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1.
Int Braz J Urol ; 46(1): 70-80, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31851461

RESUMO

OBJECTIVE: To analyze the compositions of upper urinary tract stones and investigate their distributions in different gender and age groups. MATERIALS AND METHODS: Patients diagnosed with upper urinary tract stone disease between December 2014 and March 2018 were retrospectively reviewed. Patient's age, gender, BMI, comorbidities, stone event characteristics, and compositions were collected, and proportions of stone components in different gender and age groups were analyzed. RESULTS: A total of 1532 stone analyses were performed (992 from males and 540 from females). The mean age was younger in males (p<0.001). Males included more cases with larger BMI, hyperuricemia, and obesity, while females had more urinary tract infections. Multiple components were present in 61.8% of stones. Calcium oxalate (CaOx) (67.0%) was the most common component, followed by uric acid (UA) (11.8%), infection stone (11.4%), calcium phosphate (CaP) (8.0%), cystine (1.1%), brushite (0.4%), and 2,8-dihydroxyadenine (0.2%). Men contributed with more CaOx stones than women at age 30-49 years (all p<0.01) and more UA stones at 30-59 years (all p<0.05). Women contributed with more infection stones than men in age groups 30-49 and 60-69 years (all p<0.05), and more CaP stones at 30-49 years. The prevalence peak was 50-59 years in men and 60-69 years in women. Both genders had the lowest prevalence in adolescence. Prevalence of UA stones increased while that of infection stones decreased with aging in both genders. CONCLUSIONS: Age and sex had a strong association with distribution of stone compositions in this Chinese cohort.


Assuntos
Cálculos Urinários/química , Cálculos Urinários/epidemiologia , Adenina/análogos & derivados , Adenina/análise , Adulto , Distribuição por Idade , Fatores Etários , Oxalato de Cálcio/análise , Fosfatos de Cálcio/análise , China/epidemiologia , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Fatores de Risco , Distribuição por Sexo , Fatores Sexuais , Ácido Úrico/análise , Cálculos Urinários/etiologia
2.
Nat Commun ; 10(1): 5321, 2019 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-31757965

RESUMO

Surface-enhanced Raman spectroscopy (SERS) sensing of DNA bases by plasmonic nanopores could pave a way to novel methods for DNA analyses and new generation single-molecule sequencing platforms. The SERS discrimination of single DNA bases depends critically on the time that a DNA strand resides within the plasmonic hot spot. In fact, DNA molecules flow through the nanopores so rapidly that the SERS signals collected are not sufficient for single-molecule analysis. Here, we report an approach to control the residence time of molecules in the hot spot by an electro-plasmonic trapping effect. By directly adsorbing molecules onto a gold nanoparticle and then trapping the single nanoparticle in a plasmonic nanohole up to several minutes, we demonstrate single-molecule SERS detection of all four DNA bases as well as discrimination of single nucleobases in a single oligonucleotide. Our method can be extended easily to label-free sensing of single-molecule amino acids and proteins.


Assuntos
DNA/análise , Nanopartículas Metálicas , Nanoporos , Pinças Ópticas , Imagem Individual de Molécula/métodos , Análise Espectral Raman/métodos , Adenina/análise , Citosina/análise , DNA/química , Ouro , Guanina/análise , Óptica e Fotônica , Timina/análise
3.
Anal Chim Acta ; 1079: 86-93, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31387723

RESUMO

The as-prepared SWNTs are always a mixture of metallic (m-) and semiconducting (s-) tubes with quite different electrochemical properties which is a major barrier for their application in many fields. Based on the noncovalent interactions between planar aromatic molecules and SWNTs, the pyrene derivatives 1-docosyloxylmethylpyrene (DomP) was synthesized to separate the m-SWNTs and s-SWNTs via its significant selectivity toward s-SWNTs, i.e. electronic modulation. Before and after doping with electron, the electrochemical properties of s-SWNTs were studied and compared with that of m-SWNTs by electronic absorption spectroscopy, electrochemical impedance spectroscopy and cyclic voltammogram. As demonstrated, the electrocatalytic activity of electron modulated s-SWNTs was significantly improved and even better than m-SWNTs. Thus a novel sensor was constructed with the electron modulated s-SWNTs modified electrode and successfully applied for simultaneous determination of guanine and adenine.


Assuntos
Adenina/análise , Guanina/análise , Nanotubos de Carbono/química , Espectroscopia Dielétrica , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Concentração de Íons de Hidrogênio , Limite de Detecção , Pirenos/síntese química , Pirenos/química
4.
Mikrochim Acta ; 186(7): 427, 2019 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-31187299

RESUMO

An electrochemical sensor for adefovir dipivoxil (ADV) detection was prepared by electropolymerization of o-phenylenediamine in the presence of ADV on a glassy carbon electrode modified with multi-walled carbon nanotubes and carbon nitride. The electrode was characterized by field emission scanning electron microscopy and differential pulse voltammetry. The performance was optimized by response surface methodology. The changes in differential pulse voltammetric peak currents of the redox probe, ferricyanide, were linear to ADV concentrations in the range from 0.1 to 9.9 µmol L-1, with the detection limit of 0.05 µmol L-1 (S/N = 3). The sensor was applied to the determination of ADV in drug formulations, human serum and urine samples. It is selective due to the use of an imprinted material, well reproducible, long-term stable, and regenerable. Graphical abstract By merging the unique properties of carbon nitride with intrinsic properties of MWCNTs, and molecularly imprinted polymers, a novel electrochemical sensor with selective binding sites was prepared for determination of adefovir dipivoxil in pharmaceutical and biological samples.


Assuntos
Adenina/análogos & derivados , Técnicas Eletroquímicas/métodos , Nanocompostos/química , Nanotubos de Carbono/química , Nitrilos/química , Organofosfonatos/análise , Fenilenodiaminas/química , Adenina/análise , Adenina/sangue , Adenina/urina , Técnicas Eletroquímicas/instrumentação , Eletrodos , Humanos , Limite de Detecção , Impressão Molecular , Organofosfonatos/sangue , Organofosfonatos/urina , Reprodutibilidade dos Testes
5.
BMC Genomics ; 20(1): 445, 2019 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-31159718

RESUMO

BACKGROUND: Directed DNA methylation on N6-adenine (6mA), N4-cytosine (4mC), and C5-cytosine (5mC) can potentially increase DNA coding capacity and regulate a variety of biological functions. These modifications are relatively abundant in bacteria, occurring in about a percent of all bases of most bacteria. Until recently, 5mC and its oxidized derivatives were thought to be the only directed DNA methylation events in metazoa. New and more sensitive detection techniques (ultra-high performance liquid chromatography coupled with mass spectrometry (UHPLC-ms/ms) and single molecule real-time sequencing (SMRTseq)) have suggested that 6mA and 4mC modifications could be present in a variety of metazoa. RESULTS: Here, we find that both of these techniques are prone to inaccuracies, which overestimate DNA methylation concentrations in metazoan genomic DNA. Artifacts can arise from methylated bacterial DNA contamination of enzyme preparations used to digest DNA and contaminating bacterial DNA in eukaryotic DNA preparations. Moreover, DNA sonication introduces a novel modified base from 5mC that has a retention time near 4mC that can be confused with 4mC. Our analyses also suggest that SMRTseq systematically overestimates 4mC in prokaryotic and eukaryotic DNA and 6mA in DNA samples in which it is rare. Using UHPLC-ms/ms designed to minimize and subtract artifacts, we find low to undetectable levels of 4mC and 6mA in genomes of representative worms, insects, amphibians, birds, rodents and primates under normal growth conditions. We also find that mammalian cells incorporate exogenous methylated nucleosides into their genome, suggesting that a portion of 6mA modifications could derive from incorporation of nucleosides from bacteria in food or microbiota. However, gDNA samples from gnotobiotic mouse tissues found rare (0.9-3.7 ppm) 6mA modifications above background. CONCLUSIONS: Altogether these data demonstrate that 6mA and 4mC are rarer in metazoa than previously reported, and highlight the importance of careful sample preparation and measurement, and need for more accurate sequencing techniques.


Assuntos
Adenina/análogos & derivados , Artefatos , Citosina/análogos & derivados , Metilação de DNA , DNA/genética , Eucariotos/genética , Genoma , Adenina/análise , Adenina/metabolismo , Animais , Células Cultivadas , Citosina/análise , Citosina/metabolismo , Genômica , Humanos , Camundongos , Mioblastos/citologia , Mioblastos/metabolismo
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 215: 266-275, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30831397

RESUMO

Spectrophotometric analysis method based on artificial neural network (ANN), partial least squares regression (PLS) and principal component regression (PCR) models was proposed for the simultaneous determination of Emtricitabine (ETB) and Tenofovir alafenamide fumarate (TAF) in human immunodeficiency virus (HIV) drug. An artificial neural network consisting of two, five, and seven layers with 2,3,5,7, and 9 neurons was trained by applying a feed forward back-propagation learning. In this method, Levenberg-Marquardt (LM) and gradient descent with momentum and adaptive learning rate back propagation (GDX) algorithms were used. Statistical parameters indicated that the ability of LM was better than GDX algorithm. Also, root mean square error (RMSE) and recovery (%) of the PLS and PCR methods showed that PLS has worked better than PCR. The proposed models were compared to the high- performance liquid chromatography (HPLC) as a reference method. Furthermore, the obtained results of the one-way analysis of variance (ANOVA) test at the 95% confidence level represented that there was no significant difference between the proposed and reference methods.


Assuntos
Adenina/análogos & derivados , Fármacos Anti-HIV/análise , Emtricitabina/análise , Redes Neurais de Computação , Espectrofotometria Ultravioleta/métodos , Adenina/análise , Adenina/química , Fármacos Anti-HIV/química , Calibragem , Emtricitabina/química , Análise dos Mínimos Quadrados , Análise Multivariada
8.
Nat Protoc ; 14(1): 283-312, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30559375

RESUMO

DNA contains not only canonical nucleotides but also a variety of modifications of the bases. In particular, cytosine and adenine are frequently modified. Determination of the exact quantity of these noncanonical bases can contribute to the characterization of the state of a biological system, e.g., determination of disease or developmental processes, and is therefore extremely important. Here, we present a workflow that includes detailed description of critical sample preparation steps and important aspects of mass spectrometry analysis and validation. In this protocol, extraction and digestion of DNA by an optimized spin-column and enzyme-based method are described. Isotopically labeled standards are added in the course of DNA digestion, which allows exact quantification by isotope dilution mass spectrometry. To overcome the major bottleneck of such analyses, we developed a short (~14-min-per-sample) ultra-HPLC (UHPLC) and triple quadrupole mass spectrometric (QQQ-MS) method. Easy calculation of the modification abundance in the genome is possible with the provided evaluation sheets. Compared to alternative methods, the quantification procedure presented here allows rapid, ultrasensitive (low femtomole range) and highly reproducible quantification of different nucleosides in parallel. Including sample preparation and evaluation, quantification of DNA modifications can be achieved in less than a week.


Assuntos
Adenina/análise , Cromatografia Líquida de Alta Pressão/métodos , Citosina/análise , DNA/química , Nucleosídeos/análise , Espectrometria de Massas em Tandem/métodos , Adenina/química , Animais , Linhagem Celular , Cerebelo/química , Citosina/química , Células HEK293 , Humanos , Hidrólise , Técnicas de Diluição do Indicador/instrumentação , Marcação por Isótopo/métodos , Camundongos , Camundongos Endogâmicos C57BL , Nucleosídeos/química , Células-Tronco Pluripotentes , Microextração em Fase Sólida/métodos , Fluxo de Trabalho
9.
Cell ; 175(5): 1228-1243.e20, 2018 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-30392959

RESUMO

Genetic drivers of cancer can be dysregulated through epigenetic modifications of DNA. Although the critical role of DNA 5-methylcytosine (5mC) in the regulation of transcription is recognized, the functions of other non-canonical DNA modifications remain obscure. Here, we report the identification of novel N6-methyladenine (N6-mA) DNA modifications in human tissues and implicate this epigenetic mark in human disease, specifically the highly malignant brain cancer glioblastoma. Glioblastoma markedly upregulated N6-mA levels, which co-localized with heterochromatic histone modifications, predominantly H3K9me3. N6-mA levels were dynamically regulated by the DNA demethylase ALKBH1, depletion of which led to transcriptional silencing of oncogenic pathways through decreasing chromatin accessibility. Targeting the N6-mA regulator ALKBH1 in patient-derived human glioblastoma models inhibited tumor cell proliferation and extended the survival of tumor-bearing mice, supporting this novel DNA modification as a potential therapeutic target for glioblastoma. Collectively, our results uncover a novel epigenetic node in cancer through the DNA modification N6-mA.


Assuntos
Adenina/análogos & derivados , Neoplasias Encefálicas/patologia , Metilação de DNA , Glioblastoma/patologia , Adenina/análise , Adenina/química , Adulto , Idoso , Homólogo AlkB 1 da Histona H2a Dioxigenase/antagonistas & inibidores , Homólogo AlkB 1 da Histona H2a Dioxigenase/genética , Homólogo AlkB 1 da Histona H2a Dioxigenase/metabolismo , Animais , Astrócitos/citologia , Astrócitos/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/mortalidade , Hipóxia Celular , Criança , Epigenômica , Feminino , Glioblastoma/metabolismo , Glioblastoma/mortalidade , Heterocromatina/metabolismo , Histonas/metabolismo , Humanos , Estimativa de Kaplan-Meier , Masculino , Camundongos , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/citologia , Células-Tronco Neoplásicas/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Proteína Supressora de Tumor p53/metabolismo
10.
Anal Chem ; 90(21): 12625-12630, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30290117

RESUMO

Hydroxyl radical protein footprinting (HRPF) is a powerful method for measuring protein topography, allowing researchers to monitor events that alter the solvent accessible surface of a protein (e.g., ligand binding, aggregation, conformational changes, etc.) by measuring changes in the apparent rate of reaction of portions of the protein to hydroxyl radicals diffusing in solution. Fast Photochemical Oxidation of Proteins (FPOP) offers an ultrafast benchtop method for radical generation for HRPF, photolyzing hydrogen peroxide using a UV laser to generate high concentrations of hydroxyl radicals that are consumed on roughly a microsecond time scale. The broad reactivity of hydroxyl radicals means that almost anything added to the solution (e.g., ligands, buffers, excipients, etc.) will scavenge hydroxyl radicals, altering their half-life and changing the effective radical concentration experienced by the protein. Similarly, minute changes in peroxide concentration, laser fluence, and buffer composition can alter the effective radical concentration, making reproduction of data challenging. Here, we present a simple method for radical dosimetry that can be carried out as part of the FPOP workflow, allowing for measurement of effective radical concentration in real time. Additionally, by modulating the amount of radical generated, we demonstrate that effective hydroxyl radical yields in FPOP HRPF experiments carried out in buffers with widely differing levels of hydroxyl radical scavenging capacity can be compensated on the fly, yielding statistically indistinguishable results for the same conformer. This method represents a major step in transforming FPOP into a robust and reproducible technology capable of probing protein structure in a wide variety of contexts.


Assuntos
Adenina/química , Fibrinopeptídeo B/química , Radical Hidroxila/química , Mioglobina/química , Pegadas de Proteínas/métodos , Adenina/análise , Radical Hidroxila/efeitos da radiação , Oxirredução , Espectrofotometria Ultravioleta , Raios Ultravioleta
11.
Chem Commun (Camb) ; 54(76): 10726-10729, 2018 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-30187034

RESUMO

We report a novel biosensor platform based on competitive non-covalent interaction between ssDNA and a mass tag towards AuNPs, which detects PSA biomarkers sensitively, observed using MALDI MS. A detection limit of 57 pg mL-1 has been achieved, showing an improvement of two orders of magnitude compared to the traditional spectroscopic method.


Assuntos
Biomarcadores/urina , Técnicas Biossensoriais/métodos , Antígeno Prostático Específico/urina , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Adenina/análise , Adenina/química , Aptâmeros de Nucleotídeos/química , Citosina/análise , Citosina/química , DNA de Cadeia Simples/química , Ouro/química , Guanina/análise , Guanina/química , Humanos , Limite de Detecção , Masculino , Nanopartículas Metálicas/química , Reprodutibilidade dos Testes , Timina/análise , Timina/química
12.
Anal Chim Acta ; 1031: 75-82, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30119746

RESUMO

A novel poly(glycine) (p-GLY)/graphene oxide (GO) composite based sensor (p-GLY/GO) was successfully prepared on glassy carbon electrode by simple electropolymerization. Electrochemical responses of analytes on p-GLY/GO modified electrode were studied by cyclic voltammetry and differential pulse voltammetry. The results demonstrated that p-GLY/GO modified electrode showed a favorable application for the simultaneous determination of dopamine (DA), uric acid (UA), guanine (GU) and adenine (AD). Owing to the synergistic effect of p-GLY and GO, the oxidation peaks of four analytes separated well from each other, and the potential separations of oxidation peaks of DA-UA, UA-GU and GU-AD were large up to 170, 350 and 300 mV, respectively. As-prepared p-GLY/GO modified electrode offered wide linear responses for DA, UA, GU and AD over the ranges of 0.20-62, 0.10-105, 0.15-48 and 0.090-103 µM with detection limits of 0.011, 0.061, 0.026 and 0.030 µM (S/N = 3), respectively. Moreover, p-GLY/GO modified electrode presented favorable selectivity, stability and reproducibility, which was a promising candidate as an electrochemical sensor for the simultaneous determination of DA, UA, GU and AD.


Assuntos
Adenina/análise , Dopamina/análise , Técnicas Eletroquímicas/métodos , Grafite/química , Guanina/análise , Peptídeos/química , Ácido Úrico/análise , Carbono/química , Catálise , Eletrodos , Limite de Detecção , Microscopia Eletrônica de Varredura , Oxirredução , Óxidos/química , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier
13.
J Pharm Biomed Anal ; 156: 163-169, 2018 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-29709783

RESUMO

A liquid chromatography with triple quadrupole mass spectrometry method was developed and validated for the determination of tenofovir and tenofovir alafenamide concentrations in human plasma and cerebrospinal fluid. Tenofovir and tenofovir alafenamide were extracted from matrix by solid phase extraction. The dried extraction eluents were dissolved in water for LC-MS/MS analysis. Separation was achieved with a Phenomenex Synergi 4 µm Polar-RP 80A column (50 × 2 mm) with a gradient elution of 0.1% formic acid in water and acetonitrile. The total run time was 5 min. Detection of analytes was achieved using electrospray ionization (positive mode) and triple quadrupole selected reaction monitoring. Standard curve concentrations ranged from 0.5 to 500 ng/mL for the plasma assay and 0.1-50 ng/mL for the cerebrospinal fluid assay. The intra- and inter-day accuracy and precision were less than 12% in low, medium, and high quality control samples for both matrices. The validated methods were applied to the analysis of plasma and cerebrospinal fluid samples of a patient undergoing tenofovir therapy which involved the switch from Stribild® (elvitegravir 150 mg/cobicistat 150 mg/emtricitabine 200 mg/tenofovir disoproxil fumarate 300 mg) to Genvoya® (elvitegravir 150 mg/cobicistat 150 mg/emtricitabine 200 mg/tenofovir alafenamide 10 mg).


Assuntos
Adenina/análogos & derivados , Fármacos Anti-HIV/análise , Infecções por HIV/tratamento farmacológico , Tenofovir/análise , Adenina/análise , Adenina/uso terapêutico , Cromatografia Líquida de Alta Pressão , Cobicistat/análise , Cobicistat/uso terapêutico , Combinação de Medicamentos , Combinação Elvitegravir, Cobicistat, Emtricitabina e Fumarato de Tenofovir Desoproxila/análise , Combinação Elvitegravir, Cobicistat, Emtricitabina e Fumarato de Tenofovir Desoproxila/uso terapêutico , Emtricitabina/análise , Emtricitabina/uso terapêutico , Infecções por HIV/sangue , Infecções por HIV/líquido cefalorraquidiano , Humanos , Quinolonas/análise , Quinolonas/uso terapêutico , Reprodutibilidade dos Testes , Extração em Fase Sólida , Espectrometria de Massas em Tandem , Tenofovir/análogos & derivados , Tenofovir/uso terapêutico
14.
Biosens Bioelectron ; 110: 218-224, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29625329

RESUMO

By introduction of Mo metal species (molybdenum-based polyoxometalates) into the Cu-MOF as co-precursor, molybdenum carbide nanosphere (MoxC@C) was prepared via a simple calcining routine and a further etching the metallic Cu process. The obtained MoxC@C showed a unique structure where well-dispersed MoxC nanoparticles (NPs) were encapsulated in porous carbon matrix. As-fabricated novel 3D porous architecture MoxC@C nanosphere exhibited a potent and persistent electro-oxidation behavior followed by well-separated oxidation peaks (peak to peak voltage is about 350 mV) toward adenine (A) and guanine (G) by differential pulse voltammetry (DPV). This excellent electrochemical performance can be attributed to the unique structure and composition of 3D MoxC@C. Furthermore, 3D MoxC@C also revealed high selectivity and sensitivity, good reproducibility, excellent stability and anti-interference ability. The calibration curves for quantitive analysis of G and A were obtained: 0.03-122 µM, and 0.02-122 µM, respectively, the detection limits were 0.0085 µM, 0.008 µM, respectively. The proposed procedure was successfully applied to detect G and A in human urine and serum samples with satisfactory recovery, which manifests its viability application for practical analysis.


Assuntos
Adenina/análise , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Guanina/análise , Molibdênio/química , Nanosferas/química , Adenina/sangue , Adenina/urina , Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/instrumentação , Eletrodos , Guanina/sangue , Guanina/urina , Humanos , Limite de Detecção , Nanosferas/ultraestrutura , Porosidade
15.
Anal Chem ; 90(9): 5546-5551, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29652489

RESUMO

N6-methyladenine (6mA) is a rediscovered DNA modification in eukaryotic genomes. To explore the distribution and functions of 6mA, it is of paramount option to use immunoprecipitation to select 6mA-containing DNA fragments for genome-wide sequencing. Presumably, most of the 6mA-free fragments are removed, and the copulling down of the residual is stochastic and sequence-independent and thus they should not be called as peaks by computation. Surprisingly, here we show the predominance of 6mA-free fragments in the pulled-down fractions. By taking advantage of the submicromolar affinity of the antibodies, we further develop an elegant, multiple-round immunoprecipitation (MrIP) approach and show that 6mA-containing fragments can be enriched over 9100-fold and dominate in the final pulled-down fractions. This biochemical approach would greatly reduce the peak calling bias, which is caused by handling of dominated 6mA-free DNA fragments with an assumption-based algorithm computation and facilitates 6mA-pertinent data mining. The MrIP concept is extendable for the genome-wide sequencing of diverse DNA modifications.


Assuntos
Adenina/análogos & derivados , DNA/química , Imunoprecipitação , Adenina/análise , Cromatografia Líquida de Alta Pressão , DNA/genética , Espectrometria de Massas em Tandem
17.
Food Chem ; 255: 332-339, 2018 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-29571484

RESUMO

Lacy phacelia (Phacelia tanacetifolia Borkh.) honey composition was screened by UHPLC-DAD-QqTOF-MS. The targeted analysis revealed 6 major nitrogen compounds including aromatic amino acids (tyrosine, phenylalanine), purine derivatives (adenine, xanthine), nucleoside (uridine) and rare non-cyanogenic cyanoglucoside, (-)-5-epi-lithospermoside ((2Z)-2-[(4R,5R,6S)-4,5-dihydroxy-6-(ß-d-glucopyranosyl)oxycyclohex-2-en-1-ylidene]acetonitrile). Their identity was confirmed by different analytical tools: HRMS, co-chromatography with standard compound or comprehensive NMR experiments. All the compounds, except amino acids, were reported and determined in honey for the first time. The amount of the compounds was quantified in 16 unifloral phacelia samples: adenine (18.45 ±â€¯4.63 mg/kg), xanthine (10.53 ±â€¯2.98 mg/kg), uridine (42.84 ±â€¯9.26 mg/kg), tyrosine (14.66 ±â€¯10.22 mg/kg), (-)-5-epi-lithospermoside (70.61 ±â€¯31.37 mg/kg) and phenylalanine (20.41 ±â€¯11.99 mg/kg). The (-)-5-epi-lithospermoside content is significantly correlated with P. tanacetifolia pollen percentage (R2 = 0.5612, p < 0.001) and it is proposed as a potential marker of botanical origin for phacelia honey.


Assuntos
Acetonitrilos/análise , Boraginaceae/química , Glicosídeos/análise , Mel/análise , Compostos de Nitrogênio/análise , Adenina/análise , Aminoácidos/análise , Fenilalanina/análise , Pólen/química , Tirosina/análise , Uridina/análise , Xantina/análise
18.
Anal Chem ; 90(7): 4521-4528, 2018 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-29505241

RESUMO

Isotopically labeling a metabolite and tracing its metabolic fate has provided invaluable insights about the role of metabolism in human diseases in addition to a variety of other issues. 13C-labeled metabolite tracers or unlabeled 1H-based NMR experiments are currently the most common application of NMR to metabolomics studies. Unfortunately, the coverage of the metabolome has been consequently limited to the most abundant carbon-containing metabolites. To expand the coverage of the metabolome and enhance the impact of metabolomics studies, we present a protocol for 15N-labeled metabolite tracer experiments that may also be combined with routine 13C tracer experiments to simultaneously detect both 15N- and 13C-labeled metabolites in metabolic samples. A database consisting of 2D 1H-15N HSQC natural-abundance spectra of 50 nitrogen-containing metabolites are also presented to facilitate the assignment of 15N-labeled metabolites. The methodology is demonstrated by labeling Escherichia coli and Staphylococcus aureus metabolomes with 15N1-ammonium chloride, 15N4-arginine, and 13C2-acetate. Efficient 15N and 13C metabolite labeling and identification were achieved utilizing standard cell culture and sample preparation protocols.


Assuntos
Adenina/metabolismo , Glutamina/metabolismo , Metabolômica , Ressonância Magnética Nuclear Biomolecular , Ornitina/metabolismo , Tiamina/metabolismo , Acetatos/química , Adenina/análise , Cloreto de Amônio/química , Arginina/química , Isótopos de Carbono , Escherichia coli/química , Escherichia coli/citologia , Escherichia coli/metabolismo , Glutamina/análise , Humanos , Metaboloma , Estrutura Molecular , Isótopos de Nitrogênio , Ornitina/análise , Staphylococcus aureus/química , Staphylococcus aureus/citologia , Staphylococcus aureus/metabolismo , Tiamina/análise
19.
Sci Rep ; 8(1): 5163, 2018 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-29581560

RESUMO

SERS spectra excited at 785 nm of the bacteria Chlamydia trahomatis (elementary bodies, EB) and Neisseria gonorrheoae, the causative pathogens for the two most common sexually transmitted diseases (STD), chlamydia and gonorrhea, respectively, are reported. Although both are Gram-negative bacteria, the SERS signatures of C. trachomatis and N. gonorrheoae are completely different. N. gonorrheoae SERS spectra are due to the starvation induced nucleotide metabolites adenine and guanine, and the surface associated co-enzyme nicotinamide adenine dinucleotide and are very similar on Au and Ag although the spectrum appears more rapidly on Ag. The C. trachomatis SERS spectrum is dominated by the vibrational features of cell surface proteins. While features attributable to specific residues and the amide backbone characterize the C. trachomatis spectrum on Ag, the corresponding SERS spectrum on Au substrates displays vibrational characteristics of aggregated proteins. The prospects for the development of a SERS based platform for rapid (

Assuntos
Infecções por Chlamydia/diagnóstico , Chlamydia trachomatis/metabolismo , Gonorreia/diagnóstico , Metabolômica/métodos , Neisseria gonorrhoeae/metabolismo , Análise Espectral Raman/métodos , Adenina/análise , Linhagem Celular , Infecções por Chlamydia/microbiologia , Ouro/química , Gonorreia/microbiologia , Guanina/análise , Humanos , Metaboloma , Nanopartículas Metálicas/química , Doenças Sexualmente Transmissíveis/diagnóstico , Prata/química , Vibração
20.
Urolithiasis ; 46(5): 459-470, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29392338

RESUMO

Few studies have examined the relative risk of recurrence of different stone types. The object of the present study was to evaluate the tendency for stone recurrence as a function of major mineral composition of the stones and morphological characteristics of the stones. This study was carried out using 38,274 stones for which we had data available to specify if the stone was from the first or a subsequent urinary stone episode. Stones were analyzed for morphology by stereomicroscope and for composition by infrared spectroscopy. Overall, 42.7% of stones were from patients who had had a previous stone event, with these being more frequent in men (44.4%) than in women (38.9%, p < 0.0001). Age of first stone occurrence was lowest for dihydroxyadenine (15.7 ± 16.6 years) and highest for anhydrous uric acid (62.5 ± 14.9 years), with the average age of first stones of calcium oxalate falling in the middle (40.7 ± 14.6 years for calcium oxalate dihydrate, and 48.4 ± 15.1 years for calcium oxalate monohydrate, COM). By composition alone, COM was among the least recurrent of stones, with only 38.0% of COM stones coming from patients who had had a previous episode; however, when the different morphological types of COM were considered, type Ic-which displays a light color, budding surface and unorganized section-had a significantly greater rate of recurrence, at 82.4% (p < 0.0001), than did other morphologies of COM. Similarly, for stones composed of apatite, morphological type IVa2-a unique form with cracks visible beneath a glossy surface-had a higher rate of recurrence than other apatite morphologies (78.8 vs. 39-42%, p < 0.0001). Stone mineral type alone is insufficient for identifying the potential of recurrence of the stones. Instead, the addition of stone morphology may allow the diagnosis of highly recurrent stones, even among common mineral types (e.g., COM) that in general are less recurrent.


Assuntos
Adenina/análogos & derivados , Apatitas/análise , Oxalato de Cálcio/análise , Ácido Úrico/análise , Cálculos Urinários/epidemiologia , Adenina/análise , Adolescente , Adulto , Idade de Início , Idoso , Criança , Pré-Escolar , Feminino , França/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Recidiva , Espectrofotometria Infravermelho , Cálculos Urinários/química , Adulto Jovem
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