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Biomedical subjects

M Maurizi

Publications and source records attributed to M Maurizi.

At least 73 records · Page 4Linked to original sources
PubMed1985

Human bone cell cultures: a new model for studying the mechanism of action of calcitonin.

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: a transitory increase in 45Ca uptake that returned to control values ten minutes after the hormone was added; a relation between 45Ca uptake and increased cAMP concentrations when these were measured at the same time intervals; a reproduction of the salmon calcitonin (sCT) effect after incubation of the cultures with either db-cAMP or db-cGMP and 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 beta-receptor.

Bone and Bones↗
PubMed1985

Epstein-Barr virus serology in nasopharyngeal carcinomas and other head and neck neoplasms in Italy.

This paper reports the results of the EBV-specific antibody response in 17 Italian nasopharyngeal carcinoma (NPC) patients, 15 other head and neck tumor patients and 15 normal controls. Nucleic acid hybridization has been performed on the biopsy tissue from 4 of the NPC patients, and EBV-DNA was present in two undifferentiated (WHO 3) tumors, and absent in two samples of the keratinizing (WHO 1) type. EBV serology appears to be specifically related to NPC, more evidently for VCA-IgA and EA-IgG antibodies, and useful as an aid in diagnosis of NPC. However, in order to assess a prognostic value of the above markers, a greater number of patients followed for a longer period of time (at least 5 years) is needed, and is currently being pursued.

Adult↗
PubMed1985

Audiological findings in Down's children.

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.

Acoustic Impedance Tests↗
PubMed1985

Choanal atresia: a surface and ultrastructural study of the nasal mucous membranes.

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.

Adolescent↗
PubMed1985

Pseudo aneurysm of the external carotid artery: report of a case.

The authors report a case of left otorrhagia in a 1-year-old male infant in the presence of a mass involving the parotideal and upper cervical regions, which had appeared after an infection of the upper airways. Non-invasive techniques, such as echography and CT scan, provided useful but contradicting information. Surgery allowed us to define the diagnosis of mycotic aneurysm of the external carotid artery. The authors, after pointing out the extreme rarity of such a pathology, discuss the ethiopathogenetic theories, the clinical features, the diagnosis and the surgical and medical treatment of the disease. Concerning surgery ligation of the external carotid artery is the treatment of choice, since distally the blood flow is provided by a conspicuous collateral circle and because a possible postoperative septic dissemination is avoided.

Carotid Artery, External↗
PubMed1985

Contribution to the differentiation of peripheral versus central tinnitus via auditory brain stem response evaluation.

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.

Adult↗
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

[Acute choriocapillaris occlusion in pregnancy and puerperium. Toxemias, thrombotic microangiopathies].

Six cases of gravidic toxemia (4) and thrombotic thrombocytopenic purpura (Moschowitz's disease) in puerperium with choriocapillaris occlusion, were examined. At the acute stage, the vision is improved, ophthalmoscopy of the fundus revealed cystlike bullous exudative subretinal with retinal detachment, yellowish spots (of retinal pigment epithelium) and often minimal localized arteriolar narrowing. The evolution included retina application pigmentary disturbances and Elschnig's spots. Fluorescein angiography showed delayed filling of the capillaris and dye leakage in the subretinal space (first hypofluorescence and late hyperfluorescence). There are various stages of ischaemic involvement but in all cases visual symptoms may be due to central obstructive choroidopathy with delayed filling and occlusion. The retinal detachment in toxemia or Moschowitz disease in pregnancy in secondary to microcirculatory choroidal damage (short ciliary vessels essentially) with rupture of blood retinal barrier. Other constatations are made in disseminated intravascular coagulation, periarteritis nodosa, accelerated nephrosclerosis, hemolytic uremic syndrome in puerperium, and these suggested possible relationship between the various conditions.

Choroid↗
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

[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↗