Publications by authors named "Scott J Harrison"

Importance: Bipolar disorder (BD) is frequently misdiagnosed as major depressive disorder (MDD) because of overlapping symptoms and the lack of objective diagnostic tools.

Objective: To identify a reproducible metabolomic biomarker signature in patient dried blood spots (DBSs) that differentiates BD from MDD during depressive episodes and assess its added value when combined with self-reported patient information.

Design, Setting, And Participants: This diagnostic analysis used samples and data from the Delta study, conducted in the UK between April 27, 2018, and February 6, 2020.

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Perennial ryegrass () is integral to temperate pastoral agriculture, which contributes most of the milk and meat production worldwide. Chemical profiles and diversity of ryegrass offer several opportunities to harness specific traits and elucidate underlying biological mechanisms for forage improvement. We conducted a large-scale metabolomics study of perennial ryegrass comprising 715 genotypes, representing 118 populations from 21 countries.

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Introduction: Photosensitization is a common clinical sign in cows suffering from liver damage caused by the mycotoxin sporidesmin. This disease, called facial eczema (FE), is of major importance in New Zealand. Current techniques for diagnosing animals with subclinical sporidesmin-induced liver damage (i.

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A liquid chromatography-mass spectrometry (LC-MS) library is presented containing the relative retention times of 28 fructan oligomers and MS spectra of 18 of them. It includes the main representatives of all fructan classes occurring in nature and with a degree of polymerization between three and five. This library enables a rapid and unambiguous detection of these 18 fructan structures in any type of sample without the need for fructan purification or the synthesis of fructan standards.

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Cytochromes P450 (CYP) are attractive enzyme targets in biotechnology as they catalyze stereospecific C-hydroxylations of complex core skeletons at positions that typically are difficult to access by chemical synthesis. Membrane bound CYPs are involved in nearly all plant pathways leading to the formation of high-value compounds. In the present study, we systematically maximize the heterologous expression of six different plant-derived CYP genes in Escherichia coli, using a workflow based on C-terminal fusions to the green fluorescent protein.

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Only 25% of bacterial membrane transporters have functional annotation owing to the difficulty of experimental study and of accurate prediction of their function. Here we report a sequence-independent method for high-throughput mining of novel transporters. The method is based on ligand-responsive biosensor systems that enable selective growth of cells only if they encode a ligand-specific importer.

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Small proteins of 50 amino acids or less have been understudied due to difficulties that impede their annotation and detection. In order to obtain information on small open reading frames (sORFs) in Pseudomonas putida, bioinformatic and proteomic approaches were used to identify putative sORFs in the well-characterized strain KT2440. A plasmid-based system was established for sORF validation, enabling expression of C-terminal sequential peptide affinity tagged variants and their detection via protein immunoblotting.

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Background: There has been interest in determining whether older red blood cell (RBC) units have negative clinical effects. Numerous observational studies have shown that older RBC units are an independent factor for patient mortality. However, recently published randomized clinical trials have shown no difference of clinical outcome for patients receiving old or fresh RBCs.

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Melatonin is a natural mammalian hormone that plays an important role in regulating the circadian cycle in humans. It is a clinically effective drug exhibiting positive effects as a sleep aid and a powerful antioxidant used as a dietary supplement. Commercial melatonin production is predominantly performed by complex chemical synthesis.

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Plant secondary metabolites are an underutilized pool of bioactive molecules for applications in the food, pharma and nutritional industries. One such molecule is fisetin, which is present in many fruits and vegetables and has several potential health benefits, including anti-cancer, anti-viral and anti-aging activity. Moreover, fisetin has recently been shown to prevent Alzheimer's disease in mice and to prevent complications associated with diabetes type I.

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Background: One of the bottlenecks in production of biochemicals and pharmaceuticals in Saccharomyces cerevisiae is stable and homogeneous expression of pathway genes. Integration of genes into the genome of the production organism is often a preferred option when compared to expression from episomal vectors. Existing approaches for achieving stable simultaneous genome integrations of multiple DNA fragments often result in relatively low integration efficiencies and furthermore rely on the use of selection markers.

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The objectives of this study were to examine long-term effects of feeding forage rape (Brassica napus L.) on methane yields (g methane per kg of feed dry matter intake), and to propose mechanisms that may be responsible for lower emissions from lambs fed forage rape compared to perennial ryegrass (Lolium perenne L.).

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CRISPR/Cas9 is a simple and efficient tool for targeted and marker-free genome engineering. Here, we report the development and successful application of a multiplex CRISPR/Cas9 system for genome engineering of up to 5 different genomic loci in one transformation step in baker's yeast Saccharomyces cerevisiae. To assess the specificity of the tool we employed genome re-sequencing to screen for off-target sites in all single knock-out strains targeted by different gRNAs.

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Biologically produced 3-hydroxypropionic acid (3 HP) is a potential source for sustainable acrylates and can also find direct use as monomer in the production of biodegradable polymers. For industrial-scale production there is a need for robust cell factories tolerant to high concentration of 3 HP, preferably at low pH. Through adaptive laboratory evolution we selected S.

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Forskolin is a promising medicinal compound belonging to a plethora of specialized plant metabolites that constitute a rich source of bioactive high-value compounds. A major obstacle for exploitation of plant metabolites is that they often are produced in small amounts and in plants difficult to cultivate. This may result in insufficient and unreliable supply leading to fluctuating and high sales prices.

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Rationale: Fructans are carbohydrates predominantly based on fructose which are generally considered to be soluble dietary fibers with health-promoting properties. It is known that the nutritional properties of fructans are affected by their structure. This study focused on structural determination of branched fructans, as the most important dietary fructans are branched graminan-type fructans.

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Standardization of molecular cloning greatly facilitates advanced DNA engineering, parts sharing, and collaborative efforts such as the iGEM competition. All of these attributes facilitate exploitation of the wealth of genetic information made available by genome and RNA sequencing. Standardization also comes at the cost of reduced flexibility.

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In this paper, a new liquid chromatography-mass spectrometry (LC-MS) method for the analysis of complex fructan mixtures is presented. In this method, columns with a trifunctional C18 alkyl stationary phase (T3) were used and their performance compared with that of a porous graphitized carbon (PGC) column. The separation of fructan isomers with the T3 phase improved clearly in comparison with the PGC phase, and retention times were lower and more stable.

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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.

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Oolong tea is a semi-fermented tea that is partially oxidised during the manufacturing process to create a product unique in composition. In this study, we investigated the potential of non-targeted LC-MS with two complementary chromatographic modes to provide a "comprehensive and unbiased" view of biochemical compositional changes occurring during oolong tea manufacturing in New Zealand. Tea leaf samples from throughout the manufacturing/fermentation process during three different harvest periods (spring, summer and autumn) were analysed by four different LC-MS streams.

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Factors such as fermentation methods, geographical origin and season can affect the biochemical composition of tea leaves (Camellia sinensis L.). In this study, the biochemical composition of oolong tea during the manufacturing and fermentation process was studied using a non-targeted method utilising ambient ionisation with a direct analysis in real time (DART) ion source and mass spectrometry (MS).

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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.

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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.

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Many important crop and forage plants accumulate polymeric water-soluble carbohydrates as fructooligosaccharides (or fructans). We have developed an improved method for the analysis of the full fructan complement in plant extracts based on porous graphitized carbon chromatography coupled to negative electrospray ionization mass spectrometry. By the use of profile data collection and multiple charge state ions, the effective mass range of the ion trap was extended to allow for the analysis of very high-molecular-weight oligosaccharides.

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The current developments in metabolomics and metabolic profiling technologies have led to the discovery of several new metabolic biomarkers. Finding metabolites present in significantly different levels between sample sets, however, does not necessarily make these metabolites useful biomarkers. The route to valid and applicable biomarkers (biomarker qualification) is long and demands a significant amount of work.

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