Interior modification of Macrobrachium rosenbergii nodavirus-like particle enhances encapsulation of VP37-dsRNA against shrimp white spot syndrome infection.

BACKGROUND: Application of a virus-like particle (VLP) as a nanocontainer to encapsulate double stranded (ds)RNA to control viral infection in shrimp aquaculture has been extensively reported. In this study, we aimed at improving VLP's encapsulation efficiency which should lead to a superior fighting weapon with disastrous viruses. RESULTS: We constructed 2 variants of chimeric Macrobrachium rosenbergii nodavirus (MrNV)-like particles (V1- and V2-MrN-VLPs) and tested their efficiency to encapsulate VP37 double stranded RNA as well as WSSV protection in P. vannamei. Two types of short peptides, RNA-binding domain (RBD) and deca-arginine (10R) were successfully engineered into the interior surface of VLP, the site where the contact with VP37-dsRNA occurs. TEM and dynamic light scattering (DLS) analyses revealed that the chimeric VLPs remained their assembling property to be an icosahedral symmetric particle with a diameter of about 30 nm, similar to the original MrN-VLP particle. The superior encapsulation efficiency of VP37-dsRNA into V2-MrN-VLP was achieved, which was slightly better than that of V1-MrN-VLP but far better (1.4-fold) than its parental V0-MrN-VLP which the mole ratio of 7.5-10.5 for all VLP variants. The protection effect against challenging WSSV (as gauged from the level of VP37 gene and the remaining viral copy number in shrimp) was significantly improved in both V1- and V2-MrN-VLP compared with an original V0-MrN-VLP template. CONCLUSION: MrN-VLP (V0-) were re-engineered interiorly with RBD (V1-) and 10R (V2-) peptides which had an improved VP37-dsRNA encapsulation capability. The protection effect against WSSV infection through shrimp administration with dsRNA + V1-/V2-MrN VLPs was experimentally evident.

"Endoshield": A Physical Protective Box for Pediatric Endoscopy during the COVID-19 Pandemic.

BACKGROUND/AIMS: The coronavirus disease (COVID)-19 pandemic presents challenges for gastrointestinal endoscopy. Although the virus is transmitted through contact and droplets, aerosol-generating procedures produce aerosols that can spread through airborne routes. Several gastrointestinal societies have released statements to protect patients and health care providers (HCPs). This study describes a barrier box that may be used as an adjunctive device in addition to personal protective equipment during endoscopies. METHODS: A transparent acrylic box called "Endoshield" was created to place over patient's head and shoulders and was tested for its ease of use for the endoscopist and suitability for patient size and position. RESULTS: Twelve children (66.67%, male) with a median age of 9 years (range, 2-11 years) underwent emergency or urgent endoscopy between April and June 2020 during the COVID-19 outbreak. The most common presenting symptom was life-threatening gastrointestinal bleeding (8/12, 66.67%), while the rest had urgent symptoms (4/12, 33.33%). The "Endoshield" was suitable for all patient positions (left lateral position: 9/12, 75% and supine position: 3/12, 25%). The patients and HCPs were followed up for their symptoms on day 14, and none of them had any symptoms of concern. CONCLUSION: The "Endoshield" is affordable, reusable, and suitable for both positions.