A method for determining in a sample, by mass spectrometry, the amount of one or more analytes is described. The method comprises introducing a sample to an ionization source under conditions suitable to produce one or more ions detectable by mass spectrometry from each of the one or more analytes; measuring, by mass spectrometry, the amount of the one or more ions from each of the one or more analytes and using the measured amount of the one or more ions to determine the amount of each of the one or more analytes in the sample. Also described is a kit comprising one or more isotopically labeled analogues as internal standards for each of the one or more analytes.

The invention provides methods and formulations comprising a protein comprising solvent accessible amino acid residues susceptible to oxidation wherein N-acetyl tryptophan (NAT) is used to prevent oxidation of the protein. The invention also provides methods for making such formulations and methods of using such formulations. Methods to measure degradation of NAT in protein formulations are also provided.

The present invention provides methods for aiding in the diagnosis of irritable bowel syndrome (IBS) in an individual. In particular, the present invention is useful for determining whether the individual does not have either celiac disease or inflammatory bowel disease (IBD), and has IBS and/or a subtype thereof. Thus, the present invention provides an accurate diagnostic prediction of IBS and is useful for guiding treatment decisions.

A system and method for using new biomarkers to assess individual diseases is provided. In one embodiment of the present invention, absolute quantification of annotated metabolites by mass spectrometry is used to identify certain biomarkers and derivatives thereof (i.e., signatures), which are then used to screen for, diagnose, predict, prognose, and treat various diseases, including, but not limited to, breast cancer, ovarian cancer, colorectal cancer, pancreatic cancer, and acute graft-versus-host disease.

The invention relates to compositions and methods for diagnosing and treating hyperproliferative disorders using ligands which specifically recognize the hypusine and/or folate binding region of mature eukaryotic translation initiation factor 5A (hypusine-containing eIF-5A). The invention further relates to methods of identifying molecules which displace immunoreagents binding to mature eIF-5A. Such agents are useful for treating hyperproliferative disorders.

Ageing myocardium undergoes structural and functional changes characterized by progressive cardiomyocyte hypertrophy, interstitial fibrosis and inflammation ultimately leading to diastolic and systolic dysfunction. Whilst most focus has been placed on established risk factors such as dyslipidaemia, hypertension and obesity in accelerating cardiac ageing, a potential role for amino acids has received little attention. Here the inventors show that increased phenylalanine (PA) levels induced in vitro cytosolic oxidative stress and senescence whilst in vivo led to senile-like cardiac deterioration in young mice. Moreover, they demonstrated that hepatic PA catabolism declined with age in a p21-dependent manner, whilst p21 deficiency prevented age-related cardiac dysfunction. Finally, the inventors found that Pah cofactor BH4 reversed the age-related rise in plasma PA levels and senile cardiac alterations. These observations have immediate implications for promoting cardiac health and healthspan and suggest that phenylalanine can be used as a biomarker and biotarget of cardiac dysfunction.

Provided are methods and compositions for determining methylarginine demethylase activity in test samples. The methods and compositions comprise a peptide substrate containing methylated arginine that can act as a substrate for the demethylation activity, a positive control that has methylarginine demethylation activity and a variant of the positive control that does not have methylarginine demethylation activity and that can act as a negative control.

Embodiments described herein relate generally to compositions that include a synthetic redox-active receptor, and in particular to compositions that include a boronic acid based synthetic redox-active receptor which can electrochemically sense a target analyte in a sample solution. In some embodiments, a synthetic redox-active receptor can have a composition of formula I:

##STR00001##

wherein the variables L, L′, R, R′ n and X are described herein.

The present disclosure provides, inter alia, genetically encoded recombinant peptide biosensors comprising analyte-binding framework portions and signaling portions, wherein the signaling portions are present within the framework portions at sites or amino acid positions that undergo a conformational change upon interaction of the framework portion with an analyte.

Using NMR/MS based metabonomics and targeted lipidomics approaches the inventors have explored the metabolic phenotypes of aging and longevity in a cohort including centenarians, elderly and young adults. The inventors have identified biomarkers for a reduced risk of developing ageing related chronic inflammatory disorders and propose a method of diagnosing a lifestyle that allows delaying and/or avoiding ageing related chronic inflammatory disorders using 9-oxo-HODE as biomarker.