Decreased Levels of Nasal Nitric Oxide in Children With Midline Neuroanatomical Anomalies: A Possible Connection Between Ciliary Dysfunction and Isolated Nervous System Defects

OBJECTIVES

Given the involvement of cilia in midline neurodevelopment, we set to determine whether children with midline neuroanatomical defects have increased prevalence of ciliary dysfunction, using nasal nitric oxide measurement, a screening test for primary ciliary dyskinesia.

STUDY DESIGN

We measured the nasal nitric oxide levels of 26 children ages 6-17, with congenital midline central nervous system defects, who are otherwise healthy. We evaluated the effect of variables including: age, gender, and anomaly (brain, spinal cord, or combined) on our measurements. We compared our results with the previously established normal range (153.6-509.9 nL/min) and to the cutoff for children with primary ciliary dyskinesia (77 nL/min).

RESULTS

The overall range for nasal nitric oxide in our cohort was 56.5-334.7 nL/min, with age, gender, and anomaly not having a significant effect. The overall mean, 217.7 nL/min, was significantly lower than the preestablished mean in normal children, 314.51 nL/min (P < 0.01). Four patients (15.4%) had nitric oxide levels below the lower end of normal, with two (7.7%) having values below the cutoff for primary ciliary dyskinesia.

CONCLUSIONS

This is the first study to report a possible association between ciliary dysfunction and isolated congenital midline neuroanatomical defects, not in the context of any known syndrome. We suggest that genes known to cause isolated central nervous system defects may also be involved in the function of cilia. Longitudinal studies are required to investigate whether, in children with abnormal measurements, nasal nitric oxide levels normalize over time, and whether these children suffer from any respiratory sequelae.

More Realistic Face Model Surface Improves Relevance of Pediatric In-Vitro Aerosol Studies

BACKGROUND

Various hard face models are commonly used to evaluate the efficiency of aerosol face masks. Softer more realistic "face" surface materials, like skin, deform upon mask application and should provide more relevant in-vitro tests. Studies that simultaneously take into consideration many of the factors characteristic of the in vivo face are lacking. These include airways, various application forces, comparison of various devices, comparison with a hard-surface model and use of a more representative model face based on large numbers of actual faces.

AIM

To compare mask to "face" seal and aerosol delivery of two pediatric masks using a soft vs. a hard, appropriately representative, pediatric face model under various applied forces.

METHODS

Two identical face models and upper airways replicas were constructed, the only difference being the suppleness and compressibility of the surface layer of the "face." Integrity of the seal and aerosol delivery of two different masks [AeroChamber (AC) and SootherMask (SM)] were compared using a breath simulator, filter collection and realistic applied forces.

RESULTS

The soft "face" significantly increased the delivery efficiency and the sealing characteristics of both masks. Aerosol delivery with the soft "face" was significantly greater for the SM compared to the AC (p< 0.01). No statistically significant difference between the two masks was observed with the hard "face."

CONCLUSIONS

The material and pliability of the model "face" surface has a significant influence on both the seal and delivery efficiency of face masks. This finding should be taken into account during in-vitro aerosol studies.

Computerized Dead-Space Volume Measurement of Face Masks Applied to Simulated Faces

BACKGROUND

The dead-space volume (VD) of face masks for metered-dose inhaler treatments is particularly important in infants and young children with asthma, who have relatively low tidal volumes. Data about VD have been traditionally obtained from water displacement measurements, in which masks are held against a flat surface. Because, in real life, masks are placed against the face, VD is likely to differ considerably between masks depending upon their contour and fit. The aim of this study was to develop an accurate and reliable way to measure VD electronically and to apply this technique by comparing the electronic VD of commonly available face masks.

METHODS

Average digital faces were obtained from 3-dimensional images of 270 infants and children. Commonly used face masks (small and medium) from various manufacturers (Monaghan Medical, Pari Respiratory Equipment, Philips Respironics, and InspiRx) were scanned and digitized by means of computed tomography. Each mask was electronically applied to its respective digital face, and the VD enclosed (mL) was computerized and precisely measured.

RESULTS

VD varied between 22.6 mL (SootherMask, InspiRx) and 43.1 mL (Vortex, Pari) for small masks and between 41.7 mL (SootherMask) and 71.5 mL (AeroChamber, Monaghan Medical) for medium masks. These values were significantly lower and less variable than measurements obtained by water displacement.

CONCLUSIONS

Computerized techniques provide an innovative and relatively simple way of accurately measuring the VD of face masks applied to digital faces. As determined by computerized measurement using average-size virtual faces, the InspiRx masks had a significantly smaller VD for both small and medium masks compared with the other masks. This is of considerable importance with respect to aerosol dose and delivery time, particularly in young children. (ClinicalTrials.gov registration NCT01274299.).

A reach-out system for video microscopy analysis of ciliary motions aiding PCD diagnosis

BACKGROUNDS

High-speed Video-Microscopy Analysis (HVMA) is now being used to aid diagnosis of Primary Ciliary Dyskinesia (PCD). Only a few centers however, are equipped with the available resources and equipment to perform these tests. We describe our experience in HVMA reaching-out to many more peripheral and relatively remote areas. A portable computer with HVMA software, video camera and a microscope were used. Fourteen disperse pediatric centers were reached and a total of 203 subjects were tested within a relatively short time (Clinical Trial Registration: NCT 01070914 (registered February 6, 2010).

RESULTS

With an average time of 20 minutes per patient, the system enabled us to test approximately 10-15 subjects per day. A valid HVMA result was made in 148 subjects and helped in the diagnosis of PCD in many of the patients who were subsequently confirmed to have PCD by electron microscopy and/or immunofluoresence and/or genetics and/or nasal Nitric Oxide testing. The sensitivity of abnormal HVMA to accurately predict PCD was 90.2%.

DISCUSSION AND CONCLUSION

This is the first report of an out-reach system to record HVMA for improved diagnosis of PCD in remote regions that are not within reach of PCD centers and experts. It provides immediate preliminary results and instantaneous feedback to the physician, patient and his/her family members in these areas. Future studies to compare this system to conventional desk top systems are warranted.

TRIAL REGISTRATION

NCT 01070914 (registered February 6, 2010).

Nasal versus oral aerosol delivery to the "lungs" in infants and toddlers

OBJECTIVES

The oral route has been considered superior to the nasal route for aerosol delivery to the lower respiratory tract (LRT) in adults and children. However, there are no data comparing aerosol delivery via the oral and nasal routes in infants. The aim of this study was to compare nasal and oral delivery of aerosol in anatomically correct replicas of infants' faces containing both nasal and oral upper airways.

METHODS

Three CT-derived upper respiratory tract ("URT") replicas representing infants/toddlers aged 5, 14 and 20 months were studied and aerosol delivery to the "lower respiratory tract" (LRT) by either the oral or nasal route for each of the replicas was measured at the "tracheal" opening. A radio-labeled (99mDTPA) normal saline solution aerosol was generated by a soft-mist inhaler (SMIRespimat® Boehringer Ingelheim, Germany) and aerosol was delivered via a valved holding chamber (Respichamber® TMI, London, Canada) and an air-tight mask (Unomedical, Inc., McAllen, TX). A breath simulator was connected to the replicas and an absolute filter at the "tracheal" opening captured the aerosol representing "LRT" dose. Age-appropriate mask dimensions and breathing patterns were employed for each of the airway replicas. Two different tidal volumes (V_t ) were used for comparing the nasal versus oral routes.

RESULTS

Nasal delivery to the LRT exceeded that of oral delivery in the 5- and 14-month models and was equivalent in the 20-month model. Differences between nasal and oral delivery diminished with "age"/size. Similar findings were observed with lower and higher tidal volumes (V_t ).

CONCLUSION

Nasal breathing for aerosol delivery to the "LRT" is similar to, or more efficient than, mouth breathing in infant/toddler models, contrary to what is observed in older children and adults. Pediatr Pulmonol. 2015; 50:276-283. © 2014 Wiley Periodicals, Inc.

Feasibility of aerosol drug delivery to sleeping infants: a prospective observational study

OBJECTIVES

Delivery of inhaled medications to infants is usually very demanding and is often associated with crying and mask rejection. It has been suggested that aerosol administration during sleep may be an attractive alternative. Previous studies in sleeping children were disappointing as most of the children awoke and rejected the treatment. The SootherMask (SM) is a new, gentle and innovative approach for delivering inhaled medication to infants and toddlers. The present pilot study describes the feasibility of administering inhaled medications during sleep using the SM.

DESIGN

Prospective observational study.

SETTING

Out patients.

PARTICIPANTS

13 sleeping infants with recurrent wheezing who regularly used pacifiers and were <12 months old.

INTERVENTION

Participants inhaled technetium99mDTPA-labelled normal saline aerosol delivered via a Respimat Soft Mist Inhaler (SMI) (Boehringer-Ingelheim, Germany) and SM + InspiraChamber (IC; InspiRx Inc, New Jersey, USA).

OUTCOMES

The two major outcomes were the acceptability of the treatment and the lung deposition (per cent of emitted dose).

RESULTS

All infants who fulfilled the inclusion criteria successfully received the SM treatment during sleep without difficulty. Mean lung deposition (±SD) averaged 1.6±0.5% in the right lung.

CONCLUSIONS

This study demonstrated that the combination of Respimat, IC and SM was able to administer aerosol therapy to all the sleeping infants who were regular pacifier users with good lung deposition. Administration of aerosols during sleep is advantageous since all the sleeping children accepted the mask and ensuing aerosol therapy under these conditions, in contrast to previous studies in which there was frequent mask rejection using currently available devices.

CLINICAL TRIAL REGISTRY

NCT01120938.

Design of aerosol face masks for children using computerized 3D face analysis

BACKGROUND

Aerosol masks were originally developed for adults and downsized for children. Overall fit to minimize dead space and a tight seal are problematic, because children's faces undergo rapid and marked topographic and internal anthropometric changes in their first few months/years of life. Facial three-dimensional (3D) anthropometric data were used to design an optimized pediatric mask.

METHODS

Children's faces (n=271, aged 1 month to 4 years) were scanned with 3D technology. Data for the distance from the bridge of the nose to the tip of the chin (H) and the width of the mouth opening (W) were used to categorize the scans into "small," "medium," and "large" "clusters."

RESULTS

"Average" masks were developed from each cluster to provide an optimal seal with minimal dead space. The resulting computerized contour, W and H, were used to develop the SootherMask® that enables children, "suckling" on their own pacifier, to keep the mask on their face, mainly by means of subatmospheric pressure. The relatively wide and flexible rim of the mask accommodates variations in facial size within and between clusters.

CONCLUSIONS

Unique pediatric face masks were developed based on anthropometric data obtained through computerized 3D face analysis. These masks follow facial contours and gently seal to the child's face, and thus may minimize aerosol leakage and dead space.

CCDC65 mutation causes primary ciliary dyskinesia with normal ultrastructure and hyperkinetic cilia

BACKGROUND

Primary ciliary dyskinesia (PCD) is a genetic disorder characterized by impaired ciliary function, leading to chronic sinopulmonary disease. The genetic causes of PCD are still evolving, while the diagnosis is often dependent on finding a ciliary ultrastructural abnormality and immotile cilia. Here we report a novel gene associated with PCD but without ciliary ultrastructural abnormalities evident by transmission electron microscopy, but with dyskinetic cilia beating.

METHODS

Genetic linkage analysis was performed in a family with a PCD subject. Gene expression was studied in Chlamydomonas reinhardtii and human airway epithelial cells, using RNA assays and immunostaining. The phenotypic effects of candidate gene mutations were determined in primary culture human tracheobronchial epithelial cells transduced with gene targeted shRNA sequences. Video-microscopy was used to evaluate cilia motion.

RESULTS

A single novel mutation in CCDC65, which created a termination codon at position 293, was identified in a subject with typical clinical features of PCD. CCDC65, an orthologue of the Chlamydomonas nexin-dynein regulatory complex protein DRC2, was localized to the cilia of normal nasal epithelial cells but was absent in those from the proband. CCDC65 expression was up-regulated during ciliogenesis in cultured airway epithelial cells, as was DRC2 in C. reinhardtii following deflagellation. Nasal epithelial cells from the affected individual and CCDC65-specific shRNA transduced normal airway epithelial cells had stiff and dyskinetic cilia beating patterns compared to control cells. Moreover, Gas8, a nexin-dynein regulatory complex component previously identified to associate with CCDC65, was absent in airway cells from the PCD subject and CCDC65-silenced cells.

CONCLUSION

Mutation in CCDC65, a nexin-dynein regulatory complex member, resulted in a frameshift mutation and PCD. The affected individual had altered cilia beating patterns, and no detectable ultrastructural defects of the ciliary axoneme, emphasizing the role of the nexin-dynein regulatory complex and the limitations of certain methods for PCD diagnosis.

ZMYND10 is mutated in primary ciliary dyskinesia and interacts with LRRC6

Defects of motile cilia cause primary ciliary dyskinesia (PCD), characterized by recurrent respiratory infections and male infertility. Using whole-exome resequencing and high-throughput mutation analysis, we identified recessive biallelic mutations in ZMYND10 in 14 families and mutations in the recently identified LRRC6 in 13 families. We show that ZMYND10 and LRRC6 interact and that certain ZMYND10 and LRRC6 mutations abrogate the interaction between the LRRC6 CS domain and the ZMYND10 C-terminal domain. Additionally, ZMYND10 and LRRC6 colocalize with the centriole markers SAS6 and PCM1. Mutations in ZMYND10 result in the absence of the axonemal protein components DNAH5 and DNALI1 from respiratory cilia. Animal models support the association between ZMYND10 and human PCD, given that zmynd10 knockdown in zebrafish caused ciliary paralysis leading to cystic kidneys and otolith defects and that knockdown in Xenopus interfered with ciliogenesis. Our findings suggest that a cytoplasmic protein complex containing ZMYND10 and LRRC6 is necessary for motile ciliary function.

Deposition of small particles in the developing lung

Infancy is a time of marked and rapid changes in respiratory tract development. Infants (0-1 year of age) and young children (1- 3 years of age) are a unique subpopulation with regard to therapeutic aerosols. Anatomical, physiological and emotional factors, peculiar to these age groups, present significant challenges for aerosol delivery to the respiratory tract. Most studies with inhaled corticosteroids (ICS) have administered aerosols with relatively large particles, frequently > 3 μm in mass median aerodynamic diameter (MMAD). These drugs were designed for use in adults and older children and were administered with masks which were frequently rejected by children under age 3-4 years. We review the reasons that large-particle aerosols are likely to be less effective in infants and young children. We suggest that the benefit of inhaled medications in this age group requires further evaluation to determine if better therapeutic outcomes might be achieved using smaller particles and more patient-friendly delivery systems.

Lung aerosol deposition in suckling infants

INTRODUCTION

Aerosol therapy in infants may be greatly compromised by face mask rejection due to squirming and crying. Lung aerosol deposition in crying infants may thereby be greatly reduced. Since 'suckling' on a pacifier calms infants, they should more readily accept a face mask that incorporates a pacifier. However, since infants must breathe nasally while suckling, lung aerosol deposition may be reduced due to impaction in the nose. The aim of the present pilot study was to compare lung aerosol deposition while suckling on a pacifier incorporated into a mask with that obtained while inhaling from a conventional mask.

METHODS

Twelve infants <12 months old and who regularly used pacifiers participated as their own controls. Lung aerosol deposition was measured scintigraphically (technetium-(99m)DTPA-labelled normal saline aerosol, MMAD (Mass Median Aerodynamic Diameter) 3 um and GSD (Geometric Standard Deviation) of 2) via jet nebuliser using a conventional mask versus 'suckling' on their pacifier incorporated into a unique mask.

RESULTS

Mean lung deposition (± SD) while suckling using a mask with attached pacifier (1.6 ± 0.5% in the right lung) was similar to that with a conventional mask (1.7 ± 0.9%, p=0.81).

CONCLUSIONS

Lung aerosol deposition during nasal breathing while suckling on a pacifier-equipped mask is similar to that in infants breathing quietly using a conventional mask, and results comparable with previous data in infants and in nasal breathing models of an infant's upper respiratory tract. Using a pacifier during aerosol treatment in infants may be as efficient as conventional treatment without a pacifier.

Decriminalization of cannabis--potential risks for children?

The legalization of cannabis for medicinal purposes is becoming increasingly widespread worldwide. The anticipated growing ease of access to cannabis may create an increased risk for passive and/or active ingestion by children. We report a case of a 1.5-year-old infant who presented with unexplained coma that was later proved to be associated with the ingestion of cannabis. This case highlights the importance of considering cannabis ingestion in the differential diagnosis of infantile and toddler coma and the need for public education regarding the risks of childhood exposure in the light of the legalization of cannabis for medical purposes and its greater availability.

Lung function response to bronchodilator nebulization via hood in wheezy infants: a pilot study

BACKGROUND

In infants, small volume nebulizers with a face mask are commonly used to facilitate aerosol therapy. However, infants may be disturbed by mask application, causing poor mask-to-face seal and thus reducing the dose delivered.

OBJECTIVES

To compare lung function response to bronchodilator nebulization via two delivery devices: hood versus mask.

METHODS

We studied 26 recurrently wheezy infants aged 45.8 weeks (95% confidence interval 39.6-52.0). Inhalations of 0.30 mg/kg salbutamol were administered in two alliqots 30 minutes apart using mask and hood in alternating order (M+H or H+M). Response to inhalations was measured by maximal expiratory flows at functional residual capacity (V'maxFRC) at 5 minute intervals after each dose, and area under the V'maxFRC curve (AUC) was documented.

RESULTS

A small but significant response to salbutamol was observed following the second inhalation with V'maxFRC, improving by 31.7% (7.2-56.2, P (0.02) and AUC by 425% x min (-154, 1004; P < 0.02). The improvement following salbutamol was similar by both delivery modalities but with a small but significantly better response when H was used after M (P < 0.01).

CONCLUSIONS

Nebulized salbutamol induced a variable but positive response in wheezy infants. Salbutamol via hood was as effective as conventional face mask delivery. Since it is simple and patient-friendly, it could replace the face mask method particularly with uncooperative infants.

Mediated learning experience intervention increases hope of family members coping with a relative with severe mental illness

Hope is central in recovery of the mentally ill, and family attitudes play an important role. Hope may be mediated by cognitive and communication processes. The "Keshet" program is aimed at enhancing communication of family members with the use of cognitive pathways. The present pilot study examines whether the program effectively increases hope in family members in regard to themselves versus their hope for their ill relative.

METHODS

Forty nine family members who participated in the "Keshet" program for 6 months comprised the experimental group. The control group comprised 22 family members who underwent no structural intervention. Hope was measured at baseline and after 6 months using the Hope Scale developed by Snyder. No difference in self-perception was detected in Hope Scores between groups. However, the experimental group displayed a significant increase in their hope toward the ill relative with a concomitant decrease in the gap between hope of family members in relation to themselves versus their hope toward the ill person. "Keshet" significantly increased hope of families concerning the ill person, while decreasing the gap between hope of family members regarding themselves and the affected person. Thus, the program may contribute to the increase of the families' hope in the recovery journey of mentally ill family members.

Aerosol therapy in infants and toddlers: past, present and future

Infants and toddlers are a unique subpopulation with regard to aerosol therapy. There are various anatomical, physiological and emotional factors peculiar to this age group that present significant difficulties and challenges for aerosol delivery. Most studies on the factors determining lung deposition of therapeutic aerosols are based on data from adults or older children, which cannot simply be extrapolated directly to infants. The present review describes why infants/toddlers are very different with respect to two major issues - namely their anatomy/physiology and their behavior. We suggest possible solutions and future research directions aimed at improving clinical outcomes of aerosol therapy in this age group.

Factors that affect the efficacy of inhaled corticosteroids for infants and young children

Infants (0-1 years of age) and young children (1-3 years of age) are a unique subpopulation with regard to inhaled therapies. There are various anatomic, physiological, and emotional factors peculiar to this age group that present significant difficulties and challenges for aerosol delivery. Most studies of therapeutic aerosols that have been performed with patients of this age group, particularly recent studies with inhaled corticosteroids (ICSs), administered aerosols with relatively large particles (ie, >3 microm in mass median aerodynamic diameter). These drugs were designed for use in adults and older children and were administered with masks, which are frequently rejected by patients. Based on these studies, it was recently suggested that ICSs might not be as therapeutically effective in infants and young children as in adults. We review the reasons that large-particle corticosteroid aerosols are not likely to be effective in infants and young children. This patient population differs from adults in airway anatomy and physiology, as well as in behavior and adherence to therapy. We suggest that the benefit of ICSs in this age group requires further evaluation to determine whether better therapeutic outcomes might be achieved with smaller particles.