Risk factors for the recurrence of early hepatocellular carcinoma treated by percutaneous radiofrequency ablation with a multiple-electrode switching system: a multicenter prospective study.

PURPOSE: To investigate the long-term efficacy of radiofrequency ablation (RFA) with a multiple-electrode switching system (MESS) in the treatment of early hepatocellular carcinoma (HCC) and evaluate the patterns and risk factors of intrahepatic recurrence of HCC after RFA. METHODS: In total, 139 patients with early HCC who underwent RFA with MESS as primary treatment at multiple centers were prospectively enrolled according to the inclusion criteria. We evaluated the local tumor progression (LTP), intrahepatic distant recurrence (IDR), the incidence of cumulative disease-free survival (DFS), LTP-free survival, IDR-free survival, and overall survival. We also analyzed the associated risk factors. RESULTS: A total of 139 patients were included in the study and the median follow-up time was 64 months, ranging from 11 to 72 months. The complete ablation rate was 98.56%. Sixty-nine (49.64%) were found to have intrahepatic recurrence (LTP, n = 15; IDR, n = 55) during follow-up. The 1-year, 3-year and 5-year cumulative DFS, LTP-free survival, and IDR-free survival rates were 74.82, 94.46 and 78.75%; 54.68, 88.03 and 61.79%; and 51.80, 85.67 and 60.17%, respectively. In the multivariable analysis, tumor size > 4 cm was the only important risk factor for LTP. The alkaline phosphatase (ALP) level and the number of tumors were independent risk factors for IDR; α-fetoprotein (AFP) level > 400 µg/L and recurrence interval were risk factors for the overall survival period. CONCLUSIONS: The MESS-RFA is an effective method for local control of tumors in early HCC. Early HCC with multiple high-ALP tumors has a higher rate of recurrence, which mainly occurs in an IDR pattern. Early HCC with high AFP levels and a shorter initial recurrence interval resulted in a poorer prognosis. Thus, treatments such as liver transplantation or surgical resection may be a good strategy in those cases. CLINICALTRIALS.GOV ID: NCT02046356.

Design of Double-Layer Electrically Extremely Small-Size Displacement Sensor.

In this paper, a displacement sensor with an electrically extremely small size and high sensitivity is proposed based on an elaborately designed metamaterial element, i.e., coupled split-ring resonators (SRRs). The sensor consists of a feeding structure with a rectangular opening loop and a sensing structure with double-layer coupled SRRs. The movable double-layer structures can be used to measure the relative displacement. The size of microwave displacement sensors can be significantly reduced due to the compact feeding and sensing structures. By adjusting the position of the split gap within the resonator, the detection directions of the displacement sensing can be further expanded accordingly (along with the x- or y-axis) without increasing its physical size. Compared with previous works, the extremely compact size of 0.05λ0 × 0.05λ0 (λ0 denotes the free-space wavelength), a high sensitivity, and a high quality factor (Q-factor) can be achieved by the proposed sensor. From the perspective of the advantages above, the proposed sensor holds promise for being applied in many high-precision industrial measurement scenarios.

High-efficiency directional excitation of spoof surface plasmons by periodic scattering cylinders.

In this Letter, we propose and experimentally demonstrate a simple but efficient method to excite spoof surface plasmons (SSP) through periodic metallic cylinders at microwave frequencies. The rigorous multiple scattering theory indicates that most of the incident propagating waves can pass the cylinders and be converted into the desired harmonics. Furthermore, by tuning the incident angle, controlling the directions of the excited SSP at different frequencies is also realized. The numerical simulations achieve a bidirectional efficiency of 90% at 9.68 GHz and unidirectional efficiency of 79%-85% at 7.46-9.7 GHz, when the incident angle changes from 60° to 120°. Meanwhile, the maximum contrast ratio between the powers of SSP launched in two opposite directions can reach up to 34 dB. The experimental results under 90° and 77.5° illuminations at 9.68 and 8.56 GHz provide strong support for the coupling mechanism. This method may provide technique support in the SSP-based communication and imaging systems.

Targeting autophagy enhances heat stress-induced apoptosis via the ATP-AMPK-mTOR axis for hepatocellular carcinoma.

PURPOSE: Radiofrequency ablation (RFA) is widely accepted as a curative treatment for small hepatocellular carcinoma (HCC). However, insufficient RFA (IRFA) can lead to rapid local recurrence. The underlying mechanisms remain poorly understood. This study aimed to elucidate the role and regulatory mechanisms of autophagy in the recurrence of HCC after IRFA. MATERIALS AND METHODS: SMMC7721 and Huh7 cells were exposed to sublethal heat stress to stimulate the transition zone of IRFA treatment. The levels of autophagy were measured by western blot, immunofluorescence and transmission electron microscopy. Functional assays, such as CCK-8, EdU incorporation and flow cytometry, were performed to determine the role of heat-induced autophagy. The involved signaling pathways were explored by western blot. Finally, the antitumor effects of chloroquine (CQ) on heat-treated HCC cells were evaluated via an in vivo xenograft tumor model. RESULTS: Sublethal heat stress induced autophagy in a temperature- and time-dependent manner in HCC cells. Furthermore, the inhibition of autophagy by CQ or siRNA targeting the autophagy-related genes Beclin-1 and Atg5 enhanced heat-induced apoptosis. The combination of CQ and heat treatment significantly suppressed tumor growth both in vitro and in vivo. Mechanistically, we reported for the first time that the ATP-AMPK-mTOR signaling pathway was involved in heat-induced autophagy. CONCLUSIONS: Heat stress induced protective autophagy against heat-induced apoptosis in HCC via the ATP-AMPK-mTOR axis, suggesting that targeting autophagy may be a promising strategy for improving the efficacy of RFA treatment for HCC.

Experimental demonstration of an ultra-broadband subwavelength resolution probe from microwave to terahertz regime.

An ultra-broadband subwavelength resolution probe that consists of a Teflon rod and six metallic strips is developed for the near-field imaging system. The slit between two metallic strips maintains quasi-TEM modes, avoiding the problem of low coupling efficiency caused by the cutoff effect. The numerical calculations visualize the process of energy compression into a 0.047λ diameter spot with great field enhancement at the taper apex, and the probe holds subwavelength focusing behavior from 10 GHz to 0.25 THz. Although limited by the fabrication, the resolution of 0.16 and 0.25λ are still experimentally demonstrated at 14 GHz and 0.1 THz. The properties of easy fabrication and no cutoff frequency would lower the threshold of a high-resolution near-field imaging system.

Radiofrequency ablation using a multiple-electrode switching system for hepatocellular carcinoma within the Milan criteria: long-term results.

PURPOSE: To assess the long-term outcome of 516 consecutive patients treated with multiple-electrode switching system (MESS) radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) that met the Milan criteria. MATERIALS AND METHODS: We performed 522 MESS RFAs on 516 patients from December 2006 to June 2011. A total of 956 tumours that met the Milan criteria with an average diameter of 2.64 cm (range, 0.9-4.6 cm) were treated with MESS RFA. Ultrasonic contrast and serum α-fetoprotein (AFP) were measured every 2 months during the first postoperative year and every 4 months thereafter. Enhanced computed tomography was performed every 6 months. Survival was estimated using the Kaplan-Meier method. Follow-up was censored at 60 months. Multivariate analysis was performed using the Cox proportional hazards model. RESULTS: For the 956 HCC tumours, the complete ablation rate with MESS was 98.83% (510/516). During a median of 34 months (IQR, 23-52 months) of follow-up, 171 patients died and 4 were lost to follow-up (15, 30, 38 and 42 months). The cumulative incidence of local tumour progression at 1, 3 and 5 years was 0.39%, 4.96% and 6.66%, respectively, and the 1-, 3- and 5-year overall survival was 99.42%, 83.97% and 68.42%, respectively. Tumour size >30 mm was the only parameter that was predictive of local tumour progression (p < .0001). Risk factors associated with overall survival included prothrombin time >14 s, serum AFP levels >200 ng/mL and tumour abutting vessel diameter <5 mm. The complication rate was 1.74%. CONCLUSION: MESS RFA is a safe and effective method for HCC treatment. This approach results in a high local progression-free survival for HCC tumours that meet the Milan criteria.

Long noncoding RNA expression profiles in sub-lethal heat-treated hepatoma carcinoma cells.

BACKGROUND: Sub-lethal heat treatment characterizes a transition zone of radiofrequency ablation (RFA) which explains hepatocellular carcinoma (HCC) residual cancer occurrence in this area after RFA treatment. The biochemistry of residual cancer cell recurrence is poorly understood, but long noncoding RNAs (lncRNAs) may have aberrant expression that is associated with diverse cancers. Thus, we measured lncRNA gene expression in sub-lethally heat-treated HCC cells using microarray. METHOD: Differentially expressed lncRNA and mRNA were measured with an Agilent Human lncRNA + mRNA Array V4.0 (4 × 180 K format) containing 41,000 lncRNAs and 34,000 mRNAs. Bioinformatics analysis was used to assess differentially expressed lncRNA and mRNA. Seven lncRNA and seven mRNA were validated by qRT-PCR analysis in HCC cells. RESULTS: Genome-wide lncRNA and mRNA expression data in sub-lethal heat-treated SMMC-7721 HCC cells 558 lncRNA and 250 mRNA were significantly up-regulated and 224 lncRNA and 1031 mRNA down-regulated compared to normal cultured SMMC-7721 cells. We demonstrated for the first time that ENST00000570843.1, ENST00000567668.1, ENST00000582249.1, ENST00000450304.1, TCONS_00015544, ENST00000602478.1, TCONS_00001266 and ARC, IL12RB1, HSPA6 were upregulated, whereas STAT3, PRPSAP1, MCU, URB2 were down-regulated in sub-lethally heat-treated HCC cells. CONCLUSIONS: lncRNA expression data in sub-lethally heat-treated HCC cells will provide important insights about lncRNAs' contribution to HCC recurrence after RFA treatment.

The Causal Relationships Between Extrinsic Exposures and Risk of Prostate Cancer: A Phenome-Wide Mendelian Randomization Study.

BACKGROUND: Prostate cancer is the second most common cancer in males worldwide, and multitudes of factors have been reported to be associated with prostate cancer risk. OBJECTIVES: We aim to conduct the phenome-wide exposed-omics analysis of the risk factors for prostate cancer and verify the causal associations between them. METHODS: We comprehensively searched published systematic reviews and meta-analyses of cohort studies and conducted another systematic review and meta-analysis of the Mendelian randomization studies investigating the associations between extrinsic exposures and prostate cancer, thus to find all of the potential risk factors for prostate cancer. Then, we launched a phenome-wide two-sample Mendelian randomization analysis to validate the potentially causal relationships using the PRACTICAL consortium and UK Biobank. RESULTS: We found a total of 55 extrinsic exposures for prostate cancer risk. The causal effect of 30 potential extrinsic exposures on prostate cancer were assessed, and the results showed docosahexaenoic acid (DHA) [odds ratio (OR)=0.806, 95% confidence interval (CI): 0.661-0.984, p=0.034], insulin-like growth factor binding protein 3 (IGFBP-3) (OR=1.0002, 95%CI: 1.00004-1.0004, p=0.016), systemic lupus erythematosus (SLE) (OR=0.9993, 95%CI: 0.9986-0.99997, p=0.039), and body mass index (BMI) (OR=0.995, 95%CI: 0.990-0.9999, p=0.046) were associated with prostate cancer risk. However, no association was found between the other 26 factors and prostate cancer risk. CONCLUSIONS: Our study discovered the phenome-wide exposed-omics risk factors profile of prostate cancer, and verified that the IGFBP-3, DHA, BMI, and SLE were causally related to prostate cancer risk. The results may provide new insight into the study of the pathogenesis of prostate cancer.

miR-103 promotes hepatocellular carcinoma cell proliferation and migration in the simulation transition zone of RFA through PI3K/Akt signaling pathway by targeting PTEN.

Radiofrequency ablation (RFA) is a potentially curative therapy for nontransplantable hepatocellular carcinoma (HCC). However, as tumor size increases, incomplete RFA can increase rates of local recurrence and tumor progression. As such, there remains a need to identify potential biologic mechanisms mediating HCC response to thermal ablation. Our results revealed that miR-103 was markedly upregulated in recurrent HCC tissues treated with RFA as first-line treatment and in HCC lines after heat stress in vitro, simulating the marginal zone of RFA treatment. Gain-of-function and loss-of-function studies showed that miR-103 ectopic overexpression promoted, but miR-103 silencing reduced, heat-exposed HCC proliferation, and migration in vitro. Western blotting displayed that proteins related with proliferation and migration were significantly changed in different groups. Furthermore, PTEN may be a potential target of miR-103 and miR-103 could activate the PI3K/Akt pathway by suppressing PTEN expression. Taken together, these studies provide experimental evidence supporting a role for miR-103 in HCC response to heat stress.

Tunable Terahertz Deep Subwavelength Imaging Based on a Graphene Monolayer.

The resolution of conventional terahertz (THz) imaging techniques is limited to about half wavelength, which is not fine enough for applications of biomedical sensing and nondestructive testing. To improve the resolution, a new superlens, constructed by a monolayer graphene sheet combining with a grating voltage gate, are proposed in this paper to achieve deep super-resolution imaging in the THz frequency range. The main idea is based on the Fabry-Perot resonance of graphene edge plasmon waves. By shaping the voltage gate into a radial pattern, magnified images of subwavelength targets can be obtained. With this approach, the finest resolution can achieve up to λ/150. Besides, the superlens can be conveniently tuned to work in a large frequency band ranging from 4.3 THz to 9 THz. The proposal could find potential applications in THz near-field imaging systems.

Near-Field and Far-Field Directional Conversion of Spoof Surface Plasmon Polaritons.

A compact metallic meta-structure is proposed to realize directional conversion between spoof surface plasmon polaritons (SSPPs) and propagating waves at millimeter wave and THz frequencies. The structure is constructed by embedding two slits or multi-slits array into a subwavelength metallic reflection grating. When the back-side of the structure is illuminated by an oblique beam with a fixed incident angle, the propagating wave will be unidirectionally converted into SSPPs with a considerable efficiency. Both the simulations and experiments demonstrate that the excitation ratio of the SSPPs between the two possible propagating directions (left and right) reaches up to about 340. Furthermore, assisted by the structure, near-field SSPPs can be also converted into far-field narrow beams with particular directions. Through frequency sweeping, wide-angle beam scanning is verified by theory and experiments. The work paves a new way for SSPPs launching and also provides fresh ideas for super-resolution imaging in the longer wavelength range.

Successful treatment of gastrointestinal stromal tumor with multiple liver metastases with radiofrequency ablation and imatinib: A case report.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor of the gastrointestinal tract, and typically metastasize to the liver. In patients with recurrent metastatic GISTs, no single treatment is effective. The current study reports a case of GIST with 27 metastases in the liver, which was successfully treated using radiofrequency ablation (RFA) combined with surgical resection and imatinib therapy. The patient remains tumor-free 36 months after the first RFA treatment. This case suggests that comprehensive therapy including surgical resection, RFA and imatinib, may be an effective strategy for the treatment of GIST with multiple liver metastases.

[Characteristics of volatile organic compounds during haze episode in Foshan city].

Volatile Organic Compounds (VOCs) in Foshan City were investigated in December 6 to 30 2008. The concentrations of VOCs in haze days were significantly higher than those in no-haze days. Toluene (68.93 microg x m(-3) +/- 37.78 microg x m(-3)) was the most abundant compound of VOCs in haze days and i-pentane (20.59 microg x m(-3) +/- 14.28 microg x m(-3)) was the most abundant compound in no-haze days, respectively. During haze episodes, the diurnal variations of alkanes and alkynes were not significantly; however, alkenes and aromatic hydrocarbon decreased significantly at noon. During no-haze episodes, the diurnal variations patterns of VOCs were stable. Propylene-equivalent concentrations in haze days were significantly higher than those in no-haze days, toluene was the most abundant compound of Propylene-equivalent concentration in haze days, followed by propene and ethene; propene was the most abundant compound in no-haze days, followed by ethene and 1-butene. High concentration of benzene (18.1 microg x m(-3)) in haze days posed a great health threat to public in Foshan city. Both diurnal variation of VOCs and measured ratios indicated vehicular emissions acted as the main sources of most VOCs and other sources like solvent application also contributed to VOCs (benzene and toluene).