Use of Potentially Inappropriate Medications among Older Adults with Dementia or Cognitive Impairment Attending Memory Clinics: A Protocol for a Systematic Review and Meta-Analysis.

Introduction: Older adults with dementia who are on multiple medications are more vulnerable to the use of potentially inappropriate medications (PIMs), which can significantly increase the risk of adverse events and drug-related problems. PIMs use is prevalent and varies among older adults with dementia or cognitive impairment (CI) attending memory clinics. However, the prevalence of PIMs, polypharmacy, and hyper-polypharmacy among older adults with dementia or CI who are attending memory clinics is not well understood. We will conduct a systematic review and meta-analyses to examine the overall estimate of the prevalence of the PIMs, polypharmacy, and hyper-polypharmacy use among older adults attending memory clinics, with dementia or CI. The secondary objective of this study will be to compile a list of commonly implicated PIMs and to investigate factors that may be associated with using PIMs in this population. Methods: Ovid MEDLINE, Ovid Embase, Scopus, Cochrane library, EBSCOhost CINAHL, and Ovid International Pharmaceutical Abstracts (IPA) will be systematically searched by a researcher (R.S.) with the help of a librarian (C.C.). All databases will be searched from inception to May 05, 2023. Cross-sectional, cohort, randomized clinical trials, quasi-experimental, and case-control studies will be included if they assess PIM's use among older adults with dementia and/or CI. A step-by-step guide by Pai et al. [Natl Med J India. 2004;17(2):86-95] will be followed when conducting this systematic review (S.R.). The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) checklist will be followed for reporting this SR. Conclusion: The findings from this SR/MA will identify the pooled prevalence of PIMs, providing a more precise estimate of the true prevalence of the PIMs, polypharmacy, hyper-polypharmacy in older adults with dementia or CI who are attending memory clinics at primary, secondary, or tertiary healthcare settings by considering the results of multiple studies.

Defining echocardiographic predictors of outcome in cardiac amyloidosis by subtype.

BACKGROUND: Current echocardiographic risk factors for prognosis in cardiac amyloidosis (CA) do not distinguish between the two main subtypes: transthyretin cardiomyopathy (TTR) and immunoglobulin light chain cardiomyopathy (AL), each of which require distinct diagnostic and therapeutic approaches. Additionally, only traditional parameters have been studied with little data on advanced techniques. Accordingly, we sought to determine whether differences exist in 2D transthoracic echocardiography (2DE) predictors of survival between the CA subtypes using a comprehensive approach. METHODS: 220 patients (72±12 years) with confirmed CA (AL=89, TTR=131) who underwent 2DE at the time of CA diagnosis were enrolled. Left ventricular (LV) dimensions, indexed mass (LVMi), global longitudinal strain (LVGLS), apical-sparing ratio (LVASR), diastology, right ventricular (RV) size and function indices including tricuspid annular systolic excursion (TAPSE), RV free-wall (RVFWS) and global (RVGLS) strain, indexed left (LA) and right atrial volumes (LAVi and RAVi), LA strain (reservoir and booster) and RV systolic pressure (RVSP) were measured. A propensity-score weighted stepwise variable selection Cox proportional hazards model derived from NYHA class and renal impairment status at diagnosis was used to determine the associations between 2DE parameters and mortality specific to CA subtype over a median follow-up of 36-months. RESULTS: After adjusting for age, atrial fibrillation and treatment, parameters associated with survival were RVFWS (p=0.003, HR 1.15, 95% CI[1.053,1.245]) and RVSP (p=0.03, HR 1.03, 95% CI[1.004,1.063]) in AL and LVASR (p=0.007, HR 6.68, 95% CI[1.75,25.492]) and RAVi (p=0.049, HR 1.03, 95% CI[1.000,1.052]) in TTR. CONCLUSIONS: Echocardiographic prognosticators for survival are specific to cardiac amyloid subtype. These results potentially provide information critical for clinical decision-making and follow-up in these patients.

Updated Review of Treatment of Androgenetic Alopecia.

Alopecia, a widespread issue affecting both genders, often manifests as androgenetic alopecia, although a thorough examination is needed to rule out other causes. This chapter focuses on the treatment of androgenetic alopecia. Finasteride and minoxidil, the Food and Drug Administration-approved treatments, offer stability and in some cases improvement in scalp coverage. Platelet-rich plasma exhibits positive results as an off-label alopecia therapy. For eligible individuals, hair transplantation proves effective, using healthy follicular units to restore hair-bearing areas. Multiple options allow for the tailoring of interventions to each patient.

PFAS fate using lysimeters during degraded soil reclamation using biosolids.

Carbon- and nutrient-rich biosolids are used in agriculture and land reclamation. However, per- and polyfluoroalkyl substances (PFAS) typically present in biosolids raise concerns of PFAS leaching to groundwater and plant uptake. Here, we investigated PFAS persistence and leaching from biosolids applied to a site constructed artificially to mimic degraded soils. Treatments included biosolids and biosolids blended with mulch applied at different rates to attain either one and five times the agronomic N rate for vegetable crops and a control treatment with synthetic urea and triple superphosphate fertilizer. Leachates were collected for a 2-year period from 15-cm depth zero-tension drainage lysimeters. Soils were analyzed post biosolids application. PFAS were quantified using isotope-dilution, solid-phase extraction and liquid chromatography tandem mass spectrometry. Leachate profiles exemplified an initial high total PFAS concentration, followed by a sharp decline and subsequent small fluctuations attributed to pre-existing soil conditions and rainfall patterns. Quantifiable PFAS in leachate were proportional to biosolids application rates. Short-chain perfluoroalkyl acids (CF2 < 6) were dominant in leachate, while the percentage of longer chains homologues was higher in soils. A 43% biosolids blend with mulch resulted in 21% lower PFAS leachate concentrations even with the blend application rate being 1.5 times higher than biosolids due to the blend's lower N-content. The blending effect was more pronounced for long-chain perfluoroalkyl sulfonic acids that have a greater retention by soils and the air-water interface. Biosolids blending as a pragmatic strategy for reducing PFAS leachate concentrations may aid in the sustainable beneficial reuse of biosolids.

Does salinity mediate the toxicity of perfluorooctanesulfonic acid (PFOS) in an estuarine fish?

Perfluorooctanesulfonic acid (PFOS) is detected in estuarine environments, where salinity levels fluctuate regularly. We investigated the effects of salinity on the toxicity of PFOS in embryos and larvae of Cyprinodon variegatus. We crossed six PFOS treatments (0, 1-10,000 µg/L) with two salinities (10, 30 ppt). Larvae exposed to the highest concentration of PFOS under high salinity accumulated over twice the amount of PFOS compared to larvae maintained under low salinity. Embryonic survival was unaffected by PFOS, salinity, or their interaction. PFOS delayed time to hatch and increased salinity reduced time to hatch regardless of PFOS treatment; however, no salinity by PFOS interactions were observed. Conversely, PFOS and salinity interacted in the larval stage, with decreased survival at 30 ppt salinity. This is one of the first studies evaluating interactive effects of PFOS and high salinity and highlights the importance of assessing PFAS toxicity across life stages.

Assessing the Combined Effects of Host and Parasite Exposure to Forever Chemicals in an Amphibian-Echinostome System.

Per- and polyfluoroalkyl substances (PFAS) are environmental contaminants of growing concern due to their potential negative effects on wildlife and human health. Per- and polyfluoroalkyl substances have been shown to alter immune function in various taxa, which could influence the outcomes of host-parasite interactions. To date, studies have focused on the effects of PFAS on host susceptibility to parasites, but no studies have addressed the effects of PFAS on parasites. To address this knowledge gap, we independently manipulated exposure of larval northern leopard frogs (Rana pipiens) and parasites (flatworms) via their snail intermediate host to environmentally relevant PFAS concentrations and then conducted trials to assess host susceptibility to infection, parasite infectivity, and parasite longevity after emergence from the host. We found that PFAS exposure to only the host led to no significant change in parasite load, whereas exposure of parasites to a 10-µg/L mixture of PFAS led to a significant reduction in parasite load in hosts that were not exposed to PFAS. We found that when both host and parasite were exposed to PFAS there was no difference in parasite load. In addition, we found significant differences in parasite longevity post emergence following exposure to PFAS. Although some PFAS-exposed parasites had greater longevity, this did not necessarily translate into increased infection success, possibly because of impaired movement of the parasite. Our results indicate that exposure to PFAS can potentially impact host-parasite interactions. Environ Toxicol Chem 2024;43:1537-1546. © 2024 SETAC.

Echocardiographic Detection of Regional Wall Motion Abnormalities Using Artificial Intelligence Compared to Human Readers.

BACKGROUND: Although regional wall motion abnormality (RWMA) detection is foundational to transthoracic echocardiography, current methods are prone to interobserver variability. We aimed to develop a deep learning (DL) model for RWMA assessment and compare it to expert and novice readers. METHODS: We used 15,746 transthoracic echocardiography studies-including 25,529 apical videos-which were split into training, validation, and test datasets. A convolutional neural network was trained and validated using apical 2-, 3-, and 4-chamber videos to predict the presence of RWMA in 7 regions defined by coronary perfusion territories, using the ground truth derived from clinical transthoracic echocardiography reports. Within the test cohort, DL model accuracy was compared to 6 expert and 3 novice readers using F1 score evaluation, with the ground truth of RWMA defined by expert readers. Significance between the DL model and novices was assessed using the permutation test. RESULTS: Within the test cohort, the DL model accurately identified any RWMA with an area under the curve of 0.96 (0.92-0.98). The mean F1 scores of the experts and the DL model were numerically similar for 6 of 7 regions: anterior (86 vs 84), anterolateral (80 vs 74), inferolateral (83 vs 87), inferoseptal (86 vs 86), apical (88 vs 87), inferior (79 vs 81), and any RWMA (90 vs 94), respectively, while in the anteroseptal region, the F1 score of the DL model was lower than the experts (75 vs 89). Using F1 scores, the DL model outperformed both novices 1 (P = .002) and 2 (P = .02) for the detection of any RWMA. CONCLUSIONS: Deep learning provides accurate detection of RWMA, which was comparable to experts and outperformed a majority of novices. Deep learning may improve the efficiency of RWMA assessment and serve as a teaching tool for novices.

Tools to measure barriers to medication management capacity in older adults: a scoping review.

BACKGROUND: Medication management capacity is a crucial component of medication adherence, particularly among older adults. Various factors, including physical abilities, cognitive functions, sensory capabilities, motivational, and environmental factors, influence older adults' ability to manage medications. It is, therefore, crucial to identify appropriate tools that allow clinicians to determine which factors may impact medication management capacity and, consequently, nonadherence to medications. PURPOSE: 1)To identify tools that measure physical, cognitive, sensory (vision, hearing, touch), motivational, and environmental barriers to medication self-management in older adults, and 2) to understand the extent to which these tools assess various barriers. METHODS: The scoping review was conducted using Arksey and O'Malley's scoping review framework and the PRISMA Extension for Scoping Reviews checklist. In June 2022, the relevant literature was identified by searching PubMed (MEDLINE), Ovid Embase, Ovid IPA, EBSCOhost CINAHL, APA PsycINFO, and Scopus. RESULTS AND DISCUSSION: In total, 7235 studies were identified. Following the removal of duplicates, 4607 articles were screened by title and abstract, of which 4253 did not meet the inclusion criteria. Three reviewers reviewed the full texts of the remaining 354 articles; among them, 41 articles, 4 theses and 1 conference abstract met the inclusion criteria. From the included studies, 44 tools were identified that measured a combination of physical, cognitive, sensory, motivational, and environmental barriers (n=19) or only cognition (n=13), vision (n=5), environmental factors (n=3), auditory (n=1), and motivational factors (n=1). The review also examined the psychometric properties of the identified tools and found that most of them had reported validity and reliability data. Several tools have demonstrated promise in assessing a combination of barriers with validity and reliability. These tools include the Self-Medication Assessment Tool (SMAT), ManageMed Screening (MMS), Self-Medication Risk Assessment Tool (RAT), HOME-Rx revised, and Medication Management Ability Assessment (MMAA). CONCLUSION: This scoping review identified 44 validated tools to measure various challenges that older adults encounter with medication management. However, no tool measures all five barriers (physical, cognitive, sensory, motivational, and environmental) to medication-taking at home. Therefore, utilizing a combination of tools would be most appropriate to measure these different aspects comprehensively. Further research is needed to develop a new comprehensive tool that simultaneously measures various barriers to medication self-management.

Multimodal Management of Coexisting Atlantoaxial Subluxation and Spinal Stenosis in an Older Adult: A Case Report and Literature Review.

This case report investigates the diagnostic and therapeutic challenges caused by the coexistence of atlantoaxial subluxation and spinal stenosis in a 70-year-old male patient with chronic progressive numbness in both hands. A detailed assessment showed that the patient's symptoms were primarily caused by spinal stenosis, not atlantoaxial subluxation. Considering the patient's age and preference for nonsurgical treatment, a conservative chiropractic care plan was implemented, significantly improving his symptoms and quality of life. This case highlights the potential benefit of conservative chiropractic care in managing such complex cases, emphasizes the need for meticulous diagnosis, and requires further research to validate these findings and develop comprehensive management guidelines.

Use of a Novel Artificial Intelligence System Leads to the Detection of Significantly Higher Number of Adenomas During Screening and Surveillance Colonoscopy: Results From a Large, Prospective, US Multicenter, Randomized Clinical Trial.

INTRODUCTION: Adenoma per colonoscopy (APC) has recently been proposed as a quality measure for colonoscopy. We evaluated the impact of a novel artificial intelligence (AI) system, compared with standard high-definition colonoscopy, for APC measurement. METHODS: This was a US-based, multicenter, prospective randomized trial examining a novel AI detection system (EW10-EC02) that enables a real-time colorectal polyp detection enabled with the colonoscope (CAD-EYE). Eligible average-risk subjects (45 years or older) undergoing screening or surveillance colonoscopy were randomized to undergo either CAD-EYE-assisted colonoscopy (CAC) or conventional colonoscopy (CC). Modified intention-to-treat analysis was performed for all patients who completed colonoscopy with the primary outcome of APC. Secondary outcomes included positive predictive value (total number of adenomas divided by total polyps removed) and adenoma detection rate. RESULTS: In modified intention-to-treat analysis, of 1,031 subjects (age: 59.1 ± 9.8 years; 49.9% male), 510 underwent CAC vs 523 underwent CC with no significant differences in age, gender, ethnicity, or colonoscopy indication between the 2 groups. CAC led to a significantly higher APC compared with CC: 0.99 ± 1.6 vs 0.85 ± 1.5, P = 0.02, incidence rate ratio 1.17 (1.03-1.33, P = 0.02) with no significant difference in the withdrawal time: 11.28 ± 4.59 minutes vs 10.8 ± 4.81 minutes; P = 0.11 between the 2 groups. Difference in positive predictive value of a polyp being an adenoma among CAC and CC was less than 10% threshold established: 48.6% vs 54%, 95% CI -9.56% to -1.48%. There were no significant differences in adenoma detection rate (46.9% vs 42.8%), advanced adenoma (6.5% vs 6.3%), sessile serrated lesion detection rate (12.9% vs 10.1%), and polyp detection rate (63.9% vs 59.3%) between the 2 groups. There was a higher polyp per colonoscopy with CAC compared with CC: 1.68 ± 2.1 vs 1.33 ± 1.8 (incidence rate ratio 1.27; 1.15-1.4; P < 0.01). DISCUSSION: Use of a novel AI detection system showed to a significantly higher number of adenomas per colonoscopy compared with conventional high-definition colonoscopy without any increase in colonoscopy withdrawal time, thus supporting the use of AI-assisted colonoscopy to improve colonoscopy quality ( ClinicalTrials.gov NCT04979962).

Removal of per- and polyfluoroalkyl substances from wastewater via aerosol capture.

The widespread use of per- and polyfluoroalkyl substances (PFAS)-containing products in numerous commercial and industrial applications has resulted in their occurrence in wastewater treatment plants (WWTPs). Herein, proof-of-concept bench-scale experiments were performed to measure the extent to which PFAS could be removed from a WWTP if aerosols generated during aeration were captured. Experiments were designed to mimic the aeration rate:water volume ratio, the water volume:surface area ratio, and aeration bubble size applicable to the full-scale aeration vessel. Results showed that substantial (75%) removal of perfluorooctane sulfonate (PFOS) was observed under these operating conditions in the bench-scale system; up to 97% PFOS removal was observed if the aeration rate was increased 3-fold. PFAS removal generally increased with increasing aerosol capture and with increasing PFAS surface activity. Analysis of semi-quantified PFAS showed that the semi-quantified PFAS accounted for approximately 93% of the identified PFAS in the raw wastewater, dominated largely by the presence of 2:2 fluorotelomer carboxylic acid (2:2 FTCA). This preliminary study suggests that aerosol capture in aeration basins has potential for mitigating PFAS in WWTPs. Further testing is needed to assess the feasibility of this approach at the field scale.

Comparison of assistance preferences of older adults with different functional dependence levels on domestic tasks performed by robots.

BACKGROUND: Robots have the potential to assist older adults in their home-based daily living tasks. Previous studies indicated that older adults generally accept robot assistance. However, the preferences of older adults with different functional dependence levels are lacking. These older adults encounter varying levels of difficulty in daily living and may have distinct preferences for robot assistance. This study aimed to describe and compare the preferences for robot assistance on domestic tasks in older adults with different functional dependence levels. METHODS: This cross-sectional descriptive study recruited a convenience sample of 385 older adults in Hong Kong. They were categorized as independent, partially dependent, and dependent using the Katz Index of Independence in Activities of Daily Living. Their preferences for robot assistance on a list of 48 domestic tasks under six categories were assessed through the Assistance Preference Checklist. Differences in preferences between the three groups were compared using one-way ANOVA test. RESULTS: Findings revealed the differences and similarities in preferences between participants with different dependence levels. In most domestic tasks under the personal care category, dependent and partially dependent older adults reported a significantly lower preferences for human assistance or a higher preferences for robot assistance (p < 0.001), compared with the independent ones. The effect size varied from medium to large (eta squared = 0.07 to 0.52). However, participants, regardless of functional dependence levels, preferred human to assist in some domestic tasks under the health and leisure activities category and preferred robot to assist in most of the domestic tasks under the chores, information management, and manipulating objects category. CONCLUSIONS: Older adults with different levels of functional dependence exhibit different preferences for robotic assistance. To effectively use robots and assist older adults as they age, the specific preferences of older adults must be considered before designing and introducing robots in domestic care.

Reduction of airborne and surface-borne bacteria in a medical center burn intensive care unit using active, upper-room, germicidal ultraviolet (GUV) disinfection.

OBJECTIVE: To determine the effectiveness of active, upper-room, germicidal ultraviolet (GUV) devices in reducing bacterial contamination in patient rooms in air and on surfaces as a supplement to the central heating, ventilation, and air conditioning (HVAC) air handling unit (AHU) with MERV 14 filters and UV-C disinfection. METHODS: This study was conducted in an academic medical center, burn intensive care unit (BICU), for 4 months in 2022. Room occupancy was monitored and recorded. In total, 402 preinstallation and postinstallation bacterial air and non-high-touch surface samples were obtained from 10 BICU patient rooms. Airborne particle counts were measured in the rooms, and bacterial air samples were obtained from the patient-room supply air vents and outdoor air, before and after the intervention. After preintervention samples were obtained, an active, upper-room, GUV air disinfection system was deployed in each of the patient rooms in the BICU. RESULTS: The average levels of airborne bacteria of 395 CFU/m3 before GUV device installation and 37 CFU/m3 after installation indicated an 89% overall decrease (P < .0001). Levels of surface-borne bacteria were associated with a 69% decrease (P < .0001) after GUV device installation. Outdoor levels of airborne bacteria averaged 341 CFU/m3 in March before installation and 676 CFU/m3 in June after installation, but this increase was not significant (P = .517). CONCLUSIONS: Significant reductions in air and surface contamination occurred in all rooms and areas and were not associated with variations in outdoor air concentrations of bacteria. The significant decrease of surface bacteria is an unexpected benefit associated with in-room GUV air disinfection, which can potentially reduce overall bioburden.

Beyond duodenoscope-transmitted infections: Analysis of surface bioburden and UV-C mitigation within a tertiary care endoscopy unit.

BACKGROUND: An inpatient endoscopy unit is a care hub for patients from throughout the hospital and can be the site of health care-associated infections (HAIs). Shared surfaces and other nonmedical devices (keyboards) have been increasingly recognized as sites of pathogen transmission. Beyond standard cleaning of high-touch target areas, we queried whether the addition of automated devices delivering low-intensity doses of ultraviolet (UV)-C radiation could further reduce bioburden in an academic endoscopy unit. METHODS: Bioburden on previously identified high-touch/communal surfaces was measured before and after the installation of automated, low-intensity UV-light emitting devices (UV Angel) that passively monitor and disinfect targeted surfaces with Ultraviolet-C light (UV-C) light. RESULTS: High-touch sites (keyboards) had a baseline bacterial contamination of >80%, whereas individual procedure rooms and common areas had a >57% contamination rate. Following the implementation of automated UV-C light decontamination, bioburden was reduced on average by >91% at high-touch surfaces and within procedure rooms. DISCUSSION/CONCLUSIONS: Nonsterile hubs of patient care could serve as sites of "silent" HAI transmission. We have identified high-touch surfaces within an endoscopy unit that have a high bioburden of bacterial contamination and demonstrated that the installation of passive, automated UV-C light disinfection devices can reduce bioburden significantly, possibly mitigating HAI transmission between patients.

Protein biomarkers and alternatively methylated cell-free DNA detect early stage pancreatic cancer.

OBJECTIVE: Pancreatic ductal adenocarcinoma (PDAC) is commonly diagnosed at an advanced stage. Liquid biopsy approaches may facilitate detection of early stage PDAC when curative treatments can be employed. DESIGN: To assess circulating marker discrimination in training, testing and validation patient cohorts (total n=426 patients), plasma markers were measured among PDAC cases and patients with chronic pancreatitis, colorectal cancer (CRC), and healthy controls. Using CA19-9 as an anchor marker, measurements were made of two protein markers (TIMP1, LRG1) and cell-free DNA (cfDNA) pancreas-specific methylation at 9 loci encompassing 61 CpG sites. RESULTS: Comparative methylome analysis identified nine loci that were differentially methylated in exocrine pancreas DNA. In the training set (n=124 patients), cfDNA methylation markers distinguished PDAC from healthy and CRC controls. In the testing set of 86 early stage PDAC and 86 matched healthy controls, CA19-9 had an area under the receiver operating characteristic curve (AUC) of 0.88 (95% CI 0.83 to 0.94), which was increased by adding TIMP1 (AUC 0.92; 95% CI 0.88 to 0.96; p=0.06), LRG1 (AUC 0.92; 95% CI 0.88 to 0.96; p=0.02) or exocrine pancreas-specific cfDNA methylation markers at nine loci (AUC 0.92; 95% CI 0.88 to 0.96; p=0.02). In the validation set of 40 early stage PDAC and 40 matched healthy controls, a combined panel including CA19-9, TIMP1 and a 9-loci cfDNA methylation panel had greater discrimination (AUC 0.86, 95% CI 0.77 to 0.95) than CA19-9 alone (AUC 0.82; 95% CI 0.72 to 0.92). CONCLUSION: A combined panel of circulating markers including proteins and methylated cfDNA increased discrimination compared with CA19-9 alone for early stage PDAC.

Toxicities of Legacy and Current-Use PFAS in an Anuran: Do Larval Exposures Influence Responses to a Terrestrial Pathogen Challenge?

Legacy polyfluoroalkyl substances (PFAS) [perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA)] are being replaced by various other fluorinated compounds, such as hexafluoropropylene oxide dimer acid (GenX). These alternatives are thought to be less bioaccumulative and, therefore, less toxic than legacy PFAS. Contaminant exposures occur concurrently with exposure to natural stressors, including the fungal pathogen Batrachocytrium dendrobatidis (Bd). Despite evidence that other pollutants can increase the adverse effects of Bd on anurans, no studies have examined the interactive effects of Bd and PFAS. This study tested the growth and developmental effects of PFOS, PFOA, and GenX on gray treefrog (Hyla versicolor) tadpoles, followed by a Bd challenge after metamorphosis. Despite PFAS exposure only occurring during the larval stage, carry-over effects on growth were observed post metamorphosis. Further, PFAS interacted with Bd exposure to influence growth; Bd-exposed animals had significantly shorter SVL [snout-vent length (mm)] with significantly increased body condition, among other time-dependent effects. Our data suggest that larval exposure to PFAS can continue to impact growth in the juvenile stage after exposure has ended. Contrary to predictions, GenX affected terrestrial performance more consistently than its legacy congener, PFOA. Given the role of Bd in amphibian declines, further investigation of interactions of PFAS with Bd and other environmentally relevant pathogens is warranted.

Differential Developmental Neurotoxicity and Tissue Uptake of the Per- and Polyfluoroalkyl Substance Alternatives, GenX and PFBS.

Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic chemicals with several applications. Multiple adverse health effects are reported for longer carbon chain (≤C8) PFAS. Shorter carbon chain PFAS, [e.g., hexafluoropropylene oxide dimer acid (HFPO-DA; GenX) and perfluorobutanesulfonic acid (PFBS)] were introduced as alternatives. Past studies indicate that longer-chain PFAS are neurotoxic targeting the dopamine pathway, but it is not known if shorter-chain PFAS act similarly. This study aimed to evaluate developmental neurotoxicity and tissue uptake of GenX and PFBS using the zebrafish (Danio rerio). First, acute toxicity was assessed by measuring LC50 at 120 h postfertilization (hpf). Body burden was determined after embryonic exposure (1-72 hpf) to sublethal concentrations of GenX or PFBS by LC-ESI-MS/MS. Locomotor activity using a visual motor response assay at 120 hpf and dopamine levels at 72 hpf was assessed after embryonic exposure. PFBS was more acutely toxic and bioaccumulative than GenX. GenX and PFBS caused hyperactivity at 120 hpf, but stronger behavioral alterations were observed for PFBS. An increase in whole organism dopamine occurred at 40 ppb of GenX, while a decrease was observed at 400 ppb of PFBS. Differences detected in dopamine for these two PFAS indicate differential mechanisms of developmental neurotoxicity.