INTRODUCTION The slope of phase III of the capnogram (SIII) relates to progressive emptying of the alveoli, a ventilation/perfusion mismatch, and ventilation inhomogeneity. S(III) depends not only on the airway geometry, but also on the dynamic respiratory compliance (Crs); this latter effect has not been evaluated. Accordingly, we established the value of SIII for monitoring airway resistance ...

The forced oscillation technique (FOT) and multiple-breath nitrogen washout (MBNW) are noninvasive tests that are potentially sensitive to peripheral airways, with MBNW indexes being especially sensitive to heterogeneous changes in ventilation. The objective was to study methacholine-induced changes in the lung periphery of asthmatic patients and determine how changes in FOT variables of respir...

Prostaglandin E2 (PGE2), similar to beta-adrenergic receptor agonists, can protect airways from bronchoconstriction and resulting increase in airway resistance induced by a number of agents, including cholinergic receptor agonists and antigen. We examined the impact of sustained alterations in PGE2 pathways on changes in airway resistance. Genetic methods were utilized to alter PGE2 metabolism ...

We produced transgenic mice which overexpress human IL-6 in the airway epithelial cells. Transgenic mice develop a mononuclear cell infiltrate adjacent to large and mid-sized airways. Immunohistochemistry reveals these cells to be predominantly CD4+ cells, MHC class II+ cells, and B220+ cells. Transgenic mice and nontransgenic mice had similar baseline respiratory system resistance (0.47 +/- 0....

Nasal exposure to the mixture of microbial extracts (MME) after ablactation enhanced airway resistance of newborn mice to Streptococcus pneumoniae (J Physiol Lung Cell Mol Physiol 298: L67, 2010). The present study was addressed to elucidate effective factors responsible for the enhanced innate resistance in the airway of MME-exposed newborn mice. MME exposure significantly increased the amount...

The usefulness of measuring respiratory flow in the airway and at the chest wall and of measuring respiratory input impedance (Z) to monitor high frequency ventilation was investigated by computer simulation using a monoalveolar 10-coefficient model. The latter included a central airway with its resistance (Rc) and inertance (lc), a resistive peripheral airway (Rp), a lumped bronchial complianc...

Simultaneous measurement of input (Zin) and transfer impedances (Ztr) allows separation of airway and tissue properties at a single frequency, without making assumptions concerning the structure of the two compartments. This approach offers the possibility of studying the variation in airway impedance (Zaw) during the respiratory cycle. Zin and Ztr were measured at frequencies of 10, 20, 30 and...

In adults, the upper airway (UA) contains a variety of receptors including cold receptors, which evoke reflex effects on ventilation and UA dilator muscle activity, which may be important in the regulation of UA patency. However, very little is known about UA receptors in young animals, and the effects of UA cooling on UA dilator muscle activity and resistance have not been studied. A constant ...

The typical pathological features of asthma are airway remodeling and airway hyperresponsiveness (AHR). KyoT2, a negative modulator of Notch signaling, has been linked to asthma in several previous studies. However, whether KyoT2 is involved in the regulation of airway remodeling or the modulation of airway resistance in asthma is unclear. In this study, we aimed to evaluate the therapeutic pot...