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Biomedical subjects

M Maurizi

Publications and source records attributed to M Maurizi.

At least 19 recordsLinked to original sources
PubMed1992

Cathepsin D in primary squamous laryngeal tumors: correlation with clinico-pathological parameters and receptor status.

Using an immunoradiometric assay, Cathepsin D (Cath D) levels were measured in the cytosol of 23 normal and 39 neoplastic human laryngeal tissues. Scattered Cath D levels (from 2.2 to 17.8 pM/mg protein; median = 7.6) were found in normal mucosa specimens. Cath D concentrations range from 2.0 to 29.3 pM/mg protein (median = 8.5) in laryngeal tumors. When a comparison between Cath D levels in normal and neoplastic tissue specimens from the same patient was done, Cath D levels were significantly higher in laryngeal cancers than in their normal counterparts (P = 0.03). No correlation with clinico-pathological parameters and steroid hormone and epidermal growth factor receptor status was found. Further studies should investigate whether the production of Cath D by laryngeal tumors could have a clinical relevance for this neoplasia.

Adult↗
PubMed1992

EGF receptor expression in primary laryngeal cancer: correlation with clinico-pathological features and prognostic significance.

Epidermal-growth-factor-receptor(EGFR) expression was evaluated in 103 primary laryngeal tumors and in 42 normal laryngeal tissue specimens. Significantly higher EGFR levels were found in cancer specimens than in normal mucosa (p = 0.0053). EGFR expression did not correlate with age, tumor localization, T classification, cervical-lymph-node involvement or type of surgery, whereas it was higher in poorly differentiated tumors (G3) than in well/moderately differentiated (G1-G2) tumors (p < 0.05). Follow-up data were available for 74 patients. When EGFR status and the most important clinico-pathological characteristics were submitted to univariate analysis, tumor localization, type of surgery and EGFR status were found to be significantly correlated with disease-free survival. The 24-month disease-free survival rate was 58% for EGFR+ cancer patients and 82% for EGFR- ones. With multivariate analysis, only EGFR status and tumor localization were identified as significant independent prognostic parameters. Data reported here suggest that high EGFR levels may identify a sub-set of laryngeal-cancer patients with a particularly unfavorable prognosis.

Adult↗
PubMed1991

Receptors for epidermal growth factor and steroid hormones in primary laryngeal tumors.

The authors investigated the presence of epidermal growth factor (EGF-R), estrogen (ER), progesterone (PR), and androgen (AR) receptors in 42 laryngeal squamous cell carcinomas and 20 normal laryngeal mucosa specimens. EGF-R were expressed in all tumor specimens analyzed, with significantly higher levels in tumor samples compared with normal mucosa (P less than 0.05). The immunohistochemical study demonstrated the presence of EGF-R in basal and parabasal cells of normal mucosa and in most of the cancer cells. There was no correlation between EGF-R and tumor localization or T classification. On the other hand, the authors did find an interesting correlation between EGF-R levels and grading, EGF-R levels being significantly higher in G3 than in G1-G2 tumors. Moreover, the three patients whose tumors expressed the highest EGF-R levels had disease recur within 8 months. Among tumor specimens, 9.5%, 35.7%, and 9.5% expressed very low but detectable ER, PR, and AR levels, respectively. No statistically significant difference was found between the levels of steroid receptors in the tumor and normal mucosa specimens, and neither was there any correlation of ER, PR, and AR with the pathologic findings. The authors' results suggest that the EGF-R system may play a role in regulating the growth of laryngeal cancer. Additional studies should demonstrate whether, as in other tumor types, EGF-R expression may have prognostic significance in human laryngeal cancer.

Adult↗
PubMed1991

The external ear and the tympanic membrane. A three-dimensional study.

The study of the anatomical variations of the external ear is important for the ear surgeon who assesses the middle ear in this way. Furthermore, the design of insert earmoulds for use with either hearing aids or portable radios requires a better knowledge of the shape of the external ear. We studied the external ear structures and the drumhead in 140 cadavers with no previous history of ear pathology. A silicone resin was used, employing a dental impression technique. These permanent impressions were analysed by means of an operating microscope. Different parameters were studied, to determine the average dimensions of the structures. The clinical significance of these results is discussed.

Adult↗
PubMed1991

Effects of steroids on human normal and otosclerotic osteoblastic cells: influence on thymidine and leucine uptake and incorporation.

Steroid hormones are able to influence the metabolism of bone tissue in vivo, but reports regarding their direct action on bone cells fail to agree. In this study, in vitro administration of 17 beta-estradiol, testosterone and corticosterone to normal and otosclerotic osteoblastic cells induced a drop in DNA synthesis in both populations, an increase in the neosynthesis of endocellular proteins in normal cells and a rise, mainly in proteins secreted into the medium, in otosclerotic cells. The fact that 3H-thymidine and 3H-leucine uptake were lower in otosclerotic than in normal cells suggests that the membrane permeability differs in the two populations and that steroids exert an influence on both isotope uptake and directly modulate DNA and protein synthesis.

Corticosterone↗
PubMed1991

[A report of 2 cases of Turner's syndrome with a ring X chromosome].

The authors report two cases of Turner syndrome with clinical evidence of only primitive hypogonadism and short stature. Karyotype analysis showed X ring mosaicism which is present only in 5% of cases of Turner syndrome. The authors agree with the hypothesis suggesting no relationship between break points on the X chromosome and phenotypical aspect. An earlier diagnosis is auspicious so that, using correct therapy, final height should be improved.

Adolescent↗
PubMed1990

Thyroid carcinoma mimicking a toxic adenoma.

A young woman with a thyroid papillary carcinoma behaving as an autonomously hyperfunctioning nodule is described. Only 17 similar patients have been seen in the past 25 years. It is emphasized that hyperthyroidism does not exclude malignant disease in hot nodules. This possibility suggests that all thyroid nodules, either cold or hot, require careful management. Therefore, in "at risk" cases, surgery could be the most useful treatment.

Adenoma↗
PubMed1990

Monomorphic adenomas of the major salivary glands: clinicopathological study of 44 cases.

We report 44 cases of monomorphic adenoma (MA) of the major salivary glands observed during the years 1979-1989. All of these tumours were reviewed and classified on the basis of the World Health Organisation (WHO) criteria. Histological type, site, sex and age were considered. 34 cases of adenolymphoma were observed, all of them located in the parotid glands; 10 MA without lymphoid stroma were located in both parotid and submandibular glands. Distinctive histological and clinico-pathological features of the latter group of tumours are discussed, as well as the diagnostic criteria in distinguishing these tumours from pleomorphic adenoma and adenoid-cystic carcinoma.

Adenolymphoma↗
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↗
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↗
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

[Carotid body tumors: the clinical, diagnostic and therapeutic aspects].

The authors discuss the epidemiology, histology, symptomatology, diagnosis and therapy of carotid body tumors, basing their discussion on three personal observations and on a case of cervical dermatocyst which showed clinical and radiological data consistent with diagnosis of a glomus tumor. Chemodectomas of the neck are more often seen in the carotid body and are considered histologically benign, although they might induce local or distant metastases. Clinical presentation is often non-specific and may only consist in a slowly growing mass in the higher jugular-carotid region. Among the various imaging techniques (CT, MR), supra-aortic selective angiography, including digital subtraction techniques, is now considered the most reliable tool, while ultrasonography and gammagraphy with 99mTc-gluconate or 131I-MBG are recommended for screening and family testing purposes. Biopsy is to be avoided as it is very likely to cause massive bleeding and because of the high percentage of false negatives. Surgery is the choice treatment, and lateral cervicotomy is the recommended approach for exeresis of the mass, while radiotherapy should be planned in patients with precise contra-indications for surgery and when the tumor mass has already reached the skull base. Pre-operatory selective embolization is still controversial.

Adult↗
PubMedDate not supplied

Synthesis and secretion of glycosaminoglycans and proteins in human normal and otosclerotic bone cells.

Some biosynthetic activities of normal and otosclerotic temporal bone cultures have been studied. Bone cells were cultured for 24 hrs. in medium containing 3H-glucosamine, 35SO4 or 3H-proline. Labelled glycosaminoglycans (GAG) and proteins were precipitated from cells and media. In otosclerotic bone cells there was an evident reduction in the synthesis and secretion of radiolabelled macromolecules. The inhibitory effect was always greater in the extracellular than in the intracellular compartment. Some glycosidases were also studied. Otosclerosis decreased the activity of all enzymes examined, indicating that the lower GAG synthesis and secretion in otosclerotic bone cells were not due to an increased degradation.

Bone and Bones↗