An association between Helicobacter pylori and upper respiratory tract disease: Fact or fiction?

Helicobacter pylori(H. pylori) is a major cause of chronic gastritis and gastric ulcers and considerable evidence supports the notion that infection with this bacterium is also associated with gastric malignancy in addition to various other conditions including pulmonary, vascular and autoimmune disorders. Gastric juice infected with H. pylori might play an important role in upper respiratory tract infection. Although direct and/or indirect mechanisms might be involved in the association between H. pylori and upper respiratory tract diseases, the etiological role of H. pylori in upper respiratory tract disorders has not yet been fully elucidated. Although various studies over the past two decades have suggested a relationship between H. pylori and upper respiratory tract diseases, the findings are inconsistent. The present overview describes the outcomes of recent investigations into the impact of H. pylori on upper respiratory tract and adjacent lesions.     

下呼吸道微生态在支气管哮喘中的研究进展

随着二代测序的不断发展,过去人们认为无菌的下呼吸道现已被证实有多种不同的微生物群落定植.同时,越来越多的研究也证明,微生态在宿主免疫系统的发生发展中起着重要的作用.呼吸道微生态紊乱可能与多种呼吸道疾病密切相关,包括肺结核、COPD及支气管哮喘(简称哮喘)等.该研究主要回顾了近年来对哮喘患者及健康人群呼吸道微生态的研究,探讨在哮喘患者中呼吸道菌群定植的改变趋势,以及呼吸道微生态的改变与哮喘发病机制之间的关系,并且对呼吸道微生态在哮喘治疗中的研究进展进行讨论.     

呼吸系统微生态演替与人类健康

呼吸系统微生态是人体微生态重要组成部分。呼吸道正常菌群相当于机体的天然屏障,这些固有的微生物群在抵御外籍菌入侵方面具有重要的作用,同时还发挥着局部免疫功能。正常情况下,呼吸道各部位的微生物种类和数量相对稳定。对呼吸道正常菌群演替次序和变化特征的深入研究是认识呼吸系统炎症本质、开发呼吸道益生菌的理论基础。     

下呼吸道微生物菌群对宿主免疫的影响

随着细菌鉴定技术的发展,健康成年人下呼吸道存在常驻微生物菌群的观点逐渐受到认可.这类微生物菌群具有调节天然免疫和获得性免疫反应的作用.在呼吸道疾病如哮喘、COPD的发生发展过程中,宿主下呼吸道微生态环境发生改变,免疫状态也发生了改变,但两者之间的关系尚不明确.我们将围绕下呼吸道微生物菌群对宿主免疫系统的影响进行阐述,以探讨影响呼吸道疾病发生发展的因素.     

Role of upper and lower respiratory tract immunity in resistance to Mycoplasma respiratory disease

This study determined whether respiratory tract immunization protects against mycoplasma infection and compared preferential immunization of the upper respiratory tract (nasal) with upper and lower respiratory tract (nasal-pulmonary) immunization. Small volumes of inoculum preferentially deposited antigen and induced IgA responses in nasal passages. Larger inoculums deposited antigen in both the upper and lower respiratory tracts, generating corresponding IgA responses. Mice were given nasal or nasal-pulmonary immunizations with Mycoplasma pulmonis antigen alone or with cholera toxin (CT), and resistance to infection was determined. Generation of upper respiratory tract immunity reduced mycoplasma infection at this site, but CT was needed to elicit protective responses. In the lower respiratory tract, nasal-pulmonary immunization was most effective, but nasal immunization did confer some protection from pulmonary infection. In contrast, intraperitoneal immunization resulted in little protection. Thus, respiratory tract immunity plays a major role in resisting mycoplasma infection, and it should be considered during vaccine development.     

The role of Mycoplasma in upper respiratory infections

Mycoplasma pneumoniae is a common cause of upper and lower respiratory tract infections. Pneumonia is the most clinically important manifestation, but tracheobronchitis and various nonspecific upper respiratory tract symptoms are more typically seen in clinical settings. M. pneumoniae can cause pharyngitis with or without concomitant lower respiratory tract involvement, but it is less commonly detected in other upper respiratory conditions such as otitis media, sinusitis, and the common cold. A variety of methods exist for laboratory diagnosis of M. pneumoniae infection, including culture, serology, and the polymerase chain reaction assay, but each has limitations. This article provides a summary of recent studies that have evaluated the role of M. pneumoniae in upper respiratory tract infections; a brief discussion of its cell biology, pathogenic mechanisms, and epidemiology; and recommendations for laboratory diagnosis and management.     

Glutathione deficiency in the epithelial lining fluid of the lower respiratory tract in idiopathic pulmonary fibrosis

Glutathione (L-gamma-glutamyl-L-cysteinyl-glycine, GSH), a sulfhydryl-containing tripeptide produced by most mammalian cells, is an efficient scavenger of toxic oxidants, including hydrogen peroxide, an oxidant that plays a major role in the oxidant burden placed on the epithelial surface of the lower respiratory tract in chronic inflammatory states. GSH is present in the epithelial lining fluid of the normal lower respiratory tract, where it is thought to play a major role in providing antioxidant protection to the epithelial cells. In this regard, we hypothesized that the lower respiratory tract of patients with IPF may be chronically depleted of this antioxidant, thus leading to an increased susceptibility of lung epithelial cells to oxidant injury. To evaluate this concept, the concentration of glutathione was determined in the epithelial lining fluid of the lower respiratory tract of 15 patients with IPF and compared to that of 19 normal subjects. Strikingly, whereas ELF glutathione concentrations were high in normal subjects (429 +/- 34 microM), a fourfold decrease was found in patients with IPF (97 +/- 18 microM, p less than 0.001). In the context of the known oxidant burden present in the lower respiratory tract of patients with IPF, these observations of a "GSH deficiency" in IPF ELF suggest that there is a marked oxidant-antioxidant imbalance at the alveolar surface of these persons, thus increasing the susceptibility to the severe epithelial cell damage characteristic of this disease.     

Community-acquired lower respiratory tract infections: etiology and treatment.

The current therapy for community-acquired lower respiratory tract infections is often empiric, usually involving administration of a beta-lactam or macrolide. However, the increasing prevalence of antibiotic resistance in frequently isolated respiratory tract pathogens has complicated the antimicrobial selection process. This review will discuss the incidence of various respiratory pathogens, as well as update the clinician on the various antimicrobial alternatives available, with particular emphasis on the role of the newer fluoroquinolones in the treatment of acute exacerbations of chronic bronchitis and community-acquired pneumonia.     

上皮钙粘附素在吸烟小鼠呼吸道上皮损伤修复中表达的研究

目的通过观察吸烟小鼠呼吸道上皮细胞上皮钙粘附素（Ｅｃｄ）表达的动态变化，探讨吸烟对呼吸道上皮细胞Ｅｃｄ表达的影响。方法应用免疫组织化学ＳＰ法，检测不同剂量、不同阶段吸烟小鼠呼吸道上皮细胞Ｅｃｄ的表达，并在光镜及电镜下观察其形态学变化。结果小鼠吸烟４周、１２周时，上皮细胞Ｅｃｄ表达与正常对照组比较明显下调（Ｐ＜００１），吸烟剂量加倍时其下调更为显著；形态学研究表明吸烟４周及１２周时上皮细胞间连接松散，上皮细胞损伤同时伴有增殖。吸烟８周时，Ｅｃｄ表达与正常对照组之间差异无显著性（Ｐ＞００５）。结论吸烟引起呼吸道上皮细胞Ｅｃｄ表达波浪式变化在呼吸道上皮细胞的损伤与修复中可能发挥重要作用。     

Human coronavirus NL63 infections in infants hospitalised with acute respiratory tract infections in South Africa

Background Human coronavirus NL63 (HCoV‐NL63) is a novel respiratory virus which is associated with respiratory tract infections in children. Objective To determine the role of HCoV‐NL63 in infants and young children hospitalised with acute respiratory tract infections (ARI) in Cape Town, South Africa. Methods Respiratory specimens were collected from 1055 infants and young children hospitalised with ARI in 2003–2004. Samples were screened by RT‐PCR to detect HCoV‐NL63 and human metapneumovirus (hMPV). Standard shell vial culture and immunofluoresence was used to detect the common respiratory viruses including RSV, influenza A and B viruses, parainfluenza viruses 1, 2, 3, adenovirus and CMV. Results A respiratory virus was found in 401/1055 (38·0%) samples. HCoV‐NL63 was detected in 9/1055 (0·85%) with peak activity during autumn (67%). Most patients had a diagnosis of pneumonia or lower respiratory tract infection (6/9; 67%). Conclusions This is the first report of HCoV‐NL63 infections in hospitalised children in Africa. During the 2‐year period HCoV‐NL63 played a minor role in ARI in children.     

一起军营腺病毒急性呼吸道感染暴发流行的报告

目的 描述一起军营急性呼吸道感染暴发的临床特征和病原学诊断.方法 采用统一的流行病学个案调查表现场调查225例患者,描述疾病特征.30份咽拭子标本行病原学检测,中和试验检测52份急性期、恢复期患者的血清中和抗体.隔离患者和密切接触者,对空气、物品、地面进行全面消毒.结果 225例患者分布整个营区,有明显的宿舍聚集现象,聚集率为44.9%.225例患者中,全部有发热;161例有咳嗽,占71.6%;111例有咽痛,占49.3%;102例有头痛,占45.3%;31例有胸闷,占13.8%;4例有呼吸困难,占1.8%.咽拭子标本经PCR检测腺病毒基因阳性20份(66.7%),经HepG2、Hela、RD和Vero细胞培养,16份(53.3%)出现细胞病变;24例患者经IgM抗体筛查明确为腺病毒感染,双份血清中和试验证实28份腺病毒抗体有4倍以上升高.隔离患者、全面消毒后10 d,无新发病例.结论 此次暴发流行系腺病毒引起,及时、合理的预防措施能快速控制疾病的流行.     

Current use and future directions of adenovirus vaccine

Adenoviruses are a major cause of respiratory illnesses in military recruits and also are common causes of respiratory and gastrointestinal infections during childhood. Forty-one serotypes of human respiratory and enteric adenoviruses have been identified. Live, oral adenovirus vaccines developed for the military and tested in large clinical trials have proved to be safe and highly effective in decreasing hospitalizations related to adenoviral acute respiratory diseases. Studies have demonstrated little horizontal transmission among military personnel but substantial transmission among family members. Use of recombinant techniques have opened new opportunities for the development of recombinant adenovirus vector vaccines against a number of viral pathogens such as hepatitis B, human immunodeficiency, herpes simplex and respiratory syncytial virus.     

Current issues in the management of bacterial respiratory tract disease: the challenge of antibacterial resistance

The worldwide burden of respiratory tract disease is enormous. Resistance to penicillins, macrolides, and cephalosporins is now detected among the leading bacterial pathogens that cause respiratory tract infections (RTIs)-Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. The increasing role of atypical/intracellular pathogens (eg, Chlamydia pneumoniae, Mycoplasma pneumoniae, Legionella pneumophila) in RTIs, as well as their increase in antibiotic resistance prevalence, continues to be of great concern. More recently introduced treatment options for RTIs include the newer respiratory fluoroquinolones, along with the macrolides and azalides. Although these agents demonstrate good activity against common respiratory pathogens, reduced susceptibility to these agents has been reported. The ketolides are recently developed antibacterial agents with targeted-spectrum activity against common respiratory tract pathogens, including atypical/intracellular pathogens, and a low potential for inducing resistance. These promising new drugs have shown in vitro and in vivo efficacy in the treatment of community-acquired RTIs, such as community-acquired pneumonia, acute exacerbations of chronic bronchitis, and acute bacterial maxillary sinusitis.     

Bombesin and vasoactive intestinal polypeptide in the developing lung: marked changes in acute respiratory distress syndrome

The quantitative distribution of bombesin- and vasoactive intestinal polypeptide (VIP)-like immunoreactivities was determined by RIA and immunocytochemistry in regions of trachea, bronchus, and whole lung at various stages of human fetal development and in neonates, children, and adults. In addition, these two immunoreactivities were studied in infants that had died of the acute respiratory distress syndrome. The concentration of bombesin-like immunoreactivity in the whole respiratory tract steadily increased during gestation, reaching a plateau at birth. In the lung, the bombesin concentration remained almost unchanged during childhood, but decreased to one tenth in the adult. In neonates with the acute respiratory distress syndrome, there was a significantly lower bombesin content in all regions of the respiratory tract compared to either normal full-term infants or 24- to 28-week-old fetuses. Immunocytochemistry localized bombesin immunoreactivity within mucosal neuroendocrine cells present in the airway epithelium throughout the respiratory tract and particularly in the intrapulmonary airways. The number of cells increased throughout gestation, reflecting the pattern found by RIA, and were greatly decreased in acute respiratory distress syndrome patients. VIP concentrations were much lower than those of bombesin and did not change significantly with gestational age. In contrast to bombesin, VIP was mainly concentrated in the upper respiratory tract. In infants with the respiratory distress syndrome, the VIP content was not different from normal. These results are compatible with the possibility that bombesin-like peptides may have a role in the normal development of the human lung.     

The Role of Bitter and Sweet Taste Receptors in Upper Airway Immunity

Over the past several years, taste receptors have emerged as key players in the regulation of innate immune defenses in the mammalian respiratory tract. Several cell types in the airway, including ciliated epithelial cells, solitary chemosensory cells, and bronchial smooth muscle cells, all display chemoresponsive properties that utilize taste receptors. A variety of bitter products secreted by microbes are detected with resultant downstream inflammation, increased mucous clearance, antimicrobial peptide secretion, and direct bacterial killing. Genetic variation of bitter taste receptors also appears to play a role in the susceptibility to infection in respiratory disease states, including that of chronic rhinosinusitis. Ongoing taste receptor research may yield new therapeutics that harness innate immune defenses in the respiratory tract and may offer alternatives to antibiotic treatment. The present review discusses taste receptor-protective responses and analyzes the role these receptors play in mediating airway immune function.     

Immunomodulation for the prevention and treatment of lung infections

The clearance of microbes from the respiratory tract requires the generation of a vigorous and compartmentalized host immune response. When pulmonary infection occurs in the setting of impaired innate and acquired immune responses, antimicrobial agents alone often cannot cure the host. This article reviews both conventional and experimental approaches to stimulate innate and acquired immune responses. These strategies include immunotherapy to directly enhance effector cell function of phagocytic cells (e.g., cytokine immunotherapy) or skew immune responses toward protective type 1 immunity (e.g., CD40 ligand, CpG dinucleotides, cytokines). Additionally, the role of immunization (either active or passive) in the prevention and treatment of respiratory tract infection is addressed. Although the clinical context in which these immunomodulatory approaches may be of benefit in the treatment of respiratory tract infection remains uncertain, potential applications of immunotherapy are explored.     

吸入性糖皮质激素与呼吸道黏膜免疫系统的关系

呼吸道黏膜免疫系统（respiratory passage mucosa immune system,RMIS）是黏膜免疫系统的重要组成部分,它是保护机体免于病原体侵犯的重要屏障,其中分泌型IgA（sIgA）起到了重要作用。吸入皮质激素（ICSs）在慢性炎症性气道疾病中得到了广泛的运用。综述从RMIS的组成、sIgA的功能、口腔微生态以及ICSs对支气管黏膜免疫的影响等方面进行讨论,旨在更好的认识呼吸道黏膜免疫功能以及更好的使用ICSs。     

急性出血性脑卒中开颅术后下呼吸道感染的危险因素及临床分析

目的探讨急性出血性脑卒中开颅术后下呼吸道感染的危险因素并临床分析。 方法回顾性分析天津市泰达医院神经外科自2012年1月至2020年12月收治的674例行开颅手术的出血性脑卒中患者的临床资料[包括性别、年龄、出血部位、意识障碍、瞳孔变化、糖尿病病史、慢性阻塞性肺疾病（COPD）史],根据术后是否合并下呼吸道感染将患者分为下呼吸道感染组和无下呼吸道感染组,单因素分析2组患者临床资料的差异,总结下呼吸道感染的致病菌和用药方式。 结果674例患者中术后出现下呼吸道感染者239例,无呼吸道感染者435例,2组患者的年龄、意识障碍状态、术前瞳孔散大情况、糖尿病史、COPD病史等比较,差异均有统计学意义（P<0.05）。下呼吸道感染的致病菌革兰氏阴性菌占68.4%,革兰氏阳性菌占29.8%,真菌占1.8%。下呼吸道感染组住院时间平均18.23 d。无下呼吸道感染组住院时间平均14.47 d。 结论出血性脑卒中术后下呼吸道感染的发病率与患者的年龄、意识状态、瞳孔变化、糖尿病史、COPD病史等临床特征有关,早期予以针对性抗炎治疗可以降低术后患者下呼吸道感染的发病率,改善患者预后。     

T cell memory in the lung airways

The respiratory tract poses a substantial challenge to the immune system due to its large surface area, an extensive vasculature that is in very close proximity to the external environment, and repeated exposure to potentially pathogenic organisms in the air. Yet many lung pathogens are controlled by appropriate immune responses. The underlying mechanisms of the adaptive cellular immune response in protecting the respiratory tract are poorly understood. Recently, it has emerged that memory CD4(+) and CD8(+) T cells are present in the lung airways, and evidence is mounting that these cells play a key role in pulmonary immunity to pathogen challenge by immediately engaging the pathogen at the site of infection when pathogen loads are low. For example, in the case of respiratory virus infections, there is evidence that both CD4(+) and CD8(+) memory cells in the lung airways mediate substantial control of a secondary respiratory virus infection in the lungs. Here we address recent developments in our understanding of lung airway memory T cells and their role in infectious disease.