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1.
Diab Vasc Dis Res ; 20(3): 14791641231179870, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37344962

RESUMO

We investigated whether prediabetes diagnosed by hemoglobinA1c (HbA1c) or oral glucose tolerance test (OGTT) could predict presence and severity of coronary artery disease (CAD) in symptomatic patients. The presence of plaque, stenosis, plaque characteristics, and coronary artery calcium (CAC) were evaluated by coronary CT angiography in 702 patients with suspicion of CAD. Patients were classified by glycemic status using the American Diabetes Association criteria for HbA1c and OGTT, and compared to their respective normal ranges. Prediabetes was observed in 24% by HbA1c and 72% by OGTT. Both prediabetes classifications were associated with increased presence of plaque, stenosis, calcified plaques, CAC >400, and a lower frequency of zero CAC compared to their respective normal range (all, p < 0.05). After adjusting for potential confounders, patients with HbA1c-prediabetes had an odds ratio of 2.1 (95% CI: 1.3-3.5) for CAC >400 and 1.5 (95% CI: 1.0-2.4) for plaque presence, while none of the associations for OGTT-prediabetes were significant. The receiver operating characteristic-curve for HbA1c-prediabetes showed an area under the curve of 0.81 for CAC >400 and 0.77 for plaque presence. Prediabetes defined by HbA1c predicts presence and severity of CAD. Although OGTT identified more patients with prediabetes, their risk of CAD were not explained by prediabetes using these diagnostic-criteria.


Assuntos
Doença da Artéria Coronariana , Placa Aterosclerótica , Estado Pré-Diabético , Humanos , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/epidemiologia , Teste de Tolerância a Glucose , Estado Pré-Diabético/diagnóstico , Estado Pré-Diabético/epidemiologia , Estado Pré-Diabético/complicações , Hemoglobinas Glicadas , Constrição Patológica/complicações , Placa Aterosclerótica/complicações , Angiografia Coronária , Fatores de Risco
3.
Actas Dermosifiliogr ; 114(5): 443-444, 2023 05.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-35843292
4.
Anal Chim Acta ; 1223: 340196, 2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-35999003

RESUMO

The standard method for estimating the chemical oxygen demand (COD) of water bodies uses dichromate as the main oxidant, a chemical agent whose use has been restricted in the European Union since 2017. This method is hazardous, time-consuming, and burdensome to adapt to on-site measurements. As an alternative and following the current trends of sustainable and green chemistry, a method using the less toxic reagent sodium persulfate as the oxidizing agent has been developed. In this method an excess of persulfate, activated through heating in an alkaline solution, oxidizes the chemically degradable organic fraction through a 2-step radical mechanism. The remaining persulfate is evaluated by chemiluminescence (CL) using luminol and a portable charge-coupled device (CCD) camera. The method provided quantitative recoveries and a sample throughput of >60 samples h-1. It was validated in river water samples by comparison of COD estimations with the standard dichromate method (R = 0.973, p < 0.05) and with a UV-Vis permanganate-based method (R = 0.9998, p < 0.05), the latter being also used for drinking waters. The proposed method is a sustainable and green alternative to the previous used methods. Overall, the method using activated persulfate is suitable for use as COD quantitation/screening tool in surface waters. Considering that its main components are portable, it can be ultimately adapted for in situ analysis at the point of need.


Assuntos
Água Doce , Luminol , Análise da Demanda Biológica de Oxigênio , Água Doce/análise , Oxirredução , Oxigênio/análise , Água/análise
5.
Sci Rep ; 12(1): 5112, 2022 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-35332214

RESUMO

Bones and teeth are biological archives, but their structure and composition are subjected to alteration overtime due to biological and chemical degradation postmortem, influenced by burial environment and conditions. Nevertheless, organic fraction preservation is mandatory for several archeometric analyses and applications. The mutual protection between biomineral and organic fractions in bones and teeth may lead to a limited diagenetic alteration, promoting a better conservation of the organic fraction. However, the correlation between elemental variations and the presence of organic materials (e.g., collagen) in the same specimen is still unclear. To fill this gap, chemiluminescent (CL) immunochemical imaging analysis has been applied for the first time for collagen localization. Then, Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) and CL imaging were combined to investigate the correlation between elemental (i.e., REE, U, Sr, Ba) and collagen distribution. Teeth and bones from various archeological contexts, chronological periods, and characterized by different collagen content were analyzed. Immunochemical analysis revealed a heterogeneous distribution of collagen, especially in highly degraded samples. Subsequently, LA-ICP-MS showed a correlation between the presence of uranium and rare earth elements and areas with low amount of collagen. The innovative integration between the two methods permitted to clarify the mutual relation between elemental variation and collagen preservation overtime, thus contributing to unravel the effects of diagenetic alteration in bones and teeth.


Assuntos
Restos Mortais , Dente , Colágeno/análise , Humanos , Espectrometria de Massas/métodos , Análise Espectral , Dente/química
6.
Sci Rep ; 10(1): 14017, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32820238

RESUMO

Discarding by fisheries is one of the most wasteful human marine activities, yet we have few estimates of its scale. Reliable estimates of global discards are essential for sustainable fisheries management. Using United Nations Food and Agriculture Organization databases on country-specific landings, we estimated the discard rate and magnitude for global marine and estuarine capture fisheries using fishery-specific discard rates derived from direct observations and global gear-specific discard rates estimated within a Bayesian modelling framework. An estimated 9.1 million tonnes are discarded annually (95% uncertainty interval: 7-16 M t)-or 10.8% of the global catch (95% UI: 10-12%). Encouragingly, this is about half of the annual global discard rate estimated in the late 1980s. Trawl fisheries, especially demersal otter trawls, warrant intensified efforts to reduce discards. Periodic benchmarks of global discards are needed to assess the performance of reduction efforts.

7.
Anal Biochem ; 600: 113760, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32353372

RESUMO

Hydrogen peroxide is an unavoidable by-product of cell metabolism, but when it is not properly managed by the body it can lead to several pathologies (e.g., premature aging, cardiovascular and neurodegenerative diseases, cancer). Several methods have been proposed for the measurement of intracellular H2O2 but none of them has proven to be selective. We developed a rapid all-in-one chemiluminescent bioassay for the quantification of H2O2 in living cells with a low limit of detection (0.15 µM). The method relies on an adamantylidene-1,2-dioxetane lipophilic probe containing an arylboronate moiety; upon reaction with H2O2 the arylboronate moiety is converted to the correspondent phenol and the molecule decomposes leading to an excited-state fragment that emits light. The probe has been successfully employed for quantifying intracellular H2O2 in living human endothelial, colon and keratinocyte cells exposed to different pro-oxidant stimuli (i.e., menadione, phorbol myristate acetate and lipopolysaccharide). Imaging experiments clearly localize the chemiluminescence emission inside the cells. Treatment of cells with antioxidant molecules leads to a dose-dependent decrease of intracellular H2O2 levels. As a proof of concept, the bioassay has been used to measure the antioxidant activity of extracts from Brassica juncea wastes, which contain glucosinolates, isothiocyanates and other antioxidant molecules.


Assuntos
Corantes Fluorescentes/química , Células Endoteliais da Veia Umbilical Humana/química , Peróxido de Hidrogênio/análise , Medições Luminescentes , Imagem Óptica , Células CACO-2 , Células Cultivadas , Humanos , Estrutura Molecular
8.
Iperception ; 10(3): 2041669519852643, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31219478

RESUMO

Can music be rated consistently using nonverbal descriptors such as colours and temperatures? 144 participants rated 6 experimenter-selected and 2 self-selected pieces of music along 15 bipolar icon (graphic) scales intended to portray emotions, and sensory experiences consisting of colour, temperature, shape, speed, texture, and weight. Participants also rated the same pieces using bipolar verbal scales which aimed to encompass the concepts represented by the icons (e.g., the word "red" for the colour red). Furthermore, the icons themselves were subjected to open-ended verbal labelling to validate the icon scale. Colour icons spontaneously evoked a cross-modal association on 67% of occasions: blue being cool, and red/orange being warm or hot, and the icon scale had overall good face validity. Music regularly and consistently evoked multisensory associations (using the icon scale) including shapes, colours, weight, and temperatures, in addition to emotions. Cross-modal perception is indicative of music's character rather than the enjoyment of the music. The icon scale provides new insights into music perception and for applications where language skill may limit participant expression.

9.
Oxid Med Cell Longev ; 2019: 1046504, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30881586

RESUMO

The large amount of cauliflower industry waste represents an unexplored source of bioactive compounds. In this work, peptide hydrolysates from cauliflower leaves were characterized by combined bioanalytical approaches. Twelve peptide fractions were studied to evaluate unexplored biological activities by effect-based cellular bioassays. A potent inhibition of intracellular xanthine oxidase activity was observed in human vascular endothelial cells treated with one fraction, with an IC50 = 8.3 ± 0.6 µg/ml. A different fraction significantly induced the antioxidant enzyme superoxide dismutase 1 and decreased the tumor necrosis factor α-induced VCAM-1 expression, thus leading to a significant improvement in the viability of human vascular endothelial cells. Shotgun peptidomics and bioinformatics were used to retrieve the most probable bioactive peptide sequences. Our study shows that peptides from cauliflower waste should be recycled for producing valuable products useful for the prevention of endothelial dysfunction linked to atherogenesis progression.


Assuntos
Brassica/química , Peptídeos/uso terapêutico , Xantina Oxidase/química , Células Endoteliais , Humanos , Peptídeos/farmacologia
10.
J Chromatogr A ; 1585: 70-81, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30482431

RESUMO

Bile acids (BAs) are endogenous steroids involved in the transport of lipids in bile, acting also as molecular signaling hormones. Primary BAs synthesized in the liver undergo several metabolic pathways in the intestine by gut microbiota to produce secondary BAs. Together with secondary BAs, other metabolites have been recovered from human faeces, including many oxo-BA analogues produced in the colon through oxidation of BA hydroxy groups. However, the complete oxo-BA characterization in biospecimens (particularly intestinal content and faeces) has not been reported yet, hampering the assessment of their potential physiological role. Herein, we have developed and validated a new RP-HPLC-ESI-MS/MS method in negative ionization mode for the simultaneous analysis of 21 oxo-BAs and their 7 metabolic BAs precursors in human faeces. The elution was performed in gradient mode and 28 compounds, including primary, secondary BAs, and their oxo-derivatives, were separated within 50 min at 40 °C column temperature. The method is accurate (bias% <13%), precise (CV% <10%), with limits of quantification (LOQ <30 ng/mLextract samples), similar for all the studied compounds. The matrix effect does not significantly affect the analysis accuracy, allowing the use of standard solutions for the quantifications, without matrix-matched protocols. Thanks to the high detectability and the relatively high concentration of oxo-BAs (about µg/gwet faeces), the method does not require a pre-analytical clean-up step. This method was used to identify and quantify oxo-BAs in human faecal samples from healthy subjects, serving as a proof of concept for application in patients with hepatobiliary disease and bacteria overgrowth.


Assuntos
Ácidos e Sais Biliares/análise , Cromatografia Líquida , Técnicas de Laboratório Clínico/métodos , Fezes/química , Cetoácidos/análise , Espectrometria de Massas em Tandem , Conteúdo Gastrointestinal/química , Humanos , Limite de Detecção , Reprodutibilidade dos Testes
12.
Nutr Metab Cardiovasc Dis ; 27(6): 552-563, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28511903

RESUMO

BACKGROUND AND AIMS: Oxidized LDL (oxLDL) or pro-inflammatory stimuli lead to increased oxidative stress linked to endothelial dysfunction and atherosclerosis. The oxLDL receptor-1 (LOX1) is elevated within atheromas and cholesterol-lowering statins inhibit LOX1 expression. Berberine (BBR), an alkaloid extracted from plants of gender Berberis, has lipid-lowering and anti-inflammatory activity. However, its role in regulating LOX1-mediated signaling is still unknown. The aim of this study was to investigate the effect of BBR on oxLDL- and TNFα-induced endothelial dysfunction in human umbilical vein endothelial cells (HUVECs) and to compare it with that of lovastatin (LOVA). METHODS AND RESULTS: Cytotoxicity was determined by lactate dehydrogenase assay. Antioxidant capacity was measured with chemiluminescent and fluorescent method and intracellular ROS levels through a fluorescent dye. Gene and protein expression levels were assayed by qRT-PCR and western blot, respectively. HUVECs exposure to oxLDL (30 µg/ml) or TNFα (10 ng/ml) for 24 h led to a significant increase in LOX1 expression, effect abrogated by BBR (5 µM) and LOVA (5 µM). BBR but not LOVA treatment abolished the TNFα-induced cytotoxicity and restored the activation of Akt signaling. In spite of a low direct antioxidant capacity, both compounds reduced intracellular ROS levels generated by treatment of TNFα but only BBR inhibited NOX2 expression, MAPK/Erk1/2 signaling and subsequent NF-κB target genes VCAM and ICAM expression, induced by TNFα. CONCLUSIONS: These findings demonstrated for the first time that BBR could prevent the oxLDL and TNFα - induced LOX1 expression and oxidative stress, key events that lead to NOX, MAPK/Erk1/2 and NF-κB activation linked to endothelial dysfunction. CHEMICAL COMPOUNDS STUDIED IN THIS ARTICLE: Berberine (PubChem CID: 2353); Lovastatin (PubChem CID: 53232).


Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Berberina/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Lipoproteínas LDL/farmacologia , Lovastatina/farmacologia , Receptores Depuradores Classe E/agonistas , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Citoproteção , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Glicoproteínas de Membrana/metabolismo , NADPH Oxidase 2 , NADPH Oxidases/metabolismo , NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Receptores Depuradores Classe E/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia
13.
Clin Transl Sci ; 10(4): 292-301, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28411380

RESUMO

Obeticholic acid (OCA) is a semisynthetic bile acid (BA) analog and potent farnesoid X receptor agonist approved to treat cholestasis. We evaluated the biodistribution and metabolism of OCA administered to carbon tetrachloride-induced cirrhotic rats. This was to ascertain if plasma and hepatic concentrations of OCA are potentially more harmful than those of endogenous BAs. After administration of OCA (30 mg/kg), we used liquid chromatography-mass spectrometry to measure OCA, its metabolites, and BAs at different timepoints in various organs and fluids. Plasma and hepatic concentrations of OCA and BAs were higher in cirrhotic rats than in controls. OCA and endogenous BAs had similar metabolic pathways in cirrhotic rats, although OCA hepatic and intestinal clearance were lower than in controls. BAs' qualitative and quantitative compositions were not modified by a single administration of OCA. In all the matrices studied, OCA concentrations were significantly lower than those of endogenous BAs, potentially much more cytotoxic.


Assuntos
Ácidos e Sais Biliares/metabolismo , Ácido Quenodesoxicólico/análogos & derivados , Cirrose Hepática/metabolismo , Metabolômica , Animais , Ácidos e Sais Biliares/urina , Fístula Biliar/metabolismo , Fístula Biliar/patologia , Ácido Quenodesoxicólico/metabolismo , Ácido Quenodesoxicólico/urina , Modelos Animais de Doenças , Fezes/química , Mucosa Intestinal/metabolismo , Intestinos/patologia , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática/sangue , Cirrose Hepática/patologia , Masculino , Metaboloma , Ratos Wistar , Distribuição Tecidual
14.
Anal Bioanal Chem ; 408(30): 8755-8760, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27392750

RESUMO

Xanthine oxidase (XO) is an important enzyme, expressed at high levels in the vasculature in endothelial cells, that catalyzes the hydroxylation of hypoxanthine to xanthine and xanthine to uric acid. Excessive production of uric acid results in hyperuricemia linked to gout and cardiovascular diseases. Testing inhibition of XO is important for detection of potentially effective drugs or natural products that could be used to treat diseases caused by increased XO activity. In the present study, for the first time, we developed an in vitro chemiluminescent bioassay to determine XO activity in living endothelial cells and the IC50 value of oxypurinol, the active metabolite of the inhibitor drug allopurinol. Intracellular XO activity was measured in less than 20 min with a luminol/catalyst-based chemiluminescence assay able to measure XO with a limit of 0.4 µU/mL. Oxypurinol addition to 5 × 103 cells (ranging from 5.0 to 0.0 µM) caused a linear decrease in XO activity, with an IC50 of 1.0 ± 0.5 µM. The detection system developed was low-cost, rapid, reproducible, and easily miniaturizable so suitable to be used on small quantities of cells.


Assuntos
Bioensaio , Medições Luminescentes/métodos , Ácido Úrico/antagonistas & inibidores , Xantina Oxidase/antagonistas & inibidores , Alopurinol/química , Alopurinol/farmacologia , Citoplasma/enzimologia , Inibidores Enzimáticos/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/enzimologia , Humanos , Cinética , Limite de Detecção , Luminol/química , Oxirredução , Oxipurinol/farmacologia , Ácido Úrico/metabolismo , Xantina Oxidase/metabolismo
15.
J Chromatogr A ; 1428: 154-61, 2016 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-26363943

RESUMO

A new high pressure liquid chromatography-electrospray ionization-tandem mass spectrometry method for the simultaneous determination of glucosinolates, as glucoraphanin and glucoerucin, and the corresponding isothiocyanates, as sulforaphane and erucin, was developed and applied to quantify these compounds in Eruca sativa defatted seed meals and enriched functional foods. The method involved solvent extraction, separation was achieved in gradient mode using water with 0.5% formic acid and acetonitrile with 0.5% formic acid and using a reverse phase C18 column. The electrospray ion source operated in negative and positive mode for the detection of glucosinolates and isothiocyanates, respectively, and the multiple reaction monitoring (MRM) was selected as acquisition mode. The method was validated following the ICH guidelines. Replicate experiments demonstrated a good accuracy (bias%<10%) and precision (CV%<10%). Detection limits and quantification limits are in the range of 1-400ng/mL for each analytes. Calibration curves were validated on concentration ranges from 0.05 to 50µg/mL. The method proved to be suitable for glucosinolates and isothiocyanates determination both in biomasses and in complex matrices such as food products enriched with glucosinolates, or nutraceutical bakery products. In addition, the developed method was applied to the simultaneous determination of glucosinolates and isothiocyanates in bakery product enriched with glucosinolates, to evaluate their thermal stability after different industrial processes from cultivation phases to consumer processing.


Assuntos
Brassicaceae/química , Cromatografia Líquida , Análise de Alimentos/métodos , Alimento Funcional/análise , Glucosinolatos/análise , Isotiocianatos/análise , Espectrometria de Massas por Ionização por Electrospray , Análise de Alimentos/instrumentação , Limite de Detecção , Sementes/química , Espectrometria de Massas em Tandem
16.
Adv Biochem Eng Biotechnol ; 154: 3-17, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-25898810

RESUMO

: The latest advances in molecular biology have made available several biotechnological tools that take advantage of the high detectability and quantum efficiency of bioluminescence (BL), with an ever-increasing number of novel applications in environmental, pharmaceutical, food, and forensic fields. Indeed, BL proteins are being used to develop ultrasensitive binding assays and cell-based assays, thanks to their high detectability and to the availability of highly sensitive BL instruments. The appealing aspect of molecular biology tools relying on BL reactions is their general applicability in both in vitro assays, such as cell cultures or purified proteins, and in vivo settings, such as in whole-animal BL imaging. The aim of this chapter is to provide the reader with an overview of state-of-the-art bioluminescent tools based on luciferase genes, highlighting molecular biology strategies that have been applied so far, together with some selected examples.


Assuntos
Genes Reporter , Luciferases/química , Biologia Molecular , Animais , Medições Luminescentes
17.
Anal Bioanal Chem ; 405(2-3): 933-40, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23064674

RESUMO

The characterization of the organic components in a complex, multilayered paint structure is fundamental for studying painting techniques and for authentication and restoration purposes. Proteinaceous materials, such as animal glue, are of particular importance since they are widely used as binders, adhesives and for gilding. Even though proteins are usually detected by chromatographic and proteomic techniques, immunological methods represent an alternative powerful approach to protein analysis thanks to the high specificity of antigen-antibody reactions. Our previous studies demonstrated that ovalbumin and casein could be localized in paint cross-sections with high sensitivity and good spatial resolution (i.e. within the single painting layers) by using chemiluminescent (CL) immunochemical microscope imaging. In the present research work, we describe for the first time the immunolocalization of collagen (the main protein of animal glue) in paint cross-sections by CL imaging microscopy. Two different analytical protocols have been developed, allowing either the detection of collagen or the simultaneous detection of collagen and ovalbumin in the same paint sample. The assays were used to detect collagen and ovalbumin in cross-sections from model samples and historical paintings (a wall painting dated to 1773-1774 and a painted wood panel of the Renaissance period) in order to achieve information on paint techniques and past restoration interventions.


Assuntos
Adesivos/análise , Colágeno/análise , Corantes/análise , Imunoensaio/métodos , Ovalbumina/análise , Pintura/análise , Animais
18.
Analyst ; 138(1): 211-9, 2013 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-23162810

RESUMO

A "Point-Of-Care-Testing" (POCT) system relies on portable and simply operated self-standing analytical devices. To fulfill diagnostic requirements, the POCT system should provide highly sensitive simultaneous detection of several biomarkers of the pathology of interest (multiplexing) in a short assay time. One of the main unsolved issues in POCT device development is the integration of pre-analytical sample preparation procedures in the miniaturized device. In this work, an integrated POCT system based on gravitational field-flow fractionation (GrFFF) and chemiluminescence (CL) detection is presented for the on-line sample pre-analytical treatment and/or clean-up and analysis of biological fluids. As a proof of principle for the new GrFFF-CL POCT system, the automatic on-line analysis of plasma alkaline phosphatase activity, a biomarker of obstructive liver diseases and bone disorders, starting from whole blood samples was developed. The GrFFF-CL POCT system was able to give quantitative results on blood samples from control and patients with low sample volume (0.5 µL) and reagent consumption, short analysis time (10 minutes), high reproducibility and with a linear range of 50-1400 IU L(-1). The system can be easily applied to on-line prepare plasma from whole blood for other clinical biomarkers and for other assay formats, based on immunoassay or DNA hybridization.


Assuntos
Fracionamento por Campo e Fluxo/métodos , Gravitação , Medições Luminescentes/métodos , Sistemas Automatizados de Assistência Junto ao Leito , Integração de Sistemas , Análise Química do Sangue , Humanos , Reprodutibilidade dos Testes
19.
Exp Appl Acarol ; 57(3-4): 291-308, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22402941

RESUMO

The red palm mite (Raoiella indica), an invasive pest of coconut, entered the Western hemisphere in 2004, then rapidly spread through the Caribbean and into Florida, USA. Developing effective sampling methods may aid in the timely detection of the pest in a new area. Studies were conducted to provide and compare intra tree spatial distribution of red palm mite populations on coconut in two different geographical areas, Trinidad and Puerto Rico, recently invaded by the mite. The middle stratum of a palm hosted significantly more mites than fronds from the upper or lower canopy and fronds from the lower stratum, on average, had significantly fewer mites than the two other strata. The mite populations did not vary within a frond. Mite densities on the top section of the pinna had significantly lower mite densities than the two other sections, which were not significantly different from each other. In order to improve future sampling plans for the red palm mite, the data was used to estimate the variance components associated with the various levels of the hierarchical sampling design. Additionally, presence-absence data were used to investigate the probability of no mites being present in a pinna section randomly chosen from a frond inhabited by mites at a certain density. Our results show that the most precise density estimate at the plantation level is to sample one pinna section per tree from as many trees as possible.


Assuntos
Cocos/parasitologia , Ácaros , Análise de Variância , Animais , Densidade Demográfica , Porto Rico , Trinidad e Tobago
20.
J Chromatogr A ; 1218(49): 8859-68, 2011 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-21783198

RESUMO

Liquid chromatography-mass spectrometry (LC-MS) has become an important analytical tool for quantitative proteomics and biomarker discovery. In the label-free differential LC-MS approach computational methods are required for an accurate alignment of peaks extrapolated from the experimental raw data accounting for retention time and m/z signals intensity, which are strongly affected by sample matrix and instrumental performance. A novel procedure "MassUntangler" for pairwise alignment has been developed, relying on a pattern-based matching algorithm integrated with filtering algorithms in a multi-step approach. The procedure has been optimized employing a two-step approach. Firstly, low-complexity LC-MS data derived from the enzymatic digestion of two standard proteins have been analyzed. Then, the algorithm's performance has been evaluated by comparing the results with other achieved using state-of-the-art alignment tools. In the second step, our algorithm has been used for the alignment of high-complexity LC-MS data consisting of peptides obtained by an Escherichia coli lysate available from a public repository previously used for the comparison of other alignment tools. MassUntangler gave excellent results in terms of precision scores (from 80% to 93%) and recall scores (from 68% to 89%), showing performances similar and even better than the previous developed tools. Considering the mass spectrometry sensitivity and accuracy, this approach allows the identification and quantification of peptides present in a biological sample at femtomole level with high confidence. The procedure's capability of aligning LC-MS data previously corrected for distortion in retention time has been studied through a hybrid approach, in which MassUntangler was interfaced with the OpenMS TOPP tool MapAligner. The hybrid aligner yielded better results, showing that an integration of different bioinformatic approaches for accurate label-free LC-MS data alignment should be used.


Assuntos
Cromatografia Líquida/métodos , Biologia Computacional/métodos , Bases de Dados de Proteínas , Espectrometria de Massas/métodos , Proteínas/química , Algoritmos , Escherichia coli , Fragmentos de Peptídeos/análise , Fragmentos de Peptídeos/química , Mapeamento de Peptídeos , Proteínas/análise , Software
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