The OTX2 Gene Induces Tumor Growth and Triggers Leptomeningeal Metastasis by Regulating the mTORC2 Signaling Pathway in Group 3 Medulloblastomas

Medulloblastoma (MB) encompasses diverse subgroups, and leptomeningeal disease/metastasis (LMD) plays a substantial role in associated fatalities. Despite extensive exploration of canonical genes in MB, the molecular mechanisms underlying LMD and the involvement of the orthodenticle homeobox 2 (OTX2) gene, a key driver in aggressive MB Group 3, remain insufficiently understood. Recognizing OTX2's pivotal role, we investigated its potential as a catalyst for aggressive cellular behaviors, including migration, invasion, and metastasis. OTX2 overexpression heightened cell growth, motility, and polarization in Group 3 MB cells. Orthotopic implantation of OTX2-overexpressing cells in mice led to reduced median survival, accompanied by the development of spinal cord and brain metastases. Mechanistically, OTX2 acted as a transcriptional activator of the Mechanistic Target of Rapamycin (mTOR) gene's promoter and the mTORC2 signaling pathway, correlating with upregulated downstream genes that orchestrate cell motility and migration. Knockdown of mTOR mRNA mitigated OTX2-mediated enhancements in cell motility and polarization. Analysis of human MB tumor samples (N = 952) revealed a positive correlation between OTX2 and mTOR mRNA expression, emphasizing the clinical significance of OTX2's role in the mTORC2 pathway. Our results reveal that OTX2 governs the mTORC2 signaling pathway, instigating LMD in Group 3 MBs and offering insights into potential therapeutic avenues through mTORC2 inhibition.

Paediatric emergency front-of-neck airway: issues of ethics, law, and philosophy

Practitioners can face significant challenges when managing the airways of infants and neonates because of their unique anatomical and physiological features. The requirement for emergency airway management in this age group is rare. Details of emergency airway techniques in paediatric practice guidelines are missing or lack consensus, and it is known that outcomes for affected children can be poor. Ideally, these children should be managed by experienced paediatric airway practitioners working in a team. However, situations can arise where practitioners, unfamiliar and inexperienced with infants, find themselves in charge. So, what happens when such a practitioner encounters this life-or-death scenario and feels ill-equipped to act? The ethical and legal issues surrounding the management of this emergency are clearly defined, but they can be unknown or misunderstood by doctors. Compounding the extreme stress of the scenario is the moral and ethical dilemma of whether to act or not. The following discussion explores these issues and examines the philosophical and psychological perspectives.

Disability rights and empowerment: Reflections on AJCP research and a call to action

People living with physical, sensory, intellectual, and/or developmental disabilities experience complex social, environmental, political, and cultural challenges along with stigma and marginalization in education, employment, and community life. These multiple and complex barriers often hinder their full and effective participation in society. In this reflection, we curated articles on physical, sensory, intellectual, and/or developmental disabilities published in the American Journal of Community Psychology from 1973 to 2022. We reviewed titles and abstracts to identify themes that grouped manuscripts in relevant community psychology core concepts and values. From our analysis, five themes emerged: (a) promoting empowerment and advocacy; (b) promoting organizations and settings that support people with disabilities; (c) including people with disabilities in knowledge production; (d) promoting social justice in disability research, and (e) promoting support networks of families of people with disabilities. We conclude this reflection with a discussion of recommendations for future research, practice, and a call to action.

Glioblastoma cells use an integrin- and CD44-mediated motor-clutch mode of migration in brain tissue

Glioblastoma (GBM) is an aggressive malignant brain tumor with 2-year survival rates of 6.7% [1], [2]. One key characteristic of the disease is the ability of glioblastoma cells to migrate rapidly and spread throughout healthy brain tissue[3], [4]. To develop treatments that effectively target cell migration, it is important to understand the fundamental mechanism driving cell migration in brain tissue. Here we utilized confocal imaging to measure traction dynamics and migration speeds of glioblastoma cells in mouse organotypic brain slices to identify the mode of cell migration. Through imaging cell-vasculature interactions and utilizing drugs, antibodies, and genetic modifications to target motors and clutches, we find that glioblastoma cell migration is most consistent with a motor-clutch mechanism to migrate through brain tissue ex vivo, and that both integrins and CD44, as well as myosin motors, play an important role in constituting the adhesive clutch.

RAD-TGTs: high-throughput measurement of cellular mechanotype via rupture and delivery of DNA tension probes

Mechanical forces drive critical cellular processes that are reflected in mechanical phenotypes, or mechanotypes, of cells and their microenvironment. We present here "Rupture And Deliver" Tension Gauge Tethers (RAD-TGTs) in which flow cytometry is used to record the mechanical history of thousands of cells exerting forces on their surroundings via their propensity to rupture immobilized DNA duplex tension probes. We demonstrate that RAD-TGTs recapitulate prior DNA tension probe studies while also yielding a gain of fluorescence in the force-generating cell that is detectable by flow cytometry. Furthermore, the rupture propensity is altered following disruption of the cytoskeleton using drugs or CRISPR-knockout of mechanosensing proteins. Importantly, RAD-TGTs can differentiate distinct mechanotypes among mixed populations of cells. We also establish oligo rupture and delivery can be measured via DNA sequencing. RAD-TGTs provide a facile and powerful assay to enable high-throughput mechanotype profiling, which could find various applications, for example, in combination with CRISPR screens and -omics analysis.

Closing the Information Gap: Making COVID-19 Information Accessible for People with Disabilities

It is essential that people with disabilities have equitable access to COVID-19 communication resources to protect themselves, their families, and their communities. The Accessible Materials and Culturally Relevant Messages for Individuals with Disabilities project aimed to deliver essential COVID-19 information in braille, American Sign Language (ASL), simplified text, and other alternative formats, along with providing additional tools and trainings that people with disabilities and organizations that serve them can use to apply the COVID-19 guidance. Lessons learned from this project can be implemented in future public health emergencies as well as in general public health messaging for people with disabilities. This project, led by Georgia Tech's Center for Inclusive Design and Innovation (CIDI) and with technical assistance from the Centers for Disease Control and Prevention (CDC), was supported by the CDC Foundation, using funds from the CDC Foundation's COVID-19 Emergency Response Fund.

A Scoping Review of the Pharmacy Curriculum Outcomes Assessment Literature

Objective. To identify themes, gaps, and sources of evidence from the literature regarding the Pharmacy Curriculum Outcomes Assessment (PCOA) to inform practice and additional areas for research in pharmacy education.Findings. Nineteen articles describing the administration and use of PCOA were identified. Since PCOA was made a curricular requirement by the Accreditation Council of Pharmacy Education in 2016, the focus of literature related to the PCOA has shifted from administration practices (four articles published before 2016 vs two articles published since) to determining models that may predict student performance on the assessment (two vs five articles) or how the examination might be used to predict future performance (one vs seven articles), especially on the North American Pharmacist Licensing Examination. While there is a growing body of literature focused on the PCOA's utility for measuring performance, few variables have been consistently used.Summary. This review found no studies with objectives that aligned with the initial intended use of the PCOA as defined by the National Association of Boards of Pharmacy, which included tracking individual student performance throughout the curriculum, benchmarking programs against other programs, and evaluating whether a program was meeting their desired outcomes. Additionally, no consensus across the Academy was found as to the proper use of the PCOA, and a paucity of literature exists regarding how the PCOA informs schools and colleges about the effectiveness of their curriculum. There is a need for the Academy to establish a uniform application for the PCOA in pharmacy schools, assess the resources that programs need to administer this required assessment, and determine the utility of the PCOA to measure curricular effectiveness and/or student performance.

Failure of the "Gold Standard": The Role of a Mixed Methods Research Toolkit and Human-Centered Design in Transformative WASH

From preventing cholera and diarrhea by reducing exposure to human waste, to reducing transmission of COVID-19 through handwashing, water, sanitation and hygiene (WASH) can save lives. Numerous global health initiatives have been created to combat the spread of infectious diseases. However, according to the Sanitation and Hygiene Fund, "decades of under investment in sanitation and hygiene have made this sector the weakest link in our efforts to achieve the [Sustainable Development Goals (SDGs)]." There appear to be various reasons for the lag in global attention to, funding toward, and innovation around WASH-related diseases. Firstly, WASH is comprised of three interrelated components, water, sanitation, and hygiene, each of which has its own subset of indicators, priorities, and infrastructure, thus making streamlined communications and impact measurement within the sector incredibly complex. Secondly, WASH is a field that bridges many sectors, and there has historically been a lack of understanding of where responsibility lies to consistently fund and execute WASH interventions, programming, and policymaking. Additionally, public health research and funding tend to favor evaluations using randomized controlled trials (RCTs), which are often referred to as the "gold standard." RCTs, like all single evaluative methods, have limitations which may not effectively capture the complexity of WASH interventions and their subsequent multi-sectoral outcomes. In some cases "it may be infeasible (or unethical) to randomize communities to a [WASH] intervention" which would prohibit the research from reaching the current "gold standard" threshold for academic rigor and subsequent funding. A new concept called "Transformative WASH" has recently emerged in the WASH sector as a result of three RCTs and calls for a "comprehensive package of WASH interventions" to effectively improve health and social outcomes. We believe that the current definition of the "gold standard" in academic research is failing the WASH sector and does not align with "Transformative WASH." Rather, the "gold standard" should instead be a mixed methods research toolkit that utilizes Human-Centered Design (HCD) practices, and proxy methods such as "participatory design" or "Behavior Centered Design theory" to better design and evaluate WASH interventions.

Smart Sanitation-Biosensors as a Public Health Tool in Sanitation Infrastructure

The health of individuals and communities is more interconnected than ever, and emergent technologies have the potential to improve public health monitoring at both the community and individual level. A systematic literature review of peer-reviewed and gray literature from 2000-present was conducted on the use of biosensors in sanitation infrastructure (such as toilets, sewage pipes and septic tanks) to assess individual and population health. 21 relevant papers were identified using PubMed, Embase, Global Health, CDC Stacks and NexisUni databases and a reflexive thematic analysis was conducted. Biosensors are being developed for a range of uses including monitoring illicit drug usage in communities, screening for viruses and diagnosing conditions such as diabetes. Most studies were nonrandomized, small-scale pilot or lab studies. Of the sanitation-related biosensors found in the literature, 11 gathered population-level data, seven provided real-time continuous data and 14 were noted to be more cost-effective than traditional surveillance methods. The most commonly discussed strength of these technologies was their ability to conduct rapid, on-site analysis. The findings demonstrate the potential of this emerging technology and the concept of Smart Sanitation to enhance health monitoring at the individual level (for diagnostics) as well as at the community level (for disease surveillance).

Regulation and dynamics of force transmission at individual cell-matrix adhesion bonds

Integrin-based adhesion complexes link the cytoskeleton to the extracellular matrix (ECM) and are central to the construction of multicellular animal tissues. How biological function emerges from the tens to thousands of proteins present within a single adhesion complex remains unclear. We used fluorescent molecular tension sensors to visualize force transmission by individual integrins in living cells. These measurements revealed an underlying functional modularity in which integrin class controlled adhesion size and ECM ligand specificity, while the number and type of connections between integrins and F-actin determined the force per individual integrin. In addition, we found that most integrins existed in a state of near-mechanical equilibrium, a result not predicted by existing models of cytoskeletal force transduction. A revised model that includes reversible cross-links within the F-actin network can account for this result and suggests one means by which cellular mechanical homeostasis can arise at the molecular level.

Innate Immunity in the C. elegans Intestine Is Programmed by a Neuronal Regulator of AWC Olfactory Neuron Development

Olfactory neurons allow animals to discriminate nutritious food sources from potential pathogens. From a forward genetic screen, we uncovered a surprising requirement for the olfactory neuron gene olrn-1 in the regulation of intestinal epithelial immunity in Caenorhabditis elegans. During nematode development, olrn-1 is required to program the expression of odorant receptors in the AWC olfactory neuron pair. Here, we show that olrn-1 also functions in AWC neurons in the cell non-autonomous suppression of the canonical p38 MAPK PMK-1 immune pathway in the intestine. Low activity of OLRN-1, which activates the p38 MAPK signaling cassette in AWC neurons during larval development, also de-represses the p38 MAPK PMK-1 pathway in the intestine to promote immune effector transcription, increased clearance of an intestinal pathogen, and resistance to bacterial infection. These data reveal an unexpected connection between olfactory receptor development and innate immunity and show that anti-pathogen defenses in the intestine are developmentally programmed.

Modeling distributed forces within cell adhesions of varying size on continuous substrates

Cell migration and traction are essential to many biological phenomena, and one of their key features is sensitivity to substrate stiffness, which biophysical models, such as the motor-clutch model and the cell migration simulator can predict and explain. However, these models have not accounted for the finite size of adhesions, the spatial distribution of forces within adhesions. Here, we derive an expression that relates varying adhesion radius ( R) and spatial distribution of force within an adhesion (described by s) to the effective substrate stiffness ( κ_sub ), as a function of the Young's modulus of the substrate ( E _Y ), which yields the relation, κ sub = R s E Y , for two-dimensional cell cultures. Experimentally, we found that a cone-shaped force distribution ( s = 1.05) can describe the observed displacements of hydrogels deformed by adherent U251 glioma cells. Also, we found that the experimentally observed adhesion radius increases linearly with the cell protrusion force, consistent with the predictions of the motor-clutch model with spatially distributed clutches. We also found that, theoretically, the influence of one protrusion on another through a continuous elastic environment is negligible. Overall, we conclude cells can potentially control their own interpretation of the mechanics of the environment by controlling adhesion size and spatial distribution of forces within an adhesion.

Redirection of SKN-1 abates the negative metabolic outcomes of a perceived pathogen infection

Early host responses toward pathogens are essential for defense against infection. In Caenorhabditis elegans, the transcription factor, SKN-1, regulates cellular defenses during xenobiotic intoxication and bacterial infection. However, constitutive activation of SKN-1 results in pleiotropic outcomes, including a redistribution of somatic lipids to the germline, which impairs health and shortens lifespan. Here, we show that exposing C. elegans to Pseudomonas aeruginosa similarly drives the rapid depletion of somatic, but not germline, lipid stores. Modulating the epigenetic landscape refines SKN-1 activity away from innate immunity targets, which alleviates negative metabolic outcomes. Similarly, exposure to oxidative stress redirects SKN-1 activity away from pathogen response genes while restoring somatic lipid distribution. In addition, activating p38/MAPK signaling in the absence of pathogens, is sufficient to drive SKN-1-dependent loss of somatic fat. These data define a SKN-1- and p38-dependent axis for coordinating pathogen responses, lipid homeostasis, and survival and identify transcriptional redirection, rather than inactivation, as a mechanism for counteracting the pleiotropic consequences of aberrant transcriptional activity.

The fatty acid oleate is required for innate immune activation and pathogen defense in Caenorhabditis elegans

Fatty acids affect a number of physiological processes, in addition to forming the building blocks of membranes and body fat stores. In this study, we uncover a role for the monounsaturated fatty acid oleate in the innate immune response of the nematode Caenorhabditis elegans. From an RNAi screen for regulators of innate immune defense genes, we identified the two stearoyl-coenzyme A desaturases that synthesize oleate in C. elegans. We show that the synthesis of oleate is necessary for the pathogen-mediated induction of immune defense genes. Accordingly, C. elegans deficient in oleate production are hypersusceptible to infection with diverse human pathogens, which can be rescued by the addition of exogenous oleate. However, oleate is not sufficient to drive protective immune activation. Together, these data add to the known health-promoting effects of monounsaturated fatty acids, and suggest an ancient link between nutrient stores, metabolism, and host susceptibility to bacterial infection.

The evolution of multicellular organisms has been shaped by their interactions with pathogenic microorganisms. The microscopic nematode C. elegans eats bacteria for food and has evolved inducible immune defenses toward ingested pathogens that are coordinated within intestinal epithelial cells. C. elegans, therefore, presents a genetic system to characterize the requirements for the activation of innate immune defenses. Here, we show that the monounsaturated fatty acid oleate is necessary for the induction of innate immune defenses and for protection against bacterial pathogens, which defines a new link between metabolism and the regulation of anti-pathogen responses in a metazoan host.

The nuclear hormone receptor NHR-86 controls anti-pathogen responses in C. elegans

Nuclear hormone receptors (NHRs) are ligand-gated transcription factors that control adaptive host responses following recognition of specific endogenous or exogenous ligands. Although NHRs have expanded dramatically in C. elegans compared to other metazoans, the biological function of only a few of these genes has been characterized in detail. Here, we demonstrate that an NHR can activate an anti-pathogen transcriptional program. Using genetic epistasis experiments, transcriptome profiling analyses and chromatin immunoprecipitation-sequencing, we show that, in the presence of an immunostimulatory small molecule, NHR-86 binds to the promoters of immune effectors to activate their transcription. NHR-86 is not required for resistance to the bacterial pathogen Pseudomonas aeruginosa at baseline, but activation of NHR-86 by this compound drives a transcriptional program that provides protection against this pathogen. Interestingly, NHR-86 targets immune effectors whose basal regulation requires the canonical p38 MAPK PMK-1 immune pathway. However, NHR-86 functions independently of PMK-1 and modulates the transcription of these infection response genes directly. These findings characterize a new transcriptional regulator in C. elegans that can induce a protective host response towards a bacterial pathogen.

Impact of a team-based learning drug misuse education training program on student pharmacists' confidence

BACKGROUND AND PURPOSE

With increasing deaths related to prescription medications, it is important to educate adolescents on the dangers of drug misuse. Pharmacists possess the knowledge and are accessible to provide education to patients on this topic; therefore, the objectives were to improve student pharmacist confidence in prescription drug misuse knowledge and engaging patients.

EDUCATIONAL ACTIVITY AND SETTING

As part of a co-curricular activity, pharmacy, and pre-pharmacy students participated in an informational session to establish a common foundation of drug misuse concepts using a team-based learning pedagogy. Students developed a curriculum and taught middle school children about drug and alcohol misuse. Participants' motivations for participation and confidence in drug misuse education were assessed through a 19 item pre-post survey.

FINDINGS

Out of the 19 confidence items, seven had significant improvement. Students were more confident after the intervention that they could share their knowledge on drug misuse with colleagues (p = 0.012) and implement prevention strategies in their area (p = 0.020). They were also more confident in their ability to explain the definition (p = 0.001) and consequences (p = 0.003) of drug misuse.

SUMMARY

A training session combined with the opportunity to apply learned concepts may be an effective way to improve the confidence of future pharmacists in educating their communities.

Evaluating the use of appropriate anticoagulation with lenalidomide and pomalidomide in patients with multiple myeloma

Background

Lenalidomide and pomalidomide are two immunomodulatory medications with the potential to improve outcomes for patients with multiple myeloma; however, a black box warning for venous thromboembolism exists.

Purpose

The purpose of this study was to assess overall adherence to guideline recommendations for anticoagulation therapy with lenalidomide and pomalidomide in multiple myeloma patients.

Methods

This retrospective study at an ambulatory oncology clinic utilized chart reviews from the calendar years 2013–2016. The primary endpoint was prescription of appropriate anticoagulation upon initiation of therapy based on a list of predetermined risk factors. Secondary endpoints included incidence of deep venous thromboembolism, pulmonary embolism, myocardial infarction, stroke, and major bleed; initial anticoagulant prescribed; and whether or not anticoagulation was prescribed for another disease state.

Results

A total of 130 patients met inclusion criteria: 70.8% (n = 92) and 29.2% (n = 38) were prescribed lenalidomide and pomalidomide, respectively. A total risk score of two was most common (n = 54, 41.5%). Aspirin 81 mg oral tablet was prescribed most often (n = 53, 40.8%), followed by no anticoagulation (n = 30, 23.1%). Overall, 27 patients (20.8%) were prescribed anticoagulation in accordance with National Comprehensive Cancer Network guidelines. Incidence of deep venous thromboembolism was the most common adverse event (n = 4, 3.1%), followed by major bleed (n = 1, 0.8%). No reports of pulmonary embolism, myocardial infarction, or stroke were documented.

Conclusions

Overall, a disparity exists between appropriate prescribing of prophylactic anticoagulation and current practice guidelines. However, documentation of thromboembolic events was lower than recorded in previously published literature.

Abstract P5-05-03: Obesity drives breast cancer progression through estrogen dependent and independent mechanisms

Background: More than 200,000 women are diagnosed with breast cancer each year and 75% develop estrogen receptor positive (ER+) tumors. Obesity is an independent risk factor for the development of ER+ breast cancer, particularly after menopause, and affects 40% of US women. Obese women are more likely to be diagnosed with advanced tumors, lymph node involvement, and less likely to respond to endocrine therapy versus lean women. Mechanisms underlying the increased risk and worse prognosis of obese women are poorly understood. The dogma in the field states that estrogen production is the main contributor to obesity-associated ER+ breast cancer. We show that this is not always the case. Given the epidemic proportions of obesity in the US, we need better pre-clinical models that will inform focused clinical trials and interventions for patients. In this study, we describe a novel mouse model of obesity and ER+ breast cancer patient-derived xenografts (PDX). Our studies highlight the heterogeneity of responses within the ER+ breast cancer subtype to the obese environment and implicate both estrogen-dependent and independent mechanisms of obesity-associated tumor progression.

Methods: ER+, FGFR1-amplified or non-amplified human tumors were established in ovariectomized lean and obese mice in the presence of high or low estradiol (E2). To simulate the hormonal environment of women on aromatase inhibitors, E2 was removed from half of the mice in each adiposity group and the study was terminated 3 weeks later. Weight gain, body fat percentage, and adipose tissue as well as tumor characteristics were analyzed.

Results: Prior to EWD, obese mice were heavier and had higher body fat percentage than lean mice and also displayed a phenotype of metabolic dysfunction. This trend was accelerated after EWD, with obese mice gaining more weight due to body fat accumulation. Tumors responded in one of two ways: Regardless of FGFR1 amplification, obesity promoted ER+ tumor growth in the presence of low (postmenopausal), but not high (premenopausal) E2. In the presence of low E2, tumor PR levels were higher in obese compared to lean mice, suggesting hyperactive ER signaling. In FGFR1-amplified tumors, obesity promoted tumor growth after EWD. In addition, EWD induced excess fat deposition in visceral depots in both lean and obese mice; however, obese mice also gained fat in mammary adipose depots. Mammary fat pad mass and rate of post-EWD weight gain directly correlated with adipose FGF1 levels. Tumors from obese mice had higher levels of phosphorylated FGFR1, without changes in total FGFR1, compared to lean mice.

Conclusions: Utilizing a unique PDX model system, we show that obesity promotes tumor progression in the presence of low E2, and also after EWD, and identify growth factor receptor signaling as a mediator of these phenotypes. The activation of FGFR1 may underlie increased breast cancer risk and recurrence observed in obese, postmenopausal women.

Citation Format: Wellberg EA, Johnson SJ, Jacobsen BM, Anderson SM, Sartorius CA, MacLean PS, Kabos P. Obesity drives breast cancer progression through estrogen dependent and independent mechanisms [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-05-03.

Vorapaxar: The Current Role and Future Directions of a Novel Protease-Activated Receptor Antagonist for Risk Reduction in Atherosclerotic Disease

Introduction

Despite the current standard of care, patients with cardiovascular disease remain at a high risk for recurrent events. Inhibition of thrombin-mediated platelet activation through protease-activated receptor-1 antagonism may provide reductions in atherosclerotic disease beyond those achievable with the current standard of care.

Objective

Our primary objective is to evaluate the clinical literature regarding the role of vorapaxar (Zontivity™) in the reduction of cardiovascular events in patients with a history of myocardial infarction and peripheral artery disease. In particular, we focus on the potential future directions for protease-activating receptor antagonists in the treatment of a broad range of atherosclerotic diseases.

Data Sources

A literature search of PubMed and EBSCO was conducted to identify randomized clinical trials from August 2005 to June 2016 using the search terms: ‘vorapaxar’, ‘SCH 530348’, ‘protease-activated receptor-1 antagonist’, and ‘Zontivity™’. Bibliographies were searched and additional resources were obtained.

Results

Vorapaxar is a first-in-class, protease-activated receptor-1 antagonist. The Thrombin Receptor Antagonist for Clinical Event Reduction (TRACER) trial did not demonstrate a significant reduction in a broad primary composite endpoint. However, the Thrombin-Receptor Antagonist in Secondary Prevention of Atherothrombotic Ischemic Events (TRA 2°P-TIMI 50) trial examined a more traditional composite endpoint and found a significant benefit with vorapaxar. Vorapaxar significantly increased bleeding compared with standard care. Ongoing trials will help define the role of vorapaxar in patients with peripheral arterial disease, patients with diabetes mellitus, and other important subgroups. The use of multivariate modeling may enable the identification of subgroups with maximal benefit and minimal harm from vorapaxar.

Conclusion

Vorapaxar provides clinicians with a novel mechanism of action to further reduce the burden of ischemic heart disease. Identification of patients with a high ischemic risk and low bleeding risk would enable clinicians to maximize the utility of this unique agent.

Electronic supplementary material

The online version of this article (doi:10.1007/s40268-016-0158-4) contains supplementary material, which is available to authorized users.

Experiences of adolescent lung transplant recipients: A qualitative study

Many young transplant recipients experience psychological distress and adjustment difficulties, yet there is little research investigating lung transplantation from the recipients' perspective. This qualitative study aimed to explore experiences of young people who underwent lung transplantation. Semi-structured interviews were conducted with six lung transplant recipients (aged 15-18). Interviews were analysed using IPA, a qualitative research approach examining how people make sense of their major life experiences. The analysis revealed three master themes: "Living with Dodgy Lungs" outlined how participants dealt with their experiences, managing through accepting or discussing their feelings with others, although talking was often difficult. "The Big Deal" reflected participants' experiences of the process, their expectations, and the contrast of their lives pre- and post-transplant. Inherent in their accounts was the profound meaning ascribed to transplantation, the emotional turmoil, and impact on their lives. "A Sense of Self" illustrated participants' developing identities within their social contexts and at times isolating experiences. The results highlight key areas where adolescent lung transplant recipients could be supported by clinicians, enabling the promotion of psychological well-being. Examples include supporting identity integration post-transplant, facilitating social inclusion, considering alternative means of support, and involving adolescents in healthcare decisions.

Divergent lactate dehydrogenase isoenzyme profile in cellular compartments of primate forebrain structures

The compartmentalization and association of lactate dehydrogenase (LDH) with specific cellular structures (e.g., synaptosomal, sarcoplasmic or mitochondrial) may play an important role in brain energy metabolism. Our previous research revealed that LDH in the synaptosomal fraction shifts toward the aerobic isoforms (LDH-B) among the large-brained haplorhine primates compared to strepsirrhines. Here, we further analyzed the subcellular localization of LDH in primate forebrain structures using quantitative Western blotting and ELISA. We show that, in cytosolic and mitochondrial subfractions, LDH-B expression level was relatively elevated and LDH-A declined in haplorhines compared to strepsirrhines. LDH-B expression in mitochondrial fractions of the neocortex was preferentially increased, showing a particularly significant rise in the ratio of LDH-B to LDH-A in chimpanzees and humans. We also found a significant correlation between the protein levels of LDH-B in mitochondrial fractions from haplorhine neocortex and the synaptosomal LDH-B that suggests LDH isoforms shift from a predominance of A-subunits toward B-subunits as part of a system that spatially buffers dynamic energy requirements of brain cells. Our results indicate that there is differential subcellular compartmentalization of LDH isoenzymes that evolved among different primate lineages to meet the energy requirements in neocortical and striatal cells.

Abstract P4-06-07: Fibroblast growth factor receptor activation and breast tumor progression in a mouse xenograft model of obesity

This abstract was withdrawn by the authors.

A highly prevalent equine glycogen storage disease is explained by constitutive activation of a mutant glycogen synthase

BACKGROUND

Equine type 1 polysaccharide storage myopathy (PSSM1) is associated with a missense mutation (R309H) in the glycogen synthase (GYS1) gene, enhanced glycogen synthase (GS) activity and excessive glycogen and amylopectate inclusions in muscle.

METHODS

Equine muscle biochemical and recombinant enzyme kinetic assays in vitro and homology modelling in silico, were used to investigate the hypothesis that higher GS activity in affected horse muscle is caused by higher GS expression, dysregulation, or constitutive activation via a conformational change.

RESULTS

PSSM1-affected horse muscle had significantly higher glycogen content than control horse muscle despite no difference in GS expression. GS activity was significantly higher in muscle from homozygous mutants than from heterozygote and control horses, in the absence and presence of the allosteric regulator, glucose 6 phosphate (G6P). Muscle from homozygous mutant horses also had significantly increased GS phosphorylation at sites 2+2a and significantly higher AMPKα1 (an upstream kinase) expression than controls, likely reflecting a physiological attempt to reduce GS enzyme activity. Recombinant mutant GS was highly active with a considerably lower K_m for UDP-glucose, in the presence and absence of G6P, when compared to wild type GS, and despite its phosphorylation.

CONCLUSIONS

Elevated activity of the mutant enzyme is associated with ineffective regulation via phosphorylation rendering it constitutively active. Modelling suggested that the mutation disrupts a salt bridge that normally stabilises the basal state, shifting the equilibrium to the enzyme's active state.

GENERAL SIGNIFICANCE

This study explains the gain of function pathogenesis in this highly prevalent polyglucosan myopathy.

Anxiolytic-like and anxiogenic-like effects of nicotine are regulated via diverse action at β2*nicotinic acetylcholine receptors

BACKGROUND AND PURPOSE

Nicotine dose-dependently activates or preferentially desensitizes β2 subunit containing nicotinic ACh receptors (β2*nAChRs). Genetic and pharmacological manipulations assessed effects of stimulation versus inhibition of β2*nAChRs on nicotine-associated anxiety-like phenotype.

EXPERIMENTAL APPROACH

Using a range of doses of nicotine in β2*nAChR subunit null mutant mice (β2KO; backcrossed to C57BL/6J) and their wild-type (WT) littermates, administration of the selective β2*nAChR agonist, 5I-A85380, and the selective β2*nAChR antagonist dihydro-β-erythroidine (DHβE), we determined the behavioural effects of stimulation and inhibition of β2*nAChRs in the light-dark and elevated plus maze (EPM) assays.

KEY RESULTS

Low-dose i.p. nicotine (0.05 mg·kg(-) 1) supported anxiolysis-like behaviour independent of genotype whereas the highest dose (0.5 mg·kg(-1) ) promoted anxiogenic-like phenotype in WT mice, but was blunted in β2KO mice for the measure of latency. Administration of 5I-A85380 had similar dose-dependent effects in C57BL/6J WT mice; 0.001 mg·kg(-1) 5I-A85380 reduced anxiety on an EPM, whereas 0.032 mg·kg(-1) 5I-A85380 promoted anxiogenic-like behaviour in both the light-dark and EPM assays. DHβE pretreatment blocked anxiogenic-like effects of 0.5 mg·kg(-1) nicotine. Similarly to DHβE, pretreatment with low-dose 0.05 mg·kg(-1) nicotine did not accumulate with 0.5 mg·kg(-1) nicotine, but rather blocked anxiogenic-like effects of high-dose nicotine in the light-dark and EPM assays.

CONCLUSIONS AND IMPLICATIONS

These studies provide direct evidence that low-dose nicotine inhibits nAChRs and demonstrate that inhibition or stimulation of β2*nAChRs supports the corresponding anxiolytic-like or anxiogenic-like effects of nicotine. Inhibition of β2*nAChRs may relieve anxiety in smokers and non-smokers alike.

Synaptosomal lactate dehydrogenase isoenzyme composition is shifted toward aerobic forms in primate brain evolution

With the evolution of a relatively large brain size in haplorhine primates (i.e. tarsiers, monkeys, apes, and humans), there have been associated changes in the molecular machinery that delivers energy to the neocortex. Here we investigated variation in lactate dehydrogenase (LDH) expression and isoenzyme composition of the neocortex and striatum in primates using quantitative Western blotting and isoenzyme analysis of total homogenates and synaptosomal fractions. Analysis of isoform expression revealed that LDH in synaptosomal fractions from both forebrain regions shifted towards a predominance of the heart-type, aerobic isoform LDH-B among haplorhines as compared to strepsirrhines (i.e. lorises and lemurs), while in the total homogenate of the neocortex and striatum there was no significant difference in LDH isoenzyme composition between the primate suborders. The largest increase occurred in synapse-associated LDH-B expression in the neocortex, with an especially remarkable elevation in the ratio of LDH-B/LDH-A in humans. The phylogenetic variation in the ratio of LDH-B/LDH-A was correlated with species-typical brain mass but not the encephalization quotient. A significant LDH-B increase in the subneuronal fraction from haplorhine neocortex and striatum suggests a relatively higher rate of aerobic glycolysis that is linked to synaptosomal mitochondrial metabolism. Our results indicate that there is a differential composition of LDH isoenzymes and metabolism in synaptic terminals that evolved in primates to meet increased energy requirements in association with brain enlargement.

Relational trauma: using play therapy to treat a disrupted attachment

Caregiver-child attachment results in a cognitive-emotional schema of self, other, and self-other relationships. Significantly disrupted attachments may lead to pathogenic internal working models, which may have deleterious consequences; this indicates the need for early attachment intervention. The authors consider the therapy of a 3-year-old boy with aggressive behaviors who had lacked consistent caregiving. Attachment theory can account for the child's psychotherapeutic gains, despite his insecure attachment style. The authors discuss discrepancies between treatment and current research trends.

Coat color genotypes and risk and severity of melanoma in gray quarter horses

BACKGROUND

Both graying and melanoma formation in horses have recently been linked to a duplication in the STX17 gene. This duplication, as well as a mutation in the ASIP gene that increases MC1R pathway signaling, affects melanoma risk and severity in gray horses.

OBJECTIVE

To determine if melanoma susceptibility in gray Quarter Horses (QH) is lower than gray horses from other breeds because of decreased MC1R signaling resulting from a high incidence of the MC1R chestnut coat color allele in the QH population.

ANIMALS

A total of 335 gray QH with and without dermal melanomas.

METHODS

Blood or hair root samples were collected from all horses for DNA extraction and genotyping for STX17, ASIP, and MC1R genotypes. Age, sex, and external melanoma presence and grade were recorded. The effect of age and genotype on melanoma presence and severity was evaluated by candidate gene association.

RESULTS

Melanoma prevalence (16%) and grade (0.35) in this QH cohort was lower than that reported in other breeds. Age was significantly associated with melanoma prevalence (P = 5.28 × 10(-11)) and severity (P = 2.2 × 10(-13)). No significant effect of MC1R genotype on melanoma prevalence or severity was identified. An effect of ASIP genotype on melanoma risk was not detected. Low STX17 homozygosity precluded evaluation of the gray allele effect.

CONCLUSION AND CLINICAL IMPORTANCE

Melanoma prevalence and severity is lower in this population of gray QH than what is reported in other breeds. This could be because of the infrequent STX17 homozygosity, a mitigating effect of the MC1R mutation on ASIP potentiation of melanoma, other genes in the MC1R signaling pathway, or differences in breed genetic background.

Abstract P5-10-04: Metformin mediated upregulation of microRNA-193 triggers apoptosis by decreasing fatty acid synthase

Background: We have previously shown that the anti-diabetic drug metformin kills triple negative (TN) breast cancer cells lines via apoptosis, at lower IC50 than luminal and HER2 subtypes (presented at ENDO, manuscript in preparation). Metformin reportedly shows greater efficacy against stem cells than differentiated cells, reducing mammosphere formation in in non-adherent culture. Fatty acid synthase (FASN) is an enzyme critical for de novo fatty acid synthesis that is overexpressed in breast cancer.

Hypothesis: We hypothesized that miRNAs might be involved in the ability of metformin to preferentially kill TN cell lines at a lower IC50 than luminal A lines.

Methods: TN and luminal A (LA) breast cancer cell lines (MDA-468, HCC70 and MCF7, T47D, respectively) were used to study the effects of 10mM metformin action in vitro, at physiological and hyperglycemic culture conditions. Affymetrix chips Human Gene 1.1 and the miRNA 2.0 were utilized to profile gene and miRNA expression at 6 and 24 hrs. Mimics and lentiviral expression vectors were utilized to manipulate miRNA expression and a luciferase reporter was used to confirm miR-193 direct targeting of the FASN 3′ UTR.

Results: miR-193 is significantly higher in untreated LA as compared to TN cells. MiR-193 increases 2–4 fold within 6 hrs of metformin treatment in both TN, but not LA cell lines. A predicted target of miR-193, fatty acid synthase (FASN), is decreased by 8 fold following 24 hrs 10mM metformin treatment of the TN breast cancer cells. miR-193 directly targets FASN via a binding site in the 3′ UTR, downregulating gene expression. Restoration of miR-193 to TN lines, causes a dramatic decrease in FASN protein in a dose dependent fashion.

Conclusions and future directions: Metformin stimulates an increase in mature miR-193, which mediates the dramatic downregulation of FASN. This occurs coincident with apoptotic cell death. It remains to be determined if FASN is the only relevant direct target of miR-193 in TN cell lines. The addition of exogenous non-targetable FASN, lacking its 3′ UTR, will demonstrate whether this pathway is a primary mechanism of metformin action in TN cells. Future studies will investigate the ability of metformin to inhibit FASN in non-adherent mammosphere (stem cell-like) subpopulations, the role of fatty acid metabolism in mammosphere maintenance and anoikis resistance.

Supported by Komen Breast Cancer Foundation Grants KG100575 (ADT, JKR, SME, NSS) and KG090415 (JKR, DRC)

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-10-04.

Neuropil distribution in the cerebral cortex differs between humans and chimpanzees

Increased connectivity of high-order association regions in the neocortex has been proposed as a defining feature of human brain evolution. At present, however, there are limited comparative data to examine this claim fully. We tested the hypothesis that the distribution of neuropil across areas of the neocortex of humans differs from that of one of our closest living relatives, the common chimpanzee. The neuropil provides a proxy measure of total connectivity within a local region because it is composed mostly of dendrites, axons, and synapses. Using image analysis techniques, we quantified the neuropil fraction from both hemispheres in six cytoarchitectonically defined regions including frontopolar cortex (area 10), Broca's area (area 45), frontoinsular cortex (area FI), primary motor cortex (area 4), primary auditory cortex (area 41/42), and the planum temporale (area 22). Our results demonstrate that humans exhibit a unique distribution of neuropil in the neocortex compared to chimpanzees. In particular, the human frontopolar cortex and the frontoinsular cortex had a significantly higher neuropil fraction than the other areas. In chimpanzees these prefrontal regions did not display significantly more neuropil, but the primary auditory cortex had a lower neuropil fraction than other areas. Our results support the conclusion that enhanced connectivity in the prefrontal cortex accompanied the evolution of the human brain. These species differences in neuropil distribution may offer insight into the neural basis of human cognition, reflecting enhancement of the integrative capacity of the prefrontal cortex.

Muscle microvascular recruitment predicts insulin sensitivity in middle-aged patients with type 1 diabetes mellitus

AIMS/HYPOTHESIS

Insulin delivery to muscle is rate-limiting for insulin's metabolic action and is regulated by insulin's own action to increase skeletal muscle blood flow and to recruit microvasculature. Microvascular dysfunction has been observed in insulin resistant states. We investigated the relation between insulin's action to recruit microvasculature and its metabolic action in type 1 diabetes.

METHODS

Near euglycaemia was obtained by an overnight insulin infusion during 17 inpatient admissions of participants with type 1 diabetes. This was followed by a 2 h 1 mU kg⁻¹ min⁻¹ euglycaemic-hyperinsulinaemic clamp. Microvascular blood volume (MBV) was assessed using contrast-enhanced ultrasound 10 min before and 30 min after starting the clamp.

RESULTS

We observed that, after overnight modest hyperinsulinaemia (average ≈ 286 pmol/l), MBV was positively related to the steady-state insulin sensitivity measured during the subsequent clamp (r = 0.62, p = 0.008). The more marked hyperinsulinaemia during the clamp (average steady-state insulin ≈ 900 pmol/l) increased MBV in the more insulin resistant participants within 30 min but not in the insulin sensitive participants. The change in MBV during the clamp was negatively correlated to the insulin sensitivity (r = -0.55, p = 0.022). As a result, MBV after 30 min of marked hyperinsulinaemia was comparable between the insulin sensitive and resistant participants.

CONCLUSIONS/INTERPRETATION

We conclude that moderate overnight hyperinsulinaemia recruited microvasculature in the more sensitive participants, while higher levels of plasma insulin were needed for more insulin resistant participants. This suggests that microvascular responsiveness to insulin is one determinant of metabolic insulin sensitivity in type 1 diabetes.

Loss of PKCδ results in characteristics of Sjögren's syndrome including salivary gland dysfunction

OBJECTIVES

Chronic infiltration of lymphocytes into the salivary and lacrimal glands of patients with Sjögren's syndrome (SS) leads to destruction of acinar cells and loss of exocrine function. Protein kinase C-delta (PKCδ) is known to play a critical role in B-cell maintenance. Mice in which the PKCδ gene has been disrupted have a loss of B-cell tolerance, multiple organ lymphocytic infiltration, and altered apoptosis. To determine whether PKCδ contributes to the pathogenesis of SS, we quantified changes in indicators of SS in PKCδ-/- mice as a function of age. Salivary gland histology, function, the presence of autoantibodies, and cytokine expression were examined.

MATERIALS AND METHODS

Submandibular glands were examined for the presence of lymphocytic infiltrates, and the type of infiltrating lymphocyte and cytokine deposition was evaluated by immunohistochemistry. Serum samples were tested by autoantibody screening, which was graded by its staining pattern and intensity. Salivary gland function was determined by saliva collection at various ages.

RESULTS

PKCδ-/- mice have reduced salivary gland function, B220+ B-cell infiltration, anti-nuclear antibody production, and elevated IFN-γ in the salivary glands as compared to PKCδ+/+ littermates.

CONCLUSIONS

PKCδ-/- mice have exocrine gland tissue damage indicative of a SS-like phenotype.

Loss of protein kinase C delta alters mammary gland development and apoptosis

As apoptotic pathways are commonly deregulated in breast cancer, exploring how mammary gland cell death is regulated is critical for understanding human disease. We show that primary mammary epithelial cells from protein kinase C delta (PKCδ) −/− mice have a suppressed response to apoptotic agents in vitro. In the mammary gland in vivo, apoptosis is critical for ductal morphogenesis during puberty and involution following lactation. We have explored mammary gland development in the PKCδ −/− mouse during these two critical windows. Branching morphogenesis was altered in 4- to 6-week-old PKCδ −/− mice as indicated by reduced ductal branching; however, apoptosis and proliferation in the terminal end buds was unaltered. Conversely, activation of caspase-3 during involution was delayed in PKCδ −/− mice, but involution proceeded normally. The thymus also undergoes apoptosis in response to physiological signals. A dramatic suppression of caspase-3 activation was observed in the thymus of PKCδ −/− mice treated with irradiation, but not mice treated with dexamethasone, suggesting that there are both target- and tissue-dependent differences in the execution of apoptotic pathways in vivo. These findings highlight a role for PKCδ in both apoptotic and nonapoptotic processes in the mammary gland and underscore the redundancy of apoptotic pathways in vivo.

Rechargeable wireless EMG sensor for prosthetic control

Surface electrodes in modern myoelectric prosthetics are often embedded in the prosthesis socket and make contact with the skin. These electrodes detect and amplify muscle action potentials from voluntary contractions of the muscle in the residual limb and are used to control the prosthetic's movement and function. There are a number of performance-related deficiencies associated with external electrodes including the maintenance of sufficient electromyogram (EMG) signal amplitude, extraneous noise acquisition, and proper electrode interface maintenance that are expected to be improved or eliminated using the proposed implanted sensors. This research seeks to investigate the design components for replacing external electrodes with fully-implantable myoelectric sensors that include a wireless interface to the prosthetic limbs. This implanted technology will allow prosthetic limb manufacturers to provide products with increased performance, capability, and patient-comfort. The EMG signals from the intramuscular recording electrode are amplified and wirelessly transmitted to a receiver in the prosthetic limb. Power to the implant is maintained using a rechargeable battery and an inductive energy transfer link from the prosthetic. A full experimental system was developed to demonstrate that a wireless biopotential sensor can be designed that meets the requirements of size, power, and performance for implantation.

The effect of dietary calcium on 1,25(OH)2D3 synthesis and sparing of serum 25(OH)D3 levels

Vitamin D depletion in rats causes osteopenia in at least three skeletal sites. However it is unclear whether modulation of dietary calcium intake impacts on the relationship between the level of serum 25-hydroxyvitamin D (25D) and bone loss. Nine-month-old female Sprague-Dawley rats (n=5-6/group) were pair-fed a semi-synthetic diet containing either 0 or 20 IU vitamin D3/day with either low (0.1%) or high (1%) dietary Ca for 6 months. At 15 months of age, fasting bloods were collected for biochemical analyses. Serum 25D levels were lowest in the animals fed 0 IU vitamin D and 0.1% Ca. The animals fed 1% Ca had significantly higher serum 25D levels when compared to animals fed 0.1% Ca (P<0.05). The major determinants of serum 25D were dietary vitamin D and dietary calcium (Multiple R=0.75, P<0.05). Animals fed 0.1% Ca had higher renal CYP27B1 mRNA expression and 12-18-fold increased levels of serum 1,25D. Hence, the reported effects of low calcium diets on bone loss may be, in part, due to the subsequent effects of 25D metabolism leading to reduction in vitamin D status. Such an interaction has significant implications, given the recent evidence for local synthesis of active vitamin D in bone tissue.

System to improve AED resuscitation using interactive CPR coaching

A positive impact on cardiac arrest survival has been demonstrated with the substantial reduction in time to defibrillation provided by the widespread deployment of automated external defibrillators (AEDs). However, recent studies have identified the importance of performing chest compressions before defibrillation in facilitating effective recovery from long duration ventricular fibrillation (VF). Despite the importance of cardiopulmonary resuscitation (CPR), effective performance of it in the field is hampered by many problems including the dependence on rescuer technique, which is known to be variable even with trained professionals. This research seeks to enhance survival outcomes following resuscitation. A full experimental system was developed that used an instrumented CPR manikin to provide interactive CPR coaching while collecting performance data. This system was utilized in a controlled human CPR performance study comparing the differences in chest compression performance with and without visual coaching and with and without interactive performance feedback coaching. Results from the human study support a number of conclusions and recommendations. In general using any type of coaching provided improvements in all of the CPR performance measures excluding chest recoil where there was a slight decrease in performance. The statistical results also indicated that the audio/visual coaching conditions provided a more effective coaching condition with respect to chest compression rate. Most notably, the feedback conditions both provided a statistically significant or trends toward improving chest compression effectiveness and produced superior performance as a whole.

Cocaine-induced alterations in dopamine receptor signaling: Implications for reinforcement and reinstatement

The transition from casual drug use to addiction, and the intense drug craving that accompanies it, has been postulated to result from neuroadaptations within the limbic system caused by repeated drug exposure. This review will examine the implications of cocaine-induced alterations in mesolimbic dopamine receptor signaling within the context of several widely used animal models of addiction. Extensive evidence indicates that dopaminergic mechanisms critically mediate behavioral sensitization to cocaine, cocaine-induced conditioned place preference, cocaine self-administration, and the drug prime-induced reinstatement of cocaine-seeking behavior. The propagation of the long-term neuronal changes associated with recurring cocaine use appears to occur at the level of postreceptor signal transduction. Repeated cocaine treatment causes an up-regulation of the 3',5'-cyclic adenosine monophosphate (cAMP)-signaling pathway within the nucleus accumbens, resulting in a dys-regulation of balanced D1/D2 dopamine-like receptor signaling. The intracellular events arising from enhanced D1-like postsynaptic signaling mediate both facilitatory and compensatory responses to the further reinforcing effects of cocaine.

CT colonography: determination of optimal CT technique using a novel colon phantom

The aim of this study was to determine the thickest slice at the lowest radiation dose for detection of colon polyps larger than 5mm in diameter at computed tomographic (CT) colonography. A colon phantom containing haustral folds, flexures, and straight segments was constructed of borosilicate. One hundred forty simulated polyps (5, 7, 10, and 12 mm) of various shapes (sessile, flat, and pedunculated) were attached at different colon locations (wall, base of fold, on the fold and fold tip). Polyps were positioned parallel, perpendicular, and oblique to the CT gantry. The air-filled phantom was scanned at different slice thicknesses (1.25-5 mm) and x-ray tube currents (5-308 mA). All polyps were identified in all data sets except one (1.25 mm slice thickness, 5 mA). In this acquisition, image noise reduced polyp visibility, and five of 140 (3%) polyps could not be identified. Unidentified polyps were 5 mm, flat or sessile in shape, located on the colon wall or base of the fold, and oblique or parallel to CT gantry. All tested CT techniques provided optimal polyp detection except settings at 1.25 mm and 5 mAs. Thin collimation (<5 mm) scans may not be necessary to detect clinically significant polyps.

N-ViroTech--a novel process for the treatment of nutrient limited wastewaters

As pulp and paper wastewaters are mostly deficient in nitrogen and phosphorus, historical practice has dictated that they cannot be effectively treated using microbiological processes without the addition of supplementary nutrients, such as urea and phosphoric acid. Supplementation is a difficult step to manage efficiently, requiring extensive post-treatment monitoring and some degree of overdosing to ensure sufficient nutrient availability under all conditions. As a result, treated wastewaters usually contain excess amounts of both nutrients, leading to potential impacts on the receiving waters such as eutrophication. N-ViroTech is a highly effective alternative treatment technology which overcomes this nutrient deficiency/excess paradox. The process relies on communities of nitrogen-fixing bacteria, which are able to directly fix nitrogen from the atmosphere, thus satisfying their cellular nitrogen requirements. The process relies on manipulation of growth conditions within the biological system to maintain a nitrogen-fixing population whilst achieving target wastewater treatment performance. The technology has significant advantages over conventional activated sludge operation, including: Improved environmental performance. Nutrient loadings in the final treated effluent for selected nitrogen and phosphorus species (particularly ammonium and orthophosphate) may be reduced by over 90% compared to conventional systems; Elimination of nitrogen supplementation, and minimisation of phosphorus supplementation, thus achieving significant chemical savings and resulting in between 25% and 35% savings in operational costs for a typical system; Self-regulation of nutrient requirements, as the bacteria only use as much nitrogen as they require, allowing for substantially less operator intervention and monitoring. This paper will summarise critical performance outcomes of the N-ViroTech process utilising results from laboratory-, pilot-scale and recent alpha-adopter, full-scale trials.

DNA fragmentation in leukocytes following subacute low-dose nerve agent exposure

The objective of the present study was to determine levels of DNA fragmentation in blood leukocytes from guinea pigs by single-cell gel electrophoresis (comet assay) after exposure to the chemical warfare nerve agent (CWNA), soman, at doses ranging from 0.1 LD50 to 0.4 LD50, once per day for either 5 or 10 days. Post-exposure recovery periods ranged from 0 to 17 days. Leukocytes were imaged from each animal, and the images analyzed by computer. Data obtained for exposure to soman demonstrated significant increases in DNA fragmentation in circulating leukocytes in CWNA-treated guinea pigs compared with saline-injected control animals at all doses and time points examined. Notably, significantly increased DNA fragmentation was observed in leukocytes 17 days after cessation of soman exposure. Our findings demonstrate that leukocyte DNA fragmentation assays may provide a sensitive biomarker for low-dose CWNA exposure.

IL-3 induces apoptosis in a ras-transformed myeloid cell line

Growth factors promote cell survival and proliferation. Homeostasis is maintained by programmed cell death which occurs when the growth stimulus is withdrawn, in response to negative growth regulators such as interferons, TNF-alpha and CD95 ligand, or following differentiation. Although acutely-transforming oncogenes often overcome the need for growth factors, growth regulatory cytokines can influence proliferative responses of transformed cells. In this study we investigated the effects of IL-3 on the proliferative responses of parental bone marrow-derived 32D cells and cells transformed with ras and abl oncogenes. We show that treatment of ras-transformed 32D cells with IL-3 reduced proliferative responses and decreased colony-forming ability. These effects were exacerbated in the absence of serum and associated with inhibition of tyrosine kinase activity, down-regulation of RAS and MYC expression, and induction of apoptosis as indicated by DNA fragmentation. In contrast, treatment of parental 32D cells with IL-3, which is obligatory for cell survival and proliferation, increased tyrosine kinase activity, upregulated MYC and RAS expression and maintained DNA integrity. With abl-transformed cells, proliferation and colony-forming ability were also inhibited by IL-3. Tyrosine kinase activity and MYC expression were reduced, but early apoptosis was not evident. Calcium uptake however, was stimulated by IL-3 in both parental and oncogene-transformed cells. These results suggest that threshold levels of tyrosine kinase activity are necessary for cell survival and proliferation and that with ras-transformed cells, IL-3 treatment may result in this threshold being breached. We conclude that in some situations, growth-promoting cytokines can inhibit proliferation of transformed cells and induce cell death by apoptosis.

Synergistic suppression of apoptosis in salivary acinar cells by IGF1 and EGF

Tissue homeostasis requires balancing cell proliferation and programmed cell death. IGF1 significantly suppressed etoposide-induced apoptosis, measured by caspase 3 activation and quantitation of cellular subG(1) DNA content, in rat parotid salivary acinar cells (C5). Transduction of C5 cells with an adenovirus expressing a constitutively activated mutant of Akt-suppressed etoposide-induced apoptosis, whereas a kinase-inactive mutant of Akt suppressed the protective effect of IGF1. IGF1 also suppressed apoptosis induced by taxol and brefeldin A. EGF was unable to suppress apoptosis induced by etoposide, but was able to synergize with IGF1 to further suppress caspase 3 activation and DNA cleavage after etoposide treatment. The catalytic activity of Akt was significantly higher following stimulation with both growth factors compared to stimulation with IGF1 or EGF alone. These results suggest that a threshold of activated Akt is required for suppression of apoptosis and the cooperative action of growth factors in regulating salivary gland homeostasis.

Nitrogen fixation in the activated sludge treatment of thermomechanical pulping wastewater: effect of dissolved oxygen

N-ViroTech, a novel technology which selects for nitrogen-fixing bacteria as the bacteria primarily responsible for carbon removal, has been developed to treat nutrient limited wastewaters to a high quality without the addition of nitrogen, and only minimal addition of phosphorus. Selection of the operating dissolved oxygen level to maximise nitrogen fixation forms a key component of the technology. Pilot scale activated sludge treatment of a thermomechanical pulping wastewater was carried out in nitrogen-fixing mode over a 15 month period. The effect of dissolved oxygen was studied at three levels: 14% (Phase 1), 5% (Phase 2) and 30% (Phase 3). The plant was operated at an organic loading of 0.7-1.1 kg BOD5/m3/d, a solids retention time of approximately 10 d, a hydraulic retention time of 1.4 d and a F:M ratio of 0.17-0.23 mg BOD5/mg VSS/d. Treatment performance was very stable over the three dissolved oxygen operating levels. The plant achieved 94-96% BOD removal, 82-87% total COD removal, 79-87% soluble COD removal, and >99% total extractives removal. The lowest organic carbon removals were observed during operation at 30% DO but were more likely to be due to phosphorus limitation than operation at high dissolved oxygen, as there was a significant decrease in phosphorus entering the plant during Phase 3. Discharge of dissolved nitrogen, ammonium and oxidised nitrogen were consistently low (1.1-1.6 mg/L DKN, 0.1-0.2 mg/L NH4+-N and 0.0 mg/L oxidised nitrogen). Discharge of dissolved phosphorus was 2.8 mg/L, 0.1 mg/L and 0.6 mg/L DRP in Phases 1, 2 and 3 respectively. It was postulated that a population of polyphosphate accumulating bacteria developed during Phase 1. Operation at low dissolved oxygen during Phase 2 appeared to promote biological phosphorus uptake which may have been affected by raising the dissolved oxygen to 30% in Phase 3. Total nitrogen and phosphorus discharge was dependent on efficient secondary clarification, and improved over the course of the study as suspended solids discharge improved. Nitrogen fixation was demonstrated throughout the study using an acetylene reduction assay. Based on nitrogen balances around the plant, there was a 55, 354 and 98% increase in nitrogen during Phases 1, 2 and 3 respectively. There was a significant decrease in phosphorus between Phases 1 and 2, and Phase 3 of the study, as well as a significant increase in nitrogen between Phases 2 and 3 which masked the effect of changing the dissolved oxygen. Operation at low dissolved oxygen appeared to confer a competitive advantage to the nitrogen-fixing bacteria.

Impact of experimental blockade of peripheral growth hormone (GH) receptors on the kinetics of endogenous and exogenous GH removal in healthy women and men

Organs that respond to and metabolize GH are enriched in cognate high-affinity receptors. However, whether isologous receptors mediate the de facto access of ligand to cellular degradative pathways is not known. To address this query, we assessed the distribution and whole-body elimination kinetics of (endogenous and exogenous) GH before and after administration of a novel, potent, and selective recombinant human (rh) GH receptor antagonist peptide, pegvisomant. Sixteen healthy young adults (nine men and seven women) participated in a double-blind, prospectively randomized, within-subject cross-over study. The intervention comprised a single sc injection of placebo vs. a high dose of pegvisomant (1 mg/kg sc) timed 62 and 74 h before the overnight sampling and daytime infusion sessions, respectively. The half-life, metabolic clearance rate (MCR), and distribution volume of GH were quantitated by way of: 1) deconvolution analysis of serum GH concentration time series collected every 10 min for 10 h; 2) exponential regression analysis of the decay of GH concentrations after a 6-min iv pulse of rhGH (1 and 10 micro g/kg); 3) calculation of the MCR during constant iv infusion of rhGH (0.5 and 5.0 micro g/kg every 2 h); and 4) exponential fitting of the elimination time-course of GH concentrations following cessation of each constant infusion. Concentrations of GH and pegvisomant were measured in separate, noncross-reactive, two-site monoclonal, immunofluorometric assays. Pegvisomant concentrations averaged 4860 +/- 480 micro g/liter (+/-SEM) across the infusion interval, thus exceeding low steady state GH concentrations by 3000-fold. Inhibitory efficacy of the GH receptor antagonist peptide was affirmed by way of a 34% reduction in the serum total IGF-I concentration, i.e., from 257 +/- 37 (placebo) to 170 +/- 24 (drug) micro g/liter (P < 0.001); and a reciprocal 77% elevation of the (10-h) mean GH concentration, i.e., from 1.3 +/- 0.23 (placebo) to 2.3 +/- 0.42 (drug) micro g/liter (P = 0.003). ANOVA disclosed that prior administration of pegvisomant (compared with placebo) did not alter: 1) the calculated half-life (minutes) of secreted GH, which averaged 15 +/- 1.3 (placebo) and 14 +/- 0.69 (drug); 2) the half-time of disappearance (minutes) of an iv pulse of rhGH, 15 +/- 1.0 (placebo) and 13 +/- 0.5 (drug) (for the 10 micro g/kg dose); 3) the distribution volume (milliliters per kilogram) of rhGH, 59 +/- 6.2 (placebo) and 58 +/- 3.5 (drug); 4) the steady state GH concentration (micrograms per liter) attained during constant iv infusion of rhGH (at a rate of 5 micro g/kg every 2 h), 18.2 +/- 2.4 (placebo) and 18.3 +/- 2.3 (drug); 5) the half-life (minutes) of elimination of GH from equilibrium, 16 +/- 0.98 (placebo) and 16 +/- 1.8 (drug); and 6) the steady state MCR (liters per kilogram per day) of rhGH, 3.8 +/- 0.32 (placebo) and 3.5 +/- 0.31 (drug). In ensemble, the present data refute the a priori postulate that vascular-accessible GH receptors determine the in vivo pseudoequilibrium kinetics of GH disappearance in the human.