Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
J Chromatogr A ; 1711: 464470, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37890374

RESUMO

In this work, for the first time, a stir bar sorptive extraction (SBSE) coupled with thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) was developed and validated for the determination of seven phthalates in Peruvian pisco. The phthalate compounds considered were dimethyl phthalate (DMP), diethyl phthalate (DEP), bis(2-ethylhexyl) hexahydrophthalate (BEHP), benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), di-isodecyl phthalate (DIDP) and di-isobutyl phthalate (DIBP). The best overall analytical conditions obtained from the optimization were as follow: extraction time of 120 min, size of polydimethylsiloxane (PDMS) twister (20 mm length x 1 mm thickness), NaCl content (20 %) and sample volume (40 mL). The in-house validation of SBSE/TD-GC-MS method was performed taking into account the ISO/IEC 17,025 requirements and EURACHEM/CITAC guideline. Under optimal conditions, very low limits of detection of 1.3-0.21 µg L-1 were obtained. Furthermore, the limits of quantification ranged from 4.2-70 µg L-1, and the correlation coefficients were found to be ≥ 0.991. The method was precise, with relative standard deviations (RSD, %) for inter twister repeatability and the inter day repeatability precisions from 1.1 to 11 and from 6.2 to 15.9, respectively. The pisco samples were analysed with recoveries between 91-124.4%, and DBP, BEHP, and BBP were the most commonly found compounds in the samples. The optimized methodology was also evaluated in terms of green character, and it obtained almost the best AGREE score when it was compared with other previous methods for the analysis of phthalates in alcoholic beverages. Therefore, the SBSE/TD-GC-MS method has proved to be suitable for routine practice because it is simple, less laborious, economical, precise, accurate and green, and it would be applicable for pisco safety regulations.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas , Cromatografia Gasosa-Espectrometria de Massas/métodos , Peru , Reprodutibilidade dos Testes
2.
Molecules ; 24(23)2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31795471

RESUMO

In the near future, Poland is going to have more and more favorable conditions for viticulture. Organic acids and polyphenols are among the most commonly analyzed compounds due to their beneficial properties for human health and their importance in the winemaking process. In this work, a new technique involving ultrasound-assisted solvent extraction of porous membrane-packed liquid samples (UASE-PMLS) was for the first time described and applied for real samples. The methodology based on UASE-PMLS for organic acids and polyphenols in wine samples was optimized and validated. Using the new technique coupled to GC-MS, organic acids and polyphenols were evaluated in Polish wine samples. Extraction solvent, extraction temperature, derivatization time and sample pH were optimized. Chemometric tools were used for data treatment. Good linearity was obtained for the concentration ranges evaluated with r values between 0.9852 and 0.9993. All parameters of method validation (intra- and inter-day precision and matrix effect) were over 80% with coefficient of variation (CV) up to 17%. Recovery was between (92.0 ± 8.5)% and (113 ± 16)%. Finally, green assessment was evaluated using Analytical Eco-Scale and Green Analytical Procedure Index (GAPI). The UASE-PMLS is characterized by many advantages, e.g., the extraction process is fast and easy coupled to GC-MS. Regarding other extraction techniques, the amount of used solvent is minimum, and no waste is generated. Therefore, it is an environmentally friendly technique.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas , Polifenóis/análise , Microextração em Fase Sólida , Ondas Ultrassônicas , Vinho/análise , Cromatografia Líquida de Alta Pressão , Humanos , Polônia
3.
Haematologica ; 104(5): 937-946, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30545926

RESUMO

Ruxolitinib is the front-line non-palliative treatment for myelofibrosis (MF). However, a significant number of patients lose or present suboptimal response, are resistant or have unacceptable toxicity. In an attempt to improve response and avoid the adverse effects of this drug, we evaluated the combination of 17 drugs with ruxolitinib in ex vivo models of peripheral blood mononuclear cells from MF patients and cell lines. We found that the combination ruxolitinib and nilotinib had a synergistic effect against MF cells (ΔEC50 nilotinib, -21.6%). Moreover, the addition of prednisone to combined ruxolitinib/nilotinib improved the synergistic effect in all MF samples studied. We evaluated the molecular mechanisms of combined ruxolitinib/nilotinib/prednisone and observed inhibition of JAK/STAT (STAT5, 69.2+11.8% inhibition) and MAPK (ERK, 29.4+4.5% inhibition) signaling pathways. Furthermore, we found that the triple therapy combination inhibited collagen protein and COL1A1 gene expression in human bone marrow mesenchymal cells. Taken together, we provide evidence that combined ruxolitinib/nilotinib/prednisone is a potential therapy for MF, possibly through the anti-fibrotic effect of nilotinib, the immunomodulatory effect of ruxolitinib and prednisone, and the anti-proliferative effect of ruxolitinib. This combination will be further investigated in a phase Ib/II clinical trial in MF.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Sinergismo Farmacológico , Leucócitos Mononucleares/efeitos dos fármacos , Transtornos Mieloproliferativos/tratamento farmacológico , Mielofibrose Primária/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Leucócitos Mononucleares/patologia , Masculino , Pessoa de Meia-Idade , Transtornos Mieloproliferativos/patologia , Nitrilas , Prednisona/administração & dosagem , Mielofibrose Primária/patologia , Prognóstico , Análise Serial de Proteínas , Pirazóis/administração & dosagem , Pirimidinas/administração & dosagem , Células Tumorais Cultivadas
4.
Oncotarget ; 9(40): 26019-26031, 2018 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-29899839

RESUMO

PI3Kδ (idelalisib) and BTK (ibrutinib) inhibitors have demonstrated significant clinical activity in chronic lymphocytic leukemia (CLL) interfering with the cross-talk between CLL cells and the lymph node microenviroment, yet their mechanism of action remains to be fully elucidated. Here, we developed an ex vivo model with the aim of reproducing the effects of the microenvironment that would help shed light on the in vivo mechanism of action of idelalisib and ibrutinib and predict their clinical efficacy in individual patients. First we explored the effects of various cell-extrinsic elements on CLL apoptosis and proliferation and found that the combination of CpG+IL2+HS5 stromal cell line + human serum +CLL plasma and erythrocyte fractions represented the best co-culture conditions to test the effects of the novel inhibitors. Then, using this assay, we investigated the impact of idelalisib and ibrutinib on both survival and proliferation in 30 CLL patients. While both drugs had a limited direct pro-apoptotic activity, a potent inhibition of proliferation was achieved at clinically achievable concentrations. Notably, up to 10% of CLL cells still proliferated even at the highest concentrations, likely mirroring the known difficulty to achieve complete responses in vivo. Altogether, this novel assay represents an appropriate ex vivo drug testing system to potentially predict the clinical response to novel inhibitors in particular by quantifying the antiproliferative effect.

5.
SLAS Technol ; 22(3): 325-337, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28340541

RESUMO

Functional ex vivo assays that predict a patient's clinical response to anticancer drugs for guiding cancer treatment have long been a goal, but few have yet proved to be reliable. To address this, we have developed an automated flow cytometry platform for drug screening that evaluates multiple endpoints with a robust data analysis system that can capture the complex mechanisms of action across different compounds. This system, called PharmaFlow, is used to test peripheral blood or bone marrow samples from patients diagnosed with hematological malignancies. Functional assays that use the whole sample, retaining all the microenvironmental components contained in the sample, offer an approach to ex vivo testing that may give results that are clinically relevant. This new approach can help to predict the patients' response to existing treatments or to drugs under development, for hematological malignancies or other tumors. In addition, relevant biomarkers can be identified that determine the patient's sensitivity, resistance, or toxicity to a given treatment. We propose that this approach, which better recapitulates the human microenvironment, constitutes a more predictive assay for personalized medicine and preclinical drug discovery.


Assuntos
Antineoplásicos/farmacologia , Automação Laboratorial/métodos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Citometria de Fluxo/métodos , Medicina de Precisão/métodos , Neoplasias Hematológicas/tratamento farmacológico , Humanos
6.
Acta toxicol. argent ; 23(1): 15-24, May 2015. graf, mapas, tab
Artigo em Inglês | BINACIS | ID: bin-134013

RESUMO

Chronic oiling affects seabirds, with short (individual survival) and long-term (dynamics of population) effects. Magellanic penguin is the most affected species in Argentina. The aim was to evaluate the use of blood biochemical-molecular biomarkers (MT and TBARs) to assess health status of Magellanic penguin exposed to chronic environmental oiling, in addition with routine hematological analyses (differential WBC count and PCV). Oiled specimens presented significant higher RBC metallothionein and TBARs concentrations than those from shelter; while routine hematological parameters were within normal levels for penguins and did not show any difference between both groups. These results demonstrated the higher sensibility of both biomarkers, evidencing effects on health status by chronic oiling; furthermore, they are the first report in blood metallothionein and oxidative stress in S. magellanicus. These studies will be useful for a better assessment of the health condition in rehabilitation centers (short term); and, as early warning signals in natural colonies (long term).(AU)


El empetrolamiento crónico afecta a las aves marinas, con efectos a corto (supervivencia del individuo) y largo plazo (dinámica de la población). El ping³ino de Magallanes es la especie más afectada en Argentina. El objetivo fue evaluar el uso de biomarcadores bioquímicos-moleculares (MT y TBARS) en sangre para evaluar el estado de salud del ping³ino de Magallanes expuesto a empetrolamiento crónico ambiental, además de los análisis hematológicos de rutina (recuento diferencial de leucocitos y hematocrito). Los ejemplares empetrolados presentaron concentraciones significativamente mayores de metalotioneínas en fracción celular y peroxidación lipídica que aquellos de albergue; por el contrario, los parámetros hematológicos de rutina estuvieron dentro de los niveles normales para los ping³inos y no mostraron ninguna diferencia entre los grupos. Estos resultados demuestran la mayor sensibilidad de los dos biomarcadores, evidenciando efectos del empetrolamiento crónico sobre el estado de salud; además, este es el primer reporte de concentraciones de metalotioneínas en sangre y el estrés oxidativo en S. magellanicus. Estos estudios son de utilidad para una mejor evaluación del estado de salud en los centros de rehabilitación (corto plazo); y, como señales de alerta temprana en las colonias naturales (largo plazo).(AU)

7.
Acta toxicol. argent ; 23(1): 15-24, mayo 2015. graf, mapas, tab
Artigo em Inglês | LILACS | ID: lil-757032

RESUMO

Chronic oiling affects seabirds, with short (individual survival) and long-term (dynamics of population) effects. Magellanic penguin is the most affected species in Argentina. The aim was to evaluate the use of blood biochemical-molecular biomarkers (MT and TBARs) to assess health status of Magellanic penguin exposed to chronic environmental oiling, in addition with routine hematological analyses (differential WBC count and PCV). Oiled specimens presented significant higher RBC metallothionein and TBARs concentrations than those from shelter; while routine hematological parameters were within normal levels for penguins and did not show any difference between both groups. These results demonstrated the higher sensibility of both biomarkers, evidencing effects on health status by chronic oiling; furthermore, they are the first report in blood metallothionein and oxidative stress in S. magellanicus. These studies will be useful for a better assessment of the health condition in rehabilitation centers (short term); and, as early warning signals in natural colonies (long term).


El empetrolamiento crónico afecta a las aves marinas, con efectos a corto (supervivencia del individuo) y largo plazo (dinámica de la población). El pingüino de Magallanes es la especie más afectada en Argentina. El objetivo fue evaluar el uso de biomarcadores bioquímicos-moleculares (MT y TBARS) en sangre para evaluar el estado de salud del pingüino de Magallanes expuesto a empetrolamiento crónico ambiental, además de los análisis hematológicos de rutina (recuento diferencial de leucocitos y hematocrito). Los ejemplares empetrolados presentaron concentraciones significativamente mayores de metalotioneínas en fracción celular y peroxidación lipídica que aquellos de albergue; por el contrario, los parámetros hematológicos de rutina estuvieron dentro de los niveles normales para los pingüinos y no mostraron ninguna diferencia entre los grupos. Estos resultados demuestran la mayor sensibilidad de los dos biomarcadores, evidenciando efectos del empetrolamiento crónico sobre el estado de salud; además, este es el primer reporte de concentraciones de metalotioneínas en sangre y el estrés oxidativo en S. magellanicus. Estos estudios son de utilidad para una mejor evaluación del estado de salud en los centros de rehabilitación (corto plazo); y, como señales de alerta temprana en las colonias naturales (largo plazo).


Assuntos
Animais , Peroxidação de Lipídeos/fisiologia , Metalotioneína/sangue , Argentina , Poluição por Petróleo/análise , Spheniscidae/sangue
8.
Ecotoxicol Environ Saf ; 89: 52-8, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23260181

RESUMO

In the present study, the acute toxicity of cadmium (Cd) in white shrimp (Palaemonetes argentinus) from a metal polluted lagoon (Los Padres, LP) and from unpolluted lagoon (Nahuel Ruca, NR) was evaluated. Both population, were exposed to 3.06, 12.26, 30.66, 61.32, 306 and 613.2 µg Cd · L(-1) for 96-h. The sublethal effects of Cd were examined by two cellular biomarkers: metallothionein (MT) and lipid peroxidation (LPO). The seasonal variations of biomarkers in both lagoons were also evaluated. P. argentinus demonstrated a high sensitivity to Cd, with values of 96-h LC50 lower and close to those of highly sensitive species; therefore, can be proposed as a good indicator species. The LC(50) values of shrimp from LP (24-h: 269.8, 48-h: 67.45, 72-h: 30.66, 96-h: 24.50 µg Cd · L(-1)) were higher than those from NR (24-h: 153.3, 48-h: 32.65, 72-h: 18.40, 96-h: 12.26 µg Cd · L(-1)), indicating a higher tolerance to Cd, and it was related to their origin. Differential responses in terms of MT induction and LPO between populations were also detected. In NR shrimps, the MT synthesis was induced very fast (24-h) and even at the minimum concentration tested (3.06 µg Cd · L(-1)), while no increases were observed in LPO levels. In contrast, the MT and LPO levels in LP shrimps were not increased relative to control, although they were more tolerant to Cd than those of NR; suggesting the presence of another mechanism involved in the detoxification of Cd. The differences in both sensitivity and biochemical responses to Cd may be related with their environmental histories.


Assuntos
Cádmio/toxicidade , Palaemonidae/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/análise , Monitoramento Ambiental , Peroxidação de Lipídeos/efeitos dos fármacos , Metalotioneína/metabolismo , Estações do Ano , Análise de Sobrevida
9.
BMC Microbiol ; 6: 75, 2006 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-16945142

RESUMO

BACKGROUND: Development of the post-genomic age in Dictyostelium will require the existence of rapid and reliable methods to disrupt genes that would allow the analysis of entire gene families and perhaps the possibility to undertake the complete knock-out analysis of all the protein-coding genes present in Dictyostelium genome. RESULTS: Here we present an optimized protocol based on the previously described construction of gene disruption vectors by in vitro transposition. Our method allows a rapid selection of the construct by a simple PCR approach and subsequent sequencing. Disruption constructs were amplified by PCR and the products were directly transformed in Dictyostelium cells. The selection of homologous recombination events was also performed by PCR. We have constructed 41 disruption vectors to target genes of unknown function, highly conserved between Dictyostelium and human, but absent from the genomes of S. cerevisiae and S. pombe. 28 genes were successfully disrupted. CONCLUSION: This is the first step towards the understanding of the function of these conserved genes and exemplifies the easiness to undertake large-scale disruption analysis in Dictyostelium.


Assuntos
Sequência Conservada/fisiologia , Dictyostelium/genética , Técnicas Genéticas , Genoma de Protozoário/fisiologia , Animais , Dictyostelium/fisiologia , Marcação de Genes , Vetores Genéticos , Humanos , Reação em Cadeia da Polimerase , Homologia de Sequência do Ácido Nucleico
10.
J Cell Sci ; 119(Pt 6): 1154-64, 2006 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-16507593

RESUMO

Genomic sequencing has revealed a large number of evolutionary conserved genes of unknown function. In the absence of characterized functional domains, the discovery of the role of these genes must rely on experimental approaches. We have selected 30 Dictyostelium discoideum genes of unknown function that showed high similarity to uncharacterized human genes and were absent in the complete proteomes from Saccharomyces cerevisiae and S. pombe. No putative functional motifs were found in their predicted encoded proteins. Eighteen genes were successfully knocked-out and three of them showed obvious phenotypes. A detailed analysis of one of them, midA, is presented in this report. Disruption of midA in Dictyostelium leads to pleiotropic defects. Cell size, growth rate, phagocytosis and macropinocytosis were affected in the mutant. During development, midA- cells showed an enhanced tendency to remain at the slug stage, and spore viability was compromised. The expression of MidA fused to GFP in midA- strain rescued the phenotype and the fused protein was located in the mitochondria. Although cellular oxygen consumption, mitochondrial content and mitochondrial membrane potential were similar to wild type, the amount of ATP was significantly reduced in the mutant suggesting a mitochondrial dysfunction. Metabolomic analysis by natural-abundance 13C-nuclear magnetic resonance has shown the lack of glycogen accumulation during growth. During starvation, mutant cells accumulated higher levels of ammonia, which inhibited normal development. We hypothesize that the lack of MidA reduces mitochondrial ATP synthetic capacity and this has an impact in some but not all energy-dependent cellular processes. This work exemplifies the potential of Dictyostelium as a model system for functional genomic studies.


Assuntos
Dictyostelium/genética , Genoma de Protozoário , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Proteínas de Protozoários/genética , Sequência de Aminoácidos , Animais , DNA Mitocondrial/genética , Dictyostelium/crescimento & desenvolvimento , Dictyostelium/ultraestrutura , Genoma Fúngico , Humanos , Mitocôndrias/metabolismo , Dados de Sequência Molecular , Saccharomyces cerevisiae/genética , Homologia de Sequência de Aminoácidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...