A fast and efficient liquid chromatography-tandem mass spectrometry method for measuring l- and d-amino acids in the urine of patients with immunoglobulin A nephropathy.

Immunoglobulin nephropathy (IgAN) stands as the most prevalent primary glomerular nephropathy globally, typically diagnosed through an invasive renal biopsy. Emerging research suggests the significant involvement of chiral amino acids in kidney disease progression. This study introduces a nonderivative LC-tandem mass spectrometry approach, offering efficient separation outcomes within 15 min for identifying chiral amino acids in human urine samples. Subsequently, using this method, the analysis of l- and d-amino acids in the urine of both patients with IgAN and healthy individuals was conducted. Fourteen d-amino acids and 20 l-amino acids were identified in the urine samples obtained from 17 patients with IgAN and 21 healthy individuals. The results indicated notable variances in the concentrations of both l- and d-amino acids between the IgAN and healthy control groups. In contrast to the healthy group, the IgAN group exhibited higher mean urine concentrations of most l-amino acids and lower concentrations of d-amino acids. Furthermore, correlations between amino acids and clinical markers were investigated. These results propose a novel method for monitoring trace amino acids in urine samples and introduce a new concept for potential markers of IgAN.

Urinary metabolomic profiling reveals difference between two traditional Chinese medicine subtypes of coronary heart disease.

The World Health Organization has shown that coronary heart disease (CHD) is a more common cause of death than cancer. In traditional Chinese medicine (TCM), CHD is classified as a form of thoracic obstruction that can be divided in different subtypes including Qi stagnation with blood stasis (QS) and Qi deficiency with blood stasis (QD). Different treatment strategies are used based on this subtyping. Owing to the lack of scientific markers in the diagnosis of these subtypes, subjective judgments made by clinicians have limited the objective manner for utility of TCM in the treatment of CHD. Untargeted (UHPLC-QTOF-MS) and targeted (UHPLC-MS/MS) metabolomics approaches were employed to search significantly different metabolites related to the QS or QD subtypes of CHD with angina pectoris in this study. A total of 42 metabolites were obtained in the untargeted metabolomics analysis and 34 amino acids were detected in the targeted metabolomics analysis. In total, 16 metabolites were found significantly different among different groups. The results showed distinct metabolic profiles of urine samples not only between CHD patients and healthy controls, but also between the two subtypes of CHD. Pathway analysis of the significantly varied metabolites revealed that there were subtype-related differences in the activity of pathways. Therefore, urinary metabolomics can reveal the pathological changes of CHD in different subtypes, make the diagnosis of CHD in different subtypes in an objective manner and comprehensive and contribute to personalized treatment by providing scientific evidence.

Negative association between 25-hydroxyvitamin D and inflammatory markers in rheumatologic diseases / Asociación negativa entre 25-hidroxi vitamina D y los marcadores inflamatorios en enfermedades reumatológicas

Objective: The main purpose of this study was to evaluate serum 25-hydroxyvitamin D (25OHD) levels and its association with in"ammatory markers in patients with rheumatologic diseases (RD). Methods: A cross-sectional study in 154 women with RD (rheumatoid arthritis, spondyloarthritis and other connective tissue diseases) and 112 healthy individuals as a control group (CG) was carried out. Results: No differences in serum and urine calcium, serum phosphate, and urinary deoxypyridinoline were found. RD group had lower 25OHD and higher PTH compared to CG. RD group had higher C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) compared to CG. The overall mean level of 25OHD (ng/ml) was 26.3±12.0 in the CG and 19.4±6.8 in the RD group (p<0.0001). Moreover, CG had lower percentage of individuals with 25OHD de!ciency compared to RD (29.9% vs 53.2%). The femoral neck BMD was signi!cantly lower in postmenopausal RD women compared to CG. 25OHD levels signi!cantly correlated with ESR and CRP as in"ammatory markers. Age, BMI, presence of RD, and CRP were signi!cantly and negatively associated with 25OHD levels through linear regression analysis. According to univariate logistic regression analysis for 25OHD deficiency (<20 ng/ml), a significant and negative association with BMI, presence of RD, ESR and CRP were found. Conclusion: Patients with RD had lower 25OHD levels than controls and the presence of a RD increases by 2.66 the risk of vitamin D de!ciency. In addition, 25OHD has a negative correlation with ESR and CRP as in"ammatory markers. (AU)

Objetivo El objetivo principal de este estudio fue evaluar los niveles séricos de 25-hidroxivitamina D (25OHD) y su asociación con marcadores inflamatorios en enfermedades reumatológicas. Materiales y métodos: Se realizó un estudio transversal en 154 mujeres con enfermedades reumatológicas (artritis reumatoide, espondiloartritis y otras enfermedades del tejido conectivo) y 112 individuos sanos como grupo control (GC). Resultados: No se encontraron diferencias en el calcio sérico y urinario, el fosfato sérico y la desoxipiridinolina urinaria entre el GC y los sujetos con enfermedades reumatológicas. El grupo de pacientes con enfermedades reumatológicas tenía 25OHD más bajo y PTH más alto en comparación con el GC. Asimismo, el grupo de individuos con enfermedades reumatológicas tenía proteína C reactiva (PCR) y velocidad de eritrosedimentación (VES) más altas en comparación con el GC. El nivel de 25OHD (ng/ml) fue 26,3±12,0 en el GC y 19,4±6,8 en el grupo con enfermedades reumatológicas (p<0,0001). Además, el GC presentó un porcentaje menor de deficiencia de 25OHD en comparación con el grupo con enfermedades reumatológicas (29,9% vs 53,2%). La DMO del cuello femoral fue significativamente menor en las mujeres posmenopáusicas con enfermedades reumatológicas en comparación con el GC. La 25OHD correlacionó significativamente con la VES y la PCR como marcadores inflamatorios. El análisis de regresión lineal mostró que la edad, el IMC, la presencia de una enfermedad reumatológica y la PCR se asociaron significativa y negativamente con los niveles de 25OHD. Mientras que el análisis de regresión logística univariada mostró que la deficiencia de 25OHD (<20 ng/ml), se asoció significativa y negativamente con el IMC, la presencia de una enfermedad reumatológica, la VES y los niveles de PCR. Conclusiones: Los pacientes con enfermedades reumatológicas tenían niveles de 25OHD más bajos que los controles y la presencia de una enfermedad reumatológica aumenta en 2.66 el riesgo de deficiencia de vitamina D. Además, la 25OHD mostró correlación negativa con la VES y la PCR como marcadores inflamatorios. (AU)

Analysis of Bone Tissue Condition in Patients with Diffuse Large B-Cell Lymphoma without Bone Marrow Involvement.

We studied changes in the bone tissue in patients with diffuse large B-cell lymphoma at the onset of the disease (N=41; before chemotherapy) and 5-16 years after the end of treatment (N=47). Osteodensitometry, biochemical markers of osteoporosis in the blood and urine, and gene expression in multipotent mesenchymal stromal cells were analyzed. In multipotent mesenchymal stromal cells of all patients, the expression of genes associated with bone and cartilage differentiation (FGF2, FGFR1, FGFR2, BGLAP, SPP1, TGFB1, and SOX9) was changed. In primary patients, the ratio of deoxypyridinoline/creatinine in the urine and blood level of ß-cross-laps were increased, while plasma concentration of vitamin D was reduced, which indicates activation of bone resorption. No differences between the groups were revealed by osteodensitometry. No direct relationship between changes in gene expression in multipotent mesenchymal stromal cells and osteoporosis markers was found. The presence of a tumor in the body affects the bone marrow stroma, but achievement of remission and compensatory mechanisms provide age-appropriate condition of the bone tissue.

Substitution of high-dose sucrose with fructose in high-fat diets resulted in higher plasma concentrations of aspartic acid, cystine, glutamic acid, ornithine and phenylalanine, and higher urine concentrations of arginine and citrulline.

High fructose intake has been shown to increase circulating alanine transaminase in humans, which could reflect damage to the liver by fructose but could also be linked to higher level of transamination of amino acids in liver. Therefore, we hypothesized that a diet with high content of fructose would affect the amino acid composition in rat plasma and urine differently from a diet with high sucrose content. Because high intake of sucrose and fructose is often accompanied with high intake of saturated fat in the Western-style diet, we wanted to compare the effects of high fructose/sucrose in diets with normal or high content of coconut oil on individual free amino acids plasma and urine. Male Wistar rats were fed diets with normal (10 wt%) or high (40 wt%) content of sucrose or fructose, with normal or high fat content (7 or 22 wt%) and 20 wt% protein (casein). Rats fed high-fructose high-fat diet had higher plasma concentrations of aspartic acid, cystine, glutamic acid, ornithine, and phenylalanine and higher urine concentrations of arginine and citrulline when compared to rats fed high-sucrose high-fat diet. Substituting normal content of sucrose with fructose in the diets had little impact on amino acids in plasma and urine. Serum concentrations of alanine transaminase, aspartate transaminase, and creatinine, and urine cystatin C and T cell immunoglobulin mucin-1 concentrations were comparable between the groups and within normal ranges. To conclude, substituting high-dose sucrose with high-dose fructose in high-fat diets affected amino acid compositions in plasma and urine.

Abnormalities in metabolic pathways in celiac disease investigated by the metabolic profiling of small intestinal mucosa, blood plasma and urine by NMR spectroscopy.

Celiac disease (CeD) is an autoimmune enteropathy caused by gluten intake in genetically predisposed individuals. We investigated the metabolism of CeD by metabolic profiling of intestinal mucosa, blood plasma and urine using NMR spectroscopy and multivariate analysis. The metabolic profile of the small intestinal mucosa was compared between patients with CeD (n = 64) and disease controls (DCs, n = 30). The blood plasma and urinary metabolomes of CeD patients were compared with healthy controls (HCs, n = 39). Twelve metabolites (proline (Pro), arginine (Arg), glycine (Gly), histidine (His), glutamate (Glu), aspartate, tryptophan (Trp), fumarate, formate, succinate (Succ), glycerophosphocholine (GPC) and allantoin (Alln)) of intestinal mucosa differentiated CeD from controls. The metabolome of blood plasma with 18 metabolites (Pro, Arg, Gly, alanine, Glu, glutamine, glucose (Glc), lactate (Lac), acetate (Ace), acetoacetate (AcAc), ß-hydroxybutyrate (ß-OHB), pyruvate (Pyr), Succ, citrate (Cit), choline (Cho), creatine (Cr), phosphocreatine (PCr) and creatinine) and 9 metabolites of urine (Pro, Trp, ß-OHB, Pyr, Succ, N-methylnicotinamide (NMN), aminohippurate (AHA), indoxyl sulfate (IS) and Alln) distinguished CeD from HCs. Our data demonstrated changes in nine metabolic pathways. The altered metabolites were associated with increased oxidative stress (Alln), impaired healing and repair mechanisms (Pro, Arg), compromised anti-inflammatory and cytoprotective processes (Gly, His, NMN), altered energy metabolism (Glc, Lac, ß-OHB, Ace, AcAc, Pyr, Succ, Cit, Cho, Cr and PCr), impaired membrane metabolism (GPC and Cho) and intestinal dysbiosis (AHA and IS). An orthogonal partial least square discriminant analysis model provided clear differentiation between patients with CeD and controls in all three specimens. A classification model built by combining the distinguishing metabolites of blood plasma and urine samples gave an AUC of 0.99 with 97.7% sensitivity, 93.3% specificity and a predictive accuracy of 95.1%, which was higher than for the models built separately using small intestinal mucosa, blood plasma and urine. In conclusion, a panel of metabolic biomarkers in intestinal biopsies, plasma and urine samples has potential to differentiate CeD from controls and may complement traditional tests to improve the diagnosis of CeD.

Comparison of urinary amino acid excretory pattern in patients with type 2 diabetes mellitus and non-diabetic healthy controls at a tertiary referral hospital in India.

AIM: Specific amino acids have been linked to regulation of insulin secretion from pancreatic ß-cells; on the contrary, increased concentration of certain amino acids is associated with insulin resistance (IR) and development of type 2 diabetes mellitus (T2DM). Nowadays, urine as a biological sample has attracted more attention for diagnosis of disease for its special superiority; insufficient research in the study of urinary amino acid (UAA) pattern in patients with T2DM has led to the present study with the aim to determine the levels of UAAs, their excretory patterns and the association of UAA to plasma glucose and IR in patients with T2DM. METHODS: Quantification of total urinary amino acids was done spectrophotometrically and the patterns of amino acid excretion was elucidated by thin layer chromatography technique. Fasting blood samples were used for plasma glucose and insulin estimation by fully automated analyzer. RESULT: The levels of UAA in patients with T2DM in comparison to healthy controls were higher (p < 0.0001). The frequency of urinary phenylalanine, arginine, tryptophan, tyrosine and cysteine were significantly higher in patients with T2DM than controls. There was also a strong positive correlation of UAA levels with blood glucose levels and HOMA-IR in patients with T2DM. CONCLUSION: Our study has shown subtle abnormalities in UAA patterns in patients with T2DM. The measurement of UAA levels and excretory pattern can be used as an index of hyperglycemia and IR which could serve as an inexpensive and non-invasive marker for T2DM. More studies are required to confirm this association.

FEATURES OF CLINICAL SYMPTOMS AND SIGNS, HEMATOLOGICAL AND BIOCHEMICAL PARAMETERS IN CHILDREN WITH JOINT HYPERMOBILITY IN A LATE PERIOD UPON THE CHORNOBYL NPP ACCIDENT. / OSOBLYVOSTI KLINIChNOÏ SYMPTOMATYKY, GEMATOLOGIChNYKh TA BIOKhIMIChNYKh POKAZNYKIV U DITEY̆ Z GIPERMOBIL'NISTIu SUGLOBIV U VIDDALENYY̆ PERIOD PISLIa AVARIÏ NA ChORNOBYL'S'KIY̆ AES.

OBJECTIVE: establishing the types and frequency of disembriogenetic stigma in children with joint hypermobility given the clinical and laboratory features, genetic component and endocrine regulation of these disorders in a late period upon the accident. MATERIALS AND METHODS: Children (n = 109) inhabiting the radiologically contaminated territories and having the connective tissue dysplasia (CTD) signs were involved in the study. Diseases in family history, ossalgia complaints, fractures in a personal history, bone disembriogenetic stigma, joint hypermobility, type of somatic diseases, blood serum biochemical parameters (namely calcium, alkaline phosphatase, total protein, cholesterol, creatinine, iron, ferritin content), serum cortisol, free thyroxine, pituitary thyroid-stimulating hormone (TSH) levels, free amino acid composition in urine and radiation dose were considered. RESULTS: Radiation doses in children having the CTD ranged from (0.37 ± 0.11) mSv to (0.56 ± 0.10) mSv with no difference from that in those without CTD. Joint hypermobility (JHM) correlated with cancer in family history (rs = 0.53) and lower extremity varicose vein disease (rs = 0.40) (p < 0.05). Incidence of ossalgia, easy fatigability, and bone fractures was higher in children with CTD. Anomalies of the dentofacial system were first in line (38.5 %) in these children. Proportion of children with grade II JHM and platypodia was lower (rs = 0.42), but with lower extremity deformations was higher (rs = 0.68) (p < 0.05) vs. in the control group. Iron and ferritin deficiencies both with lymphocytosis were more common in children with CTD than in the comparison group (p < 0.05). The increased content of oxyproline, lysine, proline both with glycine deficiency were detected in children having the CTD, i.e. an imbalance of amino acids from the collagen content was observed featuring a predominance of catabolic processes over anabolic ones. There was a direct correlation between the TSH level and the JHM grade (rs = 0.49), although the values of hormone concentration in these children did not exceed the reference range (maximum values were 3.3 µIU/ml). CONCLUSIONS: The revealed abnormalities in amino acid content, ferrokinetics, and thyroid function indices can affect the collagen formation, organic matrix structure of bone tissue and significantly deregulate the hemato- poiesis. The later can underlie the pathways of haematologic malignancy development.

Elevated FGF23 and disordered renal mineral handling with reduced bone mineralization in chronically erythropoietin over-expressing transgenic mice.

Fibroblast Growth Factor 23 (FGF23) is a phosphaturic factor causing increased renal phosphate excretion as well as suppression of 1,25 (OH)2-vitamin D3. Highly elevated FGF23 can promote development of rickets and osteomalacia. We and others previously reported that acute application of erythropoietin (EPO) stimulates FGF23 production. Considering that EPO is clinically used as chronic treatment against anemia, we used here the Tg6 mouse model that constitutively overexpresses human EPO in an oxygen-independent manner, to examine the consequences of long-term EPO therapy on mineral and bone metabolism. Six to eight weeks old female Tg6 mice showed elevated intact and C-terminal fragment of FGF23 but normal plasma levels of PTH, calcitriol, calcium and phosphate. Renal function showed moderate alterations with higher urea and creatinine clearance and mild albuminuria. Renal phosphate excretion was normal whereas mild hypercalciuria was found. Renal expression of the key proteins TRPV5 and calbindin D28k involved in active calcium reabsorption was reduced in Tg6 mice. Plasma levels of the bone turnover marker osteocalcin were comparable between groups. However, urinary excretion of deoxypyridinoline (DPD) was lower in Tg6 mice. MicroCT analysis showed reduced total, cortical, and trabecular bone mineral density in femora from Tg6 mice. Our data reveal that chronic elevation of EPO is associated with high FGF23 levels and disturbed mineral homeostasis resulting in reduced bone mineral density. These observations imply the need to study the impact of therapeutically applied EPO on bone mineralization in patients, especially those suffering from chronic kidney disease.

The urinary levels of CTX-II, C2C, PYD, and Helix-II increased among adults with KBD: a cross-sectional study.

BACKGROUND: Kashin-Beck disease (KBD) is an endemic osteoarthropathy, and its pathogenesis is still not entirely clear. Pathologically, many KBD changes are similar to those of osteoarthritis (OA). Therefore, this study aimed to identify changes in the levels of potential urinary biomarkers for OA, including C-telopeptide of type II collagen (uCTX-II), type II collagen cleavage neoepitope (uC2C), pyridinoline (uPYD), and uHelix-II, among adults with KBD. METHODS: Urinary samples of 83 external control (EC) subjects, 91 KBD patients, and 86 internal control (IC) subjects were tested by ELISA after the subjects completed a questionnaire and X-ray examination. RESULTS: The medians of the four markers in the KBD group were higher than those in the EC group and those in the IC group. The medians in the grade II KBD group were higher than those in the grade I group but were not statistically significant (P = 0.301, P = 0.408, P = 0.204, and P = 0.898 for uCTX-II, uC2C, uPYD, and uHelix-II, respectively). The area under the curve (AUC) of uCTX-II (0.775) was higher than that of the others (0.672, 0.639, and 0.628 for uC2C, uPYD, and uHelix-II, respectively). CONCLUSION: The levels of uCTX-II, uC2C, uPYD, and uHelix-II were elevated in adults with KBD and showed an increasing trend as the severity of KBD increased. The prediction accuracy of uCTX-II was more useful than that of the others for assisting in the diagnosis of KBD.

Application of Butylamine as a Conjugative Reagent to On-Column Derivatization for the Determination of Antioxidant Amino Acids in Brain Tissue, Plasma, and Urine Samples.

(1) Antioxidants are involved in body protection mechanisms against reactive oxygen species. Amino acids such as glutathione (GSH) and N-acetylcysteine (NAC) are known to be involved in providing protection against oxidative lethality. A quick and simple method for the determination of NAC and GSH in various biological matrices such as urine, plasma, and homogenates of brain tissues has been developed and described in this work. (2) The assay is based on reversed phase high performance liquid chromatography with spectrofluorimetric detection and on-column derivatization. Butylamine and o-phthaldialdehyde have been used as derivatization reagents. Since o-phthaldialdehyde constitutes a part of the mobile phase, the derivatization reaction and chromatographic separation occur simultaneously. (3) Linearity in the detector response for NAC in human urine was observed in the range of 5-200 nmol mL-1, and NAC and GSH in the brain tissue homogenates were observed in the range of 0.5-5 nmol mL-1 and 0.5-15 nmol mL-1, respectively. Human plasma linearity ranges covered 0.25-5.00 nmol mL-1 and 0.5-15 nmol mL-1 for NAC and GSH, respectively. The LODs for NAC and GSH were 0.01 and 0.02 nmol mL-1 while the LOQs were 0.02 and 0.05 nmol mL-1, respectively. The usefulness of the proposed method was proven through its application to real samples.

Human urine metabolomic signature after ingestion of polyphenol-rich juice of purple grumixama (Eugenia brasiliensis Lam.).

Polyphenol intake has been associated with health promotion because of its interaction with several metabolic pathways. This study investigates changes in the urine metabolome following acute intake of polyphenol-rich juice, purple grumixama juice. Grumixama (Eugenia brasiliensis Lam.) is a cherry native to Brazil that is known to be a rich source of anthocyanins and ellagitannins. In this research 15 healthy subjects consumed a single dose of grumixama juice. Urine samples were collected before grumixama juice intake, 0-1, 1-2, 2-4 h, with fasting at 24 h after intake. Plasma samples were also collected before intake, 30' and at 1 h, 2 h and 4 h, with fasting at 24 h after juice intake. The urine primary metabolites were analysed by a metabolomic approach using gas chromatography mass spectrometry with methyl chloroformate derivatisation for amino acids and organic acids. Also, an oxygen radical absorbance capacity method was carried out to evaluate the plasma samples antioxidant capacity changes. Subjects showed increase in plasma antioxidant capacity after juice intake (p-values < .05). A total of 114 metabolites were assessed in urine (1-2 h and 2-4 h), including 17 amino acids, 47 organic acids and several other metabolites. Among the 114 metabolites, 25 were significantly changed during the first 4 h following juice intake, as shown by the Orthogonal Partial Least Squares Discriminant Analysis (0.5 > p(corr) > 0.3) and univariate analysis (p-values < .05). Some metabolites were related to mitochondrial metabolism, such as glyoxylic acid and oxalic acid. Metabolites related to amino acid metabolism were also changed, such as beta-alanine, l-phenylalanine and l-tyrosine. In conclusion, results suggest that acute intake of grumixama juice could affect amino acid metabolism and mitochondrial metabolism, but the related health implications should be explored in further studies using additional approaches.

Metabolic disorder of amino acids, fatty acids and purines reflects the decreases in oocyte quality and potential in sows.

Oocyte quality is closely related to female fertility. Nevertheless, core nutritional metabolites influencing oocyte quality are unclear. Herein, comprehensive metabolomics analysis of follicular fluid, serum, and urine from low reproductive performance (LRP) and normal reproductive performance (NRP) sows was conducted. Twenty-seven, fourteen and sixteen metabolites (involved in metabolism of amino acids, fatty acids, purine and pyrimidine) were altered in follicular fluid, serum and urine, respectively, in LRP compared with NRP sows, and could decrease oocyte quality and developmental potential, ultimately leading to low fertility. Deoxyinosine, guanidine acetate, thymidine, 5,6-epoxy-eicosatrienoic acid, carnosine, docosahexaenoic acid and carbamoyl phosphate in follicular fluid, cysteine, carnitine, serotonin, hypoxanthine, valine and arginine in serum, as well as carnitine, phenyl glycine, N-acetyl glutamine, propionyl carnitine and choline in urine could be selected as diagnostic markers to indicate oocyte quality. Consistent with metabolomics data, we confirmed changes in concentrations of fatty acids and amino acids in follicular fluid. Targeting purine metabolism, elevating levels of deoxyinosine in in-vitro maturation medium of porcine oocyte significantly promoted the blastocyst rate. Collectively, this study provided new information of potential targets for predicting oocyte quality and developmental potential, and may help with strategies for early diagnosis or therapeutic/dietary intervention in improving reproductive outcomes.

The levels of urine CTX-II, C2C, and PYD in children patients with Kashin-Beck disease in Qinghai Province of China.

BACKGROUND: Kashin-Beck disease (KBD) is an endemic and chronic osteoarthropathy. At present, the diagnosis of KBD mainly depends on the X-ray examination and which could not reflect early damage of cartilage sensitively. So, the aim of this study was to find effective and sensitive biomarkers for early diagnosis of pediatric KBD. METHODS: A total of 122 children aged 7-15 years old from 3 villages of Qinghai Province were eligible for the study. Thirty-one, 41, and 50 children were assigned in case, internal, and external control groups, respectively. The levels of CTX-II, C2C, and PYD in urine were measured by using ELISA and compared statistically. In addition, the receiver operating characteristic curve (ROC) analysis was used to assess the performance of diagnostic biomarkers. RESULTS: There were significant differences in levels of CTX-II, C2C, and PYD in urine of subjects among three groups. The levels of CTX-II and PYD in the case group were significantly higher than those in external and internal control groups. On the contrary, the level of C2C in the case group was lower than that in the external control group. Compared to the external control group, the area under the curve (AUC) of CTX-II, C2C, and PYD were 0.857, 0.837, and 0.79, and the AUC of CTX-II significantly higher than that of PYD. Compared to the internal control group, the AUC of CTX-II, C2C, and PYD were 0.911, 0.875, and 0.839, and there were no significant differences in the AUC among three indicators. CONCLUSION: Both CTX-II and PYD in urine could be used as biomarkers for early diagnosis of pediatric KBD, and the prediction accuracy of CTX-II was relatively superior.

Development of a metabolic pathway-based pseudo-targeted metabolomics method using liquid chromatography coupled with mass spectrometry.

The pseudo-targeted metabolomics approach was developed recently which combined the advantages of untargeted and targeted analysis. However, the current pseudo-targeted analysis method has limitations due to the technical characteristics. In this study, a novel metabolic pathway-based pseudo-targeted approach was proposed for urine metabolomics analysis using an ultra-high-performance liquid chromatography (UPLC)-MS/MS system operated in the multiple reaction monitoring (MRM) mode. MRM ion pairs were acquired from urine samples through untargeted analysis using UPLC-HRMS, as well as by searching for metabolites in related pathways in relevant databases and from previous relevant research, including amino acids, fatty acids, nucleosides, carnitines, glycolysis metabolites, and steroids. This improved pseudo-targeted method exhibited good repeatability and precision, and no complicated peak alignment was required. As a proof of concept, the developed novel method was applied to the discovery of urine biomarkers for patients with esophageal squamous cell carcinoma (ESCC). The results showed that ESCC patients had altered acylcarnitines, amino acids, nucleosides, and steroid derivative levels et al. compared to those of healthy controls. The novelty of this study lies in the fact that it provides an approach for acquiring MRM ion pairs not only from untargeted MS analysis but also from targeted searching for metabolites in related metabolic pathways. By improving the detection limit of low-abundance metabolites, it enlarges the range for the discovery of potential biomarkers. Our work provides a foundation for achieving pseudo-targeted metabolomics analysis on the widely used LC-MS/MS MRM platform.

Dietary intake of cod protein beneficially affects concentrations of urinary markers of kidney function and results in lower urinary loss of amino acids in obese Zucker fa/fa rats.

Obesity increases the risk for developing kidney disease, and protection of kidneys through changes in diet should be investigated. Fish intake has been associated with reduced risk of developing kidney disease; therefore, we wanted to investigate whether cod protein intake could prevent or delay the development of kidney damage in an obese rat model that spontaneously develops proteinuria and focal segmental glomerulosclerosis. The aim of the study was to investigate any effects of cod protein intake on established markers of kidney function, amino acid composition, protein utilisation and growth in obese Zucker fa/fa rats in the early stage of decreased renal function. Male obese Zucker fa/fa rats (HsdOla:Zucker-Lepr) were fed cod muscle proteins in an amount corresponding to 25 % of dietary protein, with the remaining protein from a casein/whey mixture (COD diet). A control group was fed a diet with a casein/whey mixture as the only protein source (CAS diet). The intervention started when rats were 9-10 weeks old, and the rats were fed these diets for 4 weeks. At the end of the study, rats fed the COD diet had lower urine concentration of cystatin C, T-cell immunoglobulin mucin-1 (TIM-1), amino acids, carbamide, uric acid and ammonium and higher concentrations of creatine, trimethylamine N-oxide, 1-methylhistidine and 3-methylhistidine, lower kidney concentration of TIM-1 and showed better growth when compared with the CAS group. To conclude, cod protein may have the potential to delay the development of kidney damage in young obese Zucker rats and to improve protein utilisation and growth.

Clinical, Biochemical, and Genetic Findings of Cystinuria in Chinese Children.

BACKGROUND: Cystinuria is a rare inherited renal stone disease caused by mutations in the SLC3A1 and SLC7A9 genes. The Chinese cystinuria phenotype and genotype have rarely been reported in the literature. METHODS: For this research, the clinical features and genetic etiology were analyzed in seven children, and the clinical characteristics were summarized. The blood and urine amino acids and acylcarnitine were analyzed. Additionally, the whole coding sequence and exon-intron junctions of the SLC3A1 and SLC7A9 genes were analyzed. RESULTS: These seven patients with cystinuria were from seven unrelated Chinese families, and they were diagnosed between the ages of 1 month and 16 years old. The urinary amino acids, including ornithine, arginine, and threonine, were elevated in these patients. A homozygous c.325G>A mutation in SLC7A9 was identified in two patients, and six SLC3A1 mutations were found in five patients. CONCLUSIONS: The core pedigree analysis showed that most of the parents carried mutations; however, there was no association between the clinical course and the genotype.

Levetiracetam and lamotrigine effects as mono- and polytherapy on bone mineral density in epileptic patients / Efeitos do levetiracetam e lamotrigina, em mono e politerapia, na densidade mineral óssea de pacientes epilépticos

ABSTRACT The purpose of this study was to determine the effect of lamotrigine (LTG) and levetiracetam (LEV) as mono- and polytherapy on biochemical markers of bone turnover and bone mineral density in Egyptian adult patients with epilepsy. Methods Forty-eight patients were divided into four groups: two received monotherapy of either LTG or LEV, and the other two groups received polytherapy comprising (valproate [VPA] + LTG or VPA + LEV). Thirty matched healthy participants were included in the study. Participants completed a nutritional and physical activity questionnaire. Biochemical markers of bone and mineral metabolism and bone mineral density of the lumbar spine were measured at baseline and at six months. Results In the LEV monotherapy group, the bone formation markers showed a significant decrease in serum alkaline phosphatase and serum osteocalcin levels while the bone resorption marker showed a significant increase in urinary deoxypyridinoline levels. After six months of treatment, bone mineral density showed a significant decrease in all treated groups, while among monotherapy groups, this significant decrease was more prevalent in the LEV monotherapy group compared with the LTG monotherapy group. Furthermore, there was significant negative correlation between urinary deoxypyridinoline levels and bone mineral density in the LEV monotherapy group. Conclusion Using new generation antiepileptics, LEV monotherapies and polytherapy showed harmful effects on bone but LTG did not.

RESUMO O objetivo deste estudo foi determinar o efeito da lamotrigina (LTG) e levetiracetam (LEV) como mono e politerapia em marcadores bioquímicos de remodelação óssea e densidade mineral óssea em pacientes adultos egípcios com epilepsia. Métodos Quarenta e oito pacientes foram divididos em quatro grupos: dois grupos receberam monoterapia de LTG ou LEV e os outros dois grupos receberam politerapia (valproato [VPA] + LTG ou VPA + LEV). Trinta participantes saudáveis controle foram incluídos no estudo. Os participantes preencheram um questionário nutricional e de atividade física. Marcadores bioquímicos do metabolismo ósseo e mineral e densidade mineral óssea da coluna lombar foram medidos no início e aos seis meses. Resultados No grupo de monoterapia LEV, os marcadores de formação óssea mostraram uma diminuição significativa nos níveis séricos de fosfatase alcalina e osteocalcina sérica, enquanto o marcador de reabsorção óssea mostrou um aumento significativo nos níveis de desoxipiridinolina urinária. Após seis meses de tratamento, a densidade mineral óssea mostrou uma diminuição significativa em todos os grupos tratados, enquanto entre os grupos de monoterapia, esta diminuição significativa foi mais prevalente no grupo de monoterapia LEV em comparação com o grupo de monoterapia LTG. Além disso, houve correlação negativa significativa entre os níveis de desoxipiridinolina urinária e densidade mineral óssea no grupo de monoterapia LEV. Conclusão Utilizando antiepilépticos de nova geração, as monoterapias LEV e a politerapia mostraram efeitos prejudiciais no osso, mas a LTG não.

Urinary Metabolites Associated with Blood Pressure on a Low- or High-Sodium Diet.

Dietary salt intake has significant effects on arterial blood pressure and the development of hypertension. Mechanisms underlying salt-dependent changes in blood pressure remain poorly understood, and it is difficult to assess blood pressure salt-sensitivity clinically. Methods: We examined urinary levels of metabolites in 103 participants of the Dietary Approaches to Stop Hypertension (DASH)-Sodium trial after nearly 30 days on a defined diet containing high sodium (targeting 150 mmol sodium intake per day) or low sodium (50 mmol per day). Targeted chromatography/mass spectrometry analysis was performed in 24 h urine samples for 47 amino metabolites and 10 metabolites related to the tricarboxylic acid cycle. The effect of an identified metabolite on blood pressure was examined in Dahl salt-sensitive rats. Results: Urinary metabolite levels improved the prediction of classification of blood pressure salt-sensitivity based on race, age and sex. Random forest and generalized linear mixed model analyses identified significant (false discovery rate <0.05) associations of 24 h excretions of ß-aminoisobutyric acid, cystine, citrulline, homocysteine and lysine with systolic blood pressure and cystine with diastolic blood pressure. The differences in homocysteine levels between low- and high-sodium intakes were significantly associated with the differences in diastolic blood pressure. These associations were significant with or without considering demographic factors. Treatment with ß-aminoisobutyric acid significantly attenuated high-salt-induced hypertension in Dahl salt-sensitive rats. Conclusion: These findings support the presence of new mechanisms of blood pressure regulation involving metabolic intermediaries, which could be developed as markers or therapeutic targets for salt-sensitive hypertension.

Fast and accurate quantitative organic acid analysis with LC-QTOF/MS facilitates screening of patients for inborn errors of metabolism.

Since organic acid analysis in urine with gaschromatography-mass spectrometry (GC-MS) is a time-consuming technique, we developed a new liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF/MS) method to replace the classical analysis for diagnosis of inborn errors of metabolism (IEM). Sample preparation is simple and experimental time short. Targeted mass extraction and automatic calculation of z-scores generated profiles characteristic for the IEMs in our panel consisting of 71 biomarkers for defects in amino acids, neurotransmitters, fatty acids, purine, and pyrimidine metabolism as well as other disorders. In addition, four medication-related metabolites were included in the panel. The method was validated to meet Dutch NEN-EN-ISO 15189 standards. Cross validation of 24 organic acids from 28 urine samples of the ERNDIM scheme showed superiority of the UPLC-QTOF/MS method over the GC-MS method. We applied our method to 99 patient urine samples with 32 different IEMs, and 88 control samples. All IEMs were unambiguously established/diagnosed using this new QTOF method by evaluation of the panel of 71 biomarkers. In conclusion, we present a LC-QTOF/MS method for fast and accurate quantitative organic acid analysis which facilitates screening of patients for IEMs. Extension of the panel of metabolites is easy which makes this application a promising technique in metabolic diagnostics/laboratories.