[Clinical features and interventional bronchoscopic treatment of primary airway tumor in 8 children]

Objective: To summarize the clinical manifestations and to evaluate the feasibility of therapeutic bronchoscopy in pediatric primary airway tumors. Methods: The clinical data of 8 children presented with airway tumors in Beijing Children's Hospital from November 2016 to March 2018 were retrospectively analyzed. Descriptive analysis was used to summarize the outcome and prognosis of these children after interventional bronchoscopy. Results: Among the 8 children, 5 were male and 3 were female, aged from 4 years and 8 months to 9 years and 2 months. The main clinical manifestations were cough and wheezing in 6 cases, hemoptysis in 3 cases and recurrent pulmonary infection in 2 cases, and none of them had lymph node metastasis and extra-pulmonary metastasis. All 8 children underwent bronchoscopic resection of the tumors, and the 4 children with blood-rich tumors had bronchial artery embolization at the blood supply site before the resection. No major bleeding or pneumothorax occurred during or after the operation. Four cases had low grade malignant bronchial mucoepidermoid carcinoma, 2 had inflammatory myofibroblastoma, and the rest two had pleomorphic adenoma and bronchial smooth muscle spindle cell tumor. Postoperative follow-up lasted 2 to 4 years, and 3 had tumor recured. Among the 3 cases, 2 had inflammatory myofibroblastoma who underwent surgical resection of the lesion and combined chemotherapy, respectively; and one had mucoepidermoid carcinoma who was under follow-up after interventional cryotherapy. Conclusions: The clinical manifestations of primary airway tumors in children are atypical. The main clinical manifestations are dry cough, wheezing, recurrent pulmonary infection and hemoptysis. Interventional bronchoscopy is a feasible choice for the treatment of pediatric airway tumors.

Supercomputer-Based Ensemble Docking Drug Discovery Pipeline with Application to Covid-19

We present a supercomputer-driven pipeline for in silico drug discovery using enhanced sampling molecular dynamics (MD) and ensemble docking. Ensemble docking makes use of MD results by docking compound databases into representative protein binding-site conformations, thus taking into account the dynamic properties of the binding sites. We also describe preliminary results obtained for 24 systems involving eight proteins of the proteome of SARS-CoV-2. The MD involves temperature replica exchange enhanced sampling, making use of massively parallel supercomputing to quickly sample the configurational space of protein drug targets. Using the Summit supercomputer at the Oak Ridge National Laboratory, more than 1 ms of enhanced sampling MD can be generated per day. We have ensemble docked repurposing databases to 10 configurations of each of the 24 SARS-CoV-2 systems using AutoDock Vina. Comparison to experiment demonstrates remarkably high hit rates for the top scoring tranches of compounds identified by our ensemble approach. We also demonstrate that, using Autodock-GPU on Summit, it is possible to perform exhaustive docking of one billion compounds in under 24 h. Finally, we discuss preliminary results and planned improvements to the pipeline, including the use of quantum mechanical (QM), machine learning, and artificial intelligence (AI) methods to cluster MD trajectories and rescore docking poses.

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is associated with IRF7, BANK1 and TBX21 polymorphisms in two populations

BACKGROUND AND PURPOSE

Autoantibodies targeting the GluN1(NR1) subunit of the anti-N-methyl-D-aspartate receptor (NMDAR) cause encephalitis. Although it has been shown that anti-NMDAR encephalitis is associated with human leukocyte antigen (HLA) loci, susceptibility genes for the disease outside the HLA loci remain unidentified. In this study, we aimed to explore the association of anti-NMDAR encephalitis with non-HLA genes.

METHODS

Two Chinese anti-NMDAR encephalitis cohorts from Han populations were recruited for this study. The North Chinese case-control set consisted of 98 patients and 460 controls, while the South Chinese case-control set included 78 patients and 541 controls. All participants were genotyped for 28 single nucleotide polymorphisms that are associated with autoimmune disorders or infectious diseases.

RESULTS

In two independent case-control sets, we identified significant associations of anti-NMDAR encephalitis with IRF7 rs1131665 (odds ratio [OR] 3.34, 95% confidence interval [CI] 1.99-5.63; P < 0.000001, P^adjusted  = 0.00004), BANK1 rs4522865 (OR 1.44, 95% CI 1.15-1.82; P = 0.0017, P^adjusted  = 0.0149), and TBX21 rs17244587 (OR 2.03, 95% CI 1.35-3.05; P = 0.00051, P^adjusted  = 0.0066). Furthermore, analysis of the three polymorphisms with clinical features of the disease revealed that the IRF7 rs1131665 was associated with tumor status.

CONCLUSION

The present study has for the first time identified non-HLA susceptibility genes for anti-NMDAR encephalitis. The association of IRF7, BANK1 and TBX21 with anti-NMDAR encephalitis suggests that B-cell activation, Th1 responses, virus infection and the type I interferon signaling pathway are involved in the pathogenesis of the disease.

Supercomputer-Based Ensemble Docking Drug Discovery Pipeline with Application to Covid-19

We present a supercomputer-driven pipeline for in-silico drug discovery using enhanced sampling molecular dynamics (MD) and ensemble docking. We also describe preliminary results obtained for 23 systems involving eight protein targets of the proteome of SARS CoV-2. THe MD performed is temperature replica-exchange enhanced sampling, making use of the massively parallel supercomputing on the SUMMIT supercomputer at Oak Ridge National Laboratory, with which more than 1ms of enhanced sampling MD can be generated per day. We have ensemble docked repurposing databases to ten configurations of each of the 23 SARS CoV-2 systems using AutoDock Vina. We also demonstrate that using Autodock-GPU on SUMMIT, it is possible to perform exhaustive docking of one billion compounds in under 24 hours. Finally, we discuss preliminary results and planned improvements to the pipeline, including the use of quantum mechanical (QM), machine learning, and AI methods to cluster MD trajectories and rescore docking poses.

Influence of roflumilast on sepsis mice through the JAK/STAT signaling pathway

OBJECTIVE

The aim of this study was to explore the influence of roflumilast on sepsis mice through the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway.

MATERIALS AND METHODS

A total of 36 Sprague-Dawley mice were randomly divided into normal group (n=12), model group (n=12) and roflumilast group (n=12). Mice in the normal group were fed normally. However, mice in the model group and roflumilast group were intraperitoneally injected with endotoxin to establish the sepsis mouse model. Furthermore, mice in the model group and roflumilast group were intraperitoneally injected with 0.9% sodium chloride and roflumilast once a day, respectively. After 7 d of intervention, mice were sampled. Lung tissue morphology was observed via hematoxylin-eosin (HE) staining, and the pathological score was given. The protein expression levels of JAK and STAT-3 were detected via Western blotting. The expression levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were detected via enzyme-linked immunosorbent assay (ELISA). Meanwhile, the mRNA expression levels of JAK, STAT-3, IL-6 and TNF-α were detected via quantitative Polymerase Chain Reaction (qPCR). The number of inflammatory cells in the lavage fluid was counted by a biochemical detector.

RESULTS

The survival rate of mice in the roflumilast group was significantly higher than that of the model group (p<0.05). The results of HE staining revealed that lung tissue morphology in roflumilast group was significantly improved when compared with the model group. Meanwhile, the pathological score in the roflumilast group was significantly lower than that of the model group (p<0.05). Western blotting showed that the protein expression levels of JAK and STAT-3 in the roflumilast group were markedly lower than those of the model group (p<0.05). According to the results of ELISA, the expression levels of IL-6 and TNF-α in the roflumilast group were remarkably lower than the model group (p<0.05). Further qPCR results manifested that the mRNA expression levels of JAK, STAT-3, IL-6 and TNF-α in the roflumilast group were significantly lower than those of the model group (p<0.05). Moreover, the number of neutrophils, monocytes and lymphocytes in the roflumilast group was significantly smaller than the model group.

CONCLUSIONS

Roflumilast can improve lung tissue morphology of sepsis mice by inhibiting the JAK/STAT signaling pathway.

MiR-202-3p functions as a tumor suppressor and reduces cell migration and invasion in papillary thyroid carcinoma

OBJECTIVE

MicroRNAs (miRNAs) are recently identified as key regulators of tumor development and progression. MiR-202-3p functions as tumor suppressor in some cancer types. The aim of the study is to determine its expression pattern and explore the functions underlying the mechanism of miR-202-3p in papillary thyroid carcinoma (PTC).

PATIENTS AND METHODS

By using quantitative RT-PCR (QRT-PCR) analyses, we detected miR-202-3p expression in PTC tissues and cell lines. Transwell migration and invasion assays were performed to measure the migration and invasion ability of tumor cells transfected with miR-202-3p mimic. Western blot analysis was used to detect the protein expression.

RESULTS

Our results showed that miR-202-3p expression was frequently downregulated in 96 cases PTC tissues compared to adjacent normal tissues. Lower expression of miR-202-3p associated with lymph node metastasis of patients with PTC. Overexpression of miR-202-3p inhibited cell migration and invasion in TPC-1 and BCPAP cells. Furthermore, enforced expression of miR-202-3p inhibited WNT signaling by downregulating β-catenin expression in TPC-1 and BCPAP cells.

CONCLUSIONS

Our findings indicated that miR-202-3p may represent a novel therapeutic target of in PTC.

Interactions of Mutiple Biological Fields in Stored Grain Ecosystems

Biological entities such as fungi in stored grain evolve and interact with the environment in similar fashions as physical fields. An experiment was conducted to study the behavior of the biological field of fungi in stored grain, as well as the interactions between the biological field of fungi and the physical fields of temperature and moisture. A framework of the biological field is presented to describe biological systems in which multiple biological entities co-exist and interact among themselves and with the surrounding environment. The proposed biological field describes the spatio-temporal distribution of a biological entity and its ability of influencing (or being influenced by) the surrounding biotic and abiotic entities through exchange of energy, matter, and/or information. The strength of a biological field of fungi was quantified as the rate of energy conversion by fungi from grain starch to heat. The experimental data showed that the strength of biological field of fungi in stored grain varied in both space and time, with the maximum field strength of 120-133 W m-3 occurred at the location where the biological field of fungi interacted strongly with the temperature and moisture fields.

Infrared dielectric metamaterials from high refractive index chalcogenides

High-index dielectric materials are in great demand for nanophotonic devices and applications, from ultrathin optical elements to metal-free sub-diffraction light confinement and waveguiding. Here we show that chalcogenide topological insulators are particularly apt candidates for dielectric nanophotonics architectures in the infrared spectral range, by reporting metamaterial resonances in chalcogenide crystals sustained well inside the mid-infrared, choosing Bi2Te3 as case study within this family of materials. Strong resonant modulation of the incident electromagnetic field is achieved thanks to the exceptionally high refractive index ranging between 7 and 8 throughout the 2-10 μm region. Analysis of the complex mode structure in the metamaterial allude to the excitation of circular surface currents which could open pathways for enhanced light-matter interaction and low-loss plasmonic configurations by coupling to the spin-polarized topological surface carriers, thereby providing new opportunities to combine dielectric, plasmonic and magnetic metamaterials in a single platform.

Integrated analysis of mRNA-miRNA expression in Tilapia infected with Tilapia lake virus (TiLV) and identifies primarily immuneresponse genes

We investigated differential gene expression in Tilapia infected with the Tilapia Lake virus (TiLV).We used high-throughput sequencing to identify mRNAs and miRNAs involved in TiLV infection progression We identified 25,359 differentially expressed genes that included 863 new genes. We identified 1770, 4142 and 4947 differently expressed genes comparing non-infected controls with 24 and 120 h infections and between the infected groups, respectively. These genes were enriched to 291 GO terms and 62 KEGG pathways and included immune system progress and virion genes. High-throughput miRNA sequencing identified 316 conserved miRNAs, 525 known miRNAs and 592 novel miRNAs. Furthermore, 138, 198 and 153 differently expressed miRNAs were found between the 3 groups listed above, respectively. Target prediction revealed numerous genes including erythropoietin isoform X2, double-stranded RNA-specific adenosine deaminase isoform X1, bone morphogenetic protein 4 and tapasin-related protein that are involved in immune responsiveness. Moreover, these target genes overlapped with differentially expressed mRNAs obtained from RNA-seq. These target genes were significantly enriched to GO terms and KEGG pathways including immune system progress, virion and Wnt signaling pathways. Expression patterns of differentially expressed mRNA and miRNAs were validated in 20 mRNA and 19 miRNAs by qRT-PCR. We also were able to construct a miRNA-mRNA target network that can further understand the molecular mechanisms on the pathogenesis of TiLV and guide future research in developing effective agents and strategies to combat TiLV infections in Tilapia.

Evaluation of the change of outcomes over a 10-year period in patients with stage III colon cancer: pooled analysis of 6501 patients treated with fluorouracil, leucovorin, and oxaliplatin in the ACCENT database

BACKGROUND

Since 2004, adjuvant 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX or FLOX) have been the standard of care for patients with resected colon cancer. Herein we examine the change of outcomes over a 10-year period in patients with stage III colon cancer who received this regimen.

PATIENTS AND METHODS

Individual patient data from the ACCENT database was used to compare the outcomes in older (1998-2003) and newer (2004-2009) treatment eras for patients with stage III colon cancer who received adjuvant FOLFOX or FLOX. The outcomes were compared between the two groups by the multivariate Cox proportional-hazards model adjusting for age, sex, performance score, T stage, N stage, tumor sidedness, and histological grade.

RESULTS

A total of 6501 patients with stage III colon cancer who received adjuvant FOLFOX or FLOX in six randomized trials were included in the analysis. Patients enrolled in the new era group experienced statistically significant improvement in time to recurrence [3-year rate, 76.1% versus 73.0%; adjusted hazard ratio (HRadj) = 0.83 (95% CI, 0.74-0.92), P = 0.0008], disease-free survival (DFS) [3-year rate, 74.7% versus 72.3%; HRadj = 0.88 (0.79-0.98), P = 0.024], survival after recurrence (SAR) [median time, 27.0 versus 17.7 months; HRadj = 0.65 (0.57-0.74), P < 0.0001], and overall survival (OS) [5-year rate, 80.9% versus 75.7%; HRadj = 0.78 (0.69-0.88), P < 0.0001]. The improved outcomes remained in patients diagnosed at 45 years of age or older, low-risk patients (T1-3 and N1), left colon, mismatch repair proficient (pMMR), BRAF, and KRAS wild-type tumors.

CONCLUSION

Improved outcomes were observed in patients with stage III colon cancer enrolled in clinical trials who received adjuvant FOLFOX/FLOX therapy in 2004 or later compared with patients in the older era. Prolonged SAR calls for revalidation of 3-year DFS as the surrogate endpoint of OS in adjuvant clinical trials and reevaluation of optimal follow-up of OS to confirm the trial findings based on the DFS endpoints.

CLINICAL TRIALS NUMBERS

NCT00079274; NCT00096278; NCT00004931; NCT00275210; NCT00265811; NCT00112918.

Carbon nanotube-based DNA vaccine against koi herpesvirus given by intramuscular injection

Koi herpesvirus (KHV) also named Cyprinid Herpesvirus 3 (CyHV-3) is one of the most threatening pathogens affecting common carp production as well as the valued ornamental koi carp. The current commercial vaccines available are costly and potentially cause severe stress caused by live virus. KHV ORF149 gene has been proved encoding one of the main immunogenic proteins for KHV. In this study, we coupled a plasmid expression vector for ORF149 to single walled carbon nanotubes (SWCNTs) for an anti-KHV vaccine. The vaccine conferred an 81.9% protection against intraperitoneal challenge with KHV. Importantly, SWCNTs as a promising vehicle can enhanced the protective effects 33.9% over that of the naked DNA vaccine at the same dose. The protection was longer and serum antibody production, enzyme activities and immune-related gene expression were all induced in fish vaccinated with the nanotube-DNA vaccine compared with the DNA alone. Thereby, this study demonstrates that the ORF149 DNA vaccine loaded onto SWCNTs as a novel vaccine might provide an effective method of coping with KHV disease using intra-muscular vaccination.

[Prediction of acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation by the level of galectin-9 in peripheral blood]

Objective: To evaluate possible effects of Gelctin-9 on acute graft versus host disease (aGVHD) development and clinical outcomes in patients before and afer allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: Peripheral blood samples were obtained from 29 patients and 15 healthy volunteers with heparin anticoagulant tubes. Samples were analyzed using ELISA kits to measure the serum concentrations of Galectin-9. Results: Patients developing aGVHD had significantly lower level of Galectin-9 [ (7.96±1.18) μg/L] before allo-HSCT compared with those not developing aGVHD [ (12.37±0.97) μg/L, P<0.001]. And after allo-HSCT, the consentration of Galectin-9 increased markedly in patients developing aGVHD [ (17.78±1.78) μg/L] compared with those not developing aGVHD [ (9.45±0.80) μg/L, P<0.001]. Patients developing 3-4 grade aGVHD had significantly higher level of Galectin-9 [ (23.25±2.59) μg/L] compared with those developing 1-2 grade aGVHD [ (14.37±1.45) μg/L, P=0.008] and those without aGVHD [ (9.45±0.80) μg/L, P<0.001]. The patients with lower level of Galectin-9 after allo-HSCT (<13.61 μg/L) showed more favorable clinical outcomes compared with those with higher level of Galectin-9 (≥13.61 μg/L) . The 3-year overall survival rates were (100.00±6.05) % and (69.23±12.80) %, respectively (P=0.009) . The cumulative incidence of non-relapse mortality was significantly higher in high Galectin-9 group [ (23.08±11.69) %] in comparison with low Gaelctin-9 group [ (0.00±7.39) %] (P=0.023) . There was no significant difference between the two groups in terms of the cumulative incidence of relapse. The cumulative incidence of relapse at 3 years were (8.33±7.98) % and (12.50±8.27) % in high and low Galectin-9 groups, respectively (P=0.708) . Conclusions: The serum concentration of Galectin-9 at the time of engraftment after allo-HSCT may be used as a predictor for the development and severity of aGVHD. Galectin-9 might be considered as a potential new approach to regulate transplant rejection to achieve desirable survival.

[Clinical analysis of 382 immediately breast reconstruction after mastectomy in Beijing City, Tianjin City and Hebei Province from 2012 to 2016]

Objective: To summarize the status of immediate breast reconstruction (IBR) after mastectomy in Beijing City, Tianjin City and Hebei Province. Methods: A retrospective analysis was made on the data of 382 cases with breast cancer who were treated and followed up successfully with immediate breast reconstruction after mastectomy from January 2012 to December 2016 in Beijing City, Tianjin City and Hebei Province. Clinic data of the followed-up 382 cases (all female, age (38.5±4.2) years (range: 24 to 70 years)), including general information, tumor information, sugery methods, and treatments after surgery were collected. The survival status, metastasis,complications and prognosis were followed up. Cosmetic effcet was evalated by Harris method, and life quality by Functional Assessment of Cancer Therapy-Breast scale (FACT-B). χ(2) test was used to compare the difference between year 2012 and year 2013 to 2016. Bonferroni method was used to correct the inspection level, which was 0.05/10=0.005. The trend of IBR rate (ratio of IBR to modified radical mastectomy) from 2013 to 2016 was analyzed by trend χ(2) test. Results: There was 46 cases in stage 0, 152 cases in stage Ⅰ, 165 cases in stage Ⅱ, 19 cases in stage Ⅲ. Twenty-five cases was treated by neoadjuvant chemotherapy, 231 by chemotherapy and 35 by radiotherapy. The proportion of implant reconstruction was 48.7% (186/382), more than expanded of 21.5% (82/382), with latissimus dorsi of 12.0% (46/382), TRAM of 8.9% (34/382), DIEP of 2.1% (8/382), and latissimus plus implant of 6.8% (26/382). According to the Harris standard, the excellent and good rate of the cosmetic effect of the reconstructed breast was 93.7%. The score of FACT-B was 108.20±16.9 (range: 67 to 144) 1 year postoperatively. Compared with 2012, the IBR rate was significant increased, till 2015, the IBR rate was 153/10 000 cases (χ(2)=47.028, P=0.000). Conclusions: There is a significant increase on IBR rate in Beijing City, Tianjin City and Hebei province by year. Most of cases received IBR is stage Ⅰ to Ⅱ. Implant reconstruction is the main reconstructive method. Postoperative cosmetic effects and quality of life are both meet patients' demon.

How many lymph nodes should be dissected in esophagectomy with or without neoadjuvant therapy to get accurate staging?

It is essential to dissect an adequate number of lymph nodes (LNs) to ensure staging accuracy during esophagectomy with or without neoadjuvant therapy. We developed a statistical model to quantify the probability of precise nodal staging based on previous studies. Esophageal cancer patients who underwent esophagectomy were retrospectively reviewed in the Surveillance, Epidemiology, and End Results database. A β-binomial distribution was adopted to estimate the number of understaged patients based on the numbers of positive and examined LNs. Using 6,252 patients, we estimated a 90% confidence of accurate N0 staging could be achieved by examining 17 LNs without neoadjuvant therapy. To obtain similar accuracy in N1 and N2, 20 and 25 LNs should be examined. For patients with neoadjuvant therapy, 18, 19, and 28 LNs could achieve the same accuracy. Staging accuracy was a significant prognostic factor. We found when 90% confidence had been achieved, patient survival did not improve with more LNs examined and the ratio and log odds of positive LNs did not have significant prognostic values. The statistical model we developed for precise staging in patients with different N stages is of great value in guiding lymphadenectomy. It provided risk assessment for underestimated LN metastases and guided subsequent adjuvant treatment.

Autophagy triggered by MAVS inhibits Coxsackievirus A16 replication

Mitochondrial antiviral signaling protein (MAVS), a crucial adaptor protein localized on mitochondria, plays vital roles in various biological processes. Autophagy and apoptosis are two independent and closely linked cell death pathways. But whether MAVS could induce apoptosis and autophagy in rhabdomyosarcoma cells (RD cells) and what is the relationship between autophagy and apoptosis still remains elusive. Here, we reveal that overexpression of MAVS could trigger both apoptosis and autophagy in RD cells. Interestingly, MAVS-induced apoptosis was dependent on the activation of the c-Jun N-terminal kinase (JNK) signaling pathway and inhibition of the extracellular signal-regulated kinase (ERK) signaling pathway. Also, it was found that inhibition of autophagy by 3-methyladenine (3-MA) enhanced MAVS-induced apoptosis resulting in increased cleavage of caspase-3 and poly (ADP-ribose) polymerase (PARP). Meanwhile, autophagy induction by rapamycin resulted in decreased MAVS-induced apoptosis. In addition, we found that MAVS expression was inhibited upon Coxsackievirus A16 (CA16) infection and overexpression of MAVS could inhibit CA16 replication. Collectively, our study provides novel insights into the link between apoptosis and autophagy induced by MAVS overexpression in RD cells and gains a greater understanding of MAVS-induced antiviral functions, which provide new targets for CA16 treatment. Keywords: CA16; MAVS; apoptosis; autophagy.

Composite super-moiré lattices in double-aligned graphene heterostructures

When two-dimensional (2D) atomic crystals are brought into close proximity to form a van der Waals heterostructure, neighbouring crystals may influence each other's properties. Of particular interest is when the two crystals closely match and a moiré pattern forms, resulting in modified electronic and excitonic spectra, crystal reconstruction, and more. Thus, moiré patterns are a viable tool for controlling the properties of 2D materials. However, the difference in periodicity of the two crystals limits the reconstruction and, thus, is a barrier to the low-energy regime. Here, we present a route to spectrum reconstruction at all energies. By using graphene which is aligned to two hexagonal boron nitride layers, one can make electrons scatter in the differential moiré pattern which results in spectral changes at arbitrarily low energies. Further, we demonstrate that the strength of this potential relies crucially on the atomic reconstruction of graphene within the differential moiré super cell.

Comparison of the blood parameters and histopathology between grass carp infected with a virulent and avirulent isolates of genotype II grass carp reovirus

Grass carp hemorrhagic disease caused by grass carp reovirus (GCRV) is the most important disease for grass carp aquaculture. Its typical clinical symptom is haemorrhaging, although the mechanism was remained unclear. In this study, we investigated the differences in blood parameters and histopathological features between grass carp infected with a virulent and avirulent isolates of genotype II GCRV. Infection with the virulent isolate resulted in increases in 8 routine blood and 2 serum biochemical parameters (P < 0.05); while 9 routine blood and 5 biochemical parameters were significantly decreased (P < 0.05) compared with fish infected with the avirulent isolate. The majority of these alterations were related to hemorrhage, inflammatory reactions and organic damage. The histopathologic changes were primarily vasodilation and hyperaemia in multiple organs, lymphocyte and macrophage infiltration as well as severe vacuolar degeneration in spleen, kidney and liver. The histopathology changes in fish infected with the avirulent isolate were minimal. These results indicated that the pathogenicity of GCRV was primarily reflected in destruction of the blood circulatory system and parenchymatous organs. This study lays the foundation for further research on the pathogenesis of bleeding caused by GCRV infection and the use of blood parameters and histopathology as tools for disease diagnosis.

Establishment of a brain cell line obtained from hybrids of Channa argus ×Channa maculata for the detection of tilapia lake virus

A brain cell line (CAMB) derived from hybrid snakehead (Channa argus (♂) × Channa maculata (♀)) was established by trypsin and collagenase combined digestion. The culturing conditions and cell biological characteristics were systematically studied. For growth of the cells, M199 medium containing 10% fetal bovine serum was used and at 27 °C incubated. Based on morphological analysis, CAMB cells were confirmed to be epithelial. The cell line has been subcultured more than 80 times since its initial primary culture. Chromosome analysis revealed that CAMB cells had an abnormal chromosome number 2n = 64, whereas the chromosome number in the hybrid snakehead was 45. The suitability of CAMB for tilapia lake virus (TiLV) was demonstrated. A CPE was observed after infection with TiLV-2017A. The highest TiLV titer was observed after 12 days post infection (dpi) and reached 107.2 TCID50/mL. The virus replication was confirmed by electron microscopic observations. Additionally, immunofluorescence assay confirmed the presence of TiLV-2017A after infection of CAMB. Therefore, CAMB cells can be a useful tool for the investigation of the pathogenesis of the TiLV induced disease in tilapia.