小发卡RNA抗呼吸道合胞病毒效应的研究

目的 为从基因水平抑制呼吸道合胞病毒（respiratory syncytial virus，RSV）的复制，针对RSV的M2-2基因构建小发卡结构状RNA（short hairpin RNA，shRNA）重组质粒，在细胞水平观察shRNA对RSV复制的影响。方法 将成功构建的针对RSV M2-2基因的重组质粒pshRNA8260转染HEp-2细胞，利用光镜观察pshRNA8260对RSV致HEp-2细胞病变效应（cytopathogenic effect，CPE）的影响并计算CPE抑制率，空斑形成实验检测RSV滴度变化。结果 成功构建了针对人RSV M2-2基因mRNA的pshRNA8260重组质粒，研究发现pshRNA8260能明显改善RSV所致的病变效应，降低RSV在细胞内复制的病毒滴度。结论 针对RSV M2-2基因的pshRNA82（g）重组质粒具有明显的特异性抗RSV效应的作用。     

Rapid detection of respiratory viruses using mixtures of monoclonal antibodies on shell vial cultures.

Eleven hundred and thirty-three clinical specimens submitted to the laboratory for diagnosis of respiratory virus infections were tested by direct immunofluorescence (DIF) for respiratory syncytial virus (RSV), by shell vial culture, and by conventional cell culture. The shell vial cultures were stained with 8 different monoclonal antibodies both 1 day and 3-7 days after inoculation. In order to limit the cost and the workload, mixtures of monoclonal antibodies were used. Coverslips with HEp-2 cells were incubated with a mixture of FITC-labeled monoclonal antibody to RSV and nonlabeled monoclonal antibody to adenovirus. When no RSV positive IF staining was observed after the first incubation step, the same coverslip was incubated once more with FITC-labeled anti-mouse antibody. A positive reaction at this stage indicated the presence of adenovirus. Similarly, cultures of tertiary monkey kidney cells were investigated with a mixture of two FITC-labeled monoclonals to the influenza viruses A and B and three nonlabeled monoclonals to the parainfluenza viruses 1, 2 and 3. If influenza virus or parainfluenza virus was detected, the exact type was determined by staining different parts of a duplicate coverslip. Shell vial cultures for cytomegalovirus (CMV) were always performed separately on human embryonic lung fibroblasts. Using this approach, we detected RSV (n = 248), CMV (n = 42), parainfluenza virus (n = 31), influenza virus (n = 28), and adenovirus (n = 6), in most cases after only one day of culture. For RSV, the sensitivity of the shell vial method was too low (74%) to allow omission of DIF (sensitivity 95%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of psychotropic agents on the physical properties of platelet membranes in vitro

Normal platelet membranes were exposed in vitro to a variety of psychotropic medications commonly used in the treatment of patients with psychiatric disorders. Changes in structural order at the hydrocarbon region of the drug-exposed membranes were determined by steadystate fluorescence polarization measurements employing the fluorescent probe 1,6-diphenyl-1,3,5-hexatriene (DPH). Chlorpromazine, an aliphatic phenothiazine, produced a significant increase in DPH fluorescence polarization at concentrations from 2–200 M. Thioridazine, a piperidine phenothiazine, and three piperazine derivatives, perphenazine, trifluoperazine, and fluphenazine, produced significant increases in this parameter at concentrations from 20–200 M. The other agents tested, including thiothixene, lithium, antidepressants, anxiolytics, and anticonvulsants, were without effect in the concentration ranges examined. The phenothiazine-induced increase in DPH fluoresence polarization apparently depended on the structure of the phenothiazine nucleus; changes in side-chain structure appeared to modulate this effect, most likely by altering the inherent membrane solubility of the agents.     

COVID-19 and Infant Hospitalizations for Seasonal Respiratory Virus Infections,New Zealand, 2020

In March 2020, a national elimination strategy for coronavirus disease was introduced in New Zealand. Since then, hospitalizations for lower respiratory tract infection among infants <2 years of age and cases of respiratory syncytial or influenza virus infection have dramatically decreased. These findings indicate additional benefits of coronavirus disease control strategies.     

羊水葡萄糖及白介素-6在胎膜早破中的意义

目的 探讨胎膜早破患者羊水中葡萄及白介素－6(IL－6）含量与宫内感染的关系。方法 随机选择1994－1999年70例无妊娠并发症的胎膜早破的患者,在B超引导下,经腹行羊膜腔内穿刺,抽取羊水,用葡萄糖氧化酶方法测定水中葡萄糖,用酶联免疫方法测定IL－6含量。结果 胎膜早破并宫内感染者,羊水葡萄糖含量明显下降,IL－6含量则明显增高,当羊水葡萄糖含量≤0．55mmol/L,IL-6含量≥315ng/L时,预测宫内感染的敏感性100％,特异性＞80．00％。结论 胎膜早破患者,测定羊水葡萄糖及IL－6含量,能早期快速预测宫内感染。     

Cost-effectiveness of strategies for preventing paediatric lower respiratory infections associated with respiratory syncytial virus in eight Chinese cities

BackgroundNew monoclonal antibodies (mAbs) and vaccines against RSV with promising efficacy and protection duration are expected to be available in the near future. We evaluated the cost-effectiveness of the administration of maternal immunisation (MI), infant mAb (IA) and paediatric immunisation (PI) as well as their combinations in eight Chinese cities.MethodsWe used a static model to estimate the impact of these preventive interventions on reducing the burden of RSV-ALRI in twelve monthly birth cohorts from a societal perspective. In addition to year-round administration, we also considered seasonal administration of MI and IA (i.e., administered only to children born in selected months). The primary outcome was threshold strategy cost (TSC), defined as the maximum costs per child for a strategy to be cost-effective.ResultsWith a willingness-to-pay threshold of one national GDP per capita per QALY gained for all the cities, TSC of year-round strategies was: (i) US$2.4 (95% CI: 1.9-3.4) to US$14.7 (11.6-21.4) for MI; (ii) US$19.9 (16.9-25.9) to US$144.2 (124.6-184.7) for IA; (iii) US$28.7 (22.0-42.0) to US$201.0 (156.5-298.6) for PI; (iv) US$31.1 (24.0-45.5) to US$220.7 (172.0-327.3) for maternal plus paediatric immunisation (MPI); and (v) US$41.3 (32.6-58.9) to US$306.2 (244.1-441.3) for infant mAb plus paediatric immunisation (AP). In all cities, the top ten seasonal strategies (ranked by TSC) protected infants from 5 or fewer monthly birth cohorts.ConclusionsAdministration of these interventions could be cost-effective if they are suitably priced. Suitably-timed seasonal administration could be more cost-effective than their year-round counterpart. Our results can inform the optimal strategy once these preventive interventions are commercially available.     

RSV neutralization assays – Use in immune response assessment

Respiratory syncytial virus (RSV) is a leading cause of respiratory illness among children and infants worldwide, yet no licensed vaccine exists to reduce the risk of disease. At least 16 RSV vaccine candidates are currently in clinical development and many are designed to induce robust virus neutralizing immune responses. RSV neutralizing antibody (nAb)-mediated interventions such as intravenous immunoglobulin (IVIG) and palivizumab provide passive protection against serious lower respiratory tract disease due to RSV, validating nAbs as a correlate of protection. To identify correlates of protection for vaccine candidates that have demonstrated their protective efficacy, an investigator can use assays designed to measure nAb responses. However, there is no standard method of measurement; individual laboratories have developed their own methods to measure the ability of nAbs to reduce the infectivity of a defined virus dose in a variety of cell lines, leading to establishment of the broad variety of RSV neutralization assay formats currently in use.Standardizing the RSV neutralization assay is an essential step toward better assessment of nAb responses to vaccine candidates. Use of a common reference standard by all makes comparing the immunogenicity of different vaccine candidates feasible. In the context of vaccine development, the WHO 1^st International Standard for Antiserum to RSV (RSV IS) has been shown to be suitable for harmonizing results across laboratories and assay formats used to measure nAb titers to RSV/A and RSV/B in human sera.This review describes the broad variety of RSV virus neutralization assay formats currently in use and the importance of the RSV IS for harmonization of results across formats and across laboratories. It also outlines good practices for key assay components and data analysis to promote the quality and consistency of measuring RSV nAb titers in serum specimens.     

Characteristics of steroid hormone binding systems in hepatocyte plasma membranes

Parameters of binding of cortisone and estradiol to plasma membranes of rat hepatocytes were studied by the method of liquid scintillation radiometry. The presence of two systems for the binding of these hormones in the membranes was demonstrated. One system is specific (saturable) and binds hormones in physiological concentrations. The capacity and affinity of this system for cortisone are significantly higher than for estradiol. The binding parameters within the temperature range from 4 to 37°C for cortisone and estradiol respectively are: Dissociation constant 2.1–3 and 2.7–4.5 nM, number of binding sites 2–2.4 and 0.14–0.18 nmoles/mg protein. Experiments with p-chloromercuribenzoate demonstrate the role of proteins in the working of this system. The second (unsaturable) system is nonspecific and its function is determined by the lipid component of the membranes. The affinity of corticosteroids for hepatocytes is probably due to the activity of the (saturable) specific system of the plasma membranes of these cells.Department of Molecular Pharmacology and Radiobiology, Medico-Biological Faculty, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Yudaev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 2, pp. 172–174, February, 1980.