In vitro characterization and genetic diversity of Bordetella avium field strains

ABSTRACT

Bordetella avium (BA) is a respiratory pathogen of particular importance for turkeys. Specific adherence and damage to the respiratory epithelia are crucial steps of the pathogenesis, but knowledge about the mechanisms and the variety of virulence in field strains is limited. We analysed 17 BA field strains regarding their in vitro virulence-associated properties in tracheal organ cultures (TOC) of turkey embryos, and their genetic diversity. The TOC adherence assay indicated that BA field strains differ considerably in their ability to adhere to the tracheal mucosa, while the TOC ciliostasis assay illustrated a high degree of diversity in ciliostatic effects. These two virulence-associated properties were associated with each other in the investigated strains. Three of the investigated strains displayed significantly (P?>?0.05) lower in vitro virulence in comparison to other strains. Genetic diversity of BA strains was analysed by core genome multilocus sequence typing (cgMLST). We applied a cgMLST scheme comprising 2667 targets of the reference genome (77.3% of complete genome, BA strain 197N). The results showed a broad genetic diversity in BA field strains but did not demonstrate a correlation between sequence type and virulence-associated properties. The cgMLST analysis revealed that strains with less marked virulence-associated properties had a variety of mutations in the putative filamentous haemagglutinin gene. Likewise, amino acid sequence alignment indicated variations in the protein. The results from our study showed that both adherence and ciliostasis assay can be used for virulence characterization of BA. Variations in the filamentous haemagglutinin protein may be responsible for reduced virulence of BA field strains.     

哮喘模型大鼠气管的张开角及残余应变

对哮喘模型大鼠气管的无载荷状态和零应力状态进行分析。与正常组相比，模型大鼠气管软骨剪开的张开角及所对应的残余应变绝对值均较正常组显著增大（P〈0．05），而且随着x／L的增大而呈明显上升趋势。模型大鼠气管肌肉剪开的张开角及所对应的残余应变绝对值无显著变化，且沿气管轴向变化不明显。结果表明哮喘大鼠气管为了适应外在应力环境的变化，肌肉部分不断进行代偿性生长，导致哮喘大鼠气道重建。     

Immunohistochemical co-localization of transient receptor potential vanilloid (TRPV)1 and sensory neuropeptides in the guinea-pig respiratory system

Electrophysiological studies within the lung have documented the presence of heterogenous groups of afferent fibers composed of Adelta and C-fibers and studies of somatosensory nerves within the skin reveal a complex pattern of distribution of sensory neuropeptides and transient receptor potential vanilloid (TRPV)1 positive nerves. However, the anatomical location of these different subpopulations of nerves within the lung has not been extensively studied. In the present study we have demonstrated that TRPV1 axons represented only a small proportion of the total number of PGP9.5 staining nerves within guinea-pig tracheal epithelium and only half the number of TRPV1 axons was immunopositive for substance P. In contrast, most TRPV1 positive neurones found within guinea-pig intrapulmonary airways were found to co-localize with sensory neuropeptides substance P and calcitonin gene-related peptide within and beneath the epithelium, around blood vessels, within airway smooth muscle and alveoli, indicative of heterogeneity of TRPV1 positive axons throughout the airways. However, in the smooth muscle layer of the trachea there was evidence of substance P and calcitonin gene-related peptide containing nerves that did not stain for TRPV1. We also demonstrated a complete loss of TRVP1 positive axons in the trachea and intrapulmonary airways and associated loss of bronchoconstriction induced by capsaicin, in animals chronically treated with capsaicin. However, some neuropeptide immunoreactive axons remained in the smooth muscle layer of capsaicin-treated animals which could represent the small subset of neuropeptide containing fibers which do not co-localize with TRPV1. We have provided evidence of heterogeneity of TRPV1 positive nerve fibers, including fibers characterized by lack of co-localization with neuropeptides in various regions of the airways and the existence of neuropeptide containing fibers that were not TRPV1 positive in guinea-pigs.     

环甲膜切开选择性代替气管切开251例临床分析

目的:环甲膜切开选择性代替气管切开的可行性。方法:251例需行气管切开用环甲膜切开代替。结果:术后随访2年,无声音嘶哑,无气管狭窄,无特殊不适。结论:环甲膜切开速度快,出血少,定位准确,可长期戴管,在有适应证的情况可在临床推广。     

Laryngo-tracheal anastomosis: post-operative evaluation by helical CT and computerized reformations

OBJECTIVE: Our purpose was to evaluate the role of post-operative helical computed tomography (CT) and computerized reformations in patients after laryngo-tracheal segmental resection with anastomosis. METHODS: Helical CT and computerized reformations were obtained in 11 consecutive patients who underwent laryngo-tracheal resection with anastomosis for obstruction or stenosis caused by longstanding intubation or tracheostomy. Post-operative computer assisted cross-sectional area, coronal and sagittal diameter measurements at the level of maximal narrowing of the trachea were compared with clinical assessment in all patients. The additive value of various coronal and sagittal computerized reformations over axial images was subjectively evaluated by a consensus of a thoracic radiologist and a neuroradiologist who were blinded to clinical information. RESULTS: Various degrees of restriction in daily activities were reported by patients with cross-sectional area narrowing of more than 50%, by 4/6 patients with cross-sectional area of less than 90mm(2), by 4/5 and 4/6 patients with coronal or sagittal narrowing of more than 25% respectively, and by 4/5 patients with sagittal diameter of less than 12mm. All five patients with cross-sectional area stenosis of less than 50% assessed themselves as 'asymptomatic'. Sagittal multi-planar and volume rendering reformations clarified or added additional information over axial images in all six patients with significant cross-sectional area stenosis (>50%). Volume rendering scores were significantly higher than minimal intensity projection reformations (P=0.01). CONCLUSION: Our preliminary results suggest that CT-based cross-sectional area and diameter measurements of the trachea represent a clinically helpful tool for post-operative evaluation of patients with tracheoplasty. The need for post-operative endoscopy may be obviated in some cases.     

等效剂量曲马多和芬太尼术后镇痛对全麻患者拔管期循环和呼吸的影响

目的比较等效剂量曲马多和芬太尼持续静脉镇痛对全麻患者气管拔管循环和呼吸的影响。方法60例ASAⅠ、Ⅱ级全麻手术病人随机分为T组和F组,分别于手术结束前30min给予曲马多或芬太尼静脉镇痛,观察拔管后1、5和10min时的SBP、HR、SpO2和PEtCO2。结果拔管时间F组长于T组,两组同期比较拔管后F组HR明显低于T组(P<0.01),SpO2较T组低,而PEtCO2较T组高(P<0.05)。结论曲马多用于全麻术后静脉镇痛几乎不影响患者的清醒及恢复,对患者拔管期间循环和呼吸的影响小于芬太尼。     

气管腺样囊性癌5例报告及国内131例文献分析

目的 提高对气管腺样囊性癌（TACC）的认识。方法 回顾性分析长海医院1995年-2003年收治的TACC5例及检索国内期刊发表的23篇共131例患者临床资料。结果 该病临床上以咳嗽、喘鸣和进行型吸气性呼吸困难为主要表现形式；易与支气管哮喘、慢性支气管炎等混淆。122例行手术治疗，气管支架置入6例，纤支镜下介入治疗3例，局部放疗47例。死亡20例。结论 TACC临床症状不典型，术前误诊率高，尽早积极手术切除加放疗为最佳治疗方法。内镜下介入治疗是较好的姑息治疗手段，可明显改善患者生活质量。     

Microvascular remodelling in chronic airway inflammation in mice

1. Chronic inflammation is associated with blood vessel remodelling, including vessel proliferation and enlargement, and changes in vessel phenotype. We sought to characterize these changes in chronic airway inflammation and to determine whether corticosteroids that inhibit inflammation, such as dexamethasone, can also reduce microvascular remodelling. 2. Chronic airway inflammation was induced in C3H mice by infection with Mycoplasmapulmonis and the tracheal vessels treatment also decreased the immunoreactivity for P-selectin and the number of adherent leucocytes (595 +/- 203 vs 2,024 +/- 393 cells/ mm2 in treated and non-treated infected mice, respectively). 6. We conclude that microvascular enlargement and changes in vessel phenotype are features of some types of chronic inflammation and, furthermore, that dexamethasone reverses the microvascular enlargement, changes in vessel phenotype and leucocyte influx associated with chronic inflammatory airway disease.     

Electrophysiological characteristics of the Ca2+-activated Cl- channel family of anion transport proteins

1. A protein isolated from the bovine tracheal epithelium behaves as a Ca2+-activated Cl- channel (CaCC) when incorporated into planar lipid bilayers. 2. An antibody raised against this protein was used to screen a cDNA expression library and resulted in the isolation of a cDNA clone that exhibited nearly identical electrophysiological characteristics to the isolated endogenous protein when expressed. 3. Recent cloning of several related proteins has revealed that the cloned bovine CaCC is one of a large and growing family. All new family members so far examined are associated with the appearance of a novel Ca2+-mediated Cl- conductance when heterologously expressed. 4. This new group of proteins may underlie the Ca2+-mediated Cl- conductance upregulated in the cystic fibrosis (CF) knockout mouse and thought to be responsible for the escape from the significant airway pathology associated with CF.     

Pleomorphic Adenoma (Benign Mixed Tumor) of the Trachea

A 15-year-old “asthmatic” found to have a pleomorphic adenoma of the trachea was treated by staged CO₂ laser excision Primary tracheal tumors, the clinicopathologic features of mixed tumor in this rare location, and therapeutic options are briefly reviewed Immunohistochemical stains for cytokeratin, S-100 protein, and glial fibrillary acidic protein are reliable methods of evaluating component cell types in pleomorphic adenoma, but immunohistochemical evidence has not resolved the issue of tumor histogenesis.