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F Zito

Publications and source records attributed to F Zito.

66 records · Page 4Linked to original sources
PubMed1978

Effects of long rise time stimuli on the latencies of the slow V potentials.

Tone bursts with 5, 250 and 500 msec rise time and 70 dB HL (ISO) intensity at the plateau were used to evoke the slow V potentials in ten adults. The mean prolongations of the latencies have been determined and correlated with the subjective auditory thresholds, obtained before each test by conventional push-button audiometry. In normal-hearing subjects our results show a prolongation of the latencies of the slow V potentials when stimuli with longer rise time were used. In subjects with elevated auditory thresholds an almost linear correlation was found between the prolongations of the latencies and the subjective auditory thresholds.

Acoustic Stimulation↗
PubMedDate not supplied

MRI, antibody-guided scintigraphy, and glucose metabolism in uveal melanoma.

To evaluate the usefulness of structural and biochemical imaging techniques for the diagnosis of uveal melanoma, 12 patients with choroidal melanoma were examined. Magnetic resonance imaging was used in 11 of 12 patients, as one had a metal prosthesis. All the subjects underwent single photon planar scintigraphy (SPPS) and single photon emission computed tomography (SPECT) using the 99mTc-labeled F(ab')2 of the anti-melanoma monoclonal antibody 225.28S ([99mTc]MoAb) and positron emission tomography (PET) using [18F]fluorodeoxyglucose ([18F]FDG). Magnetic resonance identified 6 of 11 melanotic lesions (definite melanomas) and 4 of 11 hypomelanotic lesions (probable melanomas), whereas in one case it was inconclusive. [99mTc]MoAb uptake was observed in 5 of 12 lesions using SPPS and 8 of 12 lesions using SPECT. [18F]FDG uptake was observed in 3 of 12 lesions by PET. These results demonstrate that both MR and radioimmunoscintigraphy are sensitive techniques for the diagnosis of choroidal melanomas and suggest that the detection of melanomas by MR, SPPS, and SPECT is largely dependent upon their size. The validity of these conclusions was verified in four subjects in whom the diagnosis was based on MR and/or SPECT findings only and confirmed by histology. The finding that only some of the uveal melanomas of larger size are visualized based on [18F]FDG uptake suggests that melanomas can have either high or low glucose consumption.

Choroid Neoplasms↗
PubMedDate not supplied

Acoustic admittance measurements in human temporal bones.

Admittance component curves were studied in a series of 14 fresh human temporal bones with perfectly normal tympanic membrane, before and after experimental lesions. The lesions were all performed in successive steps in each temporal bone and consisted in section of ligaments and tendons, interruptions and fixations of the ossicular chain. The results obtained demonstrate that the tympanograms traced in fresh human temporal bones, before and after experimental lesions, are quite similar to those observed respectively in normal and pathological living ears. (a) The 'pre-experimental' tympanograms showed A-type curves with peak and admittance component values well within the range of normal living ears; (b) the tympanogram peak values increased very little and remained in the range of normal ears also after section of ligaments and tendons; (c) the ossicular chain interruptions always resulted in A-type curves at 220 Hz and in W-pattern ones at 660 Hz wherever the interruptions occurred; (d) the ossicular chain fixations always exhibited A-type tympanograms with decreased peak and admittance component values; (e) finally, the condition of the Eustachian tube, closed or opened, did not change the shape of the tympanograms; the notch depth of the curves traced with opened tube, became higher than those obtained with closed tube.

Acoustic Impedance Tests↗
PubMedDate not supplied

[Interaction between continuous and impulse noise: anatomic and functional evaluation in relation to the intensity of the exposure].

Interaction between continuous and impulse noise was studied. One group of chinchillas was exposed to octave band of noise of 0.5 kHz 95 dB SPL intensity. Three groups were exposed to impulse noises of 113, 119 and 125 prak SPL emitted at 1 imp/sec, 1 imp/4 sec and 1 imp/16 sec respectively. Three groups were exposed to noise created by a combination of above continuous and impulse noises. All exposures lasted for 5 days. Hearing thresholds were measured in 35 animals using auditory evoked potentials. The combined continuous and impulse noises showed equal energy contents, but the groups exposed to 119 and 125 dB impulse noise intensities developed an exacerbation of PTS and cell hair loss. Therefore, the critical level, under which the damage associated with noise exposure is related to the total noise energy (Equal Energy Hypothesis) was reduced when impulse noise was added to continuous noise.

Animals↗
PubMedDate not supplied

[Lombardy regional project: prevention of occupational tumors].

In Lombardy, the regional project "Prevention of occupational cancers" is ongoing. The main objectives of this project are to identify work environments in which there might be a possible exposure to carcinogenic substances and to elaborate preventive measures. A casual sample of 250 working settings representing the different economic activities has been selected and evaluated. The 10% of the examined workplaces showed a possible exposure to chemical carcinogens. The most common carcinogens were trichloroethylene, preparation of plastics materials containing acrylonitrile-butadiene-stirene, formaldehyde, wood dust, hexavalent chromium, silica and polycyclic aromatic hydrocarbons. Galvanic industries, Bitumen production and placing companies and Plastics processing plants will be studied for environmental and biological monitoring and for the development of preventive measures.

Humans↗
PubMedDate not supplied

A new method for faster blood clearance in radioimmuno-guided surgery.

A major inconvenience of intraoperative tumor detection with radiolabeled monoclonal antibody (MoAb) by means of a probe is the long interval needed between the injection of MoAb and surgery (at least 20 days). We describe a new method which entails injection of 125I-labeled biotinylated monoclonal antibodies and cold avidin in order to obtain a rapid blood clearance of the radiotracer. The first clinical application of this protocol has been carried out in a colon cancer patient operated on six days after the administration of 125I-labeled biotinylated MoAb and cold avidin, with an optimal tumor-to-normal tissue ratio and with 90% of the circulating radioactivity cleared in two days.

Abdominal Neoplasms↗
PubMedDate not supplied

[The frequency spectrum in the interaction between continuous and impulse noise: an anatomic functional evaluation].

In industrial setting impulse noise rarely occurs in isolation. Impulses are more often superimposed on a background of continuous noise. Since measurement of peak sound pressure level or energy considerations may not provide a sufficient index of danger to hearing, examining the frequency spectra of the noises appeared to be important. Seven groups of five chinchillas were used in this study. Four groups were exposed to octave bands of noise centered at 0.5, 2 or 4 kHz having intensities of 95, 90 and 86 dB SPL respectively or impulse noise of 113 dB peak SPL applied on time per 1 second. Three groups were exposed to the combination of impulse noise and one of the above continuous noises. Each exposure lasted five days. PTS was calculated on each animal using auditory evoked potentials. The cochleas were dissected and evaluated using conventional histological surface preparation and examined with scanning electron microscopy (SEM) employing a JEOL 35 microscope. The groups exposed to only the impulse or to continuous noise alone developed neither PTS nor hair cell loss. Considerable values of PTS and sensory cell loss were observed in animals exposed to impulse noise in combination with 2 and 4 kHz of continuous noise. This interaction effect increases as the spectral overlapping between the impulse and continuous noise increases. In these animals excellent information concerning the sensory cell losses or cell damage was obtained with SEM. The results of the present study demonstrate that interaction between impulse and continuous noise can indicate increased hazard, which is highly dependent not only upon the total energy of the complex exposure but also on the degree of spectral overlapping between impulse and continuous noise.

Animals↗