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R Sisto

Publications and source records attributed to R Sisto.

17 recordsLinked to original sources
PubMed2006

Neonatal pain analyzer: development and validation.

We developed a pain analyzer (ABC analyzer) to perform automatic acoustic analysis of neonatal crying and to provide an objective estimate of neonatal pain. The ABC analyzer uses a validated pain scale (ABC scale) based on three acoustic parameters: pitch frequency, normalized RMS amplitude, and presence of a characteristic frequency- and amplitude-modulated crying feature, defined as "siren cry". Here we assessed the reliability of the analyzer. We enrolled 57 healthy neonates. Each baby was recorded with a video camera during heel prick. Pain intensity was evaluated using a validated scale [Douleur Aigue du Nouveau-Né (DAN) scale] and the analyzer and the two scores were compared. We found a statistically significant concordance between the DAN score and ABC analyzer score (p < 0.0001). The ABC analyser is a novel approach to cry analysis that should now have its properties carefully evaluated in a series of studies, just as is necessary in the development of any other pain measurement tool.

Acoustics↗
PubMed2006

Variability among polysulphone calibration curves.

Within an epidemiological study regarding the correlation between skin pathologies and personal ultraviolet (UV) exposure due to solar radiation, 14 field campaigns using polysulphone (PS) dosemeters were carried out at three different Italian sites (urban, semi-rural and rural) in every season of the year. A polysulphone calibration curve for each field experiment was obtained by measuring the ambient UV dose under almost clear sky conditions and the corresponding change in the PS film absorbance, prior and post exposure. Ambient UV doses were measured by well-calibrated broad-band radiometers and by electronic dosemeters. The dose-response relation was represented by the typical best fit to a third-degree polynomial and it was parameterized by a coefficient multiplying a cubic polynomial function. It was observed that the fit curves differed from each other in the coefficient only. It was assessed that the multiplying coefficient was affected by the solar UV spectrum at the Earth's surface whilst the polynomial factor depended on the photoinduced reaction of the polysulphone film. The mismatch between the polysulphone spectral curve and the CIE erythemal action spectrum was responsible for the variability among polysulphone calibration curves. The variability of the coefficient was related to the total ozone amount and the solar zenith angle. A mathematical explanation of such a parameterization was also discussed.

Biocompatible Materials↗
PubMed2002

Linear and nonlinear transient evoked otoacoustic emissions in humans exposed to noise.

Transient evoked otoacoustic emissions (TEOAEs) have been analyzed in a population of 134 ears, divided into three classes: (1) nonexposed ears in bilaterally normal hearing subjects, (2) audiometrically normal ears of subjects exposed to noise and affected by unilateral high-frequency (f>3 kHz) hearing loss in the contralateral ear, and (3) the contralateral impaired ears of the exposed subjects. The statistical distributions of global and spectral signal-to-noise ratio (SNR) were analyzed. TEOAEs were recorded both in the linear and nonlinear acquisition mode to evaluate the effectiveness of two standard averaging techniques with respect to their sensitivity to the early effects of noise exposure. Good discrimination between nonexposed and exposed ears was obtained using either the linear or the nonlinear mode. Despite its intrinsically higher SNR, the linear mode is not more sensitive than the nonlinear mode for this purpose because it is not possible to find a window for effectively cancelling the linear artifact while keeping a suitable sensitivity to the short-latency high-frequency aspect of the response. Moreover, with respect to another measurable parameter, the TEOAE latency, good discrimination is obtained only by using the nonlinear mode because, again, the linear artifact masks the high-frequency TEOAE response.

Acoustic Stimulation↗
PubMed2002

On the frequency dependence of the otoacoustic emission latency in hypoacoustic and normal ears.

Experimental measurements of the otoacoustic emission (OAE) latency of adult subjects have been obtained, as a function of frequency, by means of wavelet time-frequency analysis based on the iterative application of filter banks. The results are in agreement with previous OAE latency measurements by Tognola et al. [Hear. Res. 106, 112-122 (1997)], as regards both the latency values and the frequency dependence, and seem to be incompatible with the steep 1/f law that is predicted by scale-invariant full cochlear models. The latency-frequency relationship has been best fitted to a linear function of the cochlear physical distance, using the Greenwood map, and to an exponential function of the cochlear distance, for comparison with derived band ABR latency measurements. Two sets of ears [94 audiometrically normal and 42 impaired with high-frequency (f > 3 kHz) hearing loss] have been separately analyzed. Significantly larger average latencies were found in the impaired ears in the mid-frequency range. Theoretical implications of these findings on the transmission of the traveling wave are discussed.

Adult↗
PubMed2002

On the detection of early cochlear damage by otoacoustic emission analysis.

Theoretical considerations and experimental evidence suggest that otoacoustic emission parameters may be used to reveal early cochlear damage, even before it can be diagnosed by standard audiometric techniques. In this work, the statistical distributions of a set of otoacoustic emission parameters chosen as candidates for the early detection of cochlear damage (global and band reproducibility, response level, signal-to-noise ratio, spectral latency, and long-lasting otoacoustic emission presence) were analyzed in a population of 138 ears. These ears have been divided, according to a standard audiometric test, in three classes: (1) ears of nonexposed bilaterally normal subjects, (2) normal ears of subjects with unilateral noise-induced high-frequency hearing loss, and (3) their hearing impaired ears. For all analyzed parameters, a statistically significant difference was found between classes 1 and 2. This difference largely exceeds the difference observed between classes 2 and 3. This fact suggests that the noise exposure, which was responsible for the unilateral hearing loss, also caused subclinical damage in the contralateral, audiometrically normal, ear. This is a clear indication that otoacoustic emission techniques may be able to early detect subclinical damages.

Adolescent↗
PubMed2001

The calibration of personal dosemeters used for evaluating exposure to solar UV in the workplace.

In the framework of an epidemiological study regarding the correlation between solar UV radiation exposure and skin pathologies in a population of outdoor workers, the possibility of using polysulphone film personal dosemeters to quantify the Subjects UVB exposure has been evaluated. An original experimental set-up is presented. in a preliminary version, which ill be used both for solar irradiance spectroradiometric measurements and for the reading of personal dosemeters. The polysulphone absorption is similar to the CIE erythemal response curve. Due to UVB radiation exposure, the polysulphone film dosemeters photodegrade with a measrable absorbance change. The absorbance variation after the dosemeter exposure to UV radiation has been correlated to the UVB effective dose. The calibration curve obtained by this method may be particularly useful for the evaluation of small closes. The method will be used to quantify the personal exposure of workers whose exposure conditions are characterised by high variability.

Biocompatible Materials↗
PubMed2001

Spontaneous otoacoustic emissions and relaxation dynamics of long decay time OAEs in audiometrically normal and impaired subjects.

The relationship between hearing loss, detected by measuring the audiometric threshold shift, and the presence of long-lasting otoacoustic emissions, has been studied in a population of 66 adult males, by analyzing the cochlear response in the 80 ms following the subministration of a click stimulus. Most long-lasting OAEs are also recognizable as Synchronized Spontaneous OAEs (SSOAEs). The OAE characteristic decay times were evaluated according to the model by Sisto and Moleti [J. Acoust. Soc. Am. 106, 1893 (1999)]. The starting hypothesis, confirmed by the results, is that long decay time and large equilibrium amplitude are both manifestations of the effectiveness of the active feedback mechanism. The prevalence and frequency distribution of long-lasting OAEs, and of their SSOAE subset, have been separately analyzed for normal and impaired ears. No long-lasting OAE was found within the hearing loss frequency range, but several were found in impaired ears outside the hearing loss range, both at lower and higher frequencies. This result suggests that the correlation between the presence of long-lasting OAEs and good cochlear functionality be local in the frequency domain. The monitor of the OAE decay time is proposed as a new possible method for early detecting hearing loss in populations exposed to noise.

Adult↗
PubMed1999

Modeling otoacoustic emissions by active nonlinear oscillators.

The phenomenology of spontaneous otoacoustic emissions (OAEs) is compared to theoretical predictions given by models in which they are produced by active nonlinear oscillators. Along with the well-known Van der Pol oscillator, a new active oscillator model is proposed and analyzed here. Numerical simulations and multi-scale analytical computation results are compared to experimental data of neonatal spontaneous and evoked OAEs. A simple analysis technique is proposed, in which the time evolution after a click stimulus of the amplitude of each spectral line corresponding to a spontaneous OAE is studied. Apart from a few stationary lines, an approximately exponential decay law, with characteristic damping coefficients in the 20-200 Hz range, was found to fit the data. These results are not compatible with a Van der Pol oscillator model, and show that some important aspects of the OAE phenomenology can be better explained by the proposed oscillator. Other interesting features of the spontaneous end evoked OAE phenomenology, such as spontaneous OAE suppression by external tones and the following recovery, as well as stimulus/response curves in the linear and nonlinear mode of acquisition, are also well reproduced by the proposed model.

Acoustic Stimulation↗
PubMed1990

[Clinical contribution to the knowledge of retroperitoneal tumors of the pelvic excavation].

Two cases of primitive retroperitoneal tumors of the pelvic excavation have been reported: a neurinosarcoma and a liposarcoma. Particular, this work emphasizes the rarity of the neurinosarcoma in that seat, the atypical clinical presentation, the complex diagnostic researches performed and the problems of the differential diagnosis. In the diagnosis of these neoplasms, the Authors emphasize, the main role performed by the "classic" radiology and its most recently acquired means as (ECO, TAC, EMR). These can give precise informations about the seat and the size of the neoplasms and especially, about it's relationship with the adjacent tissues. By using these new means, other examinations some what dangerous, can be avoided. The Authors conclude that from the therapeutical point of view, surgery is still the main weapon against these neoplasms, even if sometimes it is demolishing and does not sensibly improve the prognosis. Surgery can be associated with radiotherapy and/or chemotherapy.

Aged↗
PubMedDate not supplied

Electromagnetic radiation from VDT units: study of the effectiveness of an active shielding device.

Measurements of extremely low frequency electromagnetic fields and low frequency magnetic fields emitted by a set of video display terminal (VDT) units are reported. The field values measured at the position normally occupied by the user are below the safety limits. This is because the field amplitudes decrease rapidly (following a 1/R3 law) with the distance from the source, as has been verified in this work. Measurements with a commercial shielding device consisting of small plastic balls filled with a water solution of rare earth elements were also performed. The only physical mechanism that could be hypothesized to produce an active suppression of the VDT field is that rare earth atoms, which probably were chosen due to their large magnetic moment, behave as oscillating magnetic dipoles capable of emitting a secondary magnetic field that, along some particular directions, has a phase that is opposite to that of the exciting field. Unfortunately, if one analyzes this mechanism quantitatively, it is easy to show that the secondary magnetic field is absolutely negligible, as was confirmed by experimental measurements performed in this study.

Computer Terminals↗
PubMedDate not supplied

Infrared radiation exposure in traditional glass factories.

This article reports on a general method of evaluating exposure to infrared radiation (IR-A, IR-B, IR-C) from high temperature (T > 1000 degrees C) black body sources, simply by performing measurements with a luxometric and/or near IR detector. The method, which may be applied to any black body source, uses the universality of the Planck formula for the black body spectrum, which allows estimation of the radiated power in any wavelength range by measuring the power radiated in another range. This capability may be very useful when the range of interest is one in which radiometers are expensive and difficult to calibrate, as for the IR-B and IR-C ranges, because a more commonly available luxometer can be used instead. The results of measurements and evaluations in two traditional Italian glass factories are reported and compared with the threshold limit value given by the American Conference of Governmental Industrial Hygienists. Intense exposures in the IR-B and IR-C ranges has been found for some workers, exceeding the limit by a large factor. This exposure must be reduced, as it has been shown by epidemiologic studies that there is indeed a correlation between cataractogenesis and work with fused glass and metals.

Cataract↗
PubMedDate not supplied

[Neoplasms with unknown primary location].

Neoplasms with unknown primary location (U.P.L.N.) represent an important chapter of oncological pathology which has not yet been completely defined regarding diagnostics, therapy and prognosis. U.P.L.N. recur in clinical practice in 0.5%-10% of cases and show equal sharing in both sexes: still mortality is high. This is in agreement with the biological behavior of U.P.L.N. which is that of a neoplastic illness, systemic from the onset and therefore immediately aggressive. Treatments commonly used only slightly alter the course of the disease. If the general state of the patients allows it, treatment must include every available therapeutical remedy (CHR, RDT, CHM) conveniently evaluated in every single case and preferably under the guidance of the apparent histotype and of the onset seat. The histotype of an U.P.L.N. sensibly affects the prognosis of the patient: there is an improvement in well differentiated and lodged forms and conversely, there is a sharp impairment with fast evolution in the less differentiated and variably metastasized forms. In our case-report, the U.P.L.N. rate has been 5.37% on 1786 cancer diagnoses from February 1980 until January 1988. In 65% of these cases, the histotype sustaining the pathology was represented by adenocarcinoma, in 21% by epidermoid carcinoma and in the remaining 14% by undifferentiated carcinoma. The clinical onset most frequently observed has involved the lymph nodes, followed by involvement of the serosa, bones, lungs and liver. Complex therapeutic treatments have not provided clear results, but the use of anthracyclines and cyclophosphamide seems promising. Finally, we suggest the use of immunomodulators (such as interferons, thymus hormone, lymphokines) in association with the classic chemotherapeutics.

Adenocarcinoma↗
PubMedDate not supplied

[Pretreatment evaluation of CA 72.4 in patients with carcinoma of the stomach (0-IV stage) versus CEA, TPA, CA 19-9, FER].

Before surgical treatments, sera of 54 pts suffering from gastric cancer, histologically typed and clinically staged (from stage 0 to 4), were assayed to evaluate CEA, TPA, CA 19-9 and Ferritin versus a new tumoral marker called TAG-72, in order to determine the biological behaviour and the relation to the clinical stage of this last one. Starting from their results, Authors say that the new marker TAG 72 has an increasing sensibility according to the clinical stage (4 th more than 1 st), and that the association of the TAG-72 plus CEA and/or TPA is rather significant in order to evaluate the evolution of the gastric cancer than other markers.

Aged↗