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Biomedical subjects

L Allegra

Publications and source records attributed to L Allegra.

At least 127 records · Page 7Linked to original sources
PubMed1984

Evaluation of the elastic and viscous components of bronchial mucus before and after S-carboxymethylcysteine-Lys treatment.

The rheological profile of bronchial secretions from patients suffering from chronic bronchitis has been evaluated using the forced sinusoidal oscillations technique, which allows dynamic tests to be carried out. In these tests the shear stress can be plotted versus the strain on a XY plotter, to obtain Lissajous figures. As bronchial mucus is a viscoelastic fluid, elliptic figures were obtained that can be broken down into an elastic component separate from the viscous component. By applying this method to the study of the S-carboxymethylcysteine action on bronchial mucus, it is possible to observe that the improvement in the rheological characteristics of the mucus, after treatment, is mainly due to a decrease in viscosity rather than to a decrease in elasticity.

Adult↗
PubMed1983

Pharmacokinetics of Sobrerol in chronic bronchitis. Comparison of serum and bronchial mucus levels.

The pharmacokinetic profile of Sobrerol, a mucolytic drug, has been studied in patients with acute exacerbations of chronic bronchitis and dense sputum. In addition to measurement of serum and urine levels, the concentration in bronchial mucus was also examined, and their correlation was calculated. Mass fragmentographic analysis was used to assay free sobrerol and its principal urinary metabolites hydrated carvone and glucuronidated sobrerol. After the doses and administration routes used, there appeared to be accumulation of sobrerol in bronchial mucus. This is a feature of great interest and value for a drug which has the specific action of liquifying mucus.

Administration, Oral↗
PubMed1983

Duration of mucociliary dysfunction following antigen challenge.

Antigen-induced bronchospasm is associated with an impairment of airway mucociliary clearance, but the duration of this defect has not been examined. In the present study, we determined the time course of mucociliary dysfunction following inhalation challenge with Ascaris suum extract in conscious sheep with hypersensitivity to this antigen. Tracheal mucous velocity (TMV) as an index of mucociliary function, pulmonary resistance (RL), and arterial oxygen tension (Pao2) were measured prior to, immediately after, and serially for 8 h after inhalation challenge. TMV and Pao2 were then measured periodically for at least 2 wk. Immediately after A. suum challenge, mean RL increased to 264% of base line (P less than 0.05), and mean Pao2 decreased to 61% of base line (P less than 0.05). By 2 h postchallenge, mean RL and Pao2 had returned to base line but mean TMV had fallen to 61% of base line (P less than 0.05). Mean TMV reached a minimum of 35% of base line after 5 h (P less than 0.05) and remained significantly depressed between 37% and 54% of base line for 7 days; by day 9, mean TMV had returned to base line. Inhalation challenge with a control antigen (ragweed) failed to alter mean TMV, RL, and Pao2 during the first 8 h and TMV and Pao2 at any time throughout the 2-wk observation period.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

Pharmacokinetic behavior of S-carboxymethylcysteine-Lys in patients with chronic bronchitis.

A mass fragmentographic technique was used to study the pharmacokinetic behavior of SCMC-Lys in patients with acute exacerbations of chronic bronchitis and with dense expectoration. Serum and urine levels, as well as bronchial mucus levels and their correlations, were determined. The data suggest that SCMC-Lys diffuses well into bronchial mucus, a useful feature for a mucolytic drug.

Bronchi↗
PubMed1981

Action of sobrerol on mucociliary transport.

Some pharmacological properties of Sobrerol have been assessed, in frog palate preparation, by measuring the mucociliary transport velocity due to mucus samples obtained for patients suffering from chronic bronchial inflammatory diseases characterized by dense bronchial secretions. The patients were studied before and after 4 days of treatment with Sobrerol, 600 mg per day per os. The significant increase in the relative ratio of mucociliary transport of mucus of treated patients, together with evidence coming from previous experiments, indicates that this drug is capable of modifying rheological properties of bronchial secretions, in such patients, through an "in-vivo' muco-regulating activity, thus facilitating mucociliary clearance.

Adult↗
PubMed1980

Altered surfactant synthesis and function in rats with diet-induced hyperlipidemia.

Altered lung function in hyperlipidemic patients has been reported by many authors. An alteration of surfactant synthesis has been suggested. Isolated lungs of rats rendered hyperlipidemic by suitable diets display an increased distensibility at maximal inflation and a higher degree of alveolar stability during deflation. These alterations are related to modifications of surfactant properties. Lung lavage fluid obtained from hyperlipidemic rats displays an increase in percent content of phosphatidylglycerol and a decrease of phosphatidylethanolamine. The percent content of phosphatidylglycerol correlates with the circulating levels if free fatty acids (FFA). It is suggested that FFA might affect the activity of enzymes operating in lung phospholipid synthesis. The reported increase of surfactant phosphatidylglycerol might explain the increment of alveolar stability observed in hyperlipidemic rats.

Animals↗
PubMed1980

The decay of thoracic gas volume during forced expiration.

The MEFV curve has been analysed for the mechanical time constant distribution through the lungs, and it has been transformed into the forced decay of the thoracic gas volume (FVtD). The best regression formula to express the FVtD was the exponential in respect to the linear one, and this difference was statistically significant only in asthmatic patients. It seems likely that the FVtD will prove to be useful for detecting, already in the simple routine functional investigation, the airways obstruction due to asthma as interlobular inhomogeneity of ventilation.

Airway Obstruction↗
PubMed1980

Non-specific broncho-reactivity obtained with an ultrasonic aerosol of distilled water.

A mist of distilled water obtained by means of powerful high density ultrasonic device has been used as nonspecific challenge test for assessing bronchial hyperreactivity in asthmatics. It looks an easier and/or more physiologic stimulation when compared with the nebulisation of other substances such as histamine, acetylcholine, methacholine, carbachol, citric acid, prostaglandins. Furthermore, this test shows good correspondence to the history of fog-induced asthma. In ten normal subjects the ultrasonic mist of H2O doesn't produce any functional change, while in thirteen asthmatic patients it results in a clear-cut bronchoconstriction, with a maximal evidence within 10 minutes and a subsequent decrease up to 30 minutes. Premedication with propranolol doesn't change the negativity of the test in normal subjects. Ultrasonic mist of saline doesn't determine any remarkable bronchoconstriction in asthmatics. In forty asthmatics a trial has been then carried out on prevention of water-induced bronchoconstriction by different pharmacologic means. Ipratropium fails to protect significantly the patients, while Disodium-cromoglycate, Salbutamol and prostaglandins E reduce significantly the entity of the so induced bronchospasm. These observations support the hypothesis of a mast cell mediated mechanism and disprove the vagal contribution to this type of bronchial challenge.

Adult↗
PubMed1979

[Changes in the acid-base and water-electrolyte balance induced by salbutamol. "In vivo" studies in patients with chronic broncho-pulmonary disease and "in vitro" by tonometry of venous blood].

The Authors studied the effects of e.v. Salbutamol evaluating the acute "in vivo" variations of acid-base and hydro-electrolitic balance in 16 chronic obstructive lung patients undergoing e.v. drug administration, and also ionic variations "in vitro" of venous blood samples incubated and tonometrated with the drug. The results "in vivo" do not show variations of acid-base equilibrium (paO2, paCO2, pH, HCO3-); whereas diminution of haematocrit (Ht), rise of urinary osmolarity and variations of hydro-electrolitic balance (Na+, K+, Cl-) are demonstrated. The results "in vitro" do not show considerable variations on ionic assessment. These data, according to the other latest result, indicate the possible role of haemodilution. We think that the explanation of these phenomena could be a modification of renal water and electrolytes reabsorption, likely under the influence of antidiuretic hormone (ADH), stimulated in the hypothalamus and activated also by the beta-stimulant drug at tubular cell receptors.

Acid-Base Equilibrium↗
PubMed1979

[Comparative evaluation of the respiratory function and the acid-base equilibrium in patients with chronic bronchopulmonary disease after intravenous administration of 5 beta receptor agonists].

The Authors studied lung mechanics, acid-base balance parameters, arterial blood pressure and pulse rate in five different groups of chronic obstructive lung disease patients, undergoing e.v. different bronchodilators. The drug were: 1. group: 500 gamma of orciprenalina; 2. group: 500 gamma of idrossi-fenil-orciprenalina; 3. group: 200 gamma of salbutamolo; 4. group: 100 gamma of trimetochinolo; 5. group: 500 gamma of terbutalina. The comparative analysis of bronchodilators, their cardiovascular effects and on acid-base balance indicate that mainly salbutamol and trimetochinol have negligeable adverse effects.

Acid-Base Equilibrium↗
PubMed1977

Aspects of bronchial reactivity to prostaglandins and aspirin in asthmatic patients.

The behaviour of bronchial reactivity to PGF2alpha was studied in asthmatic patients under various experimental conditions. Premedication with aminophylline, i.v., and, to a lesser extent, with DSCG afforded a partial protection, while beclomethasone dipropionate was inactive under this point of view. Diftalone, a new non-steroid anti-inflammatory agent, was well tolerated in 9 aspirin-intolerant asthmatic patients, and did not modify the bronchial response to PGF2alpha which was found to be generally lower then that of other aspirin-tolerant asthmatic patients. PGE 1-2 and DSCG prevented the bronchospasm induced by inhalation or ingestion of acetylsalicylic acid in a small group of patients. Good protection was also reached with PGE1-2 in the exercise-induced bronchospasm.

Adolescent↗
PubMed1976

[Clinico-radiological and functional aspects of respiratory syndromes caused by collagen diseases].

The clinical and radiological features in 100 patients with collagen diseases (rheumatoid arthritis, lupus, sclerodermia, dermatomyositis, and panarteritis nodosa) were compared with respiratory performance. 56 patients were drawn from the series of Pende et Al. and 44 from a personal series. The results are set out in tables and graphs. It was found that lung lesions due to collagen disease have no special clinical and radiological features. Respiratory performance is that of a restrictive syndrome that gradually progresses from A.R. to E.S., S. and P.M., accompanied by obstruction of the large airways, as shown by hyperinsufflation in sclerodermia and reduced specific conductance in rheumatoid arthritis.

Adult↗
PubMed1976

Clinical, functional and pathogenetic aspects of bronchial reactivity to prostaglandins F2alpha, E1, and E2.

Based on our results and on those reported in literature, we may draw the following conclusions. As a rule, asthmatic patients are markedly more sensitive than normal subjects to the bronchoconstrictive action of PGF2alpha by aerosol. However, the individual response is quite variable, which predicts and justifies some exceptions. On this subject, we found a peculiar exception in a female patient with extrinsic asthma, who tolerated abnormally large amounts of PGF2alpha. In contrast, we found a normal subject, who developed a bronchial hypersensitivity to PGF2alpha of frankly asthmatic type, following a moderate postinfluenzal bronchitis. Intravenously PGF2alpha loses the most part of its bronchoconstrictive effect, probably because it is rapidly metabolized before it may reach the bronchial receptors involved in the bronchospastic response. On the contrary, the action on vascular smooth muscle of the pulmonary circulation is evident, just because it is reached before the above transformation, mainly performed by 15-PG-dehydrogenase. An important component of the PGF2alpha-induced bronchospasm, although varying individually, is surely nonspecific, as it is shown by the protection obtained with an atropine-like agent. The moderate but significant protection obtained with DSCG, may be interpreted in a way similar to the one exerted again by DSCG on other nonspecific stimuli. Since indoramine has no effect in preventing PGF2alpha-induced bronchospasm, the intervention of bronchial alpha-receptors in the pathogenesis of this type of bronchospasm may be excluded. Nonsteroid antiinflammatory agents do not seem to change in asthmatic patients bronchial reactivity to PGF2alpha, as was found recently with other specific and nonspecific stimuli. Our studies do not modify current thought regarding the poor present therapeutic value of PGE as bronchodilator agents. Prospects are no better with the stereoisomer of PGF2alpha, PGF2beta (41), with endoperoxides PGG2 and PGH2 (42) and with the analogues 15-methyl-PGE2, 15-epi-PGA2, and 8-iso-PGE1 (43). However, it is reassuring that, even in the absence of a demonstrable bronchodilator effect, both PGE1 and PGE2 are capable to prevent in a large degree the specifically and nonspecifically induced bronchospasm.

Adult↗