A cytoplasmic RNA virus generates functional viral small RNAs and regulates viral IRES activity in mammalian cells

The roles of virus-derived small RNAs (vsRNAs) have been studied in plants and insects. However, the generation and function of small RNAs from cytoplasmic RNA viruses in mammalian cells remain unexplored. This study describes four vsRNAs that were detected in enterovirus 71-infected cells using next-generation sequencing and northern blots. Viral infection produced substantial levels (\u3e105 copy numbers per cell) of vsRNA1, one of the four vsRNAs. We also demonstrated that Dicer is involved in vsRNA1 generation in infected cells. vsRNA1 overexpression inhibited viral translation and internal ribosomal entry site (IRES) activity in infected cells. Conversely, blocking vsRNA1 enhanced viral yield and viral protein synthesis. We also present evidence that vsRNA1 targets stem-loop II of the viral 5′ untranslated region and inhibits the activity of the IRES through this sequence-specific targeting. Our study demonstrates the ability of a cytoplasmic RNA virus to generate functional vsRNA in mammalian cells. In addition, we also demonstrate a potential novel mechanism for a positive-stranded RNA virus to regulate viral translation: generating a vsRNA that targets the IRES

Photoluminescence enhancement of ZnS : Mn nanoparticles by SiO2 coating

ZnS:Mn nanoparticles (~3.1?nm) of a cubic structure were prepared by a coprecipitation method and then dispersed with various weights (0.5-8?g) into a solution containing ammonium hydroxide, ethanol and tetraethyl orthosilicate (TEOS) for surface coating. X-ray diffraction (XRD) analysis of these coated ZnS:Mn powders revealed the presence of amorphous materials after the coating process. Characterization of the coated powders using a transmission electron microscope (TEM) and an electron energy loss spectrometer (EELS) showed that ZnS:Mn nanoparticles were randomly embedded in the larger particles of amorphous SiO2 (50-100?nm). The optical properties of photoluminescence (PL) and diffuse reflection of the SiO2-coated ZnS:Mn powders were found to depend on the quantity of ZnS:Mn nanoparticles in the coating solution. The increased PL intensity of ZnS:Mn at 590?nm after SiO2 coating was proposed to result from the inhibition of excitation energy transfer to quenching centers or surface states based on the observation of the reduced absorption in the region of 370-450?nm.NRC publication: Ye

Dose-Dependent Relationship Between Metformin and Colorectal Cancer Occurrence Among Patients with Type 2 Diabetes—A Nationwide Cohort Study

BACKGROUND: Increasing bodies of evidence suggest that metformin may be beneficial in the primary prevention of colorectal cancer (CRC), and a dose–response relationship has been reported. However, long-term epidemiological observations between the treatment period, cumulative dose, and intensity of metformin and CRC are rarely reported. The aim of this study was to identify the association between the effect of metformin and CRC development in a nationwide cohort study. METHODS: This nationwide population-based study examined a cohort of 1,000,000 patients randomly sampled from individuals enrolled in the Taiwan National Health Insurance system. Patients with newly diagnosed type 2 diabetes mellitus (DM) between 1997 and 2007 were enrolled. A statistical variables, including the demographic data, treatment period, cumulative dose, and intensity of metformin use, was compared between patients developing CRC and those without CRC. RESULTS: This study included 47,597 patients. The mean follow-time was 7.17 ± 3.21 years. After adjustment, metformin use was an independent protective factor against CRC development (P < .001). Although the protective ability of metformin against CRC development was reduced during long-term therapy, the risk of CRC decreased progressively with a higher cumulative dose or higher intensity of metformin use (both P < .001). CONCLUSION: This study revealed that metformin use significantly reduced the risk of CRC in a dose-dependent manner in patients with type 2 DM in the Taiwanese population. However, a gradual decline in medication adherence may reduce the protective ability of metformin against CRC development during long-term therapy

Effects of Sodium Azide, Barium Ion, d-Amphetamine and Procaine on Inward Rectifying Potassium Channel 6.2 Expressed in Xenopus Oocytes

Background/Purpose: Inward rectifying potassium channel 6.2 (Kir6.2 Δ C26 channel) is closely related to ATP-sensitive potassium channels. Whether sodium azide, barium ion, d-amphetamine or procaine acts directly on the Kir6.2 Δ C26 channel remains unclear. We studied the effects of these compounds on Kir6.2 Δ C26 channel expressed in Xenopus oocytes. Methods: The coding sequence of a truncated form of mouse Kir6.2 (GenBank accession number NP_034732.1), Kir6.21-364 (i.e. Kir6.2 Δ C26), was subcloned into the pET20b(+) vector. Plasmid containing the correct T7 promoter-Kir6.21-364 cDNA fragment [Kir6.2/pET20b(+)] was then subject to Not I digestion to generate the templates for in vitro run-off transcriptions. The channel was expressed in Xenopus laevis oocytes. Two-electrode voltage clamping was used to measure the effects of sodium azide, barium ion, d-amphetamine and procaine on Kir6.2 Δ C26 channel current. Results: Sodium azide activated and barium ion and d-amphetamine inhibited the Kir6.2 Δ C26 channel. Procaine did not have any significant effect on the Kir6.2 Δ C26 channel. Conclusion: Kir6.2 Δ C26 channel expressed in Xenopus oocytes can be used as a pharmacological tool for the study of inward rectifying potassium channels

Ultrasound-Guided Femoral Nerve Block in Geriatric Patients with Hip Fracture in the Emergency Department

Background and Objectives: Systemic analgesics, including opioids, are commonly used for acute pain control in traumatic hip fracture patients in the emergency department (ED). However, their use is associated with high rates of adverse reactions in the geriatric population. As such, the aim of this study was to investigate the impact of lidocaine-based single-shot ultrasound-guided femoral nerve block (USFNB) on the standard care for acute pain management in geriatric patients with traumatic hip fracture in the ED. Methods: This retrospective, single-center, observational study included adult patients aged ≥60 years presenting with acute traumatic hip fracture in the ED between 1 January 2017 and 31 December 2020. The primary outcome measure was the difference in the amount of opioid use, in terms of morphine milligram equivalents (MME), between lidocaine-based single-shot USFNB and standard care groups. The obtained data were evaluated through a time-to-event analysis (time to meaningful pain relief), a time course analysis, and a multivariable analysis. Results: Overall, 607 adult patients (USFNB group, 66; standard care group, 541) were included in the study. The patients in the USFNB group required 80% less MME than those in the standard care group (0.52 ± 1.47 vs. 2.57 ± 2.53, p p < 0.001). Conclusions: In geriatric patients with hip fractures, a lidocaine-based single-shot USFNB can significantly reduce opioid consumption and provide more rapid and effective pain reduction