Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 202
Filtrar
1.
J Am Coll Radiol ; 16(11): 1516-1521, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31585696

RESUMO

This is a condensed summary of an international multisociety statement on ethics of artificial intelligence (AI) in radiology produced by the ACR, European Society of Radiology, RSNA, Society for Imaging Informatics in Medicine, European Society of Medical Imaging Informatics, Canadian Association of Radiologists, and American Association of Physicists in Medicine. AI has great potential to increase efficiency and accuracy throughout radiology, but it also carries inherent pitfalls and biases. Widespread use of AI-based intelligent and autonomous systems in radiology can increase the risk of systemic errors with high consequence and highlights complex ethical and societal issues. Currently, there is little experience using AI for patient care in diverse clinical settings. Extensive research is needed to understand how to best deploy AI in clinical practice. This statement highlights our consensus that ethical use of AI in radiology should promote well-being, minimize harm, and ensure that the benefits and harms are distributed among stakeholders in a just manner. We believe AI should respect human rights and freedoms, including dignity and privacy. It should be designed for maximum transparency and dependability. Ultimate responsibility and accountability for AI remains with its human designers and operators for the foreseeable future. The radiology community should start now to develop codes of ethics and practice for AI that promote any use that helps patients and the common good and should block use of radiology data and algorithms for financial gain without those two attributes.

2.
Can Assoc Radiol J ; 70(4): 329-334, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31585825

RESUMO

This is a condensed summary of an international multisociety statement on ethics of artificial intelligence (AI) in radiology produced by the ACR, European Society of Radiology, RSNA, Society for Imaging Informatics in Medicine, European Society of Medical Imaging Informatics, Canadian Association of Radiologists, and American Association of Physicists in Medicine. AI has great potential to increase efficiency and accuracy throughout radiology, but it also carries inherent pitfalls and biases. Widespread use of AI-based intelligent and autonomous systems in radiology can increase the risk of systemic errors with high consequence and highlights complex ethical and societal issues. Currently, there is little experience using AI for patient care in diverse clinical settings. Extensive research is needed to understand how to best deploy AI in clinical practice. This statement highlights our consensus that ethical use of AI in radiology should promote well-being, minimize harm, and ensure that the benefits and harms are distributed among stakeholders in a just manner. We believe AI should respect human rights and freedoms, including dignity and privacy. It should be designed for maximum transparency and dependability. Ultimate responsibility and accountability for AI remains with its human designers and operators for the foreseeable future. The radiology community should start now to develop codes of ethics and practice for AI that promote any use that helps patients and the common good and should block use of radiology data and algorithms for financial gain without those two attributes.


Assuntos
Inteligência Artificial/ética , Radiologia/ética , Canadá , Consenso , Europa (Continente) , Humanos , Radiologistas/ética , Sociedades Médicas , Estados Unidos
3.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(5): 1641-1648, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31607326

RESUMO

OBJECTIVE: To explore the causes and specific conditions of blood donation reaction under the collective emergency unpaid blood donation, and to provide theoretical basis and decision-making reference for drafting the collective emergency unpaid blood donation and blood donation safety. METHODS: Through a combination of prospective and retrospective models, and statistical methods were used to analyze the causes and conditions of the blood donation response of 10401 people participating in collective emergency unpaid blood donation during 2016.1-2018.8. RESULTS: A total of 10401 person-times donated blood in a sitting manner, and a total of 293 blood donation reactions occurred. By improving the blood donation services year by year, the moderate blood donation reaction during the year 2017 and 2018 was significantly lower than that in 2016 (P<0.05). In the actual blood donation group of≤100, 200, 300 and 400 ml, the incidence of blood donation reaction was statistically significant (P<0.05); the incidence of blood donation reaction in the blood donors for 1,2,3 and >3 drnations was also statistically significant (P<0.05); the blood donation reactions rate of B antigen containers was significantly different from the donors without B antigen (P<0.05); the incidence of blood donation reaction with related to the weight of the donor. CONCLUSION: The blood donation reaction of collective emergency unpaid blood donation closely relates with mental factors, blood donation service, blood donation frequency and body weight of the blood donor. The first blood donation is more likely to produce blood donation reaction. The blood donation volum≤ 100 ml from blood donors is resulted mostly from blood donation reactions.


Assuntos
Doadores de Sangue , Antígenos de Grupos Sanguíneos , Humanos , Estudos Prospectivos , Estudos Retrospectivos
4.
Insights Imaging ; 10(1): 101, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31571015

RESUMO

This is a condensed summary of an international multisociety statement on ethics of artificial intelligence (AI) in radiology produced by the ACR, European Society of Radiology, RSNA, Society for Imaging Informatics in Medicine, European Society of Medical Imaging Informatics, Canadian Association of Radiologists, and American Association of Physicists in Medicine.AI has great potential to increase efficiency and accuracy throughout radiology, but also carries inherent pitfalls and biases. Widespread use of AI-based intelligent and autonomous systems in radiology can increase the risk of systemic errors with high consequence, and highlights complex ethical and societal issues. Currently, there is little experience using AI for patient care in diverse clinical settings. Extensive research is needed to understand how to best deploy AI in clinical practice.This statement highlights our consensus that ethical use of AI in radiology should promote well-being, minimize harm, and ensure that the benefits and harms are distributed among stakeholders in a just manner. We believe AI should respect human rights and freedoms, including dignity and privacy. It should be designed for maximum transparency and dependability. Ultimate responsibility and accountability for AI remains with its human designers and operators for the foreseeable future.The radiology community should start now to develop codes of ethics and practice for AI which promote any use that helps patients and the common good and should block use of radiology data and algorithms for financial gain without those two attributes.

5.
ACS Appl Mater Interfaces ; 11(43): 39624-39632, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31573175

RESUMO

To advance anti-tumor efficiency and lessen the adverse effect caused by nanodrug residues in the body, a smart nanoagent system is developed and successfully used in intracellular ATP imaging and in vivo chemo-photothermal synergetic therapy. The nanoagent system is facilely prepared using a DNA complex to modify gold nanoparticles (AuNPs). The DNA complex is formed by three oligonucleotides (ATP aptamer, rC-DNA, and rG-DNA). The CG-rich structure in a ternary DNA complex could be exploited for payload of chemotherapeutic medicine doxorubicin (DOX), thus making efficient DOX transport into the tumor site possible. In tumor cells, especially in acidic organelles (e.g., endosome and lysosome), DOX could be rapidly released via the dual stimuli of overexpressed ATP and pH. What is more, the specific recognition of a fluorescently labeled aptamer strand to ATP can achieve the intracellular ATP imaging. pH-controlled reversible folding and unfolding of intermolecular i-motif formed by C-rich strands can lead to intracellular in situ assembly of AuNP aggregates with high photothermal conversion efficiency and promote relatively facile renal clearance of AuNPs through the disassociation of the aggregates in extracellular environments. Experiments in vivo and vitro present feasibility for a synergetic chemo-photothermal therapy. Such an in situ reversible assembly strategy of a chemo-photothermal agent also presents a new paradigm for a smart and highly efficient disease treatment with reduced side effects.

6.
Radiology ; 293(2): 436-440, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31573399

RESUMO

This is a condensed summary of an international multisociety statement on ethics of artificial intelligence (AI) in radiology produced by the ACR, European Society of Radiology, RSNA, Society for Imaging Informatics in Medicine, European Society of Medical Imaging Informatics, Canadian Association of Radiologists, and American Association of Physicists in Medicine. AI has great potential to increase efficiency and accuracy throughout radiology, but it also carries inherent pitfalls and biases. Widespread use of AI-based intelligent and autonomous systems in radiology can increase the risk of systemic errors with high consequence and highlights complex ethical and societal issues. Currently, there is little experience using AI for patient care in diverse clinical settings. Extensive research is needed to understand how to best deploy AI in clinical practice. This statement highlights our consensus that ethical use of AI in radiology should promote well-being, minimize harm, and ensure that the benefits and harms are distributed among stakeholders in a just manner. We believe AI should respect human rights and freedoms, including dignity and privacy. It should be designed for maximum transparency and dependability. Ultimate responsibility and accountability for AI remains with its human designers and operators for the foreseeable future. The radiology community should start now to develop codes of ethics and practice for AI that promote any use that helps patients and the common good and should block use of radiology data and algorithms for financial gain without those two attributes. This article is a simultaneous joint publication in Radiology, Journal of the American College of Radiology, Canadian Association of Radiologists Journal, and Insights into Imaging. Published under a CC BY-NC-ND 4.0 license. Online supplemental material is available for this article.

7.
J Magn Reson Imaging ; 2019 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-31605412

RESUMO

BACKGROUND: MR elastography is a noninvasive technique that provides high diagnostic accuracy for the staging of liver fibrosis; however, it requires external hardware and mainly assesses the right lobe. PURPOSE: To evaluate the diagnostic performance of MRI cine-tagging for staging fibrosis in the left liver lobe, using biopsy as the reference standard. STUDY TYPE: Institutional Review Board (IRB)-approved two-center prospective study. POPULATION: Seventy-six patients with chronic liver disease who underwent an MRI cine-tagging examination and a liver biopsy within a 6-week interval. FIELD STRENGTH/SEQUENCE: 2D-GRE multislice sequence at 3.0T with spatial modulation of the magnetization preparation sequence and peripheral pulse-wave triggering on two coronal slices chosen underneath the heart apex to capture maximal deformation with consecutive breath-holds adapted to patient cardiac frequency. ASSESSMENT: A region of interest was selected in the liver close to the heart apex. Maximal strain was evaluated with the harmonic phase (HARP) technique. STATISTICAL TESTS: Spearman's correlation, Kruskal-Wallis test, Mann-Whitney U-test, and receiver operating characteristic (ROC) analysis were performed. RESULTS: Liver strain measured on tagged images decreased with higher histological fibrosis stage (ρ = -0.68, P < 0.0001). Strain values were significantly different between all fibrosis stages (P < 0.0001), and between groups of fibrosis stages ≤F3 vs. F4 (P < 0.05). Areas under the ROC curves were 0.95 (95% confidence interval: 0.89-1.00) to distinguish fibrosis stages F0 vs. F4, 0.81 (0.70-0.92) for stages F0 vs. ≥F1, 0.84 (0.76-0.93) for stages ≤F1 vs. ≥F2, 0.86 (0.78-0.94) for stages ≤F2 vs. ≥F3, and 0.87 (0.77-0.96) for stages ≤F3 vs. F4. DATA CONCLUSION: MRI cine-tagging is a promising technique for measuring liver strain without additional elastography hardware. It could be used to assess the left liver lobe as a complement to current techniques assessing the right lobe. LEVEL OF EVIDENCE: 1 Technical Efficacy: 3 J. Magn. Reson. Imaging 2019.

8.
Biosens Bioelectron ; 145: 111700, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31539651

RESUMO

DNA methyltransferase (MTase) and polynucleotide kinase (PNK) are both DNA-dependent enzymes that play important roles in DNA methylation and DNA repair processes, respectively. Dysregulation of their activities is associated with various human diseases. Herein, we present a specific and sensitive biosensing strategy, named terminal deoxynucleotidyl transferase (TdT)-activated nicking enzyme amplification reaction (TdT-NEAR), for their activity detection. As for MTase detection, an enclosed dumbbell-shaped oligonucleotide substrate, whose symmetric stem containing a recognition site of Dam MTase and an incomplete recognition sequence of nicking endonuclease Nt.BbvCI, was used. Typically, the substrate is methylated by Dam MTase and subsequently cleaved by Dpn I. In the presence of TdT and dGTP, poly(guanine, G) sequences are extended from the released 3'-OH ends, achieving the conversion of the incomplete Nt.BbvCI recognition sequence to an intact one. The extension products can then be used to trigger Nt.BbvCI-catalyzed cyclic cleavage of fluorophore/quencher-labelled oligonucleotide probe, giving a significantly enhanced fluorescence output. Such a sensing system can achieve sensitive and specific detection of Dam MTase with a detection limit of 0.002 U/mL. The unique working mechanism endows the sensing system with improved anti-interference capability and thus increased application potential in complex biological samples. Moreover, it was also demonstrated to work well for Dam MTase inhibitor screening and inhibitory activity evaluation, thus holding great potential in disease diagnosis and drug discovery. Using a simpler 3'-phosphorylated linear substrate and the same fluorescent probe, the TdT-NEAR strategy can be easily extended to the activity analysis of PNK, thus revealing wide application potential in bioanalysis.

9.
Anal Chem ; 91(20): 13165-13173, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31512479

RESUMO

The introduction of nanotechnology can overcome some inherent drawbacks of traditional DNA probes, thus promoting their applications in living cells. Herein, a three-dimensional DNA nanostructure, a DNA nanolantern, was prepared via simple nucleotide hybridization of four short-stranded oligonucleotides and successfully applied to the construction of a novel DNA probe and signal amplifier. Compared to most reported DNA nanostructures, a DNA nanolantern shows the distinct advantages of low cost, easy design and preparation, more and arbitrary adjusted probe numbers, and high fluorescence resonance energy transfer (FRET) signal readout. Compared to traditional DNA probes, the constructed nanolantern-based one has improved cell internalization efficiency, enhanced biostability, accelerated reaction kinetics, excellent biocompatibility, and greatly reduced false-positive output and was demonstrated to work well for probing the expression level of tumor-related mRNA and microRNA in living cells. The DNA nanolantern can also be easily integrated with some reported signal amplification strategies, e.g., isothermal hybridization chain reaction (HCR), and the obtained signal amplifier combines the advantages of the DNA nanolantern and the HCR, enabling sensitive imaging detection of ultralow abundance targets in living cells. This work demonstrated that this simple DNA nanostructure can not only improve the performance of traditional DNA probes but can also be easily integrated with reported DNA-based strategy and technology, thus showing a broad application prospect.

10.
Eur J Radiol ; 120: 108689, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31563835

RESUMO

PURPOSE: To investigate the clinical implications and natural history of observations showing a "nodule-in-nodule" architecture on hepatobiliary phase (HBP) in a cirrhotic population. METHOD: This is an IRB-approved retrospective study conducted in a single institution. We identified 20 patients (11 men and 9 women, mean age 71 years, range 51-83 years) who had a hyperintense nodule on HBP arising within a larger HBP-hypointense nodule without arterial phase hyperenhancement (APHE) at gadoxetate disodium-enhanced MRI. Size and signal intensity of the nodules were evaluated in all sequences, along with the evolution of the nodules at serial MRI studies. RESULTS: Twenty-four nodules were analyzed in 20 patients. Mean diameter of the inner hyperintense nodule on HBP was 1.1 cm (range 0.6-1.8 cm) and that of the outer hypovascular hypointense nodule was 2.1 cm (range 1.2-4.1 cm). All intranodular foci were hyperintense on HBP and showed a typical pattern for hepatocellular carcinoma (HCC) with APHE and washout on portal venous phase (PVP) (n = 11, 46%), washout only (n = 7, 29%) or APHE with no washout (n = 6, 25%). The hyperintensity on 3-, 5- and 10-minute phases was seen in 21%, 58% and 83% of the nodules, respectively. In twelve out of sixteen (75%) nodules with subsequent imaging available the hyperintensity on HBP occurred before either the appearance of APHE or washout on PVP. CONCLUSIONS: HBP-hypointense nodules without APHE may contain a hyperintense smaller nodule-in-nodule on HBP that can precede the appearance of either APHE or washout on PVP.

11.
Eur Radiol ; 29(12): 6477-6488, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31278577

RESUMO

OBJECTIVES: To perform head-to-head comparisons of the feasibility and diagnostic performance of transient elastography (TE), point shear-wave elastography (pSWE), and magnetic resonance elastography (MRE). METHODS: This prospective, cross-sectional, dual-center imaging study included 100 patients with known or suspected chronic liver disease caused by hepatitis B or C virus, nonalcoholic fatty liver disease, or autoimmune hepatitis identified between 2014 and 2018. Liver stiffness measured with the three elastographic techniques was obtained within 6 weeks of a liver biopsy. Confounding effects of inflammation and steatosis on association between fibrosis and liver stiffness were assessed. Obuchowski scores and AUCs for staging fibrosis were evaluated and the latter were compared using the DeLong method. RESULTS: TE, pSWE, and MRE were technically feasible and reliable in 92%, 79%, and 91% subjects, respectively. At univariate analysis, liver stiffness measured by all techniques increased with fibrosis stages and inflammation and decreased with steatosis. For classification of dichotomized fibrosis stages, the AUCs were significantly higher for distinguishing stages F0 vs. ≥ F1 with MRE than with TE (0.88 vs. 0.71; p < 0.05) or pSWE (0.88 vs. 0.73; p < 0.05), and for distinguishing stages ≤ F1 vs. ≥ F2 with MRE than with TE (0.85 vs. 0.75; p < 0.05). TE, pSWE, and MRE Obuchowski scores for staging fibrosis stages were respectively 0.89 (95% CI 0.85-0.93), 0.90 (95% CI 0.85-0.94), and 0.94 (95% CI 0.91-0.96). CONCLUSION: MRE provided a higher diagnostic performance than TE and pSWE for staging early stages of liver fibrosis. TRIAL REGISTRATION: NCT02044523 KEY POINTS: • The technical failure rate was similar between MRE and US-based elastography techniques. • Liver stiffness measured by MRE and US-based elastography techniques increased with fibrosis stages and inflammation and decreased with steatosis. • MRE provided a diagnostic accuracy higher than US-based elastography techniques for staging of early stages of histology-determined liver fibrosis.

12.
Chem Commun (Camb) ; 55(53): 7611-7614, 2019 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-31192323

RESUMO

We applied a modified exponential amplification reaction (EXPAR) strategy to design a label-free and "one-pot" biosensor for ultrasensitive detection of polynucleotide kinase (PNK). This method was also successfully applied in the screening of PNK inhibitors and analysis of the endogenous PNK activity at the single-cell level.


Assuntos
Técnicas Biossensoriais , Técnicas de Amplificação de Ácido Nucleico , Polinucleotídeo 5'-Hidroxiquinase/análise , Razão Sinal-Ruído , Células HeLa , Humanos , Polinucleotídeo 5'-Hidroxiquinase/metabolismo , Espectrometria de Fluorescência
13.
Chem Commun (Camb) ; 55(53): 7603-7606, 2019 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-31199419

RESUMO

A biosensor with all the advantages of ultra-high sensitivity, easy operation, straightforward signal output and universal applicability is introduced. The biosensor was demonstrated to work well in the detection of polynucleotide kinase and DAM methyltransferase, thus providing a powerful tool for clinical diagnosis, drug screening and disease therapeutic assay.


Assuntos
Técnicas Biossensoriais , DNA/química , Técnicas de Amplificação de Ácido Nucleico , Polinucleotídeo 5'-Hidroxiquinase/análise , DNA Metiltransferases Sítio Específica (Adenina-Específica)/análise , Temperatura Ambiente , Células HeLa , Humanos , Polinucleotídeo 5'-Hidroxiquinase/genética , Polinucleotídeo 5'-Hidroxiquinase/metabolismo , DNA Metiltransferases Sítio Específica (Adenina-Específica)/genética , DNA Metiltransferases Sítio Específica (Adenina-Específica)/metabolismo , Espectrometria de Fluorescência
14.
Magn Reson Imaging ; 62: 78-86, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31247250

RESUMO

PURPOSE: To identify quantitative dynamic contrast-enhanced (DCE)-MRI perfusion parameters indicating tumor response of hepatocellular carcinoma (HCC) to transarterial chemoembolization (TACE). MATERIALS AND METHODS: This prospective pilot study was approved by our institutional review board; written and informed consent was obtained for each participant. Patients underwent DCE-MRI examinations before and after TACE. A variable flip-angle unenhanced 3D mDixon sequence was performed for T1 mapping. A dynamic 4D mDixon sequence was performed after contrast injection for assessing dynamic signal enhancement. Nonparametric analysis was conducted on the time-intensity curves. Parametric analysis was performed on the time-concentration curves using a dual-input single-compartment model. Treatment response according to Liver Reporting and Data System (LI-RADS) v2018 was used as the reference standard. The comparisons within groups (before vs. after treatment) and between groups (nonviable vs. equivocal or viable tumor) were performed using nonparametric bootstrap taking into account the clustering effect of lesions in patients. RESULTS: Twenty-eight patients with 52 HCCs (size: 10-104 mm) were evaluated. For nonviable tumors (n = 27), time to peak increased from 62.5 ±â€¯18.2 s before to 83.3 ±â€¯12.8 s after treatment (P< 0.01). For equivocal or viable tumors (n = 25), time to peak and mean transit time significantly increased (from 54.4 ±â€¯24.1 s to 69.5 ±â€¯18.9 s, P < 0.01 and from 14.2 ±â€¯11.8 s to 33.9 ±â€¯36.8 s, P= 0.01, respectively) and the transfer constant from the extracellular and extravascular space to the central vein significantly decreased from 14.8 ±â€¯14.1 to 8.1 ±â€¯9.1 s-1 after treatment (P= 0.01). CONCLUSION: This prospective pilot DCE-MRI study showed that time to peak significantly changed after TACE treatment for both groups (nonviable tumors and equivocal or viable tumors). In our cohort, several perfusion parameters may provide an objective marker for differentiation of treatment response after TACE in HCC patients.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Quimioembolização Terapêutica , Meios de Contraste/farmacologia , Neoplasias Hepáticas/diagnóstico por imagem , Imagem por Ressonância Magnética , Idoso , Carcinoma Hepatocelular/patologia , Feminino , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Projetos Piloto , Estudos Prospectivos , Reprodutibilidade dos Testes , Veias/diagnóstico por imagem
15.
Artigo em Inglês | MEDLINE | ID: mdl-30990181

RESUMO

Change in viscoelastic properties of biological tissues may often be symptomatic of a dysfunction that can be correlated to tissue pathology. Shear wave elastography is an imaging method mainly used to assess stiffness but with the potential to measure viscoelasticity of biological tissues. This can enable tissue characterization; and thus, can be used as a marker to improve diagnosis of pathological lesions. In this study, a frequency-shift method based framework is presented for the reconstruction of viscosity by analyzing the spectral properties of acoustic radiation force-induced shear waves. The aim of the study was to investigate the feasibility of viscosity reconstruction maps in homogeneous as well as heterogeneous samples. Experiments were performed in four in vitro phantoms, two ex vivo porcine liver samples, two ex vivo fatty duck liver samples, and one in vivo fatty goose liver. Successful viscosity maps were reconstructed in homogeneous and heterogeneous phantoms with embedded mechanical inclusions having different geometries. Quantitative values of viscosity obtained for two porcine liver tissues, two fatty duck liver samples, and one goose fatty liver were (mean ± SD) 0.61 ± 0.21, 0.52 ± 0.35; 1.28 ± 0.54, 1.36 ± 0.73, and 1.67 ± 0.70 Pa.s, respectively.

16.
AJR Am J Roentgenol ; : 1-9, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30995098

RESUMO

OBJECTIVE. The purpose of this study is to compare imaging-based surveillance and diagnostic strategies in patients at risk for hepatocellular carcinoma (HCC) while taking into account technically inadequate examinations and patient compliance. MATERIALS AND METHODS. A Markov model simulated seven strategies for HCC surveillance and diagnosis in patients with cirrhosis: strategy A, ultrasound (US) for surveillance and CT for diagnosis; strategy B, US for surveillance and complete MRI for diagnosis; strategy C, US for surveillance and CT for inadequate or positive surveillance; strategy D, US for surveillance and complete MRI for inadequate or positive surveillance; strategy E, surveillance and diagnosis with CT followed by complete MRI for inadequate surveillance; strategy F, surveillance and diagnosis with complete MRI followed by CT for inadequate surveillance; and strategy G, surveillance with abbreviated MRI followed by CT for inadequate surveillance or complete MRI for positive surveillance. Two compliance scenarios were evaluated: optimal and conservative. For each scenario, the most cost-effective strategy was based on a willingness-to-pay threshold of $50,000 (Canadian) per quality-adjusted life year (QALY). Sensitivity analyses were performed. RESULTS. Base-case analysis revealed that strategy E was the most cost-effective when compliance was optimal ($13,631/QALY), and strategy G was the most cost-effective when compliance was conservative ($39,681/QALY). Sensitivity analyses supported the base-case analysis in the optimal compliance scenario, but several parameters altered the most cost-effective strategy in the conservative compliance scenario. CONCLUSION. In an optimal compliance scenario, CT for HCC surveillance and diagnosis and complete MRI for inadequate CT was most cost-effective. In a conservative compliance scenario, abbreviated MRI may be an alternative to US-based surveillance.

17.
Can Assoc Radiol J ; 70(2): 107-118, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30962048

RESUMO

Artificial intelligence (AI) software that analyzes medical images is becoming increasingly prevalent. Unlike earlier generations of AI software, which relied on expert knowledge to identify imaging features, machine learning approaches automatically learn to recognize these features. However, the promise of accurate personalized medicine can only be fulfilled with access to large quantities of medical data from patients. This data could be used for purposes such as predicting disease, diagnosis, treatment optimization, and prognostication. Radiology is positioned to lead development and implementation of AI algorithms and to manage the associated ethical and legal challenges. This white paper from the Canadian Association of Radiologists provides a framework for study of the legal and ethical issues related to AI in medical imaging, related to patient data (privacy, confidentiality, ownership, and sharing); algorithms (levels of autonomy, liability, and jurisprudence); practice (best practices and current legal framework); and finally, opportunities in AI from the perspective of a universal health care system.


Assuntos
Inteligência Artificial/ética , Inteligência Artificial/legislação & jurisprudência , Radiologia/ética , Radiologia/legislação & jurisprudência , Canadá , Humanos , Guias de Prática Clínica como Assunto , Radiologistas/ética , Radiologistas/legislação & jurisprudência , Sociedades Médicas
18.
ACS Sens ; 4(4): 1090-1096, 2019 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-30945529

RESUMO

Telomerase is a universal biomarker of malignant tumors. Sensitive and reliable analysis for telomerase activity is of vital importance for both early diagnosis and therapy of malignant tumors. Herein, a novel fluorescent strategy was proposed for sensitive and label-free detection of telomerase activity. One highlight of this strategy is that an exponential signal amplification can be triggered by a very short telomerase extension product (TEP). Without adding dATP, the designed telomerase primer can be easily controlled to extend five bases (GGGTT) to give short TEP with definite length. The resulting short TEP can then be constructed as a circular rolling circle amplification (RCA) template and thus initiate a nicking enzyme-mediated exponential RCA, producing G-rich amplification products that can be sensitively probed via specific binding between the fluorescent dye Thioflavin T (ThT) and the nucleic acid G-quadruplexes. Elevated telomerase translocation efficiency, combined with exponential signal amplification and specific probing of RCA products by ThT, endow the sensing platform with extraordinarily high detection sensitivity. The requirement for short TEP increases the possibility to analyze telomerase with low activity. The proposed sensing platform can achieve sensitive telomerase activity detection in individual cells, even with the interference of accumulated normal cells. It was also demonstrated to show excellent capability in screening for the inhibitors of telomerase. Therefore, the proposed sensing platform has great potential for not only clinical diagnosis but also anticancer drug development.

19.
ACS Appl Mater Interfaces ; 11(16): 14684-14692, 2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-30942569

RESUMO

Developing a highly efficient carrier for tumor-targeted delivery and site-specific release of anticancer drugs is a good way to overcome the side effects of traditional cancer chemotherapy. Benefiting from the nontoxic and biocompatible characteristics, DNA-based drug carriers have attracted increasing attention. Herein, we reported a novel and readily manipulated strategy to construct spherical DNA nanocarriers. In this strategy, terminal deoxynucleotidyl transferase (TdT)-catalyzed DNA extension reaction is used to prepare a thick DNA layer on a gold nanoparticle (AuNP) surface by extending long poly(C) sequences from DNA primers immobilized on AuNPs. The poly(C) extension products can then hybridize with G-rich oligonucleotides to give CG-rich DNA duplexes (for loading anticancer drug doxorubicin, Dox) and multiple AS1411 aptamers. Via synergic recognition of multiple aptamer units to nucleolin proteins, biomarker of malignant tumors, Dox-loaded DNA carrier can be efficiently internalized in cancer cells and achieve burst release of drugs in acidic organelles because of i-motif formation-induced DNA duplex destruction. An as-prepared pH-responsive drug carrier was demonstrated to be promising for highly efficient delivery of Dox and selective killing of cancer cells in both in vitro and in vivo experiments, thus showing a huge potential in anticancer therapy.


Assuntos
Adutos de DNA , DNA Nucleotidilexotransferase/química , Doxorrubicina , Ouro , Nanopartículas Metálicas , Neoplasias Experimentais/tratamento farmacológico , Animais , Adutos de DNA/química , Adutos de DNA/farmacologia , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacologia , Doxorrubicina/química , Doxorrubicina/farmacologia , Feminino , Ouro/química , Ouro/farmacologia , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Nanopartículas Metálicas/química , Nanopartículas Metálicas/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Células NIH 3T3 , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Oligodesoxirribonucleotídeos/química , Oligodesoxirribonucleotídeos/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Anal Chem ; 91(8): 5244-5251, 2019 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-30883097

RESUMO

An ultimate goal of synthetic DNA motor studies is to mimic natural protein motors in biological systems. Here, we rationally designed a highly integrated and biostable DNA motor system with high potential for living body operation, through simple assembly of a Mn2+-dependent DNAzyme-powered DNA motor with a degradable MnO2 nanosheet. The motor system shows outstanding high integration and improved biostability. High integration confers the motor system with the ability to deliver all the core components to the target sites as a whole, thus, enabling precise control of the spatiotemporal distribution of these components and achieving high local concentrations. At the target sites, reduction of the MnO2 nanosheet by intracellular glutathione (GSH) not only releases the DNA motor, which can then be initiated by the intracellular target, but also produces Mn2+ in situ to power the autonomous and progressive operation of the DNA motor. Interestingly, the resultant consumption of GSH in turn protects the DNA motor from destruction by physiological GSH, thus, conferring our motor system with improved biostability, reduced false-positive outputs, and consequently, an increased potential to be applied in a living body. As a proof of concept, the highly integrated DNA motor system was demonstrated to work well for amplified imaging detection of survivin mRNA (mRNA), an important tumor biomarker, in both living cancer cells and living tumor-bearing mice. This work reveals concepts and strategies promoting synthetic DNA motor applications in biological systems.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA