Astrocyte Pathophysiology in Liver Disease

Liver disease is one of the major chronic disabilities around the world. It is known that global casualties are increasing because of virus C infection, alcohol consumption, or non-alcoholic circumstances. One of the main derived comorbidities of liver disease is the hepatic encephalopathy (HE), a severe neuropsychological syndrome derived from the acute or chronic liver disease. A key feature accounting for HE symptoms in cirrhotic patients is brain edema, which is triggered by hyperammonemia. In basal conditions, ammonia can be metabolized in the central nervous system (CNS) by astrocytes, which synthetize glutamine using ammonia and glutamate as substrates. In hyperammonemic conditions, astrocytes synthetize large amounts of glutamine generating a hyperosmotic condition, inducing these cells to become swollen in shape, invoking the characteristic symptom clinically manifested in patients with HE, as brain edema; this condition is regulated by water channels called aquaporins (AQPs) and by other molecules such as myoinositol. Experimental evidence suggests that some small non-coding RNAs may regulate AQPs expression both in vivo an in vitro and that some pharmacological interventions improve cognitive impairment in cirrhotic patients. It is undeniable that astrocytes and the different signaling pathways beneath its plasma membrane play a crucial role in liver disease-derived HE and represent some of the novel pharmacological targets to treat comorbidities of the liver disease

High Diversity of vacA and cagA Helicobacter pylori Genotypes in Patients with and without Gastric Cancer

BACKGROUND: Helicobacter pylori is associated with chronic gastritis, peptic ulcers, and gastric cancer. The aim of this study was to assess the topographical distribution of H. pylori in the stomach as well as the vacA and cagA genotypes in patients with and without gastric cancer. METHODOLOGY/PRINCIPAL FINDINGS: Three gastric biopsies, from predetermined regions, were evaluated in 16 patients with gastric cancer and 14 patients with dyspeptic symptoms. From cancer patients, additional biopsy specimens were obtained from tumor centers and margins; among these samples, the presence of H. pylori vacA and cagA genotypes was evaluated. Positive H. pylori was 38% and 26% in biopsies obtained from the gastric cancer and non-cancer groups, respectively (p = 0.008), and 36% in tumor sites. In cancer patients, we found a preferential distribution of H. pylori in the fundus and corpus, whereas, in the non-cancer group, the distribution was uniform (p = 0.003). A majority of the biopsies were simultaneously cagA gene-positive and -negative. The fundus and corpus demonstrated a higher positivity rate for the cagA gene in the non-cancer group (p = 0.036). A mixture of cagA gene sizes was also significantly more frequent in this group (p = 0.003). Ninety-two percent of all the subjects showed more than one vacA gene genotype; s1b and m1 vacA genotypes were predominantly found in the gastric cancer group. The highest vacA-genotype signal-sequence diversity was found in the corpus and 5 cm from tumor margins. CONCLUSION/SIGNIFICANCE: High H. pylori colonization diversity, along with the cagA gene, was found predominantly in the fundus and corpus of patients with gastric cancer. The genotype diversity observed across systematic whole-organ and tumor sampling was remarkable. We find that there is insufficient evidence to support the association of one isolate with a specific disease, due to the multistrain nature of H. pylori infection shown in this work

Minimal hepatic encephalopathy

The term minimal hepatic encephalopathy (MHE) refers to the subtle changes in cognitive function, electrophysiological parameters, cerebral neurochemical/neurotransmitter homeostasis, cerebral blood flow, metabolism, and fluid homeostasis that can be observed in patients with cirrhosis who have no clinical evidence of hepatic encephalopathy; the prevalence is as high as 84% in patients with hepatic cirrhosis. Physician does generally not perceive cirrhosis complications, and neuropsychological tests and another especial measurement like evoked potentials and image studies like positron emission tomography can only make diagnosis. Diagnosis of minimal hepatic encephalopathy may have prognostic and therapeutic implications in cirrhotic patients. The present review pretends to explore the clinic, therapeutic, diagnosis and prognostic aspects of this complication

Salmonella sp Group A: A rare cause of bacterascites. A case report

Bacterascites (BA) is a minimally studied and defined entity. Its prognosis and clinical course are not well defined, and currently there are no management guidelines. We present a rare cause of BA in which Salmonella sp group A was isolated in a 44 year old man with cirrhosis who had diarrhea and fever three days earlier. Treatment with intravenous ceftriaxone was effective

Intestinal flora, probiotics, and cirrhosis

Intestinal microflora constitutes a symbiotic ecosystem in permanent equilibrium, composed mainly of anaerobic bacteria. However, such equilibrium may be altered by daily conditions as drug use or pathologies interfering with intestinal physiology, generating an unfavorable environment for the organism. Besides, there are factors which may cause alterations in the intestinal wall, creating the conditions for translocation or permeation of substances or bacteria. In cirrhotic patients, there are many conditions that combine to alter the amount and populations of intestinal bacteria, as well as the functional capacity of the intestinal wall to prevent the permeation of substances and bacteria. Nowadays, numerous complications associated with cirrhosis have been identified, where such mechanisms could play an important role. There is evidence that some probiotic microorganisms could restore the microbiologic and immunologic equilibrium in the intestinal wall in cirrhotic patients and help in the treatment of complications due to cirrhosis. This article has the objective to review the interactions between intestinal flora, gut permeability, and the actual role of probiotics in the field of cirrhotic patients

Portopulmonary hypertension and hepatopulmonary syndrome: a clinician-oriented overview

Liver disease and portal hypertension can be associated with pulmonary vascular complications, including portopulmonary hypertension (POPH), characterised by an elevated mean pulmonary artery pressure secondary to an increased pulmonary vascular resistance, and hepatopulmonary syndrome (HPS), characterised by hypoxaemia due to pulmonary vasodilatation and shunting. Although clear diagnostic guidelines exist for both conditions on the basis of echocardiography, right heart catheterisation and arterial blood gases, there is considerable variation between centres regarding diagnosis and management of these conditions. Awareness of evaluation and management algorithms for POPH and HPS are critical for optimisation of outcomes in patients with these conditions. Key aspects of management of POPH and HPS include identification of patients likely to benefit from liver transplantation (LTx) and management before and after LTx. Although both disorders may improve after LTx, severe forms of POPH represent a contraindication to LTx. Novel approaches to the treatment of POPH and HPS offer new management options that may expand the pool of transplantable patients and improve overall outcomes