Single-Molecule Mechanical Analysis of Strand Invasion in Human Telomere DNA.

Telomeres are essential chromosome end capping structures that safeguard the genome from dangerous DNA processing events. DNA strand invasion occurs during vital transactions at telomeres, including telomere length maintenance by the alternative lengthening of telomeres (ALT) pathway. During telomeric strand invasion, a single-stranded guanine-rich (G-rich) DNA invades at a complementary duplex telomere repeat sequence, forming a displacement loop (D-loop) in which the displaced DNA consists of the same G-rich sequence as the invading single-stranded DNA. Single-stranded G-rich telomeric DNA readily folds into stable, compact, structures called G-quadruplexes (GQs) in vitro and is anticipated to form within the context of a D-loop; however, evidence supporting this hypothesis is lacking. Here, we report a magnetic tweezers assay that permits the controlled formation of telomeric D-loops (TDLs) within uninterrupted duplex human telomere DNA molecules of physiologically relevant lengths. Our results are consistent with a model wherein the displaced single-stranded DNA of a TDL fold into a GQ. This study provides new insight into telomere structure and establishes a framework for the development of novel therapeutics designed to target GQs at telomeres in cancer cells.

Telomere DNA G-quadruplex folding within actively extending human telomerase.

Telomerase reverse transcribes short guanine (G)-rich DNA repeat sequences from its internal RNA template to maintain telomere length. G-rich telomere DNA repeats readily fold into G-quadruplex (GQ) structures in vitro, and the presence of GQ-prone sequences throughout the genome introduces challenges to replication in vivo. Using a combination of ensemble and single-molecule telomerase assays, we discovered that GQ folding of the nascent DNA product during processive addition of multiple telomere repeats modulates the kinetics of telomerase catalysis and dissociation. Telomerase reactions performed with telomere DNA primers of varying sequence or using GQ-stabilizing K+ versus GQ-destabilizing Li+ salts yielded changes in DNA product profiles consistent with formation of GQ structures within the telomerase-DNA complex. Addition of the telomerase processivity factor POT1-TPP1 altered the DNA product profile, but was not sufficient to recover full activity in the presence of Li+ cations. This result suggests GQ folding synergizes with POT1-TPP1 to support telomerase function. Single-molecule Förster resonance energy transfer experiments reveal complex DNA structural dynamics during real-time catalysis in the presence of K+ but not Li+, supporting the notion of nascent product folding within the active telomerase complex. To explain the observed distributions of telomere products, we globally fit telomerase time-series data to a kinetic model that converges to a set of rate constants describing each successive telomere repeat addition cycle. Our results highlight the potential influence of the intrinsic folding properties of telomere DNA during telomerase catalysis, and provide a detailed characterization of GQ modulation of polymerase function.

Single-molecule FRET-Rosetta reveals RNA structural rearrangements during human telomerase catalysis.

Maintenance of telomeres by telomerase permits continuous proliferation of rapidly dividing cells, including the majority of human cancers. Despite its direct biomedical significance, the architecture of the human telomerase complex remains unknown. Generating homogeneous telomerase samples has presented a significant barrier to developing improved structural models. Here we pair single-molecule Förster resonance energy transfer (smFRET) measurements with Rosetta modeling to map the conformations of the essential telomerase RNA core domain within the active ribonucleoprotein. FRET-guided modeling places the essential pseudoknot fold distal to the active site on a protein surface comprising the C-terminal element, a domain that shares structural homology with canonical polymerase thumb domains. An independently solved medium-resolution structure of Tetrahymena telomerase provides a blind test of our modeling methodology and sheds light on the structural homology of this domain across diverse organisms. Our smFRET-Rosetta models reveal nanometer-scale rearrangements within the RNA core domain during catalysis. Taken together, our FRET data and pseudoatomic molecular models permit us to propose a possible mechanism for how RNA core domain rearrangement is coupled to template hybrid elongation.

Optofluidic wavelength division multiplexing for single-virus detection.

Optical waveguides simultaneously transport light at different colors, forming the basis of fiber-optic telecommunication networks that shuttle data in dozens of spectrally separated channels. Here, we reimagine this wavelength division multiplexing (WDM) paradigm in a novel context--the differentiated detection and identification of single influenza viruses on a chip. We use a single multimode interference (MMI) waveguide to create wavelength-dependent spot patterns across the entire visible spectrum and enable multiplexed single biomolecule detection on an optofluidic chip. Each target is identified by its time-dependent fluorescence signal without the need for spectral demultiplexing upon detection. We demonstrate detection of individual fluorescently labeled virus particles of three influenza A subtypes in two implementations: labeling of each virus using three different colors and two-color combinatorial labeling. By extending combinatorial multiplexing to three or more colors, MMI-based WDM provides the multiplexing power required for differentiated clinical tests and the growing field of personalized medicine.

Integrated magnetic tweezers and single-molecule FRET for investigating the mechanical properties of nucleic acid.

Many enzymes promote structural changes in their nucleic acid substrates via application of piconewton forces over nanometer length scales. Magnetic tweezers (MT) is a single molecule force spectroscopy method widely used for studying the energetics of such mechanical processes. MT permits stable application of a wide range of forces and torques over long time scales with nanometer spatial resolution. However, in any force spectroscopy experiment, the ability to monitor structural changes in nucleic acids with nanometer sensitivity requires the system of interest to be held under high degrees of tension to improve signal to noise. This limitation prohibits measurement of structural changes within nucleic acids under physiologically relevant conditions of low stretching forces. To overcome this challenge, researchers have integrated a spatially sensitive fluorescence spectroscopy method, single molecule-FRET, with MT to allow simultaneous observation and manipulation of nanoscale structural transitions over a wide range of forces. Here, we describe a method for using this hybrid instrument to analyze the mechanical properties of nucleic acids. We expect that this method for analysis of nucleic acid structure will be easily adapted for experiments aiming to interrogate the mechanical responses of other biological macromolecules.

The telomerase essential N-terminal domain promotes DNA synthesis by stabilizing short RNA-DNA hybrids.

Telomerase is an enzyme that adds repetitive DNA sequences to the ends of chromosomes and consists of two main subunits: the telomerase reverse transcriptase (TERT) protein and an associated telomerase RNA (TER). The telomerase essential N-terminal (TEN) domain is a conserved region of TERT proposed to mediate DNA substrate interactions. Here, we have employed single molecule telomerase binding assays to investigate the function of the TEN domain. Our results reveal telomeric DNA substrates bound to telomerase exhibit a dynamic equilibrium between two states: a docked conformation and an alternative conformation. The relative stabilities of the docked and alternative states correlate with the number of basepairs that can be formed between the DNA substrate and the RNA template, with more basepairing favoring the docked state. The docked state is further buttressed by the TEN domain and mutations within the TEN domain substantially alter the DNA substrate structural equilibrium. We propose a model in which the TEN domain stabilizes short RNA-DNA duplexes in the active site of the enzyme, promoting the docked state to augment telomerase processivity.

Mechanical unfolding of human telomere G-quadruplex DNA probed by integrated fluorescence and magnetic tweezers spectroscopy.

Single-molecule techniques facilitate analysis of mechanical transitions within nucleic acids and proteins. Here, we describe an integrated fluorescence and magnetic tweezers instrument that permits detection of nanometer-scale DNA structural rearrangements together with the application of a wide range of stretching forces to individual DNA molecules. We have analyzed the force-dependent equilibrium and rate constants for telomere DNA G-quadruplex (GQ) folding and unfolding, and have determined the location of the transition state barrier along the well-defined DNA-stretching reaction coordinate. Our results reveal the mechanical unfolding pathway of the telomere DNA GQ is characterized by a short distance (<1 nm) to the transition state for the unfolding reaction. This mechanical unfolding response reflects a critical contribution of long-range interactions to the global stability of the GQ fold, and suggests that telomere-associated proteins need only disrupt a few base pairs to destabilize GQ structures. Comparison of the GQ unfolded state with a single-stranded polyT DNA revealed the unfolded GQ exhibits a compacted non-native conformation reminiscent of the protein molten globule. We expect the capacity to interrogate macromolecular structural transitions with high spatial resolution under conditions of low forces will have broad application in analyses of nucleic acid and protein folding.

Anticipating and preventing complications in spinal cord stimulator implantation.

INTRODUCTION: Spinal cord stimulation is considered a minor elective procedure. The inherent goal is to provide safe, reliable, effective treatment with mitigation of known potential risk of adverse events. AREAS COVERED: This is a comprehensive literature review evaluating the most prevalent complications encountered with SCS implantation. EXPERT OPINION: SCS-related complications are uncommon. The authors offer clinical insight and feel the best practice is to have strategies employed to avoid complications, and we assist clinicians and surgeons in appropriately identifying and treating potential complications. There is a focus on appropriate patient selection, adherence to evidence-based guidelines and best practice recommendations.

Guidance for Handling the Increasing Prevalence of Drugs Adulterated or Laced With Fentanyl.

The use of fentanyl and its analogs is the primary driver of deaths related to the opioid overdose crisis. In fall 2021, the U.S. Drug Enforcement Administration issued its first public safety alert in 6 years to raise awareness of the escalating prevalence of fentanyl in counterfeit pills and in other opioids, such as heroin, and nonopioids, such as methamphetamine. In addition to increased public awareness, specific actions are needed to remediate the risk for fentanyl overdose. The authors endorse four principles to address the opioid overdose crisis and provide guidance for remediating its impacts: an incremental approach to behavior change or harm reduction; engagement strategies for individuals with substance use disorder; an integrated care approach to ensure better access to treatment programs and effective interventions; and vigilance among clinicians, program staff, and patients to the threat of fentanyl-adulterated drugs. The authors offer specific recommendations on how to apply these principles effectively within health care systems, communities, and law enforcement agencies across the United States.

Adaptation of a Mobile Interactive Obesity Treatment Approach for Early Severe Mental Illness: Protocol for a Mixed Methods Implementation and Pilot Randomized Controlled Trial.

BACKGROUND: Obesity is common in individuals with severe mental illness (SMI), contributing to a significantly shortened lifespan when compared to the general population. Available weight loss treatments have attenuated efficacy in this population, underscoring the importance of prevention and early intervention. OBJECTIVE: Here, we describe a type 1 hybrid study design for adapting and pilot-testing an existing mobile health intervention for obesity prevention in individuals with early SMI and Class I or early-stage obesity, defined as a BMI of 30-35. METHODS: An existing, evidence-based interactive obesity treatment approach using low-cost, semiautomated SMS text messaging was selected for adaptation. Community mental health clinics and Clubhouse settings in Eastern Missouri and South Florida were identified to participate. This study has the following 3 aims. First, using the Enhanced Framework for Reporting Adaptations and Modifications to Evidence-based interventions, contextual aspects of the clinical and digital treatment environments are identified for adaptation, considering 5 main stakeholder groups (clinical administrators, prescribing clinicians, case managers, nurses, and patients). Following a 2-week trial of unadapted SMS text messaging, Innovation Corps methods are used to discover needed intervention adaptations by stakeholder group and clinical setting. Second, adaptations to digital functionality and intervention content will be made based on themes identified in aim 1, followed by rapid usability testing with key stakeholders. A process for iterative treatment adaptation will be developed for making unplanned modifications during the aim 3 implementation pilot study. Individuals working in partner community mental health clinics and Clubhouse settings will be trained in intervention delivery. Third, in a randomized pilot and feasibility trial, adults with 5 years or less of treatment for an SMI diagnosis will be randomized 2:1 to 6 months of an adapted interactive obesity treatment approach or to an attentional control condition, followed by a 3-month extension phase of SMS text messages only. Changes in weight, BMI, and behavioral outcomes, as well as implementation challenges, will be evaluated at 6 and 9 months. RESULTS: Institutional review board approval for aims 1 and 2 was granted on August 12, 2018, with 72 focus group participants enrolled; institutional review board approval for aim 3 was granted on May 6, 2020. To date, 52 participants have been enrolled in the study protocol. CONCLUSIONS: In this type 1 hybrid study design, we apply an evidence-based treatment adaptation framework to plan, adapt, and feasibility test a mobile health intervention in real-world treatment settings. Resting at the intersection of community mental health treatment and physical health promotion, this study aims to advance the use of simple technology for obesity prevention in individuals with early-stage mental illness. TRIAL REGISTRATION: ClinicalTrials.gov NCT03980743; https://clinicaltrials.gov/ct2/show/NCT03980743. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/42114.

Lived Experience-Led Research Agenda to Address Early Death in People With a Diagnosis of a Serious Mental Illness: A Consensus Statement.

Importance: People with serious mental illness (SMI), defined as a diagnosis of schizophrenia spectrum disorder, bipolar disorder, or disabling major depressive disorder) die approximately 10 to 25 years earlier than the general population. Objective: To develop the first-ever lived experience-led research agenda to address early mortality in people with SMI. Evidence Review: A virtual 2-day roundtable comprising 40 individuals convened on May 24 and May 26, 2022, and used a virtual Delphi method to arrive at expert group consensus. Participants responded to 6 rounds of virtual Delphi discussion via email that prioritized research topics and agreement on recommendations. The roundtable was composed of individuals with lived experience of mental health and/or substance misuse, peer support specialists, recovery coaches, parents and caregivers of people with SMI, researchers and clinician-scientists with and without lived experience, policy makers, and patient-led organizations. Twenty-two of 28 (78.6%) of the authors who provided data represented people with lived experiences. Roundtable members were selected by reviewing the peer-reviewed and gray literature on early mortality and SMI, direct email, and snowball sampling. Findings: The following recommendations are presented in order of priority as identified by the roundtable participants: (1) improve the empirical understanding of the direct and indirect social and biological contributions of trauma on morbidity and early mortality; (2) advance the role of family, extended families, and informal supporters; (3) recognize the importance of co-occurring disorders and early mortality; (4) redefine clinical education to reduce stigma and support clinicians through technological advancements to improve diagnostic accuracy; (5) examine outcomes meaningful to people with an SMI diagnosis, such as loneliness and sense of belonging, and stigma and their complex relationship with early mortality; (6) advance the science of pharmaceuticals, drug discovery, and choice in medication use; (7) use precision medicine to inform treatment; and (8) redefine the terms system literacy and health literacy. Conclusions and Relevance: The recommendations of this roundtable are a starting point for changing practice and highlighting lived experience-led research priorities as an option to move the field forward.

The Impact of COVID-19 on Financing of Psychiatric Services.

The onset of the COVID-19 pandemic in early 2020 had a significant impact on the delivery of behavioral health services, with significant short-term and long-range consequences. Intertwined with the delivery of services has been the financial ramifications of the pandemic. The rapid response by governmental agencies to shore up financial support for clinical services, and the swift shift to virtual care provided relief for a broad array of practice settings; however, it did not mitigate the full impact of the pandemic. Effective state, national, and international leadership, communication, and coordination are critical to improve the global response to any pandemic.

Using Innovation-Corps (I-Corps™) Methods to Adapt a Mobile Health (mHealth) Obesity Treatment for Community Mental Health Settings.

Background: We employed Innovation Corps (I-Corps™) methods to adaptation of a mobile health (mHealth) short-message-system (SMS) -based interactive obesity treatment approach (iOTA) for adults with severe mentall illness receiving care in community settings. Methods: We hypothesized "jobs to be done" in three broad stakeholder groups: "decision makers" (DM = state and community clinic administrators), "clinician consumers" (CC = case managers, peer supports, nurses, prescribers) and "service consumers" (SC = patients, peers and family members). Semistructured interviews (N = 29) were recorded and transcribed ver batim and coded based on pragmatic-variant grounded theory methods. Results: Four themes emerged across groups: education, inertia, resources and ownership. Sub-themes in education and ownership differed between DM and CC groups on implementation ownership, intersecting with professional development, suggesting the importance of training and supervision in scalability. Sub-themes in resources and intertia differed between CC and SC groups, suggesting illness severity and access to healthy food as major barriers to engagement, whereas the SC group identified the need for enhanced emotional support, in addition to pragmatic skills like menu planning and cooking, to promote health behavior change. Although SMS was percieved as a viable education and support tool, CC and DM groups had limited familiarity with use in clinical care delivery. Conclusions: Based on customer discovery, the characteristics of a minimum viable iOTA for implementation, scalability and sustainability include population- and context-specific adaptations to treatment content, interventionist training and delivery mechanism. Successful implementation of an SMS-based intervention will likely require micro-adaptations to fit specific clinical settings.

Holding Insurers Accountable for Parity in Coverage of Mental Health Treatment.

Despite a series of federal laws aimed at ensuring parity in insurance coverage of treatment for mental health and general health conditions, patients with mental disorders continue to face discrimination by insurers. This inequity is often due to overly restrictive utilization review criteria that fail to conform to accepted professional standards. A recent class action challenge to the practices of the largest U.S. health insurer may represent an important step forward in judicial enforcement of parity laws. Rejecting the insurer's guidelines for coverage determinations as inconsistent with usual practices, the court enunciated eight principles that defined accepted standards of care.

The Behavioral Health System and Its Response to COVID-19: A Snapshot Perspective.

The global experience of the COVID-19 pandemic is unprecedented. The magnitude, pace, and uncertainty of the pandemic have taxed systems and catalyzed innovation in many fields, including behavioral health. Behavioral health leaders have absorbed changing information about regulations and laws, proper use of personal protective equipment, isolation and quarantine, telepsychiatry practices (broadly defined here as the use of virtual and telephonic means to provide behavioral health care), and financial opportunities and challenges while attending to the mental health needs of local populations. This Open Forum reviews many of the adaptations of the behavioral health system in response to COVID-19 on the basis of a point-in-time snapshot and describes needed multidimensional policy and practice considerations for the future.

Impact of the CATIE findings on state mental health policy.

The authors, who are medical directors of three state mental health agencies and members of the Medical Directors' Council of the National Association of State Mental Health Program Directors (NASMHPD), describe the impact on public mental health policy of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE). Before publication of the CATIE results, the preponderance of information indicated substantial and broad-ranging advantages of second-generation antipsychotics over first-generation agents. State mental health authorities focused on improving access to and increasing utilization of the newer agents. In many states, expenditures for these agents accounted for 10% of the total pharmacy budget of the Medicaid program. After CATIE, state policy makers have had to take a more critical look at the data and formulate more nuanced approaches. The authors summarize policy recommendations of the NASMHPD Medical Directors' Council, which reviewed efficacy studies of antipsychotics and formulated a position statement. The recommendations cover three broad areas of policy. First, neither complete open access for all patients at all times nor a uniform fail-first trial of a first-generation antipsychotic is an optimal approach. A more nuanced middle ground is necessary. Second, excessive emphasis on the cost of second-generation antipsychotics has led to a lack of focus on optimizing use of all antipsychotic medication in usual practice. More research and management attention must be focused on improving how these medications are prescribed for individual patients. Third, more resources should be invested in clinical trials that more clearly and accurately reflect current practice.

When is antipsychotic polypharmacy supported by research evidence? Implications for QI.

BACKGROUND: Concurrent use of multiple standing antipsychotics (antipsychotic polypharmacy) is increasingly common among both inpatients and outpatients. Although this has often been cited as a potential quality-of-care problem, reviews of research evidence on antipsychotic polypharmacy have not distinguished between appropriate versus inappropriate use. METHODS: A MEDLINE search from 1966 to December 2007 was completed to identify studies comparing changes in symptoms, functioning, and/or side effects between patients treated with multiple antipsychotics and patients treated with a single antipsychotic. The studies were reviewed in two groups on the basis of whether prescribing was concordant with guideline recommendations for multiple-antipsychotic use. RESULTS: A review of the literature, including three randomized controlled trials, found no support for the use of antipsychotic polypharmacy in patients without an established history of treatment resistance to multiple trials of monotherapy. In patients with a history of treatment resistance to multiple monotherapy trials, limited data support antipsychotic polypharmacy, but positive outcomes were primarily found in studies of clozapine augmented with a second-generation antipsychotic. DISCUSSION: Research evidence is consistent with the goal of avoiding antipsychotic polypharmacy in patients who lack guideline-recommended indications for its use. The Joint Commission is implementing a core measure set for Hospital-Based Inpatient Psychiatric Services. Two of the measures address antipsychotic polypharmacy. The first measure assesses the overall rate. The second measure determines whether clinically appropriate justification has been documented supporting the use of more than one antipsychotic medication.

Psychiatry's Role in Improving the Physical Health of Patients With Serious Mental Illness: A Report From the American Psychiatric Association.

The American Psychiatric Association Integrated Care Workgroup recently convened an expert panel charged with addressing the role of psychiatry in improving the physical health of persons with serious mental illness. The group reviewed the peer-reviewed and gray literature and developed a set of recommendations grounded in this review. This column summarizes the panel's primary findings and recommendations to key stakeholders, including clinicians, health care organizations, researchers, and policy makers.

Single-Molecule Studies of Telomeres and Telomerase.

Telomeres are specialized chromatin structures that protect chromosome ends from dangerous processing events. In most tissues, telomeres shorten with each round of cell division, placing a finite limit on cell growth. In rapidly dividing cells, including the majority of human cancers, cells bypass this growth limit through telomerase-catalyzed maintenance of telomere length. The dynamic properties of telomeres and telomerase render them difficult to study using ensemble biochemical and structural techniques. This review describes single-molecule approaches to studying how individual components of telomeres and telomerase contribute to function. Single-molecule methods provide a window into the complex nature of telomeres and telomerase by permitting researchers to directly visualize and manipulate the individual protein, DNA, and RNA molecules required for telomere function. The work reviewed in this article highlights how single-molecule techniques have been utilized to investigate the function of telomeres and telomerase.