Cryo-electron Microscopy Structures of Novel Viruses from Mud Crab Scylla paramamosain with Multiple Infections.

Viruses associated with sleeping disease (SD) in crabs cause great economic losses to aquaculture, and no effective measures are available for their prevention. In this study, to help develop novel antiviral strategies, single-particle cryo-electron microscopy was applied to investigate viruses associated with SD. The results not only revealed the structure of mud crab dicistrovirus (MCDV) but also identified a novel mud crab tombus-like virus (MCTV) not previously detected using molecular biology methods. The structure of MCDV at a 3.5-Å resolution reveals three major capsid proteins (VP1 to VP3) organized into a pseudo-T=3 icosahedral capsid, and affirms the existence of VP4. Unusually, MCDV VP3 contains a long C-terminal region and forms a novel protrusion that has not been observed in other dicistrovirus. Our results also reveal that MCDV can release its genome via conformation changes of the protrusions when viral mixtures are heated. The structure of MCTV at a 3.3-Å resolution reveals a T= 3 icosahedral capsid with common features of both tombusviruses and nodaviruses. Furthermore, MCTV has a novel hydrophobic tunnel beneath the 5-fold vertex and 30 dimeric protrusions composed of the P-domains of the capsid protein at the 2-fold axes that are exposed on the virion surface. The structural features of MCTV are consistent with a novel type of virus.IMPORTANCE Pathogen identification is vital for unknown infectious outbreaks, especially for dual or multiple infections. Sleeping disease (SD) in crabs causes great economic losses to aquaculture worldwide. Here we report the discovery and identification of a novel virus in mud crabs with multiple infections that was not previously detected by molecular, immune, or traditional electron microscopy (EM) methods. High-resolution structures of pathogenic viruses are essential for a molecular understanding and developing new disease prevention methods. The three-dimensional (3D) structure of the mud crab tombus-like virus (MCTV) and mud crab dicistrovirus (MCDV) determined in this study could assist the development of antiviral inhibitors. The identification of a novel virus in multiple infections previously missed using other methods demonstrates the usefulness of this strategy for investigating multiple infectious outbreaks, even in humans and other animals.

Aucubin produces anti-osteoporotic effects under mechanical stretch stress and orthodontic tooth movement.

Aucubin (AU), an iridoid glycoside extracted from Eucommia ulmoides, exerts anti-osteoporotic effects by promoting osteogenesis, as reported in previous studies. Here, we investigated the effects of AU under mechanical stretch stress. MC3T3-E1 cells were treated with dexamethasone (DEX) in vitro and subjected to mechanical stretch stress to establish an osteoporotic orthodontic force cell model. AU treatment increased the mRNA and protein expressions of BMP2, OPN, RUNX2, COL-1 and other osteogenic differentiation factors in MC3T3-E1 cells. Furthermore, we established an in vivo orthodontic tooth movement (OTM) model of osteoporosis. Serum parameter detection of ALP concentration, radiography of the femur, hematoxylin-eosin (HE) staining, and micro-CT of the maxilla confirmed that AU could partially reverse the damage induced by DEX. Immunohistochemical (IHC) analysis showed that AU increased the expression of COL-1, OCN, and OPN on the tension side of the periodontium. In conclusion, AU treatment promotes osteogenic differentiation under mechanical stretch stress and positively affects bone remodeling during OTM in DEX-induced osteoporosis.

Endoscopic Removal of a Duodenal-Perforating Leg of Glasses with Dormia Basket.

Ingestion of foreign bodies is common in clinical practice. Most ingested foreign bodies will pass through the gastrointestinal (GI) tract without any problems. While GI tract injury due to the ingested foreign body such as a toothpick, a fishbone, a date pit, or a chicken bone, is common, duodenal perforation is rare. In this report, our experience with this rare entity is shared. We present a 38-year-old male patient with GI tract perforation in the bulbus of the duodenum due to a leg of glasses. The patient was admitted to our hospital with severe abdominal pain. Right upper quadrant tenderness was detected at physical examination, and leukocytosis on the laboratory test results. Plain X-ray and computerized tomography showed an ingested foreign body in the bulbus of the duodenum. A leg of glasses perforating the duodenum was removed with endoscopy. The patient was managed nonoperatively, and discharged without any complications on the eighth day after endoscopy. Endoscopic removal and nonoperative management may be feasible in carefully selected patients with duodenal-perforating foreign bodies.

Regenerating gene family member 4 promotes growth and migration of gastric cancer through protein kinase B pathway.

Regenerating gene family member 4 (REG4), a secreted protein, is overexpressed in several cancers, including gastric cancer. The present study was undertaken to determine the roles of REG4 in the growth of gastric cancer in the nude mice and in the proliferation and migration in human gastric cancer cell line and its downstream signaling pathway. Gastric cancer models were elicited by intraperitoneally injecting MKN45 human gastric cancer cells and the tumor size was measured every other day. The expressions of REG4 mRNA and protein were increased in the gastric cancer tissues from gastric cancer patients. REG4 increased the gastric tumor weight and size in the nude mice, and promoted the proliferation and migration of gastric cancer cells MKN45. Adeno-associated viral (AAV)-mediated knockdown of REG4 decreased the gastric tumor weight and size in the nude mice, and suppressed the proliferation and migration of MKN45 cells. REG4 increased the expression of phosphorylated protein kinase B (Akt). Triciribine hydrate (TCN), the inhibitor of Akt, decreased the gastric tumor weight and size in the nude mice and abolished REG4-induced weight and size increase of the tumor. TCN also inhibited proliferation and migration and abolished REG4-induced proliferation and migration increase of human gastric cell line MKN45. These results indicate that REG4 promotes the growth, proliferation and migration of gastric cancer through Akt pathway.