Fluid shear stress affects the metabolic and toxicological response of the rainbow trout gill cell line RTgill-W1.

The Rainbow trout gill cell-line (RTgill-W1) has been accepted by the Organisation for Economic Co-operation and Development (OECD TG249) as a replacement for fish in acute toxicity tests. In these tests cells are exposed under static conditions. In contrast, in vivo, water moves over fish gills generating fluid shear stress (FSS) that alters cell physiology and response to toxicants. The current study uses a specialised 3D printed chamber designed to house inserts and allows for the flow (0.2 dynes cm2) of water over the cells. This system was used to assess RTgill-W1 cell responses to FSS in the absence and presence of copper (Cu) over 24 h. FSS caused increased gene expression of mechanosensitive channel peizo1 and the Cu-transporter atp7a, elevated reactive oxygen species generation and increased expression of superoxidase dismutase. Cell metabolism was unaffected by Cu (0.163 µM to 2.6 µM Cu) under static conditions but significantly reduced by FSS + Cu above 1.3 µM. Differential expression of metallothionein (mt) a and b was observed with increased expression of mta under static conditions and mtb under FSS on exposure to Cu. These findings highlight toxicologically relevant mechanosensory responses by RTgill-W1 to FSS that may influence toxicological responses.

Proposal for Realizing Quantum Scars in the Tilted 1D Fermi-Hubbard Model.

Motivated by recent observations of ergodicity breaking due to Hilbert space fragmentation in 1D Fermi-Hubbard chains with a tilted potential [Scherg et al., arXiv:2010.12965], we show that the same system also hosts quantum many-body scars in a regime U≈Δ≫J at electronic filling factor ν=1. We numerically demonstrate that the scarring phenomenology in this model is similar to other known realizations such as Rydberg atom chains, including persistent dynamical revivals and ergodicity-breaking many-body eigenstates. At the same time, we show that the mechanism of scarring in the Fermi-Hubbard model is different from other examples in the literature: the scars originate from a subgraph, representing a free spin-1 paramagnet, which is weakly connected to the rest of the Hamiltonian's adjacency graph. Our work demonstrates that correlated fermions in tilted optical lattices provide a platform for understanding the interplay of many-body scarring and other forms of ergodicity breaking, such as localization and Hilbert space fragmentation.

Emergent SU(2) Dynamics and Perfect Quantum Many-Body Scars.

Motivated by recent experimental observations of coherent many-body revivals in a constrained Rydberg atom chain, we construct a weak quasilocal deformation of the Rydberg-blockaded Hamiltonian, which makes the revivals virtually perfect. Our analysis suggests the existence of an underlying nonintegrable Hamiltonian which supports an emergent SU(2)-spin dynamics within a small subspace of the many-body Hilbert space. We show that such perfect dynamics necessitates the existence of atypical, nonergodic energy eigenstates-quantum many-body scars. Furthermore, using these insights, we construct a toy model that hosts exact quantum many-body scars, providing an intuitive explanation of their origin. Our results offer specific routes to enhancing coherent many-body revivals and provide a step toward establishing the stability of quantum many-body scars in the thermodynamic limit.

Endothelium-derived fibronectin regulates neonatal vascular morphogenesis in an autocrine fashion.

Fibronectin containing alternatively spliced EIIIA and EIIIB domains is largely absent from mature quiescent vessels in adults, but is highly expressed around blood vessels during developmental and pathological angiogenesis. The precise functions of fibronectin and its splice variants during developmental angiogenesis however remain unclear due to the presence of cardiac, somitic, mesodermal and neural defects in existing global fibronectin KO mouse models. Using a rare family of surviving EIIIA EIIIB double KO mice, as well as inducible endothelial-specific fibronectin-deficient mutant mice, we show that vascular development in the neonatal retina is regulated in an autocrine manner by endothelium-derived fibronectin, and requires both EIIIA and EIIIB domains and the RGD-binding α5 and αv integrins for its function. Exogenous sources of fibronectin do not fully substitute for the autocrine function of endothelial fibronectin, demonstrating that fibronectins from different sources contribute differentially to specific aspects of angiogenesis.

Optimal free descriptions of many-body theories.

Interacting bosons or fermions give rise to some of the most fascinating phases of matter, including high-temperature superconductivity, the fractional quantum Hall effect, quantum spin liquids and Mott insulators. Although these systems are promising for technological applications, they also present conceptual challenges, as they require approaches beyond mean-field and perturbation theory. Here we develop a general framework for identifying the free theory that is closest to a given interacting model in terms of their ground-state correlations. Moreover, we quantify the distance between them using the entanglement spectrum. When this interaction distance is small, the optimal free theory provides an effective description of the low-energy physics of the interacting model. Our construction of the optimal free model is non-perturbative in nature; thus, it offers a theoretical framework for investigating strongly correlated systems.

Qualitative Evaluation of a Practice-based Experience Pilot Program for Master of Pharmacy Students in Scotland.

Objective. To determine the views of pharmacists in central Scotland regarding experiential education for MPharm students. Methods. A thematic analysis was completed by Ms. Gillian Hendry and Dr. Sally Wiggins of interviews conducted with ten practicing pharmacists paired with first-year master of pharmacy (MPharm) students during the 2011-2012 academic year. Relevant comments from the interviews were manually sorted in a Microsoft Excel spreadsheet to bring similarly themed material together to facilitate the identification and naming of recurring themes and subthemes. Results. The pharmacists were unanimous in their opinion that experiential education was valuable for MPharm students and, in particular, that it helped students to develop self-confidence. The pharmacists derived personal satisfaction in developing mentor/mentee relationships with students. They also recognized the value that students provided to the workforce as well as the educational value to themselves in supervising students. The participants' primary dissatisfaction was that the pharmacy workflow limited the time they could spend mentoring students. Conclusion. The results provide guidance to the academic community and the pharmacy practice community in the United Kingdom (UK) regarding the design and integration of experiential education courses in MPharm degree programs.

Description and Evaluation of an MPharm Practice-based Experience Pilot Program.

Objective. To determine the level of support among pharmacists in central Scotland to serve as mentors and provide practice-based experience to students enrolled in a master of pharmacy degree program. Methods. A study was conducted during the 2011-2012 academic year in which first-year MPharm students in Scotland were paired with practicing pharmacists for 2 half-day visits per month. The students were integrated into the pharmacy workflow and engaged in activities ranging from date checking to counseling patients. The pharmacists and students who participated were asked to complete a survey in spring 2012 regarding their experiences and, in addition, the students were asked to maintain diary entries describing their experiences. Results. Thirty-nine students were paired successfully with 38 pharmacists. Every pharmacist stated their student was welcome to return in the 2012-2013 academic year and 29 agreed to accept a second student. Nine of 12 participating chain community pharmacies asked for program expansion and 11 chain community pharmacies and one other community pharmacy that did not participate in 2011-2012 asked to join in 2012-2013. Conclusion. Large numbers of pharmacists in central Scotland are willing to mentor and provide practice-based pharmacy education for students in a manner consistent with General Pharmaceutical Council accreditation standards for the master of pharmacy degree curriculum.

Sustainability of a Practice-based Interprofessional Introductory Pharmacy Practice Experience Course.

OBJECTIVE: To describe a successfully sustained interprofessional introductory pharmacy practice experience (IPPE) in which third-year pharmacy students were paired with nonpharmacist practitioners. METHODS: Course data were retrospectively reviewed and analyzed to reveal details about the program. Provider participant numbers and student perception data were reviewed and reported on. RESULTS: The number of students and providers participating increased during the 13 years of the program. On average, preceptors participated for 3 years and hosted 4 pharmacy students. Students consistently agreed the course helped increase student communication competencies and integration into interdisciplinary practice (mean agreement of 88.4% and 91.6%, respectively). CONCLUSION: A required interprofessional IPPE course designed to develop students' self-confidence working and communicating with nonpharmacist practitioners has been successfully sustained for more than a decade. Students report improvements in self-confidence and achievement of the course's primary outcomes.

α5 and αv integrins cooperate to regulate vascular smooth muscle and neural crest functions in vivo.

The RGD-binding α5 and αv integrins have been shown to be key regulators of vascular smooth muscle cell (vSMC) function in vitro. However, their role on vSMCs during vascular development in vivo remains unclear. To address this issue, we have generated mice that lack α5, αv or both α5 and αv integrins on their vSMCs, using the SM22α-Cre transgenic mouse line. To our surprise, neither α5 nor αv mutants displayed any obvious vascular defects during embryonic development. By contrast, mice lacking both α5 and αv integrins developed interrupted aortic arches, large brachiocephalic/carotid artery aneurysms and cardiac septation defects, but developed extensive and apparently normal vasculature in the skin. Cardiovascular defects were also found, along with cleft palates and ectopically located thymi, in Wnt1-Cre α5/αv mutants, suggesting that α5 and αv cooperate on neural crest-derived cells to control the remodelling of the pharyngeal arches and the septation of the heart and outflow tract. Analysis of cultured α5/αv-deficient vSMCs suggests that this is achieved, at least in part, through proper assembly of RGD-containing extracellular matrix proteins and the correct incorporation and activation of latent TGF-ß.

Integrin-α5ß1 is not required for mural cell functions during development of blood vessels but is required for lymphatic-blood vessel separation and lymphovenous valve formation.

Integrin α5ß1 is essential for vascular development but it remains unclear precisely where and how it functions. Here, we report that deletion of the gene encoding the integrin-α5 subunit (Itga5) using the Pdgfrb-Cre transgenic mouse line, leads to oedema, haemorrhage and increased levels of embryonic lethality. Unexpectedly, these defects were not caused by loss of α5 from Pdgfrb-Cre expressing mural cells (pericytes and vascular smooth muscle cells), which wrap around the endothelium and stabilise blood vessels, nor by defects in the heart or great vessels, but were due to abnormal development of the lymphatic vasculature. Reminiscent of the pathologies seen in the human lymphatic malformation, fetal cystic hygroma, α5 mutants display defects both in the separation of their blood and lymphatic vasculature and in the formation of the lymphovenous valves. As a consequence, α5-deficient mice develop dilated, blood-filled lymphatic vessels and lymphatic capillaries that are ectopically covered with smooth muscle cells. Analysis of the expression of Pdgfrb during lymphatic development suggests that these defects probably arise from loss of α5ß1 integrin in subsets of specialised Prox1(+)Pdgfrb(+) venous endothelial cells that are essential for the separation of the jugular lymph sac from the cardinal vein and formation of the lymphovenous valve leaflets.

Ephrin-B2 controls PDGFRß internalization and signaling.

B-class ephrins, ligands for EphB receptor tyrosine kinases, are critical regulators of growth and patterning processes in many organs and species. In the endothelium of the developing vasculature, ephrin-B2 controls endothelial sprouting and proliferation, which has been linked to vascular endothelial growth factor (VEGF) receptor endocytosis and signaling. Ephrin-B2 also has essential roles in supporting mural cells (namely, pericytes and vascular smooth muscle cells [VSMCs]), but the underlying mechanism is not understood. Here, we show that ephrin-B2 controls platelet-derived growth factor receptor ß (PDGFRß) distribution in the VSMC plasma membrane, endocytosis, and signaling in a fashion that is highly distinct from its role in the endothelium. Absence of ephrin-B2 in cultured VSMCs led to the redistribution of PDGFRß from caveolin-positive to clathrin-associated membrane fractions, enhanced PDGF-B-induced PDGFRß internalization, and augmented downstream mitogen-activated protein (MAP) kinase and c-Jun N-terminal kinase (JNK) activation but impaired Tiam1-Rac1 signaling and proliferation. Accordingly, mutant mice lacking ephrin-B2 expression in vascular smooth muscle developed vessel wall defects and aortic aneurysms, which were associated with impaired Tiam1 expression and excessive activation of MAP kinase and JNK. Our results establish that ephrin-B2 is an important regulator of PDGFRß endocytosis and thereby acts as a molecular switch controlling the downstream signaling activity of this receptor in mural cells.

A three-year reflective writing program as part of introductory pharmacy practice experiences.

OBJECTIVES: To implement and evaluate a 3-year reflective writing program incorporated into introductory pharmacy practice experiences (IPPEs) in the first- through third-year of a doctor of pharmacy (PharmD) program. DESIGN: Reflective writing was integrated into 6 IPPE courses to develop students' lifelong learning skills. In their writing, students were required to self-assess their performance in patient care activities, identify and describe how they would incorporate learning opportunities, and then evaluate their progress. Practitioners, faculty members, and fourth-year PharmD students served as writing preceptors. ASSESSMENT: The success of the writing program was assessed by reviewing class performance and surveying writing preceptor's opinions regarding the student's achievement of program objectives. Class pass rates averaged greater than 99% over the 8 years of the program and the large majority of the writing preceptors reported that student learning objectives were met. A support pool of 99 writing preceptors was created. CONCLUSIONS: A 3-year reflective writing program improved pharmacy students' reflection and reflective writing skills.

NMR solution structure and condition-dependent oligomerization of the antimicrobial peptide human defensin 5.

Human defensin 5 (HD5) is a 32-residue host-defense peptide expressed in the gastrointestinal, reproductive, and urinary tracts that has antimicrobial activity. It exhibits six cysteine residues that are regiospecifically oxidized to form three disulfide bonds (Cys(3)-Cys(31), Cys(5)-Cys(20), and Cys(10)-Cys(30)) in the oxidized form (HD5(ox)). To probe the solution structure and oligomerization properties of HD5(ox), and select mutant peptides lacking one or more disulfide bonds, NMR solution studies and analytical ultracentrifugation experiments are reported in addition to in vitro peptide stability assays. The NMR solution structure of HD5(ox), solved at pH 4.0 in 90:10 H(2)O/D(2)O, is presented (PDB: 2LXZ ). Relaxation T(1)/T(2) measurements and the rotational correlation time (τ(c)) estimated from a (15)N-TRACT experiment demonstrate that HD5(ox) is dimeric under these experimental conditions. Exchange broadening of the Hα signals in the NMR spectra suggests that residues 19-21 (Val(19)-Cys(20)-Glu(21)) contribute to the dimer interface in solution. Exchange broadening is also observed for residues 7-14 comprising the loop. Sedimentation velocity and equilibrium studies conducted in buffered aqueous solution reveal that the oligomerization state of HD5(ox) is pH-dependent. Sedimentation coefficients of ca. 1.8 S and a molecular weight of 14 363 Da were determined for HD5(ox) at pH 7.0, supporting a tetrameric form ([HD5(ox)] ≥ 30 µM). At pH 2.0, a sedimentation coefficient of ca. 1.0 S and a molecular weight of 7079 Da, corresponding to a HD5(ox) dimer, were obtained. Millimolar concentrations of NaCl, CaCl(2), and MgCl(2) have a negligible effect on the HD5(ox) sedimentation coefficients in buffered aqueous solution at neutral pH. Removal of a single disulfide bond results in a loss of peptide fold and quaternary structure. These biophysical investigations highlight the dynamic and environmentally sensitive behavior of HD5(ox) in solution, and provide important insights into HD5(ox) structure/activity relationships and the requirements for antimicrobial action.

Further development of pharmacy student-facilitated diabetes management clinics.

OBJECTIVE: To further develop and evaluate a diabetes disease state management (DSM) program that provided direct patient care responsibilities to advanced pharmacy practice experience (APPE) students as members of healthcare teams. DESIGN: Nine new clinics and 3 established sites that provide self-care management education to patients with diabetes were established and maintained in rural Colorado pharmacies and supported by students in APPE training for 48 weeks per year. EVALUATION: The 12 clinics provided 120 APPE student placements in 2010-2011. Students' perceptions of their experiences were positive. Patients who completed the student-supported diabetes self-management education program had improvements in blood glucose, blood pressure, and lipid values. CONCLUSIONS: Twelve diabetes DSM clinics provided direct patient care opportunities to APPE students working as part of healthcare teams while expanding healthcare resources in underserved communities in Colorado.

Chemical shift anisotropy selective inversion.

Magic angle spinning (MAS) is used in solid-state NMR to remove the broadening effects of the chemical shift anisotropy (CSA). In this work we investigate a technique that can reintroduce the CSA in order to selectively invert transverse magnetization. The technique involves an amplitude sweep of the radio frequency field through a multiple of the spinning frequency. The selectivity of this inversion mechanism is determined by the size of the CSA. We develop a theoretical framework to describe this process and demonstrate the CSA selective inversion with numerical simulations and experimental data. We combine this approach with cross-polarization (CP) for potential applications in multi-dimensional MAS NMR.

Physician acceptance of pharmacotherapy recommendations made by pharmacy students in a rural pharmacy-based diabetes care and education clinic.

OBJECTIVE: To assess outcomes from a rural, community pharmacy-based diabetes care and education program involving collaboration between local pharmacists and physicians, fourth-year pharmacy students, and University of Colorado Denver School of Pharmacy faculty members. DESIGN: Fourth-year pharmacy students provided education and testing (hemoglobin A1c, blood glucose, blood pressure, and lipid profiles) to diabetes patients, once a month for 6 months. Clinical notes with medication recommendations were faxed to each patient's physician following each visit. ASSESSMENT: Twelve pharmacy students made 533 recommendations to 29 physicians for 52 patients over 18 months. Overall, 32% of the recommendations were accepted based on subsequent medication orders and patient reports. Three of the physicians accepted 50%-60% of the recommendations they received while 4 did not accept any recommendations. CONCLUSIONS: Physician acceptance of pharmacy students' medication recommendations for patients attending a rural community pharmacy-based diabetes management clinic varied. Further study is needed to determine the reasons for this.

In situ temperature-jump dynamic nuclear polarization: enhanced sensitivity in two dimensional 13C-13C correlation spectroscopy in solution.

Dynamic nuclear polarization is combined with temperature-jump methods to develop a new 2D 13C-13C NMR experiment that yields a factor of 100-170 increase in sensitivity. The polaization step is performed at 100 K, and the sample is subsequently melted with a 10.6 microm laser pulse to yield a sample with highly polarized 13C spins. 13C detected 2D 13C-13C spectroscopy is performed in the usual manner.

DNA oligonucleotides with A, T, G or C opposite an abasic site: structure and dynamics.

Abasic sites are common DNA lesions resulting from spontaneous depurination and excision of damaged nucleobases by DNA repair enzymes. However, the influence of the local sequence context on the structure of the abasic site and ultimately, its recognition and repair, remains elusive. In the present study, duplex DNAs with three different bases (G, C or T) opposite an abasic site have been synthesized in the same sequence context (5'-CCA AAG6 XA8C CGG G-3', where X denotes the abasic site) and characterized by 2D NMR spectroscopy. Studies on a duplex DNA with an A opposite the abasic site in the same sequence has recently been reported [Chen,J., Dupradeau,F.-Y., Case,D.A., Turner,C.J. and Stubbe,J. (2007) Nuclear magnetic resonance structural studies and molecular modeling of duplex DNA containing normal and 4'-oxidized abasic sites. Biochemistry, 46, 3096-3107]. Molecular modeling based on NMR-derived distance and dihedral angle restraints and molecular dynamics calculations have been applied to determine structural models and conformational flexibility of each duplex. The results indicate that all four duplexes adopt an overall B-form conformation with each unpaired base stacked between adjacent bases intrahelically. The conformation around the abasic site is more perturbed when the base opposite to the lesion is a pyrimidine (C or T) than a purine (G or A). In both the former cases, the neighboring base pairs (G6-C21 and A8-T19) are closer to each other than those in B-form DNA. Molecular dynamics simulations reveal that transient H-bond interactions between the unpaired pyrimidine (C20 or T20) and the base 3' to the abasic site play an important role in perturbing the local conformation. These results provide structural insight into the dynamics of abasic sites that are intrinsically modulated by the bases opposite the abasic site.

A strategy to develop advanced pharmacy practice experiences.

OBJECTIVE: To establish statewide medication, disease management, and other clinical programs to serve as advanced pharmacy practice experience (APPE) training sites for the University of Colorado at Denver and Health Sciences Center School of Pharmacy, and to guarantee year-round support for the programs by providing pharmacy students with the necessary competencies to carry a significant proportion of each program's workload. METHODS: Partnerships with pharmacies willing to use students to expand their scope of clinical practice or support existing programs were established. Partners were asked to choose the clinical program(s) they wished implemented or supported and were guaranteed that APPE students would contribute to carrying each program's clinical service workload for 48 week/year under the supervision of the partners' pharmacists. In addition, partners implementing new programs were offered other support, including equipment, supplies, and training and mentoring for their pharmacists. EVALUATION: Twenty-two partnerships involving anticoagulation, diabetes, immunization, medication reconciliation, and other clinical programs were established with hospital, community, and community health center pharmacies. The partnerships provided 213 APPE placements in the 2006-2007 academic year. CONCLUSION: This work demonstrates that by using innovative approaches, a pharmacy school can form new partnerships with hospital, community health center, and community pharmacies, as well as work with existing clinical programs, to create a variety of medication, disease management, and other APPEs to meet its increasing placement needs and evolving accreditation standards.

Regulation of angiogenesis by Eph-ephrin interactions.

The large families of Eph receptor tyrosine kinases and their ephrin ligands transduce signals in a cell-cell contact-dependent fashion and thereby coordinate the growth, differentiation, and patterning of almost every organ and tissue. Eph-ephrin interactions can trigger a wide array of cellular responses, including cell adhesion, boundary formation, and repulsion. The exact mechanisms leading to this diversity of responses are unclear but appear to involve differential signaling, proteolytic cleavage of ephrins, and endocytosis of the ligand-receptor complex. In the developing cardiovascular system, Eph and ephrin molecules control the angiogenic remodeling of blood vessels and lymphatic vessels and play essential roles in endothelial cells as well as in supporting pericytes and vascular smooth muscle cells. Recent evidence suggests that Ephs and ephrins may also be involved in pathological angiogenesis, in particular, the neovascularization of tumors. Consequently, the expression, interactions, or signaling of Eph-ephrin molecules might be targets for future therapeutic approaches.