Biorheology - Volume 20, issue 2

Authors: Silberberg, A.

Article Type: Research Article

Abstract: In mucociliary clearance mucus has been found to be essential as coupler between ciliary beat and transport. The rheological properties of mucus are carefully matched to this task. It has to be an incipient gel and deviations from this state, to a sol or to a stiff gel, both render it defective in function. The known rheological properties of normal mucus are shown to be consistent with our understanding of how a periodically interacting set of cilia produce mucus layer flow. A dual requirement has to be met: Adequate tip penetration and adequate force transfer laterally. As a result any …biorheologically properly matched system can replace mucus. Mucociliary clearance is a clear cut, rather well understood case of a general principle of biorheological matching. Show more

Keywords: Mucociliary clearance, biorheological matching, muco-ciliary interaction, Mucus viscoelasticity

DOI: 10.3233/BIR-1983-20211

Citation: Biorheology, vol. 20, no. 2, pp. 215-222, 1983

Authors: Verdugo, P. | Tam, P.Y. | Butler, J.

Article Type: Research Article

Abstract: Samples of respiratory mucus were obtained from the trachea of dogs and patients undergoing bronchoscopy. The samples were studied by laser correlation spectroscopy. The autocorrelation function of laser light scattered by both human and canine respiratory mucus was a single exponential in thick mucus or a double exponential in thin watery mucus. This finding suggests that, as in the case of uterine cervical mucus, the molecular structure of respiratory mucus is an ensemble of entangled, randomly-coiled glycoproteins forming a loose network of variable density rather than a covalently cross-linked molecular network as proposed in earlier studies.

Keywords: respiratory mucus, molecular structure, laser scattering spectroscopy

DOI: 10.3233/BIR-1983-20212

Citation: Biorheology, vol. 20, no. 2, pp. 223-230, 1983

Authors: Okubo, T. | Shimura, S. | Takishima, T. | Otubo, Y. | Umeya, K.

Article Type: Research Article

Abstract: We studies the frequency dependence of viscoelastic behavior of human sputum using our newly developed Raised Cosine Pulse (RCP) method. This method needs only 1.5 ml sputum, and allows us to estimate the responses of storage modulus (G ′ ) and loss modulus (G ″ ) to the change of angular frequency ω = 10 − 3 − 10 0 rad.sec−1 in only 2–3 minutes by applying one small pulse strain. Measurements were made at 37°C and within 2 hours …of expulsion. The results obtained by the RCP method and by a conventional method were compared and were roughly in agreement. From the behavior of G ′ and G ″ , the presence of a relaxation region at ω = 3 × 10 − 2 − 3 × 10 − 1 rad.sec−1 could be deduced. The magnitude of relaxation increased and relaxation frequencies decreased, as the purulence of sputum increased. We also observed differences in viscoelastic behavior of sputum resulting from the application of mucolytic agents in vivo, which suggest corresponding changes of mechanical structures to the different pharmacological actions of these drugs. Show more

Keywords: Sputum viscoelasticity, relaxation region, mucolytic agents

DOI: 10.3233/BIR-1983-20213

Citation: Biorheology, vol. 20, no. 2, pp. 231-238, 1983

Authors: Puchelle, E. | Zahm, J.M. | Duvivier, C.

Article Type: Research Article

Abstract: Spinability of normal mucus and of sputum collected in chronic bronchitic patients was measured using an automatic device derived from that developed by Chretien et al (1977) for cervical mucus. Spinability of sputum decreased as the purulence increased. Although significant correlations were found between spinability and apparent viscosity (r = − 0.50 , p < 0.05 ) or elasticity (r = 0.54 , P < 0.02 ), large variations in spinability were observed for sputum samples ranging in a zone of low viscosity and elasticity. Sputum with high spinability exhibited normal transport …rate on the depleted frog palate although their viscosity and elasticity were abnormally low. The significant correlation obtained between spinability and sputum transport rate (r = 0.61 , p < 0.01 ) suggests that this rheological factor, along with viscosity and elasticity, plays an important role in the mucociliary transport mechanism. Show more

Keywords: Respiratory mucus, spinability, viscoelasticity, mucociliary transport

DOI: 10.3233/BIR-1983-20214

Citation: Biorheology, vol. 20, no. 2, pp. 239-249, 1983

Authors: Majima, Yuichi | Sakakura, Yasuo | Matsubara, Takashi | Murai, Sumiko | Miyoshi, Yasuro

Article Type: Research Article

Abstract: Nasal mucociliary clearance was measured in both healthy subjects and patients with chronic sinusitis using saccharin granule technique. Nasal mucociliary transit time (ST) was significantly slower in the patients with chronic sinusitis compared with that in controls (p < 0.005 ). Nasal mucus collected from each nasal cavity was used for in vitro bullfrog palate clearance studies and compared to the in vivo nasal ST. Mucociliary clearance rate (MTR) on frog palate was 12.5 ± 2.5 mm/min in the mucus from control subjects, 6.1 ± 1.5 mm/min in the mucus from the patients. The difference was statistically significant …(p < 0.005 ). The MTR on frog palate in the patients whose nasal ST was within normal range was significantly slower than that in controls (p < 0.005 ), but not significantly different from that in the patients whose nasal ST was over the normal range. These results suggest that the nasal mucous properties which decreased the mucociliary clearance on frog palate did not contribute to the mucociliary clearance of the patients who had a normal one. No significant correlation existed between MTR on frog palate and nasal ST in both control and chronic sinusitis. In chronic sinusitis patients, decelerated nasal ST was recovered significantly by normal saline nebulization compared with the value before the nebulization (p < 0.01 ). None of the significant change of ST was observed in control before and after the nebulization. Show more

Keywords: Mucociliary transport, mucus, chronic sinusitis, chronic airway disease

DOI: 10.3233/BIR-1983-20215

Citation: Biorheology, vol. 20, no. 2, pp. 251-262, 1983