Recombinant bivalent subunit vaccine combining truncated VP4 from P[7] and P[23] induces protective immunity against prevalent porcine rotaviruses.

Porcine rotaviruses (PoRVs) cause severe economic losses in the swine industry. P[7] and P[23] are the predominant genotypes circulating on farms, but no vaccine is yet available. Here, we developed a bivalent subunit PoRV vaccine using truncated versions (VP4*) of the VP4 proteins from P[7] and P[23]. The vaccination of mice with the bivalent subunit vaccine elicited more robust neutralizing antibodies (NAbs) and cellular immune responses than its components, even at high doses. The bivalent subunit vaccine and inactivated bivalent vaccine prepared from strains PoRVs G9P[7] and G9P[23] were used to examine their protective efficacy in sows and suckling piglets after passive immunization. The immunized sows showed significantly elevated NAbs in the serum and colostrum, and the suckling piglets acquired high levels of sIgA antibodies from the colostrum. Challenging subunit-vaccinated or inactivated-vaccinated piglets with homologous virulent strains did not induce diarrhea, except in one or two piglets, which had mild diarrhea. Immunization with the bivalent subunit vaccine and inactivated vaccine also alleviated the microscopic lesions in the intestinal tissues caused by the challenge with the corresponding homologous virulent strain. However, all the piglets in the challenged group displayed mild to watery diarrhea and high levels of viral shedding, whereas the feces and intestines of the piglets in the bivalent subunit vaccine and inactivated vaccine groups had lower viral loads. In summary, our data show for the first time that a bivalent subunit vaccine combining VP4*P[7] and VP4*P[23] effectively protects piglets against the diarrhea caused by homologous virulent strains.IMPORTANCEPoRVs are the main causes of diarrhea in piglets worldwide. The multisegmented genome of PoRVs allows the reassortment of VP4 and VP7 genes from different RV species and strains. The P[7] and P[23] are the predominant genotypes circulating in pig farms, but no vaccine is available at present in China. Subunit vaccines, as nonreplicating vaccines, are an option to cope with variable genotypes. Here, we have developed a bivalent subunit candidate vaccine based on a truncated VP4 protein, which induced robust humoral and cellular immune responses and protected piglets against challenge with homologous PoRV. It also appears to be safe. These data show that the truncated VP4-protein-based subunit vaccine is a promising candidate for the prevention of PoRV diarrhea.

A newly designed disk-lobe occluder with isogenous barbs for left atrial appendage closure: Initial multicenter experience.

Background: Although the implant success rate of left atrial appendage closure (LAAC) has increased and complications have decreased over time, there are still anatomically and technically complicated cases where novel LAA occluders may simplify the procedure and thus might potentially improve the clinical outcome. Objectives: This study aimed to assess the safety and efficacy of the newly designed device with isogenous barbs in LAAC. Methods: Eight centers in China participated in this prospective study from July 2016 to April 2018. Peri- and post-procedural safety and efficacy were evaluated through scheduled follow-ups and transesophageal echocardiography (TEE). Results: A total of 175 patients with a mean age of 68.4 ± 9.2 years old, a mean CHA2DS2-VASc score of 4.7 ± 1.8, and a mean HAS-BLED score of 3.2 ± 1.3, were included. The device was successfully implanted in 173 patients (98.9%). The device size ranged from 18 to 34 mm. Clinically relevant pericardial effusion (PEF) in the perioperative period, occurred in 3 patients (1.7%). TEE follow-up was available in 167 (96.5%) patients at 12-month. During follow-up, 9 patients suffered serious adverse event: 4 death (2.3%), 1 ischemic stroke (0.6%), and 2 gastro-intestinal bleeding (1.2%) and 2 device-related thrombus (DRT) (1.2%). Estimated annual thromboembolism rate reduced by 90% and estimated annual major bleeding rate reduced by 81% after LAAC with the newly designed device. Conclusion: The newly designed device with isogenous barbs for LAAC could be performed effectively with a low incidence of adverse events and a high incidence of anatomic closure.

Overexpression of the transcription factor HAC1 improves nerolidol production in engineered yeast.

Increasing the metabolic flux of the mevalonate pathway, reducing the metabolic flux of competing pathway and utilizing the diauxie-inducible system constructed by GAL promoters are strategies commonly used in yeast metabolic engineering for the production of terpenoids. Using these strategies, we constructed a series of yeast strains with a strengthened mevalonate pathway and finally produced 336.5 mg/L nerolidol in a shake flask. The spliced HAC1 mRNA assay indicated that the unfolded protein response (UPR) occurred in the strains that we constructed. UPR strains exhibited the low transcriptional activities of GAL1 promoter. HAC1-overexpressing strain exhibited dramatically enhanced transcriptional activity of GAL1 promoter at 72 h of fermentation in flasks. HAC1 overexpression also increased the nerolidol titer by 47.7 %, reaching 497.0 mg/L and increased cell vitality. RNA-seq showed that the genes whose transcription responded to HAC1-overexpression were involved in the regulation of monocarboxylic acid metabolic processes and cellular amino acid biosynthetic process, indicating that the metabolic regulation may be part of the reason of the improved nerolidol synthesis. Our findings enrich the knowledge of the relationship between the construction of sesquiterpene-producing cell factories and UPR regulation. This study provides an effective strategy for sesquiterpene production in yeast.

Watch out for the Thrombus Adhering to the Puncture Site of the Atrial Septum during Left Atrial Appendage Closure.

We present a rare case of thrombus adhering to the puncture site of the atrial septum during left atrial appendage closure. By discussing the case, we suggest that some preventive measurements be taken during left atrial appendage closure and that conventional transesophageal echocardiography for the atrial septal puncture site be performed after the delivery sheath is removed.

Percutaneous Left Atrial Appendage Closure With LACBES® Occluder　- A Preclinical Feasibility Study.

BACKGROUND: Left atrial appendage closure (LAAC) has been developed as an alternative treatment used for the prevention of strokes in high-risk patients with atrial fibrillation. Here, a novel LAAC prosthesis (LACBES®device) is developed, and its translational potential is investigated by performing a pre-clinical study to evaluate its safety and effectiveness.Methods and Results:LACBES®occluders were implanted in 7 healthy canines percutaneously. Closure effect was evaluated by left atrial angiography. The canines were sacrificed post-procedure on days 45, 80 and 110; gross anatomy was examined subsequently. Endothelialization of device surface was evaluated by HE staining, immunofluorescence staining against CD31 and scanning electron microscope. LACBES®occluders were implanted in all canines successfully; a small residual shunt was observed in 1 canine immediately post procedure. One canine died of groin hematoma within 36 h, which was related to the procedure, but there was no device-related death. A layer of white transparent tissue that failed to cover the nut was formed on the surface of the sealing disc on day 80, but the newborn tissue completely covered the sealing disc on day 110. Immunofluorescence staining against CD31 and scanning electron microscope confirmed complete intima formation and neovascularization within 4 months. CONCLUSIONS: The current research suggested the LACBES®device is feasible for LAAC, with a high success rate, few device-related complications and complete neointima formation in canines.