THC Content on a Dry Weight Basis: Implications for Hemp Legality.

BACKGROUND: The 2018 Farm Bill defines hemp as Cannabis sativa L. with a tetrahydrocannabinol (THC) concentration not more than 0.3% on a dry weight basis where THC is implied to be total THC (THCTotal) including both acid (Δ9-THCA) and neutral (Δ9-THC) forms. OBJECTIVE: Effect of temperature and mass were studied to determine the quickest time to prepare fresh hemp suitable for grinding without affecting THCTotal. Proficiency testing program data were also analyzed to compare THCTotal contents on a dry versus wet weight basis. METHODS: Fresh hemp of 150 and 400 g were freeze-dried or heat-treated at 50 °C, 60 °C, and 70 °C for various lengths of time up to 72 hours. Ground hemp was analyzed for moisture content via AOAC 934.01 and THCTotal via liquid chromatography/mass spectrometer (LC/MS) or gas chromatography with flame ionization detection (GC/FID). A data set analyzed from a proficiency testing program included moisture and THCTotal from 20 to 67 laboratories on 12 analytical samples circulated from 2020 through 2022. RESULTS: The quickest drying time of 24 h occurred at 70 °C with 150 g. These conditions did not affect THCTotal content on a dry weight basis. Twelve proficiency testing program analytical samples ranged from 5.8 to 11.4% moisture and 0.144 to 0.399% THCTotal on a wet weight basis. An increase in reported THCTotal on a dry weight basis compared to a wet weight basis ranged from 0.002 to 0.027% with a significant difference occurring in only one analytical sample. CONCLUSIONS: Suitable condition for drying hemp without altering THCTotal content was 24 h at 70 °C. Determining residual moisture in oven-dried ground hemp to calculate THCTotal content on a dry weight basis provides no benefit given minimal difference between contents on dry versus wet weight bases, interlaboratory variability, and terpene volatilization.

Patient Perception of Physician Reimbursement by Medicare for Artificial Urinary Sphincter Placement.

INTRODUCTION: Patient perceptions of physician reimbursement commonly differ from actual reimbursement. This study aims to improve health care cost transparency and trust between patients, physicians, and the health care system by evaluating patient perceptions of Medicare reimbursement for artificial urinary sphincter (AUS) placement. METHODS: We identified patients who underwent AUS placement at a single institution from 2014 to 2023. After obtaining informed consent, we administered a telephone survey to ask patients about their perceptions of Medicare reimbursement for AUS surgery and the amount they felt the physician should be compensated. RESULTS: Sixty-four patients were enrolled and completed the survey. On average, patients estimated Medicare physician reimbursement to be $18,920, 25 times the actual average procedure reimbursement. Once informed that the actual amount was $757.52, 97% of respondents felt that the reimbursement was "somewhat lower" (13%) or "much lower" (84%) than what they considered fair. The average amount that patients felt the physician should be paid was $8,844, 12 times the actual average procedure reimbursement. Fifty-four percent of patients estimated their physician's reimbursement to be higher than what they later reported as being "fair," representing a presurvey belief that their physician was overpaid. CONCLUSIONS: Patient perceptions of physician reimbursement for AUS are vastly different than the actual amount paid. The discordance between patient perception and actual reimbursement could impact how patients view health care costs and the relationship with their provider.

Renal autotransplantation: association between preoperative disease duration and surgical outcomes.

OBJECTIVE: To determine whether early vs. delayed autotransplantation are associated with adverse outcomes in patients undergoing renal autotransplantation. METHODS: Patients who underwent renal autotransplantation from June 2012 to September 2022 were divided into two groups based on timing of autotransplant in relation to initial intervention or diagnosis (early cohort: ≤1-year; delayed cohort: >1-year). Primary outcomes were perioperative complications, aborted surgery, renal function (glomerular filtration rate [GFR]), and postoperative complications at most recent follow-up. RESULTS: Autotransplantation patients (N=72) were predominantly female (68%) and White (54%), with a median age of 49 years. 90% of patients had undergone previous interventions, including stenting (40%) and nephrostomy tubes (49%), primarily for obstruction (64%). Early vs. delayed cohorts had median preoperative disease durations of 143 (IQR 83-222) vs. 673 days (IQR 529-1,703, p<0.001), with similar median follow-up times (879 vs. 818 days, p=0.8). Groups were similar in demographics and comorbidities. There were no significant differences in rates of aborted surgery (15% vs. 4.2%, p=0.3), perioperative complications (15% vs. 17%, p>0.9), long-term complications (49% vs. 48%, p>0.9), or changes in GFR (median change +3 vs. +4, p=0.7). Outcomes were comparable across preoperative disease durations ranging from 6 to 24 months. These findings were confirmed following adjustments for sex, body mass index, American Society of Anesthesiologists classification, race, preoperative creatinine levels, laterality, gastroesophageal reflux disease, diabetes, hypertension, nephrolithiasis, hyperlipidemia, history of colon surgery, urologic surgery, abdominal surgery, and prior interventions in separate logistic models. CONCLUSIONS: Disease duration before autotransplantation does not influence outcomes, offering reassurance for clinical decision-making in complex cases.

Virus inactivation in low ozone exposure water reuse applications.

In drinking water applications, an ozone exposure (Ct) based framework has been historically used to validate ozone disinfection. However, significant viral inactivation can be achieved with little to no measurable ozone exposure. Additionally, ozone exposure depends on multiple water quality variables as well as the calculation/ozone measurement method used. In this study, we evaluated alternative ozone monitoring frameworks as well as the impact of water quality variables on ozone decay kinetics and virus/coliform inactivation. Here we show that both change in UV254 absorbance and applied O3:TOC were well correlated with viral inactivation and these frameworks were resilient to changes in water quality. Both increasing temperature (12-30 °C) and pH (5.5-8.4) was shown to significantly increase the ozone decay rate and decreased the resulting ozone exposure by as much as ∼90% in the case of pH. However, due to the increased reaction rate of ozone with viruses at elevated temperature and pH, there was only a minor impact (∼20% in the case of pH) in overall disinfection performance for a given O3:TOC. These frameworks were also considered for variable source water with TOC (5-11 mg/L) and TSS (1.2-5.8 mg/L). Change in UV254 absorbance or applied ozone dose (mg/L) were the strongest indicators of disinfection performance for source waters of variable TOC, however site-specific testing may be needed to apply this framework. Challenge testing with influent nitrite indicated that ozone disinfection performance is significantly impacted (>50% reduction in inactivation) in the presence of nitrite thus enforcing the importance of accounting for this value in the applied ozone dose. Multi-point ozone dissolution was investigated as an alternative ozone application method that may present a benefit with respect to overall disinfection performance especially if nitrite was present. Developing and validating these alternative monitoring frameworks and ozone application methods is imperative in water reuse applications where unnecessary elevated ozone exposure may lead to harmful byproduct formation.

Triage of V-V ECMO referrals for COVID-19 respiratory failure.

BACKGROUND: As the pandemic progressed, the use of extracorporeal membrane oxygenation (ECMO) for COVID-19-related acute respiratory distress syndrome increased, and patient triage and transfer to ECMO centers became important to optimize patient outcomes. Our objectives are to identify predictors of patient transfer for veno-venous extracorporeal membrane oxygenation (V-V ECMO) evaluation as well as to describe the outcomes of accepted patients. METHODS: This is a single-center, retrospective analysis of V-V ECMO transfer requests for adult patients with known or suspected COVID-19 and respiratory failure from March 2020 until March 2021. Data were collected prospectively during the triage process for transfer requests as part of clinical patient care at our institution. RESULTS: Of 341 referred patients, 112 (33%) were accepted for transfer to our facility, whereas 229 (67%) patients were declined for transfer. The Classification and Regression Tree analysis showed that patients' high pressure during airway pressure release ventilation (APRV) and age were the variables most significantly associated with the decision to accept or decline patients for transfer. CONCLUSIONS: Our triage process enabled one-third of referred patients to be transferred for evaluation, with nearly 70% of those patients ultimately receiving ECMO support. High ventilator settings on APRV and young age were associated with acceptance for transfer. Accepted patients also had a higher incidence of adjunctive therapies (proning and paralysis) prior to transfer request, less cardiac or renal dysfunction, and a shorter duration of mechanical ventilation. Further research is warranted to investigate the outcomes of nontransferred patients.

Leaf Spot Disease Development and Its Effect on Yield of Essential Oil-Producing Hemp Cultivars in Kentucky.

Leaf spot diseases are common on field hemp, causing defoliation, and blighting. The most prevalent leaf spot diseases of hemp in Kentucky are Bipolaris leaf spot (Bipolaris gigantea), Cercospora leaf spot (Cercospora flagellaris), and Septoria leaf spot (Septoria cannabis). In this study, disease progression, cultivar susceptibility, and yield loss were examined using cultivars from four relatedness groups at two locations and in two growing seasons. Septoria leaf spot was the first leaf spot disease to be observed in the field, followed by Bipolaris leaf spot. Both diseases reduced canopy density. Cercospora leaf spot developed in the late reproductive stages as harvest approached. A wide range of susceptibility was documented, suggesting genetic variability across cultivars. Trump group cultivars were the most susceptible, while Otto II group cultivars were the least susceptible. Most importantly, leaf spot diseases had minimal influence on floral biomass and no effect on CBD yield, suggesting that, regardless of disease severity, leaf spot diseases may seldom warrant management. While the importance of foliar disease and corresponding yield loss can shift over time, variation in disease progress among leaf spot diseases and susceptibility of hemp cultivars documented in this study suggest potential disease management through cultural practices such as cultivar and planting date selections.

Conservative Management of Penile and Urethral Lichen Sclerosus: A Systematic Review.

PURPOSE: We evaluate the efficacy and safety profiles of currently available conservative management options for penile and urethral lichen sclerosus. MATERIALS AND METHODS: A systematic review of existing literature on lichen sclerosus was conducted utilizing the PubMed, Embase, and Web of Science databases. References were assessed for relevance to nonsurgical management of male genital lichen sclerosus by title and abstract by 3 independent reviewers, then reviewed in full and in duplicate by 5 independent reviewers. RESULTS: Seventeen studies describing conservative management of histologically confirmed penile and urethral lichen sclerosus in male patients were included in the final review. We present available evidence supporting the use of 4 major treatment modalities represented in the existing literature: topical corticosteroids, tacrolimus, platelet-rich plasma, and CO2 laser. We also briefly discuss the limited studies on the use of oral acitretin and polydeoxyribonucleotide injections. Outcomes assessed include symptoms, clinical appearance, quality of life, sexual satisfaction, adverse effects, and long-term efficacy of treatment. CONCLUSIONS: Topical corticosteroids remain the mainstay of conservative management of penile and urethral lichen sclerosus, with current literature supporting the use of other therapies such as tacrolimus and platelet-rich plasma as alternatives or adjuvant treatments when escalation of treatment is necessary. Future research should further explore the efficacy and safety of newer therapies through additional controlled clinical trials in the targeted population.

Evaluation of putative signatures of consciousness using specific definitions of responsiveness, connectedness, and consciousness.

BACKGROUND: Understanding the neural correlates of consciousness has important ramifications for the theoretical understanding of consciousness and for clinical anaesthesia. A major limitation of prior studies is the use of responsiveness as an index of consciousness. We identified a collection of measures derived from unresponsive subjects and more specifically their association with consciousness (any subjective experience) or connectedness (specific experience of environmental stimuli). METHODS: Using published data generated through the UNderstanding Consciousness Connectedness and Intra-Operative Unresponsiveness Study (NCT03284307), we evaluated 10 previously published resting-state EEG-based measures that were derived using unresponsiveness as a proxy for unconsciousness. Measures were tested across dexmedetomidine and propofol sedation and natural sleep. These markers represent the complexity, connectivity, cross-frequency coupling, graph theory, and power spectrum measures. RESULTS: Although many of the proposed markers were associated with consciousness per se (reported subjective experience), none were specific to consciousness alone; rather, each was also associated with connectedness (i.e. awareness of the environment). In addition, multiple markers showed no association with consciousness and were associated only with connectedness. Of the markers tested, loss of normalised-symbolic transfer entropy (front to back) was associated with connectedness across all three experimental conditions, whereas the transition from disconnected consciousness to unconsciousness was associated with significant decreases in permutation entropy and spectral exponent (P<0.05 for all conditions). CONCLUSIONS: None of the proposed EEG-based neural correlates of unresponsiveness corresponded solely to consciousness, highlighting the need for a more conservative use of the term (un)consciousness when assessing unresponsive participants. CLINICAL TRIAL REGISTRATION: NCT03284307.

Delirium is associated with loss of feedback cortical connectivity.

INTRODUCTION: Post-operative delirium (POD) is associated with increased morbidity and mortality but is bereft of treatments, largely due to our limited understanding of the underlying pathophysiology. We hypothesized that delirium reflects a disturbance in cortical connectivity that leads to altered predictions of the sensory environment. METHODS: High-density electroencephalogram recordings during an oddball auditory roving paradigm were collected from 131 patients. Dynamic causal modeling (DCM) analysis facilitated inference about the neuronal connectivity and inhibition-excitation dynamics underlying auditory-evoked responses. RESULTS: Mismatch negativity amplitudes were smaller in patients with POD. DCM showed that delirium was associated with decreased left-sided superior temporal gyrus (l-STG) to auditory cortex feedback connectivity. Feedback connectivity also negatively correlated with delirium severity and systemic inflammation. Increased inhibition of l-STG, with consequent decreases in feed-forward and feed-back connectivity, occurred for oddball tones during delirium. DISCUSSION: Delirium is associated with decreased feedback cortical connectivity, possibly resulting from increased intrinsic inhibitory tone. HIGHLIGHTS: Mismatch negativity amplitude was reduced in patients with delirium. Patients with postoperative delirium had increased feedforward connectivity before surgery. Feedback connectivity was diminished from left-side superior temporal gyrus to left primary auditory sensory area during delirium. Feedback connectivity inversely correlated with inflammation and delirium severity.

Variations in the Management of Closed Salter-Harris II Distal Tibia Fractures.

BACKGROUND: There are no formal practice guidelines for the surgical management of closed, Salter-Harris (SH) II distal tibia fractures. The purpose of this study was to survey the indications for operative and nonoperative management of this injury across pediatric tertiary care centers. METHODS: We surveyed pediatric orthopedic surgeons at 20 tertiary care level-1 pediatric trauma centers. Surgeons were provided with 16 clinical scenarios that varied based on patient age and sex, and highlighted the following surgical indications: translation <3 mm, translation ≥3 mm, sagittal plane angulation >5 degrees, and coronal plane angulation >5 degrees. Each case's scenario and radiographs after closed reduction were presented in a randomized manner. Consensus was defined as 80% agreement, and descriptive statistics were used to summarize the results. RESULTS: In total, 33 of 37 surgeons completed the survey (89% response rate). All surgeons took trauma call at a level-1 pediatric trauma center and had an average of 8.8 years (SD: 6.5 y) of experience. Consensus was reached in 4 of 16 scenarios. Specifically, nonoperative management was recommended for all scenarios showing <3 mm of translation after closed reduction. The majority of surgeons recommended operative management in scenarios showing coronal plane angulation after closed reduction, but none of these scenarios reached consensus. There was a near-equal split in operative and nonoperative management in 8 of 16 scenarios. These scenarios showed ≥3 mm translation after closed reduction and sagittal plane angulation after closed reduction. Surgeons with 6 to 10 years in practice were the most likely to recommend surgery, especially in the case of >5 degrees coronal plane angulation postreduction ( P <0.05). CONCLUSIONS: There is considerable variation regarding the indications for operative and nonoperative management of closed, SHII distal tibia fractures. Consensus was reached for nonoperative management in patients with <3 mm of translation after closed reduction; however, with greater deformity consensus regarding optimal treatment was unable to be achieved. The variation in the management of distal tibia SHII fractures is significant, suggesting that perhaps clinical equipoise exists between operative and nonoperative management. LEVEL OF EVIDENCE: V.

Subanaesthetic doses of ketamine reduce but do not eliminate predictive coding responses: implications for mechanisms of sensory disconnection.

BACKGROUND: Sensory disconnection is a key feature of sleep and anaesthesia. We have proposed that predictive coding offers a framework for understanding the mechanisms of disconnection. Low doses of ketamine that do not induce disconnection should thus diminish predictive coding, but not abolish it. METHODS: Ketamine was administered to 14 participants up to a blood concentration of 0.3 µg ml-1 Participants were played a series of tones comprising a roving oddball sequence while electroencephalography evoked response potentials were recorded. We fit a Bayesian observer model to the tone sequence, correlating neural activity with the prediction errors generated by the model using linear mixed effects models and cluster-based statistics. RESULTS: Ketamine modulated prediction errors associated with the transition of one tone to the next (transitional probability), but not how often tones changed (environmental volatility), of the system. Transitional probability was reduced when blood concentrations of ketamine were increased to 0.2-0.3 µg ml-1 (96-208 ms, P=0.003); however, correlates of prediction error were still evident in the electroencephalogram (124-168 ms, P=0.003). Prediction errors related to environmental volatility were associated with electroencephalographic activity before ketamine (224-284 ms, P=0.028) and during 0.2-0.3 µg ml-1 ketamine (108-248 ms, P=0.003). At this subanaesthetic dose, ketamine did not exert a dose-dependent modulation of prediction error. CONCLUSIONS: Subanaesthetic dosing of ketamine reduced correlates of predictive coding but did not eliminate them. Future studies should evaluate whether states of sensory disconnection, including anaesthetic doses of ketamine, are associated with a complete absence of predictive coding responses. CLINICAL TRIAL REGISTRATION: NCT03284307.

Rates and Factors Associated With Hardware Removal in Physeal Ankle Fractures: Analysis of the Pediatric Health Information System.

Background: Ankle fractures are among the most common physeal fractures in children. When surgical management is warranted, subsequent hardware removal remains controversial. This study was designed to determine rates of hardware removal in patients with physeal ankle fractures and identify risk factors for removal. Procedure data was utilized to compare rates of subsequent ankle procedures in patients with hardware removed and hardware retained. Methods: We conducted a retrospective cohort study utilizing data from the Pediatric Health Information System (PHIS) for the years 2015 through 2021. We longitudinally followed patients treated for distal tibia physeal fractures to determine the rates of hardware removal and subsequent ankle procedures. Patients with open fractures or polytrauma were excluded. We used univariate, multivariate, and descriptive statistics to characterize the rates of hardware removal, identify factors associated with removal, and assess the rates of subsequent procedures. Results: This study included 1008 patients who underwent surgical management of a physeal ankle fracture. The mean age at index surgery was 12.6 years with an SD of 2.2 years, and 60% of patients identified as male. Two hundred forty-two patients (24%) had their hardware removed at an average time of 276 days (range, 21-1435 days) following index surgery. Patients with Salter Harris III (SH-III) or Salter Harris IV (SH-IV) fractures had hardware removed more often than patients with Salter-Harris II (SH-II) fractures (28.9% vs 11.7%, P < .01). Four-year rates of subsequent ankle procedures are similar between patients with hardware removed and hardware retained. Conclusion: The rate of hardware removal in children with physeal ankle fractures is higher than previously reported. Patients of younger age, higher income, and with fractures involving the epiphysis (SH-III and SH-IV) are more likely to undergo hardware removal. Level of Evidence: Level III, retrospective study.

Optimizing Ozone Disinfection in Water Reuse: Controlling Bromate Formation and Enhancing Trace Organic Contaminant Oxidation.

The use of ozone/biofiltration advanced treatment has become more prevalent in recent years, with many utilities seeking an alternative to membrane/RO based treatment for water reuse. Ensuring efficient pathogen reduction while controlling disinfection byproducts and maximizing oxidation of trace organic contaminants remains a major barrier to implementing ozone in reuse applications. Navigating these challenges is imperative in order to allow for the more widespread application of ozonation. Here, we demonstrate the effectiveness of ozone for virus, coliform bacteria, and spore forming bacteria inactivation in unfiltered secondary effluent, all the while controlling the disinfection byproduct bromate. A greater than 6-log reduction of both male specific and somatic coliphages was seen at specific ozone doses as low as 0.75 O3:TOC. This study compared monochloramine and hydrogen peroxide as chemical bromate control measures in high bromide water (Br- = 0.35 ± 0.07 mg/L). On average, monochloramine and hydrogen peroxide resulted in an 80% and 36% decrease of bromate formation, respectively. Neither bromate control method had any appreciable impact on virus or coliform bacteria disinfection by ozone; however, the use of hydrogen peroxide would require a non-Ct disinfection framework. Maintaining ozone residual was shown to be critical for achieving disinfection of more resilient microorganisms, such as spore forming bacteria. While extremely effective at controlling bromate, monochloramine was shown to inhibit TrOC oxidation, whereas hydrogen peroxide enhanced TrOC oxidation.

Resolution of elevated interleukin-6 after surgery is associated with return of normal cognitive function.

BACKGROUND: Unresolved surgical inflammation might induce chronic cognitive decline in older adults. Although inflammatory biomarkers have been correlated with perioperative cognitive impairment and delirium, the effects of prolonged inflammation on cognition are not well studied. This prospective cohort study investigated 1-yr dynamics in plasma interleukin-6 levels and executive function. METHODS: Patients undergoing major surgery (n=170) aged ≥65 yr completed Trail Making Test B and other neuropsychological assessments with plasma interleukin-6 levels collected on postoperative days 1-9 and 90, and at 1-yr. Mixed-effects analyses were conducted for Trail Making Test B (and other assessments), including interleukin-6 levels, time, and additional confounders (fixed effects), and a random effect for participant. RESULTS: Changes in interleukin-6 levels were associated with changes in Trail Making Test B over 1 yr in a generalised additive model (ß=0.074, P<0.001) supporting that unresolved inflammation impaired executive function. This result was robust to confounders, outlier rejection, and fitting to non-linear models. Changes in interleukin-6 levels also correlated with changes in Trail Making Test A and Controlled Oral Word Association Test. Sensitivity analyses conducted on binary definitions of cognitive decline (>1, >1.5, or >2 standard deviations from baseline) were also associated with interleukin-6 changes. CONCLUSIONS: Delayed resolution of inflammation is associated with cognitive impairment after surgery. Monitoring interleukin-6 might provide an opportunity to intervene with anti-inflammatory therapies in vulnerable patients. CLINICAL TRIAL REGISTRATION: NCT01980511, NCT03124303.

Critical Review on Bromate Formation during Ozonation and Control Options for Its Minimization.

Ozone is a commonly applied disinfectant and oxidant in drinking water and has more recently been implemented for enhanced municipal wastewater treatment for potable reuse and ecosystem protection. One drawback is the potential formation of bromate, a possible human carcinogen with a strict drinking water standard of 10 µg/L. The formation of bromate from bromide during ozonation is complex and involves reactions with both ozone and secondary oxidants formed from ozone decomposition, i.e., hydroxyl radical. The underlying mechanism has been elucidated over the past several decades, and the extent of many parallel reactions occurring with either ozone or hydroxyl radicals depends strongly on the concentration, type of dissolved organic matter (DOM), and carbonate. On the basis of mechanistic considerations, several approaches minimizing bromate formation during ozonation can be applied. Removal of bromate after ozonation is less feasible. We recommend that bromate control strategies be prioritized in the following order: (1) control bromide discharge at the source and ensure optimal ozone mass-transfer design to minimize bromate formation, (2) minimize bromate formation during ozonation by chemical control strategies, such as ammonium with or without chlorine addition or hydrogen peroxide addition, which interfere with specific bromate formation steps and/or mask bromide, (3) implement a pretreatment strategy to reduce bromide and/or DOM prior to ozonation, and (4) assess the suitability of ozonation altogether or utilize a downstream treatment process that may already be in place, such as reverse osmosis, for post-ozone bromate abatement. A one-size-fits-all approach to bromate control does not exist, and treatment objectives, such as disinfection and micropollutant abatement, must also be considered.

Control of contextual memory through interneuronal α5-GABAA receptors.

γ-Aminobutyric acid type A receptors that incorporate α5 subunits (α5-GABAARs) are highly enriched in the hippocampus and are strongly implicated in control of learning and memory. Receptors located on pyramidal neuron dendrites have long been considered responsible, but here we report that mice in which α5-GABAARs have been eliminated from pyramidal neurons (α5-pyr-KO) continue to form strong spatial engrams and that they remain as sensitive as their pseudo-wild-type (p-WT) littermates to etomidate-induced suppression of place cells and spatial engrams. By contrast, mice with selective knockout in interneurons (α5-i-KO) no longer exhibit etomidate-induced suppression of place cells. In addition, the strength of spatial engrams is lower in α5-i-KO mice than p-WT littermates under control conditions. Consistent with the established role of the hippocampus in contextual fear conditioning, α5-i-KO mice resisted etomidate's suppression of freezing to context, but so too did α5-pyr-KO mice, supporting a role for extra-hippocampal regions in the development of contextual fear memory. Overall, our results indicate that interneuronal α5-GABAARs serve a physiological role in promoting spatial learning and that they mediate suppression of hippocampus-dependent contextual memory by etomidate.

Changes in Memory, Sedation, and Receptor Kinetics Imparted by the ß2-N265M and ß3-N265M GABAA Receptor Point Mutations.

Point mutations in the ß2 (N265S) and ß3 (N265M) subunits of γ-amino butyric acid type A receptors (GABAARs) that render them insensitive to the general anesthetics etomidate and propofol have been used to link modulation of ß2-GABAARs to sedation and ß3-GABAARs to surgical immobility. These mutations also alter GABA sensitivity, and mice carrying the ß3-N265M mutation have been reported to have impaired baseline memory. Here, we tested the effects of the ß2-N265M and ß3-N265M mutations on memory, movement, hotplate sensitivity, anxiety, etomidate-induced sedation, and intrinsic kinetics. We found that both ß2-N265M and ß3-N265M mice exhibited baseline deficits in the Context Preexposure Facilitation Effect learning paradigm. Exploratory activity was slightly greater in ß2-N265M mice, but there were no changes in either genotype in anxiety or hotplate sensitivity. ß2-N265M mice were highly resistant to etomidate-induced sedation, and heterozygous mice were partially resistant. In rapid solution exchange experiments, both mutations accelerated deactivation two- to three-fold compared to wild type receptors and prevented modulation by etomidate. This degree of change in the receptor deactivation rate is comparable to that produced by an amnestic dose of etomidate but in the opposite direction, indicating that intrinsic characteristics of GABAARs are optimally tuned under baseline conditions to support mnemonic function.

Prospective analysis of plasma amyloid beta and postoperative delirium in the Interventions for Postoperative Delirium: Biomarker-3 study.

BACKGROUND: The effect of postoperative delirium on the amyloid cascade of Alzheimer's dementia is poorly understood. Using early postoperative plasma biomarkers, we explored whether surgery and delirium are associated with changes in amyloid pathways. METHODS: We analysed data from 100 participants in the Interventions for Postoperative Delirium: Biomarker-3 (IPOD-B3) cohort study in the USA (NCT03124303 and NCT01980511), which recruited participants aged >65 yr undergoing non-intracranial surgery. We assessed the relationship between the change in plasma amyloid beta ratio (AßR; Aß42:Aß40) and delirium incidence (defined by the 3-Minute Diagnostic Confusion Assessment Method) and severity (quantified by the Delirium Rating Scale-Revised-98, the study's primary outcome). We also tested the relationship between plasma amyloid beta and intraoperative variables. RESULTS: Across all participants, the plasma AßR increased from the preoperative period to postoperative Day 1 (Wilcoxon P<0.001). However, this increase was not associated with delirium incidence (Wilcoxon P=0.22) or peak severity after adjusting for confounders (log[incidence rate ratio]=0.43; P=0.14). Postoperative Day 1 change in plasma AßR was not associated with postoperative Day 1 change in plasma tau, neurofilament light, or inflammatory markers (interleukin [IL]-1ß, IL-1Ra, IL-2, IL-4, IL-6, IL-8, IL-10, and IL-12), or with operative time or low intraoperative arterial pressure. CONCLUSIONS: Perioperative changes in plasma amyloid do not appear to be associated with postoperative delirium. Our findings do not support associations of dynamic changes in amyloid with postoperative delirium. CLINICAL TRIAL REGISTRATION: .NCT03124303 and NCT01980511.

Electron beam treatment for the removal of 1,4-dioxane in water and wastewater.

Electron beam (e-beam) treatment uses accelerated electrons to form oxidizing and reducing radicals when applied to water without the use of external chemicals. In this study, electron beam treatment was used to degrade 1,4-dioxane in several water matrices. Removal improved in the progressively cleaner water matrices and removals as high as 94% to 99% were observed at a dose of 2.3 kGy in secondary effluent. 1,4-dioxane removal was confirmed to be primarily through hydroxyl radical oxidation. The calculated electrical energy per order was found to be 0.53, 0.26, and 0.08 kWh/m3/order for secondary effluent (Avg. total organic carbon (TOC) 9.25 mg/L), granular activated carbon effluent (TOC 3.46 mg/L), and ultrapure water, respectively, with a 70% generation and transfer efficiency applied.