Genetic modifiers of somatic expansion and clinical phenotypes in Huntington's disease reveal shared and tissue-specific effects.

Huntington's disease (HD), due to expansion of a CAG repeat in HTT , is representative of a growing number of disorders involving somatically unstable short tandem repeats. We find that overlapping and distinct genetic modifiers of clinical landmarks and somatic expansion in blood DNA reveal an underlying complexity and cell-type specificity to the mismatch repair-related processes that influence disease timing. Differential capture of non-DNA-repair gene modifiers by multiple measures of cognitive and motor dysfunction argues additionally for cell-type specificity of pathogenic processes. Beyond trans modifiers, differential effects are also illustrated at HTT by a 5'-UTR variant that promotes somatic expansion in blood without influencing clinical HD, while, even after correcting for uninterrupted CAG length, a synonymous sequence change at the end of the CAG repeat dramatically hastens onset of motor signs without increasing somatic expansion. Our findings are directly relevant to therapeutic suppression of somatic expansion in HD and related disorders and provide a route to define the individual neuronal cell types that contribute to different HD clinical phenotypes.

Bicycling for Rehabilitation of Persons With Parkinson Disease: A Scoping Review.

BACKGROUND AND PURPOSE: Exercise is beneficial for persons with Parkinson disease (PwPD). The overarching purpose of this scoping review was to provide guidance to clinicians and scientists regarding current evidence for bicycling exercise for PwPD. A scoping review was conducted to examine the heterogeneous literature on stationary bicycling for PwPD to reduce motor symptoms and body function structure impairments, improve activities and motor performance, and reduce disease severity. METHODS: The Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines were followed. PubMed, CINAHL, and PEDro were searched from inception to January 23, 2023. Articles reporting original data on relevant outcome measures were included. Search results were screened and articles were extracted. Data were analyzed quantitatively with percentages of significant and clinically meaningful findings and qualitatively to extract themes. RESULTS: Bicycling was categorized using bicycle types (assisted, nonassisted) and training modes (speed, aerobic, force). A high percentage of the 34 studies showed statistical significance for reducing motor symptoms (83%), body function structure impairments (78%), disease severity (82%), and improving activities (gait 72%, balance 60%). Clinically meaningful findings were achieved in 71% of the studies for reduction in disease severity and in 50% for improving gait. DISCUSSION AND CONCLUSIONS: The literature on bicycling for PwPD has evolved from speed to aerobic studies. The terminology describing types of bicycling was simplified. Of all the outcomes reported, reduction of disease severity achieved the highest frequency of clinical meaningful improvements. Bicycling was comparable with other forms of aerobic training for walking speed and endurance. Opportunities for translation to practice and research are presented.

Modification of Huntington's disease by short tandem repeats.

Expansions of glutamine-coding CAG trinucleotide repeats cause a number of neurodegenerative diseases, including Huntington's disease and several of spinocerebellar ataxias. In general, age-at-onset of the polyglutamine diseases is inversely correlated with the size of the respective inherited expanded CAG repeat. Expanded CAG repeats are also somatically unstable in certain tissues, and age-at-onset of Huntington's disease corrected for individual HTT CAG repeat length (i.e. residual age-at-onset), is modified by repeat instability-related DNA maintenance/repair genes as demonstrated by recent genome-wide association studies. Modification of one polyglutamine disease (e.g. Huntington's disease) by the repeat length of another (e.g. ATXN3, CAG expansions in which cause spinocerebellar ataxia 3) has also been hypothesized. Consequently, we determined whether age-at-onset in Huntington's disease is modified by the CAG repeats of other polyglutamine disease genes. We found that the CAG measured repeat sizes of other polyglutamine disease genes that were polymorphic in Huntington's disease participants but did not influence Huntington's disease age-at-onset. Additional analysis focusing specifically on ATXN3 in a larger sample set (n = 1388) confirmed the lack of association between Huntington's disease residual age-at-onset and ATXN3 CAG repeat length. Additionally, neither our Huntington's disease onset modifier genome-wide association studies single nucleotide polymorphism data nor imputed short tandem repeat data supported the involvement of other polyglutamine disease genes in modifying Huntington's disease. By contrast, our genome-wide association studies based on imputed short tandem repeats revealed significant modification signals for other genomic regions. Together, our short tandem repeat genome-wide association studies show that modification of Huntington's disease is associated with short tandem repeats that do not involve other polyglutamine disease-causing genes, refining the landscape of Huntington's disease modification and highlighting the importance of rigorous data analysis, especially in genetic studies testing candidate modifiers.

Expanding student nurse placement activity in Welsh care homes: An evaluation study.

AIM: Expanding and sustaining student nurse placements outside of the acute sector is a universal challenge. This paper aims to evaluate the Care Home Education Facilitator Role introduced in one area of Wales, United Kingdom, and to report on the outcomes achieved from this novel role. METHODS: Semi-structured interviews were undertaken with key stakeholders including the Care Home Education Facilitator postholder leading the pilot, care home managers, higher education institutions' placement managers/coordinators, student nurses and national health service staff. RESULTS: Five key areas were identified, which included timing of introducing the post and establishing a clear rationale and understanding of the intention of the role. The benefits, challenges and suggested improvements to the Care Home Education Facilitator initiative are provided. CONCLUSION: Introducing the role of the Care Home Education Facilitator to work closely with key stakeholders resulted in increased placements for student nurses, but investing time in developing relationships with these stakeholders was critical to the success of the role.

Mutant huntingtin confers cell-autonomous phenotypes on Huntington's disease iPSC-derived microglia.

Huntington's disease (HD) is a neurodegenerative disorder caused by a dominantly inherited CAG repeat expansion in the huntingtin gene (HTT). Neuroinflammation and microglia have been implicated in HD pathology, however it has been unclear if mutant HTT (mHTT) expression has an adverse cell-autonomous effect on microglial function, or if they are only activated in response to the neurodegenerative brain environment in HD. To establish a human cell model of HD microglia function, we generated isogenic controls for HD patient-derived induced pluripotent stem cells (iPSC) with 109 CAG repeats (Q109). Q109 and isogenic Q22 iPSC, as well as non-isogenic Q60 and Q33 iPSC lines, were differentiated to iPSC-microglia. Our study supports a model of basal microglia dysfunction in HD leading to elevated pro-inflammatory cytokine production together with impaired phagocytosis and endocytosis capacity, in the absence of immune stimulation. These findings are consistent with early microglia activation observed in pre-manifest patients and indicate that mHTT gene expression affects microglia function in a cell-autonomous way.

Views and experiences of opioid access amongst palliative care providers and public representatives in a low-resource setting: A qualitative interview study.

Opioids (e.g. morphine) are affordable, effective interventions for cancer-related pain. However, equity of access to this key medication remains a global challenge, particularly in low- and middle-income countries. We aimed to explore views of palliative care providers and public-representatives about opioid analgesia access in two States in India. We conducted a qualitative study using semi-structured interviews. Transcribed audio-recordings were subjected to thematic analysis using a Framework Approach. Palliative care providers and public-representatives were purposively sampled from services reporting consistent opioid availability and prescribing (≥4kg per annum) from Karnataka and Kerala. Twenty participants (doctors (10), nurses (4), pharmacists (2), service managers (2) and public-representatives (2) were interviewed. Three themes were identified: 1) Attitudes and awareness: opioid treatments are perceived as end-of-life (last days/weeks) interventions; fears of addiction and misunderstanding of pain management goals limit access. 2) Expected and unexpected inequities: patients/carers from lower socioeconomic strata accept doctor recommendations if opioids are affordable, more educated patients/families have reservations about opioids, delay access and perceive expensive medicines as better. Non-palliative care specialist doctors have negative entrenched views and require specialist training. 3) Experiential learning-positive experiences can positively alter attitudes (e.g., participants in Kerala report improved attitudes, awareness and understanding influenced by exposure and community awareness, but experience can also reinforce perceptions as end-of-life care. Entrenched negative views are reinforced by poor experiences while positive experiences improve attitudes. To promote access, opioid prescribing must be needs-based rather than prognosis-based. Addressing the lack of training for non-palliative care workforce would help overcome a major barrier.

'It's tough. It is hard': A qualitative interview study of staff and volunteers caring for hospice in-patients with delirium.

BACKGROUND: Delirium is a distressing condition often experienced by hospice in-patients. Increased understanding of current multidisciplinary care of delirium is needed to develop interventions in this setting. AIM(S): To explore hospice staff and volunteers' practice, its influences and what may need to change to improve hospice delirium care. DESIGN: Qualitative interview study using behaviour change theory from a critical realist stance. SETTING/PARTICIPANTS: Thirty-seven staff, including different professional groups and roles, and volunteers were purposively sampled from two in-patient hospices. RESULTS: We found that participants' practice focus was on managing hyperactive symptoms of delirium, through medication use and non-pharmacological strategies. Delirium prevention, early recognition and hypoactive delirium received less attention. Our theoretically-informed analysis identified this focus was influenced by staff and volunteers' emotional responses to the distress associated with hyperactive symptoms of delirium as well as understanding of delirium prevention, recognition and care, which varied between staff groups. Non-pharmacological delirium management was supported by adequate staffing levels, supportive team working and a culture of person-centred and family-centred care, although behaviours that disrupted the calm hospice environment challenged this. CONCLUSIONS: Our findings can inform hospice-tailored behaviour change interventions that develop a shared team understanding and engage staff's emotional responses to improve delirium care. Reflective learning opportunities are needed that increase understanding of the potential to reduce patient distress through prevention and early recognition of delirium, as well as person-centred management. Organisational support for adequate, flexible staffing levels and supportive team working is required to support person-centred delirium care.

Large libraries of single-chain trimer peptide-MHCs enable antigen-specific CD8+ T cell discovery and analysis.

The discovery and characterization of antigen-specific CD8+ T cell clonotypes typically involves the labor-intensive synthesis and construction of peptide-MHC tetramers. We adapt single-chain trimer (SCT) technologies into a high throughput platform for pMHC library generation, showing that hundreds can be rapidly prepared across multiple Class I HLA alleles. We use this platform to explore the impact of peptide and SCT template mutations on protein expression yield, thermal stability, and functionality. SCT libraries were an efficient tool for identifying T cells recognizing commonly reported viral epitopes. We then construct SCT libraries to capture SARS-CoV-2 specific CD8+ T cells from COVID-19 participants and healthy donors. The immunogenicity of these epitopes is validated by functional assays of T cells with cloned TCRs captured using SCT libraries. These technologies should enable the rapid analyses of peptide-based T cell responses across several contexts, including autoimmunity, cancer, or infectious disease.

Introducing the '3 Fs model of complexity' for people with dementia accessing a NHS mental health inpatient dementia assessment ward: An interpretive description study.

BACKGROUND: In the United Kingdom, the use of the terms 'complex' and 'complexity' alongside dementia is reflected in a number of policy and practice documents. However, there is a lack of evidence that explores how complexity is perceived, constructed and experienced by people with dementia, family carers and practitioners working in the NHS dementia inpatient assessment wards [dementia assessment wards]. OBJECTIVE: To explore the meaning and concept of complexity in dementia from within the setting of a dementia assessment ward and develop a practice model. METHODS: The study was conducted over three phases: 1) an online electronic survey of UK national dementia leaders; 2) individual interviews and a focus group with dementia practitioners in two dementia assessment wards; 3) case studies of four patients with dementia resident on a dementia assessment ward which included their identified family carer/consultee, the named clinician on the ward involved in that person's care and a care records review. RESULTS: The findings highlighted that complexity is constructed through a number of interconnected and interrelated domains that vary in acuity. These findings have been developed into the '3 Fs Model of Complexity' and the 3'Fs' stand for Fixed, Flexible and Fluctuating. The Fixed domain consists of six components which are always present in complexity. The Flexible domain consists of 14 components and a person with dementia may experience any number of Flexible domain components at any one time. The Fluctuating domain highlights that all components have the ability to vary in their acuity. CONCLUSION: The '3 Fs Model of Complexity' may facilitate a more holistic view of a person with dementia than when 'symptoms' are viewed in isolation. Going forward, and subject to further refinement and testing, the '3 Fs Model of Complexity' could help guide the selection of tailored, personalised interventions for people with dementia, including formulation approaches.

Repeat Detector: versatile sizing of expanded tandem repeats and identification of interrupted alleles from targeted DNA sequencing.

Targeted DNA sequencing approaches will improve how the size of short tandem repeats is measured for diagnostic tests and preclinical studies. The expansion of these sequences causes dozens of disorders, with longer tracts generally leading to a more severe disease. Interrupted alleles are sometimes present within repeats and can alter disease manifestation. Determining repeat size mosaicism and identifying interruptions in targeted sequencing datasets remains a major challenge. This is in part because standard alignment tools are ill-suited for repetitive and unstable sequences. To address this, we have developed Repeat Detector (RD), a deterministic profile weighting algorithm for counting repeats in targeted sequencing data. We tested RD using blood-derived DNA samples from Huntington's disease and Fuchs endothelial corneal dystrophy patients sequenced using either Illumina MiSeq or Pacific Biosciences single-molecule, real-time sequencing platforms. RD was highly accurate in determining repeat sizes of 609 blood-derived samples from Huntington's disease individuals and did not require prior knowledge of the flanking sequences. Furthermore, RD can be used to identify alleles with interruptions and provide a measure of repeat instability within an individual. RD is therefore highly versatile and may find applications in the diagnosis of expanded repeat disorders and in the development of novel therapies.

Large libraries of single-chain trimer peptide-MHCs enable rapid antigen-specific CD8+ T cell discovery and analysis.

CD8 + cytotoxic T cell responses against viral infection represent a major element of the adaptive immune response. We describe the development of a peptide antigen - major histompatibility complex (pMHC) library representing the full SARS-CoV-2 viral proteome, and comprised of 634 pMHC multimers representing the A*02.01, A*24.02, and B*07.02 HLA alleles, as well as specific antigens associated with the cytomegalovirus (CMV). These libraries were used to capture non-expanded CD8 + T cells from blood samples collected from 64 infected individuals, and then analyzed using single cell RNA-seq. The discovery and characterization of antigen-specific CD8 + T cell clonotypes typically involves the labor-intensive synthesis and construction of peptide-MHC tetramers. We adapted single-chain trimer (SCT) technologies into a high throughput platform for pMHC library generation, showing that hundreds can be rapidly prepared across multiple Class I HLA alleles. We used this platform to explore the impact of peptide and SCT template mutations on protein expression yield, thermal stability, and functionality. SCT libraries were an efficient tool for identifying T cells recognizing commonly reported viral epitopes. We then constructed SCT libraries designed to capture SARS-CoV-2 specific CD8 + T cells from COVID-19 participants and healthy donors. The immunogenicity of these epitopes was validated by functional assays of T cells with cloned TCRs captured using SCT libraries. These technologies should enable the rapid analyses of peptide-based T cell responses across several contexts, including autoimmunity, cancer, or infectious disease.

Challenges and opportunities for cervical screening in women over the age of 50 years: a qualitative study.

BACKGROUND: Cervical cancer is a preventable disease. Cases in women age >50 years are predicted to rise by 60% in the next two decades, yet this group are less likely to attend for screening than younger women. AIM: To seek novel solutions to the challenges of cervical screening in women >50 years of age by examining practitioner and service-user experiences. DESIGN AND SETTING: Semi-structured interviews were conducted with 28 practitioners and 24 service users >50 years of age, recruited via UK primary care networks in Northern England in 2016-2017, to explore experiences related to cervical screening. METHOD: An inductive thematic analysis was conducted to explore the data. RESULTS: Findings are presented under three key themes. The first, exploring the barriers to successful cervical screening, examines the influences of sexuality and early experiences of screening on attendance, and how preventive health care becomes a low priority as women age. The second, the role of relationships, explores how peer talk shapes attitudes towards cervical screening, how teamwork between practitioners engenders investment in cervical screening, and how interactions between service users and primary care over time can significantly affect intentions to screen. The third, what constitutes good practice, describes practical and sensitive approaches to screening tailored to women aged >50 years. CONCLUSION: Good practice involves attention to structural and practical challenges, and an understanding of the role of relationships in shaping screening intentions. Experienced practitioners adapt procedures to increase sensitivity, and balance time invested in problem solving against the benefits of reaching practice targets for attendance. Building networks of expertise across multiple practices can increase practitioner skill in screening this age group.

Huntington's disease age at motor onset is modified by the tandem hexamer repeat in TCERG1.

Huntington's disease is caused by an expanded CAG tract in HTT. The length of the CAG tract accounts for over half the variance in age at onset of disease, and is influenced by other genetic factors, mostly implicating the DNA maintenance machinery. We examined a single nucleotide variant, rs79727797, on chromosome 5 in the TCERG1 gene, previously reported to be associated with Huntington's disease and a quasi-tandem repeat (QTR) hexamer in exon 4 of TCERG1 with a central pure repeat. We developed a method for calling perfect and imperfect repeats from exome-sequencing data, and tested association between the QTR in TCERG1 and residual age at motor onset (after correcting for the effects of CAG length in the HTT gene) in 610 individuals with Huntington's disease via regression analysis. We found a significant association between age at onset and the sum of the repeat lengths from both alleles of the QTR (p = 2.1 × 10-9), with each added repeat hexamer reducing age at onset by one year (95% confidence interval [0.7, 1.4]). This association explained that previously observed with rs79727797. The association with age at onset in the genome-wide association study is due to a QTR hexamer in TCERG1, translated to a glutamine/alanine tract in the protein. We could not distinguish whether this was due to cis-effects of the hexamer repeat on gene expression or of the encoded glutamine/alanine tract in the protein. These results motivate further study of the mechanisms by which TCERG1 modifies onset of HD.

Translating qualitative data into intervention content using the Theoretical Domains Framework and stakeholder co-design: a worked example from a study of cervical screening attendance in older women.

BACKGROUND: Previous screening interventions have demonstrated a series of features related to social determinants which have increased uptake in targeted populations, including the assessment of health beliefs and barriers to screening attendance as part of intervention development. Many studies cite the use of theory to identify methods of behaviour change, but fail to describe in detail how theoretical constructs are transformed into intervention content. The aim of this study was to use data from a qualitative exploration of cervical screening in women over 50 in the UK as the basis of intervention co-design with stakeholders using behavioural change frameworks. We describe the identification of behavioural mechanisms from qualitative data, and how these were used to develop content for a service-user leaflet and a video animation for practitioner training. The interventions aimed to encourage sustained commitment to cervical screening among women over 50, and to increase sensitivity to age-related problems in screening among primary care practitioners. METHODS: Secondary coding of a qualitative data set to extract barriers and facilitators of cervical screening attendance. Barrier and facilitator statements were categorised using the Theoretical Domains Framework (TDF) to identify relevant behaviour change techniques (BCTs). Key TDF domains and associated BCTs were presented in stakeholder focus groups to guide the design of intervention content and mode of delivery. RESULTS: Behavioural determinants relating to attendance clustered under three domains: beliefs about consequences, emotion and social influences, which mapped to three BCTs respectively: (1) persuasive communication/information provision; (2) stress management; (3) role modelling and encouragement. Service-user stakeholders translated these into three pragmatic intervention components: (i) addressing unanswered questions, (ii) problem-solving practitioner challenges and (iii) peer group communication. Based on (ii), practitioner stakeholders developed a call to action in three areas - clinical networking, history-taking, and flexibility in screening processes. APEASE informed modes of delivery (a service-user leaflet and a cartoon animation for practitioners). CONCLUSION: The application of the TDF to qualitative data can provide an auditable protocol for the translation of qualitative data into intervention content.

Exome sequencing of individuals with Huntington's disease implicates FAN1 nuclease activity in slowing CAG expansion and disease onset.

The age at onset of motor symptoms in Huntington's disease (HD) is driven by HTT CAG repeat length but modified by other genes. In this study, we used exome sequencing of 683 patients with HD with extremes of onset or phenotype relative to CAG length to identify rare variants associated with clinical effect. We discovered damaging coding variants in candidate modifier genes identified in previous genome-wide association studies associated with altered HD onset or severity. Variants in FAN1 clustered in its DNA-binding and nuclease domains and were associated predominantly with earlier-onset HD. Nuclease activities of purified variants in vitro correlated with residual age at motor onset of HD. Mutating endogenous FAN1 to a nuclease-inactive form in an induced pluripotent stem cell model of HD led to rates of CAG expansion similar to those observed with complete FAN1 knockout. Together, these data implicate FAN1 nuclease activity in slowing somatic repeat expansion and hence onset of HD.

Genetic modifiers of Huntington disease differentially influence motor and cognitive domains.

Genome-wide association studies (GWASs) of Huntington disease (HD) have identified six DNA maintenance gene loci (among others) as modifiers and implicated a two step-mechanism of pathogenesis: somatic instability of the causative HTT CAG repeat with subsequent triggering of neuronal damage. The largest studies have been limited to HD individuals with a rater-estimated age at motor onset. To capitalize on the wealth of phenotypic data in several large HD natural history studies, we have performed algorithmic prediction by using common motor and cognitive measures to predict age at other disease landmarks as additional phenotypes for GWASs. Combined with imputation with the Trans-Omics for Precision Medicine reference panel, predictions using integrated measures provided objective landmark phenotypes with greater power to detect most modifier loci. Importantly, substantial differences in the relative modifier signal across loci, highlighted by comparing common modifiers at MSH3 and FAN1, revealed that individual modifier effects can act preferentially in the motor or cognitive domains. Individual components of the DNA maintenance modifier mechanisms may therefore act differentially on the neuronal circuits underlying the corresponding clinical measures. In addition, we identified additional modifier effects at the PMS1 and PMS2 loci and implicated a potential second locus on chromosome 7. These findings indicate that broadened discovery and characterization of HD genetic modifiers based on additional quantitative or qualitative phenotypes offers not only the promise of in-human validated therapeutic targets but also a route to dissecting the mechanisms and cell types involved in both the somatic instability and toxicity components of HD pathogenesis.

Multiple early factors anticipate post-acute COVID-19 sequelae.

Post-acute sequelae of COVID-19 (PASC) represent an emerging global crisis. However, quantifiable risk factors for PASC and their biological associations are poorly resolved. We executed a deep multi-omic, longitudinal investigation of 309 COVID-19 patients from initial diagnosis to convalescence (2-3 months later), integrated with clinical data and patient-reported symptoms. We resolved four PASC-anticipating risk factors at the time of initial COVID-19 diagnosis: type 2 diabetes, SARS-CoV-2 RNAemia, Epstein-Barr virus viremia, and specific auto-antibodies. In patients with gastrointestinal PASC, SARS-CoV-2-specific and CMV-specific CD8+ T cells exhibited unique dynamics during recovery from COVID-19. Analysis of symptom-associated immunological signatures revealed coordinated immunity polarization into four endotypes, exhibiting divergent acute severity and PASC. We find that immunological associations between PASC factors diminish over time, leading to distinct convalescent immune states. Detectability of most PASC factors at COVID-19 diagnosis emphasizes the importance of early disease measurements for understanding emergent chronic conditions and suggests PASC treatment strategies.

Prostate cancer: unmet supportive and palliative care needs: national survey of patients and family carers.

OBJECTIVES: Men living with prostate cancer have supportive and palliative needs. However, few studies detail unmet needs (vs quality of life measurement) or include data from those with advanced disease. We aimed to identify unmet needs of people living with prostate cancer (men, family carers), including those with advanced disease. METHODS: Mixed-methods national survey (patient Supportive Care Needs Survey; Carer Support Needs Assessment Tool) and health status (EuroQol Visual Analogue Scale). Quantitative data were explored using regression analysis. Free text data were subjected to thematic analysis. RESULTS: 216 men (mean age 65±8.5 years; active cancer 136 [63%]) and 97 carers (68 (70%) spouse/partner) provided data. 133 men (62%) reported moderate-to-high need which was more likely in advanced disease. Men's health status was worse with active vs remitted disease (mean difference -11; 95% CI -17 to -5; p<0.001). 85 (88%) carers reported at least one unmet need relating to 'enabling them to care' and 83 (86%) relating to 'their own well-being'. Carers with chronic illnesses had more unmet needs (p=0.01 to p=0.04) and patient receipt of palliative care independently predicted higher unmet carer needs (p=0.02).Free text data demonstrated widespread burden with: (1) poor communication/information, including about palliative care; (2) poorly managed symptoms/concerns and (3) poor care co-ordination. Incontinence, sexual dysfunction and hormone side-effects were serious problems, often left unaddressed. CONCLUSIONS: Many living with prostate cancer continue with wide-ranging concerns. Lack of systematic, ongoing needs assessment and poor communication compound inadequate clinical pathways. Person-centred care, interdisciplinary working and integrated palliative care should be resourced.