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Title Age-dependence and intersubject variability of tracheobronchial particle clearance
Author Robert Sturm
Abstract Background: The detailed study of tracheobronchial clearance of inhaled particles represents one of the basic research questions in lung medicine. The clearance efficiency varies in different age groups and between males and females.The differences can be partly clarified by the application of a well validated theoretical approach. This study applied a relevant model to children (1 year, 5 years, 10 years), juveniles (15 years), and adults of different ages (18, 21, 25, 34, 50, and 60 years) and to both sexes. Methods: The mathematical model used for clearance simulation is based on the concept of a stochastic lung structure and considers both early fast mucociliary clearance and a later, slow clearance fraction, fs, effected by particular uptake by tracheobronchial cells, e.g., macrophages and epithelial cells. According to this model, the calculated mucus velocities for each airway generation of the tracheobronchial compartment are normalized to a respective tracheal mucus velocity that is estimated for each of the age groups studied from an allometric function. Results: In general, tracheobronchial clearance efficiency undergoes a significant increase from childhood to young adulthood, reaching a maximum at 25-30 years and decreasing again from about 30 years to 60 years. Conversely to the improvement of clearance, the continuous change of airway morphometry with increasing age causes a decrease of the filtering effect in the trachea and main bronchi, which is of marked importance in infants. The modelling results demonstrate differences in tracheobronchial clearance between males and females, generally in the range from 0 to 5%, which are exclusively determined by the individual lung geometry. Conclusions: Based on theoretical computations it can be concluded that tracheobronchial clearance is a phenomenon that depends on both age and sex. Biological studies are necessary to determine the cellular and molecular mechanisms underlying the age-dependent development of tracheobronchial clearance.
1. Lippmann M, Albert RE. The effect of particle size on the regional deposition of inhaled aerosols in the human respiratory tract. Am Ind Hyg Assoc J 1969;30:257-75.

 2. Lippmann M, Yeates DB, Albert RE. Deposition, retention, and clearance of inhaled particles. Brit J Ind Med 1980;37:337-62.

 3. Cuddihy RG, Yeh HC. Respiratory tract clearance of particles and substances dissociated from particles. In: Mohr U (editor). Inhalation toxicology: The design and interpretation of 
inhalation studies and their use in risk assessment. Springer, Berlin, 1988, pp. 169-193.

 4. Oberdörster G. Lung clearance of inhaled insoluble and soluble particles. J Aerosol Med 1988;1:289-330.

 5. Albert RE, Lippmann M, Briscoe W. The characteristics of bronchial clearance in humans and the effects of cigarette smoking. Arch Environ Health 1969;18:738-55.

 6. Albert RE, Lippmann M, Peterson Jr HT, Berger J, Sanborn K, Bohning D. Bronchial deposition and clearance of aerosols. Arch Int Med 1973;131:115-27.

 7. Stahlhofen W, Gebhart J, Rudolf G, Scheuch G. Measurement of lung clearance with pulses of radioactivity-labelled aerosols.J Aerosol Sci 1986;17:333-6.

 8. Stahlhofen W, Koebrich R, Rudolf G, Scheuch G. Short-term and long-term clearance of particles from the upper human respiratory tract as a function of particle size. J Aerosol Sci 

 9. Stahlhofen W, Scheuch G, Bailey MR. Measurement of the tracheobronchial clearance of particles after aerosol bolus inhalation. In: Dodgson J, McCallum RI (editors). Inhaled particles VII, Proceedings of an international symposium on inhaled particles organized by the British Occupational Hygiene Society. Oxford University Press, Oxford, 1994, pp. 189-196.

 10. Stahlhofen W. Human lung clearance following bolus inhalation of radioaerosols. In: Crapo JD, Smolko ED, Miller FJ, Graham JA, Hayes AW (editors). Extrapolation of dosimetric relationships 
for inhaled particles and gases. Academic Press, Washington, 1989, pp. 153-166.

 11. Scheuch G, Kreyling W, Haas F, Stahlhofen W. The clearance of polystyrene particles from UO2 fuel element fabrication. Health Phys 1993;48:29-48.

 12. International Commission on Radiological Protection (ICRP).Human respiratory tract model for radiological protection. Publication 66. Ann. ICRP. Pergamon Press, Oxford, 1994. 13. Sturm R, Hofmann W, Scheuch G, Sommerer K, Svartengren 

M, Camner P. Particle clearance in human bronchial airways: Comparison of stochastic model predictions with experimental data. Ann Occup Hyg 2002;46(Suppl 1):329-33.

 14. Iravani JD, Van As A. Mucus transport in the tracheobronchial tree of normal and bronchitic rats. J Pathol 1972;106:81-93.

 15. Mercer RR, Russell ML, Crapo JD. Mucous lining layers in human and rat airways. Ann Rev Resp Dis 1992;145:A355.

 16. Phalen RF, Oldham MJ, Beaucage CB, Crocker TT, Mortensen JD. Postnatal enlargement of human tracheobronchial airways and implications for particle deposition. Anat Rec 1985;212: 368-80.

 17. Hofmann W, Bergmann R, Ménache MG. The effect of intersubject variability in airway morphology on intersubject variations in particle deposition. J Aerosol Sci 1998;29:S943-4.

 18. Abd El Hady M, Hofmann W, Bergmann R. The effect of intersubject variability in lung morphometry on particle deposition. J Aerosol Sci 1997;28:S623-4.

 19. Asgharian B, Hofmann W, Bergmann R. Particle deposition in a multiple-path model of the human lung. Aerosol Sci Technol 2001;34:332-9.

 20. Yeates DB, Aspin N, Levison H, Jones MT, Brian AC. Mucociliary tracheal transport rates in man. J Appl Physiol 1975;39:487-95.

 21. Goodman RM, Yergin BM, Landa JF, Golvinaux MH, Sackner MA. Relationship of smoking history and pulmonary function tests to tracheal mucous velocity in nonsmokers, young smokers, ex-smokers, and patients with chronic bronchitis. Am Rev Resp  Dis 1977;117:205-14.

 22. Santa Cruz R, Landa J, Hirsch J, Sackner MA. Tracheal mucous velocity in normal man and patients with obstructive lung disease; effects of terbutaline. Am Rev Resp Dis 1974;109:458-63.

23. Mauderly JL, Hahn FF. Advances in Veterinary Science and Comparative Medicine: The Respiratory System. Vol. 26. Academic Press, New York, 1982.

24. Wolff RK. Mucociliary Function. In: Parent RA. (editor). Comparative Biology of the Normal Lung. CRC Press, New York, 1989, pp. 659-680.

25. Valberg PA, Wolff RK, Mauderly JL. Redistribution of retained particles: effect of hypernea. Am Rev Resp Dis 1985;131:273-80.

26. Gross D, Zidulka A, O’Brien C, Wight D, Fraser R, Rosenthal L, et al. Peripheral mucociliary clearance with high-frequency chest wall compression. J Appl Physiol 1985;58:1157-63.

27. Bateman JRM, Clarke SW, Pavia D, Sheahan NF. Reduction in clearance of secretions from the human lung during sleep. J Physiol Lond 1978;284:55.

28. Sturgess JM. Mucous secretions in the respiratory tract. Ped Clin N Am 1979;26:481.

29. Ménache MG. Conducting airway geometry in the human lung as a function of age: Development of airway geometry models for dosimetry calculations. UMI Dissertation Services, Ann Arbor, MN, 1997.

30. Philipson K, Falk R, Svartengren M, Jarvis N, Bailey M, Bergmann R, et al. Does lung retention of inhaled particles depend on their geometric diameter? Exp Lung Res 2000;26:437-55.

31. Koblinger L, Hofmann W. Monte Carlo modeling of aerosol deposition in human lungs. Part I: Simulation of particle transport in a stochastic lung structure. J Aerosol Sci 1990;21:661-74.

32. Hofmann W, Sturm R. Stochastic model of particle clearance in human bronchial airways. J Aerosol Med 2004;17:73-89.

33. Sturm R, Hofmann W. Mechanistic interpretation of the slow bronchial clearance phase. Radiat Prot Dosimetry 2003;105:101-4.

34. Sturm R, Hofmann W. Stochastic modeling predictions for the clearance of insoluble particle from the tracheobronchial tree of the human lung. Bull Math Biol 2007;69:395-415.

35. Asgharian B, Hofmann W, Miller FJ. Mucociliary clearance of insoluble particles from the tracheobronchial airways of the human lung. J Aerosol Sci 2001;32:817-32.

36. Hofmann W, Koblinger L. Monte Carlo modeling of aerosol deposition in human lungs. Part III: Comparison with experimental data. J Aerosol Sci 1992;23:51-63.

37. Winkler-Heil R, Sturm R, Hofmann W. Calculation of therapeutic aerosol deposition in cystic fibrosis patients. J Aerosol Med 2001;14:414.

38. Martonen T, Kratz I, Cress W. Aerosol Deposition as a Function of Airway Disease: Cystic Fibrosis. Pharm Res 1995;12:96-102.

39. Puchelle E, Zahm JM, Bertrand A. Influence of age on bronchial mucociliary transport. Scand J Resp Dis 1979;60:307-13.

40. Pavia D, Bateman JRM, Clarke SW. Deposition and clearance of inhaled particles. Bull Eu Physiopathol Respir 1980;16: 335-66.

41. Myrianthefs PM, Sznajder JI, Baltopoulos G. Lung Edema Clearance. Pneumon 2006;19:14-21.

42. Vittοrakis S, Gaga M, Oikonomidou E, Samitas K, Xοrianopoulos D. Immunological mechanisms in the lung. Pneumon 2007;20:274-278.

Keywords Intersubject variability, deposition, clearance, tracheobronchial tree, inhaled particles
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