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Biomedical subjects

G Savio

Publications and source records attributed to G Savio.

12 recordsLinked to original sources

Comparison of statistical indicators for the automatic detection of 80 Hz auditory steady state responses.

OBJECTIVE: To evaluate, using receiver operation characteristic (ROC) curves, the performance of several statistical indicators in the objective detection of 80 Hz steady state auditory evoked responses. DESIGN: Steady state auditory evoked responses elicited by amplitude modulated tones of 500 and 1000 Hz, were obtained in 16 normal adults. Recordings were made at intensities ranging from 80 to 30 dB SPL and without stimulation. Four statistics: coherence synchrony measure, circular T2, a new variant of Hotelling T2 (labeled HT2) and a test for hidden periodicity (F test) were calculated. The statistics were compared using ROC curves and bootstrapping techniques. Two outcome measures were considered: behavioral threshold prediction and averaging efficiency. RESULTS: All indicators were highly accurate to detect a response (8 to 9 dB above mean behavioral threshold for the 1000 Hz and 14 to 16 dB for the 500 Hz carrier). Responses could be reliable detected after averaging about five individual epochs of long duration. No statistically significant differences were evidenced though in their capability to predict behavioral threshold or their averaging efficiency. CONCLUSIONS: Despite the more adequate statistical properties of some of these indicators no significant differences were found in their performance. Thus all of these indicators could be recommended for automatic detection of 80 Hz auditory steady state responses.

Adolescent

Frequency-specific audiometry using steady-state responses.

OBJECTIVE: To evaluate the audiometric usefulness of steady-state responses to multiple simultaneous tones, amplitude-modulated at 75 to 110 Hz. DESIGN: Steady-state responses to multiple tones amplitude-modulated at different rates between 75 and 110 Hz and presented simultaneously were recorded at different intensities in normal adults, well babies, normal adults with simulated hearing loss, and adolescents with known hearing losses. Response thresholds were compared with behavioral thresholds. RESULTS: In normal adults the thresholds for steady-state responses to tones of 0.5, 1, 2, and 4 kHz were 14 +/- 11, 12 +/- 11, 11 +/- 8, and 13 +/- 11 dB, respectively, above behavioral thresholds for air-conducted stimuli, and 11 +/- 5, 14 +/- 8, 9 +/- 8, and 10 +/- 10 dB above behavioral thresholds for bone-conducted stimuli. In well babies tested in a quiet environment, the thresholds were 45 +/- 13, 29 +/- 10, 26 +/- 8, and 29 +/- 10 dB SPL. In adolescents with known hearing losses, the steady-state responses thresholds predict behavioral thresholds with correlation coefficients (r) of 0.72, 0.70, 0.76, and 0.91 at 0.5, 1, 2, and 4 kHz, respectively. CONCLUSION: Steady-state responses to tone amplitude-modulated at 75 to 110 Hz can be used for frequency-specific objective audiometry. The multiple-stimulus technique allows thresholds to be estimated for eight different stimuli at the same time.

Adolescent

[Clinical evaluation of letosteine activity in the treatment of acute febrile bronchitis in children. Double-blind controlled study versus placebo].

A double blind vs placebo study was carried out to study the effect of letosteine on the symptoms and clinical course of paediatric patients suffering from acute febrile bronchitis. Forty children were recruited for the research: 20 were treated with letosteine in a dose of 25 mg x 3 g/die and 20 with placebo; treatment lasted 10 days. The following parameters were assessed during the trial: body temperature, cough, thoracic objectivity, respiratory function indices. The results of the study show that in the letosteine treated group there is a statistically significant decrease in fever, a favourable evolution of thoracic objectivity and an improvement in certain respiratory function parameters (MEF 75, PEF). It is concluded that treatment with letosteine leads to a significant increase in the rate of regression of thoracic symptomatology and a faster, more substantial reduction in fever in children suffering from acute bronchitis. This is probably the result of drug action on mucus viscosity, restoring optimal mucociliary clearance, and through action fostering the penetration of antibacterial substances into the mucus.

Acute Disease

Xibornol: multiple dose pharmacokinetics and diffusion in lung, tonsillar tissue and laryngeal mucosa.

In ten patients with severe chronic bronchitis and in a further 23 with planned resection of lung, tonsils or larynx, 500 mg doses, single or multiple, of xibornol (6-isobronyl-3, 4-xylenol) were administered for an antibacterial effect. The pharmacokinetics and diffusion of the drug in the tissues were studied. A high diffusion and distribution value of xibornol was observed, with levels in the tissues constantly higher than that in the serum. The concentrations reached within the respiratory tract were adequate for their antibacterial effect.

Administration, Oral

Non-interference of xibornol on the theophylline blood levels.

The authors have proposed the evaluation of the possible pharmacokinetic interactions between xibornol and theophylline. This study has been carried out on eight healthy volunteers of both sexes between 19 and 27 years of age. On the first day each subject was treated with 600 mg oral sustained-release formulation of aminophylline at 08h00 and at 20h00. From the 2nd day an oral administration of 500 mg of xibornol every 8 h was added to the treatment of aminophylline. On the 1st, 2nd and 5th day blood samples were taken after 30, 90, 180 and 300 min following drug administration. After serum separation an analysis was performed on them. The results have shown that theophylline levels at the programmed times during the three days tested are just overlapping. In conclusion the administration of xibornol does not introduce any interference with theophylline clearance or lengthening of its plasma half-life.

Adult

Nefopam in postoperative pain.

A comparative study between nefopam (Acupan) and pentazocine was carried out in 90 patients for treatment of postoperative pain following gynaecological operations. The results show that nefopam has an analgesic activity comparable with that of pentazocine, but its duration of action seems to be longer-lasting, even if with a longer period of latency. At equieffective analgesic action, nefopam shows a lower interference with the respiratory function. As far as side-effects are concerned a significant increase in drowsiness was observed with both types of treatment; sweating was observed only in nefopam group.

Adult

Chronic analgesic study on buprenorphine action in cancer pain. Comparison with pentazocine.

Buprenorphine appears to have an analgesic effect (evaluated after a week of treatment) statistically superior to that of the comparative drug. On the whole, during buprenorphine treatment the normal activities of life of the individual patient improved. The percentage incidence of the side-effects is similar for the two drugs. Buprenorphine, however, caused less intense side-effects than pentazocine.

Adult