Objective Tissue uptake and distribution of nano-/microplastics was studied at a single high dose by gavage in vivo.Methods Fluorescent microspheres (100 nm, 3 μm, and 10 μm) were given once at a dose of 200 mg/(kg·body weight). The fluorescence intensity (FI) in observed organs was measured using the IVIS Spectrum at 0.5, 1, 2, and 4 h after administration. Histopathology was performed to corroborate these findings.Results In the 100 nm group, the FI of the stomach and small intestine were highest at 0.5 h, and the FI of the large intestine, excrement, lung, kidney, liver, and skeletal muscles were highest at 4 h compared with the control group (P < 0.05). In the 3 μm group, the FI only increased in the lung at 2 h (P < 0.05). In the 10 μm group, the FI increased in the large intestine and excrement at 2 h, and in the kidney at 4 h (P < 0.05). The presence of nano-/microplastics in tissues was further verified by histopathology. The peak time of nanoplastic absorption in blood was confirmed.Conclusion Nanoplastics translocated rapidly to observed organs/tissues through blood circulation;however, only small amounts of MPs could penetrate the organs.

Objective: To understand immune escape mutation, drug resistance mutation, and genome evolution information of HBV genome sequence in China. Methods: The whole genome sequence information of HBV in China submitted in GenBank from 1998 to 2021 was selected as the object for analysis. MAFFT method was used for cluster analysis. Analysis of immune escape and drug-resistant mutations was performed using the online tool Gen2pheno. The BEAST 1.10.4 was used for analysis the time evolution of HBV sequences. Results: A total of 5 426 sequences were included in the dataset and distributed in 19 provinces of China. Type C accounted for the highest proportion (59.1%, 3 211/5 426), followed by type B (33.7%, 1 833/5 426). Immune escape mutations were found in 764 sequences (14.1%, 764/5 426). At least one reverse transcriptase region mutation occurred in 98.1% of the sequences. The evolutionary roots of most HBV sequences in China date from around 1801 AD. Conclusion: HBV-resistant mutation rate is high in China. HBV genomes evolve slowly.
China/epidemiology* ; DNA, Viral/genetics* ; Drug Resistance, Viral/genetics* ; Genome, Viral ; Genotype ; Hepatitis B virus/genetics* ; Humans ; Mutation

As one of the most important aquatic fish, Micropterus salmoides suffers lethal and epidemic disease caused by rhabdovirus at the juvenile stage. In this study, a new strain of M. salmoides rhabdovirus (MSRV) was isolated from Yuhang, Zhejiang Province, China, and named MSRV-YH01. The virus infected the grass carp ovary (GCO) cell line and displayed virion particles with atypical bullet shape, 300-500 nm in length and 100-200 nm in diameter under transmission electron microscopy. The complete genome sequence of this isolate was determined to include 11 526 nucleotides and to encode five classical structural proteins. The construction of the phylogenetic tree indicated that this new isolate is clustered into the Vesiculovirus genus and most closely related to the Siniperca chuatsi rhabdovirus. To explore the potential for a vaccine against MSRV, a glycoprotein (1-458 amino acid residues) of MSRV-YH01 was successfully amplified and cloned into the plasmid pFastBac1. The high-purity recombinant bacmid-glycoprotein was obtained from DH10Bac through screening and identification. Based on polymerase chain reaction (PCR), western blot, and immunofluorescence assay, recombinant virus, including the MSRV-YH01 glycoprotein gene, was produced by transfection of SF9 cells using the pFastBac1-gE2, and then repeatedly amplified to express the glycoprotein protein. We anticipate that this recombinant bacmid system could be used to challenge the silkworm and develop a corresponding oral vaccine for fish.
Animals ; Baculoviridae/metabolism* ; Bass/metabolism* ; Carps/virology* ; Cell Line ; Female ; Genetic Techniques ; Genome, Viral ; Glycoproteins/biosynthesis* ; Insecta ; Ovary/virology* ; Phylogeny ; Plasmids/metabolism* ; Recombinant Proteins/biosynthesis* ; Rhabdoviridae/metabolism*