Period 2 Suppresses the Malignant Cellular Behaviors of Colorectal Cancer Through the Epithelial-Mesenchymal Transformation Process.

INTRODUCTION: The PER2 (Period circadian regulator 2) gene is related to the circadian clock, and it has been deemed as a suppressor gene in osteosarcoma and lung carcinoma. However, the part of PER2 in CRC (colorectal cancer) needs to be further determined. METHODS: First, we collected clinical samples to detect PER2 expression in CRC. Then, we used cell transfection to knock down PER2 expression in CRC cell lines and performed a series of functional experiments to elucidate the effects of PER2 on CRC cells. We next verified whether PER2 affects the epithelial-mesenchymal transformation (EMT) process in CRC by conducting quantitative real-time PCR and western blotting. RESULTS: In the research, we revealed that the expression of PER2 decreased in CRC clinical samples. In addition, knocking down PER2 expression caused CRC cells to acquire malignant biological features. Finally, we found that PER2 knockdown may activate the Snail/Slug axis through inhibiting p53, therefore promote the activation of the EMT pathway. CONCLUSION: In conclusion, low PER2 expression reinforces migration and activates EMT in CRC, suggesting that PER2 is closely related to CRC development and could be used as a potential treatment site in the clinic.

Identification of crucial genes of pyrimidine metabolism as biomarkers for gastric cancer prognosis.

BACKGROUND: Metabolic reprogramming has been reported in various kinds of cancers and is related to clinical prognosis, but the prognostic role of pyrimidine metabolism in gastric cancer (GC) remains unclear. METHODS: Here, we employed DEG analysis to detect the differentially expressed genes (DEGs) in pyrimidine metabolic signaling pathway and used univariate Cox analysis, Lasso-penalizes Cox regression analysis, Kaplan-Meier survival analysis, univariate and multivariate Cox regression analysis to explore their prognostic roles in GC. The DEGs were experimentally validated in GC cells and clinical samples by quantitative real-time PCR. RESULTS: Through DEG analysis, we found NT5E, DPYS and UPP1 these three genes are highly expressed in GC. This conclusion has also been verified in GC cells and clinical samples. A prognostic risk model was established according to these three DEGs by Univariate Cox analysis and Lasso-penalizes Cox regression analysis. Kaplan-Meier survival analysis suggested that patient cohorts with high risk score undertook a lower overall survival rate than those with low risk score. Stratified survival analysis, Univariate and multivariate Cox regression analysis of this model confirmed that it is a reliable and independent clinical factor. Therefore, we made nomograms to visually depict the survival rate of GC patients according to some important clinical factors including our risk model. CONCLUSION: In a word, our research found that pyrimidine metabolism is dysregulated in GC and established a prognostic model of GC based on genes differentially expressed in pyrimidine metabolism.

Metallic Inverse Opals: An Electrochemiluminescence enhanced Substrate for Sensitive Bioanalysis.

Here, we proposed a novel local surface plasmon resonance (LSPR) enhanced ECL strategy based on the metallic inverse opals and Ru(bpy)32+-doped silica nanoparticles (RuSi NPs). Gold inverse opals (GIOs), as a plasmonic array, could interact with the ECL of RuSi NPs and excite the electromagnetic (EM) field at the gold surface. The triggered EM field could enhance the ECL emission of RuSi NPs. We compared the electrochemical and ECL performances of RuSi NPs modified on the gold electrodes with different surface morphologies and found that the ECL emission of RuSi NPs patterned at the inner surface of GIOs exhibited the highest intensity. The finite-difference time-domain (FDTD) simulations indicated that the EM field was related to the surface morphology of the metallic nanostructure, and the highest EM field was observed at the inner surface of the GIOs. Because of the superior ECL performances, the inner surfaces of GIOs were developed for nucleic acid detection with a detection limit of 3.3 fM (S/N = 3), which shows great promise for bioanalysis.

Electrochemiluminescence Energy Resonance Transfer System between RuSi Nanoparticles and Hollow Au Nanocages for Nucleic Acid Detection.

This paper describes an electrochemiluminescence resonance energy transfer (ECL-RET) system using Ru(bpy)32+-doped silica nanoparticles (RuSi NPs) as the ECL donor and hollow Au nanocages as the ECL acceptor. Tetrahedron DNA (TD) was used to construct the biosensing interface and control the distance (4.8 nm) between the ECL donor-acceptor pairs. The surface plasmon resonance (SPR) nanostructures, Au nanocages were assembled via the hairpin based sandwich assay. Due to the well overlap between the plasmon absorption spectrum of Au nanocages (628 nm) and the ECL emission spectrum of RuSi NPs (620 nm), high efficient energy transfer could occur. Subsequent cyclic DNA amplification further increased the binding amount of Au nanocages. Since the ECL inhibition is closely related with the binding amount of Au nanocages, a general "signal-off" ECL bioassay could thus be tailored with high sensitivity. At the optimized conditions, this ECL-RET system performed well with great stability and repeatability for nucleic acid detection in the range from 1.0 fM to 10 pM. This work manifested the great promise of hollow Au nanocages for an ECL-RET biosensor that to the best of our knowledge has not been reported. We believe that it could inspire more interest in the design and development of numerous other SPR nanostructures for advanced ECL-RET biosensors.

Ultrasmall Nanopipette: Toward Continuous Monitoring of Redox Metabolism at Subcellular Level.

Ionic current rectification (ICR) based nanopipettes allow accurate monitoring of cellular behavior in single living cells. Herein, we proposed a 30 nm nanopipette functionalized with G-quadruplex DNAzyme as an efficient biomimetic recognizer for ROS generation at subcellular level via the changes of current-voltage relationship. Taking advantages of the ultra-small tip, the nanopipette could penetrate into a single living cell repeatedly or keep measuring for a long time without compromising the cellular functions. Coupled with precision nanopositioning system, generation of ROS in mitochondria in response to cell inflammation was determined with high spatial resolution. Meanwhile, the changes of aerobic metabolism in different cell lines under drug-induced oxidative stress were monitored continuously. We believe that the ICR-nanopipette could be developed as a powerful approach for the study of cellular activities via electrochemical imaging in living cells.

Synergetic surface enhancement of quantum dots-based electrochemiluminescence with photonic crystal light scattering and metal surface plasmon resonance for sensitive bioanalysis.

Noble metal nanostructures and photonic crystals (PhCs) have been widely investigated as substrates for constructing surface enhanced electrochemiluminescence (SE-ECL) biosensors. However, their applications are hindered by the limited enhancement intensity of surface plasmon resonance (SPR) and an incomplete mechanism for the photonic enhancement effect. Hence, developing a novel SE-ECL strategy with better signal enhanced capability and enriching our understanding of the intrinsic mechanisms for efficient bioanalysis is extremely urgent. Here, a synergistic SE-ECL strategy was developed for the sensitive determination of prostate specific antigen (PSA) protein. The randomly arranged polystyrene (r-PS) spheres and PS PhC arrays were applied to enhance the ECL emission of cadmium sulfide quantum dots (CdS QDs) and the results suggested that the PhC arrays displayed superior intensity (0.22) than the r-PS interface (0.10). Au nanoparticles (NPs) were introduced onto the two kinds of surfaces and further boosted the ECL intensity. According to the ECL measurements, Au NPs modified at the r-PS surface exhibited only a slight increase (0.13), while the PhC arrays showed approximately 5-fold enhancement (0.92), benefiting from the synergistic enhancement. The finite-difference time-domain (FDTD) simulation indicated that the ECL enhancement was ascribed to the coupled electromagnetic (EM) field at the surfaces of PS PhCs and Au NPs. The SE-ECL could achieve a detection range from 1 pg/mL to 1 µg/mL with a detection limit of 0.41 pg/mL (S/N = 3). This study provides the first combination of PhC arrays and metal surface plasmon nanostructure for the synergetic enhancement of SE-ECL systems. It opens a new avenue for the rational design of advanced ECL biosensors and shows great perspective for clinical diagnosis.

AIE fluorogen-based oxidase-like fluorescence nanozyme-integrated smartphone for monitoring the freshness authenticity of soy products.

Food safety concerns about the authenticity of soy product freshness have increased due to high demand from public. Developing an accurate and convenient monitoring method for freshness authenticity is crucial for safeguarding food safety. From this motive, this study employed PtPd NPs to encapsulate tetraphenylethylene (TPE) for engineering an AIE-based fluorescent nanozyme (PtPd NPs@TPE) with oxidase-like activity, achieving the ratiometric fluorescence monitoring of putrescine (PUT) to judge the freshness authenticity of soy products. In this design, PUT acted as an antioxidant and inhibited the oxidation process of PtPd NPs@TPE to o-phenylenediamine (OPD), leading to the reduction of oxidative product 2,3-diaminophenothiazine (DAP) alone with the weaken of yellow fluorescence from DAP at 552 nm and bright of bule fluorescence from PtPd NPs@TPE at 442 nm. On this basis, a ratiometric fluorescence strategy integrated with smartphone-based sensor was developed for PUT with acceptable results to combat food freshness fraud of soy products.

Colorimetric and ECL dual-mode aptasensor for smartphone-based onsite sensitive detection of aflatoxin B1 in combination with ZnO@MWCNTs/g-C3N4 nanosheets and CuO@CuPt nanocomposites.

The development of dual-mode strategies with superior sensitivity and accuracy have garnered increasing attention for researchers in Aflatoxin B1 (AFB1) analysis. Herein, a colorimetric-electrochemiluminescence (ECL) dual-mode biosensor was constructed for onsite and ultrasensitive determination of AFB1. The multi-wall carbon nanotubes (MWCNTs) were integrated with the ZnO metal organic frameworks (MOFs) to accelerate the electron transfer and boost the ECL intensity of g-C3N4 nanoemitters. Through the aptamer-based DNA sandwich assay, the CuO@CuPt nanocomposites were introduced onto the electrode and acted as the dual functional signal nanoprobes. Due to the good spectrum overlap between the CuO@CuPt nanoprobes and g-C3N4 nanosheets, ECL signal could be efficiently quenched. Additionally, the CuO@CuPt nanoprobes show superior catalytic properties towards the TMB and H2O2 colorimetric reactions, and an obvious color alteration from colorless to blue can be observed using the smartphone. Under optimized conditions, a sensitive and accurate dual-mode analysis of the AFB1 was accomplished with the colorimetric detection limit of 3.26 fg/mL and ECL detection limit of 0.971 fg/mL (S/N = 3). This study combines innovative nanomaterial properties of ZnO@MWCNTs, g-C3N4 and CuO@CuPt for ultrasensitive dual-mode detection, which offers new opportunities for the innovative engineering of the dual-mode sensors and demonstrates significant potential in food safety analysis.

External Beam Radiation therapy After Transarterial Chemoembolization Versus Transarterial Chemoembolization Alone for Treatment of Inoperable Hepatocellular Carcinoma: A Randomized Phase 3 Trial.

PURPOSE: To compare the outcomes of transarterial chemoembolization (TACE) alone with those of TACE combined with external beam radiation therapy (EBRT) in patients with hepatocellular carcinoma (HCC) in a multicenter randomized study. METHODS AND MATERIALS: From 2017 to 2022, 74 HCC patients with tumors confined to the liver without vascular invasion were treated with either TACE only (TACE group, 39 patients) or TACE combined with EBRT (TACE + EBRT group, 35 patients). The primary outcome measured was overall survival (OS). Secondary outcomes included progression-free survival (PFS), local tumor control, and the assessment of treatment-related toxicity. RESULTS: Due to slow accrual, the trial was closed prematurely after enrolling 74 patients. All patients received 2 cycles of TACE before randomization. The TACE and TACE + EBRT groups showed comparable patient and tumor characteristics. The TACE group underwent a median of 3 TACE cycles, and the TACE + EBRT group received 2 cycles of TACE, and a median of 5500 cGy in 15 fractions. For the TACE group, the median local control (LC) duration was 13.1 months, whereas for the TACE + EBRT group, the median LC was not achieved (P < .001). The PFS was recorded at 11.6 months in the TACE group compared with 15.4 months in the TACE + EBRT group (P = .072). The median OS reached 36.8 months for the TACE group and extended to 47.1 months for the TACE + EBRT group (P = .654). The incidence of toxicity was comparable between both groups. CONCLUSIONS: Although the number of patients enrolled in this clinical trial did not meet expectations. TACE combined with EBRT was shown to be more effective than TACE alone in improving LC without increasing toxicity, whereas PFS and OS were slightly improved. TACE + EBRT can be used as a standard treatment option for patients with inoperable but confined intrahepatic HCC.

Altered Patterns of Functional Connectivity and Causal Connectivity in Salience Subnetwork of Subjective Cognitive Decline and Amnestic Mild Cognitive Impairment.

The subjective cognitive decline (SCD) may last for decades prior to the onset of dementia and has been proposed as a risk population for development to amnestic mild cognitive impairment (aMCI) and Alzheimer disease (AD). Disruptions of functional connectivity and causal connectivity (CC) in the salience network (SN) are generally perceived as prominent hallmarks of the preclinical AD. Nevertheless, the alterations in anterior SN (aSN), and posterior SN (pSN) remain unclear. Here, we hypothesized that both the functional connectivity (FC) and CC of the SN subnetworks, comprising aSN and pSN, were distinct disruptive in the SCD and aMCI. We utilized resting-state functional magnetic resonance imaging to investigate the altered FC and CC of the SN subnetworks in 28 healthy controls, 23 SCD subjects, and 29 aMCI subjects. In terms of altered patterns of FC in SN subnetworks, aSN connected to the whole brain was significantly increased in the left orbital superior frontal gyrus, left insula lobule, right caudate lobule, and left rolandic operculum gyrus (ROG), whereas decreased FC was found in the left cerebellum superior lobule and left middle temporal gyrus when compared with the HC group. Notably, no prominent statistical differences were obtained in pSN. For altered patterns of CC in SN subnetworks, compared to the HC group, the aberrant connections in aMCI group were separately involved in the right cerebellum inferior lobule (CIL), right supplementary motor area (SMA), and left ROG, whereas the SCD group exhibited more regions of aberrant connection, comprising the right superior parietal lobule, right CIL, left inferior parietal lobule, left post-central gyrus (PG), and right angular gyrus. Especially, SCD group showed increased CC in the right CIL and left PG, whereas the aMCI group showed decreased CC in the left pre-cuneus, corpus callosum, and right SMA when compared to the SCD group. Collectively, our results suggest that analyzing the altered FC and CC observed in SN subnetworks, served as impressible neuroimaging biomarkers, may supply novel insights for designing preclinical interventions in the preclinical stages of AD.

Recent advances of ratiometric electrochemiluminescence biosensors.

Ratiometric electrochemiluminescence (ECL) assays have been widely applied in biosensing because of eliminated outside interferences and improved reliability in detection. In order to construct ratiometric ECL biosensors with high sensitivity and reliability, it is critical to find two signal emitters with suitable applied potentials or emission wavelengths. This review aims to discuss recent advances and trends of ratiometric ECL biosensors in terms of ECL materials and corresponding ratiometric sensing approaches. We focus on four types of ratiometric ECL biosensors based on particular ECL materials and ratiometric sensing strategies.

The double inhibition of PDK1 and STAT3-Y705 prevents liver metastasis in colorectal cancer.

As a key glycolysis enzyme, the significance of pyruvate dehydrogenase kinase 1 (PDK1) in the development of colorectal cancer (CRC) remains unknown. This study revealed that the prognosis of CRC patients with high levels of PDK1 was poor, and PDK1 knockdown significantly reduced liver metastasis of CRC in both nude mice and immune competent BALB/C mice. When combined with cryptotanshinone (CPT), an inhibitor of STAT3-p-Y705, the liver metastasis was further inhibited. PDK1 knockdown obviously increased reactive oxygen species level in anoikis conditions and subsequently resulted in an elevated anoikis, but the combination of PDK1 knockdown and CPT showed a reduced effect on anoikis. Based on this discrepancy, the adherence ability of CRC cells to matrix protein fibronectin was further detected. It showed that PDK1 knockdown significantly decreased the adherence of CRC cells to fibronectin when combined with CPT. These results suggest that inhibition of PDK1 can decrease the surviving CRC cells in blood circulation via up-regulation of anoikis, and inhibition of STAT3-p-Y705 can prevent it to settle down on the liver premetastatic niche, which ultimately reduces liver metastasis.

Visual electrochemiluminescence ratiometry on bipolar electrode for bioanalysis.

In this work, we developed a visual ECL ratiometry on a closed bipolar electrode (BPE) for the detection of prostate specific antigen (PSA), prostate cancer biomarker. High efficient CdTe QDs was synthesized which emitted visualized red light at BPE cathode. Integrating with the anodic ECL emitters, luminol, visual emission of red-blue ratiometric ECL was achieved in BPE array chips. As a sensing probe, Au NRs nanocomposite was assembled on the surface of the cathode and acted as both the quencher of the CdTe QDs ECL and the promoter of the luminol ECL. After incubated with PSA, the Au NRs nanocomposite was peeled off from the electrode surface due to the specific recognition between PSA and aptamer. Consequently, the cathode ECL partly recovered and the anode ECL turned off. By measuring the ratio of visual ECL intensity at two poles of BPE, sensitive detection of PSA was achieved with a linear range from 1.0ng/mL to 1.0µg/mL and detection limit of 0.5ng/mL (S/N=3). This strategy combining the BPE-ECL and visual ratiometry provided an accurate and intrinsic way for the sensing of PSA and showed good perspective in the clinical diagnosis.

Three-level spaser for next-generation luminescent nanoprobe.

The development of modern biological and medical science highly depends on advanced luminescent probes. Current probes typically have wide emission spectra of 30 to 100 nm, which limits the number of resolvable colors that are simultaneously labeled on samples. Spasers, the abbreviation for surface plasmon lasers, have ultranarrow lasing spectra by stimulated light amplification in the plasmon nanocavity. However, high threshold (>102 mJ cm-2) and short lasing lifetime (approximately picoseconds to nanoseconds) still remain obstacles for current two-level spaser systems. We demonstrated a new type of a three-level spaser using triplet-state electrons. By prolonging the upper state lifetime and controlling the energy transfer, high gain compensation was generated. This probe, named delayed spasing dots (dsDs), about 50 to 60 nm in size, exhibited a spectral linewidth of ~3 nm, an ultralow threshold of ~1 mJ cm-2, and a delayed lasing lifetime of ~102 µs. As the first experimental realization of the three-level spaser system, our results suggested a general strategy to tune the spasing threshold and dynamics by engineering the energy level of the gain medium and the energy transfer process. These dsDs have the potential to become new-generation luminescent probes for super-multiplex biological analysis without disturbance from short lifetime background emission.

Prediction of radiation-induced liver disease by Lyman normal-tissue complication probability model in three-dimensional conformal radiation therapy for primary liver carcinoma.

PURPOSE: To describe the probability of RILD by application of the Lyman-Kutcher-Burman normal-tissue complication (NTCP) model for primary liver carcinoma (PLC) treated with hypofractionated three-dimensional conformal radiotherapy (3D-CRT). METHODS AND MATERIALS: A total of 109 PLC patients treated by 3D-CRT were followed for RILD. Of these patients, 93 were in liver cirrhosis of Child-Pugh Grade A, and 16 were in Child-Pugh Grade B. The Michigan NTCP model was used to predict the probability of RILD, and then the modified Lyman NTCP model was generated for Child-Pugh A and Child-Pugh B patients by maximum-likelihood analysis. RESULTS: Of all patients, 17 developed RILD in which 8 were of Child-Pugh Grade A, and 9 were of Child-Pugh Grade B. The prediction of RILD by the Michigan model was underestimated for PLC patients. The modified n, m, TD50 (1) were 1.1, 0.28, and 40.5 Gy and 0.7, 0.43, and 23 Gy for patients with Child-Pugh A and B, respectively, which yielded better estimations of RILD probability. The hepatic tolerable doses (TD5) would be MDTNL of 21 Gy and 6 Gy, respectively, for Child-Pugh A and B patients. CONCLUSIONS: The Michigan model was probably not fit to predict RILD in PLC patients. A modified Lyman NTCP model for RILD was recommended.

Radiation-induced liver disease in three-dimensional conformal radiation therapy for primary liver carcinoma: the risk factors and hepatic radiation tolerance.

PURPOSE: To identify risk factors relevant to radiation-induced liver disease (RILD) and to determine the hepatic tolerance to radiation. METHODS AND MATERIALS: The data of 109 primary liver carcinomas (PLC) treated with hypofractionated three-dimensional conformal radiation therapy (3D-CRT) were analyzed. Seventeen patients were diagnosed with RILD and 13 of 17 died of it. RESULTS: The risk factors for RILD were late T stage, large gross tumor volume, presence of portal vein thrombosis, association with Child-Pugh Grade B cirrhosis, and acute hepatic toxicity. Multivariate analyses demonstrated that the severity of hepatic cirrhosis was a unique independent predictor. For Child-Pugh Grade A patients, the hepatic radiation tolerance was as follows: (1) Mean dose to normal liver (MDTNL) of 23 Gy was tolerable. (2) For cumulative dose-volume histogram, the tolerable volume percentages would be less than: V5 of 86%, V10 of 68%, V15 of 59%, V20 of 49%, V25 of 35%, V30 of 28%, V35 of 25%, and V40 of 20%. (3) Tolerable MDTNL could be estimated by MDTNL (Gy) = -1.686 + 0.023 * normal liver volume (cm3). CONCLUSION: The predominant risk factor for RILD was the severity of hepatic cirrhosis. The hepatic tolerance to radiation could be estimated by dosimetric parameters.

p53 Is a Direct Transcriptional Repressor of Keratin 17: Lessons from a Rat Model of Radiation Dermatitis.

The intermediate filament protein keratin 17 (Krt17) shows highly dynamic and inducible expression in skin physiology and pathology. Because Krt17 exerts physiologically important functions beyond providing structural stability to keratinocytes whereas abnormal Krt17 expression is a key feature of dermatoses such as psoriasis and pachyonychia congenita, the currently unclear regulation of Krt17 expression needs to be better understood. Using a rat model of radiation dermatitis, we report here that Krt17 expression initially is down-regulated but later is strongly up-regulated by ionizing radiation. The early down-regulation correlates with the activation of p53 signaling. Deletion of p53 abolishes the initial down-regulation but not its subsequent up-regulation, suggesting that p53 represses Krt17 transcription. Because previous work reported up-regulation of Krt17 by ultraviolet irradiation, which also activates p53 signaling, the effect of ultraviolet radiation was reexamined. This revealed that the initial down-regulation of Krt17 is conserved, but the up-regulation comes much faster. Chromatin immunoprecipitation analysis in vivo and electromobility shift assay in vitro identified two p53-binding sites in the promoter region of Krt17. Thus, p53 operates as a direct Krt17 repressor, which invites therapeutic targeting in dermatoses characterized by excessive Krt17 expression.

Effect of CyberKnife stereotactic body radiation therapy for hepatocellular carcinoma on hepatic toxicity.

OBJECTIVE: To evaluate the safety of CyberKnife stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC) patients and identify the treatment-related risk factors of hepatic toxicity. MATERIALS AND METHODS: One hundred and four HCC patients treated with CyberKnife SBRT were included in this study between August 2009 and December 2012. The average dose of prescribed radiation was 42.81±4.78 Gy (28-55 Gy) with the average fraction size of 8-16 Gy to the planning target volume. The average fractions were 3.31±0.81 (2-6 fractions). Response rates were determined, and the Child-Pugh (CP) score and class following CyberKnife SBRT were obtained to evaluate hepatic toxicity. RESULTS: Seventeen patients experienced progression in CP class and 24 patients experienced CTCAE V. 4.0 grade 2-3 hepatic toxicity during the five-month follow-up period, while no patient experienced grade 4 liver toxicity. Multivariate analysis indicated that only V25 was an independent factor in grade 2-3 hepatic toxicity (P=0.029, <0.05). Radiation-induced hepatic toxicity (RIHT), defined as an increase of at least two points within three months following CyberKnife SBRT, occurred in 13 of the 104 patients (13/104, 12.5%), and only the normal liver tissue was found to be associated with RIHT (P=0.008, <0.05). CONCLUSION: CyberKnife SBRT is a feasible and safe treatment for HCC with regard to hepatic toxicity, while V25 and normal liver volume may be an independent factor of grade 2-3 hepatic toxicity and RIHT, respectively.

Spatial-resolved electrochemiluminescence ratiometry based on bipolar electrode for bioanalysis.

Herein, a spatial-resolved electrochemiluminescene (ECL) ratiometry based on a closed biopolar electrode (BPE) is reported for the highly sensitive detection of prostate specific antigen (PSA). Au@g-C3N4 NCs as one ECL emitter were firstly coated on the cathode of BPE, while the anode of the BPE served for calibration via another ECL substance, Ru(bpy)3(2+). The electroneutrality across the BPE makes the reactions on each pole of BPE electrically coupled. Thus one electrochemical sensing reaction at one pole of BPE could be quantified at both ends. A composite, Pt-PAMAM-DNAzyme was assembled on the surface of cathode via DNA hybridization between probe DNA and PSA aptamer. It acted as an ECL quencher of g-C3N4 via resonance energy transfer (RET) and catalyzing the reduction of O2, the co-reactant of g-C3N4. Meanwhile, it could promote the ECL of Ru(bpy)3(2+) at anode, since the catalytic reduction of O2 at the cathode increased the faradiac current flowing through the BPE. Based on this signal composite, an ECL "off-on" phenomenon was observed at the cathode, after Pt-PAMAM-DNAzyme was "peeled off" by PSA. Conversely, at the anode, an "on-off" ECL changing was obtained. Therefore, a sensitive ratiometry for PSA detection was achieved with a linear range from 0.10 to 200ng/mL. Since the two ECL emitters were physically separated, the ratiometric system was relatively simple and neither optical filters nor spectrometer were required. The strategy combining the ECL ratiometry and BPE broadens the applications of BPE-ECL and shows good perspective in clinical application.

[Prognostic factor of primary liver cancer treated by hypofractionated three-dimensional conformal radiotherapy].

OBJECTIVE: To evaluate the toxicity and efficacy of primary liver cancer (PLC) treated by hypofractionated three-dimensional conformal radiotherapy (3DCRT) and investigate the prognostic factors. METHODS: Between April 1999 and August 2003, 128 PLC patients received hypofractionated 3DCRT. According to UICC/AJCC staging system, there were 83 T3 patients, 45 T4, with none of them having lymph node metastasis. The mean value of gross tumor volume (GTV) was (458.92 +/- 429.8) cm(3) (6.2-2097 cm(3)). Thirty-four patients had portal vein tumor thrombosis (PVTT). 108 patients had Child-Pugh Grade A liver cirrhosis and 20 Child-Pugh Grade B liver cirrhosis. All patients received a total dose of (53.6 +/- 6.6) Gy/4-8 Gy per fraction/3 fractions per week. Forty-eight of these patients received 3DCRT combined with transarterial chemoembolization (TACE). RESULTS: Seven patients died within 3 months after the treatment were dismissed from the series. The response rate (CR + PR) was 55% (67/121). The overall 1-, 2-, and 3-year survival rate was 65.0%, 43.3%, and 33.1%, respectively. T stage (P = 0.001), GTV (P = 0.0001), PVTT (P = 0.0001) and Child-Pugh Grade (P = 0.0001) had significant impact on the overall survival. However, only GTV and Child-Pugh Grade were independent significant prognostic factors by Cox-regression analysis, (P = 0.044 and P = 0.015). CONCLUSION: T stage, GTV, PVTT and Child-Pugh Grade have significant impact on the overall survival in primary liver cancer patients treated by three-dimensional conformal radiotherapy. But only GTV and Child-Pugh Grade are independent prognostic factors.