1,623 research outputs found

    Unicentric Castleman's disease approached as a pancreatic neoplasm: case report and review of literature

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    Castleman's disease is a rare lymphoproliferative disorder. Most cases occur in the mediastinum and the pancreatic localization is uncommon; currently there are only nine reported cases in the literature about peripancreatic localization. We report a case of a 62 years old man with a Castleman's disease mimicking a pancreatic neoplasm

    Microevolution of Helicobacter pylori during prolonged infection of single hosts and within families

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    Our understanding of basic evolutionary processes in bacteria is still very limited. For example, multiple recent dating estimates are based on a universal inter-species molecular clock rate, but that rate was calibrated using estimates of geological dates that are no longer accepted. We therefore estimated the short-term rates of mutation and recombination in Helicobacter pylori by sequencing an average of 39,300 bp in 78 gene fragments from 97 isolates. These isolates included 34 pairs of sequential samples, which were sampled at intervals of 0.25 to 10.2 years. They also included single isolates from 29 individuals (average age: 45 years) from 10 families. The accumulation of sequence diversity increased with time of separation in a clock-like manner in the sequential isolates. We used Approximate Bayesian Computation to estimate the rates of mutation, recombination, mean length of recombination tracts, and average diversity in those tracts. The estimates indicate that the short-term mutation rate is 1.4×10−6 (serial isolates) to 4.5×10−6 (family isolates) per nucleotide per year and that three times as many substitutions are introduced by recombination as by mutation. The long-term mutation rate over millennia is 5–17-fold lower, partly due to the removal of non-synonymous mutations due to purifying selection. Comparisons with the recent literature show that short-term mutation rates vary dramatically in different bacterial species and can span a range of several orders of magnitude

    A Study of the Δ\Delta^--component of the wave-function in light nuclei

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    We have measured cross sections for the (π+,π±p) (\pi^+,\pi^\pm p) reactions on 3H{\rm ^3H}, 4He{\rm ^4He}, 6Li{\rm ^6Li} and 7Li{\rm ^7Li} in quasi-free kinematics at incident pion beam energy 500 MeV. An enhancement of the (π+,πp)(\pi^+,\pi^- p) cross section in this kinematics is observed. If this is interpreted as due to quasi-free scattering from pre-existing Δ\Delta components of the nuclear wave function, the extracted probabilities are in agreement with theoretical expectations.Comment: 3 pages, 3 figures, 1 tabl

    Mycobacterium tuberculosis ribosomal protein S1 (RpsA) and variants with truncated C-terminal end show absence of interaction with pyrazinoic acid.

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    Pyrazinamide (PZA) is an antibiotic used in first- and second-line tuberculosis treatment regimens. Approximately 50% of multidrug-resistant tuberculosis and over 90% of extensively drug-resistant tuberculosis strains are also PZA resistant. Despite the key role played by PZA, its mechanisms of action are not yet fully understood. It has been postulated that pyrazinoic acid (POA), the hydrolyzed product of PZA, could inhibit trans-translation by binding to Ribosomal protein S1 (RpsA) and competing with tmRNA, the natural cofactor of RpsA. Subsequent data, however, indicate that these early findings resulted from experimental artifact. Hence, in this study we assess the capacity of POA to compete with tmRNA for RpsA. We evaluated RpsA wild type (WT), RpsA ∆A438, and RpsA ∆A438 variants with truncations towards the carboxy terminal end. Interactions were measured using Nuclear Magnetic Resonance spectroscopy (NMR), Isothermal Titration Calorimetry (ITC), Microscale Thermophoresis (MST), and Electrophoretic Mobility Shift Assay (EMSA). We found no measurable binding between POA and RpsA (WT or variants). This suggests that RpsA may not be involved in the mechanism of action of PZA in Mycobacterium tuberculosis, as previously thought. Interactions observed between tmRNA and RpsA WT, RpsA ∆A438, and each of the truncated variants of RpsA ∆A438, are reported

    An unusual presentation of Castleman's Disease:a case report

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    BACKGROUND: Castleman's disease (CD), a rare condition of uncertain etiology, involves a massive proliferation of lymphoid tissues and typically presents as mediastinal masses. We describe a patient with CD who presented with diffuse adenopathy involving the inguinal, paratracheal, retroperitoneal, axillary, and pelvic regions. CASE PRESENTATION: Case report describing presentation, work-up, management and clinical course of a patient with Castleman's disease in the setting of a county hospital in metropolitan area. Patient was treated with chemotherapeutic agents. CONCLUSIONS: To our knowledge, this represents the first case of CD involving an HIV-positive patient with a negative Human Herpes Virus (HHV-8) viral panel. Because patients with similar clinical histories are at high risk for the development of non-Hodgkin's lymphoma and Kaposi sarcoma, regular medical surveillance is recommended

    Enriching Business Process Models with Decision Rules

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    Making the right decisions in time is one of the key tasks in every business. In this context, decision theory fosters decision-making based on well-defined decision rules. The latter evaluate a given set of input parameters and utilize evidenced data in order to determine an optimal alternative out of a given set of choices. In particular, decision rules are relevant in the context business processes as well. Contemporary process modeling languages, however, have not incorporated decision theory yet, but mainly consider rather simple, guard-based decisions that refer to process-relevant data. To remedy this drawback, this paper introduces an approach that allows embedding decision problems in business process models and applying decision rules to deal with them. As a major benefit, it becomes possible to automatically determine optimal execution paths during run time

    A descriptive analysis of relations between parents' self-reported smoking behavior and infants' daily exposure to environmental tobacco smoke

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    <p>Abstract</p> <p>Background</p> <p>The aims of the present study were to examine relations between parents' self-reported smoking behavior and infants' daily exposure to environmental tobacco smoke, as assessed by urinary cotinine-to-creatinine ratio (CCR), and to describe the CCR over seven days among infants at home.</p> <p>Methods</p> <p>A convenience sample of 27 households was drawn. Each household had to have at least one daily tobacco smoker and one child up to three years of age. Over a seven-day period, urine samples were obtained from the child daily. To examine relations between parents' self-reported smoking and infants' daily CCR, generalized estimating equation (GEE) analysis was used.</p> <p>Results</p> <p>The data revealed that infants from households with indoor smoking had higher CCRs than infants in households with outdoor smoking. CCRs were higher in girls than in boys. Older infants had lower CCRs than younger infants. Smoking outside the home versus inside the home, infant's gender, and infants' age accounted for 68% of the variance in CCR in a GEE data analysis model. No increase or decrease of CCR over time was found.</p> <p>Conclusion</p> <p>The findings suggest that parents' self-reported smoking indoors at home versus outdoors is predictive of CCR among infants three and younger. Higher CCR concentrations in girls' urine need further examination. Furthermore, significant fluctuations in daily CCR were not apparent in infants over a seven-day time period.</p

    Search for the Decay Υ(1S)γη\Upsilon(1S)\to \gamma\eta^{'}

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    We report on a search for the radiative decay U(1S) -> gamma + eta' in 61.3 pb^-1 of data taken with the CLEO II detector at the Cornell Electron Storage Ring. Three decay chains were investigated, all involving eta' -> pi+ pi- + eta, followed by eta -> gamma + gamma, eta -> pi0 + pi0 + pi0, or eta -> pi+ + pi- + pi0. We find no candidate events in any of the three cases and set a combined upper limit of 1.6 x 10^-5 at 90% C.L., significantly smaller than the previous limit. We compare our result to other radiative U(1S) decays, to radiative J/psi decays, and to theoretical predictions.Comment: 9 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PR

    Flow cytometry can reliably capture gut microbial composition in healthy adults as well as dysbiosis dynamics in patients with aggressive B-cell non-Hodgkin lymphoma

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    Modulation of commensal gut microbiota is increasingly recognized as a promising strategy to reduce mortality in patients with malignant diseases, but monitoring for dysbiosis is generally not routine clinical practice due to equipment, expertise and funding required for sequencing analysis. A low-threshold alternative is microbial diversity profiling by single-cell flow cytometry (FCM), which we compared to 16S rRNA sequencing in human fecal samples and employed to characterize longitudinal changes in the microbiome composition of patients with aggressive B-cell non-Hodgkin lymphoma undergoing chemoimmunotherapy. Diversity measures obtained from both methods were correlated and captured identical trends in microbial community structures, finding no difference in patients' pretreatment alpha or beta diversity compared to healthy controls and a significant and progressive loss of alpha diversity during chemoimmunotherapy. Our results highlight the potential of FCM-based microbiome profiling as a reliable and accessible diagnostic tool that can provide novel insights into cancer therapy-associated dysbiosis dynamics
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