Effect of storage conditions on salivary polyamines quantified via liquid chromatography-mass spectrometry.

Salivary polyamines are potential non-invasive tools for screening various types of cancers. For clinical use, the reproducibility of these metabolites should be evaluated under various storage conditions, including duration and temperature, to establish standard operating protocols. Polyamines and amino acids in unstimulated whole saliva were quantified via liquid chromatography-mass spectrometry. Concentrations of time course samples were analysed after short-term storage for up to 240 min and long-term storage for up to 8 days under various storage conditions. As expected, storage at the lowest temperature (-18 °C) exerted the least pronounced effects on the quantified values in both tests. At a higher temperature, polyamines were more stable than amino acids, as evident from polyamine profiling. Addition of ethanol significantly stabilized polyamine profiles even at a higher temperature. Comparative processing of saliva revealed a minor effect of the solvent, whereas drying had a more prominent effect on polyamine profiles. Computational analyses evaluated the ability of polyamines to discriminate pancreatic cancer from controls. Repeated noise added tests were designed on the basis of the results of the storage tests; these analyses confirmed that the discriminative abilities were robust. These data contribute to the standardization of salivary storage conditions, thereby highlighting the clinical utility of saliva.

Urinary Polyamine Biomarker Panels with Machine-Learning Differentiated Colorectal Cancers, Benign Disease, and Healthy Controls.

Colorectal cancer (CRC) is one of the most daunting diseases due to its increasing worldwide prevalence, which requires imperative development of minimally or non-invasive screening tests. Urinary polyamines have been reported as potential markers to detect CRC, and an accurate pattern recognition to differentiate CRC with early stage cases from healthy controls are needed. Here, we utilized liquid chromatography triple quadrupole mass spectrometry to profile seven kinds of polyamines, such as spermine and spermidine with their acetylated forms. Urinary samples from 201 CRCs and 31 non-CRCs revealed the N1,N12-diacetylspermine showing the highest area under the receiver operating characteristic curve (AUC), 0.794 (the 95% confidence interval (CI): 0.704-0.885, p < 0.0001), to differentiate CRC from the benign and healthy controls. Overall, 59 samples were analyzed to evaluate the reproducibility of quantified concentrations, acquired by collecting three times on three days each from each healthy control. We confirmed the stability of the observed quantified values. A machine learning method using combinations of polyamines showed a higher AUC value of 0.961 (95% CI: 0.937-0.984, p < 0.0001). Computational validations confirmed the generalization ability of the models. Taken together, polyamines and a machine-learning method showed potential as a screening tool of CRC.

Early gestational maternal low-protein diet diminishes hepatic response to fasting in young adult male mice.

Maternal low-protein (MLP) diet can lead to hepatic steatosis, which only develops with ageing. It is still unclear whether the young offspring show any signs of past exposure to prenatal adverse conditions. We hypothesized that early nutritional insult would first affect the dynamic responsiveness to nutritional challenges rather than the static state. We analyzed the transcriptome and metabolome profiles of the hepatic response to fasting/refeeding in young male mice offspring to identify changes induced by early gestational MLP diet. Restricted MLP exposure strictly to early gestation was achieved by the embryo transfer method. As a result, the fasting-induced upregulation of genes related to long-chain fatty acid metabolism and of stress response genes related to protein folding were significantly diminished in MLP pups. Lipid profiling after fasting showed that the hepatic signature of triacylglycerols was shifted to longer acyl-chains and higher saturation by the MLP diet. Bioinformatic analyses suggested that these phenomenological changes may be partially linked to the peroxisome proliferator activated receptor α (PPARα) pathway. Taken together, early gestational MLP diet affected the hepatic dynamic response to nutritional stress in seemingly healthy young offspring, accompanied with partial deterioration of PPARα action.

Characterization of a novel lipolytic enzyme from Aspergillus oryzae.

In this study, we report the characterization of a protein from Aspergillus oryzae, exhibiting sequence identity with paraben esterase from the genus Aspergillus. The coding region of 1,586 bp, including a 77-bp intron, encoded a protein of 502 amino acids. The gene without the signal peptide of 19 amino acids was cloned into a vector, pPICZαC, and expressed successfully in Pichia pastoris as an active extracellular protein. The purified recombinant protein had pH and temperature optima of 7.0-8.0 and 30 °C, respectively, and was stable at the pH range of 7.0-10.0 and up to 40 °C. The optimal substrate for hydrolysis by the purified recombinant protein, among a panel of α-naphthyl esters (C2-C16), was α-naphthyl butyrate (C4), with activity of 0.16 units/mg protein. The considerable hydrolytic activity of the purified recombinant enzyme toward tributyrin was determined. However, no paraben esterase activity was detected toward the ethyl, propyl, and butyl esters of 4-hydroxybenzoic acid. In addition, no activity was detected toward the methyl esters of ferulic, p-coumaric, caffeic, and sinapic acids that would indicate feruloyl esterase activity.

Human blood metabolite timetable indicates internal body time.

A convenient way to estimate internal body time (BT) is essential for chronotherapy and time-restricted feeding, both of which use body-time information to maximize potency and minimize toxicity during drug administration and feeding, respectively. Previously, we proposed a molecular timetable based on circadian-oscillating substances in multiple mouse organs or blood to estimate internal body time from samples taken at only a few time points. Here we applied this molecular-timetable concept to estimate and evaluate internal body time in humans. We constructed a 1.5-d reference timetable of oscillating metabolites in human blood samples with 2-h sampling frequency while simultaneously controlling for the confounding effects of activity level, light, temperature, sleep, and food intake. By using this metabolite timetable as a reference, we accurately determined internal body time within 3 h from just two anti-phase blood samples. Our minimally invasive, molecular-timetable method with human blood enables highly optimized and personalized medicine.

Changes in the charged metabolite and sugar profiles of pasteurized and unpasteurized Japanese sake with storage.

Japanese sake (rice wine) is commonly heat treated (pasteurized) to maintain its quality. In this study, temporal changes in the metabolite profiles of pasteurized and unpasteurized sake were investigated during storage. Metabolomic analyses were conducted for eight sets of pasteurized and unpasteurized sake obtained from single process batches stored at 8 or 20 °C for 0, 1, 2, or 4 months. Capillary electrophoresis time-of-flight mass spectrometry and liquid chromatography tandem mass spectrometry were used to obtain charged metabolite and sugar profiles, respectively. The total amino acid concentration decreased with storage, and the decrease was faster in pasteurized sake than in unpasteurized. The organic acid concentrations were relatively constant in both types of sake. Peptide and glucose concentrations increased and polysaccharide concentrations decreased in unpasteurized sake, while they were relatively constant in pasteurized sake. Rather than stabilizing the sake metabolite profile during storage, pasteurization results in characteristic changes compared to unpasteurized sake.

Serum metabolomics reveals γ-glutamyl dipeptides as biomarkers for discrimination among different forms of liver disease.

BACKGROUND & AIMS: We applied a metabolome profiling approach to serum samples obtained from patients with different liver diseases, to discover noninvasive and reliable biomarkers for rapid-screening diagnosis of liver diseases. METHODS: Using capillary electrophoresis and liquid chromatography mass spectrometry, we analyzed low molecular weight metabolites in a total of 248 serum samples obtained from patients with nine types of liver disease and healthy controls. RESULTS: We found that γ-glutamyl dipeptides, which were biosynthesized through a reaction with γ-glutamylcysteine synthetase, were indicative of the production of reduced glutathione, and that measurement of their levels could distinguish among different liver diseases. Multiple logistic regression models facilitated the discrimination between specific and other liver diseases and yielded high areas under receiver-operating characteristic curves. The area under the curve values in training and independent validation data were 0.952 and 0.967 in healthy controls, 0.817 and 0.849 in drug-induced liver injury, 0.754 and 0.763 in asymptomatic hepatitis B virus infection, 0.820 and 0.762 in chronic hepatitis B, 0.972 and 0.895 in hepatitis C with persistently normal alanine transaminase, 0.917 and 0.707 in chronic hepatitis C, 0.803 and 0.993 in cirrhosis type C, and 0.762 and 0.803 in hepatocellular carcinoma, respectively. Several γ-glutamyl dipeptides also manifested potential for differentiating between nonalcoholic steatohepatitis and simple steatosis. CONCLUSIONS: γ-Glutamyl dipeptides are novel biomarkers for liver diseases, and varying levels of individual or groups of these peptides have the power to discriminate among different forms of hepatic disease.

[Evaluation of the different doses of olprinone for continuous infusion after cardiopulmonary bypass for coronary artery bypass surgery].

BACKGROUND: We evaluated the hemodynamic efficacy of combined cathecholamine and three different continuous infusion doses of olprinone (0.05, 0.1, 0.3 microgram.kg-1.min-1) in 24 cases (0.05 group: 8 cases, 0.1 group: 8 cases, 0.3 group: 8 cases) undergoing coronary artery bypass grafting (CABG). METHODS: Olprinone was administered as a single dose (0.1 mg.kg-1) into the venous reservoir of the CPB circuit 15 min prior to the end of emergence from CPB, followed by continuous infusion. Hemodynamics were measured at the time of preCPB (M 0), just after the end of CPB (M 1), pre chest closure (M 2) and after chest closure (M 3). Cathecholamines were used to maintain mean arterial pressure (> 65 mmHg) and cardiac index (> 3.0 l.min-1.m-2). Hemodynamics (at M 0, M 1, M 2 and M 3) and the number of cases requiring combined cathecholamine were compared among the 3 doses. RESULTS: Three doses showed no significant difference on hemodynamics. In the number of cases requiring combined cathecholamine, group 0.3 were significantly lower than group 0.05 at dobutamine, and group 0.05 were significantly higher than group 0.1 and 0.3 at norepinephrine. CONCLUSIONS: The higher continuous infusion dose of olprinone (0.3 > 0.1 > 0.05 microgram.kg-1.min-1) can diminish the number of cases requiring combined cathecholamine administration during coronary artery bypass grafting.