Do Causes Influence Functional Aspects and Quality of Life in Patients with Nonfibrocystic Bronchiectasis?

Background

The denomination of noncystic fibrosis bronchiectasis (NCFB) includes several causes, and differences may be expected between the patient subgroups regarding age, comorbidities, and clinical and functional evolution. This study sought to identify the main causes of NCFB in a cohort of stable adult patients and to investigate whether such conditions would be different in their clinical, functional, and quality of life aspects.

Methods

Between 2017 and 2019, all active patients with NCFB were prospectively evaluated searching for clinical data, past medical history, dyspnea severity grading, quality of life data, microbiological profile, and lung function (spirometry and six-minute walk test).

Results

There was a female predominance; mean age was 54.7 years. Causes were identified in 82% of the patients, the most frequent being postinfections (n = 39), ciliary dyskinesia (CD) (n = 32), and chronic obstructive pulmonary disease (COPD) (n = 29). COPD patients were older, more often smokers (or former smokers) and with more comorbidities; they also had worse lung function (spirometry and oxygenation) and showed worse performance in the six-minute walk test (6MWT) (walked distance and exercise-induced hypoxemia). Considering the degree of dyspnea, in the more symptomatic group, patients had higher scores in the three domains and total score in SGRQ, besides having more exacerbations and more patients in home oxygen therapy.

Conclusions

Causes most identified were postinfections, CD, and COPD. Patients with COPD are older and have worse pulmonary function and more comorbidities. The most symptomatic patients are clinically and functionally more severe, besides having worse quality of life.

Axonemal structures reveal mechanoregulatory and disease mechanisms

Motile cilia and flagella beat rhythmically on the surface of cells to power the flow of fluid and to enable spermatozoa and unicellular eukaryotes to swim. In humans, defective ciliary motility can lead to male infertility and a congenital disorder called primary ciliary dyskinesia (PCD), in which impaired clearance of mucus by the cilia causes chronic respiratory infections1. Ciliary movement is generated by the axoneme, a molecular machine consisting of microtubules, ATP-powered dynein motors and regulatory complexes2. The size and complexity of the axoneme has so far prevented the development of an atomic model, hindering efforts to understand how it functions. Here we capitalize on recent developments in artificial intelligence-enabled structure prediction and cryo-electron microscopy (cryo-EM) to determine the structure of the 96-nm modular repeats of axonemes from the flagella of the alga Chlamydomonas reinhardtii and human respiratory cilia. Our atomic models provide insights into the conservation and specialization of axonemes, the interconnectivity between dyneins and their regulators, and the mechanisms that maintain axonemal periodicity. Correlated conformational changes in mechanoregulatory complexes with their associated axonemal dynein motors provide a mechanism for the long-hypothesized mechanotransduction pathway to regulate ciliary motility. Structures of respiratory-cilia doublet microtubules from four individuals with PCD reveal how the loss of individual docking factors can selectively eradicate periodically repeating structures.

Zebrafish Motile Cilia as a Model for Primary Ciliary Dyskinesia

Zebrafish is a vertebrate teleost widely used in many areas of research. As embryos, they develop quickly and provide unique opportunities for research studies owing to their transparency for at least 48 h post fertilization. Zebrafish have many ciliated organs that include primary cilia as well as motile cilia. Using zebrafish as an animal model helps to better understand human diseases such as Primary Ciliary Dyskinesia (PCD), an autosomal recessive disorder that affects cilia motility, currently associated with more than 50 genes. The aim of this study was to validate zebrafish motile cilia, both in mono and multiciliated cells, as organelles for PCD research. For this purpose, we obtained systematic high-resolution data in both the olfactory pit (OP) and the left-right organizer (LRO), a superficial organ and a deep organ embedded in the tail of the embryo, respectively. For the analysis of their axonemal ciliary structure, we used conventional transmission electron microscopy (TEM) and electron tomography (ET). We characterised the wild-type OP cilia and showed, for the first time in zebrafish, the presence of motile cilia (9 + 2) in the periphery of the pit and the presence of immotile cilia (still 9 + 2), with absent outer dynein arms, in the centre of the pit. In addition, we reported that a central pair of microtubules in the LRO motile cilia is common in zebrafish, contrary to mouse embryos, but it is not observed in all LRO cilia from the same embryo. We further showed that the outer dynein arms of the microtubular doublet of both the OP and LRO cilia are structurally similar in dimensions to the human respiratory cilia at the resolution of TEM and ET. We conclude that zebrafish is a good model organism for PCD research but investigators need to be aware of the specific physical differences to correctly interpret their results.

A Young Girl With Bronchiectasis and Elevated Sweat Chloride

CASE PRESENTATION

A 14-year old girl presented with history of productive cough since the age of 3 years. For the past 6 years, she complained of chest tightness and wheezing. There was also nasal stuffiness and discharge for the past 6 years. She denied history of hemoptysis, ear discharge, or chest pain. There was no history of respiratory distress at the time of birth. Her brother also suffered from productive cough and wheezing since the age of 3 years. However, both her parents were asymptomatic.

Clinical and Genetic Spectrum of Children with Primary Ciliary Dyskinesia in China

OBJECTIVE

To report detailed knowledge about the clinical manifestations, ciliary phenotypes, genetic spectrum as well as phenotype/genotype correlation in primary ciliary dyskinesia (PCD) in Chinese children.

STUDY DESIGN

We recruited 50 Chinese children with PCD. Extensive clinical assessments, nasal nitric oxide, high-speed video analysis, transmission electron microscopy, and genetic testing were performed to characterize the phenotypes and genotypes of these patients.

RESULTS

Common clinical features included chronic wet cough (85.4%), laterality defects (70.0%), and neonatal respiratory distress (55.8%). A high prevalence of congenital abnormalities (30.2%, 13/43), observed in patients who underwent comprehensive examination for comorbidities, included thoracic deformity (11.6%, 5/43), congenital heart disease (9.3%, 4/43), and sensorineural deafness (2.3%, 1/43). For 24 children age >6 years, the mean predicted values of forced expiratory volume in 1 second were 87.2%. Bronchiectasis evident on high-resolution computed tomography was reported in 38.1% of patients (16/42). Biallelic mutations (81 total; 57 novel) were identified in 13 genes: DNAAF3, DNAAF1, DNAH5, DNAH11, CCDC39, CCDC40, CCDC114, CCDC103, HYDIN, CCNO, DNAI1, OFD1, and SPAG1. Overall, ciliary ultrastructural and beat pattern correlated well with the genotype. However, variable phenotypes were also observed in CCDC39 and DNAH5 mutant cilia.

CONCLUSIONS

This large PCD cohort in China broadens the clinical, ciliary phenotypes, and genetic characteristics of children with PCD. Our findings are roughly consistent with previous studies besides some peculiarities such as high prevalence of associated abnormalities.

Translation of the quality-of-life measure for adults with primary ciliary dyskinesia and its application in patients in Brazil

Primary ciliary dyskinesia (PCD) is a genetic disorder that is typically inherited in an autosomal recessive manner. It is clinically characterized by recurrent respiratory infections. However, its repercussions for patient quality of life should not be overlooked. Studies have shown that PCD has a significant impact on the lives of patients, although there are as yet no PCD-specific markers of quality of life. To address that problem, researchers in the United Kingdom developed a quality-of-life questionnaire for patients with PCD. The present communication focuses on the process of translating that questionnaire into Brazilian Portuguese, through a partnership between researchers in Brazil and those in the United Kingdom, as well as its subsequent application in patients in Brazil.

Proof of Concept: Very Rapid Tidal Breathing Nasal Nitric Oxide Sampling Discriminates Primary Ciliary Dyskinesia from Healthy Subjects

INTRODUCTION

Nasal nitric oxide (nNO) is extremely low in individuals with primary ciliary dyskinesia (PCD) and is recommended as part of early workup. We investigated whether tidal breathing sampling for a few seconds was as discriminative between PCD and healthy controls (HC) as conventional tidal breathing sampling (cTB-nNO) for 20-30 s.

METHODS

We performed very rapid sampling of tidal breathing (vrTB-nNO) for 2, 4 and 6 s, respectively. Vacuum sampling with applied negative pressure (vrTB-nNO_vac; negative pressure was applied by pinching the sampling tube) for < 2 s resulted in enhanced suction of nasal air during measurement. Feasibility, success rate, discriminatory capacity, repeatability and agreement were assessed for all four sampling modalities.

RESULTS

We included 13 patients with PCD, median (IQR) age of 21.8 (12.2-27.7) years and 17 HC, 25.3 (14.5-33.4) years. Measurements were highly feasible (96.7% success rate). Measured NO values with vrTB-nNO modalities differed significantly from TB-nNO measurements (HC: p < 0.001, PCD: p < 0.05). All modalities showed excellent discrimination. The vacuum method gave remarkably high values of nNO in both groups (1865 vs. 86 ppb), but retained excellent discrimination. vrTB-nNO_4sec, vrTB-nNO_6sec and vrTB-nNO_vac showed identical specificity to cTB-nNO (all: 1.0, 95% CI 0.77-1.0).

CONCLUSION

vrTB-nNO sampling requires only a few seconds of probe-in-nose time, is feasible, and provides excellent discrimination between PCD and HC. Rapid TB-nNO sampling needs standardisation and further investigations in infants, young children and patients referred for PCD workup.

The effect of l-Arginine on Ciliary Beat Frequency in PCD patients, non-PCD respiratory patients and healthy controls

OBJECTIVES

Few studies have examined the potentially therapeutic effect of increasing the production of endogenous nitric oxide (NO) in Primary Ciliary Dyskinesia (PCD) and other chronic respiratory conditions. Nasal NO is low in PCD and has been found to correlate with compromised Ciliary Beat Frequency (CBF). In this study we assessed the effect of increasing l-Arginine, as the substrate of NO synthases, on CBF in biopsies of human respiratory ciliated epithelium.

METHODOLOGY

A total of 28 suspect cases with chronic respiratory manifestations referred for PCD diagnostic testing and 8 healthy controls underwent nasal brushing. Obtained epithelial cells were divided between three culture medium 199 solutions, containing different levels of l-Arginine (0.33 mM as baseline, 1 mM and 10 Mm as increased levels). CBF measurements were obtained at 37 °C and 25 °C at 1, 3 and 24 h after sample acquisition.

RESULTS

Among a total of 36 recruited subjects, 8 had PCD confirmed (PCD n = 8), 20 had PCD excluded (non-PCD n = 20) and 8 were healthy controls (Healthy Controls = 8). Among PCD subjects, ciliary motility was characterized by rotational (n = 5) or dyskinetic (n = 3) beating. At 37 °C, compared to baseline, higher levels of l-Arginine resulted in up to 9% CBF increase at 1 h (p = 0.007), up to 9% CBF increase at 3 h (p < 0.001) and up to 12% CBF increase at 24 h (p = 0.002). Similar although smaller scale increases were recorded at 25 °C. The effect of l-Arginine was time dependent (interaction p = 0.002) and was similar in PCD patients, non-PCD chronic respiratory patients and healthy controls (interaction p = 0.800).

CONCLUSIONS

l-Arginine increases CBF and merits to be evaluated as a potential stimulator of mucociliary clearance in chronic respiratory conditions and congenital ciliary disorders with residual motility. Larger human studies are needed to confirm these findings.

Diagnosis and management of children with primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is a rare, genetic disorder of the motile cilia characterised by chronic lung disease, nasal and sinus disease, chronic ear infections with glue ear leading to possible hearing impairment, and subfertility. Half of patients have organ laterality defects. Despite symptoms being present from birth, PCD remains underdiagnosed. Early diagnosis and symptom management may reduce morbidity, improve quality of life and ensure children are adequately supported to meet their full potential. This article seeks to raise awareness of PCD in children's nurses who are well placed to identify children for referral to the national PCD diagnostic service. It examines the clinical characteristics of the disease along with the complexities and limitations of diagnostic testing. In addition, it explores the management of children with PCD within the national PCD management service for children.

[Prenatal diagnosis of Meckel-Gruber syndrome. Case report and literature review]

BACKGROUND

Meckel-Gruber syndrome is a ciliopathy, a lethal autosomal recessive disorder that occurs in all races and ethnicities; it is characterized by central nervous system abnormalities, resulting in mental retardation, bilateral renal cystic dysplasia and malformations of hands and feet. To date there have been only about 200 cases reported worldwide. It is a disease with a recurrence rate of 25% whose most reliable method for diagnosis is prenatal ultrasound. The mortality rate is 100% and in view of the high index of recurrence, subsequent pregnancies should be investigated appropriately with genetic counseling.

CLINIC CASE

We present the case of a 15 years-old mother with 30.2 weeks pregnancy resulting from rape by consanguinity (grandfather), without prenatal care. On admission HD ultrasound study is performed finding fetus fetometria average 26.2 weeks (for discordant fetometria head circumference 187.5 mm to 21.0 weeks gestation -3DE-) lost in the skull shape of the shell line is observed winding mean; not cut down, cavum septum pellucidum or herniated sac cerebellum and occipital level (encephalocele) are evident. It starts cervical ripening with prostaglandins for 24 hours to conduct further labor with oxytocic and delivery care where a fetus death, female, 1516 g is obtained. Fetal autopsy family is authorized; however, it not has done because it is legal and only medical geneticist obtains medical case assessment.

CONCLUSIONS

The Meckel-Gruber syndrome is a very rare condition that occurs in cases of consanguinity occasions. Mortality occurs in 100% of cases, so you should talk to parents and explain the best maternal prognosis, with abortion in the early stages and subsequent genetic counseling.

[The functional conditions of nasal cavity mucosa and paranasal sinuses following radical and minimally invasive surgical interventions]

The data of the literature are presented concerning the state of the mucous membrane of the nasal cavity, nasal turbinates, and maxillary sinus during the postoperative period following various surgical procedures.

[HIGH INCIDENCE AND BROAD GENETIC VARIABILITY OF MECKEL-GRUBER SYNDROME IN THE ARAB POPULATION RESIDING IN NORTH-EAST ISRAEL]

BACKGROUND

Meckel-Gruber syndrome (MKS) is a lethal rare inherited autosomal recessive disease. The syndrome is characterized by multiple congenital anomalies including polycystic kidneys, occipital encephalocele and polydactyly. The presence of two out of these anomalies is sufficient for a definitive diagnosis. At least 11 genes have been reported to-date to underlie MKS.

METHODS

In the current study we have retrospectively analyzed all the families at the Ha'Emek Medical Center in which the diagnosis of MKS was determined.

RESULTS

In total, 17 affected individuals are reported, originating from 12 sibships. The diagnoses were conducted or suspected by prenatal sonography, and some of the newborns were examined. Polycystic kidneys were present in 94% of cases, occipital encephalocele in 82% and polydactyly in about half of all cases. The underlying genetic cause was identified in 11 of our families, comprising mutations in 7 different genes, revealing high genetic heterogeneity.

CONCLUSION

The identification of the genetic basis of MKS in our region allows focused and data-based genetic counseling and serves as an important tool for reproductive decisions, including the prevention of recurrence of pregnancies affected with this lethal syndrome. In the near future we plan to study the prevalence of the different MKS mutations found in each community in order to consider the expansion of national genetic screening in high risk populations.

Cilia dysfunction in lung disease

A characteristic feature of the human airway epithelium is the presence of ciliated cells bearing motile cilia, specialized cell surface projections containing axonemes composed of microtubules and dynein arms, which provide ATP-driven motility. In the airways, cilia function in concert with airway mucus to mediate the critical function of mucociliary clearance, cleansing the airways of inhaled particles and pathogens. The prototypical disorder of respiratory cilia is primary ciliary dyskinesia, an inherited disorder that leads to impaired mucociliary clearance, to repeated chest infections, and to the progressive destruction of lung architecture. Numerous acquired lung diseases are also marked by abnormalities in both cilia structure and function. In this review we summarize current knowledge regarding airway ciliated cells and cilia, how they function to maintain a healthy epithelium, and how disorders of cilia structure and function contribute to inherited and acquired lung disease.

Educational paper: ciliopathies

Cilia are antenna-like organelles found on the surface of most cells. They transduce molecular signals and facilitate interactions between cells and their environment. Ciliary dysfunction has been shown to underlie a broad range of overlapping, clinically and genetically heterogeneous phenotypes, collectively termed ciliopathies. Literally, all organs can be affected. Frequent cilia-related manifestations are (poly)cystic kidney disease, retinal degeneration, situs inversus, cardiac defects, polydactyly, other skeletal abnormalities, and defects of the central and peripheral nervous system, occurring either isolated or as part of syndromes. Characterization of ciliopathies and the decisive role of primary cilia in signal transduction and cell division provides novel insights into tumorigenesis, mental retardation, and other common causes of morbidity and mortality, including diabetes mellitus and obesity. New technologies ("Next generation sequencing/NGS") have considerably improved genetic research and diagnostics by allowing simultaneous investigation of all disease genes at reduced costs and lower turn-around times. This is undoubtedly a result of the dynamic development in the field of human genetics and deserves increased attention in genetic counselling and the management of affected families.

Ciliary dysfunction and ultrastructural abnormalities are features of severe asthma

BACKGROUND

Epithelial dysfunction has been implicated in asthma pathophysiology, but no studies have directly assessed ciliary function in asthma.

OBJECTIVE

To study the ciliary function and epithelial ultrastructure of patients with asthma and healthy controls.

METHODS

We studied ciliary beat frequency and beat pattern by using digital high-speed video imaging and ultrastructure by transmission electron microscopy of bronchial epithelial strips from 7 subjects with mild, 7 with moderate, and 19 with severe asthma and 9 healthy controls.

RESULTS

The median (interquartile range) ciliary beat frequency was decreased in moderate (6.5 [4.4-8.5] Hz) and severe asthma (6.7 [6.1-7.6] Hz) compared with controls (10.5 [9.7-11.8] Hz; P < .01). Dyskinesia and immotility indices were higher in severe asthma (65% [43%-75%]; 6.3% [1%-9.5%], respectively) compared with controls (4% [0%-6.7%; 0%, respectively; P < .01). These abnormalities were related to disease severity (ciliary beat frequency, r(s) = -0.68; dyskinesia index, r(s) = 0.86; immotility index, r(s) = 0.65; P < .0001). The ultrastructure of the epithelium was abnormal in severe asthma with a reduction in ciliated cells, an increase in dead cells, and ciliary disorientation compared with all other groups (P < .05). Compared with patients with mild asthma and healthy controls, patients with severe asthma showed increased ciliary depletion, microtubular defects, mitochondrial damage, and cytoplasmic blebbing (P < .01). All of these changes were related to disease severity.

CONCLUSION

Ciliary dysfunction and ultrastructural abnormalities are closely related to asthma severity. Ciliary dysfunction is a feature of moderate to severe asthma, and profound ultrastructural abnormalities are restricted to severe disease. Whether these changes contribute to the development of severe asthma phenotype remains to be determined.

Tubulin tyrosine ligase-like 1 deficiency results in chronic rhinosinusitis and abnormal development of spermatid flagella in mice

Tubulin tyrosine ligase-like 1 (TTLL1) protein is a member of the tubulin tyrosine ligase superfamily of proteins that are involved in the posttranslational polyglutamylation of tubulin in axonemal microtubules within cilia and flagella. To investigate the physiological role of TTLL1, the authors generated mice with a gene trap mutation in the Ttll1 gene that provide confirmation in a mammalian model that polyglutamylation plays an important role in some ciliary and flagellar functions. For the first time, mice homozygous for the Ttll1 mutation exhibited accumulations of exudates in the nasal passages and sinuses, rhinosinusitis, otitis media, and male infertility. In homozygous mutant male mice, abnormal sperm morphology and function were characterized by shortened or absent flagella and immotility. Although homozygous mutant males were infertile, the females were fertile. These findings are consistent with a diagnosis of primary ciliary dyskinesia (PCD) resulting from ciliary dysfunction. They indicate that Ttll1 is essential for normal motility of respiratory cilia and the biogenesis and function of sperm flagella but that the defect does not result in the hydrocephalus or laterality defects often seen in other forms of PCD. The absence of early-onset lethal hydrocephalus in Ttll1-mutant mice may enable studies to evaluate the long-term effects of PCD in the respiratory system of mice. Although no mutations in the orthologous gene have been linked with PCD in humans, investigating the role of TTLL1 and polyglutamylation of tubulin in cilia and flagella should advance an understanding of the biogenesis and function of these organelles in mammals and have potential diagnostic and therapeutic applications.

Liver and kidney disease in ciliopathies

Hepatorenal fibrocystic diseases (HRFCDs) are among the most common inherited human disorders. The discovery that proteins defective in the autosomal dominant and recessive polycystic kidney diseases (ADPKD and ARPKD) localize to the primary cilia and the recognition of the role these organelles play in the pathogenesis of HRFCDs led to the term "ciliopathies." While ADPKD and ARPKD are the most common ciliopathies associated with both liver and kidney disease, variable degrees of renal and/or hepatic involvement occur in many other ciliopathies, including Joubert, Bardet-Biedl, Meckel-Gruber, and oral-facial-digital syndromes. The ductal plate malformation (DPM), a developmental abnormality of the portobiliary system, is the basis of the liver disease in ciliopathies that manifest congenital hepatic fibrosis (CHF), Caroli syndrome (CS), and polycystic liver disease (PLD). Hepatocellular function remains relatively preserved in ciliopathy-associated liver diseases. The major morbidity associated with CHF is portal hypertension (PH), often leading to esophageal varices and hypersplenism. In addition, CD predisposes to recurrent cholangitis. PLD is not typically associated with PH, but may result in complications due to mass effects. The kidney pathology in ciliopathies ranges from non-functional cystic dysplastic kidneys to an isolated urinary concentration defect; the disorders contributing to this pathology, in addition to ADPKD and ARPKD, include nephronophithisis (NPHP), glomerulocystic kidney disease and medullary sponge kidneys. Decreased urinary concentration ability, resulting in polyuria and polydypsia, is the first and most common renal symptom in ciliopathies. While the majority of ADPKD, ARPKD, and NPHP patients require renal transplantation, the frequency and rate of progression to renal failure varies considerably in other ciliopathies. This review focuses on the kidney and liver disease found in the different ciliopathies.

[Mucociliary transport and motility of the ciliary system of the nasal mucosa in patients with chronic polypous rhinosinusitis]

A transport function and motor activity of the ciliary system (MACS) of the nasal mucosa was studied in 10 patients with chronic polypous rhinosinusitis (CPRS). A complex examination included optic endoscopy of the nasal cavity for assessment of nasal polypous process, timing of the saccharine test (ST) according to standard technique, and ciliary beat rate (BR) by V.S. Kozlov method. For estimation of ciliary BR epithelium was taken from five zones: inferior and middle turbinated bones, nasal septum, base and top of the polyp growing from the median nasal passage. ST time in CPRS is much higher (28.3+/-0.34 min) than normal age-specific values. Ciliary BR in different nasal anatomic zones in CPRS is not similar. MACS on the inferior turbinated bone and nasal septum was absent, none of the samples contained cells with functioning cilia. Ciliary BR remained rather high, despite the pathological process, at the site of the top and base of the polyps as well as on the middle turbinated bone (8.7+/-1.07, 8.1+/-1.02, 6.5+/-0.35 Hz, respectively).

Primary ciliary dyskinesia: recent advances in pathogenesis, diagnosis and treatment

Primary ciliary dyskinesia is a genetic disorder causing dysfunctional motility of cilia and impaired mucociliary clearance, resulting in a myriad of clinical manifestations including recurrent sinopulmonary disease, laterality defects and infertility. The heterogenous clinical presentation of primary ciliary dyskinesia and the limitations of transmission electron microscopy to assess ultrastructural defects within the cilium often delay diagnosis. Recent advances in the understanding of the basic biology and function of the cilium have led to potential diagnostic alternatives, including ciliary beat analysis and nasal nitric oxide measurements. Moreover, the identification of disease-causing mutations could lead to the development of comprehensive genetic testing that may overcome many of the current diagnostic limitations. Although the clinical manifestations of primary ciliary dyskinesia have been recognised for over a century, there are few studies examining treatments and standards of care have yet to be established. Multicentre collaborative efforts have been established in North America and Europe, which should help to develop standardised approaches to the diagnosis and treatment of primary ciliary dyskinesia.

Change of nasal function with aging in Korean

CONCLUSION

The changes of nasal resistance and cross-sectional area (CSA) with aging could suggest that it might be attributed to the change (atrophy) of the non-erectile structural tissues including bone and soft tissues rather than the erectile tissues. Subjects older than 60 years of age had significantly slower ciliary beat frequency (CBF), which could suggest nasal function might begin to decrease at around 60 years of age.

OBJECTIVES

Nasal physiology can be changed with aging, however, there has been little data that prove senile change of the nasal cavity. This study was conducted to evaluate the effect of aging on nasal resistance and ciliary movement of the nasal cavity.

METHODS

One hundred and fifty three healthy subjects were included in this study. Acoustic rhinometry and rhinomanometry before and after nasal decongestion, and CBF were measured.

RESULTS

The CSA at the attachment of the inferior turbinate was increased with age in both before and after decongestion. However, the difference of CSA between pre- and post-decongestion did not change significantly with age. At the nasal valve area, the CSA showed almost same values between age groups and the difference between pre-and post-decongestion was very small. The nasal resistance was markedly decreased from 2nd to 3rd decade and did not change significantly after 3rd decade. Subjects older than 60 years of age had significantly slower CBFs compared to those younger than 60 years (10.18+/-0.98 vs. 12.43+/-1.46) (P<.001).

Biosynthesis of Wdr16, a marker protein for kinocilia-bearing cells, starts at the time of kinocilia formation in rat, and wdr16 gene knockdown causes hydrocephalus in zebrafish

The rat ortholog of the WD40 repeat protein Wdr16 is abundantly expressed in testis and cultured ependymal cells. Low levels are found in lung and brain, respectively, while it is absent from kinocilia-free tissues. In testis and ependymal primary cultures, Wdr16 messenger RNA appears concomitantly with the messages for sperm-associated antigen 6, a kinocilia marker, and for hydin, a protein linked to ciliary function and hydrocephalus. In testis, ependyma and respiratory epithelium, the Wdr16 protein is up-regulated together with kinocilia formation. The wdr16 gene is restricted to genera in possession of kinocilia, and it is strongly conserved during evolution. The human and zebrafish proteins are identical in 62% of their aligned amino acids. On the message level, the zebrafish Wdr16 ortholog was found exclusively in kinocilia-bearing tissues by in situ hybridisation. Gene knockdown in zebrafish embryos by antisense morpholino injection resulted in severe hydrocephalus formation with unaltered ependymal morphology or ciliary beat. Wdr16 can be considered a differentiation marker of kinocilia-bearing cells. In the brain, it appears to be functionally related to water homeostasis or osmoregulation.

Genetic defects in ciliary structure and function

Cilia, hair-like structures extending from the cell membrane, perform diverse biological functions. Primary (genetic) defects in the structure and function of sensory and motile cilia result in multiple ciliopathies. The most prominent genetic abnormality involving motile cilia (and the respiratory tract) is primary ciliary dyskinesia (PCD). PCD is a rare, usually autosomal recessive, genetically heterogeneous disorder characterized by sino-pulmonary disease, laterality defects, and male infertility. Ciliary ultrastructural defects are identified in approximately 90% of PCD patients and involve the outer dynein arms, inner dynein arms, or both. Diagnosing PCD is challenging and requires a compatible clinical phenotype together with tests such as ciliary ultrastructural analysis, immunofluorescent staining, ciliary beat assessment, and/or nasal nitric oxide measurements. Recent mutational analysis demonstrated that 38% of PCD patients carry mutations of the dynein genes DNAI1 and DNAH5. Increased understanding of the pathogenesis will aid in better diagnosis and treatment of PCD.

The humidification and filtration functions of the airways

The mucociliary elevator is a highly evolved organ that humidifies inspired gases and protects the lungs from particulate, chemical, and microbiologic matter. Studies of disorders mucus and ciliary function have improved the understanding of this forgotten organ. The clinical implications of this understanding have yet to be explored.

Cilia: tuning in to the cell's antenna

Cilia are microtubule-based organelles that project like antennae from the surface of most cells in the body. Motile cilia move fluid past cells, for example mucus in the airway. Non-motile primary cilia, however, transduce a multitude of sensory stimuli, including chemical concentrations of growth factors, hormones, odorants, and developmental morphogens, as well as osmolarity, light intensity, and fluid flow. Cilia have evolved a complex ultrastructure to accommodate these diverse functions, and an extensive molecular machinery has developed to support the assembly of these organelles. Defects in the cilia themselves, or the machinery required to assemble them, lead to a broad spectrum of human disease symptoms, including polycystic kidney disease, nephronophthisis, hydrocephalus, polydactyly, situs inversus, retinal degeneration, and obesity. While these diseases highlight the pivotal roles of cilia in physiology and development, the mechanistic link between cilia, physiology, and disease remains unclear.

The roles of cilia in developmental disorders and disease

Cilia are highly conserved organelles that have diverse motility and sensory functions. Recent discoveries have revealed that cilia also have crucial roles in cell signaling pathways and in maintaining cellular homeostasis. As such, defects in cilia formation or function have profound effects on the development of body pattern and the physiology of multiple organ systems. By categorizing syndromes that are due to cilia dysfunction in humans and from studies in vertebrate model organisms, molecular pathways that intersect with cilia formation and function have come to light. Here, we summarize an emerging view that in order to understand some complex developmental pathways and disease etiologies, one must consider the molecular functions performed by cilia.

A prospective study of respiratory ciliary structure and function after stem cell transplantation

We prospectively investigated the morphological and ciliary function abnormalities in 19 consecutive Chinese patients undergoing hemopoietic stem cell transplantation (HSCT) and studied their relationship with pulmonary complications. The percentage of structural ciliary abnormalities preceding HSCT was comparable to normal controls, but increased up to 1-year post-HSCT. However, the abnormalities did not correlate with ciliary or pulmonary function. Ciliary beat frequency (CBF) for patients undergoing autologous and allogeneic SCT was lower than that of matched controls, with a further decline at one year. There was, however, no significant change in pulmonary function for the whole cohort. There was considerable variation in CBF and ciliary abnormalities in all cases during 3-month interval assessments. Regular ciliary assessment did not predict the only two patients who eventually suffered from bronchiolitis obliterans (BO). We conclude that structural and functional ciliary abnormalities are common in recipients of HSCT, and predict post-HSCT deterioration. However, there is no evidence to show that CBF monitoring may be of prospective benefit.

Development of polycystic kidney disease in juvenile cystic kidney mice: insights into pathogenesis, ciliary abnormalities, and common features with human disease

Significant progress in understanding the molecular mechanisms of polycystic kidney disease (PKD) has been made in recent years. Translating this understanding into effective therapeutics will require testing in animal models that closely resemble human PKD by multiple parameters. Similar to autosomal dominant PKD, juvenile cystic kidney (jck) mice develop cysts in multiple nephron segments, including cortical collecting ducts, distal tubules, and loop of Henle. The jck mice display gender dimorphism in kidney disease progression with more aggressive disease in male mice. Gonadectomy experiments show that testosterone aggravates the severity of the disease in jck male mice, while female gonadal hormones have protective effects. EGF receptor is overexpressed and mislocalized in jck cystic epithelia, a hallmark of human disease. Increased cAMP levels in jck kidneys and activation of the B-Raf/extracellular signal-regulated kinase pathway are demonstrated. The effect of jck mutation on the expression of Nek8, a NIMA-related (never in mitosis A) kinase, and polycystins in jck cilia is shown for the first time. Nek8 overexpression and loss of ciliary localization in jck epithelia are accompanied by enhanced expression of polycystins along the cilia. The primary cilia in jck kidneys are significantly more lengthened than the cilia in wild-type mice, suggesting a role for Nek8 in controlling ciliary length. Collectively, these data demonstrate that the jck mice should be useful for testing potential therapies and for studying the molecular mechanisms that link ciliary structure/function and cystogenesis.

Ciliary function and the role of cilia in clearance

The lungs and the nasal passages are continually exposed to respiratory pathogens, toxins, and particulate matter, and have evolved a very effective defense system to protect themselves. Mucociliary clearance is an essential part of this defence and relies on appropriate interactions between the ciliated epithelium, the height of the periciliary fluid, and mucus. Mucus acts as a physical barrier, trapping inhaled particles and pathogens, whilst cilia move both the mucus layer and fluid in the underlying periciliary layer. These defenses may be disrupted by viral and bacterial infections, by inhaled toxins, and by inherited diseases such as primary ciliary dyskinesia and cystic fibrosis.

Novel tools to unravel molecular mechanisms in cilia-related disorders

Cilia are hair-like organelles extending from the cell surface that execute motile (e.g. respiratory cilia) and/or sensory functions (e.g. renal monocilia). The basic ultrastructure of cilia and flagella has been well established by electron microscopy. Several recent reports have now provided intriguing new insights into the complex molecular composition of cilia and flagella. These data from genome, proteome and transcriptome analyses will facilitate the systematic discovery and understanding of genes responsible for human cilia-related diseases, such as primary ciliary dyskinesia, polycystic kidney disease and male sterility.

Mucociliary and long-term particle clearance in airways of patients with immotile cilia

Spherical monodisperse ferromagnetic iron oxide particles of 1.9 μm geometric and 4.2 μm aerodynamic diameter were inhaled by seven patients with primary ciliary dyskinesia (PCD) using the shallow bolus technique, and compared to 13 healthy non-smokers (NS) from a previous study. The bolus penetration front depth was limiting to the phase1 dead space volume. In PCD patients deposition was 58+/-8 % after 8 s breath holding time. Particle retention was measured by the magnetopneumographic method over a period of nine months. Particle clearance from the airways showed a fast and a slow phase. In PCD patients airway clearance was retarded and prolonged, 42+/-12 % followed the fast phase with a mean half time of 16.8+/-8.6 hours. The remaining fraction was cleared slowly with a half time of 121+/-25 days. In healthy NS 49+/-9 % of particles were cleared in the fast phase with a mean half time of 3.0+/-1.6 hours, characteristic of an intact mucociliary clearance. There was no difference in the slow clearance phase between PCD patients and healthy NS. Despite non-functioning cilia the effectiveness of airway clearance in PCD patients is comparable to healthy NS, with a prolonged kinetics of one week, which may primarily reflect the effectiveness of cough clearance. This prolonged airway clearance allows longer residence times of bacteria and viruses in the airways and may be one reason for increased frequency of infections in PCD patients.

Nitric Oxide in Health and Disease from the Point of View of the Otorhinolaryngologist

Nitric oxide (NO) plays role in a great range of important functions in the organism, such as vasodilatation, relaxation of muscles, neurotransmission, neuromediation, and host defense reactions. In the upper airways, nasal cavities and paranasal sinuses are the main sources of this biological mediator. Although the exact role of NO in nasal physiology remains poorly understood, the functions are thought to be host defense, ciliary motility and improved ventilation-perfusion ratio in the lungs by auto-inhalation. Low NO concentrations were reported in certain diseases such as primary ciliary dyskinesia, cystic fibrosis, and acute and chronic maxillary sinusitis whereas high concentrations were detected in upper airway infection, allergic rhinitis and nasal polyposis. Additionally this ubiquitous radical is being implicated in the regulation of cochlear blood flow, sensorineural hearing loss, middle ear effusions, and outer hair cell and vestibular functions. Solid tumors is another area where NO appears to have both tumor-promoting and tumor-inhibiting effects. The presence of NO with high levels within the nose and paranasal sinuses makes it reasonable to believe that this pluripotent gas is involved in a variety of physiological as well as pathophysiological events in the airways. Although NO has an ever-increasing role in various areas related to the practice of otolaryngology, further research is required to understand fully the role of NO in the upper airways.

The centrosome in human genetic disease

The centrosome is an indispensable component of the cell-cycle machinery of eukaryotic cells, and the perturbation of core centrosomal or centrosome-associated proteins is linked to cell-cycle misregulation and cancer. Recent work has expanded our understanding of the functional complexity and importance of this organelle. The centrosomal localization of proteins that are involved in human genetic disease, and the identification of novel centrosome-associated proteins, has shown that numerous, seemingly unrelated, cellular processes can be perturbed by centrosomal dysfunction. Here, we review the mechanistic relationship between human disease phenotypes and the function of the centrosome, and describe some of the newly-appreciated functions of this organelle in animal cells.

Cilia-related diseases

There are at least eight categories of cilia in the human body and malfunctioning of any one or several of them will have different consequences for the patient. A genetic error of the respiratory cilia (9 + 2) is the cause of the airways disease named immotile-cilia syndrome (or PCD), whereas defective ependymal cilia (9 + 2) carries an increased risk of hydrocephalus. When the so-called nodal cilia (9 + 0) of the early embryo are malfunctioning, there is a random determination of asymmetry of the heart and visceral organs ('a 50% risk of situs inversus'). Some genes are responsible for the synthesis, transport, and assembly of the cilia, and mutations in these genes may lead to progressive degeneration of ciliary structures, such as the connecting cilium (9 + 0) of the photoreceptor cells-this is the cause of retinitis pigmentosa. Ciliary malfunctions due to genetic errors tend to be systemic and life-long, whereas acquired diseases are local and may be temporary only.

Mice deficient in the axonemal protein Tektin-t exhibit male infertility and immotile-cilium syndrome due to impaired inner arm dynein function

The haploid germ cell-specific Tektin-t protein is a member of the Tektin family of proteins that form filaments in flagellar, ciliary, and axonemal microtubules. To investigate the physiological role of Tektin-t, we generated mice with a mutation in the tektin-t gene. The homozygous mutant males were infertile, while the females were fully fertile. Sperm morphology and function were abnormal, with frequent bending of the sperm flagella and marked defects in motility. In vitro fertilization assays showed that the defective spermatozoa were able to fertilize eggs. Electron microscopic examination showed that the dynein inner arm structure was disrupted in the sperm flagella of tektin-t-deficient mice. Furthermore, homozygous mutant mice had functionally defective tracheal cilia, as evidenced by altered dynein arm morphology. These results indicate that Tektin-t participates in dynein inner arm formation or attachment and that the loss of Tektin-t results in impaired motility of both flagella and cilia. Therefore, the tektin-t gene is one of the causal genes for immotile-cilium syndrome/primary ciliary dyskinesia.

A novel in vitro model for screening and evaluation of anti-asthenopia drugs

Patients suffering asthenopia are steadily increasing with an expanding use of visual display terminals such as computers. An attempt was made to develop an in vitro model for asthenopia. Ciliary muscle removed from eyeballs of a rabbit was stimulated with acethylcholine, resulting in contraction of the muscle. Repeated stimulations caused decreased contraction, which may be related to fatiguing of ciliary muscle and hence asthenopia. Treatment of the repeatedly stimulated muscle with cyanocobalamin restored contraction dose-dependently. Thus, the model developed in this study can be used to screen drug candidates for treating asthenopia.

Cilia and Flagella Revealed

The recent identification in Chlamydomonas of the intraflagellar transport machinery that assembles cilia and flagella has triggered a renaissance of interest in these organelles that transcends studies on their well-characterized ability to move. New studies on several fronts have revealed that the machinery for flagellar assembly/disassembly is regulated by homologs of mitotic proteins, that cilia play essential roles in sensory transduction, and that mutations in cilia/basal body proteins are responsible for cilia-related human disorders from polycystic kidney disease to a syndrome associated with obesity, hypertension, and diabetes.

Bases moléculaires des dyskinésies ciliaires primitives

INTRODUCTION

The primary ciliary dyskinesias (PCD) are rare diseases characterised by infection of the airways due to impaired muco-ciliary clearance. Half the patients have situs inversus making up Kartagener's syndrome.

STATE OF THE ART

Primary cilia play a role in development. In the adult ciliated cells occur mainly in the airways and the genital tract. The axoneme, the internal structure of the cilia, is made up of a central pair of microtubules surrounded by peripheral doublets carrying the inner and outer dynein arms. These multiprotein complexes are composed of chains of dynein whose ATPase activity is the basis of ciliary movement. Structural and functional abnormalities of the respiratory ciliated cells are the cause of PCD, diseases that are heterogeneous at both the genetic and ultrastructural levels.

PERSPECTIVES

There are more than two hundred axonemal proteins. The synthesis and assembly of these proteins are controlled by transcription factors and intraflagellar transport molecules respectively. The genes that code for these proteins are as numerous as candidate genes for PCD.

CONCLUSIONS

To date only two dynein genes, DNA11 and DNAH5, have been implicated and only in individuals suffering from PCD with absence of outer dynein arms.

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.