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Biomedical subjects

S Benito

Publications and source records attributed to S Benito.

41 records · Page 3Linked to original sources
PubMed1983

A new device for measurement of pulmonary pressure-volume curves in patients on mechanical ventilation.

Measurement of total (lung plus chest wall) pulmonary compliance is routinely obtained in mechanically ventilated patients by dividing the tidal volume (VT) by the airway pressure (Paw) gradient from end-inspiration to end-expiration. In order to obtain the pressure-volume (P-V) tracing during inspiration, we developed a method using a continuous and slow (1.7 L/min) oxygen inflow. When gas flow is kept constant, changes in lung volume are proportional to time and do not require direct measurement. In 22 patients, P-V curves traced using the continuous-flow method were identical to those obtained from the syringe method. The advantages of the inflow method are simplicity, reproducibility, and better visualization of the initial part of P-V curve.

Humans↗
PubMed1981

[Left ventricular function. Study during artificial ventilation with PEEP in the dog (author's transl)].

According to Powers et collaborators the hypothesis that intramyocardial vessels may be collapsed in artificially ventilated patient with added PEEP, could be arisen. So, myocardial ischemia may explain why in some of those ones there appear signs of left ventricular failure. To test whether this reasoning was correct we measured LVEDP in normal dogs submitted to increasing levels of PEEP up to 40 cm H2O. Our results seem to point towards the following conclusions: a) In normal dogs, Starling relation is not altered and remains within the same hypercontractility pattern. b) As PEEP increases, ventricular function remains within the same curve up to 30 cm H2O and jumps to a higher contractility curve at 40 cm H2O of PEEP. All of this would suggest that under our experimental conditions it does not seem reasonable to assume the existence of left ventricular failure due to PEEP influence.

Animals↗
PubMedDate not supplied

Phospholipid fatty acid composition affects enzymatic antioxidant defenses in cultured Swiss 3T3 fibroblasts.

The aim of this work was to study the adaptation of enzymatic antioxidant cell defense to the nature of the membrane polyunsaturated fatty acids (PUFA). 3T3 Swiss fibroblasts were grown for 5 days in a medium supplemented with 50 microM linoleic acid (LA) or eicosapentaenoic acid (EPA) and compared to control cells (C). The phospholipid fatty acid content was evaluated: LA were enriched in n-6 PUFA (27.8%) in comparison to C (6.7%) or EPA (5.6%); EPA were enriched in n-3 PUFA (26.2%) in comparison to LA (4.4%) or C (4.6%). The fatty acid double bond index (DBI) increased from C to LA and EPA. The activities of the three key enzymatic antioxidant defenses, SOD, GPx and GST, increased with the degree of unsaturation of the phospholipid fatty acids. In the cells with fatty acids that are very sensitive to oxidative stress, the higher activities of SOD and GPx might act to limit the initiation of lipid peroxidation and the higher activities of GST and GPx to decrease the toxic effects of the various species produced from lipid degradation.

3T3 Cells↗
PubMedDate not supplied

[Subaortic stenosis in ankylosing spondylitis: a new hypothesis of cardiac involvement].

Ankylosing spondylitis is a chronic inflammatory rheumatism with associated heart involvement, fundamentally circumscribed to the aortic root area. Of these anomalies, the fibrous proliferation of the supra and sub-valvular tissue appears to be pathognomonic. We present two cases of ankylosing spondylitis studied by means of bidimensional echocardiography. The study showed a fixed sub-aortic stenosis, without alterations of the mitral or aortic valves. In our opinion, the aortic subvalvular membrane, could constitute the initial alteration of the valvular affection of ankylosing spondylitis.

Adult↗