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Biomedical subjects

P Nicolai

Publications and source records attributed to P Nicolai.

At least 19 recordsLinked to original sources
PubMed1991

Electric response audiometry in infants and preschool children. Long-term control of the results.

Two hundred and four infants and preschool children (mean age 2 years and 7 months +/- 9 months) with auditory impairment according to ABR and ECochG data, and 33 subjected to SVR were followed up for periods ranging from 1 year to 4 years and 6 months until a reliable conventional pure tone audiogram was obtained. One hundred and fifty-one children had conductive hearing loss, 75 sensorineural, 7 had ABR indicating disorders of the central auditory pathways, 5 were normal. Hit, false positive and false negative rates resulted as follows: 58.62%, 17.24% and 24.14% for SVR: 98.37%, 1.63% and 0% for ABR; 99.15%, 0.85% and 0% for ECochG. In the group with sensorineural hearing loss, 75% of the children gave ECochG detectable responses at 90 dB nHL, against 51.5% with ABR. With 1 kHz tonebursts, 64% of the tested subjects gave threshold responses to ECochG and 12% to ABR. The best strategy for children who failed the behavioral hearing tests, or in whom these tests were not applicable, was that based on ABR and middle ear impedance measures, complemented, when necessary, by ECochG.

Audiometry, Evoked Response↗
PubMed1991

Basement membrane components in normal, dysplastic, neoplastic laryngeal tissue and metastatic lymph nodes.

The immunohistochemical localization of the basement membrane (BM) components laminin, type IV collagen and fibronectin was analyzed in normal, dysplastic and neoplastic laryngeal specimens. The distribution of these macromolecules was also investigated in metastatic lymph nodes. A regular and continuous staining for laminin and type IV collagen was present in normal and mild dysplastic epithelium (LIN I); interruptions and reduplications were more evident in severe dysplasia (LIN III), together with an increased positivity for fibronectin in the subepithelial connective tissue. In squamous cell carcinomas the distribution of BM components was related to the degree of cellular differentiation, with a decreased immunostaining being evident in moderately and poorly differentiated carcinomas. Furthermore, the positivity for laminin and type IV collagen was influenced by the pattern of neoplastic growth, being continuous around the "pushing" border and discontinuous where the neoplastic front had an "invading" appearance. Similar changes were present in cervical metastatic lymph nodes. These observations tend to support the theory that the neoplastic growth is a cyclic process, with BM component synthesis and reabsorbtion related to the shifts of cellular metabolism.

Antibodies, Monoclonal↗
PubMed1990

Laryngeal chondrosarcoma: incidence, pathology, biological behavior, and treatment.

Chondrosarcoma is the most common mesenchymal tumor of the larynx and approximately 200 cases have been collected in the world medical literature. It is less aggressive in the larynx than elsewhere: cervical or distant metastases are rare (8.5%), and although local recurrences are not uncommon, they are not catastrophic. A retrospective study was made on eight cases of laryngeal chondrosarcoma. Three cases had originally been diagnosed as idiopathic vocal cord paralysis, possibly because of early involvement of the cricoarytenoid joint or the distal portion of the recurrent nerve. This fact emphasizes the need for accurate laryngeal computed tomography in cases of vocal cord paralysis of unknown origin. Surgical excision is the treatment of choice for laryngeal chondrosarcoma, and conservative techniques may sometimes be appropriate. Supraglottic laryngectomy may be the technique of choice in the rare cases of epiglottic involvement.

Adult↗
PubMed1990

Audiological findings in elderly patients with chronic renal failure.

The audiological results of 46 patients (m/f 27/19, mean age; 57.4 +/- 11.1) with chronic renal failure (CRF) undergoing dialysis were compared with those of an age- and gender-matched control group (n = 25). Mean pure tone average from 0.5 to 8 kHz was about 15 dB higher in CRF patients than in control subjects. The ABR parameters of the test group were then contrasted with those recorded in a second control group (n = 47, m/f 26/21, mean age: 56.1 +/- 11.4) matched by age, gender and degree of hearing loss (HL). After assessing the normality of the groups by the usual criteria, using the data of a sample of normal young adults, the ABR were found to be abnormal in 23.9% of the controls and in the 39.13% of the CRF patients. Wave V, I-III, III-V and I-V delays were significantly shorter in the females of the control group; in the CRF group, only the V and the I-V delays were shorter in females. The only age-dependent effect was found in the CRF sample, in which older patients had significantly longer I-III IPLD. The degree of HL influenced the latency of the waves in both groups but only the I-V IPLD was longer in CRF patients with pronounced high tone loss. The most distinguishing feature between the effects of CRF plus ageing and those of normal ageing was the lengthening of the I-III IPLD in the test group. This finding is likely to reflect a subclinical disorder of the VIII nerve function that is a part of the axonal uremic neuropathy.

Acoustic Impedance Tests↗
PubMed1989

Nasopharyngeal cysts. Report of seven cases with review of the literature.

A series of seven patients with nasopharyngeal cysts is presented. A review of the pertinent literature and a description of the clinical, radiologic, and pathologic features of these lesions are also included. The role of computed tomography in differentiating nasopharyngeal cysts from other pathologic entities, as well as the importance of surgery as an elective method of treatment, is specifically emphasized.

Adult↗
PubMed1989

Lesion detection in MS patients with and without clinical brainstem disorders: magnetic resonance imaging and brainstem auditory evoked potentials compared.

The findings of the present study can be summed up in the following points: (1) brainstem auditory evoked potentials (BAEP), as compared with magnetic resonance imaging (MRI), has a greater capacity and a lower cost in disclosing brainstem plaques both in MS patients with symptoms or signs of actual brainstem involvement and in clinically silent ones. This makes BAEP a useful technique for the neurologist, who can confirm the clinical suspicion of a brainstem lesion and follow the evolution of the disease in the patient. (2) The sensitivity of BAEP is lower than that of MRI as far as the anterior lesions of the brainstem are concerned. (3) MRI is more specific than BAEP, inasmuch as several types of injuries can alter the BAEP, while the demyelinating plaque has a specific image and can only be confused with little lacunar infarcts. (4) Plaques that produced symptoms or signs in the past can eventually disappear and be no longer detected by a subsequent MRI.

Adolescent↗
PubMed1989

[Drug-induced major anomalies of ventricular repolarization masked by a left branch block].

The presence of a left bundle branch block (LBBB) may hamper the electrocardiographic diagnosis of diseases that involve the QRS complexes. That it may conceal, or even completely erase, major abnormalities of ventricular repolarization induced by certain drugs is not so well known. In this paper, two highly demonstrative examples of such abnormalities observed with bepridil (case 1) or with the amiodarone-aprindine combination (case 2) are reported. In both cases, the intermittent character of the LBBB revealed the phenomenon which deserves to be known as it is not without practical consequences: in patients under treatments likely to modify repolarization and induce severe dysrhythmias (notably torsades de pointes) the presence of a LBBB indicates that the QT and/or QU intervals must be very carefully measured. In case of phase 3 LBBB compression of the carotid sinus or intravenous ATP injection helps the diagnosis since in the presence of even moderately prolonged ventricular cycles such manoeuvres create a refinement of QRS complexes which then demonstrate the major alteration of the underlying repolarization.

Aged↗
PubMed1987

Diagnosis, staging, and treatment of juvenile nasopharyngeal angiofibroma (JNA).

Nineteen patients with juvenile nasopharyngeal angiofibroma (JNA) were surgically treated with different techniques from January 1968 through December 1985. Two patients had undergone a previous operation at another hospital; all patients were males (mean age 15.4), and the most common symptom was nasal obstruction (84.2%). Lateral extension into the pterygomaxillary fossa occurred in 14 patients (73.6%), and 2 also had intracranial invasion (10.5%). In five cases, the tumor's cytosol was analyzed for hormonal receptors. Negative values for estrogen and progesterone receptors were obtained, although the content of dehydrotestosterone receptors was highly positive. These results tend to support the hypothesis of JNA's androgen-dependence. The authors emphasize the need of a preoperative staging classification based on clinicoradiological data in selecting the most adequate surgical approach. Tumors with lateral extension into the pterygomaxillary fossa can be easily removed through a midface degloving; large involvement of the infratemporal fossa requires, also, a transzygomatic dissection. In JNAs with intracranial extension a combined intracranial-extracranial approach is advisable.

Adolescent↗
PubMed1977

[Auricular fibrillation with ventricular tachycardia. Surgical section of a left lateral bundle of Kent].

The authors report the case of a man of 22 years, with no previous cardiac history, in whom a Wolff-Parkinson-White syndrome was discovered during the course of this first episode of atrial fibrillation with a ventricular rate of 300-350/mn; investigation (vecto-cardiogram, intra-cavitory ECG) showed the presence of a short circuit of the Kent type, with a high permeability, and localised in the left lateral position; this was confirmed by pericardial cartography. After the surgical division of the accessory pathway, the electrical phenomenon of pre-excitation disappeared. The current possibilities of operating on cases of a Wolff-Parkinson-White syndrome justify carrying out a scrupulous electrophysiological study of each case, so that any accessory pathway can be precisely localised, and its refractory period determined; thus a pathway of preexcitation localised in the left lateral position, and having a short refractory period leading to a high ventricular rate under atrial fibrillation conditions, constitutes an indication for operation which may be urgent.

Adult↗
PubMed1976

[Gap phenomenon and supranormal conduction during intermittent left bundle-branch block].

The mechanism of intermittent bundle branch block, whether spontaneous or as a result of vagal stimulation, can be studied by reference to the known facts of atrial stimulation. Three cases with intermittent left bundle branch block were studied by means of an intracavitary electrode, which allowed the potential of the bundle of His to be measured, and was also used for the extrastimulus method of study. In case 1, in which the block was independent of the cardiac rate, a type 1 "Gap" phenomenon (of nodal origin) was demonstrated; the coupling zone in which the extrastimulus overcame the block was situated in two areas, one being late, and the other earlier in a region where the conduction was normal. In case 2, in which the block was dependent upon the heart rate, the "recovery" of the blocked branch after early coupling of the extrastimulus seemed to be associated with the phenomenon of "supra-normal" conduction. In case 3, in which the block was again dependent upon heart rate, the two phenomena of "Gap" and "suppranormality" seemed to act successively when the coupling of the extrastimulus is decreased progressively. These observations allow us to distinguish two types of intermittent left bundle branch block; one, which is not related to heart rate, is characterised by a prolonged refractory period of the left bundle branch, which becomes progressively shorter as the heart rate increases; the other, which is dependent upon tachycardia, is characterised on the one hand by an increased left bundle branch refractory period which does not shorten as the heart rate increases, and on the other by the phenomenon of supranormal conduction.

Bundle of His↗
PubMed1975

[Study of sinus node function. Preliminary results].

Direct exploration of the sinus node remains experimental. Indirect techniques have been put forward to assess the sinus function in man: high frequency atrial pacing; premature atrial pacing; pharmacodynamic tests using atropin and isoproterenol injection. 68 patients were so explored: in 10 of them were ECG signs suggestive of "sinus disease" or "atrium disease" (group I); 14 subjects had only a sinus bradycardia with a rate of 55/mn or below (group II); in 16 cases, the ECG tracing was normal, but there was the notion of paroxysmal tachycardia or various disturbances (group IIIa); finally, in 28 cases the ECG demonstrated atrio-ventricular or inter-ventricular conduction disturbances (group IIIb). The preliminary results reported here should be interpreted carefully; nevertheless, correlation of the data obtained by the various techniques used, seems to be able to allow a correct assessment of sinus automatism, and of sino-atrial conduction.

Adult↗