Biomedical subjects

S Joki

Publications and source records attributed to S Joki.

11 recordsLinked to original sources

PubMed1998

Correlation between ciliary beat frequency and the structure of ciliated epithelia in pathologic human nasal mucosa.

The structure and function of ciliated epithelium were studied in 44 human nasal mucosa samples using a photoelectric method and scanning electron microscopy (SEM). The ciliary beat frequency (CBF) of cases with recurrent or chronic sinusitis was 9.1 +/- 5.4 Hz. In eight of the samples (18.2%) no ciliary activity was detected. The amount of ciliated cells, the orientation of cilia, epithelial metaplasia, and secretion were found to be explanatory factors accounting for the decreased ciliary activity. Ciliary disorientation and a lack of ciliated cells in SEM correlated with low ciliary activity. In cases where sinusitis secretion was not seen, the CBF was slower than in cases with mucus or mucopurulent secretion. Sinusitis with disoriented cilia, a loss of ciliated cells, and a lack of mucosal secretion is associated with a decreased CBF. This may lead to impaired mucociliary clearance and increase the risk of recurrent and chronic sinusitis.

Adolescent↗

PubMed1997

Influence of ageing on ciliary beat frequency and on ciliary response to leukotriene D4 in guinea-pig tracheal epithelium.

1. In the present study on guinea-pig tracheal epithelium, the influence of age on ciliary beat frequency (CBF) was investigated. 2. An age-dependent decrease in CBF was seen: as the age of the guinea-pig increased from 0.9 to 16.3 months, CBF decreased from 20.2 to 6.9 Hz. 3. The effect of leukotriene D4 (LTD4) on CBF was also examined using tracheal explants from guinea-pigs of varying ages. The lower CBF of the older animal was increased by LTD4 to a larger extent than was the higher CBF seen in explants taken from younger animals. 4. Ciliary activity and possibly also the sensitivity of the cilia to drugs, seems to be dependent upon the age of the animal, which has to be taken into consideration when comparing the results of different studies on the effects of xenobiotics on mucociliary function.

Aging↗

PubMed1996

Effect of leukotriene D4 on ciliary activity in human, guinea-pig and rat respiratory mucosa.

Leukotriene D4 (LTD4) is a potent bronchoconstrictor and inflammatory mediator in asthma. Data concerning the effects of LTD4 on ciliary function in the respiratory tract are sparse and contradictory. The purpose of the present study was to clarify the effects of LTD4 on mucociliary activity using the tracheal mucosa of two laboratory animal species, guinea-pig and rat, as well as human nasal mucosa. The ciliary beat frequency (CBF) was measured photoelectrically and determined by Fast Fourier Transform computer analysis. Additionally the structure of ciliated epithelia of guinea-pig trachea after LTD4-immersion was investigated using a scanning electron microscope (SEM). In all tissues, LTD4 increased CBF showing a bell-shaped dose-response curve. The maximum effect was 75 +/- 30% in guinea-pig at 10(-9) mol/l, 119 +/- 49% in rat at 10(-7) mol/l, and 86 +/- 28% at 10(-6) mol/l in human tissue. In guinea-pig tracheal mucosa, there was an indication of an increase in the amount of mucus and disorientation of cilia were seen by SEM after immersion in LTD4. These findings suggest that LTD4 stimulates ciliary activity, but impairs the orientation of cilia.

Adolescent↗

PubMed1995

Ciliary ultrastructure and beating activity in rat and guinea-pig respiratory mucosa.

1. The rat and the guinea-pig are commonly used animals when the effects of drugs on ciliary activity in respiratory airways are studied. There are few data concerning the possible differences in ciliary function between these two animals. 2. Using a photodetector method we measured the ciliary beating frequency (CBF) from the upper part of the trachea, the lower part of the trachea and the distal part of the main bronchi (subsegmental bronchi) of rat and guinea-pig respiratory tract. In addition, the structure of the cilia was studied using scanning electron microscopy (SEM). 3. CBF in the rat respiratory tract was significantly lower than in the guinea-pigs. In the upper trachea, the CBF for rat was 12.7 beats/s and 15.3 beats/s for guinea-pig. The respective values were 9.2/16.0 beats/s in the lower part of the trachea and 6.9/13.8 beats/s in subsegmental bronchi. In both rats and guinea-pigs CBF was lower in the subsegmental bronchi than in the trachea (rat: 25.0-45.7%, guinea-pig: 9.8-13.8%). 4. In addition to higher CBF, the quality of the photo-electrical signal was better from guinea-pig tissues, probably as a result of the larger amounts of ciliated cells and longer cilia of guinea-pig respiratory epithelial compared to those in rat mucosa. 5. SEM showed that the rat cilia were on average shorter (3.6 vs 4.3 microns) and thinner (0.19 vs 0.22 microns) than those of the guinea-pig. Rat mucosa was markedly less ciliated than the respiratory mucosa of the guinea-pig.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Ciliary beat frequency at six levels of the respiratory tract in cow, dog, guinea-pig, pig, rabbit and rat.

1. The ciliary beat frequency (CBF) of six animal species from six regions of the respiratory tract were measured: inferior turbinate, nasopharynx, the upper part of trachea from first to second cartilage, the lower part of trachea, main bronchus and subsegmental bronchi. Cow, pig, dog, rabbit, guinea-pig and rat were studied. 2. There were no significant differences in the CBF values between cow, pig and dog, and the ciliary activity was essentially the same (11.3-16.9 Hz) in all parts of the respiratory tract. 3. In the rat, the CBF was slower, especially in subsegmental bronchi (6.8 Hz). 4. In general, CBF was higher in upper than lower airways, with the exception of guinea-pig. 5. Signal quality was the highest in guinea-pig tissue, whereas rat tissue produced the signal with the widest variation in CBF and the highest proportion of distorted waveforms. 6. Therefore, for studying drug effects on ciliary activity, guinea-pig seems to be a more suitable animal than the more commonly used rabbit or rat. In drug comparisons, the same part of the respiratory tract and the same animal species should be used.

Analysis of Variance↗

PubMed1993

Ciliary beating frequency in chronic sinusitis.

Ciliary beating frequency, one component of mucociliary function, was measured outside of the sinus in vitro with a photoelectric method in 150 patients with chronic sinusitis and in 26 control subjects. In the mucosal samples of 35 patients (23%), no ciliary activity was seen. Ciliary beating frequency in maxillary sinus mucosa of the rest of the 115 patients (77%) was, as an average, 16.6 +/- 3.0 Hz (range, 10.9 to 23.3 Hz) and it was 15.9 +/- 2.6 Hz (range, 13.2 to 22.8 Hz) for the control patients. No differences in ciliary beating frequency were found according to quality of sinus secretion, prevalent respiratory allergy, or mucosal thickness. However, in sinuses with purulent secretion, ciliary beating frequency was slightly better (P < .05) than in "empty" sinuses. The study suggests that in many cases of chronic sinusitis, the sinus mucosa still has a capacity to recure.

Adolescent↗

PubMed1993

Influence of chinoin-170, a novel antitussive, on the mucociliary activity in respiratory airways of rats, rabbits, guinea-pigs and man.

Chinoin-170 (Ch-170; 3,7-dihydro-1,3-dimethyl-7-[(5-methyl-1,2,4- oxadiazol-3-yl)methyl]1H-purine-2,6-dione) is a new antitussive with bronchodilating activity. Its effects on the ciliary beating frequency (CBF) and mucociliary clearance were studied. In tracheal explants of rats, Ch-170 dose-dependently at concentrations 2 and 5 mg mL-1 depressed CBF by 24 and 33%, respectively. In human mucosal explants, however, no effects were seen at concentrations up to 5 mg mL-1. In anaesthetized guinea-pigs, an intravenous 50 mg kg-1 dose of Ch-170 caused no changes, and 100 mg kg-1 increased the CBF by 15%. Intravenous Ch-170 dose-dependently increased by 93 (50 mg kg-1), 179 (70 mg kg-1) and 253% (100 mg kg-1) the tracheobronchial mucociliary clearance in rabbits. The effect, studied using 99mTc-labelled red blood cells as a marker, was of similar quantity to that brought about by administering 16, 25 and 40 mg kg-1 doses of bromhexine. It is concluded that unlike many older antitussives, Ch-170 in-vitro only slightly decreases the CBF in rats and has no adverse effects on the CBF in human mucosal explants at concentrations up to 5 mg mL-1. In-vivo, Ch-170 does not significantly alter the CBF in guinea-pigs, but dose-dependently increases the mucociliary clearance in rabbits. The increase is most probably a result of changes in the production and the properties of respiratory mucus.

Animals↗

PubMed1992

Influence of azelastine and some selected drugs on mucociliary clearance.

The effect of azelastine and some selected compounds on ciliary beating frequency (CBF) was investigated in vitro using human mucosal samples and in vivo using anesthetized guinea pigs. Further influence of azelastine on mucus secretion was evaluated in mice and on mucociliary clearance in anesthetized rabbits. Azelastine influenced the ciliary beating frequency neither in vitro nor in vivo. Azelastine, similarly to salbutamol, ambroxol, and bromhexine, increased mucus secretion measured by the tracheal output of phenol red. Azelastine dose-dependently enhanced mucociliary clearance measured by elimination of 99mTc-labeled erythrocytes in rabbits. The activity of azelastine proved to be about 10 times stronger than that of bromhexine. Since the ciliary activity remained unchanged under the influence of azelastine, it is likely that azelastine increases the mucociliary clearance by enhancing bronchial secretion. It is possible that the observed increase in mucociliary clearance may contribute to the beneficial effect of azelastine in the treatment of respiratory diseases.

Animals↗

PubMed1992

ATP induces respiratory ciliostimulation in rat and guinea pig in vitro and in vivo.

Adenosine triphosphate (ATP) has been shown to revitalize the disturbed nasal mucociliary function in man. We investigated the effects of ATP on the ciliary beat frequency (CBF) in animals by immersing tracheal explants from rats in various concentrations of ATP, and by infusing ATP intravenously to guinea pigs. CBF was measured with a photodetector technique from the surface of the explants or from the incised trachea. ATP (from 0.01 to 1 mg/ml) in vitro increased CBF in rat tracheal explants up to 10.5% (p less than 0.05). In vivo ATP (1 mg/kg) increased the CBF by 29% (p less than 0.01) in the guinea pig trachea. As the CBF was increased by ATP, both in vitro and in vivo, it can be suggested that the improvement in mucociliary transport by exogenous ATP as shown in previous studies is caused by the ciliostimulatory effect of ATP.

Adenosine Triphosphate↗

PubMed1991

Effect of codeine on rat and guinea pig tracheal ciliary beat frequency.

Codeine, the basic antitussive drug, has generally been thought to impair mucociliary function. Using the photodetection method the effect of codeine on mucociliary function was studied in rat after local and systemic administration and in guinea pig after systemic administration. In vitro rat tracheal ciliary beat frequency (CBF) was measured up to 40 min. There was 24.6 +/- 2.5% and 26.6 +/- 1.6% decrease in CBF after 1 mg/ml and after 10 mg/ml codeine solutions, respectively. In vivo codeine was administered in single i.v. doses of 10 and 15 mg/kg. No statistically significant differences were found in CBF responses, although there was a CBF decreasing tendency after the 15 mg/kg dose. The total follow-up time was 120 min. In guinea pig, 10 days s.c. codeine administration in daily doses of 3, 10 and 30 mg/kg had no effect on CBF. Although codeine was used in much higher concentrations than tissues concentrations after therapeutic doses of codeine, the effects on CBF were minimal. So it can be concluded that the generally accepted ciliostatic effect of codeine is overestimated.

Animals↗

PubMed1991

The effect of ATP on the ciliary activity of normal and pathological human respiratory mucosa in vitro.

The effect of adenosine triphosphate (ATP) on the airway ciliary beating frequency (CBF) of mucosal explants excised from human maxillary sinuses was studied by measuring CBF photoelectrically before and after immersion of the explants in a solution containing ATP. In samples from 64 patients with chronic sinusitis the CBF was not significantly different from the CBF in mucosal specimens from healthy tissue of 22 patients without infection. During 15 min immersion, ATP (1 mg/ml) slightly (by 5%, p less than 0.05 in healthy tissue; by 2.7%, p less than 0.01, in tissue from sinusitis patients) increased the CBF. The effect of 10 mg/ml concentration was more pronounced (19.6%). It is concluded that the impairment in ciliary function caused by chronic sinusitis is reversible when the mucosal endothelium is cleansed of the infected mucus, and that the ciliostimulatory action of ATP seen in animals is also present in human respiratory mucosa.

Adenosine Triphosphate↗