Epidemic Japanese B encephalitis combined with contactinassociated protein-like 2 antibody-positive autoimmune encephalitis:A case report

BACKGROUND It is not uncommon to develop viral encephalitis.Epidemic Japanese B encephalitis infection combined with contactin-associated protein-like 2(CASPR-2)antibody-positive autoimmune encephalitis has not been reported at present.In clinical work,we need to consider more options.CASE SUMMARY A 32-year-old male worker presented with headache,fever and call-unresponsive presentation.Complete cranial magnetic resonance image showed symmetrical abnormal signals in bilateral medial temporal lobe,bilateral thalamus and basal ganglia.Improved lumbar puncture showed that cerebrospinal fluid protein and cell count increased significantly.Viral encephalitis was considered,and the patient's consciousness still increased rapidly after antiviral treatment.Further detection of Cerebrospinal fluid Japanese B encephalitis virus Polymerase Chain Reaction positive,serum autoimmune encephalitis antibody showed CASPR-2 antibody positive(1:320),the patient's condition gradually improved after plasma exchange treatment.3 mo later,the serum CASPR-2 antibody was negative and the patient's condition was stable.CONCLUSION This article reports the world’s first case of Epidemic Japanese B encephalitis infection combined with CASPR-2 antibody-positive autoimmune encephalitis,with a view to raising awareness.

Shuanghuanglian injection downregulates nuclear factor-kappa B expression in mice with viral encephalitis

A mouse model of viral encephalitis was induced by intracranial injection of a Coxsackie virus B3 suspension. Quantitative real-time reverse transcription-PCR and western blot assay were applied to detect mRNA and protein expression of intelectin-2 and nuclear factor-kappa B in the viral encephalitis and control groups. Nuclear factor-kappa B and intelectin-2 mRNA and protein expression were significantly increased in mice with viral encephalitis. After intraperitoneal injection of Shuanghuanglian at a dose of 1.5 mg/kg for 5 successive days, intelectin-2 and nuclear factor-kappa B protein and mRNA expression were significantly decreased. To elucidate the relationship between intelectin-2 and nuclear factor-kappa B, mice with viral encephalitis were administered an intracerebral injection of 107 pfu recombinant lentivirus expressing intelectin shRNA. Both protein and mRNA levels of intelectin and nuclear factor-kappa B in brain tissue of mice were significantly decreased. Experimental findings suggest that Shuanghuanglian injection may downregulate nuclear factor-kappa B production via suppression of intelectin production, thus inhibiting inflammation associated with viral encephalitis.

Suramin Inhibits the In Vitro Expression of Encephalitis B Virus Proteins NS3 and E

In this study, the mechanism by which Suramin inhibits the replication of epidemic encephalitis B virus was explored to provide a theoretical basis for its further application in clinical practice. After viral infection of HepG2 and IMR 32 cells, different concentrations of Suramin were added to the culture media, and then the cultural supernatants and infected cells were collected 48 h later. For the evaluation of the curative effect, cytopathic effect (CPE), virus titers, the expression of viral protein and viral RNA were determined by Western blot, RT PCR and in vitro RNA synthesis, respectively. At the concentration of 50 μg/ml of Suramin, HepG2 and IMR 32 infected with epidemic encephalitis B virus decreased by 51.8 % and 0.03 % respectively, as compared with controls. It was suggested that expression of encephalitis B virus proteins NS3 and E was notably reduced by Suramin. This is especially true of E protein. At RNA level, however, no difference in RNA virus was found between Suramin treated virus and non treated cells. Our results suggest that Suramin can inhibit viral replication by blocking the production of viral proteins.

Construction and Preliminary Application of RT-LAMP Detection Method for Swine Japanese B Encephalitis Virus

[ Objective] This study aimed to establish a rapid, sensitive and specific method using reverse transcription loop-mediated isothermal amplification （RT-LAMP） technology to detect swine Japanese B encephalitis virus （JEV）. [ Method ] Four specific LAMP primers were designed according to six loci the conservative region of JEV E gene sequence. Positive JEV RNA sample was used as a template for one-step amplification, and the reaction conditions and reaction system were optimized. [ Result] Experimental results showed that the established method had high sensitivity, with the detection limit of 0.5pg; specificity experi- ments indicated that the method had high specificity and there was no amplification reaction for other viral pathogens. The coincidence rate between detection results of RT-LAMP and RT-Nested-PCR was 90.9%. After RT-LAMP reaction, a chemiluminescent agent was added for visual observation, which greatly reduced the detection time. This method required no special equipment but only a water bath, which was a simple, sensitive and rapid detection method for swine Japanese B encephalitis virus and could be applied in primary laboratories. [ Conclusion] An RT-LAMP detection method for swine Japanese B encephalitis virus was successfully established and preliminarily applied in clinical practice.