Distribution of MRI-derived T2 values as a biomarker for in vivo rapid screening of phenotype severity in mdx mice.

BACKGROUND: The pathology in Duchenne muscular dystrophy (DMD) is characterized by degenerating muscle fibers, inflammation, fibro-fatty infiltrate, and edema, and these pathological processes replace normal healthy muscle tissue. The mdx mouse model is one of the most commonly used preclinical models to study DMD. Mounting evidence has emerged illustrating that muscle disease progression varies considerably in mdx mice, with inter-animal differences as well as intra-muscular differences in pathology in individual mdx mice. This variation is important to consider when conducting assessments of drug efficacy and in longitudinal studies. We developed a magnetic resonance imaging (MRI) segmentation and analysis pipeline to rapidly and non-invasively measure the severity of muscle disease in mdx mice. METHODS: Wildtype and mdx mice were imaged with MRI and T2 maps were obtained axially across the hindlimbs. A neural network was trained to rapidly and semi-automatically segment the muscle tissue, and the distribution of resulting T2 values was analyzed. Interdecile range and Pearson Skew were identified as biomarkers to quickly and accurately estimate muscle disease severity in mice. RESULTS: The semiautomated segmentation tool reduced image processing time approximately tenfold. Measures of Pearson skew and interdecile range based on that segmentation were repeatable and reflected muscle disease severity in healthy wildtype and diseased mdx mice based on both qualitative observation of images and correlation with Evans blue dye uptake. CONCLUSION: Use of this rapid, non-invasive, semi-automated MR image segmentation and analysis pipeline has the potential to transform preclinical studies, allowing for pre-screening of dystrophic mice prior to study enrollment to ensure more uniform muscle disease pathology across treatment groups, improving study outcomes.

Clinical, Imaging, and Technical Factors Associated with Successful Genomic Profiling of Bone Biopsy Tissue in Prostate Cancer.

BACKGROUND AND OBJECTIVE: The source of tissue for genomic profiling of metastatic castration-resistant prostate cancer (mCRPC) is often limited to osseous metastases. To guide patient management, metastatic site selection and the technique for targeted bone biopsies are critical for identifying deleterious gene mutations. Our objective was to identify key parameters associated with successful large-panel DNA sequencing. METHODS: We analyzed parameters for 243 men with progressing mCRPC who underwent 269 bone biopsies for genomic profiling between 2014 and 2018. Univariate and multivariate analyses were performed for clinical, imaging (bone scan; fluorodeoxyglucose [FDG] positron emission tomography [PET]; computed tomography [CT]; magnetic resonance imaging), and technical (biopsy site, number of samples, needle gauge) features associated with successful genomic profiling. KEY FINDINGS AND LIMITATIONS: Overall, 159 of 269 biopsies (59%) generated sufficient tumor material for a genomic profile. Seventy (26%) of the failures were histopathologically negative for mCRPC and 40 (15%) had insufficient tumor for genomic profiling. Of 199 mCRPC samples submitted for molecular testing, 159 (80%) yielded a genomic profile. On univariate analysis, PSA, serum acid phosphatase, number of biopsy samples, FDG PET positivity, CT attenuation, and CT morphology were significantly associated with genomic profiling success. On multivariate analysis, higher FDG maximum standardized uptake value (odds ratio [OR] 7.51, 95% confidence interval [CI] 3.01-18.78; p < 0.001), higher number of biopsy samples (OR 4.73, 95% CI 1.49-15.02; p = 0.008), and lower mean CT attenuation (OR 0.4, 95% CI 0.18-0.89; p = 0.025) were significantly associated with sequencing success. CONCLUSIONS AND CLINICAL IMPLICATIONS: In patients with mCRPC, bone biopsies from sites with metabolic activity and lower CT attenuation are associated with higher success rates for genomic profiling via a large-panel DNA sequencing platform. PATIENT SUMMARY: We identified factors associated with successful genetic testing of bone tissue for patients with metastatic prostate cancer. Our findings may help in guiding the right scan technique and biopsy site for personalized treatment planning.

The Mental Health Costs of Online Heterosexism Among LGBTQ+ Individuals: Development and Initial Validation of the Perceived Online Heterosexism Scale.

Experiences of heterosexism are rampant online, where bias and harassment against LGBTQ+ individuals spread conveniently and widely. Yet, research has been limited in understanding the exposure to online heterosexism among LGBTQ+ individuals partly due to the lack of a quantitative measure to advance this research. Thus, the current study developed and examined the psychometric properties of the Perceived Online Heterosexism Scale (POHS). Items were developed via a literature review, a survey of social media platforms, and an expert review. Exploratory (N = 288) and confirmatory (N = 653) factor analyses yielded a 4-factor structure and produced a 20-item scale with the following subscales: (1) Heterosexist Cyberaggression (4 items), (2) Online Heterosexist Stereotyping (4 items), (3) Online Exposure to Systemic Heterosexism (8 items), and (4) Heterosexist Online Media (four items). Internal consistency estimates ranged from .91 to .96, and the POHS accounted for 65.9% of the variance. Examination of a second-order model suggested that a total scale score can also be used. Initial construct validity was evidenced as POHS scores were associated with an existing heterosexism measure, anxiety and depressive symptoms, internalized heterosexism, and LGBTQ+ community connectedness in line with theory and empirical evidence. Implications for research practice are discussed.

New semi-automated tool for the quantitation of MR imaging to estimate in vivo muscle disease severity in mice.

The pathology in Duchenne muscular dystrophy (DMD) is characterized by degenerating muscle fibers, inflammation, fibro-fatty infiltrate, and edema, and these pathological processes replace normal healthy muscle tissue. The mdx mouse model is one of the most commonly used preclinical models to study DMD. Mounting evidence has emerged illustrating that muscle disease progression varies considerably in mdx mice, with inter-animal differences as well as intra-muscular differences in pathology in individual mdx mice. This variation is important to consider when conducting assessments of drug efficacy and in longitudinal studies. Magnetic resonance imaging (MRI) is a non-invasive method that can be used qualitatively or quantitatively to measure muscle disease progression in the clinic and in preclinical models. Although MR imaging is highly sensitive, image acquisition and analysis can be time intensive. The purpose of this study was to develop a semi-automated muscle segmentation and quantitation pipeline that can quickly and accurately estimate muscle disease severity in mice. Herein, we show that the newly developed segmentation tool accurately divides muscle. We show that measures of skew and interdecile range based on segmentation sufficiently estimate muscle disease severity in healthy wildtype and diseased mdx mice. Moreover, the semi-automated pipeline reduced analysis time by nearly 10-fold. Use of this rapid, non-invasive, semi-automated MR imaging and analysis pipeline has the potential to transform preclinical studies, allowing for pre-screening of dystrophic mice prior to study enrollment to ensure more uniform muscle disease pathology across treatment groups, improving study outcomes.

Witnessing racism against racial minority individuals online and loneliness among White emerging adults: Anti-racism advocacy as a moderator.

Extant literature suggests that racism is associated with difficult emotional reactions and feelings of social disconnect among White individuals. These feelings of social disconnect may be particularly salient in today's digital era in which racism against racial minority individuals is conveniently and frequently witnessed via online platforms. Thus, we examined whether witnessing racism online may be associated with feelings of loneliness among White emerging adults. We also tested whether anti-racism advocacy buffered loneliness given its potential for relationship building and community organizing to promote racial justice and equity. Using data from 227 White emerging adults (Mage = 20.86, SD = 4.82), we conducted a latent moderated structural equation modeling to test individual and institutional anti-racism advocacy as moderators in the link between witnessing racism online (racial victimization of racial minority individuals in online interactions and online content on cultural devaluation/systemic racism against racial minority individuals) and loneliness. Greater exposure to online content on systemic racism and cultural devaluation of racial minority groups significantly predicted greater loneliness. Engagement in individual anti-racism advocacy (mean to high levels) buffered this link. White allies must engage in anti-racism practice to address racism in our society, and our findings advance our understanding of the associated psychosocial costs. Implications for research and practice are discussed.

Wireless multi-lateral optofluidic microsystems for real-time programmable optogenetics and photopharmacology.

In vivo optogenetics and photopharmacology are two techniques for controlling neuronal activity that have immense potential in neuroscience research. Their applications in tether-free groups of animals have been limited in part due to tools availability. Here, we present a wireless, battery-free, programable multilateral optofluidic platform with user-selected modalities for optogenetics, pharmacology and photopharmacology. This system features mechanically compliant microfluidic and electronic interconnects, capabilities for dynamic control over the rates of drug delivery and real-time programmability, simultaneously for up to 256 separate devices in a single cage environment. Our behavioral experiments demonstrate control of motor behaviors in grouped mice through in vivo optogenetics with co-located gene delivery and controlled photolysis of caged glutamate. These optofluidic systems may expand the scope of wireless techniques to study neural processing in animal models.

A transient, closed-loop network of wireless, body-integrated devices for autonomous electrotherapy.

Temporary postoperative cardiac pacing requires devices with percutaneous leads and external wired power and control systems. This hardware introduces risks for infection, limitations on patient mobility, and requirements for surgical extraction procedures. Bioresorbable pacemakers mitigate some of these disadvantages, but they demand pairing with external, wired systems and secondary mechanisms for control. We present a transient closed-loop system that combines a time-synchronized, wireless network of skin-integrated devices with an advanced bioresorbable pacemaker to control cardiac rhythms, track cardiopulmonary status, provide multihaptic feedback, and enable transient operation with minimal patient burden. The result provides a range of autonomous, rate-adaptive cardiac pacing capabilities, as demonstrated in rat, canine, and human heart studies. This work establishes an engineering framework for closed-loop temporary electrotherapy using wirelessly linked, body-integrated bioelectronic devices.

Wireless implantable optical probe for continuous monitoring of oxygen saturation in flaps and organ grafts.

Continuous, real-time monitoring of perfusion after microsurgical free tissue transfer or solid organ allotransplantation procedures can facilitate early diagnosis of and intervention for anastomotic thrombosis. Current technologies including Doppler systems, cutaneous O2-sensing probes, and fluorine magnetic resonance imaging methods are limited by their intermittent measurements, requirements for skilled personnel, indirect interfaces, and/or their tethered connections. This paper reports a wireless, miniaturized, minimally invasive near-infrared spectroscopic system designed for uninterrupted monitoring of local-tissue oxygenation. A bioresorbable barbed structure anchors the probe stably at implantation sites for a time period matched to the clinical need, with the ability for facile removal afterward. The probe connects to a skin-interfaced electronic module for wireless access to essential physiological parameters, including local tissue oxygenation, pulse oxygenation, and heart rate. In vitro tests and in vivo studies in porcine flap and kidney models demonstrate the ability of the system to continuously measure oxygenation with high accuracy and sensitivity.

The SUMO protease SENP3 regulates mitochondrial autophagy mediated by Fis1.

Mitochondria are unavoidably subject to organellar stress resulting from exposure to a range of reactive molecular species. Consequently, cells operate a poorly understood quality control programme of mitophagy to facilitate elimination of dysfunctional mitochondria. Here, we used a model stressor, deferiprone (DFP), to investigate the molecular basis for stress-induced mitophagy. We show that mitochondrial fission 1 protein (Fis1) is required for DFP-induced mitophagy and that Fis1 is SUMOylated at K149, an amino acid residue critical for Fis1 mitochondrial localization. We find that DFP treatment leads to the stabilization of the SUMO protease SENP3, which is mediated by downregulation of the E3 ubiquitin (Ub) ligase CHIP. SENP3 is responsible for Fis1 deSUMOylation and depletion of SENP3 abolishes DFP-induced mitophagy. Furthermore, preventing Fis1 SUMOylation by conservative K149R mutation enhances Fis1 mitochondrial localization. Critically, expressing a Fis1 K149R mutant restores DFP-induced mitophagy in SENP3-depleted cells. Thus, we propose a model in which SENP3-mediated deSUMOylation facilitates Fis1 mitochondrial localization to underpin stress-induced mitophagy.

Photocurable bioresorbable adhesives as functional interfaces between flexible bioelectronic devices and soft biological tissues.

Flexible electronic/optoelectronic systems that can intimately integrate onto the surfaces of vital organ systems have the potential to offer revolutionary diagnostic and therapeutic capabilities relevant to a wide spectrum of diseases and disorders. The critical interfaces between such technologies and living tissues must provide soft mechanical coupling and efficient optical/electrical/chemical exchange. Here, we introduce a functional adhesive bioelectronic-tissue interface material, in the forms of mechanically compliant, electrically conductive, and optically transparent encapsulating coatings, interfacial layers or supporting matrices. These materials strongly bond both to the surfaces of the devices and to those of different internal organs, with stable adhesion for several days to months, in chemistries that can be tailored to bioresorb at controlled rates. Experimental demonstrations in live animal models include device applications that range from battery-free optoelectronic systems for deep-brain optogenetics and subdermal phototherapy to wireless millimetre-scale pacemakers and flexible multielectrode epicardial arrays. These advances have immediate applicability across nearly all types of bioelectronic/optoelectronic system currently used in animal model studies, and they also have the potential for future treatment of life-threatening diseases and disorders in humans.

The Therapeutic and Diagnostic Potential of Amyloid ß Oligomers Selective Antibodies to Treat Alzheimer's Disease.

Improvements have been made in the diagnosis of Alzheimer's disease (AD), manifesting mostly in the development of in vivo imaging methods that allow for the detection of pathological changes in AD by magnetic resonance imaging (MRI) and positron emission tomography (PET) scans. Many of these imaging methods, however, use agents that probe amyloid fibrils and plaques-species that do not correlate well with disease progression and are not present at the earliest stages of the disease. Amyloid ß oligomers (AßOs), rather, are now widely accepted as the Aß species most germane to AD onset and progression. Here we report evidence further supporting the role of AßOs as pathological instigators of AD and introduce promising anti-AßO diagnostic probes capable of distinguishing the 5xFAD mouse model from wild type mice by PET and MRI. In a developmental study, Aß oligomers in 5xFAD mice were found to appear at 3 months of age, just prior to the onset of memory dysfunction, and spread as memory worsened. The increase of AßOs is prominent in the subiculum and correlates with concomitant development of reactive astrocytosis. The impact of these AßOs on memory is in harmony with findings that intraventricular injection of synthetic AßOs into wild type mice induced hippocampal dependent memory dysfunction within 24 h. Compelling support for the conclusion that endogenous AßOs cause memory loss was found in experiments showing that intranasal inoculation of AßO-selective antibodies into 5xFAD mice completely restored memory function, measured 30-40 days post-inoculation. These antibodies, which were modified to give MRI and PET imaging probes, were able to distinguish 5xFAD mice from wild type littermates. These results provide strong support for the role of AßOs in instigating memory loss and salient AD neuropathology, and they demonstrate that AßO selective antibodies have potential both for therapeutics and for diagnostics.

Bioresorbable, Wireless, Passive Sensors as Temporary Implants for Monitoring Regional Body Temperature.

Measurements of regional internal body temperatures can yield important information in the diagnosis of immune response-related anomalies, for precisely managing the effects of hyperthermia and hypothermia therapies and monitoring other transient body processes such as those associated with wound healing. Current approaches rely on permanent implants that require extraction surgeries after the measurements are no longer needed. Emerging classes of bioresorbable sensors eliminate the requirements for extraction, but their use of percutaneous wires for data acquisition leads to risks for infection at the suture site. As an alternative, a battery-free, wireless implantable device is reported here, which is constructed entirely with bioresorbable materials for monitoring regional internal body temperatures over clinically relevant timeframes. Ultimately, these devices disappear completely in the body through natural processes. In vivo demonstrations indicate stable operation as subcutaneous and intracranial implants in rat models for up to 4 days. Potential applications include monitoring of healing cascades associated with surgical wounds, recovery processes following internal injuries, and the progression of thermal therapies for various conditions.

Awareness, Care and Treatment In Obesity maNagement to inform Haemophilia Obesity Patient Empowerment (ACTION-TO-HOPE): Results of a survey of US haemophilia treatment centre professionals.

BACKGROUND: Despite the high prevalence of overweight and obesity in the United States, few studies have assessed the impact of obesity on haemophilia-specific outcomes or experiences/perceptions of healthcare providers (HCPs) treating haemophilia. AIM: The Awareness, Care and Treatment In Obesity maNagement to inform Haemophilia Obesity Patient Empowerment (ACTION-TO-HOPE) study was designed to identify HCP insights on the unique challenges of patients with haemophilia and obesity/overweight (PwHO) and the barriers to chronic weight management. METHODS: An online survey collected data from haemophilia treatment centre-based HCPs. Respondents included 10 adults and 29 paediatric haematologists, 27 nurses/nurse practitioners/physician assistants, 22 physical therapists and 17 social workers. RESULTS: Almost all HCPs rated obesity of moderate/high concern and reported that weight significantly affects future health and has an impact on life expectancy, yet fewer than 60% reported discussing the impact of weight on health with their patients. HCPs reported that few PwHO tried to lose weight; not many were 'successful'. HCPs perceived a desire to feel better physically and joint pain as top motivating factors. HCPs believe that PwHO would have less joint bleeding and pain and greater mobility if they lost weight. HCPs viewed lack of exercise and food preferences/habits as the biggest barriers to initiating/maintaining weight loss and therefore recommended increasing exercise and healthier eating to their patients. However, physical activity in this patient population is limited and requires advice and support. CONCLUSIONS: Most HCPs appreciated the impact of obesity on joint bleeding, pain, and function and quality of life. Reduced food intake and increased activity are the most commonly recommended weight-loss strategies but the least likely to be successful. HCPs desire additional education/materials to understand weight management for PwHO.

Wireless, battery-free subdermally implantable photometry systems for chronic recording of neural dynamics.

Recording cell-specific neuronal activity while monitoring behaviors of freely moving subjects can provide some of the most significant insights into brain function. Current means for monitoring calcium dynamics in genetically targeted populations of neurons rely on delivery of light and recording of fluorescent signals through optical fibers that can reduce subject mobility, induce motion artifacts, and limit experimental paradigms to isolated subjects in open, two-dimensional (2D) spaces. Wireless alternatives eliminate constraints associated with optical fibers, but their use of head stages with batteries adds bulk and weight that can affect behaviors, with limited operational lifetimes. The systems introduced here avoid drawbacks of both types of technologies, by combining highly miniaturized electronics and energy harvesters with injectable photometric modules in a class of fully wireless, battery-free photometer that is fully implantable subdermally to allow for the interrogation of neural dynamics in freely behaving subjects, without limitations set by fiber optic tethers or operational lifetimes constrained by traditional power supplies. The unique capabilities of these systems, their compatibility with magnetic resonant imaging and computed tomography and the ability to manufacture them with techniques in widespread use for consumer electronics, suggest a potential for broad adoption in neuroscience research.

Self-Immolative Activation of ß-Galactosidase-Responsive Probes for In Vivo MR Imaging in Mouse Models.

Our lab has developed a new series of self-immolative MR agents for the rapid detection of enzyme activity in mouse models expressing ß-galactosidase (ß-gal). We investigated two molecular architectures to create agents that detect ß-gal activity by modulating the coordination of water to GdIII . The first is an intermolecular approach, wherein we designed several structural isomers to maximize coordination of endogenous carbonate ions. The second involves an intramolecular mechanism for q modulation. We incorporated a pendant coordinating carboxylate ligand with a 2, 4, 6, or 8 carbon linker to saturate ligand coordination to the GdIII ion. This renders the agent ineffective. We show that one agent in particular (6-C pendant carboxylate) is an extremely effective MR reporter for the detection of enzyme activity in a mouse model expressing ß-gal.

Wireless, battery-free, fully implantable multimodal and multisite pacemakers for applications in small animal models.

Small animals support a wide range of pathological phenotypes and genotypes as versatile, affordable models for pathogenesis of cardiovascular diseases and for exploration of strategies in electrotherapy, gene therapy, and optogenetics. Pacing tools in such contexts are currently limited to tethered embodiments that constrain animal behaviors and experimental designs. Here, we introduce a highly miniaturized wireless energy-harvesting and digital communication electronics for thin, miniaturized pacing platforms weighing 110 mg with capabilities for subdermal implantation and tolerance to over 200,000 multiaxial cycles of strain without degradation in electrical or optical performance. Multimodal and multisite pacing in ex vivo and in vivo studies over many days demonstrate chronic stability and excellent biocompatibility. Optogenetic stimulation of cardiac cycles with in-animal control and induction of heart failure through chronic pacing serve as examples of modes of operation relevant to fundamental and applied cardiovascular research and biomedical technology.

Whole-body Imaging of Cell Death Provides a Systemic, Minimally Invasive, Dynamic, and Near-real Time Indicator for Chemotherapeutic Drug Toxicity.

PURPOSE: Response to toxicity in chemotherapies varies considerably from tissue to tissue and from patient to patient. An ability to monitor the tissue damage done by chemotherapy may have a profound impact on treatment and prognosis allowing for a proactive management in understanding and mitigating such events. For the first time, we investigated the feasibility of using whole-body imaging to map chemotherapeutic drug-induced toxicity on an individual basis. EXPERIMENTAL DESIGN: In a preclinical proof-of-concept, rats were treated with a single clinical dose of cyclophosphamide, methotrexate, or cisplatin. In vivo whole-body imaging data were acquired using 99mTc-duramycin, which identifies dead and dying cells as an unambiguous marker for tissue injury in susceptible organs. Imaging results were cross-validated using quantitative ex vivo measurements and histopathology and compared with standard blood and serum panels for toxicology. RESULTS: The in vivo whole-body imaging data detected widespread changes, where spatially heterogeneous toxic effects were identified across different tissues, within substructures of organs, as well as among different individuals. The signal changes were consistent with established toxicity profiles of these chemotherapeutic drugs. Apart from generating a map of susceptible tissues, this in vivo imaging approach was more sensitive compared with conventional blood and serum markers used in toxicology. Also, repeated imaging during the acute period after drug treatment captured different kinetics of tissue injury among susceptible organs in males and females. CONCLUSIONS: This novel and highly translational imaging approach shows promise in optimizing therapeutic decisions by detecting and managing drug toxicity on a personalized basis.Toxicity to normal tissues is a significant limitation in chemotherapies. This work demonstrated an in vivo imaging-based approach for characterizing toxicity-induced tissue injury in a systemic, dynamic, and near-real time fashion. This novel approach shows promise in optimizing therapeutic decisions by monitoring drug toxicity on a personalized basis.

Evaluating the thrombin generation profiles of four different rFVIII products in FVIII-deficient plasma using FIXa and FXIa activation.

INTRODUCTION: The thrombin generation assay (TGA) can be used to monitor factor replacement therapy in patients with haemophilia. The TGA assay is typically performed using tissue factor as the reaction activator; however, activating with FIXa or FXIa can enhance assay sensitivity when FVIII < 1%. AIMS: To evaluate the sensitivity of the TGA when FIXa (5 nmol/L) and FXIa (0.22 nmol/L) are used to activate the assay in platelet-poor plasma and to compare these data to the one-stage and chromogenic assays. METHODS: Plasma from 10 severe FVIII-deficient subjects was supplemented with FVIII (0%, 0.1%, 0.4%, 1.2%, 4%, 11% and 33%), using either Novo Eight® , Advate® , Eloctate® , turoctocog alfa pegol or a control standard. The one-stage and chromogenic assays quantified the FVIII levels. The TGA assay was activated using either FIXa or FXIa. RESULTS: Both FIXa- and FXIa-activated TGA were sensitive across FVIII concentrations, with intra-assay coefficient of variation (CV) < 10%. The FXIa-activated assay had 25% CV at the lowest level of FVIII compared to 10% CV with FIXa activation. There were strong correlations between the FIXa- and FXIa-activated TGA tests (R2  = 0.9912) and between the one-stage and chromogenic assays (R2  = 0.9469). However, there were poor relationships between the TGA tests and one-stage and chromogenic assays. CONCLUSIONS: Both FIXa- and FXIa activation results in similar TGA profiles across a FVIII range of 0.1%-33%; however, FIXa activation was more robust at the lowest levels of FVIII compared with FXIa activation.

Activating Adult Allies From a Rural Community on Lesbian, Gay, Bisexual, Transgender, and Queer Student Issues in School Using Photovoice.

PURPOSE: Many students who are lesbian, gay, bisexual, transgender, or queer (LGBTQ) face hostile school environments that can negatively impact their mental health and education. This study involved a photovoice project where high school students from a Gay-Straight Alliance in the rural southeastern United States took photographs that depicted the issues LGBTQ students were facing and then exhibited their photographs and stories to individuals from the school system and local community to promote awareness, dialogue, and action. METHODS: 20 adults who attended the photovoiceexhibit responded to an online survey about their experiences with the intervention. RESULTS: 85% of adults reported that the interventionmade them think about issues they had not previously considered, including the struggles LGBTQ youth face, gender issues, and living in a rural community. Common emotions experienced at the interventionincluded feeling excited, concern for the youth, and proud of the youth. Further, 81% of the adults indicated that they would take action or behave differently as a result of the intervention, including supporting and affirming LGBTQ students, using gender-neutral and -inclusive language, and confronting bias in themselves and others. CONCLUSIONS: Photovoice is a promising strategy for LGBTQ students to activate adult allies in their community.

Ratiometric quantitation of redox status with a molecular Fe2 magnetic resonance probe.

We demonstrate the ability of a molecular Fe2 complex to enable magnetic resonance (MR)-based ratiometric quantitation of redox status, namely through redox-dependent paramagnetic chemical exchange saturation transfer (PARACEST). Metalation of a tetra(carboxamide) ligand with FeII and/or FeIII in the presence of etidronate ion affords analogous FeII2, FeIIFeIII, and FeIII2 complexes. Both FeII2 and FeIIFeIII complexes give highly-shifted, sharp, and non-overlapping NMR spectra, with multiple resonances for each complex corresponding to exchangeable carboxamide protons. These protons can be selectively irradiated to give CEST peaks at 74 and 83 ppm vs. H2O for the FeIIFeIII complex and at 29, 40 and 68 ppm for the FeII2 complex. The CEST spectra obtained from a series of samples containing mixtures of FeII2 and FeIIFeIII are correlated with independently-determined open-circuit potentials to construct a Nernstian calibration curve of potential vs. CEST peak intensity ratio. In addition, averaged intensities of phantom images collected on a 9.4 T MRI scanner show analogous Nernstian behavior. Finally, both the FeII2 and FeIIFeIII forms of the complex are stable to millimolar concentrations of H2PO4-/HPO42-, CO32-, SO42-, CH3COO-, and Ca2+ ions, and the FeIII2 form is air-stable in aqueous buffer and shows >80% viability in melanoma cells at millimolar concentration. The stability suggests the possible application of this or related complexes for in vivo studies. To our knowledge, this concentration-independent method based on a single Fe2 probe provides the first example of MR-based ratiometric quantitation of redox environment.