S88 Neutrophil elastase increases ciliary beat frequency ex-vivo: implications for the bronchiectasis airway

Mucociliary transport is one of the most important defense mechanisms of the airway. Mucociliary transport time or rate, as measured using the saccharin test or the radioisotope technique, respectively, is clinically the most relevant parameter, although subject to large intra- and interindividual variability. There is no correlation between mucociliary transport in vivo and ciliary beat frequency ex vivo. Preliminary evidence demonstrates that mucociliary transport correlates with ciliary structure and orientation as investigated with transmission and scanning electron microscopy. A correlation is presented between ciliary beat frequency and secondary ciliary abnormalities. This correlation can best be described according to the logistic sigmoid model (r = 0.69). Based on these functional data, an ultrastructural distinction is proposed among normal (less than 5%), light (5 to 15%), moderate (15 to 25%), and severe (more than 25%) secondary ciliary dyskinesia.

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The effects of sildenafil on ciliary beat frequency in patients with pulmonary non-tuberculous mycobacteria disease: phase I/II trial

BMJ Open Respiratory Research ◽

10.1136/bmjresp-2020-000574 ◽

2020 ◽

Vol 7 (1) ◽

pp. e000574

Author(s):

Cedar Fowler ◽

Un-In Wu ◽

Robyn Shaffer ◽

Caroline Smith ◽

Lisa Barnhart ◽

...

Keyword(s):

Mucociliary Clearance ◽

Ex Vivo ◽

Beat Frequency ◽

Phosphodiesterase Inhibitors ◽

Ciliary Beat Frequency ◽

Cyclic Guanosine Monophosphate ◽

Guanosine Monophosphate ◽

Open Label ◽

Sputum Production ◽

Ciliary Beat

RationalePulmonary non-tuberculous mycobacterial (PNTM) disease has increased over the past several decades, especially in older women. Abnormal mucociliary clearance and abnormal nasal nitric oxide (nNO) have been associated with PNTM disease in other patient cohorts. Mucociliary clearance can be affected by NO-cyclic guanosine monophosphate signalling and, therefore, modulation of the pathway may be possible with phosphodiesterase inhibitors such as sildenafil as a novel therapeutic approach.ObjectiveTo define ex vivo characteristics of PNTM disease affected by sildenafil.MethodsSubjects with PNTM infections were recruited into an open-label dose-escalation trial of sildenafil. Laboratory measurements and mucociliary measurements—ciliary beat frequency, nNO and 24-hour sputum production—were collected throughout the study period. Patients received sildenafil daily during the study period, with escalation from 20 to 40 mg three times per day.Measurements and main resultsIncreased ciliary beat frequency occurred after a single dose of 40 mg sildenafil and after extended dosing of 40 mg sildenafil. The increase ciliary beat frequency was not seen with 20 mg sildenafil dosing. There were no changes in sputum production, nNO production, Quality of Life-Bronchiectasis-NTM module (QOL-B-NTM) questionnaire or the St George’s Respiratory Questionnaire during the study period.ConclusionSildenafil, 40 mg, increased ciliary beat frequency acutely as well as with extended administration.

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Comparison of ciliary beat frequencies at different temperatures in young adults

ERJ Open Research ◽

10.1183/23120541.00477-2020 ◽

2020 ◽

Vol 6 (4) ◽

pp. 00477-2020

Author(s):

Wilfried Nikolaizik ◽

Jana Hahn ◽

Monika Bauck ◽

Stefanie Weber

Keyword(s):

Young Adults ◽

High Speed ◽

Ex Vivo ◽

Beat Frequency ◽

Test Procedure ◽

Ciliary Beat Frequency ◽

Normative Values ◽

Significant Difference ◽

Different Temperatures ◽

Ciliary Beat

RationaleDirect visualisation of ciliary beat pattern (CBP) and ciliary beat frequency (CBF) has been recommended as the first-line diagnostic test in patients suspected of having primary ciliary dyskinesia (PCD). However, the test procedure is not yet completely standardised, and centres measure the CBF at different temperatures.ObjectivesIt was the aim of the study to compare CBF at different temperatures, to establish normative values, to check for age dependency and to measure the temperature on the nasal mucosa of the participants.MethodsHigh-speed video-microscopy analysis with a Sisson-Ammons Video Analysis (SAVA) system was used to determine CBP and CBF in the participants.MeasurementsNasal brushings were taken and CBF was measured in randomised order at three temperatures: 25°C, 32°C and 37°C.Main resultsIn total, 100 healthy young adults (74 female, 26 male), aged 20.2–31.9 years, were included in the study. We found a highly significant difference among the groups: the median CBF was 7.0 Hz at 25°C, 7.6 Hz at 32°C and 8.0 Hz at 37°C. The maximum time period ex vivo was 65 min and did not differ significantly. However, CBF was significantly higher when the cilia were kept at a higher temperature before the measurements were made. We found no correlation between CBF and the age of the participants. The median nasal mucosal temperature in our study participants was 30.2°C (range 24.7–35.8°C) comparable to the 30.2–34.4°C described in the literature.ConclusionsThe most appropriate temperature at which to measure CBF is 32°C. In our study, with 95% confidence for this temperature the CBF was between 6.3 and 9.0 Hz.

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Relative Roles of Pneumolysin and Hydrogen Peroxide from Streptococcus pneumoniae in Inhibition of Ependymal Ciliary Beat Frequency

Infection and Immunity ◽

10.1128/iai.68.3.1557-1562.2000 ◽

2000 ◽

Vol 68 (3) ◽

pp. 1557-1562 ◽

Cited By ~ 64

Author(s):

Robert A. Hirst ◽

Kulvinder S. Sikand ◽

Andrew Rutman ◽

Timothy J. Mitchell ◽

Peter W. Andrew ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Hemolytic Activity ◽

Ex Vivo ◽

Beat Frequency ◽

Brain Slices ◽

Ciliary Beat Frequency ◽

Ependymal Cells ◽

Ex Vivo Model ◽

The Brain ◽

Ciliary Beat

ABSTRACT Ciliated ependymal cells line the ventricular system of the brain and the cerebral aqueducts. This study characterizes the relative roles of pneumolysin and hydrogen peroxide (H2O2) in pneumococcal meningitis, using the in vitro ependymal ciliary beat frequency (CBF) as an indicator of toxicity. We have developed an ex vivo model to examine the ependymal surface of the brain slices cut from the fourth ventricle. The ependymal cells had cilia beating at a frequency of between 38 and 44Hz. D39 (wild-type) and PLN-A (pneumolysin-negative) pneumococci at 108 CFU/ml both caused ciliary slowing. Catalase protected against PLN-A-induced ciliary slowing but afforded little protection from D39. Lysed PLN-A did not reduce CBF, whereas lysed D39 caused rapid ciliary stasis. There was no effect of catalase, penicillin, or catalase plus penicillin on the CBF. H2O2 at a concentration as low as 100 μM caused ciliary stasis, and this effect was abolished by coincubation with catalase. An additive inhibition of CBF was demonstrated using a combination of both toxins. A significant inhibition of CBF at between 30 and 120 min was demonstrated with both toxins compared with either H2O2 (10 μM) or pneumolysin (1 HU/ml) alone. D39 released equivalent levels of H2O2 to those released by PLN-A, and these concentrations were sufficient to cause ciliary stasis. The brain slices did not produce H2O2, and in the presence of 108 CFU of D39 or PLN-A per ml there was no detectable bacterially induced increase of H2O2release from the brain slice. Coincubation with catalase converted the H2O2 produced by the pneumococci to H2O. Penicillin-induced lysis of bacteria dramatically reduced H2O2 production. The hemolytic activity released from D39 was sufficient to cause rapid ciliary stasis, and there was no detectable release of hemolytic activity from the pneumolysin-negative PLN-A. These data demonstrate that D39 bacteria released pneumolysin, which caused rapid ciliary stasis. D39 also released H2O2, which contributed to the toxicity, but this was masked by the more severe effects of pneumolysin. H2O2 released from intact PLN-A was sufficient to cause rapid ciliary stasis, and catalase protected against H2O2-induced cell toxicity, indicating a role for H2O2 in the response. There is also a slight additive effect of pneumolysin and H2O2 on ependymal toxicity; however, the precise mechanism of action and the role of these toxins in pathogenesis remain unclear.

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Differential effect of anesthetics on mucociliary clearance in vivo in mice

Scientific Reports ◽

10.1038/s41598-021-84605-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Kyle S. Feldman ◽

Eunwon Kim ◽

Michael J. Czachowski ◽

Yijen Wu ◽

Cecilia W. Lo ◽

...

Keyword(s):

Mucociliary Clearance ◽

Defense Mechanism ◽

Ex Vivo ◽

Beat Frequency ◽

Ciliary Beat Frequency ◽

Wild Type ◽

Sulfur Colloid ◽

Ct System

AbstractRespiratory mucociliary clearance (MCC) is a key defense mechanism that functions to entrap and transport inhaled pollutants, particulates, and pathogens away from the lungs. Previous work has identified a number of anesthetics to have cilia depressive effects in vitro. Wild-type C57BL/6 J mice received intra-tracheal installation of 99mTc-Sulfur colloid, and were imaged using a dual-modality SPECT/CT system at 0 and 6 h to measure baseline MCC (n = 8). Mice were challenged for one hour with inhalational 1.5% isoflurane, or intraperitoneal ketamine (100 mg/kg)/xylazine (20 mg/kg), ketamine (0.5 mg/kg)/dexmedetomidine (50 mg/kg), fentanyl (0.2 mg/kg)/1.5% isoflurane, propofol (120 mg/Kg), or fentanyl/midazolam/dexmedetomidine (0.025 mg/kg/2.5 mg/kg/0.25 mg/kg) prior to MCC assessment. The baseline MCC was 6.4%, and was significantly reduced to 3.7% (p = 0.04) and 3.0% (p = 0.01) by ketamine/xylazine and ketamine/dexmedetomidine challenge respectively. Importantly, combinations of drugs containing fentanyl, and propofol in isolation did not significantly depress MCC. Although no change in cilia length or percent ciliation was expected, we tried to correlate ex-vivo tracheal cilia ciliary beat frequency and cilia-generated flow velocities with MCC and found no correlation. Our results indicate that anesthetics containing ketamine (ketamine/xylazine and ketamine/dexmedetomidine) significantly depress MCC, while combinations containing fentanyl (fentanyl/isoflurane, fentanyl/midazolam/dexmedetomidine) and propofol do not. Our method for assessing MCC is reproducible and has utility for studying the effects of other drug combinations.

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