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Biomedical subjects

A Sbaffi

Publications and source records attributed to A Sbaffi.

6 recordsLinked to original sources
PubMed1991

Platelet activation by emotional stress in patients with coronary artery disease.

We studied the effects of experimentally induced emotional stress (mental arithmetic) on different hemodynamic parameters, catecholamine levels, and serum and platelet function tests in 25 postinfarction patients and in 10 apparently healthy, age-matched control subjects. Mental stress (10 minutes) induced significant increments in heart rate, systolic blood pressure, diastolic blood pressure, double product, and cardiac output, indicating a sympatho-adrenal stimulation that was confirmed by a significant increase in serum epinephrine and norepinephrine levels. All of the effects disappeared at minute 10 of recovery. Concomitantly, the test produced a significant increase in platelet aggregation (induced by 3 microM ADP or 1 microgram/ml collagen), the formation of circulating platelet aggregates, and an increase in thromboxane B2 levels in plasma and serum. These effects were also rapidly reversible. Similar activation of hemodynamic parameters and a similar but less evident increase in platelet function by emotional stress were observed in control subjects. A possible artifact due to factitious platelet activation by catheter sampling was excluded with experiments in which a 40-minute rest was introduced after the baseline period and before mental stress; platelet activation did not occur during baseline or rest periods, only after emotional stress. Furthermore, the antiplatelet drug dipyridamole reduced the stress-induced formation of platelet aggregates in postinfarction patients. These results demonstrate the existence of a direct link between emotional stress and platelet function and offer an explanation of one of the mechanisms through which mental stress may be involved in the development of coronary artery disease.

Coronary Disease↗
PubMed1989

Proposal of an easy method to improve routine sputum bacteriology.

The study of bacterial flora of the lower respiratory tract is very important for the diagnosis of pulmonary infections and proper therapy but it has to face important methodologic problems. The main problem is contamination of the sputum during its passage through the upper airways. The present study suggests an improved procedure aiming first of all at reducing the specimen contamination by upper airway bacteria by means of a preliminary mouth wash, and secondly at comparing qualitative and quantitative cultures of spit with those of sputum. In our study bronchial lavage aspirate (BLA) cultures were used as a control. Both definite (80 patients) and random (20 patients) sequence sampling procedures were considered to show the importance of a correct sequential specimen collection. Bacteria isolated in the sputum and/or in BLA but absent in the spit were considered the most probable responsible for an eventual pulmonary infection. On the contrary a germ found in the spit and eventually in the sputum but not in BLA was considered responsible for only an eventual inflammation of the upper respiratory tract. Doubtful cases were solved by comparing the different bacterial concentrations in the various samples. A preliminary mouth washing procedure decreased the mean concentration of contaminants in the sputum: 3.6 +/- 7.5 x 10E8 (E = exponent) versus 3.7 +/- 7.2 x 10E7 CFU/ml spit versus sputum (80 patients) p less than 0.001. On the contrary if sputum preceded spit (12 out of the 20 randomly treated subjects), bacterial counts were not significantly different (2.1 +/- 5.7 x 10E8 vs. 1.3 +/- 2.9 x 10E8 CFU/ml, respectively, p = NS). In the group of correctly treated patients (80 subjects) only infrequently oral contaminants were found in BLA (12.5%). The finding of bacteria in BLA but absent in spit and/or sputum was rare (4.8%) suggesting that, at least in chronic obstructive lung disease (COLD) patients, spit and sputum quantitative and qualitative cultures may be sufficient for a good microbiologic examination in almost all the cases.

Bacteria↗
PubMed1979

[Bacterial antagonism of oral secretions towards staphylococci].

Bacterial antagonism may be one of the mechanism which regulates the bacterial flora of the pharynx. We have investigated the bacterial antagonism exerted in oral secretion by alpha-hemolytic streptococci against S. aureus and S. epidermidis. We cultured viridans streptococci and staphylococci in human saliva and we noted a bactericidal activity towards staphylococci. Such activity, referable to the salivary system (peroxidase-thiocyanate) activated by hydrogen peroxide produced by streptococci, was greater on S. epidermidis. The remarkable sensitivity of S. epidermidis could explain the rare presence of this species in pharynx and oral cavity.

Humans↗
PubMed1979

[Preferential staphylococcal colonizing site in the upper airway].

150 healthy individuals and 162 tonsillopathic patients were investigated for the presence of Staphylococcus species in the upper respiratory tract. S. epidermidis was isolated from the throat in a very small percentage of all the people examined. A great number of healthy individuals (40%) and of patients (70%) were colonized by S. aureus either in the nose or in the throat; 30% of the carriers harboured S. aureus exclusively in the tonsils and in the pharynx.

Adult↗