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Biomedical subjects

G Bonsignore

Publications and source records attributed to G Bonsignore.

At least 127 records · Page 7Linked to original sources
PubMed1974

[In vitro effects of saluretics, osmotic pressure and the acidity of the medium on the evaluated globular volume in chronic bronchopneumopathies by means of microhematocrit].

The in vitro effect of diuretics, osmotic pressure and acidity of the medium on red cell volume was examined. The results showed that:1) diuretics lead to a reduction in volume;2) this reduction is enhanced at higher concentrations; 3) the effect is more noticeable in more diluted blood; 4) a decrease in volume is also displayed by cells whose volume has been increased by hypo-osmotic solutions; 5) this effect is not apparent when cell volume is reduced to the minium by hypersmotic solutions;6) the effect of the pH value is only felt in the case of extreme variations.

Acid-Base Equilibrium↗
PubMedDate not supplied

Airways remodelling in asthma: no doubt, no more?

Asthma is a chronic inflammatory disease of the airways invariably associated with healing. Remodelling of the airways can be demonstrated by the activation of airways macrophages, the release of growth factors and fibrogenic cytokines, the activation of fibroblasts and myofibroblast, elastolysis and elastosynthesis, collagen deposition, increased synthesis and release of extracellular matrix components, and an increased mass of smooth muscle and mucous glands. However, the control of remodelling is still poorly understood.

Asthma↗
PubMedDate not supplied

Cardio-respiratory function during sleep.

Respiratory function undergoes sleep-associated changes which in normal subjects leave it unaffected. However in some cases they may be more marked than usual or may be superimposed on a pre-existing disease, thus giving rise to sleep-related ventilation disorders. These include obstructive sleep apnea syndrome (OSAS), nocturnal desaturation events of chronic obstructive pulmonary disease (COPD) and restrictive syndromes, as well as nocturnal asthmatic attacks. OSAS is a condition characterized by the frequent recurrence of interruptions of oronasal flow (greater than 10 s.) due to upper airway occlusion induced by a reduction in pharyngeal muscle tone. This phenomenon, particularly prominent in REM sleep, results in oxyhemoglobin desaturation and marked cardiovascular consequences (arrhythmias, increases in pulmonary and systemic arterial pressure), as well as symptoms (loud intermittent snoring, daytime sleepiness, intellectual deterioration etc.). Obesity is often associated with OSAS or may lead to a sleep-related hypoventilation syndrome. Treatment is based on weight loss, surgery of upper airway abnormalities, if present, and on splinting of the upper airway by the application of nasal continuous positive airway pressure. In COPD and restrictive disorders, nocturnal hypoxemia is mainly due to REM-associated loss of respiratory muscle tone, as well as in the sleep-related exaggeration of functional defects due to COPD (low chemoreceptor sensitivity, high closing volume etc.). Treatment is based on oxygen administration, provided that possible side-effects are carefully monitored. Nocturnal asthma is due to circadian changes in hormonal secretion (catecholamines, cortisol), as well as supine posture, reduced muco-ciliary clearance, gastro-esophageal reflux etc. Sleep itself plays some role through a depressed arousal reaction in slow wave sleep, resulting in more marked and prolonged attacks in this stage. Slow-release theophylline or beta-mimetic medications, as well as new chromones and antimuscarinic drugs are therapeutic alternatives.

Asthma↗
PubMedDate not supplied

Obesity as a possible cause of respiratory failure in bilateral diaphragmatic paralysis. Case report.

An obese woman with respiratory failure and bilateral diaphragmatic paralysis, was studied in order to investigate the effects of weight loss on respiratory function during wakefulness and sleep. The patient was studied on 5 different occasions during which diurnal blood gas analysis, spirometry, CO2 rebreathing test, nitrogen wash-out test and a nocturnal polysomnographic study were performed. The follow-up period lasted 9 months, during which the patient progressively lost 19 kg. Progressive improvement in awake blood gas tensions (PaO2 + 21 mmHg, PaCO2 - 16 mmHg) as well as in nocturnal oxyhemoglobin saturation and transcutaneous PCO2 were observed; at the same time only minor changes in responsiveness to CO2 and in lung volumes were found. Conversely alveolar efficiency for CO2, obtained with the nitrogen wash-out test, in the supine posture increased from 81.7 to 90.5%, indicating an improvement in ventilation/perfusion ratio as a possible determinant of blood gas tension improvement during wakefulness and, as a consequence, also during sleep. We conclude that obesity is one possible cause of the occurrence of respiratory failure in bilateral diaphragmatic paralysis.

Adult↗