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Biomedical subjects

M Sergi

Publications and source records attributed to M Sergi.

26 records · Page 2Linked to original sources

Respiratory response to carbon dioxide after propranolol in normal subjects.

The ventilatory response to carbon dioxide, using the rebreathing technique, was investigated in 5 healthy nonsmoker volunteers, without obstructive bronchopathy. The administration of propranolol (20 mg) in a single oral dose did not produce significant modifications of the slopes of the response curves, but caused a significant increase of the intercept of the curves (p less than 0.05). Since no changes of the spirographic values were noted, the results obtained were attributed to a decrease of ventilation. It is concluded that propranolol, even at the dose of 20 mg, is able to induce a depression of the respiratory center, concomitant with significant reduction of heart rate and arterial blood pressure.

Adult↗

[Effort test on a treadmill in peripheral arteriopathic obstructions (author's transl)].

20 males, 48 to 66 of age, whose 10 normal and 10 with chronic arteriopatic obstruction at inferior limbs, were submitted to effort on a treadmill for 5 minutes or until pain. The clinostatic systolic aterial pressure was obtained in the four limbs before and at fixed intervals of time from the exercise. Arterial pressure increases after effort in the normal limbs; the length and the amount of the systolic pressure decrease after exercise are in correlation with the degree of the arterial involvement. The exercise on treadmill seems useful when the clinical and other diagnostic data are inadequate for a reliable diagnosis and to evaluate the progression of the arteriopathy through a non-invasive, and easy to repeat, method. The possible mechanisms of the pressor decrease in the arteriopatic limbs are discussed.

Aged↗

New PEGs for peptide and protein modification, suitable for identification of the PEGylation site.

New PEG derivatives were studied for peptide and protein modification, based upon an amino acid arm, Met-Nle or Met-beta Ala, activated as succinimidyl ester. PEG-Met-Nle-OSu or PEG-Met-beta Ala-OSu react with amino groups in protein-yielding conjugates with stable amide bond. From these conjugates PEG may be removed by BrCN treatment, leaving Nle or beta Ala as reporter amino acid, at the site where PEG was bound. The conjugation of PEG and its removal by BrCN treatment was assessed on a partial sequence of glucagone and on lysozyme as model peptide or protein. Furthermore, insulin, a protein with three potential sites of PEGylation, was modified by PEG-Met-Nle, and the PEG isomers were separated by HPLC. After removal of PEG, as reported above, the sites of PEGylation were identified by characterization of the two insulin chains obtained after reduction and carboxymethylation. Mass spectrometry, amino acid analysis and Edman sequence, could reveal the position of the reporter norleucine that corresponds to the position of PEG binding.

Dipeptides↗

Hypersomnolence in fibromyalgia syndrome.

OBJECTIVE: To evaluate hypersomnolence in patients affected by fibromyalgia syndrome. METHODS: Thirty consecutive patients affected by fibromyalgia syndrome (FMS) (28 F) completed a sleep questionnaire and underwent the following evaluations: lung function tests; polysomnography; the Epworth sleepiness scale (ESS), which measures sleep complaints and daytime hypersomnolence; and the visual analogical scale (VAS) to detect subjective pain, fatigue, anxiety and depression. RESULTS: The FMS patients were divided into two groups based on their ESS score. Patients complaining of daytime hypersomnolence had a higher number of tender points (15 +/- 2 vs. 12 +/- 1, p < 0.01), a higher subjective pain score (72 +/- 15 vs. 52 +/- 13, p < 0.05), and more fatigue (p < 0.05). The diffusing capacity of the lung (Tlco) was more impaired and the occurrence of periodic breathing was higher. FMS patients complaining of daytime somnolence had significantly less efficient sleep than the FMS patients with no daytime somnolence (p < 0.05), i.e. a lower proportion of stage 3 sleep (5 +/- 2% vs. 12 +/- 3%; p < 0.001), stage 4 sleep (1 +/- 0.5% vs. 4 +/- 1%; p < 0.001), and twice as many arousals per hour of sleep (p < 0.01). The respiratory pattern of FMS patients with hypersomnolence showed a higher occurrence of periodic breathing (p < 0.05). The short length of apneas and hypopnoeas did not affect the apnea/hypopnea index (5.1 +/- 3 vs. 7 +/- 4; ns), but FMS patients with daytime hypersomnolence had a greater number of desaturations per hour of sleep (11 +/- 6 vs. 6 +/- 5; p < 0.05). Pulmonary volumes did not differ between the two groups. The EES score was significantly correlated in FMS patients, and even more markedly in the FMS patients with hypersomnolence, TLco, A/I, and disease duration. The ESS score was correlated significantly with the number of tender points only in FMS patients with daytime hypersomnolence. CONCLUSION: The occurrence of daytime hypersomnolence in FMS patients is linked to a greater severity of fibromyalgia symptoms and to more severe polysomnographic alterations.

Adult↗