Development of a rapid visual detection technology for BmNPV based on CRISPR/Cas13a system.

Pathogenic microorganism of silkworm are important factors that threaten the high-quality development of sericulture. Among them, Bombyx mori nucleopolyhedrovirus (BmNPV) caused diseases often lead to frequent outbreaks and high mortality, resulting in huge losses to sericultural industry. Current molecular detection methods for BmNPV require expensive equipment and sikilled technical personnel. As a result, the most commonly detection method for silkworm egg production enterprises involves observing the presence of polyhedra under a microscope. However, this method has low accuracy and sensitivity. There is an urgent need to develop a new detection technology with high sensitivity, high specificity, and applicability for silkworm farms, silkworm egg production enterprises and quarantine departments. In this study, we successfully established the CRISPR/Cas13a BmNPV visualized detection technology by combining Recombinase Polymerase Amplification (RPA) technology and CRISPR/Cas13a system. This technology is based on microplate lateral, flow test strips and portable fluorescence detector. The detection sensitivity can reach up to 1 copies/µL for positive standard plasmid and 1 fg/µL for BmNPV genome in 30-45 min, demonstrating high sensitivity. By detecting silkworm tissues infected with different pathogens, we determined that CRISPR/Cas13a detection technology has good specificity. In summary, the newly established nucleic acid detection technology for BmNPV is characterized by high sensitivity, high specificity, low cost and convenience for visualization. It can be applied in field detection and silkworm egg quality monitory system.

Three-dimensional visualization technology for guiding one-step percutaneous transhepatic cholangioscopic lithotripsy for the treatment of complex hepatolithiasis.

BACKGROUND: Biliary stone disease is a highly prevalent condition and a leading cause of hospitalization worldwide. Hepatolithiasis with associated strictures has high residual and recurrence rates after traditional multisession percutaneous transhepatic cholangioscopic lithotripsy (PTCSL). AIM: To study one-step PTCSL using the percutaneous transhepatic one-step biliary fistulation (PTOBF) technique guided by three-dimensional (3D) visualization. METHODS: This was a retrospective, single-center study analyzing, 140 patients who, between October 2016 and October 2023, underwent one-step PTCSL for hepatolithiasis. The patients were divided into two groups: The 3D-PTOBF group and the PTOBF group. Stone clearance on choledochoscopy, complications, and long-term clearance and recurrence rates were assessed. RESULTS: Age, total bilirubin, direct bilirubin, Child-Pugh class, and stone location were similar between the 2 groups, but there was a significant difference in bile duct strictures, with biliary strictures more common in the 3D-PTOBF group (P = 0.001). The median follow-up time was 55.0 (55.0, 512.0) days. The immediate stone clearance ratio (88.6% vs 27.1%, P = 0.000) and stricture resolution ratio (97.1% vs 78.6%, P = 0.001) in the 3D-PTOBF group were significantly greater than those in the PTOBF group. Postoperative complication (8.6% vs 41.4%, P = 0.000) and stone recurrence rates (7.1% vs 38.6%, P = 0.000) were significantly lower in the 3D-PTOBF group. CONCLUSION: Three-dimensional visualization helps make one-step PTCSL a safe, effective, and promising treatment for patients with complicated primary hepatolithiasis. The perioperative and long-term outcomes are satisfactory for patients with complicated primary hepatolithiasis. This minimally invasive method has the potential to be used as a substitute for hepatobiliary surgery.