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1.
Clin Interv Aging ; 18: 169-179, 2023.
Article in English | MEDLINE | ID: mdl-36818546

ABSTRACT

Background: Myocardial injury after noncardiac surgery (MINS) has been associated with worse outcomes. The aim of our study was to investigate the relationship between higher red blood cell distribution width (RDW) and postoperative 30-day MINS among advanced-age patients. Methods: This was a retrospective observational study including advanced-age patients (≥65 years old) who underwent noncardiac surgery between January 2017 and August 2019 at the First Medical Center of the Chinese People's Liberation Army General Hospital. Patients were divided into two groups according to the cutoff value identified the lowest risk using Restricted Cubic Splines (RCS) model. The primary outcome was the incidence of MINS within 30 days after surgery. The relationship between RDW and MINS was investigated by univariable and multi-variable logistic regression analysis. Propensity score (PS) analysis, including propensity score matching (PSM) and inverse probability treatment weighting (IPTW), as well as subgroup analysis were also conducted to identify the effect of RDW. Results: The result of the RCS analysis showed that the risk of MINS in advanced-age patients increases when the baseline RDW is >12.8%. In the univariate analysis, baseline RDW >12.8% was a risk factor for postoperative MINS [odds ratio (OR)=2.11; 95% confidence interval (CI): 1.83-2.44; p<0.001]. After adjustment for all possible components, there was also a high risk of MINS for patients with elevated RDW [Adjusted OR (aOR)=1.43; 95% CI: 1.27-1.61; p<0.001). The relationship remained after PS analysis (aOR=1.24; 95% CI: 1.04-1.47; p=0.016 in PSM; aOR=1.23; 95% CI: 1.05-1.44; p=0.012 in IPTW, respectively). Significant differences between two groups were established in the incidence rate of postoperative cardiac complications and mortality. Conclusion: Elevated preoperative RDW is significantly associated with an increased risk of MINS within postoperative 30 days.


Subject(s)
Erythrocytes , Postoperative Complications , Humans , Aged , Retrospective Studies , Postoperative Complications/epidemiology , Risk Factors , Odds Ratio
2.
Breast Cancer Res ; 24(1): 85, 2022 11 30.
Article in English | MEDLINE | ID: mdl-36451243

ABSTRACT

BACKGROUND: There is a strong correlation between the morphological features of new tumor vessels and malignancy. However, angiogenic heterogeneity necessitates 3D microvascular data of tumor microvessels for more reliable quantification. To provide more accurate information regarding vessel morphological features and improve breast lesion characterization, we introduced a quantitative 3D high-definition microvasculature imaging (q3D-HDMI) as a new easily applicable and robust tool to morphologically characterize microvasculature networks in breast tumors using a contrast-free ultrasound-based imaging approach. METHODS: In this prospective study, from January 2020 through December 2021, a newly developed q3D-HDMI technique was evaluated on participants with ultrasound-identified suspicious breast lesions recommended for core needle biopsy. The morphological features of breast tumor microvessels were extracted from the q3D-HDMI. Leave-one-out cross-validation (LOOCV) was applied to test the combined diagnostic performance of multiple morphological parameters of breast tumor microvessels. Receiver operating characteristic (ROC) curves were used to evaluate the prediction performance of the generated pooled model. RESULTS: Ninety-three participants (mean age 52 ± 17 years, 91 women) with 93 breast lesions were studied. The area under the ROC curve (AUC) generated with q3D-HDMI was 95.8% (95% CI 0.901-1.000), yielding a sensitivity of 91.7% and a specificity of 98.2%, that was significantly higher than the AUC generated with the q2D-HDMI (p = 0.02). When compared to q2D-HDMI, the tumor microvessel morphological parameters obtained from q3D-HDMI provides distinctive information that increases accuracy in differentiating breast tumors. CONCLUSIONS: The proposed quantitative volumetric imaging technique augments conventional breast ultrasound evaluation by increasing specificity in differentiating malignant from benign breast masses.


Subject(s)
Breast Neoplasms , Humans , Female , Adult , Middle Aged , Aged , Feasibility Studies , Breast Neoplasms/diagnostic imaging , Prospective Studies , Breast/diagnostic imaging , Microvessels/diagnostic imaging
3.
J Oncol ; 2022: 7298192, 2022.
Article in English | MEDLINE | ID: mdl-36385958

ABSTRACT

Purpose: To explore the efficacy of bevacizumab in combination with PD-1 immune drug pembrolizumab on cellular immune function in the treatment of driver gene-negative stage IV lung adenocarcinoma and its short-term survival effect. Methods: From February 2020 to December 2021, 85 patients with driver gene-negative stage IV lung adenocarcinoma were admitted to our hospital and treated with first-line therapy, and their clinical records were reviewed retrospectively. According to the treatments, the patients were separated into two groups the combination group (n = 45) and the control group (n = 40). The treatment regimen of the control group was an AP chemotherapy regimen (pemetrexed combined with cisplatin) + PD-1 immune drug pembrolizumab. The treatment regimen of the combination group was AP chemotherapy regimen + PD-1 immune drug pembrolizumab combined with bevacizumab. We evaluated the pre- and post-treatment cellular immunological function of the two patient groups and discussed the difference between them. Results: There was a substantial difference in the overall effective rate and the disease control rate between the two groups, with the former being 27.50% compared to 48.89% and the latter being 72.50% compared to 93.33% among these 85 patients studied. The KPS for the combination group improved and stayed at 91.11% after treatment, which is considerably better than the KPS for the control group, which was 42.50% (χ 2 = 23.09, P < 0.05). There was no significant difference (P > 0.05) in the numbers of CD3+, CD4+, CD19+, CD8+, or CD4+/CD8+ cells pretreatment between the two groups, but after treatment, the combination group had significantly higher numbers of all these cells. Neither the CD8+ nor the CD19+ level was significantly different between the control and combination groups (P > 0.05). Furthermore, the incidence of common clinical side effects was similar between the two groups (P > 0.05). Proteinuria, tiredness, increased alanine aminotransferase, hypertension, immunological pneumonia, muscle pain, arthralgia, hypothyroidism, etc. were the most common side effects reported among both groups throughout therapy. A grade IV side effect is rare. After follow-up until March 2022, the median PFS for the control group was 9.00 ± 1.65 months (95% CI, 5.76-12.24) and the mean PFS was 11.48 ± 0.91 months (95% CI, 9.69-13.26). Comparison of the median PFS of the combination group (13.00 ± 1.10) months (95% CI: 10.84-15.16) with the average PFS of the group (15.52 ± 0.88) months (95% CI = 13.79-17.25) reveals a statistically significant difference (P < 0.05). Conclusion: Combining bevacizumab with the PD-1 immune medication pembrolizumab to treat patients with stage IV lung adenocarcinoma improves the quality of life, short-term therapeutic effectiveness, immune function, and PFS.

4.
Ultrasound Med Biol ; 48(8): 1663-1671, 2022 08.
Article in English | MEDLINE | ID: mdl-35672198

ABSTRACT

Mass characteristic frequency (fmass) is a novel shear wave (SW) parameter that represents the ratio of the averaged minimum SW speed within the regions of interest to the largest dimension of the mass. Our study objective was to evaluate if the addition of fmass to conventional 2-D shear wave elastography (SWE) parameters would improve the differentiation of benign from malignant thyroid nodules. Our cohort comprised 107 patients with 113 thyroid nodules, of which 67 (59%) were malignant. Two-dimensional SWE data were obtained using the Supersonic Imagine Aixplorer ultrasound system equipped with a 44- to 15-MHz15-MHz linear array transducer. A receiver operating characteristic curve was generated based on a multivariable logistic regression analysis to evaluate the ability of SWE parameters with/without fmass and with/without clinical factors to discriminate benign from malignant thyroid nodules. The addition of fmass to conventional SW elasticity parameters increased the area under the curve from 0.808 to 0.871 (p = 0.02). The combination of SW elasticity parameters plus fmass plus clinical factors provided the strongest thyroid nodule malignancy probability estimate, with a sensitivity of 93.4% and specificity of 91.1% at the optimal threshold. In summary, fmass can be a valuable addition to conventional 2-D SWE parameters.


Subject(s)
Elasticity Imaging Techniques , Thyroid Neoplasms , Thyroid Nodule , Elasticity Imaging Techniques/methods , Humans , Reproducibility of Results , Sensitivity and Specificity , Thyroid Nodule/diagnostic imaging , Thyroid Nodule/pathology
5.
Eur Radiol ; 32(11): 7448-7462, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35486168

ABSTRACT

OBJECTIVES: To overcome the limitations of power Doppler in imaging angiogenesis, we sought to develop and investigate new quantitative biomarkers of a contrast-free ultrasound microvasculature imaging technique for differentiation of benign from malignant pathologies of breast lesion. METHODS: In this prospective study, a new high-definition microvasculature imaging (HDMI) was tested on 521 patients with 527 ultrasound-identified suspicious breast masses indicated for biopsy. Four new morphological features of tumor microvessels, microvessel fractal dimension (mvFD), Murray's deviation (MD), bifurcation angle (BA), and spatial vascularity pattern (SVP) as well as initial biomarkers were extracted and analyzed, and the results correlated with pathology. Multivariable logistic regression analysis was used to study the performance of different prediction models, initial biomarkers, new biomarkers, and combined new and initial biomarkers in differentiating benign from malignant lesions. RESULTS: The new HDMI biomarkers, mvFD, BA, MD, and SVP, were statistically significantly different in malignant and benign lesions, regardless of tumor size. Sensitivity and specificity of the new biomarkers in lesions > 20 mm were 95.6% and 100%, respectively. Combining the new and initial biomarkers together showed an AUC, sensitivity, and specificity of 97% (95% CI: 95-98%), 93.8%, and 89.2%, respectively, for all lesions regardless of mass size. The classification was further improved by adding the Breast Imaging Reporting and Data System (BI-RADS) score to the prediction model, showing an AUC, sensitivity, and specificity of 97% (95% CI: 95-98%), 93.8%, and 89.2%, respectively. CONCLUSION: The addition of new quantitative HDMI biomarkers significantly improved the accuracy in breast lesion characterization when used as a complementary imaging tool to the conventional ultrasound. KEY POINTS: • Novel quantitative biomarkers extracted from tumor microvessel images increase the sensitivity and specificity in discriminating malignant from benign breast masses. • New HDMI biomarkers Murray's deviation, bifurcation angles, microvessel fractal dimension, and spatial vascularity pattern outperformed the initial biomarkers. • The addition of BI-RADS scores based on US descriptors to the multivariable analysis using all biomarkers remarkably increased the sensitivity, specificity, and AUC in all size groups.


Subject(s)
Breast Neoplasms , Ultrasonography, Mammary , Female , Humans , Ultrasonography, Mammary/methods , Prospective Studies , Breast Neoplasms/diagnostic imaging , Sensitivity and Specificity , Microvessels/diagnostic imaging , Biomarkers , Diagnosis, Differential
6.
Breast Cancer Res ; 24(1): 16, 2022 03 05.
Article in English | MEDLINE | ID: mdl-35248115

ABSTRACT

BACKGROUND: Low specificity in current breast imaging modalities leads to increased unnecessary follow-ups and biopsies. The purpose of this study is to evaluate the efficacy of combining the quantitative parameters of high-definition microvasculature imaging (HDMI) and 2D shear wave elastography (SWE) with clinical factors (lesion depth and age) for improving breast lesion differentiation. METHODS: In this prospective study, from June 2016 through April 2021, patients with breast lesions identified on diagnostic ultrasound and recommended for core needle biopsy were recruited. HDMI and SWE were conducted prior to biopsies. Two new HDMI parameters, Murray's deviation and bifurcation angle, and a new SWE parameter, mass characteristic frequency, were included for quantitative analysis. Lesion malignancy prediction models based on HDMI only, SWE only, the combination of HDMI and SWE, and the combination of HDMI, SWE and clinical factors were trained via elastic net logistic regression with 70% (360/514) randomly selected data and validated with the remaining 30% (154/514) data. Prediction performances in the validation test set were compared across models with respect to area under the ROC curve as well as sensitivity and specificity based on optimized threshold selection. RESULTS: A total of 508 participants (mean age, 54 years ± 15), including 507 female participants and 1 male participant, with 514 suspicious breast lesions (range, 4-72 mm, median size, 13 mm) were included. Of the lesions, 204 were malignant. The SWE-HDMI prediction model, combining quantitative parameters from SWE and HDMI, with AUC of 0.973 (95% CI 0.95-0.99), was significantly higher than the result predicted with the SWE model or HDMI model alone. With an optimal cutoff of 0.25 for the malignancy probability, the sensitivity and specificity were 95.5% and 89.7%, respectively. The specificity was further improved with the addition of clinical factors. The corresponding model defined as the SWE-HDMI-C prediction model had an AUC of 0.981 (95% CI 0.96-1.00). CONCLUSIONS: The SWE-HDMI-C detection model, a combination of SWE estimates, HDMI quantitative biomarkers and clinical factors, greatly improved the accuracy in breast lesion characterization.


Subject(s)
Breast Neoplasms , Elasticity Imaging Techniques , Breast Neoplasms/diagnostic imaging , Diagnosis, Differential , Elasticity Imaging Techniques/methods , Female , Humans , Male , Microvessels/diagnostic imaging , Middle Aged , Prospective Studies , Reproducibility of Results , Sensitivity and Specificity , Ultrasonography, Mammary/methods
7.
Article in English | MEDLINE | ID: mdl-34152984

ABSTRACT

In the above article [1]>, the authors regret that there were some mistakes pertaining to (1)-(3) and (5).

8.
Ultrasound Med Biol ; 47(8): 2193-2201, 2021 08.
Article in English | MEDLINE | ID: mdl-33994231

ABSTRACT

This purpose of this study is to correlate a new shear-wave elastography (SWE) parameter, mass characteristic frequency (fmass) and other elasticity measure with the prognostic histological factors and immunohistochemical (IHC) biomarkers for the evaluation of heterogeneous breast carcinomas. The new parameter, fmass, first introduced in this paper, is defined as the ratio of the averaged minimum shear wave speed taken spatially within regions of interest to the largest mass dimension. 264 biopsy-proven breast cancerous masses were included in this study. Mean (Emean), maximum (Emax), minimum (Emin) shear wave elasticity and standard deviation (Esd) of shear wave elasticity were found significantly correlated with tumor size, axillary lymph node (ALN) status, histological subtypes and IHC subtypes. The areas under the curve for the ALN prediction are 0.73 (95% confidence interval [CI]: 0.67-0.80) and 0.75 (95% CI: 0.69-0.81) for the combination of Emean with Breast Imaging Reporting and Data System (BI-RADS) score and Emax with BI-RADS score, respectively. fmass was significantly correlated with the presence of calcifications, ALN status, histological grade, the expressions of IHC biomarkers and IHC subtypes. To conclude, poor prognostic factors were associated with high shear wave elasticity values and low mass characteristic frequency value. Therefore, SWE provides valuable information that may help with prediction of breast cancer invasiveness.


Subject(s)
Breast Neoplasms/diagnostic imaging , Breast Neoplasms/pathology , Elasticity Imaging Techniques , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/analysis , Breast Neoplasms/chemistry , Correlation of Data , Female , Humans , Immunohistochemistry , Lymphatic Metastasis , Middle Aged , Neoplasm Invasiveness , Predictive Value of Tests , Prognosis , Prospective Studies , Ultrasonography, Mammary
9.
Breast Cancer Res ; 23(1): 52, 2021 04 29.
Article in English | MEDLINE | ID: mdl-33926522

ABSTRACT

BACKGROUND: Early prediction of tumor response to neoadjuvant chemotherapy (NACT) is crucial for optimal treatment and improved outcome in breast cancer patients. The purpose of this study is to investigate the role of shear wave elastography (SWE) for early assessment of response to NACT in patients with invasive breast cancer. METHODS: In a prospective study, 62 patients with biopsy-proven invasive breast cancer were enrolled. Three SWE studies were conducted on each patient: before, at mid-course, and after NACT but before surgery. A new parameter, mass characteristic frequency (fmass), along with SWE measurements and mass size was obtained from each SWE study visit. The clinical biomarkers were acquired from the pre-NACT core-needle biopsy. The efficacy of different models, generated with the leave-one-out cross-validation, in predicting response to NACT was shown by the area under the receiver operating characteristic curve and the corresponding sensitivity and specificity. RESULTS: A significant difference was found for SWE parameters measured before, at mid-course, and after NACT between the responders and non-responders. The combination of Emean2 and mass size (s2) gave an AUC of 0.75 (0.95 CI 0.62-0.88). For the ER+ tumors, the combination of Emean_ratio1, s1, and Ki-67 index gave an improved AUC of 0.84 (0.95 CI 0.65-0.96). For responders, fmass was significantly higher during the third visit. CONCLUSIONS: Our study findings highlight the value of SWE estimation in the mid-course of NACT for the early prediction of treatment response. For ER+ tumors, the addition of Ki-67improves the predictive power of SWE. Moreover, fmass is presented as a new marker in predicting the endpoint of NACT in responders.


Subject(s)
Breast Neoplasms/diagnostic imaging , Breast Neoplasms/drug therapy , Elasticity Imaging Techniques , Adult , Aged , Biomarkers, Tumor/metabolism , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Female , Humans , Middle Aged , Neoadjuvant Therapy , Prospective Studies , ROC Curve , Treatment Outcome
10.
Article in English | MEDLINE | ID: mdl-33635787

ABSTRACT

Passive cavitation mapping (PCM), which generates images using bubble acoustic emission signals, has been increasingly used for monitoring and guiding focused ultrasound surgery (FUS). PCM can be used as an adjunct to magnetic resonance imaging to provide crucial information on the safety and efficacy of FUS. The most widely used algorithm for PCM is delay-and-sum (DAS). One of the major limitations of DAS is its suboptimal computational efficiency. Although frequency-domain DAS can partially resolve this issue, such an algorithm is not suitable for imaging the evolution of bubble activity in real time and for cases in which cavitation events occur asynchronously. This study investigates a transient angular spectrum (AS) approach for PCM. The working principle of this approach is to backpropagate the received signal to the domain of interest and reconstruct the spatial-temporal wavefield encoded with the bubble location and collapse time. The transient AS approach is validated using an in silico model and water bath experiments. It is found that the transient AS approach yields similar results to DAS, but it is one order of magnitude faster. The results obtained by this study suggest that the transient AS approach is promising for fast and accurate PCM.


Subject(s)
Acoustics , Algorithms , Magnetic Resonance Imaging
11.
Article in English | MEDLINE | ID: mdl-33444136

ABSTRACT

mSOUND is an open-source toolbox written in MATLAB. This toolbox is intended for modeling linear/ nonlinear acoustic wave propagation in media (primarily biological tissues) with arbitrary heterogeneities, in which, the speed of sound, density, attenuation coefficient, power-law exponent, and nonlinear coefficient are all spatially varying functions. The computational model is an iterative one-way model based on a mixed domain method. In this article, a general guideline is given along with three representative examples to illustrate how to set up simulations using mSOUND. The first example uses the transient mixed-domain method (TMDM) forward projection to compute the transient acoustic field for a given source defined on a plane. The second example uses the frequency-specific mixed-domain method (FSMDM) forward projection to rapidly obtain the pressure distribution directly at the frequencies of interest, assuming linear or weakly nonlinear wave propagation. The third example demonstrates how to use TMDM backward projection to reconstruct the initial acoustic pressure field to facilitate photoacoustic tomography (PAT). mSOUND (https://m-sound.github.io/mSOUND/home) is designed to be complementary to existing ultrasound modeling toolboxes and is expected to be useful for a wide range of applications in medical ultrasound including treatment planning, PAT, transducer design, and characterization.


Subject(s)
Acoustics , Transducers , Sound , Tomography, X-Ray Computed , Ultrasonography
12.
Breast ; 54: 248-255, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33188991

ABSTRACT

PURPOSE: To investigate the diagnostic role of new metrics, defined as individualized-thresholding of Shear Wave Elastography (SWE) parameters, in association with clinical factors (such as age, mammographic density, lesion size and depth) and the BI-RADS features in differentiating benign from malignant breast lesions. METHODS: Of 644 consecutive patients (median age, 55 years), prospectively referred for evaluation, 659 ultrasound detected breast lesions underwent SWE measurements. Multivariable logistic regression analysis was used to estimate the probability of malignancy. The area under the curve (AUC), optimal cutoff value, and the corresponding sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were determined. RESULTS: 265 of 659 (40.2%) masses were malignant. Using two Emean cutoffs, 69.6 kPa for large superficial lesions (size >10 mm, depth ≤5 mm) and 39.2 kPa for the rest, the overall specificity, sensitivity, PPV and NPV were 92.6%, 86.8%, 88.8% and 91.3%, respectively. Combining multiple factors, including Emean with two cutoffs, age and BI-RADS, the new ROC curve based on the malignancy probability calculation showed the highest AUC (0.954, 95% CI: 0.938-0.969). Using the optimal probability threshold of 0.514, the corresponding specificity, sensitivity, PPV and NPV were 92.9%, 89.1%, 89.4% and 92.7%, respectively. CONCLUSIONS: The false-positive rate can be significantly reduced when applying two Emean cutoffs based on lesion size and depth. Moreover, the combination of age, Emean with two cutoffs and BI-RADS can further reduce the false negatives and false positives. Overall, this multifactorial analysis improves the specificity of ultrasound while maintaining a high sensitivity.


Subject(s)
Breast Neoplasms/diagnosis , Elasticity Imaging Techniques/statistics & numerical data , Precision Medicine/methods , Adolescent , Adult , Aged , Aged, 80 and over , Area Under Curve , Breast/diagnostic imaging , Breast/pathology , Diagnosis, Differential , Elasticity Imaging Techniques/methods , Female , Humans , Logistic Models , Middle Aged , Predictive Value of Tests , Prospective Studies , Reference Values , Reproducibility of Results , Sensitivity and Specificity , Ultrasonography, Mammary , Young Adult
13.
J Acoust Soc Am ; 147(6): 4055, 2020 06.
Article in English | MEDLINE | ID: mdl-32611145

ABSTRACT

In this paper, phase correction and amplitude compensation are introduced to a previously developed mixed domain method (MDM), which is only accurate for modeling wave propagation in weakly heterogeneous media. Multiple reflections are also incorporated with the one-way model to improve the accuracy. The resulting model is denoted as the modified mixed domain method (MMDM) and is numerically evaluated for its accuracy and efficiency using four distinct cases. It is found that the MMDM is significantly more accurate than the MDM for strongly heterogeneous media, especially when the phase aberrating layer is approximately perpendicular to the acoustic beam. Additionally, a convergence study suggests that the second-order reflection could be sufficient for cases involving high contrast inhomogeneities and large loss values (e.g., skulls). The method developed in this work could facilitate therapeutic ultrasound for treating brain-related diseases and disorders.


Subject(s)
Acoustics , Ultrasonic Therapy , Computer Simulation , Skull , Sound
14.
Article in English | MEDLINE | ID: mdl-30640608

ABSTRACT

A mixed-domain method (MDM) dubbed frequency-specific MDM (FSMDM) is introduced for the simulation of the second-harmonic ultrasound field in weakly heterogeneous media. The governing equation for the second harmonics is derived based on the quasi-linear theory. The speed of sound, nonlinear coefficient, and attenuation coefficient are all spatially varying functions in the equation. The fundamental frequency pressure field is first solved by the FSMDM and it is subsequently used as the source term for the second-harmonics equation. This equation can be again solved by the FSMDM to rapidly obtain the second-harmonic pressure field. Five 2-D cases, including one with a realistic human tissue map, are studied to systematically verify the proposed method. Results from the previously developed transient MDM are used as the benchmark solutions. Comparisons show that the two methods give similar results for all cases. More importantly, the FSMDM has a crucial advantage over the transient MDM in that it can be two orders of magnitude faster.


Subject(s)
Computer Simulation , Image Processing, Computer-Assisted/methods , Ultrasonography/methods , Connective Tissue/diagnostic imaging , Humans , Liver/diagnostic imaging
15.
Article in English | MEDLINE | ID: mdl-29993378

ABSTRACT

A mixed-domain method (MDM) is presented in this paper for modeling one-way linear/nonlinear wave propagation in biological tissue with arbitrary heterogeneities, in which sound speed, density, attenuation coefficients, and nonlinear coefficients are all spatial varying functions. The present method is based on solving an integral equation derived from a Westervelt-like equation. One-dimensional problems are first studied to verify the MDM and to reveal its limitations. It is shown that this method is accurate for cases with small variation of sound speed. A 2-D case is further studied with focused ultrasound beams to validate the application of the method in the medical field. Results from the MATLAB toolbox k-Wave are used as the benchmark. Normalized root-mean-square (rms) error estimated at the focus of the transducer is 0.0133 when the coarsest mesh (1/3 of the wavelength) is used in the MDM. Fundamental and second-harmonic fields throughout the considered computational domains are compared and good agreement is observed. Overall, this paper demonstrates that the MDM is a computationally efficient and accurate method when used to model wave propagation in biological tissue with relatively weak heterogeneities.


Subject(s)
Image Processing, Computer-Assisted/methods , Ultrasonography/methods , Computer Simulation , Fourier Analysis , Models, Theoretical , Transducers
16.
Sci Rep ; 7: 45565, 2017 03 30.
Article in English | MEDLINE | ID: mdl-28358021

ABSTRACT

Research on possible topological superconductivity has grown rapidly over the past several years, from fundamental studies to the development of next generation technologies. Recently, it has been reported that the SrxBi2Se3 exhibits superconductivity with topological surface state, making this compound a promising candidate for investigating possible topological superconductivity. However, whether or not the topological surface state is robust against impurities is not clear in this system. Here we report a detailed investigation on the lattice structure, electronic and magnetic properties, as well as the topological superconducting properties of SrxBi2Se3-ySy samples. It is found that the superconducting transition temperature keeps nearly unchanged in all samples, despite of a gradual decrease of the superconducting shielding volume fraction with increasing S doping content. Meanwhile, the Shubnikov-de Hass oscillation results of the SrxBi2Se3-ySy samples reveal that the topological surface states are destroyed in S doped samples, suggesting the topological character is degraded by nonmagnetic dopants.

17.
World J Gastroenterol ; 23(2): 256-264, 2017 Jan 14.
Article in English | MEDLINE | ID: mdl-28127199

ABSTRACT

AIM: To investigate the dynamic alteration of mitochondrial carnitine palmitoyl transferase II (CPT-II) expression during malignant transformation of rat hepatocytes. METHODS: Sprague-Dawley male rats were fed with normal, high fat (HF), and HF containing 2-fluorenylacetamide (2-FAA) diet, respectively. According to the Hematoxylin and Eosin staining of livers, rats were divided into control, fatty liver, degeneration, precancerous, and cancerous groups. Liver lipids were dyed with Oil Red O, CPT-II alterations were analyzed by immunohistochemistry, and compared with CPT-II specific concentration (µg/mg protein). Levels of total cholesterol (Tch), triglyceride (TG), and amino-transferases [alanine aminotransferase (ALT), aspartate aminotransferase (AST)] were determined by the routine methods. RESULTS: After intake of HF and/or HF+2-FAA diets, the rat livers showed mass lipid accumulation. The lipid level in the control group was significantly lower than that in other groups. The changes of serum TG and Tch levels were abnormally increasing, 2-3 times more than those in the controls (P < 0.05). During the rat liver morphological changes from normal to cancer development process with hepatocyte injury, serum AST and ALT levels were significantly higher (4-8 times, P < 0.05) than those in the control group. The specific concentration of CPT-II in liver tissues progressively decreased during hepatocyte malignant transformation, with the lowest CPT-II levels in the cancer group than in any of the other groups (P < 0.05). CONCLUSION: Low CPT-II expression might lead to abnormal hepatic lipid accumulation, which should promote the malignant transformation of hepatocytes.


Subject(s)
Carcinogenesis/metabolism , Carcinoma, Hepatocellular/metabolism , Carnitine O-Palmitoyltransferase/metabolism , Hepatocytes/metabolism , Lipid Metabolism , Liver Neoplasms, Experimental/metabolism , Mitochondria/enzymology , Non-alcoholic Fatty Liver Disease/metabolism , 2-Acetylaminofluorene/toxicity , Alanine Transaminase/blood , Animals , Aspartate Aminotransferases/blood , Carcinoma, Hepatocellular/blood , Carcinoma, Hepatocellular/chemically induced , Cholesterol/blood , Diet, High-Fat/adverse effects , Immunohistochemistry , Liver/cytology , Liver Neoplasms, Experimental/blood , Liver Neoplasms, Experimental/chemically induced , Male , Non-alcoholic Fatty Liver Disease/blood , Non-alcoholic Fatty Liver Disease/etiology , Rats , Rats, Sprague-Dawley , Triglycerides/blood
18.
World J Hepatol ; 8(23): 985-93, 2016 Aug 18.
Article in English | MEDLINE | ID: mdl-27621764

ABSTRACT

AIM: To interfere with the activation of nuclear factor-κB (NF-κB) with metformin and explore its effect in reversing multidrug resistance (MDR) of hepatocellular carcinoma (HCC) cells. METHODS: Expression of P-glycoprotein (P-gp) and NF-κB in human HepG2 or HepG2/adriamycin (ADM) cells treated with pCMV-NF-κB-small interference RNA (siRNA) with or without metformin, was analyzed by Western blot or fluorescence quantitative PCR. Cell viability was tested by CCK-8 assay. Cell cycle and apoptosis were measured by flow cytometry and Annexin-V-PE/7-AnnexinV apoptosis detection double staining assay, respectively. RESULTS: P-gp overexpression in HepG2 and HepG2/ADM cells was closely related to mdr1 mRNA (3.310 ± 0.154) and NF-κB mRNA (2.580 ± 0.040) expression. NF-κB gene transcription was inhibited by specific siRNA with significant down-regulation of P-gp and enhanced HCC cell chemosensitivity to doxorubicin. After pretreatment with metformin, HepG2/ADM cells were sensitized to doxorubicin and P-gp was decreased through the NF-κB signaling pathway. The synergistic effect of metformin and NF-κB siRNA were found in HepG2/ADM cells with regard to proliferation inhibition, cell cycle arrest and inducing cell apoptosis. CONCLUSION: Metformin via silencing NF-κB signaling could effectively reverse MDR of HCC cells by down-regulating MDR1/P-gp expression.

19.
J Clin Transl Hepatol ; 4(2): 123-30, 2016 Jun 28.
Article in English | MEDLINE | ID: mdl-27350942

ABSTRACT

Worldwide incidence of hepatocellular carcinoma (HCC) is steadily increasing, highlighting its status as a public health concern, particularly due to its significant association with other comorbidities, such as diabetes. However, nonalcoholic fatty liver disease (NAFLD) has emerged as a primary risk factor, with its own prevalence increasing in recent years, and it has gradually caught up with the historical primary etiological factors of infection with hepatitis B virus and hepatitis C virus, exposure to aflatoxin, or alcohol liver disease. The deeply worrisome aspects of all of these high risk factors, however, are their remarkable presence within populations. Systemic and genetic mechanisms involved in the malignant transformation of liver cells, as well as useful biomarkers of early stage HCC are being investigated. However, the exact mechanisms underlying the interrelation of NAFLD and HCC remain largely unknown. In this review, some of the recent advances in our understanding of liver lipid accumulation are summarized and discussed to provide insights into the relationship between NAFLD and hepatocyte malignant transformation.

20.
World J Gastroenterol ; 22(14): 3829-36, 2016 Apr 14.
Article in English | MEDLINE | ID: mdl-27076768

ABSTRACT

AIM: To investigate member 3a of Wingless-type MMTV integration site family (Wnt3a) expression in cancerous and surrounding tissues and the relationship between clinicopathologic features of hepatocellular carcinoma (HCC) and Wnt3a expression. METHODS: Wnt3a expression and cellular distribution and clinicopathologic characteristics in cancerous tissue and matched surrounding tissues were analyzed in 80 HCC patients from January 2006 to August 2008 by tissue microarrays and immunohistochemistry. The overall and disease-free survival rates were estimated using the Kaplan-Meier method and compared with the log-rank test. The prognostic analysis was carried out with univariate and multivariate Cox regressions models. RESULTS: The incidence of oncogenic Wnt3a expression in the cancerous group was up to 96.25% (77 of 80), which was significantly higher (χ(2) = 48.818, P < 0.001) than that in the surrounding group (46.25%, 37 of 80). Brown Wnt3a staining gradually increased with clinical staging that showed very strong staining in advanced HCC. The clinicopathologic features of high Wnt3a expression in HCC were related to poorly-differentiated grade (χ(2) = 20.211, P < 0.001), liver cirrhosis (χ(2) = 8.467, P < 0.004), hepatitis B virus (HBV) infection (χ(2) = 12.957, P < 0.001), higher tumor-node-metastasis stage (χ(2) = 22.960, P < 0.001), and 5-year survival rate (χ(2) = 15.469, P < 0.001). CONCLUSION: Oncogenic Wnt3a expression associated with HBV infection and cirrhotic liver might be an independent prognostic factor for HCC.


Subject(s)
Biomarkers, Tumor/analysis , Carcinoma, Hepatocellular/chemistry , Liver Neoplasms/chemistry , Wnt3A Protein/analysis , Adult , Aged , Carcinoma, Hepatocellular/mortality , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/therapy , Chi-Square Distribution , Disease-Free Survival , Female , Humans , Immunohistochemistry , Kaplan-Meier Estimate , Liver Neoplasms/mortality , Liver Neoplasms/pathology , Liver Neoplasms/therapy , Male , Middle Aged , Multivariate Analysis , Neoplasm Staging , Proportional Hazards Models , Risk Factors , Time Factors , Tissue Array Analysis , Treatment Outcome , Up-Regulation
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