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The membrane attack complex (MAC) is one of the immune system’s first responders. Complement proteins assemble on target membranes to form pores that lyse pathogens and impact tissue homeostasis of self-cells. How MAC disrupts the membrane barrier remains unclear. Here we use electron cryo-microscopy and flicker spectroscopy to show that MAC interacts with lipid bilayers in two distinct ways. Whereas C6 and C7 associate with the outer leaflet and reduce the energy for membrane bending, C8 and C9 traverse the bilayer increasing membrane rigidity. CryoEM reconstructions reveal plasticity of the MAC pore and demonstrate how C5b6 acts as a platform, directing assembly of a giant β-barrel whose structure is supported by a glycan scaffold. Our work provides a structural basis for understanding how β-pore forming proteins breach the membrane and reveals a mechanism for how MAC kills pathogens and regulates cell functions. The complement membrane attack complex (MAC) is a lytic immune pore that kills pathogens. Here the authors use cryoEM to provide a structural and biophysical mechanism for how β-pore forming proteins breach the lipid bilayer, providing pathways to explore pore-formation in molecular detail.

Cholesterol-dependent cytolysins (CDCs) are pore-forming proteins that serve as major virulence factors for pathogenic bacteria. They target eukaryotic cells using different mechanisms, but all require the presence of cholesterol to pierce lipid bilayers. How CDCs use cholesterol to selectively lyse cells is essential for understanding virulence strategies of several pathogenic bacteria, and for repurposing CDCs to kill new cellular targets. Here we address that question by trapping an early state of pore formation for the CDC intermedilysin, bound to the human immune receptor CD59 in a nanodisc model membrane. Our cryo electron microscopy map reveals structural transitions required for oligomerization, which include the lateral movement of a key amphipathic helix. We demonstrate that the charge of this helix is crucial for tuning lytic activity of CDCs. Furthermore, we discover modifications that overcome the requirement of cholesterol for membrane rupture, which may facilitate engineering the target-cell specificity of pore-forming proteins. Cholesterol-dependent cytolysins (CDCs) are bacterial pore-forming virulence factors. Cryo-EM structure of an early conformation of the CDC ILY from Streptococcus intermedius , bound to the human immune receptor CD59, provides insight into ILY oligomerization and role of cholesterol in membrane lysis.

A systematic review was conducted using Samueli Institute’s Rapid Evidence Assessment of the Literature (REAL©) process to determine the evidence base for melatonin as an agent to optimize sleep or improve sleep quality, and generalize the results to a military, civilian, or other healthy, active, adult population. Multiple databases were searched yielding 35 randomized controlled trials (RCTs) meeting the review’s inclusion criteria, which were assessed for methodological quality as well as for melatonin effectiveness. The majority of included studies were high quality (83.0%). Overall, according to Grading Recommendations, Assessment Development and Evaluation (GRADE) methodology, weak recommendations were made for preventing phase shifts from jet lag, for improving insomnia in both healthy volunteers and individuals with a history of insomnia, and for initiating sleep and/or improving sleep efficacy. Based on the literature to date, no recommendations for use in shift workers or to improve hormonal phase shift changes in healthy people can be made at this time. Larger and longer-duration RCTs utilizing well characterized products are needed to warrant melatonin recommendations in young, healthy adults.

Abstract Purpose. Pain is multi-dimensional and may be better addressed through a holistic, biopsychosocial approach. Massage therapy is commonly practiced among patients seeking pain management; however, its efficacy is unclear. This systematic review and meta-analysis is the first to rigorously assess the quality of massage therapy research and evidence for its efficacy in treating pain, function-related and health-related quality of life outcomes across all pain populations. Methods. Key databases were searched from inception through February 2014. Eligible randomized controlled trials were assessed for methodological quality using SIGN 50 Checklist. Meta-analysis was applied at the outcome level. A diverse steering committee interpreted the results to develop recommendations. Results. Sixty high quality and seven low quality studies were included in the review. Results demonstrate massage therapy effectively treats pain compared to sham [standardized mean difference (SMD) = −.44], no treatment (SMD = −1.14), and active (SMD = −0.26) comparators. Compared to active comparators, massage therapy was also beneficial for treating anxiety (SMD = −0.57) and health-related quality of life (SMD = 0.14). Conclusion. Based on the evidence, massage therapy, compared to no treatment, should be strongly recommended as a pain management option. Massage therapy is weakly recommended for reducing pain, compared to other sham or active comparators, and improving mood and health-related quality of life, compared to other active comparators. Massage therapy safety, research challenges, how to address identified research gaps, and necessary next steps for implementing massage therapy as a viable pain management option are discussed.

Neurofeedback in the treatment of psychological disorders has gained increasingly widespread interest in recent years. As the use of neurofeedback training expands, it is important to elucidate its treatment efficacy, especially for prevalent and debilitating psychopathologies such as posttraumatic stress disorder (PTSD). Likewise, furthering our understanding of the underlying neural mechanisms by which neurofeedback acts is also necessary. Here, we present the results of a PROSPERO registered (protocol number: CRD42020184659) meta-analysis of randomized controlled trials (RCTs) of neurofeedback training for treatment of PTSD in adults. We evaluate the efficacy of different neurofeedback modalities used to treat PTSD, including functional magnetic resonance imaging neurofeedback (fMRI-NF) and electroencephalogram neurofeedback (EEG-NF). We also differentiate active control (sham or yoked sham) studies from passive control (waitlist, treatment as usual, no treatment, and any non-neurofeedback based intervention) studies. Our results show that EEG-NF has a moderate to large effect in reducing PTSD symptoms pre- to post-treatment compared to passive controls (k = 5). Two fMRI-NF RCTs, both using sham controls, showed no improvement in PTSD symptoms, pre- to post-treatment. However, our confidence in these findings is very low to low due to concerns regarding risk of bias, imprecision, and conflicts of interest. Neurofeedback in passive control studies outperformed neurofeedback in active control studies relative to their respective control treatment arms. We also synthesized the neural results from these studies and found that between-group neural effects were generally inconclusive. These findings highlight the need for improved controls in studies examining neurofeedback for PTSD to reliably determine whether neurofeedback training, or other factors, are the basis for improvements in PTSD symptoms. We elaborate on some of the underlying neural mechanisms by which neurofeedback training shows potential in improving PTSD symptoms to guide future developments and provide recommendations for future neurofeedback interventions in treating PTSD.

The plasma membrane provides an essential barrier, shielding a cell from the pressures of its external environment. Pore-forming proteins, deployed by both hosts and pathogens alike, breach this barrier to lyse target cells. Intermedilysin is a cholesterol-dependent cytolysin that requires the human immune receptor CD59, in addition to cholesterol, to form giant β-barrel pores in host membranes. Here we integrate biochemical assays with electron microscopy and atomic force microscopy to distinguish the roles of these two receptors in mediating structural transitions of pore formation. CD59 is required for the specific coordination of intermedilysin (ILY) monomers and for triggering collapse of an oligomeric prepore. Movement of Domain 2 with respect to Domain 3 of ILY is essential for forming a late prepore intermediate that releases CD59, while the role of cholesterol may be limited to insertion of the transmembrane segments. Together these data define a structural timeline for ILY pore formation and suggest a mechanism that is relevant to understanding other pore-forming toxins that also require CD59.

Abstract Objective Approximately 55–76% of Service members use dietary supplements for various reasons, including pain and related outcomes. This work evaluates current research on dietary ingredients for chronic musculoskeletal pain to inform decisions for practice and self-care, specifically for Special Operations Forces personnel. Methods A steering committee convened to develop research questions and factors required for decision-making. Key databases were searched through August 2016. Eligible systematic reviews and randomized controlled trials were assessed for methodological quality. Meta-analysis was applied where feasible. GRADE was used to determine confidence in the effect estimates. The committee made evidence-informed judgments and recommendations for practice and self-care use. Results Nineteen eligible dietary ingredients were assessed for quality, efficacy, and safety. Avocado soybean unsaponifiables, capsaicin, curcuma, ginger (as a food source), glucosamine, melatonin, polyunsaturated fatty acids, and vitamin D were conditionally recommended as their benefits outweighed risks, but there was still some uncertainty about the trade-offs. No recommendations were made for boswellia, ginger (as a dietary supplement), rose hip, or s-adenosyl-L-methionine. Recommendations were made against the use of collagen, creatine, devil’s claw, l-carnitine, methylsulfonylmethane, pycnogenol, willow bark extract, and vitamin E. Research priorities were developed to address gaps precluding stronger recommendations. Conclusions Currently the scientific evidence is insufficiently robust to establish definitive clinical practice guidelines, but processes could be established to track the impact of these ingredients. Until then, providers have the evidence needed to make informed decisions about the safe use of these dietary ingredients, and future research can address existing gaps.

The increased utilization of metrology resources and expanded application of its’ approaches in the development of internationally agreed upon measurements can lay the basis for regulatory harmonization, support reproducible research, and advance scientific understanding, especially of dietary supplements and herbal medicines. Yet, metrology is often underappreciated and underutilized in dealing with the many challenges presented by these chemically complex preparations. This article discusses the utility of applying rigorous analytical techniques and adopting metrological principles more widely in studying dietary supplement products and ingredients, particularly medicinal plants and other botanicals. An assessment of current and emerging dietary supplement characterization methods is provided, including targeted and non-targeted techniques, as well as data analysis and evaluation approaches, with a focus on chemometrics, toxicity, dosage form performance, and data management. Quality assessment, statistical methods, and optimized methods for data management are also discussed. Case studies provide examples of applying metrological principles in thorough analytical characterization of supplement composition to clarify their health effects. A new frontier for metrology in dietary supplement science is described, including opportunities to improve methods for analysis and data management, development of relevant standards and good practices, and communication of these developments to researchers and analysts, as well as to regulatory and policy decision makers in the public and private sectors. The promotion of closer interactions between analytical, clinical, and pharmaceutical scientists who are involved in research and product development with metrologists who develop standards and methodological guidelines is critical to advance research on dietary supplement characterization and health effects.

Abstract Purpose. Pain is multi-dimensional and may be better addressed through a holistic, biopsychosocial approach. Massage therapy is commonly practiced among patients seeking pain management; however, its efficacy is unclear. This systematic review and meta-analysis is the first to rigorously assess the quality of massage therapy research and evidence for its efficacy in treating pain, function-related and health-related quality of life in cancer populations. Methods. Key databases were searched from inception through February 2014. Eligible randomized controlled trials were assessed for methodological quality using the SIGN 50 Checklist. Meta-analysis was applied at the outcome level. A diverse steering committee interpreted the results to develop recommendations. Results. Twelve high quality and four low quality studies were subsequently included in the review. Results demonstrate massage therapy is effective for treating pain compared to no treatment [standardized mean difference (SMD)  = −.20] and active (SMD = −0.55) comparators. Compared to active comparators, massage therapy was also found to be beneficial for treating fatigue (SMD = −1.06) and anxiety (SMD = −1.24). Conclusion. Based on the evidence, weak recommendations are suggested for massage therapy, compared to an active comparator, for the treatment of pain, fatigue, and anxiety. No recommendations were suggested for massage therapy compared to no treatment or sham control based on the available literature to date. This review addresses massage therapy safety, research challenges, how to address identified research gaps, and necessary next steps for implementing massage therapy as a viable pain management option for cancer pain populations.

ObjectiveThe study objective was to examine if interventions changing access to lethal means are associated with changes in suicide deaths and/or attempts by conducting a systematic review of controlled intervention studies.MethodsAuthors searched key databases (PubMed, PsycInfo, CINAHL) from inception to March 2024 for longitudinal controlled intervention studies with at least one contemporaneous comparator group evaluating the impact of interventions changing access to lethal means on suicide attempts and/or deaths in a primarily adult population. Reviewers dually screened articles, then extracted study characteristics and assessed methodological quality.ResultsResearchers screened 8522 studies and 36 articles met eligibility for inclusion. Most studies evaluated the impact of population-level firearm interventions on suicide deaths and found that stricter regulations were associated with a small reduction, if any, in total and/or firearm-specific suicide deaths. The ecological level of analysis precluded individual-level causal inference. Findings within interventions targeting methods other than firearms were limited, mixed and/or inconclusive. Notably, no high-quality randomised controlled trials (RCTs) were identified that met our eligibility criteria.ConclusionFuture studies should use an RCT design or advanced statistical causal inference techniques to further elucidate the effectiveness of these interventions on suicide deaths and/or attempts.PROSPERO registration numberCRD42022364775.