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@#Objective To explore the absorption characteristics of aluminum hydroxide adjuvant with inactivated enterovirus 71(EV71).Methods The morphology,purity and particle size distribution of inactivated EV71 particles were analyzed by transmission electron microscope,size exclusion chromatography HPLC(SEC-HPLC) and dynamic light scatter(DLS),and the morphology of aluminum hydroxide adjuvant nanoparticles was observed by transmission electron microscope.Using inactivated EV71 antigen content(4 000,6 000,8 000,10 000,11 000,12 000,13 000,14 000,20 000,30 000 U/mL),aluminum hydroxide adjuvant concentration [0.35,0.25,0.17,0.085 mg/mL(aluminum content)],adsorption time(0.30 and 120 min),ionic strength(sodium chloride concentration of 0.15,0.75 and 1.25 mol/L)and phosphorus-aluminum molar ratio(P/Al,0.15,0.64,2.08 and 7.87) as variables,the adsorption characteristics of aluminum hydroxide adjuvant with inactivated EV71 antigen were investigated.Results Inactivated EV71 particles mainly existed in the form of intact virus particles with a diameter of about 30 nm;Aluminum hydroxide adjuvant showed the characteristics of nanocrystallization,and the particle size was distributed within 200～700 nm.The inactivated EV71 antigen at the concentration of no more than 11 000 U/mL was completely absorbed by aluminum hydroxide adjuvant of 0.35 mg/mL(aluminum content),and no free antigen was detected in the supernatant;while from 12 000 U/mL,the content of free antigen in the supernatant increased with the increase of antigen content;the inactivated EV71 antigen of 250 U/mL was completely absorbed by various concentrations of aluminum hydroxide adjuvant,and no free antigen was detected in the supernatant;the adsorption effect of aluminum hydroxide adjuvant consistent after incubation for different time,and no free antigen was detected in the supernatant.Under the conditions of single dose of vaccine with aluminum hydroxide content(0.35 mg/mL) and inactivated EV71 antigen content(250 U/mL),sodium chloride ion strength had no effect on the adsorption of inactivated EV71 virus,while phosphate ion concentration significantly effected the adsorption.Conclusion Aluminum hydroxide adjuvant in a single dose of vaccine completely absorbed inactivated EV71 antigen,and group replacement played an important role.
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@#Objective To investigate the effect of astragalus membranaceus（AM）injection on apoptosis and autophagy of human gastric epithelial cell line（GES⁃1）induced by enterovirus 71（EV71）. Methods GES⁃1 cells were cultured in vitro and divided into infected group（EV71 infected at a MOI of 3 and control group（no virus infected）. The morpho⁃logical changes of EV71 infected cells were observed by inverted microscope. The level of VP1 in GES⁃1 cells infected with EV71 was detected by Western blot；CCK⁃8 assay was used to detect the viability of GES⁃1 cells infected with EV71；Nuclear staining with DAPI was used to observe the morphological changes of nuclear apoptosis infected with EV71. GES⁃1 cells were divided into control group（without virus infection），infection group and AM intervention group with final concentration of 1，2. 5，5 and 10 μg／mL，respectively. Western blot was used to detect the effect of AM intervention on the expression of apoptosis⁃related proteins Caspase⁃3，PARP and autophagy⁃related proteins LC3 and P62 in GES⁃1 cells infected withEV71. CCK⁃8 method was used to detect the effect of AM intervention on the viability of GES⁃1 cells infected with EV71. Results GES⁃1 cells were round，shrunken with nuclear pyknosis and uneven size；VP1 level increased（t = 41. 56，P < 0. 01），cell viability decreased（t = 19. 07，P < 0. 01），Caspase⁃3 and PARP proteins were cut off（t = 35. 29 and 3. 648， P < 0. 01 and 0. 021 8，respectively），LC3Ⅱ／LC3Ⅰ ratio increased（t = 10. 16，P = 0. 000 5）and P62 protein was degraded（t = 68. 68，P < 0. 01）；AM inhibited the degradation of Caspase⁃3，PARP and P62 proteins induced by EV71 （t = 52. 66，59. 60 and 40. 22，respectively，each P < 0. 01）and increased the ratio of LC3Ⅱ／LC3Ⅰ（t = 5. 521，P = 0. 005 3），andreducedtheinhibitoryeffectofEV71ontheviabilityofGES⁃1cells（t =4. 420，P =0. 0115）. Conclusion EV71 infection induced apoptosis of GES⁃ 1 cells and AM intervention inhibited EV71 induced apoptosis by inhibiting EV71 induced autophagy.
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Enterovirus 71 (EV71) infection is more likely to cause hand, foot and mouth disease (HFMD) in children, which can lead to neurogenic complications and higher mortality. As a commonly used clinical medicine, Reduning injection (RDN) helps to shorten the symptoms of patients with HFMD and facilitate the early recovery of children. However, the regulatory mechanism of RDN on the HFMD immune system disorder caused by EV71 remains to be discussed. This study collected detailed treatment data of 56 children with HFMD who entered the affiliated Children's Hospital of Nanjing Medical University during 2019. Retrospective analysis of clinical data showed that the symptoms of the RDN treatment group were improved compared with the untreated group. To explore its mechanism, the relevant detection indicators were detected by flow cytometry, enzyme-linked immunosorbent assay and real-time quantitative PCR. It was found that the number and function of innate immune (ILCs) and adaptive immunity (Th1, Th2 and secreted cytokines) were reduced, suggesting that RDN plays a role by regulating cellular immunity. The in vitro differentiation inhibition test further confirmed that RDN affected Th1 differentiation by inhibiting the expression of transcription factors on the basis of Th1 cell differentiation in vitro.
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Enterovirus 71(EV71)is the main pathogen of severe hand-foot-mouth disease. As the characteristics and the path?ological mechanism of EV71 gradually become clear,the therapeutic strategies of EV71 infection are clarified. Acting on specific tar?get can directly interfere the process of EV71 infection,while regulating the host immune can clean the virus,ease inflammation and protect uninfected cells. In addition,some cytokines like interferon with both broad-spectrum antiviral function and immune regulation are used in clinical. In addition,drug combination could enhance the antiviral effect and reduce toxicity and drug resistance. At pres?ent,most of the therapeutics are still in pre-clinical phase,while only a few are in clinical application. This article reviews the differ?ent types of EV71 infection treatment strategies and methods recently reported,in order to provide help for further research on anti-EV71 infection.
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Enterovirus 71 (EV71) is the main pathogen of severe hand-foot-mouth disease. As the characteristics and the pathological mechanism of EV71 gradually become clear, the therapeutic strategies of EV71 infection are clarified. Acting on specific target can directly interfere the process of EV71 infection, while regulating the host immune can clean the virus, ease inflammation and protect uninfected cells. In addition, some cytokines like interferon with both broad-spectrum antiviral function and immune regulation are used in clinical. In addition, drug combination could enhance the antiviral effect and reduce toxicity and drug resistance. At present, most of the therapeutics are still in pre-clinical phase, while only a few are in clinical application. This article reviews the different types of EV71 infection treatment strategies and methods recently reported, in order to provide help for further research on anti-EV71 infection.
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The prevalence of acute flaccid paralysis (AFP) associated with EV71 and the genetic variation in Fujian , China from 2003 to 2012 was investigated in this study .Descriptive epidemiology was used to analyze the epidemiologic and clinical features of AFP cases associated with EV 71 .Phylogenetic analysis was performed to explore the genetical characteris-tics of EV71 based on the complete VP1 nucleotide and amino acid sequences .Results showed that the mean incidence of EV71-associated AFP in children under 15 years old was 2 .24/10 000 000 in Fujian Province during 2003 and 2012 ,based on the number of EV71 isolates and the reported AFP cases .And the incidence has increased since 2008 .The EV71 strains isolated from the AFP cases or from the healthy contacts were distributed in 9 prefectures of Fujian Province ,most in the months of May and June .Of 76 .0% (19/25) of AFP cases associated with EV 71 were the children under 3 years and the male-to-female ratio was 1 .5 :1 .Twenty out of twenty-two cases (90 .91% ) had fevers before the onset of paralysis .Most cases had unilater-al limb paralysis (14/22 ,63 .6% ) .Typical manifestations of hand-foot-and-mouth disease (HFMD) were observed in five cases before the onset of paralysis .Residual paralysis was observed in two cases during the follow-up visits .The strains isolated from 25 cases belonged to genotype C4 .All other strains belonged to subtype C4a except the subtype C4b strains isolated in 2003 .The homology among the strains was high in 2009-2011 ,and the homology among these strains and the representative strains in Fuyang ,Anhui Province was also in the high level .Therefore ,it was possible that the isolated strains had the same origin and might cause the epidemic .In conclusion ,an AFP surveillance system could be developed for analyzing the incidence of AFP associated with EV71 ,determining the features of the isolates ,and describing the intensity and trends of EV71 epidem-ics .
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BACKGROUND:Hand-foot-mouth disease has become a major public health issue in children in China. In the present prospective study we investigated the clinical characteristics and emergency management of children with severe encephalitis associated with NPE caused by enterovirus 71. METHODS:The study was conducted in 2 pediatric intensive care units (PICUs) over a 2-month period. Clinical records were reviewed of critically ill children with severe encephalitis associated with NPE caused by EV71 who were admitted to PICUs during the period of May to June 2008 in Fuyang. RESULTS:We reviewed the complete records of 36 children, of whom 23 (63.9％) were male and 13 (36.1％) female. Their age ranged from 4 to 48 months, with an average of 15.8 months. Al children except one were under 3 years of age. The overal mortality in these children was 19.4％. The average duration of critical life threatening signs and symptoms was 2.1 days (12 hours-5 days). Nervous system diseases included brainstem encephalitis in 27 children (75％), brainstem encephalitis associated with myelitis in 6 children (16.7％), and general encephalitis in 3 chidren (8.3％), respectively. In 12 patients of NPE (33.3％) pink or bloody bubble sputum and asymmetric pulmonary edema or hemorrhage was the primary manifestation but no typical exanthema was observed. Five children died of acute onset of NPE and / or pulmonary hemorrhage with rapid progression of cardiopulmonary failure within hours after admission. Therapeutic management consisted of mechanical ventilation and administration of mannitol, methylprednisolone, intravenous immunoglobulin (IVIG) and vasoactive drugs, associated with the need of fluid volume resuscitation in 9 (25％) of the 36 children. CONCLUSIONS:In children less than 3 years of age found to be affected by severe EV71 encephalitis associated with NPE, one fifth may die. The major organ systems infected by severe EV71 include the central nervous system, the respiratory system, and the cardiovascular system. Early diagnosis and evaluation, respiratory support, treatment of intracranial hypertension, and mainttenance of function of the cardiovascular system are the most important therapeutic measures.
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The comparative analysis of the biological characterization and the genetic background study of EV71 circulating strains is commonly recognized as basic work necessary for development of an effective EV71 vaccine. In this study, we sequenced five EV71 circulating strains, isolated from Fuyang, Hefei, Kunming and Shenzhen city of China and named them FY-23, FY-22, H44, K9 and S1 respectively. The sequence alignment demonstrated their genotypes be C4. The genetic distance of the VP1 gene from these isolates suggested that they were highly co-related with genetic identity similar to other previously reported EV71 strains in China. Additionally, these strains were identified to display some obvious proliferation dynamics and plaque morphology when propagated in Vero cells. However, a distinctive difference in pathogenic ability in neonatal mice was found. Some differences in cross neutralization test & immunogenic analysis were also found. All these results are related to the biological characterization of circulating EV71 strains in China and aid in the development of an EV71 vaccine in the future.
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Enterovirus 71 (EV71) is a common cause of Hand, foot, and mouth disease (HFMD) and may also cause severe neurological diseases, such as encephalitis and poliomyelitis-like paralysis. To examine the genetic diversity of EV71, we determined and analyzed the complete VP1 sequences (891 nucleotides) from nine EV71 strains isolated in Fuyang, China. We found that nine EV71 strains isolated were over 98% homologous at the nucleotide level and 93%-100% homologous to members of the C4 subgenogroup. At the amino acid level, these Fuyang strains were 99% -100% homologous to one another, 97%-100% homologous to members of the C4 subgenogroup, and the histidine(H) at amino acid position 22 was conserved among the Fuyang strains. The results indicate that Fuyang isolates belong to genotype C4, and an H at position 22 appears to be a marker for the Fuyang strains.