Biomedical subjects

G Altissimi

Publications and source records attributed to G Altissimi.

33 records · Page 2Linked to original sources

PubMed1982

Auditory brainstem responses (ABR) in the aged.

86 male subjects, aged between 60 and 86 years (M = 69.5), underwent pure-tone audiometry, impedance tests and brainstem response audiometry (BRA). Subjects have been classified into four age-related groups: 1) 34 subjects, aged between 60 and 65; 2) 22, aged between 66 and 70; 3) 22 aged between 71 and 75; 4) 8, aged between 76 and 86. They have also been classified into four groups on the basis of their mean auditory threshold at 0.5, 1, 2, 4 and 8 kHz: 1) 14 subjects with mean auditory threshold less than or equal to 30 dB HL; 2) 16, between 31 and 40; 3) 24, between 41 and 50; 4) 32, with mean auditory threshold greater than or equal to 51 dB HL. 19 normally hearing adults, aged between 28 and 42, were chosen as controls. Statistically significant correlations have been found between age and mean auditory threshold (P less than or equal to 0.001), between wave latency V and age (P less than or equal to 0.001), between wave latency V and the mean pure-tone auditory threshold at 0.5, 1, 2, 4 and 8 kHz (P less than or equal to 0.001) and between the V-I interval and age (P less than or equal to 0.001). The discrepancy between the mean auditory threshold and the ABR waveform, the overall amplitude's reduction of ABR waves and the progressive lengthening of V-I interval values, seem to indicate that age-related changes involve not only the end organ but also the brainstem auditory structures.

Age Factors↗

PubMedDate not supplied

Suppression tuning characteristics of 2f1-f2 distortion product otoacoustic emissions.

The 2f1-f2 distortion product otoacoustic emission (DPOAE) is suppressed by a third tone following a frequency selective pattern and outlining tuning curves which are generally similar to neural and psychophysical findings. The most effective suppressor tone lies between f1 and f2; less suppressive effects are produced by an added tone that lies in the 2f1-f2 site. The slope of iso-suppression curves is much steeper on the higher flank than on the lower flank of the suppression curve (respectively 100-115 dB/octave and 25-35 dB/octave). A suppression fine structure can be observed in the region of the tip especially for higher DPs probably connected with the fine structure of distortion products and with the instability of cochlear activity. A saturation point, around 70 dB or more has been evidenced on the growth rate functions. Continuous and interrupted suppressor presentation can induce some differences in the responses. Suppression of DPOAEs can provide a wider knowledge on active non-linear mechanisms in the cochlea, and on frequency selectivity also in a clinical context.

Acoustic Stimulation↗

PubMedDate not supplied

[Positional rhinomanometry in hypertrophic vasomotor chronic rhinitis: considerations before and after functional surgery of turbinates].

The Authors report their experience regarding Positional Active Rhinomanometry performed before and after surgery in hypertrophic-vasomotor chronic rhinitis. Twenty-five patients suffering of hypertrophy of the turbinates and/or nasal vasomotor disorders were examined pre-operatively and 3, 6 and 12 months after inferior submucosal turbinoplasty. Tests were performed in the seated, supina, homolateral and contralateral positions with regard to the fossa in question. Values were compared with those of forty normal subjects. Pre-operative examinations showed a large number of paradoxical responses and very high increase in nasal resistance. Postoperative values were quite similar to those of normal subjects, a demonstration of the efficacy of surgical treatment of turbinates hyper-reactivity.

Adult↗

PubMedDate not supplied

Enzyme-ultracytochemical study of adenylate and guanylate cyclases in normal and pathologic human nasal mucosa.

The ultracytochemical localization of adenylate cyclase (AC) and guanylate cyclase B (GC-B) and C (GC-C) activity was studied after stimulation with pituitary adenylate cyclase activating peptide, C-type natriuretic peptide and guanylin, respectively, in normal human respiratory nasal mucosa and mucosa of nasal polyps. To demonstrate these enzymatic activities, we employed enzyme-ultracytochemical methods for electron microscopy. Both normal and pathologic nasal mucosa contained AC, GC-B and GC-C activity. In the upper portion of respiratory epithelium, the enzymes were detected on ciliary and microvillar membranes. In ciliary membranes, GC-B was the predominant form expressed. In goblet cells and in glands of the lamina propria, enzymatic activities were localized mainly on plasma membranes and on membranes lining secretory granules. The results did not reveal any evident differences between the enzymatic activities in normal and pathological nasal mucosa and suggest complementary activities for these enzymes and their stimulators in the regulation of mucociliary transport and glandular secretion.

Adenylyl Cyclases↗

PubMedDate not supplied

[Positional rhinomanometry in specific nasal hyperreactivity].

Following up the results obtained in a previous work testing Positional Rhinomanometry in normal subjects, the authors performed this test in subjects affected with specific nasal hyperreactivity. The aim was to offer an objective evaluation of decubitus-caused variations in air flow resistance through the nasal cavities. Thirty subjects suffering from allergic rhinitis (18 from seasonal and 12 perennial allergic rhinitis) underwent Anterior Active Rhinomanometry during the intercritical period of the disease. Tests were performed in the seated, supine positions homolateral and contralateral to the fossa in question. The positional tests show a marked difference between normality and specific hyperreactivity as a consequence of paradoxical responses. Moreover it can indicate the greater increase in nasal resistance, expression of a clear disreactivity of the cavernous tissue stimulated by variations in posture and found mostly in the perennial allergic rhinitis subjects.

Adult↗

PubMedDate not supplied

[Mechanical sutures of the pharynx during total laryngectomy: proposal of a closed technique].

The authors present the results of a pharyngeal autosuture technique using a 55 mm linear stapler during total laryngectomy. The stapler is inserted before the larynx has been removed, but after it has been separated from its muscular and neuro-vascular connections and after it has been adequately elevated so that no part remains within the instrument jaws. This "closed" procedure is quite rapid, does not soil the operating field and is safe in the long run. The patient does not require a feeding tube since he can swallow from the third day after surgery. None of the patients treated with this technique produced either early or late fistulas, nor did they encounter any trouble in swallowing.

Humans↗

PubMedDate not supplied

[Postural rhinomanometry in normal subjects].

Measurement of decubitus-caused variations in air flow resistance through the nasal cavities indicates the vascular reactivity of turbinate cavernous tissue and makes it possible to evaluate the variable component in nasal resistance; a component usually suppressed by previous pharmacological vasoconstriction. The aim of the present work has been to indicate normative values regarding variations in nasal resistance in different types of decubitus. The latter will be referenced for future studies regarding nasal vasomotor pathologies (specific or aspecific hyperreactivity). Eighty nasal cavities from normal subjects were examined by means of Anterior Active Rhinomanometry in the following positions: seated, supine, homolateral and contralateral to the fossa in question. As absolute values are highly variable even in normal subjects, the resistance variations in decubitus were expressed in percentage of basal value (seated position). In every decubitus there is an average increase in resistance due to the increased venous pressure in the cephalic area although the greatest statistical significance and lowest scattering of values is found in the supine position with 20 degrees head-trunk angle. Mean values and standard deviations are given and will be referenced for further studies on rhinopathology.

Adult↗

PubMedDate not supplied