292 Outward and inward mucosal permeabilities in histamine-exposed animal and human airways

1991 ◽  
Vol 87 (1) ◽  
pp. 212
Author(s):  
L GREIFF ◽  
I ERJEFALT ◽  
P WOLLMER ◽  
U ALKNER ◽  
U PIPKORN
Keyword(s):  
Author(s):  
Digamber Singh

The human respiratory tract has a complex airflow pattern. If any obstruction is present in the airways, it will change the airflow pattern and deposit particles inside the airways. This is the concern of breath quality (inspired air), and it is decreasing due to the unplanned production of material goods. This is a primary cause of respiratory illness (asthma, cancer, etc.). Therefore, it is important to identify the flow characteristics in the human airways and airways with a glomus tumour with particle deposition. A numerical diagnosis is presented with an asymmetric unsteady-state light breathing condition (10 l/min). An in vitro human respiratory tract model has been reconstructed using computed tomography scan techniques and an artificial glomus tumour developed 2 cm above a carina on the posterior wall of the trachea. The transient flow characteristics are numerically simulated with a realizable (low Reynolds number) k–ɛ turbulence model. The flow disturbance is captured around the tumour, which influenced the upstream and downstream of the flow. The flow velocity pattern, wall shear stress and probable area of inflammation (hotspot) due to suspended particle deposition are determined, which may assist doctors more effectively in aerosol therapy and prosthetics of human airways illness.


1983 ◽  
Vol 14 (3) ◽  
pp. 184-186 ◽  
Author(s):  
C. Melandri ◽  
G. Tarroni ◽  
V. Prodi ◽  
T.De Zaiacomo ◽  
M. Formignani ◽  
...  

1991 ◽  
Vol 203 (2) ◽  
pp. 187-194 ◽  
Author(s):  
Roberto Jongejan ◽  
Johan De Jongste ◽  
Rolien Raatgeep ◽  
Theo Stijnen ◽  
Ivan Bonta ◽  
...  

Thorax ◽  
2001 ◽  
Vol 56 (6) ◽  
pp. 427-431 ◽  
Author(s):  
T Tschernig ◽  
A S Debertin ◽  
F Paulsen ◽  
W J Kleemann ◽  
R Pabst

BACKGROUNDDendritic cells (DCs) in the mucosa of the respiratory tract might be involved in the early development of pulmonary allergy or tolerance. To date, little is known about when the first DCs occur in human airways.METHODSSpecimens of the distal trachea from patients who had died from sudden death in the first year of life (n=29) and in older age groups (n=59) as well as from those who had died from respiratory tract infections in the first year of life (n=8) were examined by immunohistochemistry. Transmission electron microscopy was performed in additional samples from two adults.RESULTSIn the sudden death subgroup DCs were absent in 76% of those who died in the first year of life but were present in 53 of the 59 older cases. All infants who had died of respiratory infectious diseases had DCs in the tracheal mucosa.CONCLUSIONSMature DCs are not constitutively present in the human tracheobronchial mucosa in the first year of life, but their occurrence seems to be triggered by infectious stimuli. These data support the hypothesis that DCs play a crucial role in immunoregulation in early childhood.


2018 ◽  
Vol 180 ◽  
pp. 02068
Author(s):  
Ondrej Misik ◽  
Frantisek Lizal ◽  
Vahid Farhikhteh Asl ◽  
Miloslav Belka ◽  
Jan Jedelsky ◽  
...  

Inhalers are hand-held devices which are used for administration of therapeutic aerosols via inhalation. Nebulizers are larger devices serving for home and hospital care using inhaled medication. This contribution describes the basic principles of dispersion of aerosol particles used in various types of inhalers and nebulizers, and lists the basic physical mechanisms contributing to the deposition of inhaled particles in the human airways. The second part of this article presents experimental setup, methodology and preliminary results of particle size distributions produced by several selected inhalers and nebulizers.


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