Rationally Designed Peptoid Inhibitors of Amyloid-ß Oligomerization.

While plaques comprised of fibrillar Aß aggregates are hallmarks of Alzheimer's disease, soluble Aß oligomers present higher neurotoxicity. Thus, one therapeutic approach is to prevent the formation of Aß oligomers and reduce their associated harmful effects. We have proposed a peptoid mimic of the Aß hydrophobic KLVFF core as an ideal candidate aggregation inhibitor due to its ability to evade proteolytic degradation via repositioning of the side chain from the α-carbon to the amide nitrogen. This peptoid, JPT1, utilizes chiral sidechains to achieve a helical structure, while C-terminal addition of two phenylalanine residues places aromatic groups on two sides of the helix with spacing designed to facilitate interaction with amyloid ß-sheet structure. We have previously shown that JPT1 modulates Aß fibril formation. Here, we demonstrate that JPT1 also modulates Aß oligomerization, and we explore the role of the charge on the linker between the KLVFF mimic and the extended aromatic residues. Additionally, we demonstrate that peptoid-induced changes in Aß oligomerization correlate with attenuation of oligomer-induced nuclear factor-κB activation in SH-SY5Y human neuroblastoma cells. These findings support the therapeutic potential of peptoids to target early stages of Aß aggregation and impact the associated Aß-induced cellular response.

Full-dose challenge of moderate, severe, and unknown beta-lactam allergies in the emergency department.

OBJECTIVE: This study aims to assess the outcome of challenging documented moderate, severe, or unknown beta-lactam allergies with full dose administration of a beta-lactam antibiotic in emergency department (ED) patients admitted for acute bacterial infection. METHODS: A single-center, retrospective, descriptive study of adult patients challenged with a full dose of beta-lactam in the ED from January 2021 to December 2022 was conducted. Included patients had at least one documented moderate, severe, or unknown beta-lactam allergy in the electronic medical record (EMR) without documentation of prior tolerance. Patient demographics, prior beta-lactam antibiotic reaction, beta-lactam administered in the ED, inpatient beta-lactam continuation, adverse drug reactions, and updates to allergy profiles were collected. Descriptive statistics for data analysis were performed using SPSS Version 22. RESULTS: Of the 184 ED encounters with full-dose beta-lactam challenges, five (2.7%) patients with documented moderate, severe, or unknown beta-lactam allergies experienced an allergic reaction after the challenge; one (0.5%) patient had an allergic reaction in the ED, and the remaining four (2.2%) occurred after admission. No anaphylactic reactions occurred. All allergic reactions were limited to mild rash or itching. Most patients (98.9%) were challenged with a cephalosporin. A beta-lactam was continued in 86.4% of cases, and the allergy profile was updated for future utilization in 73.4% of patients. CONCLUSIONS: This study suggests that full-dose challenge of moderate, severe, or unknown beta-lactam allergies can be safely accomplished in the ED. This approach avoids unnecessary penicillin allergy skin testing and reduces utilization of suboptimal alternative antibiotic regimens.

Modulating the RAGE-Induced Inflammatory Response: Peptoids as RAGE Antagonists.

While the primary pathology of Alzheimer's disease (AD) is defined by brain deposition of amyloid-ß (Aß) plaques and tau neurofibrillary tangles, chronic inflammation has emerged as an important factor in AD etiology. Upregulated cell surface expression of the receptor for advanced glycation end-products (RAGE), a key receptor of innate immune response, is reported in AD. In parallel, RAGE ligands, including Aß aggregates, HMGB1, and S100B, are elevated in AD brain. Activation of RAGE by these ligands triggers release of inflammatory cytokines and upregulates cell surface RAGE. Despite such observation, there are currently no therapeutics that target RAGE for treatment of AD-associated neuroinflammation. Peptoids, a novel class of potential AD therapeutics, display low toxicity, facile blood-brain barrier permeability, and resistance to proteolytic degradation. In the current study, peptoids were designed to mimic Aß, a ligand that binds the V-domain of RAGE, and curtail RAGE inflammatory activation. We reveal the nanomolar binding capability of peptoids JPT1 and JPT1a to RAGE and demonstrate their ability to attenuate lipopolysaccharide-induced pro-inflammatory cytokine production as well as upregulation of RAGE cell surface expression. These results support RAGE antagonist peptoid-based mimics as a prospective therapeutic strategy to counter neuroinflammation in AD and other neurodegenerative diseases.

Prediction of Pelvic Organ Prolapse Postsurgical Outcome Using Biomaterial-Induced Blood Cytokine Levels: Machine Learning Approach.

BACKGROUND: Pelvic organ prolapse (POP) refers to symptomatic descent of the vaginal wall. To reduce surgical failure rates, surgical correction can be augmented with the insertion of polypropylene mesh. This benefit is offset by the risk of mesh complication, predominantly mesh exposure through the vaginal wall. If mesh placement is under consideration as part of prolapse repair, patient selection and counseling would benefit from the prediction of mesh exposure; yet, no such reliable preoperative method currently exists. Past studies indicate that inflammation and associated cytokine release is correlated with mesh complication. While some degree of mesh-induced cytokine response accompanies implantation, excessive or persistent cytokine responses may elicit inflammation and implant rejection. OBJECTIVE: Here, we explore the levels of biomaterial-induced blood cytokines from patients who have undergone POP repair surgery to (1) identify correlations among cytokine expression and (2) predict postsurgical mesh exposure through the vaginal wall. METHODS: Blood samples from 20 female patients who previously underwent surgical intervention with transvaginal placement of polypropylene mesh to correct POP were collected for the study. These included 10 who experienced postsurgical mesh exposure through the vaginal wall and 10 who did not. Blood samples incubated with inflammatory agent lipopolysaccharide, with sterile polypropylene mesh, or alone were analyzed for plasma levels of 13 proinflammatory and anti-inflammatory cytokines using multiplex assay. Data were analyzed by principal component analysis (PCA) to uncover associations among cytokines and identify cytokine patterns that correlate with postsurgical mesh exposure through the vaginal wall. Supervised machine learning models were created to predict the presence or absence of mesh exposure and probe the number of cytokine measurements required for effective predictions. RESULTS: PCA revealed that proinflammatory cytokines interferon gamma, interleukin 12p70, and interleukin 2 are the largest contributors to the variance explained in PC 1, while anti-inflammatory cytokines interleukins 10, 4, and 6 are the largest contributors to the variance explained in PC 2. Additionally, PCA distinguished cytokine correlations that implicate prospective therapies to improve postsurgical outcomes. Among machine learning models trained with all 13 cytokines, the artificial neural network, the highest performing model, predicted POP surgical outcomes with 83% (15/18) accuracy; the same model predicted POP surgical outcomes with 78% (14/18) accuracy when trained with just 7 cytokines, demonstrating retention of predictive capability using a smaller cytokine group. CONCLUSIONS: This preliminary study, incorporating a sample size of just 20 participants, identified correlations among cytokines and demonstrated the potential of this novel approach to predict mesh exposure through the vaginal wall following transvaginal POP repair surgery. Further study with a larger sample size will be pursued to confirm these results. If corroborated, this method could provide a personalized medicine approach to assist surgeons in their recommendation of POP repair surgeries with minimal potential for adverse outcomes.

Feasibility evaluation to expand a collaborative practice agreement and discontinue antibiotics after an emergency department or urgent care visit.

PURPOSE: The impact of pharmacist-led culture follow-up programs for positive cultures is well established. The benefits and feasibility of evaluating negative cultures and deprescribing unnecessary antibiotics after emergency department (ED) and urgent care (UC) visits are unknown; therefore, this evaluation characterized the burden of negative urine cultures and chlamydia tests and estimated how many potential antibiotic days could be saved with deprescribing. METHODS: This retrospective, descriptive study evaluated patients discharged from an ED or UC location with a pharmacist-led culture follow-up program. The primary objective was to characterize the proportion of patients with a negative urine culture or chlamydia test where an opportunity would exist to deprescribe antibiotics at follow-up. Secondary endpoints included estimating the number of potential antibiotic days that could be saved, postvisit healthcare utilization, and documented adverse drug reactions (ADRs). RESULTS: For a 1-month period, pharmacists reviewed 398 cultures, of which 208 (52%) were urine cultures or chlamydia tests with negative results. Fifty patients (24%) with negative results had been prescribed empiric antibiotics. The median duration of antibiotic treatment was 7 days (interquartile range [IQR], 5-7 days), while the median time to culture finalization was 2 days (IQR, 1-2 days). There was an opportunity to save a median of 5 antibiotic days per patient. Thirty-two patients (15.3%) followed up with their primary care physician within 7 days; of these patients, 1 (0.05%) had their antibiotic prescription discontinued by the primary care physician. There were no documented ADRs. CONCLUSION: Expansion of pharmacist-led culture follow-up programs to deprescribe antibiotics for patients with negative cultures has the potential to save significant antibiotic exposure.

COVID-19 Vaccine Mandates: Impact on Radiology Department Operations and Mitigation Strategies.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) vaccine mandates are being implemented in health systems across the United States, and the impact on the radiology department workforce and operations becuase of vaccine hesitancy among health care workers is currently unknown. This article discusses the potential impact of the COVID-19 vaccine mandate on a large multicenter radiology department as well as strategies to mitigate those effects. METHODS: Weekly vaccine compliance data were obtained for employees across the entire health system from August 17, 2021, through September 13, 2021, and radiology department-specific data were extracted. Vaccine compliance data was mapped to specific radiology job titles and the five different hospital locations. RESULTS: A total of 6% of radiology department employees were not fully vaccine compliant by the initial deadline of September 10, 2021. MR technologists and radiology technology assistants had the highest initial rates of noncompliance of 37% and 38%, respectively. Vaccine noncompliance rates by the mandate deadline ranged from 0.5% to 7.0% at the five hospital sites. Only one hospital required a decrease in imaging hours of operation because of the vaccine mandate. CONCLUSION: Despite initial concerns about the impact of vaccine mandate noncompliance on departmental operations, there was ultimately little effect because of improved vaccine compliance after the mandate. Understanding individual employee and locoregional differences in vaccine compliance can help leaders proactively develop mitigation strategies to manage this new challenge during the COVID-19 pandemic.

Cysteine-rich granulin-3 rapidly promotes amyloid-ß fibrils in both redox states.

Granulins (GRNs 1-7) are cysteine-rich proteolytic products of progranulin (PGRN) that have recently been implicated in neurodegenerative diseases including frontotemporal dementia (FTD) and Alzheimer's disease (AD). Their precise mechanism in these pathologies remains uncertain, but both inflammatory and lysosomal roles have been observed for GRNs. Among the seven GRNs, GRN-3 is well characterized and is implicated within the context of FTD. However, the relationship between GRN-3 and amyloid-ß (Aß), a protein relevant in AD pathology, has not yet been explored. To gain insight into this mechanism, we investigated the effect of both oxidized and reduced GRN-3 on Aß aggregation and found that both GRN-3 (oxidized) and rGRN-3 (reduced) bind to monomeric and oligomeric Aß42 to promote rapid fibril formation with subtle rate differences. As low molecular weight oligomers of Aß are well-established neurotoxins, rapid promotion of fibrils by GRN-3 mitigates Aß42-induced cellular apoptosis. These data provide valuable insights in understanding GRN-3's ability to modulate Aß-induced toxicity under redox control and presents a new perspective toward AD pathology. These results also prompt further investigation into the role(s) of other GRNs in AD pathogenesis.

Pharmacist-led antimicrobial stewardship program in an urgent care setting.

PURPOSE: While many programs have demonstrated pharmacist-led antimicrobial stewardship successes in inpatient and emergency department (ED) settings, there is a paucity of literature exploring these initiatives in urgent care (UC) sites. This study aimed to determine the impact of implementing a pharmacist-led antimicrobial stewardship program (ASP) in the UC setting. METHODS: A retrospective quasi-experimental study was conducted evaluating UC patients with positive urine or wound cultures following discharge. A collaborative practice agreement was implemented in 2015 allowing for pharmacist-led UC culture follow-up via a stewardship-focused protocol. The primary outcome of this study was to compare guideline-concordant antibiotic prescribing between the pre-ASP and post-ASP groups. Secondary outcomes included comparing the number of patients who required follow-up, time to follow-up, UC or ED revisits within 72 hours, and hospital admission within 30 days between groups. RESULTS: A total of 300 patients were included in the study (pre-ASP, n = 150; post-ASP, n = 150). Total guideline-concordant prescribing for all diagnoses was significantly improved in the post-ASP group (pre-ASP, 41.3% versus post-ASP 53.3%, p = 0.037). Additionally, guideline-concordant antibiotic selection improved in the post-ASP group (pre-ASP, 51% versus post-ASP, 68%, p = 0.01). Follow-up was required for 27 (18%) patients in the pre-ASP group compared with 16 (10.7%) in the post-ASP group (p = 0.07). Median time to follow-up call was longer in the post-ASP group (38 versus 71 hours, p < 0.001). There were no differences in UC and ED revisits within 72 hours (p = 1.0) or hospital admissions within 30 days (p = 0.723). CONCLUSION: A pharmacist-led urgent care ASP was associated with significantly improved guideline-concordant antimicrobial prescribing.

Impact of an emergency medicine pharmacist on empiric antibiotic prescribing for pneumonia and intra-abdominal infections.

PURPOSE: It is critical to engage ED providers in antimicrobial stewardship programs (ASP). Emergency medicine pharmacists (EMPs) play an important role in ASP by working with providers to choose empiric antimicrobials. This study aimed to determine the impact of an EMP on appropriate empiric antibiotic prescribing for community-acquired pneumonia (CAP) and intra-abdominal infections (CA-IAI). METHODS: A retrospective cohort study was conducted evaluating adult patients admitted with CAP or CA-IAI. The primary outcome of this study was to compare guideline-concordant empiric antibiotic prescribing when an EMP was present vs. absent. We also aimed to compare the impact of an EMP in an early-ASP vs. established-ASP. RESULTS: 320 patients were included in the study (EMP n = 185, no-EMP n = 135). Overall empiric antibiotic prescribing was more likely to be guideline-concordant when an EMP was present (78% vs. 61%, p = 0.001); this was true for both the CAP (95% vs. 79%, p = 0.005) and CA-IAI subgroups (62% vs. 44%, p = 0.025). Total guideline-concordant prescribing significantly increased between the early-ASP and established-ASP (60% vs. 82.5%, p < 0.001) and was more likely when an EMP was present (early-ASP: 68.3% vs. 45.8%, p = 0.005; established-ASP: 90.5% vs. 73.7%, p = 0.005). Patients receiving guideline-concordant antibiotics in the ED continued appropriate therapy upon admission 82.5% of the time vs. 18.8% if the ED antibiotic was inappropriate (p < 0.001). CONCLUSION: The presence of an EMP significantly improved guideline-concordant empiric antibiotic prescribing for CAP and CA-IAI in both an early and established ASP. Inpatient orders were more likely to be guideline-concordant if appropriate therapy was ordered in the ED.

Fully reduced granulin-B is intrinsically disordered and displays concentration-dependent dynamics.

Granulins (Grns) are a family of small, cysteine-rich proteins that are generated upon proteolytic cleavage of their precursor, progranulin (Pgrn). All seven Grns (A-G) contain 12 conserved cysteines that form 6 intramolecular disulfide bonds, rendering this family of proteins unique. Grns are known to play multi-functional roles, including wound healing, embryonic growth, and inflammation and are implicated in neurodegenerative diseases. Despite their manifold functions, there exists a dearth of information regarding their structure-function relationship. Here, we sought to establish the role of disulfide bonds in promoting structure by investigating the fully reduced GrnB (rGrnB). We report that monomeric rGrnB is an intrinsically disordered protein (IDP) at low concentrations. rGrnB undergoes dimerization at higher concentrations to form a fuzzy complex without a net gain in the structure-a behavior increasingly identified as a hallmark of some IDPs. Interestingly, we show that rGrnB is also able to activate NF-κB in human neuroblastoma cells in a concentration-dependent manner. This activation correlates with the observed monomer-dimer dynamics. Collectively, the presented data establish that the intrinsic disorder of rGrnB governs conformational dynamics within the reduced form of the protein, and suggest that the overall structure of Grns could be entirely dictated by disulfide bonds.

Membrane-type MMPs enable extracellular matrix permissiveness and mesenchymal cell proliferation during embryogenesis.

Peri-cellular remodeling of mesenchymal extracellular matrices is considered a prerequisite for cell proliferation, motility and development. Here we demonstrate that membrane-type 3 MMP, MT3-MMP, is expressed in mesenchymal tissues of the skeleton and in peri-skeletal soft connective tissue. Consistent with this localization, MT3-MMP-deficient mice display growth inhibition tied to a decreased viability of mesenchymal cells in skeletal tissues. We document that MT3-MMP works as a major collagenolytic enzyme, enabling cartilage and bone cells to cleave high-density fibrillar collagen and modulate their resident matrix to make it permissive for proliferation and migration. Collectively, these data uncover a novel extracellular matrix remodeling mechanism required for proper function of mesenchymal cells. The physiological significance of MT3-MMP is highlighted in mice double deficient for MT1-MMP and MT3-MMP. Double deficiency transcends the combined effects of the individual single deficiencies and leads to severe embryonic defects in palatogenesis and bone formation incompatible with life. These defects are directly tied to loss of indispensable collagenolytic activities required in collagen-rich mesenchymal tissues for extracellular matrix remodeling and cell proliferation during embryogenesis.

Kinetic discrimination of sequence-specific DNA-drug binding measured by surface plasmon resonance imaging and comparison to solution-phase measurements.

We demonstrate the use of surface plasmon resonance (SPR) imaging for direct detection of small-molecule binding to surface-bound DNA probes. Using a carefully designed array surface, we quantitatively discriminate between the interactions of a model drug with different immobilized DNA binding sites. Specifically, we measure the association and dissociation intercalation rates of actinomycin-D (ACTD) to and from double-stranded 5'-TGCT-3' and 5'-GGCA-3' binding sites. The rates measured provide mechanistic information about the DNA-ACTD interaction; ACTD initially binds nonspecifically to DNA but exerts its activity by dissociating slowly from strong affinity sites. We observe a slow dissociation time of kd-1 = 3300 +/- 100 s for ACTD bound to the strong affinity site 5'-TGCT-3' and a much faster dissociation time (210 +/- 15 s) for ACTD bound weakly to the site 5'-GGCA-3'. These dissociation rates, which differ by an order of magnitude, determine the binding affinity for each site (8.8 x 10(6) and 1.0 x 10(6) M(-1), respectively). We assess the effect the surface environment has on these biosensor measurements by determining kinetic and thermodynamic constants for the same DNA-ACTD interactions in solution. The surface suppresses binding affinities approximately 4-fold for both binding sites. This suppression suggests a barrier to DNA-drug association; ACTD binding to duplex DNA is approximately 100 times slower on the surface than in solution.