五虎汤对呼吸道合胞病毒复制的抑制作用研究

传统治喘名方五虎汤在体外和活体内均具有抑制呼吸道合胞病毒作用。在Hep-2细胞单层上，五虎汤抑制50％以上病毒空斑的浓度为1：80，在此一浓度，病毒繁殖量下降10-2．4TCID50，病毒核酸合成下降率约55％。方中麻黄具有抗RSV活性，其抑制50％以上病毒空斑浓度为1．6mg／ml。在动物体内，本方通过雪化吸入或口服，能降低小鼠肺组织内RSV滴度，促使小鼠肺组织RSV提前消失，并能促进小鼠肺组织炎症吸收。

Surface Display of Rice Stripe Virus NSvc2 and Analysis of Its Membrane Fusion Activity

Rice stripe virus (RSV) infects rice and is transmitted in a propagative manner by the small brown planthopper. How RSV enters an insect cell to initiate the infection cycle is poorly understood. Sequence analysis revealed that the RSV NSvc2 protein was similar to the membrane glycoproteins of several members in the family Bunyaviridae and might induce cell membrane fusion. To conveniently study the membrane fusion activity of NSvc2, we constructed cell surface display vectors for expressing Nsvc2 on the insect cell surface as the membrane glycoproteins of the enveloped viruses. Our results showed that NSvc2 was successfully expressed and displayed on the surface of insect Sf9 cells. When induced by low pH, the membrane fusion was not observed in the cells that expressed NSvc2. Additionally, the membrane fusion was also not detected when co-expressing Nsvc2 and the viral capsid protein on insect cell surface. Thus, RSV NSvc2 is probably different from the phlebovirus counterparts, which could suggest different functions. RSV might enter insect cells other than by fusion with plasma or endosome membrane.

Molecular epidemiology of respiratory syncytial virus

Objective To determine the epidemiologic pattern of subgroups A and B and genotypes of respiratory syncytial virus (RSV) during two noncontinuous epidemics during 1990-1991 and 1997-1998 in Beijing Methods Nasopharyngeal secretion (NPS) samples of RSV positive or RSV isolates tested by indirect immunofluorescence (IIF) assay were classified into subgroups A and B Isolates of RSV were divided into at least six different lineages, designated NP1 NP6, by restriction mapping of the N gene Np1, 3 and 6 were given by subgroup B isolates, while NP2, 4 and 5 were given by subgroup A isolates Strains of subgroup A were further subdivided into six lineages SHL1 SHL6 on the basis of the SH gene sequence SH lineages were closely related to each other and to NP1 NP6 Strains of SHL1, 3 and 4 were closely related and belonged to NP2, SHL2 and 6 to NP4, and SHL5 to NP5 Results Of 145 RSV NPS samples from the 1997-1998 epidemic, 83 (57 2%) were of subgroup B RSV positive, 62 (42 8%) of subgroup A RSV positive The rate of occurrence of subgroup A to B strains was about 1∶1 3 Two of 10 isolates during the epidemic were subgroup A strains, whereas 8 were subgroup B strains The rate of occurrence of subgroup A to B strains was 1∶4 Eight subgroup A strains of 10 isolates from the 1990-1991 epidemic were dominant; the proportion of subgroup A to B strains was 4∶1 With 10 RSV isolates in 1997-1998, all 2 subgroup A strains gave N gene fragment restriction pattern NP4, and fell into SH lineage SHL2, whereas 8 subgroup B strains all belonged to NP3 All 8 subgroup A isolates from the 1990-1991 epidemic gave pattern NP4, and fell into SHL2, while 2 subgroup B strains all belonged to NP3 The classification of subgroups A and B deduced from NP patterns corresponded to the definition of these subgroups by monoclonal antibodies Conclusions These observations confirm that subgroups A and B or multiple lineages of RSV co circulated in Beijing, but different genome types predominated each year Moreover, very similar viruses were isolated up to more than 5 years ago, indicating that despite apparent diversity of the subgroup A strains, the separate lineages might be relatively stable

Effect of Gubenfangxiao decoction on respiratory syncytial virus-induced asthma and expression of asthma susceptibility gene orosomucoid 1-like protein 3 in mice

OBJECTIVE： To investigate the effect of Gubenfangxiao decoction （GBFXD） on respiratory-syncytial-virus （RSV） -induced asthma and the expression of asthma susceptibility gene, orosomucoid 1-1ike protein 3 （ORMDL3） in mice. METHODS： Seventy-two female BALB/c mice were randomly assigned to normal, model, GBFXD high dose, GBFXD moderate dose, GBFXD low dose and montelukast groups. An asthma model was induced via intraperitoneal injection and aerosol inhalation of ovalbumin （OVA） and repeated intranasal instillation of RSV in all mice, except those in the normal group. All treatments were administered at the first onset of asthma （within 8 weeks of model establishment） and the mice were euthanized after 28 days of treatment. The levels of transforming growth factor-β （TGF-β） and interleukin-6 （IL-6） in bronchoalveolar lavage fluid （BALF） of the mice were measured and the expression of asthma sus- ceptibility gene ORMDL3 in lung tissue was deter- mined using real-time polymerase chain reaction （RT-PCR） and western blotting. RESULTS： Expression of ORMDL3 and levels of TGF-β and IL-6 were significantly higher in the mod- el group （P 〈 0.05, P 〈 0.01） compared with the normal mice. Levels of ORMDL3, TGF-β and IL-6 were significantly lower in all three GBFXD treated groups （P 〈 0.05） compared with the model group. However, the levels in the GBFXD treatment groups did not differ significantly from the montelukast group. CONCLUSION： GBFXD had a therapeutic effect in this experimental model. The functional mechanism of GBFXD may involve multiple factors, including alleviation of airway inflammation, down-regulation of asthma susceptibility gene ORMDL3 and inhibition of airway remodeling.

Sensitive semi-quantitative detection of respiratory syncytial virus by dark-field light scattering imaging of the infected host cells

A novel sensitive semi-quantitative virus detection technique was developed using the respiratory syncytial virus(RSV) as an example, through dark-field light scattering imaging of the surface state of the virusinvaded host cells. In this method, anti-RSV-antibody modified gold nanoparticles(Au NPs) could bind with the invading virus on the cell membrane of the infected host cells through the specific antibody-antigen binding. Then,the host cells could be imaged by the localized surface plasmon resonance light scattering properties of Au NPs under a dark-field light scattering microscopy, which could be further used to semi-quantify the invading virus.