Complete biosynthesis of the potent vaccine adjuvant QS-21.

QS-21 is a potent vaccine adjuvant currently sourced by extraction from the Chilean soapbark tree. It is a key component of human vaccines for shingles, malaria, coronavirus disease 2019 and others under development. The structure of QS-21 consists of a glycosylated triterpene scaffold coupled to a complex glycosylated 18-carbon acyl chain that is critical for immunostimulant activity. We previously identified the early pathway steps needed to make the triterpene glycoside scaffold; however, the biosynthetic route to the acyl chain, which is needed for stimulation of T cell proliferation, was unknown. Here, we report the biogenic origin of the acyl chain, characterize the series of enzymes required for its synthesis and addition and reconstitute the entire 20-step pathway in tobacco, thereby demonstrating the production of QS-21 in a heterologous expression system. This advance opens up unprecedented opportunities for bioengineering of vaccine adjuvants, investigating structure-activity relationships and understanding the mechanisms by which these compounds promote the human immune response.

Discovery of isoflavone phytoalexins in wheat reveals an alternative route to isoflavonoid biosynthesis.

Isoflavones are a group of phenolic compounds mostly restricted to plants of the legume family, where they mediate important interactions with plant-associated microbes, including in defense from pathogens and in nodulation. Their well-studied health promoting attributes have made them a prime target for metabolic engineering, both for bioproduction of isoflavones as high-value molecules, and in biofortification of food crops. A key gene in their biosynthesis, isoflavone synthase, was identified in legumes over two decades ago, but little is known about formation of isoflavones outside of this family. Here we identify a specialized wheat-specific isoflavone synthase, TaCYP71F53, which catalyzes a different reaction from the leguminous isoflavone synthases, thus revealing an alternative path to isoflavonoid biosynthesis and providing a non-transgenic route for engineering isoflavone production in wheat. TaCYP71F53 forms part of a biosynthetic gene cluster that produces a naringenin-derived O-methylated isoflavone, 5-hydroxy-2',4',7-trimethoxyisoflavone, triticein. Pathogen-induced production and in vitro antimicrobial activity of triticein suggest a defense-related role for this molecule in wheat. Genomic and metabolic analyses of wheat ancestral grasses further show that the triticein gene cluster was introduced into domesticated emmer wheat through natural hybridization ~9000 years ago, and encodes a pathogen-responsive metabolic pathway that is conserved in modern bread wheat varieties.

Elucidation of the pathway for biosynthesis of saponin adjuvants from the soapbark tree.

The Chilean soapbark tree (Quillaja saponaria) produces soap-like molecules called QS saponins that are important vaccine adjuvants. These highly valuable compounds are sourced by extraction from the bark, and their biosynthetic pathway is unknown. Here, we sequenced the Q. saponaria genome. Through genome mining and combinatorial expression in tobacco, we identified 16 pathway enzymes that together enable the production of advanced QS pathway intermediates that represent a bridgehead for adjuvant bioengineering. We further identified the enzymes needed to make QS-7, a saponin with excellent therapeutic properties and low toxicity that is present in low abundance in Q. saponaria bark extract. Our results enable the production of Q. saponaria vaccine adjuvants in tobacco and open the way for new routes to access and engineer natural and new-to-nature immunostimulants.

Complex scaffold remodeling in plant triterpene biosynthesis.

Triterpenes with complex scaffold modifications are widespread in the plant kingdom. Limonoids are an exemplary family that are responsible for the bitter taste in citrus (e.g., limonin) and the active constituents of neem oil, a widely used bioinsecticide (e.g., azadirachtin). Despite the commercial value of limonoids, a complete biosynthetic route has not been described. We report the discovery of 22 enzymes, including a pair of neofunctionalized sterol isomerases, that catalyze 12 distinct reactions in the total biosynthesis of kihadalactone A and azadirone, products that bear the signature limonoid furan. These results enable access to valuable limonoids and provide a template for discovery and reconstitution of triterpene biosynthetic pathways in plants that require multiple skeletal rearrangements and oxidations.

Learning about the changing needs for prosthetics service provision from routinely collected digital centre management data: An exemplar study across three clinics in Cambodia.

Background: Prosthetic service development and delivery rely on data describing population needs. These needs are context-specific, but most existing data come from high-income countries or small geographic areas, which are often not comparable. This study analysed routinely collected digital patient record data at multiple time points to provide insights into characteristics of people accessing Cambodian prosthetic services. Methods: We investigated trends in birth year, sex, year and reason for limb absence, and prosthesis type, over three decades. Then, we observed data from 2005 and 2019 indicating how the population actively accessing prosthetics services has changed. Results: Temporal trends in prosthetics service user demographics corresponded with events in Cambodia's socio-political history. The predominant historical reason for limb absence prior to 2000 was weapon trauma during and following conflict. Since 2000, this was replaced by non-communicable disease and road accidents. Transtibial remained the most prevalent amputation level but transfemoral amputation had higher incidence for people with limb loss from road accidents, and people with limb loss due to disease were older. These observations are important as both transfemoral and older-aged groups experience particular rehabilitation challenges compared to the young, transtibial group. Conclusions: The study shows how standardised, routinely collected data across multiple clinics within a country can be used to characterise prosthetics service user populations and shows significant changes over time. This indicates the need to track client characteristics and provides evidence for adapting services according to population dynamics and changes in patient need.

Perceptions of people with Parkinson's and their caregivers of falling and falls-related healthcare services- a qualitative study.

INTRODUCTION: Falls are common in Parkinson's disease, and a recognised research priority. Falls lead to physical and psychological morbidity in people with Parkinson's disease and their caregivers, however, those with cognitive impairment/ dementia and caregivers have often been excluded from previous studies. This qualitative study explored how people with Parkinson's disease and their family caregivers understood and experienced falling and healthcare services relating to falls prevention and management. METHODS: A varied and purposive sample of 20 people with Parkinson's disease (40% confirmed or suspected cognitive impairment/ dementia) and 18 caregivers took part in semi-structured interviews. Eight people with Parkinson's disease and their caregivers were interviewed as a dyad, 22 participants were interviewed alone. Interviews were analysed through inductive thematic analysis. RESULTS: Four themes were developed: (i) struggling with thoughts and feelings about falling, (ii) recognising and managing risks surrounding falling, (iii) navigating health and care provision for falling, and (iv) changing as a couple due to falling. Different aspects of falls provoked a range of negative emotions and a variety of coping strategies were adopted. Falls and trying to avoid falls burdened a couple in a number of ways; beyond physical health they also affected functioning, physiological wellbeing, and relationships. Dyads analysed falls to understand their aetiology and described working together to manage them. This often happened in the absence of adequate support and advice with little involvement of healthcare professionals. When cognitive impairment/ dementia was present this brought additional challenges to falls management, with caregivers taking on a greater and more frustrating role. CONCLUSION: Dyads required relevant falls-related information and the difficulties associated with cognitive decline should be recognised by researchers and healthcare professionals. Dyads required support in attributing reasons for falls, and increased awareness of healthcare professionals' different roles to improve patient- professional communication and facilitate patient-centred care.

Pathogen-induced biosynthetic pathways encode defense-related molecules in bread wheat.

Wheat is a widely grown food crop that suffers major yield losses due to attack by pests and pathogens. A better understanding of biotic stress responses in wheat is thus of major importance. The recently assembled bread wheat genome coupled with extensive transcriptomic resources provides unprecedented new opportunities to investigate responses to pathogen challenge. Here, we analyze gene coexpression networks to identify modules showing consistent induction in response to pathogen exposure. Within the top pathogen-induced modules, we identify multiple clusters of physically adjacent genes that correspond to six pathogen-induced biosynthetic pathways that share a common regulatory network. Functional analysis reveals that these pathways, all of which are encoded by biosynthetic gene clusters, produce various different classes of compounds­namely, flavonoids, diterpenes, and triterpenes, including the defense-related compound ellarinacin. Through comparative genomics, we also identify associations with the known rice phytoalexins momilactones, as well as with a defense-related gene cluster in the grass model plant Brachypodium distachyon. Our results significantly advance the understanding of chemical defenses in wheat and open up avenues for enhancing disease resistance in this agriculturally important crop. They also exemplify the power of transcriptional networks to discover the biosynthesis of chemical defenses in plants with large, complex genomes.

Subtelomeric assembly of a multi-gene pathway for antimicrobial defense compounds in cereals.

Non-random gene organization in eukaryotes plays a significant role in genome evolution. Here, we investigate the origin of a biosynthetic gene cluster for production of defence compounds in oat-the avenacin cluster. We elucidate the structure and organisation of this 12-gene cluster, characterise the last two missing pathway steps, and reconstitute the entire pathway in tobacco by transient expression. We show that the cluster has formed de novo since the divergence of oats in a subtelomeric region of the genome that lacks homology with other grasses, and that gene order is approximately colinear with the biosynthetic pathway. We speculate that the positioning of the late pathway genes furthest away from the telomere may mitigate against a 'self-poisoning' scenario in which toxic intermediates accumulate as a result of telomeric gene deletions. Our investigations reveal a striking example of adaptive evolution underpinned by remarkable genome plasticity.

Falls Self-Management Interventions for People with Parkinson's Disease: A Systematic Review.

BACKGROUND: Falls are common in Parkinson's disease (PD). Increased involvement of people with Parkinson's (PwP) in their care has been associated with enhanced satisfaction. Self-management programmes in other long-term conditions (LTCs) have led to improvements in physical and psychological outcomes. These have been more effective when targeted toward a specific behavior. OBJECTIVE: This paper aimed to identify and review falls self-management interventions for PwP. METHODS: A systematic review was conducted. Electronic databases were searched in June 2018. Primary research studies (any design) reporting the delivery of falls self-management interventions to PwP were included. Data was extracted from each article and synthesised narratively. RESULTS: Six articles were identified, relating to five different self-management interventions. All described a self-management intervention delivered alongside physiotherapy. Intervention delivery was through either group discussion (n = 3) or falls booklets (n = 3). Interventions were often incompletely described; the most common components were information about the condition, training/ rehearsal for psychological strategies and lifestyle advice and support. Arising from the design of articles included the effects of self-management and physiotherapy could not be separated. Three articles measured falls, only one led to a reduction. Four articles measured quality of life, only one led to improvement. No articles assessed skill acquisition or adherence to the self-management intervention. CONCLUSIONS: Few falls self-management interventions for PwP have been evaluated and reported. The components of an effective intervention remain unclear. Given the benefits of self-management interventions in other LTCs, it is important that falls self-management interventions are developed and evaluated to support PwP.

Can routine clinical data identify older patients at risk of poor healthcare outcomes on admission to hospital?

OBJECTIVE: Older patients who are at risk of poor healthcare outcomes should be recognised early during hospital admission to allow appropriate interventions. It is unclear whether routinely collected data can identify high-risk patients. The aim of this study was to define current practice with regard to the identification of older patients at high risk of poor healthcare outcomes on admission to hospital. RESULTS: Interviews/focus groups were conducted to establish the views of 22 healthcare staff across five acute medicine for older people wards in one hospital including seven nurses, four dieticians, seven doctors, and four therapists. In addition, a random sample of 60 patients' clinical records were reviewed to characterise the older patients, identify risk assessments performed routinely on admission, and describe usual care. We found that staff relied on their clinical judgment to identify high risk patients which was influenced by a number of factors such as reasons for admission, staff familiarity with patients, patients' general condition, visible frailty, and patients' ability to manage at home. "Therapy assessment" and patients' engagement with therapy were also reported to be important in recognising high-risk patients. However, staff recognised that making clinical judgments was often difficult and that it might occur several days after admission potentially delaying specific interventions. Routine risk assessments carried out on admission to identify single healthcare needs included risk of malnutrition (completed for 85% patients), falls risk (95%), moving and handling assessments (85%), and pressure ulcer risk assessments (88%). These were not used collectively to highlight patients at risk of poor healthcare outcomes. Thus, patients at risk of poor healthcare outcomes were not explicitly identified on admission using routinely collected data. There is a need for an early identification of these patients using a valid measure alongside staff clinical judgment to allow timely interventions to improve healthcare outcomes.

Managing older medical patients in hospital: a study of the outcomes from a shift of resources to the 'front door'.

We performed a retrospective cohort comparison study to look at the processes for concentrating geriatric resources in the acute admissions area in a general hospital in the UK and compare key outcomes. The number of consultant geriatricians and other staff working at the 'front door' - acute medical unit (AMU) and short stay ward (SSW) - was increased. We compared 'front door' outcomes with whole department outcomes in 2013 and 2014, looking at the proportion of patients discharged within 3 and 5 days of admission, the proportion discharged from the 'front door', mean lengths of stay (LOS) and readmissions within 28 days of discharge. There were 1,147 and 1,381 discharge episodes in 2013 and 2014, respectively. 'Front door' discharges rose from 36% to 46% (p<0.001) between 2013 and 2014, and the proportion of 'front door' discharges occurring within 3 days rose from 56% (2013) to 68% (2014), compared with 35% and 33% for the department as a whole (p=0.006). The mean LOS at the 'front door' fell from 6.1 to 3.8 days (p=0.007). Readmissions from 'front door' discharges rose from 12% to 14% (p=0.004). The change in the configuration of the acute geriatric service was associated with more favourable discharge performance outcomes at the 'front door' but modest improvements in discharge performance for the geriatric service as a whole.

BIOFRAG - a new database for analyzing BIOdiversity responses to forest FRAGmentation.

Habitat fragmentation studies have produced complex results that are challenging to synthesize. Inconsistencies among studies may result from variation in the choice of landscape metrics and response variables, which is often compounded by a lack of key statistical or methodological information. Collating primary datasets on biodiversity responses to fragmentation in a consistent and flexible database permits simple data retrieval for subsequent analyses. We present a relational database that links such field data to taxonomic nomenclature, spatial and temporal plot attributes, and environmental characteristics. Field assessments include measurements of the response(s) (e.g., presence, abundance, ground cover) of one or more species linked to plots in fragments within a partially forested landscape. The database currently holds 9830 unique species recorded in plots of 58 unique landscapes in six of eight realms: mammals 315, birds 1286, herptiles 460, insects 4521, spiders 204, other arthropods 85, gastropods 70, annelids 8, platyhelminthes 4, Onychophora 2, vascular plants 2112, nonvascular plants and lichens 320, and fungi 449. Three landscapes were sampled as long-term time series (>10 years). Seven hundred and eleven species are found in two or more landscapes. Consolidating the substantial amount of primary data available on biodiversity responses to fragmentation in the context of land-use change and natural disturbances is an essential part of understanding the effects of increasing anthropogenic pressures on land. The consistent format of this database facilitates testing of generalizations concerning biologic responses to fragmentation across diverse systems and taxa. It also allows the re-examination of existing datasets with alternative landscape metrics and robust statistical methods, for example, helping to address pseudo-replication problems. The database can thus help researchers in producing broad syntheses of the effects of land use. The database is dynamic and inclusive, and contributions from individual and large-scale data-collection efforts are welcome.

Sensitization via healthy skin programs Th2 responses in individuals with atopic dermatitis.

Allergen-specific responses in atopic dermatitis (AD) are skewed toward a Th2 profile. However, individuals with AD have been shown to make effective virus-specific Th1 responses, raising the possibility that the skin itself contributes to driving the AD Th2 immunophenotype. Therefore, to explore the programming of immunological sensitization by the skin, we examined the outcome of sensitization through non-lesional skin of individuals with AD and healthy controls. Volunteers (controls, AD individuals with filaggrin gene (FLG) mutations (ADFM), and AD individuals without FLG mutations (ADWT)) were sensitized by cutaneous application of 2,4-dinitrochlorobenzene (DNCB), a small, highly lipophilic chemical sensitizer. At the doses tested, DNCB showed equal penetration into skin of all groups. Clinical reactions to DNCB were significantly reduced in AD. Although both controls and AD made systemic DNCB-specific Th1 responses, these were reduced in AD and associated with significantly Th2-skewed DNCB-specific T-cell responses. Th2 skewing was seen in both ADFM and ADWT, with no difference between these groups. After 3 months, DNCB-specific Th2 responses were persistent in individuals with AD, and Th1 responses persisted in controls. These data provide evidence that when antigen penetration is not limiting, AD skin has a specific propensity to Th2 programming, suggesting the existence of altered skin immune signaling that is AD-specific and independent of FLG status.