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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.

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.

The authors have studied auditory brainstem responses (ABR) in 33 full-term newborns at 0-9, 10-30, 31-58 h, in order to evaluate changes in the first hours after birth, particularly in relation to different repetition rates and recording procedures. The data obtained show that the characteristic newborn 3-peak tracing is observed in almost all the cases at the third recording session while, at the first, wave I is absent in two-thirds of the cases. The most reliable waves at birth are waves III, V and N II, which is often present even when other vertex-positive peaks are absent. Latency values of the considered peaks tend to decrease in a statistically significant way and this decrease is almost complete at the second recording session (30 h), while V-I interval values decrease, especially when the 9 stimuli/s repetition is employed. Stimulus repetition rate affects ABR replicability and synchronization, but it hardly influences latency values. Contralaterally recorded potentials are often absent at birth and become evident 58 h later. The authors conclude that the maturational processes probably affect both peripheral and central auditory structures in the first hours after birth. In this period, increasing repetition rates seem to have a greater effect on wave replicability than on latency values.

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.

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.

Auditory brain-stem responses (ABRs) were studied in 66 subjects with severe head trauma. Middle latency responses (MLRs) were also recorded in 22 of them. Patients were carefully selected to avoid conditions such as pre-existing or acute deafness, hypothermia or ethanol intoxication. In order to evaluate the usefulness of potentials in predicting recovery, patients were classified according to the Glasgow Coma Scale (GCS). ABR tracings were classified into 5 groups and MLR into 2 groups. The recovery was good in the presence of a type 1 ABR, poor in the presence of types 3, 4 and 5. Concerning type 2 ABR, the outcome is related to the MLR type, and to the presence of an electrophysiological improvement within the first 3 months following trauma. The reliability of ABR and MLR in predicting the outcome of severe head injury appears to be greater than other usually considered clinical and instrumental data (age, GCS, CT scan, EEG).

Auditory brain stem response (ABR) parameters were evaluated in 54 subjects with unilateral idiopathic subjective tinnitus in order to verify the possibility of detecting its site of origin. All the subjects had normal hearing or a symmetrical bilateral sensorineural hearing loss. All the cases in whom middle or inner ear disease had been diagnosed, were excluded. Subjects, classified on the basis of their mean auditory threshold and masking curves according to Feldmann, underwent a residual inhibition (RI) test and ipsilateral narrow-band noise masking before a second ABR test was performed. Patients with positive RI made up the A+ group, while those with negative RI made up the A- group. The main characteristics observed were an increase of the mean latency values of wave I in the tinnitus ear in the A+ group while, after masking, the values of the affected and unaffected ears almost overlapped. An increase in the latency values of wave V, unaffected by the masking procedure, could be observed in A- patients. The occurrence of waves I and III was often affected in the tinnitus ears in both groups, but it increased, after masking, only in the A- patients. Based on the obtained data, the authors conclude that there may be a substantial difference concerning ABR parameters between the patients in whom residual tinnitus masking is demonstrable compared with those in whom it is not.

Surface and 'core' tonsillar specimens were collected from 60 children, between 2 and 14 years of age, suffering from recurrent tonsillitis, in order to establish the reliability of surface tonsillar swabbing technique and to define the most frequently involved aerobic and anaerobic microorganisms. From the qualitative point of view, the same mixed aerobic and anaerobic flora were obtained in both samples thus demonstrating the reliability of the surface swabbing technique. From the quantitative point of view, 187 microorganisms, 129 (69.2%) aerobes and 58 (30.8%) anaerobes were isolated from surface cultures while 184, 109 (59.2%) aerobes and 75 (40.8%) anaerobes from the core cultures, thus demonstrating a greater number of anaerobes in the core of the tonsil. The most common isolated aerobic microorganisms were the alpha- and beta-hemolytic Streptococci, the Neisseriae and the Staphylococcus aureus; the predominant anaerobic ones were the Fusobacterium nucleatum, the Bacteroides sp. and the Veillonella parvula. The isolated staphylococcus aureus and the bacteroides sp. were all beta-lactamase producers.

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.

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.

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.

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.

In 13 healthy young adults, nasal mucociliary transport velocity was measured by means of albumine microsphere labeled with Tc99m as a tracer. M + ISD of clearance velocity values and of the half time radioactivity (T1/2) resulted to be respectively 1.02 + 0.22 cm/min and 1.07 + 0.24 min. A significant correlation (P less than 0.05) between half time clearance (T1/2) values of the radioactive particles and the mucociliary velocity ones could be detected, making T1/2 a reliable and rapidly obtainable parameter for determining nasal mucociliary function. Advantages and disadvantages of the different techniques are discussed.

Middle ear cholesteatomas were intraoperatively obtained from 6 male patients and studied under light (L.M.), transmission (T.E.M.) and scanning (S.E.M.) electron microscopy. Cholesteatoma proved to be formed by keratinizing squamous epithelium, or matrix, and by connective tissue, chorion or perimatrix. With regard to the matrix, a progressive differentiation of cells belonging to the stratum germinativum could be observed towards spinosum, granulosum and corneum cells with formation of keratinized lamellae. Moreover, keratinocytes and Langerhans cells were found in the stratum spinosum. The perimatrix consisted of granulation tissue, or inflamed subepithelial connective tissue displaying inflammatory cells. Furthermore, the advancing front of cholesteatoma proved to be formed by lymphocytes and plasma cells, partially covered by respiratory type epithelium.

Fifty-four patients (108 ears) with presumed noise-induced hearing loss, were subjected to tonal and speech audiometry, impedance tests and measurements of auditory brainstem responses (ABR), in order to check for possible retrocochlear involvement. ABR data indicated that latency values of waves I, III and V, as well as III-I, V-III and V-I intervals fell within the normal range in all cases (M +/- 2 SD), even for fast repetition rates (51 stim/s). Poor waveform resolution of early components, particularly of wave I, was found in 12 ears (11.1%) and a total absence of evoked potentials not always related to the hearing loss, occurred in 5 ears (4.6%).

The authors have studied auditory brainstem responses (ABR) in 33 full-term newborns at 0-9, 10-30, 31-58 h, in order to evaluate changes in the first hours after birth, particularly in relation to different repetition rates and recording procedures. The data obtained show that the characteristic newborn 3-peak tracing is observed in almost all the cases at the third recording session while, at the first, wave I is absent in two-thirds of the cases. The most reliable waves at birth are waves III, V and N II, which is often present even when other vertex-positive peaks are absent. Latency values of the considered peaks tend to decrease in a statistically significant way and this decrease is almost complete at the second recording session (30 h), while V-I interval values decrease, especially when the 9 stimuli/s repetition is employed. Stimulus repetition rate affects ABR replicability and synchronization, but it hardly influences latency values. Contralaterally recorded potentials are often absent at birth and become evident 58 h later. The authors conclude that the maturational processes probably affect both peripheral and central auditory structures in the first hours after birth. In this period, increasing repetition rates seem to have a greater effect on wave replicability than on latency values.

Biopsies taken from the anterior two-thirds of the inferior turbinate of 3 female patients affected by unilateral complete choanal atresia were studied at the light, transmission and scanning electron microscope. Several changes, such as the uneveness of the mucosal surface, the thickening of the basal membrane, and the presence of ciliary abnormalities in the respiratory mucosa of the affected cavity, were observed. Ciliary abnormalities consisted of the presence of several 'adhesive' and 'bulging' compound cilia, of cilia with excessive cytoplasm and cytoplasmatic processes, and of ciliary structures with loss of the peripheral membrane. At SEM, cilia of the affected cavity appeared bundled, irregularly oriented, flattened and covered by an increased and/or accumulated secretion. Choanal atresia represents, according to the authors, a chronic suffering condition of the nasal mucous membranes. It is characterized by peculiar aspects which are probably related, on one hand, to the increased and/or accumulated mucous secretions and, on the other, to the congenital and long-standing airflow deprivation.

Adenylate cyclase (AC) activity was studied in whole homogenates of normal and otosclerotic bone cell cultures. When Mn2+ or Ca2+ was added to the medium there was a similar increase in AC activity in both cell types. F- provoked a greater rise in normal than in pathological cells, whereas 0.01 mM guanosine triphosphate (GTP) significantly raised cAMP synthesis in otosclerotic cells only. Mn2+ + calcitonin (Ct) increased AC activity in both cell preparations. With Ca2+ as cofactor there was no significant rise in either normal or pathological cells. However, while the combination Ca2+ + Ct + GTP had little effect on normal cells, it markedly increased cAMP synthesis in the pathological cells. 1 microgram/ml of the beta-blocker propranolol inhibited the effect Ct exerts on AC in normal cells, but enhanced it in otosclerotic cells. It would, therefore, seem that the pathogenesis of otosclerosis could be associated with an alteration in the AC system associated with Ct receptors.

Nasal secretions, maxillary sinus aspirates and specimens of the maxillary sinus mucosa were collected in 44 patients aged between 25 and 60 affected by mono- or bilateral chronic maxillary sinusitis, in order to establish the best sampling technique for microbiological purposes, the most frequently involved bacteria and the physiopathological mechanism underlying chronic maxillary disease. The sinusal mucosa resulted to be the most reliable sample as it reduces contamination and microbial variability. Anaerobic bacteria were isolated in nasal swab (15.6%), in maxillary sinus aspirates (30.4%) and in maxillary sinus mucosa (36.4%) of maxillary sinusitis patients. In controls anaerobic bacteria were isolated only in one nasal swab (2.3%), while they could not be isolated in maxillary sinus aspirates and in maxillary sinus mucosa. The presence of anaerobic bacteria in chronic maxillary sinusitis patients and their absence in controls seem to confirm that anaerobic microorganisms represent the main pathogenetic agents of chronic maxillary sinusitis. The possible physiopathological mechanisms underlying chronic maxillary sinus disease are finally discussed.

The authors answer to the comments on their paper 'Auditory Brainstem Responses to middle-and low-frequency tone pips' by Dr. Paul Kileny. Physical characteristics of the stimuli employed, waveform and latency variations using different high-pass filtering (50 and 200 Hz) are discussed.

Thirty-four children with clinically and radiologically confirmed adenoid hypertrophy underwent otoscopy, impedance tests, active anterior rhinomanometry and nasal mucociliary clearance evaluation before and 6 months after adenoidectomy. Mucociliary clearance velocity increased significantly while binasal resistances decreased after surgery. The authors conclude that mucociliary evaluation and objective measurements of nasal resistances should be added to impedance tests as indicators to adenoidectomy.

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.

Forty heavy smokers, all males aged between 40 and 70 and affected by laryngeal cancer underwent mucociliary clearance evaluation the day before total laryngectomy, 60 days after and, in 6 of them, 5 years later. Specimens of nasal and tracheal mucosa were obtained during laryngectomy and other subsequent operations. Before total laryngectomy, no significant changes in nasal mucociliary clearance were observed in smokers and controls, and the nasal ciliary carpet was fairly well preserved. Bronchial mucociliary clearance was impaired in all patients, owing to the coexistent chronic obstructive bronchitis. 60 days after the operation, nasal mucociliary clearance was significantly improved when compared with the preoperative data and controls, owing to the increase in the endonasal temperature and humidity, and to the reduction of the nasal blood flow and disappearance of the nasal cycle, which follow tracheostomy. Surface morphologic studies show a change in the squamous epithelium of the anterior third of the nasal fossa into a columnar ciliated one. During the first 3 months after the operation, tracheobronchial mucociliary clearance increased of 50% vis-à-vis the preoperative data. During this period a clinically evident bronchial hypersecretion was observed. The reduction in nasal and tracheobronchial mucociliary clearance function which became evident 6 years after the operation, is probably due to secondary chronic infections.

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.

Patients with acute peripheral facial palsy (Bell's palsy) were examined by auditory brainstem response (ABR) and middle-latency response (MLR) for signs of brainstem involvement. ABR data on 30 patients indicated that wave V latencies were abnormal by greater than 3 SD in only 2 patients, 1 of whom showed abnormality contralateral to the affected side. When the criterion for abnormality was reduced to 2 SD, wave V abnormality was found in only 3 of the 30 patients. All 14 patients tested by MLR showed normal responses. These findings suggest that on the basis of evoked potential measures, brainstem involvement may not be pathognomonic of Bell's palsy.

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.

The authors have investigated the auditory function in 35 Down's subjects, aged between 1 month and 16 years. Clinical examination revealed the occurrence of impaired nasal breathing in 18 subjects (51.4%), while otoscopy results were bilaterally normal in 12 cases (34.3%). Behavioural pure-tone audiometry yielded reliable results in 10 children (28.6%), impedance tests in 28 (80.0%), and brainstem audiometry in 29 (82.9%). A clinical and audiological follow-up has been performed in 11 cases (31.4%). Pure-tone audiometry, which may be employed in all cases only beyond 8 years of age, revealed a conductive hearing loss in 7 cases (20.0%). Impedance tests, whose usefulness is limited by the high occurrence of external ear canal stenosis, showed bilateral type A tympanograms only in 8 cases (28.6%). Stapedial reflex data were often missing, even in presence of a type A tympanogram, due to the weakness of tubaric muscles and to the presence of ossicles abnormalities. ABR has been performed in 29 cases (82.9%) and resulted to be as effective as in the normal population. It revealed a normal configuration concerning threshold and morphology in 16 cases (55.1%). The authors conclude that middle ear pathology in the Down's population is more frequent than expected on clinical basis and that objective tests are mandatory in order to obtain a reliable evaluation. While impedance tests are very sensible in detecting mild middle ear pathologies, but are not effective in threshold definition, brainstem audiometry is the choice tool in the uncooperative child, even if it cannot allow a differential diagnosis between normality and mild low-frequency conductive hearing losses.

An investigation on cell cultures obtained from temporal human bone fragments showed that they provide a suitable model for studying the mechanism involved in calcitonin action on bone cells. Furthermore they demonstrated: (1) a transitory increase in 45Ca uptake that returned to control values ten minutes after the hormone was added; (2) a relation between 45Ca uptake and increased cAMP concentrations when these were measured at the same time intervals; (3) a reproduction of the salmon calcitonin (sCT) effect after incubation of the cultures with either db-cAMP or db-cGMP and (4) inhibition of 45Ca uptake and parallel decrease in cAMP levels with propanol. These results suggest that in human bone cell cultures, sCT acts as a temporary promoter of 45Ca uptake, probably by activating an adenylate-cyclase system through a β-receptor.

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.

The authors investigated the 40-Hz steady-state responses (SSR) in 32 full-term newborns and in 10 normal children (5-8 years old), using 500-Hz tone bursts. The 40-Hz SSR threshold is located at about 50 and 30 dB nHL in newborns and older children, respectively. The latencies of both P1 and N1 waves decreased significantly with age, while the amplitudes increased. No significant latency and amplitude intersex differences have been observed. Moreover, with age, the 40-Hz SSR became more stable, their test-retest replicability improved, and P1-N1 wave occurrence increased. The authors finally discuss the possible underlying mechanisms of these findings and conclude that the 40-Hz SSR are difficult to obtain and are scarcely reliable in defining the low-frequency threshold in newborns. The stability and reliability of the responses increase with age, and the electrophysiological and behavioral thresholds to low-frequency stimuli tend to overlap.