Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Anal Bioanal Chem ; 416(2): 323-327, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37996618

RESUMO

Most coagulation tests are photo-optical turbidimetric assays that require the removal of cellular components from whole blood for optical clearing. If the resulting blood plasma samples are hemolyzed, they may become unsuitable for turbidimetric analysis. To resolve this issue, whole-blood analogs to plasma turbidimetric assays need to be developed. Using samples collected from non-smokers (normal group), smokers (thrombotic group), and hemophilia A (bleeding group) patients, we demonstrate that the reaction time assessed from whole blood viscosity data of the drop-of-blood acoustic tweezing spectroscopy (ATS) technique strongly correlates (Rp ≥ 0.95) with PT/aPTT values obtained from plasma turbidimetric data. Linear correlation (Rp ≥ 0.88) was also obtained between the viscous and elastic outputs of the ATS technique and the fibrinogen concentration. The integration of ATS data enabled the assessment of the functional level of fibrin cross-linkers such as factor XIII. Overall, ATS allows comprehensive sample-sparing analysis of whole blood coagulation for reliable and safe diagnosis of bleeding/thrombosis risks.


Assuntos
Acústica , Fibrinogênio , Humanos , Tempo de Protrombina , Tempo de Tromboplastina Parcial , Testes de Coagulação Sanguínea , Fibrinogênio/análise , Análise Espectral
2.
Anal Bioanal Chem ; 413(12): 3369-3379, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33796930

RESUMO

Many patients develop coagulation abnormalities due to chronic and hereditary disorders, infectious disease, blood loss, extracorporeal circulation, and oral anticoagulant misuse. These abnormalities lead to bleeding or thrombotic complications, the risk of which is assessed by coagulation analysis. Current coagulation tests pose safety concerns for neonates and small children due to large sample volume requirement and may be unreliable for patients with coagulopathy. This study introduces a containerless drop-of-blood method for coagulation analysis, termed "integrated quasi-static acoustic tweezing thromboelastometry" (i-QATT™), that addresses these needs. In i-QATT™, a single drop of blood is forced to levitate and deform by the acoustic radiation force. Coagulation-induced changes in drop turbidity and firmness are measured simultaneously at different instants. The parameters describing early, intermediate, and late stages of the coagulation process are evaluated from the resulting graphical outputs. i-QATT™ rapidly (<10 min) detected hyper- and hypo-coagulable states and identified single deficiency in coagulation factors VII, VIII, IX, X, and XIII. The linear relationship (r2 > 0.9) was established between fibrinogen concentration and two i-QATT™ parameters: maximum clot firmness and maximum fibrin level. Factor XIII activity was uniquely measured by the fibrin network formation time (r2 = 0.9). Reaction time, fibrin formation rate, and time to firm clot formation were linearly correlated with heparin concentration (r2 > 0.7). tPA-induced hyperfibrinolysis was detected in the clot firmness output at 10 min. i-QATT™ provides comprehensive coagulation analysis in point-of-care or laboratory settings, well suited to the needs of neonatal and pediatric patients and adult patients with anemia or blood collection issues.


Assuntos
Coagulação Sanguínea , Nefelometria e Turbidimetria/métodos , Tromboelastografia/métodos , Anticoagulantes/uso terapêutico , Monitoramento de Medicamentos , Estudos de Viabilidade , Humanos
3.
Sci Rep ; 9(1): 19538, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31862927

RESUMO

Hepatocellular carcinoma (HCC) is a highly fatal disease recognized as a growing global health crisis worldwide. Currently, no curative treatment is available for early-to-intermediate stage HCC, characterized by large and/or multifocal tumors. If left untreated, HCC rapidly progresses to a lethal stage due to favorable conditions for metastatic spread. Mechanochemical disruption of cellular structures can potentially induce phenotypic alterations in surviving tumor cells that prevent HCC progression. In this paper, HCC response to mechanical vibration via high-intensity focused ultrasound and a chemical disruptive agent (ethanol) was examined in vitro and in vivo. Our analysis revealed that mechanochemical disruption caused a significant overproduction of reactive oxygen species (ROS) in multiple HCC cell lines (HepG2, PLC/PRF/5, and Hep3B). This led to a decrease in cell viability and long-term proliferation due to increased expression and activity of death receptors TNFR1 and Fas. The cells that survived mechanochemical disruption had a reduced expression of cancer stem cell markers (CD133, CD90, CD49f) and a diminished colony-forming ability. Mechanochemical disruption also impeded HCC migration and their adhesion to vascular endothelium, two critical processes in hematogenous metastasis. The HCC transformation to a non-tumorigenic phenotype post mechanochemical disruption was confirmed by a lack of tumor spheroid formation in vitro and complete tumor regression in vivo. These results show that mechanochemical disruption inhibits uncontrolled proliferation and reduces tumorigenicity and aggressiveness of HCC cells through ROS overproduction and associated activation of TNF- and Fas-mediated cell death signaling. Our study identifies a novel curative therapeutic approach that can prevent the development of aggressive HCC phenotypes.


Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Antígeno AC133/metabolismo , Animais , Apoptose/genética , Apoptose/fisiologia , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Proliferação de Células/fisiologia , Sobrevivência Celular/fisiologia , Feminino , Células Hep G2 , Células Endoteliais da Veia Umbilical Humana , Humanos , Integrina alfa6/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Células-Tronco Neoplásicas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Antígenos Thy-1/metabolismo , Receptor fas/metabolismo
4.
Mol Cancer Res ; 17(5): 1087-1101, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30617107

RESUMO

Chemical-based medicine that targets specific oncogenes or proteins often leads to cancer recurrence due to tumor heterogeneity and development of chemoresistance. This challenge can be overcome by mechanochemical disruption of cancer cells via focused ultrasound (FUS) and sensitizing chemical agents such as ethanol. We demonstrate that this disruptive therapy decreases the viability, proliferation rate, tumorigenicity, endothelial adhesion, and migratory ability of prostate cancer cells in vitro. It sensitized the cells to TNFR1-- and Fas--mediated apoptosis and reduced the expression of metastatic markers CD44 and CD29. Using a prostate cancer xenograft model, we observed that the mechanochemical disruption led to complete tumor regression in vivo. This switch to a nonaggressive cell phenotype was caused by ROS and Hsp70 overproduction and subsequent impairment of NFκB signaling. FUS induces mechanical perturbations of diverse cancer cell populations, and its combination with agents that amplify and guide remedial cellular responses can stop lethal cancer progression. IMPLICATIONS: Mechanochemical disruption therapy in which FUS is combined with ethanol can be curative for locally aggressive and castration-resistant prostate cancer.


Assuntos
Etanol/administração & dosagem , Neoplasias de Próstata Resistentes à Castração/terapia , Espécies Reativas de Oxigênio/metabolismo , Ultrassonografia/efeitos adversos , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Etanol/farmacologia , Proteínas de Choque Térmico HSP70/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Células PC-3 , Fenótipo , Neoplasias de Próstata Resistentes à Castração/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estresse Mecânico , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Ultrasound Med Biol ; 40(9): 2107-12, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24972500

RESUMO

Application of focused ultrasound stimulation (FUS) to the rat cervix during pregnancy has significant physiologic effects. One-millisecond-long pulses of 680-kHz ultrasound with a repetition frequency of 25 Hz, at ISPTA (spatial-peak, temporal-average intensity) of 1, 2 and 4W/cm(2), were applied to the rat abdomen over the cervix. FUS produced a significant change in cervical elasticity known as softening, which is part of the ripening process, comparable to the degree seen just before delivery. Timed-pregnant Sprague-Dawley rats (n = 40) were used. During gestation, the FUS system was applied to the cervix for variable times up to 1 h. Daily measurements of cervix light-induced florescence were made to estimate changes in softening. In addition, cervical stretch estimates of softening were made of isolated cervices of control and FUS-treated rats to measure distensiblity. The ultrasound power with ISPPA (spatial-peak, pulse-average intensity) of 40 W/cm(2) was considered tolerable; the U.S. Food and Drug Administration regulatory limit is 190 W/cm(2) for both the body periphery and the fetus. This is the first report of alterations induced by ultrasound in the connective tissue of the cervix and suggests the therapeutic application of ultrasound for the facilitation of labor and delivery.


Assuntos
Colo do Útero/diagnóstico por imagem , Terapia por Ultrassom/métodos , Animais , Elasticidade , Feminino , Modelos Animais , Gravidez , Ratos Sprague-Dawley , Ultrassonografia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...