Yunkai Zhu

Complexity measure and complexity rate information based detection of ventricular tachycardia and fibrillation

On the basis of non-linear dynamics, the paper uses a Lempel-Ziv complexity measure and presents a new definition of the information complexity rate: cc(n). Using such a definition, relative properties are obtained to help identify chaotic process accurately. Applying complexity analysis to abnormal ECGs recorded from patients with an implantable cardioverter defibrillator, the reasonableness of this information complexity and complexity rate approach are confirmed by means of biological experiments and computer simulations. Finally, objective analysis and explanations of the mechanisms of VT and VF are reported. The results indicate that, with the help of the complexity measure and complexity rate, recognition of ventricular tachycardia (VT) and ventricular fibrillation (VF) signals can be achieved with accuracy up to 100% (VT: 100%; VF: 98.7%).

Contrast-Enhanced Harmonic Ultrasonography for the Assessment of Prostate Cancer Aggressiveness: a Preliminary Study

Objective To determine whether contrast-enhanced harmonic ultrasonography can be used to predict the aggressiveness of prostate cancer. Materials and Methods Contrast-enhanced harmonic ultrasonography was performed in 103 patients suspected of prostate cancer before biopsy. Time intensity curves were reconstructed for systematic biopsy sites and sonographic abnormalities. The characteristics of the curves were described using hemodynamic indices including arrival time (AT), time-to-peak (TTP), and peak intensity (PI). The differences of hemodynamic indices between high-grade and low-grade cancer were analyzed and the correlations between the hemodynamic indices and biopsy Gleason score were studied. Results Prostate cancer was detected in 41 of 103 patients and there were significant differences in the hemodynamic indices between the biopsy sites of the non-malignant patients and prostate cancer lesions (p < 0.05). The prostate biopsies revealed 154 prostate cancer lesions, including 31 low-grade lesions and 123 high-grade lesions. The hemodynamic indices AT and TTP of high-grade tumors were significantly shorter than those of low-grade tumors (p = 0.001, 0.002). In addition, high-grade peripheral zone (PZ) tumors had higher PI than low-grade PZ tumors (p = 0.009). The PZ prostate cancer Gleason score correlated with PI, AT and TTP, with Spearman correlation coefficients of 0.223, -0.335, and -0.351, respectively (p = 0.013, < 0.001 and < 0.001). Conclusion Contrast-enhanced ultrasound measurements of hemodynamic indices correlate with the prostate cancer Gleason score.

Correlation between three-dimensional ultrasound features and pathological prognostic factors in breast cancer

ObjectivesTo investigate the correlation of three-dimensional (3D) ultrasound features with prognostic factors in invasive ductal carcinoma.MethodsSurgical resection specimens of 85 invasive ductal carcinomas of 85 women who had undergone 3D ultrasound were included. Morphology features and vascularization perfusion on 3D ultrasound were evaluated. Pathologic prognostic factors, including tumour size, histological grade, lymph node status, oestrogen and progesterone receptor status (ER, PR), c-erbB-2 and p53 expression, and microvessel density (MVD) were determined. Correlations of 3D ultrasound features and prognostic factors were analysed.ResultsThe retraction pattern in the coronal plane had a significant value as an independent predictor of a small tumour size (P = 0.014), a lower histological grade (P = 0.009) and positive ER or PR expression status (P = 0.001, 0.044). The retraction pattern with a hyperechoic ring only existed in low-grade and ER-positive tumours. The presence of the hyperechoic ring strengthened the ability of the retraction pattern to predict a good prognosis of breast cancer. The increased intra-tumour vascularization index (VI, the mean tumour vascularity) reflected a higher histological grade (P = 0.025) and had a positive correlation with MVD (r = 0.530, P = 0.001).ConclusionsThe retraction pattern and histogram indices of VI provided by 3D ultrasound may be useful in predicting prognostic information about breast cancer.Key Points• Three-dimensional ultrasound can potentially provide prognostic evaluation of breast cancer.• The retraction pattern and hyperechoic ring in the coronal plane suggest good prognosis.• The increased intra-tumour vascularization index reflects a higher histological grade.• The intra-tumour vascularization index is positively correlated with microvessel density.

Contrast-enhanced transrectal ultrasonography for detection and localization of prostate index tumor: correlation with radical prostatectomy findings.

OBJECTIVE To evaluate the ability of contrast-enhanced transrectal ultrasonography (CETRUS) to detect and localize prostate index tumor. METHODS Eighty-three patients with biopsy-proven prostate cancer (PCa), who were scheduled to undergo radical prostatectomy, were enrolled in this prospective study. Each patient underwent baseline grayscale and CETRUS imaging of the prostate according to a standardized protocol before the operation. Ultrasonography findings (CETRUS and grayscale imaging) were correlated with step-section histopathology. RESULTS Overall, 53 and 68 tumor foci were detected by grayscale imaging and CETRUS, respectively. The combination of grayscale imaging and CETRUS allowed identification of 89 of the 232 cancer foci (38.4%). The sensitivity of combined imaging was significantly superior to that of grayscale imaging (P<.01) and CETRUS (P<.05). Additionally, the prostate index tumor detection rate by the use of grayscale imaging, CETRUS, and their combination was 42 of 83 (50.6%), 53 of 83 (63.9%), and 67 of 83 (80.7%), respectively. The combined approach performed significantly better than grayscale and CETRUS imaging (P<.001 and P<.05, respectively). The index tumor detection rate of CETRUS was higher than that of grayscale imaging, but no significant difference was found (P>.05). CONCLUSION Our study has demonstrated significantly improved detection of both PCa and index tumor with a combined approach of CETRUS and grayscale imaging compared with baseline grayscale technique only, and this technique may be applicable to focal therapy of PCa.

Efficacy of 5α-reductase inhibitors for patients with large benign prostatic hyperplasia (>80 mL) after transurethral resection of the prostate.

Abstract Purpose: To prospectively evaluate 5α-reductase inhibitors (5αRIs) for benign prostatic hyperplasia (BPH) patients with a large prostate (>80 mL) after transurethral resection of the prostate (TURP). Materials and methods: Eighty-seven patients were recruited from January 2007 to October 2014. Patients were randomized into a trial and a control group. The trial group was treated with 5αRIs for 3 years after TURP, while the control group received a placebo. We evaluated the indicators before, peri and after TURP. Results: There were no significant differences in the indicators before and peri-TURP. Six months later, there were significant differences in PSA and hematuria (HU). Three years after TURP, there were significant differences in prostate volume (PV), level of prostate-specific antigen (PSA), the maximum flow rate (Qm), and HU between the trial and control groups. Additionally, there were significant differences in the PV, PSA, international prostate symptom score (IPSS), patient quality of life (QoL) in the trial group alone between those treated with finasteride and those treated with dutasteride. Conclusions: After TURP for large BPH, administration of 5αRIs for 3 years improved PV, PSA, Qm and HU. Additionally, dutasteride produced superior improvements in PV, PSA, IPSS and QoL compared with finasteride.

Efficient in vitro labeling of human prostate cancer cells with superparamagnetic iron oxide nanoparticles.

The purpose of this study was to investigate the feasibility and optimization of protocols using superparamagnetic iron oxide (SPIO) nanoparticles to label human prostate cancer cell lines PC3 in vitro. The PC3 cells were labeled with different concentrations (28-252 μg Fe/mL) of SPIO and increasing incubation time (6-24 hours), in the presence or absence of a transfection agent poly-l-lysine (PLL). The cell labeling efficiency was analyzed by Prussian blue stain method. The cellular viability was evaluated using trypan blue dye exclusion test. The signal intensity change of the labeled cells was assessed with magnetic resonance imaging (MRI). The results demonstrated that the iron oxide uptake by PC3 cells was dependent on dose and time. The PLL significantly increased the iron load of cells (p<0.01). A final concentration of SPIO nanoparticles of 42-126 μg/mL with 12-24 hours incubation times could be sufficient to label PC3 cells for cellular MRI without impairment of cell viability. This technology may allow for further study into the mechanisms underlying prostate cancer progression as well as permit the real-time imaging of the effectiveness of cancer therapies in vivo.