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A comprehensive study of the epidemiology and pathogenicity of infectious bronchitis virus (IBV) in China was carried out by molecular characterization of the S1 gene from 46 isolates obtained for this study and 174 reference strains isolated over a 15-year period. Nine types were found according to sequence analysis and phylogenetic study of the S1 gene. The co-circulation of multiple IBV types and the ongoing emergence of IBV variants are the epidemiological challenges in China. Factors contributing to the continual emergence include mutations, insertions and deletions in the S1 protein genes; recombination between local IBV strains circulating in chicken flocks in China; and recombination between local strains and vaccine strains. Vaccination-challenge analysis between circulating field strains and Mass-type H120 vaccine indicated the need to develop new vaccines from local IBV strains. These results also emphasize the importance of continued IBV surveillance in China.

Limited penetration of chemotherapeutic drugs through the blood brain barrier (BBB), and the increased chemo-resistance of glioma cells due to macroautophagy/autophagy, result in high tumor recurrence and extremely limited survival of glioma patients. Ultrasound-targeted microbubble destruction (UTMD) is a technique of transient and reversible BBB disruption, which greatly facilitates intracerebral drug delivery. In addition, sonodynamic therapy (SDT) based on ultrasound stimulation and a sonosensitizer, can be a safe and noninvasive strategy for treating glioma. We innovatively designed a smart "all-in-one" nanosensitizer platform by incorporating the sonoactive chlorin e6 (Ce6) and an autophagy inhibitor-hydroxychloroquine (HCQ) into angiopep-2 peptide-modified liposomes (designated as ACHL), which integrates multiple diagnostic and therapeutic functions. ACHL selectively accumulated in the brain tumors during the optimal time-window of transient UTMD-mediated BBB opening. The nanosensitizer then responded to a second ultrasonic stimulation, and simultaneously unloaded HCQ and generated ROS in the glioma cells. The sonotherapy triggered apoptosis as well as MAPK/p38-PINK1-PRKN-dependent mitophagy, in which the antioxidant relieved the sonotoxicity and MAPK/p38 activation, while the inhibition of MAPK/p38 attenuated the progression toward mitophagy by compromising redistribution of PRKN. Moreover, HCQ blocking autophagosome degradation, augmented intracellular ROS production and resulted in an oxidative-damage regenerative loop. ACHL-SDT treatment using this construct significantly inhibited the xenograft-tumor growth and prolonged the survival time of tumor-bearing mice, exhibiting an improved therapeutic efficiency. All together, we demonstrated a precision sonotherapy with simultaneous apoptosis induction and mitophagy inhibition, which served as an intelligently strategic sense of working alongside, providing new insights into the theranostics of brain tumors.

In this study, we attenuated a Chinese LX4-type nephropathogenic infectious bronchitis virus (IBV) strain, CK/CH/LHLJ/04V, by serial passage in embryonated chicken eggs. Based on sequence analysis of the 3'-7kb region, the CK/CH/LHLJ/04V virus population contained subpopulations with a mixture of genetic mutants. The titers of the virus increased gradually during serial passage, but the replication capacity decreased in chickens. The virus was partially attenuated at passage 40 (P40) and P70, and was fully attenuated at P110. It lost immunogenicity and kidney tropism at P110 and P70, respectively. Amino acid substitutions were found in the 3'-7kb region, primarily in the spike (S) protein. Substitutions in the S1 subunit occurred between P3 and P40 and all subpopulations in a virus passage showed the same substitutions. Other substitutions that occurred between P70 and P110, however, were found only in some subpopulations of the virus passages. A 109-bp deletion in the 3'-UTR was observed in most subpopulations of P70 and P110, and might be related to virus replication, transcription and pathogenicity. The changes described in the 3'-7kb region of the virus are possibly responsible for virus attenuation, immunogenicity decrease and tissue tropism changes; however, we cannot exclude the possibility that other parts of the genome may also be involved in those changes.

Avian infectious bronchitis virus (IBV) causes tremendous economic losses to the poultry industry worldwide. Different serotypes of this virus show little cross-protection. The present study investigated the genotypic relationship between CK/CH/LDL/97I-type strains and reference IBVs based on S1 gene comparisons and the protection provided by vaccination with commercial vaccines and attenuated homologous and heterologous strains. Phylogenetic analysis and the comparison of S1 showed that CK/CH/LDL/97I-type virus might be a new serotype compared to vaccine strains and other types of IBV isolates in China. Protection efficacy was evaluated by morbidity, mortality, and virus re-isolation from the challenged chicks. Complete protection by IBV vaccination was provided by the homologous strain but sufficient respiratory protection was not provided by the commercial vaccines. Heterologous strains against CK/CH/LDL/97I challenge and the development of a vaccine against CK/CH/LDL/97I-type IBV will be necessary to control infectious bronchitis disease in poultry. Further development of the attenuated CK/CH/LDL/97I strain may provide a valuable contribution towards this goal.

Objective: To monitor and study the molecular epidemiology, evolution and pathogenicity of infectious bronchitis viruses (IBVs) in China in recent years and further our knowledge of the evolution of IBVs. Methods: Thirty-seven IBV isolates were isolated from commercial chickens in China. The isolates were characterized by RT-PCR, sequencing, typing and analyzing the entire S1 gene. In addition, 4 selected IBV isolates were used to experimentally infect the specific pathogen-free chickens to study their pathogenicity. Results: Three types of IBV have been cocirculating in chicken flocks in China in recent years. Unique insertions and deletions in S1 protein regions were identified among different types of IBV. Moreover, a new IBV strain was isolated and identified in a layer hen. S1 gene analysis showed that a recombination event had occurred in the virus’s evolutionary process. In addition, experimental infection has shown that IBV isolates have been nephropathogenic in China in recent years. Conclusion: Mutations, insertions, deletions and recombination of the S1 protein gene contribute to the genetic diversity of IBV in China. Cocirculation of multiple types of IBV in field conditions in China renders its epidemiology and evolution very complicated, indicating the necessity for development of new vaccines or vaccine strategies.

BackgroundChinese medical universities typically have a high number of students, a shortage of teachers and limited equipment, and as such histology courses have been taught using traditional lecture-based formats, with textbooks and conventional microscopy. This method, however, has reduced creativity and problem-solving skills training in the curriculum. The virtual microscope (VM) system has been shown to be an effective and efficient educational strategy. The present study aims to describe a VM system for undergraduates and to evaluate the effects of promoting active learning and problem-solving skills.MethodsTwo hundred and twenty-nine second-year undergraduate students in the Third Military Medical University were divided into two groups. The VM group contained 115 students and was taught using the VM system. The light microscope (LM) group consisted of 114 students and was taught using the LM system. Post-teaching performances were assessed by multiple-choice questions, short essay questions, case analysis questions and the identification of structure of tissue. Students’ teaching preferences and satisfaction were assessed using questionnaires.ResultsTest scores in the VM group showed a significant improvement compared with those in the LM group (p < 0.05). There were no substantial differences between the two groups in the mean score rate of multiple-choice questions and the short essay category (p > 0.05); however, there were notable differences in the mean score rate of case analysis questions and identification of structure of tissue (p < 0.05). The questionnaire results indicate that the VM system improves students’ productivity and promotes learning efficiency. Furthermore, students reported other positive effects of the VM system in terms of additional learning resources, critical thinking, ease of communication and confidence.ConclusionsThe VM system is an effective tool at Chinese medical university to promote undergraduates’ active learning and problem-solving skills as an assisted teaching platform.

Oligodendrocyte precursor cells (OPCs) undergo a series of energyconsuming developmental events; however, the uptake and trafficking pathways for their energy metabolites remain unknown. In the present study, we found that 2-NBDG, a fluorescent glucose analog, can be delivered between astrocytes and oligodendrocytes through connexin-based gap junction channels but cannot be transferred between astrocytes and OPCs. Instead, connexin hemichannel-mediated glucose uptake supports OPC proliferation, and ethidium bromide uptake or increase of 2-NBDG uptake rate is correlated with intracellular Ca 2+ elevation in OPCs, indicating a Ca 2+ -dependent activation of connexin hemichannels. Interestingly, deletion of connexin 43 (Cx43, also known as GJA1) in astrocytes inhibits OPC proliferation by decreasing matrix glucose levels without impacting on OPC hemichannel properties, a process that also occurs in corpus callosum from acute brain slices. Thus, dual functions of connexin-based channels contribute to glucose supply in oligodendroglial lineage, which might pave a new way for energymetabolism-directed oligodendroglial-targeted therapies.