182 research outputs found

    Inclusive 2H(3He,t) reaction at 2 GeV

    Full text link
    The inclusive 2H(3He,t) reaction has been studied at 2 GeV for energy transfers up to 500 MeV and scattering angles from 0.25 up to 4 degrees. Data are well reproduced by a model based on a coupled-channel approach for describing the NN and N Delta systems. The effect of final state interaction is important in the low energy part of the spectra. In the delta region, the cross-section is very sensitive to the effects of Delta-N interaction and Delta N - NN process. The latter has also a large influence well below the pion threshold. The calculation underestimates the experimental cross-section between the quasi-elastic and the delta peaks; this is possibly due to projectile excitation or purely mesonic exchange currents.Comment: 9 pages, 9 figures, accepted for publication in EPJ

    Expression of the Na(+)/l(- )symporter (NIS) is markedly decreased or absent in gastric cancer and intestinal metaplastic mucosa of Barrett esophagus

    Get PDF
    BACKGROUND: The sodium/iodide symporter (NIS) is a plasma membrane glycoprotein that mediates iodide (I(-)) transport in the thyroid, lactating breast, salivary glands, and stomach. Whereas NIS expression and regulation have been extensively investigated in healthy and neoplastic thyroid and breast tissues, little is known about NIS expression and function along the healthy and diseased gastrointestinal tract. METHODS: Thus, we investigated NIS expression by immunohistochemical analysis in 155 gastrointestinal tissue samples and by immunoblot analysis in 17 gastric tumors from 83 patients. RESULTS: Regarding the healthy Gl tract, we observed NIS expression exclusively in the basolateral region of the gastric mucin-producing epithelial cells. In gastritis, positive NIS staining was observed in these cells both in the presence and absence of Helicobacter pylori. Significantly, NIS expression was absent in gastric cancer, independently of its histological type. Only focal faint NIS expression was detected in the direct vicinity of gastric tumors, i.e., in the histologically intact mucosa, the expression becoming gradually stronger and linear farther away from the tumor. Barrett mucosa with junctional and fundic-type columnar metaplasia displayed positive NIS staining, whereas Barrett mucosa with intestinal metaplasia was negative. NIS staining was also absent in intestinalized gastric polyps. CONCLUSION: That NIS expression is markedly decreased or absent in case of intestinalization or malignant transformation of the gastric mucosa suggests that NIS may prove to be a significant tumor marker in the diagnosis and prognosis of gastric malignancies and also precancerous lesions such as Barrett mucosa, thus extending the medical significance of NIS beyond thyroid disease

    ELEVATED PHENYLACETIC ACID LEVELS DO NOT CORRELATE WITH ADVERSE EVENTS IN PATIENTS WITH UREA CYCLE DISORDERS OR HEPATIC ENCEPHALOPATHY AND CAN BE PREDICTED BASED ON THE PLASMA PAA TO PAGN RATIO

    Get PDF
    Background Phenylacetic acid (PAA) is the active moiety in sodium phenylbutyrate (NaPBA) and glycerol phenylbutyrate (GPB, HPN-100), both are approved for treatment of urea cycle disorders (UCDs) - rare genetic disorders characterized by hyperammonemia. PAA is conjugated with glutamine in the liver to form phenylacetyleglutamine (PAGN), which is excreted in urine. PAA plasma levels β‰₯500 ΞΌg/dL have been reported to be associated with reversible neurological adverse events (AEs) in cancer patients receiving PAA intravenously. Therefore, we have investigated the relationship between PAA levels and neurological AEs in patients treated with these PAA pro-drugs as well as approaches to identifying patients most likely to experience high PAA levels. Methods The relationship between nervous system AEs, PAA levels and the ratio of plasma PAA to PAGN were examined in 4683 blood samples taken serially from: [1] healthy adults [2], UCD patients β‰₯2 months of age, and [3] patients with cirrhosis and hepatic encephalopathy (HE). The plasma ratio of PAA to PAGN was analyzed with respect to its utility in identifying patients at risk of high PAA values. Results Only 0.2% (11) of 4683 samples exceeded 500 ug/ml. There was no relationship between neurological AEs and PAA levels in UCD or HE patients, but transient AEs including headache and nausea that correlated with PAA levels were observed in healthy adults. Irrespective of population, a curvilinear relationship was observed between PAA levels and the plasma PAA:PAGN ratio, and a ratio > 2.5 (both in ΞΌg/mL) in a random blood draw identified patients at risk for PAA levels > 500 ΞΌg/ml. Conclusions The presence of a relationship between PAA levels and reversible AEs in healthy adults but not in UCD or HE patients may reflect intrinsic differences among the populations and/or metabolic adaptation with continued dosing. The plasma PAA:PAGN ratio is a functional measure of the rate of PAA metabolism and represents a useful dosing biomarker

    Impact Factor: outdated artefact or stepping-stone to journal certification?

    Full text link
    A review of Garfield's journal impact factor and its specific implementation as the Thomson Reuters Impact Factor reveals several weaknesses in this commonly-used indicator of journal standing. Key limitations include the mismatch between citing and cited documents, the deceptive display of three decimals that belies the real precision, and the absence of confidence intervals. These are minor issues that are easily amended and should be corrected, but more substantive improvements are needed. There are indications that the scientific community seeks and needs better certification of journal procedures to improve the quality of published science. Comprehensive certification of editorial and review procedures could help ensure adequate procedures to detect duplicate and fraudulent submissions.Comment: 25 pages, 12 figures, 6 table

    Prevalence of gastro-oesophageal reflux disease symptoms and reflux-associated respiratory symptoms in asthma

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Gastro-oesophageal reflux disease (GORD) symptoms are common in asthma and have been extensively studied, but less so in the Asian continent. Reflux-associated respiratory symptoms (RARS) have, in contrast, been little-studied globally. We report the prevalence of GORD symptoms and RARS in adult asthmatics, and their association with asthma severity and medication use.</p> <p>Methods</p> <p>A cross-sectional analytical study. A validated interviewer-administered GORD scale was used to assess frequency and severity of seven GORD symptoms. Subjects were consecutive asthmatics attending medical clinics. Controls were matched subjects without respiratory symptoms.</p> <p>Results</p> <p>The mean (SD) composite GORD symptom score of asthmatics was significantly higher than controls (21.8 (17.2) versus 12.0 (7.6); <it>P </it>< 0.001) as was frequency of each symptom and RARS. Prevalence of GORD symptoms in asthmatics was 59.4% (95% CI, 59.1%-59.6%) versus 28.5% in controls (95% CI, 29.0% - 29.4%). 36% of asthmatics experienced respiratory symptoms in association with both typical and atypical GORD symptoms, compared to 10% of controls (<it>P </it>< 0.001). An asthmatic had a 3.5 times higher risk of experiencing a GORD symptom after adjusting for confounders (OR 3.5; 95% CI 2.5-5.3). Severity of asthma had a strong dose-response relationship with GORD symptoms. Asthma medication use did not significantly influence the presence of GORD symptoms.</p> <p>Conclusions</p> <p>GORD symptoms and RARS were more prevalent in a cohort of Sri Lankan adult asthmatics compared to non-asthmatics. Increased prevalence of RARS is associated with both typical and atypical symptoms of GORD. Asthma disease and its severity, but not asthma medication, appear to influence presence of GORD symptoms.</p

    Viscoelastic Testing and Coagulopathy of Traumatic Brain Injury

    Get PDF
    A unique coagulopathy often manifests following traumatic brain injury, leading the clinician down a difficult decision path on appropriate prophylaxis and therapy. Conventional coagulation assaysβ€”such as prothrombin time, partial thromboplastin time, and international normalized ratioβ€”have historically been utilized to assess hemostasis and guide treatment following traumatic brain injury. However, these plasma-based assays alone often lack the sensitivity to diagnose and adequately treat coagulopathy associated with traumatic brain injury. Here, we review the whole blood coagulation assays termed viscoelastic tests and their use in traumatic brain injury. Modified viscoelastic tests with platelet function assays have helped elucidate the underlying pathophysiology and guide clinical decisions in a goal-directed fashion. Platelet dysfunction appears to underlie most coagulopathies in this patient population, particularly at the adenosine diphosphate and/or arachidonic acid receptors. Future research will focus not only on the utility of viscoelastic tests in diagnosing coagulopathy in traumatic brain injury, but also on better defining the use of these tests as evidence-based and/or precision-based tools to improve patient outcomes

    Myalgic encephalomyelitis/chronic fatigue Syndrome (ME/CFS) : Investigating care practices pointed out to disparities in diagnosis and treatment across European Union

    Get PDF
    ME/CFS is a chronic, complex, multisystem disease that often limits the health and functioning of the affected patients. Diagnosing patients with ME/CFS is a challenge, and many different case definitions exist and are used in clinical practice and research. Even after diagnosis, medical treatment is very challenging. Symptom relief and coping may affect how patients live with their disease and their quality of life. There is no consensus on which diagnostic criteria should be used and which treatment strategies can be recommended for patients. The purpose of the current project was to map the landscape of the Euromene countries in respect of national guidelines and recommendations for case definition, diagnosis and clinical approaches for ME/CFS patients. A 23 items questionnaire was sent out by email to the members of Euromene. The form contained questions on existing guidelines for case definitions, treatment/management of the disease, tests and questionnaires applied, and the prioritization of information for data sampling in research. We obtained information from 17 countries. Five countries reported having national guidelines for diagnosis, and five countries reported having guidelines for clinical approaches. For diagnostic purposes, the Fukuda criteria were most often recommended, and also the Canadian Consensus criteria, the International Consensus Criteria and the Oxford criteria were used. A mix of diagnostic criteria was applied within those countries having no guidelines. Many different questionnaires and tests were used for symptom registration and diagnostic investigation. For symptom relief, pain and anti-depressive medication were most often recommended. Cognitive Behavioral Therapy and Graded Exercise treatment were often recommended as disease management and rehabilitative/palliative strategies. The lack of consistency in recommendations across European countries urges the development of regulations, guidance and standards. The results of this study will contribute to the harmonization of diagnostic criteria and treatment for ME/CFS in Europe

    Genetic and transcriptomic analysis of transcription factor genes in the model halophilic Archaeon: coordinate action of TbpD and TfbA

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Archaea are prokaryotic organisms with simplified versions of eukaryotic transcription systems. Genes coding for the general transcription factors TBP and TFB are present in multiple copies in several Archaea, including <it>Halobacterium </it>sp. NRC-1. Multiple TBP and TFBs have been proposed to participate in transcription of genes via recognition and recruitment of RNA polymerase to different classes of promoters.</p> <p>Results</p> <p>We attempted to knock out all six TBP and seven TFB genes in <it>Halobacterium </it>sp. NRC-1 using the <it>ura</it>3-based gene deletion system. Knockouts were obtained for six out of thirteen genes, <it>tbp</it>CDF and <it>tfb</it>ACG, indicating that they are not essential for cell viability under standard conditions. Screening of a population of 1,000 candidate mutants showed that genes which did not yield mutants contained less that 0.1% knockouts, strongly suggesting that they are essential. The transcriptomes of two mutants, Ξ”<it>tbp</it>D and Ξ”<it>tfb</it>A, were compared to the parental strain and showed coordinate down regulation of many genes. Over 500 out of 2,677 total genes were regulated in the Ξ”<it>tbp</it>D and Ξ”<it>tfb</it>A mutants with 363 regulated in both, indicating that over 10% of genes in both strains require the action of both TbpD and TfbA for normal transcription. Culturing studies on the Ξ”<it>tbp</it>D and Ξ”<it>tfb</it>A mutant strains showed them to grow more slowly than the wild-type at an elevated temperature, 49Β°C, and they showed reduced viability at 56Β°C, suggesting TbpD and TfbA are involved in the heat shock response. Alignment of TBP and TFB protein sequences suggested the expansion of the TBP gene family, especially in <it>Halobacterium </it>sp. NRC-1, and TFB gene family in representatives of five different genera of haloarchaea in which genome sequences are available.</p> <p>Conclusion</p> <p>Six of thirteen TBP and TFB genes of <it>Halobacterium </it>sp. NRC-1 are non-essential under standard growth conditions. TbpD and TfbA coordinate the expression of over 10% of the genes in the NRC-1 genome. The Ξ”<it>tbp</it>D and Ξ”<it>tfb</it>A mutant strains are temperature sensitive, possibly as a result of down regulation of heat shock genes. Sequence alignments suggest the existence of several families of TBP and TFB transcription factors in <it>Halobacterium </it>which may function in transcription of different classes of genes.</p

    The Digital Fish Library: Using MRI to Digitize, Database, and Document the Morphological Diversity of Fish

    Get PDF
    Museum fish collections possess a wealth of anatomical and morphological data that are essential for documenting and understanding biodiversity. Obtaining access to specimens for research, however, is not always practical and frequently conflicts with the need to maintain the physical integrity of specimens and the collection as a whole. Non-invasive three-dimensional (3D) digital imaging therefore serves a critical role in facilitating the digitization of these specimens for anatomical and morphological analysis as well as facilitating an efficient method for online storage and sharing of this imaging data. Here we describe the development of the Digital Fish Library (DFL, http://www.digitalfishlibrary.org), an online digital archive of high-resolution, high-contrast, magnetic resonance imaging (MRI) scans of the soft tissue anatomy of an array of fishes preserved in the Marine Vertebrate Collection of Scripps Institution of Oceanography. We have imaged and uploaded MRI data for over 300 marine and freshwater species, developed a data archival and retrieval system with a web-based image analysis and visualization tool, and integrated these into the public DFL website to disseminate data and associated metadata freely over the web. We show that MRI is a rapid and powerful method for accurately depicting the in-situ soft-tissue anatomy of preserved fishes in sufficient detail for large-scale comparative digital morphology. However these 3D volumetric data require a sophisticated computational and archival infrastructure in order to be broadly accessible to researchers and educators

    Identification and Characterization of Inhibitors of Human Apurinic/apyrimidinic Endonuclease APE1

    Get PDF
    APE1 is the major nuclease for excising abasic (AP) sites and particular 3β€²-obstructive termini from DNA, and is an integral participant in the base excision repair (BER) pathway. BER capacity plays a prominent role in dictating responsiveness to agents that generate oxidative or alkylation DNA damage, as well as certain chain-terminating nucleoside analogs and 5-fluorouracil. We describe within the development of a robust, 1536-well automated screening assay that employs a deoxyoligonucleotide substrate operating in the red-shifted fluorescence spectral region to identify APE1 endonuclease inhibitors. This AP site incision assay was used in a titration-based high-throughput screen of the Library of Pharmacologically Active Compounds (LOPAC1280), a collection of well-characterized, drug-like molecules representing all major target classes. Prioritized hits were authenticated and characterized via two high-throughput screening assays – a Thiazole Orange fluorophore-DNA displacement test and an E. coli endonuclease IV counterscreen – and a conventional, gel-based radiotracer incision assay. The top, validated compounds, i.e. 6-hydroxy-DL-DOPA, Reactive Blue 2 and myricetin, were shown to inhibit AP site cleavage activity of whole cell protein extracts from HEK 293T and HeLa cell lines, and to enhance the cytotoxic and genotoxic potency of the alkylating agent methylmethane sulfonate. The studies herein report on the identification of novel, small molecule APE1-targeted bioactive inhibitor probes, which represent initial chemotypes towards the development of potential pharmaceuticals
    • …
    corecore