ABSTRACT
Murine norovirus (MNV) undergoes extremely large conformational changes in response to the environment. The T = 3 icosahedral capsid is composed of 180 copies of ~58-kDa VP1 comprised of N-terminus (N), shell (S), and C-terminal protruding (P) domains. At neutral pH, the P domains are loosely tethered to the shell and float ~15 Å above the surface. At low pH or in the presence of bile salts, the P domain drops onto the shell and this movement is accompanied by conformational changes within the P domain that enhance receptor interactions while blocking antibody binding. While previous crystallographic studies identified metal binding sites in the isolated P domain, the ~2.7-Å cryo-electron microscopy structures of MNV in the presence of Mg2+ or Ca2+ presented here show that metal ions can recapitulate the contraction observed at low pH or in the presence of bile. Further, we show that these conformational changes are reversed by dialysis against EDTA. As observed in the P domain crystal structures, metal ions bind to and contract the G'H' loop. This movement is correlated with the lifting of the C'D' loop and rotation of the P domain dimers about each other, exposing the bile salt binding pocket. Isothermal titration calorimetry experiments presented here demonstrate that the activation signals (bile salts, low pH, and metal ions) act in a synergistic manner that, individually, all result in the same activated structure. We present a model whereby these reversible conformational changes represent a uniquely dynamic and tissue-specific structural adaptation to the in vivo environment.IMPORTANCEThe highly mobile protruding domains on the calicivirus capsids are recognized by cell receptor(s) and antibodies. At neutral pH, they float ~15 Å above the shell but at low pH or in the presence of bile salts, they contract onto the surface. Concomitantly, changes within the P domain block antibody binding while enhancing receptor binding. While we previously demonstrated that metals also block antibody binding, it was unknown whether they might also cause similar conformational changes in the virion. Here, we present the near atomic cryo-electron microscopy structures of infectious murine norovirus (MNV) in the presence of calcium or magnesium ions. The metal ions reversibly induce the same P domain contraction as low pH and bile salts and act in a synergistic manner with the other stimuli. We propose that, unlike most other viruses, MNV facilely changes conformations as a unique means to escape immune surveillance as it moves through various tissues.
Subject(s)
Calcium , Magnesium , Norovirus , Animals , Mice , Bile Acids and Salts , Capsid/ultrastructure , Capsid Proteins/chemistry , Cryoelectron Microscopy , Norovirus/chemistry , Norovirus/ultrastructure , Calcium/chemistry , Magnesium/chemistryABSTRACT
PURPOSE: People with advanced or metastatic cancer and their caregivers may have different care goals and face unique challenges compared to those with early-stage disease or those nearing the end-of-life. These MASCC-ASCO standards and practice recommendations seek to establish consistent provision of quality survivorship care for people affected by advanced or metastatic cancer. METHODS: An expert panel comprising MASCC and ASCO members was formed. Standards and recommendations relevant to the provision of quality survivorship care for people affected by advanced or metastatic cancer were developed through conducting: (1) a systematic review of unmet supportive care needs; (2) a scoping review of cancer survivorship, supportive care, and palliative care frameworks and guidelines; and (3) an international modified Delphi consensus process. RESULTS: A systematic review involving 81 studies and a scoping review of 17 guidelines and frameworks informed the initial standards and recommendations. Subsequently, 77 experts (including 8 people with lived experience) across 33 countries (33% were low-to-middle resource countries) participated in the Delphi study and achieved ≥ 94.8% agreement for seven standards (1. Person-Centred Care; 2. Coordinated and Integrated Care; 3. Evidence-Based and Comprehensive Care; 4. Evaluated and Communicated Care; 5. Accessible and Equitable Care; 6. Sustainable and Resourced Care; 7. Research and Data-Driven Care) and ≥ 84.2% agreement across 45 practice recommendations. CONCLUSION: Standards of survivorship care for people affected by advanced or metastatic cancer are provided. These MASCC-ASCO standards will support optimization of health outcomes and care experiences by providing guidance to stakeholders in cancer care (healthcare professionals, leaders, and administrators; governments and health ministries; policymakers; advocacy agencies; cancer survivors and caregivers. Practice recommendations may be used to facilitate future research, practice, policy, and advocacy efforts.
Subject(s)
Cancer Survivors , Neoplasms , Palliative Care , Survivorship , Humans , Delphi Technique , Neoplasm Metastasis , Neoplasms/therapy , Palliative Care/standards , Palliative Care/methods , Patient-Centered Care/standards , Patient-Centered Care/organization & administration , Practice Guidelines as Topic , Quality of Health Care/standardsABSTRACT
BACKGROUND: The fear of taking away hope hinders clinicians' willingness to share serious news with patients with advanced disease. Unrealistic illness expectations, on the other hand, can complicate decision making and end-of-life care outcomes. Exploration of the association between hope and illness expectations can support clinicians in better communication with their patients. AIM: The aim of this study was to explore whether realistic illness expectations are associated with reduced hope in people with advanced cancer. DESIGN: This is a cross-sectional secondary analysis of baseline data from a primary palliative care cluster-randomized trial CONNECT (data collected from July 2016 to October 2020). Hope was measured by Herth Hope Index. Illness expectations were measured by assessing patients' understanding of their treatment goals, life expectancy, and terminal illness acknowledgement. Multivariable regression was performed, adjusting for demographical and clinical confounders. SETTING/PARTICIPANTS: Adult patients with advanced solid cancers recruited across 17 oncology clinics. RESULTS: Data from 672 patients were included in the study, with mean age of 69.3 years (±10.2), 53.6% were female. Proportion of patients indicating realistic expectations varied based on which question was asked from 10% to 46%. Median level of hope was 39 (IQR = 36-43). Multivariate non-inferiority regression did not find any significant differences in hope between patients with more and less realistic illness expectations. CONCLUSIONS: Our results suggest that hope can be sustained while holding both realistic and unrealistic illness expectations. Communication about serious news should focus on clarifying the expectations as well as supporting people's hopes.
Subject(s)
Neoplasms , Terminal Care , Adult , Aged , Female , Humans , Male , Cross-Sectional Studies , Hope , Motivation , Neoplasms/therapy , Palliative Care/methods , Middle Aged , Randomized Controlled Trials as TopicABSTRACT
Homeless persons with dogs are often the subject of stigma, with the public criticising them for not having a proper lifestyle to care for a pet. There is solid documentation of how dogs enhance a homeless person's life, but there are few publications that address the welfare of the dog. This descriptive study assesses the physical and behavioural health of dogs belonging to homeless persons through a One Welfare lens by observing animal/human well-being, environment, and "a life worth living". A survey was carried out along with a visual assessment of the condition of the dog for 100 human-dog dyads in the Western United States. Results showed that dogs of homeless persons were well cared for and physically healthy (which was consistent with other studies), and had few behavioural problems, but did display evidence of separation distress while the owner was away. Results from this study can provide information that may lead to policy and practice changes, including, for example, changes to policies and practices prohibiting dogs from being kept with their owner while staying at a homeless shelter. Typically, shelters report that they do not have the resources to care for a person with a dog.
ABSTRACT
Isoprene (2-methyl-1,3-butadiene) is emitted to the atmosphere each year in sufficient quantities to rival methane (>500 Tg C yr-1 ), primarily due to emission by trees and other plants. Chemical reactions of isoprene with other atmospheric compounds, such as hydroxyl radicals and inorganic nitrogen species (NOx ), have implications for global warming and local air quality, respectively. For many years, it has been estimated that soil-dwelling bacteria consume a significant amount of isoprene (~20 Tg C yr-1 ), but the mechanisms underlying the biological sink for isoprene have been poorly understood. Studies have indicated or confirmed the ability of diverse bacterial genera to degrade isoprene, whether by the canonical iso-type isoprene degradation pathway or through other less well-characterized mechanisms. Here, we review current knowledge of isoprene metabolism and highlight key areas for further research. In particular, examples of isoprene-degraders that do not utilize the isoprene monooxygenase have been identified in recent years. This has fascinating implications both for the mechanism of isoprene uptake by bacteria, and also for the ecology of isoprene-degraders in the environments.
Subject(s)
Bacteria , Hemiterpenes , Hemiterpenes/chemistry , Hemiterpenes/metabolism , Bacteria/genetics , Bacteria/metabolism , Butadienes/chemistry , Butadienes/metabolism , Plants/metabolism , Pentanes/chemistry , Pentanes/metabolismABSTRACT
Analyses of morphological disparity can incorporate living and fossil taxa to facilitate the exploration of how phenotypic variation changes through time. However, taphonomic processes introduce non-random patterns of data loss in fossil data and their impact on perceptions of disparity is unclear. To address this, we characterize how measures of disparity change when simulated and empirical data are degraded through random and structured data loss. We demonstrate that both types of data loss can distort the disparity of clades, and that the magnitude and direction of these changes varies between the most commonly employed distance metrics and disparity indices. The inclusion of extant taxa and exceptionally preserved fossils mitigates these distortions and clarifies the full extent of the data lost, most of which would otherwise go uncharacterized. This facilitates the use of ancestral state estimation and evolutionary simulations to further control for the effects of data loss. Where the addition of such reference taxa is not possible, we urge caution in the extrapolation of general patterns in disparity from datasets that characterize subsets of phenotype, which may represent no more than the traits that they sample.
Subject(s)
Biological Evolution , Fossils , Phylogeny , PhenotypeABSTRACT
OBJECTIVE: The objective was to qualitatively synthesize all reported cases of complications, adverse effects, side effects, or harms arising from the use of scrambler therapy (ST). METHODS AND DESIGN: A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The PubMed, Embase, Scopus, Web of Science, United States National Library of Medicine clinical trials registry, and Cochrane Central Register of Controlled Trials databases were searched from database inception to December 10, 2021. Case reports/series, abstracts, retrospective studies, and prospective studies (e.g., open-label trials, randomized controlled trials) pertaining to ST and any description of a complication, adverse effect, side effect, or harm were screened. The search protocol was developed a priori and registered via the International Prospective Register of Systematic Reviews (PROSPERO ID: CRD42021291838). RESULTS: A total of six RCTs, 19 prospective open-label trials, and 11 case series / case reports met the inclusion criteria, comprising 1,152 total patients. Two patients experienced contact dermatitis, and one patient reported minor ecchymosis that resolved without intervention. This yielded a composite complication rate of 0.26% (3/1,152). There were zero reported serious adverse events. CONCLUSIONS: When used in accordance with the treatment protocols described by the United States Food and Drug Administration and device manual, ST is associated with a reported composite complication rate that is orders of magnitude lower than those of invasive neuromodulation devices. ST neuromodulation is a safe alternative for patients who cannot undergo invasive neuromodulation device implantation because of either risk or preference.
Subject(s)
Drug-Related Side Effects and Adverse Reactions , United States , Humans , Prospective Studies , Retrospective StudiesABSTRACT
BACKGROUND: There are persistent racial and ethnic health disparities in end-of-life health outcomes in the United States. African American patients are less likely than White patients to access palliative care, enroll in hospice care, have documented goals of care discussions with their healthcare providers, receive adequate symptom control, or die at home. We developed Community Health Worker Intervention for Disparities in Palliative Care (DeCIDE PC) to address these disparities. DeCIDE PC is an integrated community health worker (CHW) palliative care intervention that uses community health workers (CHWs) as care team members to enhance the receipt of palliative care for African Americans with advanced cancer. The overall objectives of this study are to (1) assess the effectiveness of the DeCIDE PC intervention in improving palliative care outcomes amongst African American patients with advanced solid organ malignancy and their informal caregivers, and (2) develop generalizable knowledge on how contextual factors influence implementation to facilitate dissemination, uptake, and sustainability of the intervention. METHODS: We will conduct a multicenter, randomized, assessor-blind, parallel-group, pragmatic, hybrid type 1 effectiveness-implementation trial at three cancer centers across the United States. The DeCIDE PC intervention will be delivered over 6 months with CHW support tailored to the individual needs of the patient and caregiver. The primary outcome will be advance care planning. The treatment effect will be modeled using logistic regression. The secondary outcomes are quality of life, quality of communication, hospice care utilization, and patient symptoms. DISCUSSION: We expect the DeCIDE PC intervention to improve integration of palliative care, reduce multilevel barriers to care, enhance clinic and patient linkage to resources, and ultimately improve palliative care outcomes for African American patients with advanced cancer. If found to be effective, the DeCIDE PC intervention may be a transformative model with the potential to guide large-scale adoption of promising strategies to improve palliative care use and decrease disparities in end-of-life care for African American patients with advanced cancer in the United States. TRIAL REGISTRATION: Registered on ClinicalTrials.gov (NCT05407844). First posted on June 7, 2022.
Subject(s)
Hospice and Palliative Care Nursing , Terminal Care , Humans , Palliative Care , Community Health Workers , Quality of Life , Death , Randomized Controlled Trials as Topic , Multicenter Studies as TopicABSTRACT
BACKGROUND: To identify candidate inflammatory biomarkers for the underlying mechanism of auricular point acupressure (APA) on pain relief and examine the correlations among pain intensity, interference, and inflammatory biomarkers. DESIGN: This is a secondary data analysis. METHODS: Data on inflammatory biomarkers collected via blood samples and patient self-reported pain intensity and interference from three pilot studies (chronic low back pain, n = 61; arthralgia related to aromatase inhibitors, n = 20; and chemotherapy-induced neuropathy, n = 15) were integrated and analyzed. This paper reports the results based on within-subject treatment effects (change in scores from pre- to post-APA intervention) for each study group (chronic low back pain, cancer pain), between-group differences (changes in scores from pre- to post-intervention between targeted-point APA [T-APA] and non-targeted-point APA [NT-APA]), and correlations among pain intensity, interference, and biomarkers. RESULTS: Within-group analysis (the change score from pre- to post-APA) revealed statistically significant changes in three biomarkers: TNF-α (cancer pain in the APA group, p = .03), ß-endorphin (back pain in the APA group, p = .04), and IL-2 (back pain in the NT-APA group, p = .002). Based on between-group analysis in patients with chronic low back pain (T-APA vs NT-APA), IL-4 had the largest effect size (0.35), followed by TNF-α (0.29). A strong positive monotonic relationship between IL-1ß and IL-2 was detected. CONCLUSIONS: The current findings further support the potential role of inflammatory biomarkers in the analgesic effects of APA. More work is needed to gain a comprehensive understanding of the underlying mechanisms of APA on chronic pain. Because it is simple, inexpensive, and has no negative side effects, APA can be widely disseminated as an alternative to opioids.
Subject(s)
Acupressure , Cancer Pain , Low Back Pain , Humans , Low Back Pain/therapy , Treatment Outcome , Acupressure/methods , Interleukin-2 , Tumor Necrosis Factor-alphaABSTRACT
BACKGROUND: Scrambler therapy (ST) is a noninvasive method of transcutaneous neuromodulation that has 510(K) clearance from the United States Food and Drug Administration for treating acute pain, postoperative pain, and intractable chronic pain. Since its inception, ST has been used to treat many chronic pain syndromes in a variety of patient populations. We synthesized the available literature for ST to delineate its overall evidence basis. MATERIALS AND METHODS: We performed a systematic review based on conventional Preferred Reporting Items for Systematic Reviews and Meta-Analyses methods by surveying multiple data sources from January 1950 through October 2021. Two review authors, independently and in a standardized, unblinded fashion, conducted a systematic review to identify relevant studies and extract the necessary outcome measures. A conservative search strategy was implemented to identify all ST studies for the treatment of chronic pain syndromes. Primary outcome parameters collected were analgesic benefit, adverse effects, and other metrics such as sensorimotor testing. RESULTS: A total of 21 studies met the final criteria for study inclusion and comprised randomized controlled trials (n = 8), prospective observational studies (n = 10), and retrospective cohort studies (n = 3). Nearly all the reported studies explored the use of ST for the treatment of neuropathic pain, with chemotherapy-induced peripheral neuropathy being the most studied condition. Most studies were limited by small cohorts but reported ST being safe, well tolerated, and providing clinically meaningful pain reduction. The duration of posttreatment follow-up ranged from ten to 14 days (concordant with completion of typical ST protocols) to three months. Secondary benefits such as medication reduction and improvement of sensory and motor symptoms were noted by some studies. CONCLUSIONS: ST is regarded as a safe intervention with potential for significant analgesic benefit for neuropathic pain conditions. Although the available evidence is most robust for treating chemotherapy-induced peripheral neuropathy, ST has also been shown to be effective in treating other neuropathic pain syndromes. Evidence for ST use in nociceptive pain conditions is limited but appears promising. The favorable safety profile and increasing evidence basis for ST warrant more extensive recognition and consideration for use in clinical care.
Subject(s)
Antineoplastic Agents , Chronic Pain , Neuralgia , Humans , Chronic Pain/drug therapy , Retrospective Studies , Analgesics/therapeutic use , Neuralgia/therapy , Randomized Controlled Trials as Topic , Observational Studies as TopicABSTRACT
Objective: Social adjustment, including alcohol use, directly affects the success of college students. Due to an increased reliance on computer-delivered alcohol interventions (CDIs) a need has emerged to further investigate alcohol use and web-based interventions. Methods: In-depth focus group interviews were conducted with 51 undergraduate students to elicit information from students on the shared experience of participating in a CDI. Results: Participants identified the influence of gender, culture, parents, and family on alcohol use behavior. A difference in personal factors, previous exposure, and experiences can affect the attitudes, behaviors, and outcomes of a CDI. Conclusion: Multiple approaches geared towards a wide variety of students from different backgrounds and environments are needed to be truly successful in preventing alcohol misuse.
Subject(s)
Alcohol Drinking , Ethanol , Humans , Alcohol Drinking/prevention & control , Attitude , Parents , Students , UniversitiesABSTRACT
Human norovirus is the leading cause of gastroenteritis worldwide, with no approved vaccine or antiviral treatment to mitigate infection. These plus-strand RNA viruses have T = 3 icosahedral protein capsids with 90 pronounced protruding (P) domain dimers, to which antibodies and cellular receptors bind. We previously demonstrated that bile binding to the capsid of mouse norovirus (MNV) causes several major conformational changes; the entire P domain rotates by â¼90° and contracts onto the shell, the P domain dimers rotate about each other, and the structural equilibrium of the epitopes at the top of the P domain shifts toward the closed conformation, which favors receptor binding while blocking antibody binding. Here, we demonstrate that MNV undergoes reversible conformational changes at pH 5.0 that are nearly identical to those observed when bile binds. Notably, at low pH or when metals bind, a cluster of acidic resides in the G'-H' loop interact and distort the G'-H' loop, and this may drive C'-D' loop movement toward the closed conformation. Enzyme-linked immunosorbent assays with infectious virus particles at low pH or in the presence of metals demonstrated that all tested antibodies do not bind to this contracted form, akin to what was observed with the MNV-bile complex. Therefore, low pH, cationic metals, and bile salts are physiological triggers in the gut for P domain contraction and structural rearrangement, which synergistically prime the virus for receptor binding while blocking antibody binding. IMPORTANCE The protruding domains on the calicivirus capsids are recognized by cell receptors and antibodies. We demonstrated that MNV P domains are highly mobile, and bile causes contraction onto the shell surface while allosterically blocking antibody binding. We present the near-atomic cryo-electron microscopy structures of infectious MNV at pH 5.0 and pH 7.5. Surprisingly, low pH is sufficient to cause the same conformational changes as when bile binds. A cluster of acidic residues on the G'-H' loop were most likely involved in the pH effects. These residues also bound divalent cations and had the same conformation as observed here at pH 5. Binding assays demonstrated that low pH and metals block antibody binding, and thus the G'-H' loop might be driving the conformational changes. Therefore, low pH, cationic metals, and bile salts in the gut synergistically prime the virus for receptor binding while blocking antibody binding.
Subject(s)
Antibodies, Viral/metabolism , Caliciviridae Infections/virology , Capsid Proteins/metabolism , Norovirus/metabolism , Virion/metabolism , Humans , Protein Binding , Protein Conformation , Protein DomainsABSTRACT
Noroviruses, members of the Caliciviridae family, are the major cause of epidemic gastroenteritis in humans, causing â¼20 million cases annually. These plus-strand RNA viruses have T=3 icosahedral protein capsids with 90 pronounced protruding (P) domain dimers to which antibodies and cellular receptors bind. In the case of mouse norovirus (MNV), bile salts have been shown to enhance receptor (CD300lf) binding to the P domain. We demonstrated previously that the P domains of several genotypes are markedly flexible and "float" over the shell, but the role of this flexibility was unclear. Recently, we demonstrated that bile causes a 90° rotation and collapse of the P domain onto the shell surface. Since bile binds distally to the P-shell interface, it was not at all clear how it could cause such dramatic changes. Here, we present the near-atomic resolution cryo-electron microscopy (cryo-EM) structure of the MNV protruding domain complexed with a neutralizing Fab. On the basis of previous results, we show here that bile salts cause allosteric conformational changes in the P domain that block antibody recognition of the top of the P domain. In addition, bile causes a major rearrangement of the P domain dimers that is likely responsible for the bile-induced collapse of the P domain onto the shell. In the contracted shell conformation, antibodies to the P1 and shell domains are not expected to bind. Therefore, at the site of infection in the gut, the host's own bile allows the virus to escape antibody-mediated neutralization while enhancing cell attachment. IMPORTANCE The major feature of calicivirus capsids is the 90 protruding domains (P domains) that are the site of cell receptor attachment and antibody epitopes. We demonstrated previously that these P domains are highly mobile and that bile causes these "floating" P domains in mouse norovirus (MNV) to contract onto the shell surface. Here, we present the near-atomic cryo-EM structure of the isolated MNV P domain complexed with a neutralizing Fab fragment. Our data show that bile causes two sets of changes. First, bile causes allosteric conformational changes in the epitopes at the top of the P domain that block antibody binding. Second, bile causes the P domain dimer subunits to rotate relative to each other, causing a contraction of the P domain that buries epitopes at the base of the P and shell domains. Taken together, the results show that MNV uses the host's own metabolites to enhance cell receptor binding while simultaneously blocking antibody recognition.
Subject(s)
Antibodies, Viral/immunology , Bile Acids and Salts/metabolism , Immune Evasion/immunology , Norovirus/immunology , Receptors, Virus/metabolism , Animals , Capsid/immunology , Capsid Proteins/metabolism , Cryoelectron Microscopy , Hybridomas , Mice , Protein Binding/physiology , Protein Domains/immunologyABSTRACT
The aim of this study was to explore whether citizens' scientific interest and self-understanding relate to their learning enjoyment and self-efficacy in science. The sample participants consisted of 1,657 Taiwanese citizens ranging from 18 to 70 years of age. All participants were asked to complete the 2018 "Taiwan Citizens Science and Technology Literacy Survey" to assess their scientific interest, scientific self-understanding, science learning enjoyment, and scientific self-efficacy. Multiple regression models were used to analyze the data. The important findings included: (1) scientific interest was the most important predictor of science learning enjoyment, while scientific self-understanding was the most important predictor of scientific self-efficacy; and (2) the effects of scientific interest on self-understanding and the effect of science learning enjoyment on scientific self-efficacy each were significantly moderated by respondents' age, with stronger relationships observed in younger citizens than older citizens. This study provides insight into Taiwanese citizens' scientific learning enjoyment and self-efficacy and also informs potential governmental policies and/or societal practices that could be considered to promote scientific literacy.
ABSTRACT
Transmission of the crinivirus, lettuce infectious yellows virus (LIYV), is determined by a minor coat protein (CPm)-mediated virion retention mechanism located in the foregut of its whitefly vector. To better understand the functions of LIYV CPm, chimeric CPm mutants engineered with different lengths of the LIYV CPm amino acid sequence and that of the crinivirus, lettuce chlorosis virus (LCV), were constructed based on bioinformatics and sequence alignment data. The 485 amino acid-long chimeric CPm of LIYV mutant, CPmP-1, contains 60â% (from position 3 to 294) of LCV CPm amino acids. The chimeric CPm of mutants CPmP-2, CPmP-3 and CPmP-4 contains 46 (position 3 to 208), 51 (position 3 to 238) and 41â% (position 261 to 442) of LCV CPm amino acids, respectively. All four mutants moved systemically, expressed the chimeric CPm and formed virus particles. However, following acquisition feeding of the virus preparations, only CPmP-1 was retained in the foreguts of a significant number of vectors and transmitted. In immuno-gold labelling transmission electron microscopy (IGL-TEM) analysis, CPmP-1 particles were distinctly labelled by antibodies directed against the LCV but not LIYV CPm. In contrast, CPmP-4 particles were not labelled by antibodies directed against the LCV or LIYV CPm, while CPmP-2 and -3 particles were weakly labelled by anti-LIYV CPm but not anti-LCV CPm antibodies. The unique antibody recognition and binding pattern of CPmP-1 was also displayed in the foreguts of whitefly vectors that fed on CPmP-1 virions. These results are consistent with the hypothesis that the chimeric CPm of CPmP-1 is incorporated into functional virions, with the LCV CPm region being potentially exposed on the surface and accessible to anti-LCV CPm antibodies.
Subject(s)
Capsid Proteins/metabolism , Crinivirus/physiology , Hemiptera/virology , Insect Vectors/virology , Nicotiana/virology , Plant Diseases/virology , Animals , Capsid Proteins/chemistry , Capsid Proteins/genetics , Crinivirus/genetics , Digestive System/virology , Genetic Engineering , Mutant Chimeric Proteins/chemistry , Mutant Chimeric Proteins/metabolism , Mutation , Plants, Genetically Modified/virology , Virion/physiologySubject(s)
Chronic Pain , Neuralgia , Transcutaneous Electric Nerve Stimulation , Humans , Administration, Cutaneous , Neuralgia/therapy , SkinABSTRACT
Members of the Tombusviridae family have highly similar structures, and yet there are important differences among them in host, transmission, and capsid stabilities. Viruses in the Tombusviridae family have single-stranded RNA (ssRNA) genomes with T=3 icosahedral protein shells with a maximum diameter of â¼340 Å. Each capsid protein is comprised of three domains: R (RNA binding), S (shell), and P (protruding). Between the R domain and S domain is the "arm" region that studies have shown to play a critical role in assembly. To better understand how the details of structural differences and similarities influence the Tombusviridae viral life cycles, the structures of cucumber leaf spot virus (CLSV; genus Aureusvirus) and red clover necrotic mosaic virus (RCNMV; genus Dianthovirus) were determined to resolutions of 3.2 Å and 2.9 Å, respectively, with cryo-electron microscopy and image reconstruction methods. While the shell domains had homologous structures, the stabilizing interactions at the icosahedral 3-fold axes and the R domains differed greatly. The heterogeneity in the R domains among the members of the Tombusviridae family is likely correlated with differences in the sizes and characteristics of the corresponding genomes. We propose that the changes in the R domain/RNA interactions evolved different arm domain interactions at the ß-annuli. For example, RCNMV has the largest genome and it appears to have created the necessary space in the capsid by evolving the shortest R domain. The resulting loss in RNA/R domain interactions may have been compensated for by increased intersubunit ß-strand interactions at the icosahedral 3-fold axes. Therefore, the R and arm domains may have coevolved to package different genomes within the conserved and rigid shell.IMPORTANCE Members of the Tombusviridae family have nearly identical shells, and yet they package genomes that range from 4.6 kb (monopartite) to 5.3 kb (bipartite) in size. To understand how this genome flexibility occurs within a rigidly conserved shell, we determined the high-resolution cryo-electron microscopy (cryo-EM) structures of cucumber leaf spot virus and red clover necrotic mosaic virus. In response to genomic size differences, it appears that the ssRNA binding (R) domain of the capsid diverged evolutionarily in order to recognize the different genomes. The next region, the "arm," seems to have also coevolved with the R domain to allow particle assembly via interactions at the icosahedral 3-fold axes. In addition, there are differences at the icosahedral 3-fold axes with regard to metal binding that are likely important for transmission and the viral life cycle.
Subject(s)
Capsid Proteins/ultrastructure , Capsid/ultrastructure , Evolution, Molecular , Tombusviridae/ultrastructure , Cryoelectron Microscopy , NicotianaABSTRACT
Despite the wide-ranging proscription of hexavalent chromium, chromium(VI) remains among the major polluting heavy metals worldwide. Aerobic methane-oxidizing bacteria are widespread environmental microorganisms that can perform diverse reactions using methane as the feedstock. The methanotroph Methylococcus capsulatus Bath, like many other microorganisms, detoxifies chromium(VI) by reduction to chromium(III). Here, the interaction of chromium species with M. capsulatus Bath was examined in detail by using a range of techniques. Cell fractionation and high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) indicated that externally provided chromium(VI) underwent reduction and was then taken up into the cytoplasmic and membranous fractions of the cells. This was confirmed by X-ray photoelectron spectroscopy (XPS) of intact cultures that indicated negligible chromium on the surfaces of or outside the cells. Distribution of chromium and other elements within intact and sectioned cells, as observed via transmission electron microscopy (TEM) combined with energy-dispersive X-ray spectroscopy (EDX) and electron energy loss spectroscopy (EELS), was consistent with the cytoplasm/membrane location of the chromium(III), possibly as chromium phosphate. The cells could also take up chromium(III) directly from the medium in a metabolism-dependent fashion and accumulate it. These results indicate a novel pattern of interaction with chromium species distinct from that observed previously with other microorganisms. They also suggest that M. capsulatus and similar methanotrophs may contribute directly to chromium(VI) reduction and accumulation in mixed communities of microorganisms that are able to perform methane-driven remediation of chromium(VI).IMPORTANCEM. capsulatus Bath is a well-characterized aerobic methane-oxidizing bacterium that has become a model system for biotechnological development of methanotrophs to perform useful reactions for environmental cleanup and for making valuable chemicals and biological products using methane gas. Interest in such technology has increased recently owing to increasing availability of low-cost methane from fossil and biological sources. Here, it is demonstrated that this versatile methanotroph can reduce the toxic contaminating heavy metal chromium(VI) to the less toxic form chromium(III) while accumulating the chromium(III) within the cells. This is expected to diminish the bioavailability of the chromium and make it less likely to be reoxidized to chromium(VI). Thus, M. capsulatus has the capacity to perform methane-driven remediation of chromium-contaminated water and other materials and to accumulate the chromium in the low-toxicity chromium(III) form within the cells.
Subject(s)
Chromium/metabolism , Methylococcus capsulatus/metabolism , Biodegradation, Environmental , Environmental Restoration and Remediation , Oxidation-ReductionABSTRACT
OBJECTIVE: Patient-oncologist therapeutic alliance is a foundation of quality cancer care, although there is limited research demonstrating its relationship with patient outcomes. We investigated the relationship between therapeutic alliance and patient quality of life with a secondary goal of determining whether the association varied by patients' baseline level of psychological distress. METHODS: Cross-sectional analysis of baseline data from a randomized clinical trial of 672 patients with advanced cancer participating in a primary palliative care intervention trial. Patients completed baseline self-reported measures of therapeutic alliance (The Human Connection Scale, range: 16-64), overall quality of life (Functional Assessment of Cancer Therapy-Palliative Care, range: 0-184), and psychological distress (Hospital Anxiety and Depression Scale, range: 0-42). First, we determined the relationship between therapeutic alliance and quality of life using multivariable regression adjusting for confounders. We then examined if psychological distress was an effect modifier in this relationship by adding interaction effects of depression and anxiety symptoms on therapeutic alliance into the regression model. RESULTS: Patients reported high levels of therapeutic alliance (56.4 ± 7.4) and moderate quality of life (130.3 ± 25.5). Stronger therapeutic alliance was associated with better quality of life after adjusting for other confounding factors (ß = 3.7, 95% confidence interval = 2.1, 5.3, p < 0.01). The relationship between therapeutic alliance and quality of life was generally consistent regardless of psychological distress. CONCLUSIONS: Collaborative, trusting relationships between patients with advanced cancer and their oncologists are associated with better patient quality of life. Future research should investigate the causal, longitudinal nature of these relationships.
Subject(s)
Neoplasms , Oncologists , Therapeutic Alliance , Cross-Sectional Studies , Humans , Neoplasms/therapy , Quality of LifeABSTRACT
The disruption to patient and family well-being introduced by the rising costs of cancer care is a growing clinical problem. In addition to logistical questions, there is a compelling, existential one: "How should healthcare teams address patient and caregiver distress and uncertainty from financial toxicity?" We argue that the principles and practice of palliative care can help alleviate this element and often unaddressed component of human suffering.