261 research outputs found

    Evoked itch perception is associated with changes in functional brain connectivity

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    Chronic itch, a highly debilitating condition, has received relatively little attention in the neuroimaging literature. Recent studies suggest that brain regions supporting itch in chronic itch patients encompass sensorimotor and salience networks, and corticostriatal circuits involved in motor preparation for scratching. However, how these different brain areas interact with one another in the context of itch is still unknown. We acquired BOLD fMRI scans in 14 atopic dermatitis patients to investigate resting-state functional connectivity before and after allergen-induced itch exacerbated the clinical itch perception in these patients. A seed-based analysis revealed decreased functional connectivity from baseline resting state to the evoked-itch state between several itch-related brain regions, particularly the insular and cingulate cortices and basal ganglia, where decreased connectivity was significantly correlated with increased levels of perceived itch. In contrast, evoked itch increased connectivity between key nodes of the frontoparietal control network (superior parietal lobule and dorsolateral prefrontal cortex), where higher increase in connectivity was correlated with a lesser increase in perceived itch, suggesting that greater interaction between nodes of this executive attention network serves to limit itch sensation via enhanced top-down regulation. Overall, our results provide the first evidence of itch-dependent changes in functional connectivity across multiple brain regions

    In situ detection of boron by ChemCam on Mars

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    We report the first in situ detection of boron on Mars. Boron has been detected in Gale crater at levels Curiosity rover ChemCam instrument in calcium-sulfate-filled fractures, which formed in a late-stage groundwater circulating mainly in phyllosilicate-rich bedrock interpreted as lacustrine in origin. We consider two main groundwater-driven hypotheses to explain the presence of boron in the veins: leaching of borates out of bedrock or the redistribution of borate by dissolution of borate-bearing evaporite deposits. Our results suggest that an evaporation mechanism is most likely, implying that Gale groundwaters were mildly alkaline. On Earth, boron may be a necessary component for the origin of life; on Mars, its presence suggests that subsurface groundwater conditions could have supported prebiotic chemical reactions if organics were also present and provides additional support for the past habitability of Gale crater

    Effects of Gruel Feeding and Oral Dextrose on the Survivability of Pigs After Weaning

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    Two experiments were conducted using 3,087 (Exp. 1) and 988 (Exp. 2) pigs to determine the effect of gruel feeding (Exp. 1) and administering oral dextrose (Exp. 2) on pig survivability after weaning. Upon arrival to the nursery, the smallest 10% of pigs were selected and randomly placed in designated pens with 61 to 108 pigs per pen. Pens of small pigs were assigned to 1 of 2 treatments in a completely randomized design. Treatments consisted of gruel feeding two or four times per day starting 14-d post-placement. At each gruel feeding, approximately 2.5 lb of solid feed was added to a round Rotecna bowl (Rotecna S.A., Agramunt, Spain) located at the front of the pen. Water was added to feed at a decreasing rate over time such that d 0 to 5, 6 to 10, and 11 to 14 the ratio of water to feed was 3:1, 1:1, and 1:3, respectively. In Exp. 2, every other pig removed from general population or pens of small pigs for welfare considerations (lameness, sick, or fallback) received a single 10 mL oral dose of a 50% dextrose solution (Vet One, MWI Animal Health, Boise, ID), as a source of glucose, before being placed in a removal pen. All removed pigs were tagged and weighed, blood glucose measured prior to and 30 min after entering removal pens, and their body temperature recorded. Overall, gruel feeding the small pigs two or four times per day for 14-d post-placement did not influence (P \u3e 0.10) mortality from weaning to the end of gruel feeding (3.78 vs. 4.25%, respectively). Likewise, dextrose administration did not influence (P \u3e 0.10) pig mortality after removal to approximately d 38 after weaning (21.4 vs. 23.4% respectively), even though blood glucose levels increased (P \u3c 0.001) for pigs administered dextrose compared to pigs not administered dextrose (increased by 11.4 vs. 19.1 mg/dL). An interaction was observed for blood glucose and body temperature (P \u3c 0.001). Pigs with a blood glucose less than 70 mg/dL had increased mortality as body temperature at removal increased. In contrast, pigs with a blood glucose between 70 and 120 mg/dL or greater than 120 mg/dL had decreased mortality as body temperature increased. Pigs weighing less than 10 lb at removal had an increased mortality (P \u3c 0.001) compared to pigs weighing greater than 10 lb at removal. In summary, gruel feeding four times per day vs. two times per day or providing removed pigs glucose supplementation did not improve survivability of pigs after weaning. Additionally, removed pigs with low body weight, body temperature below or above the normal range, or high blood glucose had decreased survivability

    Cabozantinib Versus Mitoxantrone-prednisone in Symptomatic Metastatic Castration-resistant Prostate Cancer: A Randomized Phase 3 Trial with a Primary Pain Endpoint

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    Background: Bone metastases in patients with metastatic castration-resistant prostate cancer (mCRPC) are associated with debilitating pain and functional compromise. Objective: To compare pain palliation as the primary endpoint for cabozantinib versus mitoxantrone-prednisone in men with mCRPC and symptomatic bone metastases using patient-reported outcome measures. Design, setting, and participants: A randomized, double-blind phase 3 trial (COMET-2; NCT01522443) in men with mCRPC and narcotic-dependent pain from bone metastases who had progressed after treatment with docetaxel and either abiraterone or enzalutamide. Intervention: Cabozantinib 60 mg once daily orally versus mitoxantrone 12 mg/m2 every 3 wk plus prednisone 5 mg twice daily orally. Outcome measurements and statistical analysis: The primary endpoint was pain response at week 6 confirmed at week 12 (≥30% decrease from baseline in patient-reported average daily worst pain score via the Brief Pain Inventory without increased narcotic use). The planned sample size was 246 to achieve ≥90% power. Results and limitations: Enrollment was terminated early because cabozantinib did not demonstrate any survival benefit in the companion COMET-1 trial. At study closure, 119 participants were randomized (cabozantinib: N =61; mitoxantrone-prednisone: N = 58). Complete pain and narcotic use data were available at baseline, week 6, and week 12 for 73/106 (69%) patients. There was no significant difference in the pain response with cabozantinib versus mitoxantrone-prednisone: the proportions of responders were 15%versus 17%,a −2%difference(95%confidenceinterval:−16%to11%, p = 0.8). Barriers to accrual included pretreatment requirements for a washout period of prior anticancer therapy and a narcotic optimization period to maximize analgesic dosing. Conclusions: Cabozantinib treatment did not demonstrate better pain palliation than mitoxantrone-prednisone in heavily pretreated patients with mCRPC and symptomatic bone metastases. Future pain-palliation trials should incorporate briefer timelines from enrollment to treatment initiation. Patient summary: Cabozantinib was not better than mitoxantrone-prednisone for pain relief in patients with castration-resistant prostate cancer and debilitating pain from bone metastases

    Impact of stratospheric air and surface emissions on tropospheric nitrous oxide during ATom

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    We measured the global distribution of tropospheric N2O mixing ratios during the NASA airborne Atmospheric Tomography (ATom) mission. ATom measured concentrations of ∼ 300 gas species and aerosol properties in 647 vertical profiles spanning the Pacific, Atlantic, Arctic, and much of the Southern Ocean basins, nearly from pole to pole, over four seasons (2016–2018). We measured N2O concentrations at 1 Hz using a quantum cascade laser spectrometer (QCLS). We introduced a new spectral retrieval method to account for the pressure and temperature sensitivity of the instrument when deployed on aircraft. This retrieval strategy improved the precision of our ATom QCLS N2O measurements by a factor of three (based on the standard deviation of calibration measurements). Our measurements show that most of the variance of N2O mixing ratios in the troposphere is driven by the influence of N2O-depleted stratospheric air, especially at mid- and high latitudes. We observe the downward propagation of lower N2O mixing ratios (compared to surface stations) that tracks the influence of stratosphere–troposphere exchange through the tropospheric column down to the surface. The highest N2O mixing ratios occur close to the Equator, extending through the boundary layer and free troposphere. We observed influences from a complex and diverse mixture of N2O sources, with emission source types identified using the rich suite of chemical species measured on ATom and the geographical origin calculated using an atmospheric transport model. Although ATom flights were mostly over the oceans, the most prominent N2O enhancements were associated with anthropogenic emissions, including from industry (e.g., oil and gas), urban sources, and biomass burning, especially in the tropical Atlantic outflow from Africa. Enhanced N2O mixing ratios are mostly associated with pollution-related tracers arriving from the coastal area of Nigeria. Peaks of N2O are often associated with indicators of photochemical processing, suggesting possible unexpected source processes. In most cases, the results show how difficult it is to separate the mixture of different sources in the atmosphere, which may contribute to uncertainties in the N2O global budget. The extensive data set from ATom will help improve the understanding of N2O emission processes and their representation in global models.This research has been supported by the National Aeronautics and Space Administration (grant nos. NNX15AJ23G, NNX17AF54G, NNX15AG58A, NNX15AH33A, and 80NSSC19K0124) and the National Science Foundation (grant nos. 1852977, AGS-1547626, and AGS-1623745)

    Theory and Applications of Non-Relativistic and Relativistic Turbulent Reconnection

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    Realistic astrophysical environments are turbulent due to the extremely high Reynolds numbers. Therefore, the theories of reconnection intended for describing astrophysical reconnection should not ignore the effects of turbulence on magnetic reconnection. Turbulence is known to change the nature of many physical processes dramatically and in this review we claim that magnetic reconnection is not an exception. We stress that not only astrophysical turbulence is ubiquitous, but also magnetic reconnection itself induces turbulence. Thus turbulence must be accounted for in any realistic astrophysical reconnection setup. We argue that due to the similarities of MHD turbulence in relativistic and non-relativistic cases the theory of magnetic reconnection developed for the non-relativistic case can be extended to the relativistic case and we provide numerical simulations that support this conjecture. We also provide quantitative comparisons of the theoretical predictions and results of numerical experiments, including the situations when turbulent reconnection is self-driven, i.e. the turbulence in the system is generated by the reconnection process itself. We show how turbulent reconnection entails the violation of magnetic flux freezing, the conclusion that has really far reaching consequences for many realistically turbulent astrophysical environments. In addition, we consider observational testing of turbulent reconnection as well as numerous implications of the theory. The former includes the Sun and solar wind reconnection, while the latter include the process of reconnection diffusion induced by turbulent reconnection, the acceleration of energetic particles, bursts of turbulent reconnection related to black hole sources as well as gamma ray bursts. Finally, we explain why turbulent reconnection cannot be explained by turbulent resistivity or derived through the mean field approach.Comment: 66 pages, 24 figures, a chapter of the book "Magnetic Reconnection - Concepts and Applications", editors W. Gonzalez, E. N. Parke

    Electronic patient self-assessment and management (SAM): a novel framework for cancer survivorship

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    <p>Abstract</p> <p>Background</p> <p>We propose a novel framework for management of cancer survivorship: electronic patient Self-Assessment and Management (SAM). SAM is a framework for transfer of information to and from patients in such a way as to increase both the patient's and the health care provider's understanding of the patient's progress, and to help ensure that patient care follows best practice.</p> <p>Methods</p> <p>Patients who participate in the SAM system are contacted by email at regular intervals and asked to complete validated questionnaires online. Patient responses on these questionnaires are then analyzed in order to provide patients with real-time, online information about their progress and to provide them with tailored and standardized medical advice. Patient-level data from the questionnaires are ported in real time to the patient's health care provider to be uploaded to clinic notes. An initial version of SAM has been developed at Memorial Sloan-Kettering Cancer Center (MSKCC) and the University of California, San Francisco (UCSF) for aiding the clinical management of patients after surgery for prostate cancer.</p> <p>Results</p> <p>Pilot testing at MSKCC and UCSF suggests that implementation of SAM systems are feasible, with no major problems with compliance (> 70% response rate) or security.</p> <p>Conclusion</p> <p>SAM is a conceptually simple framework for passing information to and from patients in such a way as to increase both the patient's and the health care provider's understanding of the patient's progress, and to help ensure that patient care follows best practice.</p

    Using Expression and Genotype to Predict Drug Response in Yeast

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    Personalized, or genomic, medicine entails tailoring pharmacological therapies according to individual genetic variation at genomic loci encoding proteins in drug-response pathways. It has been previously shown that steady-state mRNA expression can be used to predict the drug response (i.e., sensitivity or resistance) of non-genotyped mammalian cancer cell lines to chemotherapeutic agents. In a real-world setting, clinicians would have access to both steady-state expression levels of patient tissue(s) and a patient's genotypic profile, and yet the predictive power of transcripts versus markers is not well understood. We have previously shown that a collection of genotyped and expression-profiled yeast strains can provide a model for personalized medicine. Here we compare the predictive power of 6,229 steady-state mRNA transcript levels and 2,894 genotyped markers using a pattern recognition algorithm. We were able to predict with over 70% accuracy the drug sensitivity of 104 individual genotyped yeast strains derived from a cross between a laboratory strain and a wild isolate. We observe that, independently of drug mechanism of action, both transcripts and markers can accurately predict drug response. Marker-based prediction is usually more accurate than transcript-based prediction, likely reflecting the genetic determination of gene expression in this cross

    Four-Gene Pan-African Blood Signature Predicts Progression to Tuberculosis.

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    Rationale: Contacts of patients with tuberculosis (TB) constitute an important target population for preventive measures because they are at high risk of infection with Mycobacterium tuberculosis and progression to disease.Objectives: We investigated biosignatures with predictive ability for incident TB.Methods: In a case-control study nested within the Grand Challenges 6-74 longitudinal HIV-negative African cohort of exposed household contacts, we employed RNA sequencing, PCR, and the pair ratio algorithm in a training/test set approach. Overall, 79 progressors who developed TB between 3 and 24 months after diagnosis of index case and 328 matched nonprogressors who remained healthy during 24 months of follow-up were investigated.Measurements and Main Results: A four-transcript signature derived from samples in a South African and Gambian training set predicted progression up to two years before onset of disease in blinded test set samples from South Africa, the Gambia, and Ethiopia with little population-associated variability, and it was also validated in an external cohort of South African adolescents with latent M. tuberculosis infection. By contrast, published diagnostic or prognostic TB signatures were predicted in samples from some but not all three countries, indicating site-specific variability. Post hoc meta-analysis identified a single gene pair, C1QC/TRAV27 (complement C1q C-chain / T-cell receptor-α variable gene 27) that would consistently predict TB progression in household contacts from multiple African sites but not in infected adolescents without known recent exposure events.Conclusions: Collectively, we developed a simple whole blood-based PCR test to predict TB in recently exposed household contacts from diverse African populations. This test has potential for implementation in national TB contact investigation programs
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