49 research outputs found
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Predicting breast cancer response to neoadjuvant treatment using multi-feature MRI: results from the I-SPY 2 TRIAL.
Dynamic contrast-enhanced (DCE) MRI provides both morphological and functional information regarding breast tumor response to neoadjuvant chemotherapy (NAC). The purpose of this retrospective study is to test if prediction models combining multiple MRI features outperform models with single features. Four features were quantitatively calculated in each MRI exam: functional tumor volume, longest diameter, sphericity, and contralateral background parenchymal enhancement. Logistic regression analysis was used to study the relationship between MRI variables and pathologic complete response (pCR). Predictive performance was estimated using the area under the receiver operating characteristic curve (AUC). The full cohort was stratified by hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status (positive or negative). A total of 384 patients (median age: 49 y/o) were included. Results showed analysis with combined features achieved higher AUCs than analysis with any feature alone. AUCs estimated for the combined versus highest AUCs among single features were 0.81 (95% confidence interval [CI]: 0.76, 0.86) versus 0.79 (95% CI: 0.73, 0.85) in the full cohort, 0.83 (95% CI: 0.77, 0.92) versus 0.73 (95% CI: 0.61, 0.84) in HR-positive/HER2-negative, 0.88 (95% CI: 0.79, 0.97) versus 0.78 (95% CI: 0.63, 0.89) in HR-positive/HER2-positive, 0.83 (95% CI not available) versus 0.75 (95% CI: 0.46, 0.81) in HR-negative/HER2-positive, and 0.82 (95% CI: 0.74, 0.91) versus 0.75 (95% CI: 0.64, 0.83) in triple negatives. Multi-feature MRI analysis improved pCR prediction over analysis of any individual feature that we examined. Additionally, the improvements in prediction were more notable when analysis was conducted according to cancer subtype
The Magellan-TESS Survey I: Survey Description and Mid-Survey Results
One of the most significant revelations from Kepler is that roughly one-third
of Sun-like stars host planets which orbit their stars within 100 days and are
between the size of Earth and Neptune. How do these super-Earth and sub-Neptune
planets form, what are they made of, and do they represent a continuous
population or naturally divide into separate groups? Measuring their masses and
thus bulk densities can help address these questions of their origin and
composition. To that end, we began the Magellan-TESS Survey (MTS), which uses
Magellan II/PFS to obtain radial velocity (RV) masses of 30 transiting
exoplanets discovered by TESS and develops an analysis framework that connects
observed planet distributions to underlying populations. In the past, RV
measurements of small planets have been challenging to obtain due to the
faintness and low RV semi-amplitudes of most Kepler systems, and challenging to
interpret due to the potential biases in the existing ensemble of small planet
masses from non-algorithmic decisions for target selection and observation
plans. The MTS attempts to minimize these biases by focusing on bright TESS
targets and employing a quantitative selection function and multi-year
observing strategy. In this paper, we (1) describe the motivation and survey
strategy behind the MTS, (2) present our first catalog of planet mass and
density constraints for 25 TESS Objects of Interest (TOIs; 20 in our population
analysis sample, five that are members of the same systems), and (3) employ a
hierarchical Bayesian model to produce preliminary constraints on the
mass-radius (M-R) relation. We find qualitative agreement with prior
mass-radius relations but some quantitative differences (abridged). The the
results of this work can inform more detailed studies of individual systems and
offer a framework that can be applied to future RV surveys with the goal of
population inferences.Comment: 101 pages (39 of main text and references, the rest an appendix of
figures and tables). Submitted to AAS Journal
The Multiplanet System TOI-421: A Warm Neptune and a Super Puffy Mini-Neptune Transiting a G9 V Star in a Visual Binary
We report the discovery of a warm Neptune and a hot sub-Neptune transiting TOI-421 (BD-14 1137, TIC 94986319), a bright (V = 9.9) G9 dwarf star in a visual binary system observed by the Transiting Exoplanet Survey Satellite (TESS) space mission in Sectors 5 and 6. We performed ground-based follow-up observations—comprised of Las Cumbres Observatory Global Telescope transit photometry, NIRC2 adaptive optics imaging, and FIbre-fed Echellé Spectrograph, CORALIE, High Accuracy Radial velocity Planet Searcher, High Resolution Échelle Spectrometer, and Planet Finder Spectrograph high-precision Doppler measurements—and confirmed the planetary nature of the 16 day transiting candidate announced by the TESS team. We discovered an additional radial velocity signal with a period of five days induced by the presence of a second planet in the system, which we also found to transit its host star. We found that the inner mini-Neptune, TOI-421 b, has an orbital period of P_b = 5.19672 ± 0.00049 days, a mass of M_b = 7.17 ± 0.66 M⊕, and a radius of R_b = 2.68^(+0.19)_(-0.18) R⊕, whereas the outer warm Neptune, TOI-421 c, has a period of Pc = 16.06819 ± 0.00035 days, a mass of M_c = 16.42^(+1.06)_(-1.04) M⊕, a radius of R_c = 5.09^(+0.16)_(-0.15) R⊕ and a density of ρ_c = 0.685^(+0.080)_(-0.072) g cm⁻³. With its characteristics, the outer planet (ρ_c = 0.685^(+0.080)_(-0.072) g cm⁻³) is placed in the intriguing class of the super-puffy mini-Neptunes. TOI-421 b and TOI-421 c are found to be well-suited for atmospheric characterization. Our atmospheric simulations predict significant Lyα transit absorption, due to strong hydrogen escape in both planets, as well as the presence of detectable CH4 in the atmosphere of TOI-421 c if equilibrium chemistry is assumed
Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer's disease
We identified rare coding variants associated with Alzheimer’s disease (AD) in a 3-stage case-control study of 85,133 subjects. In stage 1, 34,174 samples were genotyped using a whole-exome microarray. In stage 2, we tested associated variants (P<1×10-4) in 35,962 independent samples using de novo genotyping and imputed genotypes. In stage 3, an additional 14,997 samples were used to test the most significant stage 2 associations (P<5×10-8) using imputed genotypes. We observed 3 novel genome-wide significant (GWS) AD associated non-synonymous variants; a protective variant in PLCG2 (rs72824905/p.P522R, P=5.38×10-10, OR=0.68, MAFcases=0.0059, MAFcontrols=0.0093), a risk variant in ABI3 (rs616338/p.S209F, P=4.56×10-10, OR=1.43, MAFcases=0.011, MAFcontrols=0.008), and a novel GWS variant in TREM2 (rs143332484/p.R62H, P=1.55×10-14, OR=1.67, MAFcases=0.0143, MAFcontrols=0.0089), a known AD susceptibility gene. These protein-coding changes are in genes highly expressed in microglia and highlight an immune-related protein-protein interaction network enriched for previously identified AD risk genes. These genetic findings provide additional evidence that the microglia-mediated innate immune response contributes directly to AD development
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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"Transformation Tuesday": Temporal context and post valence influence the provision of social support on social media.
Social network sites (SNSs) such as Facebook have become integral in the development and maintenance of interpersonal relationships. Users of SNSs seek social support and validation, often using posts that illustrate how they have changed over time. The purpose of the present research is to examine how the valence and temporal context of an SNS post affect the likelihood of other users providing social support. Participants viewed hypothetical SNS posts and reported their intentions to provide social support to the users. Results revealed that participants were more likely to provide social support for posts that were positive and included temporal context (i.e., depicted improvement over time; Study 1). Furthermore, this research suggests that visual representations of change over time are needed to elicit social support (Study 2). Results are discussed in terms of their practical implications for SNS users and theoretical implications for the literature on social support and social media
“Transformation Tuesday”: Temporal context and post valence influence the provision of social support on social media
Social network sites (SNSs) such as Facebook have become integral in the development and maintenance of interpersonal relationships. Users of SNSs seek social support and validation, often using posts that illustrate how they have changed over time. The purpose of the present research is to examine how the valence and temporal context of an SNS post affect the likelihood of other users providing social support. Participants viewed hypothetical SNS posts and reported their intentions to provide social support to the users. Results revealed that participants were more likely to provide social support for posts that were positive and included temporal context (i.e., depicted improvement over time; Study 1). Furthermore, this research suggests that visual representations of change over time are needed to elicit social support (Study 2). Results are discussed in terms of their practical implications for SNS users and theoretical implications for the literature on social support and social media
Anesthesia Exposure and Risk of Dementia and Alzheimer’s Disease: A Prospective Study
Background/Aims: Studies have demonstrated conflicting results about the association between anesthesia exposure and subsequent dementia risk. However, prior studies were retrospective, collecting data on anesthesia exposure after determining dementia status. We used prospectively collected data to evaluate the associations between anesthesia and risk of dementia or Alzheimer’s disease (AD).
Methods: We conducted a cohort study among community-dwelling members of the Adult Changes in Thought cohort (N = 3,988) who were age 65 or older and free of dementia at baseline. Participants self-reported all prior surgical procedures with general or neuraxial (spinal or epidural) anesthesia at baseline and reported new procedures every two years. We compared people who had high-risk surgery with general anesthesia, other surgery with general anesthesia, and other surgery with neuraxial anesthesia exposures to those who had no surgery and no anesthesia. We used Cox proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for dementia and AD associated with time-varying lifetime and recent (past 5 years) anesthesia exposures.
Results: At baseline, 254 (6%) people reported never having anesthesia; 248 (6%) had one or more high-risk surgeries with general anesthesia, 3,363 (84%) had one or more other surgeries with general anesthesia, and 123 (3%) had one or more surgeries with neuraxial anesthesia. Lifetime exposure of high-risk surgery with general anesthesia was not associated with an increased risk of dementia (HR: 0.86, 95% CI: 0.58–1.28) or AD (HR: 0.95, 95% CI: 0.61–1.49) relative to no history of anesthesia. People with lifetime exposure of other surgery with general anesthesia had a lower risk of dementia (HR: 0.63, 95% CI: 0.46–0.85) and AD (HR: 0.65, 95% CI: 0.46–0.93) than people with no history of anesthesia. There was no association between recent anesthesia exposure and dementia or AD. When comparing the results for high-risk surgery with general anesthesia directly to other surgery with general anesthesia, HR was 1.37 (95% CI: 1.04–1.80) for dementia and 1.46 (95% CI: 1.07–1.99) for AD.
Conclusion: Anesthesia exposure was not associated with an increased risk of dementia or AD in older adults. Future studies should continue to explore whether there is truly an increased risk of dementia and AD following high-risk surgery
A randomized phase II study of cabozantinib versus weekly paclitaxel in the treatment of persistent or recurrent epithelial ovarian, fallopian tube or primary peritoneal cancer: An NRG Oncology/Gynecologic Oncology Group study.
INTRODUCTION: Cabozantinib is a receptor tyrosine kinases inhibitor that targets MET (c-MET), VEGF receptor 2 (VEGFR2), RET, AXL, KIT, FLT-3, and TIE-2 and previously showed promising single agent activity in recurrent ovarian cancer.
METHODS: This was an open label, 1:1 randomized study of cabozantinib 60 mg orally (PO) daily versus weekly paclitaxel 80 mg/m
RESULTS: Median PFS was similar for both treatment groups and was 5.3 months for cabozantinib and 5.5 months for weekly paclitaxel (HR 1.11 (90% CI 0.77-1.61, p = 0.64)). Secondary analyses of overall survival (OS) and event free survival (EFS) showed that cabozantinib did not perform as well as weekly paclitaxel. Median OS for cabozantinib was 19.4 months and was not reached for weekly paclitaxel (HR 2.27 (90% CI 1.17-4.41, p = 0.04). EFS was also worse in the cabozantinib arm, 3.5 months, compared to weekly paclitaxel at 5.0 months (HR 1.81 (90% CI 1.24-2.63, p = 0.01). Overall response rate (ORR) was less for cabozantinib compared to weekly paclitaxel (7% versus 24.1%). Gastrointestinal toxicities, specifically nausea, diarrhea, and abdominal pain were worse in the cabozantinib arm.
CONCLUSIONS: Median PFS was similar for cabozantinib and weekly paclitaxel. However, OS, EFS, and ORR were worse for cabozantinib compared to weekly paclitaxel. Cabozantinib given at this dose and schedule cannot be recommended as a treatment for recurrent ovarian cancer