Precise druggability of the PTH type 1 receptor.

Class B G protein-coupled receptors (GPCRs) are notoriously difficult to target by small molecules because their large orthosteric peptide-binding pocket embedded deep within the transmembrane domain limits the identification and development of nonpeptide small molecule ligands. Using the parathyroid hormone type 1 receptor (PTHR) as a prototypic class B GPCR target, and a combination of molecular dynamics simulations and elastic network model-based methods, we demonstrate that PTHR druggability can be effectively addressed. Here we found a key mechanical site that modulates the collective dynamics of the receptor and used this ensemble of PTHR conformers to identify selective small molecules with strong negative allosteric and biased properties for PTHR signaling in cell and PTH actions in vivo. This study provides a computational pipeline to detect precise druggable sites and identify allosteric modulators of PTHR signaling that could be extended to GPCRs to expedite discoveries of small molecules as novel therapeutic candidates.

Implementing a nurse-led prehabilitation program for patients undergoing spinal surgery.

ABSTRACT: Prehabilitation, or "prehab," helps patients optimize strength, function, and nutrition before surgery. This evidence-based practice project presents strategies for implementing a prehab program to prepare patients for spinal surgery. Nurses play an integral role in educating patients preoperatively about the myriad lifestyle changes associated with spinal surgery.

Going Virtual: Adapting an Institutional Annual Bereavement Event During the COVID-19 Pandemic.

Our institution's annual bereaved family event was modified to a virtual format during the COVID-19 pandemic. While necessary to comply with physical distancing directives, the transition also provided greater accessibility for families. Virtual events were feasible and appreciated by attendees. Future hybrid bereavement events should be considered to allow families more flexibility and accessibility.

Allosteric interactions in the parathyroid hormone GPCR-arrestin complex formation.

Peptide ligands of class B G-protein-coupled receptors act via a two-step binding process, but the essential mechanisms that link their extracellular binding to intracellular receptor-arrestin interactions are not fully understood. Using NMR, crosslinking coupled to mass spectrometry, signaling experiments and computational approaches on the parathyroid hormone (PTH) type 1 receptor (PTHR), we show that initial binding of the PTH C-terminal part constrains the conformation of the flexible PTH N-terminal signaling epitope before a second binding event occurs. A 'hot-spot' PTH residue, His9, that inserts into the PTHR transmembrane domain at this second step allosterically engages receptor-arrestin coupling. A conformational change in PTHR intracellular loop 3 permits favorable interactions with ß-arrestin's finger loop. These results unveil structural determinants for PTHR-arrestin complex formation and reveal that the two-step binding mechanism proceeds via cooperative fluctuations between ligand and receptor, which extend to other class B G-protein-coupled receptors.

Ca2+ allostery in PTH-receptor signaling.

The parathyroid hormone (PTH) and its related peptide (PTHrP) activate PTH receptor (PTHR) signaling, but only the PTH sustains GS-mediated adenosine 3',5'-cyclic monophosphate (cAMP) production after PTHR internalization into early endosomes. The mechanism of this unexpected behavior for a G-protein-coupled receptor is not fully understood. Here, we show that extracellular Ca2+ acts as a positive allosteric modulator of PTHR signaling that regulates sustained cAMP production. Equilibrium and kinetic studies of ligand-binding and receptor activation reveal that Ca2+ prolongs the residence time of ligands on the receptor, thus, increasing both the duration of the receptor activation and the cAMP signaling. We further find that Ca2+ allostery in the PTHR is strongly affected by the point mutation recently identified in the PTH (PTHR25C) as a new cause of hypocalcemia in humans. Using high-resolution and mass accuracy mass spectrometry approaches, we identified acidic clusters in the receptor's first extracellular loop as key determinants for Ca2+ allosterism and endosomal cAMP signaling. These findings coupled to defective Ca2+ allostery and cAMP signaling in the PTHR by hypocalcemia-causing PTHR25C suggest that Ca2+ allostery in PTHR signaling may be involved in primary signaling processes regulating calcium homeostasis.

Improving Communication Between Health Care Providers, Families, and Children with Autism Spectrum Disorder: The Linked Program.

PURPOSE: To provide easy-to-use tools and skills to decrease stress in the perioperative period for families and their children with autism spectrum disorder (ASD). DESIGN: Evidence-based practice project. METHODS: After literature review, a perioperative assessment and management program was developed to guide and individualize the care of pediatric patients with ASD. The program was piloted on a convenience sample of 31 pediatric patients diagnosed with ASD. FINDINGS: Most patients were back to their baseline behavior according to their families or caregivers within 120 minutes of the procedure (n = 29, 93.5%), with two needing more than 24 hours (6.5%). CONCLUSIONS: The Linked Program has enabled staff to be effective in meeting the perioperative needs of families and their children with ASD. Families have expressed great appreciation that they are able to share their knowledge of what their children need.

Hypoglycemia Prevention by Algorithm Design During Intravenous Insulin Infusion.

PURPOSE OF REVIEW: This review examines algorithm design features that may reduce risk for hypoglycemia while preserving glycemic control during intravenous insulin infusion. We focus principally upon algorithms in which the assignment of the insulin infusion rate (IR) depends upon maintenance rate of insulin infusion (MR) or a multiplier. RECENT FINDINGS: Design features that may mitigate risk for hypoglycemia include use of a mid-protocol bolus feature and establishment of a low BG threshold for temporary interruption of infusion. Computer-guided dosing may improve target attainment without exacerbating risk for hypoglycemia. Column assignment (MR) within a tabular user-interpreted algorithm or multiplier may be specified initially according to patient characteristics and medical condition with revision during treatment based on patient response. We hypothesize that a strictly increasing sigmoidal relationship between MR-dependent IR and BG may reduce risk for hypoglycemia, in comparison to a linear relationship between multiplier-dependent IR and BG. Guidelines are needed that curb excessive up-titration of MR and recommend periodic pre-emptive trials of MR reduction. Future research should foster development of recommendations for "protocol maxima" of IR appropriate to patient condition.

A Hospital-Based Neuroscience Nursing Course Designed to Improve Competence and Confidence.

After experiencing growth in a neuroscience service line, nurse leaders identified a need for increased competencies among clinical staff. This hospital met the need by developing a unique multidisciplinary neuroscience nursing course to improve the clinical competence, confidence, and professional development of bedside nurses.

Handedness and social anxiety: Using Bryden's research as a catalyst to explore the influence of familial sinistrality and degree of handedness.

Phil Bryden's work has impacted on many areas of laterality, including degree and measurement of hand preference, as well as influences of familial sinistrality (FS). For example, Bryden[(1977). Measuring handedness with questionnaires. Neuropsychologia, 15, 617-624] is a well-cited and influential paper that remains relevant to this day. Inspired by this we extended our analysis of the relationship between handedness and anxiety in a number of ways. We used familial handedness and strength of handedness to examine their potential influences on anxiety, and extended our research by exploring their relationship to social anxiety, using the Social Phobia Inventory (SPIN). Inconsistent left-handers (ILH) were found to be more socially anxious. In all categories of SPIN except avoidance, ILH were significantly more anxious than consistent right- and left-handers. There were FS differences between ILH with a first degree left-handed relative (FS+) compared to ILH with no first degree left-handed relative (FS-) on all categories of anxiety scores. Within FS+ participants, ILH had significantly higher anxiety scores, compared with consistent handers across all categories. This suggests that ILH's social anxiety may be influenced by a close left-handed relative. Inspired by examining Bryden's work for this special issue, we will continue to add both strength of preference and familial handedness to our work.

Accuracy of MR imaging-estimated proton density fat fraction for classification of dichotomized histologic steatosis grades in nonalcoholic fatty liver disease.

PURPOSE: To evaluate the diagnostic performance of previously proposed high-specificity magnetic resonance (MR) imaging-estimated proton density fat fraction (PDFF) thresholds for diagnosis of steatosis grade 1 or higher (PDFF threshold of 6.4%), grade 2 or higher (PDFF threshold of 17.4%), and grade 3 (PDFF threshold of 22.1%) by using histologic findings as a reference in an independent cohort of adults known to have or suspected of having nonalcoholic fatty liver disease (NAFLD). MATERIALS AND METHODS: This prospective, cross-sectional, institutional review board-approved, HIPAA-compliant single-center study was conducted in an independent cohort of 89 adults known to have or suspected of having NAFLD who underwent contemporaneous liver biopsy. MR imaging PDFF was estimated at 3 T by using magnitude-based low-flip-angle multiecho gradient-recalled-echo imaging with T2* correction and multipeak modeling. Steatosis was graded histologically (grades 0, 1, 2, and 3, according to the Nonalcoholic Steatohepatitis Clinical Research Network scoring system). Sensitivity, specificity, and binomial confidence intervals were calculated for the proposed MR imaging PDFF thresholds. RESULTS: The proposed MR imaging PDFF threshold of 6.4% to diagnose grade 1 or higher steatosis had 86% sensitivity (71 of 83 patients; 95% confidence interval [CI]: 76, 92) and 83% specificity (five of six patients; 95% CI: 36, 100). The threshold of 17.4% to diagnose grade 2 or higher steatosis had 64% sensitivity (28 of 44 patients; 95% CI: 48, 78) and 96% specificity (43 of 45 patients; 95% CI: 85, 100). The threshold of 22.1% to diagnose grade 3 steatosis had 71% sensitivity (10 of 14 patients; 95% CI: 42, 92) and 92% specificity (69 of 75 patients; 95% CI: 83, 97). CONCLUSION: In an independent cohort of adults known to have or suspected of having NAFLD, the previously proposed MR imaging PDFF thresholds provided moderate to high sensitivity and high specificity for diagnosis of grade 1 or higher, grade 2 or higher, and grade 3 steatosis. Prospective multicenter studies are now needed to further validate these high-specificity thresholds.

Diagnostic Accuracy of Preoperative Gadoxetic Acid-enhanced 3-T MR Imaging for Malignant Liver Lesions by Using Ex Vivo MR Imaging-matched Pathologic Findings as the Reference Standard.

PURPOSE: To determine per-lesion sensitivity and positive predictive value (PPV) of gadoxetic acid-enhanced 3-T magnetic resonance (MR) imaging for the diagnosis of malignant lesions by using matched (spatially correlated) hepatectomy pathologic findings as the reference standard. Materials and METHODS: In this prospective, institutional review board-approved, HIPAA-compliant study, 20 patients (nine men, 11 women; mean age, 59 years) with malignant liver lesions who gave written informed consent underwent preoperative gadoxetic acid-enhanced 3-T MR imaging for surgical planning. Two image sets were independently analyzed by three readers to detect liver lesions (set 1 without and set 2 with hepatobiliary phase [HBP] images). Hepatectomy specimen ex vivo MR imaging assisted in matching gadoxetic acid-enhanced 3-T MR imaging findings with pathologic findings. Interreader agreement was assessed by using the Cohen κ coefficient. Per-lesion sensitivity and PPV were calculated. RESULTS: Cohen κ values were 0.64-0.76 and 0.57-0.84, and overall per-lesion sensitivity was 45% (42 of 94 lesions) to 56% (53 of 94 lesions) and 58% (55 of 94 lesions) to 64% (60 of 94 lesions) for sets 1 and 2, respectively. The addition of HBP imaging did not affect interreader agreement but significantly improved overall sensitivity for one reader (P < .05) and almost for another (P = .05). Sensitivity for 0.2-0.5-cm lesions was 0% (0 of 26 lesions) to 8% (two of 26 lesions) for set 1 and 4% (one of 26 lesions) to 12% (three of 26 lesions) for set 2. Sensitivity for 0.6-1.0-cm lesions was 28% (nine of 32 lesions) to 59% (19 of 32 lesions) for set 1 and 66% (21 of 32 lesions) to 69% (22 of 32 lesions) for set 2. Sensitivity for lesions at least 1.0 cm in diameter was at least 81% (13 of 16 lesions) for set 1 and was not improved for set 2. PPV was 98% (56 of 57 lesions) to 100% (60 of 60 lesions) for all readers without differences between image sets or lesion size. CONCLUSION: Gadoxetic acid-enhanced 3-T MR imaging provides high per-lesion sensitivity and PPV for preoperative malignant liver lesion detection overall, although sensitivity for 0.2-0.5-cm malignant lesions is poor.

Spatial distribution of MRI-Determined hepatic proton density fat fraction in adults with nonalcoholic fatty liver disease.

PURPOSE: To describe the spatial distribution of liver fat,using MRI-estimated proton density fat fraction (PDFF), in adults with nonalcoholic fatty liver disease (NAFLD). MATERIALS AND METHODS: This Investigational Review Board-approved, Health Insurance Portability and Accountability Act-compliant study prospectively enrolled 50 adults (30 women, 20 men) with biopsy-proven NAFLD. Hepatic PDFF was measured by low-flip-angle multiecho spoiled gradient-recalled-echo MRI at 3 Tesla. Three nonoverlapping regions of interest were placed within each liver segment. Statistical analyses included Pearson's correlation, multivariable linear regression, and permutation-based paired tests. RESULTS: The study population's mean whole-liver PDFF was 16.1% (range: 1.6­39.6%). The mean whole-liver PDFF variability was 1.9% (range: 0.7­4.5%). Higher variability was associated with higher PDFF (r=0.34;P=0.0156). The mean PDFF was significantly higher in the right lobe than the left (16.5% versus 15.3%, P=0.0028). The mean PDFF variability was higher in the left lobe than the right (1.86% versus 1.28%; P<0.0001). Segment II had the lowest mean segmental PDFF (14.8%);segment VIII had the highest (16.7%). Segments V(0.71%) and VI (0.70%) had the lowest mean segmental PDFF variability; segment II had the highest (1.32%). CONCLUSION: IN adult NAFLD there are small but significant differences in fat content.

Inter-examination precision of magnitude-based MRI for estimation of segmental hepatic proton density fat fraction in obese subjects.

PURPOSE: To prospectively describe magnitude-based multi-echo gradient-echo hepatic proton density fat fraction (PDFF) inter-examination precision at 3 Tesla (T). MATERIALS AND METHODS: In this prospective, Institutional Review Board-approved, Health Insurance Portability and Accountability Act (HIPAA) compliant study, written informed consent was obtained from 29 subjects (body mass indexes > 30 kg/m2). Three 3T MRI examinations were obtained over 75-90 min. Segmental, lobar, and whole liver PDFF were estimated (using three, four, five, or six echoes) by magnitude-based multi-echo MRI in colocalized regions of interest. For estimate (using three, four, five, or six echoes), at each anatomic level (segmental, lobar, whole liver), three inter-examination precision metrics were computed: intra-class correlation coefficient (ICC), standard deviation (SD), and range. RESULTS: Magnitude-based PDFF estimates using each reconstruction method showed excellent inter-examination precision for each segment (ICC ≥ 0.992; SD ≤ 0.66%; range ≤ 1.24%), lobe (ICC ≥ 0.998; SD ≤ 0.34%; range ≤ 0.64%), and the whole liver (ICC = 0.999; SD ≤ 0.24%; range ≤ 0.45%). Inter-examination precision was unaffected by whether PDFF was estimated using three, four, five, or six echoes. CONCLUSION: Magnitude-based PDFF estimation shows high inter-examination precision at segmental, lobar, and whole liver anatomic levels, supporting its use in clinical care or clinical trials. The results of this study suggest that longitudinal hepatic PDFF change greater than 1.6% is likely to represent signal rather than noise.

Reproducibility of hepatic fat fraction measurement by magnetic resonance imaging.

PURPOSE: To evaluate the reproducibility of magnetic resonance imaging (MRI)-determined hepatic fat fraction (%) across imaging sites with different magnet types and field strength. Reproducibility among MRI platforms is unclear, even though evaluating hepatic fat fractions (FFs) using MRI-based methods is accurate against MR spectroscopy. MATERIALS AND METHODS: Overweight subjects were recruited to undergo eight MRI examinations at five imaging centers with a range of magnet manufacturers and field strengths (1.5 and 3 T). FFs were estimated in liver and in fat-emulsion phantoms using three methods: 1) dual-echo images without correction (nominally out-of-phase [OP] and in-phase [IP]); 2) dual-dual-echo images (two sequences) with T2* correction (nominally OP/IP and IP/IP); and 3) six-echo images with spectral model and T2* correction, at sequential alternating OP and IP echo times (Methods 1, 2, and 3, respectively). RESULTS: Ten subjects were recruited. For Methods 1, 2, and 3, respectively, hepatic FF ranged from -2.5 to 27.0, 1.9 to 29.6, and 1.3 to 34.4%. Intraclass correlation coefficients were 0.85, 0.89, and 0.91 for each method, and within-subject coefficients of variation were 18.5, 9.9, and 10.3%, respectively. Mean phantom FFs derived by Methods 2 and 3 were comparable to the known FF for each phantom. Method 1 underestimated phantom FF. CONCLUSION: Methods 2 and 3 accurately assess FF. Strong reproducibility across magnet type and strength render them suitable for use in multicenter trials and longitudinal assessments.

Molecular Mechanisms of PTH/PTHrP Class B GPCR Signaling and Pharmacological Implications.

The classical paradigm of G protein-coupled receptor (GPCR) signaling via G proteins is grounded in a view that downstream responses are relatively transient and confined to the cell surface, but this notion has been revised in recent years following the identification of several receptors that engage in sustained signaling responses from subcellular compartments following internalization of the ligand-receptor complex. This phenomenon was initially discovered for the parathyroid hormone (PTH) type 1 receptor (PTH1R), a vital GPCR for maintaining normal calcium and phosphate levels in the body with the paradoxical ability to build or break down bone in response to PTH binding. The diverse biological processes regulated by this receptor are thought to depend on its capacity to mediate diverse modes of cyclic adenosine monophosphate (cAMP) signaling. These include transient signaling at the plasma membrane and sustained signaling from internalized PTH1R within early endosomes mediated by PTH. Here we discuss recent structural, cell signaling, and in vivo studies that unveil potential pharmacological outputs of the spatial versus temporal dimension of PTH1R signaling via cAMP. Notably, the combination of molecular dynamics simulations and elastic network model-based methods revealed how precise modulation of PTH signaling responses is achieved through structure-encoded allosteric coupling within the receptor and between the peptide hormone binding site and the G protein coupling interface. The implications of recent findings are now being explored for addressing key questions on how location bias in receptor signaling contributes to pharmacological functions, and how to drug a difficult target such as the PTH1R toward discovering nonpeptidic small molecule candidates for the treatment of metabolic bone and mineral diseases.

Early Bereavement Psychosocial Outcomes in Parents of Children Who Died of Cancer With a Focus on Social Functioning.

PURPOSE: The early grief experience of parents of children who died of cancer remains understudied. Understanding psychosocial symptomology and functioning of parents early in their bereavement is essential to developing supportive interventions aimed at offsetting poor mental and physical outcomes. METHODS: Parents of children from two centers who died of cancer 6 to 24 months before were mailed a survey that included validated tools and additional Likert scale-based questions. We used correlation and univariate and multiple regression analyses to assess the associations between psychosocial and grief outcomes and parental social functioning. RESULTS: One hundred twenty-five parents representing 88 children completed the survey. Most respondents identified as female (63%), White (84%), and non-Hispanic (91%). The mean time since child's death was 14.7 (range, 8-26) months. Bereaved parents' mean score for social functioning was only slightly below normative values, and most parents indicated post-traumatic growth and adaptive coping. Parents had high symptom levels for depression, anxiety, post-traumatic stress, and prolonged grief, with those identifying as female having significantly higher symptom scores. Using multivariate analysis, parental scores for resilience and continuing bonds were associated with higher social functioning scores and parental scores for depressive symptoms and prolonged grief were associated with lower social functioning scores. CONCLUSION: Although bereaved parents exhibit resilience and positive coping, they also show high levels of psychosocial distress in the first 2 years after their child's death, which may reflect the typical parental bereavement experience. Screening for low parental social functioning may identify parents who would benefit from additional support early in bereavement.

M-health: the union of technology and healthcare regulations.

As healthcare continues to become technology-based, so too does the potential for increased governmental regulation of mobile health (m-health). "M-health" is a broad term that applies to hardware or software that is mobile and delivers healthcare wirelessly. M-health includes consumer- and provider-oriented medical applications (apps), such as weight monitoring apps, and medical devices, such as glucose meters, that send health information back to the provider. It is important for anyone entering the field of mobile healthcare, whether developing apps, providing remote medical care, or simply investing in the future of healthcare technology, to understand the impact governmental oversight can have on this industry. Understanding the different roles to be played by the federal and state governments can be the difference between success and frustration.

Bereaved Parent Perspectives and Recommendations on Best Practices for Legacy Interventions.

CONTEXT: Many pediatric hospitals offer legacy interventions for families to promote coping and support grief prior to and following the death of a child. Despite this practice, parent perceptions of the value of legacy activities are not well described, and best practices for offering and creating legacy interventions remain poorly understood. OBJECTIVES: To characterize bereaved parents' perspectives on the value of legacy activities; to describe parent recommendations for optimizing provision of legacy activities by child life specialists and music therapists. METHODS: In this qualitative study, a purposive sample of 19 bereaved parents of children who died from cancer participated in semi-structured interviews. Interviews were audio-recorded, transcribed, and analyzed inductively using content analysis to identify key concepts and emerging themes. RESULTS: Analysis of transcripts revealed bereaved parent insights and recommendations across three core themes: 1) the value of legacy items and interventions; 2) the practical roles, uses, and functions of legacy items, and 3) best practices for offering legacy interventions. Bereaved parents sought meaning and purpose in abstract and concrete manifestations of legacy. Parents often used legacy items in specific ways to promote emotional expression and process their grief. Communication, timing, and creativity significantly influenced parent perceptions of legacy-building. Parents recommended individualized assessments to optimize provision of legacy interventions. CONCLUSION: Bereaved parents emphasized the meaningfulness of legacy-building activities and the need for an individualized approach when offering these interventions. Future research should explore the perspectives and recommendations of patients and siblings on legacy activities.

Understanding SUMO-mediated adaptive responses in plants to improve crop productivity.

The response to abiotic and biotic stresses in plants and crops is considered a multifaceted process. Due to their sessile nature, plants have evolved unique mechanisms to ensure that developmental plasticity remains during their life cycle. Among these mechanisms, post-translational modifications (PTMs) are crucial components of adaptive responses in plants and transduce environmental stimuli into cellular signalling through the modulation of proteins. SUMOylation is an emerging PTM that has received recent attention due to its dynamic role in protein modification and has quickly been considered a significant component of adaptive mechanisms in plants during stress with great potential for agricultural improvement programs. In the present review, we outline the concept that small ubiquitin-like modifier (SUMO)-mediated response in plants and crops to abiotic and biotic stresses is a multifaceted process with each component of the SUMO cycle facilitating tolerance to several different environmental stresses. We also highlight the clear increase in SUMO genes in crops when compared with Arabidopsis thaliana. The SUMO system is understudied in crops, given the importance of SUMO for stress responses, and for some SUMO genes, the apparent expansion provides new avenues to discover SUMO-conjugated targets that could regulate beneficial agronomical traits.

Training in Expression of Authentic Condolences in Healthcare: A Pilot Study.

Background: Bereaved parents value receiving support from their children's health care teams. Pediatric residents are important members of the teams that care for children at end of life and can play a meaningful role in communication with bereaved families. Yet formal training in expressing condolences is currently lacking. Methods: We applied Kern's six step approach to develop, implement, and evaluate an innovative curriculum aimed at increasing pediatric residents' comfort levels with and practice of condolence expression. Results: Twelve residents participated in the pilot study. Quantitative and qualitative data demonstrate that residents' comfort levels with expressing condolences increased after implementation of the curriculum and that residents appreciated and benefitted from receiving this education. Conclusion: We successfully developed and piloted a condolence expression curriculum that was well received by pediatric residents and led to increased comfort level with expressing condolences. Research is ongoing to determine the full impact of this curriculum.