Investigation of taste tainting in salmon flesh in the Ribble catchment

This report presents the findings of the first phase of an investigation into the cause(s) of taints in salmonid fish in the River Ribble, commissioned by the North West Region of the Environment Agency. There have been reports of tainting in fish taken from both the estuary and the freshwater river for many years, but the contaminants involved and their source and transport pathway are unknown. Tainting by phenols has been of specific concern in the past. The work programme comprised: examination of tainting reports; collection of salmonids; their submission for taste testing; literature review; analysis of fish flesh using gas chromatography-mass spectrometry (GCMS) and analysis of river bed sediments. From enquiries, three common descriptors of the 'taint' were identified: disinfectanty; diesely; and muddy. The incidence of taints appears transient/irregular and may therefore relate to the incidence of discharges and specific threshold concentrations of pollutants. The literature review showed that a wide range of organic compounds including many industrial chemicals, and others which are naturally occurring, can taint fish flesh. Taste testing confirmed the presence of tainted salmon and trout in the Ribbie Catchment. It identified a low incidence of 'untainted' fish but demonstrated the 'taint' to be not specific to one tainting substance. Differences were found both between the species and fish from different parts of the catchment. Overall, most fish exhibited an unpleasant flavour, though this may have been influenced to some extent by the fact that most were sexually mature. The worst tainting was found in trout from the river Calder: a soapy/chemical aftertaste. An unpleasant earthy/musty flavour distinguished the salmon from the trout. Phenol was shown to have been a minor issue during the present study, whilst no hydrocarbon taints were identified. Examination of tissue from the eight salmon exhibiting the worst taints revealed the presence of aromatic hydrocarbons, but no phenolic compounds. Other notable substances present in the fish were siioxanes and benzophenone. Data from sediment analysis is presented which shows the main compounds present to be aromatic and polyaromatic hydrocarbons, that concentrations at two locations R. Darwen and R. Calder were significantly higher than at other sites, and that some phenolic compounds were detected at low levels. A paucity of fish flesh taste descriptors linked to specific compounds prevented an obvious correlation to be made between the tastes observed and the organic compounds detected. Descriptors frequently used by the taste testing panel (e.g. earthy, musty, astringency, chemical) cannot be linked to any of the compounds identified in the tissue analyses. No taste information was available from the literature on siioxanes. Aromatic hydrocarbons though present in tissue and sediments were not identified as tainting

Neuropsychological and functional outcomes in recent-onset major depression, bipolar disorder and schizophrenia-spectrum disorders: a longitudinal cohort study

Functional disability is the lead contributor to burden of mental illness. Cognitive deficits frequently limit functional recovery, although whether changes in cognition and disability are longitudinally associated in recent-onset individuals remains unclear. Using a prospective, cohort design, 311 patients were recruited and assessed at baseline. One hundred and sixty-seven patients met eligibility criteria (M = 21.5 years old, s.d. = 4.8) and returned for follow-up (M = 20.6 months later, s.d. = 7.8). Two-hundred and thirty participants were included in the final analysis, comprising clinically stable patients with major depression (n = 71), bipolar disorder (BD; n = 61), schizophrenia-spectrum disorders (n = 35) and 63 healthy controls. Neuropsychological functioning and self-rated functional disability were examined using mixed-design, repeated-measures analysis, across diagnoses and cognitive clusters, covarying for relevant confounds. Clinical, neuropsychological and functional changes did not differ between diagnoses (all P40.05). Three reliable neuropsychological subgroups emerged through cluster analysis, characterized by psychomotor slowing, improved sustained attention, and improved verbal memory. Controlling for diagnosis and changes in residual symptoms, clusters with improved neuropsychological functioning observed greater reductions in functional disability than the psychomotor slowing cluster, which instead demonstrated a worsening in disability (Po0.01). Improved sustained attention was independently associated with greater likelihood of follow-up employment (Po0.01). Diagnosis of BD uniquely predicted both follow-up employment and independent living. Neuropsychological course appears to be independently predictive of subjective and objective functional outcomes. Importantly, cognitive phenotypes may reflect distinct pathophysiologies shared across major psychiatric conditions, and be ideal targets for personalized early intervention

Circadian rhythmicity in emerging mood disorders: state or trait marker?

Background: Circadian rhythm disturbances overlap with the symptoms of mood episodes and may trigger or prolong mood symptoms. There is limited research on the role of circadian disturbances in mood disorders in young people and/or first episode cases of unipolar and bipolar disorders. Methods: Actigraphy was undertaken for about 14 days in 63 post-pubertal individuals aged 13–25 years with a recent onset of a mood disorder meeting recognised diagnostic criteria. We examined associations between three easily interpretable markers of circadian rhythm activity (amplitude, acrophase and rhythmicity index) and demography and clinical characteristics. Then, circadian markers were compared between diagnostic groups, controlling for potential confounders. Results: Longer duration of illness was correlated with reduced circadian rhythmicity and lower levels of activity over 24 h. A delay in the timing of maximum activity was associated with the level of manic but not depressive symptoms. The circadian rhythmicity index differentiated unipolar from bipolar cases, and in bipolar but not unipolar disorder, the rhythmicity was less robust in those with more severe manic or depressive symptoms. Conclusions: Less robust circadian rhythmicity, especially associated with increasing symptom severity, may represent a more specific or a trait marker of young people with mood disorders who are at higher risk of a bipolar course of illness

TarO : a target optimisation system for structural biology

This work was funded by the UK Biotechnology and Biological Sciences Research Council (BBSRC) Structural Proteomics of Rational Targets (SPoRT) initiative, (Grant BBS/B/14434). Funding to pay the Open Access publication charges for this article was provided by BBSRC.TarO (http://www.compbio.dundee.ac.uk/taro) offers a single point of reference for key bioinformatics analyses relevant to selecting proteins or domains for study by structural biology techniques. The protein sequence is analysed by 17 algorithms and compared to 8 databases. TarO gathers putative homologues, including orthologues, and then obtains predictions of properties for these sequences including crystallisation propensity, protein disorder and post-translational modifications. Analyses are run on a high-performance computing cluster, the results integrated, stored in a database and accessed through a web-based user interface. Output is in tabulated format and in the form of an annotated multiple sequence alignment (MSA) that may be edited interactively in the program Jalview. TarO also simplifies the gathering of additional annotations via the Distributed Annotation System, both from the MSA in Jalview and through links to Dasty2. Routes to other information gateways are included, for example to relevant pages from UniProt, COG and the Conserved Domains Database. Open access to TarO is available from a guest account with private accounts for academic use available on request. Future development of TarO will include further analysis steps and integration with the Protein Information Management System (PIMS), a sister project in the BBSRC Structural Proteomics of Rational Targets initiative.Publisher PDFPeer reviewe

Derivation of dose/volume constraints for the anorectum from clinician and patient-reported outcomes in the CHHiP trial of radiotherapy fractionation.

BACKGROUND:The CHHiP trial randomised 3216 men with localised prostate cancer (1:1:1) to three radiotherapy fractionation schedules: 74Gy/37 fractions (f) over 7.4 weeks, 60Gy/20f/4 weeks and 57Gy/19f/3.8 weeks. Literature-based dose constraints were applied with arithmetic adjustment for the hypofractionated arms. This study aimed to derive anorectal dose constraints using prospectively-collected clinician-reported outcomes (CRO) and patient-reported outcomes (PRO) and to assess the added predictive value of spatial dose metrics. METHODS:A case-control study design was used, seven CRO and five PRO bowel symptoms were evaluated. Cases experienced a moderate or worse symptom 1-5 years post-radiotherapy, and did not have the symptom pre-radiotherapy. Controls did not experience the symptom at baseline, or between 1-5 years post-radiotherapy. The anorectum was re-contoured from the anal verge to the recto-sigmoid junction; dose/volume parameters were extracted. Univariate logistic regression, atlases of complication indices and bootstrapped receiver-operating-characteristic (ROC) analysis (1000 replicates, balanced outcomes) were used to derive dose constraints for the whole cohort (hypofractionated schedules were converted to 2Gy equivalent schedules using α/β=3Gy) and separate hypofractionated/conventional fractionation cohorts. Only areas under the curve (AUC) with 95% confidence interval lower limits >0.5 were considered statistically significant. Any constraint derived in <95-99% of bootstraps was excluded. RESULTS:Statistically significant dose constraints were derived for CRO, but not PRO. Intermediate to high doses were important for rectal bleeding whereas intermediate doses were important for increased bowel frequency, faecal incontinence and rectal pain. Spatial dose metrics did not improve prediction of CRO or PRO. A new panel of dose constraints for hypofractionated schedules to 60Gy or 57Gy are V20Gy<85%, V30Gy<57%, V40Gy<38%, V50Gy<22% and V60Gy<0.01%. CONCLUSIONS:Dose constraints differed between symptoms, indicating potentially different pathogenesis of radiation-induced side effects. Derived dose constraints were stricter than those used in CHHiP and may reduce bowel symptoms post-radiotherapy

Periplasmic depolymerase provides insight into ABC transporter-dependent secretion of bacterial capsular polysaccharides

This work was supported in part by grants from the Canadian Institutes of Health Research (FDN_148364) (to C.W.). S.D.L. is a recipient of a Natural Science and Engineering Research Council Alexander Graham Bell Canada Graduate Scholarship and Michael Smith Foreign Study Supplement. C.W. is a Canada Research Chair. J.H.N. is a Wellcome Trust Investigator (100209/Z/12/Z).Capsules are surface layers of hydrated capsular polysaccharides (CPSs) produced by many bacteria. The human pathogen Salmonella enterica serovar Typhi produces "Vi antigen" CPS, which contributes to virulence. In a conserved strategy used by bacteria with diverse CPS structures, translocation of Vi antigen to the cell surface is driven by an ATP-binding cassette (ABC) transporter. These transporters are engaged in heterooligomeric complexes proposed to form an enclosed translocation conduit to the cell surface, allowing the transporter to power the entire process. We identified Vi antigen biosynthesis genetic loci in genera of the Burkholderiales, which are paradoxically distinguished from S. Typhi by encoding VexL, a predicted pectate lyase homolog. Biochemical analyses demonstrated that VexL is an unusual metal-independent endolyase with an acidic pH optimum that is specific for Oacetylated Vi antigen. A 1.22-Å crystal structure of the VexL-Vi antigen complex revealed features which distinguish common secreted catabolic pectate lyases from periplasmic VexL, which participates in cell-surface assembly. VexL possesses a right-handed parallel beta-superhelix, of which one face forms an electropositive glycan-binding groove with an extensive hydrogen bonding network that includes Vi antigen acetyl groups and confers substrate specificity. VexL provided a probe to interrogate conserved features of the ABC transporter-dependent export model. When introduced into S. Typhi, VexL localized to the periplasm and degraded Vi antigen. In contrast, a cytosolic derivative had no effect unless export was disrupted. These data provide evidence that CPS assembled in ABC transporter-dependent systems is actually exposed to the periplasm during envelope translocation.Publisher PDFPeer reviewe

Crystallization and preliminary diffraction analysis of Wzi, a member of the capsule export and assembly pathway in Escherichia coli

Wzi is a membrane protein from E. coli thought to be involved in the attachment of capsular polysaccharides to the bacterial surface. This reports describes recombinant Wzi’s purification, crystallization and the results of initial diffraction studies

A prospective evaluation of the predictive value of faecal calprotectin in quiescent Crohn’s disease

Background: The faecal calprotectin (FC) test is a non-invasive marker for gastrointestinal inflammation. Aim: To determine whether higher FC levels in individuals with quiescent Crohn’s disease are associated with clinical relapse over the ensuing 12 months.&lt;p&gt;&lt;/p&gt; Methods: A single centre prospective study was undertaken in Crohn's disease patients in clinical remission attending for routine review. The receiver operating characteristic (ROC) curve for the primary endpoint of clinical relapse by 12 months, based on FC at baseline, was calculated. Kaplan-Meier curves of time to relapse were based on the resulting optimal FC cutoff for predicting relapse.&lt;p&gt;&lt;/p&gt; Results: Of 97 patients recruited, 92 were either followed up for 12 months without relapsing, or reached the primary endpoint within that period. Of these, 10 (11%) had relapsed by 12 months. The median FC was lower for non-relapsers, 96µg/g (IQR 39-237), than for relapsers, 414µg/g (IQR 259-590), (p=0.005). The area under the ROC curve to predict relapse using FC was 77.4%. An optimal cutoff FC value of 240µg/g to predict relapse of quiescent Crohn’s had sensitivity of 80.0% and specificity of 74.4%. Negative predictive value was 96.8% and positive predictive value was 27.6%. FC≥240μg/g was associated with likelihood of relapse 5.7 (95% CI 1.9-17.3) times higher within 2.3 years than lower values (p=0.002).&lt;p&gt;&lt;/p&gt; Conclusions: In this prospective dataset, FC appears to be a useful, non-invasive tool to help identify quiescent Crohn’s disease patients at a low risk of relapse over the ensuing 12 months. FC of 240µg/g was the optimal cutoff in this cohort.&lt;p&gt;&lt;/p&gt

Benefits of early treatment with natalizumab: A real-world study

BACKGROUND: The impact of early versus later high-efficacy disease-modifying therapy (DMT) in patients with multiple sclerosis (MS) is uncertain. This study reported the association of early versus later natalizumab treatment with real-world clinical outcomes in MS patients. METHODS: The study included 661 participants diagnosed with MS in 1994 or later from 7 US centers participating in the MS Partners Advancing Technology for Health Solutions (MS PATHS) network. Time to natalizumab treatment between diagnosis and first infusion (TTNT) was determined from the Tysabri Outreach: Unified Commitment to Health (TOUCH) registry. Clinical outcomes were defined using neuroperformance tests included in the Multiple Sclerosis Performance Test. Associations were tested using TTNT as a categorical and continuous variable. Linear mixed models addressed within-subject and within-site clustering. RESULTS: TTNT varied from 0.1 to 19.8 years (median [interquartile range] 4.2 [1.8, 9.0] years). A significant association between later natalizumab use and worse outcomes was demonstrated for walking speed (p \u3c 0.001), processing speed (p \u3c 0.001), manual dexterity (p \u3c 0.001), brain atrophy (p = 0.001), and T2 lesion volume (p = 0.02). Covariate-adjusted modelling of a sensitivity population diagnosed with MS in 2006 or later (n = 424) demonstrated significant associations between longer TTNT and worse walking speed (p \u3c 0.05), processing speed (p \u3c 0.001), and manual dexterity (p \u3c 0.001). CONCLUSION: Later initiation of natalizumab was associated with worse clinical and radiologic imaging outcomes. Thus, high-efficacy DMT may have greater benefit when started earlier in MS patients. These results provide a rationale for randomized controlled trials to further assess the impact of early highly-effective DMT use versus later escalation of therapy