Synthetic Lycra spandex fibers were coated with 3-methylcholanthrene (3MC) and inserted into the lumina of 104 tracheas removed from young adult inbred Syrian hamsters. Tumors appeared 3 to 21 months after implantation of these tracheal grafts in syngeneic animals. 3MC in amounts ranging from 9 to 75 microgram/fiber induced a diversity of neoplasms in tracheal epithelium, the majority of which ...

OBJECTIVE The present study was to investigate the antiasthmatic potential from the flavonoid fraction of Apium leptophyllum fruit (FFALF) to validate its traditional claim. MATERIALS AND METHODS The antiasthmatic activity of FFALF was evaluated by histamine or acetylcholine-induced bronchospasm model in guinea pigs, compound 48/80 induced mast cell degranulation in albino rats and histamine-...

What sets the maximal size of insects? Results suggest that larger insects invest a greater fraction of their body as respiratory system (tracheal hypermetry). Simple models indicate that tracheal hypermetry prevents increases in PO2 gradients down the tracheae of larger insects. Tracheal hypermetry may lead to spatial constraints within the exoskeleton that provide a maximal limit on insect si...

Acquired tracheal stenosis remains a challenging problem for otolaryngologists. The objective of this study was to determine whether the Sendai virus (SeV)-mediated c-myc suppressor, a far upstream element (FUSE)-binding protein (FBP)-interacting repressor (FIR), modulates wound healing of the airway mucosa, and whether it prevents tracheal stenosis in an animal model of induced mucosal injury....

Respiratory tract lesions induced by sulfur mustard (SM), a chemical warfare agent, are characterized by epithelial damage associated with inflammatory cell infiltration. To test the potential role of matrix metalloproteinase gelatinases in these lesions, we evaluated gelatinase activity, albumin content, and total cell count in bronchoalveolar lavage fluid of guinea pigs 24 h after an intratra...

Several epidemiological studies suggest that exposure to house dust mite allergens plays a role in the pathogenesis of asthma. Since many of these allergens exhibit enzymatic properties, they may damage the airway epithelium. To characterize the effects of low doses of Dermatophagoides pteronyssinus on the airway epithelium, the effect of D. pteronyssinus on the epithelial bioelectric propertie...

In resting tethered locusts, the effect of slow changes in tracheal air pressure on peripheral auditory information processing was analysed. The tympanal membrane vibrations, the pressure inside the tracheal system and the summed activity of the auditory receptors were measured simultaneously. With the membrane in the resting position, laser vibrometry and Fast Fourier Transformation analysis o...

Focal non-neoplastic stenoses of the trachea are uncommon and many of these are complications of either endotracheal intubation or placement of tracheostomy tube. The pathogenesis of post-intubation tracheal stenoses (PITS) may be related to multiple factors (infection due to bacterial colonization, meccanical irritation, hypotension, gastroesophageal reflux, underlying illness), but the ischem...

This study was undertaken to investigate the putative mechanism(s) underlying the antispasmodic effect of 7-epiclusianone, a naturally occurring compound isolated from the plant Garcinia brasiliensis. Guinea pig tracheal rings were mounted in tissue baths filled with Krebs' solution, and the contractile response to distinct stimuli was measured in the presence or absence of 7-epiclusianone. We ...

Adenosine induces dyspnea, cough, and airways obstruction in asthma, a phenomenon that also occurs in various sensitized animal models in which a neuronal involvement has been implicated. Although adenosine has been suggested to activate cholinergic nerves, the precise mechanism has not been established. In the present study, the adenosine A(1) receptor agonist N(6)-cyclopentyladenosine (CPA) i...