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1.
Tomography ; 9(5): 1617-1628, 2023 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-37736982

RESUMO

To compare the diagnostic effectiveness of chest computed tomography (CT) utilizing a single- versus a dual-reviewer approach in patients with pneumonia secondary to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we conducted a retrospective observational study of data from a cross-section of 4809 patients with probable SARS-CoV-2 from March to November 2020. All patients had a CT radiological report and reverse-transcription polymerase chain reaction (PCR) results. A dual-reviewer approach was applied to two groups while conducting a comparative examination of the data. Reviewer 1 reported 108 patients negative and 374 patients positive for coronavirus disease 2019 (COVID-19) in group A, and 266 negative and 142 positive in group B. Reviewer 2 reported 150 patients negative and 332 patients positive for COVID-19 in group A, and 277 negative and 131 positive in group B. The consensus result reported 87 patients negative and 395 positive for COVID-19 in group A and 274 negative and 134 positive in group B. These findings suggest that a dual-reviewer approach improves chest CT diagnosis compared to a conventional single-reviewer approach.


Assuntos
COVID-19 , Pneumonia , Humanos , SARS-CoV-2 , COVID-19/complicações , COVID-19/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Teste para COVID-19
2.
Sensors (Basel) ; 22(21)2022 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-36365807

RESUMO

Nowadays, one of the most important objectives in health research is the improvement of the living conditions and well-being of the elderly, especially those who live alone. These people may experience undesired or dangerous situations in their daily life at home due to physical, sensorial or cognitive limitations, such as forgetting their medication or wrong eating habits. This work focuses on the development of a database in a home, through non-intrusive technology, where several users are residing by combining: a set of non-intrusive sensors which captures events that occur in the house, a positioning system through triangulation using beacons and a system for monitoring the user's state through activity wristbands. Two months of uninterrupted measurements were obtained on the daily habits of 2 people who live with a pet and receive sporadic visits, in which 18 different types of activities were labelled. In order to validate the data, a system for the real-time recognition of the activities carried out by these residents was developed using different current Deep Learning (DL) techniques based on neural networks, such as Recurrent Neural Networks (RNN), Long Short-Term Memory networks (LSTM) or Gated Recurrent Unit networks (GRU). A personalised prediction model was developed for each user, resulting in hit rates ranging from 88.29% to 90.91%. Finally, a data sharing algorithm has been developed to improve the generalisability of the model and to avoid overtraining the neural network.


Assuntos
Atividades Humanas , Redes Neurais de Computação , Humanos , Idoso , Algoritmos , Bases de Dados Factuais
3.
Healthcare (Basel) ; 9(8)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34442204

RESUMO

This article shows our work for developing an elder care platform for social interaction and physical and cognitive stimulation using the Pepper robot and Android OS as clients, based on the knowledge acquired on our long-term social robotics research experience. The first results of the user's acceptance of the solution are presented in this article. The platform is able to provide different services to the user, such as information, news, games, exercises or music. The games, which have a bi-modal way of interacting (speech and a touch screen interface), have been designed for cognitive stimulation based on the items of the mini-mental state examination. The results of the user's performance are stored in a cloud database and can be reviewed by therapists through a web interface that also allows them to establish customized therapy plans for each user. The platform has been tested and validated, first using adult people and then deployed to an elder care facility where the robot has been interacting with users for a long period of time. The results and feedback received have shown that the robot can help to keep the users physically and mentally active as well as establish an emotional link between the user and the robot.

4.
Sensors (Basel) ; 21(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34450709

RESUMO

In recent years, Artificial Intelligence Technologies (AIT) have been developed to improve the quality of life of the elderly and their safety in the home. This work focuses on developing a system capable of recognising the most usual activities in the daily life of an elderly person in real-time to enable a specialist to monitor the habits of this person, such as taking medication or eating the correct meals of the day. To this end, a prediction model has been developed based on recurrent neural networks, specifically on bidirectional LSTM networks, to obtain in real-time the activity being carried out by the individuals in their homes, based on the information provided by a set of different sensors installed at each person's home. The prediction model developed in this paper provides a 95.42% accuracy rate, improving the results of similar models currently in use. In order to obtain a reliable model with a high accuracy rate, a series of processing and filtering processes have been carried out on the data, such as a method based on a sliding window or a stacking and re-ordering algorithm, that are subsequently used to train the neural network, obtained from the public database CASAS.


Assuntos
Inteligência Artificial , Qualidade de Vida , Atividades Cotidianas , Idoso , Atividades Humanas , Humanos , Redes Neurais de Computação
5.
Front Neurorobot ; 14: 34, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32625075

RESUMO

When there is an interaction between a robot and a person, gaze control is very important for face-to-face communication. However, when a robot interacts with several people, neurorobotics plays an important role to determine the person to look at and those to pay attention to among the others. There are several factors which can influence the decision: who is speaking, who he/she is speaking to, where people are looking, if the user wants to attract attention, etc. This article presents a novel method to decide who to pay attention to when a robot interacts with several people. The proposed method is based on a competitive network that receives different stimuli (look, speak, pose, hoard conversation, habituation, etc.) that compete with each other to decide who to pay attention to. The dynamic nature of this neural network allows a smooth transition in the focus of attention to a significant change in stimuli. A conversation is created between different participants, replicating human behavior in the robot. The method deals with the problem of several interlocutors appearing and disappearing from the visual field of the robot. A robotic head has been designed and built and a virtual agent projected on the robot's face display has been integrated with the gaze control. Different experiments have been carried out with that robotic head integrated into a ROS architecture model. The work presents the analysis of the method, how the system has been integrated with the robotic head and the experiments and results obtained.

6.
Sensors (Basel) ; 19(24)2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31842496

RESUMO

This work presents an integrated Indoor Positioning System which makes use of WiFi signals and RGB cameras, such as surveillance cameras, to track and identify people navigating in complex indoor environments. Previous works have often been based on WiFi, but accuracy is limited. Other works use computer vision, but the problem of identifying concrete persons relies on such techniques as face recognition, which are not useful if there are many unknown people, or where the robustness decreases when individuals are seen from different points of view. The solution presented in this paper is based on an accurate combination of smartphones along with RGB cameras, such as those used in surveillance infrastructures. WiFi signals from smartphones allow the persons present in the environment to be identified uniquely, while the data coming from the cameras allow the precision of location to be improved. The system is nonintrusive, and biometric data about subjects is not required. In this paper, the proposed method is fully described and experiments performed to test the system are detailed along with the results obtained.

7.
Sensors (Basel) ; 17(7)2017 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-28726746

RESUMO

In this article, a system for the detection of cracks in concrete tunnel surfaces, based on image sensors, is presented. Both data acquisition and processing are covered. Linear cameras and proper lighting are used for data acquisition. The required resolution of the camera sensors and the number of cameras is discussed in terms of the crack size and the tunnel type. Data processing is done by applying a new method called Gabor filter invariant to rotation, allowing the detection of cracks in any direction. The parameter values of this filter are set by using a modified genetic algorithm based on the Differential Evolution optimization method. The detection of the pixels belonging to cracks is obtained to a balanced accuracy of 95.27%, thus improving the results of previous approaches.

8.
Rev. psicol. deport ; 26(supl.1): 27-32, 2017. tab, graf
Artigo em Inglês | IBECS | ID: ibc-162640

RESUMO

The performance of two basketball teams can be analysed by exploring their different scoring dynamics on the basis of the two time series representing the scoring process of each team throughout the game. Existing studies following this approach focused mainly on regular season and playoff games in different basketball leagues. The aim of this study was to conduct this type of analysis on games of National Teams championships, focusing specifically on final round close games, as those in which medals are decided and teams perform in a very similar level. The study considers the final round games (i.e. semi-finals games, third-place game and final game) of the main men's professional basketball International Championships of National Teams (i.e. European Championships, World Championships and Olympic Games) played during the period 2005-2013. Different methods of time series analysis were used (i.e. autocorrelation and cross-correlation functions, double backward moving averages, Hilbert transform). The results revealed an increasing scoring coordination pattern between the teams as the games unfolded, showing extremely high coordinated behaviours in the 3rd and 4th quarters (i.e. similar scoring streaks by the two teams; back-and-forth scoring patterns). This suggests that are the first two quarters of the games those leading to major fluctuations on the scoreboard (i.e. game periods in which one team’s scoring performance is very successful whilst the other team’s is not). This study may be matter of interest to coaches and performance analysts in the field of basketball, providing practical information for specific games preparations in International Championships of National Teams (AU)


El rendimiento de dos equipos de baloncesto se puede analizar mediante la exploración de sus diferentes dinámicas de anotación sobre la base de las dos series temporales que representan el proceso anotador de cada equipo durante todo el partido. Los estudios existentes siguiendo este enfoque se han centrado principalmente en partidos de temporada regular y de playoff en diferentes ligas de baloncesto. El objetivo de este estudio fue llevar a cabo este tipo de análisis en partidos de campeonatos de selecciones nacionales, centrándose específicamente en los partidos ajustados de las rondas finales, como aquellos en los que se deciden las medallas y en los que los equipos desempeñan en un nivel muy similar. El estudio considera los partidos de las rondas finales (semifinales, tercer y cuarto puesto, y final) de los principales campeonatos internacionales de baloncesto de selecciones nacionales en categoría masculina (Campeonatos Europeos, Campeonatos del Mundo y Juegos Olímpicos) disputados durante el período 2005-2013. Se utilizaron diferentes métodos de análisis de series temporales (funciones de autocorrelación y correlación cruzada, doble media móvil, transformada de Hilbert). Los resultados revelaron un patrón creciente de coordinación anotadora entre los equipos a medida que los partidos avanzaban, mostrando patrones de coordinación extremadamente altos en el tercer y último cuarto (rachas de anotación similares para los dos equipos, patrones de anotación de ida y vuelta). Esto sugiere que son los dos primeros cuartos de los partidos aquellos que conducen a mayores fluctuaciones en el marcador (períodos de juego en los que el rendimiento anotador de un equipo es muy exitoso, mientras que el del otro equipo no lo es). Este estudio puede ser de interés para los entrenadores y analistas de rendimiento en baloncesto, proporcionando información práctica para la preparación específica de partidos en los campeonatos internacionales de selecciones nacionales (AU)


Assuntos
Humanos , Basquetebol/psicologia , Desempenho Atlético/psicologia , Estudos de Séries Temporais , Processos Grupais , Logro
10.
Front Hum Neurosci ; 10: 421, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27616987

RESUMO

Persons who suffer from schizophrenia have difficulties in recognizing emotions in others' facial expressions, which affects their capabilities for social interaction and hinders their social integration. Photographic images have traditionally been used to explore emotion recognition impairments in schizophrenia patients, but they lack of the dynamism that is inherent to facial expressiveness. In order to overcome those inconveniences, over the last years different authors have proposed the use of virtual avatars. In this work, we present the results of a pilot study that explored the possibilities of using a realistic-looking avatar for the assessment of emotion recognition deficits in patients who suffer from schizophrenia. In the study, 20 subjects with schizophrenia of long evolution and 20 control subjects were invited to recognize a set of facial expressions of emotions showed by both the said virtual avatar and static images. Our results show that schizophrenic patients exhibit recognition deficits in emotion recognition from facial expressions regardless the type of stimuli (avatar or images), and that those deficits are related with the psychopathology. Finally, some improvements in recognition rates (RRs) for the patient group when using the avatar were observed for sadness or surprise expressions, and they even outperform the control group in the recognition of the happiness expression. This leads to conclude that, apart from the dynamism of the shown expression, the RRs for schizophrenia patients when employing animated avatars may depend on other factors which need to be further explored.

11.
Sensors (Basel) ; 15(8): 19369-92, 2015 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-26258779

RESUMO

The fruit fly Drosophila Melanogaster has become a model organism in the study of neurobiology and behavior patterns. The analysis of the way the fly moves and its behavior is of great scientific interest for research on aspects such as drug tolerance, aggression or ageing in humans. In this article, a procedure for detecting, identifying and tracking numerous specimens of Drosophila by means of computer vision-based sensing systems is presented. This procedure allows dynamic information about each specimen to be collected at each moment, and then for its behavior to be quantitatively characterized. The proposed algorithm operates in three main steps: a pre-processing step, a detection and segmentation step, and tracking shape. The pre-processing and segmentation steps allow some limits of the image acquisition system and some visual artifacts (such as shadows and reflections) to be dealt with. The improvements introduced in the tracking step allow the problems corresponding to identity loss and swaps, caused by the interaction between individual flies, to be solved efficiently. Thus, a robust method that compares favorably to other existing methods is obtained.


Assuntos
Algoritmos , Drosophila melanogaster/fisiologia , Animais , Automação , Fenômenos Ópticos , Reprodutibilidade dos Testes , Gravação em Vídeo
12.
J Nat Prod ; 76(8): 1413-23, 2013 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-23865778

RESUMO

In the present study, the cytotoxicity of 30 diterpenoids with an abietane or a halimane skeleton was determined against five human tumor cell lines (HL-60, U937, Molt-3, SK-MEL-1, and MCF-7). Diterpenoids containing an abietane skeleton including taxodone (1) and taxodione (2), as well as the semisynthetic derivatives 12, 14, 15, 17, and 22, were the most cytotoxic compounds for human leukemia cells. Overexpression of the protective mitochondrial proteins Bcl-2 and Bcl-x(L) did not confer resistance to abietane diterpene-induced cytotoxicity. Studies performed on HL-60 cells indicated that growth inhibition triggered by compounds 1, 12, 14, and 15 was caused by induction of apoptosis. This was prevented by the nonspecific caspase inhibitor Z-VAD-FMK and, in the case of compounds 14 and 15, reduced by the selective caspase-8 inhibitor Z-IETD-FMK. Cell death induced by these abietane diterpenes was found to be associated with the release of mitochondrial proteins, including cytochrome c, Smac/DIABLO, and AIF (apoptosis-inducing factor), accompanied by dissipation of the mitochondrial membrane potential (ΔΨ), and modulated by inhibition of extracellular signal-regulated kinases signaling and the p38 mitogen-activated protein kinase pathway.


Assuntos
Abietanos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Diterpenos/farmacologia , Abietanos/química , Clorometilcetonas de Aminoácidos/farmacologia , Antineoplásicos Fitogênicos/química , Apoptose/efeitos dos fármacos , Fator de Indução de Apoptose/metabolismo , Caspase 8/metabolismo , Citocromos c/metabolismo , Diterpenos/química , Ensaios de Seleção de Medicamentos Antitumorais , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Células HL-60 , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Potencial da Membrana Mitocondrial , Mitocôndrias/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Oligopeptídeos/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais , Proteína X Associada a bcl-2/metabolismo , Proteína bcl-X/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
13.
Eur J Med Chem ; 63: 544-57, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23537942

RESUMO

Hybridization of two different bioactive molecules with different mechanism of action is one of the methods that are being adopted to treat cancer. Molecules bearing a thiazolidine-2,4-dione scaffold have been recognized as antineoplastic agents with a broad spectrum of activity against many cancer cell lines. In this manuscript we have described the synthesis and biological evaluation of two series of N-3-substituted-5-arylidene thiazolidine-2,4-diones, bearing the α-bromoacryloylamido moiety at the para- or meta-position on the phenyl of the arylidene portion. We have observed that selected compounds 5a, 5c and 5g suppress proliferation of human myeloid leukaemia HL-60 and U937 cells by triggering morphological changes and internucleosomal DNA fragmentation, which are well-known features of apoptosis. Finally, our results indicated that the investigated compounds induced apoptotic cell death through a mechanism that involved activation of multiple caspases and was also associated with the release of cytochrome c from the mitochondria.


Assuntos
Antineoplásicos/farmacologia , Compostos de Benzilideno/farmacologia , Proliferação de Células/efeitos dos fármacos , Tiazolidinedionas/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Compostos de Benzilideno/síntese química , Compostos de Benzilideno/química , Western Blotting , Caspases/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Citocromos c/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Citometria de Fluxo , Células HL-60 , Células HeLa , Humanos , Camundongos , Microscopia de Fluorescência , Modelos Químicos , Estrutura Molecular , Tiazolidinedionas/síntese química , Tiazolidinedionas/química , Células U937
14.
Rev. psicol. deport ; 21(2): 301-308, jul.-dic. 2012. tab
Artigo em Espanhol | IBECS | ID: ibc-108305

RESUMO

El propósito de esta investigación fue estudiar el efecto de marcar primero y su relación con la ventaja de jugar en casa en la Liga de Fútbol Profesional y en la Liga Nacional de Fútbol Sala de España, para conocer el efecto que tiene marcar primero sobre el resultado final de los partidos y su relación con la localización del partido, en función de si el equipo que se adelanta en el marcador es local o visitante. Se estudió cada liga de manera individual, para después comparar los resultados entre éstas. Con este propósito se introdujeron dos nuevas métricas denominadas ‘ventaja de jugar en casa para marcar el primer gol’ y ‘ventaja de marcar primero’. Los resultados muestran una ventaja de los equipos locales para marcar el primer gol significativamente menor que la ventaja de jugar en casa en las dos ligas. Asimismo se encuentra ventaja por marcar primero en el resultado de los partidos para los equipos locales y visitantes, con diferencias significativas a favor de los equipos locales y valores superiores en la liga de fútbol. Es preciso considerar las distintas características reglamentarias y de juego del fútbol y del fútbol sala que pueden explicar las diferencias encontradas (AU)


The aim of this research was to study the effect of scoring first and its relationship with home advantage in professional Spanish football and indoor soccer leagues, in order to analyse the effect of scoring first on game outcome in relation to home advantage, whether home or away team scores first. Each league was first studied individually, and then results were compared between them. For this purpose, two new metrics were introduced: ‘home advantage in scoring the first goal’ and ‘scoring first advantage’. Results showed a significantly lower advantage for local teams to score the first goal than home advantage in both football and indoor soccer leagues. Likewise, advantage in game outcome after scoring the first goal is found in the two leagues, both for local and away teams, with significant differences in favour of teams playing at home and higher values in football than in indoor soccer league. Distinct football and indoor soccer rules and game features must be considered to explain the observed differences (AU)


Assuntos
Humanos , Masculino , Feminino , Futebol/classificação , Futebol/psicologia , Esportes/psicologia , Psicometria/métodos , Psicometria/estatística & dados numéricos , Psicometria/tendências , 28599 , Psicometria/organização & administração , Psicometria/normas
15.
Bioorg Med Chem ; 20(8): 2690-700, 2012 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-22405922

RESUMO

A variety of spirostan saponins and related glycosides were synthesized and evaluated for their cytotoxicity against the human myeloid leukemia cell line (HL-60). A linear glycosylation strategy allowed for accessing a variety of functionalization patterns at both the spirostanic and the saccharide moieties, which provides new information regarding the structure-cytotoxicity relationship of this family of steroidal glycosides. Intriguing results were achieved with respect to hecogenyl and 5α-hydroxy-laxogenyl ß-chacotriosides, turning out to be the former very cytotoxic and the latter no cytotoxic at all. Importantly, the partially pivaloylated ß-d-glucosides of 5α-hydroxy-laxogenin were the most potent cytotoxic compounds among all tested glycosides. This comprises the first report on acylated spirostanyl glucosides displaying significant cytotoxicity, and therefore, it opens up new opportunities toward the development of saponin analogues as anticancer agents.


Assuntos
Antineoplásicos/farmacologia , Glicosídeos/farmacologia , Saponinas/farmacologia , Espirostanos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Glicosídeos/síntese química , Glicosídeos/química , Células HL-60 , Humanos , Conformação Molecular , Saponinas/síntese química , Saponinas/química , Espirostanos/síntese química , Espirostanos/química , Estereoisomerismo , Relação Estrutura-Atividade , Células Tumorais Cultivadas
16.
Nat Prod Res ; 26(3): 203-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-21815723

RESUMO

A new flavone glucoside, apigenin 4'-(6″-methylglucuronide) (1), together with six known compounds, cirsilineol, jaceosidin, melitensin, apigenin, apigenin 7-(6″-methylglucuronide) and prunasin, were isolated from the ethanolic extract of the aerial parts of Centaurea nicaeensis All. var. walliana M. (Asteraceae) collected from Souk-Ahras, eastern Algeria. The structures were established by spectral analysis, mainly HRESI-MS, UV and 2D-NMR experiments (COSY, HSQC and HMBC).


Assuntos
Centaurea/química , Flavonoides/isolamento & purificação , Flavonoides/química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Ultravioleta
17.
Chem Biodivers ; 8(11): 2080-9, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22083919

RESUMO

Two new compounds, the sesquiterpene (1E,5E)-8ß-acetoxy-4α-hydroxy-7ßH-germacra-1(10),5-dien-14-oic acid (2), and a nor-sesquiterpene, (5E)-8ß-acetoxy-4α-hydroxy-7ßH-germacr-5-en-10-one (3), were isolated from Pulicaria canariensis ssp. lanata, along with ten known compounds, including the flavonoid 5,3'-dihydroxy-3,7,4'-trimethoxyflavone (4). From Pulicaria burchardii, we isolated seven known compounds; the physical and spectroscopic data of the triterpenoid 3ß-hydroxytaraxaster-20-en-30-al (1) are reported. The structures of compounds 1-3 were determined on the basis of HR-MS, and 1D- and 2D-NMR studies. The structure of 2 was corroborated by X-ray crystal diffraction. Cell viability experiments revealed that the semisynthetic flavonoid 4b was the most cytotoxic compound against human leukemia cells, and the cytotoxicity was caused by induction of apoptosis, as determined by microscopy of nuclear changes.


Assuntos
Antineoplásicos , Flavonoides , Pulicaria/química , Pulicaria/metabolismo , Sesquiterpenos , Triterpenos/farmacologia , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cromatografia em Camada Fina , Cristalografia por Raios X , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Células HL-60 , Humanos , Concentração Inibidora 50 , Espectroscopia de Ressonância Magnética , Microscopia de Fluorescência , Estrutura Molecular , Componentes Aéreos da Planta/citologia , Componentes Aéreos da Planta/crescimento & desenvolvimento , Componentes Aéreos da Planta/metabolismo , Pulicaria/crescimento & desenvolvimento , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Relação Estrutura-Atividade , Triterpenos/isolamento & purificação
18.
ChemMedChem ; 6(10): 1841-53, 2011 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-21805646

RESUMO

Induction of apoptosis is a promising strategy that could lead to the discovery of new molecules active in cancer chemotherapy. This property is generally observed when cells are treated with agents that target microtubules, dynamic structures that play a crucial role in cell division. Small molecules such as benzo[b]furans are attractive as inhibitors of tubulin polymerization. A new class of inhibitors of tubulin polymerization based on the 2-(3',4',5'-trimethoxybenzoyl)benzo[b]furan molecular skeleton, with the amino group placed at different positions on the benzene ring, were synthesized and evaluated for antiproliferative activity, inhibition of tubulin polymerization, and cell-cycle effects. The methoxy substitution pattern on the benzene portion of the benzo[b]furan moiety played an important role in affecting antiproliferative activity. In the series of 5-amino derivatives, the greatest inhibition of cell growth occurred if the methoxy substituent is placed at the C6 position, whereas C7 substitution decreases potency. The most promising compound in this series is 2-(3',4',5'-trimethoxybenzoyl)-3-methyl-5-amino-6-methoxybenzo[b]furan (3 h), which inhibits cancer cell growth at nanomolar concentrations (IC(50) =16-24 nM), and interacts strongly with tubulin by binding to the colchicine site. Sub-G(1) apoptotic cells in cultures of HL-60 and U937 cells were observed by flow cytometric analysis after treatment with 3 h in a concentration-dependent manner. We also show that compound 3 h induces apoptosis by activation of caspase-3, -8, and -9, and this is associated with cytochrome c release from mitochondria. The introduction of an α-bromoacryloyl group increased antiproliferative activity with respect to the parent amino derivatives.


Assuntos
Anisóis/síntese química , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Benzofuranos/química , Benzofuranos/síntese química , Benzofuranos/farmacologia , Moduladores de Tubulina , Tubulina (Proteína)/química , Animais , Anisóis/química , Anisóis/toxicidade , Benzofuranos/toxicidade , Sítios de Ligação , Caspases/metabolismo , Pontos de Checagem do Ciclo Celular , Linhagem Celular Tumoral , Colchicina/química , Humanos , Camundongos , Neoplasias/tratamento farmacológico , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/farmacologia
19.
Glycobiology ; 21(5): 619-24, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21147757

RESUMO

Four new steroidal glycosides such as 3-O-6-deoxy-3-O-methyl-ß-D-allopyranosyl-(1 → 4)-ß-D-oleandropyranosyl-(1 → 4)-ß-D-cymaropyranosyl-(1 → 4)-ß-D-cymaropyranoside-12-ß-tigloyl-14-ß-hydroxy-17-ß-pregnane (1), 3-O-6-deoxy-3-O-methyl-ß-D-allopyranosyl-(1 → 4)-ß-D-oleandropyranosyl-(1 → 4)-ß-D-cymaropyranosyl-(1 → 4)-ß-D-cymaropyranoside-12-ß-(2'-amino)-benzoyl-14-ß-hydroxy-17-ß-pregnane (2), 3-O-6-deoxy-3-O-methyl-ß-D-allopyranosyl-(1 → 4)-ß-D-oleandropyranosyl-(1 → 4)-ß-D-cymaropyranosyl-(1 → 4)-ß-D-cymaropyranoside-12-ß-14-ß-dihydroxy-17-α-pregnane (3) and 3-O-6-deoxy-3-O-methyl-ß-D-allopyranosyl-(1 → 4)-ß-D-oleandropyranosyl-(1 → 4)-ß-D-cymaropyranosyl-(1 → 4)-ß-D-cymaropyranoside-12-ß-14-ß-dihydroxy-17-ß-pregnane (4) were isolated from the aerial parts of Ceropegia fusca Bolle (Asclepiadaceae), a crassulacean acid metabolism plant, an endemic species to the Canary Islands that has been used in traditional medicine as a cicatrizant, vulnerary and disinfectant. The dichloromethane extract exhibited significant cytostatic activity against HL-60, A-431 and SK-MEL-1 cells, human leukemic, epidermoid carcinoma and melanoma cells, respectively. As shown in Table I, compounds 1 and 2 showed very similar IC(50) values. The acetylation of 1 to give the diacetate 5 increases 5-fold the cytotoxicity against HL-60 cells. Compounds 3 and 4 did not show cytotoxicity at the assayed concentrations. With respect to the compounds containing only the steroid ring (6-8), the presence of a charged O-amino-benzoyl but not a tigloyl group improved the cytotoxicity.


Assuntos
Antineoplásicos/farmacologia , Citostáticos/farmacologia , Glicosídeos/farmacologia , Extratos Vegetais/farmacologia , Pregnanos/farmacologia , Antineoplásicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citostáticos/isolamento & purificação , Ensaios de Seleção de Medicamentos Antitumorais , Gentiana/química , Gentiana/metabolismo , Glicosídeos/isolamento & purificação , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Componentes Aéreos da Planta/química , Componentes Aéreos da Planta/metabolismo , Extratos Vegetais/isolamento & purificação , Pregnanos/isolamento & purificação , Relação Estrutura-Atividade
20.
Nat Prod Commun ; 5(1): 35-7, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20184016

RESUMO

One novel alkaloid, 1,5-diphenyl-3-styryl-2-pyrazoline 1, in addition with six known flavonoids namely, kaempferol, kaempferol 3-O-glucoside, kaempferol 3-rutinoside, quercetin, quercetin 3-O-glucoside, and rutin, were isolated from the aerial parts of Euphorbia guyoniana. Their structures were established on the basis of physical and spectroscopic analysis, and by comparison with the literature data.


Assuntos
Alcaloides/isolamento & purificação , Euphorbia/química , Flavonoides/isolamento & purificação , Pirazóis/isolamento & purificação , Estrutura Molecular , Extratos Vegetais/química
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