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Biomedical subjects

G Paludetti

Publications and source records attributed to G Paludetti.

At least 109 records · Page 6Linked to original sources
PubMed1984

[Organotypic culture of normal and neoplastic laryngeal mucosa].

Mucous membrane's phragments from human normal and neoplastic larynx have been maintained in a organ culture system. A set of cultures has been prepared for optical microscope studies and a parallel set for incorporation studies using 3H Thymidine and 3H Leucine. The results show that there is a good incorporation of 3H Thymidine and a greater incorporation of 3H Leucine at the 7th day due to a differentiation in vitro with a new synthesis of cheratin. These data agree with the morphologic evidence of considerable horny structures in the pathological mucous membrane after 11 days at culture.

Humans↗
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

Laryngeal cancer: long-term follow-up of respiratory functions after laryngectomy.

Pulmonary function of 31 heavy smokers with laryngeal cancer was evaluated before and during the 1st year after total (n = 21) and conservative (n = 10) laryngectomy. 2 of them died because of recurrences, 1 for bronchopulmonary complications. Long-lasting hoarseness was the only presenting symptom in all patients. Preoperative lung function data and mucociliary clearance were consistent with a coexisting chronic obstructive lung disease in most subjects and was probably due to smoking. No differences were observed comparing pre- and postoperative data in the 10 conservative laryngectomy patients. On the contrary, the total-laryngectomy patients showed a progressive impairment of bronchial obstruction and bacteriological infection of the trachea during the 1st year after the operation. An impressive increase in mucociliary clearance rates has been observed 2 months after total laryngectomy during the postoperative hypersecretory phase. the obtained data allow us to hypothesize that when clinical conditions of laryngectomized patients in whom local or distant recurrences have been excluded deteriorate, this is related to a progressive bronchial obstruction at any level of the bronchial tree due to descending bacterial infection of the airways. To our knowledge this is the only work demonstrating that total laryngectomized patients need a complete pre- and postoperative evaluation of lung function, airway dynamics, mucociliary function and tracheal bacteriology for long-term prognosis and treatment.

Aged↗
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

Nasal polyps: a comparative study of morphologic and etiopathogenetic aspects.

16 nasal polyps belonging to 10 male subjects aged between 40 and 70, have been removed during the same number of ethmoidectomies; the polyps have been sectioned and specimens of mucosa corresponding to the pedicle and to the different parts of the body have been collected. During the operation parts of the mucosa of the inferior turbinates were removed. All the specimens have been prepared and observed at the scanning electron microscope. The epithelium of the inferior turbinates, of the small polyps and of the apical part of all polyps were almost normal. Marked alterations of the epithelial layer have been observed in bigger polyps. Surface characteristics of nasal polyps seem to be influenced by their relationship with neighbouring structures and by their position in the nasal cavity, but mostly by their size. On the basis of these findings the authors discuss the most recent etiopathogenetic theories of nasal polyps. They finally describe some peculiar findings concerning the mucosal layer of the polyps and of the inferior turbinates of three confirmed allergic subjects and discuss their possible clinical implications.

Adult↗
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↗
PubMed1982

Arteriovenous fistula of the mandible: a review of the literature and report of a case.

The authors, after a careful review of the literature during the last 15 years concerning arteriovenous malformation (AVM) of the jaws, report a case of congenital arteriovenous fistula of the mandible characterized by several episodes of spontaneous hemorrhage requiring emergency hemimandibulectomy. Radiologic, arteriographic and pathologic aspects of this lesion are discussed. Even though nomenclature concerning AVM of the jaws is confusing the authors draw attention to the embryologic features which are responsible for these lesions. They also point out the main diagnostic and therapeutic aspects emphasizing the small effect that ligation of the external carotid artery has on bleeding and the importance of choosing case by case the best treatment considering the great variety of clinical and pathologic aspects that characterize these lesions.

Arteriovenous Fistula↗
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↗
PubMed1980

Pulmonary function studies in adenoid hypertrophy.

Tests of pulmonary function were performed on children with severe adenoid hypertrophy, before and one month after adenoidectomy. Five types of subjects were selected: (1) normal; (2) cases with isolated increase of residual volume (RV); (3) supernormal type with increased RV; (4) obstructive type of ventilatory defect, and (5) restrictive type of ventilatory defect. Following adenoidectomy there is an objective evidence of improved pulmonary function. The data suggest that 65.7% of clinically normal children with adenoid hypertrophy show pulmonary function abnormalities.

Adenoidectomy↗
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

The use of dynamic posturography to detect neurosensorial disorder in IDDM without clinical neuropathy.

The main aim was to evaluate the relative importance of sensory interactions for postural stability in 45 patients with insulin-dependent diabetes mellitus (IDDM) with and without peripheral neuropathy. All subjects had normal electronystagmography. Dynamic posturography provides functional, selective testing of three sensory modalities in maintenance of balance, i.e., vestibular, visual, and somatosensory. The Sensory Organization Test (SOT) includes six test conditions during which the subject tries to maintain an upright stance with as little sway as possible. The subject stands on a movable platform facing a square visual surrounding, which can be rotated independently. The test is performed first with the eyes open, then with the eyes closed. The second component of posturography testing consists of the Motor Control Test (MCT) concerning motor responses routinely used in balance maintenance. Compared to control subjects, IDDM patients with peripheral neuropathy but not patients without neuropathy showed lower scores for test conditions SOT 1 (analysis of variance, ANOVA F = 8.3; Scheffe test: p = 0.0007), SOT 2 (F = 6.6; p = 0.004), SOT 3 (F = 3.4; p = 0.04), and SOT 6 (F = 3.4; p = 0.04). The muscle response latencies in MCT were prolonged for small forward perturbations (F = 4.6; p = 0.02) in neuropathic patients (148.3+/-14.2 ms) with respect to control subjects, but not in non-neuropathic patients with respect to control subjects (135.2+/-13.3 ms). Sural (r = 0.2; p = 0.002) and peroneal (r = 0.12; p = 0.02) nerve conduction velocities showed significant correlations with muscle response latencies of MCT for small forward perturbations. Our results suggest a subclinical dysequilibrium in IDDM patients with peripheral neuropathy. The results of dynamic posturography may reflect the impairment of the somatosensory system, rather than a specific lesion of vestibular and/or visual modalities.

Adult↗
PubMedDate not supplied

Clinical-morphological correlation of nasal obstruction with skull base development and otitis media. An experimental study.

Morphological changes of the middle ear were investigated by means of microotoscopy and scanning electron microscopy in 40 developing Albino rats. In 20 one nostril (group B) and in 20 both nostrils (group C) had been experimentally obstructed. 20 rats were used as controls (group A). Microotoscopy and scanning electron microscopy on the middle ear mucosa were performed when the animals were 2 months old, i.e. at 90% of their development. At microotoscopy the tympanic membranes, homolateral to the obstructed nostril, proved to be abnormal in 81% of group B rats and in almost all rats belonging to group C. Scanning electron microscopy, performed after the bullae had been removed, showed the following epithelial surface changes of the middle ear homolaterally to the obstructed nostril: (a) a significant increase of nonciliated elements with a secretory behavior as compared to controls, even of the floor where normally a large number of ciliated cells is present; (b) several ciliated cells were destroyed and their cilia were irregular and untidy; (c) thick mucous secretions covered the floor of the tympanic bulla; and (d) squamous metaplasia of the hypotympanic epithelium. Extrarotation of the eustachian tubes and developmental abnormalities of the skull base in growing rats, caused by nasal obstruction, seem to be able to induce pathological events of the middle ear.

Animals↗
PubMedDate not supplied

Morphological distribution of middle-ear epithelium in the Wistar rat: a functional hypothesis.

The authors studied the overall microscopical anatomy of the middle ear and of the eustachian tube in 20 tympanic bullae of 10 Wistar rats. Large hexagonal epithelial flat cells covered the roof of the bulla, the two upper thirds of both lateral walls, the upper half of the eustachian tube, and the upper third of the tympanic orifice; ciliated and secretory cells lined the inferior thirds of both walls of the bulla while a ciliated epithelium with strong cilia, all directed towards the tubal orifice, located on the floor of the tympanic cavity together with groups of non-ciliated cells was detectable near the tubal and antral areas and on the floor of the eustachian tube. Non-ciliated cells covered by microvilli were found near the pharyngeal orifice. These observations seem to demonstrate the following: (1) the ciliated elements present a well-defined topographic distribution; (2) a preferential pathway for mucociliary clearance made up of strong ciliated cells located on the floor of the bulla is clearly detectable, and (3) the roof of the bulla seems to be mainly involved in the ventilatory function.

Animals↗