N-Terminal Pro-Brain Type Natriuretic Peptide Predicts Cardiovascular Events Independently of Arterial Stiffness, Assessed By Carotid-to-Femoral Pulse Wave Velocity, in Apparently Healthy Subjects.

AIM: This study aimed to evaluate whether N-terminal pro-brain natriuretic peptide (NT-proBNP) and carotid-to-femoral pulse wave velocity (PWV) carried independent prognostic value in predicting cardiovascular events in apparently healthy individuals beyond traditional risk factors. METHODS: A total of 1,872 participants aged 41, 51, 61, or 71 years from the MONItoring of trends and determinants in CArdiovascular disease (MONICA) study were included. Traditional risk factors were assessed, including: smoking status; mean systolic and diastolic blood pressure; body mass index; fasting plasma glucose; serum triglycerides; total, high-density, and low-density lipoprotein cholesterol; NT-proBNP; and PWV. The principal endpoint that was assessed during 16 years of follow-up was a composite of major adverse cardiovascular events (MACE). The secondary endpoints were cardiovascular mortality (CVM), hospitalisation for coronary artery disease (CAD), and a composite of hospitalisation for heart failure (HF) or atrial fibrillation (AF). RESULTS: At baseline, NT-proBNP was associated with PWV (ß=0.14; p<0.001), but not after adjustment for traditional risk factors (ß=-0.01; p=0.67). In models including traditional risk factors and PWV, NT-proBNP was associated with all four outcomes (HRMACE=1.33, 95% CI 1.16-1.52; HRCVM=2.02, 95% CI 1.65-2.48; HRCAD=1.29, 95% CI 1.07-1.55; and HRHF or AF=1.79, 95% CI 1.40-2.28). In the same model, PWV was only associated with CVM (HRCVM=1.20, 95% CI 1.01-1.41). No interactions between NT-proBNP and PWV were found. N-terminal pro-brain natriuretic peptide significantly improved net reclassification (NRI) for MACE (NRI=0.12; p=0.03), CVM (NRI=0.33; p<0.001), and HF or AF (NRI=0.33; p<0.001) beyond traditional risk factors, while PWV did not aid in net reclassification improvement for any endpoint. CONCLUSIONS: In apparently healthy individuals, NT-proBNP and PWV predicted cardiovascular events independently. N-terminal pro-brain natriuretic peptide improved reclassification for the prediction of MACE, CVM, and hospitalisation for HF or AF beyond traditional risk factors, while PWV did not.

Sex- and age-related differences in the predictive capability of circulating biomarkers: from the MONICA 10 cohort.

OBJECTIVES: The purpose of this study was to assess whether high-sensitivity C-reactive protein (hs-CRP), N-terminal pro-brain natriuretic peptide (NT-proBNP), and soluble urokinase plasminogen activator receptor (suPAR) differed in their ability to predict cardiovascular outcomes beyond traditional risk factors in younger and older men and women without known cardiovascular disease. Design. Prospective population-based cohort study of 1951 individuals from the MONItoring of trends and determinants in Cardiovascular disease (MONICA) study, examined 1993-1994. Participants were stratified into four groups based on sex and age. Subjects aged 41 or 51 years were classified as younger; those aged 61 or 71 years were classified as older. The principal endpoint was death from cardiovascular causes. Predictive capabilities of biomarkers were tested using Cox proportional-hazards regression, Harrell's concordance-index, net reclassification improvement, and classification and regression tree (CART) analysis. Results. Median follow-up was 18.5 years, during which 19/597 younger men, 100/380 older men, 12/607 younger women, and 46/367 older women had died from a cardiovascular cause. NT-proBNP was independently associated with death from cardiovascular causes among all participants (p ≤ .02) except younger women (p = .70), whereas hs-CRP was associated with this endpoint in men (p ≤ .007), and suPAR in older men only (p < .001). None of the biomarkers improved discrimination ability beyond traditional risk factors (p ≥ .07). However, NT-proBNP enhanced reclassification in men and older women. CART-analysis showed that NT-proBNP was generally of greater value among men, and suPAR among women. Conclusions. Hs-CRP, NT-proBNP, and suPAR displayed different associations with cardiovascular death among apparently healthy younger and older men and women.

Lifetime costs and lifetime net public expenditures of smoking.

BACKGROUND: Current estimates of lifetime costs of smoking are largely based on model analyses using etiologic fractions for a variety of diseases or Markov chain models. Direct estimation studies based on individual data for health costs by smoking status over a lifetime are non-existent. METHODS: We estimated lifetime costs in a societal perspective of 18-year-old daily-smokers (continuing smoking throughout adult life) and never-smokers in Denmark, as well as lifetime public expenditures in the two groups. Main outcomes were lifetime net public expenditures and lifetime health costs according to OECD definitions and lifetime earned incomes. Estimates of these outcomes were based on registries containing individual-level data. Confounder-adjusted differences between daily-smokers and never-smokers were interpreted as smoking-attributable lifetime public expenditures and costs. RESULTS: The net lifetime public expenditure is, on average, €20 520 higher for male 18-year-old daily-smokers than for never-smokers, but €9771 lower, for female daily-smokers compared with never-smokers. In male 18-year-old daily-smokers, average lifetime health costs are €9921 higher and average lifetime earned incomes are €91 159 lower than for never-smokers. The corresponding figures are €5849 higher and €23 928 lower, respectively, for women. CONCLUSION: 18-year-old male daily-smokers are net public spenders over their lifetime compared with never-smokers, while the opposite applies for women. In Denmark, smoking is associated with higher lifetime health costs for society and losses in earned incomes-both for men and women.

Association between antecedent blood pressure, hypertension-mediated organ damage and cardiovascular outcome.

Purpose: The objective of this study was to test if combining antecedent systolic blood pressure (SBP) with traditional risk factors and hypertension-mediated organ damage (HMOD) improves risk stratification for subsequent cardiovascular disease.Materials and methods: 1910 subjects participated in this study. Antecedent SBP was defined as the average of measurements obtained in 1982 and in 1987. Current SBP was obtained in 1993. HMOD were examined in 1993. HMOD was defined as either atherosclerotic plaque(s), increased pulse wave velocity, increased urine albumin creatinine ratio (above the 90th percentile) or left ventricular hypertrophy. Major adverse cardiovascular events (MACE) including myocardial infarction, cerebrovascular disease, heart failure and arrhythmia were obtained from national registries.Results: Subjects were divided into two age categories: a middle-aged group (aged 41 or 51) and an older group (aged 61 or 71). From 1993 to 2010, 425 events were observed. In multivariable analysis with both current and antecedent SBP adjusted for traditional risk factors, current SBP was associated with each measure of HMOD whilst antecedent SBP was not significantly associated with urine albumin creatinine ratio in the older group, LVMI in the middle-aged group, or the presence of plaque in any of the age groups (all p > 0.15). When current and antecedent SBP were evaluated together, current SBP was not associated with MACE in the middle-aged subgroup [HR = 1.09 (0.96-1.22), p = 0.18] but remained associated with MACE in the older subgroup [HR = 1.21 (1.10-1.34), p < 0.01]. Contrariwise, antecedent SBP was only associated with MACE in the middle-aged subgroup [HR = 1.24 (1.04-1.48), p = 0.02]. Adding antecedent SBP to traditional risk factors did not improve the predictive accuracy of the survival model.Conclusion: In healthy non-medicated middle-aged subjects, antecedent SBP is associated with cardiovascular outcome independently of current BP, traditional risk factors and HMOD. However, improvement in risk stratification seems to be limited.

Costs associated with adverse events among acute patients.

BACKGROUND: The aim of this study was to analyse the additional treatment costs of acute patients admitted to a Danish hospital who suffered an adverse event (AE) during in-hospital treatment. METHODS: A matched case-control design was utilised. Using a combination of trigger words and patient record reviews 91 patients exposed to AEs were identified. Controls were identified among patients admitted to the same department during the same 20-month period. The matching was based on age, gender, and main diagnosis. Cost data was extracted from the Danish National Cost Database for four different periods after beginning of the admission. RESULTS: Patients exposed to an AE were associated with higher mean cost of EUR 9505 during their index admission (p = 0.014). For the period of 6 months from the beginning of the admission minus the admission itself they were associated with higher mean cost of EUR 4968 (p = 0.016). For the period from the 7th month until the end of the 12th month there was no statistically significant difference (p = 0.104). For the total period of 12 month, patients exposed to an AE were associated with statistically significant higher mean cost of EUR 13,930 (p = 0.001). CONCLUSIONS: AEs are associated with significant hospital costs. Our findings suggest that a follow-up period of 6 months is necessary when investigating the costs associated with AEs among acute patients. Further research of specific types of AEs and the costs of preventing these types of AEs would improve the understanding of the relationship between adverse events and costs.

An extracellular siderophore is required to maintain the mutualistic interaction of Epichloë festucae with Lolium perenne.

We have identified from the mutualistic grass endophyte Epichloë festucae a non-ribosomal peptide synthetase gene (sidN) encoding a siderophore synthetase. The enzymatic product of SidN is shown to be a novel extracellular siderophore designated as epichloënin A, related to ferrirubin from the ferrichrome family. Targeted gene disruption of sidN eliminated biosynthesis of epichloënin A in vitro and in planta. During iron-depleted axenic growth, ΔsidN mutants accumulated the pathway intermediate N(5)-trans-anhydromevalonyl-N(5)-hydroxyornithine (trans-AMHO), displayed sensitivity to oxidative stress and showed deficiencies in both polarized hyphal growth and sporulation. Infection of Lolium perenne (perennial ryegrass) with ΔsidN mutants resulted in perturbations of the endophyte-grass symbioses. Deviations from the characteristic tightly regulated synchronous growth of the fungus with its plant partner were observed and infected plants were stunted. Analysis of these plants by light and transmission electron microscopy revealed abnormalities in the distribution and localization of ΔsidN mutant hyphae as well as deformities in hyphal ultrastructure. We hypothesize that lack of epichloënin A alters iron homeostasis of the symbiotum, changing it from mutually beneficial to antagonistic. Iron itself or epichloënin A may serve as an important molecular/cellular signal for controlling fungal growth and hence the symbiotic interaction.

Metabolite analysis of the effects of elevated CO2 and nitrogen fertilization on the association between tall fescue (Schedonorus arundinaceus) and its fungal symbiont Neotyphodium coenophialum.

Atmospheric CO2 is expected to increase to between 550 ppm and 1000 ppm in the next century. CO2-induced changes in plant physiology can have ecosystem-wide implications and may alter plant-plant, plant-herbivore and plant-symbiont interactions. We examined the effects of three concentrations of CO2 (390, 800 and 1000 ppm) and two concentrations of nitrogen fertilizer (0.004 g N/week versus 0.2 g N/week) on the physiological response of Neotyphodium fungal endophyte-infected and uninfected tall fescue plants. We used quantitative PCR to estimate the concentration of endophyte under altered CO2 and N conditions. We found that elevated CO2 increased the concentration of water-soluble carbohydrates and decreased the concentration of plant total amino acids in plants. Fungal-derived alkaloids decreased in response to elevated CO2 and increased in response to nitrogen fertilization. Endophyte concentration (expressed as the number of copies of an endophyte-specific gene per total genomic DNA) increased under elevated CO2 and nitrogen fertilization. The correlation between endophyte concentration and alkaloid production observed at ambient conditions was not observed under elevated CO2. These results suggest that nutrient exchange dynamics important for maintaining the symbiotic relationship between fungal endophytes and their grass hosts may be altered by changes in environmental variables such as CO2 and nitrogen fertilization.

Analysis of low molecular weight metabolites in tea using mass spectrometry-based analytical methods.

Tea is the second most consumed beverage in the world after water and there are numerous reported health benefits as a result of consuming tea, such as reducing the risk of cardiovascular disease and many types of cancer. Thus, there is much interest in the chemical composition of teas, for example; defining components responsible for contributing to reported health benefits; defining quality characteristics such as product flavor; and monitoring for pesticide residues to comply with food safety import/export requirements. Covered in this review are some of the latest developments in mass spectrometry-based analytical techniques for measuring and characterizing low molecular weight components of tea, in particular primary and secondary metabolites. The methodology; more specifically the chromatography and detection mechanisms used in both targeted and non-targeted studies, and their main advantages and disadvantages are discussed. Finally, we comment on the latest techniques that are likely to have significant benefit to analysts in the future, not merely in the area of tea research, but in the analytical chemistry of low molecular weight compounds in general.

Functional characterisation and transcript analysis of an alkaline phosphatase from the arbuscular mycorrhizal fungus Funneliformis mosseae.

Alkaline phosphatases (ALP) in arbuscular mycorrhizal (AM) fungi have been suggested to be involved in transfer of phosphate from the mycorrhizal fungus to the host plant, but exact mechanisms are still unknown, partially due to the lack of molecular information. We isolated a full-length cDNA (FmALP) from the AM fungus Funneliformis mosseae (syn. Glomus mosseae) showing similarity with putative ALP genes from Rhizophagus intraradices (syn. Glomus intraradices) and Gigaspora margarita. For functional characterisation FmALP was expressed heterologously in the yeast Pichia pastoris. The recombinant FmALP protein had a pH optimum of 9.5, and catalysed the hydrolysis of glycerolphosphate and, to a lesser extent of glucose-1- and 6-phosphate, confirming it to be an alkaline phosphatase belonging to the family of alkaline phosphomonoesterases (EC 3.1.3.1). FmALP did not catalyse the hydrolysis of ATP or polyP. Relative FmALP transcript levels were analysed in intra- and extraradical hyphae isolated from F. mosseae infected ryegrass (Lolium perenne) using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). FmALP was highly expressed in intraradical hyphae at low P(i) supply, and its expression was repressed by high P(i) supply. Taken together this study provides evidence for mycorrhizal alkaline phosphatases playing a role in P mobilisation from organic substrates under P starvation conditions.

Expression of the R2R3-MYB transcription factor TaMYB14 from Trifolium arvense activates proanthocyanidin biosynthesis in the legumes Trifolium repens and Medicago sativa.

Proanthocyanidins (PAs) are oligomeric flavonoids and one group of end products of the phenylpropanoid pathway. PAs have been reported to be beneficial for human and animal health and are particularly important in pastoral agricultural systems for improved animal production and reduced greenhouse gas emissions. However, the main forage legumes grown in these systems, such as Trifolium repens and Medicago sativa, do not contain any substantial amounts of PAs in leaves. We have identified from the foliar PA-accumulating legume Trifolium arvense an R2R3-MYB transcription factor, TaMYB14, and provide evidence that this transcription factor is involved in the regulation of PA biosynthesis in legumes. TaMYB14 expression is necessary and sufficient to up-regulate late steps of the phenylpropanoid pathway and to induce PA biosynthesis. RNA interference silencing of TaMYB14 resulted in almost complete cessation of PA biosynthesis in T. arvense, whereas Nicotiana tabacum, M. sativa, and T. repens plants constitutively expressing TaMYB14 synthesized and accumulated PAs in leaves up to 1.8% dry matter. Targeted liquid chromatography-multistage tandem mass spectrometry analysis identified foliar PAs up to degree of polymerization 6 in leaf extracts. Hence, genetically modified M. sativa and T. repens plants expressing TaMYB14 provide a viable option for improving animal health and mitigating the negative environmental impacts of pastoral animal production systems.

Mathematical model of fructan biosynthesis and polymer length distribution in plants.

BACKGROUND AND AIMS: There are many unresolved issues concerning the biochemistry of fructan biosynthesis. The aim of this paper is to address some of these by means of modelling mathematically the biochemical processes. METHODS: A model has been constructed for the step-by-step synthesis of fructan polymers. This is run until a steady state is achieved for which a polymer distribution is predicted. It is shown how qualitatively different distributions can be obtained. KEY RESULTS: It is demonstrated how a set of experimental results on polymer distribution can by simulated by a simple parameter adjustments. CONCLUSIONS: Mathematical modelling of fructan biosynthesis can provide a useful tool for helping elucidate the details of the biosynthetic processes.

The cost effectiveness of telephone counselling to aid smoking cessation in Denmark: a modelling study.

AIM: To assess the cost-effectiveness of the Danish smoking cessation telephone service "quitline". METHODS: The study was based on the number of quitline callers in 2005. The outcome was measured as costs per life year saved (LYS) based on the assessment in 2001 of continued abstinence over a 12-month period (19.0%) and point prevalence of abstinence at 12 months of follow up (29.7%), respectively. The costs per LYS are estimated as the annual running costs of reactive telephone counselling service divided by the total number of LYS, which has been estimated as the difference between current smokers' and ex-smokers' life expectancies according to age group and gender based on Danish smoking proportions, relative risks of smoking-related mortality of all causes, and standard life tables. RESULTS: A total of 511 ex-smokers have been estimated to gain 2172 life years based on continued abstinence over 12 months. Using the point prevalence abstinence at 12 months, 799 ex-smokers are estimated to gain 3394 life years. Discounting LYS at 3% p.a., the costs per LYS are €213 for ex-smokers with continued abstinence and €137 for ex-smokers with point prevalence abstinence. The sensitivity analysis for a worst-case scenario indicates that the costs per LYS are €1199. For comparison the average costs per LYS of smoking cessation interventions in other Danish settings are €1592 (95% CI €1547-1636). CONCLUSIONS: The Danish reactive telephone counselling to aid smoking cessation appears to be cost-effective in comparison with other Danish smoking cessation interventions.

B7-H4-Ig treatment of normal mice changes lymphocyte homeostasis and increases the potential of regulatory T cells.

Enteroantigens (eAgs) drive tolerogenic and inflammatory immune responses in the gut and are of importance for sustained immune homeostasis in colonic mucosa. Decline of regulatory activity in the gut mucosa might result in chronic colitis. B7-H4 is a co-inhibitory receptor expressed by professional antigen-presenting cells. By delivering signal 2 during T cell activation, it inhibits T cell proliferation and inflammation. In this study, we have used a newly developed B7-H4-Ig fusion protein and evaluated its effect on eAg-activated effector and regulatory T cells (Treg) in vitro and in vivo. T cells were recovered from the mesenteric lymph nodes (MLNs) of untreated or B7-H4-Ig-treated BALB/c mice. Treatment of cells in vitro did neither affect the proliferation of effector T cells nor the function of Tregs. In vivo, B7-H4 treatment increased the total number of MLN-derived CD4⁺ and CD8⁺ T cell subsets as well as the functional activity of MLN-derived Tregs, whereas the proliferative activity of eAg or alloantigen specific effector T cells was not influenced, although treatment resulted in less secretion of inflammatory cytokines and chemokines from these cells. B7-H4-Ig treatment of severe combined immune-deficient (SCID) mice undergoing T cell transfer colitis did not influence the course of disease probably reflecting the lack of Tregs in this model of chronic colitis. In conclusion, we show that treatment with B7-H4-Ig in vivo changes lymphocyte homeostasis and increases the regulatory potential in normal mice, but does not affect the course of disease development in SCID mice undergoing T cell transfer colitis.

Carbon anhydrase IX specific immune responses in patients with metastatic renal cell carcinoma potentially cured by interleukin-2 based immunotherapy.

The majority of clear-cell renal cell carcinomas (ccRCC) show high and homogeneous expression levels of the tumor associated antigen (TAA) carbonic anhydrase IX (CAIX), and treatment with interleukin-2 (IL-2) based immunotherapy can lead to cure in patients with metastatic renal cell carcinoma (mRCC). However, the involvement of CAIX specific CD8+ T cells and/or NK cells in the tumor eradication is unknown. We investigated T cell and antibody reactivity against overlapping 15-mer CAIX-peptides as well as HLA haplotype frequency and NK cell cytotoxicity in 11 patients with no evidence of disease (NED) following treatment with IL-2 based immunotherapy, and thus potentially cured. Immune reactivity in these patients was compared with samples from patients with dramatic tumor response obtained immediately at the cessation of therapy, samples from patients that experienced progressive disease during treatment and samples from healthy controls. We observed more focused but only weak and not consistent CAIX specific T-cells in the late observation and early observation response groups compared with the healthy control group. An increased frequency of the class II alleles HLA-DRB4 01:01, HLA-DPB 01:01 and HLA-DPB 03:01 was noted in the NED patients. In contrast, NK cytotoxicity was low even in the late observation response group as compared with controls. In particular, a HLA-B*40:01 restricted CD8+ T cell response recognizing the CAIX- derived peptide SEEEGSLKL was identified. This may have interest in future cancer vaccines, but more studies are needed to elucidate the immunological mechanisms of action in potentially cured patients treated with an immunotherapeutic agent.

Linear ion trap MS(n) of enzymatically synthesized 13C-labeled fructans revealing differentiating fragmentation patterns of ß (1-2) and ß (1-6) fructans and providing a tool for oligosaccharide identification in complex mixtures.

Fructans are polymeric carbohydrates, which play important roles as plant reserve carbohydrates and stress protectants, and are beneficial for human health and animal production. Fructans are formed by the addition of ß-d-fructofuranosyl units to sucrose, leading to very complex mixtures of 1-kestose based inulins, 6-kestose linked levans, and 6G-kestose derived neoseries inulins and levans in cool season grasses such as Lolium perenne. The identification of isomeric fructan oligomers in chromatographic analysis of crude plant extracts is often hampered by the lack of authentic standards, and unambiguous peak assignment usually requires time-consuming analyses of purified fructan oligomers. We have developed a LC-MS(n) method for the separation and detection of fructan isomers and present here evidence for specific MS(n) fragmentation patterns associated with ß 1-2 (inulins) and ß 2-6 (levans) fructans. LC-MS(n) analysis of (13)C labeled fructan oligomers produced by L. perenne fructosyltransferases expressed in yeast has enabled us to account for the observed fragmentation patterns in terms of preferential cleavage of the glycosidic bond between O- and fructose C2 in both inulins and levans and to differentiate reducing-end from nonreducing end cross ring cleavages in levans. We propose that higher order MS fragmentation patterns can be used to distinguish between the two major classes of fructan, i.e., inulins and levans, without the need for authentic standards.

JNK1, but not JNK2, is required in two mechanistically distinct models of inflammatory arthritis.

The roles of the c-Jun N-terminal kinases (JNKs) in inflammatory arthritis have been investigated; however, the roles of each isotype (ie, JNK1 and JNK2) in rheumatoid arthritis and conclusions about whether inhibition of one or both is necessary for amelioration of disease are unclear. By using JNK1- or JNK2-deficient mice in the collagen-induced arthritis and the KRN T-cell receptor transgenic mouse on C57BL/6 nonobese diabetic (K/BxN) serum transfer arthritis models, we demonstrate that JNK1 deficiency results in protection from arthritis, as judged by clinical score and histological evaluation in both models of inflammatory arthritis. In contrast, abrogation of JNK2 exacerbates disease. In collagen-induced arthritis, the distinct roles of the JNK isotypes can, at least in part, be explained by altered regulation of CD86 expression in JNK1- or JNK2-deficient macrophages in response to microbial products, thereby affecting T-cell-mediated immunity. The protection from K/BxN serum-induced arthritis in Jnk1(-/-) mice can also be explained by inept macrophage function because adoptive transfer of wild-type macrophages to Jnk1(-/-) mice restored disease susceptibility. Thus, our results provide a possible explanation for the modest therapeutic effects of broad JNK inhibitors and suggest that future therapies should selectively target the JNK1 isoform.

Metabolomics of forage plants: a review.

BACKGROUND: Forage plant breeding is under increasing pressure to deliver new cultivars with improved yield, quality and persistence to the pastoral industry. New innovations in DNA sequencing technologies mean that quantitative trait loci analysis and marker-assisted selection approaches are becoming faster and cheaper, and are increasingly used in the breeding process with the aim to speed it up and improve its precision. High-throughput phenotyping is currently a major bottle neck and emerging technologies such as metabolomics are being developed to bridge the gap between genotype and phenotype; metabolomics studies on forages are reviewed in this article. SCOPE: Major challenges for pasture production arise from the reduced availability of resources, mainly water, nitrogen and phosphorus, and metabolomics studies on metabolic responses to these abiotic stresses in Lolium perenne and Lotus species will be discussed here. Many forage plants can be associated with symbiotic microorganisms such as legumes with nitrogen fixing rhizobia, grasses and legumes with phosphorus-solubilizing arbuscular mycorrhizal fungi, and cool temperate grasses with fungal anti-herbivorous alkaloid-producing Neotyphodium endophytes and metabolomics studies have shown that these associations can significantly affect the metabolic composition of forage plants. The combination of genetics and metabolomics, also known as genetical metabolomics can be a powerful tool to identify genetic regions related to specific metabolites or metabolic profiles, but this approach has not been widely adopted for forages yet, and we argue here that more studies are needed to improve our chances of success in forage breeding. CONCLUSIONS: Metabolomics combined with other '-omics' technologies and genome sequencing can be invaluable tools for large-scale geno- and phenotyping of breeding populations, although the implementation of these approaches in forage breeding programmes still lags behind. The majority of studies using metabolomics approaches have been performed with model species or cereals and findings from these studies are not easily translated to forage species. To be most effective these approaches should be accompanied by whole-plant physiology and proof of concept (modelling) studies. Wider considerations of possible consequences of novel traits on the fitness of new cultivars and symbiotic associations need also to be taken into account.

Expression and functional characterization of a white clover isoflavone synthase in tobacco.

BACKGROUND AND AIMS: Trifolium repens (white clover) is a valuable component of pastures due to its ability to fix nitrogen. Productivity of T. repens is sometimes threatened by insect pests, and it has been suggested that phenylpropanoid-derived isoflavonoids such as formononetin can protect white clover from insect damage. The aim of this study was to isolate and functionally characterize an isoflavone synthase (IFS2_12) from T. repens by expressing it in Nicotiana tabacum (tobacco), a plant which does not naturally produce isoflavonoids. METHODS: To induce anthocyanin production and increase isoflavonoid precursors in tobacco, the tomato R2R3 MYB transcription factor ANT1 was expressed in tobacco (Nt-ANT1 plants). IFS2_12 was heterologously expressed in tobacco both transiently and stably, and isoflavonoids in leaf extracts were analysed by liquid chromatography (LC) coupled to mass spectrometry (MS(n)). As a positive control, a double construct of soybean IFS and alfalfa chalcone isomerase (IFS/CHI), which had been previously shown to induce isoflavonoid production in tobacco, was also expressed. Stable transformants expressing IFS2_12, soybean/alfalfa IFS/CHI and ANT1 were crossed and the resulting plants were analysed for isoflavonoid production. KEY RESULTS: Leaves of tobacco plants expressing ANT1 had a range of phenotypes from mainly green to uniformly bronze coloured. Both transient and stable expression of the IFS2_12 or IFS/CHI constructs resulted in the production of the isoflavonoid genistein and its conjugates. The highest levels (up to 19·2 mg g(-1) d. wt) accumulated in a progeny of a cross between a purple ANT1 and a IFS/ CHI transformant, while the second highest concentration was found in a plant derived from a selfed IFS2-12 transformant. CONCLUSIONS: It is concluded that the gene IFS2_12 isolated from T. repens encodes an isoflavone synthase. This study paves the way for engineering white clover plants with higher levels of isoflavonoids than naturally found in this species for sufficient insect protection.

Non-targeted analysis of tea by hydrophilic interaction liquid chromatography and high resolution mass spectrometry.

Tea is the second most consumed beverage in the world and its consumption has been associated with numerous potential health benefits. Factors such as fermentation methods, geographical origin and season can affect the primary and secondary metabolite composition of tea. In this study, a hydrophilic interaction liquid chromatography (HILIC) method coupled to high resolution mass spectrometry in both positive and negative ionisation modes was developed and optimised. The method when combined with principal component analysis to analyse three different types of tea, successfully distinguished samples into different categories, and provided evidence of the metabolites which differed between them. The accurate mass and high resolution attributes of the mass spectrometric data were utilised and relative quantification data were extracted post-data acquisition on 18 amino acids, showing significant differences in amino acid concentrations between tea types and countries. This study highlights the potential of HILIC chromatography combined with non-targeted mass spectrometric methods to provide a comprehensive understanding of polar metabolites in plant extracts.

Seromic profiling of colorectal cancer patients with novel glycopeptide microarray.

Cancer-associated autoantibodies hold promise as sensitive biomarkers for early detection of cancer. Aberrant post-translational variants of proteins are likely to induce autoantibodies, and changes in O-linked glycosylation represent one of the most important cancer-associated post-translational modifications (PTMs). Short aberrant O-glycans on proteins may introduce novel glycopeptide epitopes that can elicit autoantibodies because of lack of tolerance. Technical barriers, however, have hampered detection of such glycopeptide-specific autoantibodies. Here, we have constructed an expanded glycopeptide array displaying a comprehensive library of glycopeptides and glycoproteins derived from a panel of human mucins (MUC1, MUC2, MUC4, MUC5AC, MUC6 and MUC7) known to have altered glycosylation and expression in cancer. Seromic profiling of patients with colorectal cancer identified cancer-associated autoantibodies to a set of aberrant glycopeptides derived from MUC1 and MUC4. The cumulative sensitivity of the array analysis was 79% with a specificity of 92%. The most prevalent of the identified autoantibody targets were validated as authentic cancer immunogens by showing expression of the epitopes in cancer using novel monoclonal antibodies. Our study provides evidence for the value of glycopeptides and other PTM-peptide arrays in diagnostic measures.