Purification and Characterization of Enterovirus 71 Viral Particles Produced from Vero Cells Grown in a Serum-Free Microcarrier Bioreactor System

[[abstract]]Background: Enterovirus 71 (EV71) infections manifest most commonly as a childhood exanthema known as hand-foot-and-mouth disease (HFMD) and can cause neurological disease during acute infection. Principal Finding: In this study, we describe the production, purification and characterization of EV71 virus produced from Vero cells grown in a five-liter serum-free bioreactor system containing 5 g/L Cytodex 1 microcarrier. The viral titer was >106 TCID50/mL by 6 days post infection when a MOI of 10?5 was used at the initial infection. Two EV71 virus fractions were separated and detected when the harvested EV71 virus concentrate was purified by sucrose gradient zonal ultracentrifugation. The EV71 viral particles detected in the 24–28% sucrose fractions had an icosahedral structure 30–31 nm in diameter and had low viral infectivity and RNA content. Three major viral proteins (VP0, VP1 and VP3) were observed by SDS-PAGE. The EV71 viral particles detected in the fractions containing 35–38% sucrose were 33–35 nm in size, had high viral infectivity and RNA content, and were composed of four viral proteins (VP1, VP2, VP3 and VP4), as shown by SDS-PAGE analyses. The two virus fractions were formalin-inactivated and induced high virus neutralizing antibody responses in mouse immunogenicity studies. Both mouse antisera recognized the immunodominant linear neutralization epitope of VP1 (residues 211–225). Conclusion:These results provide important information for cell-based EV71 vaccine development, particularly for the preparation of working standards for viral antigen quantification

SRPK1 maintains acute myeloid leukemia through effects on isoform usage of epigenetic regulators including BRD4.

We recently identified the splicing kinase gene SRPK1 as a genetic vulnerability of acute myeloid leukemia (AML). Here, we show that genetic or pharmacological inhibition of SRPK1 leads to cell cycle arrest, leukemic cell differentiation and prolonged survival of mice transplanted with MLL-rearranged AML. RNA-seq analysis demonstrates that SRPK1 inhibition leads to altered isoform levels of many genes including several with established roles in leukemogenesis such as MYB, BRD4 and MED24. We focus on BRD4 as its main isoforms have distinct molecular properties and find that SRPK1 inhibition produces a significant switch from the short to the long isoform at the mRNA and protein levels. This was associated with BRD4 eviction from genomic loci involved in leukemogenesis including BCL2 and MYC. We go on to show that this switch mediates at least part of the anti-leukemic effects of SRPK1 inhibition. Our findings reveal that SRPK1 represents a plausible new therapeutic target against AML

The role of modern immunotherapy in metastatic urothelial cancer: mini review

The approval of immune checkpoint inhibitors (ICIs) has changed the treatment landscape in many aspects of urothelial cancer (UC), in both non-muscle-invasive bladder cancer and muscle-invasive bladder cancer and has introduced the concept of long-term remission for some patients in the metastatic setting. Front-line chemotherapy remains superior at achieving initial control of disease compared to front-line immune therapy. However, long-term durable responses are limited by chemotherapy resistance. The maintenance approach, sequencing chemotherapy with ICIs, could be considered a best of both worlds approach, achieving initial control with chemotherapy, which is maintained in some individuals with avelumab. However, outcomes for patients with metastatic UC remain poor. There are three steps to improving outcomes for these patients; the first is to develop better drugs and combinations of therapies, the second is the development of novel biomarkers and techniques to better select patients for treatment, and the third area of development is to give the drugs in the most optimal setting

Using Metal-less Structures To Enhance the Raman Signals of Graphene by 100-fold while Maintaining the Band-to-Band Ratio and Peak Positions Precisely

In this study, we developed a reliable method to analyze the interference-enhanced Raman scattering (IERS) effect on graphene by considering the surface electric field (E-field), which can be calculated precisely by measuring the optical admittance of the thin-film assembly. Through accurate tuning of the optical properties of one-dimensional photonic crystals (1D-PhCs), the strong and controllable interference effect allowed the surface E-field to be maximized and, thereby, to optimize the enhancement factors of the Raman scattering signals of graphene. Using this approach, we could enhance both the G and the 2D bands of graphene largely, uniformly, and equally, by about 180 times relative to those obtained on a silicon substrate. Under certain conditions, the Raman peak of graphene could even be enhanced by over 400 times. After transferring single-layer graphene (SLG) and few-layer graphene (FLG) onto various substrates, we found that the Raman spectra of both SLG and FLG on the 1D-PhCs substrate were enhanced without changing the band-to-band ratio or the peak positions of the main Raman bands of graphene. Without inducing any additional signal disturbance, this enhancement technique allowed us to maintain the accurate and precise informational features from the Raman spectra. The experimental enhancement factors in the coenhanced Raman spectra of graphene were higher than those previously obtained using the IERS effect. Moreover, the surface E-field of 1D-PhCs could be modulated by changing the incident angle of the excited light source, thereby allowing fine-tuning of the working wavelength. Thus, by controlling only the surface E-field, the Raman signals of graphene could be enhanced dramatically without any distortion on spectra. Accordingly, using 1D-PhCs and the optimized IERS effect is very helpful for fine structural characterization of graphene through conventional Raman spectroscopy

Controllable Localized Surface Plasmonic Resonance Phenomena in Reduced Gold Oxide Films

In this study, we used reactive sputtering to prepare large-area, homogeneous gold oxide (AuO_<i>x</i>) films, which we then subjected to reduction processes under ambient conditions at room temperature to obtain reduced AuO_<i>x</i> films featuring embedded Au nanoparticles (NPs). We analyzed these films in terms of both their material characteristics and optical properties. For the first time, we obtained the optical constants of AuO_<i>x</i> films directly deposited on glass and Si substrates. Moreover, we observed localized surface plasmon resonance (LSPR) phenomena from the visible to the near-infrared (NIR) during the formation of the Au NPs in the AuO_<i>x</i> film. The plasmonic properties of the Au NPs embedded in the AuO_<i>x</i> films were much different from those of chemically synthesized Au NPs. We found that the LSPR wavelength of the Au NPs embedded in the AuO_<i>x</i> films could be tuned from 700 to 980 nm by varying the duration of the reduction process. Moreover, the reduced AuO_<i>x</i> films could be applied as surface-enhanced Raman spectroscopy (SERS)-active substrates. The minimum detection was achieved down to a concentration of 10^–10 M (R6G) when using the reduced AuO_<i>x</i> film-based substrate–a level comparable with those of other kinds of SERS substrates prepared using more complicated methods. The rapid method proposed herein provides large-areas films with tunable resonance wavelengths for applications as SERS-active substrates in optical and chemical sensing

The association of heat shock protein genetic polymorphisms with age-related hearing impairment in Taiwan

Abstract Background Age-related hearing impairment (ARHI) is a major disability among the elderly population. Heat shock proteins (HSPs) were found to be associated with ARHI in animal studies. The aim of this study was to analyze the associations of single nucleotide polymorphisms (SNPs) of HSP genes with ARHI in an elderly population in Taiwan. Methods Participants ≥65 years of age were recruited for audiometric tests and genetic analyses. The pure tone average (PTA) of the better hearing ear was calculated for ARHI evaluation. The associations of HSPA1L (rs2075800 and rs2227956), HSPA1A (rs1043618) and HSPA1B (rs2763979) with ARHI were analyzed in 146 ARHI-susceptible (cases) and 146 ARHI-resistant (controls) participants. Results The “T” allele of HSPA1B rs2763979 showed a decreased risk of ARHI. The “TT” genotype of rs2763979 also showed a decreased risk of ARHI in the dominant hereditary model. For HSPA1L (rs2075800 and rs2227956) and HSPA1A (rs1043618), the haplotype “CAG” was related to a decreased risk of ARHI. Conclusion These findings suggest that HSP70 polymorphisms are associated with susceptibility to ARHI in the elderly population. Graphical abstrac

Using Visible Laser-Based Raman Spectroscopy to Identify the Surface Polarity of Silicon Carbide

In this study we developed an approach to identify the surface polarity of silicon carbide (SiC) by using an excitation laser possessing a photon energy (2.33 eV) much lower than the band gap of 4H-SiC (3.30 eV). By gradually attenuating the intensity of the excitation laser, the effective depth that the laser could generate Raman signals could eventually be limited to within the ultrashallow region of the SiC wafer. Through three-dimensional finite-difference-time-domain (3D-FDTD) simulations, we found that the depth of the high electric field region could be limited from several micrometers below the surface to the near-surface region of 4H-SiC, merely by attenuating the power of the incident laser. Experimentally, we observed a clear trend in the Raman peak intensity ratio of the signals at 210 and 203 cm^–1 in the FTA mode: the intensity ratio of the Si face was always higher than that of the C face regardless of the measurement position on the 4H-SiC wafer. Even through the carrier concentrations in the 4H-SiC wafer were nonuniform, the resulting variability in peak intensity did not influence the trend in the intensity ratio, which could, therefore, be used to identify the surface polarity. This approach might also allow characterization of different polytypes of SiC, for example, 6H-SiC and 3C-SiC, the optical band gaps of which are lower than that of 4H-SiC. Because this optical approach using low-photon-energy laser-based Raman spectroscopy is nondestructive, simple, and rapid and employs excitation light of low photon energy, it should be very applicable for characterizing the surface properties of various other crystalline materials

Transparent, Broadband, Flexible, and Bifacial-Operable Photodetectors Containing a Large-Area Graphene–Gold Oxide Heterojunction

In this study, we combine graphene with gold oxide (AuO_<i>x</i>), a transparent and high-work-function electrode material, to achieve a high-efficient, low-bias, large-area, flexible, transparent, broadband, and bifacial-operable photodetector. The photodetector operates through hot electrons being generated in the graphene and charge separation occurring at the AuO_<i>x</i>–graphene heterojunction. The large-area graphene covering the AuO_<i>x</i> electrode efficiently prevented reduction of its surface; it also acted as a square-centimeter-scale active area for light harvesting and photodetection. Our graphene/AuO_<i>x</i> photodetector displays high responsivity under low-intensity light illumination, demonstrating picowatt sensitivity in the ultraviolet regime and nanowatt sensitivity in the infrared regime for optical telecommunication. In addition, this photodetector not only exhibited broadband (from UV to IR) high responsivity3300 A W^–1 at 310 nm (UV), 58 A W^–1 at 500 nm (visible), and 9 A W^–1 at 1550 nm (IR)but also required only a low applied bias (0.1 V). The hot-carrier-assisted photoresponse was excellent, especially in the short-wavelength regime. In addition, the graphene/AuO_<i>x</i> photodetector exhibited great flexibility and stability. Moreover, such vertical heterojunction-based graphene/AuO_<i>x</i> photodetectors should be compatible with other transparent optoelectronic devices, suggesting applications in flexible and wearable optoelectronic technologies

Síntesis y evaluación in silico e in vitro de derivados del ácido valproico como antineoplásicos

Las histonas desacetilasas son un grupo de enzimas que se caracterizan por catalizar la separación de un grupo acetilo de las lisinas acetiladas en las histonas, esto tiene como efecto la compactación del material genético involucrado en esa región y la supresión de su expresión; la función de estas enzimas es aberrante en células neoplásicas; por otro lado, se descubrió que el ácido valproico inhibe a este grupo de enzimas, promoviendo la expresión de genes suprimidos en las células tumorales, provocando detención del ciclo celular y/o apoptosis. Nuestro equipo de trabajo propuso la evaluación in silico de una seria de derivados del ácido valproico, y a partir de los resultados de esta evaluación sintetizar a aquellos derivados con mejores mejores valores de interacción predichos. Un derivado fue sintetizado y caracterizado tras el virtual screening, para posteriormente ser evaluado en cultivos celulares de cáncer cérvico-uterino y rabdomiosarcoma, buscando alteraciones en la proliferación, viabilidad celular y apoptosis. Por último se trataron células de cáncer cérvico-uterino con el derivado y con VPA, se extrajo el RNA y se realizaron microarreglos de expresión para caracterizar los cambio en el perfil de expresión de las células tumorales, provocados por el tratamiento