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1.
Signal Transduct Target Ther ; 5(1): 220, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33024075
2.
Water Sci Technol ; 82(6): 1009-1024, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33055392

RESUMO

In microalgae harvesting, flocculation is usually a compulsory preliminary step to further separation by sedimentation or flotation. For some microalgae species, and under certain growth conditions, flocculation can occur naturally. Natural flocculation presents many advantages as it does not require the addition of any flocculants to the culture medium and shows high efficiency rate. But because natural flocculation is so specific to the species and conditions, and thanks to the knowledge accumulated over the last years on flocculation mechanisms, researchers have developed strategies to induce this natural harvesting. In this review, we first decipher at the molecular scale the underlying mechanisms of natural flocculation and illustrate them by selected studies from the literature. Then we describe the developed strategies to induce natural flocculation that include the use of biopolymers, chemically modified or not, or involve mixed species cultures. But all these strategies need the addition of external compounds or microorganism which can present some issues. Thus alternative directions to completely eliminate the need for an external molecule, through genetic engineering of microalgae strains, are presented and discussed in the third part of this review.


Assuntos
Microalgas , Bioensaio , Biomassa , Meios de Cultura , Floculação
3.
PLoS One ; 15(8): e0238479, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866217

RESUMO

The performances of the ImmuView Streptococcus pneumoniae (Sp) and Legionella pneumophila (Lp) urinary antigen test were compared to that of the BinaxNOW Sp and Lp assays, using frozen urine from 166 patients with Legionnaires' disease (LD) and 59 patients with pneumococcal pneumonia. Thirty Sp-positive or contrived cerebrospinal fluids (CSF) were also tested. Test specimens were collected and tested at different sites, with each site testing unique specimens by technologists blinded to expected results. No significant differences in test concordances were detected for the ImmuView and BinaxNOW assays for the Sp or Lp targets for urine from patients with pneumococcal pneumonia or LD when performance from both sites were combined. At one of two test sites the ImmuView Lp assay was more sensitive than the BinaxNOW assay, with no correlation between test performance and Lp serogroup 1 monoclonal type. Urines from six of seven patients with LD caused by Legionella spp. bacteria other than Lp serogroup 1 were negative in both assays. Both tests had equivalent performance for Sp-positive CSF. The clinical sensitivities for pneumococcal pneumonia were 88.1 and 94.4% for the ImmuView and Binax assays, and 87.6 and 84.2% for the Lp assays, respectively. Test specificities for pneumococcal pneumonia were 96.2 and 97.0% for the ImmuView and Binax assays, and 99.6 and 99.1% for the Lp assays. Both assays were highly specific for Sp in pediatric urines from children with nasopharyngeal colonization by the bacterium. ImmuView and BinaxNOW assay performance was equivalent in these studies.


Assuntos
Antígenos de Bactérias/metabolismo , Antígenos de Bactérias/urina , Bioensaio/métodos , Líquido Cefalorraquidiano/microbiologia , Legionella pneumophila/isolamento & purificação , Streptococcus pneumoniae/isolamento & purificação , Urina/microbiologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Testes Imunológicos/métodos , Lactente , Doença dos Legionários/metabolismo , Doença dos Legionários/microbiologia , Doença dos Legionários/urina , Masculino , Meningite/metabolismo , Meningite/microbiologia , Meningite/urina , Pneumonia Pneumocócica/metabolismo , Pneumonia Pneumocócica/microbiologia , Pneumonia Pneumocócica/urina , Sensibilidade e Especificidade , Sorogrupo , Adulto Jovem
4.
Nat Commun ; 11(1): 4464, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32900994

RESUMO

The SARS-CoV-2 pandemic has shown how a rapid rise in demand for patient and community sample testing can quickly overwhelm testing capability globally. With most diagnostic infrastructure dependent on specialized instruments, their exclusive reagent supplies quickly become bottlenecks, creating an urgent need for approaches to boost testing capacity. We address this challenge by refocusing the London Biofoundry onto the development of alternative testing pipelines. Here, we present a reagent-agnostic automated SARS-CoV-2 testing platform that can be quickly deployed and scaled. Using an in-house-generated, open-source, MS2-virus-like particle (VLP) SARS-CoV-2 standard, we validate RNA extraction and RT-qPCR workflows as well as two detection assays based on CRISPR-Cas13a and RT-loop-mediated isothermal amplification (RT-LAMP). In collaboration with an NHS diagnostic testing lab, we report the performance of the overall workflow and detection of SARS-CoV-2 in patient samples using RT-qPCR, CRISPR-Cas13a, and RT-LAMP. The validated RNA extraction and RT-qPCR platform has been installed in NHS diagnostic labs, increasing testing capacity by 1000 samples per day.


Assuntos
Betacoronavirus/genética , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia , Betacoronavirus/isolamento & purificação , Bioensaio , Sistemas CRISPR-Cas , Técnicas de Laboratório Clínico/instrumentação , Técnicas de Laboratório Clínico/normas , Humanos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Pandemias , RNA Viral/análise , RNA Viral/genética , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade
5.
Rev Soc Bras Med Trop ; 53: e20200314, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32997053

RESUMO

INTRODUCTION: Rapid and accurate tuberculosis detection is critical for improving patient diagnosis and decreasing tuberculosis transmission. Molecular assays can significantly increase laboratory costs; therefore, the average time and economic impact should be evaluated before implementing a new technology. The aim of this study was to evaluate the cost and average turnaround time of smear microscopy and Xpert assay at a university hospital. METHODS: The turnaround time and cost of the laboratory diagnosis of tuberculosis were calculated based on the mean cost and activity based costing (ABC). RESULTS: The average turnaround time for smear microscopy was 16.6 hours while that for Xpert was 24.1 hours. The Xpert had a mean cost of USD 17.37 with an ABC of USD 10.86, while smear microscopy had a mean cost of USD 13.31 with an ABC of USD 6.01. The sensitivity of smear microscopy was 42.9% and its specificity was 99.1%, while the Xpert assay had a sensitivity of 100% and a specificity of 96.7%. CONCLUSIONS: The Xpert assay has high accuracy; however, the turnaround time and cost of smear microscopy were lower than those of Xpert.


Assuntos
Bioensaio/economia , Patologia Molecular/economia , Tuberculose Pulmonar/diagnóstico , Bioensaio/métodos , Custos e Análise de Custo , Humanos , Microscopia , Mycobacterium tuberculosis , Patologia Molecular/métodos , Sensibilidade e Especificidade , Tuberculose , Tuberculose Pulmonar/economia
6.
Pestic Biochem Physiol ; 170: 104705, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32980068

RESUMO

Magnolia officinalis, as a well-known herb worldwide, has been widely used to treat multiple diseases for a long time. In this study, the petroleum ether extract from M. officinalis showed effective antifungal activity against seven plant pathogens (particularly against R. solani with an inhibition rate of 100.00% at 250 µg/mL). Honokiol and magnolol, isolated by the bioassay-guided method, exhibited greater antifungal activity than tebuconazole (EC50 = 3.07 µg/mL, p ≤ 0.001) against R. solani, which EC50 values were 2.18 µg/mL and 3.48 µg/mL, respectively. We used transcriptomics to explore the mechanism of action of honokiol against R. solani. Results indicated that honokiol may exert antifungal effects by blocking the oxidative phosphorylation metabolic pathway. Further studies indicated that honokiol induced ROS overproduction, disrupted the mitochondrial function, affected respiration, and blocked the TCA cycle, which eventually inhibited ATP production. Besides, honokiol also damaged cell membranes and caused morphological changes. This study demonstrated that the lignans isolated from M. officinalis possess the potential to be developed as botanical fungicides.


Assuntos
Lignanas/farmacologia , Magnolia , Antifúngicos/farmacologia , Bioensaio , Compostos de Bifenilo
7.
J Environ Sci (China) ; 96: 163-170, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32819690

RESUMO

The treatment of wastewaters is crucial to maintain the ecological status of receiving waters, and thereby guarantee the protection of aquatic life and human health. Wastewater quality evaluation is conventionally based on physicochemical parameters, but increasing attention has been paid to integrate physicochemical and biological data. Nevertheless, the regulatory use of fish in biological testing methods has been subject to various ethical and cost concerns, and in vitro cell-based assays have thus become an important topic of interest. Hence, the present study intends: (a) to evaluate the efficiency of two different sample pre-concentration techniques (lyophilisation and solid phase extraction) to assess the toxicity of municipal effluents on rat cardiomyoblast H9c2(2-1) cells, and (b) maximizing the use of the effluent sample collected, to estimate the environmental condition of the receiving environment. The gathered results demonstrate that the H9c2(2-1) sulforhodamine B-based assay is an appropriate in vitro method to assess biological effluent toxicity, and the best results were attained by lyophilising the sample as pre-treatment. Due to its response, the H9c2(2-1) cell line might be a possible alternative in vitro model for fish lethal testing to assess the toxicity of municipal effluents. The physicochemical status of the sample suggests a high potential for eutrophication, and iron exceeded the permissible level for wastewater discharge, possibly due to the addition of ferric chloride for wastewater treatment. In general, the levels of carbamazepine and sulfamethoxazole are higher than those reported for other countries, and both surpassed the aquatic protective values for long-term exposure.


Assuntos
Poluentes Químicos da Água/análise , Animais , Bioensaio , Monitoramento Ambiental , Humanos , Miócitos Cardíacos/química , Ratos , Rodaminas , Eliminação de Resíduos Líquidos
8.
Environ Sci Pollut Res Int ; 27(30): 38360-38369, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32748353

RESUMO

Ecotoxicological bioassays have been widely applied to evaluate the toxicity of substances in standardized test organisms. Nevertheless, the main challenge for researchers is the use of native species to express the effects of pollutants on aquatic biota. Thirty years ago, Smith and collaborators evaluate the possible use of Pristina longiseta (as Pristina leidyi) in acute toxicity test, developing some experiments using cadmium and vanadium as toxicants. The present work aimed to update the use of P. longiseta, in acute bioassays, presenting the occurrence and general characteristics of the species; adaptation of cultivation to tropical conditions; sensitivity tests using potassium chloride (KCl) and copper sulfate (CuSO4) as reference substances standardized by OECD, USEPA, and ABNT; and acute exposure to zinc chloride (ZnCl2). The results showed a successful use of this species as tropical test organism, which presented easy laboratory rearing and responded to the classical ecotoxicological index. The present study can increase the utilization of P. longiseta in bioassays for tropical regions and improve the evaluation of environmental impacts using a native species in ecotoxicological studies.


Assuntos
Oligoquetos , Poluentes Químicos da Água , Animais , Bioensaio , Cádmio , Ecotoxicologia , Testes de Toxicidade Aguda
9.
Bull Environ Contam Toxicol ; 105(3): 496-501, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32844262

RESUMO

Since the Fukushima nuclear accident in 2011, various abnormalities have been reported in animals living in the contaminated area. In the present study, we examined DNA damage in cattle living in the "difficult-to-return zone" by 8-hydroxy-2'-deoxyguanosine, comet, and micronucleus assays using their peripheral blood. The radiation exposure dose rate at the sampling time was approximately 0.25 or 0.38 mGy/day and the cumulative dose was estimated at approximately 1000 mGy. Significant increase in DNA damage was not detected by any of the three methods. As DNA damage is a stochastic effect of radiation, it might be occurring in animals living in the contaminated area. However, the present results suggest that radiation-induced DNA damage in the cattle did not increase to the level detectable by the assays we used due to the low dose rate in this area.


Assuntos
Doses de Radiação , Exposição à Radiação/análise , Monitoramento de Radiação , Animais , Bioensaio , Bovinos , Dano ao DNA , Acidente Nuclear de Fukushima , Japão
10.
Aquat Toxicol ; 227: 105587, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32841885

RESUMO

Among the various environmental disturbances caused by wildfires, their impacts within burnt areas and on the downhill aquatic ecosystems has been receiving increased attention. Post-fire rainfalls and subsequent runoffs play an important role in transporting ash and soil to aquatic systems within the burnt areas. These runoffs can be a diffuse source of toxic substances such as metals. The present work aims at assessing the effects of ash-loaded runoff on feeding rates of three representative aquatic invertebrates (Daphnia magna, Corbicula fluminea and Atyaephyra desmarestii) and the mosquitofish, Gambusia holbrooki, through post-exposure feeding inhibition bioassays carried out in-situ and in the laboratory using water collected from the experimental field sites. Four sites were selected in a partially burnt basin for bioassay deployment and sample collection: one site upstream of the burnt area (RUS); three sites receiving runoff directly from the burnt area, one immediately downstream of the burnt area (RDS) and two in permanent tributary streams within the burnt area (BS1 and BS2). The in-situ exposure lasted four days and began following the first post-fire major rain events. At sites affected by the wildfire, post-exposure feeding rates for D. magna, A. desmarestii and G. holbrooki were lower, which is consistent with the highest levels of metals found at these sites compared to the unaffected site, although the individual concentrations of each metal were generally below corresponding ecological safety benchmarks. Thus, interactions between metals and/or between metals and other environmental parameters certainly played a role in modulating the ecotoxic effects of the runoffs; this was further supported by a Toxic Units Summation exercise. Even if direct causal links between the ecotoxicological effects observed in D. magna, A. desmarestii and G. holbrooki and the physicochemical parameters of the water samples could not be established, the results suggest an important role of major and trace elements in explaining post-exposure feeding rate variation.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Cinza de Carvão/toxicidade , Comportamento Alimentar/efeitos dos fármacos , Metais Pesados/toxicidade , Poluentes Químicos da Água/toxicidade , Incêndios Florestais , Animais , Organismos Aquáticos/fisiologia , Bioensaio , Corbicula/efeitos dos fármacos , Ciprinodontiformes/fisiologia , Daphnia/efeitos dos fármacos , Ecossistema , Ecotoxicologia , Água Doce/química , Modelos Teóricos , Portugal , Oligoelementos/toxicidade
11.
Exp Parasitol ; 217: 107966, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32781094

RESUMO

Toxoplasma gondii has long been considered a ubiquitous parasite possessing the capacity of infecting virtually all warm-blooded animals globally. Occasionally, this parasite can also infect cold-blooded animals such as fish if their body temperature reaches 37 °C. However, we are currently lacking an understanding of key details such as the minimum temperature required for T. gondii invasion and proliferation in these cold-blooded animals and their cells. Here, we performed in vitro T. gondii infection experiments with rat embryo fibroblasts (REF cells), grouper (Epinephelus coioides) splenocytes (GS cells) and zebra fish (Danio rerio) hepatocytes (ZFL cells), at 27 °C, 30 °C, 32 °C, 35 °C and 37 °C, respectively. We found that T. gondii tachyzoites could penetrate REF, GS nd ZFL cells at 27 °C but clear inhibition of multiplication was observed. Intriguingly, the intracellular tachyzoites retained the ability to infect mice after 12 days of incubation in GS cells cultured at 27 °C as demonstrated by bioassay. At 30 °C, 32 °C and 35 °C, we observed that the mammalian cells (REF cells) and fish cells (GS and ZFL cells) could support T. gondii invasion and replication, which showed a temperature-dependent relationship in infection and proliferation rates. Our data demonstrated that the minimum temperature for T. gondii invasion and replication was 27 °C and 30 °C respectively, which indicated that temperature should be a key factor for T. gondii invasion and proliferation in host cells. This suggests that temperature-dependent infection determines the differences in the capability of T. gondii to infect cold- and warm-blooded vertebrates.


Assuntos
Bass/parasitologia , Fibroblastos/parasitologia , Hepatócitos/parasitologia , Temperatura , Toxoplasma/fisiologia , Peixe-Zebra/parasitologia , Animais , Bioensaio , Temperatura Corporal , Feminino , Masculino , Camundongos , Ratos , Ratos Sprague-Dawley , Baço/citologia , Baço/parasitologia , Toxoplasma/crescimento & desenvolvimento
12.
J Infect Dis ; 222(9): 1462-1467, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32798217

RESUMO

The scientific community has responded to the coronavirus disease 2019 (COVID-19) pandemic by rapidly undertaking research to find effective strategies to reduce the burden of this disease. Encouragingly, researchers from a diverse array of fields are collectively working towards this goal. Research with infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is undertaken in high-containment laboratories; however, it is often desirable to work with samples at lower-containment levels. To facilitate the transfer of infectious samples from high-containment laboratories, we have tested methods commonly used to inactivate virus and prepare the sample for additional experiments. Incubation at 80°C, a range of detergents, Trizol reagents, and UV energies were successful at inactivating a high titer of SARS-CoV-2. Methanol and paraformaldehyde incubation of infected cells also inactivated the virus. These protocols can provide a framework for in-house inactivation of SARS-CoV-2 in other laboratories, ensuring the safe use of samples in lower-containment levels.


Assuntos
Betacoronavirus/crescimento & desenvolvimento , Inativação de Vírus , Animais , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/efeitos da radiação , Bioensaio , Pesquisa Biomédica , Chlorocebus aethiops , Detergentes , Formaldeído , Guanidinas , Temperatura Alta , Metanol , Fenóis , Polímeros , Raios Ultravioleta , Células Vero , Ensaio de Placa Viral
13.
Sci Total Environ ; 746: 141204, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32768784

RESUMO

Management of dredged sediments results in an environmental and social cost. Based on their level of contamination, they can be intended for beach nourishment or for alternative uses. Sediment quality is established considering their specific chemical contamination level and setting up bioassays to evaluate their toxic effects on living organisms. The integration of these different Line of Evidence (LOE) generates toxicity indexes, the Hazard Chemical Quotient (HQc), and the Hazard Ecotoxicological Quotient (HQe), which are further elaborated using the SediQualSoft software, finally providing evidence on the levels of sediment contamination. In this study, four different dredged sediments were analysed. Except for one, which was sampled in a reference area, the others were assigned to the same class of toxicity, despite they presented different levels of chemical and ecotoxicological toxicity. As a novelty, this study introduces transcriptomics as a new LOE, to provide a new tool to better categorize sediment toxicity. C. gigas embryos were exposed to sediment elutriates, sampled at 5 and 18 h post-fertilization (hpf), and the expression of a set of genes involved in immune and stress response (hsp70, gpx, sod, dehf1, galectin, lysozyme, tg) was analysed by Real-time PCR. Molecular results suggested that the 18 hpf stage represents a sensitive window of exposure during development and can be suggested as a critical time point for ecotoxicity studies. Finally, by multivariate statistical analysis, integrating the well-established LOEs with molecular data, it was demonstrated that transcriptomics could be a useful and novel LOE with the ability to provide greater accuracy in the assessment of sediment toxicity.


Assuntos
Sedimentos Geológicos , Poluentes Químicos da Água/toxicidade , Bioensaio , Ecotoxicologia , Monitoramento Ambiental
14.
Bull Environ Contam Toxicol ; 105(2): 317-324, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32601980

RESUMO

Concentration and human health risks of heavy metals (Pb, Cu, Cr, Cd, As, Ni) in water, sediment, crab (Tympanotonus fuscatus) and periwinkle (Callinectes amnicola) were assayed in New Calabar River, Nigeria. Results revealed that concentration (mg/L) of the metals in water in the two seasons studied, ranged from 1.1E-2 ± 1.0E-3…for Cd to 2.90 ± 0.03…for Cu. In sediment, the concentration (mg/kg) ranged from 1.1E-2 ± 1.0E-3…for As to 5.17 ± 0.04… for Ni. In biota, the concentration (mg/kg) ranged from 0.01…for As in crab to 19.22…for Cu also in crab. Estimated human health risk from the metals contamination due to consumption of biota gave each of HQ and HI as < 1, indicating no risk except at Agip's sample location where HI was > 1. Estimated human health risk due to dermal absorption through swimming, indicated no risk as each of HQ and HI was < 1. These make the river unpolluted except at Agip's sample location.


Assuntos
Monitoramento Ambiental , Metais Pesados/análise , Rios/química , Poluentes Químicos da Água/análise , Bioensaio , Sedimentos Geológicos , Humanos , Nigéria , Medição de Risco , Estações do Ano
15.
BMC Infect Dis ; 20(1): 515, 2020 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-32677903

RESUMO

BACKGROUND: Procalcitonin is an inflammatory biomarker that is sensitive for bacterial infections and a promising clinical decision aid in antimicrobial stewardship programs. However, there are few studies of physicians' experiences concerning the use of PCT. The objective of this study was to investigate whether hospital physicians' experience with procalcitonin after 18 months of use can inform the PCT implementation in antimicrobial stewardship programs. MATERIALS/METHODS: We deployed a qualitative approach using semi-structured interviews with 14 hospital physicians who had experience with procalcitonin in clinical practice. Interviews were audio-taped, transcribed verbatim and analysed using thematic analysis. RESULTS: Physicians reported a knowledge gap, which made them uncertain about the appropriate procalcitonin use, interpretation, and trustworthiness. Simultaneously, the physicians experienced procalcitonin as a useful clinical decision aid but emphasised that their clinical evaluation of the patient was the most important factor when deciding on antibiotic treatment. CONCLUSIONS: Procalcitonin was regarded a helpful clinical tool, but the physicians called for more knowledge about its appropriate uses. Active implementation of unambiguous procalcitonin algorithms and physician education may enhance the utility of the test as an antimicrobial stewardship adjunct.


Assuntos
Gestão de Antimicrobianos , Infecções Bacterianas/diagnóstico , Biomarcadores/sangue , Hospitais/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricos , Pró-Calcitonina/sangue , Adulto , Idoso , Algoritmos , Antibacterianos/uso terapêutico , Gestão de Antimicrobianos/organização & administração , Gestão de Antimicrobianos/normas , Infecções Bacterianas/sangue , Infecções Bacterianas/tratamento farmacológico , Bioensaio/estatística & dados numéricos , Feminino , Fidelidade a Diretrizes/estatística & dados numéricos , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Noruega/epidemiologia , Médicos/normas , Médicos/estatística & dados numéricos , Padrões de Prática Médica/normas , Pró-Calcitonina/análise , Pesquisa Qualitativa , Inquéritos e Questionários
16.
Food Chem ; 332: 127427, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32619936

RESUMO

A magnetic porous organic framework (M-POF) was rationally designed and served as a sorbent for magnetic solid-phase extraction of six nitroimidazoles from chicken meat prior to their assay by high-performance liquid chromatography with diode array detection. The M-POF exhibited good magnetic responsiveness and outstanding affinity to nitroimidazoles with large adsorption capacity up to 36 mg g-1. Under optimal conditions, the developed method offered good linearity (r greater than 0.992) in the range of 1.5-100.0 ng g-1, low limits of detection (S/N = 3) of 0.5-0.8 ng g-1, low limits of quantification of 1.5-2.5 ng g-1 and high enrichment factors of 80-175 for the nitroimidazoles. The method was successfully applied to analyze nitroimidazoles in chicken meat. The recoveries were 80.2-118% with relative standard deviations lower than 12%. The adsorption mechanism was further explored and the results showed that the M-POF exhibited adsorption potential for compounds with strong polar interactions.


Assuntos
Antibacterianos/isolamento & purificação , Contaminação de Alimentos/análise , Magnetismo/métodos , Carne/análise , Estruturas Metalorgânicas/química , Nitroimidazóis/isolamento & purificação , Extração em Fase Sólida/métodos , Adsorção , Animais , Antibacterianos/análise , Bioensaio , Galinhas , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Magnetismo/instrumentação , Músculo Esquelético/química , Nitroimidazóis/análise , Porosidade , Extração em Fase Sólida/instrumentação
17.
PLoS One ; 15(7): e0234899, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645020

RESUMO

The increasing prevalence of individuals with multiple food allergies and the need to distinguish between foods containing homologous, cross-reactive proteins have made the use of single-analyte antibody-based methods (e.g., ELISAs) sometimes insufficient. These issues have resulted in the need to conduct multiple analyses and sometimes employ orthogonal methods like mass spectrometry or DNA-based methods for confirmatory purposes. The xMAP Food Allergen Detection Assay (xMAP FADA) was developed to solve this problem while also providing increased throughput and a modular design suitable for adapting to changes in analytical needs. The use of built-in redundancy provides the xMAP FADA with built-in confirmatory analytical capability by including complementary antibody bead sets and secondary analytical end points (e.g., ratio analysis and multi-antibody profiling). A measure of a method's utility is its performance when employed by analysts of varying expertise in multiple laboratory environments. To gauge this aspect, a multi-laboratory validation (MLV) was conducted with 11 participants of different levels of proficiency. The MLV entailed the analysis of incurred food samples in four problematic food matrices, meat sausage, orange juice, baked muffins, and dark chocolate. Except for a couple of instances, involving two confirmatory components in the analysis of baked muffins, the allergenic foods were detected by all participants at concentrations in the analytical samples comparable to ≤ 10 µg/g in the original food sample. In addition, despite high levels of inter-lab variance in the absolute intensities of the responses, the intra-laboratory reproducibility was sufficient to support analyses based on the calibration standards and direct comparison controls (DCCs) analyzed alongside the samples. In contrast, ratio analyses displayed inter-laboratory %CV (RSDR) values < 20%; presumably because the ratios are based on inherent properties of the antigenic elements. The excellent performance of the xMAP FADA when performed by analysts of varying proficiency indicates a reliability sufficient to meet analytical needs.


Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Hipersensibilidade Alimentar/diagnóstico , Hipersensibilidade Alimentar/imunologia , Alérgenos/imunologia , Anticorpos/imunologia , Bioensaio , Reações Cruzadas , Análise de Alimentos/métodos , Humanos , Laboratórios , Espectrometria de Massas , Reprodutibilidade dos Testes
18.
J Chromatogr A ; 1625: 461294, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709337

RESUMO

It is significant to precisely isolate potential active compounds from medicinal herbs containing multiple compounds. Herein, a new strategy for precise separation of lysine-specific demethylase 1 (LSD1) inhibitors from the rhizome of Corydalis yanhusuo (RCY) using counter-current chromatography (CCC) guided by molecular docking and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) analysis was established. First, representative alkaloids from RCY were docked with LSD1 for screening active skeleton compounds. Simultaneously, the crude extract of RCY was preliminarily separated via pH-zone refining CCC. Subsequently, guided by LC-MS/MS analysis of the fragmentation pathways, three potential active fractions were obtained, followed by further online-storage and recycling CCC separation. Finally, three high-purity target quaternary alkaloids compound 3 (dehydrocorydaline), 7 (coptisine), and 8 (columbamine) were successfully isolated as a new class of potential natural LSD1 inhibitors by only one CCC instrument with multiple modes. Compound 3, with the highest LSD1 inhibition ratio of 2.44 µM, was tested for its ability to inhibit tumor invasion and metastasis in U2OS cells. Therefore, the CCC separation guided by virtual screening is a promising method for the targeted isolation of enzyme inhibitors from medicinal herbs.


Assuntos
Corydalis/química , Distribuição Contracorrente/métodos , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/isolamento & purificação , Histona Desmetilases/antagonistas & inibidores , Interface Usuário-Computador , Bioensaio , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Inibidores Enzimáticos/química , Histona Desmetilases/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Simulação de Acoplamento Molecular , Solventes , Espectrometria de Massas em Tandem
19.
Sci Total Environ ; 742: 140522, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-32623170

RESUMO

Disinfection By-products (DBPs) are formed during the chemical treatment of water for human consumption, by the reaction of raw water with chemical agents used in the different steps of the process. Disinfection is one of the most important steps, inactivating pathogens and preventing their regrowth during water distribution. However, it is also involved in DBPs formation due to the use of disinfectant agents, such as chlorine, which reacts with dissolved precursors, such as pharmaceuticals, toxins, pesticides, among others. Given their widespread occurrence, potential human health and (eco) toxicological impacts are of particular interest due to their potential carcinogenicity and various non-carcinogenic effects, such as endocrine disruption. In this study, the developmental toxicity of chemically- different unregulated DBPs was evaluated using zebrafish embryo bioassay. Embryos were exposed to different concentrations of the target DBPs and multiple endpoints, including, mortality, morphological abnormalities and locomotor behavior were assessed at specific developmental stages (24, 48, 72 and 96 hpf). The different families of DBPs tested included nitrosamines, aldehydes, alcohols and ketones. The results show that the effects were compound dependent, with EC10 values varying between 0.04 mg/L (2-ethyl-1-hexanal) to 9.2 mg/L (hexachloroacetone). Globally, several of the tested unregulated DBPs displayed higher toxicity when compared with the available data for some already regulated, such as trihalomethanes (THMs), which highlights the importance of screening the toxicity of still untested and poorly characterized DBPs.


Assuntos
Desinfetantes/análise , Água Potável , Poluentes Químicos da Água/análise , Purificação da Água , Animais , Bioensaio , Desinfecção , Humanos , Trialometanos , Peixe-Zebra
20.
Ecotoxicol Environ Saf ; 203: 110966, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32678755

RESUMO

We studied the effect of the chemical interaction of nutrients and the ethylenediamine tetraacetic acid (EDTA) on metals toxicity. Growth inhibition tests of Pseudokirchneriella subcapitata by nutrient metals copper (Cu) and zinc (Zn), and the non-nutrient metal lead (Pb), were performed. The high-enriched Bold's Basal medium (BBm) and two low-enriched standard media, recommended by the Organization for Economic Cooperation and Development (OECDm) and Environmental Protection Agency-algal assay procedure medium (AAPm), were used in this study. The metals toxicity was affected by the interaction of nutrients and EDTA. Cu+2 was more toxic in the OECDm (EC50 20.3 µg/L), while Pb+2 (EC50 23.1 µg/L) and Zn+2 (EC50 99.4 µg/L) in the AAPm. Non-toxic effect of these metals was observed in BBm, but the exclusion of EDTA shifted it into a toxic medium. Finally, we found that the toxicity of the studied nutrient metals is mainly influenced by EDTA, which reduced the concentration of ionized metals, while the toxicity of the non-nutrient metal is affected by EDTA and phosphates.


Assuntos
Monitoramento Biológico/métodos , Quelantes/farmacologia , Ácido Edético/farmacologia , Metais Pesados/toxicidade , Microalgas/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Bioensaio , Cobre/toxicidade , Relação Dose-Resposta a Droga , Interações Medicamentosas , Chumbo/toxicidade , Microalgas/crescimento & desenvolvimento , Modelos Teóricos , Zinco/toxicidade
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