[Technopathic hearing loss and open fitting]. / Ipoacusie tecnopatiche ed open fitting.

The purpose of this study is to value the advantage of open fitting ear-moulds in tecnopathic ipoacusies. The study was conducted on a sample of 70 tecnopathic ipoacusics with a hearing loss in the high wave frequencies (4000-8000 Hz) ammounting to at least 50 dB; 20 of which already using ear-moulds. To all of them was applied, for three weeks, an open fitting ear-mould. At the beginning and at the end of the study, the sample was given a questionary to fill out. The analysis of the questionnaries has proven that among the 20 tecnopathics already using ear-moulds: A) 16 subjects have a marked preference for the open fitting ear-moulds, B) 3 did not encounter differences between the two types of ear-moulds, C) 1 declared a better adaptability to the previous ear-moulds. Over all, in the 70 subjects examined, this research's results allow us to conclude that: the use of open fitting ear-moulds improves the quality of the natural sound of one's own voice, the natural quality of sounds, and the hearing of speech in the presence of other noises, while reducing irritation of the auditory cortex.

Free radical erythrocyte damage in tumoral disease assessed by He-Ne laser and optical microscope through "Heinz Bodies" method.

Results obtained from blood sample readings by optical microscopy and He-Ne laser (lambda = 630.1 mW), have confirmed the reduction in Heinz Bodies (HB) formation time and the Transmittance Reduction Degree (TRD), in malignancies. The results of spectrometric readings in colorectum polyposis, (TRD = 0.07) and fibrocystic mastopathy (TRD = 0.08) gave results overlapping with controls (TRD = 0.08). In neoplasias, the early HB formation in erythrocytes observed by optical microscope corresponded to TRD increase = 0.17 (P < 0.01). TRD increase was statistically significant (P < 0.01), as well as the reduction in the time of HB appearance (< 0.01). The relationship between optical and laser readings was exponential in tumors, while it was linear in controls, in polyposis and mastopathies. The values of the correlation coefficients obtained by both methods were significant (P < 0.01) for all the studied groups. Moreover, these research data further support the existence, even in the earlier stages of the disease, of the labile state of the red cell membrane due to strong lipid peroxidation by FRs.

[Changes induced by auditive monoaural and binaural fatigue in TTS and the auditory brainstem response latency]. / Modificazioni indotte da fatica uditiva monoaurale e binaurale sul TTS e sulla latenza in ABR.

The purpose of the research was to study the TTS values and latency of fifth wave Auditory Brainstem Response in human monaural and binaural fatigue, using auditory evoked potentials. From the results obtained in 12 volunteers, it is concluded that during exposure to auditory fatigue, if only one ear is protected, the unprotected ear is subject to a greater hearing loss than would be expected with both ears unprotected. The practical implication of these conclusions is that subjects with unilateral hearing loss occupationally exposed to noise run a greater risk for the healthy ear than subjects with normal hearing.

[Examination of reaction time--auditory brainstem responses--ABR in noise induced temporary and permanent threshold shift]. / Badania funkcji latencja--natezenie sluchowych potencjalów pnia mózgu--abr, w czasowych i trwalych pohalasowych ubytkach sluchu.

This study was conducted to investigate the differences between auditory brainstem responses--ABR recorded in men with temporary or permanent threshold shifts (TTS or PTS). Behaviorally, the tested ears showed insignificant differences in the hearing thresholds at frequencies in the range 0.25-8 kHz. The latency of waves I, III, V and interwave intervals I-III, III-V, I-V were analysed as functions of stimulus intensity. The comparisons between recordings obtained in groups with TTS and PTS showed significant differences in latencies of wave V at 90 dB nHl only. The latencies of waves I, III and interwave intervals were unaltered.

A panel of radiation hybrids and YAC clones specific for human chromosome 5.

We report the characterization, by reverse fluorescence in situ hybridization (FISH), of 59 hybrids retaining fragments of human chromosome 5. Most of these hybrids are radiation hybrids generated by gamma irradiating, at low dosage, a monochromosomal hybrid retaining chromosome 5 as its only human contribution. The partial chromosome paints generated from these hybrids will make powerful tools for cytogenetic investigations, especially on the cytogenetic evolution of primates, and examples are reported. The molecular characterization of these hybrids was refined using 74 sequence-tagged sites (STSs), which allowed the physical dissection of chromosome 5 into 71 distinct regions with an average length of 2.7 Mb. The panel, therefore, is also suitable for high-precision subregional mapping of new genes or sequences located on chromosome 5. As an additional resource for cytogenetic studies involving chromosome 5, we report the characterization, by FISH, of 73 YACs from CEPH. The vast majority of these YACs are recognized by at least one of the STSs used for hybrid characterization, thus enabling the integrated use of YACs and partial chromosome paints derived from the hybrids.