Grażyna Lisowska

Cochlear dysfunction and diabetic microangiopathy

The aim of this study was to evaluate the cochlear micromechanics in type 1 diabetic patients and to compare these findings with diabetic microvascular complications (retinopathy and nephropathy). Cochlear activity was evaluated by recording 2f1-f2 DPOAE. DPOAEs were performed using an ILO92 Otodynamics Ltd Analyser. DPOAEs were measured in 42 normally hearing IDDM patients aged between 21 and 42 years, and 33 age-and sex-matched non-diabetic control subjects. IDDM patients were divided into two groups: 17 patients without microangiopathy and 25 with microangiopathy. Microangiopathy was evaluated with ophthalmoscopy and 24-hour albumin excretion rate into urine. Both groups (diabetic and control) had normal and undifferentiated results in tonal and impedance audiometry. The mean amplitudes of various DPOAEs were significantly reduced in the diabetic groups (with and without microangiopathy) compared with control subjects. No correlation was found between diabetic microvascular complications and DPOAE amplitudes reduction. Our results indicate the existence of an alteration in cochlear micromechanics in diabetic patients with microangiopathy as well as in patients without microangiopathy. The lack of significant correlation between the degree of microvascular complications in the retina or kidneys and DPOAEs amplitude reduction suggest that the impaired functional properties of the outer hair cells are probably caused by early metabolic complications in diabetes (among other things non-enzymatic glycation related to hyperactivity of free oxygen radicals) and not directly by diabetic microangiopathy.

Influence of contralateral stimulation by two-tone complexes, narrow-band and broad-band noise signals on the 2f1-f2 distortion product otoacoustic emission levels in humans

In order to test the frequency specificity of the efferent suppressive effect on otoacoustic emissions, changes in the 2f 1 -f 2 distortion product otoacoustic emission (DPOAE) levels induced by contralateral stimuli of different spectra were measured in 10 normally hearing adults. Three types of contralateral stimuli were used: ( i ) a set of 6 pairs of pure tones with the same frequencies as used for DPOAE stimulation; ( ii ) 6 narrow-band noise signals with cut-off frequencies equal to the frequencies of the primary tones used for DPOAE stimulation; and ( iii ) broad-band noise with a bandwidth of 840-6,000 Hz. A small suppressive effect was observed mainly in the mid-frequency region. Broad-band noise was more effective at suppressing DPOAEs than narrow-band noises and two-tone complexes. Occasionally, small enhancements in DPOAE amplitudes were observed. Based on the results of this study, it is concluded that DPOAE changes induced by contralateral stimuli are not frequency-specific, and are too small to have routine clinical value.

Efficacy and safety of AM-111 in the treatment of acute sensorineural hearing loss: a double-blind, randomized, placebo-controlled phase II study.

Objective To evaluate the efficacy and safety of AM-111, a c-Jun N-terminal Kinase (JNK) ligand, in patients with acute sensorineural hearing loss (ASNHL). Study Design Prospective, double-blind, randomized, placebo-controlled study with follow-up visits on Days 3, 7, 30, and 90. Setting Twenty-five European sites (academic tertiary referral centers, private ENT practices). Patients Approximately 210 patients aged 18 to 61 years presenting within 48 hours after acute acoustic trauma or idiopathic sudden sensorineural hearing loss with mean hearing loss of 30 dB or greater at the 3 most affected contiguous test frequencies. Interventions Single-dose intratympanic injection of AM-111 (0.4 or 2.0 mg/ml) or placebo; optionally, oral prednisolone if hearing improvement was less than 10 dB at Day 7. Main Outcome Measures Efficacy was assessed by absolute hearing improvement (primary end point, Day 7), percentage hearing improvement, complete hearing recovery, speech discrimination improvement, and complete tinnitus remission. Safety was evaluated by the frequency of clinically relevant hearing deterioration and adverse events. Results The study failed to demonstrate a treatment benefit for the entire study population because mild-to-moderate ASNHL cases showed unexpectedly strong spontaneous recovery. In severe-to-profound ASNHL patients (threshold ≥60 dB), AM-111 0.4 mg/ml showed statistically significant, clinically relevant, and persistent improvements in hearing and speech discrimination and higher tinnitus remission compared with placebo. The study drug and the intratympanic injections were well tolerated. Conclusion The study established proof of concept for AM-111 in the treatment of severe-to-profound ASNHL. Control for spontaneous hearing recovery is essential for ASNHL studies.

Role of mannitol in reducing postischemic changes in distortion-product otoacoustic emissions (DPOAEs): a rabbit model.

Objectives The aim of this study was to observe the effects of mannitol, administered topically at the round window (RW), on cochlear blood flow (CBF) and distortion‐product otoacoustic emission (DPOAE) after repeated episodes of cochlear ischemia.

Latencies of the 2f1-f2 distortion product otoacoustic emissions measured using a phase-gradient method in young people, in the elderly and in people exposed to noise

Distortion product otoacoustic emissions (DPOAE) are generally accepted as a good tool for investigating the micromechanics of the cochlea. The 2f1-f2 DPOAE latencies provide significant data regarding travelling waves. In this study the 2f1-f2 DPOAE latencies were measured using a phase-gradient method, with a swept-f2 procedure, for three groups: Group I comprised 60 healthy young people, aged 17-32 years; Group II comprised elderly patients, aged 56-72 years, with presbyacusis; and Group III consisted of 74 miners, aged 19-35 years, who had been exposed to noise for 2-15 years. Measurements were performed for frequencies between 1.0 and 6.0 kHz. In all groups the latencies were fitted using a non-linear regression model. The aim of the study was to compare the latency and amplitude of 2f1-f2 DPOAE in different inner ear pathologies. The highest DPOAE amplitudes were recorded in Group I and in miners with 2-4 years noise exposure (Group IIIa), and the latencies showed a similar pattern. The lowest DPOAE amplitudes were recorded in the elderly and in miners with 8-15 years noise exposure (Group IIIc), but in contrast the longest latencies were measured in miners and the shortest in the elderly. The latency analysis significantly reinforces opinions on the micromechanics of the cochlea, mostly in terms of the cochlear functioning as a filter and amplifier and with regard to the elasticity of the basilar membrane.

Influence of aging on medial olivocochlear system function

Background There is still controversy regarding the influence of aging on medial olivocochlear (MOC) system function. The main objective of this study is to measure age-related changes of MOC system function in people with normal hearing thresholds. Method Bilateral assessment of the MOC effect for click-evoked otoacoustic emissions (CEOAEs; at 70±3 dB peak sound pressure level [pSPL], click at 50/second, 260 repeats, 2.5–20 millisecond window) and for distortion product otoacoustic emissions (DPOAEs; with [frequencies] f2/f1=1.22, [levels of primary tones] L1=65 dB SPL and L2=55 dB SPL; DP-grams for 2f1–f2 were collected for the f1 frequencies varying from 977 Hz to 5,164 kHz, with the resolution of four points per octave) was performed in a group of 146 (n=292 ears) healthy, right-handed subjects aged from 10–60 years with a bilateral hearing threshold from 0.25–4.0 kHz, not exceeding 20 dB hearing level; normal tympanograms; and a threshold of the contralateral stapedial reflex for broadband noise (BBN) of 75 dB SPL or higher. The MOC inhibition was assessed on the basis of changes in OAE level during BBN contralateral stimulation at 50 dB sensation level (mean, 65±3 dB SPL). Results Comparative analysis of the MOC effect for CEOAE and DPOAE showed the weakest effect in the oldest age group (41–60 years) at almost all tested frequencies. Moreover, a weak, albeit significant, positive correlation between the level of OAE and the size of the MOC effect was documented. Conclusion On the basis of our study, we have found a decrease in the strength of the MOC system with increasing age in normally hearing subjects, as reflected by a decrease of the OAE suppression effects in older individuals and an increase of the number of CEOAE and DPOAE enhancements during contralateral acoustic stimulation in the elderly, especially in the high-frequency range.

The hearing system in newborns from the Upper Silesia. Assessment of TEOAE depending on selected parameters of delivery disorders.

The hearing system in newborns from the Upper Silesia. Assessment of TEOAE depending on selected parameters of delivery disorders Transient evoked otoacoustic emission (TEOAE) is an accepted test for screening of the cochlea function in newborns. In this study 300 newborns was tested using TEOAE, as well as analysing such parameters as birth weight, Apgar scale, bilirubinaemia. The study indicated the tendency of TEOAE to decrease in newborns with low birth weight and low Apgar scores. Hyperbilirubinaemia seems to have an influence on cochlea function monitored by TEOAE, especially if there were simultaneously low Apgar scores. A similar tendency, although slightly stronger, was observed in the preterm newborn group. TEOAE seems to be a good method of recording the negative influence on the cochlea activity such factors as low birth weight and asphyxia. Hyperbilirubinaemia with asphyxia acts upon the cochlea similarly. All these tendencies were observed more strongly in the preterm newborn group. It is concluded that TEOAE analysis demonstrated its utility as a screening test assessing the hearing state in newborns, additionally the associations of cochlea activity was found with a few parameters of delivery disorders.

Contralateral suppression of TEOAE in diabetic children. Effects of 1.0 kHz and 2.0 kHz pure tone stimulation - preliminary study

The medial efferent system and its regulating outer hair cell function have not been previously studied in diabetic children. In this study, the group comprised 32 diabetic children, aged 6.0-16.0 years, with diabetes lasting 2.0-9.0 years, with normal tonal and impedance audiometry. A control group consisted of 30 healthy children with similar age and sex distribution. Contralateral stimulation (CS) was performed using 1.0 and 2.0 kHz pure tones on the level of 30 and 50 dB SL. Effects of CS on transient evoked otoacoustic emissions (TEOAE) elicited by click of a level equal to 70 and 60 dB SPL were investigated. Analysis included assessment of TEOAE amplitude and 0.8 kHz frequency bandwidth (0.8-FBW) amplitudes (signal/noise) centred at 1.0; 2.0; 3.0; 4.0; 5.0 kHz. TEOAE-RA recorded for stimulus 80, 70 and 60 dB SPL without CS were decreasing: average values respectively 7.3, 4.7 and 3.9 dB SPL. In the group of diabetic children TEOAE amplitudes, recorded for different click levels without CS, were similar to these recorded in healthy children. It suggested that normal function of the cochlea was preserved, mostly outer hair cells. However, the obtained effects of CS, in comparison with healthy children, were weaker and not so regular. Statistical analysis revealed that the reduction of TEOAE amplitudes for adequate 0.8-FBW in the control group was significantly higher, for both 1.0 kHz and 2.0 kHz CPTs of 30 dB SL and 50 dB SL, in comparison with diabetic children. It is concluded that the suppressive effect on OAE in diabetic children is rather weak and seems to be associated with pathological changes in medial olivocochlear myelinated fibres.

Ocena wybranych biomateriałów do rekonstrukcji perforacji przegrody nosa

INTRODUCTION The septal nasal perforation is an important problem for the laryngologists and plastic surgeons. The reasons of septal nasal perforations are injuries, neoplasm, self-mutilation, chronic rhinitis, allergy, Wegener granuloma, sarcoidosis, tuberculosis, toxic metals (arsenic, chrome), some drugs (steroids), narcotizing agents (cocaine) and complications after endoscopic and septal nasal operations. The surgical treatment, especially in the cases of large septal perforation, is often difficult because of the atrophy of nasal mucosa and lack of suitable material for reconstruction. In the surgical treatment many of methods and reconstructive materials have been used. The following autogenous tissues were used in the reconstruction of septal perforation: alloderm, temporal fascia, septal and auricle cartilage, cranial periosteum, perichondrium, ethmoidal and hip bone. The defect of such materials is progressive resorption. For many years the suitable synthetic material for septal nasal reconstruction has been searched for. Among the biomaterials the following have been used without success: Dacron, porous polyethylene, dolomite, bioglass. The rejection of synthetic material was the reason of failure. The aim of our study was to evaluate two different biomaterials with proper mechanical and biological features for nasal cartilage replacement. MATERIAL AND METHODS We studied two types of biomaterials: biostable terpolymer PTFE/PVDF/PP and resorbable copolymer of glycolide and L-lactide (PGLA). The pilot studies were performed on two experimental animals (rabbits). The animals were operated in the general anesthesia. The biomaterials were implanted in the rabbit auricular cartilage because of its similarity to the septum and easy surgical access. Subperichondrically 1 x 1 cm fragment of the cartilage was removed. This fragment was then replaced with the biomaterial. The rabbits were painlessly sacrificed after 4 months of observation. RESULTS A very good integration of PGLA implant with auricular cartilage was observed. In the histological examination the lack of excessive inflammatory reaction as well as no cartilage necrosis were observed. CONCLUSIONS 4 months after implantation of PGLA in the rabbit auricular cartilage very good macroscopic and histological results were achieved.Summary Introduction The septal nasal perforation is an important problem for the laryngologists and plastic surgeons. The reasons of septal nasal perforations are injuries, neoplasm, self-mutilation, chronic rhinitis, allergy, Wegener granuloma, sarcoidosis, tuberculosis, toxic metals (arsenic, chrome), some drugs (steroids), narcotizing agents (cocaine) and complications after endoscopic and septal nasal operations. The surgical treatment, especially in the cases of large septal perforation, is often difficult because of the atrophy of nasal mucosa and lack of suitable material for reconstruction. In the surgical treatment many of methods and reconstructive materials have been used. The following autogenous tissues were used in the reconstruction of septal perforation: alloderm, temporal fascia, septal and auricle cartilage, cranial periosteum, perichondrium, ethmoidal and hip bone. The defect of such materials is progressive resorption. For many years the suitable synthetic material for septal nasal reconstruction has been searched for. Among the biomaterials the following have been used without success: Dacron, porous polyethylene, dolomite, bioglass. The rejection of synthetic material was the reason of failure. The aim of our study was to evaluate two different biomaterials with proper mechanical and biological features for nasal cartilage replacement. Material and methods We studied two types of biomaterials: biostable terpolymer PTFE/PVDF/PP and resorbable copolymer of glycolide and L-lactide (PGLA). The pilot studies were performed on two experimental animals (rabbits). The animals were operated in the general anesthesia. The biomaterials were implanted in the rabbit auricular cartilage because of its similarity to the septum and easy surgical access. Subperichondrically 1 x 1 cm fragment of the cartilage was removed. This fragment was then replaced with the biomaterial. The rabbits were painlessly sacrificed after 4 months of observation. Results A very good integration of PGLA implant with auricular cartilage was observed. In the histological examination the lack of excessive inflammatory reaction as well as no cartilage necrosis were observed. Conclusions 4 months after implantation of PGLA in the rabbit auricular cartilage very good macroscopic and histological results were achieved.

The Efficacy of Perioperative Antibiotic Therapy in Tonsillectomy Patients

BACKGROUND While the results of early research suggested that perioperative antibiotic prophylaxis in tonsillectomy patients is associated with many benefits, these data were not confirmed by further studies and meta-analyses. OBJECTIVES The aim of this study was to investigate the usefulness and efficacy of antibiotic monotherapy in the healing of surgical wounds of patients undergoing bilateral resection of the palatine tonsils, based on an analysis of selected objective and subjective characteristics of wound healing during the postoperative period. MATERIAL AND METHODS The study included 50 men and women who underwent routine resection of the palatine tonsils. The patients were randomized into two groups: Group I, undergoing tonsillectomy with cefuroxime prophylaxis (n = 25), and Group II, who were not given perioperative antibiotic therapy (n = 25). The severity of signs and complaints recorded on postoperative days 1-10 was scored on 3- and 10-item scales. RESULTS The only significant intergroup differences pertained to problems with swallowing food and fluids on postoperative days 4-6, 8 and 9 (less prevalent in Group II), postoperative use of analgesics on postoperative day 9 (less frequent in Group II), the degree of mucosal swelling in the operated area on postoperative days 3 and 7 (less severe in Group II), and the amount of fibrin covering the tonsillar niches on the third postoperative day (significantly higher in Group I). CONCLUSIONS The administration of antibiotics for prevention or control of infection should be preceded by a comprehensive analysis of the potential benefits and risks. Perioperative use of antibiotics is justified only in selected cases, i.e. in individuals with comorbidities.