168 research outputs found

    Innovations in the Art of Microneurosurgery for Reaching Deep-Seated Cerebral Lesions

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    Deep-seated cerebral lesions have fascinated and frustrated countless surgical innovators since the dawn of the microneurosurgical era. To determine the optimal approach, the microneurosurgeon must take into account the characteristics and location of the pathological lesion as well as the operator’s range of technical expertise. Increasingly, microneurosurgeons must select between multiple operative corridors that can access to the surgical target. Innovative trajectories have emerged for many indications that provide more flexible operative angles and superior exposure but result in longer working distances and more technically demanding maneuvers. In this article, we highlight 4 innovative surgical corridors and compare their strengths and weaknesses against those of more conventional approaches. Our goal is to use these examples to illustrate the following principles of microneurosurgical innovation: (1) discover more efficient and flexible exposures with superior working angles; (2) ensure maximal early protection of critical neurovascular structures; and (3) effectively handle target pathology with minimal disruption of normal tissues

    Virtual Exploration of Safe Entry Zones in the Brainstem: Comprehensive Definition and Analysis of the Operative Approach

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    Background Detailed and accurate understanding of intrinsic brainstem anatomy and the inter-relationship between its internal tracts and nuclei and external landmarks is of paramount importance for safe and effective brainstem surgery. Using anatomical models can be an important step in sharpening such understanding. Objective To show the applicability of our developed virtual 3D model in depicting the safe entry zones (SEZs) to the brainstem. Methods Accurate 3D virtual models of brainstem elements were created using high-resolution magnetic resonance imaging and computed tomography to depict brainstem SEZs. Results All the described SEZs to different aspects of the brainstem were successfully depicted using our 3D virtual models. Conclusions The virtual models provide an immersive experience of brainstem anatomy, allowing users to understand the intricacies of the microdissection that is necessary to appropriately traverse the brainstem nuclei and tracts toward a particular target. The models provide an unparalleled learning environment for illustrating SEZs into the brainstem that can be used for training and research

    The Third wave in globalization theory

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    This essay examines a proposition made in the literature that there are three waves in globalization theory‚ÄĒthe globalist, skeptical, and postskeptical or transformational waves‚ÄĒand argues that this division requires a new look. The essay is a critique of the third of these waves and its relationship with the second wave. Contributors to the third wave not only defend the idea of globalization from criticism by the skeptics but also try to construct a more complex and qualified theory of globalization than provided by first-wave accounts. The argument made here is that third-wave authors come to conclusions that try to defend globalization yet include qualifications that in practice reaffirm skeptical claims. This feature of the literature has been overlooked in debates and the aim of this essay is to revisit the literature and identify as well as discuss this problem. Such a presentation has political implications. Third wavers propose globalist cosmopolitan democracy when the substance of their arguments does more in practice to bolster the skeptical view of politics based on inequality and conflict, nation-states and regional blocs, and alliances of common interest or ideology rather than cosmopolitan global structures

    Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

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    Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall‚Äôs tau for dichotomous variables, or Jonckheere‚ÄďTerpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p‚ÄČ<‚ÄČ0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC‚ÄČ=‚ÄČ0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p‚ÄČ<‚ÄČ0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

    A brief history of learning classifier systems: from CS-1 to XCS and its variants

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    © 2015, Springer-Verlag Berlin Heidelberg. The direction set by Wilson’s XCS is that modern Learning Classifier Systems can be characterized by their use of rule accuracy as the utility metric for the search algorithm(s) discovering useful rules. Such searching typically takes place within the restricted space of co-active rules for efficiency. This paper gives an overview of the evolution of Learning Classifier Systems up to XCS, and then of some of the subsequent developments of Wilson’s algorithm to different types of learning

    Reconfiguring ruins: Beyond Ruinenlust

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    What explains the global proliferation of interest in ruins? Can ruins be understood beyond their common framing as products of European Romanticism? Might a transdisciplinary approach allow us to see ruins differently? These questions underpinned the Arts and Humanities Research Council‚Äďfunded project Reconfiguring Ruins, which deployed approaches from history, literature, East Asian studies, and geography to reflect on how ruins from different historical contexts are understood by reference to different theoretical frameworks. In recognition of the value of learning from other models of knowledge production, the project also involved a successful collaboration with the Museum of London Archaeology and the artist-led community The NewBridge Project in Newcastle. By bringing these varied sets of knowledges to bear on the project‚Äôs excavations of specific sites in the United Kingdom, the United States, and Japan, the article argues for an understanding of ruins as thresholds, with ruin sites providing unique insights into the relationship between lived pasts, presents, and futures. It does so by developing three key themes that reflect on the process of working collaboratively across the arts, humanities, and social sciences, including professional archaeology: inter- and transdisciplinarity, the limits of cocreation, and traveling meanings and praxis. Meanings of specific ruins are constructed out of specific languages and cultural resonances and read though different disciplines, but can also be reconfigured through concepts and practices that travel beyond disciplinary, cultural, and linguistic borders. As we show here, the ruin is, and should be, a relational concept that moves beyond the romantic notion of Ruinenlust

    MicroRNA Expression Characterizes Oligometastasis(es)

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    Cancer staging and treatment presumes a division into localized or metastatic disease. We proposed an intermediate state defined by ‚ȧ 5 cumulative metastasis(es), termed oligometastases. In contrast to widespread polymetastases, oligometastatic patients may benefit from metastasis-directed local treatments. However, many patients who initially present with oligometastases progress to polymetastases. Predictors of progression could improve patient selection for metastasis-directed therapy.Here, we identified patterns of microRNA expression of tumor samples from oligometastatic patients treated with high-dose radiotherapy.Patients who failed to develop polymetastases are characterized by unique prioritized features of a microRNA classifier that includes the microRNA-200 family. We created an oligometastatic-polymetastatic xenograft model in which the patient-derived microRNAs discriminated between the two metastatic outcomes. MicroRNA-200c enhancement in an oligometastatic cell line resulted in polymetastatic progression.These results demonstrate a biological basis for oligometastases and a potential for using microRNA expression to identify patients most likely to remain oligometastatic after metastasis-directed treatment

    Clinical Sequencing Exploratory Research Consortium: Accelerating Evidence-Based Practice of Genomic Medicine

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    Despite rapid technical progress and demonstrable effectiveness for some types of diagnosis and therapy, much remains to be learned about clinical genome and exome sequencing (CGES) and its role within the practice of medicine. The Clinical Sequencing Exploratory Research (CSER) consortium includes 18 extramural research projects, one National Human Genome Research Institute (NHGRI) intramural project, and a coordinating center funded by the NHGRI and National Cancer Institute. The consortium is exploring analytic and clinical validity and utility, as well as the ethical, legal, and social implications of sequencing via multidisciplinary approaches; it has thus far recruited 5,577 participants across a spectrum of symptomatic and healthy children and adults by utilizing both germline and cancer sequencing. The CSER consortium is analyzing data and creating publically available procedures and tools related to participant preferences and consent, variant classification, disclosure and management of primary and secondary findings, health outcomes, and integration with electronic health records. Future research directions will refine measures of clinical utility of CGES in both germline and somatic testing, evaluate the use of CGES for screening in healthy individuals, explore the penetrance of pathogenic variants through extensive phenotyping, reduce discordances in public databases of genes and variants, examine social and ethnic disparities in the provision of genomics services, explore regulatory issues, and estimate the value and downstream costs of sequencing. The CSER consortium has established a shared community of research sites by using diverse approaches to pursue the evidence-based development of best practices in genomic medicine

    Population‚Äźbased cohort study of outcomes following cholecystectomy for benign gallbladder diseases

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    Background The aim was to describe the management of benign gallbladder disease and identify characteristics associated with all‚Äźcause 30‚Äźday readmissions and complications in a prospective population‚Äźbased cohort. Methods Data were collected on consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing all‚Äźcause 30‚Äźday readmissions and complications were analysed by means of multilevel, multivariable logistic regression modelling using a two‚Äźlevel hierarchical structure with patients (level 1) nested within hospitals (level 2). Results Data were collected on 8909 patients undergoing cholecystectomy from 167 hospitals. Some 1451 cholecystectomies (16¬∑3 per cent) were performed as an emergency, 4165 (46¬∑8 per cent) as elective operations, and 3293 patients (37¬∑0 per cent) had had at least one previous emergency admission, but had surgery on a delayed basis. The readmission and complication rates at 30 days were 7¬∑1 per cent (633 of 8909) and 10¬∑8 per cent (962 of 8909) respectively. Both readmissions and complications were independently associated with increasing ASA fitness grade, duration of surgery, and increasing numbers of emergency admissions with gallbladder disease before cholecystectomy. No identifiable hospital characteristics were linked to readmissions and complications. Conclusion Readmissions and complications following cholecystectomy are common and associated with patient and disease characteristics

    May Measurement Month 2018: a pragmatic global screening campaign to raise awareness of blood pressure by the International Society of Hypertension

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    Aims Raised blood pressure (BP) is the biggest contributor to mortality and disease burden worldwide and fewer than half of those with hypertension are aware of it. May Measurement Month (MMM) is a global campaign set up in 2017, to raise awareness of high BP and as a pragmatic solution to a lack of formal screening worldwide. The 2018 campaign was expanded, aiming to include more participants and countries. Methods and results Eighty-nine countries participated in MMM 2018. Volunteers (‚Č•18‚ÄČyears) were recruited through opportunistic sampling at a variety of screening sites. Each participant had three BP measurements and completed a questionnaire on demographic, lifestyle, and environmental factors. Hypertension was defined as a systolic BP ‚Č•140‚ÄČmmHg or diastolic BP ‚Č•90‚ÄČmmHg, or taking antihypertensive medication. In total, 74.9% of screenees provided three BP readings. Multiple imputation using chained equations was used to impute missing readings. 1 504 963 individuals (mean age 45.3‚ÄČyears; 52.4% female) were screened. After multiple imputation, 502 079 (33.4%) individuals had hypertension, of whom 59.5% were aware of their diagnosis and 55.3% were taking antihypertensive medication. Of those on medication, 60.0% were controlled and of all hypertensives, 33.2% were controlled. We detected 224 285 individuals with untreated hypertension and 111 214 individuals with inadequately treated (systolic BP ‚Č• 140‚ÄČmmHg or diastolic BP ‚Č• 90‚ÄČmmHg) hypertension. Conclusion May Measurement Month expanded significantly compared with 2017, including more participants in more countries. The campaign identified over 335 000 adults with untreated or inadequately treated hypertension. In the absence of systematic screening programmes, MMM was effective at raising awareness at least among these individuals at risk
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