29 research outputs found
Comparison of the multi-drug resistant human hepatocellular carcinoma cell line Bel-7402/ADM model established by three methods
<p>Abstract</p> <p>Background</p> <p>To compare the biological characteristics of three types of human hepatocellular carcinoma multi-drug resistant cell sub-lines Bel-7402/ADM models established by three methods.</p> <p>Methods</p> <p>Established human hepatocellular carcinoma adriamycin (ADM) multi-drug resistant cell sub-lines models Bel-7402/ADM<sub>V</sub>, Bel-7402/ADM<sub>L </sub>and Bel-7402/ADM<sub>S </sub>by three methods of in vitro concentration gradient increased induction, nude mice liver-implanted induction and subcutaneous-implanted induction respectively. Phase contrast microscopy was used to observe the cells and the MTT (methyl thiazolyl tetrazolium) method was used to detect drug resistance of the three different sub-lines of cells.</p> <p>Results</p> <p>The three groups of drug resistant cells, Bel-7402/ADM<sub>V</sub>, Bel-7402/ADM<sub>L </sub>and Bel-7402/ADM<sub>S </sub>generated cross-resistance to ADM and CDDP (cis-Diaminedichloroplatinum), but showed a significant difference in resistance to Bel-7402 IC<sub>50 </sub>value (<it>P </it>< 0.01). The doubling times were significantly extended compared to the parent cell line (39 h) and were 65 h (Bel-7402/ADM<sub>V</sub>), 46 h (Bel-7402/ADM<sub>L</sub>), and 45 h (Bel-7402/ADM<sub>S</sub>). The excretion rates of ADM were significantly increased compared with the parent cell (34.14%) line and were 81.06% (Bel-7402/ADM<sub>V</sub>), 66.56% (Bel-7402/ADM<sub>L</sub>) and 61.56% (Bel-7402/ADM<sub>S</sub>). Expression of P-gp and MRP in the three groups of resistant cells was significantly enhanced (<it>P </it>< 0.01). There was no significant variation in the expression of GSH/GST (<it>P </it>> 0.05).</p> <p>Conclusions</p> <p>Stable resistance was involved in the resistant cell line model established by the above three methods. Liver implantation was a good simulation of human hepatocellular and proved to be an ideal model with characteristics similar to human hepatocellular biology and the pharmacokinetics of anticancer drugs.</p
Neonatal rhesus monkey is a potential animal model for studying pathogenesis of EV71 infection
AbstractData from limited autopsies of human patients demonstrate that pathological changes in EV71-infected fatal cases are principally characterized by clear inflammatory lesions in different parts of the CNS; nearly identical changes were found in murine, cynomolgus and rhesus monkey studies which provide evidence of using animal models to investigate the mechanisms of EV71 pathogenesis. Our work uses neonatal rhesus monkeys to investigate a possible model of EV71 pathogenesis and concludes that this model could be applied to provide objective indicators which include clinical manifestations, virus dynamic distribution and pathological changes for observation and evaluation in interpreting the complete process of EV71 infection. This induced systemic infection and other collected indicators in neonatal monkeys could be repeated; the transmission appears to involve infecting new monkeys by contact with feces of infected animals. All data presented suggest that the neonatal rhesus monkey model could shed light on EV71 infection process and pathogenesis
Research on the application of epoxy surface in the pavement maintenance of the Yilaga Tunnel in Guizhou Province
There are high mountains and steep roads in Guizhou Province. Affected by the relatively closed environment, high humidity and other factors, the skid resistance and durability of the highway in tunnels were obviously reduced, which affects the normal operation of the asphalt pavement. Based on the pavement maintenance project of the highway in the Yilaga Tunnel in Guizhou Province, a new kind of epoxy surface treatment maintenance technology for asphalt pavement has been introduced in this paper. Through the comparative analysis of friction coefficient, structural depth and other anti-sliding performance before and after construction, the results has shown that the technology can effectively solve the early diseases and significantly improve the anti-sliding performance of the pavement, and assist to reduce the occurrence of traffic accidents
An approach for medical event detection in Chinese clinical notes of electronic health records
Abstract Background Medical event detection in narrative clinical notes of electronic health records (EHRs) is a task designed for reading text and extracting information. Most of the previous work of medical event detection treats the task as extracting concepts at word granularity, which omits the overall structural information of the clinical notes. In this work, we treat each clinical note as a sequence of short sentences and propose an end-to-end deep neural network framework. Methods We redefined the task as a sequence labelling task at short sentence granularity, and proposed a novel tag system correspondingly. The dataset were derived from a third-level grade-A hospital, consisting of 2000 annotated clinical notes according to our proposed tag system. The proposed end-to-end deep neural network framework consists of a feature extractor and a sequence labeller, and we explored different implementations respectively. We additionally proposed a smoothed Viterbi decoder as sequence labeller without additional parameter training, which can be a good alternative to conditional random field (CRF) when computing resources are limited. Results Our sequence labelling models were compared to four baselines which treat the task as text classification of short sentences. Experimental results showed that our approach significantly outperforms the baselines. The best result was obtained by using the convolutional neural networks (CNNs) feature extractor and the sequential CRF sequence labeller, achieving an accuracy of 92.6%. Our proposed smoothed Viterbi decoder achieved a comparable accuracy of 90.07% with reduced training parameters, and brought more balanced performance across all categories, which means better generalization ability. Conclusions Evaluated on our annotated dataset, the comparison results demonstrated the effectiveness of our approach for medical event detection in Chinese clinical notes of EHRs. The best feature extractor is the CNNs feature extractor, and the best sequence labeller is the sequential CRF decoder. And it was empirically verified that our proposed smoothed Viterbi decoder could bring better generalization ability while achieving comparable performance to the sequential CRF decoder
Aptamer-Conjugated Multifunctional Nanoflowers as a Platform for Targeting, Capture, and Detection in Laser Desorption Ionization Mass Spectrometry
Although many different nanomaterials have been tested as substrates for laser desorption and ionization mass spectrometry (LOWS), this emerging field still requires more efficient multifuncional nanomaterials for targeting, enrichment, and detection. Here, we report the use of gold manganese oxide (Au@MnO) hybrid nanoflowers as an efficient matrix for LDI-MS. The nanoflowers were also functionalized with two different aptamers to target cancer cells and capture adenosine triphosphate (ATP). These nanoflowers were successfully used for metabolite extraction from cancer cell lysates. Thus, in one system, OUT multifunctional nanoflowers can (1) act as an ionization substrate for mass spectrometry, (2) target cancer cells, and (3) detect and analyze metabolites from cancer cells
DNA Branch Migration Reactions Through Photocontrollable Toehold Formation
Strand
displacement cascades are commonly used to make dynamically
assembled structures. Particularly, the concept of “toehold-mediated
DNA branch migration reactions” has attracted considerable
attention in relation to dynamic DNA nanostructures. However, it is
a challenge to obtain and control the formation of pure 1:1 ratio
DNA duplexes with toehold structures. Here, for the first time, we
report a photocontrolled toehold formation method, which is based
on the photocleavage of 2-nitrobenzyl linker-embedded DNA hairpin
precursor structures. UV light irradiation (λ ≈ 365 nm)
of solutions containing these DNA hairpin structures causes the complete
cleavage of the nitrobenzyl linker, and pure 1:1 DNA duplexes with
toehold structures are easily formed. Our experimental results indicate
that the amount of toehold can be controlled by simply changing the
dose of UV irradiation and that the resulting toehold structures can
be used for subsequent toehold-mediated DNA branch migration reactions,
e.g., DNA hybridization chain reactions. This newly established method
will find broad application in the construction of light-powered,
controllable, and dynamic DNA nanostructures or large-scale DNA circuits
DNA-Guided Metal-Nanoparticle Formation on Graphene Oxide Surface
A simple and universal route for the preparation of metal-graphene oxide (GO) heterostructures with controllable nanoparticle size and shape using double-stranded DNA (dsDNA) as a template is reported. This proof-of-concept work successfully demonstrates that dsDNA can be adsorbed onto GO to create biocompatible and easily functionalizable Ag-GO, Au-GO, Cu-GO, Pt-GO, and Au/Cu/Pt-GO heterostructures using the same experimental conditions for each of the multicomposite nanoparticles