105 research outputs found

    Deep neural networks allow expert-level brain meningioma segmentation and present potential for improvement of clinical practice

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    Accurate brain meningioma segmentation and volumetric assessment are critical for serial patient follow-up, surgical planning and monitoring response to treatment. Current gold standard of manual labeling is a time-consuming process, subject to inter-user variability. Fully-automated algorithms for meningioma segmentation have the potential to bring volumetric analysis into clinical and research workflows by increasing accuracy and efficiency, reducing inter-user variability and saving time. Previous research has focused solely on segmentation tasks without assessment of impact and usability of deep learning solutions in clinical practice. Herein, we demonstrate a three-dimensional convolutional neural network (3D-CNN) that performs expert-level, automated meningioma segmentation and volume estimation on MRI scans. A 3D-CNN was initially trained by segmenting entire brain volumes using a dataset of 10,099 healthy brain MRIs. Using transfer learning, the network was then specifically trained on meningioma segmentation using 806 expert-labeled MRIs. The final model achieved a median performance of 88.2% reaching the spectrum of current inter-expert variability (82.6-91.6%). We demonstrate in a simulated clinical scenario that a deep learning approach to meningioma segmentation is feasible, highly accurate and has the potential to improve current clinical practice

    Chemotherapy-Induced Neuronal Maturation in Sinonasal Teratocarcinosarcoma—a Unique Observation

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    Sinonasal teratocarcinosarcoma (SNTCS) is a rare and highly malignant tumour with combined features of a teratoma and carcinosarcoma. We report the first case of a SNTCS in 23 year old male treated with neo-adjuvant chemotherapy followed by cranio-facial resection. The resection specimen displayed cellular maturation in the neuroectodermal component. The patient presented with a short history of nasal obstruction, epistaxis and headache. On imaging, a bone destroying lesion of left paranasal sinuses and nasal cavity was identified. The diagnosis of SNTCS could be offered only on the third biopsy which showed heterogeneous admixture of primitive neuroectodermal, epithelial and mesenchymal elements. An adequate sampling with high index of suspicion is needed to catch hold this rare tumor. Tumor was excised after 4 cycles of neo-adjuvant chemotherapy. On microscopic examination, it showed similar epithelial and mesenchymal components as the pretreatment biopsies. However, the primitive neuroectodermal component displayed extensive neuronal maturation. The undifferentiated neuroectodermal cells were completely absent in the post chemotherapy specimen. This case throws light on the morphologic evidence of chemotherapy induced maturation in the neuroectodermal component within SNTCS, an event hitherto not reported in the literature in case of SNTCS

    Mortality from external causes in Africa and Asia: evidence from INDEPTH Health and Demographic Surveillance System Sites.

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    BACKGROUND: Mortality from external causes, of all kinds, is an important component of overall mortality on a global basis. However, these deaths, like others in Africa and Asia, are often not counted or documented on an individual basis. Overviews of the state of external cause mortality in Africa and Asia are therefore based on uncertain information. The INDEPTH Network maintains longitudinal surveillance, including cause of death, at population sites across Africa and Asia, which offers important opportunities to document external cause mortality at the population level across a range of settings. OBJECTIVE: To describe patterns of mortality from external causes at INDEPTH Network sites across Africa and Asia, according to the WHO 2012 verbal autopsy (VA) cause categories. DESIGN: All deaths at INDEPTH sites are routinely registered and followed up with VA interviews. For this study, VA archives were transformed into the WHO 2012 VA standard format and processed using the InterVA-4 model to assign cause of death. Routine surveillance data also provide person-time denominators for mortality rates. RESULTS: A total of 5,884 deaths due to external causes were documented over 11,828,253 person-years. Approximately one-quarter of those deaths were to children younger than 15 years. Causes of death were dominated by childhood drowning in Bangladesh, and by transport-related deaths and intentional injuries elsewhere. Detailed mortality rates are presented by cause of death, age group, and sex. CONCLUSIONS: The patterns of external cause mortality found here generally corresponded with expectations and other sources of information, but they fill some important gaps in population-based mortality data. They provide an important source of information to inform potentially preventive intervention designs

    Malaria mortality in Africa and Asia: evidence from INDEPTH health and demographic surveillance system sites.

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    BACKGROUND: Malaria continues to be a major cause of infectious disease mortality in tropical regions. However, deaths from malaria are most often not individually documented, and as a result overall understanding of malaria epidemiology is inadequate. INDEPTH Network members maintain population surveillance in Health and Demographic Surveillance System sites across Africa and Asia, in which individual deaths are followed up with verbal autopsies. OBJECTIVE: To present patterns of malaria mortality determined by verbal autopsy from INDEPTH sites across Africa and Asia, comparing these findings with other relevant information on malaria in the same regions. DESIGN: From a database covering 111,910 deaths over 12,204,043 person-years in 22 sites, in which verbal autopsy data were handled according to the WHO 2012 standard and processed using the InterVA-4 model, over 6,000 deaths were attributed to malaria. The overall period covered was 1992-2012, but two-thirds of the observations related to 2006-2012. These deaths were analysed by site, time period, age group and sex to investigate epidemiological differences in malaria mortality. RESULTS: Rates of malaria mortality varied by 1:10,000 across the sites, with generally low rates in Asia (one site recording no malaria deaths over 0.5 million person-years) and some of the highest rates in West Africa (Nouna, Burkina Faso: 2.47 per 1,000 person-years). Childhood malaria mortality rates were strongly correlated with Malaria Atlas Project estimates of Plasmodium falciparum parasite rates for the same locations. Adult malaria mortality rates, while lower than corresponding childhood rates, were strongly correlated with childhood rates at the site level. CONCLUSIONS: The wide variations observed in malaria mortality, which were nevertheless consistent with various other estimates, suggest that population-based registration of deaths using verbal autopsy is a useful approach to understanding the details of malaria epidemiology

    Association between lung function and dyspnoea and its variation in the multinational Burden of Obstructive Lung Disease (BOLD) study

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    Background: Dyspnoea is a common symptom of respiratory disease. However, data on its prevalence in general populations and its association with lung function are limited and are mainly from high-income countries. This study aimed to estimate the prevalence of dyspnoea across several world regions and to investigate the association of dyspnoea with lung function. Methods: Dyspnoea was assessed, and lung function was measured in 25,806 adult participants of the multinational Burden of Obstructive Lung Disease study. Dyspnoea was defined as ≥2 on the modified Medical Research Council (mMRC) dyspnoea scale. The prevalence of dyspnoea was estimated for each of the study sites and compared across countries and world regions. Multivariable logistic regression was used to assess the association of dyspnoea with lung function in each site. Results were then pooled using random-effects meta-analysis. Results: The prevalence of dyspnoea varied widely across sites without a clear geographical pattern. The mean prevalence of dyspnoea was 13.7 % (SD=8.2 %), ranging from 0 % in Mysore (India) to 28.8 % in Nampicuan-Talugtug (Philippines). Dyspnoea was strongly associated with both spirometry restriction (FVC<LLN: OR 2.07, 95 %CI 1.75–2.45) and spirometry airflow obstruction (FEV1/FVC<LLN: OR 3.76, 95 %CI 1.04–4.65). These associations did not significantly differ between sexes, age groups, or smoking history. The association of dyspnoea with airflow obstruction was weaker among obese participants (OR 2.20, 95 %CI 1.61–3.01). Conclusion: The prevalence of dyspnoea varies substantially across the world and is strongly associated with lung function impairment. Using the mMRC scale in epidemiological research should be discussed.info:eu-repo/semantics/publishedVersio

    Proteasome Inhibitors Block DNA Repair and Radiosensitize Non-Small Cell Lung Cancer

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    Despite optimal radiation therapy (RT), chemotherapy and/or surgery, a majority of patients with locally advanced non-small cell lung cancer (NSCLC) fail treatment. To identify novel gene targets for improved tumor control, we performed whole genome RNAi screens to identify knockdowns that most reproducibly increase NSCLC cytotoxicity. These screens identified several proteasome subunits among top hits, including the topmost hit PSMA1, a component of the core 20 S proteasome. Radiation and proteasome inhibition showed synergistic effects. Proteasome inhibition resulted in an 80–90% decrease in homologous recombination (HR), a 50% decrease in expression of NF-κB-inducible HR genes BRCA1 and FANCD2, and a reduction of BRCA1, FANCD2 and RAD51 ionizing radiation-induced foci. IκBα RNAi knockdown rescued NSCLC radioresistance. Irradiation of mice with NCI-H460 xenografts after inducible PSMA1 shRNA knockdown markedly increased murine survival compared to either treatment alone. Proteasome inhibition is a promising strategy for NSCLC radiosensitization via inhibition of NF-κB-mediated expression of Fanconi Anemia/HR DNA repair genes.American Society for Radiation Oncology (Junior Faculty Career Research Training Award)Harvard University. Joint Center for Radiation Therapy (Foundation Grant)Dana-Farber/Harvard Cancer Center (SPORE Developmental Research Project Award in Lung Cancer Research)National Cancer Institute (U.S.) (Award K08CA172354

    Chronic respiratory disease surveys in adults in low- and middle-income countries: a systematic scoping review of methodological approaches and outcomes

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    Background Chronic respiratory diseases (CRDs) contribute significantly towards the global burden of disease, but the true prevalence and burden of these conditions in adults is unknown in the majority of low- and middle-income countries (LMICs). We aimed to identify strategies - in particular the definitions, study designs, sampling frames, instruments, and outcomes - used to conduct prevalence surveys for CRDs in LMICs. The findings will inform a future RESPIRE Four Country ChrOnic Respiratory Disease (4CCORD) study, which will estimate CRD prevalence, including disease burden, in adults in LMICs.Methods We conducted a scoping review to map prevalence surveys conducted in LMICs published between 1995 and 2018. We followed Arksey and O'Malley's six-step framework. The search was conducted in OVID Medline, EMBASE, ISI Web of Science, Global Health, WHO Global Index Medicus and included three domains: CRDs, prevalence and LMICs. After an initial title sift, eight trained reviewers undertook duplicate study selection and data extraction. We charted: country and populations, random sampling strategies, CRD definitions/phenotypes, survey procedure (questionnaires, spirometry, tests), outcomes and assessment of individual, societal and health service burden of disease.Results Of 36 872 citations, 281 articles were included: 132 from Asia (41 from China). Study designs were cross-sectional surveys (n = 260), cohort studies (n = 11) and secondary data analysis (n= 10). The number of respondents in these studies ranged from 50 to 512 891. Asthma was studied in 144 studies, chronic obstructive pulmonary disease (COPD) in 112. Most studies (100/144) based identification of asthma on symptom-based questionnaires. In contrast, COPD diagnosis was typically based on spirometry findings (94/112); 65 used fixed-ratio thresholds, 29 reported fixed-ratio and lower-limit-of-normal values. Only five articles used the term `phenotype'. Most studies used questionnaires derived from validated surveys, most commonly the European Community Respiratory Health Survey (n = 47). The burden/impact of CRD was reported in 33 articles (most commonly activity limitation).Conclusion Surveys remain the most practical approach for estimating prevalence of CRD but there is a need to identify the most predictive questions for diagnosing asthma and to standardise diagnostic criteria.Public Health and primary carePrevention, Population and Disease management (PrePoD

    Why population-based data are crucial to achieving the Sustainable Development Goals.

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    Fast Statistical Alignment

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    We describe a new program for the alignment of multiple biological sequences that is both statistically motivated and fast enough for problem sizes that arise in practice. Our Fast Statistical Alignment program is based on pair hidden Markov models which approximate an insertion/deletion process on a tree and uses a sequence annealing algorithm to combine the posterior probabilities estimated from these models into a multiple alignment. FSA uses its explicit statistical model to produce multiple alignments which are accompanied by estimates of the alignment accuracy and uncertainty for every column and character of the alignment—previously available only with alignment programs which use computationally-expensive Markov Chain Monte Carlo approaches—yet can align thousands of long sequences. Moreover, FSA utilizes an unsupervised query-specific learning procedure for parameter estimation which leads to improved accuracy on benchmark reference alignments in comparison to existing programs. The centroid alignment approach taken by FSA, in combination with its learning procedure, drastically reduces the amount of false-positive alignment on biological data in comparison to that given by other methods. The FSA program and a companion visualization tool for exploring uncertainty in alignments can be used via a web interface at http://orangutan.math.berkeley.edu/fsa/, and the source code is available at http://fsa.sourceforge.net/

    Data Resource Profile: The World Health Organization Study on global AGEing and adult health (SAGE)

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    Population ageing is rapidly becoming a global issue and will have a major impact on health policies and programmes. The World Health Organization's Study on global AGEing and adult health (SAGE) aims to address the gap in reliable data and scientific knowledge on ageing and health in low- and middle-income countries. SAGE is a longitudinal study with nationally representative samples of persons aged 50+ years in China, Ghana, India, Mexico, Russia and South Africa, with a smaller sample of adults aged 18-49 years in each country for comparisons. Instruments are compatible with other large high-income country longitudinal ageing studies. Wave 1 was conducted during 2007-2010 and included a total of 34 124 respondents aged 50+ and 8340 aged 18-49. In four countries, a subsample consisting of 8160 respondents participated in Wave 1 and the 2002/04 World Health Survey (referred to as SAGE Wave 0). Wave 2 data collection will start in 2012/13, following up all Wave 1 respondents. Wave 3 is planned for 2014/15. SAGE is committed to the public release of study instruments, protocols and meta- and micro-data: access is provided upon completion of a Users Agreement available through WHO's SAGE website (www.who.int/healthinfo/systems/sage) and WHO's archive using the National Data Archive application (http://apps.who.int/healthinfo/systems/surveydata
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