708 research outputs found

    Multiple Stellar Populations in the Globular Cluster omega Centauri as Tracers of a Merger Event

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    The discovery of the Sagittarius dwarf galaxy, which is being tidally disrupted by and merging with the Milky Way, supports the view that the halo of the Galaxy has been built up at least partially by the accretion of similar dwarf systems. The Sagittarius dwarf contains several distinct populations of stars, and includes M54 as its nucleus, which is the second most massive globular cluster associated with the Milky Way. The most massive globular cluster is omega Centauri, and here we report that omega Centauri also has several distinct stellar populations, as traced by red-giant-branch stars. The most metal-rich red-giant-branch stars are about 2 Gyr younger than the dominant metal-poor component, indicating that omega Centauri was enriched over this timescale. The presence of more than one epoch of star formation in a globular cluster is quite surprising, and suggests that omega Centauri was once part of a more massive system that merged with the Milky Way, as the Sagittarius dwarf galaxy is in the process of doing now. Mergers probably were much more frequent in the early history of the Galaxy and omega Centauri appears to be a relict of this era.Comment: 7 pages, 3 figures, Latex+nature.sty (included), To appear in November 4th issue of Natur

    Mesenteric Pseudocyst of the Small Bowel in Gastric Cancer Patient: A Case Report

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    Mesenteric pseudocyst is rare. This term is used to describe the abdominal cystic mass, without the origin of abdominal organ. We presented a case of mesenteric pseudocyst of the small bowel in a 70-year-old man. Esophago-gastro-duodenoscopy showed a 3.5 cm sized excavated lesion on the posterior wall of angle. Endocopic biopsy confirmed a histologic diagnosis of the poorly differentiated adenocarcinoma, which includes the signet ring cell component. Abdominal computed tomography scan showed a focal mucosal enhancement in the posterior wall of angle of the stomach, a 2.4 cm sized enhancing mass on the distal small bowel loop, without distant metastases or ascites in rectal shelf, and multiple gallbladder stones. The patient underwent subtotal gastrectomy with gastroduodenostomy, segmental resection of the small bowel, and cholecystectomy. The final pathological diagnosis was mesenteric pseudocyst. This is the first case report describing incidentally detected mesenteric pseudocyst of the small bowel in gastric cancer patients

    A study of the relationship between clinical phenotypes and plasma iduronate-2-sulfatase enzyme activities in Hunter syndrome patients

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    PurposeMucopolysaccharidosis type II (MPS II or Hunter syndrome) is a rare lysosomal storage disorder caused by iduronate-2-sulfatase (IDS) deficiency. MPS II causes a wide phenotypic spectrum of symptoms ranging from mild to severe. IDS activity, which is measured in leukocyte pellets or fibroblasts, was reported to be related to clinical phenotype by Sukegawa-Hayasaka et al. Measurement of residual plasma IDS activity using a fluorometric assay is simpler than conventional measurements using skin fibroblasts or peripheral blood mononuclear cells. This is the first study to describe the relationship between plasma IDS activity and clinical phenotype of MPS II.MethodsWe hypothesized that residual plasma IDS activity is related to clinical phenotype. We classified 43 Hunter syndrome patients as having attenuated or severe disease types based on clinical characteristics, especially intellectual and cognitive status. There were 27 patients with the severe type and 16 with the attenuated type. Plasma IDS activity was measured by a fluorometric enzyme assay using 4-methylumbelliferyl-α-iduronate 2-sulphate.ResultsPlasma IDS activity in patients with the severe type was significantly lower than that in patients with the attenuated type (P=0.006). The optimal cut-off value of plasma IDS activity for distinguishing the severe type from the attenuated type was 0.63 nmol·4 hr-1·mL-1. This value had 88.2% sensitivity, 65.4% specificity, and an area under receiver-operator characteristics (ROC) curve of 0.768 (ROC curve analysis; P=0.003).ConclusionThese results show that the mild phenotype may be related to residual lysosomal enzyme activity

    Chemotherapy with or without avelumab followed by avelumab maintenance versus chemotherapy alone in patients with previously untreated epithelial ovarian cancer (JAVELIN Ovarian 100): an open-label, randomised, phase 3 trial

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    BACKGROUND: Although most patients with epithelial ovarian cancer respond to frontline platinum-based chemotherapy, around 70% will relapse within 3 years. The phase 3 JAVELIN Ovarian 100 trial compared avelumab (anti-PD-L1 monoclonal antibody) in combination with chemotherapy followed by avelumab maintenance, or chemotherapy followed by avelumab maintenance, versus chemotherapy alone in patients with treatment-naive epithelial ovarian cancer. METHODS: JAVELIN Ovarian 100 was a global, open-label, three-arm, parallel, randomised, phase 3 trial run at 159 hospitals and cancer treatment centres in 25 countries. Eligible women were aged 18 years and older with stage III-IV epithelial ovarian, fallopian tube, or peritoneal cancer (following debulking surgery, or candidates for neoadjuvant chemotherapy), and had an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients were randomly assigned (1:1:1) via interactive response technology to receive chemotherapy (six cycles; carboplatin dosed at an area under the serum-concentration-time curve of 5 or 6 intravenously every 3 weeks plus paclitaxel 175 mg/m2 every 3 weeks or 80 mg/m2 once a week [investigators' choice]) followed by avelumab maintenance (10 mg/kg intravenously every 2 weeks; avelumab maintenance group); chemotherapy plus avelumab (10 mg/kg intravenously every 3 weeks) followed by avelumab maintenance (avelumab combination group); or chemotherapy followed by observation (control group). Randomisation was in permuted blocks of size six and stratified by paclitaxel regimen and resection status. Patients and investigators were masked to assignment to the two chemotherapy groups without avelumab at the time of randomisation until completion of the chemotherapy phase. The primary endpoint was progression-free survival assessed by blinded independent central review in all randomly assigned patients (analysed by intention to treat). Safety was analysed in all patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, NCT02718417. The trial was fully enrolled and terminated at interim analysis due to futility, and efficacy is no longer being assessed. FINDINGS: Between May 19, 2016 and Jan 23, 2018, 998 patients were randomly assigned (avelumab maintenance n=332, avelumab combination n=331, and control n=335). At the planned interim analysis (data cutoff Sept 7, 2018), prespecified futility boundaries were crossed for the progression-free survival analysis, and the trial was stopped as recommended by the independent data monitoring committee and endorsed by the protocol steering committee. Median follow-up for progression-free survival for all patients was 10·8 months (IQR 7·1-14·9); 11·1 months (7·0-15·3) for the avelumab maintenance group, 11·0 months (7·4-14·5) for the avelumab combination group, and 10·2 months (6·7-14·0) for the control group. Median progression-free survival was 16·8 months (95% CI 13·5-not estimable [NE]) with avelumab maintenance, 18·1 months (14·8-NE) with avelumab combination treatment, and NE (18·2 months-NE) with control treatment. The stratified hazard ratio for progression-free survival was 1·43 (95% CI 1·05-1·95; one-sided p=0·99) with the avelumab maintenance regimen and 1·14 (0·83-1·56; one-sided p=0·79) with the avelumab combination regimen, versus control treatment. The most common grade 3-4 adverse events were anaemia (69 [21%] patients in the avelumab maintenance group, 63 [19%] in the avelumab combination group, and 53 [16%] in the control group), neutropenia (91 [28%], 99 [30%], and 88 [26%]), and neutrophil count decrease (49 [15%], 45 [14%], and 59 [18%]). Serious adverse events of any grade occurred in 92 (28%) patients in the avelumab maintenance group, 118 (36%) in the avelumab combination group, and 64 (19%) in the control group. Treatment-related deaths occurred in one (<1%) patient in the avelumab maintenance group (due to atrial fibrillation) and one (<1%) patient in the avelumab combination group (due to disease progression). INTERPRETATION: Although no new safety signals were observed, results do not support the use of avelumab in the frontline treatment setting. Alternative treatment regimens are needed to improve outcomes in patients with advanced epithelial ovarian cancer. FUNDING: Pfizer and Merck KGaA, Darmstadt, Germany

    Fluorescence characterization of clinically-important bacteria

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    Healthcare-associated infections (HCAI/HAI) represent a substantial threat to patient health during hospitalization and incur billions of dollars additional cost for subsequent treatment. One promising method for the detection of bacterial contamination in a clinical setting before an HAI outbreak occurs is to exploit native fluorescence of cellular molecules for a hand-held, rapid-sweep surveillance instrument. Previous studies have shown fluorescence-based detection to be sensitive and effective for food-borne and environmental microorganisms, and even to be able to distinguish between cell types, but this powerful technique has not yet been deployed on the macroscale for the primary surveillance of contamination in healthcare facilities to prevent HAI. Here we report experimental data for the specification and design of such a fluorescence-based detection instrument. We have characterized the complete fluorescence response of eleven clinically-relevant bacteria by generating excitation-emission matrices (EEMs) over broad wavelength ranges. Furthermore, a number of surfaces and items of equipment commonly present on a ward, and potentially responsible for pathogen transfer, have been analyzed for potential issues of background fluorescence masking the signal from contaminant bacteria. These include bedside handrails, nurse call button, blood pressure cuff and ward computer keyboard, as well as disinfectant cleaning products and microfiber cloth. All examined bacterial strains exhibited a distinctive double-peak fluorescence feature associated with tryptophan with no other cellular fluorophore detected. Thus, this fluorescence survey found that an emission peak of 340nm, from an excitation source at 280nm, was the cellular fluorescence signal to target for detection of bacterial contamination. The majority of materials analysed offer a spectral window through which bacterial contamination could indeed be detected. A few instances were found of potential problems of background fluorescence masking that of bacteria, but in the case of the microfiber cleaning cloth, imaging techniques could morphologically distinguish between stray strands and bacterial contamination

    Knowledge of Oral Cancer and Screening Practices of Primary Care Providers at Federally Qualified Health Centers

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    Objectives: Primary care providers (PCPs) who worked in Federally-Qualified Health Centers (FQHC) in Michigan were surveyed to assess their knowledge level and practices related to screening and preventing oral cancer. Methods: A questionnaire was developed with the assistance of dental and medical experts, and revised through focus groups. The questionnaire included one case scenario describing a suspicious oral lesion in a 55-year old female patient, followed by questions assessing PCPs' knowledge level, attitude, opinion, and screening practices for oral cancer. This mail survey was conducted in 2003. Results: Survey response rate was 56.4%. Over 70% of the respondents reported that they screen patients for oral cancer during a routine physical examination. Forty-four percent of PCPs had high knowledge level, based on the scenario questions. Those who had high knowledge level were more likely to be physicians, males, and more likely to perform screening for oral cancer than those with low knowledge level. There was no difference in age and race/ethnicity between high and low knowledge groups. Perceived barriers included (1) lack of education; (2) lack of specialists to refer patients; and (3) lack of reimbursement. Conclusions: The majority of PCPs in this survey had positive attitudes about performing screening for oral cancer. To involve PCPs in screening for oral cancer, oral health programs should focus on providing up-to-date education, setting up a referral system, and providing proper reimbursement.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65814/1/j.1752-7325.2005.tb02806.x.pd

    Intraventricular dyssynchrony in light chain amyloidosis: a new mechanism of systolic dysfunction assessed by 3-dimensional echocardiography

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    <p>Abstract</p> <p>Background</p> <p>Light chain amyloidosis (AL) is a rare but often fatal disease due to intractable heart failure. Amyloid deposition leads to diastolic dysfunction and often preserved ejection fraction. We hypothesize that AL is associated with regional systolic dyssynchrony. The aim is to compare left ventricular (LV) regional synchrony in AL subjects versus healthy controls using 16-segment dyssynchrony index measured from 3-dimension-al (3D) echocardiography.</p> <p>Methods</p> <p>Cardiac 3D echocardiography full volumes were acquired in 10 biopsy-proven AL subjects (60 ± 3 years, 5 females) and 10 healthy controls (52 ± 1 years, 5 females). The LV was subdivided into 16 segments and the time from end-diastole to the minimal systolic volume for each of the 16 segments was expressed as a percent of the cycle length. The standard deviations of these times provided a 16-segment dyssynchrony index (16-SD%). 16-SD% was compared between healthy and AL subjects.</p> <p>Results</p> <p>Left ventricular ejection fraction was comparable (control vs. AL: 62.4 ± 0.6 vs. 58.6 ± 2.8%, p = NS). 16-SD% was significantly higher in AL versus healthy subjects (5.93 ± 4.4 vs. 1.67 ± 0.87%, p = 0.003). 16-SD% correlated with left ventricular mass index (R 0.45, p = 0.04) but not to left ventricular ejection fraction.</p> <p>Conclusion</p> <p>Light chain amyloidosis is associated with left ventricular regional systolic dyssynchrony. Regional dyssynchrony may be an unrecognized mechanism of heart failure in AL subjects.</p

    Development and Clinical Evaluation of a Rapid Serodiagnostic Test for Toxoplasmosis of Cats Using Recombinant SAG1 Antigen

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    Rapid serodiagnostic methods for Toxoplasma gondii infection in cats are urgently needed for effective control of transmission routes toward human infections. In this work, 4 recombinant T. gondii antigens (SAG1, SAG2, GRA3, and GRA6) were produced and tested for the development of rapid diagnostic test (RDT). The proteins were expressed in Escherichia coli, affinity-purified, and applied onto the nitrocellulose membrane of the test strip. The recombinant SAG1 (rSAG1) showed the strongest antigenic activity and highest specificity among them. We also performed clinical evaluation of the rSAG1-loaded RDT in 182 cat sera (55 household and 127 stray cats). The kit showed 0.88 of kappa value comparing with a commercialized ELISA kit, which indicated a significant correlation between rSAG1-loaded RDT and the ELISA kit. The overall sensitivity and specificity of the RDT were 100% (23/23) and 99.4% (158/159), respectively. The rSAG1-loaded RDT is rapid, easy to use, and highly accurate. Thus, it would be a suitable diagnostic tool for rapid detection of antibodies in T. gondii-infected cats under field conditions

    The Transcriptional Repressor TupA in Aspergillus niger Is Involved in Controlling Gene Expression Related to Cell Wall Biosynthesis, Development, and Nitrogen Source Availability.

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    The Tup1-Cyc8 (Ssn6) complex is a well characterized and conserved general transcriptional repressor complex in eukaryotic cells. Here, we report the identification of the Tup1 (TupA) homolog in the filamentous fungus Aspergillus niger in a genetic screen for mutants with a constitutive expression of the agsA gene. The agsA gene encodes a putative alpha-glucan synthase, which is induced in response to cell wall stress in A. niger. Apart from the constitutive expression of agsA, the selected mutant was also found to produce an unknown pigment at high temperatures. Complementation analysis with a genomic library showed that the tupA gene could complement the phenotypes of the mutant. Screening of a collection of 240 mutants with constitutive expression of agsA identified sixteen additional pigment-secreting mutants, which were all mutated in the tupA gene. The phenotypes of the tupA mutants were very similar to the phenotypes of a tupA deletion strain. Further analysis of the tupA-17 mutant and the DeltatupA mutant revealed that TupA is also required for normal growth and morphogenesis. The production of the pigment at 37 degrees C is nitrogen source-dependent and repressed by ammonium. Genome-wide expression analysis of the tupA mutant during exponential growth revealed derepression of a large group of diverse genes, including genes related to development and cell wall biosynthesis, and also protease-encoding genes that are normally repressed by ammonium. Comparison of the transcriptome of up-regulated genes in the tupA mutant showed limited overlap with the transcriptome of caspofungin-induced cell wall stress-related genes, suggesting that TupA is not a general suppressor of cell wall stress-induced genes. We propose that TupA is an important repressor of genes related to development and nitrogen metabolism

    Sample size calculation for microarray experiments with blocked one-way design

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    <p>Abstract</p> <p>Background</p> <p>One of the main objectives of microarray analysis is to identify differentially expressed genes for different types of cells or treatments. Many statistical methods have been proposed to assess the treatment effects in microarray experiments.</p> <p>Results</p> <p>In this paper, we consider discovery of the genes that are differentially expressed among <it>K </it>(> 2) treatments when each set of <it>K </it>arrays consists of a block. In this case, the array data among <it>K </it>treatments tend to be correlated because of block effect. We propose to use the blocked one-way ANOVA <it>F</it>-statistic to test if each gene is differentially expressed among <it>K </it>treatments. The marginal p-values are calculated using a permutation method accounting for the block effect, adjusting for the multiplicity of the testing procedure by controlling the false discovery rate (FDR). We propose a sample size calculation method for microarray experiments with a blocked one-way design. With FDR level and effect sizes of genes specified, our formula provides a sample size for a given number of true discoveries.</p> <p>Conclusion</p> <p>The calculated sample size is shown via simulations to provide an accurate number of true discoveries while controlling the FDR at the desired level.</p
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