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Ciliary Beat Frequency (ciliary + beat_frequency)
Selected AbstractsAlcohol Stimulates Ciliary Motility of Isolated Airway Axonemes Through a Nitric Oxide, Cyclase, and Cyclic Nucleotide-Dependent Kinase MechanismALCOHOLISM, Issue 4 2009Joseph H. Sisson Background:, Lung mucociliary clearance provides the first line of defense from lung infections and is impaired in individuals who consume heavy amounts of alcohol. Previous studies have demonstrated that this alcohol-induced ciliary dysfunction occurs through impairment of nitric oxide (NO) and cyclic nucleotide-dependent kinase-signaling pathways in lung airway ciliated epithelial cells. Recent studies have established that all key elements of this alcohol-driven signaling pathway co-localize to the apical surface of the ciliated cells with the basal bodies. These findings led us to hypothesize that alcohol activates the cilia stimulation pathway at the organelle level. To test this hypothesis we performed experiments exposing isolated demembranated cilia (isolated axonemes) to alcohol and studied the effect of alcohol-stimulated ciliary motility on the pathways involved with isolated axoneme activation. Methods:, Isolated demembranated cilia were prepared from bovine trachea and activated with adenosine triphosphate. Ciliary beat frequency, NO production, adenylyl and guanylyl cyclase activities, cAMP- and cGMP-dependent kinase activities were measured following exposure to biologically relevant concentrations of alcohol. Results:, Alcohol rapidly stimulated axoneme beating 40% above baseline at very low concentrations of alcohol (1 to 10 mM). This activation was specific to ethanol, required the synthesis of NO, the activation of soluble adenylyl cyclase (sAC), and the activation of both cAMP- and cGMP-dependent kinases (PKA and PKG), all of which were present in the isolated organelle preparation. Conclusions:, Alcohol rapidly and sequentially activates the eNOS,NO,GC,cGMP,PKG and sAC,cAMP, PKA dual signaling pathways in isolated airway axonemes. These findings indicate a direct effect of alcohol on airway cilia organelle function and fully recapitulate the alcohol-driven activation of cilia known to exist in vivo and in intact lung ciliated cells in vitro following brief moderate alcohol exposure. Furthermore, these findings indicate that airway cilia are exquisitely sensitive to the effects of alcohol and substantiate a key role for alcohol in the alterations of mucociliary clearance associated with even low levels of alcohol intake. We speculate that this same axoneme-based alcohol activation pathway is down regulated following long-term high alcohol exposure and that the isolated axoneme preparation provides an excellent model for studying the mechanism of alcohol-mediated cilia dysfunction. [source] Smoke Exposure Exacerbates an Ethanol-Induced Defect in Mucociliary Clearance of Streptococcus pneumoniaeALCOHOLISM, Issue 5 2005Elizabeth A. Vander Top Background: Alcoholics and smokers are particularly susceptible to pulmonary infections caused by Streptococcus pneumoniae, the pneumococcus. Infection begins when pneumococci colonizing the nasopharynx are aspirated into the lower respiratory tract. The major host defense against this movement is the mucociliary clearance apparatus. Both cigarette smoke and ethanol (EtOH) exposure alter ciliary beating and protein kinase activity in the respiratory mucosa in vitro, but their effects on bacterial clearance in the intact animal have not been determined. Methods: Male Sprague Dawley rats were exposed twice daily for 12 weeks to either the smoke generated from 30 cigarettes (smoke,exposed) or room air (sham,exposed). For the last five weeks of smoke exposure, the rats were fed Lieber-DeCarli liquid diets containing 0%, 16%, 26%, or 36% EtOH calories. The rats then were infected intranasally with S. pneumoniae, and movement of the organisms into the lower respiratory tract was quantified by plate counts of the tracheas and lungs 4 hr later. Ciliary beat frequency (CBF) analysis was performed on tracheal ring explants from each animal before and after stimulation with the ,-agonist isoproterenol, and tracheal epithelial cell protein kinase C (PKC) activity was measured. Results: Ingestion of any of the EtOH-containing diets resulted in a dose-dependent increase in movement of S. pneumoniae into the rats' lungs. This EtOH-induced defect was augmented further by concurrent smoke exposure, although smoke exposure alone had little effect on S. pneumoniae movement. Smoke, but not EtOH exposure, activated tracheal epithelial cell PKC. Increased movement of organisms into lungs correlated with a decrease in CBF and loss of the ciliary response to isoproterenol. Conclusion: EtOH ingestion in our model facilitated movement of S. pneumoniae into rats' lungs, a phenomenon exacerbated by concurrent smoke exposure. Furthermore, the organism's movement into the lungs correlated with a blunting of the rats' ciliary response to an established stimulus. Defects in mucociliary clearance thus may be one cause of the increased risk of pneumococcal infections in people who abuse alcohol, particularly if they also smoke. [source] In-vitro nasal drug delivery studies: comparison of derivatised, fibrillar and polymerised collagen matrix-based human nasal primary culture systems for nasal drug delivery studiesJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 11 2001Remigius Uchenna Agu The aim of this study was to establish a collagen matrix-based nasal primary culture system for drug delivery studies. Nasal epithelial cells were cultured on derivatised (Cellagen membrane CD-24), polymerised (Vitrogen gel) and fibrillar (Vitrogen film) collagen substrata. Cell morphology was assessed by microscopy. The cells were further characterised by measurement of ciliary beat frequency (CBF), transepithelial resistance (TER), permeation of sodium fluorescein, mitochondrial dehydrogenase (MDH) activity and lactate dehydrogenase (LDH) release upon cell exposure to sodium tauro-24, 25 dihydrofusidate (STDHF). Among the three collagen substrata investigated, the best epithelial differentiated phenotype (monolayer with columnar/cuboidal morphology) occurred in cells grown on Cellagen membrane CD-24 between day 4 and day 11. Cell culture reproducibility was better with Cellagen membrane CD-24 (90%) in comparison with Vitrogen gel (70%) and Vitrogen film (< 10%). TER was higher in cells grown on Vitrogen gel than on Cellagen membrane CD-24 and Vitrogen film. The apparent permeability coefficient (Papp × 10,7 cm s,1) of sodium fluorescein in these conditions was 0.45 ± 0.08 (Vitrogen gel) and 1.91 ± 0.00 (Cellagen membrane CD-24). Except for LDH release, CBF and cell viability were comparable for all the substrata. Based on MDH activity, LDH release, CBF, TER and permeation studies, Cellagen membrane CD-24- and Vitrogen gel-based cells were concluded to be functionally suitable for in-vitro nasal drug studies. Vitrogen film-based cultures may be limited to metabolism and cilio-toxicity studies. [source] Influence of topical antifungal drugs on ciliary beat frequency of human nasal mucosa,THE LARYNGOSCOPE, Issue 7 2010An In Vitro Study Abstract Objectives/Hypothesis: Topical antifungal treatment is a subject of discussion in the treatment of chronic rhinosinusitis. The aim of this research was to study the effects of antifungal drugs on ciliary beat frequency (CBF) of human nasal mucosa under in vitro conditions. Study Design: Case series of in vitro experiments and in vitro study of cultured ciliated cells of human nasal mucosa. Methods: Human nasal mucosa was acquired during routine endoscopic sinus surgery. Cells were cultivated on object slides and exposed to different antifungal drugs in a newly developed test system. This system allowed continuous and reproducible exposure to different drugs at constant temperature, pH value, and osmolarity. The drugs were amphotericin B in two different concentrations and itraconazole. Results: Rinsing with higher concentrations of amphotericin B led to an immediate decrease of CBF, with a total stop after 15 minutes. A different result was seen in the group with lower concentrations; CBF decreased again quickly after rinsing with the test drug, but all of them recovered after rinsing with neutral solution. When using itraconazole a decline in CBF was observed again; one half of the samples returned to activity. Conclusions: Our in vitro results demonstrate a dose-dependent effect of the antifungal drugs amphotericin B and itraconazole on ciliary beat frequency of human nose epithelium. Laryngoscope, 2010 [source] Culture of nasal epithelial cells using chitosan-based membranesTHE LARYNGOSCOPE, Issue 10 2009Tsung-Wei Huang MD Abstract Objectives/Hypothesis: The aim of this study was to evaluate whether chitosan-based membranes can be used as scaffolds for growth and differentiation of nasal epithelial cells (NECs). Our final goal was to establish a novel methodology for enhancing the regeneration of the respiratory system. Study Design: Prospective study. Methods: Human NECs were cultured on three various substrates, e.g., chitosan membranes, collagen, and chitosan-collagen membranes. Morphology of NECs was examined via light and electron microscopy, the area of ciliated cells was measured by confocal microscopy, and ciliary beat frequency was also evaluated. Expression of mucin genes was investigated with reverse-transcription polymerase chain reaction. Results: NECs were found to be successfully adhesive with collagen and chitosan-collagen membranes at day 3 after seeding, but not with chitosan membranes. The cilia area on collagen were 6.1% ± 1.2%, 8.4% ± 1.4%, and 12.5% ± 1.9% at days 7, 14, and 21 after confluence, respectively, compared with 5.1% ± 0.9%, 8.6% ± 1.6%, and 12.3% ± 2.1% in chitosan-collagen membranes, exhibited nonsignificant difference (P > .05). There were no significant differences in ciliary beat frequency between each group. The expression levels of mucin genes, namely, MUC5AC, MUC5B, and MUC2, in NECs on both collagen and chitosan-collagen membranes did not differ significantly (P > .05). Conclusions: A small amount collagen mixed with chitosan substrate may improve the biocompatibility and promote the mucociliary differentiation in NECs. It appears that chitosan-collagen membrane is a promising scaffold for culture of the nasal epithelium, which sets the stage for studying tissue regeneration in the respiratory system. Laryngoscope, 2009 [source] Effects of ,-Toxin of Staphylococcus aureus on Ciliary Activity of Nasal Epithelial Cells ,THE LARYNGOSCOPE, Issue 12 2000Chung Seop Kim MD Abstract Objectives To investigate the in vitro effects of staphylococcal ,-to-in on ciliary activity and the in vivo effects on sinusitis induction. Study Design The in vitro effects of staphylococcal ,-to-in on ciliary activity were investigated at different concentrations and e-posure times. E-perimental sinusitis was induced in rabbits with application of ,-to-in and confirmed 7 days later. Methods Ciliated epithelial cells were taken from the ma-illary sinus mucosa of 10 rabbits. Five culture dishes from each rabbit were used for the e-perimental group, and one culture dish from each rabbit was used for the control group. In the experimental group, ciliary beat frequency (CBF) was measured at concentrations of 0.1, 1, 2, 5 and 10 U/mL of ,-toxin using a video-computerized analysis technique, while in the control group, culture medium containing no toxin was used. CBF was measured 1, 2, 4, 6, 8, 12, 24, and 48 hours after administration of ,-toxin. To induce experimental sinusitis, 2 U/mL of ,-toxin was percutaneously applied to the maxillary sinus of 10 rabbits without occlusion of the natural ostium, while normal saline was percutaneously applied to the right-side maxillary sinus of 4 rabbits in the control group. At 7 days, mucosal membranes were taken from the inferomedial wall of the maxillary sinus for light microscopic study. Results CBF dropped significantly after an 8-hour incubation at 2, 5, and 10 U/mL of ,-to-in. No ciliary activity was observed after a 24-hour incubation at 2 and 5 U/mL and a 12-hour incubation at 10 U/mL of ,-to-in. Mucoid, purulent discharge was observed in the ma-illary sinuses of the ,-to-in,applied group. Prominent epithelial disruption and infiltration of inflammatory cells into the epithelium and lamina propria were observed in the ,-to-in,applied group. Conclusions Staphylococcal ,-to-in may reduce ciliary activity and induce sinusitis without occlusion of the natural ostium of the ma-illary sinus in rabbits. This study provides another animal model of sinusitis for understanding the pathogenesis of sinusitis induced by bacterial e-oto-ins. [source] | ||||||||||