Modified aptamers enable quantitative sub-10-nm cellular DNA-PAINT imaging.

Although current implementations of super-resolution microscopy are technically approaching true molecular-scale resolution, this has not translated to imaging of biological specimens, because of the large size of conventional affinity reagents. Here we introduce slow off-rate modified aptamers (SOMAmers) as small and specific labeling reagents for use with DNA points accumulation in nanoscale topography (DNA-PAINT). To demonstrate the achievable resolution, specificity, and multiplexing capability of SOMAmers, we labeled and imaged both transmembrane and intracellular targets in fixed and live cells.

Selection of DNA aptamers with two modified bases.

The nucleobases comprising DNA and RNA aptamers provide considerably less chemical diversity than protein-based ligands, limiting their versatility. The introduction of novel functional groups at just one of the four bases in modified aptamers has recently led to dramatic improvement in the success rate of identifying nucleic acid ligands to protein targets. Here we explore the benefits of additional enhancement in physicochemical diversity by selecting modified DNA aptamers that contain amino-acid-like modifications on both pyrimidine bases. Using proprotein convertase subtilisin/kexin type 9 as a representative protein target, we identify specific pairwise combinations of modifications that result in higher affinity, metabolic stability, and inhibitory potency compared with aptamers with single modifications. Such doubly modified aptamers are also more likely to be encoded in shorter sequences and occupy nonoverlapping epitopes more frequently than aptamers with single modifications. These highly modified DNA aptamers have broad utility in research, diagnostic, and therapeutic applications.

Predicting patterns of service utilization within children's mental health agencies.

BACKGROUND: Some children with mental health (MH) problems have been found to receive ongoing care, either continuously or episodically. We sought to replicate patterns of MH service use over extended time periods, and test predictors of these patterns. METHODS: Latent class analyses were applied to 4 years of visit data from five MH agencies and nearly 6000 children, 4- to 13-years-old at their first visit. RESULTS: Five patterns of service use were identified, replicating previous findings. Overall, 14% of cases had two or more episodes of care and 23% were involved for more than 2 years. Most children (53%) were seen for just a few visits within a few months. Two patterns represented cases with two or more episodes of care spanning multiple years. In the two remaining patterns, children tended to have just one episode of care, but the number of sessions and length of involvement varied. Using discriminant function analyses, we were able to predict with just over 50% accuracy children's pattern of service use. Severe externalizing behaviors, high impairment, and high family burden predicted service use patterns with long durations of involvement and frequent visits. CONCLUSIONS: Optimal treatment approaches for children seen for repeated episodes of care or for care lasting multiple years need to be developed. Children with the highest level of need (severe pathology, impairment, and burden) are probably best served by providing high intensity services at the start of care.

Nitroglycerin: An unusual solution to intraoperative hypothermia in a 4-year-old burn patient.

We describe the case of a 4-year-old child undergoing extensive burn surgery with refractory intraoperative hypothermia. A low-dose nitroglycerin infusion was initiated to reverse vasoconstriction and improve heat absorption, after which the child's temperature steadily improved. In hypothermic burn patients, topical vasoconstrictors may hinder surface warming efforts. A vasodilator infusion may aid in warming the pediatric patient undergoing extensive excision and grafting.

Pulsed EPR characterization of HIV-1 protease conformational sampling and inhibitor-induced population shifts.

The conformational landscape of HIV-1 protease (PR) can be experimentally characterized by pulsed-EPR double electron-electron resonance (DEER). For this characterization, nitroxide spin labels are attached to an engineered cysteine residue in the flap region of HIV-1 PR. DEER distance measurements from spin-labels contained within each flap of the homodimer provide a detailed description of the conformational sampling of apo-enzyme as well as induced conformational shifts as a function of inhibitor binding. The distance distribution profiles are further interpreted in terms of a conformational ensemble scheme that consists of four unique states termed "curled/tucked", "closed", "semi-open" and "wide-open" conformations. Reported here are the DEER results for a drug-resistant variant clinical isolate sequence, V6, in the presence of FDA approved protease inhibitors (PIs) as well as a non-hydrolyzable substrate mimic, CaP2. Results are interpreted in the context of the current understanding of the relationship between conformational sampling, drug resistance, and kinetic efficiency of HIV-1PR as derived from previous DEER and kinetic data for a series of HIV-1PR constructs that contain drug-pressure selected mutations or natural polymorphisms. Specifically, these collective results support the notion that inhibitor-induced closure of the flaps correlates with inhibitor efficiency and drug resistance. This body of work also suggests DEER as a tool for studying conformational sampling in flexible enzymes as it relates to function.

Continuing Medical Education Improves Gastroenterologists' Compliance with Inflammatory Bowel Disease Quality Measures.

BACKGROUND: Low rates of compliance with quality measures for inflammatory bowel disease (IBD) have been reported for US gastroenterologists. AIMS: We assessed the influence of quality improvement (QI) education on compliance with physician quality reporting system (PQRS) measures for IBD and measures related to National Quality Strategy (NQS) priorities. METHODS: Forty community-based gastroenterologists participated in the QI study; 20 were assigned to educational intervention and control groups, respectively. At baseline, randomly selected charts of patients with moderate-to-severe ulcerative colitis were retrospectively reviewed for the gastroenterologists' performance of 8 PQRS IBD measures and 4 NQS-related measures. The intervention group participated in a series of accredited continuing medical education (CME) activities focusing on QI. Follow-up chart reviews were conducted 6 months after the CME activities. Independent t tests were conducted to compare between-group differences in baseline-to-follow-up rates of documented compliance with each measure. RESULTS: The analysis included 299 baseline charts and 300 follow-up charts. The intervention group had significantly greater magnitudes of improvement than the control group for the following measures: assessment of IBD type, location, and activity (+14 %, p = 0.009); influenza vaccination (+13 %, p = 0.025); pneumococcal vaccination (+20 %, p = 0.003); testing for latent tuberculosis before anti-TNF-α therapy (+10 %, p = 0.028); assessment of hepatitis B virus status before anti-TNF-α therapy (+9 %, p = 0.010); assessment of side effects (+17 %, p = 0.048), and counseling patients about cancer risks (+13 %, p = 0.013). CONCLUSIONS: QI-focused CME improves community-based gastroenterologists' compliance with IBD quality measures and measures aligned with NQS priorities.

Applications of Cone-Beam Computed Tomography in Oral and Maxillofacial Surgery: An Overview of Published Indications and Clinical Usage in United States Academic Centers and Oral and Maxillofacial Surgery Practices.

PURPOSE: The American Association of Oral and Maxillofacial Surgeons appointed a task force to study the indications, safety, and clinical practice patterns of cone-beam computed tomography (CBCT) in oral and maxillofacial surgery (OMS). The charge was to review the published applications of CBCT in OMS, identify the current position of academic thought leaders in the field, and research the adoption and usage of the technology at the clinical practitioner level. MATERIALS AND METHODS: This study reviewed the CBCT world literature and summarized published indications for the modality. A nationwide survey of academic thought leaders and practicing oral and maxillofacial surgeons was compiled to determine how the modality is currently being used and adopted by institutions and practices. RESULTS: This report summarizes published applications of CBCT that have been vetted by the academic and practicing OMS community to define current indications. The parameters of patient safety, radiation exposure, accreditation, and legal issues are reviewed. An overview of third-party adoption of CBCT is presented. CONCLUSION: CBCT is displacing 2-dimensional imaging in the published literature, academia, and private practice. Best practices support reading the entire scan volume with a written report defining results, patient exposure, and field of view. Issues of patient safety, ALARA ("as low as reasonably achievable"), accreditation, and the legal and regulatory environment are reviewed. Third-party patterns for reimbursements vary widely and seem to lack consistency. There is much confusion within the provider community about indications, authorizations, and payment policies. The current medical and dental indications for CBCT in the clinical practice of OMS are reviewed and an industry guideline is proposed. These guidelines offer a clear way of differentiating consensus medical indications and common dental uses for clinicians. This matrix should bring a predictable logic to third-party authorizations, billing, and predictable payments for this emerging technology in OMS.

Chemically modified DNA aptamers bind interleukin-6 with high affinity and inhibit signaling by blocking its interaction with interleukin-6 receptor.

Interleukin-6 (IL-6) is a pleiotropic cytokine that regulates immune and inflammatory responses, and its overproduction is a hallmark of inflammatory diseases. Inhibition of IL-6 signaling with the anti-IL-6 receptor antibody tocilizumab has provided some clinical benefit to patients; however, direct cytokine inhibition may be a more effective option. We used the systematic evolution of ligands by exponential enrichment (SELEX) process to discover slow off-rate modified aptamers (SOMAmers) with hydrophobic base modifications that inhibit IL-6 signaling in vitro. Two classes of IL-6 SOMAmers were isolated from modified DNA libraries containing 40 random positions and either 5-(N-benzylcarboxamide)-2'-deoxyuridine (Bn-dU) or 5-[N-(1-naphthylmethyl)carboxamide]-2'-deoxyuridine (Nap-dU) replacing dT. These modifications facilitate the high affinity binding interaction with IL-6 and provide resistance against degradation by serum endonucleases. Post-SELEX optimization of one Bn-dU and one Nap-dU SOMAmer led to improvements in IL-6 binding (10-fold) and inhibition activity (greater than 20-fold), resulting in lead SOMAmers with sub-nanomolar affinity (Kd = 0.2 nm) and potency (IC50 = 0.2 nm). Although similar in inhibition properties, the two SOMAmers have unique sequences and different ortholog specificities. Furthermore, these SOMAmers were stable in human serum in vitro for more than 48 h. Both SOMAmers prevented IL-6 signaling by blocking the interaction of IL-6 with its receptor and inhibited the proliferation of tumor cells in vitro as effectively as tocilizumab. This new class of IL-6 inhibitor may be an effective therapeutic alternative for patients suffering from inflammatory diseases.

Crystal structure of interleukin-6 in complex with a modified nucleic acid ligand.

IL-6 is a secreted cytokine that functions through binding two cell surface receptors, IL-6Rα and gp130. Because of its involvement in the progression of several chronic inflammatory diseases, IL-6 is a target of pharmacologic interest. We have recently identified a novel class of ligands called SOMAmers (S low Off-rate Modified Aptamers) that bind IL-6 and inhibit its biologic activity. SOMAmers exploit the chemical diversity of protein-like side chains assembled on flexible nucleic acid scaffolds, resulting in an expanded repertoire of intra- and intermolecular interactions not achievable with conventional aptamers. Here, we report the co-crystal structure of a high affinity SOMAmer (Kd = 0.20 nm) modified at the 5-position of deoxyuridine in a complex with IL-6. The SOMAmer, comprised of a G-quartet domain and a stem-loop domain, engages IL-6 in a clamp-like manner over an extended surface exhibiting close shape complementarity with the protein. The interface is characterized by substantial hydrophobic interactions overlapping the binding surfaces of the IL-6Rα and gp130 receptors. The G-quartet domain retains considerable binding activity as a disconnected autonomous fragment (Kd = 270 nm). A single substitution from our diversely modified nucleotide library leads to a 37-fold enhancement in binding affinity of the G-quartet fragment (Kd = 7.4 nm). The ability to probe ligand surfaces in this manner is a powerful tool in the development of new therapeutic reagents with improved pharmacologic properties. The SOMAmer·IL-6 structure also expands our understanding of the diverse structural motifs achievable with modified nucleic acid libraries and elucidates the nature with which these unique ligands interact with their protein targets.

Unique motifs and hydrophobic interactions shape the binding of modified DNA ligands to protein targets.

Selection of aptamers from nucleic acid libraries by in vitro evolution represents a powerful method of identifying high-affinity ligands for a broad range of molecular targets. Nevertheless, a sizeable fraction of proteins remain difficult targets due to inherently limited chemical diversity of nucleic acids. We have exploited synthetic nucleotide modifications that confer protein-like diversity on a nucleic acid scaffold, resulting in a new generation of binding reagents called SOMAmers (Slow Off-rate Modified Aptamers). Here we report a unique crystal structure of a SOMAmer bound to its target, platelet-derived growth factor B (PDGF-BB). The SOMAmer folds into a compact structure and exhibits a hydrophobic binding surface that mimics the interface between PDGF-BB and its receptor, contrasting sharply with mainly polar interactions seen in traditional protein-binding aptamers. The modified nucleotides circumvent the intrinsic diversity constraints of natural nucleic acids, thereby greatly expanding the structural vocabulary of nucleic acid ligands and considerably broadening the range of accessible protein targets.

Defining Episodes of Care in Children's Mental Health Using Administrative Data.

Criteria to define an episode of care in children's mental health services are needed. Various criteria were applied to 5 years of visit data from children 4-11 years (N = 5,206) at their first visit to 1 of 3 children's mental health agencies. A minimum of 3 visits with 180 days between episodes optimized agreement with other dates (e.g., telephone intake assessment) marking the start and end of an episode, and clinician-rated number of episodes. Grouping visits into episodes provides a clearer representation of how services are distributed over extended periods of time, facilitating research and enhancing accuracy in service planning.

Autologous Skin Cell Suspension for Full-Thickness Skin Defect Reconstruction: Current Evidence and Health Economic Expectations.

Despite differing etiologies, acute thermal burn injuries and full-thickness (FT) skin defects are associated with similar therapeutic challenges. When not amenable to primary or secondary closure, the conventional standard of care (SoC) treatment for these wound types is split-thickness skin grafting (STSG). This invasive procedure requires adequate availability of donor skin and is associated with donor site morbidity, high healthcare resource use (HCRU), and costs related to prolonged hospitalization. As such, treatment options that can facilitate effective healing and donor skin sparing have been highly anticipated. The RECELL® Autologous Cell Harvesting Device facilitates preparation of an autologous skin cell suspension (ASCS) for the treatment of acute thermal burns and FT skin defects. In initial clinical trials, the approach showed superior donor skin-sparing benefits and comparable wound healing to SoC STSG among patients with acute thermal burn injuries. These findings led to approval of RECELL for this indication by the US Food and Drug Administration (FDA) in 2018. Subsequent clinical evaluation in non-thermal FT skin wounds showed that RECELL, when used in combination with widely meshed STSG, provides donor skin-sparing advantages and comparable healing outcomes compared with SoC STSG. As a result, the device received FDA approval in June of 2023 for treatment of FT skin defects caused by traumatic avulsion or surgical excision or resection. Given that health economic advantages have been demonstrated for RECELL ± STSG versus STSG alone when used for burn therapy, it is prudent to examine similarities in the burn and FT skin defect treatment pathways to forecast the potential health economic advantages for RECELL when used in FT skin defects. This article discusses the parallels between the two indications, the clinical outcomes reported for RECELL, and the HCRU and cost benefits that may be anticipated with use of the device for non-thermal FT skin defects.

Iterative refinement of a histologic algorithm for burn depth categorization based on 798 consecutive burn wound biopsies.

INTRODUCTION: Our group previously reported a burn biopsy algorithm (BBA-V1) for categorizing burn wound depth. Here, we sought to promulgate a newer, simpler version of the BBA (BBA-V2). METHODS: Burn wounds undergoing excision underwent 4 mm biopsies procured every 25 cm2. Serial still photos were obtained at enrollment and at excision intraoperatively. Burn wounds assessed as likely to heal by 21 days were imaged within 72 h of injury and at 21 days. A sample of 798 burn wound biopsies were classified by both BBAV1 and BBAV2 algorithms. For nonoperative burn wounds, the proportion of healing versus nonhealing pixels at 21 days after injury were compared. RESULTS: The 798 biopsies were classified by BBAV1 as 24% SPT, 47% DPT, 28% FT and by BBAV2 as 3% SPT, 67% DPT, and 30% FT (p < 0.0001). Overall, the proportion of biopsies whose wound reclassification changed from a nonoperative to operative pathway was 21% (95% CI: 18-24%). Nonoperative wounds judged at injury as being SPT contained 12.8 million pixels. Repeat 21-day imaging revealed 11.3 million healed pixels (accuracy = 89.6% (95% CI: 89.59-89.62)). CONCLUSIONS: BBA-V2 was associated with a significantly higher concordance with visual assessment for burn wounds clinically judged as deep partial and full thickness.

The Burden of Burns: An Analysis of Public Health Measures.

Accurate analysis of injuries is paramount when allocating resources for prevention, research, education, and legislation. As burn mortality has improved over recent decades, the societal burden of burn injuries has grown ambiguous to the public while a scarcity of investigational funding for survivors has led to a gap in understanding lifelong sequela. We aim to compare national references reporting the incidence of burn injuries in the United States. The American Burn Association Burn Injury Summary Report (ABA-BISR), American Burn Association Fact Sheet, Centers for Disease Control and Prevention (CDC) Web-based Injury Statistics Query and Reporting (WISQARS) database, the CDC National Center for Health Statistics' National Hospital Ambulatory Medical Care Survey (NHAMCS), National Inpatient Sample (NIS), National Emergency Department Sample (NEDS), and commercially available claims databases were queried for 2020 or the most recent data available. The BISR estimated 30,135 burn admissions in 2022. The 2016 ABA Fact Sheet reported 486,000 burns presented to US emergency departments (ED). In 2020, CDC's WISQARS database reported 3,529 fatal, and 287,926 non-fatal, burn injuries. The 2020 NEDS reported 438,185 ED visits while the 2020 NIS estimated 103,235 inpatients. The NHAMCS reported 359,000 ED visits for burn injuries in the same period, and an analysis of ICD-10 burn codes demonstrated over 698,555 claims. Our study demonstrates a large variability in the reported incidence of burn injury by the ABA, CDC, national samples, and claims databases. Per our analyses, we estimate that 600,000 individuals annually suffer a burn injury which merits emergent care in the United States.

Development of the national injury resource database (NIRD).

INTRODUCTION: Lack of an accurate, publicly available database of burn/trauma resources creates challenges in providing burn care. In response to this gap, our group developed the National Injury Resource Database (NIRD), a comprehensive database of all US burn centers (BC) and trauma centers (TC) and their capabilities. METHODS: Lists of all national BC and TC were obtained from the American Burn Association (ABA), the American College of Surgeons, and every state department of health. Data was cross-checked and included BC/TC were linked with a 7-digit identification number using the American Hospital Association Quick Search guide. Each center's resources and verification status were validated with electronic or telephonic communications. RESULTS: The final database includes 135 BC and 617 TC, of which 18 are BC-only, 500 are TC-only, and 117 are combined BC/TC. ABA-verified BC (n = 76) are only found in Washington DC and 31 states, and 8 states have no BC. In the last 10 years, a net increase of 7 burn centers was found nationally. The ABA's online BC directory is outdated. CONCLUSIONS: NIRD represents the only up-to-date, comprehensive listing of BC and TC in existence. It categorizes all currently operating BC and TC across myriad classifications of designation and capabilities.

Discovery and SAR of PF-4693627, a potent, selective and orally bioavailable mPGES-1 inhibitor for the potential treatment of inflammation.

Inhibition of mPGES-1, the terminal enzyme in the arachidonic acid/COX pathway to regulate the production of pro-inflammatory prostaglandin PGE2, is considered an attractive new therapeutic target for safe and effective anti-inflammatory drugs. The discovery of a novel series of orally active, selective benzoxazole piperidinecarboxamides as mPGES-1 inhibitors is described. Structure-activity optimization of lead 5 with cyclohexyl carbinols resulted in compound 12, which showed excellent in vitro potency and selectivity against COX-2, and reasonable pharmacokinetic properties. Further SAR studies of the benzoxazole ring substituents lead to a novel series of highly potent compounds with improved PK profile, including 23, 26, and 29, which were effective in a carrageenan-stimulated guinea pig air pouch model of inflammation. Based on its excellent in vitro and in vivo pharmacological, pharmacokinetic and safety profile and ease of synthesis, compound 26 (PF-4693627) was advanced to clinical studies.

Synthesis and biological evaluation of substituted benzoxazoles as inhibitors of mPGES-1: use of a conformation-based hypothesis to facilitate compound design.

Microsomal prostaglandin E(2) synthase-1 (mPGES-1) is a novel therapeutic target for the treatment of inflammation and pain. In the preceding letter, we detailed the discovery of clinical candidate PF-04693627, a potent mPGES-1 inhibitor possessing a novel benzoxazole structure. While PF-04693627 was undergoing further preclinical profiling, we sought to identify a back-up mPGES-1 inhibitor that differentiated itself from PF-04693627. The design, synthesis, mPGES-1 activity and in vivo PK of a novel set of substituted benzoxazoles are described herein. Also described is a conformation-based hypothesis for mPGES-1 activity based on the preferred conformation of the cyclohexane ring within this class of inhibitors.

Ultrafast shock initiation of exothermic chemistry in hydrogen peroxide.

We report observations of shock compressed, unreacted hydrogen peroxide at pressures up to the von Neumann pressure for a steady detonation wave, using ultrafast laser-driven shock wave methods. At higher laser drive energy we find evidence of exothermic chemical reactivity occurring in less than 100 ps after the arrival of the shock wave in the sample. The results are consistent with our MD simulations and analysis and suggest that reactivity in hydrogen peroxide is initiated on a sub-100 ps time scale under conditions found just subsequent to the lead shock in a steady detonation wave.

Generating Team-Based Strategies to Reduce Health Inequity in Cancer Care.

PURPOSE/OBJECTIVES: Despite increased emphases on reducing racial disparities in the U.S. health care system, interprofessional care teams may inadvertently perpetuate health disparities through lack of awareness or experience in supporting individualized, patient-centered goals of care. Racial disparities can lead to health inequity. Persistent health disparity gaps exist among Black patients with multiple myeloma (MM) when compared with non-Black patients. Black patients experience a two-fold increase in MM risk and earlier age of onset compared with non-Black patients. Black patients are also less likely to receive timely access to some therapies, undergo autologous stem cell transplant, or enroll in clinical trials. This article describes a large-scale, equity-focused implementation science initiative aimed at identifying and overcoming racial disparities and health inequity among patients with MM through quality improvement goals identified by each of the interprofessional cancer care teams. PRIMARY PRACTICE SETTINGS: Interprofessional cancer care teams in two large oncology systems as well as four community clinics were engaged in this study along with their patients with MM. Geographic areas included the following: Chicago, IL; Washington, DC; Charlotte, NC; Columbus, OH; Denver, CO; and Indianapolis, IN. Interprofessional teams included hematologists/oncologists, primary care physicians, nurse practitioners/physician assistants, and case managers/nurse navigators. Teams collectively examined and compared their own beliefs and attitudes about their patients' goals for MM treatment and management versus those of their patients to uncover and address discordances. Medical records from the clinics were audited to evaluate disparities in treatment and practice at the point of care. Live, team-based audit-feedback sessions were implemented among teams to examine data sets, as well as utilize the data to address interprofessional factors that could enhance more equitable care. FINDINGS/CONCLUSIONS: Data from comparative surveys between patients and interprofessional team members revealed significant discordances that enabled health care teams to recognize gaps and identify ways to improve patient-centered care, such as shared decision-making. Through audit-feedback sessions, interprofessional teams were able to collaboratively meet and discuss methods to improve access to care coordination services and other strategies aimed at alleviating disparities. Baseline chart audits revealed and confirmed disparities of care including patient/disease characteristics, treatment history, clinical practice metrics, and patient-centered measures. Follow-up chart audits conducted 6 months later measured changes in documented practice behavior. Action plans developed by the interprofessional teams as a result of this study intend to address sustainable reductions in health disparities among patients with MM to improve health equity and overall care. IMPLICATIONS FOR CASE MANAGEMENT PRACTICE: This implementation science initiative and data results have several implications for case managers caring for diverse patients with MM in both large health systems and smaller community practices. Results punctuate the importance of identifying and supporting diverse patients' individualized goals and preferences in their care journey to mitigate health inequity and maximize health outcomes. The value of working collaboratively as an interprofessional team is evident in the study results, as is the role of the case manager in appropriate resource allocation to mitigate health disparities. Lessons learned from this initiative may also be applied to other case management settings where complex care delivery and interprofessional teams are at work.