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1.
Eur J Pain ; 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38348557

RESUMO

BACKGROUND: Acceptance and Commitment Therapy (ACT) is a type of Cognitive Behavioural Therapy, which has demonstrated positive outcomes in individuals with chronic pain. The purpose of this study was to compare the effect of an 8-week programme combining Exercise with Acceptance and Commitment Therapy (ExACT) with a standalone supervised exercise programme at 1-year follow-up. METHODS: One hundred and seventy-five people with chronic pain were randomly assigned to ExACT or supervised exercise only. The primary outcome was pain interference measured with the Brief Pain Inventory-Interference Scale. Secondary and treatment process outcomes included pain severity, depression, anxiety, pain catastrophizing, pain self-efficacy, fear avoidance, pain acceptance, committed action, healthcare utilization, patient satisfaction, and global impression of change. Estimates of treatment effects at 1-year follow-up were based on intention-to-treat analyses, implemented using a linear mixed-effects model. RESULTS: Eighty-three participants (47.4%) returned the outcome measures at 1-year follow-up. No significant difference was observed between the groups for the primary outcome, pain interference. There was a statistically significant difference between the groups, in favour of ExACT for pain catastrophizing. Within group improvements that were observed within both groups at earlier timepoints were maintained at 1-year follow-up for many of the secondary and treatment process outcomes. ExACT group participants reported higher levels of satisfaction with treatment and global perceived change. CONCLUSIONS: The study results showed no significant difference between the two groups for the primary outcome pain interference at 1-year follow-up. Future research could investigate factors that may predict and optimize outcomes from these types of intervention for people living with chronic pain. SIGNIFICANCE: Few previous randomized controlled trials investigating ACT for chronic pain have included long-term follow-up. This study found that Exercise combined with ACT was not superior to supervised exercise alone for reducing pain interference at 1-year follow-up. Further research is necessary to identify key processes of therapeutic change and to explore how interventions may be modified to enhance clinical outcomes for people with chronic pain.

2.
Sci Robot ; 8(80): eade7811, 2023 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-37494462

RESUMO

To realize the potential of autonomous underwater robots that scale up our observational capacity in the ocean, new techniques are needed. Fleets of autonomous robots could be used to study complex marine systems and animals with either new imaging configurations or by tracking tagged animals to study their behavior. These activities can then inform and create new policies for community conservation. The role of animal connectivity via active movement of animals represents a major knowledge gap related to the distribution of deep ocean populations. Tracking underwater targets represents a major challenge for observing biological processes in situ, and methods to robustly respond to a changing environment during monitoring missions are needed. Analytical techniques for optimal sensor placement and path planning to locate underwater targets are not straightforward in such cases. The aim of this study was to investigate the use of reinforcement learning as a tool for range-only underwater target-tracking optimization, whose promising capabilities have been demonstrated in terrestrial scenarios. To evaluate its usefulness, a reinforcement learning method was implemented as a path planning system for an autonomous surface vehicle while tracking an underwater mobile target. A complete description of an open-source model, performance metrics in simulated environments, and evaluated algorithms based on more than 15 hours of at-sea field experiments are presented. These efforts demonstrate that deep reinforcement learning is a powerful approach that enhances the abilities of autonomous robots in the ocean and encourages the deployment of algorithms like these for monitoring marine biological systems in the future.


Assuntos
Robótica , Animais , Algoritmos , Aprendizagem , Reforço Psicológico
3.
Sci Rep ; 12(1): 6362, 2022 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-35430586

RESUMO

Low-field MRI scanners are significantly less expensive than their high-field counterparts, which gives them the potential to make MRI technology more accessible all around the world. In general, images acquired using low-field MRI scanners tend to be of a relatively low resolution, as signal-to-noise ratios are lower. The aim of this work is to improve the resolution of these images. To this end, we present a deep learning-based approach to transform low-resolution low-field MR images into high-resolution ones. A convolutional neural network was trained to carry out single image super-resolution reconstruction using pairs of noisy low-resolution images and their noise-free high-resolution counterparts, which were obtained from the publicly available NYU fastMRI database. This network was subsequently applied to noisy images acquired using a low-field MRI scanner. The trained convolutional network yielded sharp super-resolution images in which most of the high-frequency components were recovered. In conclusion, we showed that a deep learning-based approach has great potential when it comes to increasing the resolution of low-field MR images.


Assuntos
Aprendizado Profundo , Encéfalo/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , Redes Neurais de Computação , Razão Sinal-Ruído
4.
Phys Med ; 84: 116-124, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33894581

RESUMO

PURPOSE: To investigate the displacement forces and image artifacts associated with passive medical implants for recently-developed low-field (<100 mT) MRI systems, and to compare these with values from higher field strengths used for clinical diagnosis. METHODS: Setups were constructed to measure displacement forces in a permanent magnet-based Halbach array used for in vivo MRI at 50 mT, and results compared with measurements at 7 T. Image artifacts were assessed using turbo (fast) spin echo imaging sequences for four different passive medical implants: a septal occluder, iliac stent, pedicle screw and (ferromagnetic) endoscopic clip. Comparisons were made with artifacts produced at 1.5, 3 and 7 T. Finally, specific absorption rate (SAR) simulations were performed to determine under what operating conditions the limits might be approached at low-field. RESULTS: Displacement forces at 50 mT on all but the ferromagnetic implant were between 1 and 10 mN. Image artifacts at 50 mT were much less than at clinical field strengths for all passive devices, and with the exception of the ferromagnetic clip. SAR simulations show that very long echo train (>128) turbo spin echo sequences can be run with short inter-pulse times (5-10 ms) within SAR limits. CONCLUSIONS: This work presents the first evaluation of the effects of passive implants at field strengths less than 100 mT in terms of displacement forces, image artifacts and SAR. The results support previous claims that such systems can be used safely and usefully in challenging enviroments such as the intensive care unit.


Assuntos
Artefatos , Imãs , Imageamento por Ressonância Magnética , Próteses e Implantes
5.
Sci Robot ; 5(48)2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33239320

RESUMO

Knowing the displacement capacity and mobility patterns of industrially exploited (i.e., fished) marine resources is key to establishing effective conservation management strategies in human-impacted marine ecosystems. Acquiring accurate behavioral information of deep-sea fished ecosystems is necessary to establish the sizes of marine protected areas within the framework of large international societal programs (e.g., European Community H2020, as part of the Blue Growth economic strategy). However, such information is currently scarce, and high-frequency and prolonged data collection is rarely available. Here, we report the implementation of autonomous underwater vehicles and remotely operated vehicles as an aid for acoustic long-baseline localization systems for autonomous tracking of Norway lobster (Nephrops norvegicus), one of the key living resources exploited in European waters. In combination with seafloor moored acoustic receivers, we detected and tracked the movements of 33 tagged lobsters at 400-m depth for more than 3 months. We also identified the best procedures to localize both the acoustic receivers and the tagged lobsters, based on algorithms designed for off-the-shelf acoustic tags identification. Autonomous mobile platforms that deliver data on animal behavior beyond traditional fixed platform capabilities represent an advance for prolonged, in situ monitoring of deep-sea benthic animal behavior at meter spatial scales.


Assuntos
Pesqueiros , Nephropidae , Robótica/instrumentação , Acústica , Algoritmos , Animais , Comportamento Animal , Simulação por Computador , Conservação dos Recursos Naturais/métodos , Conservação dos Recursos Naturais/estatística & dados numéricos , Ecossistema , Desenho de Equipamento , Nephropidae/fisiologia , Oceanos e Mares , Tecnologia de Sensoriamento Remoto/instrumentação , Tecnologia de Sensoriamento Remoto/estatística & dados numéricos , Robótica/estatística & dados numéricos , Alimentos Marinhos
6.
J Magn Reson ; 307: 106578, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31470234

RESUMO

Modern clinical MRI systems utilise very high magnetic fields strengths to produce high resolution images of the human body. The high up-front and maintenance cost of these systems means that much of the world lacks access to this technology. In this paper we propose a low cost, head-only, homogenous Halbach magnet array with the potential for paediatric neuroimaging in low-resource settings. The homogeneity of the Halbach array is improved by allowing the diameter of the Halbach array to vary along its length, and also adding smaller internal shim magnets. The constructed magnet has a bore diameter of 27 cm, mean B0 field strength of 50.4 mT and a homogeneity of 2400 ppm over a 20 cm diameter spherical volume. The level of homogeneity of the system means that coil-based gradients can be used for spatial encoding which greatly increases the flexibility in image acquisition. 3D images of a "brain phantom" were acquired over a 22 × 22 × 22 cm field of view with a 3.5 mm isotropic resolution using a spin-echo sequence. Future development of a low-cost gradient amplifier and an open-source spectrometer has the potential of offering a fully open-source, low-cost MRI system for paediatric neuroimaging in low-resource settings.

7.
J Magn Reson ; 270: 108-114, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27434779

RESUMO

Improvements are proposed for practical design and use of high permittivity materials in high field neuroimaging in three different areas: (i) a simple formula to predict the permittivity of tri-component aqueous-based perovskite suspensions with relative permittivities between 110 and 300, (ii) characterization of addition of a hydroxyethyl-cellulose gelling agent to improve the long-term stability and material properties of "dielectric pads", and (iii) investigation of the integration of, for example, headphones into the dielectric pads to increase patient comfort within tightly-fitting receive coil arrays.


Assuntos
Neuroimagem , Humanos , Aumento da Imagem , Imageamento por Ressonância Magnética
8.
Clin Exp Immunol ; 147(1): 112-9, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17177970

RESUMO

Experiments to evaluate the effect of the level and duration of endotoxaemia on the meningeal inflammatory response were performed in order to determine if systemic inflammation alters meningitis. Rabbits received either saline or Escherichia coli O111:B4 lipopolysacharide (LPS) intravenously at various doses (1, 3 or 10 microg) and times (-8, -2 or 0 h) before an intracisternal injection of 20 ng LPS. An intracisternal LPS injection together with saline intravenously produced a peak cerebrospinal fluid (CSF) tumour necrosis factor (TNF) level (95 +/- 26 ng/ml) at 2 h and peak leucocyte level (5413 +/- 764 cells/microl) at 4 h post-injection. Blood leucocytes were slightly elevated (12 000 +/- 500/microl at 0 h; 16 900 +/- 280/microl at 8 h) but plasma TNF was always undetectable (< 0.05 ng/ml). Conversely, intravenous injection of 3 or 10 microg LPS 2 h prior to intracisternal LPS injection impaired pleocytosis (peak < 220 cells/microl) and delayed ( approximately 4 h) and reduced peak CSF TNF levels (3 microg LPS 5.0 +/- 1.2 ng/ml; 10 microg LPS 6.9 +/- 1.9; P < 0.05). Intravenous administration of 1 microg LPS was less inhibitory to CSF inflammation, but delayed onset (peak 1100 +/- 60 leucocytes/microl CSF at 8 h; 6.3 +/- 0.3 ng TNF/ml CSF at 4 h; both P < 0.05). Neutropenia nadirs were dependent on LPS dose (1 microg, 4500 +/- 1700; 3 microg, 1900 +/- 60; 10 microg, 1100 +/- 100 all at 4 h post-intravenous dose). Peak plasma TNF levels were not dose-dependent (> 8 ng/ml), but plasma TNF was always detectable (> 0.2 ng/ml at 10 h post-intravenous dose). Intravenous LPS administration at 0 h also blocked pleocytosis, but the inhibitory effect was lost when administration at -8 h. In conclusion, the degree and duration of endotoxaemia affect the meningeal inflammatory response to LPS in experimental meningitis.


Assuntos
Endotoxemia/imunologia , Meningites Bacterianas/imunologia , Modelos Animais , Animais , Líquido Cefalorraquidiano/microbiologia , Relação Dose-Resposta Imunológica , Escherichia coli , Injeções/métodos , Injeções Intravenosas , Contagem de Leucócitos , Lipopolissacarídeos/farmacologia , Masculino , Coelhos , Fator de Necrose Tumoral alfa/líquido cefalorraquidiano
9.
Cancer Chemother Pharmacol ; 55(4): 307-317, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15723258

RESUMO

PURPOSE: The microtubule-stabilizing agent patupilone (epothilone B, EPO906) and the tyrosine kinase inhibitor imatinib (STI571, Glivec) which primarily inhibits Bcr-Abl, PDGF and c-Kit tyrosine kinase receptors, were combined in vivo to determine if any interaction would occur with respect to antitumour effect and tolerability using rat C6 glioma xenografted into nude mice. METHODS: Patupilone and imatinib were administered alone or in combination at suboptimal doses. Imatinib treatment (orally once daily) was initiated 4 days after s.c. injection of rat C6 glioma cells into athymic nude mice and patupilone administration (i.v. once per week) was started 3 or 4 days after imatinib treatment. RESULTS: As a single agent, imatinib was inactive in the regimens selected (100 mg/kg: T/C 86% and 116%; 200 mg/kg: T/C 68% and 84%; two independent experiments), but well tolerated (gain in body weight and no mortalities). Patupilone weekly monotherapy demonstrated dose-dependent antitumour effects (1 mg/kg: T/C 67% and 70%; 2 mg/kg: T/C 32% and 63%; 4 mg/kg: T/C 3% and 46%). As expected, dose-dependent body weight losses occurred (final body weight changes at 1 mg/kg were -7% and -3%; at 2 mg/kg were -23% and -13%; and at 4 mg/kg were -33% and -15%). Combining 2 mg/kg patupilone and 200 mg/kg per day imatinib in one experiment produced a non-statistically significant trend for an improved antitumour effect over patupilone alone (combination, T/C 9%), while in the second experiment, enhancement was seen with the combination and reached statistical significance versus patupilone alone (combination, T/C 22%; P=0.008). Reduction of the imatinib dose to 100 mg/kg per day resulted in no enhancement of antitumour activity in combination with 2 mg/kg patupilone. Reduction of the patupilone dose to 1 mg/kg resulted in a reduced antitumour effect, and only a trend for synergy with either imatinib dose (combination, T/C 46% and 40%). Pooling the data from the two experiments confirmed a significant synergy for the combination of 2 mg/kg patupilone and 200 mg/kg per day imatinib (P=0.032), and a trend for synergy at the 1 mg/kg patupilone dose. Reduction in the imatinib dose to 100 mg/kg per day resulted only in additivity with either dose of patupilone. Body weight losses were dominated by the effect of patupilone, since no greater body weight loss was observed in the combination groups. CONCLUSION: Combining patupilone with high-dose imatinib produced an increased antitumour effect without affecting the tolerability of treatment in a relatively chemoresistant rat C6 glioma model. Such results indicate that further evaluation is warranted, in particular to elucidate possible mechanisms of combined action.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Epotilonas/administração & dosagem , Glioma/tratamento farmacológico , Piperazinas/administração & dosagem , Pirimidinas/administração & dosagem , Animais , Benzamidas , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Mesilato de Imatinib , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias , Ratos
10.
Br J Cancer ; 88(10): 1622-30, 2003 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-12771932

RESUMO

We have generated fusion proteins between vascular endothelial growth factor (VEGF) and the bacterial enzyme carboxypeptidase G2 (CPG2) that can activate the prodrug 4-[(2-chloroethyl)(2-mesyloxyethyl)amino]benzoyl-L-glutamic acid (CMDA). Three asparagine residues of CPG2 were mutated to glutamine (CPG2(Q)3) to prevent glycosylation during secretion, and truncations of VEGF(165) were fused to either the C- or N-terminal of CPG2. The K(m) of the fusion proteins (37.5 microM) was similar to that of secreted CPG2(Q)3 (29.5 microM) but greater than that of wild-type CPG2 (8 microM). The affinity of the fusion proteins for VEGF receptor-2 (VEGFR2) (K(d)=0.5-1.1 nM) was similar to that of [(125)I]VEGF (K(d)=0.5 nM) (ELISA) or slightly higher (K(d)=1.3-9.6 nM) (competitive RIA). One protein, VEGF(115)-CPG2(Q)3-H(6), possessed 140% of the enzymic activity of secreted CPG2(Q)3, and had a faster half-maximal binding time for VEGFR2 (77 s), than the other candidates (330 s). In vitro, VEGF(115)-CPG2(Q)3-H(6) targeted CMDA cytotoxicity only towards VEGFR-expressing cells. The plasma half-life of VEGF(115)-CPG2(Q)3-H(6) in vivo was 3 h, comparable to equivalent values observed in ADEPT. We conclude that enzyme prodrug therapy using VEGF as a targeting moiety represents a promising novel antitumour therapy, with VEGF(115)-CPG2(Q)3-H(6) being a lead candidate.


Assuntos
Fatores de Crescimento Endotelial/farmacologia , Glutamatos/farmacologia , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Linfocinas/farmacologia , Compostos de Mostarda Nitrogenada/farmacologia , Pró-Fármacos/farmacologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , gama-Glutamil Hidrolase/farmacologia , Adenocarcinoma/patologia , Fatores de Crescimento Endotelial/genética , Endotélio/citologia , Feminino , Glutamina , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Linfocinas/genética , Mutagênese Sítio-Dirigida , Neovascularização Patológica , Neoplasias Ovarianas/patologia , Plasmídeos , Mutação Puntual , Fator A de Crescimento do Endotélio Vascular , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/efeitos dos fármacos , Fatores de Crescimento do Endotélio Vascular , gama-Glutamil Hidrolase/genética
11.
Rev. Soc. Esp. Dolor ; 9(8): 485-501, dic. 2002. ilus, graf
Artigo em Es | IBECS | ID: ibc-18902

RESUMO

En este artículo se describe el primer modelo conocido de dolor por cáncer de huesos en la rata. Ratas SpragueDawley recibieron inyecciones intratibiales de células M R M T-1 singénicas de carcinoma de glándula mamaria de rata y exhibieron conductas indicativas de dolor, como: alodinia mecánica, diferencia en el peso apoyado en las patas traseras e hiperalgesia mecánica. La aparición del tumor óseo y el daño estructural del hueso se vigilaron mediante análisis radiológico, medidas cuantitativas del contenido mineral e histología. Las inyecciones intratibiales de 3 x 103 ó 3 x 104 células M R M T-1 singénicas produjeron un tumor que se propagó rápidamente dentro de la tibia, causando una intensa remodelación del hueso. Las radiografías mostraron importantes daños en el hueso cortical y las trabéculas entre 10 y 14 días después de la inoculación de 3 x 103 células MRMT-1 y, al cabo de 20 días, los daños amenazaban la integridad de la tibia. Mientras que el contenido mineral y la densidad mineral disminuyeron significativamente en hueso afectado por el cáncer, el número de osteoclastos en el hueso compacto peritumoral no experimentó cambios. Sin embargo, la tinción con fosfatasa ácida resistente al tartarato puso de manifiesto la existencia de un gran número de células policariotas parecidas a los osteoclastos presentes dentro del tumor. No se observó crecimiento tumoral después de la inyección de células MRMT-1 destruidas con calor. Las inyecciones intratibiales de 3 x 103 ó 3 x 104 de células MRMT-1, células destruidas con calor o excipiente no p ro d u j e ron cambios en el peso corporal ni en la temperatura interna en los 19-20 días siguientes. La actividad general en los animales que recibieron una inyección de células MRMT-1 vivas o destruidas con calor fue mayor que en los animales de control, pero la actividad del grupo tratado con células MRMT-1 disminuyó al avanzar la enfermedad. En las ratas que recibieron inyecciones intratibiales de células MRMT-1 se produjo la aparición gradual de alodinia mécanica e hiperalgesia mecánica/disminución del peso apoyado en el miembro afectado, a partir de 12-14 ó 1012 días después de la inyección de 3 x 103 ó 3 x 104 células, respectivamente. Estos síntomas no se observaron en las ratas que recibieron células destruidas con calor o excipiente. Los datos sobre la conducta de los animales sugieren un intervalo razonable para la evaluación de los agentes antinociceptivos entre el día 14 y el día 20 después de la inoculación de las células cancerosas en este modelo. El tratamiento agudo con morfina (1-3 mg.kg- 1, por vía subcutánea (s.c.)) consiguió una disminución proporcional a la dosis de la frecuencia de respuesta de retirada de la pata trasera frente a estimulación con filamentos de von Fre y 17 ó 19 días después de la inyección de 3 x 103 células M R M T-1. Se observó también una reducción significativa de la diferencia en el peso apoyado en las patas traseras. El tratamiento agudo con celebrex (10-30 mg.kg- 1 s.c.) no influyó en la alodinia mecánica ni en el diferente peso apoyado en las patas traseras de las ratas 20 días después del tratamiento con 3 x 103 células MRMT- 1 .Aunque la fisiopatología del dolor oncológico no se conoce bien, el aumento significativo de la tinción con proteína acídica fibrilar glial (GFAP) en los correspondientes segmentos de la médula espinal ipsilateral sugiere una posible participación de los astrocitos. En resumen, la inducción de cáncer de huesos en la rata con la línea de células MRMT-1 singénicas de cáncer mamario constituye un modelo preclínico válido del dolor asociado a metástasis óseas. Al progresar el tumor en la cavidad de la médula ósea parece una marcada hiperalgesia mecánica y alodinia, aunque el estado general del animal sigue siendo satisfactorio. El tratamiento agudo con morfina tiene cierto efecto analgésico en el peso apoyado en las patas traseras, pero celebrex, un inhibidor selectivo de COX-2, no influye en los cambios de conducta relacionados con el dolor en este modelo. (AU)


Assuntos
Animais , Ratos , Dor/induzido quimicamente , Neoplasias Ósseas/induzido quimicamente , Dor/fisiopatologia , Dor/tratamento farmacológico , Sintomas Cancerínicos , Nociceptores , Hiperalgesia/induzido quimicamente , Densidade Óssea , Redução de Peso , Morfina/farmacologia , Neoplasias Ósseas/fisiopatologia
12.
J Sci Med Sport ; 5(1): 55-7, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12054387

RESUMO

This summary review is not, and should not be relied upon as, legal advice. It has been prepared at the request of the Journal of Science and Medicine in Sport as a discussion paper for the purposes of providing a background in the legal issues arising from the participation of pregnant women in sport. The discussion is necessarily pitched at a very general level, and without any specific circumstances in mind. Readers with particular concerns, or with specific issues to be addressed, should seek independent legal advice.


Assuntos
Gravidez/fisiologia , Medicina Esportiva/legislação & jurisprudência , Austrália , Ética Profissional , Feminino , Humanos , Responsabilidade Legal , Esportes/normas
13.
Pain ; 96(1-2): 129-40, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11932069

RESUMO

This study describes the first known model of bone cancer pain in the rat. Sprague-Dawley rats receiving intra-tibial injections of syngeneic MRMT-1 rat mammary gland carcinoma cells developed behavioural signs indicative of pain, including: mechanical allodynia, difference of weight bearing between hind paws and mechanical hyperalgesia. The development of the bone tumour and structural damage to the bone was monitored by radiological analysis, quantitative measurement of mineral content and histology. Intra-tibial injections of 3 x 10(3) or 3 x 10(4) syngeneic MRMT-1 cells produced a rapidly expanding tumour within the boundaries of the tibia, causing severe remodelling of the bone. Radiographs showed extensive damage to the cortical bone and the trabeculae by day 10-14 after inoculation of 3 x 10(3) MRMT-1 cells, and by day 20, the damage was threatening the integrity of the tibial bone. While both mineral content and mineral density decreased significantly in the cancerous bone, osteoclast numbers in the peritumoural compact bone remained unchanged. However, tartarate-resistant acid phosphatase staining revealed a large number of polykariotic cells, resembling those of osteoclasts within the tumour. No tumour growth was observed after the injection of heat-killed MRMT-1 cells. Intra-tibial injections of 3 x 10(3) or 3 x 10(4) MRMT-1 cells, heat-killed cells or vehicle did not show changes in body weight and core temperature over 19-20 days. The general activity of animals after injection with live or heat-killed MRMT-1 cells was higher than that of the control group, however, the activity of the MRMT-1 treated group declined during the progress of the disease. Rats receiving intra-tibial injections of MRMT-1 cells displayed the gradual development of mechanical allodynia and mechanical hyperalgesia/reduced weight bearing on the affected limb, beginning on day 12-14 or 10-12 following injection of 3 x 10(3) or 3 x 10(4) cells, respectively. These symptoms were not observed in rats receiving heat-killed cells or vehicle. Behavioural data suggest a reasonable time window for evaluation of anti-nociceptive agents between day 14 and 20 after cancer cell inoculation in this model. Acute treatment with morphine (1-3mg/kg, subcutanously (s.c.)) produced a dose-dependent reduction in the response frequency of hind paw withdrawal to von Frey filament stimulation 17 or 19 days following intra-tibial injections of 3 x 10(3) MRMT-1 cells. A significant reduction in the difference in hind limb weight bearing was also observed. Acute treatment with celebrex (10-30 mg/kg, s.c.) did not affect mechanical allodynia or difference in weight bearing in rats 20 days following treatment with 3 x 10(3) MRMT-1 cells. Although the pathophysiology of cancer pain is largely unknown, significant enhancement of glial fibrillary acidic protein (GFAP) staining in the corresponding segments of the ipsilateral spinal cord highlights the possible involvement of astrocytes. In summary, the induction of bone cancer in the rat by the syngeneic MRMT-1 mammary tumour cell line provides a valid pre-clinical model for pain associated with bone metastases. Significant mechanical hyperalgesia and allodynia develops in association with the progression of the tumour in the bone marrow cavity, while the general condition of the animal remains satisfactory. While acute treatment with morphine has some analgesic effect on hind limb sparing the selective COX-2 inhibitor, celebrex, has no influence on the pain-related behavioural changes in this model.


Assuntos
Neoplasias Ósseas/complicações , Modelos Animais de Doenças , Dor/fisiopatologia , Ratos Sprague-Dawley , Analgésicos Opioides/farmacologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Comportamento Animal , Temperatura Corporal , Peso Corporal , Densidade Óssea , Proteínas Morfogenéticas Ósseas/análise , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/patologia , Celecoxib , Feminino , Proteína Glial Fibrilar Ácida/análise , Neoplasias Mamárias Experimentais , Morfina/administração & dosagem , Transplante de Neoplasias , Osteoclastos/patologia , Dor/tratamento farmacológico , Dor/patologia , Estimulação Física , Pirazóis , Radiografia , Ratos , Medula Espinal/química , Sulfonamidas/farmacologia , Tíbia/química , Tíbia/diagnóstico por imagem , Tíbia/patologia , Suporte de Carga
14.
Med Res Rev ; 21(6): 499-512, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11607931

RESUMO

Protein kinases play a crucial role in signal transduction as well as in cellular proliferation, differentiation, and various regulatory mechanisms. The inhibition of growth related kinases, especially tyrosine kinases, might provide new therapies for diseases such as cancer. The progress made in the crystallization of protein kinases has confirmed that the ATP-binding domain of tyrosine kinases is an attractive target for drug design. Three successful examples of drug design at Novartis using a tyrosine kinase as a molecular target are described. PKI166, a pyrrolo[2,3,-d]pyrimidine derivative, is a dual inhibitor of both the EGFR and the ErbB2 kinases. The compound entered clinical trials in 1999, based on its favorable preclinical profile: potent inhibition of EGF-mediated signalling in cells, in vivo antitumor activity in several EGFR overexpressing xenograft tumor models in nude mice, long-lasting inhibition of EGF-stimulated EGFR autophosphorylation in tumor tissue, good oral bioavailability in animals, and no prohibitive in vitro and in vivo toxicity findings. The anilino-phthalazine derivative PTK787/ZK222584 (Phase I, co-developed by Schering AG, Berlin) is a potent and selective inhibitor of both the KDR and Flt-1 kinases with interesting anti-angiogenic and pharmacokinetic properties (orally bioavailable). STI571 (Glivec, Gleevec), a phenylamino-pyrimidine derivative, is a potent inhibitor of the Abl tyrosine kinase, which is present in 95% of patients with chronic myelogenous leukemia (CML). The compound specifically inhibits proliferation of v-Abl and Bcr-Abl expressing cells (including cells from CML patients) and shows anti-tumor activity as a single agent in animal models at well-tolerated doses. Pharmacologically relevant concentrations are achieved in the plasma of animals (oral administration). Promising data from phase I and II clinical trials in CML patients (98% haematological response rate in Phase I) support the fact that the STI571 represents a new treatment modality for CML. In addition, potent inhibition of the PDGFR and c-Kit tyrosine kinases also indicates its possible clinical use in solid tumors.


Assuntos
Antineoplásicos/química , Ensaios Clínicos como Assunto , Inibidores Enzimáticos/química , Neoplasias/tratamento farmacológico , Proteínas Tirosina Quinases/antagonistas & inibidores , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Humanos , Camundongos
15.
J Ultrasound Med ; 20(9): 959-66, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11549156

RESUMO

OBJECTIVE: To assess the use of intraoperative sonography for localization of breast masses at excisional biopsy, with specimen and surgical bed sonography to confirm excision. METHODS: A computer search of the 5-year period from January 1993 through January 1998 revealed 138 consecutive women referred for sonographically guided excisional biopsy of 148 masses; 35 masses were excluded because they had no postoperative mammograms. One hundred thirteen masses constituted the study group. Specimen sonography (n = 60) or surgical bed sonography (n = 53) was performed as the initial evaluation to confirm excision, but ultimately, surgical bed sonography may have been necessary after specimen sonography, and specimen sonography may have been necessary after surgical bed sonography. The miss rates determined by postoperative imaging were calculated for each group and compared with those of mammographically guided needle localization series from the literature. RESULTS: Follow-up physical examination and mammography showed no residual mass in the region of surgery in any patient. However, follow-up sonography had 1 miss in the initial specimen sonogram group (1 [1.7%] of 60) and 1 miss in the initial surgical bed group (1 [1.9%] of 53). As shown by the Fisher exact test, there was no significant difference between the miss rates of the 2 initial methods of confirming lesion excision or between the miss rates of these initial methods, both groups combined, and 6 mammographic localization series from the literature. CONCLUSION: Intraoperative breast sonography, using specimen sonography and scanning the surgical bed, has miss rates comparable with those of mammographic needle localization. Follow-up sonography must be performed if there is any doubt of complete excision.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Mama/patologia , Ultrassonografia Mamária , Adulto , Idoso , Biópsia por Agulha/métodos , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Feminino , Humanos , Cuidados Intraoperatórios , Mamografia , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos
16.
Nucl Med Commun ; 22(9): 1003-13, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11505210

RESUMO

INTRODUCTION: In the present study, (99m)Tc-radiolabelled E-selectin binding peptide ((99m)Tc-IMP-178) was investigated for its potential to image acute pyogenic osteomyelitis in a new animal model. Intraindividual comparisons were performed using an irrelevant peptide ((99m)Tc-IMP-100) to demonstrate specificity. METHODS: An acute pyogenic osteomyelitis was induced by injecting 0.05 ml of 5% sodium morrhuate and 5x10(8) CFU of Staphylococcus aureus into the medullary cavity of the right tibia in 16 rats. Sixteen additional rats served as untreated controls. Whole-body imaging of pyogenic (n=4) and untreated (n=4) animals was performed continuously during the first 8 h (12 MBq i.v. of (99m)Tc-IMP-178 and (99m)Tc-IMP-100 for control), and one further single image was acquired after 16 h p.i. Tissue biodistribution studies were performed in 12 rats with an acute pyogenic osteomyelitis and in 12 untreated rats 1, 4 and 24 h after injection. Data of the histological/radiological and haematological investigations were obtained in all animals. RESULTS: Histopathologically, 15 of 16 treated rats (93%) developed an acute pyogenic osteomyelitis showing a major infiltration of the bone marrow by polymorphonuclear leukocytes as well as the formation of sequestra. Haematologically, the number of leukocytes increased by 100%, the lymphocytes by 11% and the granulocytes decreased by 39%. After i.v. injection, (99m)Tc-IMP-178 rapidly cleared from the body resulting in good scintigraphic target-to-background (T/B) ratios. The highest uptake of the tracer in the pyogenic bone was observed at 60 min p.i. (0.43+/-0.02% ID.g-1 for (99m)Tc-IMP-178 and 0.30+/-0.02% ID.g-1 for (99m)Tc-IMP-100), resulting in a higher osteomyelitis-to-healthy collateral ratio with T/B of 2.40+/-0.65 ((99m)Tc-IMP-178) compared with 1.85+/-0.48 ((99m)Tc-IMP-100). No adverse reactions were seen after injection of (99m)Tc-IMP-178. CONCLUSIONS: (99m)Tc-IMP-178 allows imaging of an acute osteomyelitic lesions, presumably by interaction of (99m)Tc-IMP-178 with activated upregulated vascular endothelium.


Assuntos
Proteínas de Transporte/metabolismo , Selectina E/metabolismo , Osteomielite/diagnóstico por imagem , Tecnécio , Doença Aguda , Sequência de Aminoácidos , Animais , Modelos Animais de Doenças , Masculino , Dados de Sequência Molecular , Osteomielite/sangue , Osteomielite/patologia , Cintilografia , Ratos , Ratos Wistar , Distribuição Tecidual
17.
J Natl Cancer Inst ; 93(6): 436-46, 2001 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-11259469

RESUMO

BACKGROUND: Cyclin-dependent kinase 4 (Cdk4) represents a prime target for the treatment of cancer because most human cancers are characterized by overexpression of its activating partner cyclin D1, loss of the natural Cdk4-specific inhibitor p16, or mutation(s) in Cdk4's catalytic subunit. All of these can cause deregulated cell growth, resulting in tumor formation. We sought to identify a small molecule that could inhibit the kinase activity of Cdk4 in vitro and to then ascertain the effects of that inhibitor on cell growth and tumor volume in vivo. METHODS: A triaminopyrimidine derivative, CINK4 (a chemical inhibitor of Cdk4), was identified by screening for compounds that could inhibit Cdk4 enzyme activity in vitro. Kinase assays were performed on diverse human Cdks and on other kinases that were expressed in and purified from insect cells to determine the specificity of CINK4. Cell cycle effects of CINK4 on tumor and normal cells were studied by flow cytometry, and changes in phosphorylation of the retinoblastoma protein (pRb), a substrate of Cdk4, were determined by western blotting. The effect of the inhibitor on tumor growth in vivo was studied by use of tumors established through xenografts of HCT116 colon carcinoma cells in mice. Statistical tests were two-sided. RESULTS: CINK4 specifically inhibited Cdk4/cyclin D1 in vitro. It caused growth arrest in tumor cells and in normal cells and prevented pRb phosphorylation. CINK4 treatment resulted in statistically significantly (P: =.031) smaller mean tumor volumes in a mouse xenograft model. CONCLUSIONS: Like p16, the natural inhibitor of Cdk4, CINK4 inhibits Cdk4 activity in vitro and slows tumor growth in vivo. The specificity of CINK4 for Cdk4 raises the possibility that this small molecule or one with a similar structure could have therapeutic value.


Assuntos
Antineoplásicos/farmacologia , Neoplasias do Colo/tratamento farmacológico , Quinases Ciclina-Dependentes/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Genes do Retinoblastoma/efeitos dos fármacos , Osteossarcoma/tratamento farmacológico , Pirimidinas/farmacologia , Animais , Western Blotting , Neoplasias do Colo/enzimologia , Quinases Ciclina-Dependentes/metabolismo , Humanos , Camundongos , Osteossarcoma/enzimologia , Fosforilação/efeitos dos fármacos , Testes de Precipitina , Fase S/efeitos dos fármacos , Transplante Heterólogo , Células Tumorais Cultivadas
18.
Rapid Commun Mass Spectrom ; 15(1): 41-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11135423

RESUMO

Epothilone B is a 16-membered macrolide produced by the myxobacterium Sorangium cellulosum and is currently under clinical investigation. Experimentally, epothilone B demonstrates potent antiproliferative activity at the nanomolar level in vitro, and potent regression-producing antitumor activity in vivo, similar to paclitaxel (Taxol). In order to foster the design of improved derivatives, the potential biotransformation products of epothilone B formed in liver of tumor-bearing mice after intravenous administration of 10 mg/kg were characterized in an early stage of compound development. Solely on the basis of capillary high-performance liquid chromatography, combined either with electrospray tandem mass spectrometry (in precursor and product ion scan mode) and single analyzing time-of-flight mass spectrometry (H/D exchange and accurate mass measurement), three main metabolites could be detected. The three metabolites, formed by the liver, have in common that the epoxide ring was hydrolyzed and that the macrocyclic lactone ring was opened to the acid. In two cases it is assumed that open-chain intermediates re-cycled either to a lactone or, after conjugation with taurine, to the respective lactam. The proposed structures were additionally supported by the determination of the number of the exchangeable hydrogen atoms and by confirmation of the proposed elemental composition by exact mass measurement.


Assuntos
Antineoplásicos/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Epotilonas , Compostos de Epóxi/metabolismo , Espectrometria de Massas/métodos , Neoplasias Experimentais/metabolismo , Tiazóis/metabolismo , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Biotransformação , Compostos de Epóxi/química , Compostos de Epóxi/farmacocinética , Feminino , Humanos , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Tiazóis/química , Tiazóis/farmacocinética
19.
Cancer Res ; 60(18): 5143-50, 2000 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-11016641

RESUMO

Glioblastoma multiforme is the most common primary human brain tumor, and it is, for all practical purposes, incurable in adult patients. The high mortality rates reflect the fact that glioblastomas are resistant to adjuvant therapies (radiation and chemicals), the mode of action of which is cytotoxic. We show here that an p.o.-active small molecule kinase inhibitor of the 2-phenylaminopyrimidine class may have therapeutic potential for glioblastomas. STI571 inhibits the growth of U343 and U87 human glioblastoma cells that have been injected into the brains of nude mice, but it does not inhibit intracranial growth of ras-transformed cells. Studies on a broad panel of genetically validated human and animal cell lines show that STI571 acts by disruption of the ligand:receptor autocrine loops for platelet-derived growth factor that are a pervasive feature of malignant astrocytoma. The cellular response of glioblastoma cells to STI571 does not appear to involve an apoptotic mechanism.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Inibidores Enzimáticos/farmacologia , Glioblastoma/tratamento farmacológico , Piperazinas , Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Pirimidinas/farmacologia , Células 3T3 , Animais , Apoptose/efeitos dos fármacos , Benzamidas , Neoplasias Encefálicas/patologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Transformação Celular Viral , Relação Dose-Resposta a Droga , Glioblastoma/patologia , Inibidores do Crescimento/farmacologia , Células HeLa , Humanos , Mesilato de Imatinib , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias , Fator de Crescimento Derivado de Plaquetas/fisiologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Receptores do Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Receptores do Fator de Crescimento Derivado de Plaquetas/biossíntese , Receptores do Fator de Crescimento Derivado de Plaquetas/fisiologia , Células Tumorais Cultivadas
20.
Infect Immun ; 68(10): 5756-63, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10992482

RESUMO

Interleukin-8 (IL-8) is elevated in the cerebrospinal fluid (CSF) of patients with meningitis and is proposed to participate in subarachnoid-space pleocytosis. However, intracisternal injection of IL-8 into rabbits failed to induce indices typical of meningitis (leukocyte, tumor necrosis factor, or protein accumulation in the CSF or histopathological changes), indicating that merely increasing the CSF level of this chemokine is insufficient to induce inflammation in this anatomical site. IL-8 treatment did not affect inflammatory responses to subsequently intracisternally administered lipopolysaccharide (LPS). IL-8 was chemotactic for rabbit neutrophils in vitro, and subcutaneous injection of IL-8 (diluted in buffer or CSF) proved the in vivo activity of this peptide and suggested the absence of an IL-8 inhibitor in normal rabbit CSF. LPS-dependent pleocytosis was only slightly diminished by intracisternally administered murine anti-rabbit IL-8 monoclonal antibody (MAb) WS-4 but was dramatically reduced by intravenously administered MAb. Therefore, elevated CSF IL-8 levels may contribute to, but cannot solely account for, neutrophil influx into the subarachnoid space during meningitis. However, inhibition of IL-8 activity of the bloodstream side of the blood-brain barrier effectively reduces pleocytosis, indicating a central role of IL-8 in neutrophil influx into CSF during bacterial meningitis. Thus, inhibition of IL-8 is a possible therapeutic target for adjunct treatment of meningitis.


Assuntos
Interleucina-8/imunologia , Leucocitose/imunologia , Lipopolissacarídeos/imunologia , Meningites Bacterianas/imunologia , Neutrófilos/imunologia , Animais , Anticorpos Monoclonais/imunologia , Quimiotaxia de Leucócito , Humanos , Interleucina-8/administração & dosagem , Interleucina-8/sangue , Interleucina-8/líquido cefalorraquidiano , Testes de Neutralização , Coelhos
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