The pharmacological effects of ozone on isolated guinea pig tracheal preparations

Ozone is a potent oxidizing agent with a variety of potential uses, including its antimicrobial and deodorising properties. The recent increased use of ozone led to questions regarding its safety in humans. This study specifically focussed on the in vitro effect of ozone on isolated guinea pig tracheal tissue as well as its effect on the isolated trachea in the presence of various drugs with well-known effects, including methacholine and isoproterenol. The results found in this study identified two direct effects on the isolated trachea due to ozone exposure: (1) a definite contraction of the isolated trachea immediately after exposure to ozone, and (2) a clearly visible and significant hyper responsiveness of the isolated trachea to irritants, e.g. methacholine. Although ozone has a negative effect on the trachea, it was concluded that ozone has no adverse effect on muscarinic receptors. We found that ozone has a significant desensitizing effect on the pharmacological response of β sympathomimetics (isoproterenol), while isoproterenol itself has a relaxing effect on the ozone-induced contraction of the isolated trachea. Observations in this in vitro study further emphasised that ozone does have a negative effect on respiratory health. It is underlined that the inhalation of ozone should be avoided by workers who are often in contact with the gas, and especially by those with existing airway diseases. An apparent EC₅₀ value of ozone on the trachea was established by two different methods as 5.71 and 9.78 × 10⁻³ M, respectively.     

NOX2-CONTAINING NADPH OXIDASE AND XANTHINE OXIDASE ARE SOURCES OF SUPEROXIDE IN MOUSE TRACHEA

• 1 Superoxide anion plays an important role in host defence against invading pathogens and in the inflammation that arises in lungs. The aim of the present study was to elucidate whether the two key candidate superoxide‐producing enzymes in mammalian cells, namely Nox2‐containing NADPH oxidase and xanthine oxidase, are responsible for superoxide production in mouse trachea.
• 2 Superoxide production by isolated trachea, as measured by L‐012‐dependent chemiluminescence, was markedly reduced by superoxide dismutase (300 U/mL) and the xanthine oxidase inhibitor allopurinol (100 µmol/L). Tracheas from Nox2^?/– mice had significantly lower levels (~60%) of superoxide than control mice.
• 3 These novel findings suggest that superoxide production by mouse trachea is attributed to both Nox2‐containing NADPH oxidase and xanthine oxidase.

     

静电纺丝技术构建组织工程气管支架的研究进展

支架的选择是组织工程气管替代研究的核心内容之一.阐述了电纺技术的概况及新发展,分析比较天然、合成和复合材料的电纺支架的优缺点,其在气管支架的选材及制作处理方法上的独特优势.对于具体实验或临床对象,应选择合适的聚合物,改进表面修饰技术及调控电纺纤维的结构尺寸和配置,以符合组织特异性和多样性,更好地构建组织工程气管支架.     

In Vivo Effect of Wood Smoke on the Expression of Two Mucin Genes in Rat Airways

A short-term, time-dependent smoke exposure of rats in a nose-only chamber to burning wood and 24-h recovery time revealed inflammation of the airways with varying degrees of injury from loss of cilia, degeneration of epithelium, and squamous metaplasia to submucosal edema. These histological changes were reflected in variable expression of the secretory Muc5AC and low expression of membrane-associated Muc4 mucin genes. 20-min smoke exposure in extended recovery experiments showed marked disorder of tracheal epithelium for up to 72 h of recovery with a return to normal by 7 days. Gene expressions were elevated at 24 and 48 h of recovery. 30-min smoke exposure showed a more severe degeneration of the epithelium and a longer recovery time. Muc5AC expression decreased after 72 h of recovery, while there was upregulation of Muc4 gene from 48 through 96 h. Because Muc4 upregulation and histological results correlate and it has reportedly been associated with epithelium renewal, Muc4 gene may be a useful marker for the regeneration of tracheal epithelium.     

Ocular exposure to infectious laryngotracheitis virus alters leukocyte subsets in the head-associated lymphoid tissues and trachea of 6-week-old White Leghorn chickens

ABSTRACT

Infectious laryngotracheitis virus (ILTV), an alphaherpesvirus, causes acute respiratory disease primarily infecting the upper respiratory tract and conjunctiva. Administration of live attenuated ILTV vaccines via eye drop, drinking water, or by coarse spray elicits protective mucosal immunity in the head-associated lymphoid tissues (HALT), of which conjunctiva-associated lymphoid tissue (CALT) and the Harderian gland (HG) are important tissue components. The trachea, a non-lymphoid tissue, also receives significant influx of inflammatory cells that dictate the outcome of ILTV infection. The objective of this study was to evaluate leukocyte cellular and phenotypic changes in the CALT, HG and trachea following ocular infection with a virulent ILTV strain. At 1, 3, 5, 7 and 9 days post-infection, CALT, HG, and trachea of 6-week-old specific pathogen free (SPF) chickens ocularly-exposed to vehicle or virulent ILTV strain 63140 were dissociated, the cells enumerated and then phenotyped using flow cytometry. The CALT had the highest viral genomic load, which peaked on day 3. In ILTV-infected birds, the CALT had a decreased percentage of leukocytes. This was reflected by decreased numbers of MHCI⁺MHCII^–, MHCI⁺MHCII^low+, and CD4⁺ cells, while IgM⁺ and MHCI⁺MHCII^High+ expressing cell populations increased. In the HG, the most notable change in cells from ILTV-infected birds was a decrease in IgM expressing cells and histologically, an increase in Mott cells. In summary, an acute, ocular exposure to ILTV strain 63140 in young birds shifts subsets of lymphocyte populations in the CALT and HG with minimal impact on the trachea.     

Propranolol for airway hemangiomas: Case report of novel treatment

Infantile hemangiomas arising in the trachea are rare. These lesions pose a management dilemma as several treatment options can provide safe management. Propranolol, a nonselective beta‐blocker, has recently been introduced as a novel modality for the treatment of proliferating hemangiomas. This report illustrates the successful management of tracheal hemangiomas using oral propranolol in a young patient with otherwise treatment‐resistant airway lesions. Despite various endoscopic therapeutic attempts, the patient remained stridulous with airway disease that persisted into the involution phase of the average hemangioma cycle. Within 6 weeks of beginning oral propranolol (2 mg/kg/day), her airway compromise was eliminated and she had complete resolution of endoscopically visible disease. No side effects from propranolol occurred. We propose that oral propranolol should be considered for use in airway hemangiomas. Laryngoscope, 2009     

组织工程气管研究进展

气管切除超过原长度的一半时便需要一个人工气管以进行安全的重建.本文就组织工程化气管构建的研究进展进行了综述,并指出组织工程化气管研究领域所面临的问题和今后的研究方向.     

喉罩与气管内插管在侧卧位下肢全麻手术病人中的应用比较

目的对侧卧位下肢手术病人给予全身麻醉时,应用喉罩和气管内插管,并进行临床观察。方法60例病人分为两组,每组30例。观察组（A组）采用喉罩通气全麻,对照组（B组）采用经口气管内插管全麻。A组病人在摆好侧卧位后再行喉罩插管,全程自主呼吸;B组病人行气管内插管后再摆侧卧位,全程控制通气,观察两组病人在不同时点血液动力学（MAP、HR）、呼吸状况（SpO2、PETCO2）,及麻醉开始到手术开始时间,通气管置入1次性成功率,术后咽喉疼痛发生率,口腔黏膜损伤发生率,返流误吸发生率。结果在通气装置置入前后、拔管期间A组比B组血液动力学更稳定,呼吸状况无显著差异;麻醉开始至手术开始时间两组差异有显著性,A组