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Biomedical subjects

M Maurizi

Publications and source records attributed to M Maurizi.

At least 55 records · Page 3Linked to original sources
PubMed1990

Relationships between middle latency auditory responses (MLR) and speech discrimination tests in the elderly.

74 subjects aged between 60 and 80 years underwent tonal audiometry, speech discrimination tests (phonetically balanced words, normal sentences and compressed sentences) and middle latency responses (MLRs) in order to evaluate possible correlations between behavioural and electrophysiological tests. The results showed that in elderly patients normal sentences are better understood than phonetically balanced words, that performances decrease dramatically when listening conditions became difficult, that auditory threshold seems to influence speech discrimination scores more than does age per se. MLRs seem to be unaffected both by age and by auditory threshold and Pa occurrence is a more reliable parameter than its latency. No correlation between speech discrimination tests and MLRs could be observed; on the contrary in the presence of abnormal speech discrimination tests the MLRs were almost normal and vice versa.

Aged↗
PubMed1990

Auditory brainstem responses in the aged.

The auditory brainstem responses (ABR) in a group of 74 aged subjects (60-80 years), affected by presbycusis were evaluated for presence of a retrocochlear involvement. The comparison of results from subjects with presbycusis with those from normally-hearing elderly subjects, and young subjects, affected by a cochlear sloping hearing loss, revealed that the latency increase of ABR observed in presbycusis is mainly correlated to the audiometric shape of the hearing loss and not to age per se.

Acoustic Impedance Tests↗
PubMed1990

40-Hz steady-state responses in newborns and in children.

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.

Audiometry, Evoked Response↗
PubMed1989

Altered adenylate cyclase activity in human otosclerotic bone cell cultures.

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.

Adenylyl Cyclases↗
PubMed1989

Immunopathology of nasal polyps: an immunohistochemical approach.

We studied the mast cells and the T-lymphocyte subpopulations of four patients' nasal polyps using immunohistochemical procedures. The data showed that MC displayed IL2-receptor and that they were very often closely related to CD4+ and MHC class II-positive T-lymphocytes. CD8-positive T-cells represented only 10% to 15% of the whole lymphoid population and were not localized near mast cells. These findings suggest a possible role of cell-mediated immune reactions in the pathogenesis of nasal polyps.

Adult↗
PubMed1988

Effects of sex on auditory brainstem responses in infancy and early childhood.

The effects of sex on I-III, III-V and I-V interwave intervals and I, III, V ABR waves latency values have been studied in 171 normal children born at term, 94 males and 77 females, aged between 2 and 720 days. The obtained data confirm that latency values decrease progressively with age, and show that there is a statistically significant difference in wave III and V latency values and in III-V and I-V intervals between males and females. Moreover, these differences seem to increase with age. The authors also discuss the possible underlying mechanisms and claim that even in infancy, sex-related variability should be taken into account.

Brain Stem↗
PubMed1987

Influences of birthweight upon brainstem maturation as reflected by auditory brainstem response (ABR) evaluation.

The authors have studied auditory brainstem responses (ABR) in 49 preterm (Group A) and in 54 fullterm (Group B) newborns, classified according to the birthweight related to conceptional age, in order to verify the influences of this latter parameter upon ABR. In Group A newborns, 4 recording sessions were performed, while only 3 in Group B, to evaluate data obtained at the same extra-uterine age. The obtained data show that birthweight related to conceptional age seems to play a major role on the development of ABR, since no significant differences were detected between preterm and fullterm newborns, provided the birthweight was appropriate for conceptional age (ACA). On the contrary, small for conceptional age (SCA) newborns showed an abnormal ABR pattern at birth, which tended to normalize at the following recording sessions. The authors conclude that birthweight related to conceptional age represents an important factor in the development of auditory brainstem responses and that the audiological diagnosis has to be very cautious in SCA newborns, regardless if they are pre- or fullterm.

Birth Weight↗
PubMed1987

Primary malignant melanoma of the nasal cavity: report of two cases and review of the literature.

Primary malignant melanomas of the nasal cavity are rare, as only 400 cases have been reported to date. The present paper describes two cases recently seen in Caucasian women. The authors point out the difficult clinical diagnosis, as the symptoms are rather aspecific. From the histopathological point of view, diagnosis is easy in the melanotic cases while can show interpretating problems in the amelanotic ones, when melanoma is almost indistinguishable from other malignant neoplasms. A correlation between histological grading and prognosis was not detected, as both cases showed local recurrences within one year after surgery although they were, respectively, of epithelioid and undifferentiated type. While surgery appears to be the choice treatment of the primary lesion, the treatment of cervical metastasis is still disputable. On the whole, most authors think that the role played by radio- and mainly chemo-therapy is still limited and that cervical adenopathies should be treated by a simple lympho-adenectomy rather than by a neck dissection.

Aged↗
PubMed1987

Auditory brainstem and middle-latency responses in Bell's palsy.

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.

Adolescent↗
PubMed1986

Mucociliary function and nasal resistance evaluation before and after adenoidectomy.

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.

Adenoidectomy↗
PubMed1986

[Acute respiratory distress syndrome in adults in colchicine poisoning].

Two cases of adult respiratory distress syndrome were treated in a series of 26 patients suffering from colchicine overdose. The syndrome appeared between the 24th and 72nd hours. It was characterized by the presence of interstitial as well as alveolar oedema seen on chest roentgenograms. Haemodynamic investigation showed a hyperkinetic state with moderate precapillary pulmonary arterial hypertension. In addition, multivisceral phenomena were observed in all cases. Post-mortem examination revealed interstitial and alveolar pulmonary oedema with haemorrhagic or macrophagic alveolitis often accompanied by hyaline membrane. The physiopathology of ARDS occurring in colchicine poisoning appeared to involve such different factors as infection, the presence of a state of shock and disseminated intravascular coagulopathy. The direct toxic action of colchicine on pneumocyte microtubules and the inhibition of surfactant production were a probable cause. The responsibility of colchicine in leukocyte aggregation remains to be determined.

Adult↗
PubMed1986

[Severe thrombopenia associated with treatment with pentosan polysulfate].

Two cases of severe thrombocytopaenia associated with acute thrombo-embolic manifestations during treatment by pentosan polysulphate, a low molecular weight heparinoid, are reported. Plasma samples from both patients caused in vitro aggregation in the presence of pentosan polysulphate. Interruption of the drug led to the recovery of the platelet count. The hypothesis of an immunoallergic mechanism similar to heparin associated thrombocytopaenia is supported. Furthermore, it seemed likely to be found with all the polysulphated X glycosaminoglycans. During treatment by pentosan polysulphate, platelet count should be monitored to avoid this potentially life-threatening syndrome.

Drug Hypersensitivity↗
PubMed1986

Microbial flora of nose and paranasal sinuses in chronic maxillary sinusitis.

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.

Adolescent↗
PubMed1986

Auditory brainstem responses in the full-term newborn: changes in the first 58 hours of life.

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.

Brain Stem↗
PubMed1986

Some aspects of the secretory activity of the human olfactory glands.

Two kinds of secretions, both merocrine and apocrine, have been detected in the serous adenomeres of the human olfactory glands. While the low-density vesicles secrete their products into the glandular lumen by a merocrine way (exocytosis), the electron-dense granules are produced by an apocrine mechanism.

Apocrine Glands↗