Detection of viral infection in the respiratory tract of virus antibody free mice: advantages of high-resolution imaging for respiratory toxicology

Using a highly sensitive membrane permeability assay, a viral infection was discovered in the lungs of virus antibody free (VAF) Swiss-Webster mice purchased for respiratory toxicology studies. The assay is based on the uptake of a charged fluorescent compound by cells lacking an intact plasma membrane. Lungs from 74% of the untreated animals from a single vendor tested positive for injury in this assay. High-resolution histopathologic analysis of 1-microm epoxy resin sections from affected animals identified increased peribronchiolar lymphocytic infiltration and markers of epithelial cell injury. Viral particles were directly observed to be budding from the membranes of infiltrating lymphocytic cells by transmission electron microscopy. Standard histological analysis of paraffin-embedded tissues from lungs of the same mice failed to detect obvious pathology. Serological analyses failed to detect the presence of a virus in the affected mice. Therefore, we conclude that (1) a pathogenic condition was present in the respiratory systems of mice judged pathogen free by standard methodologies, (2) the observed condition produced a pattern of injury comparable to those caused by pulmonary toxicants, (3) high-resolution histopathology and advanced imaging techniques can increase the potential for detection of pathological conditions, and (4) apparently healthy animals can have unrecognized infections with the potential for confounding respiratory toxicology studies.     

免疫功能缺陷对儿童反复呼吸道感染的影响

目的探究免疫功能缺陷对儿童反复呼吸道感染的影响。方法选取2014年1月~2016年8月在我院接受治疗的反复呼吸道感染患儿96例,作为实验组,同时选取门诊体检健康儿童62例为对照组,检测并比较两组血清免疫球蛋白及IgG亚类水平。结果 RRTI组患儿的血清IgG2和IgG4水平均低于对照组(P<0.05);在3~5岁时,实验组和对照组的IgA分别为(1.05±0.51)、(1.50±0.52)g/L,实验组低于对照组,数据差异具有统计学意义(P<0.05);96例RRTI患儿中IgG亚类缺陷共17例,检出率为48.9%(47/96)。结论 IgG亚类等免疫功能缺陷对儿童反复呼吸道感染的影响较大,应及时的预防和监测,以提高患儿的免疫力,预防反复呼吸道感染的发生。     

Activity of cyclosporin A in experimental influenza virus infection in mice

Oral administration of the immunosuppressive fungal metabolite cyclosporin A increased the mortality of Balb/c mice infected intranasally with influenza A/Hong Kong/1/68 (H3N2) virus. Cyclosporin A also increased the amount of virus that could be recovered from the lungs of infected mice and delayed the rate at which it was eliminated. Treatment with cyclosporin A did not, however, prevent the appearance of haemagglutination inhibiting antibody in the sera of animals that had been infected with a sub-lethal concentration of virus.     

Further studies with short duration ribavirin aerosol for the treatment of influenza virus infection in mice and respiratory syncytial virus infection in cotton rats.

Ribavirin aerosol administration has been shown to be effective in the treatment of respiratory syncytial virus (RSV) infections in infants and in influenza A and B virus infections in young adults. Long treatment schedules and potential for environmental contamination have stimulated the search for alternative dosing schedules. Thus, we attempted to determine the length of time of ribavirin aerosol necessary for effective treatment of influenza and RSV. In RSV-infected cotton rats, aerosolization for just 30 min with high-dose ribavirin (HDR:60 mg ribavirin/ml in reservoir), 3 times daily, reduced viral lung titers/gm of tissue by 1.1 log10. In influenza virus-infected mice, 15 min of aerosolized HDR, 3 times daily, was effective in reducing both mortality and pulmonary virus titers (1.1 log10 reduction). When the intervals between aerosol administration each day were equally divided (i.e., q.8 h), the treatments were most effective. Treatment for 45 min, once daily, was not as effective as divided doses. Calculations of ribavirin concentrations in respiratory secretions following 15 min treatment in mice with HDR indicated that drug levels dropped below the ED50 for influenza viruses after about 9 h. A daily dosage of ribavirin, estimated to be 8-15 mg/kg, was effective for the treatment of influenza and RSV infections.     

Protective effects of immunoactive peptide, FK565 against systemic and local infections with herpes simplex virus and murine cytomegalovirus and respiratory tract infection with influenza virus in mice.

The protective effects of FK565 against systemic infections with herpes simplex virus (HSV) and murine cytomegalovirus (MCMV), respiratory tract infection with influenza virus and zosteriform rash with HSV investigated in mice. FK565 showed excellent protective activities against systemic infections with both acyclovir (ACV)-sensitive and -resistant HSV at intravenous and subcutaneous doses of 0.1 and 1 mg/kg and oral dose of 1 mg/kg. FK565 showed superior protective activities at subcutaneous doses of 0.01 and 0.1 mg/kg compared to ACV at subcutaneous dose of 15 mg/kg against MCMV infection. In respiratory tract infection with influenza virus, FK565 showed potent protective effects at intravenous, subcutaneous and oral doses of 0.001 to 1 mg/kg. FK565 markedly inhibited zosteriform spread of HSV on the flank skin at an intravenous dose of 0.1 mg/kg and the mice given FK565 survived longer than the control mice. The peritoneal exudate cells from FK565-treated mice suppressed the growth of HSV in mouse embryo fibroblast more strongly than those from the control mice, although FK565 had no direct antiviral activity against HSV. These findings suggest that FK565 enhanced the host defense ability against viral infections by nonspecific activation of macrophages.     

Time course of changes in ETB receptor density and function in tracheal airway smooth muscle during respiratory tract viral infection in mice.

1. In the current study, the density and function of ETA and ETB receptors in mouse tracheal airway smooth muscle were determined over the time course of respiratory tract infection with influenza A/PR-8/34 virus. 2. Quantitative autoradiographic studies using [125I]-endothelin-1 revealed that the tracheal airway smooth muscle from control mice contained ETA and ETB sites in the ratio of 49%:51% (+/- 2%, n = 29 mice). Respiratory tract viral infection was associated with increases in the density of ETA sites and decreases in the density of ETB sites at days 1, 2 and 4 post-inoculation which were reversible by day 19. For example, at day 4 post-inoculation, a time when the manifestations of viral infection were at or near their peak, the ratio of ETA:ETB sites was 72%:28% (+/- 4%, n = 6 mice, P < 0.05). In contrast, at day 19 post-inoculation, by which time viral infection had essentially resolved, the ratio of ETA:ETB sites was similar to control (51%:49% (+/- 3%), n = 6 mice). 3. Endothelin-1 was a potent spasmogen in isolated tracheal airway smooth muscle preparations from control mice (ED70 = concentration producing 70% of contraction induced by 10 microM carbachol = 6.3 nM (95% confidence limits, 4.0-10; n = 6 mice)). Neither the ETA receptor-selective antagonist, BQ-123 (3 microM), nor the ETB receptor-selective antagonist, BQ-788 (1 microM) alone had any significant inhibitory effect on endothelin-1-induced contractions of mouse isolated tracheal smooth muscle. However, simultaneous treatment with BQ-123 (3 microM) and BQ-788 (1 microM) resulted in a 10 fold rightward shift in the concentration-effect curve to endothelin-1 (ED70 = 60 nM, (44-90; n = 6 mice, P < 0.05)), indicating that contraction was mediated via both ETA and ETB receptors. 4. Endothelin-1 evoked similar concentration-dependent contractions of tracheal smooth muscle isolated from control and virus-inoculated mice. In the presence of the ETB receptor-selective-antagonist, BQ-788 (1 microM), the potency and maximum response to endothelin-1 were similar in preparations from control and virus-inoculated mice at all time points investigated. However, unlike control responses, endothelin-1-induced contractions in preparations from virus-infected mice were significantly inhibited by the ETA receptor-selective antagonist, BQ-123. For example, at day 4 post-inoculation, the contractile response to 30 nM endothelin-1, in the presence of BQ-123 (3 microM), was only 20 +/- 12% (n = 6 mice, P < 0.05) of that produced in control preparations under similar conditions. However, at day 19 post-inoculation, contraction evoked by 30 nM endothelin-1 in the presence of BQ-123 (3 microM), was similar to that in preparations from control mice. 5. In summary, during the early stages (days 1-8 post-inoculation) of respiratory tract infection with influenza A/PR-8/34 virus, we observed decreases in the density of tracheal airway smooth muscle ETB receptors which were reflected in decreases in ETB receptor-mediated airway smooth muscle contraction. In addition, during the same period of viral infection we observed increases in the density of tracheal airway smooth muscle ETA receptors which were not associated with increased function of the ETA receptor-effector system linked to contraction. Virus-associated modulation of ETA and ETB receptor density and function was reversible with recovery from infection.     

Effect of anti-interferon serum of influenza virus infection in mice

Mice were infected by an aerosol of influenza virus Type A (0.5 LD50) and subsequently treated with 4 intranasal instillations of anti-interferon antiserum over a period of 72 h. All the mice treated with antiserum died within 7 days post-infection, whilst the mice in the control groups survived. In mice that did not receive the antibody, virus titers in the lung peaked on day 3 and then decreased again. Also, interferon was detectable both in lung homogenates and serum. In mice treated with antiserum, no interferon was detectable and the virus concentrations in the lung increased until death. These results suggest that interferon produced in the respiratory tract plays an important role in the early stages of influenza virus infection.     

干扰素雾化治疗小儿病毒性上呼吸道感染疗效观察

目的 观察干扰素雾化治疗小儿病毒性上呼吸道感染的临床疗效.方法 选取60例上呼吸道感染患儿,按照抽签方法分为两组,观察组采用干扰素-α1b高频雾化进行治疗,对照组采用利巴韦林注射液治疗,两组疗程均为7d,疗程结束后比较临床疗效.结果 观察组总有效率为90％,对照组总有效率为70％,观察组总有效率显著高于对照组(x2=5.684,P＜0.05);观察组患儿退烧时间为(16.39±5.34)h,对照组患儿退烧时间为(32.37±8.14)h,观察组退烧时间明显短于对照组(t=3.584,P＜0.05).结论 干扰素雾化治疗小儿病毒性上呼吸道感染,具有显著的疗效,且能够有效减少不良反应,提高安全度,在临床中是一种值得推荐的方法.     

白细胞介素2治疗反复呼吸道感染的临床观察

目的 观察白细胞介素2治疗小儿反复呼吸道感染的临床疗效.方法 选择门诊患儿160例随机分为两组,治疗组80例,给予皮下注射白细胞介素2,10～20万IU/次,皮下注射1次/周×6周;对照组80例,口服转移因子10 ml/次,1次/d～2次/d×3月,比较两组疗效.结果 治疗组总有效率为96.2%,对照组58.8%,两组总有效率比较,x2=32.99,P〈0.01.结论 白细胞介素2可增强患儿免疫功能,降低反复呼吸道感染的发生率且疗效优于口服转移因子.     

Oral administration of Bifidobacterium longum ameliorates influenza virus infection in mice

We investigated whether the oral administration of Bifidobacterium longum BB536 could ameliorate influenza virus (IFV) infection in a mice model. Mice were orally administrated BB536 or saline for 2 weeks and then infected with IFV. Orally administered BB536 significantly alleviated symptoms, reduced the loss of body weight, and inhibited viral proliferation in the lungs relative to the control group findings. Histopathological findings in the lungs were improved in the BB536 group compared to control group findings. There was no significant difference in the levels of interleukin-6 (IL-6), interferon-γ (IFN-γ), IL-10 and IL-12p40 in the lungs between the groups, but the levels of IL-6 and IFN-γ were lower (p=0.076, 0.103, respectively) in the BB536 group compared with those of control group. The levels of IL-6 and IL-10 correlated significantly with the values of weight loss, and the levels of IFN-γ correlated with the virus titers in the lungs. These results suggested the potential of the oral administration of BB536 in ameliorating IFV infection and the possible involvement of anti-inflammatory effects of BB536 in the anti-infection effects against IFV.     

北京市4种病毒性呼吸道感染治疗药物使用情况调查分析

本项研究通过对北京市二级以上医院4种病毒性呼吸道感染治疗药物使用情况的普遍调查,了解北京市4种病毒性呼吸道感染治疗药物的使用情况．探索重点品种监测方法,提高药品不良反应监测信息的服务性。     

天津地区儿童急性呼吸道和消化道感染Saffold病毒的检出和临床流行特征

目的 调查天津地区儿童急性呼吸道和消化道感染中是否存在 Saffold 病毒（SAFV）感染及其流行病学特征。 方法 收集 360 份急性呼吸道感染患儿鼻咽抽吸物和 384 份消化道感染患儿粪便标本, 以针对 SAFV 5′-UTR 基因序列设计的特异性引物进行荧光定量 PCR 扩增, 随机取阳性扩增产物进行核苷酸序列测定, 并将所测序列在 GenBank 中进行比对。 计算呼吸道和消化道 SAFV 感染阳性者的阳性率, 不同年龄段及季节的 SAFV 阳性构成比和阳性检出率。 同时考察 SAFV 与其他病毒的混合感染情况。 结果 呼吸道和消化道检测 SAFV 阳性率分别为 11.9%（43/360）和 16.4%（63/384）。 不同性别的呼吸道 SAFV 阳性检出率差异无统计学意义［ 男 、女分别为 11.5% （28/243）和 12.8%（15/117）, χ2=0.13, P > 0.05］, 年龄 6 d～ 12 岁, ＜ 1 岁者占 79.0%（34/43）;消化道检测 SAFV 阳性患儿阳性检出率差异有统计学意义［ 男 、女分别为 13.4%（33/246）和 21.7%（30/138）, χ2=4.47, P＜ 0.05］, 年龄 5 h～ 11 岁。 不同年龄段的呼吸道和消化道 SAFV 阳性检出率差异均无统计学意义。 不同季节呼吸道 SAFV 阳性检出率差异有统计学意义, 以冬季和夏季为主（P＜ 0.01）, 而消化道 SAFV 阳性检出率差异无统计学意义。 呼吸道和消化道 SAFV 与其他病毒混合感染率分别为 7.0%（3/43）和 12.7%（8/63）。 结论 天津地区儿童存在 SAFV 感染, 在急性呼吸道和消化道感染患儿中具有较高的阳性检出率, 且在 1 岁以内患儿中的阳性检出率较高, 应该引起临床重视。     

人偏肺病毒与呼吸道合胞病毒感染患儿外周血细胞因子变化及意义

目的探讨细胞因子在人类偏肺病毒(hMPV)与呼吸道合胞病毒(RSV)感染发病机制中的作用。方法应用流式细胞微球阵列技术(CBA)检测25例hMPV感染(hMPV组)、35例RSV感染患儿(RSV组)和10例正常对照组儿童(C组)外周血细胞因子IL-8、IL-6、IL-1β、TNF-α、IL-10、IL-12p70水平;hMPV组和RSV组根据临床表现分为支气管肺炎亚组、毛细支气管炎亚组和哮喘急性发作亚组,分析不同喘息状态患儿外周血细胞因子的变化。结果 hMPV组和RSV组患儿外周血IL-8、IL-1β、IL-6、TNF-α、IL-10水平显著高于C组;hMPV组TNF-α水平低于RSV组。hMPV组和RSV组哮喘急性发作亚组患儿IL-6水平均高于其他两亚组。hMPV组毛细支气管炎亚组和哮喘急性发作亚组TNF-α水平显著高于支气管肺炎亚组。结论 IL-8、IL-6、IL-1β、TNF-α和IL-10等细胞因子参与了hMPV感染、RSV感染后炎症反应;IL-6、TNF-α在hMPV感染和RSV感染喘息发生过程中起重要作用;hMPV感染诱生的细胞因子与RSV并不完全相同,可能通过不同的免疫途径介导炎症反应。     

蓝芩口服液治疗病毒性上呼吸道感染发热疗效观察

目的观察蓝芩口服液治疗病毒性上呼吸道感染发热的治疗效果。方法130例病毒性上呼吸道感染发热患者,其中包括甲型H1N1流感确诊病例20例,疑似病例8例,临床诊断病例41例,予蓝芩口服液治疗3d,随访1d,观察退热效果和退热时间。结果治疗后,4h内退热39例（30．0％）,72h退热118例（90．8％）,平均退热时间为（23．7±14．9）h。结论蓝芩口服液治疗病毒性上呼吸道感染发热疗效确切。     

盐酸阿比朵尔干混悬剂治疗病毒性上呼吸道感染的临床研究

目的评价盐酸阿比朵尔干混悬剂治疗病毒性上呼吸道感染的有效性与安全性。方法急性上呼吸道病毒感染患者62例,随机分为2组,试验组30例,给予盐酸阿比朵尔干混悬剂,对照组32例,给予盐酸阿比朵尔胶囊,疗程均5 d,观察患者临床症状和体征改变。结果治疗后,试验组有效病例为28例(93.33%),对照组有效病例为30例(93.75%),2组疗效差异无统计学差异(P>0.05)。2组患者治疗前后症状总积分差异有统计学意义(P<0.01)。结论盐酸阿比朵尔干混悬剂可有效治疗病毒性上呼吸道感染,临床疗效确切、安全性高。     

New developments in the treatment of viral respiratory tract infections

Most respiratory tract infections are viral in origin, yet until recently only a few effective therapies had been developed. This reflected the large number of causative agents and the generally benign course of most infections. However, increasing numbers of serious respiratory infections have been seen in recent years, due to the rising prevalence of immunodeficient patients and the emergence of previously unrecognised pathogens. Better understanding of viral structure, and novel methods of drug design and discovery are leading to the development of potentially valuable new treatments, particularly for influenza and respiratory syncytial virus infection.     

New developments in the treatment of viral respiratory tract infections

Most respiratory tract infections are viral in origin, yet until recently only a few effective therapies had been developed. This reflected the large number of causative agents and the generally benign course of most infections. However, increasing numbers of serious respiratory infections have been seen in recent years, due to the rising prevalence of immunodeficient patients and the emergence of previously unrecognised pathogens. Better understanding of viral structure, and novel methods of drug design and discovery are leading to the development of potentially valuable new treatments, particularly for influenza and respiratory syncytial virus infection.