A promising eco-sustainable wound dressing based on cellulose extracted from Spartium junceum L. and impregnated with Glycyrrhiza glabra L extract: Design, production and biological properties.

Glycyrrhiza glabra extract is widely known for its antioxidant and anti-inflammatory properties and can improve the wound healing process. The aim of this work was to shorten the time of the healing process by using an eco-sustainable wound dressing based on Spanish broom flexible cellulosic fabric by impregnation with G. glabra extract-loaded ethosomes. Chemical analysis of G. glabra extract was performed by LC-DAD-MS/MS and its encapsulation into ethosomes was obtained using the ethanol injection method. Lipid vesicles were characterized in terms of size, polydispersity index, entrapment efficiency, zeta potential, and stability. In vitro release studies, biocompatibility, and scratch test on 3T3 fibroblasts were performed. Moreover, the structure of Spanish broom dressing and its ability to absorb wound exudate was characterized by Synchrotron X-ray phase contrast microtomography (SR-PCmicroCT). Ethosomes showed a good entrapment efficiency, nanometric size, good stability over time and a slow release of polyphenols compared to the free extract, and were not cytotoxic. Lastly, the results revealed that Spanish broom wound dressing loaded with G. glabra ethosomes is able to accelerate wound closure by reducing wound healing time. To sum up, Spanish broom wound dressing could be a potential new green tool for biomedical applications.

Cochlear function and speech recognition in the elderly.

The aim of the current study was to evaluate the performance of elderly subjects in advanced tests that assess primary cochlear functions (temporal summation, frequency selectivity, cochlear mechanics) and relate them to speech recognition scores. The results show that measures of primary cochlear function in elderly subjects are worse than in young adults, suggesting that receptor failure primarily involved presbyacusis'. Moreover, the data suggest that significant changes in the conductive structures within the inner ear could be involved in age-related hearing loss. Peripheral function deterioration seems to be highly relevant for speech recognition; in fact, it was found that the elderly with the poorest speech recognition scores also had the worst frequency selectivity.

Effects of salicylates on evoked otoacoustic emissions and remote masking in humans.

The aim of this study was to evaluate, in young volunteer subjects, the effects of salicylates on evoked otoacoustic emissions (EOAEs), which presumably reflect an active mechanical process in the cochlea due to outer hair cell (OHC) activity, and on remote masking (RM), which has been proposed as a useful tool in the study of the non-linear cochlear distortion products generated by high-frequency maskers. Data from the present research are consistent with the literature showing a reversible effect of salicylate leading to elevated hearing thresholds and reduced EOAE amplitudes. From the point of view of new findings, the results demonstrate a reversible effect of salicylates on RM magnitude, which decreases as serum salicylate concentration increases. As described previously by other authors, salicylate selectivity inhibits OHC motility and, in consequence, reduces the amplitude of the motion of the basilar membrane. According to these data it is very likely that the observed reduction in RM magnitude after salicylate administration is also the result of the decreased ability of the OHCs to contract and of the reduced basilar membrane motion. The results are consistent with the conclusion that the OHC system function plays a role in producing RM.

Long-term outcome of Ménière's disease: endolymphatic mastoid shunt versus natural history.

This retrospective study evaluates the outcome of 38 patients with intractable Ménière's disease with a minimum of 7 years follow-up. Twenty underwent endolymphatic-mastoid shunt (EMS) and 18 were offered surgery but declined (natural history, NH, group). At the last control, 85% of the patients who were operated on (EMS group) and 74% of the NH patients had complete or substantial control of vertigo. The difference between the two groups was not significant. However, it was significant at 2 and 4 years follow-up. At 2 years, EMS patients had complete or substantial control of vertigo in 65% of the cases, at 4 and 6 years in 85% of the cases. Only 32 % of the NH patients had complete or substantial control of vertigo at 2 years. This percentage rose to 50% at 4 years and to 74% at 6 years. Hearing results in the two groups were not significantly different. Tinnitus disappeared or decreased in 56% of the EMS patients and in 18% of the NH patients. Sixty-seven percent of the EMS patients and 29% of the NH patients reported that their aural fullness was abolished. In conclusion, over the years, approximately 8 out of 10 of our patients with Ménière's disease achieved complete or substantial control of vertigo; however, this reduction was observed earlier in EMS patients than in those who declined surgery.

Development of resistance to noise.

Recent investigations have demonstrated that in animal models repeated exposures to mid-intensity noise induce a progressive reduction of the temporary threshold shift (TTS) following the exposures. This phenomenon is named "conditioning" and it is actually able to reduce the permanent threshold shift (PTS) following exposure to high intensity noise; this finding is named "toughening". In the present work the fundamental steps of the research concerning the toughening are reviewed and the biological mechanisms supposed to be underlying this phenomenon discussed. The few preliminary results of the studies on humans are also reported.

Auditory dysfunction in occupational noise exposed workers.

Occupational noise-induced hearing loss (NIHL) is well known to be an epidemiologically relevant problem. The subjects affected with NIHL show alteration of hearing thresholds as well as a worsening of the cochlear analysis functions and, usually, an impaired speech discrimination in presence of background noise. The study has evaluated the relationships between hearing threshold and equivalent exposure lever per day (Lepd), age and working seniority in a homogeneous sample of occupationally noise exposed workers. Three subgroups were also selected to study the most important cochlear functions as well as nerve and central functions. The first subgroup (Nn) contained normal hearing workers exposed to non-hazardous noise, while the second (Bn) contained workers exposed to high level continuous noise during their work day without clinical evidence of NIHL. The third subgroup (Bd) included subjects affected with the typical 4 kHz notch exposed to the same noise conditions than subgroup Bn. The results show that the hearing impaired subjects have the worst overall cochlear performance; however also the normal hearing workers exposed to hazardous noise have worse performance than subgroup Nn, relatively to high frequency thresholds, frequency resolution, TEOAEs, DPOAEs, stapedial acoustic reflex dynamic parameters. The results suggest that these measures could be used in the monitoring of the NIHL as indicators of subtle alterations of the hearing function.

Comparison of long-term hearing results after vestibular neurectomy, endolymphatic mastoid shunt, and medical therapy.

OBJECTIVE: This study aimed to compare the hearing changes in the long term after vestibular neurectomy, endolymphatic mastoid shunt, and medical treatment in classic Meniere's disease. STUDY DESIGN: A retrospective case review was conducted based on audiologic follow-up between 5 and 21 years. SETTING: The study was performed at two centers in Bari University Hospital, one performing vestibular neurectomy as the first surgical procedure for Meinere's disease and the other, endolymphatic mastoid shunt. PATIENTS AND INTERVENTIONS: Of 68 patients with intractable idiopathic Meniere's disease, 29 underwent middle fossa vestibular neurectomy, and 17 had endolymphatic mastoid shunt; 22 were offered surgery but declined. MAIN OUTCOME MEASURES: Outcome measures were puretone average (PTA), speech reception threshold, and speech discrimination score before and after treatment. RESULTS: PTA declined by an average of 9.3 dB in neurectomy patients, 13.3 dB in patients undergoing endolymphatic mastoid shunt, and 18.1 dB in patients who were offered surgery but declined. Patients were subdivided into two cohorts based on their preoperative or initial PTA. In the patients who had PTA scores worse than 50 dB initially, the PTA declined an average of 4.3 dB in the vestibular neurectomy group, 11.5 dB in the endolymphatic sac group, and 4 dB in the nonsurgical group. In the patients with PTA > or = 50 dB initially, the PTA declined an average of of 25.3 dB in the vestibular neurectomy group, 16.1 in the endolymphatic sac group, and 26.2 dB in the nonsurgical group. Although shunt patients with good hearing initially deteriorated less than neurectomy patients and less than patients who declined surgery, the difference was not significant. CONCLUSIONS: These results indicate that patients with poor hearing stabilized, while patients with good hearing continued to deteriorate. The same conditions were observed in the patients who had surgery and those who were offered surgery but declined.

Remote masking in noise-exposed chinchillas.

Remote masking (RM), the phenomenon whereby an intense high-frequency masker elevates thresholds for low-frequency signals, has been shown to be sensitive to various types of hearing loss in humans and to temporary threshold shifts in chinchillas. In this experiment, RM was evaluated in chinchillas with permanent threshold shift (PTS). Thresholds for 0.5 and 1 kHz tones were measured in quiet and in the presence of an 88 dB SPL narrow band noise centered at 3 kHz in the animals exposed for 30 h to impact noise at 125 dB SPL as intensity. The results show that RM values are significantly lower in chinchillas with PTS than in normal hearing chinchillas.

Epidemiology of hearing problems among adults in Italy.

Estimates for the prevalence of self-reported hearing disability and measured hearing impairment as a function of age in the adult population of Italy are reported. The study was conducted in Bari, Florence, Milan, Padua, Palermo with questionnaire and audiological assessment; neither stage showed any gross bias arising from the particular cities chosen. The results have demonstrated that: 22% of subjects think their hearing abnormal, 24.4% report some difficulty understanding speech, 14.5% experienced prolonged spontaneous tinnitus and 17% have a > or = 25 dB HL bilateral hearing impairment; hearing problems increase progressively with age and show no significant differences between men and women; the occupational groups most at risk as far as hearing impairments are concerned are manual workers and workers exposed to occupational noise; the systemic disorders most significantly connected to hearing problems are dyslipidosis, diabetes, hypertension, cardiovascular diseases, liver diseases and cervical arthrosis; among every day habits, the consumption of alcohol seems the only element of risk, above all for tinnitus.

The effect of 'conditioning' exposures on hearing loss from impulse noise.

Research has shown that prior noise exposures or 'conditioning' can moderate the amount of permanent threshold shift (PTS) from subsequent high intensity noise exposures. The aim of this experiment was to study the effect of 'conditioning' on subsequent exposure to high intensity impulse noise. The subjects were seven experimental and 14 control monaural chinchillas. Evoked potential (EVP) thresholds were measured before and after the noise exposures. Experimental animals received 10 days of exposure to an octave band noise (OBN) centered at 0.5 kHz OBN at 95 dB SPL (6 h on/18 h off) and allowed to recover for 5 days. The subjects were then exposed to an impulse noise at 150 dB SPL. The temporal spacing of the impulses consisted of a series of 50 pairs of impulses presented 50 ms apart with 1000 ms between the onset of each pair. The total duration of exposure was approximately 1 min. Control animals received only the impulse noise exposure. PTS was measured after 4 weeks. The threshold shift (TS) patterns during the 'conditioning' phase were consistent with previous research, with the greatest amount of TS occurring on the second day and decreasing with continued exposures. Four weeks after recovery from the impulse noise, the experimental animals showed significantly less PTS than the control animals. In addition, histological examination revealed significantly less hair cell loss in the experimental than in the control subjects. The results are discussed in the context of previous studies on 'toughening' and on the effects of impulse noise.