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https://www.readbyqxmd.com/read/28798081/a-role-for-tight-junction-associated-marvel-proteins-in-larval-sea-lamprey-petromyzon-marinus-osmoregulation
#1
Dennis Kolosov, Phuong Bui, Andrew Donini, Mike P Wilkie, Scott P Kelly
This study reports on tight junction-associated MARVEL proteins of larval sea lamprey (Petromyzon marinus) and their potential role in ammocoete osmoregulation. Two Occludin isoforms (designated Ocln and Ocln-a) and a tricellulin (Tric) were identified. Transcripts encoding ocln, ocln-a, and tric were broadly expressed in larval lamprey, with greatest abundance of ocln in gut, liver and kidney, ocln-a in the gill and skin, and tric in the kidney. Ocln and Ocln-a resolved as ∼63 kDa and ∼35 kDa MW proteins respectively while Tric resolved as a ∼50 kDa protein...
August 10, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/28790119/complementary-value-of-contralateral-parenchymal-enhancement-on-dce-mri-to-prognostic-models-and-molecular-assays-in-high-risk-er-her2-breast-cancer
#2
Bas H M van der Velden, Sjoerd G Elias, Tycho Bismeijer, Claudette E Loo, Max A Viergever, Lodewyk F A Wessels, Kenneth G A Gilhuijs
Purpose: To determine whether markers of healthy breast stroma are able to select a subgroup of patients at low risk of death or metastasis from patients considered at high risk according to routine markers of the tumor. <p>Experimental Design: Patients with ER-positive/HER2-negative breast cancer were consecutively included for retrospective analysis. The contralateral parenchyma was segmented automatically on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), whereupon the average of the top-10% late enhancement was calculated...
August 8, 2017: Clinical Cancer Research: An Official Journal of the American Association for Cancer Research
https://www.readbyqxmd.com/read/28755569/the-impact-of-methods-to-handle-missing-data-on-the-estimated-prevalence-of-dementia-and-mild-cognitive-impairment-in-a-cross-sectional-study-including-non-responders
#3
Ji-Ping Tan, Nan Li, Xiao-Yang Lan, Shi-Ming Zhang, Bo Cui, Li-Xin Liu, Xin He, Lin Zeng, Li-Yuan Tau, Hua Zhang, Xiao-Xiao Wang, Lu-Ning Wang, Yi-Ming Zhao
OBJECTIVE: Although several statistical methods for adjusting for missing data have been developed and are widely applied in research, few studies have investigated these methods in adjusting for missingness in datasets that aim to estimate the prevalence of dementia. We attempted to develop a more feasible approach for handling missingness in a cross-sectional study among elderly. METHODS: Five methods of estimating prevalence, including stratified weighting (SW), inverse-probability weighting (IPW), hot deck imputation (HDI), ordinal logistic regression (OLR) and multiple imputation (MI), were applied to handle the missing data yielded by a dataset that include 2231 non-responders...
July 20, 2017: Archives of Gerontology and Geriatrics
https://www.readbyqxmd.com/read/28712346/a-model-averaging-approach-for-estimating-propensity-scores-by-optimizing-balance
#4
Yuying Xie, Yeying Zhu, Cecilia A Cotton, Pan Wu
Many approaches, including traditional parametric modeling and machine learning techniques, have been proposed to estimate propensity scores. This paper describes a new model averaging approach to propensity score estimation in which parametric and nonparametric estimates are combined to achieve covariate balance. Simulation studies are conducted across different scenarios varying in the degree of interactions and nonlinearities in the treatment model. The results show that, based on inverse probability weighting, the proposed propensity score estimator produces less bias and smaller standard errors than existing approaches...
January 1, 2017: Statistical Methods in Medical Research
https://www.readbyqxmd.com/read/28710501/polycyclic-aromatic-hydrocarbons-pahs-and-hopanes-in-plastic-resin-pellets-as-markers-of-oil-pollution-via-international-pellet-watch-monitoring
#5
Bee Geok Yeo, Hideshige Takada, Junki Hosoda, Atsuko Kondo, Rei Yamashita, Mahua Saha, Thomas Maes
Oil pollution in the marine environment is an unavoidable problem due to chronic input from local sources, particularly in urban areas and oil spills. Oil pollution not only causes immediate physical damages to surrounding wildlife but also some components, including higher molecular weight PAHs, can persist in the environment for many years and pose insidious threats to the ecosystem. Long-term and nontargeted monitoring of oil pollution is important. This paper examines the ability of International Pellet Watch (IPW) for initial identification and monitoring of oil pollution by analysing PAHs and hopanes in plastic pellet samples collected globally by volunteers...
July 14, 2017: Archives of Environmental Contamination and Toxicology
https://www.readbyqxmd.com/read/28709404/accounting-for-treatment-use-when-validating-a-prognostic-model-a-simulation-study
#6
Romin Pajouheshnia, Linda M Peelen, Karel G M Moons, Johannes B Reitsma, Rolf H H Groenwold
BACKGROUND: Prognostic models often show poor performance when applied to independent validation data sets. We illustrate how treatment use in a validation set can affect measures of model performance and present the uses and limitations of available analytical methods to account for this using simulated data. METHODS: We outline how the use of risk-lowering treatments in a validation set can lead to an apparent overestimation of risk by a prognostic model that was developed in a treatment-naïve cohort to make predictions of risk without treatment...
July 14, 2017: BMC Medical Research Methodology
https://www.readbyqxmd.com/read/28705200/the-prognostic-value-of-lymph-node-yield-in-the-earliest-stage-of-colorectal-cancer-a-multicenter-cohort-study
#7
Yara Backes, Sjoerd G Elias, Bibie S Bhoelan, John N Groen, Jeroen van Bergeijk, Tom C J Seerden, Hendrikus J M Pullens, Bernhard W M Spanier, Joost M J Geesing, Koen Kessels, Marjon Kerkhof, Peter D Siersema, Wouter H de Vos Tot Nederveen Cappel, Niels van Lelyveld, Frank H J Wolfhagen, Frank Ter Borg, G Johan A Offerhaus, Miangela M Lacle, Leon M G Moons
BACKGROUND: In patients with stage II colorectal cancer (CRC) the number of surgically retrieved lymph nodes (LNs) is associated with prognosis, resulting in a minimum of 10-12 retrieved LNs being recommended for this stage. Current guidelines do not provide a recommendation regarding LN yield in T1 CRC. Studies evaluating LN yield in T1 CRC suggest that such high LN yields are not feasible in this early stage, and a lower LN yield might be appropriate. We aimed to validate the cut-off of 10 retrieved LNs on risk for recurrent cancer and detection of LN metastasis (LNM) in T1 CRC, and explored whether this number is feasible in clinical practice...
July 14, 2017: BMC Medicine
https://www.readbyqxmd.com/read/28649172/control-function-assisted-ipw-estimation-with-a-secondary-outcome-in-case-control-studies
#8
Tamar Sofer, Marilyn C Cornelis, Peter Kraft, Eric J Tchetgen Tchetgen
Case-control studies are designed towards studying associations between risk factors and a single, primary outcome. Information about additional, secondary outcomes is also collected, but association studies targeting such secondary outcomes should account for the case-control sampling scheme, or otherwise results may be biased. Often, one uses inverse probability weighted (IPW) estimators to estimate population effects in such studies. IPW estimators are robust, as they only require correct specification of the mean regression model of the secondary outcome on covariates, and knowledge of the disease prevalence...
April 2017: Statistica Sinica
https://www.readbyqxmd.com/read/28585024/job-displacement-and-first-birth-over-the-business-cycle
#9
Barbara Hofmann, Michaela Kreyenfeld, Arne Uhlendorff
In this article, we investigate the impact of job displacement on women's first-birth rates as well as the variation in this effect over the business cycle. We use mass layoffs to estimate the causal effects of involuntary job loss on fertility in the short and medium term, up to five years after displacement. Our analysis is based on rich administrative data from Germany, with an observation period spanning more than 20 years. We apply inverse probability weighting (IPW) to flexibly control for the observed differences between women who were and were not displaced...
June 2017: Demography
https://www.readbyqxmd.com/read/28548236/renal-functional-outcomes-in-patients-undergoing-percutaneous-cryoablation-or-partial-nephrectomy-for-a-solitary-renal-mass
#10
Ross J Mason, Thomas D Atwell, Christine Lohse, Bimal Bhindi, Adam Weisbrod, Stephen A Boorjian, Bradley C Leibovich, Grant D Schmit, R Houston Thompson
OBJECTIVES: To compare renal functional changes after percutaneous cryoablation (PCA) or partial nephrectomy (PN). PATIENTS AND METHODS: Patients who underwent PCA or PN for a solitary renal mass at a single institution were identified (2003-2013). Estimated glomerular filtration rates (eGFRs) were calculated at baseline, discharge, and at the 3-month follow-up using the Chronic Kidney Disease Epidemiology Collaboration equation. Changes in renal function were compared between groups using 1:1 propensity score (PS) matching, adjustment for PS quintile, and inverse probability weighting (IPW)...
May 26, 2017: BJU International
https://www.readbyqxmd.com/read/28542299/preoperative-cardiac-troponin-level-is-associated-with-all-cause-mortality-of-liver-transplantation-recipients
#11
Jungchan Park, Seung Hwa Lee, Sangbin Han, Hyun Sook Jee, Suk-Koo Lee, Gyu-Seong Choi, Gaab Soo Kim
This study was aimed to evaluate the association between preoperative high-sensitivity cardiac troponin I (hs-cTnI) level and mortality in patients undergoing liver transplantation (LT). From January 2011 to May 2016, preoperative hs-cTnI level was measured in consecutive 487 patients scheduled for LT. Patients with elevated preoperative hs-cTnI were compared with those who had normal level. The primary outcome was all-cause death in follow-up period of 30 days to 1 year after operation. Of the 487 patients, 58 (11...
2017: PloS One
https://www.readbyqxmd.com/read/28520946/early-cannabis-initiation-and-educational-attainment-is-the-association-causal-data-from-the-french-tempo-study
#12
Maria Melchior, Camille Bolze, Eric Fombonne, Pamela J Surkan, Laura Pryor, Marie Jauffret-Roustide
Background: : Adolescent cannabis use has been reported to predict later educational attainment; however, results of past studies may be confounded by inappropriate control for factors that make some youths more likely to use cannabis precociously than others. We aimed to test the possibility of a causal relationship between early cannabis initiation and later academic achievement. Methods: : Analyses are based on data collected among TEMPO cohort study participants (France, 2009, n  = 1103, 22-35 years)...
May 18, 2017: International Journal of Epidemiology
https://www.readbyqxmd.com/read/28486574/assessing-the-potential-for-bias-from-non-response-to-a-study-follow-up-interview-an-example-from-the-agricultural-health-study
#13
Jessica L Rinsky, David B Richardson, Steve Wing, John D Beard, Michael Alavanja, Laura E Beane Freeman, Honglei Chen, Paul K Henneberger, Freya Kamel, Dale P Sandler, Jane A Hoppin
Prospective cohort studies are important tools for identifying causes of disease. However, these studies are susceptible to attrition. When information collected after enrollment is through interview or exam, attrition leads to missing information for non-respondents. The Agricultural Health Study enrolled 52,394 farmers in 1993-1997 and collected additional information during subsequent interviews. Forty-six percent of enrolled farmers responded to the 2005-2010 interview; 7% of farmers died prior to interview...
May 9, 2017: American Journal of Epidemiology
https://www.readbyqxmd.com/read/28455153/multi-institutional-analysis-of-radiation-modality-use-and-postoperative-outcomes-of-neoadjuvant-chemoradiation-for-esophageal-cancer
#14
Steven H Lin, Kenneth W Merrell, Jincheng Shen, Vivek Verma, Arlene M Correa, Lu Wang, Peter F Thall, Neha Bhooshan, Sarah E James, Michael G Haddock, Mohan Suntharalingam, Minesh P Mehta, Zhongxing Liao, James D Cox, Ritsuko Komaki, Reza J Mehran, Michael D Chuong, Christopher L Hallemeier
PURPOSE: Relative radiation dose exposure to vital organs in the thorax could influence clinical outcomes in esophageal cancer (EC). We assessed whether the type of radiation therapy (RT) modality used was associated with postoperative outcomes after neoadjuvant chemoradiation (nCRT). PATIENTS AND METHODS: Contemporary data from 580 EC patients treated with nCRT at 3 academic institutions from 2007 to 2013 were reviewed. 3D conformal RT (3D), intensity modulated RT (IMRT) and proton beam therapy (PBT) were used for 214 (37%), 255 (44%), and 111 (19%) patients, respectively...
April 25, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/28436047/propensity-scores-based-methods-for-estimating-average-treatment-effect-and-average-treatment-effect-among-treated-a-comparative-study
#15
Younathan Abdia, K B Kulasekera, Somnath Datta, Maxwell Boakye, Maiying Kong
Propensity score based statistical methods, such as matching, regression, stratification, inverse probability weighting (IPW), and doubly robust (DR) estimating equations, have become popular in estimating average treatment effect (ATE) and average treatment effect among treated (ATT) in observational studies. Propensity score is the conditional probability receiving a treatment assignment with given covariates, and propensity score is usually estimated by logistic regression. However, a misspecification of the propensity score model may result in biased estimates for ATT and ATE...
April 24, 2017: Biometrical Journal. Biometrische Zeitschrift
https://www.readbyqxmd.com/read/28346824/weighted-pseudolikelihood-for-snp-set-analysis-with-multiple-secondary-outcomes-in-case-control-genetic-association-studies
#16
Tamar Sofer, Elizabeth D Schifano, David C Christiani, Xihong Lin
We propose a weighted pseudolikelihood method for analyzing the association of a SNP set, example, SNPs in a gene or a genetic pathway or network, with multiple secondary phenotypes in case-control genetic association studies. To boost analysis power, we assume that the SNP-specific effects are shared across all secondary phenotypes using a scaled mean model. We estimate regression parameters using Inverse Probability Weighted (IPW) estimating equations obtained from the weighted pseudolikelihood, which accounts for case-control sampling to prevent potential ascertainment bias...
March 27, 2017: Biometrics
https://www.readbyqxmd.com/read/28249009/current-use-of-statins-reduces-risk-of-hiv-rebound-on-suppressive-haart
#17
Henning Drechsler, Colby Ayers, James Cutrell, Naim Maalouf, Pablo Tebas, Roger Bedimo
BACKGROUND: Despite compelling evidence for activity against HIV-1 in vitro, a virologic effect of statins has not been shown in clinical studies. Given their short plasma half-lives, such an effect may be transient and only apparent during ongoing exposure. METHODS: We studied all HIV infected US-Veterans who started HAART 1995-2011, had a documented HIV viral load (VL) >1000 copies/mL, reached an undetectable VL on HAART, and had ≥1 follow-up VL within 13 months...
2017: PloS One
https://www.readbyqxmd.com/read/28219110/estimating-inverse-probability-weights-using-super-learner-when-weight-model-specification-is-unknown-in-a-marginal-structural-cox-model-context
#18
Mohammad Ehsanul Karim, Robert W Platt
Correct specification of the inverse probability weighting (IPW) model is necessary for consistent inference from a marginal structural Cox model (MSCM). In practical applications, researchers are typically unaware of the true specification of the weight model. Nonetheless, IPWs are commonly estimated using parametric models, such as the main-effects logistic regression model. In practice, assumptions underlying such models may not hold and data-adaptive statistical learning methods may provide an alternative...
June 15, 2017: Statistics in Medicine
https://www.readbyqxmd.com/read/28183157/improve-efficiency-and-reduce-bias-of-cox-regression-models-for-two-stage-randomization-designs-using-auxiliary-covariates
#19
Xue Yang, Yong Zhou
Two-stage randomization designs are broadly accepted and becoming increasingly popular in clinical trials for cancer and other chronic diseases to assess and compare the effects of different treatment policies. In this paper, we propose an inferential method to estimate the treatment effects in two-stage randomization designs, which can improve the efficiency and reduce bias in the presence of chance imbalance of a robust covariate-adjustment without additional assumptions required by Lokhnygina and Helterbrand (Biometrics, 63:422-428)'s inverse probability weighting (IPW) method...
February 9, 2017: Statistics in Medicine
https://www.readbyqxmd.com/read/28118173/symptom-relief-and-retreatment-after-vaginal-open-or-robotic-surgery-for-apical-vaginal-prolapse
#20
Mallika Anand, Amy L Weaver, Kristin M Fruth, Emanuel C Trabuco, John B Gebhart
OBJECTIVES: The aim of this work was to determine the degree of symptom relief and survival free of retreatment after Mayo-McCall culdoplasty (MMC), open abdominal sacrocolpopexy (ASC), and robotic sacrocolpopexy (RSC) for posthysterectomy vaginal vault prolapse. METHODS: We retrospectively studied patients who had undergone surgery for posthysterectomy apical vaginal prolapse from January 1, 2000, through June 30, 2012, at our institution. Baseline characteristics and perioperative outcomes were abstracted from electronic health records...
January 24, 2017: Female Pelvic Medicine & Reconstructive Surgery
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