Burst kinetics and CNNM binding are evolutionarily conserved properties of phosphatases of regenerating liver.

Phosphatases of regenerating liver (PRL or PTP4A) are a family of enigmatic protein phosphatases implicated in cell growth and metabolism. Despite their relevance in metastatic cancer, much remains unknown about the PRL family. They act as pseudophosphatases to regulate the CNNM family of magnesium transporters yet also have enzymatic activity on unknown substrates. In mammals, PRLs are mostly found trapped in an intermediate state that regulates their pseudophosphatase activity. Phosphocysteine, which is formed as an intermediate in the phosphatase catalytic cycle, is inefficiently hydrolyzed leading to burst enzyme kinetics and turnover numbers of less than one per hour. In flies, PRLs have recently been shown to have neuroprotective and neurodevelopmental roles raising the question whether they act as phosphatases, pseudophosphatases, or both. Here, we characterize the evolutionary development of PRLs and ask whether their unique structural and functional properties are conserved. We purified recombinant PRL proteins from 15 phylogenetically diverse organisms and characterized their catalytic activities and ability to bind CNNM proteins. We observed PRLs from humans to amoebae form a stable phosphocysteine intermediate and exhibit burst kinetics. Isothermal titration calorimetry experiments confirmed that the PRL-CNNM interaction is broadly conserved with nanomolar affinity in vertebrates. Lastly, we determined the crystal structure of the Drosophila melanogaster PRL-CNNM complex and identified mutants that specifically impair either phosphatase activity or CNNM binding. Our results reveal the unique properties of PRLs are conserved throughout the animal kingdom and open the door to using model organisms to dissect PRL function in cell signaling.

Principles for Ending Human Immunodeficiency Virus as an Epidemic in the United States: A Policy Paper of the Infectious Diseases Society of America and the HIV Medical Association.

While we have the tools to achieve this goal, the persistent barriers to healthcare services experienced by too many individuals will need to be addressed to make significant progress and improve the health and quality of life of all people with human immunodeficiency virus (HIV). The necessary structural changes require actions by federal, state, and local policymakers and range from ensuring universal access to healthcare services to optimizing care delivery to ensuring a robust and diverse infectious diseases and HIV workforce. In this article, we outlines 10 key principles for policy reforms that, if advanced, would make ending the HIV epidemic in the United States possible and could have much more far-reaching effects in improving the health of our nation.

Assessing and Addressing the Risk of Venous Thromboembolism Across the Spectrum of Gender Affirming Care: A Review.

OBJECTIVE: Accumulating evidence demonstrates that gender affirming hormone therapy (GAHT) improves mental health outcomes in transgender persons. Data specific to the risks associated with GAHT for transgender persons continue to emerge, allowing for improvements in understanding, predicting, and mitigating adverse outcomes while informing discussion about desired effects. Of particular concern is the risk of venous thromboembolism (VTE) in the context of both longitudinal GAHT and the perioperative setting. Combining what is known about the risk of VTE in cisgender individuals on hormone therapy (HT) with the evidence for transgender persons receiving HT allows for an informed approach to assess underlying risk and improve care in the transgender community. OBSERVATIONS: Hormone formulation, dosing, route, and duration of therapy can impact thromboembolic risk, with transdermal estrogen formulations having the lowest risk. There are no existing risk scores for VTE that consider HT as a possible risk factor. Risk assessment for recurrent VTE and bleeding tendencies using current scores may be helpful when assessing individual risk. Gender affirming surgeries present unique perioperative concerns, and certain procedures include a high likelihood that patients will be on exogenous estrogens at the time of surgery, potentially increasing thromboembolic risk. CONCLUSIONS AND RELEVANCE: Withholding GAHT due to potential adverse events may cause negative impacts for individual patients. Providers should be knowledgeable about the management of HT in transgender individuals of all ages, as well as in the perioperative setting, to avoid periods in which transgender individuals are off GAHT. Treatment decisions for both anticoagulation and HT should be individualized and tailored to patients' overall goals and desired outcomes, given that the physical and mental health benefits of gender affirming care may outweigh the risk of VTE.

The Invisibility of Scotomas I: The Carving Hypothesis.

SIGNIFICANCE: Veridical depictions of scene appearance with scotomas allow better understanding of the impact of field loss and may improve the development and implementation of rehabilitation. Explanation and depiction of the invisibility of scotoma may lead to patients' understanding and thus better compliance with related treatments. PURPOSE: Simulations of perception with scotomas guide training, patient education, and rehabilitation research. Most simulations incorrectly depict scotomas as black patches, although the scotomas and the missing contents are usually invisible to patients. We present a novel approach to capture the reported appearance of scenes with scotomas. METHODS: We applied a content-aware image resizing algorithm to carve out the content elided under the scotomas. With video sequences, we show how and why eye movements fail to increase the visibility of the carved scotomas. RESULTS: Numerous effects, reported by patients, emerge naturally from the scotoma carving. Carving-eliminated scotomas over natural images are barely visible, despite causing substantial distortions. Low resolution and contrast sensitivity at farther eccentricities and saccadic blur reduce the visibility of the distortions. In a walking scenario, static objects moving smoothly to the periphery disappear into and then reemerge out of peripheral scotomas, invisibly. CONCLUSIONS: Scotoma carving provides a viable hypothetical simulation of vision with scotomas due to loss of neurons at the retinal ganglion cell level and higher. As a hypothesis, it generates predictions that lend themselves to future clinical testing. The different effects of scotomas due to loss of photoreceptors are left for follow-up work.

Determining the Incidence of Asymptomatic SARS-CoV-2 Among Early Recipients of COVID-19 Vaccines (DISCOVER-COVID-19): A Prospective Cohort Study of Healthcare Workers Before, During and After Vaccination.

The impact of coronavirus disease 2019 vaccination on viral characteristics of breakthrough infections is unknown. In this prospective cohort study, incidence of severe acute respiratory syndrome coronavirus 2 infection decreased following vaccination. Although asymptomatic positive tests were observed following vaccination, the higher cycle thresholds, repeat negative tests, and inability to culture virus raise questions about their clinical significance.

Health equity in the implementation of genomics and precision medicine: A public health imperative.

Recent reviews have emphasized the need for a health equity agenda in genomics research. To ensure that genomic discoveries can lead to improved health outcomes for all segments of the population, a health equity agenda needs to go beyond research studies. Advances in genomics and precision medicine have led to an increasing number of evidence-based applications that can reduce morbidity and mortality for millions of people (tier 1). Studies have shown lower implementation rates for selected diseases with tier 1 applications (familial hypercholesterolemia, Lynch syndrome, hereditary breast and ovarian cancer) among racial and ethnic minority groups, rural communities, uninsured or underinsured people, and those with lower education and income. We make the case that a public health agenda is needed to address disparities in implementation of genomics and precision medicine. Public health actions can be centered on population-specific needs and outcomes assessment, policy and evidence development, and assurance of delivery of effective and ethical interventions. Crucial public health activities also include engaging communities, building coalitions, improving genetic health literacy, and building a diverse workforce. Without concerted public health action, further advances in genomics with potentially broad applications could lead to further widening of health disparities in the next decade.

Health Profession Students' Awareness, Knowledge, and Confidence Regarding Preexposure Prophylaxis: Results of a National, Multidisciplinary Survey.

BACKGROUND: Preexposure prophylaxis (PrEP) is a highly effective, pharmacologic method of HIV prevention. Despite its safety and efficacy, PrEP prescription remains low in those patients who are at highest risk for HIV infection. One possible reason for this may be the lack of inclusion of PrEP and HIV prevention discussions within the curricula of health professions education. METHODS: An online survey was administered to a cross-sectional sample of future prescribers (osteopathic/allopathic medical and physician assistant students), future nurses, and future pharmacists (n = 2085) in the United States between January and July 2019 to assess and compare awareness of PrEP, PrEP education, PrEP knowledge, and confidence in 2 areas related to PrEP. RESULTS: We show that, overall, awareness of PrEP is high among future health care providers (81.6%), with the future pharmacists reporting the greatest awareness (92.2%; P < 0.001) and more commonly reporting PrEP education (71.0%). Students had mixed knowledge of PrEP, with future pharmacists reporting the highest knowledge of PrEP. Approximately 30% of students in all disciplines reported having low confidence counseling a patient about PrEP and low confidence educating a colleague about PrEP. Knowledge of PrEP was a significant predictor of confidence counseling a patient about PrEP (P < 0.001) and educating a colleague about PrEP (P < 0.001). CONCLUSIONS: This study identifies opportunities to improve and incorporate evidence-based strategies for educating future health care providers about PrEP for HIV prevention within health professions curricula.

Automatic processing of gaze movements to quantify gaze scanning behaviors in a driving simulator.

Eye and head movements are used to scan the environment when driving. In particular, when approaching an intersection, large gaze scans to the left and right, comprising head and multiple eye movements, are made. We detail an algorithm called the gaze scan algorithm that automatically quantifies the magnitude, duration, and composition of such large lateral gaze scans. The algorithm works by first detecting lateral saccades, then merging these lateral saccades into gaze scans, with the start and end points of each gaze scan marked in time and eccentricity. We evaluated the algorithm by comparing gaze scans generated by the algorithm to manually marked "consensus ground truth" gaze scans taken from gaze data collected in a high-fidelity driving simulator. We found that the gaze scan algorithm successfully marked 96% of gaze scans and produced magnitudes and durations close to ground truth. Furthermore, the differences between the algorithm and ground truth were similar to the differences found between expert coders. Therefore, the algorithm may be used in lieu of manual marking of gaze data, significantly accelerating the time-consuming marking of gaze movement data in driving simulator studies. The algorithm also complements existing eye tracking and mobility research by quantifying the number, direction, magnitude, and timing of gaze scans and can be used to better understand how individuals scan their environment.

Student Education About Pre-exposure Prophylaxis (PrEP) Varies Between Regions of the United States.

BACKGROUND: Daily, oral pre-exposure prophylaxis (PrEP) is an effective and safe prevention strategy for people at risk for HIV. However, prescription of PrEP has been limited for patients at the highest risk. Disparities in PrEP prescription are pronounced among racial and gender minority patients. A significant body of literature indicates that practicing healthcare providers have little awareness and knowledge of PrEP. Very little work has investigated the education about PrEP among health professionals in training. OBJECTIVE: The objective of this study was to compare health professions students' awareness of PrEP and education about PrEP between regions of the US, and to determine if correlations between regional HIV incidence and PrEP use were present. DESIGN: Survey study. PARTICIPANTS: A cross-sectional sample of health professions students (N = 1859) representing future prescribers (MD, DO, PA), pharmacists, and nurses in the US. KEY RESULTS: Overall, 83.4% of students were aware of PrEP, but only 62.2% of fourth-year students indicated they had been taught about PrEP at any time during their training. Education about PrEP was most comprehensive in the Northeastern US, the area with the highest PrEP to need ratio (4.7). In all regions, transgender patients and heterosexual men and women were least likely to be presented in education as PrEP candidates, and men who have sex with men were the most frequently presented. CONCLUSIONS: There are marked differences in education regarding PrEP both between academic programs and regions of the USA.

Physician Assistant's Knowledge and Confidence Regarding Prescribing Preexposure Prophylaxis for HIV Prevention.

Physician assistants (PAs) have an important role to play in increasing preexposure prophylaxis (PrEP) prescriptions. We surveyed PAs regarding knowledge of Centers for Disease Control and Prevention guidelines for PrEP and confidence regarding PrEP. Physician assistants in primary care reported more accurate knowledge and higher confidence. However, knowledge and confidence gaps were present among all PAs, regardless of specialty.

The promise of human induced pluripotent stem cells for research and therapy.

Induced pluripotent stem (iPS) cells are human somatic cells that have been reprogrammed to a pluripotent state. There are several hurdles to be overcome before iPS cells can be considered as a potential patient-specific cell therapy, and it will be crucial to characterize the developmental potential of human iPS cell lines. As a research tool, iPS-cell technology provides opportunities to study normal development and to understand reprogramming. iPS cells can have an immediate impact as models for human diseases, including cancer

Design and construction of a Maxwell-type induction coil for magnetic nanoparticle hyperthermia.

Purpose: We describe a modified Helmholtz induction coil, or Maxwell coil, that generates alternating magnetic fields (AMF) having field uniformity (≤10%) within a = 3000 cm3 volume of interest for magnetic hyperthermia research.Materials and methods: Two-dimensional finite element analysis (2D-FEA) was used for electromagnetic design of the induction coil set and to develop specifications for the required matching network. The matching network and induction coil set were fabricated using best available practices and connected to a 120 kW industrial induction heating power supply. System performance was evaluated by magnetic field mapping with a magnetic field probe, and tests were performed using gel phantoms.Results: Tests verified that the system generated a target peak AMF amplitude along the coil axis of ∼35 kA/m (peak) at a frequency of 150 ± 10 kHz while maintaining field uniformity to >90% of peak for a volume of ∼3000 cm3.Conclusions: The induction coil apparatus comprising three independent loops, i.e., Maxwell-type improves upon the performance of simple solenoid and Helmholtz coils by providing homogeneous flux density fields within a large volume while minimizing demands on power and stray fields. Experiments with gel phantoms and analytical calculations show that future translational research efforts should be devoted to developing strategies to reduce the impact of nonspecific tissue heating from eddy currents; and, that an inductor producing a homogeneous field has significant clinical potential for deep-tissue magnetic fluid hyperthermia.

Feasibility of removable balloon implant for simultaneous magnetic nanoparticle heating and HDR brachytherapy of brain tumor resection cavities.

AIM: Hyperthermia (HT) has been shown to improve clinical response to radiation therapy (RT) for cancer. Synergism is dramatically enhanced if HT and RT are combined simultaneously, but appropriate technology to apply treatments together does not exist. This study investigates the feasibility of delivering HT with RT to a 5-10mm annular rim of at-risk tissue around a tumor resection cavity using a temporary thermobrachytherapy (TBT) balloon implant. METHODS: A balloon catheter was designed to deliver radiation from High Dose Rate (HDR) brachytherapy concurrent with HT delivered by filling the balloon with magnetic nanoparticles (MNP) and immersing it in a radiofrequency magnetic field. Temperature distributions in brain around the TBT balloon were simulated with temperature dependent brain blood perfusion using numerical modeling. A magnetic induction system was constructed and used to produce rapid heating (>0.2°C/s) of MNP-filled balloons in brain tissue-equivalent phantoms by absorbing 0.5 W/ml from a 5.7 kA/m field at 133 kHz. RESULTS: Simulated treatment plans demonstrate the ability to heat at-risk tissue around a brain tumor resection cavity between 40-48°C for 2-5cm diameter balloons. Experimental thermal dosimetry verifies the expected rapid and spherically symmetric heating of brain phantom around the MNP-filled balloon at a magnetic field strength that has proven safe in previous clinical studies. CONCLUSIONS: These preclinical results demonstrate the feasibility of using a TBT balloon to deliver heat simultaneously with HDR brachytherapy to tumor bed around a brain tumor resection cavity, with significantly improved uniformity of heating over previous multi-catheter interstitial approaches. Considered along with results of previous clinical thermobrachytherapy trials, this new capability is expected to improve both survival and quality of life in patients with glioblastoma multiforme.

Hemodynamic Effects of Late Sodium Current Inhibitors in a Swine Model of Heart Failure.

OBJECTIVES: To evaluate possible treatment-related hemodynamic changes, we administered ranolazine or mexiletine to swine with heart failure (HF) and to controls. BACKGROUND: Ranolazine and mexiletine potently inhibit depolarizing late Na+ current (INa,late) and Na+ entry into cardiomyocytes. Blocking Na+ entry may increase forward-mode Na/Ca exchange and reduce cellular Ca+2 load, further compromising systolic contraction during HF. METHODS AND RESULTS: Anesthetized tachypaced HF swine received ranolazine (n = 9) or mexiletine (n = 7) as boluses, then as infusions; the same experiments were performed in 10 nonpaced controls. The swine with HF had characteristic elevated left ventricular end-diastolic pressure (LVEDP) and reduced maximal left ventricular pressure rise (+dP/dtmax) and left ventricular peak systolic pressure (LVSP). No significant change occurred after ranolazine dosing for any parameter: LVEDP, +dP/dtmax, LVSP, heart rate, maximal LV pressure fall rate (-dP/dtmax), or time constant for isovolumic relaxation. Similar results seen in additional swine with HF: 7 were given mexiletine, and 7 others were given ranolazine after a 27% rate decrement to maximize INa,late. Patch-clamped HF cardiomyocytes confirmed drug-induced INa,late blockade. CONCLUSIONS: Ranolazine or mexiletine blocking INa,late neither worsened nor improved hemodynamics during advanced HF. Although results must be clinically confirmed, they suggest inhibition of INa,late by ranolazine or mexiletine may not exacerbate HF in patients.

Merkel Cell Carcinoma in the HIV-1/AIDS Patient.

Merkel cell carcinoma (MCC) is a highly aggressive, primary neuroendocrine cancer of the skin. The majority of MCC cases are associated with the recently discovered Merkel cell polyomavirus (MCPyV), while the remaining are caused by ultraviolet (UV) light-induced mutations from excessive sunlight exposure. The risk of developing MCC is much higher in the white population relative to all other races. Approximately 10% of all patients with MCC have some form of immunosuppression including HIV-1/AIDS, chronic inflammatory conditions, solid organ transplantation, or hematological malignancies. The age of onset of MCC is lower and the mortality is higher in immunosuppressed individuals than in immune-competent patients. It is plausible that HIV-1/AIDS predisposes to virus-positive MCC, but it should be noted that HIV-1/AIDS increases the risk for developing of UV-induced skin cancers such as cutaneous squamous cell carcinoma and basal cell carcinoma and therefore may also increase the risk for virus-negative MCC. Surgical management is considered standard of care for localized Merkel cell carcinoma with current recommendations advising a wide local excision of the lesion. Most international guidelines support the use of local adjuvant radiotherapy coupled with tumor staging to improve the frequency of cure. For advanced, metastatic, and recurrent MCC, checkpoint blockade inhibitors targeting PD-1 and PD-L1 have shown remarkable activity including durable long-term. MCC in patients living with HIV-1/AIDS are treated with similar modalities as HIV-1 uninfected individuals with MCC.