Positron Emission Tomography-Computed Tomography Compared with Invasive Mediastinal Staging in Non-small Cell Lung Cancer: Results of Mediastinal Staging in the Early Lung Positron Emission Tomography Trial

IntroductionPatients with non-small cell lung cancer (NSCLC) require careful preoperative staging to define resectability for potential cure. 18Fluorodeoxyglucose positron emission tomography combined with computed tomography (18FDG PET-CT) is widely used to stage NSCLC. If the mediastinum is positive on PET-CT examination, some practitioners conclude that the patient is inoperable and refer the patient for nonsurgical treatment.MethodsIn this analysis of a previously reported trial comparing PET-CT with conventional imaging in the diagnostic work-up of patients with clinical stage I, II, or IIIA NSCLC, we determined the accuracy of PET-CT in mediastinal staging compared with invasive mediastinal staging either by mediastinoscopy alone or by mediastinoscopy combined with thoracotomy.ResultsAll 149 patients had mediastinal nodal staging at mediastinoscopy alone (14), thoracotomy alone (64), or both (71). The sensitivity of PET-CT was 70% (95% confidence interval [CI], 48–85%), and specificity was 94% (95% CI, 88–97%). Of 22 patients with a PET-CT interpreted as positive for mediastinal nodes, 8 did not have tumor. The positive predictive value and negative predictive value were 64% (95% CI, 43–80%) and 95% (95% CI, 90–98%), respectively. Based on PET-CT alone, eight patients would have been denied potentially curative surgery if the mediastinal abnormalities detected by PET-CT had not been evaluated with an invasive mediastinal procedure.ConclusionsPET-CT assessment of the mediastinum is associated with a clinically relevant false-positive result. Our study confirms the need for pathologic confirmation of mediastinal lymph node abnormalities detected by PET-CT

Oscillating Asymmetric Dark Matter

We study the dynamics of dark matter (DM) particle-antiparticle oscillations within the context of asymmetric DM. Oscillations arise due to small DM number-violating Majorana-type mass terms, and can lead to recoupling of annihilation after freeze-out and washout of the DM density. We derive the density matrix equations for DM oscillations and freeze-out from first principles using nonequilibrium field theory, and our results are qualitatively different than in previous studies. DM dynamics exhibits particle-vs-antiparticle "flavor" effects, depending on the interaction type, analogous to neutrino oscillations in a medium. "Flavor-sensitive" DM interactions include scattering or annihilation through a new vector boson, while "flavor-blind" interactions include scattering or s-channel annihilation through a new scalar boson, or annihilation to pairs of bosons. In particular, we find that flavor-sensitive annihilation does not recouple when coherent oscillations begin, and that flavor-blind scattering does not lead to decoherence.Comment: 23 pages, 4 figures, A typo fixed, References adde

Risk-taking attitudes and their association with process and outcomes of cardiac care: a cohort study

<p>Abstract</p> <p>Background</p> <p>Prior research reveals that processes and outcomes of cardiac care differ across sociodemographic strata. One potential contributing factor to such differences is the personality traits of individuals within these strata. We examined the association between risk-taking attitudes and cardiac patients' clinical and demographic characteristics, the likelihood of undergoing invasive cardiac procedures and survival.</p> <p>Methods</p> <p>We studied a large inception cohort of patients who underwent cardiac catheterization between July 1998 and December 2001. Detailed clinical and demographic data were collected at time of cardiac catheterization and through a mailed survey one year post-catheterization. The survey included three general risk attitude items from the Jackson Personality Inventory. Patients' (n = 6294) attitudes toward risk were categorized as risk-prone versus non-risk-prone and were assessed for associations with baseline clinical and demographic characteristics, treatment received (i.e., medical therapy, coronary artery bypass graft (CABG) surgery, percutaneous coronary intervention (PCI)), and survival (to December 2005).</p> <p>Results</p> <p>2827 patients (45%) were categorized as risk-prone. Having risk-prone attitudes was associated with younger age (p < .001), male sex (p < .001), current smoking (p < .001) and higher household income (p < .001). Risk-prone patients were more likely to have CABG surgery in unadjusted (Odds Ratio [OR] = 1.21; 95% CI 1.08–1.36) and adjusted (OR = 1.18; 95% CI 1.02–1.36) models, but were no more likely to have PCI or any revascularization. Having risk-prone attitudes was associated with better survival in an unadjusted survival analysis (Hazard Ratio [HR] = 0.78 (95% CI 0.66–0.93), but not in a risk-adjusted analysis (HR = 0.92, 95% CI 0.77–1.10).</p> <p>Conclusion</p> <p>These exploratory findings suggest that patient attitudes toward risk taking may <b>contribute to </b>some of the documented differences in use of invasive cardiac procedures. An awareness of these associations could help healthcare providers as they counsel patients regarding cardiac care decisions.</p

GA4GH: International policies and standards for data sharing across genomic research and healthcare.

The Global Alliance for Genomics and Health (GA4GH) aims to accelerate biomedical advances by enabling the responsible sharing of clinical and genomic data through both harmonized data aggregation and federated approaches. The decreasing cost of genomic sequencing (along with other genome-wide molecular assays) and increasing evidence of its clinical utility will soon drive the generation of sequence data from tens of millions of humans, with increasing levels of diversity. In this perspective, we present the GA4GH strategies for addressing the major challenges of this data revolution. We describe the GA4GH organization, which is fueled by the development efforts of eight Work Streams and informed by the needs of 24 Driver Projects and other key stakeholders. We present the GA4GH suite of secure, interoperable technical standards and policy frameworks and review the current status of standards, their relevance to key domains of research and clinical care, and future plans of GA4GH. Broad international participation in building, adopting, and deploying GA4GH standards and frameworks will catalyze an unprecedented effort in data sharing that will be critical to advancing genomic medicine and ensuring that all populations can access its benefits

Neuropathologic validation of the Alzheimer\u27s Questionnaire

The Alzheimer\u27s Questionnaire (AQ) is an informant-based screening tool with good diagnostic accuracy for Alzheimer\u27s disease (AD) and amnestic mild cognitive impairment (aMCI). The aim of this study is to validate the AQ with AD-associated neuritic plaque (NP) and neurofibrillary tangle (NFT) pathology. Data from 205 prospectively followed autopsy cases clinically classified as AD (n = 90), aMCI (n = 42), or cognitively unimpaired (CU, n = 73) were used. Semi-quantitative measures of NP and NFT pathology were correlated with the AQ, Clinical Dementia Rating Sum of Boxes (CDR-SOB), and the Mini-Mental State Exam (MMSE). The AQ correlated significantly (p \u3c 0.001) with NP load (r = 0.37) and NFT load (r = 0.57). The MMSE and CDR-SOB showed similar correlations with NP load (r = - 0.37, r = 0.35, respectively) and NFT load (r = - 0.58, r = 0.55, respectively). The AQ correlates well with NP and NFT pathology of AD, which provides additional confidence to clinicians using the AQ to screen for AD-related cognitive impairment

Quantified,multi-scale X-ray fluorescence element mapping using the Maia detector array: Application to mineral deposit studies

The Maia large solid-angle detector array and imaging system is capable of collecting high-resolution images of up to ~100 M pixels in size with dwell times of less than 0.2 ms per pixel and thus it is possible to document variation in textures associated with trace element chemistry by collecting quantified elemental maps of geological samples on the scale of entire thin sections in a short time frame (6–8 hr). The analysis is nondestructive and allows variation to be recognised on a centimetre scale while also recognising zonations at the micron scale.Studies of ore systems require microanalysis of samples to collect information on mineral chemistry in order to understand physiochemical conditions during ore genesis and alteration. Such studies contribute to the debate on whether precious metals are remobilised or introduced in multiple hydrothermal events. In this study we demonstrate the microanalytical capabilities of the Maia large solid-angle detector array and imaging system on the X-ray fluorescence microscopy beamline at the Australian Synchrotron to provide data for these studies. We present a series of case studies from orogenic gold deposits that illustrate the power of the Maia detector for constraining chemical zonations in sulphides and associated alteration minerals, which can be used to decipher ore-forming processes associated with gold deposition. A series of large-area (<7 cm2) elemental maps were collected with 2 to 4 μm pixel size using the Maia detector array. The data was processed using the GeoPIXE™ software package which allows variation in trace, minor and major element chemistry to be visualised in element maps. These maps are used to target further investigation with bulk spectra extracted and fitted for specific mineral grains and transects drawn through regions of interest. Analysis using the Maia detector offers a complementary method to map element distribution in geological samples that is both relatively fast and has a low detection limit for many elements of interest