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Biomedical subjects

G B Ratto

Publications and source records attributed to G B Ratto.

At least 73 records · Page 4Linked to original sources
PubMed1983

[Small-caliber arterial prosthesis: effect of porosity].

Thirty-two pyrolytic carbon-coated weanenit Dacron grafts and 32 segments of human umbilical vein treated with glutaraldehyde were implanted into the carotid arteries of 32 dogs. Prosthesis segments were removed after intervals of from 10 to 120 days and sections examined by standard optical microscopy, and the internal surfaces by scanning electron microscopy. Overall percentage permeability was 93.7 p. cent for Dacron prostheses and 84.3 p.cent for human umbilical vein sections. Fundamental stages of pseudo intima organization were compared for the two types of prosthesis.

Animals↗
PubMed1983

Can heterologous collagen enhance the granulation tissue growth? An experimental study.

A purified and lyophilized sponge of native bovine tendon collagen (Gelfix) was used to plug gastric, jejunal and colonic surgical holes (phi = 6 mm) on 78 white rats. In a control group (18 rats) colonic holes were plugged with autologous epiploon. The mortality rate due to generalized peritonitis, was higher (Fischer test = 4%) in the control group than in animals treated with the heterologous collagen. The healing process was evaluated by light microscopy at sequential intervals ranging from 4 to 120 days after implantation. The heterologous collagen biological activity was evaluated as follows: 1. The sponge was labelled with Tyrosine 125I or mixed with Collagen Methyl 14C methylated. Then the radioactivity of the isolated granulation tissue cells was evaluated. The electrophoresis of these lysed cells, as well as histoautoradiography were performed. 2. Indirect immunofluorescence studies employing rabbit antibodies against fibronectin were also carried out. The heterologous collagen seemed to act as a mechanical support and as a stimulus to chemotactic migration of fibroblasts. It also appeared to participate as a nutrient substitute in the metabolic activity of the granulation tissue. Finally, heterologous collagen fibers were found to be massively bound by fibronectin.

Animals↗
PubMed1983

An experimental study on fluorocarbons as blood substitutes.

A fluorocarbon emulsion (Fluosol DA 20%) was experimented as a blood substitute. Fourty-five rats weighing 320 +/- 30 g. underwent different degrees of hemodilution, by isovolemic exanguino-transfusions. A first group (15 rats) had maximal exchange transfusion (Ht = 0,5%) with Fluosol DA 20% and was followed for 12 hours. A second group (15 rats) (control group) underwent the same procedure, but hydrolyzed gelatin 3% (Emagel) was used instead of Fluosol DA 20%. A third group (15 rats) had partial exchange-transfusion (Ht = 23 +/- 2%) with Fluosol DA 20%, and was followed for 2 months. Cerebral and cardiovascular activity, respiratory exchanges and acid-base balance as well as other basic biological parameters were evaluated in the first and second group. The initial signs of altered cerebral activity were observed with a Ht = 2%, while death occurred at Ht = 0,5% due to respiratory arrest. In the third group, a retention of fluorocarbon particles was demonstrated by gas chromatography in all the organs examined. In this group, lung and spleen lesions were also observed by light microscopy and transmission electron microscopy.

Acid-Base Equilibrium↗
PubMed1983

The surgical treatment of bronchial carcinoid adenoma: a personal experience.

Clinical and pathological observations on 7 resected cases of bronchial carcinoid have been reviewed. Bronchoscopy was the most definitive diagnostic procedure. Bronchoplastic procedures were the treatment of choice for these low-grade potentially malignant lesions. Indications for extensive lung resection were distal suppuration and tumor extention into the parenchyma. There were no operative deaths or major complications. All the patients are still alive (mean follow-up 39.4 months) with no recurrence of tumor.

Adult↗
PubMed1982

Scanning electron microscopy evaluation of porous and nonporous arterial substitutes.

The fate of two different kinds of new small arterial substitutes, porous and nonporous, has been compared, particularly with regard to the structure of the luminal surface. Twenty-eight weavenit Dacron pyrolytic carbon coated grafts and 28 glutaraldehyde-tanned human umbilical vein segments were implanted into the carotid arteries of dogs. Grafts were removed at intervals, from ten to 120 days after implantation, and examined by scanning electron microscopy. The cumulative patency rate was 96.4 per cent for Dacron and 85.7 per cent for umbilical vein grafts. Ten days after implantation, the Dacron grafts were uniformly covered by a thin thrombus layer, while the umbilical vein grafts showed a thin network of fibrin on the central portion of the luminal surface of the graft and thrombotic deposits at the anastomoses. Thirty days after implantation, both types of prostheses showed the development of a thin fibrous tissue layer on the inner surface. Finally, at 120 days, an endothelial lining was observed.

Aldehydes↗
PubMed1981

[Experimental research on the use of fluorocarbon compounds (FC 43) as blood substitutes].

The authors have experimented a fluorocarbon compound (FC 43) in form of a stable emulsion (20%), in the presence of a suitable surfactant agent (Pluronic F 68: 2,5%), as an hematic substitute. The animals (fifteen rabbits) underwent substitution of 50% of the total hematic volume with same volumes of the emulsion and thereafter have been examined for a period of twenty-four hours. During the time of observation there were no changes on: 1) acid-base equilibrium; 2) respiratory homeostasis and 3) major circulatory parameters.

Acid-Base Equilibrium↗
PubMed1981

[Platelet function in the dog].

Platelet aggregation with Born test was performed in 9 normal dogs. ADP, Epinephrine and Collagen were employed to stimulate platelets. With ADP, canine platelet aggregation was lower than human platelet aggregation, while, with Epinephrine and Collagen, aggregation was similar to that obtained with human platelets. Therefore the dog might be a model to study pharmacological interactions on platelet function.

Adenosine Diphosphate↗
PubMed1981

[An experimental investigation of the use of a fluorocarbon (FC 43) as blood substitute].

A fluorocarbonate emulsion was infused into 30 rabbits after the removal of varying amounts of blood. Parameters relating to the transport of respiratory gases and the fundamental features of the macrocirculation were monitored. The animals were sacrificed after 6 or 24 hr and the histological changes in the main parenchymas were assessed. The material injected displayed low toxicity, a good ability to act as a vehicle for oxygen and carbon dioxide, and no tendency to alter the macrocirculation. Numerous problems remain, however, with regard to the stability of fluorocarbonates over the course of time and the effect of their uptake by tissues.

Animals↗
PubMed1980

[Personal experience in the treatment of serious hepatic insufficiency].

Personal clinical experience and the results obtained in the treatment of patients suffering from severe hepatic insufficiency observed in the last seven years, out of a total of some 200 cases, are reported. The modalities employed in the application of intensive basic care and special treatment in 50 cases of initial or clear hepatic coma of various aetiological origin are reviewed. Whereas basic treatment involves more purely medical measures, such as reintegrative and nutritional treatment by the venous route, activation of renal function, the prophylaxis of infectious complications and reinfusion of ascitic fluid, that applied to cases of clear coma involves a more properly surgical technique. It makes use of an original biological clarification technique in extracorporeal circulation by means of isolated and perfused heterologous liver, and an isovolaemic exsanguinotransfusion technique. Indications and features are illustrated in detail.

Ascitic Fluid↗
PubMed1980

[Clinical observations on the rheological and hemodynamic effects of some drugs acting on the microcirculation].

A clinical research was carried out on the rheological and haemodynamic effects of various drugs commonly employed in the treatment of certain disturbances of the microcirculation. In addition to low molecular weight dextrane, a comparison was also made of three other substances theoretically capable of interfering with the fundamental relationship between viscosity, volume and haemodynamics. Assessment of the clinical signs was made both via evaluation of the peripheral haemodynamics during rest and during post-ischaemic hyperaemia and through determination of changes in blood viscosity by means of an original capillary viscosimeter. Some conclusions of a certain speculative and practical interest are drawn from the research as a whole.

Aged↗
PubMed1979

[Mixed aorta-popliteal by-pass: a new proposal for the treatment of extensive ilio-femoral obstruction].

The nosological polymorphism of peripheral arterial obstruction (A.O.P.) continuously requires new surgical techniques of vascular repair. This led the AA. to develop a new composed aorto-popliteal by-pass. It consists of a proximal (aorto-femoral) synthetic segment (Dacron D.V.) which is distally anastomozed to a biological (Meadox-Dardik Biograft) femoral-popliteal segment. Indications for aorto-popliteal by-pass, technical problems, patient selection and results are here discussed.

Aged↗
PubMed1978

[Oxygenating intra-alveolar lavage (OAL) with the use of some new fluorinated compounds].

Certain fluorinated carbonate compounds can carry O2 and CO2 in a physiological manner. This faculty was exploited in the elaboration of an experimental intra-alveolar oxygenating washing protocol employing such compounds as intrapulmonary oxygenating liquids conveyed by transtracheal flooding of the alveoli in 20 rabbits. AP, PaP, CVP and EP were monitored in accordance with a 35' protocol, during which the positive oxygenation and negative emptying phases of the washing process were repeated at an average 2 cycles/min. A respiratory exchange capable of keeping all the animals alive until the recommencement of spontaneous ventilation was noted, along with only slight changes in lung structure. Once an in-depth study is made of certain fundamental phenomena related to structure and lung function, it is felt that this washing method can be used clinically for the treatment of hypoxaemic situations in which normal alveocapillary exchange is impeded by extraneous material, as in desquamative interstitial pneumonia, pulmonary alveolar proteinosis, etc.

Animals↗