of Defective NADPH Oxidase Activity and Myeloperoxidase Release in Neutrophils From Patients With Cirrhosis

Patients with decompensated cirrhosis are highly susceptible to develop bacterial infections and these can trigger multiorgan failure associated with high in-hospital mortality. Neutrophils from patients with decompensated cirrhosis exhibit marked alterations that may explain the susceptibility of these patients to develop bacterial infections. These neutrophil alterations include marked defects in intracellular signaling pathways involving serine/threonine kinases such as protein kinase B (AKT), p38-mitogen-activated protein kinase (MAPK), and the MAP kinases1/2; activation of the NADPH oxidase complex; myeloperoxidase (MPO) release; and bactericidal activity of neutrophils stimulated by the bacterial peptide formyl-Methionine-Leucine-Phenylalanine (fMLF). Impaired activity of the NADPH oxidase 2 (NOX2) complex is also related to reduced levels of expression of its major components through post-transcriptional mechanisms. In addition, the catalytic NOX2 component gp91 ^phox is subject to degradation by elastase highly present in patients' plasma. A defect in the protein kinase B (AKT) and p38 MAPK-mediated signaling pathways may explain the decrease in phosphorylation of p47 ^phox (an important component of the NADPH oxidase complex) and MPO release, in response to neutrophil stimulation by fMLF. Most of these alterations are reversible ex vivo with TLR7/8 agonists (CL097, R848), raising the possibility that these agonists might be used in the future to restore neutrophil antibacterial functions in patients with cirrhosis.

Impaired brain glymphatic flow in experimental hepatic encephalopathy

BACKGROUND & AIMS

Neuronal function is exquisitely sensitive to alterations in the extracellular environment. In patients with hepatic encephalopathy (HE), accumulation of metabolic waste products and noxious substances in the interstitial fluid of the brain is thought to result from liver disease and may contribute to neuronal dysfunction and cognitive impairment. This study was designed to test the hypothesis that the accumulation of these substances, such as bile acids, may result from reduced clearance from the brain.

METHODS

In a rat model of chronic liver disease with minimal HE (the bile duct ligation [BDL] model), we used emerging dynamic contrast-enhanced MRI and mass-spectroscopy techniques to assess the efficacy of the glymphatic system, which facilitates clearance of solutes from the brain. Immunofluorescence of aquaporin-4 (AQP4) and behavioural experiments were also performed.

RESULTS

We identified discrete brain regions (olfactory bulb, prefrontal cortex and hippocampus) of altered glymphatic clearance in BDL rats, which aligned with cognitive/behavioural deficits. Reduced AQP4 expression was observed in the olfactory bulb and prefrontal cortex in HE, which could contribute to the pathophysiological mechanisms underlying the impairment in glymphatic function in BDL rats.

CONCLUSIONS

This study provides the first experimental evidence of impaired glymphatic flow in HE, potentially mediated by decreased AQP4 expression in the affected regions.

LAY SUMMARY

The 'glymphatic system' is a newly discovered brain-wide pathway that facilitates clearance of various substances that accumulate in the brain due to its activity. This study evaluated whether the function of this system is altered in a model of brain dysfunction that occurs in cirrhosis. For the first time, we identified that the clearance of substances from the brain in cirrhosis is reduced because this clearance system is defective. This study proposes a new mechanism of brain dysfunction in patients with cirrhosis and provides new targets for therapy.

Why and when to measure ammonemia in cirrhosis?

Hyperammonemia plays a key role in the pathophysiology of hepatic encephalopathy (HE) and most HE treatments are ammonia-lowering drugs. However, the usefulness of measuring ammonemia in routine practice remains controversial and not recommended systematically even when neurological symptoms are present. First, ammonemia measurement should be carefully performed in order to avoid a falsely elevated result. When performed, a normal ammonemia in a cirrhotic patient with neurological symptoms should lead to reconsider the diagnosis of HE. Indeed, literature data show that most cirrhotic patients with HE have an elevated ammonemia, which is however individually poorly correlated with the severity of symptoms. Nevertheless, elevated ammonemia seems to be a factor of bad prognosis in cirrhosis. A decrease in ammonemia after treatments is well proven but it is not determined whether it is associated with clinical efficacy. Repeated measurements could be useful in this context, especially in non-responders, to help differentiating other causes of encephalopathy, such as drug induced. In acute liver failure, the prognostic value of hyperammonemia is well described and could help an early recognition the most severe forms of this disease. We will also discuss how integrating ammonemia into the diagnostic work-up of liver failure and/or encephalopathy. Ammonemia is also essential to diagnose urea cycle disorders or drug toxicity that both need specific interventions.

Novel spheroid reservoir bioartificial liver improves survival of nonhuman primates in a toxin-induced model of acute liver failure

This study aims to evaluate the effectiveness and safety of the spheroid reservoir bioartificial liver (SRBAL) with porcine hepatocyte organoids in a preclinical nonhuman primate model of acute liver failure (ALF). Methods: Thirty healthy rhesus monkeys were infused with α-amanitin and lipopolysaccharide and randomized into five groups (ALF alone control group; sham no-cell SRBAL treatment group; groups A, B and C with SRBAL treatment started at 12 h, 24 h and 36 h after induction of ALF, respectively). Animals were continuously treated with the SRBAL device for 6 h and followed for up to 336 h. Results: Survival of ALF monkeys improved with hepatocyte SRBAL treatment compared to control groups. Blood ammonia and total bilirubin were lower, and albumin levels were higher in all hepatocyte SRBAL treatment groups. No evidence of porcine endogenous retrovirus was identified in monkey liver or blood after SRBAL treatment. Titers of monkey antibody (IgG, IgM) did not rise after SRBAL treatment. In survival cases, the proportion of necrotic and apoptotic hepatocytes was lower in SRBAL-treated groups, with earlier liver regeneration leading to recovery. Cytokines TNF-α, IL-6, IL-12, IL-1β, IL-8, IFN-γ and IL-2 were ameliorated by the SRBAL treatment, while levels of M-CSF; HGF, EGF and VEGF; IL-1RA and MIF rose on priming, proliferation and the late phase of liver regeneration. Conclusions: The benefit of SRBAL therapy included preventive effects and therapeutic effects. SRBAL improved survival rate and prolonged median survival time in a nonhuman primate model of drug-induced ALF, and these benefits declined with a delay in the initiation of therapy. Improved survival and recovery of ALF monkeys was associated with a reduction in blood ammonia levels, inhibition of the pro-inflammatory response of ALF, and provided a microenvironment more suitable for regeneration of the injured liver.

Resveratrol Restores Neuronal Tight Junction Proteins Through Correction of Ammonia and Inflammation in CCl4-Induced Cirrhotic Mice

Systemic inflammation and ammonia (hyperammonemia) act synergistically in the pathogenesis of hepatic encephalopathy (HE), the neurobehavioral sequelae of advanced liver disease. In cirrhotic patients, we have recently observed elevated levels of circulating neuronal tight junction (TJ) protein, zonula occludens 1 (ZO-1), reflective of a change to blood-brain barrier (BBB) integrity. Moreover, ZO-1 levels positively correlated with hyperammonemia, although any potential relationship remains unclear. Using a carbon tetrachloride (CCl₄)-induced mouse model of cirrhosis, we primarily looked to explore the relationship between neuronal TJ protein expression and hyperammonemia. Secondarily, we assessed the potential role of a natural antioxidant, resveratrol, on neuronal TJ protein expression and hyperammonemia. Over 12 weeks, male Swiss mice were randomized (n = 8/group) to either naïve controls or induced cirrhosis, using two doses of intraperitoneal CCl₄ (0.5 ml/kg/week). After 12 weeks, naïve and cirrhotic mice were randomized to receive either 2 weeks of par-oral resveratrol (10 mg/kg). Plasma samples were analyzed for ammonia, liver biochemistry (ALT, AST, albumin, and bilirubin), and pro-inflammatory cytokines (TNF-α and IL-1β), and brain tissue for brain water content, TJ protein expression (e.g., ZO-1, claudin 5, and occludin), and tissue oxidative stress and inflammatory markers (NF-κB and iNOS) using western blotting. Compared to naïve mice, cirrhosis significantly increased circulating ammonia, brain water, ALT, AST, TNF-α, IL-1β, 4HNE, NF-κB, and iNOS levels, with a concomitant reduction in all TJ proteins (P < 0.05, respectively). In cirrhotic mice, resveratrol treatment ameliorated these changes significantly (P < 0.05, respectively). Our findings provide evidence for a causal association between hyperammonemia and inflammation in cirrhosis linked to TJ protein alterations, BBB disruption, and HE predilection. Moreover, this is the first report of a potential role for resveratrol as a novel therapeutic approach to managing neurological sequelae complicating cirrhosis.

Immunodeficiency caused by cirrhosis

The syndrome of decreased immunity caused by cirrhosis is a combination of different immunological mechanisms and reactions which result from an advanced stage of the liver disease. The synthesis of proteins of the acute phase becomes impaired, there develop different deficiencies of the complement system, and there ensues a decrease of receptors that are meant to recognize antigens. The negative changes become apparent in the field of cell responses, e.g. there are changes in the amounts of generated monocytes and macrophages, and their phagocytic capabilities and chemotaxic reactions are impacted as well. The humoral response results in distorted synthesis of particular antigen categories. The risk of detrimental immunoresponses with the end result of endotoxemia is not rarely coupled with both local and global infections. The combination of the aforesaid immunodeficiencies worsens the healing chances of cirrhosis sufferers and more often than not it increases the mortality of the affected patients.