Pyruvic oxime nitrification and copper and nickel resistance by a Cupriavidus pauculus, an active heterotrophic nitrifier-denitrifier.

Heterotrophic nitrifiers synthesize nitrogenous gasses when nitrifying ammonium ion. A Cupriavidus pauculus, previously thought an Alcaligenes sp. and noted as an active heterotrophic nitrifier-denitrifier, was examined for its ability to produce nitrogen gas (N2) and nitrous oxide (N2O) while heterotrophically nitrifying the organic substrate pyruvic oxime [CH3-C(NOH)-COOH]. Neither N2 nor N2O were produced. Nucleotide and phylogenetic analyses indicated that the organism is a member of a genus (Cupriavidus) known for its resistance to metals and its metabolism of xenobiotics. The microbe (a Cupriavidus pauculus designated as C. pauculus strain UM1) was examined for its ability to perform heterotrophic nitrification in the presence of Cu(2+) and Ni(2+) and to metabolize the xenobiotic phenol. The bacterium heterotrophically nitrified well when either 1 mM Cu(2+) or 0.5 mM Ni(2+) was present in either enriched or minimal medium. The organism also used phenol as a sole carbon source in either the presence or absence of 1 mM Cu(2+) or 0.5 mM Ni(2+). The ability of this isolate to perform a number of different metabolisms, its noteworthy resistance to copper and nickel, and its potential use as a bioremediation agent are discussed.

The Spectrum of Sarcina Colonization in the Gastrointestinal Tract of Pediatric and Adolescent Patients.

Introduction. Sarcina organisms are rare, gram-positive, sugar-fermenting cocci, identifiable in tissues only by histologic examination or molecular testing. Since its discovery, the pathogenicity and relevance of Sarcina in the human gastrointestinal tract has remained ill-defined. A recent literature review of 66 reported examples demonstrated the potential for severe complications such as emphysematous gastritis and gastric perforation. In pediatrics, colonization is associated with mucosal alterations and/or gastrointestinal dysmotility/obstruction with variable outcomes, including death secondary to gastric perforation. Yet, the features of Sarcina colonization within the gastrointestinal tract of adolescents are poorly understood and rarely reported. Methods. We present the gastrointestinal histopathological findings and the complete history of 4 pediatric patients with Sarcina colonization at our institution. Additionally a literature review with focus in the keywords "Sarcina" and "gastrointestinal' was performed, and the clinical and histopathological features of all previously reported examples of Sarcina in the gastrointestinal tract of pediatric patients were summarized. Results. All 4 patients had delayed gastric emptying, 3 of them due to neurologic disease, and one with pyloric obstruction due to duodenal ulceration with Helicobacter gastritis. In the 3 patients with available esophageal biopsies, it was associated to esophagitis with increased intraepithelial eosinophils. Conclusion. The potential pathogenicity of Sarcina colonization in the gastrointestinal tract of pediatric patients needs to be reevaluated. Due to potential serious complications, the identification of these organisms in the gastrointestinal tract sample should be reported and warrants further evaluation for possible gastrointestinal dysmotility or other mucosal alterations.

Inhibiting Wnt Signaling Reduces Cholestatic Injury by Disrupting the Inflammatory Axis.

BACKGROUND & AIMS: ß-Catenin, the effector molecule of the Wnt signaling pathway, has been shown to play a crucial role in bile acid homeostasis through direct inhibition of farnesoid X receptor (FXR), which has pleiotropic effects on bile acid homeostasis. We hypothesize that simultaneous suppression of ß-catenin signaling and activation of FXR in a mouse model of cholestasis will reduce injury and biliary fibrosis through inhibition of bile acid synthesis. METHODS: To induce cholestasis, we performed bile duct ligation (BDL) on wild-type male mice. Eight hours after surgery, mice received FXR agonists obeticholic acid, tropifexor, or GW-4064 or Wnt inhibitor Wnt-C59. Severity of cholestatic liver disease and expression of target genes were evaluated after either 5 days or 12 days of treatment. RESULTS: We found that although the FXR agonists worsened BDL-induced injury and necrosis after 5 days, Wnt-C59 did not. After 12 days of BDL, Wnt-C59 treatment, but not GW-4064 treatment, reduced both the number of infarcts and the number of inflammatory cells in liver. RNA sequencing analysis of whole livers revealed a notable suppression of nuclear factor kappa B signaling when Wnt signaling is inhibited. We then analyzed transcriptomic data to identify a cholangiocyte-specific signature in our model and demonstrated that Wnt-C59-treated livers were enriched for genes expressed in quiescent cholangiocytes, whereas genes expressed in activated cholangiocytes were enriched in BDL alone. A similar decrease in biliary injury and inflammation occurred in Mdr2 KO mice treated with Wnt-C59. CONCLUSIONS: Inhibiting Wnt signaling suppresses cholangiocyte activation and disrupts the nuclear factor kappa B-dependent inflammatory axis, reducing cholestatic-induced injury.

Perspectives on Sarcopenia as a Predictor for Outcomes in Pediatric Patients with Chronic Liver Disease.

Sarcopenia, a pathologic deficiency of muscle mass and function, has emerged as an important secondary feature of many chronic disease states. For adults with end stage liver disease, there are multiple mechanisms which contribute to sarcopenia and its presence has proven to be an important predictor of morbidity and mortality. In children, there are only a limited number of reports which investigate the role of sarcopenia in liver disease. These studies, which are discussed and summarized in this review, report small, single-center analyses with dissimilar study cohorts and varying clinical definitions. Still, children meeting the study entry criteria have sarcopenia with a reported prevalence of 24-70%. When assessed, sarcopenia appears to be associated with more severe disease but is independent of the Pediatric End-Stage Liver Disease (PELD) score and does not correlate with age, gender, or traditional anthropometric measures such as weight, height, weight-for-height, or body mass index (BMI). While individual studies may identify sarcopenia as a statistically significant risk factor for certain post-transplant outcomes such as longer ICU stay, longer duration of intubation, repeat operation, development of serious infection, longer hospital stay, death, or long-term growth failure, such associations are not consistently replicated across studies. Finally, although various methods of muscle mass quantification are utilized, the most reported is the total psoas muscle surface area (tPMSA) on computed tomography. This method, along with others such as skeletal muscle area and skeletal muscle index, have had normative values recently defined and these collective efforts should enable researchers a common basis of comparison when delineating sarcopenia, and its impact, across various study populations in future investigations - including in children with liver disease.

Mitochondrial Hepatopathy.

Mitochondrial hepatopathies are a subset of mitochondrial diseases defined by primary dysfunction of hepatocyte mitochondria leading to a phenotype of hepatocyte cell injury, steatosis, or liver failure. Increasingly, the diagnosis is established by new sequencing approaches that combine analysis of both nuclear DNA and mitochondrial DNA and allow for timely diagnosis in most patients. Despite advances in diagnostics, for most affected children their disorders are relentlessly progressive, and result in substantial morbidity and mortality. Treatment remains mainly supportive; however, novel therapeutics and a more definitive role for liver transplantation hold promise for affected children.

Changes in beta-catenin expression and activation during progression of primary sclerosing cholangitis predict disease recurrence.

Primary sclerosing cholangitis (PSC) is a rare, chronic, cholestatic liver disease characterized by progressive inflammation and fibrosis of the bile ducts. We have previously demonstrated the importance of Wnt/ß-catenin signaling in mouse models of PSC. In this study, we wished to determine the clinical relevance of ß-catenin localization in patient samples. In livers explanted from patients diagnosed with PSC, the majority (12/16; 75%) lacked ß-catenin protein expression. Biopsies from patients post-transplant were classified as recurrent or non-recurrent based on pathology reports and then scored for ß-catenin activation as a function of immunohistochemical localization. Despite lack of statistical significance, patients with recurrent primary disease (n = 11) had a greater percentage of samples with nuclear, transcriptionally active ß-catenin (average 58.8%) than those with no recurrence (n = 10; 40.53%), while non-recurrence is correlated with ß-catenin staining at the cell surface (average 52.63% for non-recurrent vs. 27.34% for recurrent), as determined by three different methods of analysis. ß-catenin score and years-to-endpoint are both strongly associated with recurrence status (p = 0.017 and p = 0.00063, respectively). Finally, there was significant association between higher ß-catenin score and increased alkaline phosphatase, a marker of biliary injury and disease progression. Thus, ß-catenin expression and activation changes during the progression of PSC, and its localization may be a useful prognostic tool for predicting recurrence of this disease.

Health-related quality-of-life evaluation of crohn disease patients after receiving natalizumab therapy.

Crohn disease (CD) is a chronic inflammatory condition without a permanent medical cure and commonly requiring a lifetime of care. This article discusses the impact of natalizumab induction and maintenance therapy on the health-related quality of life (HRQoL) of CD patients. Two natalizumab phase III studies were evaluated: the Efficacy of Natalizumab in Crohn's Disease Response and Remission (ENCORE) study evaluated the HRQoL of CD patients during 12 weeks of natalizumab induction therapy, and the Evaluation of Natalizumab As Continuous Therapy (ENACT-2) trial evaluated the effect of natalizumab maintenance therapy on HRQoL for a period of 48 weeks past a 12-week induction period (ENACT-1). HRQoL assessments were made with the Inflammatory Bowel Disease Questionnaire (IBDQ) and the Short Form-36 (SF-36). In the ENCORE study, induction therapy with natalizumab was demonstrated to significantly increase HRQoL scores at 12 weeks when compared with patients on placebo. During the ENACT-2 trial, IBDQ and SF-36 scale scores of patients who responded to natalizumab induction remained stable whereas those on placebo worsened. At week 60, the mean change from baseline on all scales of the IBDQ and the SF-36 were significantly higher for those who continued to receive natalizumab as compared to those who received placebo (p

Expanding etiology of progressive familial intrahepatic cholestasis.

BACKGROUND: Progressive familial intrahepatic cholestasis (PFIC) refers to a disparate group of autosomal recessive disorders that are linked by the inability to appropriately form and excrete bile from hepatocytes, resulting in a hepatocellular form of cholestasis. While the diagnosis of such disorders had historically been based on pattern recognition of unremitting cholestasis without other identified molecular or anatomic cause, recent scientific advancements have uncovered multiple specific responsible proteins. The variety of identified defects has resulted in an ever-broadening phenotypic spectrum, ranging from traditional benign recurrent jaundice to progressive cholestasis and end-stage liver disease. AIM: To review current data on defects in bile acid homeostasis, explore the expanding knowledge base of genetic based diseases in this field, and report disease characteristics and management. METHODS: We conducted a systemic review according to PRISMA guidelines. We performed a Medline/PubMed search in February-March 2019 for relevant articles relating to the understanding, diagnosis, and management of bile acid homeostasis with a focus on the family of diseases collectively known as PFIC. English only articles were accessed in full. The manual search included references of retrieved articles. We extracted data on disease characteristics, associations with other diseases, and treatment. Data was summarized and presented in text, figure, and table format. RESULTS: Genetic-based liver disease resulting in the inability to properly form and secrete bile constitute an important cause of morbidity and mortality in children and increasingly in adults. A growing number of PFIC have been described based on an expanded understanding of biliary transport mechanism defects and the development of a common phenotype. CONCLUSION: We present a summary of current advances made in a number of areas relevant to both the classically described FIC1 (ATP8B1), BSEP (ABCB11), and MDR3 (ABCB4) transporter deficiencies, as well as more recently described gene mutations -- TJP2 (TJP2), FXR (NR1H4), MYO5B (MYO5B), and others which expand the etiology and understanding of PFIC-related cholestatic diseases and bile transport.

Multispecialty Opioid Risk Reduction Program Targeting Chronic Pain and Addiction Management in Veterans.

A primary care pain clinic and telehealth program manages veterans at high-risk for noncancer chronic pain and addiction, offering education and support to multidisciplinary health care providers to reduce dependence on high-level opioids.