Treatment fidelity in einem neuen konversationsorientierten Therapieansatz für Menschen mit Agrammatismus und deren Konversationspartner

Background: When conducting a speech and language therapy intervention study, one essential part lies in the evaluation of the outcomes. The underlying therapy itself and its delivery are aspects which are mostly done in the background. There is little focus on the question: Was therapy delivered with fidelity, i.e. to what extent does the actual therapy delivery correspond to the planned delivery? If treatment fidelity (TF) is discussed in a paper, researchers often report on therapy manuals, training and supervision of therapists, or adherence to the therapeutic techniques. However, according to Cherney et al. (2013), TF is regarded as a crucial component of any behavioural treatment study (ibid.) and should therefore be assessed in a speech and language therapy intervention study. Aim: The present thesis is part of a wider research project in which a new conversation-based therapy - called Better Conversations with Aphasia (BCA; Beeke et al., 2011; Beeke et al., submitted; Beckley et al., 2013) – was designed. The therapy was provided to eight people with agrammatism and their conversation partners (CPs), together called a dyad. It is an adaptation of a conversation training programme called SPPARC (Supporting Partners of People with Aphasia in Relationships and Conversation; Lock et al., 2001a). Every dyad was treated by the same speech and language therapist (SLT) and all therapy sessions were videotaped. The aim of the present thesis is to examine aspects of TF retrospectively and thereby assess the degree of uniform therapy delivery as planned. Methods: The multifaceted concept of TF is introduced and applied to the wider research project. Using this concept, the degree to which the BCA therapy programme was delivered as planned, can be measured. This can be achieved by developing a pilot fidelity tool, which is based on a conceptual framework of TF (Carroll et al., 2007), on practices reported in the TF literature and on the generic session plans of the BCA therapy. The first step was to observe 23% of the therapy sessions and rate them with the tool. These observations were conducted on data of seven dyads. In addition, descriptive data were collected to enlarge the fidelity evaluation. In a last step, inter-rater reliability (IRR) of parts of the fidelity tool was also assessed with the help of a second observer who rated 20% of the sessions already used for the fidelity check. Results: The results indicate that, in terms of therapy content, a high fidelity level of 91.9% was reached for the BCA therapy programme. Dyad-specific fidelity scores thereby ranged between 86% and 97%, which shows a certain degree of variability, even when only one therapist was delivering the intervention. It also suggests that each dyad received a satisfactorily equivalent intervention. The duration and frequency of the therapy sessions varied across the dyads. However, this reflects the individual and interactive nature of a conversation-based therapy. Qualitatively, the therapist showed a high degree of desired behaviour associated with the delivery of the BCA therapy programme (averaged across the dyads: 96.7%). Other potential moderators of fidelity, such as the acceptance of components of the therapy programme and the clients’ motivation, were also investigated in the present thesis, providing a multifaceted evaluation of TF. In terms of the inter-rater reliability of the designed fidelity tool, acceptable levels have been reached for almost all of the sessions observed by two qualified SLTs. Future directions: For future investigations, the procedural section of the fidelity tool could be refined in terms of fewer, essential elements of the BCA therapy. Moreover, clearer rating guidelines are necessary for rating the fidelity tool reliably. A potential next step for future research might be to identify potential essential components of the BCA therapy and to relate the outcomes of the main BCA research project to TF data. However, the importance and value of a fidelity evaluation is already being demonstrated in the present thesis.Theoretischer Hintergrund: Eine Sprachtherapieevaluation besteht typischerweise aus der Messung des tatsächlichen Therapieeffekts. Die Evaluierung der Therapiephase, also inwieweit die ursprünglich vorgesehene Therapie übermittelt wurde (z.B. wie in einem Therapiemanual beschrieben), wird hingegen oft vernachlässigt. Die englischsprachige Literatur spricht in diesem Zusammenhang häufig von dem Konzept der treatment fidelity (TF) (was übersetzt in etwa dem Begriff ‚Therapiegenauigkeit‘ entspricht). Berichten Forscher über Aspekte dieses Konzeptes, dann wird dies meist auf das Therapiemanual, Therapeutenschulungen oder -supervisionen, oder auf die Messung der Therapiekonformität des Sprachtherapeuten bezogen. Jedoch wird das Konzept der TF nach Cherney et al. (2013) als eine wichtige Komponente einer verhaltenstherapeutisch orientierten (Sprach-)Therapiestudie angesehen. Ziel: Die vorliegende Arbeit ist Teil eines übergreifenden Forschungsprojekts, in dem ein konversationsorientierter Therapieansatz entwickelt wurde (Better Conversations with Aphasia; BCA; Beeke et al., 2011; Beeke et al., submitted; Beckley et al., 2013). Dieser Therapieansatz basiert auf dem bereits vorhandenen Konversationstraining SPPARC (Supporting Partners of People with Aphasia in Relationships and Conversation; Lock et al., 2001a). Für die Umsetzung der BCA Therapie wurden acht Paare therapiert, die jeweils aus einer aphasischen Person mit agrammatischer Sprachproduktion sowie einer primären Bezugsperson bestanden. Die Therapie wurde dabei für alle Probanden von der gleichen Sprachtherapeutin durchgeführt und alle Therapiesitzungen wurden auf Video aufgezeichnet. Das Ziel der vorliegenden Arbeit besteht in der Anwendung des TF Konzeptes auf den BCA Therapieansatz, um den Grad der Konformität mit der ursprünglich vorgesehenen Therapie zu ermitteln. Methodik: Zunächst wird das Konzept der TF beschrieben und auf die Daten von sieben Paaren der Hauptstudie angewendet. Um die Therapieübermittlung zu quantifizieren, also inwieweit sich die Therapeutin an dem vorgegebenen Therapieprogramm orientiert hat, wird sodann ein fidelity tool (d.h. ein Beobachtungsinstrument) entwickelt. Dieses Instrument basiert auf einem speziellen TF-Modell (Carroll et al., 2007), weiteren Methoden aus der TF Literatur und BCA-spezifischen Therapieplänen. Es werden insgesamt 23% der Therapiesitzungen mit Hilfe dieses Instruments beurteilt. Zusätzlich werden schriftliche Dokumente der Hauptstudie analysiert, um TF möglichst umfassend zu erörtern. Abschließend werden 20% der beurteilten Sitzungen von einem zweiten trainierten Beobachter eingeschätzt, um erste Aussagen über die Inter-rater Reliabilität des fidelity tools treffen zu können. Ergebnisse: Die Analyse der Videoaufnahmen mithilfe des fidelity tools zeigt einen sog. fidelity score (Genauigkeitswert) von 91,9%, was laut Literatur eine hohe Therapiekonformität der Therapeutin anzeigt. Die individuellen fidelity scores liegen dabei zwischen 86% und 97%. Dies deutet einerseits auf einen gewissen Grad an Variabilität in der Therapieübermittlung hin, auch wenn ein und dieselbe Therapeutin die Therapie übermittelt. Andererseits lassen diese Ergebnisse annehmen, dass jedes Paar die Therapie zu einem zufriedenstellenden Ausmaß erhalten hat. Im Hinblick auf die Dauer und Frequenz der Therapiesitzungen zeigt sich ein eher heterogenes Muster. Dies spiegelt jedoch die interaktive Natur dieser Therapie wider. Zu durchschnittlich 96,7% wendet die Therapeutin erwünschte Therapieprinzipien während der Sitzungen an. Weitere Faktoren, die in der vorliegenden Arbeit erhoben wurden, zeigen, dass die Studienteilnehmer motiviert in der Therapie partizipieren, jedoch gibt es Hinweise auf einzelne Therapiekomponenten, die verbessert werden könnten. Fast alle der untersuchten Teile des fidelity tools weisen eine gute Inter-rater-Übereinstimmung auf. Ausblick: In weiteren Forschungsbemühungen könnte angestrebt werden, die Anzahl der Items des fidelity tools zu minimieren, idealerweise auf die essentiellen Elemente der BCA Therapie. Außerdem wäre eine Einführung klarer Beurteilungsrichtlinien von Nöten, damit alle Teile des Instrumentes zuverlässig angewendet werden können. Ein nächster Schritt könnte darin bestehen, essentielle Komponenten des BCA Therapieprogrammes zu identifizieren, wofür die vorliegende Untersuchung eine erste Grundlage darstellt. Die vorliegende Arbeit demonstriert insgesamt die Wichtigkeit und das Potential einer fidelity Evaluation anhand der Anwendung des TF Konzepts auf die BCA Therapie

A usage-based approach to language processing and intervention in aphasia

Non-fluent aphasia (NFA) is characterized by grammatically impoverished language output. Yet there is evidence that a restricted set of multi-word utterances (e.g., “don’t know”) are retained. Analyses of connected speech often dismiss these as stereotypical, however, these high-frequency phrases are an interactional resource in both neurotypical and aphasic discourse. One approach that can account for these forms is usage-based grammar, where linguistic knowledge is thought of as an inventory of constructions, i.e., form-meaning pairings such as familiar collocations (“wait a minute”) and semi-fixed phrases (“I want X”). This approach is used in language development and second language learning research, but its application to aphasiology is currently limited. This thesis applied a usage-based perspective to language processing and intervention in aphasia. Study 1 investigated use of word combinations in conversations of nine participants with Broca’s aphasia (PWA) and their conversation partners (CPs), combining analysis of form (frequency-based approach) and function (interactional linguistics approach). In study 2, an on-line word monitoring task was used to examine whether individuals with aphasia and neurotypical controls showed sensitivity to collocation strength (degree of association between units of a word combination). Finally, the impact of a novel intervention involving loosening of slots in semi-fixed phrases was piloted with five participants with NFA. Study 1 revealed that PWA used stronger collocated word combinations compared to CPs, and familiar collocations are a resource adapted to the constraints of aphasia. Findings from study 2 indicated that words were recognised more rapidly when preceded by strongly collocated words in both neurotypical and aphasic listeners, although effects were stronger for controls. Study 3 resulted in improved connected speech for some participants. Future research is needed to refine outcome measures for connected speech interventions. This thesis suggests that usage-based grammar has potential to explain grammatical behaviour in aphasia, and to inform interventions

Coordinate-based co-localization-mediated analysis of arrestin clustering upon stimulation of the C-C chemokine receptor 5 with RANTES/CCL5 analogues

G protein-coupled receptor activation and desensitization leads to recruitment of arrestin proteins from cytosolic pools to the cell membrane where they form clusters difficult to characterize due to their small size and further mediate receptor internalization. We quantitatively investigated clustering of arrestin 3 induced by potent anti-HIV analogues of the chemokine RANTES after stimulation of the C-C chemokine receptor 5 using single-molecule localization-based super-resolution microscopy. We determined arrestin 3 cluster sizes and relative fractions of arrestin 3 molecules in each cluster through image-based analysis of the localization data by adapting a method originally developed for co-localization analysis from molecular coordinates. We found that only classical agonists in the set of tested ligands were able to efficiently recruit arrestin 3 to clusters mostly larger than 150nm in size and compare our results with existing data on arrestin 2 clustering induced by the same chemokine analogues

Conversation therapy with people with aphasia and conversation partners using video feedback: a group and case series investigation of changes in interaction

Conversation therapies employing video for feedback and to facilitate outcome measurement are increasingly used with people with post-stroke aphasia and their conversation partners; however the evidence base for change in everyday interaction remains limited. We investigated the effect of Better Conversations with Aphasia (BCA), an intervention that is freely available online at https://extend.ucl.ac.uk/. Eight people with chronic agrammatic aphasia, and their regular conversation partners participated in the tailored 8 week program involving significant video feedback. We explored changes in: (i) conversation facilitators (such as multi-modal turns by people with aphasia); and (ii) conversation barriers (such as use of test questions by conversation partners). The outcome of intervention was evaluated directly by measuring change in video-recorded everyday conversations. The study employed a pre-post design with multiple 5 minute samples of conversation before and after intervention, scored by trained raters blind to the point of data collection. Group level analysis showed no significant increase in conversation facilitators. There was, however, a significant reduction in the number of conversation barriers. The case series data revealed variability in conversation behaviors across occasions for the same dyad and between different dyads. Specifically, post-intervention there was a significant increase in facilitator behaviors for two dyads, a decrease for one and no significant change for five dyads. There was a significant decrease in barrier behaviors for five dyads and no significant change for three dyads. The reduction in barrier behaviors was considerable; on average change from over eight to fewer than three barrier behaviors in 5 minutes of conversation. The pre-post design has the limitation of no comparison group. However, change occurs in targeted conversational behaviors and in people with chronic aphasia and their partners. The findings suggest change can occur after eight therapy sessions and have implications for clinical practice. A reduction in barrier behaviors may be easier to obtain, although the controlled case series results demonstrate a significant increase in conversation facilitators is also possible. The rehabilitation tool is available online and video technology was central to delivering intervention and evaluating change

Biased activation of the receptor tyrosine kinase HER2

HER2 belongs to the ErbB sub-family of receptor tyrosine kinases and regulates cellular proliferation and growth. Different from other ErbB receptors, HER2 has no known ligand. Activation occurs through heterodimerization with other ErbB receptors and their cognate ligands. This suggests several possible activation paths of HER2 with ligand-specific, differential response, which has so far remained unexplored. Using single-molecule tracking and the diffusion profile of HER2 as a proxy for activity, we measured the activation strength and temporal profile in live cells. We found that HER2 is strongly activated by EGFR-targeting ligands EGF and TGFα, yet with a distinguishable temporal fingerprint. The HER4-targeting ligands EREG and NRGβ1 showed weaker activation of HER2, a preference for EREG, and a delayed response to NRGβ1. Our results indicate a selective ligand response of HER2 that may serve as a regulatory element. Our experimental approach is easily transferable to other membrane receptors targeted by multiple ligands

The prevalence and specificity of local protein synthesis during neuronal synaptic plasticity

To supply proteins to their vast volume, neurons localize mRNAs and ribosomes in dendrites and axons. While local protein synthesis is required for synaptic plasticity, the abundance and distribution of ribosomes and nascent proteins near synapses remain elusive. Here, we quantified the occurrence of local translation and visualized the range of synapses supplied by nascent proteins during basal and plastic conditions. We detected dendritic ribosomes and nascent proteins at single-molecule resolution using DNA-PAINT and metabolic labeling. Both ribosomes and nascent proteins positively correlated with synapse density. Ribosomes were detected at ~85% of synapses with ~2 translational sites per synapse; ~50% of the nascent protein was detected near synapses. The amount of locally synthesized protein detected at a synapse correlated with its spontaneous Ca2+ activity. A multifold increase in synaptic nascent protein was evident following both local and global plasticity at respective scales, albeit with substantial heterogeneity between neighboring synapses

Biased activation of the receptor tyrosine kinase HER2

HER2 belongs to the ErbB sub-family of receptor tyrosine kinases and regulates cellular proliferation and growth. Different from other ErbB receptors, HER2 has no known ligand. Activation occurs through heterodimerization with other ErbB receptors and their cognate ligands. This suggests several possible activation paths of HER2 with ligand-specific, differential response, which so far remained unexplored. Using single-molecule tracking and the diffusion profile of HER2 as a proxy for activity, we measured the activation strength and temporal profile in live cells. We found that HER2 is strongly activated by EGFR-targeting ligands EGF and TGFα, yet with a distinguishable temporal fingerprint. The HER4-targeting ligands EREG and NRGβ1 showed weaker activation of HER2, a preference for EREG, and a delayed response to NRGβ1. Our results indicate a selective ligand response of HER2 that may serve as a regulatory element. Our experimental approach is easily transferable to other membrane receptors targeted by multiple ligands

Channelrhodopsin-2 Oligomerization in Cell Membrane Revealed by Photo-Activated Localization Microscopy

Microbial rhodopsins are retinal membrane proteins that found a broad application in optogenetics. The oligomeric state of rhodopsins is important for their functionality and stability. Of particular interest is the oligomeric state in the cellular native membrane environment. Fluorescence microscopy provides powerful tools to determine the oligomeric state of membrane proteins directly in cells. Among these methods is quantitative photoactivated localization microscopy (qPALM) allowing the investigation of molecular organization at the level of single protein clusters. Here, we apply qPALM to investigate the oligomeric state of the first and most used optogenetic tool Channelrhodopsin-2 (ChR2) in the plasma membrane of eukaryotic cells. ChR2 appeared predominantly as a dimer in the cell membrane and did not form higher oligomers. The disulfide bonds between Cys34 and Cys36 of adjacent ChR2 monomers were not required for dimer formation and mutations disrupting these bonds resulted in only partial monomerization of ChR2. The monomeric fraction increased when the total concentration of mutant ChR2 in the membrane was low. The dissociation constant was estimated for this partially monomerized mutant ChR2 as 2.2±0.9 proteins/μm2. Our findings are important for understanding the mechanistic basis of ChR2 activity as well as for improving existing and developing future optogenetic tools.</p

Channelrhodopsin-2 Oligomerization in Cell Membrane Revealed by Photo-Activated Localization Microscopy

Microbial rhodopsins are retinal membrane proteins that found a broad application in optogenetics. The oligomeric state of rhodopsins is important for their functionality and stability. Of particular interest is the oligomeric state in the cellular native membrane environment. Fluorescence microscopy provides powerful tools to determine the oligomeric state of membrane proteins directly in cells. Among these methods is quantitative photoactivated localization microscopy (qPALM) allowing the investigation of molecular organization at the level of single protein clusters. Here, we apply qPALM to investigate the oligomeric state of the first and most used optogenetic tool Channelrhodopsin-2 (ChR2) in the plasma membrane of eukaryotic cells. ChR2 appeared predominantly as a dimer in the cell membrane and did not form higher oligomers. The disulfide bonds between Cys34 and Cys36 of adjacent ChR2 monomers were not required for dimer formation and mutations disrupting these bonds resulted in only partial monomerization of ChR2. The monomeric fraction increased when the total concentration of mutant ChR2 in the membrane was low. The dissociation constant was estimated for this partially monomerized mutant ChR2 as 2.2±0.9 proteins/μm2. Our findings are important for understanding the mechanistic basis of ChR2 activity as well as for improving existing and developing future optogenetic tools.</p

Quantitative morphological analysis of arrestin2 clustering upon G protein-coupled receptor stimulation by super-resolution microscopy

Clustering of arrestins upon G protein-coupled receptor stimulation is a phenomenon that is well-known but difficult to describe quantitatively due to the size of the clusters close to the diffraction limit of visible light. We introduce a general method to quantitatively investigate the clustering of arrestin following stimulation of the C-C chemokine receptor 5 (CCR5) using single-molecule super-resolution imaging and coordinate and image-based cluster analysis. We investigated the effect of potent anti-HIV ligands of CCR5 with different pharmacological profiles on arrestin2 cluster formation and found that only the ligands capable of inducing CCR5 internalization induced arrestin2 recruitment and clustering. We further demonstrate that the fraction of arrestin2 molecules found in clusters larger than 100nm correlates with the magnitude of ligand-induced CCR5 internalization, but not with G protein activation, indicating that recruitment of arrestin2 to CCR5 is independent of G protein activation. Pre-treatment of the cells with the drug cytochalasin D, which blocks actin polymerization, led to the formation of larger clusters, whereas the inhibitor of microtubule polymerization nocodazole had little effect on arrestin2 recruitment, suggesting an active role of actin in the organization and dynamics of these aggregates