Development of DNAzyme-based PCR signal cascade amplification for visual detection of Listeria monocytogenes in food.

Listeria monocytogenes is an important foodborne pathogen, and it can cause severe diseases. Rapid detection of L. monocytogenes is crucial to control this pathogen. A simple and robust strategy based on the cascade of PCR and G-quadruplex DNAzyme catalyzed reaction was used to detect L. monocytogenes. In the presence of hemin and the aptamer formed during PCR, the catalytic horseradish peroxidase-mimicking G-quadruplex DNAzymes allow the colorimetric responses of target DNA from L. monocytogenes. This assay can detect genomic DNA of L. monocytogenes specifically with as low as 50 pg/reaction with the naked eye. Through 20 pork samples assay, visual detection assay had the same results as conventional detection methods, and had a good performance. This is a powerful demonstration of the ability of G-quadruplex DNAzyme to be used for PCR-based assay with significant advantages of high sensitivity, low cost and simple manipulation over existing approaches and offers the opportunity for application in pathogen detection.

Homeobox B9 is overexpressed in hepatocellular carcinomas and promotes tumor cell proliferation both in vitro and in vivo.

HomeoboxB9 (HOXB9), a nontransforming transcription factor that is overexpressed in multiple tumor types, alters tumor cell fate and promotes tumor progression. However, the role of HOXB9 in hepatocellular carcinoma (HCC) development has not been well studied. In this paper, we found that HOXB9 is overexpressed in human HCC samples. We investigated HOXB9 expression and its prognostic value for HCC. HCC surgical tissue samples were taken from 89 HCC patients. HOXB9 overexpression was observed in 65.2% of the cases, and the survival analysis showed that the HOXB9 overexpression group had significantly shorter overall survival time than the HOXB9 downexpression group. The ectopic expression of HOXB9 stimulated the proliferation of HCC cells; whereas the knockdown of HOXB9 produced an opposite effect. HOXB9 also modulated the tumorigenicity of HCC cells in vivo. Moreover, we found that the activation of TGF-ß1 contributes to HOXB9-induced proliferation activities. The results provide the first evidence that HOXB9 is a critical regulator of tumor growth factor in HCC.

Application of artificial intelligence in diagnosis and treatment of colorectal cancer: A novel Prospect.

In the past few decades, according to the rapid development of information technology, artificial intelligence (AI) has also made significant progress in the medical field. Colorectal cancer (CRC) is the third most diagnosed cancer worldwide, and its incidence and mortality rates are increasing yearly, especially in developing countries. This article reviews the latest progress in AI in diagnosing and treating CRC based on a systematic collection of previous literature. Most CRCs transform from polyp mutations. The computer-aided detection systems can significantly improve the polyp and adenoma detection rate by early colonoscopy screening, thereby lowering the possibility of mutating into CRC. Machine learning and bioinformatics analysis can help screen and identify more CRC biomarkers to provide the basis for non-invasive screening. The Convolutional neural networks can assist in reading histopathologic tissue images, reducing the experience difference among doctors. Various studies have shown that AI-based high-level auxiliary diagnostic systems can significantly improve the readability of medical images and help clinicians make more accurate diagnostic and therapeutic decisions. Moreover, Robotic surgery systems such as da Vinci have been more and more commonly used to treat CRC patients, according to their precise operating performance. The application of AI in neoadjuvant chemoradiotherapy has further improved the treatment and efficacy evaluation of CRC. In addition, AI represented by deep learning in gene sequencing research offers a new treatment option. All of these things have seen that AI has a promising prospect in the era of precision medicine.

Development of an in-situ signal amplified electrochemical assay for detection of Listeria monocytogenes with label-free strategy.

Listeria monocytogenes is an important foodborne pathogen, which imposes great burdens on public health. The current methods for detecting L. monocytogene are limited in several ways such as time consuming and lab equipment dependent. In this study, we developed a new electrochemical assay to improve the efficacy. This assay allows us to generate numerous G-quadruplex sequences while loop-mediated isothermal amplification happens. Then, these G-quadruplex sequences form DNAzyme to produce a color change and an electrochemical signal by oxidizing tetramethylbenzidine. This assay could be finished in 2 h, which significantly reduced the detection time. Also, we confirmed the limit of detection of this assay at 6.8 CFU/mL according to 3σ criterion. Our assay shows good sensitivity to detect bacteria range from 52.5 to 5.25 × 104 CFU/mL. This assay's reliability was also confirmed by detecting artificially contaminated pork samples. Thus, we propose this electrochemical assay for rapid and sensitive detection of L. monocytogenes in food.

Molecular mechanism underlying miR­130b­Sp1 transcriptional regulation in LPS­induced upregulation of MUC5AC in the bile duct epithelium.

Hepatolithiasis is a common disease that represents a serious health threat to the Chinese population. The pathological mechanism underlying hepatolithiasis is closely related to bacterial infections of the intrahepatic bile duct, followed by chronic inflammation and the overexpression of mucin 5AC (MUC5AC). However, the exact mechanism responsible for the lipopolysaccharide (LPS)­induced upregulation of MUC5AC has yet to be elucidated. Specificity protein 1 (Sp1) is a ubiquitous transcription factor that plays a vital role in the regulation of a number of genes that are responsible for normal cellular function. microRNA (miR/miRNA)­130b is a member of the miRNA family. miRNAs can bind to the 3'­untralsated region (3'­UTR) of a target gene and influence its expression levels. The present study found that LPS increases the expression of MUC5AC by influencing Sp1 secretion. Chromatin immunoprecipitation­quantitative PCR experiments further verified three Sp1 binding sites in the MUC5AC promoter sequence that can regulate the expression of MUC5AC. Further analysis demonstrated that Sp1 expression was regulated by miR­130b. Luciferase experiments identified one miR­130b binding site in the Sp1 3'­UTR region. In vivo experiments also confirmed the role of the miR­130b­Sp1­MUC5AC signaling pathway in the formation of biliary stones and indicated that this pathway may provide targeted therapeutic strategies for the treatment of intrahepatic bile duct stones.

Degradation of ronidazole by electrochemically simultaneously generated persulfate and ferrous ions.

Nitroimidazoles are found in pharmaceuticals and personal care products (PPCPs) and, when discharged into the environment, have adverse effects on human health and survival. Advanced oxidation technologies (AOTs) based on persulfate (PS) can rapidly and efficiently degrade organic pollutants via strong oxidizing radicals under activation conditions. This study investigated the degradation of ronidazole (RNZ) by indirect electrolytic generation of PS and its activator, ferrous ion (Fe2+). An electrochemical system was developed, with a high concentration of PS generated at the anode while the activator Fe2+ was produced at the cathode. It showed that ammonium polyphosphate (APP) could effectively promote the electrolysis of PS. A high current efficiency (88%) at the anode could be obtained after 180 min at a high current density (300 mA cm-2). However, Fe2+ was inhibited at the cathode due to material control. The degradation of RNZ in the Fe2+/PS system generated from the electrochemical system was also explored. Increasing PS concentration and Fe2+/PS ratio were beneficial to the RNZ degradation. In homogeneous reactions, the degradation efficiency of RNZ could be improved by decreasing the Fe2+ addition rate through a peristaltic pump. Five intermediates were also detected and the degradation pathways were proposed. These findings provide a new method and mechanism for rapid and efficient degradation of RNZ.

T-tube-free single-incision laparoscopic common bile duct exploration plus cholecystectomy: a single centre experience.

BACKGROUND: The present study aimed to explore the indications and feasibility of T-tube-free trans-umbilical single-incision laparoscopic common bile duct exploration (SILCBDE) plus laparoscopic cholecystectomy (LC) for treating choledocholithiasis. METHODS: Patients hospitalized in the Second Affiliated Hospital (Shengjing Hospital) of China Medical University from January 2010 to January 2017 with the diagnosis of common bile duct stones and treated with T-tube-free trans-umbilical single-incision LC plus common bile duct exploration were retrospectively analysed. RESULTS: A total of 37 male/female choledocholithiasis patients (mean age 65 years, range 29-86) were treated with T-tube-free trans-umbilical SILCBDE plus LC. No intraoperative complication or conversion to open surgery occurred in any of the cases. The mean operative time was 99.8 min (range 84-125) for endoscopic nasobiliary drainage group (n = 6), 113.8 min (range 70-150) for endoscopic retrogradebiliary drainage group (n = 2), 131.1 min (range 75-161) for pigtail J-tube group (n = 24), 113.7 min (range 100-150) for primary closure group (n = 5). The mean post-operative hospital stay length was 5.5 days (range 4-7) for endoscopic nasobiliary drainage group, 12.5 days (range 10-15) for endoscopic retrogradebiliary drainage group, 6.5 days (range 4-10) for J-tube group, 5.8 days (range 4-9) for primary closure group. Pancreatitis, bile leakage and peritonitis were not presented in any of the group. After 17-101 months follow-up, three patients presented recurrent common bile duct stones. CONCLUSION: In selected cases, T-tube-free trans-umbilical SILCBDE plus LC is feasible and safe for experienced surgeons, and can achieve similar therapeutic effects as common LC plus common bile duct exploration procedures.

An adult gerbil model for evaluating potential coxsackievirus A16 vaccine candidates.

A suitable animal model of CVA16 infection is crucial in order to understand its pathogenesis and to help develop antiviral vaccines or screen therapeutic drugs. The neonatal mouse model has a short sensitivity period to CA16 infection, which is a major limitation. In this study, we demonstrate that adult (60-day-old) gerbils are susceptible to CVA16 infection at high doses (108.0 TCID50). A clinical isolate strain of CVA16 was inoculated intraperitoneally into adult gerbils, which subsequently developed significant clinical symptoms, including hind limb weakness, paralysis of one or both hind limbs, tremors, and eventual death from neurological disorders. Real-time RT-PCR revealed that viral loads in the spinal cord and brainstem were higher than those in other organs/tissues. Histopathological changes, such as neuronal degeneration, neuronal loss, and neuronophagia, were observed in the spinal cord, brainstem, and heart muscle, along with necrotizing myositis. Gerbils receiving both prime and boost immunizations of alum adjuvant inactivated vaccine exhibited no clinical signs of disease or mortality following challenge by CVA16, whereas 80% of control animals showed obvious clinical signs, including slowness, paralysis of one or both hind limbs, and eventual death, suggesting that the CVA16 vaccine can fully protect gerbils against CVA16 challenge. These results demonstrate that an adult gerbil model provides us with a useful tool for studying the pathogenesis and evaluating antiviral reagents of CVA16 infection. The development of this animal model would also be conducive to screening promising CVA16 vaccine candidates as well as further vaccination evaluation.

Visual diagnostic of Helicobacter pylori based on a cascade amplification of PCR and G-quadruplex DNAzyme as a color label.

Helicobacter pylori is a spiral-shaped, Gram-negative, microaerophilic and fastidious bacterium. It is the main cause of chronic gastritis as well as gastric and duodenal ulcers. The diagnosis of H. pylori infection is significant for the selection of therapy and for the follow up of eradication success. A simple and robust strategy based on the cascade of PCR and DNAzyme catalyzed reaction was utilized to detect H. pylori. The design of the primer pair would enable PCR to synthesize aptamer of DNAzyme at the 3' end of PCR products. G-quadruplex DNAzyme as a color label can exhibit peroxidase-like activity to amplify the specific signal and demonstrate a colorimetric signal to indicate the diagnostic result. This assay can detect genomic DNA of H. pylori specifically with as low as 100 pg/reaction by the naked eye. This is a powerful demonstration of G-quadruplex DNAzyme to be used for PCR-based assay with significant advantages of high sensitivity, low cost and simple manipulation over existing approaches and offers the potential opportunity for clinical application.

Potassium complexes supported by monoanionic tetradentate amino-phenolate ligands: synthesis, structure and catalysis in the ring-opening polymerization of rac-lactide.

A series of potassium complexes bearing monoanionic tetradentate amino-phenolate ligands, [LK]2 (L = {(2-R1)C6H4CH2N[(CH2)2R2]CH2(4-R4-6-R3)C6H2O-}, R1 = NMe2, R2 = NEt2, R3 = CPh3, R4 = Me (1); R1 = R2 = NEt2, R3 = CPh3, R4 = Me (2); R1 = NMe2, R2 = NEt2, R3 = R4 = cumyl (4); R1 = R2 = OMe, R3 = tBu, R4 = Me (6); L = (2-NMe2)C6H4CH2N[[CH2-(S)-1-butylpyrrolidinyl]CH2(4-Me-6-CPh3)C6H2O-] (3)), have been synthesized via reactions of KN(SiMe3)2 and 1 equiv. of the corresponding aminophenols. The solid-state structures of typical complexes 4 and 6 are determined via X-ray diffraction studies, which reveal the dinuclear nature of these complexes. By contrast, DOSY measurements of 1, 4 and 6 suggest that these complexes are monomeric in solution. It is noteworthy that the coordination chemistry of these potassium complexes is versatile, which is closely related to the nature of the ortho-substituent of the phenolate ring, as indicated by the results of the corresponding spectroscopic studies. In the presence of iPrOH, 1-4 and 6 could initiate the polymerization of 500 equiv. of rac-lactide to achieve high monomer conversions within several minutes but afford atactic PLAs with slightly isotactic-enriched microstructures (Pm = 0.58-0.60). Experimental results also demonstrated that a bulky trityl substituent at the ortho-position of the phenolate ring of the ligand framework is beneficial for the enhancement of the activities of these potassium complexes.

Morphological changes in network of enteric nerve-interstitial cells of Cajal-smooth muscle cells in rats with multiple organ dysfunction syndrome and therapeutic effects of Dachengqi decoction (大承气汤).

OBJECTIVE: To observe the effects of Dachengqi Decoction (大承气汤, DCQD) on morphological changes in the network of enteric nerve-interstitial cells of Cajal (ICCs)-smooth muscle cells (SMC) of enteric deep muscular plexuses (DMP) in the rats with multiple organ dysfunction syndrome (MODS). METHODS: One hundred Wistar rats of both sexes weighing 200 to 250 g were randomly divided into the control group, MODS group, and DCQD group. The morphologic changes of enteric nerve-ICC-SMC network in the DMP of intestine was observed using c-Kit and vesicular acetylcholine transporter/neuronal nitric oxide synthase immunohistochemical double-staining with whole-mount preparation technique, confocal laser scanning microscopy, and electron microscopy. RESULTS: Compared with the control group, the distribution and densities of cholinergic/nitrergic nerves and ICC in the DMP (ICC-DMP) of intestine in the MODS group were significantly decreased (P<0.01), and the network of cholinergic nerve-ICC-SMC was disrupted; and the ultrastructural features of ICC-DMP, enteric nerve, and SMC were severely damaged. After treatment with DCQD, the damage in the network of enteric nerve-ICC-SMC was significantly recovered. Compared with the MODS group, the distribution and densities of cholinergic/nitrergic nerves and ICC-DMP in the DCQD group were significantly increased (P<0.01); and the ultrastructural features of ICC-DMP, enteric nerve, smooth muscle cells were significantly recovered. CONCLUSIONS: DCQD can improve the gastrointestinal motility in MODS. The mechanism may be related to the effect of repairing the damages in the network of enteric nerve-ICC-SMC.

[Molecular evolution analysis of hantaviruses in Zhejiang Province].

In order to analyze the molecular epidemiology of Hantavirus (HV) in Zhejiang Province, the complete M and S genome sequences of 12 HV strains from different hosts and locations in Zhejiang Province of China during the period of 1981-2007 were analyzed on genetic evolution by DNAstar and MEGA 4.0 software in this research. Phylogenetic analyses revealed that HTN and SEO strains were co-circulating in Zhejiang Province, and the difference in sequence similarity and the phylogeny was closely related to the isolated regions, but had no distinct relationship with the isolate year and the host, indicating a relationship between epidemiology of HFRS and the distribution region, especially in HTNV. The isolates in the same region could be assigned in same or near phylogenetic clade sharing high sequence similarity. Interestingly, the Gou3 strain and ZJ5 strain isolated from Jiande region in Zhejiang Province formed a distinct phylogenetic lineage in SEOV clade, and different from the other SEOV variants outside China. We believed that the special SEOV variants were distributed in Jiande region.