Measles pathogenic surveillance from 2005 to 2007 in Guangdong Province / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To develop pathogenic surveillance on measles and to effectively isolate measles virus. To know the genetic characterizations and molecular epidemiology of wildtype measles viruses from 2005 to 2007 in Guangdong Province, and provide the scientific basis for measles control and eradication.</p><p><b>METHODS</b>Vero/Slam cell line were used, measles viruses were isolated from throat swabs or urine specimens collected from uspected measles patients in outbreaks and sporadic patients. A 450 nucleotides fragment of the C-terminal of the nucleoprotein (N) gene was amplified and by RT-PCR and subjected to sequence and phylogenetic analysis using Bio-Edit software.</p><p><b>RESULTS</b>82 wild-type measels virus were obtained from 377 throat swabs and urine specimens from 2005 to 2007 in Guangdong Province measles lab. The measles isolation rate was 23.58% in 2005, 17.11% in 2006, 39.13% in 2007. The succeed rate of virus isolation is related to the quality of specimens collected and the days after rash occurrence.</p><p><b>CONCLUSIONS</b>We have grasped the technicalability of measles virus isolation and confirm action, and got higher isolation ratio. The wild-type measles virus isolated from Guangdong Province is of H1 genotype from 2005 to 2007, which is the same as the dominant genotype circulation.</p>

The epidemiology character of the 503 residual paralysis of acute flaccid paralysis cases / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>Analyze the epidemiology character of the residual paralysis(RP) of acute flaccid paralysis (AFP) in Guangdong during 1994-2007.</p><p><b>METHODS</b>The viruses isolated from the excrement of RP cases were identified and typed in Guangdong from 1994 to 2007. Statistics analysis was performed to reveal the relationship among the immunization history,age,gender and the distribution of the etiology.</p><p><b>RESULTS</b>A total of 503 RP cases were reported. 150 of which were isolated with PV and 59 were isolated with NPEV. From 1994 to 2007, The PV isolating rate ranged from 18.92% to 47.06% and was higher in winter and spring, while the NPEV isolating rate ranged from 4.17% to 25.00%. and was higher in summer and autumn. The PV isolating rate decreased as the age increased,and its isolating rate (61.11%) was highest in "0" year group. The PV isolating rate of the population of < or =2 times OPV was far higher than 3 times. The PV and NPEV isolating rate of the RP cases was higher than without RP.</p><p><b>CONCLUSION</b>The case with RP caused by wild poliovirus wasn't found from 1994 to 2007 in Guangdong, but the relationship of RP case was observed between < or =2 years group and < or =1 time OPV, and NPEVs probably are the potential etiological agent that cause children RP.</p>

Comparison of effectiveness of whole viral, N and N199 proteins by ELISA for the rapid diagnosis of severe acute respiratory syndrome coronavirus / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Although severe acute respiratory syndrome (SARS) has been controlled, the subsequently emerging sporadic cases in 2004 emphasize the necessity of developing a rapid diagnostic method, which would be of great help in clinical diagnosis and also wild host screening. This study aims to establish an effective and rapid serological tool for the diagnosis of SARS-CoV by comparison among whole viral, N and N199 proteins by ELISA.</p><p><b>METHODS</b>SARS-CoV N and N199 (a truncated nucleocapsid gene) genes were cloned, expressed, identified by Western blotting, and applied in screening of human and swine samples. Sera of SARS convalescent-phase patients, normal human sera, sera of patients with other respiratory diseases, and swine sera were screened by ELISA, with whole SARS-CoV F69, N and N199 proteins as antigens.</p><p><b>RESULTS</b>The sensitivity and specificity of N and N199 proteins in human sera diagnosis were approximate (P = 0.743), which was higher than whole viral protein but the difference was not significant (P = 0.234). The N199 protein proved to be more specific in swine sera screening than whole viral and N protein (P < 0.001).</p><p><b>CONCLUSION</b>N199 protein is feasible in both clinical diagnosis and SARS-CoV reservoir screening.</p>

Immune Responses and Histopathological Changes in Rabbits Immunized with Inactivated SARS Coronavirus / 中国病毒学

To evaluate the immunogenicity of inactivated SARS coronavirus (SARS-CoV), three groups of rabbits were immunized three times at 2-week intervals with inactivated vaccine + adjuvant, adjuvant,and normal saline respectively. Eight batchs of serum were sampled from the auricular vein at day 7 to day 51, and specific IgG antibody titers and neutralizing antibody titers were detected by indirect ELISA and micro-cytopathic effect neutralizing test. Antibody specificity was identified by proteinchip assay.Histopathological changes were detected by H&E staining. The results showed that, rabbits in the experimental group immunized with inactivated SARS-CoV all generated specific IgG antibodies with neutralizing activity, which suggested the inactivated SARS-CoV could preserve its antigenicity well and elicit an effective humoral immune responses. The peak titer value of specific IgG antibody and neutralizing antibody reached 1:40960 and 1:2560 respectively. In the experimental group, no obvious histopathological changes was detected in the H&E stained slides of heart, spleen, kidney and testis samples, but the livers had slight histopathological changes, and the lungs presented remarkable histopathological changes. These findings are of importance for SARS-CoV inactivated vaccine development.

Human cytomegalovirus induces apoptosis of ECV304 endothelial-like cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the mechanisms for the cytopathic effect (CPE) of human cytomegalovirus (HCMV) in ECV304 endothelial-like cells.</p><p><b>METHODS</b>PCR and indirect immunofluorescence were used to detect HCMV infection by examining immediate-early (IE) gene and protein expression of the virus in ECV304 cells. Phase-contrast and electron microscopies were performed to observe the morphological changes of the infected and uninfected cells, and DNA ladder analysis and flow cytometry were carried out to study HCMV-induced cell apoptosis.</p><p><b>RESULTS</b>In HCMV-infected ECV304 cells, cytopathic effects were first observed at approximately 72 h post-infection. The cells with CPE changes exhibited detachment from the monolayer, cell rounding and shrinkage. The expression of the IE gene was detected. Chromatin condensation and nuclear fragmentation along with dramatic changes of the mitochondria were observed by electron microscopy at 96 h post-infection. Cellular DNA fragmentation was observed in the infected cells, which had cells apoptotic rates of 4.1% and 45.7% at 96 h and 144 h post-infection, respectively.</p><p><b>CONCLUSION</b>HCMV can induce apoptosis of ECV304 endothelial-like cells.</p>

Morphological changes of ECV304 cells infected by herpes simplex virus type 2 / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the pathological changes and morphological alterations of ECV304 cells after the infection by herpes simplex virus type 2 (HSV-2) in vitro.</p><p><b>METHODS</b>Passaged ECV304 cells were infected with HSV-2, TCID50 and morphological changes were observed by optical microscopy and tissue staining.</p><p><b>RESULTS</b>One day after HSV-2 infection, swelling, rounding, and increase of thickened cytoplasmic granules occurred in the ECV304 cells, and on day 2, cell fusion was observed with weakened nuclear staining.</p><p><b>CONCLUSION</b>ECV304 cells mostly undergo necrosis after HSV-2 infection without obvious evidence of cell apoptosis.</p>

Humoral immune responses in rabbits induced by an experimental inactivated severe acute respiratory syndrome coronavirus vaccine prepared from F69 strain / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The etiologic agent of severe acute respiratory syndrome (SARS) has been confirmed to be a novel coronavirus (CoV), namely SARS-CoV. Developing safe and effective SARS-CoV vaccines is essential for us to prevent the possible reemergence of its epidemic. Previous experiences indicate that inactivated vaccine is conventional and more hopeful to be successfully developed. Immunogenicity evaluation of an experimental inactivated SARS-CoV vaccine in rabbits was conducted and reported in this paper.</p><p><b>METHODS</b>The large-scale cultured SARS-CoV F69 strain was inactivated with 0.4% formaldehyde and purified, then used as the immunogen combined with Freund's adjuvant. Eight adult New Zealand rabbits were immunized four times with this experimental inactivated vaccine. Twelve sets of rabbit serum were sampled from the third day to the seventy-fourth day after the first vaccination. The titers of specific anti-SARS-CoV IgG antibody were determined by indirect enzyme-linked immunosorbent assay, and the neutralizing antibody titers were detected with micro-cytopathic effect neutralization test.</p><p><b>RESULTS</b>Rapid and potent humoral immune responses were induced by the inactivated SARS-CoV vaccine in all the eight test rabbits. Titers of both specific IgG antibody and neutralizing antibody peaked at about six weeks after first vaccination, with the maximum value of 1:81 920 and 1:20 480, respectively. After that, serum antibody levels remained at a plateau or had a slight decrease, though two boosters were given in the succedent 4 to 5 weeks. Cross neutralization response existed between SARS-CoV F69 strain and Z2-Y3 strain.</p><p><b>CONCLUSIONS</b>The inactivated SARS-CoV vaccine made from F69 strain owns strong immunogenicity, and the cross neutralization response between the two different SARS-CoV strains gives a hint of the similar neutralizing epitopes, which provide stable bases for the development of inactivated SARS-CoV vaccines.</p>