RESUMO
Two microscale separation techniques for the analysis of bioactive naphthoquinones in Eleutherine americana were developed and validated. By MEKC four compounds (eleuthoside B, isoeleutherin, eleutherol and eleutherinoside A) could be determined in plant extracts using an aqueous electrolyte solution composed of 25 mM sodium tetraborate, 50 mM sodium cholate and 20% THF. CEC on a polymeric methacrylate-based monolith with strong cationic properties showed promising results, as it additionally enabled the separation of two enantiomers, eleutherin and isoeleutherin. The mobile phase for CEC experiments comprised 3 mM ammonium formate in a mixture of ACN and water. At an applied voltage of -25 kV, all five markers were baseline separated in less than 12 min. Both methods were successfully validated for linearity (MEKC: R(2) > or = 0.999; CEC: R(2) > or = 0.997), sensitivity (MEKC: LOD = 4-5 microg/mL; CEC: LOD=2-8 microg/mL), accuracy (MEKC: 96.5-102.7% recovery; CEC: 97.1-103.5% recovery) and precision (MEKC: sigma(rel) < or = 2.43%; CEC: sigma(rel) < or = 2.21%). The quantitative analysis of naphthoquinone derivatives in several E. americana samples showed that both methods are suitable for practical applications, because the results were well comparable to those obtained by established techniques such as HPLC.
Assuntos
Eletrocromatografia Capilar/métodos , Cromatografia Capilar Eletrocinética Micelar/métodos , Iridaceae/química , Naftoquinonas/análise , Extratos Vegetais/química , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Extratos Vegetais/análise , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
The recently disclosed next generation of reversible, selective, and potent MetAP-2 inhibitors introduced a cyclic tartronic diamide scaffold. However, the lead compound 1a suffered from enterohepatic circulation, preventing further development. Nevertheless, 1a served as a starting point for further optimization. Maintaining potent antiproliferation activity, while improving other compound properties, enabled the generation of an attractive array of new MetAP-2 inhibitors. The most promising derivatives were identified by a multiparameter analysis of the compound properties. Essential for the efficient selection of candidates with in vivo activity was the identification of molecules with a long residence time on the target protein, high permeability, and low efflux ratio not only in Caco-2 but also in the MDR-MDCK cell line. Orally bioavailable, potent, and reversible MetAP-2 inhibitors impede the growth of primary endothelial cells and demonstrated antitumoral activity in mouse models. This assessment led to the nomination of the clinical development compound M8891, which is currently in phase I clinical testing in oncology patients.
Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Glioma/tratamento farmacológico , Indóis/farmacologia , Metionil Aminopeptidases/antagonistas & inibidores , Células A549 , Animais , Antineoplásicos/química , Apoptose , Células CACO-2 , Proliferação de Células , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Inibidores Enzimáticos/química , Feminino , Glioma/metabolismo , Glioma/patologia , Humanos , Indóis/química , Camundongos , Camundongos Nus , Modelos Moleculares , Relação Estrutura-Atividade , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The quality of every dynamic multi-projection mapping system is limited by the quality of the projector to tracking device calibration. Common problems with poor calibration result in noticeable artifacts for the user, such as ghosting and seams. In this work we introduce a new, fully automated calibration algorithm that is tailored to reduce these artifacts, based on consumer-grade hardware. We achieve this goal by repurposing a structured-light scanning setup. A structured-light scanner can generate 3D geometry based on a known intrinsic and extrinsic calibration of its components (projector and RGB camera). We revert this process by providing the resulting 3D model to determine the intrinsic and extrinsic parameters of our setup (including those of a variety of tracking systems). Our system matches features and solves for all parameters in a single pass while respecting the lower quality of our sensory input.
RESUMO
Recent publications and art performances demonstrate amazing results using projection mapping. To our knowledge, there exists no multi-projection system that can project onto non-rigid target geometries. This constrains the applicability and quality for live performances with multiple spectators. Given the cost and complexity of current systems, we present a low-cost easy-to-use markerless non-rigid face multi-projection system. It is based on a non-rigid, dense face tracker and a real-time multi-projection solver adapted to imprecise tracking, geometry and calibration. Using this novel system we produce compelling results with only consumer-grade hardware.
RESUMO
Magnetic resonance imaging with arterial spin labeling (ASL) is a noninvasive approach to measure organ perfusion. The purpose of this study was to evaluate the reproducibility of ASL kidney perfusion measurements with semiautomatic segmentation, which allows separate quantification of cortical and medullary perfusion. The right kidneys of 14 healthy volunteers were examined 6 times on 2 occasions (3 times at each occasion). There was a 10-minute pause between each examination and a 14-day interval between the 2 occasions. Cortical, medullary, and whole kidney parenchymal perfusion was determined with customized semiautomatic segmentation software. Coefficient of variances (CVs) and intraclass correlations (ICCs) were calculated. Mean whole, cortical, and medullary kidney perfusion was 307.26â±â25.65, 337.10â±â34.83, and 279.61â±â26.73âmL/min/100âg, respectively. On session 1, mean perfusion for the whole kidney, cortex, and medulla was 307.08â±â26.91, 336.79â±â36.54, and 279.60â±â27.81âmL/min/100âg, respectively, and on session 2, 307.45â±â24.65, 337.41â±â33.48, and 279.61â±â25.94âmL/min/100âg, respectively (Pâ>â0.05; R²â=â0.60/0.59/0.54). For whole, cortical, and medullary kidney perfusion, the total ICC/CV were 0.97/3.43â±â0.86%, 0.97/4.19â±â1.33%, and 0.96/4.12â±â1.36%, respectively. Measurements did not differ significantly and showed a very good correlation (Pâ>â0.05; R²â=â0.75/0.76/0.65). ASL kidney measurements combined with operator-independent semiautomatic segmentation revealed high correlation and low variance of cortical, medullary, and whole kidney perfusion.