Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 197
Filtrar
1.
Anal Chim Acta ; 1141: 221-229, 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-33248656

RESUMO

Accurate measurement of naturally occurring radionuclides in blast furnace slag, a by-product of the steel industry, is required for compliance with building regulations where it is often used as an ingredient in cement. A matrix reference blast furnace slag material has been developed to support traceability in these measurements. Raw material provided by a commercial producer underwent stability and homogeneity testing, as well as characterisation of matrix constituents, to provide a final candidate reference material. The radionuclide content was then determined during a comparison exercise that included 23 laboratories from 14 countries. Participants determined the activity per unit mass for 226Ra, 232Th and 40K using a range of techniques. The consensus values obtained from the power-moderated mean of the reported participant results were used as indicative activity per unit mass values for the three radionuclides: A0(226Ra) = 106.3 (34) Bq·kg-1, A0(232Th) = 130.0 (48) Bq·kg-1 and A0(40K) = 161 (11) Bq·kg-1 (where the number in parentheses is the numerical value of the combined standard uncertainty referred to the corresponding last digits of the quoted result). This exercise helps to address the current shortage of NORM industry reference materials, putting in place infrastructure for production of further reference materials.

2.
Braz. j. biol ; 79(2): 191-200, Apr.-June 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-989448

RESUMO

Abstract The hygienic and sanitary control in Food and Nutrition Units (FNU) is considered a standard procedure to produce adequate meals and reduce the risk of foodborne diseases and hospital infections. This study aimed to evaluate the isolation and identification of bacteria from equipment and food contact surfaces in a hospital FNU as well as to evaluate the sanitary condition. Likewise, it was analyzed the adhesion of the microorganisms on polyethylene cutting boards. The presence of aerobic mesophilic microorganisms, yeasts, molds, coagulase-positive staphylococci, coliform and fecal coliform, and Escherichia coli were analyzed on eating tables, countertop surfaces and cutting boards used for meat or vegetable handling, and equipment such as microwaves and refrigerators. The molecular identification it was done by 16S rRNA gene sequencing. The adhesion of the microorganisms (biofilm formation) on meat and vegetable cutting boards was also evaluated by scanning electron microscopy. The results showed high numbers of all microorganisms, except for E. coli , which was not observed in the samples. The molecular analysis identified species of the Enterobacteriaceae family and species of the Pseudomonadaceae family. Scanning electron microscopy analyses revealed bacterial adhesion on the cutting board surfaces. The results obtained in this study indicated that the hygienic conditions of surfaces like plastic cutting boards and equipment in this hospital FNU were inadequate. The achievement and application of standard operating procedures could positively help in the standardization of sanitary control, reducing the microbial contamination and providing a safe food to hospitalized patients.


Resumo O controle higiênico e sanitário nas Unidades de Alimentação e Nutrição (UAN) é considerado um procedimento padrão para produzir refeições adequadas e reduzir o risco de doenças transmitidas pelos alimentos e infecções hospitalares. Este estudo teve como objetivo isolar e identificar bactérias de equipamentos e superfícies de contato com alimentos em uma UAN hospitalar, bem como avaliar a condição sanitária. Do mesmo modo, analisou-se a adesão dos micro-organismos em tábuas de corte de polietileno. A presença de micro-organismos aeróbios mesófilos, leveduras, fungos, Sthapylococcus coagulase-positivos, coliformes, coliformes fecais e Escherichia coli foi analisadas na superfície de mesas do refeitório, superfícies de bancada e tábuas de corte usadas para manuseio de carne ou vegetais e, em equipamentos como micro-ondas e refrigeradores. A identificação molecular foi feita pelo sequenciamento do gene 16S rRNA. A adesão dos micro-organismos (formação de biofilmes) em tábuas de corte de carne e de vegetais também foi avaliada por microscopia eletrônica de varredura. Os resultados mostraram elevada contagem para todos os micro-organismos analisados, exceto para E. coli, a qual não foi observada nas amostras. A análise molecular identificou espécies da família Enterobacteriaceae e Pseudomonadaceae. A análise de microscopia eletrônica de varredura revelaram adesão bacteriana nas superfícies das placsa de corte. Os resultados obtidos neste estudo indicaram que as condições higiênicas das superfícies e de equipamentos nesta UAN hospitalar estavam inadequadas. A aplicação de procedimentos operacionais padrão poderia auxiliar positivamente na padronização do controle higiênico-sanitário, reduzindo a contaminação microbiana e fornecendo um alimento seguro para pacientes hospitalizados.


Assuntos
Humanos , Microbiologia Ambiental , Tipagem Molecular , Microbiologia de Alimentos , Serviço Hospitalar de Nutrição/tendências , Bactérias/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Biofilmes , Fungos/isolamento & purificação , Fungos/classificação , Fungos/genética
3.
Braz J Biol ; 79(2): 191-200, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30365634

RESUMO

The hygienic and sanitary control in Food and Nutrition Units (FNU) is considered a standard procedure to produce adequate meals and reduce the risk of foodborne diseases and hospital infections. This study aimed to evaluate the isolation and identification of bacteria from equipment and food contact surfaces in a hospital FNU as well as to evaluate the sanitary condition. Likewise, it was analyzed the adhesion of the microorganisms on polyethylene cutting boards. The presence of aerobic mesophilic microorganisms, yeasts, molds, coagulase-positive staphylococci, coliform and fecal coliform, and Escherichia coli were analyzed on eating tables, countertop surfaces and cutting boards used for meat or vegetable handling, and equipment such as microwaves and refrigerators. The molecular identification it was done by 16S rRNA gene sequencing. The adhesion of the microorganisms (biofilm formation) on meat and vegetable cutting boards was also evaluated by scanning electron microscopy. The results showed high numbers of all microorganisms, except for E. coli , which was not observed in the samples. The molecular analysis identified species of the Enterobacteriaceae family and species of the Pseudomonadaceae family. Scanning electron microscopy analyses revealed bacterial adhesion on the cutting board surfaces. The results obtained in this study indicated that the hygienic conditions of surfaces like plastic cutting boards and equipment in this hospital FNU were inadequate. The achievement and application of standard operating procedures could positively help in the standardization of sanitary control, reducing the microbial contamination and providing a safe food to hospitalized patients.


Assuntos
Microbiologia Ambiental , Microbiologia de Alimentos , Serviço Hospitalar de Nutrição/normas , Tipagem Molecular , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Biofilmes , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Humanos
4.
ChemMedChem ; 13(21): 2281-2289, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30184341

RESUMO

The metabolism of xenobiotics by humans and other organisms is a complex process involving numerous enzymes that catalyze phase I (functionalization) and phase II (conjugation) reactions. Herein we introduce MetScore, a machine learning model that can predict both phase I and phase II reaction sites of drugs in a single prediction run. We developed cheminformatics workflows to filter and process reactions to obtain suitable phase I and phase II data sets for model training. Employing a recently developed molecular representation based on quantum chemical partial charges, we constructed random forest machine learning models for phase I and phase II reactions. After combining these models with our previous cytochrome P450 model and calibrating the combination against Bayer in-house data, we obtained the MetScore model that shows good performance, with Matthews correlation coefficients of 0.61 and 0.76 for diverse phase I and phase II reaction types, respectively. We validated its potential applicability to lead optimization campaigns for a new and independent data set compiled from recent publications. The results of this study demonstrate the usefulness of quantum-chemistry-derived molecular representations for reactivity prediction.


Assuntos
Fenômenos Bioquímicos , Sistema Enzimático do Citocromo P-450/metabolismo , Aprendizado de Máquina , Compostos Orgânicos/metabolismo , Bases de Dados de Compostos Químicos , Humanos , Modelos Químicos , Compostos Orgânicos/química , Processos Estocásticos
5.
Health Serv Res ; 53(4): 2027-2046, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29473156

RESUMO

OBJECTIVE: To estimate how labor force participation is affected when adult children provide informal care to their parents. DATA SOURCE: Survey of Health, Ageing and Retirement in Europe from 2004 to 2013. STUDY DESIGN: To offset the problem of endogeneity, we exploit the availability of other potential caregivers within the family as predictors of the probability to provide care for a dependent parent. Contrary to most previous studies, the dataset covers the whole working-age population in the majority of European countries. Individuals explicitly had to opt for or against the provision of care to their care-dependent parents, which allows us to more precisely estimate the effect of caregiving on labor force participation. PRINCIPAL FINDINGS: Results reveal a negative causal effect that indicates that informal care provision reduces labor force participation by 14.0 percentage points (95 percent CI: -0.307, 0.026). Point estimates suggest that the effect is larger for men; however, this gender difference is not significantly different from zero at conventional levels. CONCLUSIONS: Results apply to individuals whose consideration in long-term care policy is highly relevant, that is, children whose willingness to provide informal care to their parents is altered by available alternatives of family caregivers.


Assuntos
Cuidadores/estatística & dados numéricos , Emprego/estatística & dados numéricos , Assistência ao Paciente , Adulto , Idoso , Emprego/tendências , Europa (Continente) , Serviços de Assistência Domiciliar , Humanos , Pessoa de Meia-Idade , Modelos Econômicos , Inquéritos e Questionários
6.
Health Econ ; 27(1): 129-140, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28512768

RESUMO

There is widespread concern about the quality of care in nursing homes. On the basis of administrative data of a large health insurance fund, we investigate whether nursing home prices are associated with relevant quality of care indicators at the resident level. Our results indicate negative associations between price and both inappropriate and psychotropic medication. In contrast, we do not find any relationship between the price and impairments of physical health.


Assuntos
Comércio , Casas de Saúde/normas , Indicadores de Qualidade em Assistência à Saúde/normas , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Erros de Medicação/prevenção & controle , Psicotrópicos/efeitos adversos , Psicotrópicos/uso terapêutico
7.
ChemMedChem ; 12(8): 606-612, 2017 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-28322513

RESUMO

Machine learning models for site of metabolism (SoM) prediction offer the ability to identify metabolic soft spots in low-molecular-weight drug molecules at low computational cost and enable data-based reactivity prediction. SoM prediction is an atom classification problem. Successful construction of machine learning models requires atom representations that capture the reactivity-determining features of a potential reaction site. We have developed a descriptor scheme that characterizes an atom's steric and electronic environment and its relative location in the molecular structure. The partial charge distributions were obtained from fast quantum mechanical calculations. We successfully trained machine learning classifiers on curated cytochrome P450 metabolism data. The models based on the new atom descriptors showed sustained accuracy for retrospective analyses of metabolism optimization campaigns and lead optimization projects from Bayer Pharmaceuticals. The results obtained demonstrate the practicality of quantum-chemistry-supported machine learning models for hit-to-lead optimization.


Assuntos
Descoberta de Drogas , Modelos Moleculares , Compostos Orgânicos/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Aprendizado de Máquina , Estrutura Molecular , Compostos Orgânicos/química , Pirazinas/química , Pirazinas/metabolismo , Piridinas/química , Piridinas/metabolismo , Teoria Quântica , Tiazóis/química , Tiazóis/metabolismo
8.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1467219

RESUMO

Abstract The hygienic and sanitary control in Food and Nutrition Units (FNU) is considered a standard procedure to produce adequate meals and reduce the risk of foodborne diseases and hospital infections. This study aimed to evaluate the isolation and identification of bacteria from equipment and food contact surfaces in a hospital FNU as well as to evaluate the sanitary condition. Likewise, it was analyzed the adhesion of the microorganisms on polyethylene cutting boards. The presence of aerobic mesophilic microorganisms, yeasts, molds, coagulase-positive staphylococci, coliform and fecal coliform, and Escherichia coli were analyzed on eating tables, countertop surfaces and cutting boards used for meat or vegetable handling, and equipment such as microwaves and refrigerators. The molecular identification it was done by 16S rRNA gene sequencing. The adhesion of the microorganisms (biofilm formation) on meat and vegetable cutting boards was also evaluated by scanning electron microscopy. The results showed high numbers of all microorganisms, except for E. coli , which was not observed in the samples. The molecular analysis identified species of the Enterobacteriaceae family and species of the Pseudomonadaceae family. Scanning electron microscopy analyses revealed bacterial adhesion on the cutting board surfaces. The results obtained in this study indicated that the hygienic conditions of surfaces like plastic cutting boards and equipment in this hospital FNU were inadequate. The achievement and application of standard operating procedures could positively help in the standardization of sanitary control, reducing the microbial contamination and providing a safe food to hospitalized patients.


Resumo O controle higiênico e sanitário nas Unidades de Alimentação e Nutrição (UAN) é considerado um procedimento padrão para produzir refeições adequadas e reduzir o risco de doenças transmitidas pelos alimentos e infecções hospitalares. Este estudo teve como objetivo isolar e identificar bactérias de equipamentos e superfícies de contato com alimentos em uma UAN hospitalar, bem como avaliar a condição sanitária. Do mesmo modo, analisou-se a adesão dos micro-organismos em tábuas de corte de polietileno. A presença de micro-organismos aeróbios mesófilos, leveduras, fungos, Sthapylococcus coagulase-positivos, coliformes, coliformes fecais e Escherichia coli foi analisadas na superfície de mesas do refeitório, superfícies de bancada e tábuas de corte usadas para manuseio de carne ou vegetais e, em equipamentos como micro-ondas e refrigeradores. A identificação molecular foi feita pelo sequenciamento do gene 16S rRNA. A adesão dos micro-organismos (formação de biofilmes) em tábuas de corte de carne e de vegetais também foi avaliada por microscopia eletrônica de varredura. Os resultados mostraram elevada contagem para todos os micro-organismos analisados, exceto para E. coli, a qual não foi observada nas amostras. A análise molecular identificou espécies da família Enterobacteriaceae e Pseudomonadaceae. A análise de microscopia eletrônica de varredura revelaram adesão bacteriana nas superfícies das placsa de corte. Os resultados obtidos neste estudo indicaram que as condições higiênicas das superfícies e de equipamentos nesta UAN hospitalar estavam inadequadas. A aplicação de procedimentos operacionais padrão poderia auxiliar positivamente na padronização do controle higiênico-sanitário, reduzindo a contaminação microbiana e fornecendo um alimento seguro para pacientes hospitalizados.

9.
Interface Focus ; 5(5): 20150025, 2015 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-26442147

RESUMO

Marine propellers display several forms of cavitation. Of these, propeller-tip vortex cavitation is one of the important factors in propeller design. The dynamic behaviour of the tip vortex is responsible for hull vibration and noise. Thus, cavitation in the vortices trailing from tips of propeller blades has been studied extensively. Under certain circumstances cavitating vortices have been observed to have wave-like disturbances on the surfaces of vapour cores. Intense sound at discrete frequencies can result from a coupling between tip vortex disturbances and oscillating sheet cavitation on the surfaces of the propeller blades. This research article focuses on the dynamics of vortex cavitation and more in particular on the energy and frequency content of the radiated pressures.

10.
Soc Sci Med ; 145: 44-52, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26448164

RESUMO

There is a paucity of evidence on the heterogeneous impacts of financial incentives on weight loss. Between March 2010 and January 2012, in a randomized controlled trial, we assigned 700 obese persons to three experimental arms. We test whether particular subgroups react differently to financial incentives for weight loss. Two treatment groups obtained a cash reward (€150 and €300 with 237 and 229 participants, respectively) for achieving an individually-assigned target weight within four months; the control group (234 participants) was not incentivized. Participants and administrators were not blinded to the intervention. We find that monetary rewards effectively induced obese individuals to reduce weight across all subgroups. However, there is no evidence for treatment-effect heterogeneity for those groups that were incentivized. Among those who were in the €300 group, statistically significant and large weight losses were observed for women, singles, and those who are not working (all above 4 kg in four months). In addition, the magnitude of the reward matters only for women and migrants. The effectiveness of financial incentives to reduce weight nevertheless raises sensitive ethical issues that should be taken into consideration by policymakers.


Assuntos
Motivação , Obesidade/terapia , Redução de Peso , Adolescente , Adulto , Idoso , Feminino , Promoção da Saúde/economia , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/economia , Obesidade/prevenção & controle , Fatores Sexuais , Adulto Jovem
11.
Phys Rev Lett ; 114(19): 192503, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-26024167

RESUMO

New results are reported from a measurement of π^{0} electroproduction near threshold using the p(e,e^{'}p)π^{0} reaction. The experiment was designed to determine precisely the energy dependence of s- and p-wave electromagnetic multipoles as a stringent test of the predictions of chiral perturbation theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. For the first time, complete coverage of the ϕ_{π}^{*} and θ_{π}^{*} angles in the pπ^{0} center of mass was obtained for invariant energies above threshold from 0.5 up to 15 MeV. The 4-momentum transfer Q^{2} coverage ranges from 0.05 to 0.155 (GeV/c)^{2} in fine steps. A simple phenomenological analysis of our data shows strong disagreement with p-wave predictions from ChPT for Q^{2}>0.07 (GeV/c)^{2}, while the s-wave predictions are in reasonable agreement.

12.
Health Econ ; 24(1): 8-25, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24123554

RESUMO

An inverse relationship between job insecurity and sickness absence has been established in the literature, which is explained by employees avoiding to send signals of both poor health and uncooperative behavior towards the employer. In this paper, we focus on whether the same mechanism applies to the demand for medical rehabilitation measures. This question has recently gained much interest in the context of the current public debate on presenteeism. Using county-level unemployment rates as instrument for the employees' fear of job loss on the individual level, we find that an increase in subjective job insecurity substantially decreases the probability of participating in medical rehabilitation.


Assuntos
Medo , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Reabilitação/psicologia , Licença Médica , Desemprego/psicologia , Absenteísmo , Adulto , Fatores Etários , Feminino , Alemanha , Serviços de Saúde/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Econométricos , Fatores Sexuais , Fatores Socioeconômicos
13.
Inorg Chem ; 53(22): 11890-902, 2014 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-25345467

RESUMO

Oxygen activation at the active sites of [FeFe] hydrogenases has been proposed to be the initial step of irreversible oxygen-induced inhibition of these enzymes. On the basis of a first theoretical study into the thermodynamics of O2 activation [Inorg. Chem. 2009, 48, 7127] we here investigate the kinetics of possible reaction paths at the distal iron atom of the active site by means of density functional theory. A sequence of steps is proposed to either form a reactive oxygen species (ROS) or fully reduce O2 to water. In this reaction cascade, two branching points are identified where water formation directly competes with harmful oxygen activation reactions. The latter are water formation by O-O bond cleavage of a hydrogen peroxide-bound intermediate competing with H2O2 dissociation and CO2 formation by a putative iron-oxo species competing with protonation of the iron-oxo species to form a hydroxyo ligand. Furthermore, we show that proton transfer to activated oxygen is fast and that proton supply to the active site is vital to prevent ROS dissociation. If sufficiently many reduction equivalents are available, oxygen activation reactions are accelerated, and oxygen reduction to water becomes possible.


Assuntos
Biologia Computacional , Hidrogenase/química , Proteínas Ferro-Enxofre/química , Modelos Moleculares , Oxigênio/química , Sítios de Ligação , Clostridium/enzimologia , Transferência de Energia , Peróxido de Hidrogênio/química , Hidrogenase/antagonistas & inibidores , Proteínas Ferro-Enxofre/antagonistas & inibidores , Prótons , Espécies Reativas de Oxigênio/química , Água/química
14.
Inorg Chem ; 52(24): 14205-15, 2013 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-24328345

RESUMO

[Fe] hydrogenase is a hydrogen activating enzyme that features a monoiron active site, which can be well characterized by Mössbauer spectroscopy. Mössbauer spectra have been measured of the CO and CN(-) inhibited species as well as under turnover conditions [Shima, S. et al., J. Am. Chem. Soc., 2005, 127, 10430]. This study presents calculated Mössbauer parameters for various active-site models of [Fe] hydrogenase to provide structural information about the species observed in experiment. Because theoretical Mössbauer spectroscopy requires the parametrization of observables from first-principles calculations (i.e., electric-field gradients and contact densities) to the experimental observables (i.e., quadrupole splittings and isomer shifts), nonrelativistic and relativistic density functional theory methods are parametrized against a reference set of Fe complexes specifically selected for the application to the Fe center in [Fe] hydrogenase. With this methodology, the measured parameters for the CO and CN(-) inhibited complexes can be reproduced. Evidence for the protonation states of the hydroxyl group in close proximity to the active site and for the thiolate ligand, which could participate in proton transfer, is obtained. The unknown resting state measured in the presence of the substrate and under pure H2 atmosphere is identified to be a water-coordinated complex. Consistent with previous assignments based on infrared and X-ray absorption near-edge spectroscopy, all measured Mössbauer data can be reproduced with the active site's iron atom being in oxidation state +2.


Assuntos
Hidrogenase/química , Proteínas Ferro-Enxofre/química , Modelos Moleculares , Teoria Quântica , Domínio Catalítico , Espectroscopia de Mossbauer
15.
Chem Commun (Camb) ; 49(73): 8099-101, 2013 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-23917389

RESUMO

The effect of a homogeneous electric field--as exerted by the protein environment and by an electrode potential--on the reactivity of the active site of [FeFe] hydrogenases is unravelled by density functional theory calculations.

16.
J Phys Chem B ; 117(17): 4806-17, 2013 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-23560849

RESUMO

By means of density functional theory, we investigate the catalytic cycle of active-site model complexes of [Fe] hydrogenase and study how ligand substitutions in the first coordination sphere of the reactive Fe center affect the free-energy surface of the whole reaction pathway. Interestingly, dispersion interactions between the active site and the hydride acceptor MPT render the hydride transfer step less endergonic and lower its barrier. Substitution of CO by CN(-), which resembles [FeFe] hydrogenase-like coordination, inverts the elementary steps H(-) transfer and H2 cleavage. A simplified kinetic model reveals the specifics of the interplay between active-site composition and catalysis. Apparently, the catalytic efficiency of [Fe] hydrogenase can be attributed to a flat energy profile throughout the catalytic cycle. Intermediates that are too stable, as they occur, e.g., when one CO ligand is substituted by CN(-), significantly slow down the turnover rate of the enzyme. The catalytic activity of the wild-type form of the active-site model could, however, be enhanced by a PH3 ligand substitution of the CO ligand.


Assuntos
Hidrogênio/metabolismo , Hidrogenase/metabolismo , Proteínas Ferro-Enxofre/metabolismo , Modelos Moleculares , Biocatálise , Domínio Catalítico , Hidrogênio/química , Hidrogenase/química , Proteínas Ferro-Enxofre/química , Cinética , Oxigênio/química , Oxigênio/metabolismo , Teoria Quântica , Termodinâmica
17.
Acta Physiol (Oxf) ; 207(4): 700-8, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23336369

RESUMO

BACKGROUND: Urinary calprotectin has recently been identified as a promising biomarker for the differentiation of pre-renal and intrinsic acute kidney injury (AKI). This study compares the diagnostic performance of calprotectin and neutrophil gelatinase-associated lipocalin (NGAL) in this differential diagnosis. METHODS: Urinary calprotectin and NGAL concentrations were assessed in a study population of 87 subjects including 38 cases of intrinsic AKI, 24 cases of pre-renal AKI and 25 healthy controls. Urinary tract obstruction, renal transplantation and metastatic cancer were defined as exclusion criteria. RESULTS: Mean calprotectin concentrations were significantly lower in pre-renal (190.2 ± 205.7 ng mL(-1) ) than in intrinsic AKI (6250.1 ± 7167.2 ng mL(-1) , P < 0.001). Receiver-operating characteristic (ROC) analysis provided an AUC of 0.99. Mean NGAL concentrations were significantly higher in intrinsic than in pre-renal AKI as well (458.1 ± 695.3 vs. 64.8 ± 62.1 ng mL(-1) , P = 0.001) providing an AUC of 0.82. A combination of the present study population with the cohort of the proof of concept study led to a population of 188 subjects (58 pre-renal AKI, 90 intrinsic AKI, 40 healthy controls). ROC analyses provided an AUC of 0.97 for calprotectin and 0.76 for NGAL yielding sensitivity and specificity values of 93.3 and 94.8% (calprotectin) vs. 75.3 and 72.4% (NGAL). Optimal cut-off values were 440 ng mL(-1) (calprotectin) and 52 ng mL(-1) (NGAL). Pyuria increased calprotectin concentrations independent of renal failure. CONCLUSION: This study shows that both calprotectin and NGAL are able to differentiate between pre-renal and intrinsic AKI after exclusion of pyuria. In the present population, calprotectin presents a higher sensitivity and specificity than NGAL.


Assuntos
Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/urina , Proteínas de Fase Aguda/urina , Rim/metabolismo , Complexo Antígeno L1 Leucocitário/urina , Lipocalinas/urina , Proteínas Proto-Oncogênicas/urina , Injúria Renal Aguda/patologia , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Biomarcadores/urina , Biópsia , Estudos de Casos e Controles , Estudos Transversais , Diagnóstico Diferencial , Feminino , Humanos , Rim/patologia , Lipocalina-2 , Masculino , Pessoa de Meia-Idade , Curva ROC , Sensibilidade e Especificidade
20.
Melanoma Res ; 12(5): 471-7, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12394189

RESUMO

5-S-cysteinyldopa (5-S-CD) has been described as a tumour marker for the detection of human metastatic melanoma. We investigated the clinical utility of a new and optimized method to detect 5-S-CD by analysing 207 plasma samples derived from 138 patients with clinical stage I/II ( = 60), III ( = 32) or IV ( = 46) melanoma. Control groups consisted of 27 patients with non-melanoma skin diseases and 30 healthy volunteers. 5-S-CD plasma levels were determined using a new analytical technique based on a fully automated solid phase extraction coupled online to a novel high performance liquid chromatography method. In all the samples from the healthy control subjects 5-S-CD plasma concentrations were below 2.0 microg/l. Increased 5-S-CD-levels (>/=2.0 microg/l) were found in 52%, 67% and 81% of the plasma samples from patients with stages I/II, III and IV malignant melanoma, respectively. The mean values of 5-S-CD were found to rise with increasing tumour stage. Among 27 samples from patients with non-melanoma skin disease, slightly elevated 5-S-CD levels between 2.3 and 2.6 microg/l were found in only four samples from patients with multiple dysplastic naevi. In conclusion, our improved analytical technique provides a high sensitivity in all stages of the disease and represents a useful technique for monitoring melanoma patients.


Assuntos
Biomarcadores Tumorais , Cisteinildopa/sangue , Melanoma/sangue , Melanoma/metabolismo , Estudos de Casos e Controles , Cromatografia Líquida de Alta Pressão , Progressão da Doença , Feminino , Humanos , Masculino , Melanoma/diagnóstico , Prognóstico , Sensibilidade e Especificidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...