Key considerations for developing an equitable faculty teaching workload.

PURPOSE: Faculty teaching workload has become a focus for many academic institutions given the increasing amount of faculty burnout and need for equitable distribution of effort. Many gaps exist in faculty workload guidance which contribute to decreased faculty productivity, lack of appropriate recognition, faculty burnout, and subsequently, retention of faculty. A task force was created to develop teaching workload guidance and to outline minimum teaching expectations at our school of pharmacy. DESCRIPTION: This manuscript highlights the need for clarity around the definition of roles of the contemporary educator and considerations when developing guidance around teaching workload expectations using the "What? So What? Now What?" reflection framework. ANALYSIS/INTERPRETATION: Teaching workload guidance first starts with establishing a definition of the contemporary roles of the educator. Challenges, considerations, and eight next steps are outlined that are critical to address before equitable teaching workload guidance is established. CONCLUSIONS: Teaching workload guidance should include transparency, clarity, credit, norms, context, and accountability. Additionally, solutions created to address the gaps in workload policies should be data driven. IMPLICATIONS: The current traditional system of evaluating faculty workload has many gaps due to forces driving change in pharmacy education. Roles of the pharmacy educator should be valued and recognized across all mission centric learning programs.

Defining contemporary roles of the pharmacy educator: The essential first step in developing equitable faculty teaching workload.

INTRODUCTION: Faculty workload policy has gained increased attention recently given the growing amount of faculty burnout leading to decreased productivity, worsened faculty morale, and impaired retention. Faculty are one of the most valuable resources of an academic institution; thus, it is essential that a clear picture of the "jobs to be done" are defined and valued. PERSPECTIVE: The approach of a task force charged with developing a teaching workload policy is described. Through this work, it was recognized that essential roles of the contemporary pharmacy educator have not been defined, resulting in workload policies that might only value and recognize "traditional" educator roles. This led the task force to evaluate the forces driving change in education and to identify the roles of faculty as educators. The stepwise approach used to define nine essential roles of contemporary pharmacy educators is described. IMPLICATIONS: Roles of the educator have become more complex, and traditional definitions of these roles do not recognize and value the multifaceted nature of the job to be done. Consideration of contemporary definitions of educator roles is a critical first step for developing workload policies. The new definition of educator roles will allow the academic institution to have more clarity around total teaching effort and recognize the value faculty provide the institution. We believe this is the essential first step for the Academy when developing teaching workload policies that are fair and equitable, while also understanding the overall faculty needs for executing their educational enterprise.

Development of a self-report instrument for measuring in-class student engagement reveals that pretending to engage is a significant unrecognized problem.

Student engagement during classes includes behavioural, cognitive and emotional components, and is a pre-requisite for successful active learning environments. A novel approach to measuring student engagement was developed, involving triangulation of real-time student-self report, observation by trained observers and heart rate measurement. The self-report instrument was evaluated in four separate cohorts (n = 123) at Monash University and the University of North Carolina. The six item self-report demonstrated good reliability (Cronbach's alpha values ranged from 0.7-0.81). The self-report showed predictive validity in that small group activities were rated as significantly more engaging than didactic lecturing. Additionally, there was significant inter-instructor variability and within-class variability, indicating good discrimination between classroom activities. This self-report may prove useful to academic teaching staff in evaluating and refining their active learning activities. Independent observation was not found to correlate with student self-report, due in part to students who were pretending to engage being rated as engaged by an observer. Strikingly, students reported that they were pretending to engage for 23% of class time, even for highly regarded instructors. Individual participants were rated as engaged for 42 of the 46 intervals for which they reported that they had "pretended to engage", indicating that the two observers were unable to detect disengagement during periods in which students pretended to engage. Instructors should be aware that student cues such as eye contact and nodding may indicate pretending to engage. One particular self-report item; "I tried a new approach or way of thinking about the content", correlated positively with heart rates, and a controlled study reproduced this finding during two activities that required students to try a new approach to understanding a concept. Agreement with this item also correlated with superior performance on two in-class written assessment tasks (n = 101, p<0.01). Further use of this tool and related educational research may be useful to identify in-class activities that are engaging and likely to lead to improved student attainment of learning outcomes.

A renaissance in pharmacy education at the University of North Carolina at Chapel Hill.

The UNC Eshelman School of Pharmacy is transforming its doctor of pharmacy program to emphasize active engagement of students in the classroom, foster scientific inquiry and innovation, and immerse students in patient care early in their education. The admissions process is also being reengineered.

Inhibitors of Streptococcus pneumoniae surface endonuclease EndA discovered by high-throughput screening using a PicoGreen fluorescence assay.

The human commensal pathogen Streptococcus pneumoniae expresses a number of virulence factors that promote serious pneumococcal diseases, resulting in significant morbidity and mortality worldwide. These virulence factors may give S. pneumoniae the capacity to escape immune defenses, resist antimicrobial agents, or a combination of both. Virulence factors also present possible points of therapeutic intervention. The activities of the surface endonuclease, EndA, allow S. pneumoniae to establish invasive pneumococcal infection. EndA's role in DNA uptake during transformation contributes to gene transfer and genetic diversification. Moreover, EndA's nuclease activity degrades the DNA backbone of neutrophil extracellular traps (NETs), allowing pneumococcus to escape host immune responses. Given its potential impact on pneumococcal pathogenicity, EndA is an attractive target for novel antimicrobial therapy. Herein, we describe the development of a high-throughput screening assay for the discovery of nuclease inhibitors. Nuclease-mediated digestion of double-stranded DNA was assessed using fluorescence changes of the DNA dye ligand, PicoGreen. Under optimized conditions, the assay provided robust and reproducible activity data (Z'= 0.87) and was used to screen 4727 small molecules against an imidazole-rescued variant of EndA. In total, six small molecules were confirmed as novel EndA inhibitors, some of which may have utility as research tools for understanding pneumococcal pathogenesis and for drug discovery.

A new in vivo Raman probe for enhanced applicability to the body.

This paper describes a new in vivo Raman probe that allows investigation of areas of the body that are otherwise difficult to access. It is coupled to a previously described commercially available in vivo Raman spectrometer that samples the skin through an optical flat. In the work presented here, the laser light emerges from a smaller pen-shaped probe. It thus works on the same principles as the original spectrometer, while its relative performance in terms of signal-to-noise ratio of the spectra and obtained spatial resolution is only slightly diminished. It allows the window to be placed against the subject in more curved and recessed areas of subject's body and also for them to be more comfortable while the measurements take place. Results from three areas of the body that have previously been very difficult to study are described, the mouth, axilla, and scalp. Results from the scalp and axilla strata cornea (SC) show significant differences from the "normal" SC of the volar forearm. For instance, the scalp is observed to have lower amounts of natural moisturizing factors (NMF) compared to the volar forearm within the same subjects. Also for both the axilla and scalp the lipids show a change in order as compared to the lipids in the volar forearm and also differences from each other. The potential significance of these observations is discussed. Further, we show how we can probe the mouth, in this case observing the presence of the astringent tea polyphenol epigallocatechin gallate within the oral mucosa.

Evidence for dynamics in proteins as a mechanism for ligand dissociation.

Signal transduction, regulatory processes and pharmaceutical responses are highly dependent upon ligand residence times. Gaining insight into how physical factors influence residence times (1/k(off)) should enhance our ability to manipulate biological interactions. We report experiments that yield structural insight into k(off) involving a series of eight 2,4-diaminopyrimidine inhibitors of dihydrofolate reductase whose binding affinities vary by six orders of magnitude. NMR relaxation-dispersion experiments revealed a common set of residues near the binding site that undergo a concerted millisecond-timescale switching event to a previously unidentified conformation. The rate of switching from ground to excited conformations correlates exponentially with the binding affinity K(i) and k(off), suggesting that protein dynamics serves as a mechanical initiator of ligand dissociation within this series and potentially for other macromolecule-ligand systems. Although the forward rate of conformational exchange, k(conf,forward), is faster than k(off), the use of the ligand series allowed for connections to be drawn between kinetic events on different timescales.

High-throughput screening for RecA inhibitors using a transcreener adenosine 5'-O-diphosphate assay.

The activities of the bacterial RecA protein are involved in the de novo development and transmission of antibiotic resistance genes, thus allowing bacteria to overcome the metabolic stress induced by antibacterial agents. RecA is ubiquitous and highly conserved among bacteria, but has only distant homologs in human cells. Together, this evidence points to RecA as a novel and attractive antibacterial drug target. All known RecA functions require the formation of a complex formed by multiple adenosine 5'-O-triphosphate (ATP)-bound RecA monomers on single-stranded DNA. In this complex, RecA hydrolyzes ATP. Although several methods for assessing RecA's ATPase activity have been reported, these assay conditions included relatively high concentrations of enzyme and ATP and thereby restricted the RecA conformational state. Herein, we describe the validation of commercial reagents (Transcreener(®) adenosine 5'-O-diphosphate [ADP](2) fluorescence polarization assay) for the high-throughput measurement of RecA's ATPase activity with lower concentrations of ATP and RecA. Under optimized conditions, ADP detection by the Transcreener reagent provided robust and reproducible activity data (Z'=0.92). Using the Transcreener assay, we screened 113,477 small molecules against purified RecA protein. In total, 177 small molecules were identified as confirmed hits, of which 79 were characterized by IC(50) values ≤ 10 µM and 35 were active in bioassays with live bacteria. This set of compounds comprises previously unidentified scaffolds for RecA inhibition and represents tractable hit structures for efforts aimed at tuning RecA inhibitory activity in both biochemical and bacteriological assays.

Direct detection of structurally resolved dynamics in a multiconformation receptor-ligand complex.

Structure-based drug design relies on static protein structures despite significant evidence for the need to include protein dynamics as a serious consideration. In practice, dynamic motions are neglected because they are not understood well enough to model, a situation resulting from a lack of explicit experimental examples of dynamic receptor-ligand complexes. Here, we report high-resolution details of pronounced ~1 ms time scale motions of a receptor-small molecule complex using a combination of NMR and X-ray crystallography. Large conformational dynamics in Escherichia coli dihydrofolate reductase are driven by internal switching motions of the drug-like, nanomolar-affinity inhibitor. Carr-Purcell-Meiboom-Gill relaxation dispersion experiments and NOEs revealed the crystal structure to contain critical elements of the high energy protein-ligand conformation. The availability of accurate, structurally resolved dynamics in a protein-ligand complex should serve as a valuable benchmark for modeling dynamics in other receptor-ligand complexes and prediction of binding affinities.

Dynamic in vivo mapping of model moisturiser ingress into human skin by GARfield MRI.

We describe the development of in vivo one-dimensional MRI (profiling) using a GARField (Gradient At Right angles to Field) magnet for the characterisation of side-of-hand human skin. For the first time and in vivo, we report measurements of the NMR longitudinal and transverse relaxation parameters and self-diffusivity of the upper layers of human skin with a nominal spatial resolution better than 10 µm. The results are correlated with in vivo confocal Raman spectroscopy measurements of water concentration and natural moisturiser factors, and discussed in terms of known skin biology and microstructure of the stratum corneum and viable epidermis. The application of model moisturiser solutions to the skin is followed and their dynamics of ingress are characterised using the MRI methodology developed. Selected hydrophilic and lipophilic formulations are studied. The results are corroborated by standard in vivo measurements of transepidermal water loss and hydration status. A further insight into moisturisation mechanisms is gained. The effect of two different penetration enhancers on a commonly used skin care oil is also discussed, and different timescales of oil penetration into the skin are reported depending on the type of enhancer.

Novel Inhibitors of E. coli RecA ATPase Activity.

The bacterial RecA protein has been implicated as a bacterial drug target not as an antimicrobial target, but as an adjuvant target with the potential to suppress the mechanism by which bacteria gain drug resistance. In order to identify small molecules that inhibit RecA/ssDNA nucleoprotein filament formation, we have adapted the phosphomolybdate-blue ATPase assay for high throughput screening to determine RecA ATPase activity against a library of 33,600 compounds, which is a selected representation of diverse structure of 350,000. Four distinct chemotypes were represented among the 40 validated hits. SAR and further chemical synthesis is underway to optimize this set of inhibitors to be used as antimicrobial adjuvant agents.

Inhibitors of RecA activity discovered by high-throughput screening: cell-permeable small molecules attenuate the SOS response in Escherichia coli.

The phenomenon of antibiotic resistance has created a need for the development of novel antibiotic classes with nonclassical cellular targets. Unfortunately, target-based drug discovery against proteins considered essential for in vitro bacterial viability has yielded few new therapeutic classes of antibiotics. Targeting the large proportion of genes considered nonessential that have yet to be explored by high-throughput screening, for example, RecA, can complement these efforts. Recent evidence suggests that RecA-controlled processes are responsible for tolerance to antibiotic chemotherapy and are involved in pathways that ultimately lead to full-fledged antibiotic resistance. Therefore inhibitors of RecA may serve as therapeutic adjuvants in combination chemotherapy of bacterial infectious diseases. Toward the goal of validating RecA as a novel target in the chemotherapy of bacterial infections, the authors have screened 35,780 small molecules against RecA. In total, 80 small molecules were identified as primary hits and could be clustered in 6 distinct chemotype clades. The most potent class of hits was further examined, and 1 member compound was found to inhibit RecA-mediated strand exchange and prevent ciprofloxacin-induced SOS expression in Escherichia coli. This compound represents the first small molecule demonstrating an ability to inhibit the bacterial SOS response in live bacterial cell cultures.

Rapid metabolic and newborn screening of thyroxine (T4) from dried blood spots by MS/MS.

BACKGROUND: Thyroxin (T(4)) plays an important role in the regulation of the rate of metabolism of proteins, fats, and carbohydrates. Congenital hypothyroidism, an inherited deficiency of thyroid hormones, is screened in newborns using a variety of methods that include total T(4) or thyroid stimulating hormone (TSH). Some laboratories measure either total T(4) or TSH as a means of detecting infants with hypothyroidism with a subset that analyzes both total T(4) and TSH as a primary screen or a combination of primary and secondary screens. METHODS: We have developed a new MS/MS method that measures T(4) from a filter paper blood spot following methanol extraction using the essentially the same method as MS/MS analysis of amino acids. Product ion spectra show a transition of 833.8-->731.8 (102 Da). An SRM for T(4) and (13)C(6)-T(4) was added to the MS/MS analysis of acylcarnitines and amino acids. RESULTS: Analysis of T(4) by MS/MS compares well with the immunoassay. The mean of 10,225 newborn screening specimens was 14.4 microg/dl (range 2.4-33) for MS/MS and 16.9 microg/dl (range 1.4-71.8) for AutoDELFIA. The MS/MS assay was linear with a correlation coefficient of 0.998. Regression analysis of MS/MS with the AutoDELFIA had a slope of 0.7, a y-intercept of 3.25, and a correlation coefficient of 0.727. We determined a MS/MS detection limit of 0.97 microg/dl and a lower LoQ (limit of quantification) of 2 microg/dl. CONCLUSION: This method may provide a cost effective means of analyzing both T(4) and TSH by consolidating a T(4) analysis into the MS/MS panel.

Probing the structure of RecA-DNA filaments. Advantages of a fluorescent guanine analog.

The RecA protein of Escherichia coli plays a crucial roles in DNA recombination and repair, as well as various aspects of bacterial pathogenicity. The formation of a RecA-ATP-ssDNA complex initiates all RecA activities and yet a complete structural and mechanistic description of this filament has remained elusive. An analysis of RecA-DNA interactions was performed using fluorescently labeled oligonucleotides. A direct comparison was made between fluorescein and several fluorescent nucleosides. The fluorescent guanine analog 6-methylisoxanthopterin (6MI) demonstrated significant advantages over the other fluorophores and represents an important new tool for characterizing RecA-DNA interactions.

A complementary pair of rapid molecular screening assays for RecA activities.

The bacterial RecA protein has been implicated in the evolution of antibiotic resistance in pathogens, which is an escalating problem worldwide. The discovery of small molecules that can selectively modulate RecA's activities can be exploited to tease apart its roles in the de novo development and transmission of antibiotic resistance genes. Toward the goal of discovering small-molecule ligands that can prevent either the assembly of an active RecA-DNA filament or its subsequent ATP-dependent motor activities, we report the design and initial validation of a pair of rapid and robust screening assays suitable for the identification of inhibitors of RecA activities. One assay is based on established methods for monitoring ATPase enzyme activity and the second is a novel assay for RecA-DNA filament assembly using fluorescence polarization. Taken together, the assay results reveal complementary sets of agents that can either suppress selectively only the ATP-driven motor activities of the RecA-DNA filament or prevent assembly of active RecA-DNA filaments altogether. The screening assays can be readily configured for use in future automated high-throughput screening projects to discover potent inhibitors that may be developed into novel adjuvants for antibiotic chemotherapy that moderate the development and transmission of antibiotic resistance genes and increase the antibiotic therapeutic index.

Inhibition of Escherichia coli RecA by rationally redesigned N-terminal helix.

Bacterial RecA promotes the development and transmission of antibiotic resistance genes by self-assembling into an ATP-hydrolyzing filamentous homopolymer on single-stranded DNA. We report the design of a 29mer peptide based on the RecA N-terminal domain involved in intermonomer contact that inhibits RecA filament assembly with an IC50 of 3 microM.

Directed molecular screening for RecA ATPase inhibitors.

The roles of bacterial RecA in the evolution and transmission of antibiotic resistance genes make it an attractive target for inhibition by small molecules. We report two complementary fluorescence-based ATPase assays that were used to screen for inhibitors of RecA. We elected to employ the ADP-linked variation of the assay, with a Z' factor of 0.83 in 96-well microplates, to assess whether 18 select compounds could inhibit ATP hydrolysis by RecA. The compounds represented five sets of related inhibitor scaffolds, each of which had the potential to cross-inhibit RecA. Although nucleotide analogs, known inhibitors of GHL ATPases, and known protein kinase inhibitors were not active against RecA, we found that three suramin-like agents substantially inhibited RecA's ATPase activity.

Direct evaluation of a kinetic model for RecA-mediated DNA-strand exchange: the importance of nucleic acid dynamics and entropy during homologous genetic recombination.

The Escherichia coli RecA protein is the prototype of a class of proteins that play central roles in genomic repair and recombination in all organisms. The unresolved mechanistic strategy by which RecA aligns a single strand of DNA with a duplex DNA and mediates a DNA strand switch is central to understanding homologous recombination. We explored the mechanism of RecA-mediated DNA-strand exchange using oligonucleotide substrates with the intrinsic fluorophore 6-methylisoxanthopterin. Pre-steady-state spectrofluorometric analysis elucidated the earliest transient intermediates formed during recombination and delineated the mechanistic strategy by which RecA facilitates this process. The structural features of the first detectable intermediate and the energetic characteristics of its formation were consistent with interactions between a few bases of the single-stranded DNA and the minor groove of a locally melted or stretched duplex DNA. Further analysis revealed RecA to be an unusual enzyme in that entropic rather than enthalpic contributions dominate its catalytic function, and no unambiguously active role for the protein was detected in the earliest molecular events of recombination. The data best support the conclusion that the mechanistic strategy of RecA likely relies on intrinsic DNA dynamics.

Origins of sequence selectivity in homologous genetic recombination: insights from rapid kinetic probing of RecA-mediated DNA strand exchange.

Despite intense effort over the past 30 years, the molecular determinants of sequence selectivity in RecA-mediated homologous recombination have remained elusive. Here, we describe when and how sequence homology is recognized between DNA strands during recombination in the context of a kinetic model for RecA-mediated DNA strand exchange. We characterized the transient intermediates of the reaction using pre-steady-state kinetic analysis of strand exchange using oligonucleotide substrates containing a single fluorescent G analog. We observed that the reaction system was sensitive to heterology between the DNA substrates; however, such a "heterology effect" was not manifest when functional groups were added to or removed from the edges of the base-pairs facing the minor groove of the substrate duplex. Hence, RecA-mediated recombination must occur without the involvement of a triple helix, even as a transient intermediate in the process. The fastest detectable reaction phase was accelerated when the structure or stability of the substrate duplex was perturbed by internal mismatches or the replacement of G.C by I.C base-pairs. These findings indicate that the sequence specificity in recombination is achieved by Watson-Crick pairing in the context of base-pair dynamics inherent to the extended DNA structure bound by RecA during strand exchange.

Conformationally selective binding of nucleotide analogues to Escherichia coli RecA: a ligand-based analysis of the RecA ATP binding site.

The roles of the RecA protein in the survival of bacteria and the evolution of resistance to antibiotics make it an attractive target for inhibition by small molecules. The activity of RecA is dependent on the formation of a nucleoprotein filament on single-stranded DNA that hydrolyzes ATP. We probed the nucleotide binding site of the active RecA protein using modified nucleotide triphosphates to discern key structural elements of the nucleotide and of the binding site that result in the activation of RecA for NTP hydrolysis. Our results show that the RecA-catalyzed hydrolysis of a given nucleotide triphosphate or analogue thereof is exquisitely sensitive to certain structural elements of both the base and ribose moieties. Furthermore, our ligand-based approach to probing the RecA ATP binding site indicated that the binding of nucleotides by RecA was found to be conformationally selective. Using a binding screen that can be readily adapted to high-throughput techniques, we were able to segregate nucleotides that interact with RecA into two classes: (1) NTPs that preferentially bind the active nucleoprotein filament conformation and either serve as substrates for or competitively inhibit hydrolysis and (2) nonsubstrate NTPs that preferentially bind the inactive RecA conformation and facilitate dissociation of the RecA-DNA species. These results are discussed in the context of a recent structural model for the active RecA nucleoprotein filament and provide us with important information for the design of potent, conformationally selective modulators of RecA activities.