Asymmetric activation of the calcium-sensing receptor homodimer.

The calcium-sensing receptor (CaSR), a cell-surface sensor for Ca2+, is the master regulator of calcium homeostasis in humans and is the target of calcimimetic drugs for the treatment of parathyroid disorders1. CaSR is a family C G-protein-coupled receptor2 that functions as an obligate homodimer, with each protomer composed of a Ca2+-binding extracellular domain and a seven-transmembrane-helix domain (7TM) that activates heterotrimeric G proteins. Here we present cryo-electron microscopy structures of near-full-length human CaSR in inactive or active states bound to Ca2+ and various calcilytic or calcimimetic drug molecules. We show that, upon activation, the CaSR homodimer adopts an asymmetric 7TM configuration that primes one protomer for G-protein coupling. This asymmetry is stabilized by 7TM-targeting calcimimetic drugs adopting distinctly different poses in the two protomers, whereas the binding of a calcilytic drug locks CaSR 7TMs in an inactive symmetric configuration. These results provide a detailed structural framework for CaSR activation and the rational design of therapeutics targeting this receptor.

Enhanced ferroelectricity in ultrathin films grown directly on silicon.

Ultrathin ferroelectric materials could potentially enable low-power perovskite ferroelectric tetragonality logic and nonvolatile memories1,2. As ferroelectric materials are made thinner, however, the ferroelectricity is usually suppressed. Size effects in ferroelectrics have been thoroughly investigated in perovskite oxides-the archetypal ferroelectric system3. Perovskites, however, have so far proved unsuitable for thickness scaling and integration with modern semiconductor processes4. Here we report ferroelectricity in ultrathin doped hafnium oxide (HfO2), a fluorite-structure oxide grown by atomic layer deposition on silicon. We demonstrate the persistence of inversion symmetry breaking and spontaneous, switchable polarization down to a thickness of one nanometre. Our results indicate not only the absence of a ferroelectric critical thickness but also enhanced polar distortions as film thickness is reduced, unlike in perovskite ferroelectrics. This approach to enhancing ferroelectricity in ultrathin layers could provide a route towards polarization-driven memories and ferroelectric-based advanced transistors. This work shifts the search for the fundamental limits of ferroelectricity to simpler transition-metal oxide systems-that is, from perovskite-derived complex oxides to fluorite-structure binary oxides-in which 'reverse' size effects counterintuitively stabilize polar symmetry in the ultrathin regime.

Publisher Correction: Enhanced ferroelectricity in ultrathin films grown directly on silicon.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Characterization of peripheral artery disease and associations with traditional risk factors, mobility, and biomarkers in the project baseline health study.

BACKGROUND: There is a dearth of research on immunophenotyping in peripheral artery disease (PAD). This study aimed to describe the baseline characteristics, immunophenotypic profile, and quality of life (QoL) of participants with PAD in the Project Baseline Health Study (PBHS). METHODS: The PBHS study is a prospective, multicenter, longitudinal cohort study that collected clinical, molecular, and biometric data from participants recruited between 2017 and 2018. In this analysis, baseline demographic, clinical, mobility, QoL, and flow cytometry data were stratified by the presence of PAD (ankle brachial index [ABI] ≤0.90). RESULTS: Of 2,209 participants, 58 (2.6%) had lower-extremity PAD, and only 2 (3.4%) had pre-existing PAD diagnosed prior to enrollment. Comorbid smoking (29.3% vs 14%, P < .001), hypertension (54% vs 30%, P < .001), diabetes (25% vs 14%, P = .031), and at least moderate coronary calcifications (Agatston score >100: 32% vs 17%, P = .01) were significantly higher in participants with PAD than in those with normal ABIs, as were high-sensitivity C-reactive protein levels (5.86 vs 2.83, P < .001). After adjusting for demographic and risk factors, participants with PAD had significantly fewer circulating CD56-high natural killer cells, IgM+ memory B cells, and CD10/CD27 double-positive B cells (P < .05 for all). CONCLUSIONS: This study reinforces existing evidence that a large proportion of PAD without claudication may be underdiagnosed, particularly in female and Black or African American participants. We describe a novel immunophenotypic profile of participants with PAD that could represent a potential future screening or diagnostic tool to facilitate earlier diagnosis of PAD. GOV IDENTIFIER: NCT03154346, https://clinicaltrials.gov/ct2/show/NCT03154346.

Enhancement of dual zero phonon line emissions in nanodiamonds using quasiperiodic photonic structures.

Color centers in nanodiamonds (NDs) have been largely explored by coupling to a photonic structured matrix (PSM) to amplify visible range emission features, enhancing their use in quantum technologies. Here, we study the emission enhancement of dual near-infrared zero phonon line (ZPL) emission from silicon-boron (SiB) and silicon-vacancy (SiV-) centers in NDs using a spontaneously emerged low index-contrast quasiperiodic PSM, having micron-scale air pores. An intensity enhancement factor of 6.15 for SiV- and 7.8 for SiB ZPLs is attained for the PSM sample compared to a control sample. We find Purcell enhancement of 2.77 times for the PSM sample using spatial-dependent decay rate measurements, supported by localized field intensity confinement in the sample. Such cavity-like emission enhancement and lifetime reduction are enabled by an in-plane order-disorder scattering in the PSM sample substantiated by pump-dependent emission measurements. The results put forward a facile approach to tailor the near-infrared dual ZPL emission from NDs using nanophotonic structures.

Polymorphism-driven Distinct Nanomechanical, Optical, Photophysical, and Conducting Properties in a Benzothiophene-quinoline.

Polymorphic forms of organic conjugated small molecules, with their unique molecular shapes, packing arrangements, and interaction patterns, provide an excellent opportunity to uncover how their microstructures influence their observable properties. Ethyl-2-(1-benzothiophene-2-yl)quinoline-4-carboxylate (BZQ) exists as dimorphs with distinct crystal habits - blocks (BZB) and needles (BZN). The crystal forms differ in their molecular arrangements - BZB has a slip-stacked column-like structure in contrast to a zig-zag crystal packing with limited π-overlap in BZN. The BZB crystals characterized by extended π-stacking along [100] demonstrated semiconductor behavior, whereas the BZN, with its zig-zag crystal packing and limited stacking characteristics, was reckoned as an insulator. Monotropically related crystal forms also differ in their nanomechanical properties, with BZB crystals being considerably softer than BZN crystals. This discrepancy in mechanical behavior can be attributed to the distinct molecular arrangements adopted by each crystal form, resulting in unique mechanisms to relieve the strain generated during nanoindentation experiments. Waveguiding experiments on the acicular crystals of BZN revealed the passive waveguiding properties. Excitation of these crystals using a 532 nm laser confirmed the propagation of elastically scattered photons (green) and the subsequent generation of inelastically scattered (orange) photons by the crystals. Further, the dimorphs display dissimilar photoluminescence properties; they are both blue-emissive, but BZN displays twice the quantum yield of BZB. The study underscores the integral role of polymorphism in modulating the mechanical, photophysical, and conducting properties of functional molecular materials. Importantly, our findings reveal the existence of light-emitting crystal polymorphs with varying electric conductivity, a relatively scarce phenomenon in the literature.

Females have lower salivary flow than males, before and after radiation therapy for head/neck cancer.

OBJECTIVE: To compare salivary flow rates between females and males, before and after radiation therapy (RT) for head and neck cancer (HNC). METHODS: Prospective observational multicenter cohort study (OraRad). Stimulated whole salivary flow was measured before RT and at 6 and 18 months after RT. RESULTS: Mean (95% confidence interval) salivary flow in g/min before RT was 0.81 (0.71, 0.90) in females (n = 107) and 1.20 (1.15, 1.25) in males (n = 391) (p < 0.001); at 6 months was 0.34 (0.24, 0.44) in females and 0.50 (0.44, 0.55) in males (p = 0.01); at 18 months was 0.49 (0.38, 0.59) in females and 0.70 (0.64, 0.75) in males (p < 0.001). Median nadir salivary flow after RT was 0.22 in females and 0.35 in males (p < 0.001). A lower nadir salivary flow in females, but not males, was associated with an increased risk for tooth failure (p = 0.02). CONCLUSIONS: Females with HNC have lower stimulated whole salivary flow than males, before and after RT. Low salivary flow after RT may be a risk factor for tooth failure among females. The lower pre-RT salivary flow rates in females, combined with prior literature in other populations, indicates that, in general, females have lower stimulated salivary flow than males.

Polyvascular Disease: A Narrative Review of Risk Factors, Clinical Outcomes and Treatment.

PURPOSE OF REVIEW: Polyvascular disease has a significant global burden and is associated with increased risk of major adverse cardiac events with each additional vascular territory involved. The purpose of this review is to highlight the risk factors, associated outcomes, emerging genetic markers, and evidence for screening and treatment of polyvascular disease. RECENT FINDINGS: Polyvascular disease is the presence of atherosclerosis in two or more vascular beds. It has a significant global burden, with a prevalence of 30-70% in patients with known atherosclerosis. Patients with polyvascular disease experience elevated rates of cardiovascular death, myocardial infarction and stroke, especially among high-risk subgroups like those with type 2 diabetes mellitus and there is a step-wise increased risk of adverse outcomes with each additional vascular territory involved. Genetic analyses demonstrate that some individuals may carry a genetic predisposition, while others exhibit higher levels of atherogenic lipoproteins and inflammatory markers. Routine screening for asymptomatic disease is not currently recommended by major cardiovascular societies unless patients are high-risk. While there are no established protocols for escalating treatment, existing guidelines advocate for lipid-lowering therapy. Additionally, recent studies have demonstrated benefit from antithrombotic agents, such as P2Y12 inhibitors and low-dose anticoagulation, but the optimal timing and dosage of these agents has not been established, and the ischemic benefit must be balanced against the increased risk of bleeding in the polyvascular population. Due to the high prevalence and risks associated with polyvascular disease, early identification and treatment intensification are crucial to reduce disease progression. Future research is needed to develop screening protocols and determine the optimal timing and dosing of therapy to prevent ischemic events.

Central Adiposity Increases Risk of Kidney Stone Disease through Effects on Serum Calcium Concentrations.

SIGNIFICANCE STATEMENT: Kidney stone disease is a common disorder with poorly understood pathophysiology. Observational and genetic studies indicate that adiposity is associated with an increased risk of kidney stone disease. However, the relative contribution of general and central adipose depots and the mechanisms by which effects of adiposity on kidney stone disease are mediated have not been defined. Using conventional and genetic epidemiological techniques, we demonstrate that general and central adiposity are independently associated with kidney stone disease. In addition, one mechanism by which central adiposity increases risk of kidney stone disease is by increasing serum calcium concentration. Therapies targeting adipose depots may affect calcium homeostasis and help to prevent kidney stone disease. BACKGROUND: Kidney stone disease affects approximately 10% of individuals in their lifetime and is frequently recurrent. The disease is linked to obesity, but the mechanisms mediating this association are uncertain. METHODS: Associations of adiposity and incident kidney stone disease were assessed in the UK Biobank over a mean of 11.6 years/person. Genome-wide association studies and Mendelian randomization (MR) analyses were undertaken in the UK Biobank, FinnGen, and in meta-analyzed cohorts to identify factors that affect kidney stone disease risk. RESULTS: Observational analyses on UK Biobank data demonstrated that increasing central and general adiposity is independently associated with incident kidney stone formation. Multivariable MR, using meta-analyzed UK Biobank and FinnGen data, established that risk of kidney stone disease increases by approximately 21% per one standard deviation increase in body mass index (BMI, a marker of general adiposity) independent of waist-to-hip ratio (WHR, a marker of central adiposity) and approximately 24% per one standard deviation increase of WHR independent of BMI. Genetic analyses indicate that higher WHR, but not higher BMI, increases risk of kidney stone disease by elevating adjusted serum calcium concentrations (ß=0.12 mmol/L); WHR mediates 12%-15% of its effect on kidney stone risk in this way. CONCLUSIONS: Our study indicates that visceral adipose depots elevate serum calcium concentrations, resulting in increased risk of kidney stone disease. These findings highlight the importance of weight loss in individuals with recurrent kidney stones and suggest that therapies targeting adipose depots may affect calcium homeostasis and contribute to prevention of kidney stone disease.

Ap2s1 mutation causes hypercalcaemia in mice and impairs interaction between calcium-sensing receptor and adaptor protein-2.

Adaptor protein 2 (AP2), a heterotetrameric complex comprising AP2α, AP2ß2, AP2µ2 and AP2σ2 subunits, is ubiquitously expressed and involved in endocytosis and trafficking of membrane proteins, such as the calcium-sensing receptor (CaSR), a G-protein coupled receptor that signals via Gα11. Mutations of CaSR, Gα11 and AP2σ2, encoded by AP2S1, cause familial hypocalciuric hypercalcaemia types 1-3 (FHH1-3), respectively. FHH3 patients have heterozygous AP2S1 missense Arg15 mutations (p.Arg15Cys, p.Arg15His or p.Arg15Leu) with hypercalcaemia, which may be marked and symptomatic, and occasional hypophosphataemia and osteomalacia. To further characterize the phenotypic spectrum and calcitropic pathophysiology of FHH3, we used CRISPR/Cas9 genome editing to generate mice harboring the AP2S1 p.Arg15Leu mutation, which causes the most severe FHH3 phenotype. Heterozygous (Ap2s1+/L15) mice were viable, and had marked hypercalcaemia, hypermagnesaemia, hypophosphataemia, and increases in alkaline phosphatase activity and fibroblast growth factor-23. Plasma 1,25-dihydroxyvitamin D was normal, and no alterations in bone mineral density or bone turnover were noted. Homozygous (Ap2s1L15/L15) mice invariably died perinatally. Co-immunoprecipitation studies showed that the AP2S1 p.Arg15Leu mutation impaired protein-protein interactions between AP2σ2 and the other AP2 subunits, and also with the CaSR. Cinacalcet, a CaSR positive allosteric modulator, decreased plasma calcium and parathyroid hormone concentrations in Ap2s1+/L15 mice, but had no effect on the diminished AP2σ2-CaSR interaction in vitro. Thus, our studies have established a mouse model that is representative for FHH3 in humans, and demonstrated that the AP2S1 p.Arg15Leu mutation causes a predominantly calcitropic phenotype, which can be ameliorated by treatment with cinacalcet.

Familial Hypocalciuric Hypercalcemia Type 1 and Autosomal-Dominant Hypocalcemia Type 1: Prevalence in a Large Healthcare Population.

The calcium-sensing receptor (CaSR) regulates serum calcium concentrations. CASR loss- or gain-of-function mutations cause familial hypocalciuric hypercalcemia type 1 (FHH1) or autosomal-dominant hypocalcemia type 1 (ADH1), respectively, but the population prevalence of FHH1 or ADH1 is unknown. Rare CASR variants were identified in whole-exome sequences from 51,289 de-identified individuals in the DiscovEHR cohort derived from a single US healthcare system. We integrated bioinformatics pathogenicity triage, mean serum Ca concentrations, and mode of inheritance to identify potential FHH1 or ADH1 variants, and we used a Sequence Kernel Association Test (SKAT) to identify rare variant-associated diseases. We identified predicted heterozygous loss-of-function CASR variants (6 different nonsense/frameshift variants and 12 different missense variants) in 38 unrelated individuals, 21 of whom were hypercalcemic. Missense CASR variants were identified in two unrelated hypocalcemic individuals. Functional studies showed that all hypercalcemia-associated missense variants impaired heterologous expression, plasma membrane targeting, and/or signaling, whereas hypocalcemia-associated missense variants increased expression, plasma membrane targeting, and/or signaling. Thus, 38 individuals with a genetic diagnosis of FHH1 and two individuals with a genetic diagnosis of ADH1 were identified in the 51,289 cohort, giving a prevalence in this population of 74.1 per 100,000 for FHH1 and 3.9 per 100,000 for ADH1. SKAT combining all nonsense, frameshift, and missense loss-of-function variants revealed associations with cardiovascular, neurological, and other diseases. In conclusion, FHH1 is a common cause of hypercalcemia, with prevalence similar to that of primary hyperparathyroidism, and is associated with altered disease risks, whereas ADH1 is a major cause of non-surgical hypoparathyroidism.

Neurodevelopmental Abnormalities in Patients with Familial Hypocalciuric Hypercalcemia Type 3.

OBJECTIVES: To evaluate the prevalence and degree of any neurodevelopmental abnormalities in children with familial hypocalciuric hypercalcemia type 3 (FHH3). STUDY DESIGN: A formal neurodevelopmental assessment was performed in children diagnosed with FHH3. The Vineland Adaptive Behavior Scales, which is a standardized parent report assessment tool for adaptive behavior, was used to assess communication, social skills, and motor function and to generate a composite score. RESULTS: Six patients were diagnosed with hypercalcemia between 0.1 and 8 years of age. All had neurodevelopmental abnormalities in childhood consisting of either global developmental delay, motor delay, expressive speech disturbances, learning difficulties, hyperactivity, or autism spectrum disorder. Four out of the 6 probands had a composite Vineland Adaptive Behavior Scales SDS of < -2.0, indicating adaptive malfunctioning. Significant deficits were observed in the domains of communication (mean SDS: -2.0, P < .01), social skills (mean SDS: -1.3, P < .05), and motor skills (mean SDS: 2.6, P < .05). Individuals were equally affected across domains, with no clear genotype-phenotype correlation. All family members affected with FHH3 also described evidence of neurodevelopmental dysfunction, including mild-to-moderate learning difficulties, dyslexia, and hyperactivity. CONCLUSION: Neurodevelopmental abnormalities appear to be a highly penetrant and common feature of FHH3, and early detection is warranted to provide appropriate educational support. This case series also supports consideration of serum calcium measurement as part of the diagnostic work-up in any child presenting with unexplained neurodevelopmental abnormalities.

Oral health-related quality of life after radiation therapy for head and neck cancer: the OraRad study.

PURPOSE: Head and neck cancer (HNC) treatment results in morbidity impacting quality of life (QOL) in survivorship. This analysis evaluated changes in oral health-related QOL (OH-QOL) up to 2 years after curative intent radiation therapy (RT) for HNC patients and factors associated with these changes. METHODS: 572 HNC patients participated in a multicenter, prospective observational study (OraRad). Data collected included sociodemographic, tumor, and treatment variables. Ten single-item questions and 2 composite scales of swallowing problems and senses problems (taste and smell) from a standard QOL instrument were assessed before RT and at 6-month intervals after RT. RESULTS: The most persistently impacted OH-QOL variables at 24 months included: dry mouth; sticky saliva, and senses problems. These measures were most elevated at the 6-month visit. Aspects of swallowing were most impacted by oropharyngeal tumor site, chemotherapy, and non-Hispanic ethnicity. Problems with senses and dry mouth were worse with older age. Dry mouth and sticky saliva increased more among men and those with oropharyngeal cancer, nodal involvement, and use of chemotherapy. Problems with mouth opening were increased by chemotherapy and were more common among non-White and Hispanic individuals. A 1000 cGy increase in RT dose was associated with a clinically meaningful change in difficulty swallowing solid food, dry mouth, sticky saliva, sense of taste, and senses problems. CONCLUSIONS: Demographic, tumor, and treatment variables impacted OH-QOL for HNC patients up to 2 years after RT. Dry mouth is the most intense and sustained toxicity of RT that negatively impacts OH-QOL of HNC survivors. GOV IDENTIFIER: NCT02057510; first posted February 7, 2014.

From particle attachment to space-filling coral skeletons.

Reef-building corals and their aragonite (CaCO3) skeletons support entire reef ecosystems, yet their formation mechanism is poorly understood. Here we used synchrotron spectromicroscopy to observe the nanoscale mineralogy of fresh, forming skeletons from six species spanning all reef-forming coral morphologies: Branching, encrusting, massive, and table. In all species, hydrated and anhydrous amorphous calcium carbonate nanoparticles were precursors for skeletal growth, as previously observed in a single species. The amorphous precursors here were observed in tissue, between tissue and skeleton, and at growth fronts of the skeleton, within a low-density nano- or microporous layer varying in thickness from 7 to 20 µm. Brunauer-Emmett-Teller measurements, however, indicated that the mature skeletons at the microscale were space-filling, comparable to single crystals of geologic aragonite. Nanoparticles alone can never fill space completely, thus ion-by-ion filling must be invoked to fill interstitial pores. Such ion-by-ion diffusion and attachment may occur from the supersaturated calcifying fluid known to exist in corals, or from a dense liquid precursor, observed in synthetic systems but never in biogenic ones. Concomitant particle attachment and ion-by-ion filling was previously observed in synthetic calcite rhombohedra, but never in aragonite pseudohexagonal prisms, synthetic or biogenic, as observed here. Models for biomineral growth, isotope incorporation, and coral skeletons' resilience to ocean warming and acidification must take into account the dual formation mechanism, including particle attachment and ion-by-ion space filling.

International Union of Basic and Clinical Pharmacology. CVIII. Calcium-Sensing Receptor Nomenclature, Pharmacology, and Function.

The calcium-sensing receptor (CaSR) is a class C G protein-coupled receptor that responds to multiple endogenous agonists and allosteric modulators, including divalent and trivalent cations, L-amino acids, γ-glutamyl peptides, polyamines, polycationic peptides, and protons. The CaSR plays a critical role in extracellular calcium (Ca2+ o) homeostasis, as demonstrated by the many naturally occurring mutations in the CaSR or its signaling partners that cause Ca2+ o homeostasis disorders. However, CaSR tissue expression in mammals is broad and includes tissues unrelated to Ca2+ o homeostasis, in which it, for example, regulates the secretion of digestive hormones, airway constriction, cardiovascular effects, cellular differentiation, and proliferation. Thus, although the CaSR is targeted clinically by the positive allosteric modulators (PAMs) cinacalcet, evocalcet, and etelcalcetide in hyperparathyroidism, it is also a putative therapeutic target in diabetes, asthma, cardiovascular disease, and cancer. The CaSR is somewhat unique in possessing multiple ligand binding sites, including at least five putative sites for the "orthosteric" agonist Ca2+ o, an allosteric site for endogenous L-amino acids, two further allosteric sites for small molecules and the peptide PAM, etelcalcetide, and additional sites for other cations and anions. The CaSR is promiscuous in its G protein-coupling preferences, and signals via Gq/11, Gi/o, potentially G12/13, and even Gs in some cell types. Not surprisingly, the CaSR is subject to biased agonism, in which distinct ligands preferentially stimulate a subset of the CaSR's possible signaling responses, to the exclusion of others. The CaSR thus serves as a model receptor to study natural bias and allostery. SIGNIFICANCE STATEMENT: The calcium-sensing receptor (CaSR) is a complex G protein-coupled receptor that possesses multiple orthosteric and allosteric binding sites, is subject to biased signaling via several different G proteins, and has numerous (patho)physiological roles. Understanding the complexities of CaSR structure, function, and biology will aid future drug discovery efforts seeking to target this receptor for a diversity of diseases. This review summarizes what is known to date regarding key structural, pharmacological, and physiological features of the CaSR.

Exposed bone in patients with head and neck cancer treated with radiation therapy: An analysis of the Observational Study of Dental Outcomes in Head and Neck Cancer Patients (OraRad).

BACKGROUND: Patients with head and neck cancer (HNC) treated with radiation therapy (RT) are at risk for jaw osteoradionecrosis (ORN), which is largely characterized by the presence of exposed necrotic bone. This report describes the incidence and clinical course of and risk factors for exposed intraoral bone in the multicenter Observational Study of Dental Outcomes in Head and Neck Cancer Patients (OraRad) cohort. METHODS: Participants were evaluated before RT and at 6, 12, 18, and 24 months after RT. Exposed bone was characterized by location, sequestrum formation, and other associated features. The radiation dose to the affected area was determined, and the history of treatment for exposed bone was recorded. RESULTS: The study enrolled 572 participants; 35 (6.1%) were diagnosed with incident exposed bone at 6 (47% of reports), 12 (24%), 18 (20%), and 24 months (8%), with 60% being sequestrum and with 7 cases (20%) persisting for >6 months. The average maximum RT dose to the affected area of exposed bone was 5456 cGy (SD, 1768 cGy); the most frequent associated primary RT sites were the oropharynx (42.9%) and oral cavity (31.4%), and 76% of episodes occurred in the mandible. The diagnosis of ORN was confirmed in 18 participants for an incidence rate of 3.1% (18 of 572). Risk factors included pre-RT extractions (P = .008), a higher RT dose (P = .039), and tobacco use (P = .048). CONCLUSIONS: The 2-year incidence of exposed bone in the OraRad cohort was 6.1%; the incidence of confirmed ORN was 3.1%. Exposed bone after RT for HNC is relatively uncommon and, in most cases, is a short-term complication, not a recurring or persistent one.

Electronic alerts to initiate anticoagulation dialogue in patients with atrial fibrillation.

IMPORTANCE: The benefit of an electronic support system for the prescription and adherence to oral anticoagulation therapy among patients with atrial fibrillation (AF) and atrial flutter at heightened risk for of stroke and systemic thromboembolism is unclear. OBJECTIVE: To evaluate the effect of a combined alert intervention and shared decision-making tool to improve prescription rates of oral anticoagulation therapy and adherence. DESIGN, SETTING, AND PARTICIPANTS: A prospective single arm study of 939 consecutive patients treated at a large tertiary healthcare system. EXPOSURES: An electronic support system comprising 1) an electronic alert to identify patients with AF or atrial flutter, a CHA2DS2-VASc score ≥ 2, and not on oral anticoagulation and 2) electronic shared decision-making tool to promote discussions between providers and patients regarding therapy. MAIN OUTCOMES AND MEASURES: The primary endpoint was prescription rate of anticoagulation therapy. The secondary endpoint was adherence to anticoagulation therapy defined as medication possession ratio ≥ 80% during the 12 months of follow-up. RESULTS: Between June 13, 2018 and August 31, 2018, the automated intervention identified and triggered a unique alert for 939 consecutive patients with AF or atrial flutter, a CHA2DS2-VASc score ≥2 who were not on oral anticoagulation. The median CHA2DS2-VASc score among all patients identified by the alert was 2 and the median untreated duration prior to the alert was 495 days (interquartile range 123 - 1,831 days). Of the patients identified by the alert, 345 (36.7%) initiated anticoagulation therapy and 594 (63.3%) did not: 68.7% were treated with a non-Vitamin K antagonist oral anticoagulant (NOAC), 22.0% with warfarin, and 9.3 % combination of NOAC and warfarin. Compared with historical anticoagulation rates, the electronic alert was associated with a 23.6% increase in anticoagulation prescriptions. The overall 1-year rate of adherence to anticoagulant therapy was 75.4% (260/345). CONCLUSION AND RELEVANCE: An electronic automated alert can successfully identify patients with AF and atrial flutter at high risk for stroke, increase oral anticoagulation prescription, and support high rates of adherence.

Genetics of monogenic disorders of calcium and bone metabolism.

Disorders of calcium homeostasis are the most frequent metabolic bone and mineral disease encountered by endocrinologists. These disorders usually manifest as primary hyperparathyroidism (PHPT) or hypoparathyroidism (HP), which have a monogenic aetiology in 5%-10% of cases, and may occur as an isolated endocrinopathy, or as part of a complex syndrome. The recognition and diagnosis of these disorders is important to facilitate the most appropriate management of the patient, with regard to both the calcium-related phenotype and any associated clinical features, and also to allow the identification of other family members who may be at risk of disease. Genetic testing forms an important tool in the investigation of PHPT and HP patients and is usually reserved for those deemed to be an increased risk of a monogenic disorder. However, identifying those suitable for testing requires a thorough clinical evaluation of the patient, as well as an understanding of the diversity of relevant phenotypes and their genetic basis. This review aims to provide an overview of the genetic basis of monogenic metabolic bone and mineral disorders, primarily focusing on those associated with abnormal calcium homeostasis, and aims to provide a practical guide to the implementation of genetic testing in the clinic.

Pharmacometric approach to assist dosage regimen design in neonates undergoing therapeutic hypothermia.

BACKGROUND: Therapeutic hypothermia (TH) is the treatment of choice for neonates diagnosed with perinatal asphyxia (PA). Dosing recommendations of various therapeutic agents including antimicrobials were not specifically available for the neonates undergoing TH. METHODS: A systematic search methodology was used to identify pharmacokinetic (PK) studies of antimicrobials during TH. Antimicrobials with multiple PK studies were identified to create a generalizable PK model. Pharmacometric simulations were performed using the PUMAS software platform to reproduce the results of published studies. A suitable model that could reproduce the results of all other published studies was identified. With the help of a generalizable model, an optimal dosage regimen was designed considering the important covariates of the identified model. RESULTS: With the systematic search, only gentamicin had multiple PK reports during TH. A generalizable model was identified and the model predictions could match the reported/observed concentrations of publications. Birth weight and serum creatinine were the significant covariates influencing the PK of gentamicin in neonates. A dosage nomogram was designed using pharmacometric simulations to maintain gentamicin concentrations below 10 µg/mL at peak and below 2 µg/mL at trough. CONCLUSIONS: A generalizable PK model for gentamicin during TH in neonates was identified. Using the model, a dosing nomogram for gentamicin was designed. IMPACT: Dosing guidelines for antimicrobials during TH in neonates is lacking. This is the first study to identify the generalizable model for gentamicin during TH in neonates. Nomogram, proposed in the study, will aid the clinicians to individualize gentamicin dosing regimen for neonates considering the birth weight and serum creatinine.

Thermodynamic evaluation of solar assisted ZnO/Zn thermochemical CO2 splitting cycle.

The solar thermochemical CO2 splitting (CDS) is scrutinized via a redox ZnO/Zn cycle. The second law efficiency analysis is carried out by acquiring the required thermodynamic data from HSC Chemistry software. The main focus of this study is to explore the influence of reduction temperature (Tred), molar flow rate of inert sweep gas (n˙inert), and energy required for the gas separation on the solar-to-fuel energy conversion efficiency (ηsolar-to-fuel) of the ZnO/Zn cycle. All the calculations are conducted at a constant gas-to-gas heat recovery effectiveness (εgg) equal to 0.5. n˙inert required is recorded to be too high (5050 mol/s) at Tred equal to 1500 K and moderately low (15 mol/s) for Tred equal to 2000 K. The amount of thermal energy required to heat the inert/O2 gas mixture (from CDS temperature to separator-1 temperature) and inert sweep gas (from separator-1 temperature to reduction temperature) has a significant impact on the total thermal energy requirement of the cycle (Q˙TC). The rise in Tred from 1500 K to 2000 K shows a considerable decline in Q˙TC from 77417.5 kW to 1161.8 kW, respectively. Consequently, the highest ηsolar-to-fuel (17.0%) is recorded for Tred equal to 2000 K.