Telocytes in trachea and lungs

We show the existence of a novel type of interstitial cell-telocytes (TC) in mouse trachea and lungs. We used cell cultures, vital stainings, as well as scanning electron microscopy (SEM), transmission electron microscopy (TEM) and immunohistochemistry (IHC). Phase contrast microscopy on cultured cells showed cells with unequivocally characteristic morphology of typical TC (cells with telopodes-Tp). SEM revealed typical TC with two to three Tp-very long and branched cell prolongations. Tp consist of an alternation of thin segments (podomers) and thick segments (podoms). The latter accommodate mitochondria (as shown by Janus Green and MitoTracker), rough endoplasmic reticulum and caveolae. TEM showed characteristic podomers and podoms as well as close relationships with nerve endings and blood capillaries. IHC revealed positive expression of TC for c-kit, vimentin and CD34. In conclusion, this study shows the presence in trachea and lungs of a peculiar type of cells, which fulfils the criteria for TC.     

Notch signaling in the mammalian respiratory system,specifically the trachea and lungs,in development,homeostasis, regeneration,and disease

The respiratory system has ideal tissue structure and cell types for efficient gas exchange to intake oxygen and release carbon dioxide. This complex system develops through orchestrated intercellular signaling among various cell types, such as club, ciliated, basal, neuroendocrine, AT1, AT2, endothelial, and smooth muscle cells. Notch signaling is a highly conserved cell–cell signaling pathway ideally suited for very short-range cellular communication because Notch signals are transmitted by direct contact with an adjacent cell. Enthusiastic efforts by Notch researchers over the last two decades have led to the identification of critical roles of this signaling pathway during development, homeostasis, and regeneration of the respiratory system. The dysregulation of Notch signaling results in a wide range of respiratory diseases such as pulmonary artery hypertension (PAH), chronic obstructive pulmonary disease (COPD), interstitial pulmonary fibrosis (IPF), and lung cancer. Thus, a deep understanding of the biological functions of Notch signaling will help identify novel treatment targets in various respiratory diseases.     

Molecular cytology of the respiratory tract and pleura

There is growing evidence that molecular testing is feasible on all types of cytological preparation, which is fortunate as more diagnostic markers and biomarkers for targeted therapies are discovered for use in pulmonary and pleural malignancies. In this article we will discuss the pre-analytic, analytic, and post-analytic (interpretive) considerations for successful implementation of molecular tests for diagnostic and predictive markers in respiratory and pleural cytology. The vast majority of laboratories are familiar with, and have validated their molecular protocols for, formalin-fixed paraffin-embedded surgical specimens, which are not directly applicable to cytology specimens. Thus, rigorous validation must be performed for each type of fixative and cytology preparation before it is implemented in the clinical setting.     

Saccadic head and thorax movements in freely walking blowflies

Visual information processing is adapted to the statistics of natural visual stimuli, and these statistics depend to a large extent on the movements of an animal itself. To investigate such movements in freely walking blowflies, we measured the orientation and position of their head and thorax, with high spatial and temporal accuracy. Experiments were performed on Calliphora vicina, Lucilia cuprina and L. caesar. We found that thorax and head orientation of walking flies is typically different from the direction of walking, with differences of 45° common. During walking, the head and the thorax turn abruptly, with a frequency of 5–10 Hz and angular velocities in the order of 1,000°/s. These saccades are stereotyped: head and thorax start simultaneously, with the head turning faster, and finishing its turn before the thorax. The changes in position during walking are saccade-like as well, occurring synchronously, but on average slightly after the orientation saccades. Between orientation saccades the angular velocities are low and the head is held more stable than the thorax. We argue that the strategy of turning by saccades improves the performance of the visual system of blowflies.     

Ventilation by high-frequency oscillation of thorax or at trachea in rats

The efficiency of ventilation by high-frequency oscillation (HFO) applied to the thorax (external HFO) has been compared with that of HFO applied through a tracheal cannula (internal HFO) in a group of normal rats. Anesthetized, paralyzed, tracheotomized rats were placed in a whole-body plethysmograph. External HFO was achieved by varying the pressure surrounding the animal by means of a piston pump connected to the body plethysmograph; internal HFO was obtained in the same animals by connecting the pump to the tracheal cannula. Arterial CO2 and O2 partial pressures were measured in blood sampled from a carotid artery and were compared for external and internal HFO applied at 20 Hz with matched tidal volumes of 0.8, 1.4, 1.9, and 2.4 ml/kg. With increasing tidal volume, the mean arterial CO2 partial pressure decreased progressively from 68 to 30 Torr and was identical in the two modes of HFO; no difference was noted for the CO2 elimination or for the arterial O2 partial pressure. These results indicate that, in terms of gas exchange, external and internal HFO are equally efficient in normal rats.