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Introduction: Stroke-associated pneumonia (SAP) is common, however, data on the economic impact of SAP are scarce. This study aimed to prospectively evaluate the impact of SAP on acute stroke care costs in a UK setting. Methods: Prospective cohort study of 213 consecutive patients with stroke (196 ischemic, 17 hemorrhagic) was admitted to a UK hospital over 1 year. Socio demographic and clinical characteristics were recorded along with all treatments and rehabilitation activity. Patients were classified as having SAP if they fulfilled criteria for “probable” or “definite” respiratory tract infection according to the Centres for Disease Control and Prevention definition, within the first seven days following stroke. Resource use was calculated using a “bottom up” approach of cumulative unit costs. Univariate and multivariate regression analyses were used to establish independent predictors of direct costs. Results: Probable or definite SAP occurred in 13.2% (28/213) of patients. Patients with SAP experienced greater inpatient stays (31 days vs. 9 days, p ≤ 0.001) and higher in-hospital mortality (29.2% vs. 10.2%, p = 0.007). Mean (SD) acute care costs per patient was £7035 (6767), but costs were significantly greater for patients with SAP than without [£14,371 (9484) versus £6,103 (5,735); p ≤ 0.001]. SAP was an independent predictor of costs along with increasing stroke severity (NIHSS) and age. Occurrence of SAP resulted in an adjusted incremental additional cost of £5817 (95% CI 4945-6689; p = 0.001) per patient. Conclusions: SAP increased acute care costs for stroke by approximately 80%. This provides further impetus for research aimed at reducing SAP, and will inform cost-effectiveness analyses of potential therapeutic strategies. [ABSTRACT FROM AUTHOR]

COVID-19 has had an impact globally with millions infected, high mortality, significant economic ramifications, travel restrictions, national lockdowns, overloaded healthcare systems, effects on healthcare workers' health and well-being, and large amounts of funding diverted into rapid vaccine development and implementation. Patients with COVID-19, especially those who become severely ill, have frequently developed dysphagia and dysphonia. Health professionals working in the field have needed to learn about this new disease while managing these patients with enhanced personal protective equipment. Emerging research suggests differences in the clinical symptoms and journey to recovery for patients with COVID-19 in comparison to other intensive care populations. New insights from outpatient clinics also suggest distinct presentations of dysphagia and dysphonia in people after COVID-19 who were not hospitalized or severely ill. This international expert panel provides commentary on the impact of the pandemic on speech pathologists and our current understanding of dysphagia and dysphonia in patients with COVID-19, from acute illness to long-term recovery. This narrative review provides a unique, comprehensive critical appraisal of published peer-reviewed primary data as well as emerging previously unpublished, original primary data from across the globe, including clinical symptoms, trajectory, and prognosis. We conclude with our international expert opinion on what we have learnt and where we need to go next as this pandemic continues across the globe., (© 2021. The Author(s).)

Introduction: Stroke-associated pneumonia (SAP) is a common complication associated with poor outcomes. Early dysphagia screening and specialist assessment is associated with a reduced risk of SAP. Evidence about oral care and nasogastric tube (NGT) placement is equivocal. This study aimed to expose variations in dysphagia management practices and explore their associations with SAP., Participants and Methods: Speech pathologists from 166 stroke units in England and Wales were surveyed about dysphagia assessment and management, oral care, and NGT placement. Survey data were then linked to the Sentinel Stroke National Audit Programme (SSNAP), the national register of stroke. Univariable and multivariable linear regression models were fitted to estimate the association between dysphagia management practices and SAP incidence., Results: 113 hospitals completed the survey (68%). Variation was evident in dysphagia screening protocols (DSPs), oral care, and NGT practice while specialist swallow assessment data patterns were more consistent. Multivariable analysis showed no evidence of an association in incidence of SAP when using a water-only hospital DSP compared to a multiconsistency DSP (B -0.688, 95% CI: -2.912 to 1.536), when using written swallow assessment guidelines compared to not using written guidelines (B 0.671, 95% CI: -1.567 to 2.908), when teams inserted NGTs overnight compared to teams which did not (B -0.505, 95% CI: -2.759 to 1.749), and when teams had a written oral care protocol compared to those which did not (B -1.339, 95% CI: -3.551 to 0.873)., Discussion and Conclusion: Variation exists in dysphagia screening and management, but there was no evidence of an association between clinical practice patterns and incidence of SAP. Further research with larger sample sizes is needed to examine association with SAP., (© 2021 The Author(s). Published by S. Karger AG, Basel.)

Post-stroke dysphagia (PSD) is present in more than 50% of acute stroke patients, increases the risk of complications, in particular aspiration pneumonia, malnutrition and dehydration, and is linked to poor outcome and mortality. The aim of this guideline is to assist all members of the multidisciplinary team in their management of patients with PSD. These guidelines were developed based on the European Stroke Organisation (ESO) standard operating procedure and followed the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. An interdisciplinary working group identified 20 relevant questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence and wrote evidence-based recommendations. Expert opinion was provided if not enough evidence was available to provide recommendations based on the GRADE approach. We found moderate quality of evidence to recommend dysphagia screening in all stroke patients to prevent post-stroke pneumonia and to early mortality and low quality of evidence to suggest dysphagia assessment in stroke patients having been identified at being at risk of PSD. We found low to moderate quality of evidence for a variety of treatment options to improve swallowing physiology and swallowing safety. These options include dietary interventions, behavioural swallowing treatment including acupuncture, nutritional interventions, oral health care, different pharmacological agents and different types of neurostimulation treatment. Some of the studied interventions also had an impact on other clinical endpoints such as feedings status or pneumonia. Overall, further randomized trials are needed to improve the quality of evidence for the treatment of PSD., Competing Interests: Declaration of conflicting interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: RD reports non-financial support from Phagenesis, other from Phagenesis, personal fees from Nestle Healthcare, grants from Olympus, personal fees from Sanofi, personal fees from Pfizer, personal fees from Daiichi Sankyo, outside the submitted work; EM has nothing to disclose; MTG reports personal fees from Phagenesis, outside the submitted work; AL has nothing to disclose; MA reports personal fees from Kabi Fresenius, personal fees from Nutricia, personal fees from Kocak Pharma, personal fees from Sanofi, personal fees from Bayer Healthcare, personal fees from Daichi Sankyo, personal fees from Pfizer, personal fees from Abbott, grants from TUBITAK, outside the submitted work; PMB reports personal fees from Phagenesis Ltd, grants from MRC (Medical Research Council, UK), personal fees from DiaMedica Inc, personal fees from Moleac, outside the submitted work; PC reports grants and contracts from Nutricia Advanced Medical Nutrition, Fresenius Kabi Deutschland GmbH, Nestle Health Science, Nestle Research, DJO Global, Phagenesis, Sanofi Research; consulting fees from Nestle Health Science, Nestle Research; honoraria for lectures from Nutricia Advanced Medical Nutrition; Support for attending meetings and/or travel from Nutricia Advanced Medical Nutrition, Sanofi Research; Participation on a Data Safety Monitoring Board or Advisory Board from Nutricia Advanced Medical Nutrition, Fresenius Kabi Deutschland GmbH, Nestle Health Science, Nestle Research, DJO Global, Sanofi Research, outside the submitted work. JG has nothing to disclose; SH reports other from Phagenesis Ltd, grants from MRC (Medical Research Council, UK), outside the submitted work; SP has nothing to disclose; AS has nothing to disclose; MS has nothing to disclose; DW reports personal fees from Desitin Pharma, outside the submitted work; RW has nothing to disclose; EV has nothing to disclose., (© European Stroke Organisation 2021.)

Background and Aim: In preparation for the Public Health England Impact Assessment of the 2014 AHP Public Health Strategy a follow up rapid literature review was commissioned. The aim was to identify primary studies in which Allied Health Professionals (AHP) contribute to public health outcomes, based on UK research evidence. This review was used to inform further UK policy and implementation for AHPs in the UK via Public Health England., Methods: A rapid mixed methods review was conducted, limiting the selection of studies to those published after December 2014 and recognising the same 12 Allied Health Professions that were used in the previous review. The rapid review included all age groups and patient populations but limited the searches to studies that reflected UK AHP practices and research outcomes. The literature search included title, abstract and full-text screening with data extraction of selected papers. A nominal group method invited expert AHPs to review and select the interventions for potential impact at population level., Results: 11 selected articles were grouped into two areas of interventions; health intervention/public health and secondary prevention/health improvement, based on the Public Health England Strategic Framework. AHP interventions were effective for Chronic Fatigue Syndrome and Osteoarthritis and specifically used to manage musculoskeletal conditions (e.g. frozen shoulder). AHPs leading vocational rehabilitation and falls management were also effective. These areas were additional to those previously identified and represented some additional specialist activity undertaken to affect health outcomes., Conclusions: This study also contributed to the UK AHP Public Health Strategic Framework 2019-2024 by appraising the UK evidence and impact of some AHP practices. Further improvement is required; for AHPs to measure the impact of their interventions which would demonstrate evidence of outcomes at population level., Competing Interests: There are no known conflict of interests., (© 2021 The Authors.)

Dysphagia is associated with increased risk of stroke-associated pneumonia (SAP). However, it is unclear what other factors contribute to that risk or which measures may reduce it. This systematic review aimed to provide evidence on interventions and care processes associated with SAP in patients with dysphagia. Studies were screened for inclusion if they included dysphagia only patients, dysphagia and non-dysphagia patients or unselected patients that included dysphagic patients and evaluated factors associated with a recorded frequency of SAP. Electronic databases were searched from inception to February 2017. Eligible studies were critically appraised. Heterogeneity was evaluated using I 2 . The primary outcome was SAP. Eleven studies were included. Sample sizes ranged from 60 to 1088 patients. There was heterogeneity in study design. Measures of immunodepression are associated with SAP in dysphagic patients. There is insufficient evidence to justify screening for aerobic Gram-negative bacteria. Prophylactic antibiotics did not prevent SAP and proton pump inhibitors may increase risk. Treatment with metoclopramide may reduce SAP risk. Evidence that nasogastric tube (NGT) placement increases risk of SAP is equivocal. A multidisciplinary team approach and instrumental assessment of swallowing may reduce risk of pneumonia. Patients with impaired mobility were associated with increased risk. Findings should be interpreted with caution given the number of studies, heterogeneity and descriptive analyses. Several medical interventions and care processes, which may reduce risk of SAP in patients with dysphagia, have been identified. Further research is needed to evaluate the role of these interventions and care processes in clinical practice.

(1) Background: Swallowing difficulties (dysphagia) after stroke are not uncommon and is a consistent risk factor for stroke-associated pneumonia. This interview study explores the perspectives of stroke survivors, who had their swallowing assessed in the first few days of admission to hospital, and their informal caregivers. (2) Methods: A participatory approach was used involving people affected by stroke in the interpretation and analysis of the interview data. Data was thematically analysed and six themes were identified. (3) Results: These themes included how past-future experiences may influence a person's emotional response to events; understanding what is happening and adjustment; the impact of dysphagia; attitudes to care; communication to patients and procedural issues. (4) Conclusion: The findings highlight the importance of effective public health messages to improve people's responsiveness to the signs of stroke, standardisation of assessment and management procedures, effective communication to patients about the consequences of dysphagia, and the impact of dysphagia on the person who had the stroke and their informal caregiver.

(1) Background: Patients with dysphagia are at increased risk of stroke-associated pneumonia. There is wide variation in the way patients are screened and assessed. The aim of this study is to explore staff opinions about current practice of dysphagia screening, assessment and clinical management in acute phase stroke. (2) Methods: Fifteen interviews were conducted in five English National Health Service hospitals. Hospitals were selected based on size and performance against national targets for dysphagia screening and assessment, and prevalence of stroke-associated pneumonia. Participants were purposefully recruited to reflect a range of healthcare professions. Data were analysed using a six-stage thematic process. (3) Results: Three meta themes were identified: delays in care, lack of standardisation and variability in resources. Patient, staff, and service factors that contribute to delays in dysphagia screening, assessment by a speech and language therapist, and delays in nasogastric tube feeding were identified. These included admission route, perceived lack of ownership for screening patients, prioritisation of assessments and staff resources. There was a lack of standardisation of dysphagia screening protocols and oral care. There was variability in staff competences and resources to assess patients, types of medical interventions, and care processes. (4) Conclusion: There is a lack of standardisation in the way patients are assessed for dysphagia and variation in practice relating to staff competences, resources and care processes between hospitals. A range of patient, staff and service factors have the potential to impact on stroke patients being assessed within the recommended national guidelines.

Dysphagia is a debilitating condition with significant consequences in terms of physical and mental health. This study demonstrates that it is feasible to provide an intensive therapy program combining neuromuscular electrical stimulation (NMES) with exercise against resistance in the treatment of dysphagia in a public healthcare setting. Thirty-one patients (17 stroke, 14 non-stroke) who experienced dysphagia with reduced laryngeal elevation completed the therapy program. After checking the data sets for comparability, it was deemed appropriate for the outcome data from these patients to be combined with that of 12 stroke patients previously reported to enable statistical analysis on a larger data set (n = 43). A repeated-measures ANOVA revealed a statistically significant increase in amount and variety of food a patient was able to take orally (FOIS) following completion of treatment ( p < 0.001). There was no significant between-subject effect of stroke status ( p = 0.43), or interaction between treatment and stroke status ( p = 0.68). There was a significant improvement in secondary outcome measures of swallow safety with fluids (PAS) ( p < 0.001) and swallow-related quality of life (Swal-Qol ( p < 0.001). These findings indicate that the therapy program may be associated with reduced impairment in a subset of patients with dysphagia resulting from stroke and non-stroke atiologies, and the data will inform the design of future research to address unanswered questions.

Good nutrition is a recognised outcome in the health and well-being of older care home residents and dysphagia is a known risk factor associated with under nutrition and poor outcomes. The study co-produced a digital Dysphagia Guide with Care Homes using a consensus method with interviews and focus groups to prioritise the need for information and explore acceptability of an educational tool for care home workers. Evaluation of use, acceptability of design, and content of the guide were completed via remote monitoring. The workforce prioritised the need for training as well as the knowledge and skills in relation to planning resident-centred care and advice on textured diets. The technology was a means of offering 'bite-size' learning to enhance planning for nutrition across the whole organisation including managers, kitchen staff, and care workers. The Guide to Dysphagia was produced on a tablet and piloted in four care homes over 12 weeks, by 57 staff. Integrated analytics allowed user activity to be monitored. Findings showed that 73% of respondents reported the guide helped them in their job. Additionally, 88% of respondents stated they would recommend the guide to other staff, with 90% reporting it was easy to use. Engagement with staff and managers in four homes resulted in a co-designed, dysphagia guide.

There is an increase in the demand for community services to provide care closer to home, and care teams are placing a growing emphasis on admission avoidance and early discharge. Community and district nurses are key professionals in this care delivery and are required to be alert to the risk factors for clinical deterioration, such as dysphagia (swallowing problems). Especially in older adults and those with frailty, dysphagia can cause a wide range of problems, from dehydration and malnutrition to respiratory tract infections that warrant antibiotic use and even hospitalisation. This article describes how dysphagia can be identified and managed in the community setting and explains the benefits and impact of speech and language therapy and wider multidisciplinary team intervention.

Background: Dysphagia is common after stroke, affecting up to 50% of patients initially. It can lead to post-stroke pneumonia, which causes 30% of stroke-related deaths, a longer hospital stay and poorer health outcomes. Dysphagia care post-stroke generally focuses on the management of symptoms, via modified oral intake textures and adapted posture, rather than direct physical rehabilitation of the swallowing function. Transcutaneous neuromuscular electrical stimulation (NMES) is a promising rehabilitation technology that can be used to stimulate swallowing; however, findings regarding efficacy have been conflicting., Aims: This pilot randomized controlled study involving three UK sites compared the efficacy of the Ampcare Effective Swallowing Protocol (ESP), combining NMES with swallow-strengthening exercises, with usual care in order to clarify evidence on NMES in the treatment of dysphagia post-stroke. A further objective was to pilot recruitment procedures and outcome measures in order to inform the design of a full-scale trial., Methods & Procedures: Thirty patients were recruited and randomized into either (1) usual speech and language therapy dysphagia care; or (2) Ampcare ESP, receiving treatment 5 days/week for 4 weeks. Outcome measures included: the Functional Oral Intake Scale (FOIS), the Rosenbek Penetration-Aspiration Scale (PAS) and patient-reported outcomes (Swallow Related Quality of Life-SWAL-QOL)., Outcomes & Results: Thirty patients were recruited; 15 were randomized to the Ampcare ESP intervention arm and 15 to usual care. A greater proportion (75%, or 9/12) of patients receiving Ampcare ESP improved compared with 57% (or 8/14) of the usual-care group. Patients receiving Ampcare ESP also made clinically meaningful change (a comparative benefit of 1.5 on the FOIS, and on the PAS: 1.35 for diet and 0.3 for fluids) compared with usual care. The intervention group also reported much better outcome satisfaction., Conclusions & Implications: The pilot demonstrated successful recruitment, treatment safety and tolerability and clinically meaningful outcome improvements, justifying progression to a fully powered study. It also showed clinically meaningful treatment trends for the Ampcare ESP intervention., (© 2017 Royal College of Speech and Language Therapists.)

Background: Patients with dysphagia are at an increased risk of stroke-associated pneumonia. There is wide variation in the way patients are screened and assessed during the acute phase. The aim of this review was to identify the methods of assessment and management in acute stroke that influence the risk of stroke-associated pneumonia. Studies of stroke patients that reported dysphagia screening, assessment or management and occurrence of pneumonia during acute phase stroke were screened for inclusion after electronic searches of multiple databases from inception to November 2016. The primary outcome was association with stroke-associated pneumonia., Summary: Twelve studies of 87,824 patients were included. The type of dysphagia screening protocol varied widely across and within studies. There was limited information on what comprised a specialist swallow assessment and alternative feeding was the only management strategy, which was reported for association with stroke-associated pneumonia. Use of a formal screening protocol and early dysphagia screening (EDS) and assessment by a speech and language pathologist (SLP) were associated with a reduced risk of stroke-associated pneumonia. There was marked heterogeneity between the included studies, which precluded meta-analysis. Key Messages: There is variation in the assessment and management of dysphagia in acute stroke. There is increasing evidence that EDS and specialist swallow assessment by an SLP may reduce the odds of stroke-associated pneumonia. There is the potential for other factors to influence the incidence of stroke-associated pneumonia during the acute phase., (© 2018 S. Karger AG, Basel.)

Background: Swallowing difficulties challenge patient safety due to the increased risk of malnutrition, dehydration and aspiration pneumonia. A theoretically driven study was undertaken to examine the spread and sustainability of a locally developed innovation that involved using the Inter-Professional Dysphagia Framework to structure education for the workforce. A conceptual framework with 3 spread strategies (hierarchical control, participatory adaptation and facilitated evolution) was blended with a processual approach to sustaining organisational change. The aim was to understand the processes, mechanism and outcomes associated with the spread and sustainability of this safety initiative., Methods: An instrumental case study, prospectively tracked a dysphagia innovation for 34 months (April 2011 to January 2014) in a large health care organisation in England. A train-the-trainer intervention (as participatory adaptation) was deployed on care pathways for stroke and fractured neck of femur. Data were collected at the organisational and clinical level through interviews (n = 30) and document review. The coding frame combined the processual approach with the spread mechanisms. Pre-determined outcomes included the number of staff trained about dysphagia and impact related to changes in practice., Results: The features and processes associated with hierarchical control and participatory adaptation were identified. Leadership, critical junctures, temporality and making the innovation routine were aspects of hierarchical control. Participatory adaptation was evident on the care pathways through stakeholder responses, workload and resource pressures. Six of the 25 ward based trainers cascaded the dysphagia training. The expected outcomes were achieved when the top-down mandate (hierarchical control) was supplemented by local engagement and support (participatory adaptation)., Conclusions: Frameworks for spread and sustainability were combined to create a 'small theory' that described the interventions, the processes and desired outcomes a priori. This novel methodological approach confirmed what is known about spread and sustainability, highlighted the particularity of change and offered new insights into the factors associated with hierarchical control and participatory adaptation. The findings illustrate the dualities of organisational change as universal and context specific; as particular and amendable to theoretical generalisation. Appreciating these dualities may contribute to understanding why many innovations fail to become routine.

Adipose tissue is crucial for the maintenance of energy and metabolic homeostasis and its deregulation can lead to obesity and type II diabetes (T2D). Using gene disruption in the mouse, we discovered a function for a RhoA-specific guanine nucleotide exchange factor PDZ-RhoGEF (Arhgef11) in white adipose tissue biology. While PDZ-RhoGEF was dispensable for a number of RhoA signaling-mediated processes in mouse embryonic fibroblasts, including stress fiber formation and cell migration, it's deletion led to a reduction in their proliferative potential. On a whole organism level, PDZ-RhoGEF deletion resulted in an acute increase in energy expenditure, selectively impaired early adipose tissue development and decreased adiposity in adults. PDZ-RhoGEF-deficient mice were protected from diet-induced obesity and T2D. Mechanistically, PDZ-RhoGEF enhanced insulin/IGF-1 signaling in adipose tissue by controlling ROCK-dependent phosphorylation of the insulin receptor substrate-1 (IRS-1). Our results demonstrate that PDZ-RhoGEF acts as a key determinant of mammalian metabolism and obesity-associated pathologies.

Aims and Objectives: To evaluate the learning effect and resource use cost of workplace-based, blended e-learning about dysphagia for stroke rehabilitation nurses., Background: Dysphagia is a potentially life-threatening problem that compromises quality of life. In many countries, nurses play a crucial role in supporting the management of patients with swallowing problems, yet the literature reports a need for training., Design: A single-group, pre- and post-study with mixed methods., Methods: Each blended e-learning session comprised a needs analysis, e-learning programmes, practical skills about modifying fluids and action planning to transfer learning into practice. Participants were the population of registered nurses (n = 22) and healthcare assistants (n = 10) on a stroke rehabilitation ward in a large, teaching hospital in England between August 2010-March 2011. Data collection comprised observation (34 hours), questionnaires administered at four time points to examine change in attitude, knowledge and practice, and estimating the resource use cost for the service. Nonparametric tests and content analysis were used to analyse the data., Results: All participants achieved a nationally recognised level of competence. The learning effect was evident on the post- and follow-up measures, with some items of dysphagia knowledge and attitude achieving significance at the p ≤ 0·05 level. The most common self-reported changes in practice related to medicines management, thickening fluids and oral hygiene. The resource use cost was estimated at £2688 for 108 hours training., Conclusions: Workplace-based, blended e-learning was an acceptable, cost effective way of delivering essential clinical knowledge and skills about dysphagia., Relevance to Clinical Practice: Dysphagia should be viewed as a patient safety issue because of the risks of malnutrition, dehydration and aspiration pneumonia. As such, it is pertinent to many members of the interdisciplinary team. Consideration should be given to including dysphagia management in initial education and continuing professional development programmes., (© 2013 John Wiley & Sons Ltd.)

Background: Adoption, adaptation, scale-up, spread, and sustainability are ill-defined, undertheorised, and little-researched implementation science concepts. An instrumental case study will track the adoption and adaptation, or not, of a locally developed innovation about dysphagia as a patient safety issue. The case study will examine a conceptual framework with a continuum of spread comprising hierarchical control or 'making it happen', participatory adaptation or 'help it happen', and facilitated evolution or 'let it happen'., Methods: This case study is a prospective, longitudinal design using mixed methods. The fifteen-month (October 2012 to December 2013) instrumental case study is set in large, healthcare organisation in England. The innovation refers to introducing a nationally recognised, inter-disciplinary dysphagia competency framework to guide workforce development about fundamental aspects of care. Adoption and adaptation will be examined at an organisational level and along two, contrasting care pathways: stroke and fractured neck of femur. A number of educational interventions will be deployed, including training a cadre of trainers to cascade the essentials of dysphagia management and developing a Dysphagia Toolkit as a learning resource. Mixed methods will be used to investigate scale-up, spread, and sustainability in acute and community settings. A purposive sample of senior managers and clinical leaders will be interviewed to identify path dependency or the context specific particularities of implementation. A pre- and post-evaluation, using mealtime observations and a survey, will investigate the learning effect on staff adherence to patient specific dysphagia recommendations and attitudes towards dysphagia, respectively. Official documents and an ethnographic field journal allow critical junctures, temporal aspects and confounding factors to be explored., Discussion: Researching spread and sustainability presents methodological and practical challenges. These include fidelity, adaptation latitude, time, and organisational changes. An instrumental case study will allow these confounding factors to be tracked over time and in place. The case study is underpinned by, and will test a conceptual framework about spread, to explore theoretical generalizability.

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are incretin hormones that play important roles in maintaining glucose homeostasis and are being actively pursued as novel therapeutic agents for diabetes. GIP is produced by dispersed enteroendocrine cells and interestingly at times is coexpressed with GLP-1. We sought to determine the factors that selectively define GIP- vs. GLP-1-expressing cells. We performed comparative immunostaining of Pax6 and Pdx1 in GIP- and GLP-1-secreting cells. We investigated whether Pax6 and Pdx1 activate the human GIP promoter in control IEC-6 cells and GIP-expressing STC-1 cells. EMSA was performed to assess the binding of these transcription factors to the GIP promoter. Pax6 and Pdx1 consistently colocalized in GIP-immunoreactive cells. Cells that coexpress GIP and GLP-1 were Pax6 and Pdx1 positive, whereas cells expressing only GLP-1 were Pax6 positive but did not express Pdx1. GIP promoter activity was enhanced in IEC-6 cells by exogenous Pax6 or Pdx1 and diminished in STC-1 cells by inhibition of endogenous Pax6 or Pdx1 by dominant-negative forms. Promoter truncation analysis revealed a major loss of promoter activity when the sequence between -184 to -145 bp was deleted. EMSA studies indicated that Pax6 and Pdx1 bind to this proximal sequence of the human GIP promoter. Our findings indicate that concomitant expression of Pax6 and Pdx1 is important for GIP expression. Our results also suggest that the presence of Pdx1 defines whether GLP-1-expressing gastrointestinal L cells also coexpress GIP.

Proteins containing a caspase recruitment domain (CARD) play pivotal roles in signal transduction leading to apoptosis and NF-kappaB activation and inflammation. Here we identify and characterize human and mouse CARD protein 6 (CARD6), CARD-containing proteins of unique structure. CARD6 associates with microtubules and interacts with receptor-interacting protein (RIP)-like interacting caspase-like apoptosis regulatory protein kinase (RICK), a CARD-containing member of the RIP family of protein kinases. These kinases are involved in multiple NF-kappaB signaling pathways important for innate and adaptive immune responses. Surprisingly, the CARDs of CARD6 and RICK were not required for their interaction; instead, mutational analysis revealed that the CARD of CARD6 negatively controls the association of these molecules. CARD6 also binds to RIP1, a RIP kinase homologue that lacks a CARD but contains a C-terminal death domain. Coexpression of RICK targets CARD6 to aggresomes via a mechanism that requires the CARD of RICK. Importantly, CARD6 expression has a synergistic effect on NF-kappaB activation induced by several independent signal transduction pathways. In summary, our results indicate that CARD6 is a regulator of NF-kappaB activation that modulates the functions of RIP kinase family members.

Mutations of the DJ-1 (PARK7) gene are linked to familial Parkinson's disease. We used gene targeting to generate DJ-1-deficient mice that were viable, fertile, and showed no gross anatomical or neuronal abnormalities. Dopaminergic neuron numbers in the substantia nigra and fiber densities and dopamine levels in the striatum were normal. However, DJ-1-/- mice showed hypolocomotion when subjected to amphetamine challenge and increased striatal denervation and dopaminergic neuron loss induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyrindine. DJ-1-/-embryonic cortical neurons showed increased sensitivity to oxidative, but not nonoxidative, insults. Restoration of DJ-1 expression to DJ-1-/- mice or cells via adenoviral vector delivery mitigated all phenotypes. WT mice that received adenoviral delivery of DJ-1 resisted 1-methyl-4-phenyl-1,2,3,6-tetrahydropyrindine-induced striatal damage, and neurons overexpressing DJ-1 were protected from oxidative stress in vitro. Thus, DJ-1 protects against neuronal oxidative stress, and loss of DJ-1 may lead to Parkinson's disease by conferring hypersensitivity to dopaminergic insults.

Detection of aspiration by bedside examination has frequently been found to be clinically inadequate when compared with videofluoroscopy (VF) as the gold standard. In Doncaster, UK, a new multidisciplinary approach to bedside assessment was devised using physiotherapists (PT) performing bronchial auscultation (BA) in combination with the speech and language therapists' (SLT) clinical examination of dysphagia. In this study 105 patients referred for VF examination of dysphagia were first tested by the BA team. Comparison was made between the results of the VF team and the results of the BA team in classifying the patients as "aspirating" or at "risk of aspirating." A high degree of agreement was found for risk of aspiration (sensitivity 87%), although specificity was low (37%). BA was highly specific (88%) when confirming the absence of aspiration, but sensitivity to the presence of aspiration was 45%. From the 105 patients tested, the BA team would have failed to modify the diet in only one subject who was aspirating and would have unnecessarily modified the diet of 17 subjects. In conclusion, in the sample population of individuals with complex dysphagia, the BA team approach reliably detected patients identified by VF as at risk of aspiration. In the group of patients identified by VF as aspirating, the BA team proved unreliable in detecting the presence of aspiration, although it did reliably identify patients who were not aspirating. BA is a potentially useful clinical tool which requires further research.

Protein tyrosine phosphatase epsilon (PTP epsilon)-deficient mice were generated by targeted deletion of exons 3, 4, and 5 of the Ptpre gene. Mice homozygous for this deletion (Ptpre(Delta3-5)) were fertile, bred and developed normally and exhibited no overt phenotype. However, closer examination of the function of macrophages from these mice revealed a defect in the regulation of the respiratory burst. While bacterial lipopolysaccharide (LPS) or tumour necrosis factor alpha (TNFalpha) were able to prime bone marrow-derived macrophages (BMM) from wild type (Ptpre(+)) macrophages for an enhanced respiratory burst, they were unable to do so in macrophages from PTP epsilon-deficient mice. PTP epsilon-deficient BMM also had abnormalities in cytokine production with a reduced ability to produce TNFalpha and enhanced IL-10 production in response to challenge with LPS. These findings suggest an important role for PTP epsilon in the control of macrophage function., (Copyright 2001 Academic Press.)

Mucopolysaccharidosis type I (MPS I) is considered to represent the prototypical mucopolysaccharide storage disorder. Although a spectrum of severity is seen within the MPS I subgroup, Hurler syndrome represents the most severe and frequent manifestation of MPS I. We describe here the generation of a murine model for Hurler syndrome by targeted disruption of the murine Idua gene. Homozygous Idua -/- mice have no detectable alpha-L-iduronidase enzyme activity and show increased urinary glycosaminoglycan levels. Although normal appearing at birth, Idua -/- mice develop a flattened facial profile and thickening of the digits discernible by 3 weeks of age. No obvious growth deficiency nor mortality is seen within the first 20 weeks of life. Radiographs reveal anterior flaring of the ribs and thickening of the facial bones as early as 4 weeks of age with more extensive dysostosis detectable by 15 weeks of age. At 4 weeks of age, lysosomal storage is noted primarily within reticuloendothelial cells with abundant lysosomes noted in Kupffer cells, splenic sinusoidal lining cells, and glial cells. More widespread lysosomal storage is noted by 8 weeks of age in hepatocytes, chondrocytes, neurons, as well as renal tubular cells. Thus, targeted disruption of the murine Idua locus has produced a murine strain representative of the severe form of MPS I. This model should permit detailed evaluation of the pathophysiology of lysosomal storage disorders and provide a small animal model for the testing and development of enzyme replacement and gene therapy regimes.

To assess DNA mutations in vivo, we have established a new transgenic mouse line, BC-1, carrying a lacI target gene for mutation detection within a bacteriophage shuttle-vector. The lacI gene was positioned within sequences derived from a rearranged murine immunoglobulin gene locus, a feature that distinguishes the BC-1 transgene from other shuttle vector systems. As mutations in lacI transgenes likely reflect mutations occurring throughout the genome, these systems have been successfully used to investigate spontaneous and induced mutations in a variety of tissues. An important additional application of the transgenic systems is the characterization of lacI mutations occurring in murine strains having specific DNA repair defects. For this study, scid (severe combined immunodeficiency) mice were selected as animals with this mutation have a defect in double-strand DNA break repair. To determine what impact the scid mutation might have on spontaneous mutation frequencies within DNA recovered from various tissues, these mice were crossed with the BC-1 line. Interestingly, mutation frequencies within BC-1/scid mouse DNA were not significantly different from those of BC-1 control mice. Furthermore, spontaneous lacI mutations obtained from BC-1 and from BC-1/scid liver DNA were similar in spectrum. As spontaneous BC-1 liver mutations were similar to those reported previously for other lacI systems, such as the Big Blue transgenic line, this suggested that the nature of the DNA sequences flanking the reporter gene did not modify lacI mutation rate or character.

The mammalian Sin3 gene (mSin3) encodes four paired amphipathic helix (PAH) motifs, three of which and an extended region beyond PAH3 share between 59 and 70% sequence similarity with the yeast transcriptional regulator, SIN3. However, mSin3/SIN3 fusion proteins were not able to substitute for the yeast molecule in complementation assays. Transcripts encoding this putative transcriptional regulator, which maps to human chromosome 15q24, were detected in multiple mouse tissues, with highest levels seen in testis, lung, and thymus. Its wide tissue distribution suggests that mSin3, like yeast SIN3, may regulate the transcription of multiple genes.

The biosynthesis of protein-bound complex N-glycans in mammals requires a series of covalent modifications governed by a large number of specific glycosyltransferases and glycosidases. The addition of oligosaccharide to an asparagine residue on a nascent polypeptide chain begins in the endoplasmic reticulum. Oligosaccharide processing continues in the Golgi apparatus to produce a diversity of glycan structures. UDP-N-acetylglucosamine:alpha-3-D-mannoside beta-1,2-N-acetylglucosaminyltransferase I (EC 2.4.1.101; GlcNAc-TI) is a key enzyme in the process because it is essential for the conversion of high-mannose N-glycans to complex and hybrid N-glycans. We have isolated the mouse gene encoding GlcNAc-TI (Mgat-1) from a genomic DNA library. The mouse sequence is highly conserved with respect to the human and rabbit homologs and exists as a single protein-encoding exon. Mgat-1 was mapped to mouse Chromosome 11, closely linked to the gene encoding interleukin-3 by the analysis of multilocus interspecies backcrosses. RNA analyses of Mgat-1 expression levels revealed significant variation among normal tissues and cells.

Oligonucleotide probes containing multiple non-radioactive labels have been prepared by utilising and extending the methods used to prepare polyamide-oligonucleotide conjugates. The probes were prepared by incorporating suitable amino acid residues, such as lysines, in the polyamide, which were then used as sites for the attachment of the non-radioactive labels. The procedures developed give control over the distance of the label from the oligonucleotide, and also the inter-label distance. The labels can be conveniently introduced while the substrate is still on the solid support. Even though fluorescent oligonucleotide probes prepared in this way carrying multiple carboxyfluorescein labels gave low levels of fluorescence due to quenching, the probes containing ten biotin labels gave a detection sensitivity of approximately 5 attomole (3 million molecules).