A novel dual-signal output strategy for POCT of CEA based on a smartphone electrochemical aptasensing platform.

A smartphone-based electrochemical aptasensing platform was developed for the point-of-care testing (POCT) of carcinoembryonic antigen (CEA) based on the ferrocene (Fc) and PdPt@PCN-224 dual-signal labeled strategy. The prepared PdPt@PCN-224 nanocomposite showed a strong catalytic property for the reduction of H2O2. Phosphate group-labeled aptamer could capture PdPt@PCN-224 by Zr-O-P bonds to form PdPt@PCN-224-P-Apt. Therefore, a dual signal labeled probe was formed by the hybridization between Fc-DNA and PdPt@PCN-224-P-Apt. The presence of CEA forced PdPt@PCN-224-P-Apt to leave the electrode surface due to the specific affinity, leading to the decrease of the reduction current of H2O2. At the same time, the Fc-DNA strand changed to hairpin structure, which made Fc closer to the electrode and resulted in the increase of the oxidation current of Fc. Thus, CEA can be accurately determined through both signals: the decrease of H2O2 reduction current and the increase of Fc oxidation current, which could avoid the false positive signal. Under the optimal conditions, the prepared aptasensor exhibited a wide linear range from 1 pg·mL-1 to 100 ng·mL-1 and low detection limits of 0.98 pg·mL-1 and 0.27 pg·mL-1 with Fc and PdPt@PCN-224 as signal labels, respectively. The aptasensor developed in this study has successfully demonstrated its capability to detect CEA in real human serum samples. These findings suggest that the proposed sensing platform will hold great potential for clinical tumor diagnosis and monitoring.

Distinguishable Magnetic Reporter Coordination with Buoyancy-Magnetism Separation for Immobilization-Free Dual-Target Electrochemical Immunosensing.

Simultaneous sensitive and precise determination of multibiomarkers is of great significance for improving detection efficiency, reducing diagnosis and treatment expenses, and elevating survival rates. However, the development of simple and portable biosensors for simultaneous determination of multiplexed targets in biological fluids still faces challenges. Herein, a unique and versatile immobilization-free dual-target electrochemical biosensing platform, which combines distinguishable magnetic signal reporters with buoyancy-magnetism separation, was designed and constructed for simultaneous detection of carcinoembryonic (CEA) and α-fetoprotein (AFP) in intricate biological fluids. To construct such distinguishable magnetic signal reporters with signal transduction, amplification, and output, secondary antibodies of CEA and AFP were respectively functionalized on methylene blue (MB) and 6-(ferrocenyl)hexanethiol (FeC) modified Fe3O4@Au magnetic nanocomposites. Meanwhile, a multifunctional flotation probe with dual target recognition, capture, and isolation capability was prepared by conjugating primary antibodies (Ab1-CEA, Ab1-AFP) to hollow buoyant microspheres. The target antigens of CEA and AFP can trigger a flotation-mediated sandwich-type immunoreaction and capture a certain amount of the distinguishable magnetic signal reporter, which enables the conversion of the target CEA and AFP quantities to the signal of the potential-resolved MB and FeC. Thus, the MB and FeC currents of magnetically adsorbed distinguishable magnetic reporters can be used to determine the CEA and AFP targets simultaneously and precisely. Accordingly, the proposed strategy exhibited a delightful linear response for CEA and AFP in the range of 100 fg·mL-1-100 ng·mL-1 with detection limits of 33.34 and 17.02 fg·mL-1 (S/N = 3), respectively. Meanwhile, no significant nonspecific adsorption and cross-talk were observed. The biosensing platform has shown satisfactory performance in the determination of real clinical samples. More importantly, the proposed approach can be conveniently extended to universal detection just by simply substituting biorecognition events. Thus, this work opens up a new promising perspective for dual and even multiple targets and offers promising potential applications in clinical diagnosis.

Dual-potential ratiometric electrochemiluminescence based on single emitter and single coreactant for the sensitive detection of carcinoembryonic antigen.

Dual-potential ratiometric electrochemiluminescence (ECL) is in favor of resistance to environmental interference. However, two kinds of emitters or coreactants, and a wide scan potential range (>2 V) are mandatory. This work developed a new dual-potential ratiometric ECL sensor for detection of carcinoembryonic antigen (CEA) using single emitter (luminol) and single coreactant (H2O2) with a mild potential range from -0.1 to 0.6 V. Luminol could produce a strong cathodic ECL (Ec) induced by hydroxyl radicals (HO‧) from the reduction of H2O2, and a relatively weak anodic ECL (Ea). After the ferrocene modified CEA aptamer (Apt-Fc) was attached, Fc could promote Ea by catalyzing the oxidation of H2O2, and reduce Ec by consuming HO‧. With the cycling amplification of the exonuclease I, CEA could substantially reduce the amount of Apt-Fc, resulting in the decrease of Ea and the rise of Ec. So, the ratio of Ec to Ea (Ec/Ea) was used as the detection signal, realizing the sensitive determination of CEA from 0.1 pg mL-1 to 10 ng mL-1 with a LOD of 41.85 fg mL-1 (S/N = 3). The developed sensor demonstrated excellent specificity, stability and reproducibility, with satisfactory results in practical detection.

A smartphone-based electrochemical POCT for CEA based on signal amplification of Zr6MOFs.

Carcinoembryonic antigen (CEA) is a biomarker of high expression in cancer cells. Highly sensitive and selective detection of CEA holds significant clinical value in the diagnosis, monitoring and efficacy evaluation of malignant tumors. In this work, a smartphone-based electrochemical point-of-care testing (POCT) platform for the detection of CEA was developed based on a Zr6MOF signal amplification strategy. Ferrocene labeled DNA strands (Fc-DNA) were immobilized on Zr6MOFs to form a Fc-DNA/Zr6MOF signal probe. Double-stranded DNA (dsDNA) formed by complementary DNA (cDNA) and CEA aptamer was assembled on a screen-printed electrode via an Au-S bond. When CEA was added, the aptamer specifically bound with CEA, resulting in the exposure of cDNA. Then, Fc-DNA/Zr6MOF signal probes were introduced on the electrode surface through hybridization between Fc-DNA and cDNA. The detection of CEA was realized by measuring the electrochemical response of Fc. The POCT device was made by connecting a modified electrode with a smartphone through a Sensit Smart USB flash disk. Due to the signal amplification of Zr6MOFs, this POCT platform exhibited high sensitivity, wide linear range, and low detection limit for CEA detection. The developed POCT platform has been used for the detection of CEA in actual human serum samples with satisfactory results.

A label-free electrochemical aptasensor based on Bi-Sb alloy materials for potential POCT of HER-2.

As a prognostic biomarker for breast cancer, human epidermal growth factor receptor 2 (HER-2) is of crucial diagnostic value. Here, a label-free electrochemical aptasensor was established for the ultrasensitive detection of HER-2 using a modified electrode of Bi-Sb alloy materials (Bi-Sb AMs). The performance of the aptasensor was enhanced greatly due to the introduction of Bi-Sb alloy materials (Bi-Sb AMs) with high conductivity. Furthermore, by integrating the aptasensor with the Sensit Smart U-disk electrochemical analyzer, the point-of-care testing (POCT) for HER-2 was realized. Under the optimal experimental parameters, the POCT analyzer showed a wide linear response from 0.01 pg mL-1 to 100 ng mL-1, with a low detection limit (LOD) of 5.96 fg mL-1 for the detection of HER-2. The presented POCT analyzer exhibited good specificity, stability, and reproducibility. Benefiting from the simple operation and rapid testing, the developed analyzer will have potential application in the prognostic diagnosis and treatment of breast cancer.

Fascinating Immobilization-Free Electrochemical Immunosensing Strategy Based on the Cooperation of Buoyancy and Magnetism.

Rapid and accurate detection of biomolecules is of vital importance for the diagnosis of disease and for performing timely treatments. The point-of-care analysis of cancer biomarkers in the blood with low cost and easy processing is still challenging. Herein, an advanced and robust strategy, which integrates the buoyant recognition probe with the magnetic reporter probe in one solution, was first proposed for immobilization-free electrochemical immunosensing. The tumor marker of alpha fetoprotein (AFP) can be captured immune-buoyantly, and then a multifunctional magnetic reporter probe in pseudo-homogeneous solution was further captured to fulfill a sandwich-type immunoreaction. The residual magnetic reporter probe can be firmly and efficiently attracted on a magnetic glassy carbon electrode to fulfill the conversion of the target AFP amount into the residual magnetic electrochemical signal indicator. As a result, the electrochemical signal of methylene blue can accurately reflect the original level of target antigen AFP concentration. By integrating buoyancy-driven quasi-homogenous biorecognition with magnetism-mediated amplification and signal output, the proposed immobilization-free electrochemical immunosensing strategy displayed a wide range of linear response (100 fg mL-1 to 10 ng mL-1), low detection limit (14.52 fg mL-1), and good reproducibility, selectivity, and stability. The designed strategy manifests remarkable advantages including assay simplicity, rapidness, and high sensitivity owing to the in-solution instead of on-electrode biorecognition that could accelerate and improve the biorecognition efficiency. To the best of our knowledge, this is the first cooperation of buoyancy-driven biorecognition with magnetism-mediated signal output in bioanalysis, which would be attractive for rapid clinic biomedical application. Thus, this work provides a fresh perspective for convenient and favorable immobilization-free electrochemical biosensing of universal biomolecules.

Ratiometric Electrochemiluminescence Sensing of Carcinoembryonic Antigen Based on Luminol.

Ratiometric electrochemiluminescence (ECL) sensors can efficiently remove environmental interference to attain precise detection. Nonetheless, two eligible luminophores or coreactants were usually needed, increasing the complexity and restricting their practical application. In this study, a single luminophore of luminol with a single coreactant of H2O2 was employed to construct a dual-potential ratiometric ECL sensor for the detection of carcinoembryonic antigen (CEA). The produced palladium nanoclusters (Pd NCs) employing a DNA duplex as a template could not only stimulate luminol to produce cathodic ECL (Icathodic) but also quench its anodic ECL (Ianodic). During the detection process, CEA could damage the double-stranded structure and reduce the Pd NCs' amount, triggering a significant decrease in the ratio of Icathodic to Ianodic (Icathodic/Ianodic) and thereby achieving sensitive CEA's detection. Furthermore, the Icathodic/Ianodic was independent of the H2O2 concentration, which avoided a prejudicial effect from H2O2 decomposition and considerably enhanced the detection's reliability. The developed ratiometric ECL sensor demonstrated a sensitive detection toward CEA with a wide linear range from 100 ag/mL to 10 ng/mL and a detection limit of 87.1 ag/mL (S/N = 3). In conclusion, this study offers a new idea for constructing ratiometric ECL sensors based on a single luminophore and technical support for cancer's early diagnosis.

Responses of nickel bioavailability and toxicity of Prorocentrum Donghaienses to dissolved organic matter (DOM) fractions incubated in urea.

Urea, nickel (Ni) and dissolved organic matter (DOM) from land varied with different sources have a great impact on the offshore ecosystem. The heterogeneity of Ni bioavailability and toxicity of Prorocentrum donghaiense influenced by DOM fractions incubated in urea was investigated in this study. On the occasion, chlorophyll (Chl a) concentration, growth rate, and photosynthesis parameters were monitored to track changes occurring in the test organism. Chl a concentration and photosynthesis parameters in the treatment of hydrophilic DOM (HPI) with Ni-free was significantly higher than that in the control treatment, and similar data were shown in the treatment of hydrophobic DOM（HPO）with the low Ni environment (0.17µmol L-1). However, the opposite phenomena were observed in the treatments of HPO with the higher Ni environment (over 170µmol L-1). Moreover, the EC50 of Ni for P.donghaiense incubated in HPO was relatively lower than that in HPI and control treatment, which implied that HPO elevated the toxicity of Ni. Therefore, the varied DOM compositions because of different origins, as a chelating agent and potential nutrient source in coastal waters, shows the significantly different bioavailability and toxicity of Ni with the increasing inputs of urea, which in turn influences the dynamics of phytoplankton.

Graphene-PtPd nanocomposite for low-potential-driven electrochemiluminescent determination of carcinoembryonic antigen using Ru(bpy)32.

As well known, the electrochemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(II) (Ru(bpy)32+) heavily relies on highly positive or negative triggered voltage, prejudicing the detection toward the bio-molecules. In this work, Ru(bpy)32+ could generate enhanced and stable ECL at a low potential of 0.05 V (vs. Ag/AgCl) on graphene-PtPd hybrid, attributing to its excellent electrocatalysis from the synergistic effect between Pt and Pd. The obtained low-potential-driven ECL could be quenched by MoS2 nanoflowers. Based on the quenching effect, a sandwich "signal-off" ECL immunosensor was fabricated to sensitively detect carcinoembryonic antigen (CEA). A linear calibration curve from 1 fg mL-1 to 1 ng mL-1 was obtained along with a low detection limit of 0.54 fg mL-1 (S/N = 3) under optimal conditions. The sensor showed satisfactory specificity, stability, and reproducibility and was successfully applied to determine CEA in actual samples. The recoveries ranged from 98.80 to 100.23%, and the relative standard deviation (RSD) was lower than 5%. Above all, this work explored new materials in low-potential-driven ECL system and provided a reliable sensing strategy for clinical applications.

A novel signature of two long non-coding RNAs in BRCA mutant ovarian cancer to predict prognosis and efficiency of chemotherapy.

BACKGROUND: In this study we aimed to identify a prognostic signature in BRCA1/2 mutations to predict disease progression and the efficiency of chemotherapy ovarian cancer (OV), the second most common cause of death from gynecologic cancer in women worldwide. METHODS: Univariate Cox proportional-hazards and multivariate Cox regression analyses were used to identifying prognostic factors from data obtained from The Cancer Genome Atlas (TCGA) database. The area under the curve of the receiver operating characteristic curve was assessed, and the sensitivity and specificity of the prediction model were determined. RESULTS: A signature consisting of two long noncoding RNAs(lncRNAs), Z98885.2 and AC011601.1, was selected as the basis for classifying patients into high and low-risk groups (median survival: 7.2 years vs. 2.3 years). The three-year overall survival (OS) rates for the high- and low-risk group were approximately 38 and 100%, respectively. Chemotherapy treatment survival rates indicated that the high-risk group had significantly lower OS rates with adjuvant chemotherapy than the low-risk group. The one-, three-, and five-year OS were 100, 40, and 15% respectively in the high-risk group. The survival rate of the high-risk group declined rapidly after 2 years of OV chemotherapy treatment. Multivariate Cox regression associated with other traditional clinical factors showed that the 2-lncRNA model could be used as an independent OV prognostic factor. Analyses of data from the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) indicated that these signatures are pivotal to cancer development. CONCLUSION: In conclusion, Z98885.2 and AC011601.1 comprise a novel prognostic signature for OV patients with BRCA1/2 mutations, and can be used to predict prognosis and the efficiency of chemotherapy.

Alteration of tumor associated neutrophils by PIK3CA expression in endometrial carcinoma from TCGA data.

Uterine corpus endometrial carcinoma (UCEC) is one of the most common cancer in female worldwide. PIK3CA has been proven to be a strong prognostic biomarker in UCEC. Nevertheless, current studies have not investigated what effects PIK3CA had on tumor associated neutrophils (TANss). Kaplan-Meier methods were used to compute the survival time of TCGA UCEC patients. GO and KEGG enrichment analysis unveiled relevant pathways PIK3CA affected using DEGs between PIK3CA high expression group and PIK3CA low expression group in TCGA UCEC, as well as GSEA. immune infiltration status was calculated using TIMER. We found that PIK3CA influenced a number of pathways including immune related pathways. The fraction of TANs was certainly altered by PIK3CA expression in UCEC. Our findings suggest that PIK3CA expression may play an important role in tumor immune microenvironment and could alter fraction of TANs in UCEC.

An ultrasensitive luminol cathodic electrochemiluminescence probe with highly porous Pt on ionic liquid functionalized graphene film as platform for carcinoembryonic antigen sensing.

The low-potential electrochemiluminescence (ECL) sensors based on cathodic light emission of luminol have caused more and more concerns due to their good stability and reproducibility. In this work, highly porous platinum (Pt) nanostructures on ionic liquid functionalized graphene film (GR-IL/pPt) were prepared as platform to construct a label-free ECL sensor for the detection of carcinoembryonic antigen (CEA). Due to their good biocompatibility, excellent electrocatalytic activity and highly porous structure, the as-prepared GR-IL/pPt composites benefited amplified cathodic ECL signal of luminol and high loading density of the CEA antibody. After CEA was incubated with the CEA antibody, the cathodic ECL signal of luminol decreased thanks to the less conductive immunocomplex. The proposed ECL immunosensor realized high sensitivity for CEA detection with a wide linear range from 0.001 fg mL-1 to 1 ng mL-1 and an extremely low detection limit of 0.0003 fg mL-1 (S/N = 3). Moreover, the sensor showed good specificity, stability and reproducibility, indicating that the provided strategy had a promising potential in clinical detection.

A versatile label-free electrochemical biosensor for circulating tumor DNA based on dual enzyme assisted multiple amplification strategy.

A versatile label-free electrochemical biosensor based on dual enzyme assisted multiple amplification strategy was developed for ultrasensitive detection of circulating tumor DNA (ctDNA). The biosensor consists of a triple-helix molecular switch (THMS) as molecular recognition and signal transduction probe, ribonuclease HII (RNase HII) and terminal deoxynucleotidyl transferase (TdT) as dual enzyme assisted multiple amplification accelerator. The presence of target ctDNA could open THMS and trigger RNase HII-assisted homogenous target recycling amplification to produce substantial signal transduction probe (STP). The released STP hybridized with the capture probe immobilized on a gold electrode, then TdT and assistant probe were further employed to fulfill TdT-mediated cascade extension and generate stable DNA dendritic nanostructures. The electroactive methyl blue (MB) was finally used as the signal reporter to realize the multiple electrochemical amplification ctDNA detection as the amount of MB is positively correlated with the target ctDNA. Combined with the efficient recognition capacity of the designed THMS and the excellent multiple amplification ability of RNase HII and TdT, the constructed sensing platform could detect KRAS G12DM with a wide detection range from 0.01 fM to 1 pM, and the limit of detection as low as 2.4 aM. Besides, the platform is capable of detecting ctDNA in biological fluid such as plasma. More importantly, by substituting the loop of THMS with different sequences, this strategy could be conveniently expanded into the detection of other ctDNA, showing promising potential applications in clinical cancer screening and prognosis.

Aptamer based electrochemical assay for protein kinase activity by coupling hybridization chain reaction.

The present work reported a simple, lable-free and sensitive electrochemical method for the detection of protein kinase A (PKA) activity. This method was based on the specific recognition of aptamer and the aptamer-induced hybridization chain reaction (HCR) amplification strategy. The aptasensor was constructed by immobilizing capture probe on a gold electrode via an Au-S bond. When adenosine triphosphate (ATP) aptamer was introduced, its one terminus hybridized with capture probe and the other hybridized with the complementary region of an auxiliary probe, which other region triggered HCR between two hairpin DNA (H1 and H2) to form a long DNA concatamer. At last a large number of electroactive methyle blue (MB) molecules were assembled on the dsDNA concatamer, which generated a significantly amplified electrochemical signal. In the presence of ATP, the HCR would not be performed because the aptamer specifically bond to ATP and the electrochemical response would decrease. However, when ATP and PKA coexisted, the electrochemical response would recovery because that ATP had been translated into ADP by PKA. So the activity of PKA could be effectively monitored according to the change of electrochemical signal. Based on the HCR amplification strategy, the aptasensor showed a wide linear range (4 - 4 ×105 U L-1) and a low detection limit (1.5 U L-1) for the detection of PKA. Furthermore, the method was applied to study the inhibitory effect of H-89 on PKA activity. The developed aptasensor was also used to the analysis of drug-induced PKA activity in cell lysates, indicating the potential application of the developed method in the fields of clinical diagnostics and discovery of new targeted drugs.

Perylenetetracarboxylic acid and carbon quantum dots assembled synergistic electrochemiluminescence nanomaterial for ultra-sensitive carcinoembryonic antigen detection.

It is important to design a nice electrochemiluminescence (ECL) biological nanomaterial for fabricating sensitive ECL immunosensor to detect tumor markers. Most reported ECL nanomaterial was decorated by a number of mono-luminophore. Here, we report a novel ECL nanomaterial assembled by dual luminophores perylenetetracarboxylic acid (PTCA) and carbon quantum dots (CQDs). In the ECL nanomaterial, graphene was chosen as nanocarrier. Significant ECL intensity increases are seen in the ECL nanomaterial, which was interpreted with the proposed synergistic promotion ECL meachanism of PTCA and CQDs. Furthermore, this ECL nanomaterial was used to label secondary antibody and fabricate a sandwiched carcinoembryonic antigen (CEA) immunosensor. The CEA immunosensor exhibits high sensitivity and the linear semilogarithmical range was from 0.001fgmL-1 to 1ngmL-1 with low detection limit 0.00026fgmL-1. And the CEA immunosensor is also suitable for various cancers' sample detection providing potential specific applications in diagnostics.

A novel sandwiched electrochemiluminescence immunosensor for the detection of carcinoembryonic antigen based on carbon quantum dots and signal amplification.

In this study, a novel sandwiched electrochemiluminescence (ECL) immunosensor for the detection of carcinoembryonic antigen (CEA) was developed. The nanocomposite of polydopamine and Ag nanoparticles (PDA-AgNPs) was prepared by the redox reaction between Ag+ and dopamine. This nanocomposite not only provided an effective matrix for the immobilization of primary antibody (Ab1) but also enhanced the conductivity of the electrode. Carbon quantum dots (CQDs) were immobilized on the poly(ethylenimine) functionalized graphene oxide (PEI-GO) through amido-bond. Then Au nanoparticles were decorated on the CQDs modified PEI-GO matrix, and the resulted complex AuNPs/CQDs-PEI-GO was introduced to link secondary antibody (Ab2). The CQDs can be connected to the electrode surface through the combination of CEA with Ab1 and Ab2, and then the amplified electrochemiluminescence signal of CQDs was obtained with the synergistic effect of AgNPs, polydopamine, AuNPs and PEI-GO. Under the optimal conditions, the ECL intensity was proportional to the logarithm value of CEA concentration in the linear range from 5pgmL-1 to 500ngmL-1 with a detection limit of 1.67pgmL-1 for CEA detection. The immunosensor was applied for the CEA detection in real samples with satisfactory results. The proposed ECL immunosensor showed good performance with high sensitivity, specificity, reproducibility, stability and will be potential in clinical detection.

[Detection and genotyping of human bocavirus 2 in children with acute diarrhea].

To investigate the prevalence of HBoV2 in pediatric patients with acute diarrhea in Beijing and the characteristic of the genome of the virus, 553 stool specimens were collected from pediatric outpatients with acute diarrhea in Affiliated Children's Hospital of Capital Institute of Pediatrics during Nov. 2010 to Oct. 2011. TaqMan-based Real-time polymerase chain reaction was performed to detect HBoV2 DNA from these specimens. Two positive specimens with high viral loads were selected for segmented amplification and then the amplified fragments were cloned into the plasmid vector pGEM-T, transformed into Escherichia coli DH5alpha and sequenced. Then genomic sequences assembled from those DNA fragments were compared with other parvovirus genomic sequences in the GenBank. Among these 553 specimens tested, 15 (2.7%) were HBoV2 DNA positive. The highest positive rate was shown in July (7.0%) through the whole year and in 3-6 month age group (4.1%) among different age groups. All these 15 specimens positive for HBoV2 DNA were collected from patients younger than 2 years old, including 4 simultaneously positive for norovirus, 3 positive for rotavirus and 1 positive for adenovirus. By sequence analysis, 2 almost complete HBoV2 genomic sequences assembled from gene fragments amplified from specimens BJQ19 and BJQ390 were typical HBoV2. And they shared high homology with each other (99.2%), while they shared the highest homology with FJ375129 from Shanghai China (99.1% and 99.2%) among other parvoviruses. These data suggest that some of acute diarrhea in pediatric patients in Beijing were associated with HBoV2, and infants and young children aged from 3 months to 2 years, are more likely to be infected by HBoV2.

[Investigation of adenovirus infection in hospitalized children with diarrhea during 2010 in Beijing, China].

OBJECTIVE: The study was designed to evaluate adenovirus infection in hospitalized children with diarrhea. METHOD: Stool specimens were collected from 519 hospitalized children with diarrhea during 2010, including those defined as community-acquired diarrhea (CAD) who developed diarrhea symptoms within 48 hours after admission, and those defined as hospital-acquired diarrhea (HAD) whose symptoms of diarrhea occurred beyond 48 hours after admission. PCR was employed to identify adenovirus in fecal samples by using universal primers for adenoviruses of all types, and specific primers for adenovirus group F. PCR products with expected size were sequenced for adenovirus typing. Clinical data for children with adenovirus positive specimens were analyzed. RESULT: A total of 519 hospitalized children, including 289 with CAD and 230 with HAD, were enrolled in the study. Out of 519 stool specimens, 76 showed PCR products with expected 301 bp and identified as adenovirus by sequencing, and the overall positive rate was 14.6%. Out of 289 CAD samples, 43 were positive (positive rate was 14.9%). Of them, 20 were identified as enteric adenovirus infection (adenovirus type 41, Ad41). Thirty-three out of 230 HAD samples were positive (positive rate was 14.3%). Of them, 13 were characterized as enteric adenovirus infection (one was Ad40 and others were Ad41). Ad41 in this study could be divided into two genotypes by phylogenetic tree analysis. Non-enteric adenoviruses were identified in 43 specimens (43/76, 56.6%) including 5 of serotype 1, 8 of serotype 2, 15 of serotype 3, 10 of serotype 7, 1 of serotype 12, and 4 of serotype 31. In this study, the positive rate of adenovirus between CAD children and HAD children did not differ (χ(2) = 0.03, P > 0.05), while the positive rate of enteric adenovirus was high in CAD children. CONCLUSION: Adenovirus infection was the main cause of diarrhea in hospitalized children. In this study, the positive rate of adenovirus was similar between children with CAD and with HAD. Enteric adenovirus (adenovirus group F) was the most common adenovirus serotype detected in 2010 in Beijing, and Ad41 was the dominant type.

Inhibition of the cystathionine-gamma-lyase/hydrogen sulfide pathway in rat vascular smooth muscle cells by cobalt-60 gamma radiation.

BACKGROUND: Radiation is a promising treatment for in stent restenosis and restenosis following percutaneous transluminal coronary angioplasty, which has troubled interventional cardiologists for a long time. It inhibits neointima hyperplasia, vascular remodeling, and increases the mean luminal diameter. The mechanism of intracoronary brachytherapy for restenosis is not well understood. Endogenous gaseous transmitters including nitric oxide and carbon monoxide are closely related to restenosis. Hydrogen sulfide, a new endogenous gaseous transmitter, is able to inhibit the proliferation of vascular smooth muscle cells and vascular remodeling. This study aimed to clarify the effect of radiation on cystathionine-gamma-lyase/hydrogen sulfide pathway in rat smooth muscle cells. METHODS: We studied the effect of radiation on the cystathionine-gamma-lyase/hydrogen sulfide pathway. Rat vascular smooth muscle cells were radiated with (60)Co gamma at doses of 14 Gy and 25 Gy respectively. Then the mRNA level of cystathionine-gamma-lyase was studied by quantitative reverse-transcription competitive polymerase chain reaction. Hydrogen sulfide concentration in culture medium was determined by methylene blue spectrophotometry. Cystathionine-gamma-lyase activity in vascular smooth muscle cells was also studied. RESULTS: (60)Co gamma radiation at a dose of 1 Gy did not affect the cystathionine-gamma-lyase/hydrogen sulfide pathway significantly. However, (60)Co gamma radiation at doses of 14 Gy and 25 Gy decreased the hydrogen sulfide synthesis by 21.9% (P<0.05) and 26.8% (P<0.01) respectively. At the same time, they decreased the cystathionine-gamma-lyase activity by 15.1% (P<0.05) and 20.5% (P<0.01) respectively, and cystathionine-gamma-lyase mRNA expression by 29.3% (P<0.01) and 38.2% (P<0.01) respectively. CONCLUSION: Appropriate (60)Co gamma radiation inhibits the H(2)S synthesis by inhibiting the gene expression of cystathionine-gamma-lyase and the cystathionine-gamma-lyase activity.

[Comparison of methods for Norovirus detection in stool specimens collected from hospitalized patients with hospital acquired diarrhea].

OBJECTIVE: In order to find out a more convenient, rapid and efficient way in detecting human Norovirus infections in specimens collected from hospitalized patients with acute non-bacterial diarrhea in Beijing. METHODS: Two kits for enzyme immunoassay (EIA) were used to detect human Noroviruses in stool specimens collected from 69 infants and young children as well as 15 adults who were all diagnosed as acute non-bacterial diarrhea in 4 different hospitals. Reverse transcription-polymerase chain reaction(RT-PCR) was performed to evaluate the data from two kits in this study. Data were statistically analyzed by SPSS 11.5 software. chi2 test was used to test categorical variables. RESULTS: Out of 84 stool specimens collected from infants and young children or adults with acute non-bacterial diarrhea, 17 (20.2%) were Norovirus positive determined by EIA kit A and 31 (36.9%) were Norovirus positive determined by EIA kit B. chi2 test used to test categorical variables showed significant differences (P < 0.01), suggesting that the EIA kit B was superior to the EIA kit A. Among these 84 stool specimens, 20 were tested by RT-PCR simultaneously. Out of those 20 specimens, 11 (55.0%) were Norovirus positive as determined by RT-PCR, which was higher than that from 2 EIA kits. RESULTS: from 10 (50.0%) samples detected by EIA kit A were consistent with those detected by RT-PCR. Through chi2 test, the categorical variables showed significant differences with P < 0.05, suggesting that RT-PCR was superior to the EIA kit A. Results from 14 (70.0%) samples detected by EIA kit B were consistent with those detected by RT-PCR while chi2 test showed that the differences were not significant (P > 0.05), among categorical variables suggesting that EIA kit B was as sensitive as RT-PCR in detecting Norovirus. The were hospital acquired diarrhea outbreaks in these three hospitals since at least 2 Norovirus positive specimens were detected in each of the hospitals. CONCLUSION: To detect human Noroviruses infection, EIA seemed to be more convenient and time saving than RT-PCR which had been used worldwide. The EIA kit B in this study was comparable to RT-PCR for detecting Norovirus in stool specimens. Norovirus was a pathogen causing hospital acquired diarrhea outbreaks in these three hospitals.