Human untargeted metabolomics studies annotate only ~10% of molecular features. We introduce reference-data-driven analysis to match metabolomics tandem mass spectrometry (MS/MS) data against metadata-annotated source data as a pseudo-MS/MS reference library. Applying this approach to food source data, we show that it increases MS/MS spectral usage 5.1-fold over conventional structural MS/MS library matches and allows empirical assessment of dietary patterns from untargeted data.
Metadata , Tandem Mass Spectrometry , Humans , Metabolomics/methods
Peroxyoxalate chemiluminescence is used in self-contained light sources, such as glow sticks, where oxidation of aromatic oxalate esters produces a high-energy intermediate (HEI) that excites fluorescence dyes via electron transfer chemistry, mimicking bioluminescence for efficient chemical energy-to-light conversion. The identity of the HEI and reasons for the efficiency of the peroxyoxalate reaction remain elusive. We present here unequivocal proof that the HEI of the peroxyoxalate system is a cyclic peroxidic carbon dioxide dimer, namely, 1,2-dioxetanedione. Oxalic peracids bearing a substituted phenyl group were unable to directly excite fluorescent dyes; hence, they could be ruled out as the HEI. However, base-catalyzed cyclization of these species results in bright chemiluminescence, with decay rates and chemiexcitation quantum yields that are influenced by the electronic phenylic substituent properties. Hammett (ρ = +2.2 ± 0.1) and Brønsted (ß = -1.1 ± 0.1) constants for the cyclization step preceding chemiexcitation imply that the loss of the phenolate-leaving group and intramolecular nucleophilic attack of the percarboxylate anion occur in a concerted manner, generating 1,2-dioxetanedione as the unique outcome. The presence of better leaving groups influences the reaction mechanism, favoring the chemiluminescent reaction pathway over the nonemissive formation of aryl-1,2-dioxetanones.
INTRODUCTION: To date, there has been little effort to develop standards for metabolome-based gut microbiome measurements despite the significant efforts toward standard development for DNA-based microbiome measurements. OBJECTIVES: The National Institute of Standards and Technology (NIST), The BioCollective (TBC), and the North America Branch of the International Life Sciences Institute (ILSI North America) are collaborating to extend NIST's efforts to develop a Human Whole Stool Reference Material for the purpose of method harmonization and eventual quality control. METHODS: The reference material will be rationally designed for adequate quality assurance and quality control (QA/QC) for underlying measurements in the study of the impact of diet and nutrition on functional aspects of the host gut microbiome and relationships of those functions to health. To identify which metabolites deserve priority in their value assignment, NIST, TBC, and ILSI North America jointly conducted a workshop on September 12, 2019 at the NIST campus in Gaithersburg, Maryland. The objective of the workshop was to identify metabolites for which evidence indicates relevance to health and disease and to decide on the appropriate course of action to develop a fit-for-purpose reference material. RESULTS: This document represents the consensus opinions of workshop participants and co-authors of this manuscript, and provides additional supporting information. In addition to developing general criteria for metabolite selection and a preliminary list of proposed metabolites, this paper describes some of the strengths and limitations of this initiative given the current state of microbiome research. CONCLUSIONS: Given the rapidly evolving nature of gut microbiome science and the current state of knowledge, an RM (as opposed to a CRM) measured for multiple metabolites is appropriate at this stage. As the science evolves, the RM can evolve to match the needs of the research community. Ultimately, the stool RM may exist in sequential versions. Beneficial to this evolution will be a clear line of communication between NIST and the stakeholder community to ensure alignment with current scientific understanding and community needs.
Feces/microbiology , Gastrointestinal Microbiome , Metabolome , Metagenome , Diet , Feces/chemistry , Humans , Metabolomics , Metagenomics
Online water bioburden analyzers (OWBAs) can provide real-time feedback on viable bacteria in high-purity water (HPW) systems for pharmaceutical manufacturers. To calibrate and validate OWBAs, which detect bacteria using scattered light and bacterial autofluorescence, standards are needed that mimic the characteristics of bacteria in HPW. To guide selection of potential standards, e.g., fluorescent microspheres, a relevant bacterial contaminant, Ralstonia pickettii, was characterized for size, count, viability, and autofluorescence after exposure for 24 h to HPW or a nutrient environment. The cells exposed to HPW showed smaller sizes, with lower counts and autofluorescence intensities, but similar spectral features. The cell characteristics are discussed in comparison with a set of fluorescent microspheres, considering factors relevant to OWBAs. These studies suggest that fluorescent microspheres should be relatively small (< 1 µm diameter) and dim, while covering a broad emission range from ≈ (420 to 600) nm to best mimic the representative R. pickettii.
Ralstonia pickettii/isolation & purification , Calibration , Water , Water Microbiology
Breast cancer remains a leading cause of morbidity and mortality worldwide yet methods for early detection remain elusive. We describe the discovery and validation of biochemical signatures measured by mass spectrometry, performed upon blood samples from patients and controls that accurately identify (>95%) the presence of clinical breast cancer. Targeted quantitative MS/MS conducted upon 1225 individuals, including patients with breast and other cancers, normal controls as well as individuals with a variety of metabolic disorders provide a biochemical phenotype that accurately identifies the presence of breast cancer and predicts response and survival following the administration of neoadjuvant chemotherapy. The metabolic changes identified are consistent with inborn-like errors of metabolism and define a continuum from normal controls to elevated risk to invasive breast cancer. Similar results were observed in other adenocarcinomas but were not found in squamous cell cancers or hematologic neoplasms. The findings describe a new early detection platform for breast cancer and support a role for pre-existing, inborn-like errors of metabolism in the process of breast carcinogenesis that may also extend to other glandular malignancies. Statement of Significance: Findings provide a powerful tool for early detection and the assessment of prognosis in breast cancer and define a novel concept of breast carcinogenesis that characterizes malignant transformation as the clinical manifestation of underlying metabolic insufficiencies.
Resumen Se estudiaron nanofibras de TiO2/ZnO preparadas por calcinación de fibras precursoras de poli (vinil acetato), isopropóxido de titanio y nano polvo de zinc elaboradas por la técnica de electrohilado. La estructura y la morfología de las nanofibras de TiO2/ZnO y fibras precursoras se caracterizaron por Microscopia Electrónica de Barrido (SEM), Microscopia Electrónica de Barrido de Emisión de Campo equipado con Espectroscopia Dispersiva de Rayos X (FESEM-EDS), Espectroscopia de Infrarrojo con Transformada de Fourier (FTIR) y Difracción de Rayos X (XRD). El análisis XRD mostró la estructura cristalina de los óxidos de titanio (anatasa) y de zinc (wurzita hexagonal), después de calcinar las fibras precursoras a 500°C. Las microfotografías de SEM muestran que tanto las fibras precursoras como las nanofibras forman redes uniformes y buena morfología. Estas nanofibras de dióxido de titanio /óxido de zinc presentan buen área de superficie y diámetros de 200 nm apropiados que podrían ser de aplicación potencial en el campo de energía renovable, en particular, para la fabricación de celdas solares.
Abstract The TiO2 /ZnO nanofibers prepared by the calcination of polyvinyl acetate of precursor fibers, titanium isopropoxide and nano zinc powder produced by the electrospinning technique were studied. The structu-re and morphology of TiO2 /ZnO nanofibers and precursor fibers were characterized by Scanning Electron Microscopy (SEM), Field Emission Scanning Electron Microscopy coupled to Energy Dispersive X-ray spectroscopy (FESEM-EDS), Fourier Transform Infrared Spectroscopy (FTIR) and XRD (X Ray Diffraction). XRD analysis displayed crystalline structures of titanium oxides (anatase) and zinc (hexagonal wurzite), after calcining the precursor fibers at 500 °C. SEM microphotographs display that both precursor fibers and nanofibers form uniform networks and good morphology. These titanium dioxide / zinc oxide nanofibers get good surface area and appropriate 200 nm diameters which could potentially be applied in the renewable energy field, particularly for solar cells manufacturing.
Resumo Nanofibras de TiO2 /ZnO preparado por calcinação de fibras precursoras de poli (acetato de vinila), isopropóxido de titânio e pó nano de zinco produzidos por eletrofiação técnica estudada. A estrutura e morfologia das nanofibras de TiO2/ ZnO e fibras precursores foram caracterizados por microscopia eletrônica de varredura (SEM), Microscopia eletrônica de varredura de emissão de campo equipada com espectroscopia de raios-X dispersiva (FESEM-EDS), Espectroscopia de Fourier Transform Infrared (FTIR) e difração de raios X (DRX). A análise de XRD mostrou a formação de estruturas de cristal de óxido de titânio (anatase) e zinco (wurtzita hexagonal), depois de fibras precursoras de calcinação a 500 °C. Micrografias mostram que tanto o precursor e fibras nanofibras uniformes formar redes e boa morfologia. Estas nanofibras de dióxido de titanio /óxido de zinco apresentam bom área de superfície e diâmetros de 200 nm apropriados que poderiam ser de aplicativo potencial no campo de energia renovável, em particular, para a fabricação de celas solares.
This work reports the optimization of degradation conditions and toxicity decrease in the tannery wastewater, collected in the retanning and dyeing steps. This effluent was filtered, diluted in a 1:200 proportion, and investigated as a case study on a bench scale by heterogeneous photocatalysis. These conditions were attained when the suspension, containing 1 g L-1 of ZnO and effluent, was irradiated for 4h at pH 8.0 and 30 degrees C. Physico-chemical parameters such as chemical oxygen demand (COD) decreased from 15,023 to 350 mg O2 L-1; fifth-day biochemical oxygen demand (BODs) from 4374 to 10 mg O2 L-1; total solids from 28,500 to 188 mg L-1; total organic carbon (TOC) from 4685 to 4.93 mg L-1, and turbidity from 331 to 1.15NTU after 4h of irradiation. The LC50 increase from 14.90% to 56.82% in the lethality assay of Artemia salina L. microcrustacean as well as the dissolved oxygen of 6.45mg L-1 indicated efficiency in this treatment.
Photolysis , Waste Disposal, Fluid/methods , Zinc Oxide/chemistry , Animals , Artemia , Biological Oxygen Demand Analysis , Industrial Waste , Tanning , Wastewater/toxicity
In order to evaluate the effects of domestic landfill leachate to bivalves Corbicula fluminea, clams were exposed to different leachate concentrations (v/v): 2, 3, 6 and 10 percent, corresponding to dilutions observed along a stream that receives this effluent, or only to clean water for comparisons. After 5 and 15 days of exposure the activity of the biotransformation enzymes 7-ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST), the multixenobiotic resistance mechanism (MXR) and lipid peroxidation (LPO) in gills and digestive gland and metallothionein (MT) content in gills were evaluated. Differences in biomarkers responses were observed between gills and digestive gland, except for MXR that decreased in both tissues of clams exposed to 6 percent for 5 days. EROD activity in gills was reduced in all leachate concentrations after 5 days and only in 2 percent after 15 days exposure, while an EROD increase was observed in digestive gland after 15 days exposure to 6 percent. GST activity increased only in the gills of clams exposed to 10 percent for 5 days. LPO varied between tissues and different conditions. A significant increase in LPO was observed in the gills, after 5 days exposure to 2 and 6 percent, and in digestive gland after 5 and 15 days exposure to 2 and 3 percent. MT content in the gills increased after 15 days exposure to 2 percent. In conclusion, different leachate concentrations tested here caused biochemical changes in C. fluminea, but due to the observed variability in biomarkers responses among leachate concentrations, it was difficult to determine patterns or thresholds concentrations.
Corbicula/drug effects , Water Pollutants, Chemical/toxicity , Animals , Biomarkers/analysis , Cytochrome P-450 CYP1A1/metabolism , Electric Conductivity , Gills/drug effects , Glutathione Transferase/metabolism , Hydrogen-Ion Concentration , Lipid Peroxidation/drug effects , Metallothionein/analysis , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/chemistry
The induced decomposition of 1,2-dioxetanes results in the efficient formation of singlet-excited carbonyl compounds. This transformation has been assumed to involve two sequential electron-transfer steps, and the viscosity dependence of the chemiexcitation efficiency (solvent cage effect) has been considered as evidence for the occurrence of an intermolecular electron back-transfer, despite the very high chemiexcitation quantum yields observed. However, all other chemiluminescent reactions assumed to occur according to the entirely intermolecular mechanism, referred to as CIEEL, are inefficient, except for the peroxyoxalate system. Therefore, we have investigated the solvent cage effect on the singlet quantum yields in both the induced decomposition of 1,2-dioxetanes and the peroxyoxalate reaction. Analysis of the viscosity effect observed for both systems, using a collisional as well as a free-volume model, indicates a very distinct behavior, which was interpreted as the occurrence of intramolecular chemiexcitation in the induced 1,2-dioxetane decomposition. We propose a general mechanism for efficient chemiluminescence in which the required electron back-transfer and C-C bond cleavage are concerted and compete with conformational changes that compromise the chemiexcitation. This mechanism is in agreement with both experimental and theoretical data available on the induced 1,2-dioxetane decomposition as well as with the high quantum efficiency of this transformation.
The aim of the present study was to define leachate plume by using two techniques: geophysical and groundwater sampling in order to evaluate groundwater contamination. After performing a topographic survey and using geophysics, the leachate plume was identified. With this data, the wells for groundwater monitoring were located. Groundwater samples were analyzed for: COD, BOD, pH, alkalinity, conductivity, TKN and heavy metals. Through the electroresistivity method it was possible to define the shape of plume contamination. This method was important to locate the groundwater monitoring wells. The results of the physicochemical parameters showed the suitability of the geophysical study. The highest values of electric conductivity and alkalinity correspond to the wells located in the area interpreted as contaminated by leachate in the map of the resistivity. Even with seasonal variations, BOD values are low if compared to Brazilian environmental regulations, but COD values are higher up to 40 times the values of BOD. The concentrations of Ni, Zn, Cd and Cu in the groundwater are below the limits established by the potable water quality standards in Brazil, except for Pb whose concentration in groundwater were higher if compared to Brazilian legislation.
Environmental Monitoring/methods , Groundwater/analysis , Refuse Disposal/methods , Water Pollutants, Chemical/analysis , Brazil
Environmental sampling for microbiological contaminants is a key component of hygiene monitoring and risk characterization practices utilized across diverse fields of application. However, confidence in surface sampling results, both in the field and in controlled laboratory studies, has been undermined by large variation in sampling performance results. Sources of variation include controlled parameters, such as sampling materials and processing methods, which often differ among studies, as well as random and systematic errors; however, the relative contributions of these factors remain unclear. The objective of this study was to determine the relative impacts of sample processing methods, including extraction solution and physical dissociation method (vortexing and sonication), on recovery of Gram-positive (Bacillus cereus) and Gram-negative (Burkholderia thailandensis and Escherichia coli) bacteria from directly inoculated wipes. This work showed that target organism had the largest impact on extraction efficiency and recovery precision, as measured by traditional colony counts. The physical dissociation method (PDM) had negligible impact, while the effect of the extraction solution was organism dependent. Overall, however, extraction of organisms from wipes using phosphate-buffered saline with 0.04% Tween 80 (PBST) resulted in the highest mean recovery across all three organisms. The results from this study contribute to a better understanding of the factors that influence sampling performance, which is critical to the development of efficient and reliable sampling methodologies relevant to public health and biodefense.
Bacillus cereus/isolation & purification , Bacteriological Techniques/methods , Burkholderia/isolation & purification , Environmental Microbiology , Escherichia coli/isolation & purification , Specimen Handling/methods , Sensitivity and Specificity
The need for the precise and reliable collection of potential biothreat contaminants has motivated research in developing a better understanding of the variability in biological surface sampling methods. In this context, the objective of this work was to determine parameters affecting the efficiency of extracting Bacillus anthracis Sterne spores from commonly used wipe sampling materials and to describe performance using the interfacial energy concept. In addition, surface thermodynamics was applied to understand and predict surface sampling performance. Wipe materials were directly inoculated with known concentrations of B. anthracis spores and placed into extraction solutions, followed by sonication or vortexing. Experimental factors investigated included wipe material (polyester, cotton, and polyester-rayon), extraction solution (sterile deionized water [H(2)O], deionized water with 0.04% Tween 80 [H(2)O-T], phosphate-buffered saline [PBS], and PBS with 0.04% Tween 80 [PBST]), and physical dissociation method (vortexing or sonication). The most efficient extraction from wipes was observed for solutions containing the nonionic surfactant Tween 80. The increase in extraction efficiency due to surfactant addition was attributed to an attractive interfacial energy between Tween 80 and the centrifuge tube wall, which prevented spore adhesion. Extraction solution significantly impacted the extraction efficiency, as determined by statistical analysis (P < 0.05). Moreover, the extraction solution was the most important factor in extraction performance, followed by the wipe material. Polyester-rayon was the most efficient wipe material for releasing spores into solution by rank; however, no statistically significant difference between polyester-rayon and cotton was observed (P > 0.05). Vortexing provided higher spore recovery in H(2)O and H(2)O-T than sonication, when all three wipe materials and the reference control were considered (P < 0.05).
Bacillus anthracis/isolation & purification , Bacteriological Techniques/methods , Environmental Microbiology , Spores, Bacterial/isolation & purification , Buffers , Sonication , Specimen Handling/methods
Nós descrevemos o caso clínico de uma criança do sexo feminino, com 7 anos de idade, portadora de sarcoma de Ewing, que evoluiu com leucemia aguda mielóide pouco diferenciada (LMA-M0) após vinte meses de tratamento utilizando o protocolo EW92. Ela recebeu uma dose total de 1.500 mg de etoposídio, irradiação tumoral na dose total de 35G, e fator de estimulação de colônia granulocítica (G-CSF) conforme programação do protocolo terapêutico. Os exames laboratoriais, por ocasião do diagnóstico da segunda malignidade, mostraram células blásticas imaturas caracterizadas pela expressão de CD34+/CD33-/aMPO+ e a translocação t(4;11) (q 21;q23). A exclusão do G-CSF nos esquemas terapêuticos que associam etoposídio e irradiação tumoral se justifica devido a esta séria complicação no tratamento do sarcoma de Ewing.
Humans , Female , Child , Leukemia, Myeloid, Acute/drug therapy , Sarcoma, Ewing
The peroxyoxalate reaction is utilized in a wide variety of analytical applications; however, its mechanism is still not very well understood, especially with respect to the excitation step, where the 'chemical energy' is transformed into 'excitation energy'. This base-catalysed reaction of activated oxalic phenyl esters with hydrogen peroxide in the presence of highly fluorescent aromatic hydrocarbons with low oxidation potentials is the only known chemiluminescence system for which exists experimental evidence for the occurrence of the intermolecular chemically initiated electron exchange luminescence (CIEEL) mechanism of proven high efficiency for excited state formation. We report here the singlet quantum yields and relative rate constants of the excitation step (k(CAT)/k(D)), obtained in the peroxyoxalate reaction, utilizing steroid-substituted oxazolinylidenes as activators. In agreement with the CIEEL mechanism, a linear correlation of ln(k(CAT)/k(D)) with the oxidation potential of the activators is obtained, and the singlet quantum yields can be rationalized in terms of the free energy balance of the back electron transfer, leading to the formation of the activator's excited state. Thus, these results contribute to the experimental validation of the widely employed, thus still controversial, CIEEL mechanism.
Luminescent Measurements , Oxalates/chemistry , Steroids/chemistry , Fluorescence , Kinetics , Models, Chemical
OBJECTIVE: To assess the prevalence of high blood pressure (PHBP) and its association with age, sex, socioeconomic status (SES), and body mass index (BMI = kg/m2). MATERIAL AND METHODS: A cross-sectional survey was carried out in 1996, in a random sample of 356 adults aged 20 and older, residents of Bucaramanga, Colombia. Weight, height, and blood pressure readings were obtained, plus data on age and gender. Robust linear and log-binomial regression was used to estimate the independent effect of different risk factors on systolic (SBP) and diastolic (DBP) blood pressure and HBP. RESULTS: Mean SBP and DBP were significantly higher in men (122.5 and 88.1 mmHg) than in women (117.2 and 75.4 mmHg). The adjusted SBP increased with age, more in men than in women; DBP did not change with age. For each unit increase in BMI, SBP and DBP increased 0.76 and 0.69 mmHg, respectively. SBP was 6.8 and DBP was 9.8 mmHg higher in low-SES than in high-SES subjects. The adjusted PHBP increased with age and was higher in subjects > or = 50 years than in those 20-30 years old. Sex had no significant effect on PHBP (p = 0.795). For each unit increase in BMI the PHBP increased 3%, and low-SES subjects had a PHBP 1.84 times higher than high-SES subjects. CONCLUSIONS: A high PHBP was found. There is a great potential for prevention by weight control. Further studies are needed to confirm the increasing PHBP in low-SES subjects and to identify its causes.
Hypertension/epidemiology , Adult , Age Factors , Aged , Blood Pressure , Body Mass Index , Colombia/epidemiology , Cross-Sectional Studies , Female , Humans , Male , Mass Screening , Middle Aged , Obesity/epidemiology , Prevalence , Random Allocation , Risk Factors , Sex Factors
Although more currently utilized as analytical tool because of its high sensitivity and good reproducibility, the mechanism of the peroxyoxalate system, a chemiluminescence reaction with quantum yields only comparable to bioluminescence systems, has been extensively studied. The light emission mechanism can be divided in the pathway before chemiexcitation, which contains the rate-limiting steps, and the fast and kinetically non-observable chemiexcitation step. In this work, we obtain information on the mechanism of the slow pathways, attribute values to several rate constants prior to chemiexcitation and suggest a mechanistic scheme that could help optimization of conditions when the peroxyoxalate reaction is used as analytical tool.
Oxalates , Hydrogen Peroxide , Kinetics , Luminescent Measurements , Molecular Structure
OBJECTIVE: To assess the prevalence of high blood pressure (PHBP) and its association with age, sex, socioeconomic status (SES), and body mass index (BMI = kg/m2). MATERIAL AND METHODS: A cross-sectional survey was carried out in 1996, in a random sample of 356 adults aged 20 and older, residents of Bucaramanga, Colombia. Weight, height, and blood pressure readings were obtained, plus data on age and gender. Robust linear and log-binomial regression was used to estimate the independent effect of different risk factors on systolic (SBP) and diastolic (DBP) blood pressure and HBP. RESULTS: Mean SBP and DBP were significantly higher in men (122.5 and 88.1 mmHg) than in women (117.2 and 75.4 mmHg). The adjusted SBP increased with age, more in men than in women; DBP did not change with age. For each unit increase in BMI, SBP and DBP increased 0.76 and 0.69 mmHg, respectively. SBP was 6.8 and DBP was 9.8 mmHg higher in low-SES than in high-SES subjects. The adjusted PHBP increased with age and was higher in subjects > or = 50 years than in those 20-30 years old. Sex had no significant effect on PHBP (p = 0.795). For each unit increase in BMI the PHBP increased 3, and low-SES subjects had a PHBP 1.84 times higher than high-SES subjects. CONCLUSIONS: A high PHBP was found. There is a great potential for prevention by weight control. Further studies are needed to confirm the increasing PHBP in low-SES subjects and to identify its causes.
Humans , Male , Female , Adult , Middle Aged , Hypertension/epidemiology , Sex Factors , Mass Screening , Prevalence , Cross-Sectional Studies , Risk Factors , Colombia , Obesity , Random Allocation , Age Factors , Body Mass Index , Arterial Pressure
Este trabalho discute fatores intervenientes na continuidade ou interrupcao da psicoterapia, mediante a investigacao com 11 pacientes atendidos por uma clinica-escola. Trata-se de pesquisa qualitativa, conforme o procedimento clinico, para verificacao da hipotese de que existe uma estreita relacao entre os tipos de vinculos que os pacientes estabelecem e sua aderencia a um tratamento bem-sucedido. Os pacientes foram categorizados, conforme os vinculos, como simbiotico, parasitario ou comensal e os resultados confirmaram a importancia de se observar o tipo de vinculo que cada um estabelece. Demonstraram ainda que e necessario treinar a observacao do aluno estagiario, provocando uma reflexao sobre o assunto, independente da abordagem adotada, para que a missao da clinica-escola possa ser atingida na sua dupla funcao de formar terapeutas e servir a comunidade.
Psychotherapy , Psychotherapy , Patient Compliance
