High viral load of human bocavirus correlates with duration of wheezing in children with severe lower respiratory tract infection

Background

Human bocavirus (HBoV) is a newly discovered parvovirus and increasing evidences are available to support its role as an etiologic agent in lower respiratory tract infection (LRTI). The objective of this study is to assess the impact of HBoV viral load on clinical characteristics in children who were HBoV positive and suffered severe LRTI.

Methods

Lower respiratory tract aspirates from 186 hospitalized children with severe LRTI were obtained by bronchoscopy. HBoVs were detected by real-time PCR and other 10 infectious agents were examined using PCR and/or direct fluorescent assay.

Results

Thirty-one patients (24.6%) were tested positive for HBoV in the respiratory tract aspirates. Fifteen samples had a high viral load (>10⁴ copies/mL) and the other sixteen samples had a low viral load (<10⁴ copies/mL). The duration of presented wheezing and hospitalization was longer in children with high viral load of HBoV than that in children with low viral load. The days of wheezing showed a correlation with viral load of HBoV.

Conclusion

We confirmed that HBoV was frequently detected in patients with severe LRTI. Wheezing was one of the most common symptoms presented by patients with positive HBoV. A high HBoV viral load could be an etiologic agent for LRTI, which led to more severe lower respiratory tract symptom, longer duration of wheezing and hospitalization.     

Cytology of tracheobronchial amyloidosis

Localized amyloidosis of the respiratory tract is seldom diagnosed in cytologic specimens. This report describes a case of the tracheobronchial form of amyloidosis in which diagnostic material was present in a cytologic specimen obtained during bronchoscopy.     

Raised respiratory rate in elderly patients: a valuable physical sign.

Measurements of respiratory rate in 82 long-stay patients aged 67-101 years yielded a normal range of 16-25 breaths a minute. In a prospective study of 60 consecutive acute admissions to a geriatric unit, 19 out of 21 patients diagnosed as lower respiratory tract infections had respiratory rates above the upper limit of normal on the day of diagnosis; the rise in respiratory rate preceded the clinical diagnosis. All eight patients who were diagnosed on admission as having a lower respiratory tract infection had a respiratory rate greater than 26, with a mean of 29.7 breaths a minute. Patients admitted for other conditions-for example, urinary tract infection-rarely had respiratory rates outside the normal range. Accurate measurement of respiratory rate is a valuable diagnostic aid in elderly patients.     

下呼吸道不动杆菌医院感染的危险因素及耐药性分析

目的了解引起下呼吸道医院感染的不动杆菌耐药现状及存在的危险因素。方法用常规的方法对下呼吸道的标本进行病原菌的培养及分离,用全自动微生物分析仪VITEK 2对细菌进行鉴定及药物敏感性试验,同时对由不动杆菌引发的158例院内感染患者的危险因素进行分析。结果不动杆菌引起下呼吸道医院感染相关的危险因素主要为使用糖皮质激素类药物或机械插管或患有糖尿病等;除亚胺培南、左氧氟沙星、头孢吡肟、头孢哌酮、头孢哌酮/舒巴坦及头孢他啶等对不动杆菌有较好的体外抗菌活性外(耐药率小于40.0%),临床常用的其他多种抗菌药物耐药较严重,耐药率均在40.0%以上。结论糖皮质激素,机械插管,糖尿病等是不动杆菌引起下呼吸道医院感染的主要危险因素,不动杆菌对临床常用的抗生素有多重耐药性。     

Combined oral/nasal immunization protects mice from Sendai virus infection

Based on the concept of a common mucosal immune system wherein mucosal associated lymphocytes traffic among the various mucous membranes, the murine gastrointestinal tract was immunized with Sendai virus antigens in order to elicit a virus-specific immune response in the respiratory tract. Multiple intragastric (oral) administration of live or killed Sendai virus induced IgA and IgG antiviral antibodies in both gastrointestinal secretions and serum. When cholera toxin as an adjuvant was included along with virus, gut IgA and IgG as well as serum IgA responses were enhanced. Antiviral antibodies induced in respiratory secretions by oral killed virus plus cholera toxin, however, were variable and protection from virus challenge was not demonstrated. Significantly higher levels of respiratory antiviral antibodies were induced if immunization with oral killed Sendai virus/cholera toxin was combined with intranasal administration of small amounts of killed virus. The combined immunization also resulted in protection of both the upper and lower respiratory tracts from virus infection. Protection of the upper respiratory tract was correlated with the presence of IgA antiviral antibodies in nasal washings. On the other hand, protection of the lower respiratory tract was correlated with IgG antiviral antibodies in bronchoalveolar lavage fluids. Immunization with intranasal killed virus alone conferred partial protection to the lower respiratory tract and no protection to the upper respiratory tract. Thus, oral immunization with killed virus antigen could prime for a protective immune response in the murine respiratory tract and this protective response included IgA antibodies.     

Decoding the distribution of glycan receptors for human-adapted influenza A viruses in ferret respiratory tract

Ferrets are widely used as animal models for studying influenza A viral pathogenesis and transmissibility. Human-adapted influenza A viruses primarily target the upper respiratory tract in humans (infection of the lower respiratory tract is observed less frequently), while in ferrets, upon intranasal inoculation both upper and lower respiratory tract are targeted. Viral tropism is governed by distribution of complex sialylated glycan receptors in various cells/tissues of the host that are specifically recognized by influenza A virus hemagglutinin (HA), a glycoprotein on viral surface. It is generally known that upper respiratory tract of humans and ferrets predominantly express α2→6 sialylated glycan receptors. However much less is known about the fine structure of these glycan receptors and their distribution in different regions of the ferret respiratory tract. In this study, we characterize distribution of glycan receptors going beyond terminal sialic acid linkage in the cranial and caudal regions of the ferret trachea (upper respiratory tract) and lung hilar region (lower respiratory tract) by multiplexing use of various plant lectins and human-adapted HAs to stain these tissue sections. Our findings show that the sialylated glycan receptors recognized by human-adapted HAs are predominantly distributed in submucosal gland of lung hilar region as a part of O-linked glycans. Our study has implications in understanding influenza A viral pathogenesis in ferrets and also in employing ferrets as animal models for developing therapeutic strategies against influenza.     

纤维支气管镜对急诊重症肺炎合并呼吸衰竭患者呼吸功能及血清炎症因子水平的影响

目的:探讨纤维支气管镜对急诊重症肺炎合并呼吸衰竭患者呼吸功能及炎症反应的影响。方法:选择2013年9月-2015年9月在我院接受治疗的重症肺炎合并呼吸衰竭患者89例作为研究对象,根据治疗方法不同,将患者分为研究组(47例)与对照组(42例)。对照组患者采用常规抗感染治疗,研究组患者在对照组基础上采用纤维支气管镜肺泡灌洗治疗。观察并比较两组患者治疗前后的动态顺应性(Cdyn)、氧合指数(Pa O2/Fi O2)、呼吸做功(WOB)、血清炎症因子水平的变化情况。结果:治疗前,两组患者Cdyn,WOB,Pa O2/Fi O2,CD11b+中性粒细胞、STREM-1及HMGB-1水平比较,差异均无统计学意义(P0.05);治疗后,对照组患者Cdyn、Pa O2/Fi O2及WOB均较治疗前显著升高,差异具有统计学意义(P0.05);研究组患者Cdyn及Pa O2/Fi O2较治疗前显著升高,而WOB较治疗前显著降低,差异具有统计学意义(P0.05);研究组患者Cdyn及Pa O2/Fi O2高于对照组,而WOB低于对照组,差异具有统计学意义(P0.05);两组患者CD11b+中性粒细胞、STREM-1及HMGB-1水平均较治疗前显著降低,且研究组显著低于对照组,差异均具有统计学意义(P0.05)。结论:纤维支气管镜肺泡灌洗能够改善急诊重症肺炎合并呼吸衰竭患者的呼吸功能,缓解机体炎症反应,具有重要的临床意义。     

ELISA间接法检测呼吸道合胞病毒和副流感病毒血清IgM和IgA抗体

建立了检测呼吸道合胞病毒(RSV)和副流感病毒(PFV)血清特异性IgM和IgA抗体的间接ELISA方法。在方法统一的基础上比较了检测IgG、IgM和IgA抗体的结果,证明检测血清IgM和IgA可以作为RSV和PFV感染的早期诊断指标。检测了120份临床急性下呼吸道感染患儿的血清,RSV-IgM检出率为33.3％,RSV-IgA为36.7％;PFV-IgM为27.5％,PFV-IgA为31.6％。提出了对RSV和PFV感染以检测特异性IgA替代IgM或两者互补的设想。     

Breast feeding and lower respiratory tract illness in the first year of life. Group Health Medical Associates.

OBJECTIVE--To assess the relation between breast feeding and subsequent experience of lower respiratory tract illness. DESIGN--Prospective (from well child visits) and retrospective (from maternal recall) study of breast feeding and prospective assessment by paediatricians of lower respiratory tract illness in infants during first year of life. SETTING--Health maintenance organisation. PARTICIPANTS--Over 1000 infants who were healthy at birth and whose parents used the paediatricians of a local health maintenance organisation. MAIN OUTCOME MEASURES--Duration of breast feeding and type of lower respiratory tract illness (wheezing and non-wheezing) at different age intervals during the first year of life. RESULTS--Breast feeding was associated with a decreased incidence of wheezing illnesses only in the first four months of life. Interactions existed between breast feeding and sharing a room, being Mexican American, and being a boy. Multivariate techniques showed that after controlling for a variety of factors children who received minimal breast milk had a greater risk of early wheezing illnesses; the risk was further increased by simultaneous exposure to sharing a room. CONCLUSION--Breast feeding seems to protect against wheezing respiratory tract illnesses in the first four months of life, particularly when other risk factors are present.     

Flexible Bronchoscopy with Multiple Modalities for Foreign Body Removal in Adults

Objectives

Aspiration of the lower airways due to foreign body is rare in adults. This study aimed to determine the outcome of patients who received flexible bronchoscopy with different modalities for foreign body removal in the lower airways.

Patients and Methods

Between January 2003 and January 2014, 94 patients diagnosed with foreign body in the lower airways underwent flexible bronchoscopy with different modalities, which included forceps, loop, basket, knife, electromagnet, and cryotherapy. The clinical presentation, foreign body location and characteristics, and applications of flexible bronchoscopy were analyzed.

Results

Forty (43%) patients had acute aspiration, which developed within one week of foreign body entry and 54 (57%) had chronic aspiration. The most common foreign bodies were teeth or bone. More patients with chronic aspiration than those with acute aspiration were referred from the out-patient clinic (48% vs. 28%), but more patients with acute aspiration were referred from the emergency room (35% vs. 6%) and intensive care unit (18% vs. 2%). Flexible bronchoscopy with different modalities was used to remove the foreign bodies (85/94, 90%). Electromagnet or cryotherapy was used in nine patients to eliminate the surrounding granulation tissue before foreign body removal. In the nine patients with failed flexible bronchoscopy, eight underwent rigid bronchoscopy instead and one had right lower lung lobectomy for lung abscess.

Conclusions

Flexible bronchoscopy with multiple modalities is effective for diagnosing and removing foreign bodies in the lower respiratory airways in adults, with a high success rate (90%) and no difference between acute and chronic aspirations.     

Impact of massive dose of vitamin A given to preschool children with acute diarrhoea on subsequent respiratory and diarrhoeal morbidity.

OBJECTIVE--To assess the impact of vitamin A supplementation on morbidity from acute respiratory tract infections and diarrhoea. DESIGN--Double blind randomised placebo controlled field trial. SETTING--An urban slum area in New Delhi, India. SUBJECTS--900 children aged 12-60 months attending a local health facility for acute diarrhoea of less than seven days'' duration randomly allocated to receive vitamin A 200,000 IU or placebo. MAIN OUTCOME MEASURES--Incidence and prevalence of acute lower respiratory tract infections and diarrhoea during the 90 days after termination of the enrolment diarrhoeal episode measured by twice weekly household surveillance. RESULTS--The incidence (relative risk 1.07; 95% confidence interval 0.92 to 1.26) and average number of days spent with acute lower respiratory tract infections were similar in the vitamin A supplementation and placebo groups. Among children aged 23 months or less there was a significant reduction in the incidence of measles (relative risk 0.06; 95% confidence interval 0.01 to 0.48). The incidence of diarrhoea was also similar (relative risk 0.95; 0.86 to 1.05) in the two groups. There was a 36% reduction in the mean daily prevalence of diarrhoea associated with fever in the vitamin A supplemented children older than 23 months. CONCLUSIONS--Results were consistent with a lack of impact on acute lower respiratory tract related mortality after vitamin A supplementation noted in other trials and a possible reduction in the severity of diarrhoea.     

吸烟对人体呼吸道厌氧菌的影响

目的探究吸烟对人体内的呼吸道微生态的影响。方法采用细菌鉴定及药敏分析系统鉴定健康吸烟者与非吸烟者,患下呼吸道感染吸烟与非吸烟者咽后壁分泌物的细菌密度、细菌数量及种类的改变。结果在健康吸烟者与患有下呼吸道感染患者的呼吸道中,厌氧菌明显升高,其中以韦荣菌和消化链球菌为主。结论吸烟可使人体的呼吸道微生态中细菌密度,细菌数量及种类的改变,易患呼吸系统疾病。     

肺结核合并下呼吸道感染患者CT影像特点及IL-23R水平表达的临床意义

摘要 目的：探讨肺结核合并下呼吸道感染患者CT影像特点及IL-23R水平表达的临床意义。方法：选取2015年1月-2018年8月于我院就诊的123例肺结核患者,将所选取的患者按是否合并下呼吸道感染分为单纯肺结核组73例和肺结核合并下呼吸道感染组50例。分析两组组患者临床表现、CT影像学图片、CT影像学表现、血清IL-23R的表达水平的差异。结果：单纯肺结核组患者出现14例低热、11例胸闷、17例消瘦、14例气短、18例痰中带血、14例颈部淋巴结肿大、23例咳嗽、21例胸痛。肺结核合并下呼吸道感染组患者出现16例低热、13例胸闷、21例消瘦、19例气短、20例痰中带血、15例颈部淋巴结肿大、26例咳嗽、23例胸痛,两组患者临床表现差异均无统计学意义（P＞0.05）。单纯肺结核组CT影像学图片显示可见结节影或包块影,呈明显分叶征、短毛刺征、空泡征并发肺不张、棘状突起,边缘较清晰,增强扫描后明显强化。肺结核合并下呼吸道感染组CT影像学图片显示有分叶、毛刺,同时肺内肿物周边存在晕征、血管聚集征、卫星灶征、胸膜凹陷等表现,此外伴纵膈及肺门淋巴结明显肿大,胸壁侵犯。肺结核合并下呼吸道感染组CT影像中毛刺状结节、胸膜凹陷、空洞、分叶征、肿块、条索影比例均高于单纯肺结核组,差异有统计学意义（P＜0.05）。肺结核合并下呼吸道感染组患者IL-23R水平明显高于单纯肺结核组,差异有统计学意义（P＜0.05）。结论：与单纯肺结核患者相比较,肺结核合并下呼吸道感染患者临床表现更为严重,CT影像学特点更为明显,患者血清中IL-23R表达水平明显升高,临床可通过CT影像学结合血清IL-23R检测,以提高肺结核合并下呼吸道感染患者的临床诊断。     

Anaerobic bacteria colonizing the lower airways in lung cancer patients

Anaerobes comprise most of the endogenous oropharyngeal microflora, and can cause infections of airways in lung cancer patients who are at high risk for respiratory tract infections. The aim of this study was to determine the frequency and species diversity of anaerobes in specimens from the lower airways of lung cancer patients. Sensitivity of the isolates to conventional antimicrobial agents used in anaerobe therapy was assessed. Respiratory secretions obtained by bronchoscopy from 30 lung cancer patients were cultured onto Wilkins-Chalgren agar in anaerobic conditions at 37°C for 72-96 hours. The isolates were identified using microtest Api 20A. The minimal inhibitory concentrations for penicillin G, amoxicillin/clavulanate, piperacillin/tazobactam, cefoxitin, imipenem, clindamycin, and metronidazole were determined by E-test. A total of 47 isolates of anaerobic bacteria were detected in 22 (73.3%) specimens. More than one species of anaerobe was found in 16 (53.3%) samples. The most frequently isolated were Actinomyces spp. and Peptostreptococcus spp., followed by Eubacterium lentum, Veillonella parvula, Prevotella spp., Bacteroides spp., Lactobacillus jensenii. Among antibiotics used in the study amoxicillin/clavulanate and imipenem were the most active in vitro (0% and 2% resistant strains, respectively). The highest resistance rate was found for penicillin G and metronidazole (36% and 38% resistant strains, respectively). The results obtained confirm the need to conduct analyses of anaerobic microflora colonizing the lower respiratory tract in patients with lung cancer to monitor potential etiologic factors of airways infections, as well as to propose efficient, empirical therapy.     

下呼吸道真菌感染的临床特点及耐药性分析

目的探讨住院患者下呼吸道真菌感染的临床特点,对其耐药性进行分析,以指导临床合理用药。方法回顾性调查2008年1月至2009年12月间安徽医科大学第一附属医院发生下呼吸道真菌感染的病例,并进行统计学分析。结果 374例下呼吸道真菌感染患者检出白色念珠菌253例(67.6%),光滑念珠菌74例(19.8%),热带念珠菌28例(7.5%),克柔念珠菌10例(2.7%),其他假丝酵母菌3例(0.8%),毛霉菌4例(1.1%),烟曲霉菌2例(0.5%)。本组资料药敏结果显示各种真菌对多种抗真菌药物敏感率较高,其中两性霉素B、伏立康唑和氟康唑的敏感率较高,而伊曲康唑的耐药率最高,达到12.2%。结论下呼吸道真菌感染仍以白色念珠菌感染为主,光滑念珠菌和热带念珠菌其次,3种念珠菌占总分离真菌的94.9%,5种抗真菌药物的耐药率以伊曲康唑最高,社区获得性感染患者预后明显优于医院感染患者。     

Distinct mechanisms for cross-protection of the upper versus lower respiratory tract through intestinal priming

A main feature of the common mucosal immune system is that lymphocytes primed in one mucosal inductive site may home to distant mucosal effector sites. However, the mechanisms responsible for such cross-protection remain elusive. To address these we have used a model of local mucosal infection of mice with reovirus. In immunocompetent mice local duodenal priming protected against subsequent respiratory challenge. In the upper respiratory tract this protection appeared to be mainly mediated by specific IgA- and IgG2a-producing B cells, whereas ex vivo active effector memory CTL were found in the lower respiratory tract. In accordance with these findings, clearance of reovirus from the lower respiratory tract, but not from the upper respiratory tract, of infected SCID mice upon transfer of gut-primed lymphocytes depended on the presence of T cells. Taken together this study reveals that intestinal priming leads to protection of both the upper and lower respiratory tracts, however through distinct mechanisms. We suggest that cross-protection in the common mucosal immune system is mediated by trafficking of B cells and effector memory CTL.     

吸烟对下呼吸道感染患者诱导痰中 IL-4和IL-17的影响

目的探究吸烟对下呼吸道感染患者诱导痰中白介素4(IL-4)和白介素17(IL-17)的影响。方法采用酶联免疫吸附法分别对吸烟与非吸烟下呼吸道感染患者(共88例)以及76例健康体检者诱导痰中IL-4和IL-17水平进行检测,并对结果进行分析。结果下呼吸道感染患者中吸烟者与非吸烟者IL-4和IL-17水平比较差异均有统计学意义(P0.05)。健康体检者中吸烟者与非吸烟者IL-4、IL-17比较差异也具有统计学意义(P0.05)。结论吸烟与下呼吸道诱导痰中IL-4、IL-17的表达水平具有相关性,吸烟可使下呼吸道诱导痰中IL-4、IL-17水平升高。     

Diagnosis methods for pneumococcal etiology determination in lower respiratory tract infections

A comparative study of etiological diagnosis in lower respiratory tract infections (LRTI), by conventional bacteriological methods and by pneumococcal antigen direct detection in sputum was performed. This work followed the establishing of rapid methods place, respectively of coagglutination (CoA), counterimmunoelectrophoresis (CIE), within the methodology of bacteriological diagnosis in lower respiratory tract infections presenting pneumococcal etiology. The results of investigations performed on 84 sputa from LRTI patients proved the utility of CoA method in determining a rapid etiological diagnosis, important for applying an emergence targetted antibiotherapy. CoA method, with the reagents in use, covering only 10 out of 83 serological types of S. pneumoniae in not capable of replacing conventional methods of bacteriological diagnosis; they complete each other, increasing the efficiency of etiological diagnosis in LRTI. CIE method is less sensitive and more difficult to perform, being less useful in rapid etiological diagnosis of LRTI.     

Mechanisms of illness during respiratory syncytial virus infection: the lungs, the virus and the immune response

Multiple factors, including cardiopulmonary anatomy, direct viral effects and the immune response can affect the severity of lower respiratory tract disease caused by respiratory syncytial virus (RSV). RSV is the most frequent viral respiratory cause of hospitalization in infants and young children in the world. In this review, we discuss the mechanisms of illness associated with severe RSV lower respiratory tract disease. A better understanding of the factors affecting the course of illness and their interplay should allow development of effective therapies in the future.     

Estimation of volume of epithelial lining fluid recovered by lavage using urea as marker of dilution

Bronchoalveolar lavage is a powerful technique for sampling the epithelial lining fluid (ELF) of the lower respiratory tract but also results in a significant dilution of that fluid. To quantify the apparent volume of ELF obtained by bronchoalveolar lavage, urea was used as an endogenous marker of ELF dilution. Since urea diffuses readily through the body, plasma and in situ ELF urea concentrations are identical; thus ELF volume can be calculated using simple dilution principles. Using this approach, we determined that with a standard lavage procedure, the volume of ELF recovered from a normal human is 1.0 +/- 0.1 ml/100 ml of recovered lavage fluid. Time course experiments in which the saline used for lavage was permitted to remain in the lower respiratory tract for various "dwell times" suggested that diffusion of urea from sources other than recovered ELF can contribute to the total urea recovered resulting in an overestimate of the volume of ELF recovered. Thus, while reasonably accurate, the volume of ELF determined by urea must be considered an overestimate, or "apparent" volume. The ELF albumin concentration based on the apparent ELF volume was 3.7 +/- 0.3 mg/ml, a value that is in good agreement with direct measurements made by other techniques in experimental animals. The density of all inflammatory and immune effector cells on the epithelial surface of the lower respiratory tract, based on the apparent ELF volume, was 21,000 +/- 3,000 cells/microliter, a value that is twofold greater than that in blood.(ABSTRACT TRUNCATED AT 250 WORDS)