Biomedical subjects

G Azzena

Publications and source records attributed to G Azzena.

23 records · Page 2Linked to original sources

PubMedDate not supplied

[Extracorporeal liver support systems].

Acute liver failure is very life-threatening since the conventional medical treatments have little effects on the clinical outcome. Artificial liver support systems based on blood detoxification alone have proven ineffective because they cannot correct the severe biochemical disorders. An effective liver support system should be capable of carrying out essential functions such as phase I reaction in which lipid-soluble toxic substance are rendered water-soluble by the enzyme system of the cytochrome P450 and NADPH-cytochrome reductase, and are therefore conjugated by the phase II reaction, before excretion. Liver support systems should be capable of sustaining patients with fulminant liver failure until an organ is available for liver transplantation (bridging treatment), or improving the survival in patients for whom liver transplantation is not a therapeutic option. Recent advances in cell biology and tissue culture techniques have led the way for potential clinical use of isolated hepatocytes so that they are now an important element of bioartificial liver support devices. Some of these systems are currently under clinical investigation in the USA and Europe, and the results of the prospective controlled trials will be soon available.

Bioprosthesis↗

PubMedDate not supplied

["Artificial liver"].

Acute liver failure is a life-threatening condition since conventional medical treatments have little effect on survival. Artificial liver support systems based on blood detoxification alone have proven to be ineffective. A liver support system should carry out essential functions such as the phase I reaction in which lipid-soluble toxic substance are rendered water-soluble by the enzyme system of the cytochrome P450 and NADPH-cytochrome reductase, and are therefore conjugated by the phase II reaction, before excretion. Liver support systems should be capable of sustaining patients until an organ is available for liver transplantation (bridging treatment), or improving the survival in patients for whom liver transplantation is not a therapeutic option. Recent advances in cell biology and tissue culture techniques have led the way for potential clinical use of isolated hepatocytes so that they are now an important element of bioartificial liver (BAL) support devices. Some of these BAL are currently under clinical investigation in the USA and Europe, and the results of the prospective controlled trials will be soon available.

Forecasting↗

PubMedDate not supplied

[In vitro experimentation of a new model of radial flow bioreactor containing isolated hepatocytes].

Hepatocyte based artificial liver support systems are under investigation to support acute liver failure patients. The main purpose of such systems is to serve as a bridge to liver transplantation, or to promote spontaneous liver recovery. Limitation in mass-transfer capacity makes hollow-fiber bioreactors unsuited for long-term functioning of hybrid devices. We developed a novel radial-flow bioreactor in which the fluid perfuses the module from the center to the periphery, after having diffused through a space occupied by a three-dimensional structure filled with the hepatocytes. Five grams of freshly isolated porcine hepatocytes were seeded into uncoated, woven-non woven, hydrophilic polyester fabric, overlaid by two polyethersulfone membranes. Liver cells were perfused with 37 degrees C-warm, oxygenated, serum-free tissue culture medium, in which NH4Cl and Lidocaine were added at the final concentration of 1 mM and 60 micrograms/ml, respectively. Ammonium chloride removal, urea synthesis, monoethylglycinexylide (MEGX), pO2, pCO2, and pH were measured throughout the 14 day duration of the study. In a separate set of experiments, a scaled-up version of the radial flow bioreactor containing 150 grams of cells was perfused for 7 h with recirculating human plasma and MEGX production was monitored. During the 2 weeks of the study, an increasing production of urea was paralleled by constant ammonium removal. MEGX concentration after Lidocaine addition increased throughout the 14 days of perfusion with tissue culture medium, as well as after 7 hour perfusion with human plasma. Under transmission and scanning electron microscopy cells appeared attached to the polyester and one to each other, displaying ultrastructural features typical of functioning hepatocytes. Our study showed that liver cells were metabolically active when perfused into the radial-flow bioreactor. This configuration allowed close contact between media, or plasma, and cells at a physiological flow rate, by equalizing the concentration of the perfusing components, including O2, throughout the module. Our results suggest a potential use of this system for temporary extracorporeal liver support in acute hepatic failure patients.

Animals↗

PubMedDate not supplied

Angioplasty of the profunda femoris in revascularisation of the lower extremity.

Excellent results with respect to preservation of the limb and improvement of claudication were obtained with profundaplasty in 29 patients with Fontaine's stage III or IV chronic obliteration. The method is regarded as one of choice for saving the limb, but not as a replacement for other methods of direct revascularisation of the femoropopliteal axis in cases where complete functional recovery is also required. A comparison is made between the results of profundaplasty and reconstruction of the axis in a personal series.

Amputation, Surgical↗

PubMedDate not supplied

[Tools for assessing the quality of care in health facilities. Experience in Ferrara].

Studies of health care quality are based on the evaluation of the way of how knowledges and available resources interact in order to guide individual behaviour as well as organisational planning. We have tested a sample of patient's impressions, using an anonymous questionnaire. During a period of 12 months 1039 patients have been questions. The result of our study demonstrates the necessity of a closer cooperation between general practitioner and in-hospital physician even in order to guarantee communication and promote trusting between hospital and patients.

Female↗