45 research outputs found

    Systems comparison of direct and relay link data return modes for advanced planetary missions

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    Advanced planetary missions using direct and relay link data return mode

    Risk Factors for Neurocognitive Functioning in Children with Autosomal Recessive Polycystic Kidney Disease

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    This mini review provides an overview of the issues and challenges inherent in autosomal recessive polycystic kidney disease (ARPKD), with a particular focus on the neurological factors and neurocognitive functioning of this population. ARPKD typically is discovered at the end of pregnancy or during the neonatal developmental period and occurs in approximately 1 in 20,000 live births. During the neonatal period, there is a relatively high risk of death, with many infants dying from respiratory failure. As the child ages, they experience progressive kidney disease and become increasingly vulnerable to liver disease, with many individuals eventually requiring dual organ transplants. This mini review provides a brief description of ARPKD and describes the various factors that place children with ARPKD at risk for neurological and neuropsychological impairment (e.g., a genetic condition leading to chronic kidney disease and eventual transplant; difficult-to-treat hypertension; eventual liver disease; possible dual transplantation of the kidneys and liver; chronic lung disease), including that these factors are present during a critical period of brain development. Further, the mini review discusses the available studies that have addressed the neurocognitive functioning in children with ARPKD. This paper concludes by providing the key clinical and research challenges that face the field of pediatric nephrology with respect to the clinical and scientific study of the neurocognitive functioning of children with ARPKD. Selected directions are offered in both the clinical and research arenas for this multiorgan chronic condition

    Outcome in patients with cystic fibrosis liver disease

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    AbstractBackgroundLiver disease is an important complication in CF.AimsTo determine if CFLD is a risk factor for mortality in CF, and which baseline characteristics predict all-cause mortality.MethodsIrish children with CFLD, and their age and gender matched controls were enrolled at baseline and reviewed after 10years to determine which characteristics predict mortality.Results72/84 (85.71%) participants were followed, (mean age Cases 21.71yrs SD 6.5, CF controls 23.62 SD 5.6, 22 (61%) males), with no difference in duration of follow-up. Nineteen participants (26.4%) died, 38.9% (14/36) with CFLD and 13.89% (5/36) CF controls (Odds Ratio (OR) 3.94 95% CI:1.23–12.56 p=0.005). In logistic regression, liver disease (OR 4.28 95% CI 1.07–17.16) female gender (OR 12.25 95% CI 2.37–63.24), reduced pulmonary function, (OR 5.11 95% CI 1.09–23.81) were each independent risk factors for mortality in CF.ConclusionsLiver disease is an independent risk factor for mortality in CF

    NADPH oxidase-derived H2O2 subverts pathogen signaling by oxidative phosphotyrosine conversion to PB-DOPA

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    Strengthening the host immune system to fully exploit its potential as antimicrobial defense is vital in countering antibiotic resistance. Chemical compounds released during bidirectional host–pathogen cross-talk, which follows a sensing-response paradigm, can serve as protective mediators. A potent, diffusible messenger is hydrogen peroxide (H(2)O(2)), but its consequences on extracellular pathogens are unknown. Here we show that H(2)O(2), released by the host on pathogen contact, subverts the tyrosine signaling network of a number of bacteria accustomed to low-oxygen environments. This defense mechanism uses heme-containing bacterial enzymes with peroxidase-like activity to facilitate phosphotyrosine (p-Tyr) oxidation. An intrabacterial reaction converts p-Tyr to protein-bound dopa (PB-DOPA) via a tyrosinyl radical intermediate, thereby altering antioxidant defense and inactivating enzymes involved in polysaccharide biosynthesis and metabolism. Disruption of bacterial signaling by DOPA modification reveals an infection containment strategy that weakens bacterial fitness and could be a blueprint for antivirulence approaches

    Cj1411c Encodes for a Cytochrome P450 Involved in Campylobacter jejuni 81-176 Pathogenicity

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    Cytochrome P450s are b-heme-containing enzymes that are able to introduce oxygen atoms into a wide variety of organic substrates. They are extremely widespread in nature having diverse functions at both biochemical and physiological level. The genome of C. jejuni 81-176 encodes a single cytochrome P450 (Cj1411c) that has no close homologues. Cj1411c is unusual in its genomic location within a cluster involved in the biosynthesis of outer surface structures. Here we show that E. coli expressed and affinity-purified C. jejuni cytochrome P450 is lipophilic, containing one equivalent Cys-ligated heme. Immunoblotting confirmed the association of cytochrome P450 with membrane fractions. A Cj1411c deletion mutant had significantly reduced ability to infect human cells and was less able to survive following exposure to human serum when compared to the wild type strain. Phenotypically following staining with Alcian blue, we show that a Cj1411c deletion mutant produces significantly less capsular polysaccharide. This study describes the first known membrane-bound bacterial cytochrome P450 and its involvement in Campylobacter virulence

    Irish cardiac society - Proceedings of annual general meeting held 20th & 21st November 1992 in Dublin Castle

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    Crohn’s Strictures—Moving Away from the Knife

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    Crohn’s disease (CD) is a lifelong inflammatory bowel disease with a rapidly rising incidence in the pediatric population. A common complication of CD is the development of fibrotic strictures, which may be present at initial diagnosis or develop many years later. Clinical presentation depends on stricture location and degree of obstruction, and strictures frequently contain a mixture of inflammatory and fibrotic tissue. Histological examination of Crohn’s strictures shows thickening of the muscular layers and the submucosa, where increased collagen deposition by activated myofibroblasts is concentrated around islands of smooth muscle cells and at the superficial margin of the muscularis propria. No antifibrotic therapies for Crohn’s strictures exist. Profibrotic transforming growth factor-β (TGFβ)/bone morphogenetic protein signaling stimulates myofibroblast differentiation and extracellular matrix deposition. Understanding and targeting TGFβ1 downstream signaling is the main focus of current research, raising the possibility of specific antifibrotic therapy in CD becoming available in the future

    Will Treatment of Helicobacter Pylori Infection in Childhood Alter the Risk of Developing Gastric Cancer?

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    Helicobacter pylori has been classified as a group 1 carcinogen for gastric cancer. It is estimated that there is between a two- and sixfold increase in the risk of developing gastric cancer among infected patients. Among different populations, the risk of H pylori-infected individuals developing gastric cancer varies greatly. However, on a worldwide scale, gastric cancer is the second most common cause of cancer-related death. Therefore, H pylori eradication could help prevent up to three to four million gastric cancer deaths per year. H pylori is usually acquired in childhood. Because infected children have not harboured the organism for long enough to have developed precancerous lesions, childhood is theoretically an attractive time for H pylori eradication and, thus, could help prevent gastric cancer later in life. However, as H pylori prevalence and the incidence of gastric cancer are falling rapidly in developed nations, widespread population screening programs aimed at the eradication of H pylori in these countries would be enormously expensive. Therefore, except in groups with a high risk for development of gastric cancer (eg, Japanese or those with a strong positive family history of gastric cancer), a population-based test-and-treat policy is not justified

    The Most Beautiful Girl

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