Reduced generation of multiple motile cilia (RGMC) is a rare mucociliary clearance disorder. Affected persons suffer from recurrent infections of upper and lower airways because of highly reduced numbers of multiple motile respiratory cilia. Here we report recessive loss-of-function and missense mutations in MCIDAS-encoding Multicilin, which was shown to promote the early steps of multiciliated cell differentiation in Xenopus. MCIDAS mutant respiratory epithelial cells carry only one or two cilia per cell, which lack ciliary motility-related proteins (DNAH5; CCDC39) as seen in primary ciliary dyskinesia. Consistent with this finding, FOXJ1-regulating axonemal motor protein expression is absent in respiratory cells of MCIDAS mutant individuals. CCNO, when mutated known to cause RGMC, is also absent in MCIDAS mutant respiratory cells, consistent with its downstream activity. Thus, our findings identify Multicilin as a key regulator of CCNO/FOXJ1 for human multiciliated cell differentiation, and highlight the 5q11 region containing CCNO and MCIDAS as a locus underlying RGMC.

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The aim of the present study was to examine the use of low-dose ACTH-(1-24) stimulation for assessment of adrenal function and the detection of mild adrenal insufficiency. The criteria for normal response to ACTH-(1-24) are a peak cortisol level of more than 500 nmol/L (18.1 micrograms/dL) and an increment of the cortisol level above the basal one of more than 200 nmol/L (7.2 micrograms/dL). These criteria were satisfied by 32 of 33 healthy children and adults subjected to an ACTH-(1-24) dose 500 times lower (0.5 micrograms/1.73 m2) than the dose of 250 micrograms in the standard test. At 20 min, the peak cortisol level was the same in the low-dose test [(621 +/- 28 nmol/L) (22.5 +/- 1.0 microgram/dL)] as in the standard ACTH test [(654 +/- 31 nmol/L) (23.7 +/- 1.1 microgram/dL)]. Of 46 asthmatic patients who had been treated with inhaled beclomethasone dipropionate (482 +/- 42 micrograms/m2 daily; n = 32) or budesonide (507 +/- 62 micrograms/m2 daily; n = 14) for over 6 months, 16 (35%) failed to reach a cortisol peak of more than 500 nmol/L (18.1 micrograms/dL) following stimulation with 0.5 micrograms ACTH-(1-24)/1.73 m2. Of these, 11 (24%) showed a cortisol increment of less than 200 nmol/L (7.2 micrograms/dL). These 16 patients, showing insufficient response to low-dose ACTH-(1-24), also had a significantly lower (P < 0.01) mean 24-h urinary free cortisol excretion [(71 +/- 10 nmol/m2.24 h) (25.7 +/- 3.6 micrograms/m2.24 h)] than patients who responded normally [(118 +/- 11 nmol/m2.24 h) (42.8 +/- 4.0 micrograms/m2.24 h). Nonetheless, all but one of the poor responders to a 0.5 microgram ACTH showed normal stimulation with the standard 250 micrograms ACTH test. Therefore, it appears that a low-dose ACTH test is capable of revealing mild adrenal insufficiency, which is not detected by the standard high-dose ACTH test.

To investigate fractional exhaled nitric oxide (FeNO) levels in infants during acute respiratory syncytial virus (RSV) bronchiolitis and during convalescence.Design: Prospective cohort study. Comparison of FeNO levels between infants with laboratory-confirmed acute RSV bronchiolitis and 2 control groups: healthy infants and infants with recurrent wheezing.