Epidemiologic changes of a longitudinal surveillance study spanning 51 years of scrub typhus in mainland China.

Scrub typhus may be one of the world's most prevalent, neglected and serious, but easily treatable, febrile diseases. It has become a significant potential threat to public health in China. In this study we used national disease surveillance data to analyze the incidence and spatial-temporal distribution of scrub typhus in mainland China during 1952-1989 and 2006-2018. Descriptive epidemiological methods and spatial-temporal epidemiological methods were used to investigate the epidemiological trends and identify high-risk regions of scrub typhus infection. Over the 51-year period, a total of 182,991 cases and 186 deaths were notified. The average annual incidence was 0.13 cases/100,000 population during 1952-1989. The incidence increased sharply from 0.09/100,000 population in 2006 to 1.93/100,000 population in 2018 and then exponentially increased after 2006. The incidence was significantly higher in females than males (χ2 = 426.32, P < 0.001). Farmers had a higher incidence of scrub typhus than non-farmers (χ2 = 684.58, P < 0.001). The majority of cases each year were reported between July and November with peak incidence occurring during October each year. The trend surface analysis showed that the incidence of scrub typhus increased gradually from north to south, and from east and west to the central area. The spatial autocorrelation analysis showed that a spatial positive correlation existed in the prevalence of scrub typhus on a national scale, which had the characteristic of aggregated distribution (I = 0.533, P < 0.05). LISA analysis showed hotspots (High-High) were primarily located in the southern and southwestern provinces of China with the geographical area expanding annually. These findings provide scientific evidence for the surveillance and control of scrub typhus which may contribute to targeted strategies and measures for the government.

Inhibitory effects and mechanisms of proanthocyanidins against enterovirus 71 infection.

Proanthocyanidins (PC), a natural flavonoid compound, was reported to possess a variety of pharmacological activities such as anti-tumor and anti-viral effects. In this study, the anti-Enterovirus 71 (EV71) activities and mechanisms of PC were investigated both in vitro and in vivo. The results showed that PC possessed anti-EV71 activities in different cell lines with low toxicity. PC can block both the adsorption and entry processes of EV71 via directly binding to virus VP1 protein. PC may competitively interfere with the binding of VP1 to its receptor SCARB2. PC can also regulate three different MAPK signaling pathways to reduce EV71 infection and attenuate virus induced inflammatory responses. Importantly, intramuscular therapy of EV71-infected mice with PC markedly improved their survival and attenuated the severe clinical symptoms. Therefore, the natural compound PC has potential to be developed into a novel anti-EV71 agent targeting viral VP1 protein and MAPK pathways.

Reduced the Food Effect and Enhanced the Oral Bioavailability of Ivacaftor by Self-Nanoemulsifying Drug Delivery System (SNEDDS) Using a New Oil Phase.

Purpose: The purpose of this work was to develop an ivacaftor self-nanoemulsion drug delivery system (IVA-SNEDDS) using the newly developed double headed miscellaneous lipid (DHML) as oil phase to reduce the food effect and inter-individual absorption variability of IVA. Methods: The lipids with the greatest solubility to IVA were selected as the oil phase of IVA-SNEDDS by saturation solubility method. Then, among different surfactants and co-surfactants, those with good emulsifying ability for the selected oil phase were selected, and the proportion of surfactant and co-surfactant was further selected by pseudo-ternary phase diagram. The prepared IVA-SNEDDS were screened and evaluated in vitro and in beagle dogs. Results: The optimized IVA-SNEDDS formulation consisting of DHML, Tween 80, and Transcutol HP with the weight ratio of 2:2:1 was physically stable and it was easy to disperse in water, pH 1.2 hydrochloric acid and pH 6.8 phosphate buffer solution, and generated a fine homogeneous nanoemulsion, with mean globule size less than 75 nm regardless of dilution ratio. In vitro drug release studies showed that the drug in IVA-SNEDDS could be completely released in a short time, while the drug release in IVA-suspension was less than 1% at 60 min. In vivo, using IVA-suspension (Fed) as a reference, the relative oral bioavailability of IVA-suspension (Fasted), IVA-SNEDDS (Fasted), and IVA-SNEDDS (Fed) were 23.35%, 153.63%, and 149.89%, respectively. This showed that IVA-SNEDDS could eliminate the positive food effect, improve the oral bioavailability, and reduce the IVA absorption difference between individuals. Conclusion: As the oil phase of SNEDDS, DHML can significantly improve the drug solubility and drug loading of IVA-SNEDDS. Moreover, DHML was easily emulsified and can effectively form a nanoemulsion in vivo and in vitro. The prepared IVA-SNEDDS can reduce the inter-individual absorption variability of IVA, eliminate its food effect and improve its oral bioavailability.

Eukaryotic initiation factor 4A3 inhibits Wnt/ß-catenin signaling and regulates axis formation in zebrafish embryos.

A key step in the activation of canonical Wnt signaling is the interaction between ß-catenin and Tcf/Lefs that forms the transcription activation complex and facilitates the expression of target genes. Eukaryotic initiation factor 4A3 (EIF4A3) is an ATP-dependent DEAD box-family RNA helicase and acts as a core subunit of the exon junction complex (EJC) to control a series of RNA post-transcriptional processes. In this study, we uncover that EIF4A3 functions as a Wnt inhibitor by interfering with the formation of ß-catenin/Tcf transcription activation complex. As Wnt stimulation increases, accumulated ß-catenin displaces EIF4A3 from a transcriptional complex with Tcf/Lef, allowing the active complex to facilitate the expression of target genes. In zebrafish embryos, eif4a3 depletion inhibited the development of the dorsal organizer and pattern formation of the anterior neuroectoderm by increasing Wnt/ß-catenin signaling. Conversely, overexpression of eif4a3 decreased Wnt/ß-catenin signaling and inhibited the formation of the dorsal organizer before gastrulation. Our results reveal previously unreported roles of EIF4A3 in the inhibition of Wnt signaling and the regulation of embryonic development in zebrafish.

Enhanced oral bioavailability of lurasidone by self-nanoemulsifying drug delivery system in fasted state.

OBJECTIVE: The purpose of this work was to develop a new formulation to enhance the bioavailability and reduce the food effect of lurasidone using self-nanoemulsifying drug delivery systems (SNEDDSs). METHODS: The formulation of lurasidone-SNEDDS was selected by the solubility and pseudo-ternary phase diagram studies. The prepared lurasidone-SNEDDS formulations were characterized for self-emulsification time, effect of pH and robustness to dilution, droplet size analysis, zeta potential and in vitro drug release. Lurasidone-SNEDDSs were administered to beagle dogs in fed and fasted state and their pharmacokinetics were compared to commercial available tablet as a control. RESULTS: The result showed lurasidone-SNEDDS was successfully prepared using Capmul MCM, Tween 80 and glycerol as oil phase, surfactant and co-surfactant, respectively. In vitro drug release studies indicated that the lurasidone-SNEDDS showed improved drug release profiles and the release behavior was not affected by the medium pH with total drug release of over 90% within 5 min. Pharmacokinetic study showed that the AUC(0-∞) and Cmax for lurasidone-SNEDDS are similar in the fasted and fed state, indicating essentially there is no food effect on the drug absorption. CONCLUSION: It was concluded that enhanced bioavailability and no food effect of lurasidone had been achieved by using SNEDDS.