143 research outputs found

    Long survival of primary diffuse leptomeningeal gliomatosis following radiotherapy and temozolomide: case report and literature review

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    <p>Abstract</p> <p>Objective</p> <p>Primary diffuse leptomeningeal gliomatosis (PDLG) is a rare neoplasm with a short survival time of a few months. there is currently no standardized therapeutic approach for PDLG.</p> <p>Materials and methods</p> <p>We report on a 53-year-old male patient who presented with epileptic seizures, gait disturbance, paraparesis and sensory deficits in the dermatomes T8-10.</p> <p>Results</p> <p>Magnetic resonance imaging (MRI) revealing numerous spinal and cranial gadolinium-enhancing nodules in the meninges and histopathology led us to diagnose primary diffuse leptomeningeal gliomatosis with WHO grade III astrocytic cells. Consecutively, the patient underwent craniospinal radiotherapy (30 Gy) and 11 sequential cycles of temozolomide. This regimen led to partial tumor regression. Thirteen months later, spinal MRI revealed tumor progression. Second-line chemotherapy with 5 cycles of irinotecan and bevacizumab did not prevent further clinical deterioration. The patient died twenty-two months after diagnosis, being the longest survival time described thus far with respect to PDLG consisting of astrocytic tumor cells.</p> <p>Conclusions</p> <p>Radiochemotherapy including temozolomide, as established standard therapy for brain malignant astrocytomas, might be valid as a basic therapeutic strategy for this PDLG subtype.</p

    Comparing adaptive and fixed bandwidth-based kernel density estimates in spatial cancer epidemiology

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    Background: Monitoring spatial disease risk (e.g. identifying risk areas) is of great relevance in public health research, especially in cancer epidemiology. A common strategy uses case-control studies and estimates a spatial relative risk function (sRRF) via kernel density estimation (KDE). This study was set up to evaluate the sRRF estimation methods, comparing fixed with adaptive bandwidth-based KDE, and how they were able to detect ‘risk areas’ with case data from a population-based cancer registry. Methods: The sRRF were estimated within a defined area, using locational information on incident cancer cases and on a spatial sample of controls, drawn from a high-resolution population grid recognized as underestimating the resident population in urban centers. The spatial extensions of these areas with underestimated resident population were quantified with population reference data and used in this study as ‘true risk areas’. Sensitivity and specificity analyses were conducted by spatial overlay of the ‘true risk areas’ and the significant (α=.05) p-contour lines obtained from the sRRF. Results: We observed that the fixed bandwidth-based sRRF was distinguished by a conservative behavior in identifying these urban ‘risk areas’, that is, a reduced sensitivity but increased specificity due to oversmoothing as compared to the adaptive risk estimator. In contrast, the latter appeared more competitive through variance stabilization, resulting in a higher sensitivity, while the specificity was equal as compared to the fixed risk estimator. Halving the originally determined bandwidths led to a simultaneous improvement of sensitivity and specificity of the adaptive sRRF, while the specificity was reduced for the fixed estimator. Conclusion: The fixed risk estimator contrasts with an oversmoothing tendency in urban areas, while overestimating the risk in rural areas. The use of an adaptive bandwidth regime attenuated this pattern, but led in general to a higher false positive rate, because, in our study design, the majority of true risk areas were located in urban areas. However, there is a strong need for further optimizing the bandwidth selection methods, especially for the adaptive sRRF.<br

    Detecting cancer clusters in a regional population with local cluster tests and Bayesian smoothing methods: a simulation study

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    Background: There is a rising public and political demand for prospective cancer cluster monitoring. But there is little empirical evidence on the performance of established cluster detection tests under conditions of small and heterogeneous sample sizes and varying spatial scales, such as are the case for most existing population-based cancer registries. Therefore this simulation study aims to evaluate different cluster detection methods, implemented in the open soure environment R, in their ability to identify clusters of lung cancer using real-life data from an epidemiological cancer registry in Germany. Methods: Risk surfaces were constructed with two different spatial cluster types, representing a relative risk of RR = 2.0 or of RR = 4.0, in relation to the overall background incidence of lung cancer, separately for men and women. Lung cancer cases were sampled from this risk surface as geocodes using an inhomogeneous Poisson process. The realisations of the cancer cases were analysed within small spatial (census tracts, N = 1983) and within aggregated large spatial scales (communities, N = 78). Subsequently, they were submitted to the cluster detection methods. The test accuracy for cluster location was determined in terms of detection rates (DR), false-positive (FP) rates and positive predictive values. The Bayesian smoothing models were evaluated using ROC curves. Results: With moderate risk increase (RR = 2.0), local cluster tests showed better DR (for both spatial aggregation scales > 0.90) and lower FP rates (both < 0.05) than the Bayesian smoothing methods. When the cluster RR was raised four-fold, the local cluster tests showed better DR with lower FPs only for the small spatial scale. At a large spatial scale, the Bayesian smoothing methods, especially those implementing a spatial neighbourhood, showed a substantially lower FP rate than the cluster tests. However, the risk increases at this scale were mostly diluted by data aggregation. Conclusion: High resolution spatial scales seem more appropriate as data base for cancer cluster testing and monitoring than the commonly used aggregated scales. We suggest the development of a two-stage approach that combines methods with high detection rates as a first-line screening with methods of higher predictive ability at the second stage.<br

    Prognostic factors in localized Ewing's tumours and peripheral neuroectodermal tumours: the third study of the French Society of Paediatric Oncology (EW88 study)

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    Purpose: (1) To improve survival rates in patients with Ewing's sarcoma (ES) or peripheral neuroectodermal tumours (PNET) using semi-continuous chemotherapy and aiming to peform surgery in all; (2) To identify early prognostic factors to tailor therapy for future studies. Patients and methods One hundred and forty-one patients were entered onto the trial between January 1988 and December 1991. Induction therapy consisted of five courses of Cytoxan, 150 mg/m2 × 7 days, followed by Doxorubicin, 35 mg/m2 i.v on day 8 given at short intervals. Surgery was recommended whenever possible. The delivery of radiation therapy was based on the quality of resection and the histological response to CT. Maintenance chemotherapy consisted of vincristine + actinomycin and cytoxan + doxorubicin. The total duration of therapy was 10 months. Results After a median follow-up of 8.5 years, the projected overall survival at 5 years was 66% and disease-free survival (DFS) was 58%. In patients treated by surgery, only the histological response to CT had an influence on survival: 75% DFS for patients with a good histological response (less than 5% of cells), 48% for intermediate responders and only 20% for poor responders (≥ 30% of cells), P < 0.0001. The initial tumor volume by itself had no influence on DFS in these patients. In contrast, the tumour volume had a strong impact on DFS in patients treated by radiation therapy alone. Age had no impact on outcome. Conclusion Therapeutic trials for localized Ewing's sarcoma should be based on the histological response to chemotherapy or on the tumour volume according to the modality used for local therapy. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Implementing the European guidelines for cardiovascular disease prevention in the primary care setting in Cyprus: Lessons learned from a health care services study

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    <p>Abstract</p> <p>Background</p> <p>Recent guidelines recommend assessment and treatment of the overall risk for cardiovascular disease (CVD) through management of multiple risk factors in patients at high absolute risk. The aim of our study was to assess the level of cardiovascular risk in patients with known risk factors for CVD by applying the SCORE risk function and to study the implications of European guidelines on the use of treatment and goal attainment for blood pressure (BP) and lipids in the primary care of Cyprus.</p> <p>Methods</p> <p>Retrospective chart review of 1101 randomly selected patients with type 2 diabetes mellitus (DM2), or hypertension or hyperlipidemia in four primary care health centres. The SCORE risk function for high-risk regions was used to calculate 10-year risk of cardiovascular fatal event. Most recent values of BP and lipids were used to assess goal attainment to international standards. Most updated medications lists were used to compare proportions of current with recommended antihypertensive and lipid-lowering drug (LLD) users according to European guidelines.</p> <p>Results</p> <p>Implementation of the SCORE risk model labelled overall 39.7% (53.6% of men, 31.3% of women) of the study population as high risk individuals (CVD, DM2 or SCORE ≥5%). The SCORE risk chart was not applicable in 563 patients (51.1%) due to missing data in the patient records, mostly on smoking habits. The LDL-C goal was achieved in 28.6%, 19.5% and 20.9% of patients with established CVD, DM2 (no CVD) and SCORE ≥5%, respectively. BP targets were achieved in 55.4%, 5.6% and 41.9% respectively for the above groups. There was under prescription of antihypertensive drugs, LLD and aspirin for all three high risk groups.</p> <p>Conclusion</p> <p>This study demonstrated suboptimal control and under-treatment of patients with cardiovascular risk factors in the primary care in Cyprus. Improvement of documentation of clinical information in the medical records as well as GPs training for implementation and adherence to clinical practice guidelines are potential areas for further discussion and research.</p

    Massive multiplication of genome and ribosomes in dormant cells (akinetes) of Aphanizomenon ovalisporum (Cyanobacteria)

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    Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in The ISME Journal 6 (2012): 670–679, doi:10.1038/ismej.2011.128.Akinetes are dormancy cells commonly found among filamentous cyanobacteria, many of which are toxic and/or nuisance, bloom-forming species. Development of akinetes from vegetative cells is a process that involves morphological and biochemical modifications. Here we applied a single cell approach to quantify genome and ribosome content of akinetes and vegetative cells in Aphanizomenon ovalisporum (Cyanobacteria). Vegetative cells of A. ovalisporum were naturally polyploid and contained on average 8 genome copies per cell. However, the chromosomal content of akinetes increased up to 450 copies, with an average value of 119 genome copies per akinete, 15 fold higher that in vegetative cells. Based on fluorescence in situ hybridization with a probe targeting 16S rRNA and detection with confocal laser scanning microscopy we conclude that ribosomes accumulated in akinetes to a higher level than that found in vegetative cells. We further present evidence that this massive accumulation of nucleic acids in akinetes is likely supported by phosphate supplied from inorganic polyphosphate bodies that were abundantly present in vegetative cells, but notably absent from akinetes. These results are interpreted in the context of cellular investments for proliferation following long term dormancy, as the high nucleic acid content would provide the basis for extended survival, rapid resumption of metabolic activity and cell division upon germination.Supported by the Gruss Lipper Foundation research award (AS). This study was part of the Joint German-Israeli-Project (FKZ 02WT0985, WR803) funded by the German Ministry of Research and Technology (BMBF) and Israel Ministry of Science and Technology (MOST)

    Genetically enhanced asynapsis of autosomal chromatin promotes transcriptional dysregulation and meiotic failure

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    During meiosis, pairing of homologous chromosomes and their synapsis are essential prerequisites for normal male gametogenesis. Even limited autosomal asynapsis often leads to spermatogenic impairment, the mechanism of which is not fully understood. The present study was aimed at deliberately increasing the size of partial autosomal asynapsis and analysis of its impact on male meiosis. For this purpose, we studied the effect of t12 haplotype encompassing four inversions on chromosome 17 on mouse autosomal translocation T(16;17)43H (abbreviated T43H). The T43H/T43H homozygotes were fully fertile in both sexes, while +/T43H heterozygous males, but not females, were sterile with meiotic arrest at late pachynema. Inclusion of the t12 haplotype in trans to the T43H translocation resulted in enhanced asynapsis of the translocated autosome, ectopic phosphorylation of histone H2AX, persistence of RAD51 foci, and increased gene silencing around the translocation break. Increase was also on colocalization of unsynapsed chromatin with sex body. Remarkably, we found that transcriptional silencing of the unsynapsed autosomal chromatin precedes silencing of sex chromosomes. Based on the present knowledge, we conclude that interference of meiotic silencing of unsynapsed autosomes with meiotic sex chromosome inactivation is the most likely cause of asynapsis-related male sterility
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