Concurrent functional ultrasound imaging with graphene-based DC-coupled electrophysiology as a platform to study slow brain signals and cerebral blood flow under control and pathophysiological brain states.

Current methodology used to investigate how shifts in brain states associated with regional cerebral blood volume (CBV) change in deep brain areas, are limited by either the spatiotemporal resolution of the CBV techniques, and/or compatibility with electrophysiological recordings; particularly in relation to spontaneous brain activity and the study of individual events. Additionally, infraslow brain signals (<0.1 Hz), including spreading depolarisations, DC-shifts and infraslow oscillations (ISO), are poorly captured by traditional AC-coupled electrographic recordings; yet these very slow brain signals can profoundly change CBV. To gain an improved understanding of how infraslow brain signals couple to CBV we present a new method for concurrent CBV with wide bandwidth electrophysiological mapping using simultaneous functional ultrasound imaging (fUS) and graphene-based field effect transistor (gFET) DC-coupled electrophysiological acquisitions. To validate the feasibility of this methodology visually-evoked neurovascular coupling (NVC) responses were examined. gFET recordings are not affected by concurrent fUS imaging, and epidural placement of gFET arrays within the imaging window did not deteriorate fUS signal quality. To examine directly the impact of infra-slow potential shifts on CBV, cortical spreading depolarisations (CSDs) were induced. A biphasic pattern of decreased, followed by increased CBV, propagating throughout the ipsilateral cortex, and a delayed decrease in deeper subcortical brain regions was observed. In a model of acute seizures, CBV oscillations were observed prior to seizure initiation. Individual seizures occurred on the rising phase of both infraslow brain signal and CBV oscillations. When seizures co-occurred with CSDs, CBV responses were larger in amplitude, with delayed CBV decreases in subcortical structures. Overall, our data demonstrate that gFETs are highly compatible with fUS and allow concurrent examination of wide bandwidth electrophysiology and CBV. This graphene-enabled technological advance has the potential to improve our understanding of how infraslow brain signals relate to CBV changes in control and pathological brain states.

Roles and Responsibilities in the Transition to Working Independently: A Qualitative Study of Recently Graduated Radiographers' Perspectives in Australia.

Background: Medical imaging features along the entire healthcare continuum and is known for its fast-paced technological evolution which enables it to keep up with the demands of the healthcare system to provide safe, quality services. The overall efficacy and efficiency of the system depends on practitioners' clinical competence, achieved through professional education and continuous professional development. Recent studies have revealed concerns regarding newly graduated healthcare professionals' preparedness and readiness to handle actual practice. Methods: We conducted qualitative face-to-face and telephonic interviews with a convenient and purposive sample of 23 participants consisting of recently graduated radiographers (n=14), radiography students (n=5) and supervising radiographers (n=4) in Australia. Verbatim transcriptions were analyzed inductively to identify themes pertaining to perspectives and experiences of the work readiness of novice radiographers. Results: The findings of our study suggest that the workplace immersion and transitioning of recently graduated radiographers into their professional roles requires a process of experiential learning and honing of knowledge and skills if they are to function efficiently and independently in a team-oriented workplace. Radiographic services are spread across various levels of care and are an integral part of the organizational structure of a healthcare system. Maladaptive transitions to the workplace may be the result of low self-confidence, a lack of support, uncertainty in inter-collegial interactions, or unrealistic performance expectations. The overarching themes of communication and interaction emerged clearly as recently graduated radiographers navigated the four roles of coordinator, collaborator, mediator, and advocate. Conclusion: The application of radiographic skills is embedded in a workplace culture of communication and safety. Transitioning to independent practice takes place in a complex, multifaceted environment and is accompanied by internal and external expectations. Because each workplace has a unique context, system and culture, no novice radiographic professional can ever be fully prepared through pre-service training and workplace induction.

Australian graduate radiographers' perspectives and experiences of work readiness.

INTRODUCTION: Graduate radiographers entering their qualified positions need to orientate and familiarise themselves with a rapidly changing work environment to deliver a high standard of diagnostic imaging services. During this transitional phase, these newcomers also strive to meet self-expectations and workplace expectations. This study was performed to understand the work readiness perspectives and initial experiences of graduate radiographers on beginning their newly qualified roles. METHODS: The study used a qualitative phenomenological approach to collect data through individual semi-structured in-depth telephone interviews with 14 purposively sampled undergraduate and postgraduate radiographers. The rich data were transcribed verbatim and then thematically analysed. RESULTS: Four major themes emerged: (1) preparing to be 'work-ready', (2) initial encounters as qualified radiographers, (3) personal and professional challenges and (4) support strategies and advice for new graduates. CONCLUSIONS: New graduate radiographers face many personal and professional challenges but agree that they thrive in supportive collegial environments. Most participants had a high perspective of their work readiness strongly related to their clinical placements as students, workplace familiarity, support networks and coping strategies. Further review into individual workplace orientations by organisation leaders may benefit the immersion and enhancement of graduate radiographers' initial experiences in their new role.

Characterizing the portability of phage-encoded homologous recombination proteins.

Efficient genome editing methods are essential for biotechnology and fundamental research. Homologous recombination (HR) is the most versatile method of genome editing, but techniques that rely on host RecA-mediated pathways are inefficient and laborious. Phage-encoded single-stranded DNA annealing proteins (SSAPs) improve HR 1,000-fold above endogenous levels. However, they are not broadly functional. Using Escherichia coli, Lactococcus lactis, Mycobacterium smegmatis, Lactobacillus rhamnosus and Caulobacter crescentus, we investigated the limited portability of SSAPs. We find that these proteins specifically recognize the C-terminal tail of the host's single-stranded DNA-binding protein (SSB) and are portable between species only if compatibility with this host domain is maintained. Furthermore, we find that co-expressing SSAPs with SSBs can significantly improve genome editing efficiency, in some species enabling SSAP functionality even without host compatibility. Finally, we find that high-efficiency HR far surpasses the mutational capacity of commonly used random mutagenesis methods, generating exceptional phenotypes that are inaccessible through sequential nucleotide conversions.

A microplanning model to improve door-to-door health service delivery: the case of Seasonal Malaria Chemoprevention in Sub-Saharan African villages.

BACKGROUND: Malaria incidence has plateaued in Sub-Saharan Africa despite Seasonal Malaria Chemoprevention's (SMC) introduction. Community health workers (CHW) use a door-to-door delivery strategy to treat children with SMC drugs, but for SMC to be as effective as in clinical trials, coverage must be high over successive seasons. METHODS: We developed and used a microplanning model that utilizes population raster to estimate population size, generates optimal households visit itinerary, and quantifies SMC coverage based on CHWs' time investment for treatment and walking. CHWs' performance under current SMC deployment mode was assessed using CHWs' tracking data and compared to microplanning in villages with varying demographics and geographies. RESULTS: Estimates showed that microplanning significantly reduces CHWs' walking distance by 25%, increases the number of visited households by 36% (p < 0.001) and increases SMC coverage by 21% from 37.3% under current SMC deployment mode up to 58.3% under microplanning (p < 0.001). Optimal visit itinerary alone increased SMC coverage up to 100% in small villages whereas in larger or hard-to-reach villages, filling the gap additionally needed an optimization of the CHW ratio. CONCLUSION: We estimate that for a pair of CHWs, the daily optimal number of visited children (assuming 8.5mn spent per child) and walking distance should not exceed 45 (95% CI 27-62) and 5 km (95% CI 3.2-6.2) respectively. Our work contributes to extend SMC coverage by 21-63% and may have broader applicability for other community health programs.

Using Experiential Simulation-Based Learning to Increase Engagement in Global Health Education: an Evaluation of Self-reported Participant Experience.

BACKGROUND: Simulations aim to supplement historic teacher-centric methods by facilitating experiential, self-guided learning and the application of students' knowledge in a controlled environment. The objective of our study is to describe the methodology of developing and facilitating simulations, and to assess their effectiveness as an educational tool for global health training. METHODS: We describe the methodology used by Global Health Sim between October 2016 and March 2019 to design and facilitate simulations for participants at the high school through graduate school levels, and at conferences and online. Using a mixed-methods evaluation design, we assessed self-reported quantitative measures of content knowledge before and after participating in the simulation and different aspects of the simulation experience. We also conducted a qualitative thematic analysis of the experience and lessons learned as reported by evaluation respondents. RESULTS: We conducted a total of 20 simulations on six unique topics for 213 evaluation respondents. Self-reported knowledge of the topic increased an average of 3.3 points on a 10-point scale (4.1-7.4) and the seven aspects of the experience were rated highly (3-5 points on a 5-point Likert scale). Thematic analysis revealed an increased understanding of the complexity of global health problems and strategies for effectively responding to issues in a multidisciplinary manner. CONCLUSIONS: Respondents valued the opportunity to learn about the complexities of responding to global health events, which confirmed that simulations can be utilized as teaching tools for students and professionals. Further research is required to assess the long-term educational impact of simulations in global health.

A monomethyl auristatin E-conjugated antibody to guanylyl cyclase C is cytotoxic to target-expressing cells in vitro and in vivo.

Guanylyl cyclase C (GCC) is a cell-surface protein that is expressed by normal intestinal epithelial cells, more than 95% of metastatic colorectal cancers (mCRC), and the majority of gastric and pancreatic cancers. Due to strict apical localization, systemically delivered GCC-targeting agents should not reach GCC in normal intestinal tissue, while accessing antigen in tumor. We generated an investigational antibody-drug conjugate (TAK-264, formerly MLN0264) comprising a fully human anti-GCC monoclonal antibody conjugated to monomethyl auristatin E via a protease-cleavable peptide linker. TAK-264 specifically bound, was internalized by, and killed GCC-expressing cells in vitro in an antigen-density-dependent manner. In GCC-expressing xenograft models with similar GCC expression levels/patterns observed in human mCRC samples, TAK-264 induced cell death, leading to tumor regressions and long-term tumor growth inhibition. TAK-264 antitumor activity was generally antigen-density-dependent, although some GCC-expressing tumors were refractory to TAK-264-targeted high local concentrations of payload. These data support further evaluation of TAK-264 in the treatment of GCC-expressing tumors.

Your Way to a Better Theory of Mind: A Healthy Diet Relates to Better Faux Pas Recognition in Older Adults.

BACKGROUND/STUDY CONTEXT: Aging is characterized by a well-documented worsening of general cognition, and also a decline in social understanding such as the ability to recognize emotions or detect socially inappropriate behavior (faux pas). Several studies have demonstrated that lifestyle factors (diet, exercise, social integration, smoking) tend to offset general cognitive decline, and we examined whether they also help to offset age-related declines in social cognition. METHODS: There were 56 participants aged 60 years or over. General cognition was measured using a matrices task and the Mini-Mental State Examination (MMSE). Emotion recognition was measured by the matching of faces to emotion sounds and bodies to sounds. Faux pas recognition was measured by 16 videos, examining participants' ability to differentiate appropriate and inappropriate social behavior. Diet, exercise, social integration, and smoking habits were measured via questionnaires. RESULTS: For general cognition, diet, pr = .32, p < .02, smoking, pr = -.32, p = .02, and education, pr = .48, p < .001, explained unique variance in matrices performance. For social cognition, even after accounting for participants' education, age, exercise habits, smoking, and social integration, a healthy diet explained independent variance in the ability to identify appropriate social behavior, pr = .29, p = .04. CONCLUSION: We replicated previous research in finding that lifestyle factors were related to fluid intelligence. In addition, we obtained the novel finding that a healthy diet is associated with better recognition of faux pas in older adults, likely acting through facilitation of brain health, and providing initial support for a means of enhancing social functioning and well-being in old age.

Evaluation of Automated Fracture Risk Assessment Based on the Canadian Association of Radiologists and Osteoporosis Canada Assessment Tool.

Fracture risk assessments are not always clearly communicated on bone mineral density (BMD) reports; evidence suggests that structured reporting (SR) tools may improve report clarity. The aim of this study is to compare fracture risk assessments automatically assigned by SR software in accordance with Canadian Association of Radiologists and Osteoporosis Canada (CAROC) recommendations to assessments from experts on narrative BMD reports. Charts for 500 adult patients who recently received a BMD exam were sampled from across University of Toronto's Joint Department of Medical Imaging. BMD measures and clinical details were manually abstracted from charts and were used to create structured reports with assessments generated by a software implementation of CAROC recommendations. CAROC calculations were statistically compared to experts' original assessments using percentage agreement (PA) and Krippendorff's alpha. Canadian FRAX calculations were also compared to experts', where possible. A total of 25 (5.0%) reported assessments did not conform to categorizations recommended by Canadian guidelines. Across the remainder, the Krippendorff's alpha relating software assigned assessments to physicians was high at 0.918; PA was 94.3%. Lower agreement was associated with reports for patients with documented modifying factors (alpha = 0.860, PA = 90.2%). Similar patterns of agreement related expert assessments to FRAX calculations, although statistics of agreement were lower. Categories of disagreement were defined by (1) gray areas in current guidelines, (2) margins of assessment categorizations, (3) dictation/transcription errors, (4) patients on low doses of steroids, and (5) ambiguous documentation of modifying factors. Results suggest that SR software can produce fracture risk assessments that agree with experts on most routine, adult BMD exams. Results also highlight situations where experts tend to diverge from guidelines and illustrate the potential for SR software to (1) reduce variability in, (2) ameliorate errors in, and (3) improve clarity of routine adult BMD exam reports.

Symptom Burden, Medication Detriment, and Support for the Use of the 15D Health-Related Quality of Life Instrument in a Chronic Pain Clinic Population.

Chronic noncancer pain is a prevalent problem associated with poor quality of life. While symptom burden is frequently mentioned in the literature and clinical settings, this research highlights the considerable negative impact of chronic pain on the individual. The 15D, a measure of health-related quality of life (HRQOL), is a user-friendly tool with good psychometric properties. Using a modified edmonton symptom assessment scale (ESAS), we examined whether demographics, medical history, and symptom burden reports from the ESAS would be related statistically to HRQOL measured with the 15D. Symptom burden, medication detriment scores, and number of medical comorbidities were significant negative predictors of 15D scores with ESAS symptom burden being the strongest predictor. Our findings highlight the tremendous symptom burden experienced in our sample. Our data suggest that heavier prescription medication treatment for chronic pain has the potential to negatively impact HRQOL. Much remains unknown regarding how to assess and improve HRQOL in this relatively heterogeneous clinical population.

MLN4924, a NEDD8-activating enzyme inhibitor, is active in diffuse large B-cell lymphoma models: rationale for treatment of NF-{kappa}B-dependent lymphoma.

MLN4924 is a potent and selective small molecule NEDD8-activating enzyme (NAE) inhibitor. In most cancer cells tested, inhibition of NAE leads to induction of DNA rereplication, resulting in DNA damage and cell death. However, in preclinical models of activated B cell-like (ABC) diffuse large B-cell lymphoma (DLBCL), we show that MLN4924 induces an alternative mechanism of action. Treatment of ABC DLBCL cells with MLN4924 resulted in rapid accumulation of pIkappaBalpha, decrease in nuclear p65 content, reduction of nuclear factor-kappaB (NF-kappaB) transcriptional activity, and G(1) arrest, ultimately resulting in apoptosis induction, events consistent with potent NF-kappaB pathway inhibition. Treatment of germinal-center B cell-like (GCB) DLBCL cells resulted in an increase in cellular Cdt-1 and accumulation of cells in S-phase, consistent with cells undergoing DNA rereplication. In vivo administration of MLN4924 to mice bearing human xenograft tumors of ABC- and GCB-DLBCL blocked NAE pathway biomarkers and resulted in complete tumor growth inhibition. In primary human tumor models of ABC-DLBCL, MLN4924 treatment resulted in NF-kappaB pathway inhibition accompanied by tumor regressions. This work describes a novel mechanism of targeted NF-kappaB pathway modulation in DLBCL and provides strong rationale for clinical development of MLN4924 against NF-kappaB-dependent lymphomas.

An inhibitor of NEDD8-activating enzyme as a new approach to treat cancer.

The clinical development of an inhibitor of cellular proteasome function suggests that compounds targeting other components of the ubiquitin-proteasome system might prove useful for the treatment of human malignancies. NEDD8-activating enzyme (NAE) is an essential component of the NEDD8 conjugation pathway that controls the activity of the cullin-RING subtype of ubiquitin ligases, thereby regulating the turnover of a subset of proteins upstream of the proteasome. Substrates of cullin-RING ligases have important roles in cellular processes associated with cancer cell growth and survival pathways. Here we describe MLN4924, a potent and selective inhibitor of NAE. MLN4924 disrupts cullin-RING ligase-mediated protein turnover leading to apoptotic death in human tumour cells by a new mechanism of action, the deregulation of S-phase DNA synthesis. MLN4924 suppressed the growth of human tumour xenografts in mice at compound exposures that were well tolerated. Our data suggest that NAE inhibitors may hold promise for the treatment of cancer.

Enhanced calcium cycling and contractile function in transgenic hearts expressing constitutively active G alpha o* protein.

In contrast to the other heterotrimeric GTP-binding proteins (G proteins) Gs and Gi, the functional role of G o is still poorly defined. To investigate the role of G alpha o in the heart, we generated transgenic mice with cardiac-specific expression of a constitutively active form of G alpha o1* (G alpha o*), the predominant G alpha o isoform in the heart. G alpha o expression was increased 3- to 15-fold in mice from 5 independent lines, all of which had a normal life span and no gross cardiac morphological abnormalities. We demonstrate enhanced contractile function in G alpha o* transgenic mice in vivo, along with increased L-type Ca2+ channel current density, calcium transients, and cell shortening in ventricular G alpha o*-expressing myocytes compared with wild-type controls. These changes were evident at baseline and maintained after isoproterenol stimulation. Expression levels of all major Ca2+ handling proteins were largely unchanged, except for a modest reduction in Na+/Ca2+ exchanger in transgenic ventricles. In contrast, phosphorylation of the ryanodine receptor and phospholamban at known PKA sites was increased 1.6- and 1.9-fold, respectively, in G alpha o* ventricles. Density and affinity of beta-adrenoceptors, cAMP levels, and PKA activity were comparable in G alpha o* and wild-type myocytes, but protein phosphatase 1 activity was reduced upon G alpha o* expression, particularly in the vicinity of the ryanodine receptor. We conclude that G alpha o* exerts a positive effect on Ca2+ cycling and contractile function. Alterations in protein phosphatase 1 activity rather than PKA-mediated phosphorylation might be involved in hyperphosphorylation of key Ca2+ handling proteins in hearts with constitutive G alpha o activation.

Comparison of biochemical and biological effects of ML858 (salinosporamide A) and bortezomib.

Strains within the genus Salinospora have been shown to produce complex natural products having antibiotic and antiproliferative activities. The biochemical basis for the cytotoxic effects of salinosporamide A has been linked to its ability to inhibit the proteasome. Synthetically accessible salinosporamide A (ML858) was used to determine its biochemical and biological activities and to compare its effects with those of bortezomib. ML858 and bortezomib show time- and concentration-dependent inhibition of the proteasome in vitro. However, unlike bortezomib, which is a reversible inhibitor, ML858 covalently binds to the proteasome, resulting in the irreversible inhibition of 20S proteasome activity. ML858 was equipotent to bortezomib in cell-based reporter stabilization assays, but due to intramolecular instability is less potent in long-term assays. ML858 failed to maintain levels of proteasome inhibition necessary to achieve efficacy in tumor models responsive to bortezomib. Our results show that ML858 and bortezomib exhibit different kinetic and pharmacologic profiles and suggest that additional characterization of ML858 is warranted before its therapeutic potential can be fully appreciated.

Chronic cardiac-specific thyrotoxicosis increases myocardial beta-adrenergic responsiveness.

Whereas many cardiac symptoms of thyrotoxicosis resemble those of the hyperadrenergic state, circulating catecholamines are reduced or normal in this condition. To test the hypothesis that the thyrotoxic heart is hypersensitive to catechol-amines, we studied beta-adrenergic signaling in a transgenic (TG) mouse in which the human type 2 iodothyronine deiodinase (D2) gene is expressed in myocardium. Because D2 converts T4 to T3, the active form of thyroid hormone, the D2 TG mouse exhibits mild, chronic thyrotoxicosis that is limited to the myocardium. In the current study, we determined that cAMP accumulation in response to either norepinephrine or forskolin treatment was increased in isolated ventricular myocardiocytes and membrane-enriched fractions prepared from these D2 TG hearts as compared with wild type. This increase in adenylyl cyclase (AC) Vmax could not be explained by changes in AC isoform expression or changes in the long or short forms of stimulatory G-protein Gsalpha, which were approximately 10% decreased in D2 TG membranes. However, Western analysis and ADP-ribosylation studies suggest that the increase in AC Vmax is mediated by a decrease in the expression of inhibitory G proteins (Gialpha-3 and/or Goalpha). These data suggest that cardiac thyrotoxicosis leads to increased beta-adrenergic responsiveness of cardiomyocytes via alterations in the regulatory G-protein elements of the AC membrane complex.

Leukocyte antigen-related protein tyrosine phosphatase receptor: a small ectodomain isoform functions as a homophilic ligand and promotes neurite outgrowth.

The identities of ligands interacting with protein tyrosine phosphatase (PTP) receptors to regulate neurite outgrowth remain mainly unknown. Analysis of cDNA and genomic clones encoding the rat leukocyte common antigen-related (LAR) PTP receptor predicted a small, approximately 11 kDa ectodomain isoform, designated LARFN5C, containing a novel N terminal followed by a C-terminal segment of the LAR fifth fibronectin type III domain. RT-PCR and Northern blot analysis confirmed the presence of LARFN5C transcripts in brain. Transfection of COS cells with LARFN5C-Fc cDNA resulted in expression of the predicted protein, and Western blot analysis verified expression of approximately 11 kDa LARFN5C protein in vivo and its developmental regulation. Beads coated with rLARFN5C demonstrated aggregation consistent with homophilic binding, and pull-down and immunoprecipitation assays demonstrated that rLARFN5C associates with the LAR receptor. rLARFN5C binding to COS cells was dependent on LAR expression, and rLARFN5C binding to LAR +/+ hippocampal neurons was fivefold greater than that found by using LAR-deficient (-/-) neurons. Substratum-bound rLARFN5C had potent neurite-promoting effects on LAR +/+ neurons, with a fivefold loss in potency with the use of LAR -/- neurons. rLARFN5C in solution at low nanomolar concentrations inhibited neurite outgrowth induced by substratum-bound rLARFN5C, consistent with receptor-based function. These studies suggest that a small ectodomain isoform of a PTP receptor can function as a ligand for the same receptor to promote neurite outgrowth.