Metabolic studies on the transformation of trichodiene to trichothecene mycotoxins

Trichodiene and [14C]trichodiene have been produced in high yields by treatment of Fusarium culmorum CMI 14764 cultures with the furanocoumarin xanthotoxin. Smaller amounts of isotrichodermin (ITD) and the unsubstituted trichothecene 12,13-epoxytrichothec-9-ene (EPT) were obtained in the same way. EPT was also produced by semi-synthesis from ITD. Trichodiene (TDN) was shown to be a precursor of the trichothecene mycotoxins in F. culmorum, including EPT, ITD, calonectrin (CAL), 7a-hydroxycalonectrin (7-hydroxyCAL), 15-deacetylcalonectrin, 3-acetyldeoxynivalenol (3-AcDON) and 7,8-dihydroxycalonectrin (DHC). When large amounts of TDN were supplied, a new trichodiene metabolite was found to accumulate which was fully characterised as 12,13-epoxy-2a, 11 adihydroxytrichodiene, and given the trivial name isotrichodiol. A method for the production of 14C-labelled isotrichodiol (ITdiol) was developed, and the incorporation of ["C]ITdiol into 3-AcDON, DHC and 7-hydroxyCAL was demonstrated. Slow, acid-catalysed cyclisation of ITdiol to EPT and pre-sambucoin was demonstrated, and allylic isomerisation to both 9a- and 9p-trichodiol was also detected. Labelled pre-sambucoin was incorporated into sambucoin by F. culmorwn, and ITdiol is thus proposed as a precursor to both sambucoin and sambucinol, aswel as to the trichothecenes. A range of semi-synthetic derivatives of TDN were prepared and tested as possible inhibitors of the post-TDN biosynthesic pathway to trichothecenes in F. culmorum. In whole-cell systems all the derivatives inhibited the incorporation of labelled TDN into trichothecenes, and also initiated the production of ITdiol. One derivative, 9P, 10ß-epoxytrichodiene, was shown to be biotransformed by the fungus, undergoing 12,13-epoxidation with subsequent hydroxylation at C-3 producing 3a-hydroxy-9(3,10(3; 12,13-diepoxytrichodiene. 9ß-Trichodiol was isolated from Trichothecium roseum, and its slow, acidcatalysed cyclisation to EPT was demonstrated. 9a-Trichotriol, 9ß-trichotriol and isotrichotriol were isolated from F. culmorum for the first time, and literature assignments for the stereochemistry of the C-9 hydroxyl in trichodiol and trichotriol are reassessed. The incorporation of [`4C]ITdiol into trichothecenes in F. culmorum was found to be approximately 5 times greater than the incorporation of [14C]-913-trichotriol, and was shown to be inhibited by isotrichotriol but not by 9ß-trichodiol and 9ß-trichotriol. It is proposed that trichodiol and trichotriol are not biosynthetic intermediates in the pathway to the trichothecenes, and that they are non-enzymic metabolites produced from ITdiol and isotrichotriol, respectively, by acid-catalysed isomerisations. A new scheme for the biosynthesis of trichothecenes is proposed in which ITdiol and isotrichotriol are intermediates in the production of isotrichodermol from TDN. Two novel compounds, 15-deacetyl-7,8-dihydroxycalonectrin (15-deacetylDHC) and 8a-hydroxyisotrichodiol were isolated from F. culmorum, and 15-deacetylDHC and DHC were shown to be precursors to 3-AcDON. It is proposed that the post-cyclisation biosynthesis of 3-AcDON involves sequential oxygenation of isotrichodermol at C-15, C-7 and C-8 producing DHC, which then undergoes deacylation to 15-deacetylDHC followed by oxidation at C-8 to 3-AcDON

Synthetic RNA Silencing of Actinorhodin Biosynthesis in Streptomyces coelicolor A3(2)

We demonstrate the first application of synthetic RNA gene silencers in Streptomyces coelicolor A3(2). Peptide nucleic acid and expressed antisense RNA silencers successfully inhibited actinorhodin production. Synthetic RNA silencing was target-specific and is a new tool for gene regulation and metabolic engineering studies in Streptomyces.Peer reviewe

Vitamins D2 and D3 Have Overlapping But Different Effects on the Human Immune System Revealed Through Analysis of the Blood Transcriptome

Vitamin D is best known for its role in maintaining bone health and calcium homeostasis. However, it also exerts a broad range of extra-skeletal effects on cellular physiology and on the immune system. Vitamins D(2) and D(3) share a high degree of structural similarity. Functional equivalence in their vitamin D-dependent effects on human physiology is usually assumed but has in fact not been well defined experimentally. In this study we seek to redress the gap in knowledge by undertaking an in-depth examination of changes in the human blood transcriptome following supplementation with physiological doses of vitamin D(2) and D(3). Our work extends a previously published randomized placebo-controlled trial that recruited healthy white European and South Asian women who were given 15 µg of vitamin D(2) or D(3) daily over 12 weeks in wintertime in the UK (Nov-Mar) by additionally determining changes in the blood transcriptome over the intervention period using microarrays. An integrated comparison of the results defines both the effect of vitamin D(3) or D(2) on gene expression, and any influence of ethnic background. An important aspect of this analysis was the focus on the changes in expression from baseline to the 12-week endpoint of treatment within each individual, harnessing the longitudinal design of the study. Whilst overlap in the repertoire of differentially expressed genes was present in the D(2) or D(3)-dependent effects identified, most changes were specific to either one vitamin or the other. The data also pointed to the possibility of ethnic differences in the responses. Notably, following vitamin D(3) supplementation, the majority of changes in gene expression reflected a down-regulation in the activity of genes, many encoding pathways of the innate and adaptive immune systems, potentially shifting the immune system to a more tolerogenic status. Surprisingly, gene expression associated with type I and type II interferon activity, critical to the innate response to bacterial and viral infections, differed following supplementation with either vitamin D(2) or vitamin D(3), with only vitamin D(3) having a stimulatory effect. This study suggests that further investigation of the respective physiological roles of vitamin D(2) and vitamin D(3) is warranted

Elevation and cholera: an epidemiological spatial analysis of the cholera epidemic in Harare, Zimbabwe, 2008-2009

BACKGROUND: In highly populated African urban areas where access to clean water is a challenge, water source contamination is one of the most cited risk factors in a cholera epidemic. During the rainy season, where there is either no sewage disposal or working sewer system, runoff of rains follows the slopes and gets into the lower parts of towns where shallow wells could easily become contaminated by excretes. In cholera endemic areas, spatial information about topographical elevation could help to guide preventive interventions. This study aims to analyze the association between topographic elevation and the distribution of cholera cases in Harare during the cholera epidemic in 2008 and 2009. METHODS: We developed an ecological study using secondary data. First, we described attack rates by suburb and then calculated rate ratios using whole Harare as reference. We illustrated the average elevation and cholera cases by suburbs using geographical information. Finally, we estimated a generalized linear mixed model (under the assumption of a Poisson distribution) with an Empirical Bayesian approach to model the relation between the risk of cholera and the elevation in meters in Harare. We used a random intercept to allow for spatial correlation of neighboring suburbs. RESULTS: This study identifies a spatial pattern of the distribution of cholera cases in the Harare epidemic, characterized by a lower cholera risk in the highest elevation suburbs of Harare. The generalized linear mixed model showed that for each 100 meters of increase in the topographical elevation, the cholera risk was 30% lower with a rate ratio of 0.70 (95% confidence interval=0.66-0.76). Sensitivity analysis confirmed the risk reduction with an overall estimate of the rate ratio between 20% and 40%. CONCLUSION: This study highlights the importance of considering topographical elevation as a geographical and environmental risk factor in order to plan cholera preventive activities linked with water and sanitation in endemic areas. Furthermore, elevation information, among other risk factors, could help to spatially orientate cholera control interventions during an epidemic

EMBIO trial study protocol: left gastric artery embolisation for weight loss in patients living with obesity with a BMI 35–50 kg/m²

Introduction: Left gastric artery embolisation (LGAE) is a well-established treatment for major upper gastrointestinal (GI) bleeding when control is not established via upper GI endoscopy and recently has shown promising results for weight loss in small single arm studies. LGAE could be a treatment option in between our current tier-3 and tier-4 services for obesity. EMBIO is a National Institute for Health Research funded trial, a multicentre double-blinded randomised controlled trial between Imperial College National Health Service Trust and University College London Hospital, comparing LGAE versus Placebo procedure. The key aims of the trial is to evaluate LGAE efficacy on weight loss, its mechanism of action, safety profile and obesity-related comorbidities. / Methods and analysis: 76 participants will be recruited from the existing tier-3 database after providing informed consent. Key inclusion criteria include adults aged 18–70 with a body mass index 35–50 kg/m2 and appropriate anatomy of the left gastric artery and coeliac plexus on CT Angiogram. Key exclusion criteria included previous major abdominal and bariatric surgery, weight >150 kg, type 2 diabetes on any medications other than metformin and the use of weight modifying medications. Participants will undergo mechanistic visits 1 week prior to the intervention and 3, 6 and 12 months postintervention. Informed consent will be received from each participant and they will be randomised in a 1:1 ratio to left gastric artery embolisation and placebo treatment. Blinding strategies include the use of moderate doses of sedation, visual and auditory isolation. All participants will enter a tier-3 weight management programme postintervention. The primary analysis will estimate the difference between the groups in the mean per cent weight loss at 12 months. / Ethics and dissemination: This trial shall be conducted in full conformity with the 1964 Declaration of Helsinki and all subsequent revisions. Local research ethics approval was granted by London-Central Research Ethics Committee, (Reference 19/LO/0509) on 11 October 2019. The Medicines and Healthcare products Regulatory Agency (MHRA) issued the Letter of No Objection on 8 April 2022 (Reference CI/2022/0008/GB). The trial’s development and progress are monitored by an independent trial steering committee and data monitoring and ethics committee. The researchers plan to disseminate results at conferences, in peer- reviewed journals as well as lay media and to patient organisations. / Trial registration number: ISRCTN16158402

'Everyday memory' impairments in autism spectrum disorders

‘Everyday memory’ is conceptualised as memory within the context of day-to-day life and, despite its functional relevance, has been little studied in individuals with autism spectrum disorders (ASDs). In the first study of its kind, 94 adolescents with an ASD and 55 without an ASD completed measures of everyday memory from the Rivermead Behavioural Memory Test (RBMT) and a standard word recall task (Children’s Auditory Verbal Learning Test-2: CAVLT-2). The ASD group showed significant impairments on the RBMT, including in prospective memory, alongside impaired performance on the CAVLT-2. Social and communication ability was significantly associated with prospective remembering in an everyday memory context but not with the CAVLT-2. The complex nature of everyday memory and its relevance to ASD is discussed

Do emotional difficulties and peer problems hew together from childhood to adolescence? The case of children with a history of developmental language disorder (DLD)

Children and adolescents with developmental language disorder (DLD) are, overall, vulnerable to difficulties in emotional adjustment and in peer relations. However, previous research has shown that different subgroups follow different trajectories in respect of quality of peer relations. Less is known of the trajectories of emotional development. We consider here the possibility that development in these two domains is interrelated: that is, the trajectories of emotional and peer problems will proceed in parallel. We conducted longitudinal joint trajectories analyses of emotional and peer relations in a sample of young people identified as having DLD at age 7 years and seen at intervals up to 16 years. Potential influences on joint trajectory group membership were examined. Findings revealed five distinct joint trajectories. Emotional and peer difficulties do hew together from childhood to adolescence for just over half of the sample, but not all. The variables most clearly associated with group membership were pragmatic language ability, prosociality and parental mental health. This is the first study to examine joint longitudinal trajectories of emotional and peer difficulties in individuals with DLD. We demonstrate that development in individuals with DLD is heterogeneous and identify three key variables associated with personal and social adjustment from childhood to adolescence. Theoretical and clinical implications of these findings are discussed

Improving Health and Building Human Capital Through an Effective Primary Care System

To improve population health, one must put emphasis on reducing health inequities and enhancing health protection and disease prevention, and early diagnosis and treatment of diseases by tackling the determinants of health at the downstream, midstream, and upstream levels. There is strong theoretical and empirical evidence for the association between strong national primary care systems and improved health indicators. The setting approach to promote health such as healthy schools, healthy cities also aims to address the determinants of health and build the capacity of individuals, families, and communities to create strong human and social capitals. The notion of human and social capitals begins to offer explanations why certain communities are unable to achieve better health than other communities with similar demography. In this paper, a review of studies conducted in different countries illustrate how a well-developed primary health care system would reduce all causes of mortalities, improve health status, reduce hospitalization, and be cost saving despite a disparity in socioeconomic conditions. The intervention strategy recommended in this paper is developing a model of comprehensive primary health care system by joining up different settings integrating the efforts of different parties within and outside the health sector. Different components of primary health care team would then work more closely with individuals and families and different healthy settings. This synergistic effect would help to strengthen human and social capital development. The model can then combine the efforts of upstream, midstream, and downstream approaches to improve population health and reduce health inequity. Otherwise, health would easily be jeopardized as a result of rapid urbanization

Arabidopsis Plasmodesmal Proteome

The multicellular nature of plants requires that cells should communicate in order to coordinate essential functions. This is achieved in part by molecular flux through pores in the cell wall, called plasmodesmata. We describe the proteomic analysis of plasmodesmata purified from the walls of Arabidopsis suspension cells. Isolated plasmodesmata were seen as membrane-rich structures largely devoid of immunoreactive markers for the plasma membrane, endoplasmic reticulum and cytoplasmic components. Using nano-liquid chromatography and an Orbitrap ion-trap tandem mass spectrometer, 1341 proteins were identified. We refer to this list as the plasmodesmata- or PD-proteome. Relative to other cell wall proteomes, the PD-proteome is depleted in wall proteins and enriched for membrane proteins, but still has a significant number (35%) of putative cytoplasmic contaminants, probably reflecting the sensitivity of the proteomic detection system. To validate the PD-proteome we searched for known plasmodesmal proteins and used molecular and cell biological techniques to identify novel putative plasmodesmal proteins from a small subset of candidates. The PD-proteome contained known plasmodesmal proteins and some inferred plasmodesmal proteins, based upon sequence or functional homology with examples identified in different plant systems. Many of these had a membrane association reflecting the membranous nature of isolated structures. Exploiting this connection we analysed a sample of the abundant receptor-like class of membrane proteins and a small random selection of other membrane proteins for their ability to target plasmodesmata as fluorescently-tagged fusion proteins. From 15 candidates we identified three receptor-like kinases, a tetraspanin and a protein of unknown function as novel potential plasmodesmal proteins. Together with published work, these data suggest that the membranous elements in plasmodesmata may be rich in receptor-like functions, and they validate the content of the PD-proteome as a valuable resource for the further uncovering of the structure and function of plasmodesmata as key components in cell-to-cell communication in plants

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700