Adaptation of a risk-based framework for evaluating indirect effects of dredging on sensitive habitats near federal navigation channels: An application of the framework to coral reefs at Honolulu Harbor, Hawai'i.

In major harbors and ports in the United States and its territories, the US Army Corps of Engineers maintains federal navigation channels in proximity to coral reefs (e.g., Honolulu Harbor, HI; Miami Harbor, FL; Apra Harbor, Guam) and other sensitive habitats. To effectively predict potential adverse impacts from dredging activities near these sensitive habitats, a holistic approach to improve understanding of the pressures on these habitats is needed to foster a more complete prediction of risk drivers. To achieve this, risk-based frameworks that account for the full range of natural and anthropogenic impacts need to be adapted and applied specifically for assessing and managing indirect dredging impacts on sensitive environments. In this article, we address this need by incorporating a drivers-pressures-stressors-condition-response (DPSCR4 ) conceptual framework to broaden a comprehensive conceptual model of the coupled human-ecological system. To help understand these complex interactions, DPSCR4 was applied to evaluate dredging and other unrelated environmental pressures (e.g., terrestrial runoff) in a proof-of-concept dredging project in Honolulu Harbor, Hawai'i, USA, with a focus on the indirect effects of dredge plumes. Particle tracking models and risk-based tools were used to evaluate sediment resuspended during a hypothetical mechanical dredging activity near sensitive coral habitats. Stoplight indicators were developed to predict indirect sediment plume impacts on coral and then compared to exposure modeling results. The strengths and limitations of the approach are presented and the incorporation of the risk framework into environmental management decisions is discussed. Integr Environ Assess Manag 2024;20:547-561. Published 2023. This article is a U.S. Government work and is in the public domain in the USA.

Automated Detection of Aortic Stenosis Using Machine Learning.

BACKGROUND: Aortic stenosis (AS) is a degenerative valve condition that is underdiagnosed and undertreated. Detection of AS using limited two-dimensional echocardiography could enable screening and improve appropriate referral and treatment of this condition. The aim of this study was to develop methods for automated detection of AS from limited imaging data sets. METHODS: Convolutional neural networks were trained, validated, and tested using limited two-dimensional transthoracic echocardiographic data sets. Networks were developed to accomplish two sequential tasks: (1) view identification and (2) study-level grade of AS. Balanced accuracy and area under the receiver operator curve (AUROC) were the performance metrics used. RESULTS: Annotated images from 577 patients were included. Neural networks were trained on data from 338 patients (average n = 10,253 labeled images), validated on 119 patients (average n = 3,505 labeled images), and performance was assessed on a test set of 120 patients (average n = 3,511 labeled images). Fully automated screening for AS was achieved with an AUROC of 0.96. Networks can distinguish no significant (no, mild, mild to moderate) AS from significant (moderate or severe) AS with an AUROC of 0.86 and between early (mild or mild to moderate AS) and significant (moderate or severe) AS with an AUROC of 0.75. External validation of these networks in a cohort of 8,502 outpatient transthoracic echocardiograms showed that screening for AS can be achieved using parasternal long-axis imaging only with an AUROC of 0.91. CONCLUSION: Fully automated detection of AS using limited two-dimensional data sets is achievable using modern neural networks. These methods lay the groundwork for a novel method for screening for AS.

The Role of Serious Video Games in the Treatment of Disordered Eating Behaviors: Systematic Review.

BACKGROUND: Eating disorders and other forms of disordered eating cause significant complications and comorbidities in patients. However, full remission with current standard treatment remains low. Challenges to treatment include underdiagnosis and high dropout rates, as well as difficulties in addressing underlying emotion dysregulation, poor impulse control, and personality traits. Serious video games (SVGs), which have the advantages of being highly engaging and accessible, may be potential tools for delivering various forms of treatment in addressing the underlying psychopathology of disordered eating. OBJECTIVE: This review aims to provide an overview of the possible mechanisms by which SVGs may affect the clinical course of disordered eating, while evaluating the outcomes of studies that have assessed the role of SVGs in the treatment of disordered eating. METHODS: A systematic search was performed on PubMed, PsycINFO, and Embase, using keywords related to SVGs, disordered eating, and eating disorders. A narrative synthesis was subsequently carried out. RESULTS: In total, 2151 papers were identified, of which 11 (0.51%) were included. Of these 11 studies, 10 (91%) were randomized controlled trials, and 1 (9%) was a quasi-experimental study. The types of SVG interventions varied across the studies and targeted different mechanisms of disordered eating, ranging from addressing problem-solving and emotion regulation skills to neurocognitive training for inhibitory control. Most (10/11, 91%) of the studies showed some benefit of the SVGs in improving certain physical, behavioral, or psychological outcomes related to disordered eating. Some (4/11, 36%) of the studies also showed encouraging evidence of the retention of these benefits at follow-up. CONCLUSIONS: The studies included in this review provide collective evidence to suggest the various roles SVGs can play in plugging potential gaps in conventional therapy. Nonetheless, challenges exist in designing these games to prevent potential pitfalls, such as excessive stress arising from the SVGs themselves or potential gaming addiction. Further studies will also be required to assess the long-term benefits of SVGs as well as explore their potential preventive, and not just curative, effects on disordered eating.

Beneficial use of dredged sediment as a sustainable practice for restoring coastal marsh habitat.

Coastal Louisiana (USA) continues to sustain immense land and habitat losses due to subsidence, sea-level rise, and storm events. Approximately 65 million m3 (85 million cubic yards) of sediment is dredged annually from Gulf Coast federal navigation channels to maintain safe waterway passage. The beneficial use of these sediments continues to increase, and now this sediment is recognized as a critical resource in large-scale (estimated multibillion dollar) ecosystem restoration efforts to mitigate land and habitat losses along the US Gulf Coast. However, the documentation of restoration benefits where dredged sediments are the primary resource is lacking, which limits the potential for future applications. Therefore, this study documents the progress to restore marsh habitat and the resultant benefits in West Bay, Louisiana, and investigates how the restoration practices align with principles of the US Army Corps of Engineers (USACE) Engineering with Nature® (EWN® ) and UN Sustainable Development Goals (UN SDGs). West Bay, a 4964-ha subdelta adjacent to the Mississippi River, typifies risks of coastal land loss that also threatens the integrity of the adjacent federal navigation channel. To help restore coastal marsh habitat on a large spatial and temporal scale, the USACE constructed an uncontrolled diversionary channel from the Mississippi River and with subsequent direct and strategic placement of dredged sediment. Restoration performance was assessed through remotely sensed methods using data spanning approximately 70 years. To date, placement of dredged sediment in the bay has facilitated the creation of over 800 ha of new land in the formerly open waters of West Bay. The West Bay restoration project aligns with the principles of the EWN initiative, which supports more sustainable practices to deliver economic, environmental, and social benefits through collaborative processes and meaningfully integrates 10 of the UN SDGs designed to achieve a better and more sustainable future. Integr Environ Assess Manag 2022;18:1162-1173. Published 2021. This article is a U.S. Government work and is in the public domain in the USA.

Controllable X-Ray Pulse Trains from Enhanced Self-Amplified Spontaneous Emission.

We report the demonstration of optical compression of an electron beam and the production of controllable trains of femtosecond, soft x-ray pulses with the Linac Coherent Light Source (LCLS) free-electron laser (FEL). This is achieved by enhanced self-amplified spontaneous emission with a 2 µm laser and a dechirper device. Optical compression was achieved by modulating the energy of an electron beam with the laser and then compressing with a chicane, resulting in high current spikes on the beam which we observe to lase. A dechirper was then used to selectively control the lasing region of the electron beam. Field autocorrelation measurements indicate a train of pulses, and we find that the number of pulses within the train can be controlled (from 1 to 5 pulses) by varying the dechirper position and undulator taper. These results are a step toward attosecond spectroscopy with x-ray FELs as well as future FEL schemes relying on optical compression of an electron beam.

Improving Antibody-Tubulysin Conjugates through Linker Chemistry and Site-Specific Conjugation.

Tubulysins have emerged in recent years as a compelling drug class for delivery to tumor cells via antibodies. The ability of this drug class to exert bystander activity while retaining potency against multidrug-resistant cell lines differentiates them from other microtubule-disrupting agents. Tubulysin M, a synthetic analogue, has proven to be active and well tolerated as an antibody-drug conjugate (ADC) payload, but has the liability of being susceptible to acetate hydrolysis at the C11 position, leading to attenuated potency. In this work, we examine the ability of the drug-linker and conjugation site to preserve acetate stability. Our findings show that, in contrast to a more conventional protease-cleavable dipeptide linker, the ß-glucuronidase-cleavable glucuronide linker protects against acetate hydrolysis and improves ADC activity in vivo. In addition, site-specific conjugation can positively impact both acetate stability and in vivo activity. Together, these findings provide the basis for a highly optimized delivery strategy for tubulysin M.

Structure-activity relationships of tubulysin analogues.

The tubulysins are an emerging antibody-drug conjugate (ADC) payload that maintain potent anti-proliferative activity against cells that exhibit the multi-drug resistant (MDR) phenotype. These drugs possess a C-11 acetate known to be hydrolytically unstable in plasma, and loss of the acetate significantly attenuates cytotoxicity. Structure-activity relationship studies were undertaken to identify stable C-11 tubulysin analogues that maintain affinity for tubulin and potent cytotoxicity. After identifying several C-11 alkoxy analogues that possess comparable biological activity to tubulysin M with significantly improved plasma stability, additional analogues of both the Ile residue and N-terminal position were synthesized. These studies revealed that minor changes within the tubulin binding site of tubulysin can profoundly alter the activity of this chemotype, particularly against MDR-positive cell types.

Intestinal Barrier Integrity in Heat-Stressed Modern Broilers and Their Ancestor Wild Jungle Fowl.

High environmental temperature has strong adverse effects on poultry production, welfare, and sustainability and, thereby, constitutes one of the most challenging stressors. Although colossal information has been published on the effects of heat stress on poultry productivity and gut health, the fundamemntal mechanisms associated with heat stress responses and intestinal barrier function are still not well defined. The aim of the present study was, therefore, to determine the effects of acute (2 h) heat stress on growth performance, gut integrity, and intestinal expression of heat shock and tight junction proteins in slow- (broilers of the 1950's, ACRB), moderate- (broilers of 1990's, 95RAN), rapid-(modern broilers, MRB) growing birds, and their ancestor wild jungle fowl (JF). Heat stress exposure significantly increased the core body temperature of 95RAN and MRB chickens by ~0.5-1°C, but not that of JF and ACRB compared to their counterparts maintained at thermoneutral conditions. Heat stress also depressed feed intake and increased serum fluorescein isothiocyanate-dextran (FITC-D) levels (P < 0.05) in modern broilers (95RAN and MRB) but not in JF and ACRB, indicating potential leaky gut syndrome. Molecular analyses showed that heat stress exposure significantly up regulated the duodenal expression of occludin (OCLN) and lipocalin (LCN2) in ACRB, zonula occludens (ZO-2), villin1 (VIL1), and calprotectin (CALPR) in 95 RAN, and only CALPR in MRB compared to their TN counterparts. In the jejunum however, heat stress down regulated the expression of PALS1-associated tight junction protein (PATJ) in ACRB, 95RAN, and MRB, and that of cadherin1 (CDH1) in MRB. In the ileum, heat stress significantly down regulated the expression of OCLN in 95 RAN, ZO-1 in MRB, gap junction protein alpha1 (GJA1) in JF, and VIL1 in ACRB compared to their TN counterparts. In summary, this is the first report, to our knowledge, showing that tight junction protein expression is environmental-, genotype-, and intestinal segment-dependent and identifying molecular signatures, such as CDH1, CALPR, and ZO-1, potentially involved in leaky gut syndrome-induced by heat stress in MRB.

Propensity for seizure-related cortical laminar necrosis in hepatic encephalopathy.

•Hepatic encephalopathy may predispose to seizure-related cortical laminar necrosis.•Elevated ammonia levels potentially compound the excitotoxic effects of epilepsy.•Early identification and treatment of seizures in liver disease could be protective.

Altered steady state and activity-dependent de novo protein expression in fragile X syndrome.

Whether fragile X mental retardation protein (FMRP) target mRNAs and neuronal activity contributing to elevated basal neuronal protein synthesis in fragile X syndrome (FXS) is unclear. Our proteomic experiments reveal that the de novo translational profile in FXS model mice is altered at steady state and in response to metabotropic glutamate receptor (mGluR) stimulation, but the proteins expressed differ under these conditions. Several altered proteins, including Hexokinase 1 and Ras, also are expressed in the blood of FXS model mice and pharmacological treatments previously reported to ameliorate phenotypes modify their abundance in blood. In addition, plasma levels of Hexokinase 1 and Ras differ between FXS patients and healthy volunteers. Our data suggest that brain-based de novo proteomics in FXS model mice can be used to find altered expression of proteins in blood that could serve as disease-state biomarkers in individuals with FXS.

Glucuronide-Linked Antibody-Tubulysin Conjugates Display Activity in MDR+ and Heterogeneous Tumor Models.

Although antibody-drug conjugates (ADCs) find increasing applications in cancer treatment, de novo or treatment-emergent resistance mechanisms may impair clinical benefit. Two resistance mechanisms that emerge under prolonged exposure include upregulation of transporter proteins that confer multidrug resistance (MDR+) and loss of cognate antigen expression. New technologies that circumvent these resistance mechanisms may serve to extend the utility of next-generation ADCs. Recently, we developed the quaternary ammonium linker system to expand the scope of conjugatable payloads to include tertiary amines and applied the linker to tubulysins, a highly potent class of tubulin binders that maintain activity in MDR+ cell lines. In this work, tubulysin M, which contains an unstable acetate susceptible to enzymatic hydrolysis, and two stabilized tubulysin analogues were prepared as quaternary ammonium-linked glucuronide-linkers and assessed as ADC payloads in preclinical models. The conjugates were potent across a panel of cancer cell lines and active in tumor xenografts, including those displaying the MDR+ phenotype. The ADCs also demonstrated potent bystander activity in a coculture model comprised of a mixture of antigen-positive and -negative cell lines, and in an antigen-heterogeneous tumor model. Thus, the glucuronide-tubulysin drug-linkers represent a promising ADC payload class, combining conjugate potency in the presence of the MDR+ phenotype and robust activity in models of tumor heterogeneity in a structure-dependent manner. Mol Cancer Ther; 17(8); 1752-60. ©2018 AACR.

Wound Discharge After Pharmacological Thromboprophylaxis in Lower Limb Arthroplasty.

BACKGROUND: The benefits vs risk of pharmacological prophylaxis for thromboembolic disease in orthopedic patients remain controversial. Pharmacological thromboprophylaxis regimes are commonly used in this patient group. Few studies specifically examine wound complications attributable to this therapy. In this prospective trial, we investigated the effect of various regimens on postoperative wounds. METHODS: A prospective, observational, multicenter study involving patients undergoing elective hip or knee arthroplasty was undertaken. Patients were divided into 3 groups depending on thromboprophylaxis: no anticoagulation, aspirin, or low molecular weight heparin (LMWH) (enoxaparin). Surgical wounds were evaluated for each regime using the Southampton Wound Assessment Score. RESULTS: Over a 12-month period, 327 patients were enrolled with a mean age of 68.1 years (±11.2 years). There were 105 patients in the no anticoagulation group (32.1%), 97 patients in the aspirin group (29.7%), and 125 patients in the LMWH group (38.2%). Wound scores were evaluated for evidence and amount of discharge. The use of LMWH conferred a 4.92 times greater risk and aspirin a 3.64 times greater risk of wound discharge than no pharmacological thromboprophylaxis (P < .0001). There were no significant differences in the incidence of deep vein thrombosis or pulmonary embolus between groups either as an inpatient or postdischarge. CONCLUSION: There is a significant increase in the risk of wound discharge when aspirin or LMWH is used in arthroplasty patients. As potential complications of wound problems are significant, a more balanced view of risk vs benefit needs to be taken when prescribing thromboprophylaxis for this patient group.

Access to and Payment for Office-Based Buprenorphine Treatment in Ohio.

IMPORTANCE: Office-based opiate agonist therapy has dramatically expanded access to medication-assisted treatment over the past decade but has also led to increased buprenorphine diversion. OBJECTIVE: Our study sought to characterize physicians who participate in office-based therapy (OBT) to assess patient access to OBT in Ohio 10 years after its introduction. DESIGN/SETTING/PARTICIPANTS: Cross-sectional telephone survey of Drug Addiction Treatment Act-waivered physicians in Ohio listed by the Center for Substance Abuse Treatment (CSAT). MAIN OUTCOMES: This study sought to determine what proportion of eligible physicians are actively prescribing buprenorphine, whether they accept insurance for OBT, and whether they accept insurance for non-OBT services. In addition, we evaluated what physician characteristics predicted those primary outcomes. We hypothesized that a significant minority of eligible physicians are not active prescribers of buprenorphine. In addition, we expected that a significant minority of OBT prescribers do not accept insurance, further restricting patient access. We further hypothesized that a large subset of OBT prescribers accept insurance in their regular practices but do not take insurance for OBT. RESULTS: Of the 466 listed physicians, 327 (70.2%) practice representatives were reached for interview. Thirty-three physicians were excluded, with a true response rate of 75.5%. In total, 80.7% of providers reached were active OBT prescribers. Of these, 52.7% accepted insurance for OBT, 20.8% accepted insurance for non-OBT services but not for OBT, and 26.5% did not accept insurance for any services. Practices who did not accept insurance were more likely among dedicated addiction clinics located outside of Ohio's 6 major cities. Practices who normally accepted insurance but did not for OBT services were more likely in urban locations and were not associated with dedicated addiction practices. Neither business practice was associated with physician specialty. CONCLUSIONS AND RELEVANCE: Access to OBT in Ohio is far lower than what the 466 listed physicians suggests. Nearly 1 in 5 of those physicians are not active OBT prescribers, and 1 in 2 active prescribers do not accept insurance for OBT. Further research is needed to determine whether practices who do not accept insurance provide care consistent with CSAT guidelines and whether such practice patterns contribute to buprenorphine diversion.

Safety of BTZ retreatment for patients with low-grade peripheral neuropathy during the initial treatment.

OBJECTIVE: Neuropathy is an important complication that may limit treatment options for patients with multiple myeloma. Previous studies have focused on treatment efficacy and have shown that retreatment with bortezomib (BTZ) is an effective treatment option. The goal of this study was to focus on the clinical manifestations of peripheral neuropathy (PN) and to retrospectively compare the incidence and severity of PN between the initial BTZ regimen and upon retreatment. Furthermore, this study evaluated how certain factors affect BIPN, which will help determine what conditions should be considered prior to retreatment. METHODS: Charts were reviewed from 93 patients who were retreated with a BTZ-containing regimen after previously being treated with this drug. RESULTS: Among the patients who developed PN, most patients in the study had low-grade neuropathy during the initial BTZ treatment (n = 52, 68%). The results showed no evidence of cumulative toxicity, and there was no significant difference in the incidence and severity of PN upon retreatment. Factors such as the presence of baseline PN, number of prior treatments, dose of BTZ, and comorbidities did not increase the severity of PN upon retreatment. The lapse of time between the two regimens also did not affect the severity of PN. CONCLUSION: The results suggest that retreatment with BTZ may be a feasible option, without additional risks of PN, for MM patients even with peripheral neuropathy during their initial treatment with this drug.

Optimization of a PEGylated Glucuronide-Monomethylauristatin E Linker for Antibody-Drug Conjugates.

The emergence of antibody-drug conjugates (ADC), such as brentuximab vedotin and ado-trastuzumab emtansine, has led to increased efforts to identify new payloads and develop improved drug-linker technologies. Most antibody payloads impart significant hydrophobicity to the ADC, resulting in accelerated plasma clearance and suboptimal in vivo activity, particularly for conjugates with high drug-to-antibody ratios (DAR). We recently reported on the incorporation of a discrete PEG24 polymer as a side chain in a ß-glucuronidase-cleavable monomethylauristatin E (MMAE) linker to provide homogeneous DAR 8 conjugates with decreased plasma clearance and increased antitumor activity in xenograft models relative to a non-PEGylated control. In this work, we optimized the drug-linker by minimizing the size of the PEG side chain and incorporating a self-stabilizing maleimide to prevent payload de-conjugation in vivo Multiple PEG-glucuronide-MMAE linkers were prepared with PEG size up to 24 ethylene oxide units, and homogeneous DAR 8 ADCs were evaluated. A clear relationship was observed between PEG length and conjugate pharmacology when tested in vivo Longer PEG chains resulted in slower clearance, with a threshold length of PEG8 beyond which clearance was not impacted. Conjugates bearing PEG of sufficient length to minimize plasma clearance provided a wider therapeutic window relative to faster clearing conjugates bearing shorter PEGs. A lead PEGylated glucuronide-MMAE linker was identified incorporating a self-stabilizing maleimide and a PEG12 side chain emerged from these efforts, enabling highly potent, homogeneous DAR 8 conjugates and is under consideration for future ADC programs. Mol Cancer Ther; 16(1); 116-23. ©2016 AACR.

Spectral and Hydrodynamic Analysis of West Nile Virus RNA-Protein Interactions by Multiwavelength Sedimentation Velocity in the Analytical Ultracentrifuge.

Interactions between nucleic acids and proteins are critical for many cellular processes, and their study is of utmost importance to many areas of biochemistry, cellular biology, and virology. Here, we introduce a new analytical method based on sedimentation velocity (SV) analytical ultracentrifugation, in combination with a novel multiwavelength detector to characterize such interactions. We identified the stoichiometry and molar mass of a complex formed during the interaction of a West Nile virus RNA stem loop structure with the human T cell-restricted intracellular antigen-1 related protein. SV has long been proven as a powerful technique for studying dynamic assembly processes under physiological conditions in solution. Here, we demonstrate, for the first time, how the new multiwavelength technology can be exploited to study protein-RNA interactions, and show how the spectral information derived from the new detector complements the traditional hydrodynamic information from analytical ultracentrifugation. Our method allows the protein and nucleic acid signals to be separated by spectral decomposition such that sedimentation information from each individual species, including any complexes, can be clearly identified based on their spectral signatures. The method presented here extends to any interacting system where the interaction partners are spectrally separable.

Development of Novel Quaternary Ammonium Linkers for Antibody-Drug Conjugates.

A quaternary ammonium-based drug-linker has been developed to expand the scope of antibody-drug conjugate (ADC) payloads to include tertiary amines, a functional group commonly present in biologically active compounds. The linker strategy was exemplified with a ß-glucuronidase-cleavable auristatin E construct. The drug-linker was found to efficiently release free auristatin E (AE) in the presence of ß-glucuronidase and provide ADCs that were highly stable in plasma. Anti-CD30 conjugates comprised of the glucuronide-AE linker were potent and immunologically specific in vitro and in vivo, displaying pharmacologic properties comparable with a carbamate-linked glucuronide-monomethylauristatin E control. The quaternary ammonium linker was then applied to a tubulysin antimitotic drug that contained an N-terminal tertiary amine that was important for activity. A glucuronide-tubulysin quaternary ammonium linker was synthesized and evaluated as an ADC payload, in which the resulting conjugates were found to be potent and immunologically specific in vitro, and displayed a high level of activity in a Hodgkin lymphoma xenograft. Furthermore, the results were superior to those obtained with a related tubulysin derivative containing a secondary amine N-terminus for conjugation using previously known linker technology. The quaternary ammonium linker represents a significant advance in linker technology, enabling stable conjugation of payloads with tertiary amine residues. Mol Cancer Ther; 15(5); 938-45. ©2016 AACR.

Predicting dredging-associated effects to coral reefs in Apra Harbor, Guam - Part 1: Sediment exposure modeling.

Model studies were conducted to investigate the potential coral reef sediment exposure from dredging associated with proposed development of a deepwater wharf in Apra Harbor, Guam. The Particle Tracking Model (PTM) was applied to quantify the exposure of coral reefs to material suspended by the dredging operations at two alternative sites. Key PTM features include the flexible capability of continuous multiple releases of sediment parcels, control of parcel/substrate interaction, and the ability to efficiently track vast numbers of parcels. This flexibility has facilitated simulating the combined effects of sediment released from clamshell dredging and chiseling within Apra Harbor. Because the rate of material released into the water column by some of the processes is not well understood or known a priori, the modeling approach was to bracket parameters within reasonable ranges to produce a suite of potential results from multiple model runs. Sensitivity analysis to model parameters is used to select the appropriate parameter values for bracketing. Data analysis results include mapping the time series and the maximum values of sedimentation, suspended sediment concentration, and deposition rate. Data were used to quantify various exposure processes that affect coral species in Apra Harbor. The goal of this research is to develop a robust methodology for quantifying and bracketing exposure mechanisms to coral (or other receptors) from dredging operations. These exposure values were utilized in an ecological assessment to predict effects (coral reef impacts) from various dredging scenarios.

BONLAC: A combinatorial proteomic technique to measure stimulus-induced translational profiles in brain slices.

Stimulus-triggered protein synthesis is critical for brain health and function. However, due to technical hurdles, de novo neuronal translation is predominantly studied in cultured cells, whereas electrophysiological and circuit analyses often are performed in brain slices. The different properties of these two experimental systems create an information gap about stimulus-induced alterations in the expression of new proteins in mature circuits. To address this, we adapted two existing techniques, BONCAT and SILAC, to a combined proteomic technique, BONLAC, for use in acute adult hippocampal slices. Using BDNF-induced protein synthesis as a proof of concept, we found alterations in expression of proteins involved in neurotransmission, trafficking, and cation binding that differed from those found in a similar screen in cultured neurons. Our results indicate important differences between cultured neurons and slices, and suggest that BONLAC could be used to dissect proteomic changes underlying synaptic events in adult circuits. This article is part of the Special Issue entitled 'Synaptopathy--from Biology to Therapy'.

Next-Generation AUC Adds a Spectral Dimension: Development of Multiwavelength Detectors for the Analytical Ultracentrifuge.

We describe important advances in analytical ultracentrifugation (AUC) hardware, which add new information to the hydrodynamic information observed in traditional AUC instruments. In contrast to the Beckman-Coulter XLA UV/visible detector, multiwavelength (MWL) detection is able to collect sedimentation data not just for one wavelength, but for a large wavelength range in a single experiment. The additional dimension increases the data density by orders of magnitude, significantly improving the statistics of the measurement and adding important information to the experiment since an additional dimension of spectral characterization is now available to complement the hydrodynamic information. The new detector avoids tedious repeats of experiments at different wavelengths and opens up new avenues for the solution-based investigation of complex mixtures. In this chapter, we describe the capabilities, characteristics, and applications of the new detector design with biopolymers as the focus of study. We show data from two different MWL detectors and discuss strengths and weaknesses of differences in the hardware and different data acquisition modes. Also, difficulties with fiber optic applications in the UV are discussed. Data quality is compared across platforms.