Effects of DDT on Amyloid Precursor Protein Levels and Amyloid Beta Pathology: Mechanistic Links to Alzheimer’s Disease Risk

Background: The interaction of aging-related, genetic, and environmental factors is thought to contribute to the etiology of late-onset, sporadic Alzheimer’s disease (AD). We previously reported that serum levels of p,p′-dichlorodiphenyldichloroethylene (DDE), a long-lasting metabolite of the organochlorine pesticide dichlorodiphenyltrichloroethane (DDT), were significantly elevated in patients with AD and associated with the risk of AD diagnosis. However, the mechanism by which DDT may contribute to AD pathogenesis is unknown.Objectives: This study sought to assess effects of DDT exposure on the amyloid pathway in multiple in vitro and in vivo models.Methods: Cultured cells (SH-SY5Y and primary neurons), transgenic flies overexpressing amyloid beta (Aβ), and C57BL/6J and 3xTG-AD mice were treated with DDT to assess impacts on the amyloid pathway. Real time quantitative polymerase chain reaction, multiplex assay, western immunoblotting and immunohistochemical methods were used to assess the effects of DDT on amyloid precursor protein (APP) and other contributors to amyloid processing and deposition.Results: Exposure to DDT revealed significantly higher APP mRNA and protein levels in immortalized and primary neurons, as well as in wild-type and AD-models. This was accompanied by higher levels of secreted Aβ in SH-SY5Y cells, an effect abolished by the sodium channel antagonist tetrodotoxin. Transgenic flies and 3xTG-AD mice had more Aβ pathology following DDT exposure. Furthermore, loss of the synaptic markers synaptophysin and PSD95 were observed in the cortex of the brains of 3xTG-AD mice.Discussion: Sporadic Alzheimer’s disease risk involves contributions from genetic and environmental factors. Here, we used multiple model systems, including primary neurons, transgenic flies, and mice to demonstrate the effects of DDT on APP and its pathological product Aβ. These data, combined with our previous epidemiological findings, provide a mechanistic framework by which DDT exposure may contribute to increased risk of AD by impacting the amyloid pathway. https://doi.org/10.1289/{"type":"entrez-protein","attrs":{"text":"EHP10576","term_id":"372009961","term_text":"EHP10576"}}EHP10576     

Effectiveness of novel,lower cost molecular human papillomavirus‐based tests for cervical cancer screening in rural china

This study examined the efficacy of the OncoE6? Cervical Test, careHPV? and visual inspection with acetic acid (VIA) in identifying women at risk for cervical cancer and their capability to detect incident cervical precancer and cancer at 1‐year follow‐up. In a population of 7,543 women living in rural China, women provided a self‐collected and two clinician‐collected specimens and underwent VIA. All screen positive women for any of the tests, a ～10% random sample of test‐negative women that underwent colposcopy at baseline, and an additional ～10% random sample of test‐negative women who did not undergo colposcopy at baseline (n = 3,290) were recruited. 2,904 women were rescreened 1 year later using the same tests, colposcopic referral criteria, and procedures. Sensitivities of baseline tests to detect 1‐year cumulative cervical intraepithelial neoplasia Grade 3 or cancer (CIN3+) were 96.5% and 81.6% for careHPV? on clinician‐collected and self‐collected specimens, respectively, and 54.4% for OncoE6? test. The OncoE6? test was very specific (99.1%) and had the greatest positive predictive value (PPV; 47.7%) for CIN3+. Baseline and 1‐year follow‐up cervical specimens testing HPV DNA positive was sensitive (88.0%) but poorly predictive (5.5–6.0%) of incident CIN2+, whereas testing repeat HPV16, 18 and 45 E6 positive identified only 24.0% of incident CIN2+ but had a predictive value of 33.3%. This study highlights the different utility of HPV DNA and E6 tests, the former as a screening and the latter as a diagnostic test, for detection of cervical precancer and cancer.     

High prevalence of severe nausea and vomiting of pregnancy and hyperemesis gravidarum among relatives of affected individuals

Objective

The goal of this study was to determine the prevalence of severe nausea and vomiting of pregnancy/hyperemesis gravidarum among relatives of affected individuals.

Study design

Family history data were obtained on 1224 self-reported cases of hyperemesis gravidarum. Cases completed an online survey administered by the Hyperemesis Education and Research Foundation between 2003 and 2006.

Results

Approximately 28% of cases reported their mother had severe nausea and vomiting or hyperemesis gravidarum while pregnant with them. Of the 721 sisters with a pregnancy history, 137 (19%) had hyperemesis gravidarum. Among the most severe cases, those requiring total parenteral nutrition or nasogastric feeding tube, the proportion of affected sisters was even higher, 49/198 (25%). Nine percent of cases reported having at least two affected relatives including sister(s), mother, grandmother, daughters, aunt(s), and cousin(s).

Conclusion

There is a high prevalence of severe nausea and vomiting of pregnancy/hyperemesis gravidarum among relatives of hyperemesis gravidarum cases in this study population. Because the incidence of hyperemesis gravidarum is most commonly reported to be 0.5%, this study provides strong but preliminary evidence for a genetic component to extreme nausea and vomiting of pregnancy.     

REACT: Rapid Evaluation Assessment of Clinical Reasoning Tool

IntroductionClinical reasoning encompasses the process of data collection, synthesis, and interpretation to generate a working diagnosis and make management decisions. Situated cognition theory suggests that knowledge is relative to contextual factors, and clinical reasoning in urgent situations is framed by pressure of consequential, time-sensitive decision-making for diagnosis and management. These unique aspects of urgent clinical care may limit the effectiveness of traditional tools to assess, teach, and remediate clinical reasoning.MethodsUsing two validated frameworks, a multidisciplinary group of clinicians trained to remediate clinical reasoning and with experience in urgent clinical care encounters designed the novel Rapid Evaluation Assessment of Clinical Reasoning Tool (REACT). REACT is a behaviorally anchored assessment tool scoring five domains used to provide formative feedback to learners evaluating patients during urgent clinical situations. A pilot study was performed to assess fourth-year medical students during simulated urgent clinical scenarios. Learners were scored using REACT by a separate, multidisciplinary group of clinician educators with no additional training in the clinical reasoning process. REACT scores were analyzed for internal consistency across raters and observations.ResultsOverall internal consistency for the 41 patient simulations as measured by Cronbach’s alpha was 0.86. A weighted kappa statistic was used to assess the overall score inter-rater reliability. Moderate reliability was observed at 0.56.DiscussionTo our knowledge, REACT is the first tool designed specifically for formative assessment of a learner’s clinical reasoning performance during simulated urgent clinical situations. With evidence of reliability and content validity, this tool guides feedback to learners during high-risk urgent clinical scenarios, with the goal of reducing diagnostic and management errors to limit patient harm.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11606-022-07513-5.     

Oxidative Balance Score during Pregnancy Is Associated with Oxidative Stress in the CANDLE Study

The objective of this study was to calculate an oxidative balance score (OBS) utilizing diet and lifestyle information collected from 1322 women during the second trimester of pregnancy in the Conditions Affecting Neurocognitive Development and Learning in Early Childhood study. An energy-adjusted OBS was calculated using nutrient information from a Food Frequency Questionnaire (FFQ), lifestyle measures, and plasma folate and vitamin D levels. Using the least absolute shrinkage and selection operator method, 91 food items from the FFQ were selected and they accounted for 82% of the variance in the OBS, with cruciferous vegetables, citrus fruits, fruit juice, and coffee being among the highest anti-oxidant predictors, and red meats and alcohol among the highest pro-oxidant contributors. Urinary F₂-isoprostane, an objective indicator of oxidative stress, was lower with increasing OBS quintiles in a stairstep manner (p for trend = 0.0003), suggesting the possible utility of the OBS as an indicator of oxidative stress. The OBS was moderately correlated with the Healthy Eating Index (correlation coefficient = 0.6076), suggesting it provides a distinct measure of a healthy diet. In conclusion, the OBS may serve as a valid reflective indicator of urinary F₂-isoprostanes and an epidemiological tool to inform intervention studies, in order to minimize oxidative stress during pregnancy.