Antiviral effect of emodin from Rheum palmatum against coxsakievirus B5 and human respiratory syncytial virus in vitro / 华中科技大学学报（医学）（英德文版）

Viral infections are the major causes of morbidity and mortality in elderly people and young children throughout the world. The most common pathogens include coxsackie virus (CV) and respiratory syncytial virus (RSV). However, no antiviral agents with low toxicity and drug resistance are currently available in clinic therapy. The present study aimed to examine the antiviral activities of emodin (an ingredient of Rheum palmatum) against CVB5 and RSV infections, in an attempt to discover new antiviral agents for virus infection. The monomer emodin was extracted and isolated from Rheum palmatum. The antiviral activities of emodin on HEp-2 cells were evaluated, including virus replication inhibition, virucidal and anti-absorption effects, by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tet-razolium bromide (MTT) assay and plaque reduction assay (PRA). The kinetics of virus inhibition by emodin in a period of 14 h was further determined by plaque assay and quantitative real time PCR (qPCR). Cytokine (IFN-γ, TNF-α) mRNA expressions after emodin treatment (7.5, 15, 30 μmol/L) were also assessed by qPCR post-infection. The results showed that emodin had potent inhibitory activities against CVB5 and RSV, with the 50% effective concentration (EC50) ranging from 13.06 to 14.27 μmol/L and selectivity index (SI) being 5.38-6.41 μmol/L. However, emodin couldn't directly inactivate the viruses or block their absorption to cells. It acted as a biological synthesis inhibitor against CVB4 and RSV in a concentration- and time-dependent manner, especially during the first 0-4 h post-infection. Moreover, emodin could decrease the mRNA expression of IFN-α but enhance TNF-γ expression significantly compared to the viral controls in vitro. Our results provide a molecular basis for development of emodin as a novel and safe antiviral agent for human enterovirus and respiratory virus infection in the clinical therapy.

Genetic analysis on S segment of hantaviruses in rodent hosts from Wuhan area, Hubei province / 中华流行病学杂志

Objective To investigate the infection and genotype of hantaviruses in rodents from Wuhan area,Hubei province.Methods Rodents were trapped in fields and residential areas of Xinzhou and Jiangxia districts of Wuhan in autumn and winter seasons,from 2000 to 2003 and from 2009 to 2011.Trapped rodents were identified,and hantavirus antigens were detected in the lung tissues with indirect immunofluorescence assay (IFA).Partial S segment sequences were amplified with RT-PCR in hantavirus antigen positive samples and then sequenced.Phylogenetic tree was constructed to analyze the genetic characteristics of hantaviruses.Results From 2000 to 2003,437 rodents were trapped,with 24 (5.49％) lung tissues showed hantavirus antigen positive.From 2009 to 2011,173 rodents were trapped and 7 (4.05％) were hantavirus antigen positive.Rattus norvegicus were the dominant species of rodents.Partial S segment sequences were amplified from 22 samples with Hantaan and Seoul viruses specific primers and sequenced.Partial S segments of Seoul viruses (nucleotide 588-1147) were amplified from 17 rodents (13 R.norvegicus and 4 Apodemus agrarius).Seven of these sequences belonged to 3 genetic lineage,while two novel genetic lineages were formed by 9 and 1 sequences,respectively.Partial S segments of Hantaan viruses (nucleotide 615-1141 ) were amplified from 5 A.agrarius.One of these sequences belonged to 7 genetic lineages,and 4 sequences formed one novel genetic subtype.Conclusion Hantaan and Seoul viruses co-circulated in Wuhan area.Hubei province.Novel genetic lineages were identified in this study and Seoul virus might have caused spillover infection in A.agrarius.

A study of immunoassay by using quantum dots to detect Hantavirus infection / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To develop a new method to detect anti-Hantavirus IgG antibodies (HV IgG) based on quantum dots (QDs) and indirect immune technique.</p><p><b>METHODS</b>The carbodiimide crosslinking method was used to couple protein G and goat antihuman IgG on the surface of water-solubility QDs. The coverglass covered HV antigen was used as carrier, and QDs-PG-IgG conjugates was used as labeled second antibody to detect the HV-IgG in the serum samples. The detecting conditions were optimized.</p><p><b>RESULTS</b>The optimum reaction time, pH and goat antihuman IgG concentration for conjugating the QDs with goat antihuman IgG were 6.0, 2h, and 20 microg/ml, respectively. The optimum working dilution of QDs-PG-IgG conjugates was 1: 200. The detection limit of the serum samples was about 1: 1280 dilution.</p><p><b>CONCLUSION</b>The method established in this study has been demonstrated to be a specific, sensitive, rapid test for detecting HV antibodies, laying the foundation of single molecule detection. The anti-fluorescence quenching ability of this method was significant improved.</p>

Study on the transmission of Hantaan virus and Orientia tsutsugamushi by naturally dual infected Leptotrombidium scutellare through stinging / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate whether Leptotrombidium scutellare could be naturally infected by both Hantaan virus (HV) and Orientia tsutsugamushi (OT) and transmission status by stinging.</p><p><b>METHODS</b>3459 Leptotrombidium scutellares from mice bodies and 3265 which were free were collected in the epidemic area of hemorrhagic fever with renal syndrome (HFRS) and tsutsugamushi disease.15 days later, the suspensions of lung and spleen of mice with 6 in a group stung by 1, 5 or 10 infected mites were injected intra-cerebrally into other mice for the detection of HV and OT in the next 6 generations of the mice, with immunofluorescent antibody technique (IFAT) and Giemsa staining technique. The passages of Vero-E6 cells inoculated on the aseptic filtrations from different number of infected mites were used to detect HV and OT pathogens. HV-RNA and OT-DNA were detected by PCR.</p><p><b>RESULTS</b>After passage, HV positive mouse body mite group out of both 5 and 10 mites in the sixth generation, OT positive mouse body mite group out of the 10 mites in the sixth generation, both HV and OT positive mouse body mite group out of 1 mite in the fifth and sixth generation, both HV and OT positive mouse body mite group out of 5 and 10 mites in the sixth generation, and free mites group out of 1, 5 and 10 mites in the sixth generation, were found one mouse infected by both HV and OT, respectively. Out of the fourth generation of Vero-E6 cells, one sample was found both HV and OT positive out of 5 and 10 HV and OT mouse body mite group, respectively. In the sixth generation, both HV and OT positive cells were detected in one mouse mite group and the 1, 5, 10 free mite groups, respectively. HV-RNA and OT-DNA were all detected by PCR.</p><p><b>CONCLUSION</b>Both HV and OT could be coexisted in wild Leptotrombidium scutellare and transmitted by stinging.</p>

Molecular evolution analysis of hantaviruses in Zhejiang Province / 病毒学报

In order to analyze the molecular epidemiology of Hantavirus (HV) in Zhejiang Province, the complete M and S genome sequences of 12 HV strains from different hosts and locations in Zhejiang Province of China during the period of 1981-2007 were analyzed on genetic evolution by DNAstar and MEGA 4.0 software in this research. Phylogenetic analyses revealed that HTN and SEO strains were co-circulating in Zhejiang Province, and the difference in sequence similarity and the phylogeny was closely related to the isolated regions, but had no distinct relationship with the isolate year and the host, indicating a relationship between epidemiology of HFRS and the distribution region, especially in HTNV. The isolates in the same region could be assigned in same or near phylogenetic clade sharing high sequence similarity. Interestingly, the Gou3 strain and ZJ5 strain isolated from Jiande region in Zhejiang Province formed a distinct phylogenetic lineage in SEOV clade, and different from the other SEOV variants outside China. We believed that the special SEOV variants were distributed in Jiande region.

Association of hemorrhagic fever with renal syndrome and HLA-DRB allele polymorphisms in Han nationality, Hubei province / 中华流行病学杂志

Objective To understand the association of human leukocyte antigen (HLA)-DRB polymorphism and patients diagnosed as hemorrhagic fever with renal syndrome (HFRS). Methods HLA-DR allele polymorphism was detected by PCR-sequence specific primers (PCR-SSP). Hantavirus (HV) typed as Hantaan virus (HTNV) and Seoul virus (SEOV) in patients were detected by RT-heminested PCR. Results The gene frequency of DRB1*0401-0411, *1001 and *1101-1105 in HFRS case group were 3.1%, 2.2% and 15.7% respectively. Compared with control group, it was significant higher in HFRS case group (RR=13.87, 9.72 and 2.00 respectively with Chi-square value as 10.006,6.324 and 6.472 respectively, P<0.05). When compared with HFRS case group, the gene frequency of DRB1*1501-1502, DRB4 and DRB5 in control group were 11.0%, 19.0% and 16.9% respectively, markedly lower than in patients (RR=0.45, 0.58 and 0.23 respectively. Chi-square values were 6.138, 4.583 and 21.076 respectively, P<0.05). There was no significant difference in other HLA-DR gene frequencies. Mixed infection was found in Hubei, with HTNV slightly more than SEOV. Distinct hantaviruses could coexist in either different or the same geographic or ecological zores in Hubei province. Patients with HLA-DRB1*1101-1105 alleles were 81.8%(27/33) infected by HTNV and only 18.2% infected by SEOV, which had significant difference (P<0.05). Conclusion DRB1*0401-0411,*1001 and *1101-1105 were possibly associated with increased susceptibility to HV infection. On the other hand there was an inverse correlation among HFRS, DRB1*1501-1502, DRB4 and DRB5.

Establishment of a rat model of mycoplasma pneumonia and the treatment / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a rat model of mycoplasma pneumonia (MP) for investigating the pathogenesis of MP and its therapy with drugs.</p><p><b>METHODS</b>Thirty Wistar rats were randomly divided into 6 groups (n=5), including a control group, a MP model group, a erythromycin lactobionate group and 3 erythromycin microspheres groups (high, middle, and low dose groups). With the exception of those in the control group, all the rats received intranasal MP administration followed by corresponding treatments administered via tail vein injection. At different time points after inoculation of the pathogen, the lungs of the rats were taken for histopathological scoring.</p><p><b>RESULTS</b>In the MP model group, the lung pathology was characterized by patchy interstitial pneumonitis with predominantly lymphocyte infiltration and mucosal edema. The bronchiolar walls became thickened and the lumens narrowed. In erythromycin lactobionate and erythromycin microspheres treatment (high and middle dose) groups, clear cell boundaries were observed in the lungs where no obvious pathological changes were found. RT-PCR amplification showed positive results of MP RNA in the model group, erythromycin lactobionate group and erythromycin microsphere groups.</p><p><b>CONCLUSION</b>The approach described is practicable to establish rat models of MP. Erythromycin microspheres can effectively relieve the lung inflammations and has therapeutic effect on MP.</p>

The reactivity of sera from hemorrhagic fever in patients with renal syndromes to the recombination nucleotide proteins from European hantaviruses in Hubei province / 中华流行病学杂志

Objective Five yeast-expressed recombination nucleotide proteins of European hantaviruses were prepared as coated antigens to detect hantavirus-specific antibodies in sera from hemorrhagic fever with renal syndromes (HFRS) in Hubei province, through ELISA assay. The relativity among hantaviruses prevailing in different areas was investigated. Methods 34 pairs of acute/convalescent serum samples were collected from HFRS patients in Hubei during 1985 - 1989 and 1996-2000. ELISA assay was performed to detect the reactivity of these sera to different hantavirus-recombinant nucleocapsid proteins(HV-rNP) which were derived from puumala virus (PUUV), dobrava virus (DOBV) while using hantaan virus (HTNV) to serve as control. Qualitative results were used to analyze the detection rate and the quantitative results of optical density values were used to investigate the antibodies' level and the changes. Results The detective efficiency of rNP against IgG antibody in samples was as follows:HTNV-rNP＞DOBV-rNP＞PUUV-rNP. As to the detection of IgA, it was: DOBV-rNP＞HTNV-rNP＞PUUV-rNP. However, there was no difference between DOBV-rNP and HTNV-rNP when the hantavirus-specific IgM was detected. PUUV-rNP showed a very weak reactivity to all the antibodies in samples, but 3-pair samples reacted strongly to all the three subtype-rNP of PUUV. Results from quantitative analysis revealed that there was a relative higher level of IgM and IgA in acute phase sera. No significant difference between IgM and IgA levels was found and the level of IgG was low. A high level of IgA was detected in convalescent sera. Moreover, the level of IgA and IgG significantly increased with the progress of the disease. Conclusion DOBV-rNP had a high detective efficiency to serum samples from HFRS patients in Hubei. HV-specific IgA was kept on a high level in acute and convalescent phases and had important implications for the surveillance of HFRS. Also,it is assumed that PUUV and DOBV might have existed in Hubei province.

Antimicrobial effects of erythromycin microspheres against Mycoplasma Pneumoniae in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the antimicrobial effects of erythromycin microspheres against Mycoplasma pneumoniae in rats.</p><p><b>METHODS</b>With erythromycin lactobionate as the positive control, erythromycin microspheres at 3 non-toxic doses (0.1, 0.5, and 1.2 g.kg(-1).d(-1)) were administered intragastrically for 6 consecutive days in Wistar rats with Mycoplasma pneumoniae infection. The general condition and lung index of the rats were observed and measured to assess the therapeutic effects of the treatments against Mycoplasma pneumoniae infection.</p><p><b>RESULTS</b>The erythromycin microspheres at 0.1, 0.5, 1.2 g.kg(-1).d(-1) significantly alleviated the symptoms of the rats infected with Mycoplasma pneumoniae and reduced the pulmonary index of the infected rats from 1.75 to 1.45, 1.38 and 1.25, respectively (P < 0.01). An obvious dosage-effect relationship was noted between the dose of erythromycin microsphere and the tissue pathologies due to the infection.</p><p><b>CONCLUSION</b>Erythromycin microspheres possess strong activity against Mycoplasma pneumoniae in rats.</p>

Antiviral effect of epigallocatechin gallate (EGCG) on influenza A virus / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effects of epigallocatechin gallate (EGCG) against the influenza A virus in vitro and in vivo.</p><p><b>METHOD</b>The cell culture technique was used in MDCK cells to get cell viability at different concentration of EGCG by MTT assay. Cytopathic effect (CPE) and MTT were applied to observe the protective function of EGCG and it's ingredients were administered to cells in three different ways (method I: administration before infection, method II: administration upon infection, and method II: administration after infection) to treat the infectious model in vitro. The anti-viral activity in vivo was performed on BALB/c mice, which were divided to receive EGCG. The mean survival days and the pulmonary pathological lesions of the infected mice were observed to evaluate the therapeutic efficacy of EGCG.</p><p><b>RESULT</b>EGCG effectively inhibited influenza A virus in vitro. The death rate and pulmonary pathological lesions were decreased, and the mean survival days were prolonged by oral administration of EGCG in the mice infected by influenza A virus.</p><p><b>CONCLUSION</b>EGCG has a strong effect against influenza A H1 N1 virus in vitro and in vivo, in a dose-dependent manner.</p>

Molecular epidemiological study on the host and role of the Hantavirus and Orientia tsutsugamushi in the same epidemic area / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate whether Hantavirus (HV) and Orientia tsutsugamushi ( OT) can naturally infect and coexist in their host and role.</p><p><b>METHODS</b>By field epidemiological study, Leptotrombidium scutellare (3829) was collected and separated from mice(166) in epidemic areas. The cells of mites separated from their host and role were cultured. PCR was used to detect HV-RNA and OT-DNA in the cell culture.</p><p><b>RESULTS</b>In 105 Apodemus agrarius, 3 HV-RNA positive, 2 OT-DNA positive and 2 coinfection with HV and OT were detected;in 41 Brown rattus, 2 HV-RNA positive, 1 OT-DNA positive and 1 co-infection with HV and OT were detected. From 15 mites co-infected with HV and OT, 2 strains of HV pathogen, 2 strains of OT pathogen were separated and 1 HV and OT pathogen in the same mite were separate.</p><p><b>CONCLUSION</b>The study demonstrates that co-infection of HV and OT did simultaneously exist in wild Leptotrombidium scutellare. This theory has some significance to the epidemic and precaution of HV and OT.</p>

Effects of Alternanthera philoxeroides Griseb against respiratory syncytial virus infection in mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of an oral preparation of Alternathera philoxeroides Griseb (APG) against respiratory syncytical virus (RSV) in mice.</p><p><b>METHODS</b>APG preparation was administered orally in RSV-infected mice at different daily doses (2.5, 4.5 and 6.5 g/kg) to observe the therapeutic effect of the preparation.</p><p><b>RESULTS</b>Distinct differences were observed between the death rate of the mice treated with APG at daily dose of 4.5 and 6.5 g/kg and that of the untreated mice with infection. After AGP treatment of the mice at 6.5 g/kg, the detection rate of the virus was 31.3% in the blood and 37.5% in the lung tissue, significantly lower than that in the untreated mice. The virus detection rate was 43.8% in the lung tissues of mice treated with APG at 4.5 g/kg, also significantly lower than that in the untreated control. APG treatment at the 3 doses resulted in different lung indices from that of the control.</p><p><b>CONCLUSION</b>APG may be effective for treatment of RSV infection.</p>

Investigation of viral pathogens contributing to habitual abortion / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the association of Coxsackie B virus (CBV) with habitual abortion.</p><p><b>METHODS</b>CBV IgM antibody, viral RNA and virions were detected in 86 women with habitual abortion and 40 with induced abortion by means of enzyme-linked immunosorbent assay (ELISA), RT-PCR and virus isolation, respectively.</p><p><b>RESULTS</b>The positivity rate of CBV IgM were 87.2% and 35% in the two groups, respectively, and the detection rate of the viral RNA was 53.5% and 17.5% in blood lymphocytes, and 59.3% and 17.5% in the placentas. The virions were found in the placentas in 41.9% and 6.9% of the women, respectively. The positivity rates of CBV IgM, viral DNA and virions showed significant difference between the two groups (P<0. 01).</p><p><b>CONCLUSION</b>CBV might be one of the causes responsible for habitual abortion.</p>

Antiviral effect of Folium Isatidis on herpes simplex virus type I / 中国中药杂志

<p><b>OBJECTIVE</b>To evaluate the antiviral effect of different chemical fractions isolated from Folium Isatidis on herpes simplex virus type I (HSV- I).</p><p><b>METHOD</b>Anti- HSV- I effects of Folium Isatidis were investigated in Hep-2 cell by adopting MTT colorimetric assay and observing cytopathic effect (CPE). Treatment index (TI) was used to evaluate the antiviral activity of different chemical fractions from Folium Isatidis. The antiviral mechanism of Folium Isatidis was investigated by changing the different ways of drug administration.</p><p><b>RESULT</b>The fractions II approximately V from Folium Isatidis inactivate HSV- I directly. None of the chemical fractions had antiviral effects of adsorption-blocking. The chemical fractions except fraction III and fraction V inhibited the biological synthesis of HSV- I. The fraction IV significantly reduce death rate of mice infected with HSV- I.</p><p><b>CONCLUSION</b>The fraction IV from Folium Isatidis has powerful anti-HSV-lI effect in vitro and in vivo.</p>