Correlations among mucociliary transport, ciliary function, and ciliary structure

Design and Synthesis of Dual-Targeting Inhibitors of sEH and HDAC6 for the Treatment of Neuropathic Pain and Lipopolysaccharide-Induced Mortality

Epoxyeicosatrienoic acids with anti-inflammatory effects are inactivated by soluble epoxide hydrolase (sEH). Both sEH and histone deacetylase 6 (HDAC6) inhibitors are being developed as neuropathic pain relieving agents. Based on the structural similarity, we designed a new group of compounds with inhibition of both HDAC6 and sEH and obtained compound M9. M9 exhibits selective inhibition of HDAC6 over class I HDACs in cells. M9 shows good microsomal stability, moderate plasma protein binding rate, and oral bioavailability. M9 exhibited a strong analgesic effect in vivo, and its analgesic tolerance was better than gabapentin. M9 improved the survival time of mice treated with lipopolysaccharide (LPS) and reversed the levels of inflammatory factors induced by LPS in mouse plasma. M9 represents the first sEH/HDAC6 dual inhibitors with in vivo antineuropathic pain and anti-inflammation.

High-throughput bioprinting of the nasal epithelium using patient-derived nasal epithelial cells

Progenitor human nasal epithelial cells (hNECs) are an essential cell source for the reconstruction of the respiratory pseudostratified columnar epithelium composed of multiple cell types in the context of infection studies and disease modeling. Hitherto, manual seeding has been the dominant method for creating nasal epithelial tissue models through biofabrication. However, this approach has limitations in terms of achieving the intricate three-dimensional (3D) structure of the natural nasal epithelium. 3D bioprinting has been utilized to reconstruct various epithelial tissue models, such as cutaneous, intestinal, alveolar, and bronchial epithelium, but there has been no attempt to use of 3D bioprinting technologies for reconstruction of the nasal epithelium. In this study, for the first time, we demonstrate the reconstruction of the nasal epithelium with the use of primary hNECs deposited on Transwell inserts via droplet-based bioprinting (DBB), which enabled high-throughput fabrication of the nasal epithelium in Transwell inserts of 24-well plates. DBB of progenitor hNECs ranging from one-tenth to one-half of the cell seeding density employed during the conventional cell seeding approach enabled a high degree of differentiation with the presence of cilia and tight-junctions over a 4 weeks air-liquid interface culture. Single cell RNA sequencing of these cultures identified five major epithelial cells populations, including basal, suprabasal, goblet, club, and ciliated cells. These cultures recapitulated the pseudostratified columnar epithelial architecture present in the native nasal epithelium and were permissive to respiratory virus infection. These results denote the potential of 3D bioprinting for high-throughput fabrication of nasal epithelial tissue models not only for infection studies but also for other purposes, such as disease modeling, immunological studies, and drug screening.

High-Throughput Bioprinting of the Nasal Epithelium using Patient-derived Nasal Epithelial Cells

Human nasal epithelial cells (hNECs) are an essential cell source for the reconstruction of the respiratory pseudostratified columnar epithelium composed of multiple cell types in the context of infection studies and disease modeling. Hitherto, manual seeding has been the dominant method for creating nasal epithelial tissue models. However, the manual approach is slow, low-throughput and has limitations in terms of achieving the intricate 3D structure of the natural nasal epithelium in a uniform manner. 3D Bioprinting has been utilized to reconstruct various epithelial tissue models, such as cutaneous, intestinal, alveolar, and bronchial epithelium, but there has been no attempt to use of 3D bioprinting technologies for reconstruction of the nasal epithelium. In this study, for the first time, we demonstrate the reconstruction of the nasal epithelium with the use of primary hNECs deposited on Transwell inserts via droplet-based bioprinting (DBB), which enabled high-throughput fabrication of the nasal epithelium in Transwell inserts of 24-well plates. DBB of nasal progenitor cells ranging from one-tenth to one-half of the cell seeding density employed during the conventional cell seeding approach enabled a high degree of differentiation with the presence of cilia and tight-junctions over a 4-week air-liquid interface culture. Single cell RNA sequencing of these cultures identified five major epithelial cells populations, including basal, suprabasal, goblet, club, and ciliated cells. These cultures recapitulated the pseudostratified columnar epithelial architecture present in the native nasal epithelium and were permissive to respiratory virus infection. These results denote the potential of 3D bioprinting for high-throughput fabrication of nasal epithelial tissue models not only for infection studies but also for other purposes such as disease modeling, immunological studies, and drug screening.

Advantages and prospects of stem cells in nanotoxicology

Nanomaterials have been widely used in many fields, especially in biomedical and stem cell therapy. However, the potential risks associated with nanomaterials applications are also gradually increasing. Therefore, effective and robust toxicology models are critical to evaluate the developmental toxicity of nanomaterials. The development of stem cell research provides a new idea of developmental toxicology. Recently, many researchers actively investigated the effects of nanomaterials with different sizes and surface modifications on various stem cells (such as embryonic stem cells (ESCs), adult stem cells, etc.) to study the toxic effects and toxic mechanisms. In this review, we summarized the effects of nanomaterials on the proliferation and differentiation of ESCs, mesenchymal stem cells and neural stem cells. Moreover, we discussed the advantages of stem cells in nanotoxicology compared with other cell lines. Finally, combined with the latest research methods and new molecular mechanisms, we analyzed the application of stem cells in nanotoxicology.

Cilia proteins CFAP36 and sentan in induced sputum as possible new markers of epithelial damage in obstructive lung diseases: A preliminary study

Background: Asthma and chronic obstructive pulmonary disease (COPD) are the most common chronic respiratory diseases characterized by inflammation in the lower airways and epithelium remodeling. Dysfunction of cilium is related to severe asthma and COPD, the role of cilium proteins in obstructive lung diseases is not known. The aim of the study was to evaluate the concentration of cilia associated proteins: sentan and CFAP36 in induced sputum (IS) of asthma and COPD patients. Materials/Methods: The study involved 15 patients with asthma, 12 patients with COPD and 17 control subjects (9 non-smoking, 8 smoking) who underwent lung function tests and sputum induction. Sentan, CFAP36, IL-6, IL-8, concentrations were measured in induced sputum supernatants by ELISA. Results: The level of CFAP36 in induced sputum was elevated in asthma patients and subjects with atopy. Cilium protein levels in sputum were not related to spirometric tests results. Both CFAP36 and sentan concentrations were positively correlated with age. The level of sentan was associated with airway neutrophilic inflammation and active smoking status. CFAP36 concentration was negatively related to cell viability, whereas sentan level was positively related, but only in COPD patients. Conclusions: The results of our study revealed CFAP36 and sentan as possible new markers of epithelial damage of different origin in obstructive lung diseases.

Transcriptomic response of primary human airway epithelial cells to flavoring chemicals in electronic cigarettes

The widespread use of electronic cigarettes (e-cigarettes or e-cig) is a growing public health concern. Diacetyl and its chemical cousin 2,3-pentanedione are commonly used to add flavors to e-cig; however, little is known about how the flavoring chemicals may impair lung function. Here we report that the flavoring chemicals induce transcriptomic changes and perturb cilia function in the airway epithelium. Using RNA-Seq, we identified a total of 163 and 568 differentially expressed genes in primary normal human bronchial epithelial (NHBE) cells that were exposed to diacetyl and 2,3-pentanedione, respectively. DAVID pathway analysis revealed an enrichment of cellular pathways involved in cytoskeletal and cilia processes among the set of common genes (142 genes) perturbed by both diacetyl and 2,3-pentanedione. Consistent with this, qRT-PCR confirmed that the expression of multiple genes involved in cilia biogenesis was significantly downregulated by diacetyl and 2,3-pentanedione in NHBE cells. Furthermore, immunofluorescence staining showed that the number of ciliated cells was significantly decreased by the flavoring chemicals. Our study indicates that the two widely used e-cig flavoring chemicals impair the cilia function in airway epithelium and likely contribute to the adverse effects of e-cig in the lung.

Airway Epithelial Cell Cilia and Obstructive Lung Disease

Airway epithelium is the first line of defense against exposure of the airway and lung to various inflammatory stimuli. Ciliary beating of airway epithelial cells constitutes an important part of the mucociliary transport apparatus. To be effective in transporting secretions out of the lung, the mucociliary transport apparatus must exhibit a cohesive beating of all ciliated epithelial cells that line the upper and lower respiratory tract. Cilia function can be modulated by exposures to endogenous and exogenous factors and by the viscosity of the mucus lining the epithelium. Cilia function is impaired in lung diseases such as COPD and asthma, and pharmacologic agents can modulate cilia function and mucus viscosity. Cilia beating is reduced in COPD, however, more research is needed to determine the structural-functional regulation of ciliary beating via all signaling pathways and how this might relate to the initiation or progression of obstructive lung diseases. Additionally, genotypes and how these can influence phenotypes and epithelial cell cilia function and structure should be taken into consideration in future investigations.

Solubilizing agents in nasal formulations and their effect on ciliary beat frequency

The purpose of this study was to determine the concentration-dependent effect of selected solubilizers, used in common nasal drug formulations, on ciliary beat frequency (CBF) in human nasal epithelial cell cultures. CBF was measured by a high-speed digital imaging method. Excised ciliated human nasal epithelial cells were incubated for 60min with the solubilizers and determination of the half maximal inhibitory concentration (IC(50)), followed by a reversibility test. LDH test was performed on human nasal epithelial cells with the solubilizing agents. These were applied to nasal epithelial cells in IC(50) values. The following rank order in IC(50) values was obtained for the solubilizers: glycerol>propylene glycol>polyethylene glycol 300>N,N-dimethylacetamide>polyethylene glycol 400>ethanol>ethylendiamindihydrochloride>polyvinylpyrrolidon 25>polyvinylpyrrolidon 90. The highest reversibility of approximately 75% was shown by propylene glycol and polyethylene glycol 300 at a concentration of 30% (v/v). Results from the LDH test showed that N,N-dimethylacetamide displayed the highest cytotoxicity with 5.2% at a concentration of 14.5% (v/v). According to these results, several solubilizers can alter the CBF frequency and thus, have an impact on the nasal mucosa. Therefore, CBF studies with solubilizers used at a concentration relevant for nasal formulations are essential in the design of efficient and most notably safe nasal medicinal products.

Cilia motility and structure in primary and secondary ciliary dyskinesia

BACKGROUND

Primary ciliary dyskinesia (PCD) is a clinically uniform entity, although cilia motility and structure can vary among patients, making diagnosis difficult. Chronic sinusitis, bronchiectasis, sinus hypoplasia, secretory otitis media, and low fertility are common in PCD patients. The aim of this work was to correlate nasal ciliary activity with clinical and structural abnormalities in PCD. A secondary aim was to evaluate the usefulness of high-resolution digital high-speed video (DHSV) in the diagnosis of PCD.

METHODS

We analyzed nasal mucociliary transport and cilia ultrastructure by electron microscopy and studied nasal ciliary beat frequency (CBF) and beat pattern using high-resolution DHSV imaging in 34 healthy volunteers, 25 individuals with PCD (including 11 with Kartagener's syndrome [KS]with situs inversus), and 27 with secondary ciliary dyskinesia (SCD).

RESULTS

Nasal mucociliary transport was defective in the PCD and SCD patients. Ciliary immotility was observed in only six KS patients and was correlated with the absence of dynein. We observed a correlation between partial dynein deficiency and an uncoordinated, stiffly vibrating ciliary beat. Cilia activity and structure were normal in the SCD patients.

CONCLUSION

Nasal mucociliary transport showed a sensitivity of 100% for the diagnosis of PCD but has low specificity. High-resolution DHSV imaging has high sensitivity and specificity for the diagnosis of PCD. Video analysis is probably more useful than the study of mucociliary transport and cilia ultrastructure in screening for PCD. The absence of dynein was correlated with ciliary immotility and was more common in KS patients.

Beneficial effect of antibiotics on ciliary beat frequency of human nasal epithelial cells exposed to bacterial toxins

In the present study, we explored whether the cilio-inhibitory effect induced by toxins derived from bacterial infections could be compensated for by a cilio-stimulatory effect of antibiotics. Human nasal epithelial cells (HNEC) expressing beating cilia were grown as monolayers. Ciliary beat frequency (CBF) was determined using an inverted microscope coupled with a high-speed digital camera. Clarithromycin and neomycin did not influence ciliary activity. Bacitracin, clindamycin, gramicidin and roxithromycin increased CBF significantly: by 50 +/- 12%, 54 +/- 16%, 31 +/- 16% and 31 +/- 18%, respectively. A 30 min exposure to Staphylococcus aureus enterotoxin B (SEB) and Pseudomonas aeruginosa lipopolysaccharide (PAL) decreased CBF significantly, by 37 +/- 16 and 28 +/- 12%, respectively. In contrast with exposure to the toxin alone, co-incubation of the nasal monolayer cells with PAL and bacitracin or clindamycin did not result in a decrease in CBF after 30 and 60 min. The effect of SEB could be compensated for by bacitracin but not by clindamycin. After a 12 h preincubation period with SEB, co-incubation with either bacitracin or clindamycin resulted in the complete recovery of CBF. This study suggests that topical antibiotic treatment of nasal infections could result in a dual positive effect, namely treatment of the bacterial infection and recovery of ciliary activity.

Clinical and ultrastructural study after partial inferior turbinectomy

We report clinical and histological results obtained after partial inferior turbinectomy (PIT), surgery indicated for the treatment of chronic nasal obstruction.

Methods

Twenty patients were divided into two groups submitted to PIT plus septoplasty and PIT alone. The patients were reassessed clinically and histologically by means of a biopsy of the regenerated areas in the inferior turbinates at two different times after PIT, i.e., after 8 to 12 months (group A) and after two years (group B).

Results

The clinical results proved to be satisfactory for the relief of nasal obstruction in group A and unsatisfactory in group B. However, better histological results with better recovery and epithelial differentiation of the regenerated mucosa of the inferior turbinates after PIT were observed in group B.

Conclusion

Surgery proved to be effective on a short-term but not on a long-term basis, and histological recovery did not accompany improvement of clinical signs and symptoms.

Effect of preservatives on ciliary beat frequency in human nasal epithelial cell culture: single versus multiple exposure

As preservatives may impair mucociliary clearance, we wanted to systematically study their time-dependent effect on the ciliary beat frequency (CBF) in human nasal epithelial cells (HNEC). CBF was determined using a high-speed digital imaging method. Five preservatives were selected including benzalkonium chloride, phenylethyl alcohol, methylparaben, propylparaben and chlorbutol. We were interested in the effect of these preservatives on CBF after single and repetitive exposure. Methylparaben (0.0033%), propylparaben (0.0017%) and chlorbutol (0.005%) did not impair CBF, neither after a single short-term exposure period, nor after a single long-term exposure period. Long-term exposure to benzalkonium chloride (0.001%), phenylethyl alcohol (0.125%) and a combination of methyl- and propylparaben (0.0033 and 0.0017%) significantly decreased CBF. After a short-term exposure period, CBF recovered for phenylethyl alcohol and the combination of methyl- and propylparaben. Benzalkonium chloride decreased CBF non-reversibly. For two compounds, the effect on CBF was evaluated after repetitive exposure during 15min for 5 consecutive days. Benzalkonium chloride resulted in ciliostasis for all concentrations tested after 5 days. Phenylethyl alcohol revealed a concentration-dependent effect on CBF, but no ciliostasis was observed. In conclusion, methylparaben, propylparaben and chlorbutol can be considered as cilio-friendly. Repetitive exposure revealed a cumulative effect on CBF for benzalkonium chloride and phenylethyl alcohol.

Rotation frequency of human bronchial and nasal epithelial spheroids as an indicator of mucociliary function

BACKGROUND

We evaluated a new in vitro model for mucociliary transport function. Spheroids of human respiratory epithelium show beating cilia at their surface. When cultured in their own mucus, spheroids can rotate along their axis due to coordinated ciliary beating.

OBJECTIVE AND METHODS

To assess whether this setup yields meaningful results we measured rotation frequency (RF) of human bronchial or nasal epithelial spheroids under different temperatures and concentrations of isoproterenol. Isoproterenol was administered either as caged compound releasing active isoproterenol after illumination with UV light, or through a permeable membrane in a two-chamber system.

RESULTS

Under stable conditions, RF remained constant over 200 min. Between 27 and 35 degrees C, there was a temperature-dependent increase: RF(27)( degrees )(C) = 0.27 +/- 0.08 s(-1), and RF(37)( degrees )(C) = 0.43 +/- 0.10 s(-1) (means +/- SEM). Isoproterenol (10(-5), 10(-4) and 10(-3) mmol/l) induced concentration-dependent increases in RF (9, 20 and 25%, respectively; medians) if applied in the two-chamber system. The experiments with caged isoproterenol did not yield conclusive results, probably because the byproducts from photolysis negatively affected ciliary function. The transport velocity at the surface of bronchial and nasal spheroids was estimated to be 2.96 and 3.62 mm/min (medians), respectively, which is in the same range as mucus transport velocity measured in vivo in humans.

CONCLUSIONS

This setup can be used to study mucociliary transport function under controlled conditions in vitro, in particular as RF is likely to reflect not only ciliary beat frequency, but also the coordination of ciliary beating and the properties of the mucus.

Effect of hypo-, iso- and hypertonic saline irrigation on secretory mucins and morphology of cultured human nasal epithelial cells

CONCLUSION

We speculate that isotonic saline is the most physiological irrigation solution in terms of mucus secretion and the cellular morphology of nasal epithelial cells.

OBJECTIVE

To determine the most physiologic and effective saline concentration for nasal irrigation in terms of mucus secretion and cellular morphology by using normal human nasal epithelial cells treated with hypo-, iso- and hypertonic saline.

MATERIAL AND METHODS

Fully differentiated passage-2 normal human nasal epithelial cells were treated with pure water and with 0.3% (hypotonic), 0.9% (isotonic) and 3% (hypertonic) saline solutions. mRNA expression levels of MUC5AC and MUC5B, which are known to be major airway mucins, were analyzed after 30 min using reverse transcriptase polymerase chain reaction. Total mucin and MUC5AC and MUC5B mucin secretions were analyzed using dot-blotting. Cellular morphology was observed with light microscopy after hematoxylin-eosin staining and with scanning electron microscopy.

RESULTS

MUC5AC and MUC5B mRNA levels did not change after treatment with pure water and various concentrations of saline. Total mucin and MUC5AC mucin secretions only increased following pure water treatment, while MUC5B mucin secretion increased with pure water, hypo- and hypertonic saline treatment. Morphologic analysis revealed that pure water severely damaged normal human nasal epithelial cells and that only isotonic saline did not affect their morphology.

The use of human nasal in vitro cell systems during drug discovery and development

The nasal route is widely used for the administration of drugs for both topical and systemic action. At an early stage in drug discovery and during the development process, it is essential to gain a thorough insight of the nasal absorption potential, metabolism and toxicity of the active compound and the components of the drug formulation. Human nasal epithelial cell cultures may provide a reliable screening tool for pharmaco-toxicological assessment of potential nasal drug formulations. The aim of this review is to give an overview of the information relevant for the development of a human nasal epithelial cell culture model useful during drug discovery and development. A primary goal in the development of in vitro cell culture systems is to maintain differentiated morphology and biochemical features, resembling the original tissue as closely as possible. The potential and limitations of the existing in vitro human nasal models are summarized. The following topics related to cell culture methodology are discussed: (i) primary cultures versus cell lines; (ii) cell-support substrate; (iii) medium and medium supplements; and (iv) the air-liquid interface model versus liquid-liquid. Several considerations with respect to the use of in vitro systems for pharmaceutical applications (transport, metabolism, assessment of ciliary toxicity) are also discussed.

Alterations of nasal mucociliary clearance in association with HIV infection and the effect of guaifenesin therapy

OBJECTIVES

To determine if human immunodeficiency virus (HIV) infection is associated with a prolonged mucociliary clearance time (MCT) and to evaluate the effect of guaifenesin on MCT in HIV+ patients.

STUDY DESIGN

A cross-sectional study comparing HIV+ and HIV- volunteers followed by a prospective, randomized, double-blind, placebo-controlled study of HIV+ patients before and after guaifenesin treatment.

METHODS

Twenty-five HIV+ patients and 29 HIV- controls were enrolled and MCT was measured using the saccharin method. A separate group of 20 HIV+ patients participated in the second arm of the study and underwent saccharin testing before and after a 3-week course of guaifenesin or placebo. All study participants completed a medical history questionnaire, a sinonasal symptom (SNOT-16) survey, and were examined with both anterior rhinoscopy and rigid nasal endoscopy.

RESULTS

There was a significant difference (P < .002) in the MCT between the HIV+ group (13.3 +/- SD 7.5 minutes) and the HIV- controls (9.2 +/- SD 3.9 minutes). The difference in MCT between the guaifenesin and placebo groups did not reach statistical significance (P >.05). The HIV+ group had a higher SNOT-16 score compared to HIV- controls (21.1 vs. 7.4, P < .001). Guaifenesin therapy in HIV+ patients led to a significant improvement in the SNOT-16 score (P < .05).

CONCLUSIONS

Compared to HIV- controls, HIV+ patients have a prolonged MCT and more sinonasal symptoms as indicated by a higher SNOT-16 score. Guaifenesin therapy was associated with improved SNOT-16 scores, although there was not a detectable improvement in MCT. Use of guaifenesin in HIV+ patients with sinonasal disease may lead to improved patient perception of quality of life.

Stable ciliary activity in human nasal epithelial cells grown in a perfusion system

PURPOSE

Explore the usefulness of a perfusion system in order to establish human nasal epithelial cell cultures suitable for long-term in vitro ciliary beat frequency (CBF) and cilio-toxicity studies.

METHODS

The cells were obtained by protease digestion of nasal biopsy material. The cells were plated at a density of 0.8-1 x 10(6)/cm2 on Vitrogen-coated polyethylene terephthalate membranes, and cultured under submerged conditions in a CO2 incubator or in a perfusion system (initiated on days 8-9 after plating). The CBF was determined at 24.1 +/- 0.8 degrees C by a computerized microscope photometry system. The morphology of the cultured cells was characterized by transmission electron microscopy (TEM).

RESULTS

Under CO2 incubator culture conditions, stable ciliary activity was expressed and maintained from day 2 to day 24. Under perfusion system culture conditions, the CBF (mean+/-S.D., n = 4) amounted to 8.4 +/- 0.9 and 8.8 +/- 0.4 Hz on days 7 and 14, respectively. These values were lower as compared to the corresponding CBF obtained in the CO2 incubator cultures (9.5 +/- 0.6 and 9.9 +/- 1.0 Hz, respectively). Reference cilio-stimulatory (glycocholate) and cilio-inhibitory (chlorocresol) compounds were used to assess CBF reactivity. In the CO2 incubator and 7- and 14-days perfusion system cultures, glycocholate (0.5%) showed a reversible cilio-stimulatory effect of 23, 26 and 21%, respectively, while chlorocresol (0.005%) exerted a reversible cilio-inhibitory effect of 36, 40 and 36%, respectively. TEM revealed polarized cuboidal to columnar epithelial morphology, with well-differentiated ciliated cells under CO2 and perfusion system conditions (up to day 23).

CONCLUSION

Culturing human nasal epithelial cells on Vitrogen-coated polyethylene terephthalate membranes in submerged conditions in a CO2 incubator and in a perfusion system offers the possibility for long-term preservation (up to 22-24 days) of stable and reactive CBF in vitro.

Effects of surgery on the function of maxillary sinus mucosa

For chronic maxillary sinusitis, the most popular surgical approach for treatment is endoscopic sinus surgery (ESS). After these operations, however, it is not clear how well the surgery restores the normal mucociliary function. We examined the mucociliary clearance (MCC) in maxillary sinuses in chronic sinusitis before ESS and 6 months after the operations. The correlation of histology to MCC was also studied. Measurements of the mean residual mucociliary clearance (MCC) of maxillary sinuses was studied pre- and postoperatively with an isotope method. Biopsies taken during ESS and 6 months postoperatively were studied by electron microscopy (EM). Preoperative residual MCC from the maxillary sinuses was 77+/-26% (mean+/-SD). Six months postoperatively, residual MCC was 70+/-22%, only slightly better than preoperatively. Residual MCC was considered good (< or = 50%) in 12% of sinuses preoperatively and in 20% postoperatively. In preoperative sinuses, 14% did not show any mucociliary clearance compared to 11% postoperatively. As a single EM finding, metaplasia gave the poorest MCC (91%) and microvilli the best (68%). Mucociliary function in maxillary sinusitis remains poor even 6 months postoperatively, with many pathological findings still visible in the sinus epithelium. MCC correlates well with the histology of the mucosa. Surgery does not significantly improve the mucociliary function of sinus mucosa in chronic maxillary sinusitis.

The secondary nature of ciliary (dis)orientation in secondary and primary ciliary dyskinesia

OBJECTIVE

Ciliary orientation (COR) is an important parameter of mucociliary clearance and ciliary disorientation has been reported in cases of acquired abnormalities [secondary ciliary dyskinesia (SCD)] and in a very few cases as the single abnormality in primary ciliary dyskinesia (PCD). The etiology, pathogenesis, consequences and relevance of ciliary (dis)orientation are still unclear.

MATERIAL AND METHODS

To elucidate the primary or secondary nature of ciliary (dis)orientation, COR was measured in 179 non-PCD and 59 PCD patients. COR was measured in biopsies and after ciliogenesis in culture and was correlated with a number of functional and ultrastructural parameters. COR was defined as the SD of the angles of lines through the central pair of microtubules using transmission electron microscopy. Internationally accepted normal values for COR are < or = 20 degrees; COR values of 20-35 degrees indicate increased disorientation; and COR values > 35 degrees represent a random orientation.

RESULTS

For non-PCD biopsies, COR increased with increasing SCD, from 15 +/- 7 degrees (n = 54) for normal (< 5%) SCD to 28 +/- 8 degrees (n = 16) for severe (> 25%) SCD. No correlation was found between COR and ciliary beat frequency. However, increased COR values (28 +/- 8 degrees) were found for immotility (n = 8), compared to (coordinated) ciliary activity (19 +/- 9 degrees) (n = 121). After ciliogenesis no ultrastructural abnormalities were found and COR was normal (13 +/- 5 degrees; n = 308). COR can therefore be considered to be secondary in non-PCD and correlates with SCD percentage and ciliary motility. In biopsies from PCD patients with dynein deficiency and with normal ultrastructure, COR was increased, to 28 +/- 11 degrees (n = 32) and 21 +/- 7 degrees (n = 15), respectively, and in cases with central pair abnormalities COR was random (38 +/- 11 degrees; n = 12). After ciliogenesis COR remained random in the PCD group with central pair abnormalities (38 +/- 9 degrees; n = 15), and was increased in the PCD groups with dynein deficiency (24 +/- 10 degrees; n = 35) and normal ultrastructure (25 +/- 8 degrees; n = 17). Ciliary disorientation was never found as the single abnormality.

CONCLUSION

COR can be considered to be secondary in PCD. Both ciliary (im)motility and SCD percentage contribute to COR.

Head and neck manifestations of cystic fibrosis and ciliary dyskinesia

Cystic fibrosis and the various conditions associated with ciliary dysmotility are well known to the otolaryngologist. Although the underlying pathophysiology and clinical courses of these diseases are quite different, they both involve chronic and acute infection in the paranasal sinuses. Some patients may suffer from persistent ear disease beyond early childhood. A high index of suspicion and early diagnosis are key to managing these conditions. The otolaryngologist often is the first to suspect and confirm the diagnosis and may have an important role in the overall management of these patients.

Diagnostic evaluation of mucociliary transport: from symptoms to coordinated ciliary activity after ciliogenesis in culture

Mucociliary transport is one of the most important local defense mechanisms of the airways, but it is prone to many and frequent acquired abnormalities and to inherited abnormalities. These abnormalities result in basic physiologic disturbances leading to a number of respiratory symptoms and signs. In order to critically evaluate the diagnostic value of parameters of this mucociliary cascade, the results of ciliary investigations in over 500 individuals (controls, acquired, and inherited abnormalities) were reviewed. Ciliary beat frequency, ciliary coordination and ultrastructural abnormalities were measured and evaluated in biopsies and after ciliogenesis in culture. There is a considerable overlap for all investigated parameters in biopsy material of controls, secondary, and primary ciliary dyskinesia. There is not one parameter that is diagnostic for primary ciliary dyskinesia or can be used as an exclusion criterion. After ciliogenesis in culture, cilia are always completely normal except for the inherited abnormalities. Absence of coordinated ciliary activity after ciliogenesis in culture is 100% sensitive and specific for the diagnosis of primary ciliary dyskinesia.

Ciliary function analysis for the diagnosis of primary ciliary dyskinesia: advantages of ciliogenesis in culture

The gold standard for the diagnosis of primary ciliary dyskinesia (PCD) is a dynein deficiency shown with transmission electron microscopy. However, there are many cases of PCD without dynein deficiency. When considering ciliary function, there are similar problems of sensitivity in diagnosis and there is also a major lack of specificity. Based on the normal ciliary function and ultrastructure and the absence of secondary abnormalities after ciliogenesis in sequential monolayer-suspension culture, the diagnostic value of ciliary function analysis after ciliogenesis was investigated in more than 70 PCD and 640 non-PCD cases. In biopsies, ciliary immotility was found in 66% of PCD cases but was also found in 8% of non-PCD cases. PCD was later confirmed in 61% of the biopsies with ciliary immotility. Normal ciliary beat frequency (CBF) was found in 20% of PCD biopsies. Coordinated ciliary activity was observed in 10% of PCD cases. After ciliogenesis in culture, ciliary immotility was present in 78% of the PCD cases but never in non-PCD cases. CBF was normal after ciliogenesis in 7% of the PCD cases and was always found in non-PCD cases. Absence of coordinated ciliary activity was found in 100% of PCD cases and 0% of non-PCD cases. In conclusion, while ciliary function analysis in a biopsy never proves, nor excludes the diagnosis of PCD, after ciliogenesis in culture CBF measurement can be diagnostic for PCD and reaches 100% specificity and sensitivity when considering coordinated ciliary activity, making it the single 100% diagnostic parameter for PCD.