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Biomedical subjects

F Aug

Publications and source records attributed to F Aug.

15 recordsLinked to original sources
PubMed1988

[Methods of studying mucociliary function].

The mucociliary system represents the first respiratory tract barrier which acts by removing insoluble particles from the conductive airways. Impairment of mucociliary clearance, due to respiratory mucus and ciliary activity abnormalities, leads to mucus stasis, responsible for infection and bronchial obstruction. In obstructive airway diseases, the efficiency of the mucociliary function can be investigated quantitatively by in vivo and in vitro tests. In vivo mucociliary clearance can be measured by radioactive marker techniques. In vitro tests can evaluate the physical properties and transportability of mucus. The ciliary function can easily be analyzed on ciliated cells collected by nasal or bronchial brushing. Coupled with respiratory function tests, the investigation of the mucociliary function by in vivo and in vitro tests, provides a guideline for selection and assessment of drugs used to correct mucociliary disorders.

Bronchi↗
PubMed1986

[Effects of hemodilution on the ventricular function of the coronary patient].

Ten patients (9 males and 1 female: mean age: 64.8 +/- 7 yr) were studied. They were all stabilized coronary heart disease patients free of cardiac failure who where to undergo normovolaemic haemodilution as medical treatment of lower limb arteritis. Ventricular function was assessed by a radioisotope method: myocardial perfusion (thallium-201 and dipyridamole scintillation scan) and left ventricular contraction by technetium-99m angiography. Blood volume was measured by iodine-131 marked albumin. The following parameters were also measured: plasma viscosity, blood viscosity at seven different speeds, red blood cell aggregation index and filtration index. These were all measured before and 24 h after normovolaemic haemodilution which was carried out with à 5% albumin solution. This haemodilution was well tolerated: 1,062 +/- 335 ml of blood were sampled, the same volume of albumin being transfused, thus reducing the mean haematocrit from 0.42 +/- 0.05 to 0.32 +/- 0.02 (p less than 0.01). Normovolaemia was respected. Blood viscosity was reduced, especially at low speeds and the red blood cell aggregation index was also reduced. Ventricular contraction did not vary. Moreover, the basal myocardial state as assessed by the thallium scintillation count was not modified by the haemodilution, even being improved in three cases. The dipyridamole perfusion (the equivalent of an effort test) gave no changes in seven patients, resolved the ischaemic signs in two patients and slightly increased ischaemia in one case.

Aged↗
PubMed1982

Square-wave endurance exercise test (SWEET) for training and assessment in trained and untrained subjects. III. Effect on VO2 max and maximal ventilation.

The effect of training on VO2 max, endurance capacity (EC) and ventilation during maximal exercise (VE max) were studied in 17 normal subjects aged 21--51 years. At the beginning of the study 11 of the subjects (eight women and three men) were untrained (U) and six others (three women and three men) trained regulatory (T). A maximal intensity exercise (on a cycle ergometer) which could be sustained for 45 min (MIE45) was performed three times per week for 6 weeks; the total mechanical work (TMW) corresponding to the MIE45 per session varied between 3.14 and 9.24 kJ . kg-1. Before training, VO2 max (a), VEmax (b), and TMW (c) were higher in T than in U subjects. Training increased these variables in most of the subjects; the increase being significantly higher (mean +/- SEM) in U (a = +29.9 +/- 3.8%; b = 49.6 +/- 6.5%; c = 47 +/- 6.9%) than in T subjects (a = 6.6 +/- 3.8%; b = 17.5 +/- 3.6+; c = 19.1 +/- 2.8%). In all but three cases the % increase of TMW was higher than that of VO2 max, suggesting a higher sensitivity of TMW in measuring EC. The significant increase in VE max, maximal voluntary ventilation, peak flows (inspiratory and expiratory) and static maximum voluntary ventilation, peak flows (inspiratory and expiratory) and static maximum pressures indicate that this training protocol improves in healthy subjects the performance of respiratory muscles as well.

Adult↗
PubMed1982

Comparison of nasal and bronchial mucociliary clearance in young non-smokers.

1. Nasal and bronchial mucociliary clearance have been studied in ten non-smokers (aged 19-23 years). Nasal mucociliary transport was evaluated by measuring the transport rate of a single radioactive (99mTc) particle deposited on the nasal mucosa. Bronchial clearance was measured after inhalation of insoluble radioactive anionic particles (diameter 7.4 +/- 1.5 micrometer). The initial deposition of the aerosol and subsequent clearance over 1 h was monitored with a gamma-camera. 2. The initial particle deposition was concentrated centrally and was similar in all subjects. The percentage of the total deposition located in the central zone was 78.2 +/- 5.8. The range for nasal transport rate (0-12.6 mm/min) and bronchial mucociliary clearance (18.6-77.0%) was large. 3. An inverse relationship (rS = -0.63, P less than 0.05) was observed between nasal transport rate and bronchial clearance, suggesting that, in young non-smokers, the lower the rate of the nasal mucociliary transport the faster the bronchial mucociliary clearance.

Adult↗
PubMed1981

Effect of terbutaline on mucociliary transport and sputum properties in chronic bronchitis.

A double-blind study with placebo control was carried out in 20 patients with chronic bronchitis to analyze the effect of oral terbutaline on mucociliary transport and sputum properties. Terbutaline (2.5 mg tablets) was given 3 times a day for 1 week. The clinical score, forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) significantly improved after treatment with terbutaline and confirmed the bronchodilating action of this drug. The mucociliary clearance measured with a radioactive aerosol tracer did not significantly differ after treatment with terbutaline and placebo although the initial site of aerosol deposition was similar in the two groups before and after treatment. The viscoelastic properties of sputum and their in vitro transport rate on the frog palate were not modified by terbutaline. The decrease in sputum volume and serum albumin concentration suggests a bronchial anti-inflammatory effect of this medication.

Bronchitis↗
PubMed1980

Mucociliary transport in vivo and in vitro. Relations to sputum properties in chronic bronchitis.

In vivo and in vitro mucociliary clearance have been investigated in 27 patients with chronic bronchitis with relation to the rheological, cytobacteriological and biochemical characteristics of sputum. In normal subjects, the mean percentage of bronchial radioactivity cleared (PBRC) by mucociliary clearance was 30.1 +/- SD: 12.5. The patients studied were differentiated into two groups: 1) 10 patients showing a PBRC similar to that of the normal subjects (30.6 +/- SD: 14.3), 2) 17 patients with a markedly decreased mucociliary clearance (PBRC: 4.1 +/- SD: 4.2). In the healthy subjects, PBRC by coughing was significantly lower than by mucociliary clearance, while no consistent difference was observed in the patients. A weak but significant positive correlation (r = 0.53, P less than 0.01) was observed between in vivo mucociliary clearance and the relative transport rate of the sputum measured on the ciliated frog palate mucosa. The optimal rheological conditions for mucociliary transport were characterized by an apparent viscosity (eta 0) ranging from 25 to 180 poise, a strain recovery (SR) ranging from 4 to 12 units and an elastic modulus (G) ranging from 4 to 8 dyn/cm-2. The apparent viscosity and the elastic modulus G respectively, were significantly correlated with the concentration of serum albumin and of secretory IgA. Patients with a sputum leukocyte count higher than 3500/mm3 had a significantly decreased mucociliary clearance in comparison with non-purulent sputum patients.

Bronchi↗
PubMed1978

Effect of the mucoregulator S-carboxy-methyl-cysteine in patients with chronic bronchitis.

Twenty patients with stable chronic bronchitis entered a double-blind study in which changes in clinical and respiratory function and biochemical and rheological variations were examined after treatment with the mucoregulator S-carboxy-methyl-cysteine (S.C.M.C.). After one week of single-blind placebo, a two week double-blind study was initiated with placebo or oral S.C.M.C. 3 g/24h. After two weeks, a significant clinical improvement was observed in patients treated with S.C.M.C. During treatment, there was no change in respiratory function, although a drop in FEV1/VC was noted in the placebo group. A significant increase in the viscosity of the expectorations was observed after treatment with S.C.M.C. for two weeks. The levels of secretory IgA and of serum albumin in the expectorations remained stable, whereas in the placebo group, there was a slight but significant increase in serum albumin. In this group of non-infected chronic bronchitic patients, S.C.M.C. appeared to normalize the secretory function of the bronchial mucosa by preventing inflammation and enhancing the viscoelastic properties of bronchial secretions.

Aged↗
PubMed1978

[Pathophysiology of chronic, bronchial hypersecretion (author's transl)].

The biochemical and rheological analysis of sputum allows one to detect abnormalities of the bronchial secretion and to describe the development of the bronchial disease. The main biochemical components of sputum and their biological activities are first described. The fibrillar structure of the mucus is related to heavy weight glycoproteins and these macromolecules contribute to the viscoelastic properties of the bronchial secretion, by their capacity to combine with other proteins such as secretory immunoglobulin A (S-IgA). As the chronic bronchial hypersecretory state progresses, the glandular synthesis of mucins and/or secretory proteins decreases while the passive filtration of blood-derived proteins, such as serumalbumin, increases. Such biochemical changes are frequently associated with a rise in viscosity and a loss in elasticity of sputum. These rheological modifications result in an impairment of the mucociliary clearance and therefore contribute to airway obstruction. The assessment of different indices such as the equilibrium in mucin secretion, S-IgA/serum-albumin ratio, viscosity and elasticity of sputum and its mucociliary transport rate, should lead to a better knowledge of the defense properties of the bronchial mucosa.

Airway Obstruction↗
PubMedDate not supplied

Comparison of three methods for measuring nasal mucociliary clearance in man.

Three techniques for studying nasal mucociliary clearance have been compared in 20 normal subjects, aged 19 to 26. Three different tracers used were deposited on the septum or the nasal floor. The transport rate of a 250 micron anion resin particle tagged with 99mTc was measured over a distance of 3.5 cm. This method was used as reference. The transport time of saccharin was measured when the subjects tasted its sweetness on swallowing. The transport time of 600 micron aluminium discs was measured by observing their arrival at the pharynx. For each method, duplicate measurements were carried out over a 24 hour period. Despite the large variations in the results from one day to the next, a significant negative correlation (r = -0.59, p less than 0.001) was observed between the transport rate of the radioactive particles and the transport time of the saccharin. The daily variations in nasal clearance for these two methods were also significantly correlated (r = -0.53, p less than 0.02). These results validate the suitability of the saccharin method as a simple screening test for detecting abnormally low values of nasal mucociliary clearance. In our group of 20 subjects, 5 were characterized by a low nasal mucociliary clearance, whichever method was used.

Adult↗
PubMedDate not supplied

[Pathophysiology of chronic, bronchial hypersecretion (author's transl)].

The biochemical and rheological analysis of sputum allows one to detect abnormalities of the bronchial secretion and to describe the development of the bronchial disease. The main biochemical components of sputum and their biological activities are first described. The fibrillar structure of the mucus is related to heavy weight glycoproteins and these macromolecules contribute to the viscoelastic properties of the bronchial secretion, by their capacity to combine with other proteins such as secretory immunoglobulin A (S-IgA). As the chronic bronchial hypersecretory state progresses, the glandular synthesis of mucins and/or secretory proteins decreases while the passive filtration of blood-derived proteins, such as serumalbumin, increases. Such biochemical changes are frequently associated with a rise in viscosity and a loss in elasticity of sputum. These rheological modifications result in an impairment of the mucociliary clearance and therefore contribute to airway obstruction. The assessment of different indices such as the equilibrium in mucin secretion, S-IgA/serum-albumin ratio, viscosity and elasticity of sputum and its mucociliary transport rate, should lead to a better knowledge of the defense properties of the bronchial mucosa.

Bronchi↗
PubMedDate not supplied

[Value of isotopic methods in the diagnosis of myocardial infarction of the right ventricle].

In the left ventricle, isotope techniques can be used to study the perfusion of the myocardium or the ventricular function. Because of the thinness of the walls of the right heart, the classical examinations and Thallium 201 perfusion cannot be used to demonstrate a disorder of perfusion in the right ventricle. Nevertheless, it is possible, with the aid of Technetium 99m labeled pyrophosphate, to diagnose and localise necrosis of the inferior wall with an acceptable degree of sensitivity, during the acute phase of the infarction. However, the major value of isotope techniques is to evaluate right ventricular function by determining the value of the global ejection fraction and the kinetic anomalies of the different walls. These methods, together with echocardiography, allow the diagnosis of lesions of the inferior part of the right ventricle in patients with inferior necrosis... Furthermore, because these methods allow quantification and because they are reproducible and repeatable, they can be used to follow the course of the right ventricular function in response to treatment.

Evaluation Studies as Topic↗
PubMedDate not supplied

[Efficiency of mucociliary clearance and cough in bronchitis].

Progressive alterations in the in vitro transport properties of airway secretions according to the severity and duration of bronchitis have been previously reported, but the potential in vivo dysfunction of bronchial clearance during different phases of bronchitis has not yet been studied. We measured bronchial mucociliary clearance (CMC) and clearance by cough (CTx) using a radioactive aerosol technique (resin particles 7.4 micron in diameter, tagged with technetium-99 m) in patients with recurrent bronchitis (group I, n = 5) and in chronic bronchitic patients, either at an early (group II, n = 13) or advanced (group III, n = 17) stage of their disease. The results were compared with those obtained from a control group (group 0, n = 10) and the respective efficiencies of the mucociliary system and cough were analysed with reference to respiratory function. The initial deposition of the aerosol in central airways is similar in all the patients and healthy subjects. In comparison with group 0, the mucociliary clearance is only significantly reduced in groups II and III (p less than 0.02). In healthy subjects, the clearance by cough is very weak, whereas in bronchitic patients it can be roughly equal to or greater than the CMC. However, the cough is less efficient in group III than in group II (p less than 0.05). A reduced efficiency of the clearance by cough occurs together with abnormalities in the gas exchange.

Adult↗