Point-of-need mastitis pathogen biosensing in bovine milk: From academic sample preparation novelty to industry prototype field testing.

Bovine mastitis is an inflammation of the mammary gland, and it is the most common infectious disease in dairy cattle. Mastitis reduces milk yield and quality, costing dairy farmers millions of dollars each year. The aim of this study was to develop a point-of-need test for identifying mastitis pathogens that is field portable, cost-effective and can be used with minimal training. Using a proprietary polymer-based milk sample preparation method to rapidly extract pathogen DNA in milk samples, we demonstrated quantitative Polymerase Chain Reaction (qPCR) assays for six common bovine bacterial mastitis pathogens: Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Mycoplasma bovis and Escherichia coli. We also implemented this sample preparation method on a prototype point-of-need system in a proof-of-concept field trial to evaluate user experience. Importantly, the protype system enabled a sample-to-result turnaround time of within 70 min to quantitatively detect all six target pathogens. The key advantage of our point-of-need prototype system is being culture-independent yet providing automated milk sample preparation for molecular identification of key mastitis pathogens by non-expert users. Our point-of-need prototype system showed a good correlation to laboratory-based qPCR for target pathogen detection outcomes, thus potentially removing the need for milk samples to be transported off-site for laboratory testing. Above all, we successfully achieved our objective of developing a point-of-need biosensor technology for mastitis and increased its readiness level with industry partners towards technology commercialization.

Multi-site integrated optical addressing of trapped ions.

One of the most effective ways to advance the performance of quantum computers and quantum sensors is to increase the number of qubits or quantum resources in the system. A major technical challenge that must be solved to realize this goal for trapped-ion systems is scaling the delivery of optical signals to many individual ions. In this paper we demonstrate an approach employing waveguides and multi-mode interferometer splitters to optically address multiple 171Yb+ ions in a surface trap by delivering all wavelengths required for full qubit control. Measurements of hyperfine spectra and Rabi flopping were performed on the E2 clock transition, using integrated waveguides for delivering the light needed for Doppler cooling, state preparation, coherent operations, and detection. We describe the use of splitters to address multiple ions using a single optical input per wavelength and use them to demonstrate simultaneous Rabi flopping on two different transitions occurring at distinct trap sites. This work represents an important step towards the realization of scalable integrated photonics for atomic clocks and trapped-ion quantum information systems.

Post-synthesis Oxidation of Superparamagnetic Iron Oxide Nanoparticles to Enhance Magnetic Particle Imaging Performance.

This study investigates the impact of post-synthesis oxidation on the performance of superparamagnetic iron oxide nanoparticles (SPIONs) in magnetic particle imaging (MPI), an emerging technology with applications in diagnostic imaging and theranostics. SPIONs synthesized from iron oleate were subjected to a post-synthesis oxidation treatment with a 1% Oxygen in Argon mixture. MPI performance, gauged via signal intensity and resolution using a MOMENTUM™ scanner, was correlated to the nanoparticles' physical and magnetic properties. Post-synthesis oxidation did not alter physical attributes like size and shape, but significantly enhanced magnetic properties. Saturation magnetization increased from 52% to 93% of the bulk value for magnetite, leading to better MPI performance in terms of signal intensity and resolution. However, the observed MPI performance did not fully align with predictions based on the ideal Langevin model, indicating the need for considering factors like relaxation and shape anisotropy. The findings underscore the potential of post-synthesis oxidation as a method to fine-tune magnetic properties of SPIONs and improve MPI performance, and the need for reproducible synthesis methods that afford finely tuned control of nanoparticle size, shape, and magnetic properties.

Barriers to endocrine therapy adherence: perspectives of Black breast cancer survivors and their providers.

PURPOSE: Adherence to oral endocrine therapy (ET) remains an issue for up to half of women prescribed these medications. There is emerging data that Black breast cancer survivors (BCS) have lower rates of ET adherence. Given the disparities in breast cancer recurrence and survival for Black BCS compared to their White counterparts, the goal of this study is to better understand barriers to ET adherence among Black BCS from the patient and provider perspectives. METHODS: In this qualitative study, we conducted semi-structured interviews between October 29, 2021, and March 1, 2023. Interviews were recorded and transcribed, and coded data were organized into primary and secondary themes. Participants were recruited from a single academic cancer center. A convenience sample of 24 Black BCS and 9 medical oncology providers was included. Eligible BCS were 18 years or older, English-speaking, diagnosed with stage I-III hormone receptor-positive breast cancer, who had initiated ET. RESULTS: Mean age of the BCS was 55 years (interquartile range, IQR 17 years). About one-fourth had a high school diploma or less (26.1%) and 47% completed a college education or higher. Approximately one-third of participants had annual household incomes of $40,000 or less (30.4%) or more than $100,000 (30.4%). Forty-three percent of the patient participants had private insurance; 11% were insured through Medicaid or the federal healthcare exchange; 26.1% had Medicare; and 13% were uninsured. Of the 9 medical oncology providers interviewed, 2 were advanced practice providers, and 7 were medical oncologists. We found 3 major themes: (1) Black BCS often had concerns about ET before initiation; (2) after initiation, both BCS and providers reported side effects as the most impactful barrier to ET adherence; and (3) survivors experienced challenges with managing ET side effects. CONCLUSIONS: Our results suggest that multifaceted support interventions for managing ET-related symptoms may lead to improved adherence to ET among Black women and may reduce disparities in outcomes. IMPLICATIONS FOR CANCER SURVIVORS: Multifaceted support interventions for managing ET-related symptoms may lead to improved adherence to ET among Black breast cancer survivors.

The Training and Tapering Practices of Highland Games Heavy Event Athletes.

ABSTRACT: Winwood, PW, Keogh, JW, Travis, SK, Grieve, I, and Pritchard, HJ. The training and tapering practices of Highland Games heavy event athletes. J Strength Cond Res 38(3): e116-e124, 2024-This study provides the first empirical evidence of how Highland Games heavy event athletes train and taper for Highland Games competitions. Athletes (n = 169) (mean ± SD: age 40.8 ± 10.7 years, height 181.2 ± 9.5 cm, weight 107.2 ± 23.0 kg, 18.8 ± 10.3 years of general resistance training, and 8.1 ± 6.9 years of competitive Highland Games experience) completed a self-reported 4-page online survey on training and tapering practices. Analysis by sex (male and female) and competitive standard (local or regional, national, and international) was conducted. Seventy-eight percent (n = 132) of athletes reported that they used a taper. Athletes stated that their taper length was 5.2 ± 3.5 days, with the step (36%) and linear tapers (33%) being the most performed. Athletes reported that their highest training volume and intensity were 5.5 and 3.8 weeks out (respectively) from competition, and all training ceased 2.4 ± 1.4 days before competition. Training volume decreased during the taper by 34%. Athletes typically stated that, tapering was performed to achieve recovery, peak performance, and injury prevention; training intensity, frequency, and duration stayed the same or decreased; game-specific training increased with reductions in traditional exercises; the caber toss, weight for height, and heavy weight throw were performed further out from competition than other events; muscular power and strength were the most common types of training performed; static stretching, foam rolling, and massage were strategies used in the taper; and poor tapering occurred because of life/work circumstances, lack of sleep/rest, or training too heavy/hard. These results may aid Highland Games athletes to optimize training and tapering variables leading to improved performances.

"I couldn't connect the wires in my brain." Young adult cancer survivors' experience with cognitive functioning.

OBJECTIVE: There is a dearth of literature describing young adult (YA) cancer survivors' experiences with cancer-related cognitive impairment (CRCI). We aimed to elucidate CRCI among YA cancer survivors and identify potentially modifiable risk factors. METHODS: We conducted individual qualitative interviews with YA cancer survivors aged 18-30 years at study enrollment and used applied thematic analysis to identify themes across three topics (i.e., affected cognitive abilities, risk and protective factors influencing the impact of CRCI, and strategies for coping with CRCI). RESULTS: YA cancer survivors (N = 20) were, on average, 23 years old at diagnosis and 26 years old when interviewed. Diverse cancer types and treatments were represented; most participants (85%) had completed cancer treatment. Participants described experiences across three qualitative topics: (1) affected cognitive abilities (i.e., concentration and attention, prospective memory, and long-term memory), (2) Risk factors (i.e., fatigue, sleep problems, mood, stress/distractions, and social isolation) and protective factors (i.e., social support), and (3) coping strategies, including practical strategies that helped build self-efficacy (e.g., writing things down, reducing distractions), beneficial emotion-focused coping strategies (e.g., focus on health, faith/religion), strategies with mixed effects (i.e., apps/games, medications/supplements, and yoga), and "powering through" strategies that exacerbated stress. CONCLUSIONS: YA cancer survivors experience enduring cognitive difficulties after treatment. Specific concerns highlight the importance of attention and executive functioning impairments, long-term memory recall, and sensitivity to distractions. Future work is needed to improve assessment and treatment of CRCI among YA cancer survivors.

Cryptic splicing of stathmin-2 and UNC13A mRNAs is a pathological hallmark of TDP-43-associated Alzheimer's disease.

Nuclear clearance and cytoplasmic accumulations of the RNA-binding protein TDP-43 are pathological hallmarks in almost all patients with amyotrophic lateral sclerosis (ALS) and up to 50% of patients with frontotemporal dementia (FTD) and Alzheimer's disease. In Alzheimer's disease, TDP-43 pathology is predominantly observed in the limbic system and correlates with cognitive decline and reduced hippocampal volume. Disruption of nuclear TDP-43 function leads to abnormal RNA splicing and incorporation of erroneous cryptic exons in numerous transcripts including Stathmin-2 (STMN2, also known as SCG10) and UNC13A, recently reported in tissues from patients with ALS and FTD. Here, we identify both STMN2 and UNC13A cryptic exons in Alzheimer's disease patients, that correlate with TDP-43 pathology burden, but not with amyloid-ß or tau deposits. We also demonstrate that processing of the STMN2 pre-mRNA is more sensitive to TDP-43 loss of function than UNC13A. In addition, full-length RNAs encoding STMN2 and UNC13A are suppressed in large RNA-seq datasets generated from Alzheimer's disease post-mortem brain tissue. Collectively, these results open exciting new avenues to use STMN2 and UNC13A as potential therapeutic targets in a broad range of neurodegenerative conditions with TDP-43 proteinopathy including Alzheimer's disease.

Magnetic Cellular Backpacks for Spatial Targeting, Imaging, and Immunotherapy.

Adoptive cell transfer (ACT) therapies are growing in popularity due to their ability to interact with diseased tissues in a specific manner. Disc-shaped particles, or "backpacks", that bind to cellular surfaces show promise for augmenting the therapeutic potential of adoptively transferred cells by resisting phagocytosis and locally releasing drugs to maintain cellular activity over time. However, many ACTs suffer from limited tumor infiltration and retention and lack a method for real-time spatial analysis. Therefore, we have designed biodegradable backpacks loaded with superparamagnetic iron oxide nanoparticles (SPIONs) to improve upon current ACT strategies by (i) controlling the localization of cell-backpack complexes using gradient magnetic fields and (ii) enabling magnetic particle imaging (MPI) to track complexes after injection. We show that magnetic backpacks bound to macrophages and loaded with a proinflammatory drug, resiquimod, maintain anticancer phenotypes of carrier macrophages for 5 days and create cytokine "factories" that continuously release IL-12. Furthermore, we establish that forces generated by gradient magnet fields are sufficient to displace cell-backpack complexes in physiological settings. Finally, we demonstrate that MPI can be used to visualize cell-backpack complexes in mouse tumors, enabling a potential strategy to track the biodistribution of ACTs in real time.

Interferometric metrology probe for highly sloped freeform optics.

A wide variety of systems are employed to measure the surface profile of aspheric and freeform optical surfaces. Freeform metrology systems must accurately characterize the full surface under test, which can be difficult with steep surface slopes. Here we present an interferometric surface metrology probe for highly sloped aspheric and freeform optical surfaces. The optical design of this probe allows the measurement of surface slopes up to 50 deg without tilting the probe, which simplifies stage design and increases the accuracy of the system. A spectrally controlled light source is used to create a virtual ball in front of the probe tip to measure the surface distance and angle. This system produces a cloud of points, to which Zernike polynomials are fit and used to reconstruct the surface. We will show sensitivity tests and accuracy results.

A Near Real-Time Risk Analytics Algorithm Predicts Elevated Lactate Levels in Pediatric Cardiac Critical Care Patients.

BACKGROUND: Postoperative pediatric congenital heart patients are predisposed to develop low-cardiac output syndrome. Serum lactate (lactic acid [LA]) is a well-defined marker of inadequate systemic oxygen delivery. OBJECTIVES: We hypothesized that a near real-time risk index calculated by a noninvasive predictive analytics algorithm predicts elevated LA in pediatric patients admitted to a cardiac ICU (CICU). DERIVATION COHORT: Ten tertiary CICUs in the United States and Pakistan. VALIDATION COHORT: Retrospective observational study performed to validate a hyperlactatemia (HLA) index using T3 platform data (Etiometry, Boston, MA) from pediatric patients less than or equal to 12 years of age admitted to CICU (n = 3,496) from January 1, 2018, to December 31, 2020. Patients lacking required data for module or LA measurements were excluded. PREDICTION MODEL: Physiologic algorithm used to calculate an HLA index that incorporates physiologic data from patients in a CICU. The algorithm uses Bayes' theorem to interpret newly acquired data in a near real-time manner given its own previous assessment of the physiologic state of the patient. RESULTS: A total of 58,168 LA measurements were obtained from 3,496 patients included in a validation dataset. HLA was defined as LA level greater than 4 mmol/L. Using receiver operating characteristic analysis and a complete dataset, the HLA index predicted HLA with high sensitivity and specificity (area under the curve 0.95). As the index value increased, the likelihood of having higher LA increased (p < 0.01). In the validation dataset, the relative risk of having LA greater than 4 mmol/L when the HLA index is less than 1 is 0.07 (95% CI: 0.06-0.08), and the relative risk of having LA less than 4 mmol/L when the HLA index greater than 99 is 0.13 (95% CI, 0.12-0.14). CONCLUSIONS: These results validate the capacity of the HLA index. This novel index can provide a noninvasive prediction of elevated LA. The HLA index showed strong positive association with elevated LA levels, potentially providing bedside clinicians with an early, noninvasive warning of impaired cardiac output and oxygen delivery. Prospective studies are required to analyze the effect of this index on clinical decision-making and outcomes in pediatric population.

A descriptive assessment of the informed consent document used by congenital cardiac surgery centres.

BACKGROUND: Informed consent for surgery is a complex process particularly in paediatrics. Complexity increases with procedures such as CHD surgery. Regulatory agencies outline informed consent contents for surgery. We assessed and described CHD surgical informed consent contents through survey dissemination to paediatric CHD centres across United States of America. METHODS: Publicly available email addresses for 125 paediatric cardiac clinicians at 70 CHD surgical centres were obtained. Nine-item de-identified survey assessing adherence to The Joint Commission informed consent standards was created and distributed via RedCap® 14 March, 2023. A follow-up email was sent 29 March, 2023. Survey link was closed 18 April, 2023. RESULTS: Thirty-seven surveys were completed. Results showed informed consent documents were available in both paper (25, 68%) and electronic (3, 8%) format. When both (9, 24%) formats were available, decision on which format to use was based on centre protocols (1, 11%), clinician personal preference (3, 33%), procedure being performed (1, 11%), or other (4, 45%). Five (13%) centres' informed consent documents were available only in English, with 32 (87%) centres also having a Spanish version. Review of informed consent documents demonstrated missing The Joint Commission elements including procedure specific risks, benefits, treatment alternatives, and expected outcomes. CONCLUSIONS: Informed consent for CHD surgery is a complex process with multiple factors involved. Majority of paediatric CHD surgical centres in the United States of America used a generic informed consent document which did not uniformly contain The Joint Commission specified information nor reflect time spent in discussion with families. Further research is needed on parental comprehension during the informed consent process.

Axial shift mapping: a self-referencing test for measuring the axial figure of near-cylindrical surfaces.

Lateral shearing self-referencing interferometry methods shift the surface under test between measurements to separate its topography from that of the reference surface. However, rigid body errors occur during shifting, creating an ambiguity in the quadratic term of the extracted surfaces. We present axial shift mapping, a lateral shearing self-referencing interferometry method for cylinders, in which the quadratic ambiguity is resolved by measuring the rigid body errors using known artifact mirrors residing in the interferometer's field of view. First, one-dimensional lines of a flat mirror are measured with 2.8 nm RMS difference compared to a three flat test. Then, axial shift mapping is extended to cylindrical surfaces using a computer generated hologram. We find that axial shift mapping results in full surface extraction of cylindrical optics, along the axial direction, with a repeatability of 4.4 nm RMS. We also find that the reference surface extracted through axial shift mapping is within 4.5 nm RMS of the transmitted wavefront error of the computer generated hologram substrate, which was expected to be the largest contribution of reference wavefront error.

Autistic traits at neurodevelopmental assessment for very preterm infants.

Aim The aim of this study was to establish the prevalence of autistic traits at childhood neurodevelopmental assessment in a premature cohort and to assess associated perinatal exposures. Methods An observational retrospective case-control study was conducted in a single tertiary neonatal unit. All infants born weighing =1500 grams and/or =32/40 weeks who attended for neurodevelopmental assessment in 2019 were eligible. Results 96 preterm infants met the inclusion criteria. 22 (23%) in the case group demonstrated clinical features of autism at early childhood assessment. The remaining 74 acted as a control group. In the case group 18 (82%) were male. There was no difference in rate of multiple births between the groups. There was no statistically significant difference in maternal age or indication for delivery. Male phenotype (p=0.003), non-Irish ethnicity (p=0.005), vaginal delivery (p=0.005) and abnormal cranial ultrasound (p=0.009) occurred more frequently in the case group. Use of assistive reproductive technologies occurred less frequently in the case group (p=0.047). In the case group, 10/14 of the composite scores measured on Bayleys-3 at a median (IQR) age of 32 (31-35) months showed statistically significant differences (p<0.003). Discussion Our study strongly supports increasing awareness of the association between prematurity and autism. It highlights the need for targeted neurodevelopmental follow-up to support early detection of autism, allowing for timely intervention. Further investigation in a larger prospective cohort may further delineate the various perinatal risk factors for autism.

Mitigating a TDP-43 proteinopathy by targeting ataxin-2 using RNA-targeting CRISPR effector proteins.

The TDP-43 proteinopathies, which include amyotrophic lateral sclerosis and frontotemporal dementia, are a devastating group of neurodegenerative disorders that are characterized by the mislocalization and aggregation of TDP-43. Here we demonstrate that RNA-targeting CRISPR effector proteins, a programmable class of gene silencing agents that includes the Cas13 family of enzymes and Cas7-11, can be used to mitigate TDP-43 pathology when programmed to target ataxin-2, a modifier of TDP-43-associated toxicity. In addition to inhibiting the aggregation and transit of TDP-43 to stress granules, we find that the in vivo delivery of an ataxin-2-targeting Cas13 system to a mouse model of TDP-43 proteinopathy improved functional deficits, extended survival, and reduced the severity of neuropathological hallmarks. Further, we benchmark RNA-targeting CRISPR platforms against ataxin-2 and find that high-fidelity forms of Cas13 possess improved transcriptome-wide specificity compared to Cas7-11 and a first-generation effector. Our results demonstrate the potential of CRISPR technology for TDP-43 proteinopathies.

Anorexia Nervosa in vivo cytokine production: a systematic review.

INTRODUCTION: The underlying psychobiology that contributes to Anorexia Nervosa (AN) onset and disease progression remains unclear. New research is emerging suggesting a possible link between inflammation and a variety of mental illnesses. Alterations of cytokines may play a role in the pathogenesis of AN. Some studies have found differences in the cytokine profile of those with AN compared to healthy controls, but results are heterogeneous. The aim of this work was to systematically review existing studies investigating in-vivo cytokine production in those with AN before and after weight restoration compared to controls. METHODS: A comprehensive literature search of four electronic databases (PubMed, PsychInfo, EMBASE and CINAH) was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to identify human in-vivo studies investigating the relationship between AN and cytokine production. Data extracted from included studies related to population characteristics (e.g. age, gender, mean mBMI/%IBW), cytokine measurement and relevant findings. Confounding factors (e.g. smoking status, co-morbid mental illness, menstruation status) were also collected. RESULTS: 36 studies were eligible for this systematic review of which the majority were conducted in Europe (77.8%) and involved female subjects (97.2%). Those with AN ranged in age from 13 to 47 years and had an illness duration of 3 months to 24 years. 15 candidate cytokines and 3 receptors were identified (TNF-alpha, IL-6, IL-1B, CRP, IL-2, IL-7, IL-10, IFN-γ, TNF-R2, IL-1 α, IL-15, TNF-R1, IL-17, IL-18, TGF-B1, IL-12, IL-6R and TGF-B2) exploring in-vivo levels in patients with AN and comparing to controls. TNF-alpha and IL-6 were the most extensively studied with IL-6 being significantly elevated in 4 out of 8 (50%) of longitudinal studies when comparing AN patients at baseline compared to post weight restoration. Following weight restoration, there was no difference in IL-6 levels when comparing to HC in 7 of 8 (87.5%) longitudinal studies examined. CONCLUSIONS: The most promising cytokine potentially involved in the pathogenesis of AN appears to be IL-6, and possibly TNF-alpha pathways. The heterogeneity of clinical and methodology factors impedes the generalizability of results. Future studies may wish to address these methodological shortcomings as alterations in cytokine levels in AN could act as therapeutic targets assisting with weight restoration and psychopathology and may offer diagnostic potential.

A review of the impairments, preserved visual functions, and neuropathology in 21 patients with visual form agnosia - A unique defect with line drawings.

We present a comprehensive review of the rare syndrome visual form agnosia (VFA). We begin by documenting its history, including the origins of the term, and the first case study labelled as VFA. The defining characteristics of the syndrome, as others have previously defined it, are then described. The impairments, preserved aspects of visual perception, and areas of brain damage in 21 patients who meet these defining characteristics are described in detail, including which tests were used to verify the presence or absence of key symptoms. From this, we note important similarities along with notable areas of divergence between patients. Damage to the occipital lobe (20/21), an inability to recognise line drawings (19/21), preserved colour vision (14/21), and visual field defects (16/21) were areas of consistency across most cases. We found it useful to distinguish between shape and form as distinct constructs when examining perceptual abilities in VFA patients. Our observations suggest that these patients often exhibit difficulties in processing simplified versions of form. Deficits in processing orientation and size were uncommon. Motion perception and visual imagery were not widely tested for despite being typically cited as defining features of the syndrome - although in the sample described, motion perception was never found to be a deficit. Moreover, problems with vision (e.g., poor visual acuity and the presence of hemianopias/scotomas in the visual fields) are more common than we would have thought and may also contribute to perceptual impairments in patients with VFA. We conclude that VFA is a perceptual disorder where the visual system has a reduced ability to synthesise lines together for the purposes of making sense of what images represent holistically.

Qualitative evaluation of the implementation and future sustainability of an e-referral system for smoking cessation at a US NCI-designated comprehensive cancer center: lessons learned.

BACKGROUND: Promoting smoking cessation is recognized as an essential part of cancer care. Moffitt Cancer Center, supported by the National Cancer Institute Cancer Moonshot Cancer Center Cessation Initiative, developed and implemented an opt-out-based automatic electronic health record (EHR)-mediated referral (e-referral) system for Tobacco Quitline services along with options for local group cessation support and an in-house tobacco treatment specialist. This study evaluated barriers and facilitators for implementation of the e-referral system. METHOD: Steering committee members (N=12) responsible for developing and implementing the new clinical workflow and nurses (N=12) who were expected to use the new e-referral system completed semi-structured interviews. Qualitative thematic content analyses were conducted. RESULTS: Interviewees perceived the e-referral system as an effective strategy for identifying and referring smokers to cessation services. However, barriers were noted including competing demands and perceptions that smoking cessation was a low priority and that some patients were likely to have low motivation to quit smoking. Suggestions to improve future implementation and sustainability included providing regular trainings and e-referral outcome reports and increasing the visibility of the e-referral system within the EHR. CONCLUSION: Initial implementation of the e-referral system was perceived as successful; however, additional implementation strategies are needed to ensure sustainability at both the clinician and system levels. Recommendations for future modifications include providing regular clinician trainings and developing a fully closed-loop system. Implications for cancer survivors Initial implementation of an e-referral system for smoking cessation for cancer patients revealed opportunities to improve the smoking cessation referral process at cancer centers.

Inter-user Comparison for Quantification of Superparamagnetic Iron Oxides with Magnetic Particle Imaging Across Two Institutions Highlights a Need for Standardized Approaches.

PURPOSE: Magnetic particle imaging (MPI) is being explored in biological contexts that require accurate and reproducible quantification of superparamagnetic iron oxide nanoparticles (SPIONs). While many groups have focused on improving imager and SPION design to improve resolution and sensitivity, a few have focused on improving quantification and reproducibility of MPI. The aim of this study was to compare MPI quantification results by two different systems and the accuracy of SPION quantification performed by multiple users at two institutions. PROCEDURES: Six users (3 from each institute) imaged a known amount of Vivotrax + (10 µg Fe), diluted in a small (10 µL) or large (500 µL) volume. These samples were imaged with or without calibration standards in the field of view, to create a total of 72 images (6 users × triplicate samples × 2 sample volumes × 2 calibration methods). These images were analyzed by the respective user with two region of interest (ROI) selection methods. Image intensities, Vivotrax + quantification, and ROI selection were compared across users, within and across institutions. RESULTS: MPI imagers at two different institutes produce significantly different signal intensities, that differ by over 3 times for the same concentration of Vivotrax + . Overall quantification yielded measurements that were within [Formula: see text] 20% from ground truth; however, SPION quantification values obtained at each laboratory were significantly different. Results suggest that the use of different imagers had a stronger influence on SPION quantification compared to differences arising from user error. Lastly, calibration conducted from samples in the imaging field of view gave the same quantification results as separately imaged samples. CONCLUSIONS: This study highlights that there are many factors that contribute to the accuracy and reproducibility of MPI quantification, including variation between MPI imagers and users, despite pre-defined experimental setup, image acquisition parameters, and ROI selection analysis.

Mitigating a TDP-43 proteinopathy by targeting ataxin-2 using RNA-targeting CRISPR effector proteins.

The TDP-43 proteinopathies, which include amyotrophic lateral sclerosis and frontotemporal dementia, are a devastating group of neurodegenerative disorders that are characterized by the mislocalization and aggregation of TDP-43. Here we demonstrate that RNA-targeting CRISPR effector proteins, a programmable class of gene silencing agents that includes the Cas13 family of enzymes and Cas7-11, can be used to mitigate TDP-43 pathology when programmed to target ataxin-2, a modifier of TDP-43-associated toxicity. In addition to inhibiting the aggregation and transit of TDP-43 to stress granules, we find that the in vivo delivery of an ataxin-2-targeting Cas13 system to a mouse model of TDP-43 proteinopathy improved functional deficits, extended survival, and reduced the severity of neuropathological hallmarks. Further, we benchmark RNA-targeting CRISPR platforms against ataxin-2 and find that high-fidelity forms of Cas13 possess improved transcriptome-wide specificity compared to Cas7-11 and a first-generation effector. Our results demonstrate the potential of CRISPR technology for TDP-43 proteinopathies.