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1.
J Environ Sci (China) ; 108: 164-174, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34465430

RESUMO

Surface-active organic molecules (surfactants) may influence the ability of an aerosol particle to act as a cloud condensation nuclei by reducing its surface tension. One source of organic mass in aerosol particles, which may also contain surfactants, is bubble bursting on the sea surface. In order to directly compare these molecules in the ocean and aerosol particles, we developed a method using multiple solid phase extractions and high resolution mass spectrometry to characterize surface active organic molecules in both. This method has extraction efficiencies greater than 85%, 75%, and 60% for anionic, cationic, and nonionic surfactant standards, respectively. In this study, we demonstrate the presence of three ionic classes of surface active organics in atmospheric aerosol particles and estuarine water from Skidaway Island, GA. With this extraction method, organic molecules from both estuarine water and atmospheric aerosol particles significantly reduced surface tension of pure water (surface tension depression of ~ 18 mN/m) and had high ratios of hydrogen to carbon (H/C) and low ratios of oxygen to carbon (O/C), indicative of surfactants. While previous work has observed a larger fraction of anionic surface active organics in seawater and marine aerosol particles, here we show cationic surface active organics may make up a large fraction of the total surface active molecules in estuarine water (43%-47%).


Assuntos
Água do Mar , Tensoativos , Aerossóis , Espectrometria de Massas , Extração em Fase Sólida
2.
Zhongguo Zhong Yao Za Zhi ; 46(16): 4145-4149, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34467726

RESUMO

With repeated silica gel, octadecyl silica(ODS), and Sephadex LH-20 column chromatography, normal-phase and reverse-phase high performance liquid chromatography(HPLC), etc., a pair of new enantiomers and 5 known compounds were separated from the 95% ethanol extract of Chloranthus multistachys. These compounds were identified by the nuclear magnetic resonance spectroscopy(including 1 D-NMR and 2 D-NMR), single-crystal X-ray diffraction, circular dichroism(CD) spectroscopy, mass spectrometry(MS), and some other methods as(1R,4R,5R,8S,10R)-chloraeudolide H(1 a),(1S,4S,5S,8R,10S)-chloraeudolide H(1 b), hydroxyisogermafurenolide(2), 4α-hydroxy-5α,8ß(H)-eudesm-7(11)-en-8,12-olide(3), chloraniolide A(4), chlorantene D(5), 4α,8ß-dihydroxy-5α(H)-eudesm-7(11)-en-8,12-olide(6). Compounds 1 a and 1 b are a pair of new eudesmane-type sesquiterpene enantiomers, and compounds 2-4 were isolated from C. multistachys for the first time.


Assuntos
Sesquiterpenos , Cromatografia Líquida de Alta Pressão , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Estereoisomerismo
3.
Artigo em Chinês | MEDLINE | ID: mdl-34488272

RESUMO

Objective: To establish a direct dilution-inductively coupled plasma mass spectrometry method for the determination of manganese in urine. Methods: Using 1% nitric acid solution as diluent, the urine dilution factor and internal standard elements were determined by single factor rotation experiment. The linear range, correlation coefficient, precision, accuracy and detection limit of the direct dilution-inductively coupled plasma mass spectrometry for the determination of manganese in urine were evaluated. Results: The linear range of this method was 0.0-20 µg/L, the correlation coefficient was 0.999 9, the detection limit was 0.02 µg/L, the recoveries were 84.65%-103.40%, the relative standard deviations were 0.26%-8.17%. Conclusion: This method has the advantages of simple operation, high sensitivity and low detection limit. It can be used for the determination of urine manganese at the same time with other elements. It is suitable for the determination of urine manganese in workers and ordinary people.


Assuntos
Manganês , Ácido Nítrico , Humanos , Íons , Espectrometria de Massas , Análise Espectral
4.
Anal Chim Acta ; 1178: 338551, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34482862

RESUMO

Single-cell analysis can allow for an in-depth understanding of diseases, diagnostics, and aid the development of therapeutics. However, single-cell analysis is challenging, as samples are both extremely limited in size and complex. But the concept is gaining promise, much due to novel sample preparation approaches and the ever-improving field of mass spectrometry. The mass spectrometer's output is often linked to the preceding compound separation step, typically being liquid chromatography (LC). In this review, we focus on LC's role in single-cell omics. Particle-packed nano LC columns (typically 50-100 µm inner diameter) have traditionally been the tool of choice for limited samples, and are also used for single cells. Several commercial products and systems are emerging with single cells in mind, featuring particle-packed columns or miniaturized pillar array systems. In addition, columns with inner diameters as narrow as 2 µm are being explored to maximize sensitivity. Hence, LC column down-scaling is a key focus in single-cell analysis. But narrow columns are associated with considerable technical challenges, while single cell analysis may be expected to become a "routine" service, requiring higher degrees of robustness and throughput. These challenges and expectations will increase the need and attention for the development (and even the reinvention) of alternative nano LC column formats. Therefore, monolith columns and even open tubular columns may finally find their "killer-application" in single cell analysis.


Assuntos
Análise de Célula Única , Cromatografia Líquida , Espectrometria de Massas
5.
Anal Chim Acta ; 1178: 338809, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34482865

RESUMO

We present a new analytical approach for the analysis of triacylglycerol fatty acyls distribution by normal phase liquid chromatography (NPLC) coupled with APPI+-HRMS. The NPLC method used allows the separation of more than 30 classes of lipids. The energy of the APPI+ source enables the formation of low-intensity ions B fragments ([RC = O+74]+ <3%), characteristic of lipids with a glycerol esterified by one or more fatty acyls. We found the relative intensities of ions B were close to the fatty acyl distribution. To establish the proof of concept, we decided to focus on the triacylglycerols (TGs) class, the major component of plant oils. By either NPLC or FIA, the TGs class appeared as a single peak. In our experimental conditions, ions B are always present in the mass spectra of TGs and each ion B is specific to a fatty acyl group. The Orbitrap mass spectrometer featured high enough resolution and accuracy to identify ions B and distinguish them from other TG fragment ions. A further adjustment of the fatty acyls relative quantities calculation from ions B intensities was computed using weighting coefficients of ions B response. The methodology was developed and validated using plant oils characterized by a GC-FID reference method. NPLC-APPI+-HRMS method offers the advantage of analyzing the fatty acyl composition of complex lipid extracts without the need for sample preparation.


Assuntos
Pressão Atmosférica , Monoglicerídeos , Cromatografia Líquida de Alta Pressão , Lipídeos , Espectrometria de Massas , Triglicerídeos
6.
Anal Chim Acta ; 1177: 338770, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34482891

RESUMO

The plug-and-play hyphenation of UV-laser ablation (LA) and mass spectrometry is presented, using dielectric barrier discharge ionization (DBDI). The DBDI source employed here is characterized by its unique geometry, being directly mounted onto the inlet capillary of a mass spectrometer. In the literature, this particular kind of DBDI source is also referred to as active capillary plasma ionization. It has been commercialized as soft ionization by chemical reaction in transfer (SICRIT) and will be addressed as DBDI in this study. LA-DBDI-MS was used for the direct, molecule-specific and spatially resolved analysis of various solid samples, such as coffee beans and pain killer tablets without extensive sample preparation. The combination of fast washout UV-laser ablation and the principle of the DBDI source used here allowed for highly efficient soft ionization as well as high spatial resolution down to 10 µm for molecular imaging.


Assuntos
Terapia a Laser , Espectrometria de Massas , Imagem Molecular
7.
Anal Chim Acta ; 1177: 338522, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34482894

RESUMO

The search for molecular species that are differentially expressed between biological states is an important step towards discovering promising biomarker candidates. In imaging mass spectrometry (IMS), performing this search manually is often impractical due to the large size and high-dimensionality of IMS datasets. Instead, we propose an interpretable machine learning workflow that automatically identifies biomarker candidates by their mass-to-charge ratios, and that quantitatively estimates their relevance to recognizing a given biological class using Shapley additive explanations (SHAP). The task of biomarker candidate discovery is translated into a feature ranking problem: given a classification model that assigns pixels to different biological classes on the basis of their mass spectra, the molecular species that the model uses as features are ranked in descending order of relative predictive importance such that the top-ranking features have a higher likelihood of being useful biomarkers. Besides providing the user with an experiment-wide measure of a molecular species' biomarker potential, our workflow delivers spatially localized explanations of the classification model's decision-making process in the form of a novel representation called SHAP maps. SHAP maps deliver insight into the spatial specificity of biomarker candidates by highlighting in which regions of the tissue sample each feature provides discriminative information and in which regions it does not. SHAP maps also enable one to determine whether the relationship between a biomarker candidate and a biological state of interest is correlative or anticorrelative. Our automated approach to estimating a molecular species' potential for characterizing a user-provided biological class, combined with the untargeted and multiplexed nature of IMS, allows for the rapid screening of thousands of molecular species and the obtention of a broader biomarker candidate shortlist than would be possible through targeted manual assessment. Our biomarker candidate discovery workflow is demonstrated on mouse-pup and rat kidney case studies.


Assuntos
Pesquisa Biomédica , Aprendizado de Máquina , Animais , Testes Diagnósticos de Rotina , Espectrometria de Massas , Camundongos , Ratos
8.
Anal Chim Acta ; 1177: 338760, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34482897

RESUMO

Beta-lactam antibiotics are of vital importance for the treatment of infections in a broad range of patients. Although most systemically administered antibiotics will be excreted renally, a fraction will reach the gastro-intestinal tract, affecting the intestinal microbiome by eradicating a wide range of bacterial species while facilitating the growth of antimicrobial-resistant species. A better understanding of the kinetics of beta-lactam antibiotics in the gastro-intestinal tract is essential to study their role in the development of antibiotic resistance in bacteria and to help develop future therapies to prevent damage to, or restore, the intestinal microbiome. Analysis of beta-lactam antibiotics in faeces is particularly challenging due to the heterogeneous nature of the matrix, rapid degradation of some beta-lactam antibiotics in faeces and very strong ion suppression when using mass spectrometry. Sample preparation was optimized using a sequential strategy of experimental designs. It resulted in lyophilization, a MOPS buffer system and the addition of the beta-lactamase inhibitor avibactam to minimize degradation of antibiotics allowing sensitive quantification. The developed liquid chromatography method with high-resolution mass spectrometric detection was successfully validated according to bioanalytical EMA guidelines and had a linear range of 1-200 µg g-1 lyophilized faeces for amoxicillin, piperacillin and meropenem; and 0.5-100 µg g-1 lyophilized faeces for tazobactam. Despite the highly complex and heterogeneous composition of faeces, the accuracy (0.1-15%) and precision (1.7-12.1%) were in line with those obtained for quantification methods of beta-lactam antibiotics in plasma, the golden standard matrix for therapeutic drug monitoring. The applicability of the method was illustrated by successful quantification of piperacillin and tazobactam in faeces from an intensive care unit patient receiving piperacillin/tazobactam in a continuous intravenous infusion. Both piperacillin and tazobactam were still present six days after discontinuation of the therapy.


Assuntos
Amoxicilina , Piperacilina , Antibacterianos , Cromatografia Líquida , Fezes , Humanos , Espectrometria de Massas , Meropeném , Projetos de Pesquisa , Tazobactam
9.
Anal Chim Acta ; 1177: 338646, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34482900

RESUMO

It is now well-established that dysregulation of the tricarboxylic acid (TCA) cycle enzymes succinate dehydrogenase, fumarate hydratase, and isocitrate dehydrogenase leads to the abnormal cellular accumulation of succinate, fumarate, and 2-hydroxyglutarate, respectively, which contribute to the formation and malignant progression of numerous types of cancers. Thus, these metabolites, called oncometabolites, could potentially be useful as tumour-specific biomarkers and as therapeutic targets. For this reason, the development of analytical methodologies for the accurate identification and determination of their levels in biological matrices is an important task in the field of cancer research. Currently, hyphenated gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) techniques are the most powerful analytical tools in what concerns high sensitivity and selectivity to achieve such difficult task. In this review, we first provide a brief description of the biological formation of oncometabolites and their oncogenic properties, and then we present an overview and critical assessment of the GC-MS and LC-MS based analytical approaches that are reported in the literature for the determination of oncometabolites in biological samples, such as biofluids, cells, and tissues. Advantages and drawbacks of these approaches will be comparatively discussed. We believe that the present review represents the first attempt to summarize the applications of these hyphenated techniques in the context of oncometabolite analysis, which may be useful to new and existing researchers in this field.


Assuntos
Neoplasias , Biomarcadores Tumorais , Cromatografia Líquida , Humanos , Espectrometria de Massas
10.
BMC Bioinformatics ; 22(1): 423, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34493210

RESUMO

BACKGROUND: Assessing the reproducibility of measurements is an important first step for improving the reliability of downstream analyses of high-throughput metabolomics experiments. We define a metabolite to be reproducible when it demonstrates consistency across replicate experiments. Similarly, metabolites which are not consistent across replicates can be labeled as irreproducible. In this work, we introduce and evaluate the use (Ma)ximum (R)ank (R)eproducibility (MaRR) to examine reproducibility in mass spectrometry-based metabolomics experiments. We examine reproducibility across technical or biological samples in three different mass spectrometry metabolomics (MS-Metabolomics) data sets. RESULTS: We apply MaRR, a nonparametric approach that detects the change from reproducible to irreproducible signals using a maximal rank statistic. The advantage of using MaRR over model-based methods that it does not make parametric assumptions on the underlying distributions or dependence structures of reproducible metabolites. Using three MS Metabolomics data sets generated in the multi-center Genetic Epidemiology of Chronic Obstructive Pulmonary Disease (COPD) study, we applied the MaRR procedure after data processing to explore reproducibility across technical or biological samples. Under realistic settings of MS-Metabolomics data, the MaRR procedure effectively controls the False Discovery Rate (FDR) when there was a gradual reduction in correlation between replicate pairs for less highly ranked signals. Simulation studies also show that the MaRR procedure tends to have high power for detecting reproducible metabolites in most situations except for smaller values of proportion of reproducible metabolites. Bias (i.e., the difference between the estimated and the true value of reproducible signal proportions) values for simulations are also close to zero. The results reported from the real data show a higher level of reproducibility for technical replicates compared to biological replicates across all the three different datasets. In summary, we demonstrate that the MaRR procedure application can be adapted to various experimental designs, and that the nonparametric approach performs consistently well. CONCLUSIONS: This research was motivated by reproducibility, which has proven to be a major obstacle in the use of genomic findings to advance clinical practice. In this paper, we developed a data-driven approach to assess the reproducibility of MS-Metabolomics data sets. The methods described in this paper are implemented in the open-source R package marr, which is freely available from Bioconductor at http://bioconductor.org/packages/marr .


Assuntos
Metabolômica , Espectrometria de Massas , Reprodutibilidade dos Testes
11.
Anticancer Res ; 41(9): 4271-4276, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34475046

RESUMO

BACKGROUND/AIM: The anticancer mechanism of itraconazole remains unsolved; therefore, we studied itraconazole-induced alterations in specialized pro-resolving mediators (SPMs) in cancer cells. MATERIALS AND METHODS: The human cervical squamous carcinoma cell line CaSki was cultured with or without 1 µM itraconazole. Liquid chromatography/mass spectrometry analysis was conducted to identify SPMs that were influenced by itraconazole. Cell growth experiments were conducted using itraconazole and inhibitors targeting the metabolic pathways of candidate SPMs. RESULTS: Resolvin E3, resolvin E2, prostaglandin J2 (PGJ2), delta-12-PGJ2, and maresin 2 were identified as candidate SPMs. The 12/15-lipoxygenase inhibitor, which is involved in the conversion of 18-hydroxy-eicosapentaenoic acid to resolvin E3, attenuated the inhibitory effect of itraconazole. Inhibition of the PGJ2 metabolic pathway did not interfere with itraconazole treatment. CONCLUSION: The metabolic pathway of SPMs, including resolving E3, could be proposed as an anticancer target of itraconazole.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Ácidos Graxos Insaturados/metabolismo , Itraconazol/farmacologia , Inibidores de Lipoxigenase/farmacologia , Neoplasias do Colo do Útero/metabolismo , Carcinoma de Células Escamosas/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Espectrometria de Massas , Redes e Vias Metabólicas/efeitos dos fármacos , Neoplasias do Colo do Útero/tratamento farmacológico
12.
Se Pu ; 39(10): 1118-1127, 2021 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-34505434

RESUMO

The late endosomal/lysosomal adaptor MAPK and mTOR activator 1 (LAMTOR1) is an important regulator protein in the response to energy stress. Public gene expression data shows that the expression of LAMTOR1 is abnormally high in nonalcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC); hence, LAMTOR1 may play an important role in the development of NASH and HCC. Therefore, exploring the LAMTOR1 regulatory mechanism in the progression of NASH and malignant transformation of liver inflammation may be crucial for translational medicine. First, a NASH mouse model was established by feeding a methionine choline-deficient (MCD) diet. Hematoxylin-eosin staining of liver tissues showed successful modeling of inflammatory injury in the mouse liver. Immunoblot analysis confirmed LAMTOR1- and LAMTOR1-mediated protein expression in LAMTOR1 specifically depleted mouse livers. Subsequently, metabolic profiling of liver tissues was performed using an ultra-performance liquid chromatography-time-of-flight mass spectrometry strategy. Based on the retention time, m/z value, and tandem mass spectra, 134 metabolites were identified. Among these, the levels of 45 metabolite were significantly influenced by hepatic LAMTOR1 depletion. According to the metabolomics results, uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc) was significantly upregulated in LAMTOR1-depleted (LAMTOR1LKO) hepatocyte tissues. As the final product of the hexosamine biosynthetic pathway (HBP), alteration in UDP-GlcNAc levels may regulate LAMTOR1 and metabolic regulatory genes downstream of HBP. Moreover, there was an obvious increase in the levels of several methylation-related metabolites. Thus, upregulated S-adenosylmethionine, S-adenosylhomocysteine, and N6,N6,N6-trimethyl-L-lysine indicated that LAMTOR1 may regulate the process of DNA or protein methylation. In addition, downregulation of 9-oxo-octadecadienoate, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) was also observed in LAMTOR1LKO mice liver tissues. Alterations in polyunsaturated fatty acids, such as EPA and DHA, link LAMTOR1 to inflammatory and immune processes, which are known to play important roles in NASH pathogenesis. These metabolic disorders demonstrated that LAMTOR1 significantly contributed to the metabolic mechanism of NASH. Furthermore, gene expression correlations were analyzed to interpret the regulatory role of LAMTOR1 from the perspective of genetic networks. Owing to a paucity of liver whole-transcriptome studies in NASH, correlation analysis was performed based on HCC transcriptome data from public databases. First, a negatively regulated relationship was observed between LAMTOR1 and MAT1A (R=-0.47). MAT1A encodes methionine adenosyltransferase 1A, an essential enzyme that catalyzes the formation of S-adenosylmethionine. Based on the upregulation of UDP-GlcNAc under hepatocyte LAMTOR1 depletion, it was predicted that LAMTOR1 positively influenced MGAT1 (R=0.47), a gene encoding alpha-1,3-mannosyl-glycoprotein 2-beta-N-acetylglucosaminyltransferase. Together with changes in succinyladenosine caused by hepatocyte LAMTOR1 deletion, predicted correlation results showed that LAMTOR1 may also participate in the pathogenesis through the positive regulatory relationship with ADSL (R=0.59). The ADSL gene provides instructions for making an enzyme called adenylosuccinate lyase, which can dephosphorylate the substrate succinyladenosine. In this study, LAMTOR1 was identified to specifically regulate multiple key metabolic pathways based on both NASH mouse models and gene expression correlations. These results illustrate the important role of LAMTOR1 in the progression of NASH and malignant transformation of liver inflammation, which provides a theoretical basis for the diagnosis and treatment of NASH or possible NASH-driven HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Cromatografia Líquida , Modelos Animais de Doenças , Inflamação , Fígado , Espectrometria de Massas , Metionina , Camundongos
13.
Zhongguo Zhong Yao Za Zhi ; 46(13): 3368-3376, 2021 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-34396757

RESUMO

This study aims to investigate Erythrina alkaloids from the stems of Erythrina corallodendron. Eighteen Erythrina alkaloids were isolated from the 95% ethanol extract of the stems of E. corallodendron by silica gel,octadecyl silica( ODS),Sephadex LH-20 column chromatography and preparative HPLC. With nuclear magnetic resonance( NMR) spectroscopy and mass spectrometry( MS),their structures were identified as crstanine A( 1),erytharbine( 2),cristamine C( 3),( +)-erystramindine( 4),10,11-dioxoerythraline( 5),8-oxoerythraline( 6),8-oxo-11ß-methoxyerythradine( 7),11-methoxyerythradine( 8),( ±)-11-epi-methoxyerythraline( 9),( +)-erythraline( 10),crystamidine( 11),8-oxoerythrinine( 12),( +)-11α-hydroxyerysotrine( 13),erythrinine( 14),erysodine( 15),erysotrine-N-oxide( 16),( +)-erythratidine( 17),erythratine( 18). Compounds 1-4,7,9,11,13,16 and 17 were isolated from E. corallodendron for the first time. Furthermore,the cytotoxic activities of these Erythrina alkaloids were screened by MTT assay. The results showed that all compounds had no obvious cytotoxic activity. The analgesic activities of compounds1,6 and 8 were evaluated using an acetic acid-induced writhing test in mice. The writhing inhibition rates of compounds 1,6 and 8 at20 mg·kg~(-1)( ip) were 69%,70% and 62%,respectively( P<0. 01),indicating they have significant analgesic activity.


Assuntos
Alcaloides , Erythrina , Animais , Cromatografia Líquida de Alta Pressão , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Camundongos
14.
Front Cell Infect Microbiol ; 11: 695134, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34368015

RESUMO

The objective of this study was to evaluate the value of molecular methods in the management of community-acquired pneumonia (CAP) in children. Previously developed mass spectrometry (MS)-based methods combined with quantitative real-time PCR (combined-MS methods) were used to describe the aetiology and evaluate antibiotic therapy in the enrolled children. Sputum collected from 302 children hospitalized with CAP were analyzed using the combined-MS methods, which can detect 19 viruses and 12 bacteria related to CAP. Based on the results, appropriate antibiotics were determined using national guidelines and compared with the initial empirical therapies. Respiratory pathogens were identified in 84.4% of the patients (255/302). Co-infection was the predominant infection pattern (51.7%, 156/302) and was primarily a bacterial-viral mixed infection (36.8%, 111/302). Compared with that using culture-based methods, the identification rate for bacteria using the combined-MS methods (61.8%, 126/204) increased by 28.5% (p <0.001). Based on the results of the combined-MS methods, the initial antibiotic treatment of 235 patients was not optimal, which mostly required switching to ß-lactam/ß-lactamase inhibitor combinations or reducing unnecessary macrolide treatments. Moreover, using the combined-MS methods to guide antibiotic therapy showed potential to decrease the length of stay in children with severe CAP. For children with CAP, quantitative molecular testing on sputum can serve as an important complement to traditional culture methods. Early aetiology elucidated using molecular testing can help guide the antibiotic therapy.


Assuntos
Infecções Comunitárias Adquiridas , Pneumonia , Antibacterianos/uso terapêutico , Bactérias/genética , Criança , Infecções Comunitárias Adquiridas/tratamento farmacológico , Humanos , Espectrometria de Massas , Pneumonia/tratamento farmacológico
15.
Anal Chim Acta ; 1176: 338620, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34399890

RESUMO

Omic methodologies have become key analytical tools in a wide number of research topics such as systems biology, environmental analysis, biomedicine or food analysis. They are especially useful when they are combined providing a new perspective and a holistic view of the analytical problem. Methodologies for microbiota analysis have been mostly focused on genome sequencing. However, information provided by these metagenomic studies is limited to the identification of the presence of genes, taxa and their inferred functionality. To achieve a deeper knowledge of microbial functionality in health and disease, especially in dysbiosis conditions related to metal and metalloid exposure, the introduction of additional meta-omic approaches including metabolomics, metallomics, metatranscriptomics and metaproteomics results essential. The possible impact of metals and metalloids on the gut microbiota and their effects on gut-brain axis (GBA) only begin to be figured out. To this end new analytical workflows combining powerful tools are claimed such as high resolution mass spectrometry and heteroatom-tagged proteomics for the absolute quantification of metal-containing biomolecules using the metal as a "tag" in a sensitive and selective detector (e.g. ICP-MS). This review focus on current analytical methodologies related with the analytical techniques and procedures available for metallomics and microbiota analysis with a special attention on their advantages and drawbacks.


Assuntos
Microbiota , Espectrometria de Massas , Metabolômica , Metais , Proteômica
16.
Analyst ; 146(17): 5389-5402, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34346415

RESUMO

This study reports novel approaches for the detection of gunshot residues (GSR) from the hands of individuals using Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). The methods' performance was evaluated using 159 GSR standard and authentic samples. Forty specimens generated from characterized microparticles were used as matrix-matched primer gunshot residue (pGSR) standards to examine the elemental profiles of leaded and lead-free residues, compared to SEM-EDS and solution-ICP-MS. Also, 119 authentic skin samples were analyzed to estimate error rates. Shooter samples were correctly classified into three categories based on their elemental composition (leaded, lead-free, or mixed pGSR). A total of 60 non-shooter samples were used to establish background thresholds and estimate specificity (93.4% for LA-ICP-MS and 100% for LIBS). All the authentic leaded items resulted in the detection of particle(s) with composition characteristic of pGSR (Pb-Ba-Sb), as observed by simultaneous elemental identification of target analytes at the exact ablation times and locations. When considering the pre-characterized elemental composition of these primers as the "ground truth", LA-ICP-MS resulted in 91.8% sensitivity (true positive rate), while LIBS resulted in 89.2% sensitivity. Particles containing Ba, Bi, Bi-Cu-K, and Cu-Ti-Zn were found in the lead-free residues. Identification of lead-free GSR proved more challenging as some of these elements are common in the environment, resulting in 85.2% sensitivity for LA-ICP-MS and 44.4% for LIBS. Overall accuracies of 94.9% and 88.2% were obtained for the LA-ICP-MS and LIBS sets, respectively. LA-ICP-MS provided an additional level of confidence in the results by its superior analytical capabilities, complementing the LIBS chemical profiles. The laser-based methods provide rapid chemical profiling and micro-spatial information of gunshot residue particles, with minimal destruction of the sample and high accuracy. Chemical mapping of 25 micro-regions per sample is possible in 2-10 minutes by LIBS and LA-ICP-MS, offering new tools for more comprehensive forensic case management and quick GSR screening in environmental and occupational sciences.


Assuntos
Terapia a Laser , Medicina Legal , Humanos , Lasers , Espectrometria de Massas , Análise Espectral
17.
Nat Commun ; 12(1): 4787, 2021 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-34373457

RESUMO

Label-free proteomics by data-dependent acquisition enables the unbiased quantification of thousands of proteins, however it notoriously suffers from high rates of missing values, thus prohibiting consistent protein quantification across large sample cohorts. To solve this, we here present IceR (Ion current extraction Re-quantification), an efficient and user-friendly quantification workflow that combines high identification rates of data-dependent acquisition with low missing value rates similar to data-independent acquisition. Specifically, IceR uses ion current information for a hybrid peptide identification propagation approach with superior quantification precision, accuracy, reliability and data completeness compared to other quantitative workflows. Applied to plasma and single-cell proteomics data, IceR enhanced the number of reliably quantified proteins, improved discriminability between single-cell populations, and allowed reconstruction of a developmental trajectory. IceR will be useful to improve performance of large scale global as well as low-input proteomics applications, facilitated by its availability as an easy-to-use R-package.


Assuntos
Espectrometria de Massas/métodos , Proteoma , Proteômica/métodos , Peptídeos , Espectrometria de Massas em Tandem , Fluxo de Trabalho
18.
Methods Mol Biol ; 2351: 275-288, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34382195

RESUMO

Functionalization of the genome is carried out by proteins that bind to DNA to regulate gene expression. Since this process is highly dynamic, context-dependent, and rarely performed by single proteins alone, we here describe ChIP-SICAP to identify proteins that co-localize with a protein of interest on the genome. Benefiting from its nature as a dual purification approach via ChIP and DNA biotinylation, ChIP-SICAP distinguishes genuine chromatin-binders and is uniquely placed to identify novel players in genome regulation.


Assuntos
Imunoprecipitação da Cromatina/métodos , Cromatina/genética , Cromatina/metabolismo , Proteínas de Ligação a DNA/metabolismo , Sítios de Ligação , Biotinilação , DNA/genética , DNA/metabolismo , Histonas/metabolismo , Espectrometria de Massas , Peptídeo Hidrolases , Ligação Proteica , Proteômica/métodos
19.
Anal Chem ; 93(32): 11268-11274, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34347440

RESUMO

Discrimination of isomers in a mixture is a subject of ongoing interest in biology, pharmacology, and forensics. We demonstrate that femtosecond time-resolved mass spectrometry (FTRMS) effectively quantifies mixtures of ortho-, para-, and meta-nitrotoluenes, the first two of which are common explosive degradation products. The key advantage of the FTRMS approach to mixture quantification lies in the ability of the pump-probe laser control scheme to capture distinct fragmentation dynamics of each nitrotoluene cation isomer on femtosecond timescales, thereby allowing for discrimination of the isomers using only the signal of the parent molecular ion at m/z 137. Upon measurement of reference dynamics of each individual isomer, the molar fractions of binary and ternary mixtures can be predicted to within ∼5 and ∼7% accuracy, respectively.


Assuntos
Lasers , Cátions , Isomerismo , Espectrometria de Massas
20.
Nat Commun ; 12(1): 4855, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381044

RESUMO

The vertebrate brain consists of diverse neuronal types, classified by distinct anatomy and function, along with divergent transcriptomes and proteomes. Defining the cell-type specific neuroproteomes is important for understanding the development and functional organization of neural circuits. This task remains challenging in complex tissue, due to suboptimal protein isolation techniques that often result in loss of cell-type specific information and incomplete capture of subcellular compartments. Here, we develop a genetically targeted proximity labeling approach to identify cell-type specific subcellular proteomes in the mouse brain, confirmed by imaging, electron microscopy, and mass spectrometry. We virally express subcellular-localized APEX2 to map the proteome of direct and indirect pathway spiny projection neurons in the striatum. The workflow provides sufficient depth to uncover changes in the proteome of striatal neurons following chemogenetic activation of Gαq-coupled signaling cascades. This method enables flexible, cell-type specific quantitative profiling of subcellular proteome snapshots in the mouse brain.


Assuntos
Ascorbato Peroxidases/metabolismo , Núcleo Celular/metabolismo , Corpo Estriado/metabolismo , Proteoma/metabolismo , Animais , Ascorbato Peroxidases/genética , Corpo Estriado/citologia , Citosol/metabolismo , Espectrometria de Massas , Camundongos , Vias Neurais , Neurônios/citologia , Neurônios/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais , Coloração e Rotulagem , Fluxo de Trabalho
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