Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Ann Biomed Eng ; 52(6): 1678-1692, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38532173

RESUMO

We developed the open-source bIUreactor research platform for studying 3D structured tissues. The versatile and modular platform allows a researcher to generate 3D tissues, culture them with oxygenated perfusion, and provide cyclic loading, all in their own lab (in laboratorium) for an all in cost of $8,000 including 3D printer, printing resin, and electronics. We achieved this by applying a design philosophy that leverages 3D printing, open-source software and hardware, and practical techniques to produce the following: 1. perfusible 3D tissues, 2. a bioreactor chamber for tissue culture, 3. a module for applying cyclic compression, 4. a peristaltic pump for providing oxygenated perfusion to 3D tissues, 5. motor control units, and 6. open-source code for running the control units. By making it widely available for researchers to investigate 3D tissue models and easy for them to use, we intend for the bIUreactor to democratize 3D tissue research, therefore increasing the pace and scale of biomedical research discoveries using 3D tissue models.


Assuntos
Reatores Biológicos , Impressão Tridimensional , Humanos , Engenharia Tecidual/métodos , Software , Animais
2.
MAGMA ; 31(2): 309-320, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28894997

RESUMO

OBJECTIVE: To develop a novel framework for evaluating the accuracy of quantitative analysis on dynamic contrast-enhanced (DCE) MRI with a specific combination of imaging technique, scanning parameters, and scanner and software performance and to test this framework with breast DCE MRI with Time-resolved angiography WIth Stochastic Trajectories (TWIST). MATERIALS AND METHODS: Realistic breast tumor phantoms were 3D printed as cavities and filled with solutions of MR contrast agent. Full k-space raw data of individual tumor phantoms and a uniform background phantom were acquired. DCE raw data were simulated by sorting the raw data according to TWIST view order and scaling the raw data according to the enhancement based on pharmaco-kinetic (PK) models. The measured spatial and temporal characteristics from the images reconstructed using the scanner software were compared with the original PK model (ground truth). RESULTS: Images could be reconstructed using the manufacturer's platform with the modified 'raw data.' Compared with the 'ground truth,' the RMS error in all images was <10% in most cases. With increasing view-sharing acceleration, the error of the initial uptake slope decreased while the error of peak enhancement increased. Deviations of PK parameters varied with the type of enhancement. CONCLUSION: A new framework has been developed and tested to more realistically evaluate the quantitative measurement errors caused by a combination of the imaging technique, parameters and scanner and software performance in DCE-MRI.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Mama/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , Aceleração , Algoritmos , Simulação por Computador , Meios de Contraste/química , Feminino , Humanos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Modelos Estatísticos , Tamanho da Partícula , Imagens de Fantasmas , Reprodutibilidade dos Testes , Software , Processos Estocásticos
3.
Int J Hyperthermia ; 26(1): 79-90, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20100055

RESUMO

A magnetic resonance (MR) technique is developed to produce controlled radio-frequency (RF) hyperthermia (HT) in subcutaneously-implanted 9L-gliosarcoma in Fisher rats using an MR scanner and its components; the scanner is also simultaneously used to monitor the tumour temperature and the metabolic response of the tumour to the therapy. The method uses the (1)H chemical shift of thulium 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetra-acetic acid (TmDOTA(-)) to monitor temperature. The desired HT temperature is achieved and maintained using a feedback loop mechanism that uses a proportional-integral-derivative controller. The RF HT technique was able to heat the tumour from 33 degrees to 45 degrees C in approximately 10 min and was able to maintain the tumour temperature within +/-0.2 degrees C of the target temperature (45 degrees C). Simultaneous monitoring of the metabolic changes with RF HT showed increases in total tissue and intracellular Na(+) as measured by single-quantum and triple-quantum filtered (23)Na MR spectroscopy (MRS), respectively, and decreases in intra- and extracellular pH and cellular bioenergetics as measured by (31)P MRS. Monitoring of metabolic response in addition to the tumour temperature measurements may serve as a more reliable and early indicator of therapy response. In addition, such measurements during HT treatment will enhance our understanding of the tumour response mechanisms during HT, which may prove valuable in designing methods to improve therapeutic efficiency.


Assuntos
Gliossarcoma/terapia , Hipertermia Induzida/métodos , Espectroscopia de Ressonância Magnética/métodos , Ondas de Rádio , Animais , Temperatura Corporal , Masculino , Transplante de Neoplasias , Compostos Organometálicos , Fósforo/metabolismo , Ratos , Ratos Endogâmicos F344 , Sódio/metabolismo
4.
ILAR J ; 49(1): 54-65, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18172333

RESUMO

Positron emission tomography (PET) is well established as an important research and clinical molecular imaging modality. Although the size differences between humans and rodents create formidable challenges for the application of PET imaging in small animals, advances in technology over the past several years have enabled the translation of this imaging modality to preclinical applications. In this article we discuss the basic principles of PET instrumentation and radiopharmaceuticals, and examine the key factors responsible for the qualitative and quantitative imaging capabilities of small animal PET systems. We describe the criteria that PET imaging agents must meet, and provide examples of small animal PET imaging to give the reader a broad perspective on the capabilities and limitations of this evolving technology. A crucial driver for future advances in PET imaging is the availability of molecular imaging probes labeled with positron-emitting radionuclides. The strong translational science potential of small animal and human PET holds great promise to dramatically advance our understanding of human disease. The assessment of molecular and functional processes using imaging agents as either direct or surrogate biomarkers will ultimately enable the characterization of disease expression in individual patients and thus facilitate tailored treatment plans that can be monitored for their effectiveness in each subject.


Assuntos
Modelos Animais , Tomografia por Emissão de Pósitrons/métodos , Animais , Humanos , Modelos Teóricos , Tomografia por Emissão de Pósitrons/instrumentação , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...