Clinical and ultrastructural correlations in nasal mucociliary function observed in children with recurrent airways infections

Evaluation of Mucociliary Clearance by Three Dimension Micro-CT-SPECT in Guinea Pig: Role of Bitter Taste Agonists

Different image techniques have been used to analyze mucociliary clearance (MCC) in humans, but current small animal MCC analysis using in vivo imaging has not been well defined. Bitter taste receptor (T2R) agonists increase ciliary beat frequency (CBF) and cause bronchodilation but their effects in vivo are not well understood. This work analyzes in vivo nasal and bronchial MCC in guinea pig animals using three dimension (3D) micro-CT-SPECT images and evaluates the effect of T2R agonists. Intranasal macroaggreggates of albumin-Technetium 99 metastable (MAA-Tc99^m) and lung nebulized Tc99^m albumin nanocolloids were used to analyze the effect of T2R agonists on nasal and bronchial MCC respectively, using 3D micro-CT-SPECT in guinea pig. MAA-Tc99^m showed a nasal mucociliary transport rate of 0.36 mm/min that was increased in presence of T2R agonist to 0.66 mm/min. Tc99^m albumin nanocolloids were homogeneously distributed in the lung of guinea pig and cleared with time-dependence through the bronchi and trachea of guinea pig. T2R agonist increased bronchial MCC of Tc99^m albumin nanocolloids. T2R agonists increased CBF in human nasal ciliated cells in vitro and induced bronchodilation in human bronchi ex vivo. In summary, T2R agonists increase MCC in vivo as assessed by 3D micro-CT-SPECT analysis.

Pathological study of otitis media with effusion after treatment with intranasal pulmonary surfactant

OBJECTIVES/HYPOTHESIS

To evaluate the histopathological effect of intranasal pulmonary surfactant (PS) on the eustachian tube (ET) in guinea pigs with otitis media with effusion (OME).

STUDY DESIGN

Randomized control trial.

METHODS

Nonviable heat-killed Hemophilus influenzae solution was injected into the tympanum of guinea pigs by a trans-eardrum approach to establish OME. Guinea pigs were divided into four groups: normal controls (group A), untreated OME (group B), saline-treated (group C), PS-treated (group D). The response threshold of the guinea pigs was measured by auditory brainstem response (ABR), and data were analyzed by one-way analysis of variance. The histopathological changes in the osseous, cartilaginous, and muscular portions of the ET were observed systematically by light microscopy.

RESULTS

The ABR threshold in OME group B was raised significantly compared with normal group (A). The response in saline-treated group C was not statistically significantly different compared with OME group B. Seven days after intranasal dripping of pulmonary surfactant in PS-treated group D, the response threshold showed at statistically significant decrease compared with OME B and saline-treated C groups. In OME group B and saline-treated group C, mucosa showed swelling with goblet cell hyperplasia, and cilia were irregularly arranged. In PS-treated group D, there was slight mucosal swelling with fewer goblet cells, and cilia were regularly arranged, similar to the normal group A.

CONCLUSIONS

The findings of the study indicate that intranasal pulmonary surfactant drops have protective and hyposecretory effects on the mucociliary system of the ET in guinea pigs suffering from OME.

Antioxidant components of naturally-occurring oils exhibit marked anti-inflammatory activity in epithelial cells of the human upper respiratory system

BACKGROUND

The upper respiratory tract functions to protect lower respiratory structures from chemical and biological agents in inspired air. Cellular oxidative stress leading to acute and chronic inflammation contributes to the resultant pathology in many of these exposures and is typical of allergic disease, chronic sinusitis, pollutant exposure, and bacterial and viral infections. Little is known about the effective means by which topical treatment of the nose can strengthen its antioxidant and anti-inflammatory defenses. The present study was undertaken to determine if naturally-occurring plant oils with reported antioxidant activity can provide mechanisms through which upper respiratory protection might occur.

METHODS

Controlled exposure of the upper respiratory system to ozone and nasal biopsy were carried out in healthy human subjects to assess mitigation of the ozone-induced inflammatory response and to assess gene expression in the nasal mucosa induced by a mixture of five naturally-occurring antioxidant oils--aloe, coconut, orange, peppermint and vitamin E. Cells of the BEAS-2B and NCI-H23 epithelial cell lines were used to investigate the source and potential intracellular mechanisms of action responsible for oil-induced anti-inflammatory activity.

RESULTS

Aerosolized pretreatment with the mixed oil preparation significantly attenuated ozone-induced nasal inflammation. Although most oil components may reduce oxidant stress by undergoing reduction, orange oil was demonstrated to have the ability to induce long-lasting gene expression of several antioxidant enzymes linked to Nrf2, including HO-1, NQO1, GCLm and GCLc, and to mitigate the pro-inflammatory signaling of endotoxin in cell culture systems. Nrf2 activation was demonstrated. Treatment with the aerosolized oil preparation increased baseline levels of nasal mucosal HO-1 expression in 9 of 12 subjects.

CONCLUSIONS

These data indicate that selected oil-based antioxidant preparations can effectively reduce inflammation associated with oxidant stress-related challenge to the nasal mucosa. The potential for some oils to activate intracellular antioxidant pathways may provide a powerful mechanism through which effective and persistent cytoprotection against airborne environmental exposures can be provided in the upper respiratory mucosa.

Protective effect of pulmonary surfactant on cilia of Eustachian tube in otitis media with effusion

OBJECTIVE

The aim of this study was to evaluate the effect of pulmonary surfactant (PS) on cilia of Eustachian tube (ET) in guinea pigs suffering from otitis media with effusion (OME).

METHODS

A nonviable heat-killed pneumococci (HKP) solution was injected into the tympanum of guinea pig via a transtympanic approach therefore establishing models of OME (effusion in tympanum and hearing loss). After being injected with physiologic saline solution or pulmonary surfactant transtympanically, the response threshold of each guinea pig was taken by ABR. Changes of effusion and ciliary ultrastructure were observed.

RESULTS

Normal group (A), the response threshold is 14.00+/-3.08 dBHL. Abundant and intact cilia were observed, ciliary morphology was normal, cilia regularly arranged in concord, no goblet cells was observed. Model-control group (B0), 5 days following the inoculation of HKP, serous effusion was present in tympanum. The response threshold is 45.00+/-5.67 dBHL. Cilia lost and arranged irregularly, hyperplasia of the goblet cells was observed. Saline group, the previously observed serous effusion of tympanum was increased or unchanged. The response threshold is 65.50+/-6.85 dBHL. Cilia were coalescing and swelling. A lot of cilia lost and arranged disorderly. A number of compound cilia of the bulging type were formed by cytoplasmic protuberances of ciliated cells. Massive mucoid secretions stuck on the surface of the ET. PS group, the previously observed serous effusion of tympanum was reduced in amount or disappeared completely. The response threshold is 23.53+/-6.32 dBHL. Ciliary morphology was generally normal. Cilia comparatively arrange in concord. A mucus deposits was adhering to the tips of cilia.

CONCLUSION

The findings of the study suggest that pulmonary surfactant plays an important role in protecting of cilia of ET of guinea pigs suffering from OME.

Airway infectious disease emergencies

Upper and lower respiratory infections are encountered commonly in the emergency department. Visits resulting from occurrences of respiratory disease account for 10% of all pediatric emergency department visits and 20% of all pediatric hospital admissions. Causes of upper airway infections include croup, epiglottitis, retropharyngeal abscess, cellulitis, pharyngitis, and peritonsillar abscesses. Lower airway viral and bacterial infections cause illnesses such as pneumonia and bronchiolitis. Signs and symptoms of upper and lower airway infections overlap, but the differentiation is important for appropriate treatment of these conditions. This article reviews the varied clinical characteristics of upper and lower airway infections.

Pediatric pneumonia

Respiratory disease is common in pediatrics and diagnosing pneumonia may be clinically challenging. Changes in pneumococcal resistance and immunization practices continue to change the incidence and etiologies of pneumonia. Careful attention to epidemiologic, seasonal, and specific pediatric clinical factors and using adjunct radiographs and laboratory tests should guide the emergency physician in his or her management strategy, including selection of antibiotics and inpatient or outpatient disposition.

Surfactant in the middle ear and eustachian tube: a review

There has been a recent surge in research on surfactant and surfactant proteins. Fields ranging from immunology to surface chemistry are making contributions to our understanding of this multifunctional compound. This paper reviews the literature on the structure and function of Eustachian tube surfactant. It covers the proposed functions of endogenous surfactant in normal physiology, as well as the experimental applications of exogenous surfactant in the treatment of otitis media. The analysis is based on four platforms of research: the role of surfactant in the innate immune system, the effect of surfactant on surface tension and Eustachian tube opening pressure, the capacity of surfactant to alter the rheological properties of mucus and the efficiency of the mucociliary system, and the ability of surfactant to mitigate oxygen free radical damage.