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Biomedical subjects

G Motta

Publications and source records attributed to G Motta.

At least 145 records · Page 8Linked to original sources
PubMed1983

[Morphological findings and functional considerations on the structural adaptation of colonic grafts on the rat stomach].

Structural changes of colonic patches implanted in rat stomachs for periods of 2 to 12 months were evaluated by standard light and scanning electron microscopy. Colonic patches were sutured on the posterior wall of 116 white rats stomach body according to the following models: 1) mucosal surface to gastric lumen (60 rats); one third of the animals were given chronic doses of histamine subcutaneously; 2) peritoneal surface to gastric lumen (28 rats); 3) leiomuscular layers to gastric lumen by removing of the colonic mucosa (20 rats). Eight rats were used as controls. The colonic mucosa was shown to be highly resistant to acid secretions; only minimal surface erosions were found in animals with gastric hypersecretion following histamine stimulation. In contrast both the peritoneal surface and the colonic leiomuscular components were completely destroyed by contact with the acid juice. Both these structures were subsequently and completely colonised by the gastric mucosa.

Adaptation, Biological↗
PubMed1983

Detection of antibody secreting hybridomas with diazobenzyloxymethyl paper: an easy, sensitive and versatile assay.

A sensitive and universal assay for the detection of monoclonal antibodies is described. One microliter of each hybrid cell supernatant is transferred to activated diazobenzyloxymethyl paper and, after coating the uncovered activated sites by incubation with bovine serum albumin, the paper is dipped in a solution of 125I-labeled antigen. After incubation to allow for fixation of antigen to antibody present in the supernatants, the paper is rinsed and autoradiographed. As many as 96 wells can be tested on one paper and more than 20 papers can be treated in 1 day (approximately 2000 wells). The sensitivity and reliability of the method were tested with monoclonal antibodies against a subunit of scorpion (Androctonus australis) hemocyanin. Unlike other immunobinding assays the test depends only on antigen-antibody interaction and not on class or subclass of immunoglobulin. It is suitable for a variety of hybridomas.

Animals↗
PubMed1983

[Artificial blood. Experimental studies on fluorocarbons as chemical blood substitutes].

Fluorocarbonates are organic compounds capable of carrying oxygen and surrendering it to tissues by means of biological sound modalities. Experimentation of an emulsion consisting of perfluorotripropylamine and perfluorodecaline (Fluosol DA 20%) as a blood substitute is reported. Acute (Ht less than 1%) and chronic morphological (Ht = 15%) studies were performed on rats, and a semi-acute biochemical and morphological protocol (Ht = 21%) was experimented in pigs. The first signs of altered cerebral electrical activity occurred at Ht = 2% in the acute experiments, and death due to respiratory arrest took pace at Ht = 0.5%. In the semiacute and chronic experiments, widespread infiltration of fluorocarbonic micelles was noted on histological and electron microscope lung and liver preparations.

Acid-Base Equilibrium↗
PubMed1983

Morphological evaluation of the human umbilical vein graft. An experimental study.

23 human umbilical vein segments (5 mm X 4-5 cm) were implanted into the carotid and iliac arteries of 15 dogs, removed at intervals ranging from 10 to 360 days after surgery and analyzed by light and scanning electron microscopy. 10 days after implantation, a thin layer of fibrin covered the central areas of the grafts, while thick platelet aggregates were found near the anastomoses. After 30 days, the progressive connective tissue ingrowth led to the organization of a thin fibrous inner layer on which endothelial-like cells grew, spreading from both anastomoses. The endothelialization process appeared to be almost complete at 120 days after implantation, while at 360 days the flow surface was totally lined.

Animals↗
PubMed1983

[Small-caliber arterial prostheses: influence of porosity].

Thirty-two pyrolytic carbon coated Weavenit dacron grafts and 32 human umbilical vein segments treated with glutaraldehyde were implanted in the carotid arteries of 32 dogs. Prosthesis samples were removed after periods varying from 10 to 120 days, and sections examined by optical microscopy. Internal surfaces were studied by scanning electron microscopy. Overall permeability was 93.7 p. cent for the dacron prosthesis and 84.3 p. cent for human umbilical vein sections. Fundamental stages of the pseudointimal organization process were compared for the two types of prosthesis.

Animals↗
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↗
PubMed1983

Iatrogenic spinal accessory nerve palsy.

Four patients were referred to the Royal National Orthopaedic Hospital with iatrogenic accessory nerve palsy because their symptoms were severe enough to warrant surgical treatment. The definitive diagnosis was made several months after the initial procedure, when wasting of the trapezius and shoulder dysfunction became apparent. The reasons for this delay are discussed along with prophylaxis and surgical technique of treatment. Less significant degrees of paralysis manifest themselves on return to activity in which the hands are required to be above shoulder level. Electromyograms in these cases will confirm the diagnosis (1).

Accessory Nerve Injuries↗
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

[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↗
PubMed1981

[Durene derivates. IV. N-((2,3,5,6-tetramethylbenzoyl)alkyl)imidazoles and N-((beta-(2,3,5,6-tetramethylphenyl)-beta-hydroxy)ethyl)imidazoles with anticonvulsant activity].

A series of N-[(2,3,4,6-tetramethylbenzoyl)alkyl]imidazoles and of N-([beta-(2,3,5,6-tetramethylphenyl)-beta-hydroxy]ethyl)imidazoles has been synthesized. All compounds were tested in mice for anticonvulsant activity against electroshock and pentylenetetrazole convulsions. These durene-derivatives showed good activity, whereas the corresponding benzene-derivatives were inactive.

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↗