Exponent

About: Exponent is a company organization based out in Menlo Park, California, United States. It is known for research contribution in the topics: Population & Risk assessment. The organization has 1589 authors who have published 2680 publications receiving 88140 citations.

Bone development in laboratory mammals used in developmental toxicity studies

Abstract: Evaluation of the skeleton in laboratory animals is a standard component of developmental toxicology testing. Standard methods of performing the evaluation have been established, and modification of the evaluation using imaging technologies is under development. The embryology of the rodent, rabbit, and primate skeleton has been characterized in detail and summarized herein. The rich literature on variations and malformations in skeletal development that can occur in the offspring of normal animals and animals exposed to test articles in toxicology studies is reviewed. These perturbations of skeletal development include ossification delays, alterations in number, shape, and size of ossification centers, and alterations in numbers of ribs and vertebrae. Because the skeleton is undergoing developmental changes at the time fetuses are evaluated in most study designs, transient delays in development can produce apparent findings of abnormal skeletal structure. The determination of whether a finding represents a permanent change in embryo development with adverse consequences for the organism is important in study interpretation. Knowledge of embryological processes and schedules can assist in interpretation of skeletal findings.

Identifying priority health conditions, environmental data, and infrastructure needs: a synopsis of the Pew Environmental Health tracking project.

Abstract: In this article we describe the methodologic approaches of the Pew Environmental Health Commission at the Johns Hopkins Bloomberg School of Public Health used to identify priority environmental health conditions and develop recommendations to establish a national environmental public health tracking network. We present the results of a survey of public health and environmental practitioners to uncover state and local health tracking needs and priorities. We describe the steps that combined the findings from the state and local health tracking survey and a review of the state of the science on environmental impacts on health to identify priority health end points. Through an examination of national health and health care databases, we then describe trends and public health effects of those diseases that may be linked to the environment. Based on this analysis, respiratory diseases and neurologic diseases are recommended as priorities for tracking. Specific end points recommended for tracking include asthma and chronic respiratory diseases, and chronic neurodegenerative diseases such as multiple sclerosis. Based on trends in reported prevalence, consideration should also be given to developmental disabilities, reproductive disorders, and endocrine/metabolic disorders. Strengthening of current efforts to track cancer and birth defects should also be included as components of a nationwide health tracking network. Finally, we present the recommendations for environmental public health tracking. These recommendations provided the groundwork for the development of the Centers for Disease Control and Prevention's National Environmental Public Health Tracking Progam that now includes 21 states, three cities, and three academic centers throughout the nation.

Scientific integrity issues in Environmental Toxicology and Chemistry: Improving research reproducibility, credibility, and transparency

Abstract: High-profile reports of detrimental scientific practices leading to retractions in the scientific literature contribute to lack of trust in scientific experts. Although the bulk of these have been in the literature of other disciplines, environmental toxicology and chemistry are not free from problems. While we believe that egregious misconduct such as fraud, fabrication of data, or plagiarism is rare, scientific integrity is much broader than the absence of misconduct. We are more concerned with more commonly encountered and nuanced issues such as poor reliability and bias. We review a range of topics including conflicts of interests, competing interests, some particularly challenging situations, reproducibility, bias, and other attributes of ecotoxicological studies that enhance or detract from scientific credibility. Our vision of scientific integrity encourages a self-correcting culture that promotes scientific rigor, relevant reproducible research, transparency in competing interests, methods and results, and education. Integr Environ Assess Manag 2019;00:000-000. © 2019 SETAC.

Revision After Total Knee Arthroplasty and Unicompartmental Knee Arthroplasty in the Medicare Population

Abstract: This study compares the relative risk of revision and associated risk factors after total or unicompartmental knee arthroplasty (TKA or UKA) in the Medicare population. A total of 61 767 TKA and 2848 UKA patients were identified. Reviewed data included type of treatment, gender, age, race, Charlson Index for comorbidity, length of stay, Medicare buy-in for socioeconomic status, region, and year. Unicompartmental knee arthroplasty patients were at increased risk for revision at 2 and 5 years. Those patients undergoing UKA were significantly more likely to require revision in the first 5 years as compared with those undergoing TKA. Risk factors contributing to TKA revision included younger male patients with higher comorbidities and lower socioeconomic status. About UKA, lower revision rates tend to favor those surgeons with higher volume.