Metabolomic Signatures Differentiate Immune Responses in Avian Influenza Vaccine Recipients.

BACKGROUND: Avian influenza viruses pose significant risk to human health. Vaccines targeting the hemagglutinin of these viruses are poorly immunogenic without the use of adjuvants. METHODS: Twenty healthy men and women (18-49 years of age) were randomized to receive 2 doses of inactivated influenza A/H5N1 vaccine alone (IIV) or with AS03 adjuvant (IIV-AS03) 1 month apart. Urine and serum samples were collected on day 0 and on days 1, 3, and 7 following first vaccination and subjected to metabolomics analyses to identify metabolites, metabolic pathways, and metabolite clusters associated with immunization. RESULTS: Seventy-three differentially abundant (DA) serum and 88 urine metabolites were identified for any postvaccination day comparison. Pathway analysis revealed enrichment of tryptophan, tyrosine, and nicotinate metabolism in urine and serum among IIV-AS03 recipients. Increased urine abundance of 4-vinylphenol sulfate on day 1 was associated with serologic response based on hemagglutination inhibition responses. In addition, 9 DA urine metabolites were identified in participants with malaise compared to those without. CONCLUSIONS: Our findings suggest that tryptophan, tyrosine, and nicotinate metabolism are upregulated among IIV-AS03 recipients compared with IIV alone. Metabolites within these pathways may serve as measures of immunogenicity and may provide mechanistic insights for adjuvanted vaccines. CLINICAL TRIALS REGISTRATION: NCT01573312.

Detection of 3-O-methyldopa in dried blood spots for neonatal diagnosis of aromatic L-amino-acid decarboxylase deficiency: The northeastern Italian experience.

OBJECTIVE: Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare inherited autosomal recessive disorder of biogenic amine metabolism. Diagnosis requires analysis of neurotransmitter metabolites in cerebrospinal fluid, AADC enzyme activity analysis, or molecular analysis of the DDC gene. 3-O-methyldopa (3-OMD) is a key screening biomarker for AADC deficiency. METHODS: We describe a rapid method for 3-OMD determination in dried blood spots (DBS) using flow-injection analysis tandem mass spectrometry with NeoBase™ 2 reagents and 13C6-tyrosine as an internal standard, which are routinely used in high-throughput newborn screening. We assessed variability using quality control samples over a range of 3-OMD concentrations. RESULTS: Within-day and between-day precision determined with quality control samples demonstrated coefficients of variation <15%. 3-OMD concentrations in 1000 healthy newborns revealed a mean of 1.33 µmol/L (SD ± 0.56, range 0.61-3.05 µmol/L), 100 non-AADC control subjects (age 7 days - 1 year) showed a mean of 1.19 µmol/L (SD ± 0.35-2.00 µmol/L), and 81 patients receiving oral L-Dopa had a mean 3-OMD concentration of 14.90 µmol/L (SD ± 14.18, range 0.4-80.3 µmol/L). A patient with confirmed AADC was retrospectively analyzed and correctly identified (3-OMD 10.51 µmol/L). In April 2020, we started a pilot project for identifying AADC deficiency in DBSs routinely submitted to the expanded newborn screening program. 3-OMD concentrations were measured in 21,867 samples; no patients with AADC deficiency were identified. One newborn had a high 3-OMD concentration due to maternal L-Dopa treatment. DISCUSSION: We demonstrated a rapid new method to identify AADC deficiency using reagents and equipment already widely used in newborn screening programs. Although our study is limited, introduction of our method in expanded neonatal screening is feasible and could facilitate deployment of screening, allowing for early diagnosis that is important for effective treatment.

Effect of BH4 on blood phenylalanine and tyrosine variations in patients with phenylketonuria.

BACKGROUND: In patients with phenylketonuria, stability of blood phenylalanine and tyrosine concentrations might influence brain chemistry and therefore patient outcome. This study prospectively investigated the effects of tetrahydrobiopterin (BH4), as a chaperone of phenylalanine hydroxylase on diurnal and day-to-day variations of blood phenylalanine and tyrosine concentrations. METHODS: Blood phenylalanine and tyrosine were measured in dried blood spots (DBS) four times daily for 2 days (fasting, before lunch, before dinner, evening) and once daily (fasting) for 6 days in a randomized cross-over design with a period with BH4 and a period without BH4. The sequence was randomized. Eleven proven BH4 responsive PKU patients participated, 5 of them used protein substitutes during BH4 treatment. Natural protein intake and protein substitute dosing was adjusted during the period without BH4 in order to keep DBS phenylalanine levels within target range. Patients filled out a 3-day food diary during both study periods. Variations of DBS phenylalanine and Tyr were expressed in standard deviations (SD) and coefficient of variation (CV). RESULTS: BH4 treatment did not significantly influence day-to-day phenylalanine and tyrosine variations nor diurnal phenylalanine variations, but decreased diurnal tyrosine variations (median SD 17.6 µmol/l, median CV 21.3%, p = 0.01) compared to diet only (median SD 34.2 µmol/l, median CV 43.2%). Consequently, during BH4 treatment diurnal phenylalanine/tyrosine ratio variation was smaller, while fasting tyrosine levels tended to be higher. CONCLUSION: BH4 did not impact phenylalanine variation but decreased diurnal tyrosine and phenylalanine/tyrosine ratio variations, possibly explained by less use of protein substitute and increased tyrosine synthesis.

Tyrosine supplementation for phenylketonuria.

BACKGROUND: Phenylketonuria is an inherited disease for which the main treatment is the dietary restriction of the amino acid phenylalanine. The diet has to be initiated in the neonatal period to prevent or reduce mental handicap. However, the diet is very restrictive and unpalatable and can be difficult to follow. A deficiency of the amino acid tyrosine has been suggested as a cause of some of the neuropsychological problems exhibited in phenylketonuria. Therefore, this review aims to assess the efficacy of tyrosine supplementation for phenylketonuria. This is an update of previously published versions of this review. OBJECTIVES: To assess the effects of tyrosine supplementation alongside or instead of a phenylalanine-restricted diet for people with phenylketonuria, who commenced on diet at diagnosis and either continued on the diet or relaxed the diet later in life. To assess the evidence that tyrosine supplementation alongside, or instead of a phenylalanine-restricted diet improves intelligence, neuropsychological performance, growth and nutritional status, mortality rate and quality of life. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Register which is comprised of references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. Additional studies were identified from handsearches of the Journal of Inherited Metabolic Disease (from inception in 1978 to 1998). The manufacturers of prescribable dietary products used in the treatment of phenylketonuria were also contacted for further references. Date of the most recent search of the Group's Inborn Errors of Metabolism Trials Register: 07 December 2020. SELECTION CRITERIA: All randomised or quasi-randomised trials investigating the use of tyrosine supplementation versus placebo in people with phenylketonuria in addition to, or instead of, a phenylalanine-restricted diet. People treated for maternal phenylketonuria were excluded. DATA COLLECTION AND ANALYSIS: Two authors independently assessed the trial eligibility, methodological quality and extracted the data. MAIN RESULTS: Six trials were found, of which three trials reporting the results of a total of 56 participants, were suitable for inclusion in the review. The blood tyrosine concentrations were significantly higher in the participants receiving tyrosine supplements than those in the placebo group, mean difference 23.46 (95% confidence interval 12.87 to 34.05). No significant differences were found between any of the other outcomes measured. The trials were assessed as having a low to moderate risk of bias across several domains. AUTHORS' CONCLUSIONS: From the available evidence no recommendations can be made about whether tyrosine supplementation should be introduced into routine clinical practice. Further randomised controlled studies are required to provide more evidence. However, given this is not an active area of research, we have no plans to update this review in the future.

Using circulating O-sulfotyrosine in the differential diagnosis of acute kidney injury and chronic kidney disease.

BACKGROUND: Sulfation of tyrosine, yielding O-sulfotyrosine, is a common but fixed post-translational modification in eukaryotes. Patients with increased circulating O-sulfotyrosine levels experience a faster decline in renal function with progression to end-stage renal disease (ESRD). In the present study, we measured serum O-sulfotyrosine levels in individuals with chronic kidney disease (CKD) and acute kidney injury (AKI) to explore its ability to differentiate AKI from CKD. METHODS: A total of 135 patients (20 with AKI and 115 with CKD) were recruited prospectively for liquid chromatography-mass spectrometry assessment of circulating O-sulfotyrosine. We also studied C57BL/6 mice with CKD after 5/6 nephrectomy (Nx). Blood samples were drawn from the tail vein on Day 1, 3, 5, 7, 14, 30, 60, and 90 after CKD. Serum separation and characterization of creatinine, blood urea nitrogen (BUN), and O-sulfotyrosine was performed. Thus, the time-concentration curves of the O-sulfotyrosine level demonstrate the variation of kidney dysfunction. RESULTS: The serum levels of O-sulfotyrosine were markedly increased in patients with CKD compared with AKI. Median O-sulfotyrosine levels in CKD patients versus AKI, respectively, were as follows:243.61 ng/mL(interquartile range [IQR] = 171.90-553.86) versus 126.55 ng/mL (IQR = 48.19-185.03, P = 0.004). In patients with CKD, O-sulfotyrosine levels were positively correlated with creatinine, BUN, and Cystatin C (r = 0.63, P < 0.001; r = 0.49, P < 0.001; r = 0.61, P < 0.001, respectively) by the multivariate linear regression analysis (ß = 0.71, P < 0.001; ß = 0.40, P = 0.002; ß = 0.73, P < 0.001, respectively). However, this association was not statistically significant in patients with AKI (r = - 0.17, P = 0.472; r = 0.11, P = 0.655; r = 0.09, P = 0.716, respectively). The receiver operating characteristic (ROC) analysis illustrated that the area under the curve was 0.80 (95% confidence interval [CI] 0.71-0.89; P < 0.001) and the optimal cut-off value of serum O-sulfotyrosine suggesting AKI was < 147.40 ng/mL with a sensitivity and specificity of 80.90 and 70.00% respectively. In animal experiments, serum levels of O-sulfotyrosine in mice were elevated on Day 7 after 5/6 nephrectomy (14.89 ± 1.05 vs. 8.88 ± 2.62 ng/mL, P < 0.001) until Day 90 (32.65 ± 5.59 vs. 8.88 ± 2.62 ng/mL, P < 0.001). CONCLUSION: Serum O-sulfotyrosine levels were observed correlated with degrading renal function and in CKD patients substantially higher than those in AKI patients. Thus serum O-sulfotyrosine facilitated the differential diagnosis of AKI from CKD.

Assessment of serum phenylalanine and tyrosine isomers in patients with ST-segment elevation vs non-ST-segment elevation myocardial infarction.

BACKGROUND: Under conditions of oxidative stress, hydroxyl radicals can oxidize phenylalanine (Phe) into various tyrosine (Tyr) isomers (meta-, ortho-, and para-tyrosine; m-, o-, and p-Tyr), depending on the location of the hydroxyl group on the oxidized benzyl ring. This study aimed to compare patients with ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) and the serum levels of Phe and Tyr isomers at the aortic root and distal to the culprit lesion in both groups. METHODS: Forty-four patients participated in the study: 23 with STEMI and 21 with NSTEMI. Arterial blood samples were taken from the aortic root through a guiding catheter and from the culprit vessel segment distal from the primary lesion with an aspiration catheter, during the percutaneous coronary intervention. Serum levels of Phe, p-Tyr, m-Tyr, and o-Tyr were determined using reverse-phase high-performance liquid chromatography. RESULTS: Serum levels of Phe were significantly higher distal to the culprit lesion compared to the aortic root in patients with STEMI. Serum p-Tyr/Phe and m-Tyr/Phe concentration ratios were both lower distal to the culprit lesion than at the aortic root in patients with STEMI. There were no statistically significant differences with respect to changes in serum Phe and Tyr isomers distal to the culprit lesion compared to the aortic root in patients with NSTEMI. CONCLUSION: Our data suggest that changes in serum levels of different Tyr isomers can mediate the effects of oxidative stress during myocardial infarction.

Effect of catechin and commercial preparation of green tea essence on the pharmacokinetics of l-dopa in rabbits.

The aim of this study was to investigate drug interactions of L-dopa/carbidopa with catechin and green tea essence in rabbits following the simultaneous administration via an intramuscular injection of catechin or via an intragastric route for green tea essence with L-dopa/carbidopa. The results indicated that catechin at doses of 10, 20 and 50 mg/kg increased the area under the plasma concentration-time curve from time zero to the time of the last quantifiable concentration (AUC0-t ) of L-dopa by about 69, 78 and 42%, respectively. The metabolic ratios of the AUC0-t for 3-O-methyldopa (3-OMD)/L-dopa significantly decreased by about 56, 68 and 76% (P < 0.05), respectively. In addition, a single dose of 5/1.25 mg/kg L-dopa/carbidopa was co-administrated with 150 mg/kg green tea essence via an intragastric route with an oral-gastric tube. Comparing the related pharmacokinetic parameters of L-dopa, the clearance and metabolic ratio of L-dopa decreased by 20 and 19% (P < 0.05), respectively. In conclusion, catechin and green tea essence can significantly affect the metabolism of L-dopa by the catechol-O-methyltransferase (COMT) metabolic pathway. Catechin can enhance L-dopa bioavailability, and both catechin and green tea essence decreased 3-OMD formation. Therefore, catechin and green tea essence may increase L-dopa efficacy for Parkinson's disease treatment.

Metabolomics analysis revealed significantly higher synovial Phe/Tyr ratio in reactive arthritis and undifferentiated spondyloarthropathy.

OBJECTIVE: To compare the synovial phenylalanine/tyrosine (Phe/Tyr) ratio between ReA/uSpA and RA and OA by NMR spectroscopy. METHODS: Paired SF and serum of 30 patients with ReA/uSpA were collected and analysed using a 1D 1H Carr Purcell Meiboom Gill NMR spectra recorded on 800 MHz NMR spectrometer equipped with a TCI Cryoprobe (at 300 K). Phe and Tyr were quantified. SF from 25 patients with RA fulfilling ACR classification criteria and 21 patients with OA were taken as inflammatory and non-inflammatory controls. RESULTS: The synovial Phe/Tyr ratio was significantly higher in ReA/uSpA compared with RA and OA. Synovial Phe/Tyr ratios were comparable in RA and OA patients. Compared with serum, the Phe/Tyr was significantly higher in the SF in ReA/uSpA. The Phe/Tyr ratio was also found to be positively correlated between serum and SF samples, with a regression coefficient (r2) of 0.287. CONCLUSIONS: This NMR-based metabolomics study demonstrates that the synovial Phe/Tyr ratio is specifically elevated in ReA/uSpA.

Tryptophan degradation is associated with risk-taking propensity in methamphetamine users with treated HIV infection.

Few studies have examined neuroimmune pathways that could contribute to impulsivity in people living with HIV who use substances. Eighty-four methamphetamine-using, sexual minority men with an undetectable HIV viral load were administered the Balloon Analogue Risk Task (BART), a behavioral measure of risk-taking propensity. We examined the associations between kynurenine/tryptophan ratio and phenylalanine/tyrosine ratio with BART scores using multiple linear regression. A higher kynurenine/tryptophan ratio was independently associated with greater BART scores (beta = 0.25; 95% CI = 0.05-1.23; p = 0.034). The phenylalanine/tyrosine ratio was not significantly associated with BART scores. Findings support the need for further research to elucidate the neuroimmune mechanisms linking tryptophan degradation with impulsivity to catalyze the development novel pharmacologic treatments for people living with HIV who use methamphetamine.

First-in-human phase I study of JPH203, an L-type amino acid transporter 1 inhibitor, in patients with advanced solid tumors.

This open-label first-in-human study evaluated JPH203, which is a novel selective L-type amino acid transporter 1 inhibitor. We also evaluated the association between the N-acetyltransferase 2 phenotype and outcomes. Japanese patients with advanced solid tumors received daily intravenous JPH203 treatment for 7 days, followed by a 21-day rest period, at escalating doses of 12-85 mg/m2. Dose-limiting toxicities were evaluated during the first cycle using a 3 + 3 design. The study enrolled 17 patients, although grade 3 liver dysfunction was detected in one of six patients receiving 60 mg/m2 and in the first patient to receive 85 mg/m2. Further enrollment was terminated and the maximum tolerated dose was defined as 60 mg/m2. The AUC∞ increased between 12 mg/m2 and 25 mg/m2, although no differences were observed at 25-40 mg/m2. Partial response was observed for one patient with biliary tract cancer (BTC) at the 12 mg/m2 dose, and disease control was achieved by 3 of 6 patients at the 12 mg/m2 and 25 mg/m2 dose levels. Based on these results, we recommend a phase II dose of 25 mg/m2. The disease control rate for BTC was 60%. Two patients with grade 3 liver dysfunction had the rapid N-acetyltransferase 2 phenotype, and disease control was more common for the non-rapid phenotype (50% vs. 12.5%). It appears that JPH203 was well-tolerated and provided promising activity against BTC. The N-acetyltransferase 2 phenotype might help predict the safety and efficacy of JPH203. Clinical trial registration: UMIN000016546.

Peroxynitrite is a novel risk factor and treatment target of glaucoma.

To investigate the association between systemic nitrotyrosine (NT) levels and primary angle-closure glaucoma (PACG) and primary open-angle glaucoma (POAG) and the mechanism involved. A case control study was conducted in the Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Fudan University from April 2017 to December 2017. A total of 400 participants were consecutively recruited into this study (100 PACG, 100 POAG and 200 controls). Multivariable logistic regression analysis was performed to identify the association between serum NT level and PACG or POAG. Clinical results were validated in cell and animal models. Among 200 glaucoma patients, 101 (50.5%) were women; the age was 57.07 ± 14.51 years. 106 (53%) control participants were women and age was 58.34 ± 14.04 years. Serum levels of NT in PACG and POAG patients are significantly higher than controls (1808.53 ± 417.76 nmol/L vs. 1270.62 ± 454.60 nmol/L, p < 0.001; 1718.63 ± 437.29 nmol/L vs. 1258.38 ± 460.72 nmol/L, p < 0.001). Further, elevated serum NT level increases the risk of developing PACG (OR = 1.003, 95% CI: 1.002 to 1.004, p < 0.001) and POAG (OR = 1.002, 95% CI: 1.002 to 1.003, p < 0.001). Consistent with the clinical data, serum and aqueous humour NT levels are significantly higher in caveolin 1 knockout (Cav1 KO) mice, an animal model of glaucoma. More importantly, peroxynitrite (PN) scavenger MnTMPyP and its transduction molecule PARP inhibitor significantly reduce intraocular pressure in Cav1 KO mice. Our data show for the first time that NT is a systemic risk factor and local treatment target of glaucoma.

Serum Nutritional Markers as Prognostic Factors for Hepatic and Extrahepatic Carcinogenesis in Japanese Patients with Nonalcoholic Fatty Liver Disease.

Serum zinc (Zn) levels and the branched chain amino acid/tyrosine molar ratio (BTR) were reported to decrease with the progression of various chronic liver diseases. We investigated the impact of BTR and Zn on the incidence of malignancies in patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD). A total of 179 Japanese NAFLD patients who underwent liver biopsy were enrolled. Hepatocellular carcinoma (HCC) and extrahepatic malignancies developed in 7 (3.9%) and 10 (5.6%) patients, respectively, during the follow-up period (median 7.9 years). Patients with low BTR levels (<5.0) and Zn deficiency (<70 µg/dL) had significantly higher incidences of HCC and extrahepatic malignancies (P < 0.001 and 0.026), respectively. Multiple logistic regression analyses revealed the following risk factors: liver fibrosis (F3-4) (hazard ratio [HR] 24.292, 95% confidence interval [CI] 2.802-210.621, P = 0.004) and BTR < 5.0 (HR 5.462, 95% CI 1.095-27.253, P = 0.038) for HCC, and serum Zn level <70 µg/dL (HR 3.504, 95% CI 1.010-12.157, P = 0.048) and liver inflammation (A2-3) (HR 3.445, 95% CI 0.886-13.395, P = 0.074) for extra-hepatic malignancies. In conclusion, serum BTR and Zn levels were useful for predicting HCC and extrahepatic malignancies in NAFLD, respectively.

High throughput newborn screening for aromatic ʟ-amino-acid decarboxylase deficiency by analysis of concentrations of 3-O-methyldopa from dried blood spots.

Aromatic l-amino-acid decarboxylase (AADC) deficiency is an inherited disorder of biogenic amine metabolism with a broad neurological phenotype. The clinical symptoms overlap with other diseases resulting in an often delayed diagnosis. Innovative disease-changing treatment options, particularly gene therapy, have emphasised the need for an early diagnosis. We describe the first method for 3-O-methyldopa (3-OMD) analysis in dried blood spots (DBS) suitable for high throughput newborn screening (NBS). We established a novel tandem mass spectrometry method to quantify 3-OMD in DBS and successfully tested it in 38 888 unaffected newborns, 14 heterozygous DDC variant carriers, seven known AADC deficient patients, and 1079 healthy control subjects. 3-OMD concentrations in 38 888 healthy newborns revealed a mean of 1.16 µmol/L (SD = 0.31, range 0.31-4.6 µmol/L). 1079 non-AADC control subjects (0-18 years) showed a mean 3-OMD concentration of 0.78 µmol/L (SD = 1.75, range 0.24-2.36 µmol/L) with a negative correlation with age. Inter- and intra-assay variability was low, and 3-OMD was stable over 32 days under different storage conditions. We identified seven confirmed AADC deficient patients (mean 3-OMD 9.88 µmol/L [SD = 13.42, range 1.82-36.93 µmol/L]). The highest concentration of 3-OMD was found in a NBS filter card of a confirmed AADC deficient patient with a mean 3-OMD of 35.95 µmol/L. 14 DDC variant carriers showed normal 3-OMD concentrations. We demonstrate a novel high-throughput method to measure 3-OMD in DBS, which allows integration in existing NBS programs enabling early diagnosis of AADC deficiency.

Consuming decaffeinated coffee with milk and sugar added before a high-glycaemic index meal improves postprandial glycaemic and insulinaemic responses in healthy adults.

The present study aimed to compare the effects of drinking different types of coffee before a high-glycaemic index (GI) meal on postprandial glucose metabolism and to assess the effects of adding milk and sugar into coffee. In this randomised, crossover, acute feeding study, apparently healthy adults (n 21) consumed the test drink followed by a high-GI meal in each session. Different types of coffee (espresso, instant, boiled and decaffeinated, all with milk and sugar) and plain water were tested in separate sessions, while a subset of the participants (n 10) completed extra sessions using black coffees. Postprandial levels of glucose, insulin, active glucagon-like peptide 1 (GLP-1) and nitrotyrosine between different test drinks were compared using linear mixed models. Results showed that only preloading decaffeinated coffee with milk and sugar led to significantly lower glucose incremental AUC (iAUC; 14 % lower, P = 0·001) than water. Preloading black coffees led to greater postprandial glucose iAUC than preloading coffees with milk and sugar added (12-35 % smaller, P < 0·05 for all coffee types). Active GLP-1 and nitrotyrosine levels were not significantly different between test drinks. To conclude, preloading decaffeinated coffee with milk and sugar led to a blunted postprandial glycaemic response after a subsequent high-GI meal, while adding milk and sugar into coffee could mitigate the impairment effect of black coffee towards postprandial glucose responses. These findings may partly explain the positive effects of coffee consumption on glucose metabolism.

Enhancing the selectivity of liquid chromatography-mass spectrometry by using trilinear decomposition on LC-MS data: An application to three-way calibration of coeluting analytes in human plasma.

The high selectivities of liquid chromatography and mass spectrometry make liquid chromatography-mass spectrometry one of the most popular tools for quantitative analysis in complex chemical, biological, and environmental systems, while the potential mathematical selectivity of liquid chromatography-mass spectrometry is rarely investigated. This work discussed the mathematical selectivity of liquid chromatography-mass spectrometry by three-way calibration based on the trilinear model, with an application to quantitative analysis of coeluting aromatic amino acids in human plasma. By the trilinear decomposition of the constructed liquid chromatography-mass spectrometry-sample trilinear model and individual regression of the decomposed relative intensity versus concentration, the proposed three-way calibration method successfully achieved quantitative analysis of coeluting aromatic amino acids in human plasma, even in the presence of uncalibrated interferent(s) and a varying background. This analytical method can ease the requirements for sample preparation and complete chromatographic separation of components, reduce the use of organic solvents, decrease the time of chromatographic separation, and increase the peak capacity of liquid chromatography-mass spectrometry. As a "green analytical method", the liquid chromatography-mass spectrometry three-way calibration method can provide a promising tool for direct and fast quantitative analysis in complex systems containing uncalibrated spectral interferents, especially for the situation where the coelution problem is difficult to overcome.

Silk sericin intake leads to increases in L-serine and L-tyrosine levels in the mouse brain and the simultaneous facilitation of brain noradrenergic turnover.

Sericin is a protein component of the silkworm cocoon, and contains a high proportion of L-serine, but it has been mostly disposed of as an industrial waste. However, recent studies have revealed its unique biological functionalities beneficial to human health. This study aimed to evaluate the effect of acute oral intake of sericin on amino acid and neurotransmitter metabolism in the mouse brain. Acute administration of chemically modified sericin (0.26 g/30 g body weight) increased L-serine and L-tyrosine levels in the serum and brain, although the L-tyrosine content in the sericin was less than 3% (w/w). In addition, sericin administration led to a significant facilitation of noradrenergic turnover via enhancement of 3-methoxy-4-hydroxyphenylethyleneglycol, a principal metabolite of noradrenaline, in several of the brain regions examined. These present findings suggest that oral intake of sericin efficiently delivers L-serine and L-tyrosine to the brain, thus stimulating noradrenergic activity in the brain.Abbreviations: DA: dopamine; 5-HIAA: 5-hydroxyindoleicetic acid; 5-HT: 5-hydroxytryptamine; HVA: homovanillic acid; MHPG: 3-methoxy-4-hydroxyphenylethyleneglycol; 3-MT: 3-methoxytyramine; NA: noradrenaline; NM: normetanephrine; Veh: vehicle.

Maternal serum nitrotyrosine, 8-isoprostane and total antioxidant capacity levels in pre-gestational or gestational diabetes mellitus.

OBJECTIVE: To evaluate serum concentration of 8-isoprostane, nitrotyrosine (NT), and total antioxidant capacity (TAC) in pregnant women with diabetes mellitus (DM) considering preconception planning and method of diabetes correction in 11-14 and 30-34 weeks. MATERIALS AND METHODS: The study included 130 women: T1DM (n = 40), T2DM (n = 35), gestational diabetes (GDM, n = 40) and the control group (n = 15). The serum concentrations of NT, 8-isoprostane, and TAC were measured by ELISA methods. RESULTS: Elevated 8-isoprostane levels were observed in all patients with DM, but this biomarker's maximum values have been seen in T1DM and T2DM on insulin groups. A similar tendency was observed for the concentration of NT in both the 1st and 3rd trimesters. TAC levels showed a statistically relevant decrease in all DM groups compared to the control. The correlation analysis showed a direct correlation between HbA1c and serum 8-isoprostane levels in the 1st (r = .27) and 3rd (r = .3) pregnancy trimesters as well as inverse correlation with TAC level (r = -.48). Direct (NT, 8-isoprostane) and inverse correlations (TAC) were fixated for this biomarker concentration and preeclampsia rates. CONCLUSION: DM in pregnancy is related to oxidative stress activation, which might lead to the development of adverse perinatal outcomes.

Sexual Dimorphism in Energy Metabolism of Wistar Rats Using Data Analysis.

The prevalence of some chronic diseases, such as cancer or neurodegenerative disorders, differs between sexes. Animal models provide an important tool to adopt potential therapies from preclinical studies to humans. Laboratory rats are the most popular animals in toxicology, neurobehavioral, or cancer research. Our study aimed to reveal the basic differences in blood metabolome (amino acids, biogenic amines, and acylcarnitines) of the adult male (n = 10) and female (n = 10) Wistar rats. Partial least square-discrimination analysis (PLS-DA) and a variance im portance in projection (VIP) score was used to identify the key sex-specific metabolites. All groups of metabolites, as the main markers of energy metabolism, showed a significant sex-dependent pattern. The most important features calculated in PLS-DA according to VIP score were free carnitine (C0), tyrosine (Tyr), and acylcarnitine C5-OH. While aromatic amino acids, such as Tyr and phenylalanine (Phe), were significantly elevated in the blood plasma of males, tryptophan (Trp) was found in higher levels in the blood plasma of females. Besides, significant sex-related changes in urea cycle were found. Our study provides an important insight into sex-specific differences in energy metabolism in rats and indicates that further studies should consider sex as the main aspect in design and data interpretation.

Simultaneous LC-MS/MS-Based Quantification of Free 3-Nitro-l-tyrosine, 3-Chloro-l-tyrosine, and 3-Bromo-l-tyrosine in Plasma of Colorectal Cancer Patients during Early Postoperative Period.

Quantification with satisfactory specificity and sensitivity of free 3-Nitro-l-tyrosine (3-NT), 3-Chloro-l-tyrosine (3-CT), and 3-Bromo-l-tyrosine (3-BT) in biological samples as potential inflammation, oxidative stress, and cancer biomarkers is analytically challenging. We aimed at developing a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method for their simultaneous analysis without an extract purification step by solid-phase extraction. Validation of the developed method yielded the following limits of detection (LOD) and quantification (LOQ) for 3-NT, 3-BT, and 3-CT: 0.030, 0.026, 0.030 ng/mL (LODs) and 0.100, 0.096, 0.098 ng/mL (LOQs). Coefficients of variation for all metabolites and tested concentrations were <10% and accuracy was within 95-105%. Method applicability was tested on colorectal cancer patients during the perioperative period. All metabolites were significantly higher in cancer patients than healthy controls. The 3-NT was significantly lower in advanced cancer and 3-BT showed a similar tendency. Dynamics of 3-BT in the early postoperative period were affected by type of surgery and presence of surgical site infections. In conclusion, a sensitive and specific LC-MS/MS method for simultaneous quantification of free 3-NT, 3-BT, and 3-CT in human plasma has been developed.

Insights into the Effects of Crack Abuse on the Human Metabolome Using a NMR Approach.

Approximately 255 million people consume illicit drugs every year, among which 18 million use cocaine. A portion of this drug is represented by crack, but it is difficult to estimate the number of users since most are marginalized. However, there are no recognized efficacious pharmacotherapies for crack-cocaine dependence. Inflammation and infection in cocaine users may be due to behavior adopted in conjunction with drug-related changes in the brain. To understand the metabolic changes associated with the drug abuse disorder and identify biomarkers, we performed a 1H NMR-based metabonomic analysis of 44 crack users' and 44 healthy volunteers' blood serum. The LDA model achieved 98% of accuracy. From the water suppressed 1H NMR spectra analyses, it was observed that the relative concentration of lactate was higher in the crack group, while long chain fatty acid acylated carnitines were decreased, which was associated with their nutritional behavior. Analyses of the aromatic region of CPMG 1H NMR spectra demonstrated histidine and tyrosine levels increased in the blood serum of crack users. The reduction of carnitine and acylcarnitines and the accumulation of histidine in the serum of the crack users suggest that histamine biosynthesis is compromised. The tyrosine level points to altered dopamine concentration.