502 research outputs found

    Editorial

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    An introduction to this re-launch edition of the journal by the new members of the editorial tea

    Some topics in the theory of supermanifolds

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    We introduce a new type of supermanifold modelled on the whole exterior algebra. The structure of the resulting objects is more simple than supermanifolds previously studied yet still reflects the typical problems in the subject. An analysis of the structure of these objects leads to a greater understanding of the structure of supermanifolds in general. In particular, we are able to give criteria for a supermanifold to admit a vector bundle over its core manifold as a covering manifold. We are also able to identify the vector bundle underlying the z-thickening of a C" manifold as a tensor power of the tangent bundle and to prove that compact supermanifolds admit no embedding.-, into their model spaces. The structure of those supermanifolds defined by the vanishing of G ** functions is also analyzed in depth. Finally, we are able to exhibit supermanifolds that do not admit vector bundles as covering manifolds and we point to the need to investigate the existence of compact simply connected supermanifolds

    Finding Cyclic Redundancy Check Polynomials for Multilevel Systems

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    This letter describes a technique for finding cyclic redundancy check polynomials for systems for transmission over symmetric channels which encode information in multiple voltage levels, so that the resulting redundancy check gives good error protection and is efficient to implement. The codes which we construct have a Hamming distance of 3 or 4. We discuss a way to reduce burst error in parallel transmissions and some tricks for efficient implementation of the shift register for these polynomials. We illustrate our techniques by discussing a particular example where the number of levels is 9, but they are applicable in general

    Impact of age and socioeconomic status on treatment and survival from aggressive lymphoma : a UK population-based study of diffuse large B-cell lymphoma

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    AIM: To examine the influence of patient's age and socio-economic status on treatment and outcome in diffuse large B-cell lymphoma (DLBCL); an aggressive curable cancer, with an incidence rate that increases markedly with age but varies little with socio-economic status. METHODS: Set within a representative UK population of around 4 million, data are from an established patient cohort. This report includes all patients (≥18years) newly diagnosed with DLBCL 2004-2012, with follow-up to February 2015. RESULTS: Of the 2137 patients (median age 70.2 years) diagnosed with denovo DLBCL, 1709 (80%) were treated curatively/intensively and 1161(54.3%) died during follow-up. Five-year overall and relative survival (RS) estimates were 46.2% (95% CI 44.0-48.4%) and 54.6% (52.1%-57.0%) respectively for all patients, and 58.5% (56.1-60.9%) and 67.0% (64.3-69.6%) for intensively treated patients. 96.3% of patients <55 years (366/380) and 96.4% of those with the best performance status (543/563) were treated curatively: 5-year RSs being 77.9% (73.1-82%) and 87.1% (82.5-90.6%) respectively. At the other end of the age/fitness spectrum, 33.3% of those ≥85 years (66/198) and 41.1% with the worst performance (94/225) were treated curatively: the corresponding 5-year RSs being 50.5% (27.1-69.0%) and 22.9% (14.0-33.2%). The proportion of patients whose cancer was fully staged fell with increasing age and worsening performance status. No socio-economic variations with treatment, stage at presentation or outcome were detected. CONCLUSIONS: Performance status is more discriminatory of survival than chronological age, with fitter patients benefiting from treatment across all ages. Socio-economic factors are not predictive of outcome in patients with DLBCL in the UK

    Estimating the prevalence of hematological malignancies and precursor conditions using data from Haematological Malignancy Research Network (HMRN)

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    Objective: Well-established cancer registries that routinely link to death registrations can estimate prevalence directly by counting patients alive at a particular point in time (observed prevalence). Such direct methods can only provide prevalence for the years over which the registry has been operational. Time-defined estimates, including 5- and 10-year prevalence, may however underestimate the total cancer burden, and compared with other cancers, there is a lack of accurate information on the total prevalence of hematological malignancy subtypes. Accordingly, we aimed to estimate prevalence (observed and total prevalence) of hematological malignancies and precursor conditions by clinically meaningful subtypes using data from the UK’s specialist population-based register, the Haematological Malignancy Research Network (www.hmrn.org). Methods: Observed and total prevalences were estimated from 15,810 new diagnoses of hematological malignancies from 2004 to 2011 and followed up to the 31 August 2011 (index data). Observed prevalence was calculated by the counting method, and a method based on modelling incidence and survival was used to estimate total prevalence. Estimates were made according to current disease classification for the HMRN region and for the UK. Results: The overall observed and total prevalence rates were 281.9 and 548.8 per 100,000, respectively; the total number of observed and total prevalent cases in the UK was estimated as 165,841 and 327,818 cases, as expected variation existed by disease subtype reflecting the heterogeneity in underlying disease incidence, survival and age distribution of hematological cancers. Conclusions: This study demonstrates the importance of estimating ‘total’ prevalence rather than ‘observed’ prevalence by current disease classification (ICD-O-3), particularly for subtypes that have a more indolent nature and for those that are curable. Importantly, these analyses demonstrate that relying on observed prevalence alone would result in a significant underestimation of the relative burden of some subtypes. While many of these cases may be considered cured and no longer being actively treated, people in this survivorship phase may have long-term medical needs and accordingly, it is important to provide accurate counts to allow for healthcare planning

    A Generic Model for Follicular Lymphoma: Predicting Cost, Life Expectancy, and Quality-Adjusted-Life-Year Using UK Population–Based Observational Data

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    Objectives To use real-world data to develop a flexible generic decision model to predict cost, life expectancy, and quality-adjusted life-years (QALYs) for follicular lymphoma (FL) in the general patient population. Methods All patients newly diagnosed with FL in the UK’s population-based Haematological Malignancy Research Network (www.hmrn.org) between 2004 and 2011 were followed until 2015 (N = 740). Treatment pathways, QALYs, and costs were incorporated into a discrete event simulation to reflect patient heterogeneity, including age and disease management. Two scenario analyses, based on the latest National Institute for Health and Clinical Excellence (NICE) guidelines (rituximab induction therapy for newly diagnosed asymptomatic patients and rituximab maintenance therapy for patients between treatments), were conducted and their economic impacts were compared to current practice. Results Incidence-based analysis revealed expected average lifetime costs ranging from £6,165 [US7,709]to£63,864[US7,709] to £63,864 [US79,862] per patient, and average life expectancy from 75 days to 17.56 years. Prevalence-based analysis estimated average annual treatment costs of £60–65 million [US75−80million],accountingforapproximately1075-80 million], accounting for approximately 10% of the United Kingdom’s annual National Health Service budget for hematological cancers as a whole. Assuming that treatment effects reported in trials are applicable to all patient groups, scenario analyses for two recent NICE guidelines demonstrated potential annual cost savings for the United Kingdom that ranged with uptake frequency from £0.6 million to £11 million [US0.75-2.75 million]. Conclusions Costs, survival, and QALYs associated with FL vary markedly with patient characteristics and disease management. Allowing the production of more realistic outcomes across the patient population as a whole, our model addresses this heterogeneity and is a useful tool with which to evaluate new technologies/treatments to support healthcare decision makers

    Illness patterns prior to diagnosis of lymphoma : Analysis of UK medical records

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    Background: Increased understanding of the relationship between lymphomas and co-morbidities is likely to provide valuable insights into the natural history of these disorders. Methods: 761 cases with lymphoma (310 diffuse large B-cell [DLBCL]; 226 follicular [FL]; and 225 Hodgkin [HL]) and 761 unaffected age and sex matched controls were recruited and their histories of infection and non-infection diagnoses in primary care records were compared using negative binomial regression. Results: No differences were observed between the infectious illness patterns of DLBCL and FL cases and their matched controls over the 15 years preceding lymphoma diagnosis. A marked excess of infectious illness episodes was recorded for HL cases compared to their controls; evident at least a decade prior to HL diagnosis. For non-infectious consultations an excess of case over control visits emerged 4-6 years before DLBCL and FL diagnosis; no specific co-morbidity associations were found. No case-control differences for non-infectious conditions were apparent for HL. Conclusion: There are substantial variations in patterns of illness prior to diagnosis of the three lymphoma subtypes examined. The excess of infectious diagnoses prior to HL may point to underlying immune abnormality, but there was no suggestion of this for DLBCL and FL where a generalized excess of non-infectious conditions was evident. (C) 2010 Elsevier Ltd. All rights reserved

    Editorial

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    The use of targeted sequencing and flow cytometry to identify patients with a clinically significant monocytosis

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    The diagnosis of chronic myelomonocytic leukaemia (CMML) remains centred on morphology, meaning the distinction from a reactive monocytosis is challenging. Mutational analysis and immunophenotyping have been proposed as potential tools for diagnosis however have not been formally assessed in combination. We aimed to investigate the clinical utility of these technologies by performing targeted sequencing, in parallel to current gold standard techniques, on consecutive samples referred for investigation of monocytosis over a 2-year period (n=283). Results were correlated with the morphological diagnosis and objective outcome measures including overall survival (OS) and longitudinal blood counts. Somatic mutations were detected in 79% of patients, being invariably identified in those with a confirmed diagnosis (99%) though also in 57% of patients with non-diagnostic BM features. The OS in non-diagnostic mutated patients was indistinguishable from those with CMML (p=0.118) and significantly worse than unmutated patients (p=0.0002). On multivariate analysis age, ASXL1, CBL, DNMT3A, NRAS & RUNX1 mutations retained significance. Furthermore, the presence of a mutation was associated with a progressive fall in haemoglobin/platelet levels and increasing monocyte counts compared with mutation negative patients. Of note, the immunophenotypic features of non-diagnostic mutated patients were comparable to CMML patients and the presence of aberrant CD56 was highly specific for detecting a mutation. Overall, somatic mutations are detected at high frequency in patients referred with a monocytosis irrespective of diagnosis. In those without a WHO defined diagnosis, the mutation spectrum, immunophenotypic features and OS are indistinguishable from CMML patients and these patients should be managed as such
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