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Biomedical subjects

M J Dulfano

Publications and source records attributed to M J Dulfano.

At least 19 recordsLinked to original sources
PubMed1985

Effect of N-acetylcysteine on the ciliary beat frequency of human bronchial explants.

The effect of N-acetylcysteine on human bronchial cilia was evaluated by measuring the changes in ciliary beat frequency (CBF) on human bronchial explants exposed to 1%, 2%, 3%, 4%, and 5% concentrations of N-acetylcysteine solution in nutrient medium. There was a progressive reduction in CBF at increasing concentration, indicating an inhibitory effect on human ciliary activity in vitro (P less than 0.05).

Acetylcysteine↗
PubMed1984

Ciliary beat frequency of human respiratory tract by different sampling techniques.

The intrinsic ciliary beat frequency of human respiratory epithelium collected by 3 different biopsy techniques was examined. Ciliated epithelium was obtained by nasal brush, endobronchial brush, and endobronchial forceps biopsies from 15 patients during bronchoscopy, and ciliary beat frequency was determined in vitro at 37 degrees C using a photoelectric technique. The overall mean beat frequencies of nasal brush biopsy, endobronchial brush biopsy, and endobronchial forceps biopsy specimens were 14.3, 14.4, and 14.6 hertz, respectively. There were no significant differences (p greater than 0.05) in the overall means. Although for a given patient ciliary beat frequency was not significantly different between specimens obtained by the 3 different biopsy techniques, the pooled mean beat frequency varied from one subject to another (p less than 0.01).

Biopsy↗
PubMed1983

Effect of pH, viscosity and ionic-strength changes on ciliary beating frequency of human bronchial explants.

1. Ciliary activity is significantly influenced by chemical and physical properties of the liquid medium in which the cilia beat. 2. We studied the effect of changes in pH, ionic strength and viscosity on the ciliary beat frequency (CBF) of explants of human respiratory mucosa. 3. Optimal CBF was elicited at pH 7 . 0-9 . 0, with a marked reduction of CBF outside these limits. The CBF was well preserved at NaCl concentrations between 5 g/l (80 mmol/l) and 12 g/l (200 mmol/l), but there was rapid loss at concentrations below 0 . 5 g/l (10 mmol/l). The cilia beat best at viscosities below 1 . 0 centipoises (1 mN s m-2). Increase of the viscosity gradually decreases CBF with a significant drop at viscosities above 87 millipoises. 4. It is concluded that the above limits may fairly accurately indicate the actual physical characteristics of the periciliary environment ('sol layer') in vivo.

Bronchi↗
PubMed1982

Ciliary inhibitory effects of asthma patients' sputum.

1. Sputum sols, obtained from patients with chronic obstructive pulmonary diseases, were applied to frogs' isolated palates and the effect on ciliary beat frequency was examined. 2. During clinical exacerbations, a significant number of asthmatic patients produced a distinct, slurry type of sputum, which induced ciliostasis. This ciliary inhibition largely disappeared with clinical improvement, at which time there was also a change of the type of sputum from slurry to mucoid. 3. Samples obtained from normal volunteers and from the great majority of the patients, excluding those with asthma, had no effect on ciliary beating.

Animals↗
PubMed1982

Sputum and ciliary inhibition in asthma.

Twenty-eight sputum samples collected from 20 patients with chronic bronchial asthma of atopic and intrinsic clinical types were incubated with human bronchial explants to study their influence on ciliary motility. Of these, 19 (68%) of the sputa exerted a ciliary inhibitory effect of varying degree in a two-hour period. Analysis of the data indicates that (1) the ciliary inhibitory effect was invariably present when patients produced a distinctive slurry sputum; (2) this occurred more frequently during clinical exacerbations; (3) the induced ciliary inhibition was reversible on removal of the sputum; (4) the intensity of the ciliary inhibitory effect decreased with clinical improvement of the patient; (5) the inhibitory effect was unrelated to the medications used; (6) it was equally common in the atopic and the intrinsic types of asthmatic patients; (7) the effect was not pH dependent or related to the degree of eosinophilia. The ciliary inhibitory factor in sputum was identified as having a molecular weight of 6000-8000. It may play a part in the pathogenesis of asthma and recognition of sputum containing it carries implications for treatment.

Asthma↗
PubMed1981

Ciliary beat frequency in human respiratory explants.

Ciliary beat frequency was measured in 60 human bronchial explants obtained by bronchoscopic biopsy. The average rate of beating, at 37 degrees C, was 12.8 +/- 1.3 beats/s, and this rate remained quite constant for periods as long as 4 h. This basic rate of ciliary beat did not seem to be affected by factors such as age, topographical source of the biopsy, underlying disease, smoking history, or chronic alcohol consumption. The values obtained probably represented the "intrinsic" or automatic beat pattern. It remains to be seen if this pattern might be subject to modulation in situ.

Bronchi↗
PubMed1980

Human ciliary beat frequency at three levels of the tracheobronchial tree.

The intrinsic beating frequency of human ciliated respiratory epithelium at 3 different levels of the respiratory tree was examined. Ciliated epithelium was collected from the trachea, mainstem, and basal segment of 30 patients during fiberoptic bronchoscopy, and ciliary beat frequency was measured in vitro using a photoelectric technique. Specimens from the first group of 15 patients were measured at room temperature (23 to 25 degrees C) and those of the second group of 15 were measured at 37 degrees C. For group I the over-all mean beat frequencies at the trachea, right mainstem, and basal segment were 11.3, 11.1, and 11.4 beats/s, respectively, and for group II the over-all mean beat frequencies were 14.7, 14.7, and 14.8 beats/s, respectively. Within each group there were no significant differences (P greater than 0.05) in the over-all means recorded at the 3 sample sites. Although for a given subject, ciliary beat frequency was not significantly different for specimens taken from the trachea, mainstem, and basal segment, the pool mean beat frequency varied from 1 patient to another. Variations in beat frequency among patients could not be related to age, smoking habits, alcohol consumption, or disease history.

Adult↗
PubMed1978

Measurement of frequency of ciliary beats of human respiratory epithelium.

A method for accurate measurement of beats on ciliated respiratory epithelial cells in vitro is described. The technique allows the frequency of ciliary beats to be recorded directly on minute specimens of human respiratory epithelium obtained by bronchoscopic brushing. A "hanging-drop" preparation of the scraped material is placed on a thin, flat welled slide and is viewed with a phase-contrast microscope at a magnification of x450. Light transmitted through the specimen is deflected in varying intensities due to the beating action of the cilia and is detected by a photomultiplier cell, amplified and transduced as peaks on an oscilloscope. Due to the relatively high magnification, a small group of cilia may be focused upon and their activity measured. Specimens from two groups totaling 53 patients were measured; in the first group the frequency of ciliary beats was measured at 23 degrees C and ranged from 9.1 to 12.9 beats per second with a mean and standard deviation of 11.0 +/- 1.3 beats per second. The second group was measured at 37 degrees C, and values ranged from 10.3 to 16.8 beats per second, with a mean and standard deviation of 13.8 +/- 1.8 beats per second. These values are interpreted to reflect the autonomous frequency of ciliary beats of the isolated respiratory cells. This simple method may be applied to screen for abnormalities of ciliary beating in patients with altered respiratory mucous clearance, as well as to examine the specific effects in vitro of chemicals, drugs, or pollutants on human ciliary activity.

Adult↗
PubMed1978

Mucus viscoelasticity and mucociliary transport rate.

The aim of this research was to define in quantitative terms the relationship between the viscoelastic properties of mucus and the velocity at which it can be transported by a ciliated mucosa. To this effect, tests were performed on frog palates with normal beating cilia which were washed free of endogenous mucus. Experimental sputum samples encompassing a wide range of viscoelastic properties were applied to the palates, and their transport velocity was measured under a dissecting microscope. The results indicated that the fastest transport, per palate, was achieved by sputa whose Newtonian viscosity and linear elastic modulus fell within the range of 1,000 to 3,000 poises and 10 to 25 dynes/cm2, respectively. The transport velocity decreased when the sputum viscoelasticity was above or below this optimal range. The latter condition is of particular importance since it indicates that marked fluidification may hinder rather than promote mucus clearance.

Animals↗
PubMed1978

Improved homogenization techniques for sputum cytology counts.

Liquefaction of sputum with dithiothreitol induces regular distribution of cells and facilitates total and differential counting without affecting morphology or staining characteristics. The reagent is cheap and stable. The process is predictable, reasonably quick and obviates the need for examination of multiple preparations, otherwise mandatory in quantitative studies of inflammatory conditions of the lower respiratory tract.

Cell Count↗
PubMed1977

A comparison of the bronchodilator effects of the same amounts of terbutaline aerosol given as a single or in divided doses.

Inhalation of 0.5 mg of terbutaline, given as a single dose or as two immediately consecutive doses of 0.25 or four consecutive doses 0.125 mg, produced the same degree of effective bronchodilation in 12 asthmatic patients at all measured intervals from 30 seconds to four hours after administration. Each treatment regimen produced equivalent improvement in FVC, FEV1, MMEF, MVV, PEFR, V Max 50% VC and V Max 25% VC. The most sensitive indicators were MMEF and V Max 50% VC. No significant side effects were encountered with this dosage and route of administration. The clinical significance of this study is that in patients who are trained in the proper use of metered dose dispensers a single 0.5 mg inhalation may be sufficient to deliver the required dose to obtain an effective and safe therapeutic response.

Adult↗
PubMed1976

The bronchodilator effects of terbutaline: route of administration and patterns of response.

The effectiveness and clinical indications of Terbutaline as a bronchodilator were analyzed by the subcutaneous, oral and aerosol route in 56 patients. A significant improvement in air flow rates both in major and smaller airways was achieved by all routes of administration. The inhalation route offered the fastest onset of action, maximal response and longest duration. Similar trends, but of decreased magnitude, were seen following the subcutaneous and oral routes. Overall analysis of results did not indicate a definite dose-response dependency within the aerosol and oral routes at the tested dosages, whereas the incidence of side effects was clearly dose-dependent. On this basis it is recommended that for maintenance therapy treatment should begin with oral Terbutaline 2.5 mg every 6-8 hours and this dose be adjusted according to the clinical response. For the treatment of acute bronchospasm 0.50 mg or 0.25 mg subcutaneously, or a dose as low as 0.375 mg by aerosol, would be highly effective within five minutes. A combination of oral and aerosol administration represents a highly effective synergistic combination for most clinical situations requiring maintenance therapy.

Administration, Oral↗
PubMed1976

The rheological factor in mucociliary clearance.

The viscoelastic properties of sputum samples obtained from bronchitic patients were measured and correlated with the speed at which the samples were transported by the ciliary action of isolated pharyngeal palates of bull frogs maintained in amphibian Ringers solution at 28 degrees C. The viscoelastic properties were measured at very low shear stress which allowed to express them in terms of Newtonian viscosity and linear elastic modulus, which greatly minimized the variations in such measurements previously experienced with sputum. Samples with lower values of viscosity and moduli (less than 10,000 poises and 15 dynes per square centimeter, respectively) showed faster transport rates in a system where ciliary beat frequency and volume of added mucus were kept relatively constant.

Animals↗
PubMed1975

Physical properties of sputum. VII. Rheologic properties and mucociliary transport.

Sputums from bronchitic patients were measured for viscosity and elastic recoil and then placed on an isolated frog pharyngeal palate to study the velocity of transport by beating mucosal cilia. Purulent sputum, as a group, demonstrated a higher viscosity and a lower elastic recoil, and was transported at a slower rate than mucoid samples of low viscosity and high recoil. Indigenous frog mucus, collected and reapplied to the palate, had the lowest viscosity, the highest elastic recoil, and the fastest transport rate. Thus, it was concluded that high elastic recoil and low viscosity represent the best rheologic combination for maximal velocity by a mucociliary system.

Animals↗