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Biomedical subjects

F Ottaviani

Publications and source records attributed to F Ottaviani.

At least 109 records · Page 6Linked to original sources
PubMed1985

Auditory brainstem responses (ABR) in multiple sclerosis.

Thirty-two multiple sclerosis (MS) patients, 10 males and 22 females, aged between 21 and 55, underwent pure-tone audiometry and testing of auditory brainstem response (ABR). Thirteen were classified as 'definite', 12 as 'probable' and 7 as 'possible', according to the McAlpine criteria. Each ear of each patient was tested monoaurally. The most common alterations were seen in the parameters of the cross-correlation between the normal template and the template of the individual MS patient. The second most altered parameters were those concerning the V wave which was absent in most cases but, when present, rarely showed latency-amplitude values falling outside the 90% confidence limit ellipses. Test-retest replicability and stimulations with increasing numbers of stimuli per second were useful in detecting intra-individual variability of waveform characteristics. When considering all the tests performed, 88% of the 'definite', 71% of 'probable' and 64% of 'possible' MS patients' ears showed ABR abnormalities. We stress the importance of a separate evaluation of the two ears due to the frequent unilateral alterations, and of an accurate evaluation of the ABR characteristics. We conclude that brainstem audiometry is a more reliable test for detecting demyelinating processes than is usually described in the literature.

Adult↗
PubMed1985

Functional evaluation of velar insufficiency by means of the rhinomanometric method.

25 subjects aged between 5 and 17 years, 15 females and 10 males, underwent anterior rhinomanometry. 10 of them were normal and 15 affected by velar insufficiency following adenotonsillectomy in 11 case and palatosynthesis in 4. The rhinomanometric tracing was obtained while the patient repeatedly pronounced oral vowels such as a, e, i, c, u and CVs such as ka, ga. In normal subjects intranasal pressure modifications were represented by a series of dyphasic waves with a positive-negative polarity. In the subjects with velar insufficiency the waves were almost monophasic with positive polarity. During and after the phoniatric rehabilitation, waves returned to be dyphasic together with a progressive reduction of hypernasality. While morphology of the rhinomanometric tracing can be considered a reliable index of velar function, wave's amplitude is influenced by the anatomical conditions of the nasal cavity and by the intensity with which the subject pronounces the vowels and the CVs. Rhinomanometry represents therefore an atraumatic, rapid and reliable technique, easy to perform, in order to evaluate velopharyngeal function and to monitor the increase of velar function during and after treatment.

Adolescent↗
PubMed1984

Adenoid hypertrophy and nasal mucociliary clearance in children. A morphological and functional study.

The authors have studied nasal mucociliary function and adenoid surface characteristics in a group of 86 children, aged between 4 and 10 years, divided in two groups according to the presence or absence of clinical, instrumental and röntgenographic signs of nasal obstruction due to hypertrophied adenoids. Each group was divided into 3 age-related subgroups (group I: 4-5 years; group II: 6-7 years; group III: 8-10 years). A population of normal adults was chosen both for functional and ultrastructural characteristics. Nasal mucociliary clearance velocity values were evaluated by means of the saccharine method and the surface characteristics of the adenoid tissue by means of scanning electron microscopy. The data obtained show that the nasal mucociliary function is generally reduced in children but, while in the group with poorly developed adenoids an early and progressive improvement can be observed, the children with severely hypertrophied adenoids show an impaired function up to 10 years, without age-related improvements. At almost 10 years, children with poorly developed adenoids reach normal adult clearance values. These functional data can be related to the surface characteristics of adenoid tissue. In fact, while poorly developed adenoids are characterized by a compact layer of ciliated cells, severely hypertrophied adenoids are characterized by a metaplasic epithelium, with almost complete loss of cilia. Such findings, which are probably due to the inflammatory events frequently complicating adenoid hypertrophy, could explain, together with the obstructive effects, the impairment of the nasal mucociliary clearance in childhood.

Adenoids↗
PubMed1984

Auditory brainstem responses to middle- and low-frequency tone pips.

Auditory brainstem responses (ABR) evoked by clicks allow a threshold evaluation for the high-frequency range (2-4 kHz) but not for middle and low frequencies (0.5-1 kHz). In 19 normally hearing subjects aged between 24 and 40 years. ABRs have been recorded using clicks and 0.5- and 1-kHz tone pips, with durations of 6 and 3 ms, respectively, and rise-decay times of 3 and 1.5 ms. The input signal was filtered by a passband filter of 20-5 000 Hz. Parameters of tracings elicited by the different kinds of stimuli are compared. Tone-pip ABR morphology does not show the conventional seven peaks but a single large vertex-positive wave. On the ascending branch high-frequency potentials, probably corresponding to the I, II, III and IV-V click-evoked peaks, were visible in some cases, but they rapidly disappeared as the stimulus intensity was decreased. Their 2.3-3 ms greater mean latency values are presumably related to the rise times of the stimuli employed. In terms of bioelectric generators, this large vertex-positive peak probably corresponds to the Jewett V wave. It probably represents a generalized asynchronous dendritic activity. Thus it is possible to obtain ABRs to middle- and low-frequency stimuli. Mean amplitude values of the slow wave are considerably higher than those of the Jewett V wave, but standard deviations are also larger. The positive wave has been identified in response to 1-kHz tone pips in 100% of cases at 30 dB nHL and in 52% of cases at 20 dB, while for 0.5-kHz tone pips in 73.7% of cases at 30 dB and in 57% at 20 dB. On the whole the threshold is located between 15 and 30 dB nHL.

Acoustic Stimulation↗
PubMed1984

Middle-latency auditory components in response to clicks and low- and middle-frequency tone pips (0.5-1 kHz).

Middle-latency auditory components (MLC) in response to clicks and tone pips have been recorded in 20 normal subjects, aged between 26 and 32 years, in order to verify their reliability in response to frequency-specific stimuli (0.5 and 1kHz). The results indicate a good reliability of MLC obtained when using tone pips. The responses show the conventionally labeled Po, Na, Nb, Pb waves. The latencies of these waves tend to be greater than those of the corresponding waves elicited by clicks and their amplitudes are smaller. This is probably due to an asynchrony of the responses. The Po and Pa waves are the most resistant to decreasing stimulus intensity, as both are clearly detectable down to 20 dB nHL, but Po is the best threshold index because at 20 dB it has a more clear-cut shape than Pa. According to the latency values obtained for MLC elicited by both clicks and tone pips, the Po wave is probably generated at the inferior colliculus level. The latency shift towards the click-elicited Jewett wave V is mainly due to the different filter settings employed. The morphology of MLC elicited by tone pips is less affected by changes in stimulus frequency than that of corresponding auditory brainstem responses. Thus, MLC are a reliable indicator for defining low- and middle-frequency auditory thresholds.

Acoustic Stimulation↗
PubMed1984

Ciliary ultrastructure and nasal mucociliary clearance in chronic and allergic rhinitis.

The authors have studied nasal specimens collected by means of nasal brushing in eight patients affected by allergic rhinitis and in eight affected by chronic rhinitis, while in other four patients affected by allergic rhinitis a lower turbinate biopsy was performed. All twenty patients showed an increased mucociliary clearance time and a reduced velocity regardless to the pathology during a previously performed saccharin test. Different ultrastructural alterations have been observed, such as: both central and peripheral microtubules alterations; absence of dynein arms; absence of radial spokes; ciliary membrane alterations; "compound" cilia; disorientation of central tubules. These alterations have been observed variously associated in both allergic and chronic rhinitis patients groups. Basing on their data, the authors state that ciliary abnormalities cannot be considered specific of a particular pathology but they can coexist in different situations. They also think that the mucociliary clearance parameters determination represents the only method to evaluate, even if in an indirect fashion, the percentage of ciliary abnormalities, as no direct quantitative method has been described. Ciliary ultrastructural alterations can be of diagnostic value only if associated with mucociliary clearance time and velocity determination.

Cilia↗
PubMed1983

Morphological and functional characteristics of human temporal-bone cell cultures.

Morphology and calcium metabolism have been studied on five different cell cultures from human normal adult temporal-bone biopsies obtained during five stapedectomies. Control cell cultures were obtained from normal human skin. Four different cell types were observed in the bone biopsies: 1) osteoblast-like cells; 2) osteoclast-like cells; 3) fibroblast-like cells; 4) intermediate cells. However, morphology by itself is inadequate for clear differentiation of the four cell types. Hormonal stimulation with calcitonin and dibutyryl-cAMP in presence of 45Ca++ showed a clear-cut difference in 45Ca++ uptake between cultured cells deriving from bone and skin. Functional responses to hormonal stimulation are therefore more specific than cell shape and morphology in differentiating fibroblasts from bone cells. Since responses to hormonal stimulation confirm that temporal-bone cell cultures actually contain bone cells, such cultures seem to be a good experimental model for the study of bone morphology and physiology.

Biological Transport, Active↗
PubMed1983

Effects of stimulus repetition rate on the auditory brain stem responses (ABR).

Brain stem auditory evoked potentials were recorded from 26 normal subjects who listened to 100 ms clicks at 10, 20, 50, and 100 repetitions per second at varying intensities. A 0.5+/-0.3 ms shift of the V wave latency was observed between 10 clicks per second and 100 clicks per second; a lesser difference was found when the repetition rate was shifted between 10 to 50, 20 to 50, or 20 to 100 clicks per second. No significant differences were observed when the repetition rate moved from 10 to 20 or between 50 and 100 clicks per second. Whatever latency shifts were observed appeared to be independent of the stimulus intensity. Waveform morphology seemed to be the same between 10 and 20 clicks per second, with only minor changes observed at the 50 clicks per second rate. At 100 clicks per second a decrease or a complete disappearance of some components or both was seen. These changes are accounted for by peripheral phenomena for the most part, and a number of clinical applications are suggested based on these observations.

Acoustic Stimulation↗
PubMed1983

Identification of the motoneurons innervating the stapedius muscle in Gallus gallus: a horseradish peroxidase study.

The location of the stapedial motoneurons in Gallus gallus was investigated by means of the retrograde transport of HRP, injected into the stapedius muscle. The labeled neurons are located in both the ventral and dorsal divisions of the VII nerve nucleus, in a lateral and ventral position respectively, facing the superior olivary nucleus. The neurons are distributed in two size classes. The functional implications of these findings are discussed, in relation both to the absence of the acoustic stapedial reflex in birds and to the functional properties of the stapedius muscle.

Animals↗
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↗
PubMed1981

Reference values and characteristics of brain stem audiometry in neonates and children.

ABR (Auditory Brainstem Response) delivering the acoustic stimulus both through a headphone (PHN) and in free field (FF), have been recorded in 59 "normal" children divided into four age-related groups: (1) 22 children born at a gestational age ranging between the 36th and the 41st week; (2) 12 with ages ranging from 1 to 6 months; (3) 15 with ages ranging from 6 to 12 months; (4) 10 with ages ranging from 12 to 36 months. Peak latency values obtained with FF technique have been corrected by calculating the delay due to the distance between the loudspeaker and the tested ears (2.04 ms). When using this correction, no statistically significant differences were found between latency values of peaks JI and JV recorded using the two technique. While JI latency values of various groups do not differ significantly, groups 2--and especially group 1--JV latency values are statistically different from those of the 3rd and 4th group. This observation was confirmed by JV--JI interval values. JV wave in neonates (group 1), using PHN technique, is detectable at 60 dB p.e. SPL (82%) while in all other groups at 60 dB this wave is clearly detectable in all children (100%). Using FF technique, JV wave is still visible at 60 dB in 78% of the neonates (group 1) and in almost all children of the other groups. Considering ABR waveform, using PHN technique, in the first two groups only three waves are visible and the first one disappears at about 80 dB, while the typical 4--5 waves of normal adult tracings are detectable since 8--12 months of age. FF tracings instead show three peaks in all groups, the first (JI) being less evident when compared with the one obtained using PHN technique. JV amplitude values observed in FF are higher than those obtained delivering the stimulus through the headphone.

Acoustic Stimulation↗
PubMed1976

[Determination of CPK isoenzymes by column chromatography (author's transl)].

The AA. have carried out in patients affected by proved myocardial infarct, by other cardiac diseases and by muscular dystrophy the following enzymes determinations: total CPK, total LDH, SGOT, SGPT, HBDH, CPK isoenzymes by column chromatography (Mercer's method) and LDH isoenzymes either by column chromatography (Mercer's method) and by electrophoretic separation. Some results concerning the appearance of the CK-MB isoenzymes during the acute period of the myocardial infarction are described.

Adult↗
PubMed1976

[Platelets aggregation employing ADP and cephalin. Comparative tests (author's transl)].

The AA. have carried out researches into the results of the platelets aggregation test (PAT) on 375 people by use of the Born method; they have employed ADP and a commercial available cephalin (Thrombofax, Ortho). In the first case the parameters taken into consideration are: the minimum dose of ADP able to cause a "double wave aggregation", the slope and the maximum increase in light transmission; in the second case the parameters considered are: the latency period, the maximum speed and the maximum amplitude. The normal values, in 75 persons, are: --6 +/- 2 X 10(-7)M (min dose wor "double wave"); --15,5 +/- 4,9 UT/min (slope); -- 46,3 +/- 6,8 UT (max increase in light transmission); regarding ADP aggregation. --90 +/- 40 sec (latency period); -- 30 +/- 15 UT/min (max speed); -- 52 +/- 4,63 UT (max amplitude); relating to Thrombofax aggregation. Analyses of PAT, by parallel using both aggregating agents, have been made on 260 women undergoina an oestrogen-progestative therapy, on 25 daibetic subjects and on 15 subjects undergoing an anti-aggregation oral therapy (Ageroplas, Serono, Roma). The AA. stress on the validity of ADP as an aggregation agent in routine tests, while Trombofax has revealed itself to be not very sensitive in all the cases with hyperaggregation. However it is to be noted that use of cephalin results interesting in tests made on subjects undergoing an anti-aggregation therapy, as the PAT parameters seen proportional to the quantity of the drug given to the patient, which is just the opposite of what happens with ADP.

Adenosine Diphosphate↗
PubMedDate not supplied

Study on normal and otosclerotic bone cell cultures: an advance in understanding the pathogenesis of otosclerosis.

The authors first reviewed the main theories concerning the pathogenesis of otosclerosis and studied the morphologic and functional characteristics of cell cultures derived from normal and otosclerotic bones. Light transmission and scanning electron microscopy did not permit definite identification of the cultured cells as predominantly osteoblasts, nor did these techniques show significant differences between cultured cells derived from normal and pathologic bone. Functional tests of the cell cultures proved more interesting. First, the bony nature of the cultured cells was demonstrated by studying the intracellular 45Ca++ uptake after stimulation with calcitonin and dybutryl-cAMP. Second, cell cultures derived from otosclerotic bone behaved differently from those derived from normal bone. Their peak uptake of calcium appeared later, and post-stimulatory values were higher, suggesting that cells derived from otosclerotic bone store a greater quantity of 45Ca++. Furthermore, after stimulation with calcitonin and propranolol, we observed an inhibition of the calcium uptake and decreased intracellular cAMP levels in normal bone cell cultures. In contrast, the cell cultures derived from otosclerotic bone exhibited an initial inhibition of calcium absorption followed by massive calcium penetration. The response of adenylate cyclase to the action of Mg++, Ca++, and F- ions was evaluated in cultures derived from normal bone, otosclerotic bone, and normal skin fibroblasts. The resulting data show that activation due to Mg++ is much lower in cultured cells derived from otosclerotic bone than in those from either normal bone or skin fibroblasts. No significant differences were found after Ca++ inhibition in any of the cell cultures. Moreover, in cell cultures derived from normal bone, F- ions induced a strong activation that was lower than the levels observed in cultures of otosclerotic bone or in normal fibroblasts. We hypothesize that an alteration at the calcitonin receptor site is responsible for the difference in calcium uptake and cAMP levels observed in the cells derived from otosclerotic bone as compared to those cultured from normal cells.

Adenylyl Cyclases↗
PubMedDate not supplied

Os odontoideum in a patient with cervical vertigo: a case report.

Cervical vertebral anomalies are often associated with malformations or traumas, they may be completely asymptomatic and represent an occasional finding in vertigo or can cause severe neurologic complications (ie, compression of the upper cervical spine with myelopathy, epilepsy, or respiratory failure). This clinical case is a patient who came to us for observation for a peripheral harmonic vestibular syndrome, and in whom a malformation of the cervical vertebral joint (os odontoideum) was occasionally found on magnetic resonance imaging.

Anti-Inflammatory Agents↗
PubMedDate not supplied

Hormonal receptor site alterations in the etiopathogenesis of otosclerosis.

The authors have studied calcium 45 uptake and cAMP intracellular levels in normal and otosclerotic bone cell cultures after stimulation with calcitonin in the presence or absence of propranolol. The results seem to demonstrate that poststimulatory 45Ca incorporation is slightly different in normal and otosclerotic cell cultures, being slower but longer lasting in the latter. Propranolol administration markedly inhibits 45Ca uptake in normal cells, while in otosclerotic cells a massive intracellular penetration becomes evident after an initial inhibitory phase. Also cAMP intracellular levels behave differently; a marked increase, followed by a rapid decrease, can be detected in normal cells after stimulation with calcitonin, while in otosclerotic cells, the increase is slower and followed by a long lasting reduction. Adding propranolol reduces cAMP levels in normal cells, while it increases levels in otosclerotic cells. The different behavior of calcium metabolism and cAMP levels after stimulation with calcitonin, depending upon the presence or absence of propranolol, seems to indicate an alteration of the transducing mechanism between stimulus, receptor, and cellular effector in otosclerotic cells.

Animals↗