Patient-Centred, Technology-Based Interventions for High Treatment Burden: An Overview of the State of the Art

This study provides an overview of recent efforts to develop technology-based interventions for patients with high treatment burden. Adoption of a technological intervention for high treatment burden will depend on a range of factors, including: the reliability and accessibility of the technology, patient factors including age, socio-economic factors, technology literacy, overall health status and personal priorities - as well as the perceived benefits provided by the technology intervention, from the perspectives of both patients and clinicians.

Caregiver experiences of hospice dementia care: a systematic review and meta-ethnography

OBJECTIVES

Hospices are regarded as gold standard providers of end-of-life care. The term hospice, however, is broadly used, and can describe a type of care offered in a variety of health care services (e.g. nursing homes). It thus becomes complex for families to decide between services. We aimed to review the evidence around the experience of family carers of people with dementia accessing in-patient hospice settings for end-of-life care.

METHOD

We registered the review protocol on PROSPERO. We used PerSPE(C)TiF to systematically organise our search strategy. The evidence was reviewed across six databases: PubMed, EMBASE, PsycINFO, ASSIA, ISI Web, and CINAHL. We used meta-ethnography as per the eMERGe guidance for data interpretation.

RESULTS

Four studies were included. Two third-order constructs were generated through meta-ethnography: expectations of care and barriers to quality of care. We found that carers had expectations of care, and these could change over time. If discussion was not held with hospice staff early on, the carers could experience reduced care quality due to unmatched expectations. Unmatched expectations acted as barriers to care and these were found in terms of carers not feeling adequately supported, and/or having the person discharged from hospice, which would entail increased care responsibility for carers.

CONCLUSION

In view of an increase in new dementia cases over time and with hospice services being under pressure, integrating palliative care services within community-based models of care is key to reducing the risk of having inadequate and under resourced services for people with dementia.

A national co-design workshop of a mobile-based application for vascular access as a patient decision aid

BACKGROUND

Increasing options for vascular access have increased the need for more effective communication to optimize patient engagement and ensure effective consent. An advanced prototype of the mobile application (VA App) was developed over 3 years as a patient decision aid. For the first time, entry to the 2021 UK Kidney Week was opened to all professions and patients and was held online. The VA App was presented in an inter-active session. This report summarizes the findings.

METHODS

A 30-min interactive session was allocated with the session delivered in four sections: (1) demographic data was collected; (2) an overall opinion was obtained about current patient information sources and satisfaction with these; (3) the participants were asked a series of eight questions regarding the main problem areas previously identified; (4) following a 6-min demonstration video, the participants were then re-asked the same questions to determine if the VA App would improve/worsen these areas.

RESULTS

Completed data from 30 participants showed great variation in all demographics. The most cited source was verbal and rated the best, whilst all other sources were felt to be poor by 90%. All eight aspects of current information sources rated poorly. There was a unanimous agreement that the VA App could make this better. Interestingly, when the eight aspects were ranked by order of the worst to best, this matched the order of the benefits of the VA App.

DISCUSSION

This is the first report of an on-line, multi-professional co-design workshop. With a unanimous view that current systems are very limited and that better patient information systems are required, the VA App was found to be a potential solution as a patient decision aid. Interestingly, paper leaflets were widely viewed as the least used and the least effective mechanism for communicating information to patients. Funding for a commercially produced mobile application has been secured and will be further tested in the near future.

Participatory development of a 3D telemedicine system during COVID: The future of remote consultations

BACKGROUND

The COVID pandemic brought the need for more realistic remote consultations into focus. 2D Telemedicine solutions fail to replicate the fluency or authenticity of in-person consultations. This research reports on an international collaboration on the participatory development and first validated clinical use of a novel, real-time 360-degree 3D Telemedicine system worldwide. The development of the system - leveraging Microsoft's Holoportation™ communication technology - commenced at the Canniesburn Plastic Surgery Unit, Glasgow, in March 2020.

METHODS

The research followed the VR CORE guidelines on the development of digital health trials, placing patients at the heart of the development process. This consisted of three separate studies - a clinician feedback study (23 clinicians, Nov-Dec 2020), a patient feedback study (26 patients, Jul-Oct 2021), and a cohort study focusing on safety and reliability (40 patients, Oct 2021-Mar 2022). "Lose, Keep, and Change" feedback prompts were used to engage patients in the development process and guide incremental improvements.

RESULTS

Participatory testing demonstrated improved patient metrics with 3D in comparison to 2D Telemedicine, including validated measures of satisfaction (p<0.0001), realism or 'presence' (Single Item Presence scale, p<0.0001), and quality (Telehealth Usability Questionnaire, p = 0.0002). The safety and clinical concordance (95%) of 3D Telemedicine with a face-to-face consultation were equivalent or exceeded estimates for 2D Telemedicine.

CONCLUSIONS

One of the ultimate goals of telemedicine is for the quality of remote consultations to get closer to the experience of face-to-face consultations. These data provide the first evidence that Holoportation™ communication technology brings 3D Telemedicine closer to this goal than a 2D equivalent.

Experiences of hospice dementia care: A qualitative study of bereaved carers and hospice clinicians

BACKGROUND

Nearly 50 million people worldwide have dementia and the increasing numbers requiring end-of-life and palliative care, has led to national efforts to define standards of care for this patient group. Little research, however, has been done to date about the experience of hospice care for people with dementia accessing these services. This study explores the views of hospice dementia care for bereaved carers of people with dementia and hospice clinicians.

METHODS

We used purposive sampling for participant recruitment. Semi-structured qualitative interviews were conducted with bereaved carers and hospice clinical staff. Interviews were audio recorded and the transcriptions were analysed through thematic analysis. A total of 12 participants were interviewed from one service in the Northwest region in the UK. All were female and white British.

RESULTS

Participants described their experience of hospice dementia care in three main themes: Pre-access to service, roles and responsibility within hospice care, ease and difficulty of last period of end-of-life care.

CONCLUSION

Rapid response teams delivering hospice home care could represent a better option to inpatient care and may be preferred by patients. This type of service, however, may require joined-up care with other community services, and this type of care needs to be considered and planned. Future studies should evaluate this type of community care.

Validation of a vascular access specific quality of life measure (VASQoL)

BACKGROUND

A self-administered 11 item vascular access specific quality of life measure (VASQoL) was previously derived from detailed qualitative interviews with adult patients with kidney failure who have experienced vascular access using the Capabilities Approach as a theoretical base. This study reports the psychometric validation of the VASQoL measure including its reliability, content validity and responsiveness to change.

METHODS

Cognitive interviews were conducted with 23 adult patients with kidney failure after completion of the VASQoL measure. Focus group discussion with a vascular access professional multidisciplinary team was undertaken (n = 8) and subsequently a further 101 adult kidney failure patients with vascular access (TCVC, AVF or AVG) completed the digital VASQoL measure, EQ-5D and SF-36 questionnaires in a longitudinal study with prospectively recorded vascular access events.

RESULTS

Transcript analysis of cognitive interviews after VASQoL completion indicated that the content was comprehensive and well understood by participants. Assessment of Internal reliability for the VASQoL measure was high (Cronbach's alpha 0.858). Test-retest reliability of the overall VASQoL measure was high (intra class correlation coefficient 0.916). In those patients who experienced a vascular access event, significant differences were observed in paired analysis of the VASQoL physical domain questions and vascular access function domain questions and in the EQ-5D usual activities, pain and anxiety domains. In those with no vascular access event, variation was observed in longitudinal analysis in VASQoL questions relating to worry about VA function and capability domains, whilst no variation was observed in the EQ5D measure.

CONCLUSION

The VASQoL measure has good internal consistency, test-retest reliability, convergent validity and responsiveness to change for clinically relevant vascular access outcomes. This provides a validated, vascular access specific quality of life measure that can be used in future trials of vascular access, evaluation of new technologies and routine use as a patient reported outcome measure (PROM).

Patients' and Clinicians' Perspectives on the Acceptability of Completing Digital Quality of Life Questionnaires During Routine Haemodialysis Clinics: A Mixed-Methods Study

Advanced chronic kidney disease is a serious and common medical condition with significant treatment choices incurring varying high treatment burdens. Better understanding on how to best collect quality of life (QoL) in this unique situation may help guide critical decisions. This study investigates the acceptability of digital QoL questionnaires completed during routine haemodialysis sessions. Qualitative data was collected from patient (n=23) and clinical researcher (n=2) interviews alongside analysis of data from questionnaires completed by patients (n=101) during a 6-week validation study. Interviews refined the content and format of digital QoL questionnaires and provided novel insights regarding how patients assessed and completed QoL questions. This study suggests collecting QoL data using digital tablet technology during routine haemodialysis clinics is both feasible and acceptable to patients and has provided novel insights that are not routinely available with traditional methods.

Tele-rehabilitation for people with dementia in the COVID-19 pandemic: A case-study

Introduction

The Promoting Activity, Independence and Stability in Early Dementia (PrAISED) is delivering an exercise programme for people with dementia. The Lincolnshire partnership NHS foundation Trust successfully delivered PrAISED through a video-calling platform during the COVID-19 pandemic.

Objectives

This qualitative case-study identified participants that video delivery worked for, and highlighted its benefits and challenges.

Methods

Interviews were conducted with participants with dementia, caregivers and therapists, and analysed through thematic analysis.

Results

Video delivery worked best when participants had a supporting carer, when therapists showed enthusiasm and had an established rapport with the client. Benefits included time-efficiency of sessions, enhancing participants’ motivation, caregivers’ dementia awareness and therapists’ creativity. Limitations included users’ poor IT skills and resources.

Conclusions

The COVID-19 pandemic required innovative ways of delivering rehabilitation. This study supports that people with dementia can use tele rehab, but success is reliant on having a caregiver and an enthusiastic and known therapist.

The use of technology in the management of children with phonological delay and adults with acquired dysarthria: A UK survey of current speech-language pathology practice

PURPOSE

Technology is increasingly important for the speech-language pathology profession, but little is currently known about its use by clinicians. This study aimed to determine (i) the types of technology that speech-language pathologists (SLPs) in the UK have access to and use in practice and (ii) the barriers they encounter when assessing and treating adults with acquired dysarthria and children with phonological delay.

METHOD

UK SLPs were invited to complete two online surveys covering device availability, the use of technology for the assessment and treatment of acquired dysarthria and phonological delay, and barriers to using technology. Results were analysed using descriptive statistics.

RESULT

126 SLPs completed the surveys. Most respondents had a range of devices available in clinic, including computer and touchscreen devices. Technology was primarily used for treatment to engage clients, provide direct feedback in sessions and encourage home practice. Reported key barriers include lack of knowledge and training, and technical support issues.

CONCLUSION

The use of technology in UK clinical practice varies widely, and technology adoption is hampered by various barriers. Findings indicate a need for more collaborative work between SLPs, technologists and policy-makers to develop the evidence-base for technology use in the management of acquired dysarthria and phonological delay.

Experts Views on the Use of Mobile Devices to Support Patients with Mild Learning Disabilities During Clinical Consultations

Due to several factors including time and budget constraints, General Practitioners (GPs) are often under-trained on the communication needs of patients with learning disabilities (LDs). As such, they may find it difficult to extract accurate information from these patients. Digital technologies have the potential to alleviate communication barriers, yet their use in this context remains vastly unexplored. Hence, we conducted 2 focus groups with 12 experts in LDs to investigate how tablet applications may be used to promote the information exchange process between GPs and patients with mild LDs. The experts identified an initial set of design criteria for the future implementation of these technologies and were enthusiastic about the potential impact they may have on primary care. In addition, they also discussed a potential model for extracting medical information from this population, which focused on breaking the overall consultation down into smaller, less cognitively challenging segments.

Design Requirements for a Digital Aid to Support Adults With Mild Learning Disabilities During Clinical Consultations: Qualitative Study With Experts

Background

Adults with mild learning disabilities (MLDs) face a plethora of obstacles when accessing effective health care. Central to many of these barriers is communication, with medical practitioners often remaining untrained on how to interact with patients who have learning disabilities (LDs). To date, research on how to promote this communication has largely centered on the development of low-tech aids.

Objective

The objective of this study was to assess the feasibility of utilizing tablet technologies to promote communication between general practitioners and patients with MLDs. We achieved this by identifying a set of design requirements from experts in LDs.

Methods

A set of design guidelines was formed during a 2-phase process. Phase 1 involved conducting a series of requirements-gathering interviews with 10 experts in LDs—the protocol of which emerged from the results of a separate scoping review. The interviews were subjected to a framework analysis to discern the key requirements discussed by the experts, and these were embedded within a technology probe. In phase 2, this probe was presented to a subset (n=4) of the experts during a round of usability studies, and the feedback received was used to update the requirements identified in phase 1.

Results

An initial set of design requirements has been produced that may assist in the development of clinical Alternative and Augmentative Communication technologies for adults with MLDs. Factors that must be considered range from the health, physical and cognitive needs of stakeholders, to the more individual needs of users.

Conclusions

The experts involved in the study were optimistic about the proposed app. They believe that such technologies can help to alleviate time constraints and promote communication by presenting information in a form understood by both practitioners and patients.

Analysis of Skeletal Muscle Torque Capacity and Circulating Ceramides in Patients with Advanced Heart Failure

BACKGROUND

Heart failure (HF)-related exercise intolerance is thought to be perpetuated by peripheral skeletal muscle functional, structural, and metabolic abnormalities. We analyzed specific dynamics of muscle contraction in patients with HF compared with healthy, sedentary controls.

METHODS

Isometric and isokinetic muscle parameters were measured in the dominant upper and lower limbs of 45 HF patients and 15 healthy age-matched controls. Measurements included peak torque normalized to body weight, work normalized to body weight, power, time to peak torque, and acceleration and deceleration to maximum strength times. Body morphometry (dual energy X-ray absorptiometry scan) and circulating fatty acids and ceramides (lipodomics) were analyzed in a subset of subjects (18 HF and 9 controls).

RESULTS

Extension and flexion time-to-peak torque was longer in the lower limbs of HF patients. Furthermore, acceleration and deceleration times in the lower limbs were also prolonged in HF subjects. HF subjects had increased adiposity and decreased lean muscle mass compared with controls. Decreased circulating unsaturated fatty acids and increased ceramides were found in subjects with HF.

CONCLUSIONS

Delayed torque development suggests skeletal muscle impairments that may reflect abnormal neuromuscular functional coupling. These impairments may be further compounded by increased adiposity and inflammation associated with increased ceramides.

Odour, dust and non-methane volatile organic-compound emissions from tunnel-ventilated layer-chicken sheds: a case study of two farms

An observational study was undertaken to measure odour and dust (PM10 and PM2.5) emission rates and identify non-methane volatile organic compounds (NMVOCs) and odorants in the exhaust air from two tunnel-ventilated layer-chicken sheds that were configured with multi-tiered cages and manure belts. The study sites were located in south-eastern Queensland and the West Gippsland region of Victoria, Australia. Samples were collected in summer and winter on sequential days across the manure-belt cleaning cycle. Odour emissions ranged from 58 to 512 ou/s per 1000 birds (0.03–0.27 ou/s.kg) and dust emission rates ranged 0.014–0.184 mg/s per 1000 birds for PM10 and 0.001–0.190 mg/s per 1000 birds for PM2.5. Twenty NMVOCs were identified, including three that were also identified as odorants using thermal desorption–gas chromatography–mass spectrometry/olfactometry analysis. Odour emission rates were observed to vary with the amount of manure accumulation on the manure belts, being lowest 2–4 days after removing manure. Odour emission rates were also observed to vary with diurnal and seasonal changes in ventilation rate. Dust emissions were observed to increase with ventilation rate but not with manure accumulation. Some NMVOCs were identified at both farms and in different seasons whereas others were observed only at one farm or in one season, indicating that odorant composition was influenced by farm-specific practices and season.

The value of FDG positron emission tomography/computerised tomography (PET/CT) in pre-operative staging of colorectal cancer: a systematic review and economic evaluation

OBJECTIVES

In the UK, colorectal cancer (CRC) is the third most common malignancy (behind lung and breast cancer) with 37,514 cases registered in 2006: around two-thirds (23,384) in the colon and one-third (14,130) in the rectum. Treatment of cancers of the colon can vary considerably, but surgical resection is the mainstay of treatment for curative intent. Following surgical resection, there is a comprehensive assessment of the tumour, it's invasion characteristics and spread (tumour staging). A number of imaging modalities are used in the pre-operative staging of CRCs including; computerised tomography (CT), magnetic resonance imaging, ultrasound imaging and positron emission tomography (PET). This report examines the role of CT in combination with PET scanning (PET/CT 'hybrid' scan). The research objectives are: to evaluate the diagnostic accuracy and therapeutic impact of fluorine-18-deoxyglucose (FDG) PET/CT for the pre-operative staging of primary, recurrent and metastatic cancer using systematic review methods; undertake probabilistic decision-analytic modelling (using Monte Carlo simulation); and conduct a value of information analysis to help inform whether or not there is potential worth in undertaking further research.

DATA SOURCES

For each aspect of the research - the systematic review, the handsearch study and the economic evaluation - a database was assembled from a comprehensive search for published and unpublished studies, which included database searches, reference lists search and contact with experts. In the systematic review prospective and retrospective patient series (diagnostic cohort) and randomised controlled trials (RCTs) were eligible for inclusion. Both consecutive series and series that are not explicitly reported as consecutive were included.

REVIEW METHODS

Two reviewers extracted all data and applied the criteria independently and resolved disagreements by discussion. Data to populate 2 × 2 contingency tables consisting of the number of true positives, true negatives, false positives and false negatives using the studies' own definitions were extracted, as were data relating to changes in management. Fourteen items from the Quality Assessment of Diagnostic Accuracy Studies checklist were used to assess the methodological quality of the included studies. Patient-level data were used to calculate sensitivity and specificity with confidence intervals (CIs). Data were plotted graphically in forest plots. For the economic evaluation, economic models were designed for each of the disease states: primary, recurrent and metastatic. These were developed and populated based on a variety of information sources (in particular from published data sources) and literature, and in consultation with clinical experts.

RESULTS

The review found 30 studies that met the eligibility criteria. Only two small studies evaluated the use of FDG PET/CT in primary CRC, and there is insufficient evidence to support its routine use at this time. The use of FDG PET/CT for the detection of recurrent disease identified data from five retrospective studies from which a pooled sensitivity of 91% (95% CI 0.87% to 0.95%) and specificity of 91% (95% CI 0.85% to 0.95%) were observed. Pooled accuracy data from patients undergoing staging for suspected metastatic disease showed FDG PET/CT to have a pooled sensitivity of 91% (95% CI 87% to 94%) and a specificity of 76% (95% CI 58% to 88%), but the poor quality of the studies means the validity of the data may be compromised by several biases. The separate handsearch study did not yield any additional unique studies relevant to FDG PET/CT. Models for recurrent disease demonstrated an incremental cost-effectiveness ratio of £ 21,409 per quality-adjusted life-year (QALY) for rectal cancer, £ 6189 per QALY for colon cancer and £ 21,434 per QALY for metastatic disease. The value of handsearching to identify studies of less clearly defined or reported diagnostic tests is still to be investigated.

CONCLUSIONS

The systematic review found insufficient evidence to support the routine use of FDG PET/CT in primary CRC and only a small amount of evidence supporting its use in the pre-operative staging of recurrent and metastatic CRC, and, although FDG PET/CT was shown to change patient management, the data are divergent and the quality of research is generally poor. The handsearch to identify studies of less clearly defined or reported diagnostic tests did not find additional studies. The primary limitations in the economic evaluations were due to uncertainty and lack of available evidence from the systematic reviews for key parameters in each of the five models. In order to address this, a conservative approach was adopted in choosing DTA estimates for the model parameters. Probabilistic analyses were undertaken for each of the models, incorporating wide levels of uncertainty particularly for the DTA estimates. None of the economic models reported cost-savings, but the approach adopted was conservative in order to determine more reliable results given the lack of current information. The economic evaluations conclude that FDG PET/CT as an add-on imaging device is cost-effective in the pre-operative staging of recurrent colon, recurrent rectal and metastatic disease but not in primary colon or rectal cancers. There would be value in undertaking an RCT with a concurrent economic evaluation to evaluate the therapeutic impact and cost-effectiveness of FDG PET/CT compared with conventional imaging (without PET) for the pre-operative staging of recurrent and metastatic CRC.

Steps for successful funding applications

Trauma- and injury-related research is recognised in Australia as a National Health Priority Area. Within the past 5 years (2005-2009) 926 trauma-related research publications with an Australian author can be retrieved from the Thomson-Reuters ISI Web of Science database. These publications are written with co-authors from 725 institutions world-wide and span 110 discipline areas from surgery to interdisciplinary social science. Each of these disciplines can represent an opportunity to bridge the gulf between research and health practice, but must be supported by major funding if this translational research is to continue. There are ways in which junior researchers and experience research teams can optimise their trauma-related research proposals to convince funding agencies of the continuing importance of the field and obtain the necessary funding.

COGENT (COlorectal cancer GENeTics): an international consortium to study the role of polymorphic variation on the risk of colorectal cancer

It is now recognised that a part of the inherited risk of colorectal cancer (CRC) can be explained by the co-inheritance of low-penetrance genetic variants. The accumulated experience to date in identifying these variants has served to highlight difficulties in conducting statistically and methodologically rigorous studies and follow-up analyses. The COGENT (COlorectal cancer GENeTics) consortium includes 20 research groups in Europe, Australia, the Americas, China and Japan. The overarching goal of COGENT is to identify and characterise low-penetrance susceptibility variants for CRC through association-based analyses. In this study, we review the rationale for identifying low-penetrance variants for CRC and our proposed strategy for establishing COGENT.

Odour emissions from tunnel-ventilated broiler sheds: case study of nine Queensland farms

Odour emission rates were measured from nine tunnel-ventilated broiler farms in south-eastern Queensland, Australia. At one farm, odour emission rates were measured over two sequential batches approximately weekly, while at the remaining farms, odour emission rates were measured just before the first pickup (around Day 35 of the batch) when bird liveweight was greatest and peak odour emission rates were expected. Odour samples were analysed using dynamic olfactometry (to AS/NZS 4323.3:2001), and an artificial olfaction system was used to continuously monitor odour emission rates at one farm. Odour emission rates ranged from 330 to 2960 ou/s per 1000 birds and from 0.19 to 2.12 ou/s.kg, with a significant amount of variability observed throughout the batch and throughout each sampling day. While the wide range in odour emission rates was primarily due to changes in bird liveweight and ventilation requirements, other factors were also involved. The artificial olfaction system proved useful for quantifying the range and variability of odour emission rates, especially when olfactometry analysis was impractical.

Dust emissions from a tunnel-ventilated broiler poultry shed with fresh and partially reused litter

Dust emissions from large-scale, tunnel-ventilated poultry sheds could have negative health and environmental impacts. Despite this fact, the literature concerning dust emissions from tunnel-ventilated poultry sheds in Australia and overseas is relatively scarce. Dust measurements were conducted during two consecutive production cycles at a single broiler shed on a poultry farm near Ipswich, Queensland. Fresh litter was employed during the first cycle and partially reused litter was employed during the second cycle. This provided an opportunity to study the effect that partial litter reuse has on dust emissions. Dust levels were characterised by the number concentration of suspended particles having a diameter between 0.5 and 20 μm and by the mass concentration of dust particles of less than 10 μm diameter (PM10) and 2.5 μm diameter (PM2.5). In addition, we measured the number size distributions of dust particles. The average concentration and emission rate of dust was higher when partially reused litter was used in the shed than when fresh litter was used. In addition, we found that dust particles emitted from the shed with partially reused litter were finer than the particles emitted with fresh litter. Although the change in litter properties is certainly contributing to this observed variability, other factors such as ventilation rate and litter moisture content are also likely to be involved.

Comparison of odour emission rates measured from various sources using two sampling devices

Two commonly used sampling devices (a wind tunnel and the US EPA dynamic emission chamber), were used to collect paired samples of odorous air from a number of agricultural odour sources. The odour samples were assessed using triangular, forced-choice dynamic olfactometry. The odour concentration data was combined with the flushing rate data to calculate odour emission rates for both devices on all sources. Odour concentrations were consistently higher in samples collected with a flux chamber (ratio ranging from 10:7 to 5:1, relative to wind tunnel samples), whereas odour emission rates were consistently larger when derived from wind tunnels (ratio ranging from 60:1 to 240:1, relative to flux chamber values). A complex relationship existed between emission rate estimates derived from each device, apparently influenced by the nature of the emitting surface. These results have great significance for users of odour dispersion models, for which an odour emission rate is a key input parameter.

Long-term assessment of efficacy of permeable pond covers for odour reduction

Three anaerobic ponds used to store and treat piggery wastes were fully covered with permeable materials manufactured from polypropylene geofabric, polyethylene shade cloth and supported straw. The covers were assessed in terms of efficacy in reducing odour emission rates over a 40-month period. Odour samples were collected from the surface of the covers, the surface of the exposed liquor and from the surface of an uncovered (control) pond at one of the piggeries. Relative to the emission rate of the exposed liquor at each pond, the polypropylene, shade cloth and straw covers reduced average emission rates by 76%, 69% and 66%, respectively. At the piggery with an uncovered control pond, the polypropylene covers reduced average odour emission rates by 50% and 41%, respectively. A plausible hypothesis, consistent with likely mechanisms for the odour reduction and the olfactometric method used to quantifying the efficacy of the covers, is offered.

Odour emissions from anaerobic piggery ponds. 1. Results of a three season, 14-month survey

Odour emission rates were measured for seven different anaerobic ponds treating piggery wastes at six to nine discrete locations across the surface of each pond on each sampling occasion over a 14-month period. Emission rate values varied between ponds, between seasons for the same pond and even for the same pond on different days of a sampling week. Average seasonal emission rates ranged from 7.9 to 46.5OU/m(2)s, while average emission rates ranged from 16.0 to 29.0OU/m(2)s. Factors potentially responsible for the variability in emission rates were investigated, including air and pond liquor temperatures, time of day of sample collection, season and the impact of a prolonged drought.

Disease severity and genetic pathways in attenuated familial adenomatous polyposis vary greatly but depend on the site of the germline mutation

BACKGROUND

Attenuated familial adenomatous polyposis (AFAP) is associated with germline mutations in the 5', 3', and exon 9 of the adenomatous polyposis coli (APC) gene. These mutations probably encode a limited amount of functional APC protein.

METHODS AND RESULTS

We found that colonic polyp number varied greatly among AFAP patients but members of the same family tended to have more similar disease severity. 5' Mutants generally had more polyps than other patients. We analysed somatic APC mutations/loss of heterozygosity (LOH) in 235 tumours from 35 patients (16 families) with a variety of AFAP associated germline mutations. In common with two previous studies of individual kindreds, we found biallelic changes ("third hits") in some polyps. We found that the "third hit" probably initiated tumorigenesis. Somatic mutation spectra were similar in 5' and 3' mutant patients, often resembling classical FAP. In exon 9 mutants, in contrast, "third hits" were more common. Most "third hits" left three 20 amino acid repeats (20AARs) on the germline mutant APC allele, with LOH (or proximal somatic mutation) of the wild-type allele; but some polyps had loss of the germline mutant with mutation leaving one 20AAR on the wild-type allele.

CONCLUSIONS

We propose that mutations, such as nt4661insA, that leave three 20AARs are preferentially selected in cis with some AFAP mutations because the residual protein function is near optimal for tumorigenesis. Not all AFAP polyps appear to need "three hits" however. AFAP is phenotypically and genetically heterogeneous. In addition to effects of different germline mutations, modifier genes may be acting on the AFAP phenotype, perhaps influencing the quantity of functional protein produced by the germline mutant allele.

Association of MUTYH and colorectal cancer

Mutations in the MUTYH gene have been reported to be associated with increased risk of developing colorectal cancer. In this study, we confirmed this association using original data on 928 colorectal cancer cases and 845 healthy controls from Scotland. We then conducted a meta-analysis from published data on the association between mutations at MUTYH and colorectal cancer risk. We show for the first time a small but significant mono-allelic effect with a genotype relative risk (GRR) of 1.27 (95% confidence interval (CI): 1.01-1.61), and confirm and give a more precise estimate of the strong bi-allelic effect with an estimated GRR of 117 (95% CI: 74-184). This study underscores the need for large sample sizes in order to identify small gene effects when the disease allele frequency is low.

Is it acceptable to approach colorectal cancer patients at diagnosis to discuss genetic testing? A pilot study

In this pilot study, the acceptability of approaching 111 newly diagnosed colorectal cancer patients with the offer of genetic testing for hereditary nonpolyposis colorectal cancer (HNPCC) was assessed. A total of 78% of participants found it highly acceptable to have the information about HNPCC brought to their attention at that time.

Effects of free fatty acids on insulin secretion in obesity

The prevalence of obesity in Western society has reached epidemic proportions and its aetiological role in the development of type 2 diabetes has made finding an effective treatment for the condition of crucial importance. Of the many consequences of obesity, derangements in glucose metabolism present one of the greatest problems to health. While the role of obesity in causing insulin resistance has received much attention, the effect of obesity on beta-cell failure and the consequent development of type 2 diabetes requires re-emphasis. In this review, the current understanding of the effects of elevated free-fatty acids on beta-cell function will be examined, including a discussion of potential mechanisms. In particular, dysregulation of biochemical pathways and alterations in key enzymes, proteins and hormones will be considered as grounds for the progression to a diabetic phenotype.

Temporal evolution of the electric field accelerating electrons away from the auroral ionosphere

The bright night-time aurorae that are visible to the unaided eye are caused by electrons accelerated towards Earth by an upward-pointing electric field. On adjacent geomagnetic field lines the reverse process occurs: a downward-pointing electric field accelerates electrons away from Earth. Such magnetic-field-aligned electric fields in the collisionless plasma above the auroral ionosphere have been predicted, but how they could be maintained is still a matter for debate. The spatial and temporal behaviour of the electric fields-a knowledge of which is crucial to an understanding of their nature-cannot be resolved uniquely by single satellite measurements. Here we report on the first observations by a formation of identically instrumented satellites crossing a beam of upward-accelerated electrons. The structure of the electric potential accelerating the beam grew in magnitude and width for about 200 s, accompanied by a widening of the downward-current sheet, with the total current remaining constant. The 200-s timescale suggests that the evacuation of the electrons from the ionosphere contributes to the formation of the downward-pointing magnetic-field-aligned electric fields. This evolution implies a growing load in the downward leg of the current circuit, which may affect the visible discrete aurorae.

Aldose reductase and the role of the polyol pathway in diabetic nephropathy

BACKGROUND; In diabetic renal complications, hyperglycemia may cause damage at a cellular level in both glomerular and tubular locations, often preceding overt dysfunction. Our previous work has implicated aldose reductase in a pathway whereby aldose reductase-induced use of nicotinamide adenine dinucleotide phosphate (reduced form) (NADPH) drives the pentose phosphate pathway, which culminates in a protein kinase C-induced increase in glomerular prostaglandin production and loss of mesangial cell contractility as a possible cause of hyperfiltration and glomerular dysfunction in diabetes. In this model, aldose reductase inhibition in vitro redresses all aspects of the pathway proposed to lead to hyperfiltration; aldose reductase inhibition in vivo gives only a partial amelioration over the short-term or is without effect in the longer term on microalbuminuria, which follows glomerular and tubular dysfunction. In diabetes, hyperglycemia-induced renal polyol pathway activity does not occur in isolation but instead in tandem with oxidative changes and the production of reactive dicarbonyls and alpha,beta-unsaturated aldehydes. Aldose reductase may detoxify these compounds. We investigated this aspect in a transgenic rat model with human aldose reductase cDNA under the control of the cytomegalovirus promoter with tubular expression of transgene.

METHODS

Tubules (S3 region-enriched) from transgenic and control animals were prepared, exposed to oxidative stress, and analyzed to determine the cellular protein dicarbonyl content.

RESULTS

In tubules from transgenic animals, oxidative stress-induced dicarbonyls were significantly reduced, an effect not seen when an aldose reductase inhibitor was present.

CONCLUSIONS

Aldose reductase may both exacerbate and alleviate the production of metabolites that lead to hyperglycemia-induced cellular impairment, with the balance determining the extent of dysfunction.

Analysis of genetic and phenotypic heterogeneity in juvenile polyposis

BACKGROUND

Juvenile polyposis syndrome (JPS) is characterised by gastrointestinal (GI) hamartomatous polyposis and an increased risk of GI malignancy. Juvenile polyps also occur in the Cowden (CS), Bannayan-Ruvalcaba-Riley (BRRS) and Gorlin (GS) syndromes. Diagnosing JPS can be problematic because it relies on exclusion of CS, BRRS, and GS. Germline mutations in the PTCH, PTEN and DPC4 (SMAD4) genes can cause GS, CS/BRRS, and JPS, respectively.

AIMS

To examine the contribution of mutations in PTCH, PTEN, and DPC4 (SMAD4) to JPS.

METHODS

Forty seven individuals from 15 families and nine apparently sporadic cases with JPS were screened for germline mutations in DPC4, PTEN, and PTCH.

RESULTS

No patient had a mutation in PTEN or PTCH. Five different germline mutations were detected in DPC4; three of these were deletions, one a single base substitution creating a stop codon, and one a missense change. None of these patients had distinguishing clinical features.

CONCLUSIONS

Mutations in PTEN and PTCH are unlikely to cause juvenile polyposis in the absence of clinical features indicative of CS, BRRS, or GS. A proportion of JPS patients harbour DPC4 mutations (21% in this study) but there remains uncharacterized genetic heterogeneity in JPS.

Screening SMAD1, SMAD2, SMAD3, and SMAD5 for germline mutations in juvenile polyposis syndrome

BACKGROUND AND AIMS

Juvenile polyps occur in several Mendelian disorders, whether in association with gastrointestinal cancer alone (juvenile polyposis syndrome, JPS) or as part of known syndromes (Cowden, Gorlin, and Bannayan-Zonana) in association with developmental abnormalities, dysmorphic features, or extraintestinal tumours. Recently, some JPS families were shown to harbour germline mutations in the SMAD4 (DPC4) gene, providing further evidence for the importance of the TGFbeta signalling pathway in colorectal cancer. There remains, however, considerable, unexplained genetic heterogeneity in JPS. Other members of the SMAD family are excellent candidates for JPS, especially SMAD2 (which, like SMAD4, is mutated somatically in colorectal cancers), SMAD3 (which causes colorectal cancer when "knocked out" in mice), SMAD5, and SMAD1.

METHODS

SMAD1, SMAD2, SMAD3, and SMAD5 were screened for germline mutations in 30 patients with JPS and without SMAD4 mutations.

RESULTS

No mutations were found in any of these genes. A G-A C89Y polymorphism with possible effects on protein function was found in SMAD3, but the frequencies of the G and A alleles did not differ between patients with JPS and controls.

CONCLUSIONS

It remains to be determined whether or not this polymorphism is involved in a minor predisposition to colorectal or other carcinomas. SMAD4 may be the only member of the SMAD family which causes JPS when mutant in the germline. The other genes underlying JPS remain to be identified.