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Biomedical subjects

T Longo

Publications and source records attributed to T Longo.

At least 37 records · Page 2Linked to original sources
PubMed1979

[Effects of dopamine, noradrenaline and isoproterenol on pulmonary circulation in anesthetized dogs].

Experiments were performed on 19 anaesthetized open-chest dog instrumented with polyethylene catheters inserted: into the aorta, in pulmonary artery and in left atrium and with an electromagnetic flow-transducer placed around the ascending aorta in order to record : systemic arterial and pulmonary pressures, mean left auricular pressure and phasic aortic flow. Heart rate, stroke volume, total systemic and pulmonary resistance, cardiac work were moreover calculated. Each dog was given intravenously by slow infusione : Dopamine (micrograms 5--10--20/kg/min/ 5 min), Isoproterenol (microgram 0.125--0.25--0.5/kg/min/5 min) and Norepinephrine (microgram 0.25--0.5--1 /kg/min/5 min). Results obtained on systemic hemodynamics agree with those reported by many other investigators. On pulmonary circulation : Isoproterenol, at the tested doses, elicited vasodilator effects, Norepinephrine increased total pulmonary resistance but not pulmonary vascular resistance, while Dopamine did not modify or slightly reduced vascular pulmonary tone.

Animals↗
PubMed1979

A comparative study of poly(glycolic acid) and catgut as suture materials. Histomorphology and mechanical properties.

The "quality" of poly(glycolic acid) as an absorbable suture material was investigated in comparison with catgut. Tissue reactions to poly(glycolic acid) and plain catgut were examined histomorphologically at different time intervals after implantation in rats, and compared. Four mechanical properties were also examined as relevant quality factors: elastic stiffness, tensile strength, toughness, and percent elongation at rupture of the suture material per se (unknotted). The variation of these properties in poly(glycolic acid) implants was followed since their insertion in the tissues. Histological behavior and mechanical properties appear to be more closely correlated in the case of poly(glycolic acid) than in the case of catgut, as a consequence of a greater regularity of tissue reaction towards the synthetic material. Both tissue reaction and tensile properties variation are independent of size in the case of the braided poly(glycolic acid) sutures examined. Elastic stiffness and tensile strength decrease steadily in time; toughness and ultimate elongation display an increase up to a maximum within one day since implantation, and then decrease.

Abdominal Muscles↗
PubMed1978

Hemodynamic and metabolic changes induced by temporary clamping of the thoracic aorta.

Numerous authors reported a significant deterioration of heart function induced by aortic cross-clamping. Nevertheless, the aorta has been clamped during various surgical procedures without any complication. We studied the hemodynamic and metabolic variations induced by 20 min thoracic aorta cross-clamping in 6 open-chest dogs. During clamping the most striking modifications were an increase in coronary blood flow of over 65%, an increase in cardiac work of over 77% and an increase in total peripheral resistances of over 68% compared to base values. No significant variations were found in the heart rate and cardiac index. Metabolic parameters, such as O2 consumption and lactate consumption increased significantly during the clamping period. The increase in lactate consumption and the progressive and continuous improvement in oxygenation indexes (lactate/pyruvate, redox potential, excess of lactate) proved the absence of any myocardial anoxia during this period. Within 15--30 min after declamping all hemodynamic and metabolic parameters reverted to values close to basal values. These data strongly suggest that the mammalian heart can tolerate this procedure satisfactorily for a limited period of time. In clinical settings, one should consider the base conditions of the cardiovascular system before transposing these conclusions.

Animals↗
PubMed1977

[Porto-systemic anastomosis in the treatment of portal hypertension due to intrahepatic block. Advanced surgical technics].

A physiopathological interpretation is offered of the possibilities given by recent selective or portally regulated reduction of pressure in achieving a balance between reduction of pressure and diversion. Classic demonstrations, in fact, prove effective in the prevention of haemorrhage due to rupture of oesophageal varices. On the other hand, by over-diversion of the portal flow from the liver, they may cause a further deterioration in liver performance and more imposing the greater the flow of portal blood through the liver preoperatively. Procedures aimed at de-tension of the portal system, particularly the gastro-oesophageal segment, and at ensuring an intrahepatic venous flow sufficient to obviate steal syndrome damage, are described. Some of these procedures are still at the experimental stage. The techniques involved are explained, along with the underlying principles achieved by or prospected for each of them.

Drainage↗
PubMed1975

[Glycolic acid/polymer as suture material].

Tissue reactions to polyglycol acid and plain catgut threads were compared. The second part of the paper deals with changes in the mechanical properties of the polymer. Their reduction after insertion in tissues was proportionally equal for threads of different sizes. This finding is explicable histologically, since it can be shown that cell and humoral attack of the single filaments is homogenous throughout the entire cross-section of the thread.

Abdominal Muscles↗
PubMedDate not supplied

Anatomical concepts to be observed when performing a vascular junction.

An anatomical study shows that the vascular junctions are always very well rounded in accordance with the direction of the blood flow. When performing an anastomosis, the further one departs from this configuration, which we can define as perfect, the more flow disturbances are likely to arise. This may jeopardize the satisfactory outcome of surgery.

Aorta↗
PubMedDate not supplied

Atherosclerotic aortic-bisiliac aneurysms in two monocorial twins.

Two cases of aorto-bisiliac aneurysms in monocorial twins in their sixties were observed. We report experimental and clinical data from the literature about genetic involvement in the formation of aneurysms, especially when associated with other risk factors. In addition to the genetic factors in the twins we studied, we also found other risk factors, such as hypertension and smoking, which took a long time to affect the patients before the aneurysms were detected.

Aneurysm↗