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Biomedical subjects

A Gazzaniga

Publications and source records attributed to A Gazzaniga.

67 records · Page 4Linked to original sources

Pharmacokinetics of oral acetylcysteine: absorption, binding and metabolism in patients with respiratory disorders.

The fate of an oral 100 mg dose of 35S-acetylcysteine, a mucolytic agent, was studied in 10 patients with respiratory disorders, 5 of whom underwent pneumonectomy or lobectomy a few hours after administration of the drug. In the 5 nonoperated patients, plasma radioactivity concentrations were maximal after 2 to 3 hours and remained high after 24 hours; about 22% of radioactivity was excreted in urine after 24 hours. In the 5 operated patients, plasma radioactivity concentrations were comparable with those in the nonoperated patients. Lung tissue radioactivity concentrations after 5 hours were comparable with those in plasma, while the presence of small amounts of radioactivity in the bronchial secretions indicates that acetylcysteine passes into the mucus. Total radioactivity after 5 hours consisted of free, unchanged drug and metabolites (about 22% of total in plasma, 48% in lung tissue), unchanged drug bound to protein by means of labile disulphide bridges (about 14% in plasma, 47% in lung tissue), and drug firmly bound to protein (about 64% in plasma, 5% in lung tissue). Oral acetylcysteine is rapidly absorbed and slowly excreted and is available in the lung in an active form for at least 5 hours at high concentrations.

Acetylcysteine↗

Hyaluronidase-injectable microparticles intended for the treatment of extravasation.

Hyaluronidase is a protein whose enzymatic activity is successfully employed in extravasation therapy. Taking into account that several proteins (e.g. gelatin and albumin) have been employed as natural polymers for the preparation of microspheres, this work approaches a comprehensive investigation on hyaluronidase injectable microparticles. The goals are either to obtain a sustained release preparation of hyaluronidase or to use the enzyme as drug carrier. Microspheres have been prepared using a water-in-oil emulsification technique, and they have been crosslinked either by thermal or chemical means. Results show that hyaluronidase microspheres with good morphological characteristics can be obtained by this preparation method. Manufacturing variables influence the enzymatic activity of the microspheres, which can be highly preserved under mild experimental conditions. Moreover, the suitability of this enzyme as a microparticulate drug carrier has been shown by the successful encapsulation of hydrocortisone sodium succinate.

Animals↗

Successful treatment of acute allograft failure using pneumatic biventricular assistance.

A 61-year-old man underwent orthotopic heart transplantation complicated by acute allograft failure. Management entailed placement of two ventricular assist devices, and there was subsequent hemodynamic stabilization. Ventricular assistance continued for 8 days, at which time graft recovery resulted in successful explanation of the devices. Subsequent recovery was uneventful, and the patient was discharged on the 28th postoperative day. Methods of optimizing interoperative device cardiac output and synchronous-mode weaning are discussed.

Cardiomyopathy, Dilated↗

Cross-linked sodium carboxymethylcellulose as a carrier for dissolution rate improvement of drugs.

The dissolution rate is often the limiting step in gastrointestinal absorption of water insoluble drugs from solid oral dosage forms. The aim of this work was to use a swellable polymer chosen among superdisintegrants, for improving the dissolution rate of a sparingly soluble drug, loaded on its surface. Nifedipine, which has a very low water solubility, was chosen as a model drug, while cross-linked sodium carboxymethylcellulose (Ac-Di-Sol) was chosen as the swellable polymer. The Nifedipine/Ac-Di-Sol systems were prepared using two different techniques: evaporation and spraying; in some preparations polyethylene glycol (PEG 1500), or sucrose palmitate (Sucrodet), or dioctyl sodium sulfosuccinate (Aerosol OT) were added. The results of the dissolution tests showed that the dissolution rate of Nifedipine from the systems prepared increases, particularly in the case of the preparation composed of Ac-Di-Sol plus surfactant agents.

Carboxymethylcellulose Sodium↗