复方倍他米松增加流感病毒感染小鼠受损嗅黏膜嗅觉标记蛋白表达

目的探讨复方倍他米松对流感病毒感染小鼠受损的嗅黏膜嗅觉标记蛋白(OMP)表达的影响。方法模拟建立流感病毒性嗅觉障碍小鼠模型,分别于第2天和第4天给予复方倍他米松干预,腹腔内注射复方倍他米松,采用免疫组化和Western blot的方法检测嗅黏膜OMP蛋白的表达水平。结果流感病毒感染1组和2组嗅黏膜OMP的表达水平下调,流感病毒感染后复方倍他米松干预1组和2组嗅黏膜OMP的表达水平明显上调。结论复方倍他米松能够增加流感病毒损伤的嗅黏膜OMP的表达。     

Influenza virus infection of newborn rats: Virulence of recombinant strains prepared from a cold-adapted,attenuated parent

Summary Infant rats were infected with one of a series of influenza A viruses. The growth of viruses in the turbinates or lungs, and the ability of virus infection to potentiate a subsequent bacterial infection by Haemophilus influenzae (HIb), were measured. The three virus strains known to be virulent for man grew to relatively high titres-of 10^5.0–10^6.8 EBID₅₀/ml in the turbinates of infant rats at 48 hours post-infection, and virus infection enhanced subsequent systemic infection following intranasal inoculation of rats with HIb. In contrast, influenza virus A/Ann Arbor/6/60—P17 and the three recombinant viruses prepared from this strain, all of which are attenuated for man, replicated to significantly lower titres of 10^2.6–10^4.1 EBID₅₀/ml in infant rats turbinates, and failed to promote systemic infection by HIb to the same degree. The results, together with those of previous studies, suggest that the behaviour of influenza viruses in infant rats may be an indication for virus virulence for man, and thus provide a test which could facilitate the development of live, attenuated virus vaccines.With 3 Figures     

Pathogenesis of a Venezuelan encephalitis virus strain lethal for adult white rats

The pathogenesis for adult rats of a Venezuelan encephalitis virus (VEE) strain, V-198, was studied. This virus strain was chosen following virulence-testing of 12 prototype alphavirus strains, selected from the Semliki Forest, Venezuelan, Eastern, and Western encephalitis virus complexes; only VEE strain V-198 killed all adult rats when inoculated subcutaneously (sc) with 6.0–6.5 log₁₀ plaque-forming units (PFU). Lower doses of strain V-198 by the same route were also lethal: 5.0 and 3.0 log₁₀ PFU killed 100%, and 1.0 log₁₀ PFU killed 70% of rats. Viral infectivity titrations of tissues obtained from V-198 straininfected rats demonstrated that virus replicated early in thymus and spleen, but did not replicate in bone marrow or liver. Following a brief viremia, virus infectivity titers peaked in brain, but did not persist there. A biphasic neutrophilia also occurred. Lower doses of inoculum virus affected the timing but not the degree of neutrophil fluctuations, virus replication, and clinical disease. Rats, moribund seven days after inoculation of 4.3 log₁₀ PFU, exhibited central nervous system signs and histologic evidence of encephalomyelitis. Significant proportions of rats, otherwise lethally infected with V-198 virus, were protected by a single intraperitoneal inoculation of hyperimmune V-198 antiserum, administered 3 or 4, but not 5 days after virus. Since the rat has been well characterized with respect to metabolic alterations following other infectious diseases, it is anticipated that this model for lethal virus-induced disease will be useful for defining more precisely the functional relationships between viral growth, tissue destruction, metabolic alterations, and clinical course of disease, and that it may suggest specific approaches for effective treatment of viral diseases in general.     

Purine nucleoside phosphorylase, a possible histochemical marker for T-cells in man.

A procedure is described for the histochemical detection of purine nucleoside phosphorylase (PNP) activity in circulating lymphocytes of man. The number of PNP-positive cells, as evaluated on smears of Ficoll--Hypaque purified cells, correlated well with the number of E-rosette-forming cells of the same blood samples of healthy and diseased people with normal or abnormal numbers of E-rosettes. In healthy people, the number of PNP-positive cells was within the range of 70-80% of the total lymphocyte population, whilst the corresponding E-rosette-forming cells were scored between 60-75%. Patients with unusually low or high E-rosettes had equally low or high numbers of PNP-reactive cells. More substantial evidence for the presence of PNP activity in T-cells and not in B cells was gathered from experiments in which PNP activity and surface membrane immunoglobulins (SMIg) were simultaneously demonstrated on the same preparation. These results showed, on the one hand, that the bulk of lymphocytes that are reactive for PNP do not reveal SMIg and, on the other hand, that most Ig-bearing cells were unreactive for PNP.     

Identification of genetic mutations associated with attenuation and changes in tropism of Urabe mumps virus

Although several effective mumps virus vaccines have been developed, almost nothing is known about the genetic changes responsible for loss of virulence. One vaccine, Urabe AM9, was withdrawn from the market because of insufficient attenuation. The vaccine was found to contain a mixture of viruses that could be distinguished based on the sequence of the hemagglutinin‐neuraminidase gene (HN). Viruses containing lysine at HN amino acid position 335 were isolated from cases of post‐vaccination parotitis or meningitis whereas viruses containing glutamic acid at this position were not associated with post‐vaccination disease. Using a rat based model of mumps neurovirulence, we demonstrate that this latter virus is significantly attenuated compared to a virus isolated from a patient with post‐vaccination meningitis. Complete sequence analysis of the genomes of the two viruses identified sixteen genetic differences, some or all of which must be responsible for differences in virulence. These same genetic differences also account for changes in tropism in cell culture. J. Med. Virol. 81:130–138, 2009. © 2008 Wiley‐Liss, Inc.     

Differential response of ferrets to infection with virulent and avirulent influenza viruses: A possible marker of virus attenuation

Summary The behaviour of three recombinant strains of influenza virus A/England/939/69 and A/PR/8, together with the parent A/England/939/69 strain, all of known virulence to man, were examined in ferrets. For the virulent A/England/939/69 strain, the peak temperature response and the time of peak virus excretion occurred 48 hours post-infection, and peak protein and secretory antibody responses occurred on days 7 and 9. In contrast, the peak temperatures and maximum virus excretions for the recombinant attenuated viruses, clones 7 and 6a, occurred on day 3 and 6, and the maximum protein and nasal antibody responses on days 9 and 11, respectively. Although the peak responses for these strains were distinct, the magnitudine of the symptoms was comparable. Similar studies with the over attenuated clone 64C virus showed a milder infection. In addition, the maximum temperature response and virus excretion occurred on day 5 post-infection, and the maximum nasal protein concentration was found on day 11 after virus infection. These differences between the strains were only apparent when animals were given an inoculum of 10 EID₅₀; no differences were observed between the four strains when larger inocula were used. The results suggest that virus infection of ferrets was distinct for strains of differing human virulence, and that the ferret model may provide a test for virulence for man.With 3 Figures     

Development of a Vaccine Against Pandemic Influenza Viruses: Current Status and Perspectives

The constant threat of a new influenza pandemic, which may be caused by a highly pathogenic avian influenza virus, necessitates the development of a vaccine capable of providing efficient, long-term, and cost-effective protection. Proven avenues for the development of vaccines against seasonal influenza as well as novel approaches have been explored over the past decade. Whereas significant insights are consistently being made, the generation of a highly efficient and cross-protective vaccine against the future pandemic influenza strain remains as the ultimate goal in the field. In this review, we re-examine these efforts and outline the scientific, political, and economic problems that befall this area of biotechnological research.     

Lymphocytopenia as a marker for pandemic influenza A/H1N1 2009 virus infection in children

Lymphocytopenia has been reported in adults with pandemic influenza A/H1N1 2009 infection, but data in children are inconclusive. Data from 76 children presented with flu‐like symptoms between July and November 2009 and tested for pandemic influenza A/H1N1 2009 virus and white blood cell (WBC) counts were analyzed. Samples from 37 (48.7%) children resulted in a positive PCR assay for pandemic influenza A/H1N1 2009 virus. When comparing data from these children with data from 39 (51.3%) children with uncomplicated flu‐like illness and negative PCR assay for pandemic influenza A/H1N1 2009 virus, no difference in disease duration, median age, red blood cell count, hemoglobin concentration, C reactive protein concentration, and absolute neutrophil count was observed, whereas significant differences were apparent when considering WBC count, relative and absolute lymphocyte count, absolute lymphocyte count z‐score, and platelet count. Receiver operating characteristic curve analysis revealed that the best absolute lymphocyte count and absolute lymphocyte count z‐score cut‐points that simultaneously maximized sensitivity and specificity were 2,256 cells/µl and ?0.89, respectively, sensitivity being 0.81 (95% CI: 0.68–0.94), specificity 0.87 (95% CI: 0.77–0.98), positive predictive value 0.85 (95% CI: 0.74–0.97), and negative predictive value 0.83 (95% CI: 0.71–0.94). In conclusion, lymphocytopenia is a marker for influenza A/H1N1 2009 virus infection in children. Absolute lymphocyte count <2,556 cells/µl or absolute lymphocyte count z‐score < ?0.89 may be useful cut‐offs to discriminate against children at higher risk of infection during epidemics. Considering that the pandemic virus is highly likely to continue to circulate in the coming winter season, these findings provide direct and practical implications for the near future. J. Med. Virol. 83:1–4, 2011. © 2010 Wiley‐Liss, Inc.     

金刚烷胺与利巴韦林对不同甲型流感病毒株的体外作用敏感性比较

目的评价金刚烷胺和利巴韦林对不同甲型流感病毒株的体外抑制作用,为临床选择抗流感病毒药物提供实验依据。方法分别接种甲型流感病毒标准实验株[H1H1（A/PR/8/34、A/FM1/47）,H3N2（A/Aichi/2/1968）]和临床分离株[H1N1（A/Guangzhou/GIRD02/2009、A/Guangzhou/GIRD166/2009）,H3N2（A/Guangzhou/GIRD18/2009、A/Guangzhou/GIRD26/2009）],于狗肾细胞（MDCK）,采用空斑试验观察金刚烷胺和利巴韦林对甲1和甲3型流感病毒不同实验株和分离株的敏感性。对测试毒株的MP基因进行序列测定和分析,了解金刚烷胺的药物敏感性。结果金刚烷胺在MDCK细胞的半数毒性浓度（TC50）为335μg/ml,对部分甲型流感病毒标准实验株[A/FM1/47（H1N1）、A/Aichi/2/1968（H3N2）]及临床分离株[A/Guangzhou/GIRD02/2009（H1N1）]有抑制作用（半数有效浓度IC50分别为14.9、20.1、16.8μg/ml）。利巴韦林的TC50为2.05mg/ml,对测试的所有毒株均有抑制作用（IC50为6.8～37μg/ml）。金刚烷胺耐药毒株均为单位点突变（第31位的丝氨酸S置换为天冬酰胺N,S31N）。结论甲型流感病毒对金刚烷胺较易出现耐药,而利巴韦林体外对金刚烷胺敏感株和耐药株均有显著的抑制作用,临床抗流感病毒治疗时可考虑应用。     

Evidence for infection of the human embryo with adeno-associated virus in pregnancy.

Previous reports have demonstrated the presence of DNA of the human helper virus-dependent adeno-associated parvovirus (AAV) in uterine tissue and curettage material from early miscarriage. To examine infection of embryonic tissue during pregnancy, amnion fluids were analysed for the presence of AAV. Using polymerase chain reaction, AAV DNA was detected in 64 out of 238 DNA samples extracted from amnion cells. DNA of helper viruses were found in 12% (papillomavirus) and 18% (cytomegalovirus) of the samples (double infections with AAV in eight and nine cases, respectively). Furthermore, infectious AAV virions were found in 13 out of 43 AAV DNA-containing samples. In mothers with AAV DNA-positive amnion fluids, premature amniorrhexis and premature labour occurred significantly more frequently (P < 0.001). Using an immunofluorescence assay, 24% of newborn sera (unrelated to the amnion fluid samples) were found to contain IgM antibodies to AAV, in most cases paralleled by IgM antibodies in the mother's sera. The data demonstrate that AAV infection can occur in utero at early and at late stages of pregnancy. The observed complications at delivery should encourage studies to clarify possible pathological consequences of AAV infection in pregnancy and a possible latent infection of the fetus.     

脱氧核酶在培养人气道上皮细胞体系内的抗甲型流感病毒NS基因效应

目的 探讨针对甲型病毒(influenza A virus,IFV)NS基因特异性的脱氧核酶(DNAzyme,DZ-NS)在培养的人气道上皮细胞(9HTEo)体系内对甲型流感病毒复制的抑制效应,方法 光镜观察DZ-NS对IFV致9HTEo细胞病变效应变化的影响;病毒空斑形成阻断试验及四甲基偶氮唑盐比色试验(MTT)检测脱氧核酶DZ-NS对IFV复制的抑制和对感染IFV的9HTEo细胞的保护作用;RT-PCR检测DZ-NS对IFV mRNA表达的抑制作用.结果 DZ-NS可明显改善IFV所致的细胞病变并能明显提高细胞感染IFV后的存活率(P＜0.01);可显著抑制IFV-NS基因mRNA的表达;空斑实验病毒抑制率可达80.11%;DZ-NS在细胞内对IFA病毒表达的抑制效率,明显高于作为对照的反义寡核苷酸(antisense oligonucleotides,AS-NS)(P＜0.05).结论 在9HTEo 感染IFV细胞模型系统,DZ-NS能高效阻断IFV的NS基因的表达,是一种特异性的、高效的抗IFV基因治疗剂.     

Prevalence of hepatitis E virus infection among hemodialysis patients in Japan: evidence for infection with a genotype 3 HEV by blood transfusion

To investigate the prevalence of hepatitis E virus (HEV) infection among patients on maintenance hemodialysis, serum samples collected in January 2003 from 416 patients who had been undergoing hemodialysis for 7.6 +/- 6.3 (mean +/- standard deviation) (range, 0.3-26.0) years in a dialysis unit in Japan and serum samples that had been collected from these patients at the start of hemodialysis were tested for IgG antibodies to HEV (anti-HEV IgG) by an "in-house" enzyme-linked immunosorbent assay (ELISA). Overall, 39 patients (9.4%) had anti-HEV IgG in January 2003, and included 35 patients (8.4%) who had already been positive for anti-HEV IgG at the start of hemodialysis and 4 patients (1%) who seroconverted after initiation of hemodialysis. Periodic serum samples that had been collected from the four seroconverted patients were tested for HEV antibodies and HEV RNA. The four patients became positive for anti-HEV IgG in 1979, 1980, 1988, or 2003, and continued to be seropositive until the end of the observation period. Although anti-HEV IgM was not detectable in the four patients, three were infected transiently with apparently Japanese indigenous HEV strains of genotype 3. The patient who contracted HEV infection in 1979 had been transfused with 2 U of blood 21 days before the transient viremia: one of the two stored pilot serum samples had detectable HEV RNA with 100% identity to that recovered from the patient. Our study provides evidence of transfusion-transmitted HEV infection in Japan in 1979, and that the prevalence of de novo HEV infection during hemodialysis was low (1.1% or 4/374).     

Recent advances in the detection of respiratory virus infection in humans

Respiratory tract viral infection caused by viruses or bacteria is one of the most common diseases in human worldwide, while those caused by emerging viruses, such as the novel coronavirus, 2019-nCoV that caused the pneumonia outbreak in Wuhan, China most recently, have posed great threats to global public health. Identification of the causative viral pathogens of respiratory tract viral infections is important to select an appropriate treatment, save people's lives, stop the epidemics, and avoid unnecessary use of antibiotics. Conventional diagnostic tests, such as the assays for rapid detection of antiviral antibodies or viral antigens, are widely used in many clinical laboratories. With the development of modern technologies, new diagnostic strategies, including multiplex nucleic acid amplification and microarray-based assays, are emerging. This review summarizes currently available and novel emerging diagnostic methods for the detection of common respiratory viruses, such as influenza virus, human respiratory syncytial virus, coronavirus, human adenovirus, and human rhinovirus. Multiplex assays for simultaneous detection of multiple respiratory viruses are also described. It is anticipated that such data will assist researchers and clinicians to develop appropriate diagnostic strategies for timely and effective detection of respiratory virus infections.     

Effect of Quercetin on lipid peroxidation and changes in lung morphology in experimental influenza virus infection

Influenza virus infection, induced experimentally in mice, was associated with marked changes in lung morphology viz. epithelial damage with focal areas of reactive papillary hyperplasia, infiltration of leukocytes and development of oxidative stress, as evidenced by increased superoxide radical production and lipid peroxidation (LPO) products by alveolar macrophages. These effects were observed on the 5th day after virus instillation. The levels of superoxide and LPO were measured spectrophotometrically by the nitroblue tetrazolium (NBT) assay and thiobarbituric acid reactive species (TBARS) assay, respectively. The former increased by 1.5-2 fold and the latter was raised by 85% when compared with normal control. Supplementation of intranasal viral instillation with the anti-oxidant, Quercetin, given orally, resulted in a significant decrease in the levels of both superoxide radicals and LPO products. There was also a significant decrease in the number of infiltrating cells. A mild to moderate protective effect was observed in lung morphology. Thus, Quercetin may be useful as a drug in reducing the oxidative stress induced by influenza virus infection in the lung, and protect it from the toxic effects of the free radicals.     

Predilection of a nasopharyngeal carcinoma-derived isolate of Epstein-Barr virus for infection of specific subsets of B lymphocytes

It is important to know whether there are variants of Epstein-Barr virus (EBV) with biological properties that are different from the prototype viruses that have been studied in detail, such as P3HR-1 and B95-8. We have studied an EBV isolate derived from a nasopharyngeal carcinoma (NPC) tumor, designated NPC-EBV. We have examined the target B lymphocytes infected and growth-transformed with NPC-EBV as compared with two common EBV isolates, B95-8 and AG876 EBV, for stage of maturation using antibodies to several immunoglobulin chains. Typing of the NPC-EBV transformed lymphoblastoid cell lines revealed the predilection of the NPC-EBV isolate to infect immature B lymphocytes. This was not the case for the B95-8 and AG876 isolates. The reason for the predilection of NPC-EBV for immature B lymphocytes remains to be explored further. However, these results may be important in understanding the pathophysiology of EBV-associated diseases.     

The impact of influenza viruses on hospitalizations in infants younger than two years old during epidemics of respiratory syncytial virus infection

In order to evaluate the association of influenza viruses with hospitalizations for acute respiratory infection in infants younger than two years old during epidemics of respiratory syncytial virus infection, we studied 512 nasal washes from this population. The samples were obtained from 1997 to 2000. A total of 337 viruses were isolated: 264 respiratory syncytial viruses, 62 influenza viruses, eight parainfluenza viruses, two adenovirus and one rhinovirus. Hospitalizations for acute respiratory infection were owing to influenza and respiratory syncytial viruses in 18.3% vs. 78.3% of all cases, and 32.5% vs. 65.8%, respectively, in the group of infants between 6 months and 2 years old.     

Spectrum of respiratory viruses circulating in eastern India: Prospective surveillance among patients with influenza‐like illness during 2010–2011

In developing countries, viruses causing respiratory disease are a major concern of public health. During January 2010–December 2011, 2,737 patients with acute respiratory infection from the outpatient departments as well as patients admitted to hospitals were screened for different respiratory viruses. Nasal and or throat swabs were collected and transported to the laboratory where initial screening of influenza A and influenza B viruses was performed. The samples were tested further for influenza C virus, parainfluenza viruses 1–4, human rhinovirus, metapneumovirus and respiratory syncytial virus by conventional RT‐ PCR. The study revealed that the majority of the patients were under 5 years of age; both due to their higher susceptibility to respiratory infections and presentation to hospitals. Out of 2,737 patients enrolled in this study, 59% were found positive for one or more respiratory viruses. Influenza B infection was detected in 12% of patients followed by influenza A (11.7%), respiratory syncytial virus (7.1%), parainfluenza virus‐2 (6%), metapneumovirus (3%), parainfluenza virus‐3 (1%), parainfluenza virus‐4 (0.6%), parainfluenza virus‐1 (0.3%), influenza C (0.2%) and human rhinovirus (0.2%). Distinct seasonal infection was observed only for influenza A and influenza B viruses. J. Med. Virol. 85:1459–1465, 2013 . © 2013 Wiley Periodicals, Inc.