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https://www.readbyqxmd.com/read/28624481/mir-34a-overexpression-predicts-poor-prognostic-outcome-in-colorectal-adenocarcinoma-independently-of-clinicopathological-factors-with-established-prognostic-value
#1
Stamatia-Maria Rapti, Christos K Kontos, Spyridon Christodoulou, Iordanis N Papadopoulos, Andreas Scorilas
OBJECTIVES: MicroRNA-34a (miR-34a) is regulated by TP53 and, in response, downregulates the expression of a gamut of protein-coding genes, including apoptosis regulators, transcription factors, cyclins, and cyclin-dependent kinases. Its upregulation initiates a reprogramming of gene expression and promotes apoptosis. The purpose of this study was the investigation of the potential clinical significance of miR-34a as a molecular prognostic biomarker in colorectal adenocarcinoma using an in-house real-time quantitative PCR (qPCR) methodology...
June 14, 2017: Clinical Biochemistry
https://www.readbyqxmd.com/read/28616413/the-condition-of-interdisciplinary-communication-among-various-educational-and-research-departments-of-isfahan-university-of-medical-sciences
#2
Elaheh Mazaheri, Ehsan Geraei, Firoozeh Zare-Farashbandi, Ahmad Papi
BACKGROUND: The study aimed to assess interdisciplinary communication among various Educational and Research Departments of Isfahan University of Medical Sciences (IUMS) in clinical medical sciences using social network analysis. MATERIALS AND METHODS: The study was carried out using scientometrics method and interdisciplinary communication network analysis. Interdisciplinary network of 1298 articles in medical sciences published in Journal of Isfahan Medical School was evaluated using macro- and micro-level criteria of network analysis...
2017: Journal of Education and Health Promotion
https://www.readbyqxmd.com/read/28605047/stratified-exact-tests-for-the-weak-causal-null-hypothesis-in-randomized-trials-with-a-binary-outcome
#3
Yasutaka Chiba
Fisher's exact test is commonly used to compare two groups when the outcome is binary in randomized trials. In the context of causal inference, this test explores the sharp causal null hypothesis (i.e. the causal effect of treatment is the same for all subjects), but not the weak causal null hypothesis (i.e. the causal risks are the same in the two groups). Therefore, in general, rejection of the null hypothesis by Fisher's exact test does not mean that the causal risk difference is not zero. Recently, Chiba (Journal of Biometrics and Biostatistics 2015; 6: 244) developed a new exact test for the weak causal null hypothesis when the outcome is binary in randomized trials; the new test is not based on any large sample theory and does not require any assumption...
June 12, 2017: Biometrical Journal. Biometrische Zeitschrift
https://www.readbyqxmd.com/read/28584366/biostatistics-series-module-9-survival-analysis
#4
Avijit Hazra, Nithya Gogtay
Survival analysis is concerned with "time to event" data. Conventionally, it dealt with cancer death as the event in question, but it can handle any event occurring over a time frame, and this need not be always adverse in nature. When the outcome of a study is the time to an event, it is often not possible to wait until the event in question has happened to all the subjects, for example, until all are dead. In addition, subjects may leave the study prematurely. Such situations lead to what is called censored observations as complete information is not available for these subjects...
May 2017: Indian Journal of Dermatology
https://www.readbyqxmd.com/read/28584028/here-comes-trouble-a-career-as-a-tobacco-control-activist
#5
Stanton A Glantz, John D Rutherford
Dr Glantz is Professor of Medicine in the Division of Cardiology, the Truth Initiative Distinguished Professor of Tobacco Control, and Director of the Center for Tobacco Control Research and Education at the University of California, San Francisco School of Medicine. He obtained a BSc in aerospace engineering from the University of Cincinnati in 1969 and an MSc and PhD in applied mechanics from Stanford University. He is the author of 4 books, including The Cigarette Papers and Primer of Biostatistics He is also a member of the University of California, San Francisco Cardiovascular Research Institute and Institute for Health Policy Studies and Co-leader of the University of California, San Francisco Comprehensive Cancer Center Tobacco Program...
June 6, 2017: Circulation
https://www.readbyqxmd.com/read/28575330/the-utility-of-gene-expression-profiling-from-tissue-samples-to-support-drug-safety-assessments
#6
Daniel P Stiehl, Elaine Tritto, Salah-Dine Chibout, André Cordier, Pierre Moulin
Originally conceptualized as an integrated approach combining conventional toxicology methods with genome-wide expression profiling, toxicogenomics has promised to provide unequivocal relationships between the molecular changes elicited by a compound or a target pathway and the lesions that appear subsequently in the tissues. However, the discipline has only partially delivered on this promise, and the number of publications and submissions related to toxicogenomics is stagnating. The purpose of this article is to outline key factors contributing to a successful implementation of toxicogenomics in the drug discovery and development process...
May 31, 2017: ILAR Journal
https://www.readbyqxmd.com/read/28562502/prescribers-knowledge-and-skills-for-interpreting-research-results-a-systematic-review
#7
Leila Kahwati, Dennis Carmody, Nancy Berkman, Helen W Sullivan, Kathryn J Aikin, Jessica DeFrank
INTRODUCTION: Appropriate medication prescribing may be influenced by a prescriber's ability to understand and interpret medical research. The objective of this review was to synthesize the research related to prescribers' critical appraisal knowledge and skills-defined as the understanding of statistical methods, biases in studies, and relevance and validity of evidence. METHODS: We searched PubMed and other databases from January 1990 through September 2015. Two reviewers independently screened and selected studies of any design conducted in the United States, the United Kingdom, or Canada that involved prescribers and that objectively measured critical appraisal knowledge, skills, understanding, attitudes, or prescribing behaviors...
April 2017: Journal of Continuing Education in the Health Professions
https://www.readbyqxmd.com/read/28544956/dna-commission-of-the-international-society-for-forensic-genetics-isfg-guidelines-on-the-use-of-x-strs-in-kinship-analysis
#8
Andreas O Tillmar, Daniel Kling, John M Butler, Walther Parson, Mechthild Prinz, Peter M Schneider, Thore Egeland, Leonor Gusmão
Forensic genetic laboratories perform an increasing amount of genetic analyses of the X chromosome, in particular to solve complex cases of kinship analysis. For some biological relationships X-chromosomal markers can be more informative than autosomal markers, and there are a large number of markers, methods and databases that have been described for forensic use. Due to their particular mode of inheritance, and their physical location on a single chromosome, some specific considerations are required when estimating the weight of evidence for X-chromosomal marker DNA data...
May 13, 2017: Forensic Science International. Genetics
https://www.readbyqxmd.com/read/28532207/tutorial-on-biostatistics-statistical-analysis-for-correlated-binary-eye-data
#9
Gui-Shuang Ying, Maureen G Maguire, Robert Glynn, Bernard Rosner
PURPOSE: To describe and demonstrate methods for analyzing correlated binary eye data. METHODS: We describe non-model based (McNemar's test, Cochran-Mantel-Haenszel test) and model-based methods (generalized linear mixed effects model, marginal model) for analyses involving both eyes. These methods were applied to: (1) CAPT (Complications of Age-related Macular Degeneration Prevention Trial) where one eye was treated and the other observed (paired design); (2) ETROP (Early Treatment for Retinopathy of Prematurity) where bilaterally affected infants had one eye treated conventionally and the other treated early and unilaterally affected infants had treatment assigned randomly; and (3) AREDS (Age-Related Eye Disease Study) where treatment was systemic and outcome was eye-specific (both eyes in the same treatment group)...
May 22, 2017: Ophthalmic Epidemiology
https://www.readbyqxmd.com/read/28520893/using-bayesian-modeling-in-frequentist-adaptive-enrichment-designs
#10
Noah Simon, Richard Simon
Our increased understanding of the mechanistic heterogeneity of diseases has pushed the development of targeted therapeutics. We do not expect all patients with a given disease to benefit from a targeted drug; only those in the target population. That is, those with sufficient dysregulation in the biomolecular pathway targeted by treatment. However, due to complexity of the pathway, and/or technical issues with our characterizing assay, it is often hard to characterize the target population until well into large-scale clinical trials...
May 17, 2017: Biostatistics
https://www.readbyqxmd.com/read/28504870/a-critical-evaluation-of-the-current-p-value-controversy
#11
REVIEW
Stefan Wellek
This article has been triggered by the initiative launched in March 2016 by the Board of Directors of the American Statistical Association (ASA) to counteract the current p-value focus of statistical research practices that allegedly "have contributed to a reproducibility crisis in science." It is pointed out that in the very wide field of statistics applied to medicine, many of the problems raised in the ASA statement are not as severe as in the areas the authors may have primarily in mind, although several of them are well-known experts in biostatistics and epidemiology...
May 15, 2017: Biometrical Journal. Biometrische Zeitschrift
https://www.readbyqxmd.com/read/28504080/expected-p-values-in-light-of-an-roc-curve-analysis-applied-to-optimal-multiple-testing-procedures
#12
Albert Vexler, Jihnhee Yu, Yang Zhao, Alan D Hutson, Gregory Gurevich
Many statistical studies report p-values for inferential purposes. In several scenarios, the stochastic aspect of p-values is neglected, which may contribute to drawing wrong conclusions in real data experiments. The stochastic nature of p-values makes their use to examine the performance of given testing procedures or associations between investigated factors to be difficult. We turn our focus on the modern statistical literature to address the expected p-value (EPV) as a measure of the performance of decision-making rules...
January 1, 2017: Statistical Methods in Medical Research
https://www.readbyqxmd.com/read/28487962/embryotoxicity-estimation-of-commonly-used-compounds-with-embryonic-stem-cell-test
#13
Hui Liu, Caiping Ren, Weidong Liu, Xingjun Jiang, Lei Wang, Bin Zhu, Wei Jia, Jianxing Lin, Jun Tan, Xiuying Liu
The embryonic stem cell test (EST), an alternative model to animal studies, is a reliable and scientifically validated in vitro system for testing embryotoxicity. In contrast to most in vivo animal tests, two permanent cell lines, murine fibroblasts (BALB/c‑3T3 cells) and murine embryonic stem cells (mES‑D3 cells), are used in EST instead of animals in standard tests of toxicity. The embryotoxic potential of compounds (non, weak or strong embryotoxicity) may be obtained with a biostatistics‑based prediction model and calculated from three different experimental endpoint values: The potency to inhibit growth of i) BALB/c‑3T3 cells and ii) mES‑D3 cells (IC503T3 and IC50ES) as presented using a cell cytotoxicity assay, and iii) the potency to inhibit differentiation of mES‑D3 cells into contracting cardiomyocytes (ID50 D3) as demonstrated in a mES‑D3 cell differentiation assay...
July 2017: Molecular Medicine Reports
https://www.readbyqxmd.com/read/28466379/bayesian-and-phylogenic-approaches-for-studying-relationships-among-table-olive-cultivars
#14
Rayda Ben Ayed, Karim Ennouri, Fathi Ben Amar, Fabienne Moreau, Mohamed Ali Triki, Ahmed Rebai
To enhance table olive tree authentication, relationship, and productivity, we consider the analysis of 18 worldwide table olive cultivars (Olea europaea L.) based on morphological, biological, and physicochemical markers analyzed by bioinformatic and biostatistic tools. Accordingly, we assess the relationships between the studied varieties, on the one hand, and the potential productivity-quantitative parameter links on the other hand. The bioinformatic analysis based on the graphical representation of the matrix of Euclidean distances, the principal components analysis, unweighted pair group method with arithmetic mean, and principal coordinate analysis (PCoA) revealed three major clusters which were not correlated with the geographic origin...
May 2, 2017: Biochemical Genetics
https://www.readbyqxmd.com/read/28444218/current-dilemmas-in-defining-the-boundaries-of-disease
#15
Jenny Doust, Mary Jean Walker, Wendy A Rogers
Boorse's biostatistical theory states that diseases should be defined in ways that reflect disturbances of biological function and that are objective and value free. We use three examples from contemporary medicine that demonstrate the complex issues that arise when defining the boundaries of disease: polycystic ovary syndrome, chronic kidney disease, and myocardial infarction. We argue that the biostatistical theory fails to provide sufficient guidance on where the boundaries of disease should be drawn, contains ambiguities relating to choice of reference class, and is out of step with medical processes for identifying disease boundaries...
April 21, 2017: Journal of Medicine and Philosophy
https://www.readbyqxmd.com/read/28442941/competency-based-tool-for-evaluation-of-community-based-training-in-undergraduate-medical-education-in-india-a-delphi-approach
#16
Hemant Deepak Shewade, Kathiresan Jeyashree, Selvaraj Kalaiselvi, Chinnakali Palanivel, Krishna Chandra Panigrahi
INTRODUCTION: A community-based training (CBT) program, where teaching and training are carried out in the community outside of the teaching hospital, is a vital part of undergraduate medical education. Worldwide, there is a shift to competency-based training, and CBT is no exception. We attempted to develop a tool that uses a competency-based approach for assessment of CBT. METHODS: Based on a review on competencies, we prepared a preliminary list of major domains with items under each domain...
2017: Advances in Medical Education and Practice
https://www.readbyqxmd.com/read/28441139/empirical-likelihood-in-nonignorable-covariate-missing-data-problems
#17
Yanmei Xie, Biao Zhang
Missing covariate data occurs often in regression analysis, which frequently arises in the health and social sciences as well as in survey sampling. We study methods for the analysis of a nonignorable covariate-missing data problem in an assumed conditional mean function when some covariates are completely observed but other covariates are missing for some subjects. We adopt the semiparametric perspective of Bartlett et al. (Improving upon the efficiency of complete case analysis when covariates are MNAR. Biostatistics 2014;15:719-30) on regression analyses with nonignorable missing covariates, in which they have introduced the use of two working models, the working probability model of missingness and the working conditional score model...
April 20, 2017: International Journal of Biostatistics
https://www.readbyqxmd.com/read/28422593/fundamentals-in-biostatistics-for-investigation-in-pediatric-dentistry-part-ii-biostatistical-methods
#18
Amaury Pozos-Guillén, Socorro Ruiz-Rodríguez, Arturo Garrocho-Rangel
The main purpose of the second part of this series was to provide the reader with some basic aspects of the most common biostatistical methods employed in health sciences, in order to better understand the validity, significance and reliability of the results from any article on Pediatric Dentistry. Currently, as mentioned in the first paper, Pediatric Dentists need basic biostatistical knowledge to be able to apply it when critically appraise a dental article during the Evidence-based Dentistry (EBD) process, or when participating in the development of a clinical study with dental pediatric patients...
2017: Journal of Clinical Pediatric Dentistry
https://www.readbyqxmd.com/read/28414848/-abstract-bodies-concrete-risks-clinical-devices-and-the-health-of-ova-donors-in-argentine-reproductive-medicine
#19
Lucía Ariza
Using a methodological perspective grounded in science and technology studies, this article analyzes two sociotechnical devices used in Argentine reproductive medicine (biostatistical measures and donation registries) with the aim of controlling both the so-called "genetic risk" arising from the use of donated ova as well as the health risks to female donors. By examining how the deployment of monitoring criteria disregards the specificity of ova donation, the article suggests that it is not the absence of control measures and clinical criteria that produces an inadequate monitoring of such risks, but rather the concrete ways in which such measures are implemented that results in potential harms to the health of female donors...
July 2016: Salud Colectiva
https://www.readbyqxmd.com/read/28400629/biostatistics-series-module-8-assessing-risk
#20
Avijit Hazra, Nithya Gogtay
In observational studies, as well as in interventional ones, it is frequently necessary to estimate risk that is the association between an observed outcome or event and exposure to one or more factors that may be contributing to the event. Understanding incidence and prevalence are the starting point in any discussion of risk assessment. Incidence rate uses person-time as the denominator rather than a simple count. Ideally, rates and ratios estimated from samples should be presented with their corresponding 95% confidence intervals (CIs)...
March 2017: Indian Journal of Dermatology
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