ABSTRACT
OBJECTIVE: To identify and agree on what outcome domains should be measured in research and clinical practice when working with stroke survivors who have dysarthria. DESIGN: Delphi process, two rounds of an online survey followed by two online consensus meetings. SETTING: UK and Australia. PARTICIPANTS: Stroke survivors with experience of dysarthria, speech and language therapists/pathologists working in stroke and communication researchers. METHODS: Initial list of outcome domains generated from existing literature and with our patient and public involvement group to develop the survey. Participants completed two rounds of this survey to rate importance. Outcomes were identified as 'in', 'unclear' or 'out' from the second survey. All participants were invited to two consensus meetings to discuss these results followed by voting to identify critically important outcome domains for a future Core Outcome Set. All outcomes were voted on in the consensus meetings and included if 70% of meeting participants voted 'yes' for critically important. RESULTS: In total, 148 surveys were fully completed, and 28 participants attended the consensus meetings. A core outcome set for dysarthria after stroke should include four outcome domains: (a) intelligibility of speech, (b) ability to participate in conversations, (c) living well with dysarthria, (d) skills and knowledge of communication partners (where relevant). CONCLUSIONS: We describe the consensus of 'what' speech outcomes after stroke are valued by all stakeholders including those with lived experience. We share these findings to encourage the measurement of these domains in clinical practice and research and for future research to identify 'how' best to measure these outcomes.
Subject(s)
Delphi Technique , Dysarthria , Stroke Rehabilitation , Stroke , Humans , Dysarthria/etiology , Dysarthria/rehabilitation , Stroke/complications , Female , Male , Outcome Assessment, Health Care , Middle Aged , Australia , Consensus , Aged , Surveys and Questionnaires , United KingdomABSTRACT
BACKGROUND: The complexity of communication presents challenges for clinical assessment, outcome measurement and intervention for people with acquired brain injury. For the purposes of assessment or treatment, this complexity is usually managed by isolating specific linguistic functions or speech acts from the interactional context. Separating linguistic functions from their interactional context can lead to discourse being viewed as a static entity comprised of discrete features, rather than as a dynamic process of co-constructing meaning. The ecological validity of discourse assessments which rely on the deconstruction of linguistic functions is unclear. Previous studies have reported assessment tasks that preserve some of the dialogic features of communication, but as yet, these tasks have not been identified as a distinct genre of assessment. We suggest the term 'co-constructed communication' to describe tasks which are specifically designed to capture the dynamic, jointly produced nature of communication within a replicable assessment task. AIMS: To identify and summarize how co-constructed communication has been assessed with individuals with non-progressive acquired communication disability regarding task design, measures and psychometric robustness. METHODS: A scoping review methodology was used to identity relevant studies. Systematic database searches were conducted on studies published before July 2021. Studies in the yield were assessed against eligibility criteria, with 37 studies identified as eligible for inclusion. MAIN CONTRIBUTION: This is the first time that co-constructed communication has been defined as a genre of discourse assessment for stroke and traumatic brain injury populations. Co-constructed communication has been assessed for 144 individuals with aphasia and 111 with cognitive-communication disability. Five categories of co-constructed communication tasks were identified, ranging in complexity. Variability exists in how these assessment tasks are labelled and measured. Assessment measures require further psychometric profiling, specifically regarding test-retest reliability and validity. CONCLUSIONS: Co-constructed communication is a discourse genre which offers researchers and clinicians a replicable method to assess language and communication in an experimentally rigorous way, within an ecologically valid context, bridging the gap between experimental and ecological assessment approaches. WHAT THIS PAPER ADDS: What is already known on this subject Standardized assessments of language skills and monologue offer reliable, replicable ways to measure language. However, isolating language from an interactional context fundamentally changes the behaviour under study. This raises questions about the ecological validity of the measures we routinely use to determine diagnoses, guide treatment planning and measure the success of treatment. What this study adds to the existing knowledge This review highlights studies that conceptualize, and often quantify, interaction by combining experimental rigour and aspects of everyday dialogue. This is the first time this genre of discourse assessment has been identified. We propose the term 'co-constructed communication' to describe this genre and provide an operational definition for the term. What are the practical and clinical implications of this study? Co-constructed communication assessment tasks require refinement, particularly regarding aspects of psychometric robustness. In the future, these tasks offer pragmatic, meaningful ways to capture the effect and impact of aphasia and cognitive-communication disability within interaction.
ABSTRACT
Plasminogen (Plg) is the inactive form of plasmin (Plm) that exists in two major glycoforms, referred to as glycoforms I and II (GI and GII). In the circulation, Plg assumes an activation-resistant "closed" conformation via interdomain interactions and is mediated by the lysine binding site (LBS) on the kringle (KR) domains. These inter-domain interactions can be readily disrupted when Plg binds to lysine/arginine residues on protein targets or free L-lysine and analogues. This causes Plg to convert into an "open" form, which is crucial for activation by host activators. In this study, we investigated how various ligands affect the kinetics of Plg conformational change using small-angle X-ray scattering (SAXS). We began by examining the open and closed conformations of Plg using size-exclusion chromatography (SEC) coupled with SAXS. Next, we developed a high-throughput (HTP) 96-well SAXS assay to study the conformational change of Plg. This method enables us to determine the Kopen value, which is used to directly compare the effect of different ligands on Plg conformation. Based on our analysis using Plg GII, we have found that the Kopen of ε-aminocaproic acid (EACA) is approximately three times greater than that of tranexamic acid (TXA), which is widely recognized as a highly effective ligand. We demonstrated further that Plg undergoes a conformational change when it binds to the C-terminal peptides of the inhibitor α2-antiplasmin (α2AP) and receptor Plg-RKT. Our findings suggest that in addition to the C-terminal lysine, internal lysine(s) are also necessary for the formation of open Plg. Finally, we compared the conformational changes of Plg GI and GII directly and found that the closed form of GI, which has an N-linked glycosylation, is less stable. To summarize, we have successfully determined the response of Plg to various ligand/receptor peptides by directly measuring the kinetics of its conformational changes.
Subject(s)
Lysine , Plasminogen , Ligands , Scattering, Small Angle , X-Rays , X-Ray Diffraction , Serine Proteases , AntibodiesABSTRACT
"Reagentless" immunosensors are emerging to address the challenge of practical and sensitive detection of important biomarkers in real biological samples without the need for multistep assays and user intervention, with applications ranging from research tools to point-of-care diagnostics. Selective target binding to an affinity reagent is detected and reported in one step without the need for washing or additional reporters. In this study, we used a structure-guided approach to identify a mutation site in an antibody fragment for the polarity-dependent fluorophore, Anap, such that upon binding of the protein target cardiac troponin I, the Anap-labeled antibody would produce a detectable and dose-dependent shift in emission wavelength. We observed a significant emission wavelength shift of the Anap-labeled anti-cTnI mutant, with a blue shift of up to 37 nm, upon binding to the cTnI protein. Key differences in the resulting emission spectra between target peptides in comparison to whole proteins were also found; however, the affinity and binding characteristics remained unaffected when compared to the wild-type antibody. We also highlighted the potential flexibility of the approach by incorporating a near-infrared dye, IRDye800CW, into the same mutation site, which also resulted in a dose-dependent wavelength shift upon target incubation. These reagents can be used in experiments and devices to create simpler and more efficient biosensors across a range of research, medical laboratory, and point-of-care platforms.
Subject(s)
Biosensing Techniques , Biosensing Techniques/methods , Immunoassay , Antibodies/chemistry , Peptides , Immunoglobulin Fragments , Troponin I/geneticsABSTRACT
BACKGROUND: Evidence-based recommendations for a core outcome set (COS; minimum set of outcomes) for aphasia treatment research have been developed (the Research Outcome Measurement in Aphasia-ROMA, COS). Five recommended core outcome constructs: communication, language, quality of life, emotional well-being and patient-reported satisfaction/impact of treatment, were identified through three international consensus studies. Constructs were paired with outcome measurement instruments (OMIs) during an international consensus meeting (ROMA-1). Before the current study (ROMA-2), agreement had not been reached on OMIs for the constructs of communication or patient-reported satisfaction/impact of treatment. AIM: To establish consensus on a communication OMI for inclusion in the ROMA COS. METHODS & PROCEDURES: Research methods were based on recommendations from the Core Outcome Measures in Effectiveness Trials (COMET) Initiative. Participants with expertise in design and conduct of aphasia trials, measurement instrument development/testing and/or communication outcome measurement were recruited through an open call. Before the consensus meeting, participants agreed on a definition of communication, identified appropriate OMIs, extracted their measurement properties and established criteria for their quality assessment. During the consensus meeting they short-listed OMIs and participants without conflicts of interest voted on the two most highly ranked instruments. Consensus was defined a priori as agreement by ≥ 70% of participants. OUTCOMES & RESULTS: In total, 40 researchers from nine countries participated in ROMA-2 (including four facilitators and three-panel members who participated in pre-meeting activities only). A total of 20 OMIs were identified and evaluated. Eight short-listed communication measures were further evaluated for their measurement properties and ranked. Participants in the consensus meeting (n = 33) who did not have conflicts of interest (n = 29) voted on the top two ranked OMIs: The Scenario Test (TST) and the Communication Activities of Daily Living-3 (CADL-3). TST received 72% (n = 21) of 'yes' votes and the CADL-3 received 28% (n = 8) of 'yes' votes. CONCLUSIONS & IMPLICATIONS: Consensus was achieved that TST was the preferred communication OMI for inclusion in the ROMA COS. It is currently available in the original Dutch version and has been adapted into English, German and Greek. Further consideration must be given to the best way to measure communication in people with mild aphasia. Development of a patient-reported measure for satisfaction with/impact of treatment and multilingual versions of all OMIs of the COS is still required. Implementation of the ROMA COS would improve research outcome measurement and the quality, relevance, transparency, replicability and efficiency of aphasia treatment research. WHAT THIS PAPER ADDS: What is already known on this subject International consensus has been reached on five core constructs to be routinely measured in aphasia treatment studies. International consensus has also been established for OMIs for the three constructs of language, quality of life and emotional well-being. Before this study, OMIs for the constructs of communication and patient-reported satisfaction/impact of treatment were not established. What this paper adds to existing knowledge We gained international consensus on an OMI for the construct of communication. TST is recommended for inclusion in the ROMA COS for routine use in aphasia treatment research. What are the potential or actual clinical implications of this work? The ROMA COS recommends OMIs for a minimum set of outcomes for adults with post-stroke aphasia within phases I-IV aphasia treatment research. Although not intended for clinical use, clinicians may employ the instruments of the ROMA COS, considering the quality of their measurement properties. The systematic inclusion of a measure of communication, such as TST, in clinical practice could ultimately support the implementation of research evidence and best practices.
Subject(s)
Aphasia , Communication , Quality of Life , Adult , Humans , Activities of Daily Living , Aphasia/diagnosis , Aphasia/therapy , Delphi Technique , Language , Outcome Assessment, Health Care/methods , Research Design , Treatment OutcomeABSTRACT
Acalculia, an acquired disability following a brain injury, involves difficulty processing numerical information and/or calculations. Acalculia is not routinely screened for, and as a result there is a lack of understanding about the nature and prevalence and the impact of the condition. This qualitative study was initiated by stroke survivors with a strong interest in acalculia. Sixteen stroke/brain injury survivors with acalculia and seven carers were interviewed using semi-structured online interviews. Participants ranged in age, gender, time post-onset, country of residence and numeracy level prior to brain injury. Data were analysed using thematic analysis. Three main themes were identified: Awareness and Diagnosis; Emotional and Practical Impact (independence); Support, Coping Strategies and Self-training. Participants and carers repeatedly referred to the lack of awareness and treatment for acalculia and the impact acalculia has had on their lives and independence. Practical impacts included managing money, making appointments, using timetables, organizing social activities and employment, and managing medication. Our results highlight the urgent need to develop suitable assessments and interventions for acalculia and the scope for this to be Patient, Carer and Public involvement (PCPI)-led. The data also reveal useful strategies and suggestions regarding effective timing, targets and approaches for intervention.
Subject(s)
Brain Injuries , Dyscalculia , Stroke Rehabilitation , Stroke , Humans , Stroke/complications , Stroke/psychology , Qualitative Research , Caregivers/psychologyABSTRACT
Background: Despite the clinical importance of assessing the efficiency and accuracy of fluency in terms of content words production during connected speech, assessments based on discourse tasks are very time-consuming and thus not clinically feasible. Aims: (1) Examine the relationship between single-word naming and word retrieval during discourse production. (2) Investigate the relationship between word retrieval and content word fluency derived from a simple versus naturalistic discourse tasks. (3) Develop and validate an efficient and accurate index of content word fluency that is clinically viable. Methods: Two discourse tasks (simple picture description and naturalistic storytelling narrative) were collected from 46 participants with post-stroke aphasia, and 20 age/education matched neuro-typical controls. Each discourse sample was fully transcribed and quantitative analysis was applied to each sample to measure word retrieval and content word fluency. Three single-word naming tasks were also administered to each participant with aphasia. Results: Correlational analyses between single-word naming and word retrieval in connected speech revealed weak/moderate relationships. Conversely, strong correlations were found between measures derived from simple picture description against naturalistic storytelling discourse tasks. Moreover, we derived a novel, transcription-less index of content word fluency from the discourse samples of an independent group (neuro-typical controls), and then we validated this index across two discourse tasks in the tested group (persons with aphasia). Correlation and regression analyses revealed extremely strong relationships between participants' (neuro-typical controls and persons with aphasia) scores on the novel index and measures of content word fluency derived from the formal transcription and quantitative analyses of discourse samples, indicating high accuracy and validity of the new index. Conclusions: Simple picture description rather than picture naming provides a better estimate of word retrieval in naturalistic connected speech. The novel developed index is transcription-less and can be implemented online to provide an accurate and efficient measure of content word fluency. Thus, it is viable during clinical practice for assessment purposes, and possibly as an outcome measure to monitor therapy effectiveness, which can also be used in randomised clinical trials.
ABSTRACT
BACKGROUND: Written communication has become an increasingly important part of everyday life in social, educational and professional spheres. The substantial increase in writing via the internet and mobile technologies provides both an opportunity for social engagement and distinct challenges for people with aphasia. Within the current literature there has been limited research into the lived experiences of people with aphasia of their writing difficulties and how these affect their ability to communicate. AIMS: This qualitative study aimed to explore the experiences of people with aphasia of living with language-related writing difficulties and the impact of these on their lives. METHODS & PROCEDURES: Eight people with post-stroke aphasia and writing difficulties took part in semi-structured interviews. The interviews were analysed using inductive reflexive thematic analysis. OUTCOMES & RESULTS: Two themes were found in the data. The first theme was a gradual and effortful improvement to writing: Participants described how writing had improved since their stroke due to strategies and support, but they still found writing to be difficult and frustrating and described many barriers to writing. The second theme was the importance of writing for fulfilling adult social roles: Participants found writing to be important for communicating with family, friends and organizations, but their participation in society and self-esteem and confidence were impacted by writing difficulties; reduced social roles meant reduced need for writing, but participants were still motivated to work towards writing goals. CONCLUSIONS & IMPLICATIONS: The findings demonstrate the emerging importance of writing skills for people with aphasia with respect to communication, well-being, participation and inclusion in society, and carrying out social roles. They provide an insight into the process of improvement, including the difficulties, facilitators and barriers. Implications for speech and language therapy assessment and management are discussed. WHAT THIS PAPER ADDS: What is already known on the subject People with aphasia have difficulties with writing that can affect their ability to communicate. A small body of qualitative research has provided insights into individuals' experiences of literacy difficulties. More research is needed to understand the writing experiences of people with aphasia to help design appropriate assessments and interventions. What this paper adds to existing knowledge Participants experienced gradual and effortful improvement since their stroke. They felt negative about aspects of their writing, including speed, accuracy and range of vocabulary. Writing was facilitated through assistive technologies, spelling practice and support from others; barriers included technology, lack of time, stroke-related symptoms and others' lack of awareness about aphasia. Participants considered writing skills to be important, particularly for communication, carrying out adult social roles and participating in society, and were therefore still working towards goals related to everyday writing activities. What are the potential or actual clinical implications of this work? This study suggests that speech and language therapy assessment should include interviewing participants about their activities, strengths, difficulties, facilitators and barriers in writing, and informal assessment of a range of functional writing tasks. Intervention should be tailored to the individual's needs. This should include meaningful activities that relate to functional everyday writing and, where appropriate, self-management, compensatory technologies and group approaches, while making use of existing strategies identified by the individual.
Subject(s)
Agraphia , Aphasia , Stroke Rehabilitation , Stroke , Adult , Humans , Aphasia/diagnosis , Speech Therapy , Stroke Rehabilitation/methods , Stroke/complications , Stroke/therapy , WritingABSTRACT
Although limited and reduced connected speech production is one, if not the most, prominent feature of aphasia, few studies have examined the properties of content words produced during discourse in aphasia, in comparison to the many investigations of single-word production. In this study, we used a distributional analysis approach to investigate the properties of content word production during discourse by 46 participants spanning a wide range of chronic poststroke aphasia and 20 neurotypical adults, using different stimuli that elicited three discourse genres (descriptive, narrative, and procedural). Initially, we inspected the discourse data with respect to the quantity of production, lexical-semantic diversity, and psycholinguistic features (frequency and imageability) of content words. Subsequently, we created a "lexical-semantic landscape," which is sensitive to subtle changes and allowed us to evaluate the pattern of changes in discourse production across groups. Relative to neurotypical adults, all persons with aphasia (both fluent and nonfluent) showed significant reduction in the quantity and diversity of production, but the lexical-semantic complexity of word production directly mirrored neurotypical performance. Specifically, persons with aphasia produced the same rate of nouns/verbs, and their discourse samples covered the full range of word frequency and imageability, albeit with reduced word quantity. These findings provide novel evidence that, unlike in other disorders (e.g., semantic dementia), discourse production in poststroke aphasia has relatively preserved lexical-semantic complexity but demonstrates significantly compromised quantity of content word production. Voxel-wise lesion-symptom mapping using both univariate and multivariate approaches revealed left frontal regions particularly the pars opercularis, insular cortex, and central and frontal opercular cortices supporting word retrieval during connected speech, irrespective of their word class or lexical-semantic complexity.
Subject(s)
Aphasia , Semantics , Adult , Aphasia/etiology , Humans , Insular Cortex , Language , SpeechABSTRACT
The diagnosis and treatment of prostate cancer (PCa) is a major health-care concern worldwide. This cancer can manifest itself in many distinct forms and the transition from clinically indolent PCa to the more invasive aggressive form remains poorly understood. It is now universally accepted that glycan expression patterns change with the cellular modifications that accompany the onset of tumorigenesis. The aim of this study was to investigate if differential glycosylation patterns could distinguish between indolent, significant, and aggressive PCa. Whole serum N-glycan profiling was carried out on 117 prostate cancer patients' serum using our automated, high-throughput analysis platform for glycan-profiling which utilizes ultra-performance liquid chromatography (UPLC) to obtain high resolution separation of N-linked glycans released from the serum glycoproteins. We observed increases in hybrid, oligomannose, and biantennary digalactosylated monosialylated glycans (M5A1G1S1, M8, and A2G2S1), bisecting glycans (A2B, A2(6)BG1) and monoantennary glycans (A1), and decreases in triantennary trigalactosylated trisialylated glycans with and without core fucose (A3G3S3 and FA3G3S3) with PCa progression from indolent through significant and aggressive disease. These changes give us an insight into the disease pathogenesis and identify potential biomarkers for monitoring the PCa progression, however these need further confirmation studies.
Subject(s)
Biomarkers , Metabolome , Metabolomics , Polysaccharides/metabolism , Prostatic Neoplasms/metabolism , Aged , Chromatography, High Pressure Liquid , Glycoproteins/metabolism , High-Throughput Screening Assays , Humans , Male , Metabolomics/methods , Middle Aged , Neoplasm Staging , Prostatic Neoplasms/blood , Prostatic Neoplasms/diagnosisABSTRACT
BACKGROUND & AIMS: The protease plasmin is an important wound healing factor, but it is not clear how it affects gastrointestinal infection-mediated damage, such as that resulting from Clostridioides difficile. We investigated the role of plasmin in C difficile-associated disease. This bacterium produces a spore form that is required for infection, so we also investigated the effects of plasmin on spores. METHODS: C57BL/6J mice expressing the precursor to plasmin, the zymogen human plasminogen (hPLG), or infused with hPLG were infected with C difficile, and disease progression was monitored. Gut tissues were collected, and cytokine production and tissue damage were analyzed by using proteomic and cytokine arrays. Antibodies that inhibit either hPLG activation or plasmin activity were developed and structurally characterized, and their effects were tested in mice. Spores were isolated from infected patients or mice and visualized using super-resolution microscopy; the functional consequences of hPLG binding to spores were determined. RESULTS: hPLG localized to the toxin-damaged gut, resulting in immune dysregulation with an increased abundance of cytokines (such as interleukin [IL] 1A, IL1B, IL3, IL10, IL12B, MCP1, MP1A, MP1B, GCSF, GMCSF, KC, TIMP-1), tissue degradation, and reduced survival. Administration of antibodies that inhibit plasminogen activation reduced disease severity in mice. C difficile spores bound specifically to hPLG and active plasmin degraded their surface, facilitating rapid germination. CONCLUSIONS: We found that hPLG is recruited to the damaged gut, exacerbating C difficile disease in mice. hPLG binds to C difficile spores, and, upon activation to plasmin, remodels the spore surface, facilitating rapid spore germination. Inhibitors of plasminogen activation might be developed for treatment of C difficile or other infection-mediated gastrointestinal diseases.
Subject(s)
Clostridioides difficile/drug effects , Enterocolitis, Pseudomembranous/etiology , Enterocolitis, Pseudomembranous/pathology , Plasminogen/pharmacology , Spores, Bacterial/drug effects , Animals , Disease Models, Animal , Humans , Intestine, Small , Mice , Mice, Inbred C57BLABSTRACT
Tumor-associated peptide-human leukocyte antigen complexes (pHLAs) represent the largest pool of cell surface-expressed cancer-specific epitopes, making them attractive targets for cancer therapies. Soluble bispecific molecules that incorporate an anti-CD3 effector function are being developed to redirect T cells against these targets using 2 different approaches. The first achieves pHLA recognition via affinity-enhanced versions of natural TCRs (e.g., immune-mobilizing monoclonal T cell receptors against cancer [ImmTAC] molecules), whereas the second harnesses an antibody-based format (TCR-mimic antibodies). For both classes of reagent, target specificity is vital, considering the vast universe of potential pHLA molecules that can be presented on healthy cells. Here, we made use of structural, biochemical, and computational approaches to investigate the molecular rules underpinning the reactivity patterns of pHLA-targeting bispecifics. We demonstrate that affinity-enhanced TCRs engage pHLA using a comparatively broad and balanced energetic footprint, with interactions distributed over several HLA and peptide side chains. As ImmTAC molecules, these TCRs also retained a greater degree of pHLA selectivity, with less off-target activity in cellular assays. Conversely, TCR-mimic antibodies tended to exhibit binding modes focused more toward hot spots on the HLA surface and exhibited a greater degree of crossreactivity. Our findings extend our understanding of the basic principles that underpin pHLA selectivity and exemplify a number of molecular approaches that can be used to probe the specificity of pHLA-targeting molecules, aiding the development of future reagents.
Subject(s)
HLA Antigens/immunology , Peptides/immunology , Receptors, Antigen, T-Cell/immunology , Amino Acid Sequence , Antibodies, Bispecific/chemistry , Antibodies, Bispecific/genetics , Antibodies, Bispecific/immunology , Antibodies, Neoplasm/chemistry , Antibodies, Neoplasm/genetics , Antibodies, Neoplasm/immunology , Antibody Specificity , Antigens, Neoplasm/chemistry , Antigens, Neoplasm/genetics , Antigens, Neoplasm/immunology , Cell Line , Cell Line, Tumor , Crystallography, X-Ray , HLA Antigens/chemistry , HLA Antigens/genetics , Humans , Indicators and Reagents , Models, Molecular , Molecular Dynamics Simulation , Molecular Mimicry/genetics , Molecular Mimicry/immunology , Peptides/chemistry , Peptides/genetics , Receptors, Antigen, T-Cell/chemistry , Receptors, Antigen, T-Cell/genetics , T-Lymphocytes/immunologyABSTRACT
The clinical profiles of individuals with post-stroke aphasia demonstrate considerable variation in the presentation of symptoms. Recent aphasiological studies have attempted to account for this individual variability using a multivariate data-driven approach (principal component analysis) on an extensive neuropsychological and aphasiological battery, to identify fundamental domains of post-stroke aphasia. These domains mainly reflect phonology, semantics and fluency; however, these studies did not account for variability in response to different forms of connected speech, i.e. discourse genres. In the current study, we initially examined differences in the quantity, diversity and informativeness between three different discourse genres, including a simple descriptive genre and two naturalistic forms of connected speech (storytelling narrative, and procedural discourse). Subsequently, we provided the first quantitative investigation on the multidimensionality of connected speech production at both behavioural and neural levels. Connected speech samples across descriptive, narrative, and procedural discourse genres were collected from 46 patients with chronic post-stroke aphasia and 20 neurotypical adults. Content analyses conducted on all connected speech samples indicated that performance differed across discourse genres and between groups. Specifically, storytelling narratives provided higher quantities of content words and lexical diversity compared to composite picture description and procedural discourse. The analyses further revealed that, relative to neurotypical adults, patients with aphasia, both fluent and non-fluent, showed reduction in the quantity of verbal production, lexical diversity, and informativeness across all discourses. Given the differences across the discourses, we submitted the connected speech metrics to principal component analysis alongside an extensive neuropsychological/aphasiological battery that assesses a wide range of language and cognitive skills. In contrast to previous research, three unique orthogonal connected speech components were extracted in a unified model, reflecting verbal quantity, verbal quality, and motor speech, alongside four core language and cognitive components: phonological production, semantic processing, phonological recognition, and executive functions. Voxel-wise lesion-symptom mapping using these components provided evidence on the involvement of widespread cortical regions and their white matter connections. Specifically, left frontal regions and their underlying white matter tracts corresponding to the frontal aslant tract and the anterior segment of the arcuate fasciculus were particularly engaged with the quantity and quality of fluent connected speech production while controlling for other co-factors. The neural correlates associated with the other language domains align with existing models on the ventral and dorsal pathways for language processing.
Subject(s)
Aphasia/etiology , Aphasia/physiopathology , Brain/physiopathology , Models, Neurological , Stroke/complications , Stroke/physiopathology , Aged , Aged, 80 and over , Female , Humans , Image Interpretation, Computer-Assisted , Magnetic Resonance Imaging , Male , Middle Aged , NeuroimagingABSTRACT
CUB-domain containing protein 1 (CDCP1) is a cancer associated cell surface protein that amplifies pro-tumorigenic signalling by other receptors including EGFR and HER2. Its potential as a cancer target is supported by studies showing that anti-CDCP1 antibodies inhibit cell migration and survival in vitro, and tumor growth and metastasis in vivo. Here we characterize two anti-CDCP1 antibodies, focusing on immuno-conjugates of one of these as a tool to detect and inhibit ovarian cancer. Methods: A panel of ovarian cancer cell lines was examined for cell surface expression of CDCP1 and loss of expression induced by anti-CDCP1 antibodies 10D7 and 41-2 using flow cytometry and Western blot analysis. Surface plasmon resonance analysis and examination of truncation mutants was used to analyse the binding properties of the antibodies for CDCP1. Live-cell spinning-disk confocal microscopy of GFP-tagged CDCP1 was used to track internalization and intracellular trafficking of CDCP1/antibody complexes. In vivo, zirconium 89-labelled 10D7 was detected by positron-emission tomography imaging, of an ovarian cancer patient-derived xenograft grown intraperitoneally in mice. The efficacy of cytotoxin-conjugated 10D7 was examined against ovarian cancer cells in vitro and in vivo. Results: Our data indicate that each antibody binds with high affinity to the extracellular domain of CDCP1 causing rapid internalization of the receptor/antibody complex and degradation of CDCP1 via processes mediated by the kinase Src. Highlighting the potential clinical utility of CDCP1, positron-emission tomography imaging, using zirconium 89-labelled 10D7, was able to detect subcutaneous and intraperitoneal xenograft ovarian cancers in mice, including small (diameter <3 mm) tumor deposits of an ovarian cancer patient-derived xenograft grown intraperitoneally in mice. Furthermore, cytotoxin-conjugated 10D7 was effective at inhibiting growth of CDCP1-expressing ovarian cancer cells in vitro and in vivo. Conclusions: These data demonstrate that CDCP1 internalizing antibodies have potential for killing and detection of CDCP1 expressing ovarian cancer cells.
Subject(s)
Cell Adhesion Molecules/antagonists & inhibitors , Immunoconjugates/immunology , Membrane Proteins/metabolism , Ovarian Neoplasms/metabolism , Surface Plasmon Resonance/methods , Animals , Antigens, Neoplasm/immunology , Cell Adhesion Molecules/immunology , Cell Line, Tumor , Cell Membrane/metabolism , Cell Movement/immunology , Female , Mice , Models, Animal , Positron-Emission Tomography/methods , Radioisotopes/chemistry , Radioisotopes/metabolism , Transplantation, Heterologous/methods , Zirconium/chemistry , Zirconium/metabolism , src-Family Kinases/metabolismABSTRACT
Naming and word retrieval deficits are two of the most persistent symptoms in chronic post-stroke aphasia. Naming success or failure on specific words can sometimes be predicted by the psycholinguistic properties of the word. Despite a wealth of literature investigating the influence of psycholinguistic properties in neuro-typical and clinical language processing, the underlying structure of these properties and their relation to the fundamental language components and neural correlates are unexplored. In this study, a multivariate data-decomposition approach was used to identify the underlying structure within a collection of psycholinguistic properties (word imageability, frequency, age-of-acquisition, familiarity, length, semantic diversity and phonological neighbourhood density) and their influence on naming accuracy was explored in a cohort of 42 participants with a diverse range of chronic post-stroke aphasia classifications and severities. The results extracted three principal psycholinguistic factors, which were best described as 'lexical usage', 'semantic clarity' and 'phonological complexity'. Furthermore, a novel approach was used to systematically relate the influence of these psycholinguistic properties to participants' neuropsychological and lesion profiles. The findings did not show a one-to-one mapping between psycholinguistic features and core language components. 'Lexical usage' was the only factor that showed a significant difference between fluent versus non-fluent aphasia groups in terms of the influence of this lexical factor on successful naming, and it was the only factor that was related to the pattern of patients' brain lesions. Voxel-wise whole brain lesion-symptom mapping identified left frontal regions, aligning with previous evidence that these regions are related to language production functions, including word retrieval and repetition. The evidence from the current study suggests that the functional locus of psycholinguistic properties is distributed across multiple language components rather than being localised to a single language element.
Subject(s)
Aphasia , Stroke , Brain Mapping , Humans , Magnetic Resonance Imaging , Psycholinguistics , Semantics , Stroke/complicationsABSTRACT
Purpose: To identify which elements of the therapeutic alliance are important to people with aphasia (PWA) attending speech-language pathology post-stroke.Method: A Q methodology design was adopted to explore which elements of the therapeutic alliance were valued by PWA. Statements (n = 453) relevant to the research question were extrapolated from the literature and qualitative interviews. A representative sample of statements (n = 38) was identified from the expansive data set. PWA (n = 23) sorted statements hierarchically according to whether they thought the statement was important or unimportant. Completed Q sorts were analysed using a by-person factor analysis.Result: Analysis yielded a five-factor solution, representing five distinct viewpoints: (1) acknowledge me, help me to understand; (2) respect me, listen to me; (3) challenge me, direct me; (4) understand me, laugh with me; and (5) hear me, encourage me.Conclusion: The findings highlight the need for clinicians to adopt a flexible and idiosyncratic approach to therapeutic alliance construction in order to meet the relational needs of a heterogeneous population. This is the first study to use Q methodology with PWA, demonstrating that Q methodology is an effective and viable method for investigating subjectivity in this population.
Subject(s)
Aphasia/therapy , Language Disorders/therapy , Professional-Patient Relations , Stroke Rehabilitation/methods , Aphasia/etiology , Humans , Language Disorders/etiology , Speech-Language Pathology/methods , Stroke/complicationsABSTRACT
Macrophage-expressed gene 1 (MPEG1/Perforin-2) is a perforin-like protein that functions within the phagolysosome to damage engulfed microbes. MPEG1 is thought to form pores in target membranes, however, its mode of action remains unknown. We use cryo-Electron Microscopy (cryo-EM) to determine the 2.4 Å structure of a hexadecameric assembly of MPEG1 that displays the expected features of a soluble prepore complex. We further discover that MPEG1 prepore-like assemblies can be induced to perforate membranes through acidification, such as would occur within maturing phagolysosomes. We next solve the 3.6 Å cryo-EM structure of MPEG1 in complex with liposomes. These data reveal that a multi-vesicular body of 12 kDa (MVB12)-associated ß-prism (MABP) domain binds membranes such that the pore-forming machinery of MPEG1 is oriented away from the bound membrane. This unexpected mechanism of membrane interaction suggests that MPEG1 remains bound to the phagolysosome membrane while simultaneously forming pores in engulfed bacterial targets.
Subject(s)
Cell Membrane/metabolism , Membrane Proteins/metabolism , Pore Forming Cytotoxic Proteins/metabolism , Bacteria/immunology , Cryoelectron Microscopy , Humans , Liposomes/metabolism , Lysosomes/physiology , Macrophages/immunology , Microscopy, Atomic Force , Protein Domains , Protein Structure, SecondaryABSTRACT
Purpose: The therapeutic alliance, also known as the therapeutic relationship, may influence treatment process and outcome in aphasia rehabilitation; however, we currently lack a reliable tool to measure this relationship. This study aimed to develop a novel measure of the therapeutic alliance applicable to this population and provide preliminary evidence of the measure's psychometric properties. Method: Statements were generated from the: (1) therapeutic alliance literature, (2) qualitative interviews with stakeholders, and (3) Q methodological insights with people with aphasia (PWA) (n = 455). A representative sample of statements was identified from the data set (n = 57) and reviewed by expert panels (professionals and PWA), culminating in a 42-item clinician and patient version of the aphasia and stroke therapeutic alliance measure (A-STAM). Reliability and validity of both the clinician and patient versions of A-STAM were investigated with 34 Clinician-patient dyads engaging in therapy. Result: Internal consistency and test-retest reliability were excellent for both clinician (α = 92; ICC = 0.93) and patient versions of A-STAM (α = 0.92; ICC = 0.97). In both versions, scores correlated highly with psychotherapeutic measures of therapeutic alliance, indicative of good construct validity (rs = 0.75; rs = 0.77). Conclusion: The findings establish the preliminary reliability and validity of A-STAM and support further investigation into the measure's psychometric properties in larger samples.
Subject(s)
Aphasia/therapy , Psychometrics , Speech-Language Pathology/methods , Stroke Rehabilitation/methods , Stroke/therapy , Surveys and Questionnaires , Therapeutic Alliance , Adult , Aged , Aged, 80 and over , Aphasia/diagnosis , Aphasia/etiology , Aphasia/psychology , Female , Humans , Interviews as Topic , Male , Middle Aged , Qualitative Research , Recovery of Function , Stakeholder Participation , Stroke/complications , Stroke/diagnosis , Stroke/psychology , Treatment OutcomeABSTRACT
Plasminogen (Plg)-binding M protein (PAM) is a group A streptococcal cell surface receptor that is crucial for bacterial virulence. Previous studies revealed that, by binding to the kringle 2 (KR2) domain of host Plg, the pathogen attains a proteolytic microenvironment on the cell surface that facilitates its dissemination from the primary infection site. Each of the PAM molecules in their dimeric assembly consists of two Plg binding motifs (called the a1 and a2 repeats). To date, the molecular interactions between the a1 repeat and KR2 have been structurally characterized, whereas the role of the a2 repeat is less well defined. Here, we report the 1.7-Å x-ray crystal structure of KR2 in complex with a monomeric PAM peptide that contains both the a1 and a2 motifs. The structure reveals how the PAM peptide forms key interactions simultaneously with two KR2 via the high-affinity lysine isosteres within the a1a2 motifs. Further studies, through combined mutagenesis and functional characterization, show that a2 is a stronger KR2 binder than a1, suggesting that these two motifs may play discrete roles in mediating the final PAM-Plg assembly.