Nitric oxide (NO) has witnessed an explosion of interest of scientists all over the world during the last decade. This small gaseous molecule is produced in many systems such as the nervous system, cardiovascular system, the upper and lower airways. In all of these it contributes to a number of (patho)physiological processes. Concerning the airways, NO concentrations in the upper respiratory tract are much higher (i.e. ranging from 200 to 2000 parts per billion (ppb)) than NO levels in the lower respiratory tract (i.e. ranging from 4 to 160 ppb). NO is most frequently measured using a chemiluminescence method, based on a reaction of NO with O3 resulting in the emission of light. In the airways NO exerts many functions in host defense, ciliary activity, inflammation and it is also an aerocrine messenger between the upper and lower airways. Nasal NO concentrations are influenced by age, physical exercise, smoking and certain drugs. Nasal NO is conveniently measured in all ages and can be used for screening of disease or monitoring the effects of treatment. Pathological conditions, as in allergic rhinitis, sinusitis, nasal polyps, cystic fibrosis and primary ciliary dyskinesia, result in altered nasal NO concentrations. The clinical relevance for measurement of nasal NO in different conditions, however, remains to be established.
Mucociliary transport is a major defense mechanism of the airways. Mucociliary clearance is functionally and ultrastructurally organized at different levels from individual cilia to the ciliated tapestry. The correlations among ciliary beat frequency (CBF), secondary abnormalities (SCD), ciliary (dis)orientation (COR), coordinated ciliary activity and ciliary immotility were investigated based on the findings in over 700 non-PCD biopsies taken in the context of diagnostic investigations for respiratory problems. CBF decreased with increasing percentages of SCD, from 7.6 +/- 1.8 Hz (0-5% SCD) to 4.9 +/- 3.3 Hz (> 25% SCD). COR increased with increasing percentages of SCD, from 15 +/- 7 degrees for < 5% SCD to 28 +/- 8 degrees (> 25% SCD). SCD also correlated with ciliary (im)motility, but not with ciliary coordination. No correlation was found between COR and CBF. However, increased COR (28 +/- 8 degrees) was found in samples with only immotile cilia, compared to those with ciliary activity (19 +/- 9 degrees). Similar findings were demonstrated between COR and coordinated activity, particularly between immotile cilia (28 +/- 8 degrees) and those with coordinated ciliary activity (19 +/- 9 degrees). CBF values from samples with no coordinated activity (5.5 +/- 2.9 Hz) were significantly different from those with coordinated ciliary activity (7.4 +/- 1.6 Hz). In conclusion, mucociliary transport is a well organized, complex process with many interactions between parameters at various levels of functional and structural organization. SCD seems to play a crucial role. The correlations among the different parameters can help us further understand the functional and ultrastructural mechanisms needed for efficient mucociliary clearance.
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.
This article disentangles the complex relationship between depoliticisation and anti-politics in public-private partnership (PPP) policies and practices. By identifying three social mechanisms that underlie dynamics of depoliticisation in PPPs, namely consultocracy, yield bias, and complex contracting, it contrib-utes to the growing interdisciplinary literature on depoliticisation. The article argues that as depoliticisation continues to evolve, it further increases the unbalance between depoliticisation and politicisation, which has negative implications for democratic governance. The depoliticised logic behind PPPs feeds broad sen-timents of political distrust and disappointment, because political decision makers tend to use PPPs as mir-acle solutions for the delivery of public infrastructure without bearing the long-term budgetary conse-quences of their own decisions. This constitutes an expectations gap: the difference between what is prom-ised or expected by politicians on the one hand, and what they can actually deliver on the other. It is here that the short-term rationales and incentives of political decision makers collide with the wider public inter-est in the longer term.
