The present invention provides: a method for assisting the evaluation of renal pathological conditions, said method comprising using, as an index, a combination of renal reabsorption and excretion ratios of D-serine and/or D-asparagine in a subject with the blood D-serine and/or D-asparagine levels; a system for evaluating renal pathological conditions; and a program for evaluating renal pathological conditions. The present invention also provides: a method for monitoring renal pathological conditions; and a method for monitoring an effect of treating a renal disease.

The present invention relates to methods, kits, and compositions for: i) detecting the level of 3-bromotyrosine in a sample that has been treated to liberate 3-bromotyrosine from 4-O-glucuronide-3-bromotyrosine, and/or ii) detecting the level of 4-O-glucuronide-3-bromotyrosine, and/or the combined level of both 4-O-glucuronide-3-bromotyrosine and 3-bromotyrosine, in a sample that has not been treated to liberate 3-bromotyrosine from 4-O-glucuronide-3-bromotyrosine. In certain embodiments, such detected levels are used to: i) identify the presence, severity, or risk of an eosinophilic disorder (e.g., asthma or a TH2-high eosinophilic disorder); ii) identify therapy effective for treating asthma or an eosinophilic disorder; or iii) identify patients suitable for treatment with therapeutic agents targeted to asthma or an eosinophilic disorder.

The disclosure is directed to methods and apparatus for the determination, diagnosis, progression and prognosis of kidney disease and mortality associated with kidney disease. The disclosure includes methods for determining renal function, in particular estimating glomerular filtration rate (GFR), in an animal. GFR can be useful in the diagnosis and treatment of kidney disease or dysfunction. In various aspects, the disclosure is directed to the use of free symmetrical dimethylarginine (SDMA) and creatinine in blood samples from animals, in particular cats and dogs, to determine glomerular filtration rate and kidney disease.

The present invention relates to a method for metabolite sampling and analysis for reproducibly sampling as many metabolites as possible in a urine sample without changing to metabolites. The method has effects of presenting a biomarker detection method according to the sex or the like, by establishing optimal conditions for metabolite sampling in urine samples and presenting a metabolite comparison analysis method between different groups on the basis of the optimal conditions.

A biomarker panel and method for a urine test for detecting lung cancer detects a biomarker selected from the group of biomarkers consisting of DMA, C5:1, C10:1, ADMA, C5-OH, SDMA, and kynurenine, or a combination thereof.

The present invention provides a mutated histidine decarboxylase suitable for a practical use. Specifically, the present invention provides a mutated histidine decarboxylase having at least one amino acid residue mutated as compared to a wild-type histidine decarboxylase, and having higher histidine decarboxylase activity and/or stability than the wild-type histidine decarboxylase, and also a use thereof. The mutated histidine decarboxylase has Motifs (1) to (6), and an amino acid residue in at least one motif thereof can be mutated. The mutated histidine decarboxylase can also have a mutation of at least one amino acid residue in an amino acid sequence designated by SEQ ID NO: 3 and in a homologous sequence thereto.

A method for quantitative determination of bioavailable L-tryptophan in faeces and a method of diagnosis whether a subject is suffering from impaired fructose absorption or from a lack of bioavailable tryptophan. The latter includes the localization of a previously hidden aetiology of decreased blood tryptophan levels and a method of in vitro diagnosis of the aetiology of gastrointestinal (IBD), Crohn's disease, depression symptoms, anxiety, insomnia, sleep disorders, dysphoric disorders. A kit of parts for determining the ratio of free L-tryptophan to blocked glycated tryptophan or fructosyl-tryptophan adduct for immediate treatment of these disorders by providingpatients with appropriate dietary recommendations or an intake of tryptophan that is not blocked or glycated in the acidic environment of the stomach or gastrointestinal tract.

A method and a sensor for detecting L-arginine are provided. The method includes synthesizing ferrocene-functionalized hexadecapeptide dithiocyclopentane (FC-P16 Peptide), preparing a polypeptide composite membrane-modified electrode (FC-P16 Peptide/AuE), detecting L-Arg and other steps. The results show that the polypeptide composite membrane-modified electrode (FC-P16 Peptide/AuE) exhibits excellent electrochemical response properties to L-Arg. In 10 mmol/L phosphate-buffered saline (PBS, pH=7.4), the DPV response peak current of the polypeptide composite membrane-modified electrode has an excellent linear relationship with the L-Arg concentration of 1.0×10.sup.−13 mol/L to 1.0×10.sup.−7 mol/L, with a detection limit of 1.0×10.sup.−13 mol/L. With prominent reproducibility, repeatability and selectivity, the modified electrode has potential application in life science and nutritional health.

A method for increasing peptide fragmentation by labelling the peptide at the C-terminal end with a guanidinium group or other basic functional group and distinguishing isobaric amino acids and amino acid combinations of asparagine and glycine-glycine; glutamine and glycine-alanine; and/or glutamine and alanine-glycine, during polypeptide sequencing. The method involves: obtaining a peptide of interest and/or digesting a polypeptide of interest with a protease, such as pepsin, chymotrypsin or trypsin, or by chemical cleavage to produce shorter peptides; reacting the obtained and/or generated peptides with a coupling reagent to derivatize the free C-terminal carboxylic acid function of the peptides, thus adding a basic functional group rendering C-terminal peptide fragment ions detectable by mass spectrometry; selecting a charge state of 2+ or more, and fragmenting the derivatized peptides in a mass spectrometer under conditions effective to generate at least w ions; and detecting the w ions by mass spectrometry, and identifying derivatized peptides which incorporate the additional mass of the basic functional group.

Provided herein are methods for selecting a subject with a disease or disorder for treatment, as well as methods of treating the subject, determining the efficacy of the treatment, and adjusting the treatment dosage and frequency.