须恙螨作为肾综合征出血热宿主的初步调查及实验研究

通过本次流行病学调查和实验研究，发现须恙螨主要分布于肾综合征出血热流行区，其地理分布与疫区的病例分布基本一致。主要传染源黑线姬鼠鼠体带螨指数为２５．１；从鼠肺抗原阳性鼠体所采集的须恙螨幼虫和小黑板采集经叮刺吸食已感染本病病毒的小白鼠乳鼠体液后的游离螨幼虫，分别分离到１株病毒，证明须恙螨具备传播媒介的先决条件。     

HSV-2W株对Vero细胞分裂指数影响的研究

HSV-2 W株感染Vero细胞后,对细胞的分裂指数可产生以下影响:在一定作用时间内,接种病毒的细胞其分裂指数高于对照细胞而低于接种秋水仙素的细胞;接种病毒最多的细胞高于接种病毒量少的细胞;但超过一定时间,则差别不显著;接种病毒时间长的细胞低于接种病毒时间短的细胞;接种灭活病毒的细胞高于接种未来灭活病毒的细胞。根据以上结果就HSV-2对宿主的某些生物学作用讲行了讨论。     

丙型肝炎患者PBMC的mIL-2R表达及其临床意义

目的 探讨丙型肝炎患mIL-2R表达水平及其临床意义。方法 用生物素-链酶亲和素法对56例抗-HCV阳性患外周血单个核细胞(PBMC)进行植物血凝素(PHA)诱导前后mIL-2R的的检测。结果 急、慢性丙型肝炎患静息状态mIL-2R表达水平，诱导状态mIL-2R表达水平分别与正常对照相比，差异均有显性。结论 丙型肝炎患体内存在明显的细胞免疫功能紊乱，T细胞活化障碍，并与肝病的慢性化有关。     

Changes in lymphocyte subset distribution aid in the differential diagnosis of renal allograft dysfunction

The distribution of selected lymphocyte subset populations in renal transplant patients was used to assist in the differential diagnosis of graft dysfunction. Patients experiencing dysfunction due to rejection showed consistent and significant decreases in relative numbers of CD 8 (cytotoxic/suppressor) lymphocytes. The ratio of CD 4 cells to CD 8 cells in this group of patients was generally greater than 2.00 due to decreases in CD 8 cells. Patients showing graft dysfunction due to viral infections showed consistent and significant increases in CD 8 cells which also bear the HNK-1 or the HLA-Dr determinants. Serial monitoring for these dual-marked lymphocytes on a weekly basis can be of considerable use in determining the etiology of graft dysfunction. Increases in other "activation" markers, including transferrin receptors, CD 38, and a T cell lineage specific activation antigen (TLiSA) were not specific for rejection; in fact, increases in CD38 were more often associated with viral infections. These studies indicated that lymphocyte subset determinations done on a regular basis can help distinguish graft dysfunction due to viral infections from other causes. The ability to distinguish rejection episodes from stable grafts is less obvious. Although the alterations in lymphocyte subset distribution are not entirely specific, they can distinguish viral infections from rejection.     

Currently used nucleic acid amplification tests for the detection of viruses and atypicals in acute respiratory infections

For the detection of respiratory viruses conventional culture techniques are still considered as the gold standard. However, results are mostly available too late to have an impact on patient management. The latest developments include appropriate DNA- and RNA-based amplification techniques (both NASBA and PCR) for the detection of an extended number of agents responsible for LRTI. Real time amplification, the latest technical progress, produces, within a considerable shorter time, results with a lower risk of false positives. As results can be obtained within the same day, patient management with appropriate therapy or reduction of unnecessary antibiotic therapy in LRTI will be possible. A number of technical aspects of these amplification assays, and their advantages are discussed.The availability and use of these new diagnostic tools in virology has contributed to a better understanding of the role of respiratory viruses in LRTI. The increasing importance of the viral agents, Mycoplasma pneumoniae and Chlamydophila pneumoniae in ARI is illustrated. A great proportion of ARI are caused by viruses, but their relative importance depends on the spectrum of agents covered by the diagnostic techniques and on the populations studied, the geographical location and the season. The discovery of new viruses is ongoing; examples are the hMPV and the increasing number of coronaviruses. Indications for the use of these rapid techniques in different clinical situations are discussed. Depending on the possibilities, the laboratory could optimize its diagnostic strategy by applying a combination of immunofluorescence for the detection of RSV an IFL, and a combination of real-time amplification tests for other respiratory viruses and the atypical agents. When implementing a strategy, a compromise between sensitivity, clinical utility, turn around time and cost will have to be found.     

Sequence Analysis of the Washington/1964 Strain of Human Parainfluenza Virus Type 1 (HPIV1) and Recovery and Characterization of Wild-Type Recombinant HPIV1 Produced by Reverse Genetics

A complete consensus sequence was determined for the genomic RNA of human parainfluenza virus type 1 (HPIV1) strain Washington/20993/1964 (HPIV1 WASH/64), a clinical isolate that previously was shown to be virulent in adults. The sequence exhibited a high degree of relatedness to both Sendai virus, a PIV1 virus recovered from mice, and human PIV3 (HPIV3) with regard to cis-acting regulatory regions and protein-coding sequences. This consensus sequence was used to generate a full-length antigenomic cDNA and to recover a recombinant wild-type HPIV1 (rHPIV1). Interestingly, the rHPIV1 could be rescued from full-length antigenomic rHPIV1 cDNA using HPIV3 support plasmids, HPIV1 support plasmids, or a mixture thereof. The replication of rHPIV1 in vitro and in the respiratory tract of hamsters was similar to that of its biologically derived parent virus. The similar biological properties of rHPIV1 and HPIV1 WASH/64 in vitro and in vivo, together with the previous demonstration of the virulence of this specific isolate in humans, authenticates the rHPIV1 sequence as that of a wild-type virus. This rHPIV1 can now be used to study the biological properties of HPIV1 and as a substrate to introduce attenuating mutations for the generation of live-attenuated HPIV1 vaccine candidates.An erratum to this article can be found at     

Virus-inhibiting surgical glove to reduce the risk of infection by enveloped viruses

Needle puncture and other accidents that occur during surgery and other procedures may lead to viral infections of medical personnel, notably by hepatitis C (HCV) and human immunodeficiency virus (HIV), now that hepatitis B can be prevented by vaccination. A new surgical glove called G-VIR, which contains a disinfecting agent for enveloped viruses, has been developed. Herpes simplex type 1 (HSV) was used as a standard enveloped virus in both in vitro and in vivo tests of the virucidal capacity of the glove. Bovine viral diarrhea virus (BVDV) and feline immunodeficiency virus (FIV) were used as models for HCV and HIV, respectively. For in vitro study, a contaminated needle was passed through a glove and residual virus was titrated; for in vivo studies, animals were stuck with a contaminated needle through a glove. Despite variation in virus enumeration inherent in the puncture technique, statistical evaluation showed that infection was reproducibly and substantially reduced by passage through the virucidal layer. For BVDV, the amount of virus passing through the virucidal glove was reduced in 82% of pairwise comparisons with control gloves that lacked the virucidal agent; when plaque counts were adjusted to a common dilution, the median count for the virucidal glove was on the average reduced >10-fold. In experiments in which the proportion of wells infected with FIV was measured, the ratio of TCID(50) values (control glove to G-VIR) was >15, and probably much higher. For HSV, the amount of virus passing through the virucidal glove was reduced in 81% of comparisons with control gloves; the median of adjusted plaque counts was reduced on the average approximately eightfold or ninefold. In vivo tests with FIV and HSV in cats and mice, respectively, found smaller percentage reductions in infection than the in vitro tests but confirmed the virucidal effect of the gloves.     

Isolation of equine infectious anemia virus glycoproteins. Lectin affinity chromatography procedures for high avidity glycoproteins

Lectin affinity chromatography procedures were evaluated for the isolation of enveloped virus glycoproteins. The major glycoprotein of equine infectious anemia virus (E1AV) bound to concanavalin A (Con A)-Sepharose through interactions which could not be reversed by α-methylglucoside, but elution could be accomplished with buffers containing guanidine hydrochloride or sodium dodecyl sulfate. These denaturants, however, also released about one-half of the Con A protein from the Sepharose matrix. This degradation does not appear to have been recognized previously, as denaturants are frequently employed for the isolation of virus glycoproteins from Con A-Sepharose. In contrast, the virus glycoprotein bound equally well to Sepharose-bound Lens culinaris (lentil) lectin affinity columns and was effectively eluted with buffer containing 0.2 M α-methylglucoside. The lentil lectin-Sepharose procedure described is rapid, inexpensive and results in the efficient separation and recovery of EIAV glycoproteins. Thus, lentil lectin-Sepharose can provide a useful alternative to Con A-Sepharose for isolating other high avidity glycoproteins from viral envelopes or cell membranes.     

Lineage extinction and replacement in dengue type 1 virus populations are due to stochastic events rather than to natural selection

Between 1996 and 1998, two clades (B and C; genotype I) of dengue virus type 1 (DENV-1) appeared in Myanmar (Burma) that were new to that location. Between 1998 and 2000, a third clade (A; genotype III) of DENV-1, which had been circulating at that locality for at least 25 years, became extinct. These changes preceded the largest outbreak of dengue recorded in Myanmar, in 2001, in which more than 95% of viruses recovered from patients were DENV-1, but where the incidence of severe disease was much less than in previous years. Phylogenetic analyses of viral genomes indicated that the two new clades of DENV-1 did not arise from the, now extinct, clade A viruses nor was the extinction of this clade due to differences in the fitness of the viral populations. Since the extinction occurred during an inter-epidemic period, we suggest that it was due to a stochastic event attributable to the low rate of virus transmission in this interval.     

慢性乙肝患者血清趋化因子RANTES水平与肝功能生化指标等的相关性研究

Objective To investigate the level of the serum chemokine RANTES and its correlation with serum biochemical indices of liver function test, HBeAg and HBV DNA load in patients with chronic hepatitis B.Methods 144 patients with chronic hepatitis B (observed group) and 18 normal cases (control group) were enrolled in this study. The serum level of chemokine RANTES was detected with an ABC-ELISA assay. Statistical analysis was performed on the software of SPSS13.0. Results The serum chemokine RANTES level in the observed group (3930.12 ng/ml±2856.96) ng/ml was significantly higher than that in the control group (329.46 ng/ml±152.23) ng/ml. The results from the observed group indicated the positive correlation of serum RANTES level with indices of liver function test, including ALT (r=0. 197, P=0.018), AST(r=0.239, P=0.004) and TBil (r=0.316, P=0.001), but did not with PTA (r=-0.078, P=0.357). Neither difference of serum chemokine RANTES level between HBeAg-positive group and HBeAg-negative group nor that between high HBV DNA load group (≥105 copies/ml) and low HBV DNA load group (< 105 copies/ml) were statistically significant (P=0.407 and 0.185, respectively). Conclusions Serum chemokine RANTES level in patients with chronic hepatitis B elevates significantly and is not affected by HBeAg or HBV DNA load. Its positive correlation with indices of liver function test indicates that RANTES might play an important rule in the pathogenesis of chronic hepatitis B.