Effect of roflumilast on airway remodelling in a murine model of chronic asthma.

BACKGROUND: Airway remodelling is associated with irreversible, or partially reversible, airflow obstruction and ultimately unresponsiveness to asthma therapies such as corticosteroids. Roflumilast is a selective phosphodiesterase-4 inhibitor that has an anti-inflammatory effect in chronic obstructive pulmonary disease (COPD). OBJECTIVE: The objective of this study was to study the effect of roflumilast on airway inflammation and remodelling in a murine model of chronic asthma. METHODS: BALB/c mice sensitized to ovalbumin (OVA) were chronically exposed to intranasal OVA administration twice a week for additional 3 months. Roflumilast was administered orally during the intranasal OVA challenge. A lung fibroblast cell line was used in the proliferation assay. RESULTS: Compared with control mice, mice chronically exposed to OVA developed eosinophilic airway inflammation, airway hyper-responsiveness (AHR), and exhibited features of airway remodelling. Administration of roflumilast significantly inhibited airway inflammation and AHR. Roflumilast also significantly decreased goblet cell hyperplasia and pulmonary fibrosis, which are parameters of airway remodelling. The levels of interleukin (IL)-4, IL-5, and IL-13 in the bronchoalveolar lavage (BAL) fluids were significantly lower in the roflumilast group. In vitro, roflumilast significantly inhibited stem cell factor (SCF)-induced cell proliferation of fibroblasts. The SCF concentration and mRNA expression in a murine model also significantly decreased with roflumilast treatment. CONCLUSIONS: These results suggest that the administration of roflumilast regulates airway inflammation, AHR, and airway remodelling in a model of chronic asthma. The beneficial effects from roflumilast may be related to the SCF/c-kit pathway.

Effect of fudosteine on mucin production.

Fudosteine is a novel mucoactive agent, although little is known about how fudosteine decreases mucin production. The present study examined the effects of fudosteine on MUC5AC mucin synthesis and cellular signalling. An animal model of lipopolysaccharide (LPS)-induced inflammation and a bronchial epithelial cell line model of tumour necrosis factor (TNF)-alpha-induced inflammation were used. Fudosteine was administered before stimulation with LPS or TNF-alpha. The MUC5AC mucin levels were assayed and the expression of the MUC5AC gene was measured. Western blotting was carried out for the detection of phosphorylated epidermal growth factor receptor (p-EGFR), phosphorylated p38 mitogen-activated protein kinase (p-p38 MAPK) and phosphorylated extracellular signal-related kinase (p-ERK). MUC5AC mucin synthesis and the expression of the MUC5AC gene were increased by LPS in rats or TNF-alpha in NCI-H292 cells; these effects were inhibited by fudosteine treatment. After stimulation with LPS or TNF-alpha, the expression of p-EGFR, p-p38 MAPK and p-ERK were detected. Fudosteine treatment reduced the expression levels of p-p38 MAPK and p-ERK in vivo and of p-ERK in vitro. The present results suggest fudosteine inhibits MUC5AC mucin hypersecretion by reducing MUC5AC gene expression and the effects of fudosteine are associated with the inhibition of extracellular signal-related kinase and p38 mitogen-activated protein kinase in vivo and extracellular signal-related kinase in vitro.

Novel synthesis of nanorod ZnO and Fe-doped ZnO by the hydrolysis of metal powders.

Fe-doped ZnO nanorods have been synthesized by a novel process employing a hydrolysis of metal powders. Zn and Fe nano-powders were used as starting materials and incorporated into distilled water. The solution was refluxed at 60 degrees C for 24 h to obtain the precipitates from the hydrolysis of Zn and Fe. X-ray diffraction patterns for all the samples showed a pure wurtzite single phase, without any segregation of the Fe into the particulates within the instrumental resolution limit. The TEM results for ZnO with and without an Fe-doping showed that the produced powders had a rod-like shape. The rod shape was attributable to the zinc oxide from the hydrolysis of Zn. With an increasing Fe content, the UV-vis spectra were shifted to a long wave length and this result indicates that the band gap was changed by an Fe-doping.

Occupational exposure and idiopathic pulmonary fibrosis: a multicentre case-control study in Korea.

SETTING: Multicentred hospital-based cases and control subjects in Korea. OBJECTIVE: To evaluate the association between idiopathic pulmonary fibrosis (IPF) and hazardous materials to which people are occupationally exposed. DESIGN: A multicentre, hospital-based, matched case-control study was performed. The ratio of IPF cases to controls was 1:1 (n = 78 in each group). IPF cases and controls were matched in terms of age group, sex and place of residence. Conditional logistic regression analysis was performed. RESULTS: In simple logistic regression analysis, exposure to metal dust and any exposure for >1 year in an occupational setting were significantly associated with IPF (metal dust OR 4.00, 95%CI 1.34-11.97; any exposure OR 3.67, 95%CI 1.02-13.14). After adjustment for environmental and military exposures and smoking history, the OR for metal dust exposure was 4.97 (95%CI 1.36-18.17) in multiple logistic regression analysis. CONCLUSIONS: Metal dust was associated with incident IPF in Seoul and Gyeonggi Provinces in Korea. This information will be used to support a tailored preventive strategy in specific industries or occupations.

Incidence and prevalence of idiopathic interstitial pneumonia and idiopathic pulmonary fibrosis in Korea.

SETTING: Although the incidence and prevalence of idiopathic interstitial pneumonia (IIP) and idiopathic pulmonary fibrosis (IPF) have been assessed in Western countries, their epidemiology has not been analysed in Asian countries, including the Republic of Korea. OBJECTIVE: To estimate the prevalence and incidence of IIP, including IPF, in Korea, using a large, nationwide database. DESIGN: The Health Insurance Review and Assessment Services claims database, which includes information on every patient with diagnostic codes for IPF and IIP from 2010 to 2013, was reviewed. Age- and sex-specific IPF and IIP prevalence and incidence rates were estimated. RESULTS: Among Korean males and females, IPF prevalence from 2010 to 2013 was estimated at respectively 39.7 and 24.3 per 100 000 population, while IIP prevalence was estimated at respectively 97.1 and 66.5/100 000. The annual incidence rates among Korean males and females during 2011 and 2012 were respectively 16.4 and 9.7/100 000, for IPF, and respectively 42.3 and 27.5/100 000 for IIP. CONCLUSIONS: IPF is more prevalent in Korea than previously reported; its prevalence may be similar to or higher than in the United States and in European countries.

Risk factors for lung function impairment among the general non-smoking Korean population.

SETTING: Nationwide general population in South Korea. OBJECTIVE: Except for tobacco smoking, risk factors for the impairment of lung function have not been widely evaluated. We evaluated the risk factors for lung function impairment among the general non-smoking Korean population. DESIGN: A total of 8164 non-smokers from the spirometry data set of the Korean National Health and Nutrition Examination Surveys IV and V (2008-2010) were included in the study. After sex stratification, multiple survey logistic regression analyses were performed to estimate the association between potential risk factors and impaired lung function in this nationwide cross-sectional study. RESULTS: The proportion of non-smokers among the general Korean population with forced expiratory volume in 1 s (FEV1) < 80% of predicted, forced vital capacity (FVC) < 80% of predicted and FEV1/FVC ratio < 0.7 were respectively 46.2%, 50.3% and 30.2%. In multiple survey logistic regression analyses, lung function impairment was associated with tuberculosis (TB) and asthma in female non-smokers and asthma in male non-smokers. CONCLUSIONS: TB and asthma are risk factors for lung function impairment among Korean non-smokers. To prevent further lung function impairment, a careful control system for these factors should be considered when setting health policy priorities.

Audiologic evaluation of neonates with severe hyperbilirubinemia using transiently evoked otoacoustic emissions and auditory brainstem responses.

OBJECTIVES: To audiologically clarify the lesion site and to test the reliability of transiently evoked otoacoustic emissions (TEOAEs) in hearing screening of hyperbilirubinemic neonates. STUDY DESIGN: Eleven neonates with severe hyperbilirubinemia who had exchange transfusion in the neonatal intensive care unit of an academic hospital over a 3-year period were included in this study. They were tested with auditory brainstem response (ABR) and TEOAEs after exchange transfusion during hospitalization or at an immediate follow-up visit after discharge. Follow-up ABR tests were performed when infants showed significant hearing loss. METHODS: ABR and TEOAE tests were performed on the 11 neonates with severe hyperbilirubinemia after exchange transfusion. Follow-up ABR tests were carried out in 3-month intervals in the four neonates who showed abnormal or no response on initial ABR. RESULTS: Four neonates showed abnormal or no response and the other seven demonstrated normal response in ABR. All 11 neonates passed TEOAEs. Two neonates showed improvement in auditory function at 3- or 6-month follow-up ABR. CONCLUSION: The results of this study indicate that the site of lesion in hearing loss caused by hyperbilirubinemia may be at the retrocochlear location while the cochlea remains intact. TEOAEs may have limitations in evaluation of hearing in the neonates with hyperbilirubinemia.

Intratumoral hypericin and KTP laser therapy for transplanted squamous cell carcinoma.

OBJECTIVES/HYPOTHESIS: To test intratumoral photodynamic therapy (IPDT) as a new treatment for squamous cell carcinoma in a preclinical tumor model. STUDY DESIGN AND METHODS: Human P3 squamous carcinoma cells were transplanted subcutaneously in athymic nude mice and allowed to grow into 300- to 500-mm3 tumors. Hypericin dye at 1 microg/gm of body weight was injected intratumorally (IT) or intravenously (IV). After 4 hours hypericin biodistribution was assessed in ethanol extracts from tissues by fluorescence spectroscopy. IPDT also was tested by KTP laser fiberoptic insertion in tumors 4 hours after IT dye injection compared to KTP532 laser therapy alone (532 nm, 1W, 40-60 J, 0.6-mm fiber). RESULTS: Hypericin concentration in tissues was as follows: (IT vs. IV) for tumors (3660 vs. 135 ng dye/gm tissue), lung (760 vs. 6345), liver (75 vs. 935), blood (65 vs. 480) compared to skin (465 vs. 110) or muscle (335 vs. 80) adjacent to the squamous cell tumors. Four hours after dye injection, the tumor exhibited bright orange fluorescence when excited by KTP 532-nm green laser light. The IPDT-treated tumors had a 3.32+/-0.32-mm radius of cell destruction when H&E-stained sections were examined compared with 2.5+/-0.38 mm for the laser only control group (n = 10, P = .003). CONCLUSIONS: This pilot study indicates laser IPDT with hypericin induces a significant increase in tumor necrosis compared with laser alone and may be useful as a less invasive adjuvant treatment for recurrent or inoperable human squamous cell cancers of the head and neck.

Hypericin uptake in rabbits and nude mice transplanted with human squamous cell carcinomas: study of a new sensitizer for laser phototherapy.

Tissue uptake and biodistribution of hypericin was measured in rabbits and in nu/nu mice xenografted with P3 human squamous cell carcinoma to assess the value of this dye as an in vivo sensitizer for laser photoinactivation of solid tumors. Hypericin has absorption maxima at 545 and 590 nm with a fluorescence emission peak at 640 nm in ethanol. Dye uptake after intravenous injection was tested at 4 and 24 hours in rabbit tissues by ethanol extraction and quantitative fluorescence spectrophotometry. Maximum dye levels were seen at 4 hours in most vascular organs with lung having fivefold higher uptake than spleen followed by liver, blood, and kidney. Mice were examined after 2, 4, 6, 8, and 24 hours and after 3 and 7 days for dye uptake. The peak concentration of hypericin in murine organs was reached at 4 hours with uptake per gram of tissue as follows: lung > spleen > liver > blood > kidney > heart > gut > tumor > stomach > skin > muscle > brain. Elimination of hypericin was rapid in most murine organs with residual dye under 10% of maximum by 7 days compared to 25% to 30% retention for the squamous cell tumors and several normal tissues. These results suggest that hypericin may be a useful photosensitizer for KTP/532 laser interstitial therapy of human cancer.

Experimental otitis media with effusion induced by platelet activating factor.

This study tested the hypothesis that platelet activating factor (PAF) in the middle ear can induce otitis media with effusion (OME) and that PAF antagonists can prevent PAF-induced OME. An initial trial of 16 micrograms of PAF was injected into chinchilla bullae, and all ears developed middle ear effusion (MEE) within 48 hours. Subsequent trials were performed to test dose dependency. Interestingly, 1 or 16 micrograms of PAF caused more MEE and inflammation than did 4 or 8 micrograms. A dose of 0.5 micrograms PAF did not cause MEE. Middle ear effusion from injected bullae contained the full spectrum of lipoxygenase and cyclooxygenase products; additionally, more PAF was detected than was injected. Finally, a PAF antagonist (WEB 2170) injected intraperitoneally prevented PAF-induced OME. This study demonstrates that PAF injected into the middle ear can induce OME and that PAF antagonists effectively prevent PAF-induced OME. These findings suggest that PAF plays an important role in the pathogenesis of OME.

Ultrastructural changes in platelet activating factor-induced epithelial damage in rabbit maxillary sinus mucosa.

Platelet activating factor (PAF), a potent chemical mediator in inflammation and allergic reaction, has been thought to induce mucociliary inhibition and epithelial damage in the airway mucosa. However, several recent papers have reported that PAF may not readily damage the airway epithelium. The aim of this study was to elucidate the pathogenesis of PAF-induced epithelial damage in terms of ultrastructural changes. Sixteen micrograms of PAF (1 mL of 16 microg/mL) was administered into the maxillary sinuses of rabbits. The rabbits were divided into 2 groups according to time intervals, and the antral mucosa was taken 1 and 3 days after administration of PAF. The tissue was processed for routine transmission electron microscopy. No epithelial degeneration was observed other than platelet aggregation, red blood cell stasis, and swelling of the endothelial cells 1 day after administration of PAF. Migration of inflammatory cells into the perivascular connective tissue, infiltration of eosinophils into the subepithelial and intraepithelial spaces, and vacuolar degeneration of the epithelial cells with focal loss of cilia were seen 3 days after administration of PAF. In conclusion, PAF induced infiltration of eosinophils into the epithelium, and resulted in epithelial degeneration that varied according to the time interval. Our findings suggest that PAF may cause epithelial damage through a series of secondary events, probably due to cytotoxicity of eosinophils infiltrating the epithelium.

Effects of platelet activating factor on vascular permeability of the middle ear mucosa.

Platelet activating factor (PAF), a potent inflammatory mediator, seems to play a significant role in the pathogenesis of otitis media with effusion (OME), along with other inflammatory mediators such as leukotrienes and prostaglandins. The purpose of this study was to investigate the effect of PAF on the vascular permeability of middle ear mucosa, in an experimental OME model using chinchillas. We injected PAF in doses of 1, 4, 8, and 16 micrograms and normal saline as a control into the bullae of chinchillas. Vascular permeability was measured by the Evans blue vital dye technique. All the PAF-injected animals showed a significant increase in middle ear vascular permeability compared to the control group. This study demonstrated that PAF in the middle ear cavity contributes significantly to the development of OME by increasing the vascular permeability of the middle ear mucosa.

Effect of corticosteroid treatment on salicylate ototoxicity.

Our previous studies showed that salicylate ototoxicity is associated with decreased levels of prostaglandins (PGs) and elevated levels of leukotrienes (LTs) in the perilymph. The purpose of this study was to determine whether or not pretreatment with corticosteroid, which suppresses both PGs and LTs in arachidonic acid metabolism, prevents salicylate ototoxicity. Salicylate ototoxicity was induced in chinchillas with or without treatment with dexamethasone. Hearing thresholds were measured by auditory brain stem response, and perilymph samples were assayed by high-performance liquid chromatography. Dexamethasone pretreatment, given by either systemic or local round window membrane application, partially prevented salicylate-induced hearing loss. Prevention of salicylate ototoxicity by dexamethasone seems to be correlated with increased PG levels and decreased LT levels in the perilymph. This is another piece of evidence that salicylate ototoxicity may be mediated by abnormal arachidonic acid metabolism in the inner ear.

Effect of platelet activating factor and its antagonist on the mucociliary clearance of the eustachian tube in guinea pigs.

The purpose of this study was to test whether platelet activating factor (PAF) impairs the mucociliary clearance function of the eustachian tube (ET) in a dose-dependent manner and whether PAF antagonist can prevent the impairment of mucociliary function of the ET induced by PAF. Coomassie brilliant blue dye transport time (DTT) in normal guinea pigs was 69 seconds. The DTTs after the application of normal saline and PAF at I and 2 microg/mL into bullae were 66, 74, and 157 seconds. The time was over 15 minutes when 4, 8, and 16 microg/mL of PAF were applied. The DTT was 62 seconds when the animals were pretreated with PAF antagonist (WEB 2170). There were significant delays of the DTTs after treatment with 2, 4, 8, and 16 microg/mL of PAF. Histopathologic examination of ETs from groups with a significant delay in DTTs showed intact cilia, mucous plugs, increased inflammatory cells, and exfoliation of cells. This study demonstrated that PAF impaired the mucociliary clearance function of the ET in a dose-dependent manner. This impairment of mucociliary clearance function was prevented by pretreatment with PAF antagonist. The findings of the study suggest that PAF plays an important role in the pathogenesis of otitis media with effusion by impairing the ET clearance function.

Otolaryngologic approach to the diagnosis and management of otitis media.

Otitis media is a common childhood disease caused by multiple factors. Understanding the pathogenesis of otitis media is important in the diagnosis and management of it. The mode of therapy should be chosen depending on the type and stage of the disease. Treatment options available to an otolaryngologist include antibiotics, tympanocentesis, myringotomy and tympanostomy tube insertions, adenoidectomy with or without tonsillectomy, exploratory tympanotomy, atympanoplasty, and mastoidectomy.

Ototoxicity of salicylate, nonsteroidal antiinflammatory drugs, and quinine.

Salicylates and most NSAIDS in high doses cause mild to moderate temporary hearing loss, either flat or greater in the high frequencies. Hearing loss is accompanied by tinnitus and suprathreshold changes. Salicylates may or may not exacerbate hearing loss and cochlear damage induced by noise. The mechanism of salicylate ototoxicity seems to be multifactorial. Morphologic studies suggest that no permanent cochlear damage occurs with salicylate ototoxicity. Electrophysiologic, morphologic, and in vitro data conclusively demonstrate that salicylate affects outer hair cells. In addition, salicylates appear to decrease cochlear blood flow. Salicylates and NSAIDs inhibit PG-forming cyclooxygenase, and recent studies suggest that abnormal levels of arachidonic acid metabolites consisting of decreased PGs and increased LTs may mediate salicylate ototoxicity. As with salicylate, quinine ototoxicity appears to be multifactorial in origin. The mechanism includes vasoconstriction and decreases in cochlear blood flow, as measured by laser Doppler flowmetry, motion photographic studies, and histologic studies. Reversible alterations of outer hair cells also appear to play an important role, as demonstrated by histology, electron microscopy, isolated hair cell studies, and cochlear potential evaluations. Unlike with salicylate, however, the role of prostaglandins in quinine ototoxicity has not been clearly demonstrated. Also, one of quinine's principal actions, antagonism of calcium-dependent potassium channels, has yet to be investigated for its potential role in ototoxicity.

Effect of leukotriene inhibitor on cochlear blood flow in salicylate ototoxicity.

Our previous studies showed that salicylate ototoxicity is associated with decreased levels of vasodilating prostaglandins (PGs) and increased vasoconstricting leukotrienes (LTs) in the perilymph and reduced cochlear blood flow (CoBF). The purpose of this study was to test the hypothesis that leukotriene inhibitor prevents salicylate ototoxicity by preventing abnormal elevation of LT levels in the inner ear, thus averting a decrease in CoBF resulting from abnormal levels of arachidonic acid metabolites in the inner ear. Ototoxicity was induced in chinchillas by either local round window membrane (RWM) application or systemic treatment with salicylate both with and without pretreatment with leukotriene inhibitor (Sch 37224). A moderate reduction in CoBF was documented with both local RWM and systemic treatment with salicylate. Salicylate induced hearing loss and reduction in CoBF were prevented by pretreatment with a leukotriene inhibitor. This study suggests that leukotriene inhibitor prevents salicylate ototoxicity by averting a decrease in CoBF mediated by abnormal levels of arachidonic acid metabolites in the inner ear.

Arachidonic acid metabolites in antrochoanal polyp and nasal polyp associated with chronic paranasal sinusitis.

The aim of this study was to investigate the role of arachidonic acid metabolites (AAMs) in the pathogenesis of antrochoanal polyp (ACP). Using high-performance liquid chromatography (HPLC), we assayed the tissue concentrations of 6-keto-PGF1alpha, leukotrienes (LTs) and hydroxyeicosatetraenoic acids (HETE). Concentrations of AAMs in ACP were compared with the level in the control turbinate tissues and nasal polyps associated with chronic paranasal sinusitis (NPS). The concentrations of 6-keto-PGF1alpha were not significantly different in the control turbinate, ACP and NPS groups. In ACP, concentrations of LTC4, 15-HETE and 12-HETE were significantly lower than in the control turbinate. The striking differences in the profile of AAMs between ACP and NPS included a lack of production of LTD4 and LTE4 in ACP, also detectable in NPS, and markedly lower concentrations of 15-HETE and 12-HETE in ACP. The results of this study indicate that decreased lipoxygenase pathway products in arachidonic acid metabolism may be involved in the pathogenesis of ACP. However, in the pathogenesis of NPS, increased production of LTD4 and LTE4 may have an important role. Taken together, our results demonstrate a difference in pathogenesis between ACP and NPS, particularly in terms of arachidonic acid metabolism.

Synthesis and biological studies of catechol ether type derivatives as potential phosphodiesterase (PDE) IV inhibitors.

New series of catechol ether type derivatives 5, 6 have been synthesized and applied to biological tests. Even though it is a preliminary data, some of our target molecules show the promising result against PDE IV inhibition. SAR and biological studies with synthetic compounds will be discussed in detail.