Biomedical subjects

E Toskala

Publications and source records attributed to E Toskala.

11 recordsLinked to original sources

PubMed2000

Three-dimensional organization of the lamina reticularis in the rat tracheal basement membrane zone.

The airway basement membrane zone is a region specialized for the attachment of the epithelium with the matrix. The epithelium is attached to the lamina densa, which, in turn, is connected to types I and III collagen of the lamina reticularis with anchoring fibrils. The purpose of this study was to define the three-dimensional organization of the structural proteins of the lamina reticularis in the rat trachea. We approached this problem by using whole mounts to look down on the flat surface of the basement-membrane zone rather than a cross section of its thin profile. Fluorescent microscopy with long working distance water immersion objectives and scanning electron microscopy revealed that the structural proteins are arranged as a mat of large fibers oriented along the longitudinal axis of the airway. Smaller fibers are crosslinked with the larger fibers to complete this structure. Other small fibers are oriented around the large fibers and an amorphous material covers individual fibers. The large fibers oriented along the longitudinal axis of the airway are consistent with prior descriptions of fibers composed of collagen III with some collagen I and V; small fibers encircling the large fibers may be collagen VI. The crosslinking fibers are made up of elastin and probably elastin-associated microfibrils. The amorphous proteins covering the fibrous framework may contain proteoglycans and other nonstructural proteins reported to be in the lamina reticularis. The present studies demonstrate that the structural proteins of the lamina reticularis in the rat trachea are arranged as fibers in a highly organized manner.

Animals↗

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

Ciliary ultrastructure in experimental sinusitis.

Ultrastructure of respiratory cilia was observed in experimental sinusitis of rabbit maxillary sinuses. Sinus mucosa of 15 rabbits was inoculated with Streptococcus pneumonia bacteria and of 16 rabbits with Bacteroides fragilis bacteria. Specimens were taken during 12 weeks' observation time and they were studied by transmission electron microscopy from the cross-sections. A special emphasis was paid to the number of cilia, the ciliary orientation, the tubular anomalies, the presence of dynein arms and the compound cilia. It seems likely that pneumococcal sinusitis is a more toxic infection to the epithelium causing loss of ciliated cells and cilia than B. fragilis infection. In anaerobic infection ciliary ultrastructure remains normal and dynein arms as well as normal tubular ultrastructure were seen even after 12 weeks' infection.

Animals↗

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

Scanning electron microscopy findings of human respiratory cilia in chronic sinusitis and in recurrent respiratory infections.

Acute and chronic infections cause morphological changes in the respiratory mucosa. The ultrastructure of human respiratory mucosa was studied by scanning electron microscopy from the maxillary sinuses of 28 patients, with chronic sinusitis, from middle turbinates of 60 patients, with recurrent respiratory infections, and from healthy sphenoidal sinuses of 31 patients. A loss of ciliated cells and an increasing number of nonciliated columnar cells with microvilli were seen in 62 per cent of the maxillary sinus mucosa. Ciliary disorientation was seen in 81 per cent of the chronically infected sinus mucosa and eight per cent in the healthy sphenoidal sinuses. Also metaplasia and extrusion of epithelial cells were prominent in chronic infections. Compound cilia were seen in 52 per cent of the samples from patients with chronic sinusitis and in 31 per cent of the healthy sphenoidal sinuses. Short cilia were often seen in infected mucosa indicating ciliogenesis.

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↗

PubMed1995

The correlation of mucociliary transport and scanning electron microscopy of nasal mucosa.

The ciliary ultrastructure studied by scanning electron microscopy (SEM), nasal mucociliary transport rate (MTR) measured by a radioisotopic method and their correlation with each other were studied in 56 patients with recurrent or chronic respiratory infections. Patients were divided into three groups according to MTR. The number of pathological SEM findings increased remarkably in groups with moderate or poor MTR. Loss of ciliated cells and microvilli were seen in 86% of specimens with poor MTR, in 71% with moderate MTR, and in 50% with good MTR. There was ciliary disorientation in 45% of cases with poor MTR compared with 25% in cases with good MTR. Epithelial metaplasia and the number of short cilia increased in groups with poor or moderate MTR.

Adolescent↗

PubMed1995

The influence of specimen preparation on artefacts in scanning electron microscopy of respiratory cilia.

The effects of various handling procedures used in preparing specimens of human and pig respiratory mucosa for scanning electron microscopy (SEM) were studied. Using five different washing methods, the percentage area of mucosa covered with extracellular material varied from 1.5 to 53.1%. The best results were achieved when specimens were washed by gently inverting a sample 30 times in a container filled with physiological saline. Fixation and drying of the surface layer caused disorientation of cilia and made examination difficult. Mechanical damage caused loss of cilia and rupture of the cell membrane. For SEM of respiratory cilia it is important to wash the specimen in saline before fixation and to use biopsy forceps as little as possible.

Animals↗

PubMed1995

Gold coating of respiratory cilia for scanning electron microscopy.

The optimal thickness of gold coating of cilia for scanning electron microscopy was studied using respiratory mucosa obtained from pigs. We tested 8 different coating times, from 10 seconds to 4 minutes, which resulted in gold layer thicknesses varying from 16 +/- 1 nm to 100 +/- 3 nm. The thickness of the gold layer with a coating time of 60 seconds and voltage of 2.5 kV was 43 +/- 5 nm. This thickness of gold layer gave good image quality without causing any electric charging. With thinner gold films, the amount of electric charging increased. When the coating time was longer, the gold layer was thicker but image quality did not improve. The thicknesses of the gold layers were measured using transmission electron microscopy (TEM).

Animals↗

PubMed1994

Scanning and transmission electron microscopic findings in cilia from human nasal turbinate and sinus mucosa following respiratory infection.

Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to study the ultrastructure of human respiratory cilia in 34 patients with chronic or recurrent respiratory infections and 11 control patients. Specimens of pathological mucosa were taken from 12 maxillary sinuses and 22 middle turbinates. Control tissues were taken from middle turbinates or from sphenoid sinuses during transsphenoidal pituitary surgery. Findings in control tissues or specimens with minimal amounts of pathological findings showed that TEM and SEM findings correlated well. TEM revealed axoneme structure better, while much larger populations of cilia could be studied three-dimensionally with SEM. SEM also was the better study when cilia orientations or lengths were evaluated. Optimal examination of ciliary ultrastructure required both TEM and SEM studies.

Adolescent↗

PubMed1992

A controlled study on the effect of beta-glucan-rich oat bran on serum lipids in hypercholesterolemic subjects: relation to apolipoprotein E phenotype.

The effects of beta-glucan-rich oat bran on serum lipids and lipoproteins were examined in a randomized 8-week study. After a 4-week run-in phase, subjects with mild to moderate hypercholesterolemia [serum total cholesterol (TC) 5.5-8.5 mmol/l] on cholesterol-lowering diets were randomly allocated to an oat bran (10.3 g beta-glucan/day) or wheat bran group. Thirty-six subjects (20 in the oat bran group, 16 in the wheat bran group) completed the study. The diet was identical in both groups during the trial and no significant changes in body weight were found. Serum TC and low-density lipoprotein cholesterol (LDL-C) significantly declined in the oat bran group during the first 4 weeks from 7.03 +/- 0.81 to 6.72 +/- 0.97 (p = 0.028) and from 4.90 +/- 0.69 to 4.61 +/- 0.89 mmol/l (p = 0.038), respectively, but at 8 weeks the values were not significantly different from baseline. Changes in serum TC were mainly confined to those who ate at least two-thirds of the planned daily dose of oat bran. In wheat bran group no changes were observed in serum TC or LDL-C levels. Apolipoprotein A1 and B did not change significantly in either group. Only subjects with apolipoprotein E 3/3 phenotype (n = 12) had hypocholesterolemic response to oat bran at 4 weeks, but no change was found in those with apolipoprotein E 4/4 or 4/3 (n = 7).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗