Study Protocol: Predicting the Quality of Response to Specific Treatments (PQRST) in Chronic Graft-versus-Host Disease.

BACKGROUND: Chronic graft-versus-host disease (GVHD) is a leading cause of late morbidity and mortality after allogeneic hematopoietic cell transplantation. Despite significant progress in chronic GVHD therapies, challenges remain in understanding pleomorphic phenotypes and varying response to treatment. The goal of the Predicting the Quality of Response to Specific Treatments (PQRST) in chronic GVHD study is to identify predictors of treatment response. This report describing the study design seeks to raise awareness and invite collaborations with investigators who wish to access clinical data and research samples from this study. METHODS: This is a prospective, observational cohort study involving data collection from patients who are beginning first-, second-, or third-line systemic therapy for chronic GVHD with defined agents. Evaluable participants will have baseline assessments and research samples prior to starting the index therapy, and 1 month after starting treatment. Response assessments occur at 3 and 6 months after start of treatment, or if a new systemic therapy is started before 6 months. Target enrollment is approximately 200 patients at 8 institutions, with at least 6 months of follow up to determine response to index therapy. RESULTS: Enrollment started in July 2020 and was delayed due to the COVID-19 pandemic; as of 3/1/2024, 137 evaluable participants have been enrolled. DISCUSSION: The Chronic GVHD Consortium "PQRST" is a large longitudinal cohort study that aims to investigate predictors of treatment response by identifying biologically and clinically defined patient subgroups. We welcome investigators to collaborate in the use of these data. TRIAL REGISTRATION: NCT04431479.

Community emergency medical services approaches to fall prevention: a systematic review.

BACKGROUND: Falls are a leading cause of morbidity and mortality among older adults in the USA. Current approaches to fall prevention often rely on referral by primary care providers or enrolment during inpatient admissions. Community emergency medical services (CEMS) present a unique opportunity to rapidly identify older adults at risk for falls and provide fall prevention interventions in the home. In this systematic review, we seek to assess the efficacy and qualitative factors determining success of these programs. METHODS: Studies reporting the outcomes of fall prevention interventions delivered by EMS were identified by searching the electronic databases PubMed, Embase, Web of Science Core Collection, CINAHL and the Cochrane Central Register of Controlled Trials through 11 July 2023. RESULTS: 35 studies including randomised and non-randomised experimental trials, systematic reviews and qualitative research primarily from Western Europe, the USA, Australia and Canada were included in our analysis. Current fall prevention efforts focus heavily on postfall referral of at-risk community members. CEMS fall prevention interventions reduced all-cause and fall-related emergency department encounters, subsequent falls and EMS calls for lift assist. These interventions also improved patient health-related quality of life, independence with activities of daily living, and secondary health outcomes. CONCLUSIONS: CEMS programmes provide an opportunity for direct, proactive fall prevention on the individual level. Addressing barriers to implementation in the context of current emergency medical systems in the USA is the next step toward widespread implementation of these novel fall prevention interventions.

The impact of using reverse polarity text for children with vision impairment assessed using light-adapted flicker electroretinogram.

CLINICAL RELEVANCE: Children with vision impairment can have difficulty accessing classroom reading material and knowledge of which students are likely to have improved performance reading performance with reverse polarity would be of value to educators. BACKGROUND: Printed material is typically presented as black text on a white background; however, reversing the polarity to white text on a black background may improve the reading speed for children with vision impairment. This study sought to identify the visual function or pathological features of children with vision impairment where reversing the polarity of text would improve their reading performance. METHODS: Forty-eight vision-impaired participants (27 male), aged 5-18 years with binocular visual acuities between 0.18-1.52 logMAR, were included. Reading performance was assessed by changes in Critical Print Size (ΔCPS), Maximum Reading Speed (ΔMRS) in normal and reverse polarity digital print, and numeric reading speed (ΔNRS) with normal and reverse polarity fonts. Correlations were made with 30 Hz flicker electroretinogram amplitude and high/low contrast acuity. Paired nonparametric tests evaluated significance in pathological condition groups. RESULTS: Significant negative correlations were only found between the 30 Hz flicker amplitude and ΔMRS (r = -.42, p = .028) and ΔNRS (r = -.46, p = .027). Follow-up pairwise comparisons based on pathology group only showed a significant effect of the retinal dystrophy group and CPS (n = 12, z = -2.24, p = .025). All other pairwise comparisons based on group were non-significant (p > .05). CONCLUSIONS: This study did not identify a specific pathological group or visual functional measure that could be used as a clinical marker to predict the impact of reversing polarity. However, significant improvements could be made in reading performance for some children and so a reading performance assessment is recommended for all children with vision impairment.

Steroid metabolism and hormonal dynamics in normal and malignant ovaries.

The ovaries are key steroid hormone production sites in post-pubertal females. However, current research on steroidogenic enzymes, endogenous hormone concentrations and their effects on healthy ovarian function and malignant development is limited. Here, we discuss the importance of steroid enzymes in normal and malignant ovaries, alongside hormone concentrations, receptor expression and action. Key enzymes include STS, 3ß-HSD2, HSD17B1, ARK1C3, and aromatase, which influence ovarian steroidal action. Both androgen and oestrogen action, via their facilitating enzyme, drives ovarian follicle activation, development and maturation in healthy ovarian tissue. In ovarian cancer, some data suggest STS and oestrogen receptor α may be linked to aggressive forms, while various oestrogen-responsive factors may be involved in ovarian cancer metastasis. In contrast, androgen receptor expression and action vary across ovarian cancer subtypes. For future studies investigating steroidogenesis and steroidal activity in ovarian cancer, it is necessary to differentiate between disease subtypes for a comprehensive understanding.

Spatial variation in genomic signatures of local adaptation during the cane toad invasion of Australia.

Adaptive evolution can facilitate species' range expansions across environmentally heterogeneous landscapes. However, serial founder effects can limit the efficacy of selection, and the evolution of increased dispersal during range expansions may result in gene flow swamping local adaptation. Here, we study how genetic drift, gene flow and selection interact during the cane toad's (Rhinella marina) invasion across the heterogeneous landscape of Australia. Following its introduction in 1935, the cane toad colonised eastern Australia and established several stable range edges. The ongoing, more rapid range expansion in north-central Australia has occurred concomitant with an evolved increase in dispersal capacity. Using reduced representation genomic data of Australian cane toads from the expansion front and from two areas of their established range, we test the hypothesis that high gene flow constrains local adaptation at the expansion front relative to established areas. Genetic analyses indicate the three study areas are genetically distinct but show similar levels of allelic richness, heterozygosity and inbreeding. Markedly higher gene flow or recency of colonisation at the expansion front have likely hindered local adaptation at the time of sampling, as indicated by reduced slopes of genetic-environment associations (GEAs) estimated using a novel application of geographically weighted regression that accounts for allele surfing; GEA slopes are significantly steeper in established parts of the range. Our work bolsters evidence supporting adaptation of invasive species post-introduction and adds novel evidence for differing strengths of evolutionary forces among geographic areas with different invasion histories.

Monte Carlo-Based Nanoscale Dosimetry Holds Promise for Radiopharmaceutical Therapy Involving Auger Electron Emitters.

Radiopharmaceutical therapy (RPT) is evolving as a promising strategy for treating cancer. As interest grows in short-range particles, like Auger electrons, understanding the dose-response relationship at the deoxyribonucleic acid (DNA) level has become essential. In this study, we used the Geant4-DNA toolkit to evaluate DNA damage caused by the Auger-electron-emitting isotope I-125. We compared the energy deposition and single strand break (SSB) yield at each base pair location in a short B-form DNA (B-DNA) geometry with existing simulation and experimental data, considering both physical direct and chemical indirect hits. Additionally, we evaluated dosimetric differences between our high-resolution B-DNA target and a previously published simple B-DNA geometry. Overall, our benchmarking results for SSB yield from I-125 decay exhibited good agreement with both simulation and experimental data. Using this simulation, we then evaluated the SSB and double strand break (DSB) yields caused by a theranostic Br-77-labeled poly ADP ribose polymerase (PARP) inhibitor radiopharmaceutical. The results indicated a predominant contribution of chemical indirect hits over physical direct hits in generating SSB and DSB. This study lays the foundation for future investigations into the nano-dosimetric properties of RPT.

Multicenter Registry of Adenomas of the Pituitary and Related Disorders: Initial Description of Cushing Disease Cohort, Surgical Outcomes, and Surgeon Characteristics.

BACKGROUND AND OBJECTIVES: To address the lack of a multicenter pituitary surgery research consortium in the United States, we established the Registry of Adenomas of the Pituitary and Related Disorders (RAPID). The goals of RAPID are to examine surgical outcomes, improve patient care, disseminate best practices, and facilitate multicenter surgery research at scale. Our initial focus is Cushing disease (CD). This study aims to describe the current RAPID patient cohort, explore surgical outcomes, and lay the foundation for future studies addressing the limitations of previous studies. METHODS: Prospectively and retrospectively obtained data from participating sites were aggregated using a cloud-based registry and analyzed retrospectively. Standard preoperative variables and outcome measures included length of stay, unplanned readmission, and remission. RESULTS: By July 2023, 528 patients with CD had been treated by 26 neurosurgeons with varying levels of experience at 9 academic pituitary centers. No surgeon treated more than 81 of 528 (15.3%) patients. The mean ± SD patient age was 43.8 ± 13.9 years, and most patients were female (82.2%, 433/527). The mean tumor diameter was 0.8 ± 2.7 cm. Most patients (76.6%, 354/462) had no prior treatment. The most common pathology was corticotroph tumor (76.8%, 381/496). The mean length of stay was 3.8 ± 2.5 days. The most common discharge destination was home (97.2%, 513/528). Two patients (0.4%, 2/528) died perioperatively. A total of 57 patients (11.0%, 57/519) required an unplanned hospital readmission within 90 days of surgery. The median actuarial disease-free survival after index surgery was 8.5 years. CONCLUSION: This study examined an evolving multicenter collaboration on patient outcomes after surgery for CD. Our results provide novel insights on surgical outcomes not possible in prior single-center studies or with national administrative data sets. This collaboration will power future studies to better advance the standard of care for patients with CD.

Exercise training induces mild skeletal muscle adaptations without altering disease progression in a TDP-43 mouse model.

Exercise training is considered a non-pharmacological therapeutic approach for many diseases. Mild-to-moderate endurance exercise training is suggested to improve the mental and physical state of people with Amyotrophic Lateral Sclerosis (ALS). The aim of the present study was to determine the capacity of symptomatic rNLS8 mice, which develop ALS-reminiscent TAR DNA-binding protein 43 (TDP-43) pathology and motor dysfunction, to perform mild-to-moderate intensity treadmill exercise training and to evaluate the effects of this training on skeletal muscle health and disease progression. Symptomatic rNLS8 mice were able to complete four weeks of mild-to-moderate treadmill running (30 min at 6-13 m/min, 3 days a week). Exercise training induced an increase in the percentage of type IIA fibers in the tibialis anterior muscle as well as minor adaptations in molecular markers of myogenic, mitochondrial and neuromuscular junction health in some forelimb and hindlimb muscles. However, this exercise training protocol did not attenuate the loss in motor function or delay disease progression. Alternative exercise regimes need to be investigated to better understand the role exercise training may play in alleviating symptoms of ALS.

Cyanotoxin accumulation and growth patterns of biocrust communities under variable environmental conditions.

Biocrusts dominate the soil surface in deserts and are composed of diverse microbial communities that provide important ecosystem services. Cyanobacteria in biocrusts produce many secondary metabolites, including the neurotoxins BMAA, AEG, DAB, anatoxin-a(S) (guanitoxin), and the microcystin hepatotoxins, all known or suspected to cause disease or illness in humans and other animals. We examined cyanobacterial growth and prevalence of these toxins in biocrusts at millimeter-scales, under a desert-relevant illumination gradient. In contrast to previous work, we showed that hydration had an overall positive effect on growth and toxin accumulation, that nitrogen was not correlated with growth or toxin production, and that phosphorus enrichment negatively affected AEG and BMAA concentrations. Excess illumination positively correlated with AEG, and negatively correlated with all other toxins and growth. Basic pH negatively affected only the accumulation of BMAA. Anatoxin-a(S) (guanitoxin) was not correlated with any tested variables, while microcystins were not detected in any of the samples. Concerning toxin pools, AEG and BMAA were good predictors of the presence of one another. In a newly conceptualized scheme, we integrate aspects of biocrust growth and toxin pool accumulations with arid-relevant desertification drivers.

Change in spinal bone mineral density as estimated by Hounsfield units following osteoporosis treatment with romosozumab, teriparatide, denosumab, and alendronate: an analysis of 318 patients.

OBJECTIVE: The purpose of this study was to determine the effect of osteoporosis medications on opportunistic CT-based Hounsfield units (HU). METHODS: Spine and nonspine surgery patients were retrospectively identified who had been treated with romosozumab for 3 to 12 months, teriparatide for 3 to 12 months, teriparatide for > 12 months, denosumab for > 12 months, or alendronate for > 12 months. HU were measured in the L1-4 vertebral bodies. One-way ANOVA was used to compare the mean change in HU among the five treatment regimens. RESULTS: In total, 318 patients (70% women) were included, with a mean age of 69 years and mean BMI of 27 kg/m2. There was a significant difference in mean HU improvement (p < 0.001) following treatment with romosozumab for 3 to 12 months (n = 32), teriparatide for 3 to 12 months (n = 30), teriparatide for > 12 months (n = 44), denosumab for > 12 months (n = 123), and alendronate for > 12 months (n = 100). Treatment with romosozumab for a mean of 10.5 months significantly increased the mean HU by 26%, from a baseline of 85 to 107 (p = 0.012). Patients treated with teriparatide for > 12 months (mean 23 months) experienced a mean HU improvement of 25%, from 106 to 132 (p = 0.039). Compared with the mean baseline HU, there was no significant difference after treatment with teriparatide for 3 to 12 months (110 to 119, p = 0.48), denosumab for > 12 months (105 to 107, p = 0.68), or alendronate for > 12 months (111 to 113, p = 0.80). CONCLUSIONS: Patients treated with romosozumab for a mean of 10.5 months and teriparatide for a mean of 23 months experienced improved spinal bone mineral density as estimated by CT-based opportunistic HU. Given the shorter duration of effective treatment, romosozumab may be the preferred medication for optimization of osteoporotic patients in preparation for elective spine fusion surgery.

Sex-differential testosterone response to long-term weight loss.

OBJECTIVES: Obesity-associated gonadal dysfunction is a common comorbidity in patients seeking weight loss interventions. We examined the incremental effect of weight loss on gonadal axes in men and women over 3 years. Changes in sex hormones were compared between dietary intervention (Diet) and bariatric procedures: Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG) and laparoscopic adjustable gastric banding (LAGB). Additional analysis assessed changes in corticotropic, somatotropic and thyroid axes after weight loss interventions. METHODS: This prospective, observational study included 61 adults with Body Mass Index >30 kg/m2, mean age 51 (SD = 11) years. Endocrine parameters were measured at baseline and at 6 timepoints over 36-months. RESULTS: For each 1 kg of weight lost, between baseline and 36 months, total testosterone increased by 0.6% (95% CI: 0.2%, 1.0%, p = 0.002) in males and decreased by 0.8% (95% CI: -1.4%, -0.3%, p = 0.003) in females. These changes remained statistically significant when controlled for age and for menopausal status in females. At 36 months, in comparison with Diet, RYGB women had lower total testosterone by 54% (95% CI: -90%, -17%, p = 0.004), reduced free androgen index (FAI) by 65% (95% CI; -114%, -17%, p = 0.009) while SG had reduced FAI by 39% (95% CI; -77%, 0%, p = 0.05). No such differences between groups were noted for male subjects. Adrenocorticotropic hormone declined by 0.3% (95% CI: 0.0, -0.5%, p = 0.05), insulin-like growth factor-1 increased by 0.4% (95% CI; 0.2%, 0.7%, p = 0.005), without such thyrotrophin change for each 1 kg of weight loss, for entire cohort, over 36 months. CONCLUSIONS: The testosterone changes observed in this study were proportional to the amount of weight loss. In females, reduction in androgens was independent of age and menopausal status and more pronounced after bariatric procedures. This study finding warrants further clinical research to explore an impact of androgen reduction on functional and cognitive status in postmenopausal women. The observed changes in pituitary hormones may contribute to the metabolic benefits of bariatric surgery.

Evaluation of the sensitivity of a measles diagnostic real-time RT-PCR assay incorporating recently observed priming mismatch variants, 2024.

We investigated a variant of measles virus that encodes three mismatches to the reverse priming site for a widely used diagnostic real-time RT-PCR assay; reduction of sensitivity was hypothesised. We examined performance of the assay in context of the variant using in silico data, synthetic RNA templates and clinical specimens. Sensitivity was reduced observed at low copy numbers for templates encoding the variant sequence. We designed and tested an alternate priming strategy, rescuing the sensitivity of the assay.

Usefulness of the Clinical Frailty Scale in patients with end-stage kidney disease.

Background: The frailty index (FI) is commonly used to estimate frailty in end-stage kidney disease (ESKD) patients. The Clinical Frailty Scale (CFS) is a less time-consuming alternative. We aimed to determine the test performance of the CFS for pre-dialysis and dialysis patients and patients receiving conservative therapy from the Dialysis Centre Apeldoorn. Methods: In this cross-sectional study, haemodialysis, peritoneal dialysis, pre-dialysis patients and patients receiving conservative therapy from the Dialysis Centre Apeldoorn were included and subjected to frailty assessment. Nephrologists not familiar with the CFS completed the frailty score after medical consultation. The sensitivity, specificity and area under the curve (AUC) of the CFS were determined. The FI was used as the gold standard. Results: Included were 144 patients, of whom 60 (41.7%) were considered frail according to the FI. The mean age was 67.4 ± 13.5 years and 56 (38.9%) were female. The cut-off point of the CFS for 'vulnerable' (CFS ≥4) had a sensitivity of 63.3%, a specificity of 81.0% and an AUC of 0.72. The cut-off point of the CFS for 'frail' (CFS ≥5) had a sensitivity of 50.0%, a specificity of 91.7% and an AUC of 0.71. Conclusions: The CFS is a quick and easy-to-use tool for the determination of frailty in ESKD patients with a high prevalence of frailty. Nevertheless, the sensitivity of the CFS in the present study was considered too low to implement into daily clinical practice. The sensitivity might be increased by training nephrologists in the use of the CFS.

Microplastics and Anthropogenic Particles in Recreationally Caught Freshwater Fish from an Urbanized Region of the North American Great Lakes.

BACKGROUND: Microplastics are a pervasive contaminant cycling through food webs-leading to concerns regarding exposure and risk to humans. OBJECTIVES: We aimed to quantify and characterize anthropogenic particle contamination (including microplastics) in fish caught for human consumption from the Humber Bay region of Lake Ontario. We related quantities of anthropogenic particles to other factors (e.g., fish size) that may help in understanding accumulation of microplastics in fish. METHODS: A total of 45 samples of six fish species collected from Humber Bay in Lake Ontario near Toronto, Ontario, Canada, were examined for anthropogenic particles in their gastrointestinal (GI) tracts and fillets. Using microscopy and spectroscopy, suspected anthropogenic particles were identified and characterized. RESULTS: We observed anthropogenic particles in the GI tracts and fillets of all species. Individual fish had a mean±standard deviation of 138±231 anthropogenic particles, with a single fish containing up to 1,508 particles. GI tracts had 93±226 particles/fish (9.8±32.6 particles/gram), and fillets had 56±61 particles/fish (0.5±0.8 particles/gram). Based on a consumption rate of 2 servings/week, the average yearly human exposure through the consumption of these fish fillets would be 12,800±18,300 particles. DISCUSSION: Our findings suggest that consumption of recreationally caught freshwater fish can be a pathway for human exposure to microplastics. The elevated number of particles observed in fish from Humber Bay highlights the need for large-scale geographic monitoring, especially near sources of microplastics. Currently, it is unclear what the effects of ingesting microplastics are for humans, but given that recreationally caught freshwater fish are one pathway for human exposure, these data can be incorporated into future human health risk assessment frameworks for microplastics. https://doi.org/10.1289/EHP13540.

Development and validation of a mouse model to investigate post surgical pain after laparotomy.

Background: Postoperative pain following abdominal surgery is a significant obstacle to patient recovery, often necessitating high analgesic doses associated with adverse effects like cognitive impairment and cardiorespiratory depression. Reliable animal models are crucial for understanding the pathophysiology of post surgical pain and developing more effective pain-relieving strategies. Methods: We developed a mouse model to replicate peritoneal trauma induced by abdominal surgery. 30 C57BL/6 mice underwent laparotomy, with half undergoing standardised peritoneal abrasion and the rest serving as controls. Mouse recovery was assessed using two validated scoring systems of surgical recovery: Post surgery Severity Assessment (PSSA) and Mouse Grimace Score (MGS). Blood samples were taken for cytokine analysis. Adhesions were evaluated on day 6, and peritoneal tissue was examined for healing markers. Results: After laparotomy, all mice exhibited expected pain profiles. Mice with peritoneal abrasion had significantly higher PSSA (7.2 ± 1.2 vs 4.68 ± 0.82, p ≤ 0.001) and MGS scores (3.62 ± 0.74 vs 0.82 ± 0.40, p ≤ 0.05) with slower recovery. Serum inflammatory cytokine levels were significantly elevated in the abraded group, and adhesion formation was higher in this group. Immunohistochemical analysis showed significantly increased expression of α-SMA, CD31, CD68, and F4/80 in peritoneal tissue in the abraded group. Discussion: A mouse model involving laparotomy and standardised peritoneal abrasion replicates the expected pathophysiological changes following abdominal surgery. It will be a useful model for better understanding the mechanisms of post surgical pain and developing improved pain-relief strategies. It also has utility for the study of intra-abdominal adhesion formation. Key message: To understand the intricate relationship between peritoneal trauma-induced pain, cytokine response, and post-operative adhesion formation in mouse models for advancing therapeutic interventions and enhancing post-operative recovery outcomes.

Pharmacologic inhibition of dipeptidyl peptidase 1 (cathepsin C) does not block in vitro granzyme-mediated target cell killing by CD8 T or NK cells.

Recently developed small-molecule inhibitors of the lysosomal protease dipeptidyl peptidase 1 (DPP1), also known as cathepsin C (CatC), can suppress suppurative inflammation in vivo by blocking the processing of zymogenic (pro-) forms of neutrophil serine proteases (NSPs), including neutrophil elastase, proteinase 3, and cathepsin G. DPP1 also plays an important role in activating granzyme serine proteases that are expressed by cytotoxic T lymphocytes (CTL) and natural killer (NK) cells. Therefore, it is critical to determine whether DPP1 inhibition can also cause off-target suppression of CTL/NK-cell-mediated killing of virus-infected or malignant cells. Herein, we demonstrate that the processing of human granzymes A and B, transitioning from zymogen to active proteases, is not solely dependent on DPP1. Thus, the killing of target cells by primary human CD8+ T cells, NK cells, and gene-engineered anti-CD19 CAR T cells was not blocked in vitro even after prior exposure to high concentrations of the reversible DPP1 inhibitor brensocatib. Consistent with this observation, the turnover of model granzyme A/B peptide substrates in the human CTL/NK cell lysates was not significantly reduced by brensocatib. In contrast, preincubation with brensocatib almost entirely abolished (>90%) both the cytotoxic activity of mouse CD8+ T cells and granzyme substrate turnover. Overall, our finding that the effects of DPP1 inhibition on human cytotoxic lymphocytes are attenuated in comparison to those of mice indicates that granzyme processing/activation pathways differ between mice and humans. Moreover, the in vitro data suggest that human subjects treated with reversible DPP1 inhibitors, such as brensocatib, are unlikely to experience any appreciable deficits in CTL/NK-cell-mediated immunities.

Characterization of hyperactive mutations in the renal potassium channel ROMK uncovers unique effects on channel biogenesis and ion conductance.

Hypertension affects one billion people worldwide and is the most common risk factor for cardiovascular disease, yet a comprehensive picture of its underlying genetic factors is incomplete. Amongst regulators of blood pressure is the renal outer medullary potassium (ROMK) channel. While select ROMK mutants are prone to premature degradation and lead to disease, heterozygous carriers of some of these same alleles are protected from hypertension. Therefore, we hypothesized that gain-of-function (GoF) ROMK variants which increase potassium flux may predispose people to hypertension. To begin to test this hypothesis, we employed genetic screens and a candidate-based approach to identify six GoF variants in yeast. Subsequent functional assays in higher cells revealed two variant classes. The first group exhibited greater stability in the endoplasmic reticulum, enhanced channel assembly, and/or increased protein at the cell surface. The second group of variants resided in the PIP2-binding pocket, and computational modeling coupled with patch-clamp studies demonstrated a lower free energy for channel opening and slowed current rundown, consistent with an acquired PIP2-activated state. Together, these findings advance our understanding of ROMK structure-function, suggest the existence of hyperactive ROMK alleles in humans, and establish a system to facilitate the development of ROMK-targeted antihypertensives.