Determination of radioactivity levels in feldspathic dental ceramics.

Activity concentrations of 42 different feldspathic dental ceramic powders were determined using a gamma spectrometer with an HPGe detector. The average 238U, 232Th and 226Ra activity concentrations of the specimens were 126 ± 8 Bq kg-1, 5.6 ± 0.5 Bq kg-1 and 12.7 ± 1.2 Bq kg-1, respectively. The average 40K activity was found as 2855 ± 89 Bq kg-1 ranging from 2252 ± 70 Bq kg-1 to 3522 ± 110 Bq kg-1 due to high potassium content in dental ceramics. None of the activity concentration measurements exceeded the limits by EC and ISO.

A musical perception test for people with hearing loss: Turkish adaptation and normalization of the Music Perception Test (MPT).

OBJECTIVES: The aim of this study was to develop a Turkish musical perception test that provide the opportunity to measure music performance of people with hearing loss. SUBJECTS AND METHODS: In the study, the Music Perception Test (MPT), which was translated and adapted into Turkish, was applied randomly to 100 individuals aged between 18-40 years. The test was applied with computers and professional head phones to 20 individuals chosen as a pilot study. Data obtained after the pilot study were evaluated and the application to the other 80 participants were completed. In order to obtain validity and credibility data, 20 randomly chosen participants were retested. RESULTS: The average total score of the MPT of the participants was 97.5 ± 12.2 (Min: 69, Max: 120). As the total score of the MPT has been examined, low value for ± 1SD was 85.3/top value was 109.7; low value for ± 2SS was 73.1/top value was 121.9; low value for ± 3SS was 60.9/top value was 134.1. In our study, the value of internal consistency of the Turkish MPT was 0.898. This value indicates that the test was reliable. In a similar manner, considering the correlation of test-retest parameters, both subtests and total score results showed the results were reliable. With the examination of the results there were no relation between the total scores of the MPT and age (r:0.176, p: 0.080) but the interest in music (r: 0.641, P < 0.001) and the frequency of listening to music (r:0.479, P < 0.001) had an important effect on the total scores of musical perception. The difference in the total scores of the MPT between female and male participants were found to be statistically significant (p < 0.001). CONCLUSIONS: Results of this study show that the Turkish MPT is a valid and reliable musical perception test for the Turkish people who have normal hearing and hearing loss.

Potassium compounds for gamma spectrometer efficiency verification.

Now-a-days several standard and well calibrated radioactive sources are available for gamma spectrometer efficiency calibration but at some situations, like lack of standard calibrators, in need of verification of standards or preparation a standard with the same properties with the interested sample, 40K is a cheap and easily available radioisotope that could be used. In this study, eighteen different inorganic potassium compounds that have different potassium abundances, types of elements, densities and particle sizes were studied as efficiency verification sources. Gamma spectrometric measurements were performed and it was dawn on the compounds which have low density, low molecular weight and high potassium abundance showed higher 40K activity concentration. It was also indicated that potassium abundance of the compound was the dominant property in these parameters. The activity concentrations were also calculated theoretically and results were in good agreement with the experimental results. Thus it was reported that the 40K compounds with these properties are much suitable for to use as verifying sources or gamma calibrators.

Binaural squelch and head shadow effects in children with unilateral cochlear implants and contralateral hearing aids.

The aim of this study was to investigate the amount of binaural squelch effect (BSE) and head shadow effect (HSE) in children who use unilateral cochlear implants (CI) and contralateral hearing aids (HA). The study group consisted of 19 CI recipient children who consistently wore a contralateral HA. Speech sounds were used to evaluate speech perception performance in noise. Testing was performed in three listening conditions: (1) bimodal listening with noise source on HA side; (2) CI only with noise source contralaterally (HA off); (3) CI only with noise source on the CI side. Statistical analysis revealed a significant difference between the three listening conditions and post hoc tests indicated significant differences for all pairwise comparisons (p < 0.001). The average BSE and HSE were 11.8% and 17.1% respectively. The majority of bimodal CI users showed BSE and HSE with significant speech perception improvement in the presence of noise.

A multidisciplinary approach to the management of individuals with fragile X syndrome.

BACKGROUND: Fragile X syndrome (FXS) is the most common inherited form of intellectual disability. Since the identification of the responsible gene (FMR1) and its protein (FMRP), there has been enormous progress in both clinical and pathogenetic research on the neurobehavioural aspects of the condition. However, studies regarding other medical problems anticipated in individuals with FXS are limited. A multidisciplinary study evaluating various causes of morbidity in the same group has not been published yet. METHODS: Twenty-four boys with FXS full mutation were recruited out of a larger group of 103 diagnosed in one centre over the past 10 years. Ear nose and throat, eye and cardiac examinations were performed in addition to routine cognitive, behavioural, neurological and speech and language assessments. RESULTS: The average IQ score was 49.8 +/- 20 (range 25-90). There were four patients (18%) with IQ above 70. Using DSM-IV, attention deficit hyperactivity disorder was diagnosed in five boys out of 22 examined (23%), while 32% were diagnosed with pervasive developmental disorder. The seizure frequency was 17%. A psychiatric disorder was diagnosed in six out of eight boys with electroencephalogram abnormalities (75%). Minimal conductive hearing loss was found in five (5/22) patients. There was significant delay in both expressive and receptive language skills. Ocular findings were refractive errors (13%) and strabismus (4.4%). Mitral valve prolapsus (MVP) was observed in 3/22 (13.7%) patients and aortic annulus dilatation was present in 2/22 (9%) patients. CONCLUSIONS: Frequency of psychiatric diagnoses made with DSM-IV were in parallel to those reported in the literature. Comorbidity of seizures and psychiatric disorders was noteworthy. The percentage of 'high-functioning' full mutation males supports the previous observations. Ear nose and throat and eye examination revealed remarkably lower prevalence of abnormal findings than reported. MVP was slightly less frequent compared with the single study in the literature. Age at the time of examination had an effect on the outcome of cardiac evaluation. These findings will guide us in future management of the group of patients followed in our institution. The protocol applied provides an applicable outline for multidisciplinary institutional settings dealing with individuals with FXS.

Audiologic findings in children with biotinidase deficiency in Turkey.

OBJECTIVE: Biotinidase deficiency is an autosomal recessively inherited disorder characterized by neurological and cutaneous features, including sensorineural hearing loss. Although many features of the disorder are reversible following treatment with biotin, the hearing loss appears to be irreversible. In the present study, hearing status of patients with biotinidase deficiency is characterized in a Turkish population. METHODS: Subjective and objective audiologic tests were performed on 20 children with profound biotinidase deficiency. RESULTS: Sensorineural hearing loss occurs in approximately 55% of the children with biotinidase deficiency. The hearing loss varies in severity from mild to profound hearing loss. In children diagnosed immediately after birth because they had an older sibling with the disorder, statistically significant differences were found between ABR results and age of diagnosis (p<0.05). Greater prolongation in ABR latencies were observed in the late-diagnosed children compared to that in the early-diagnosed children (p<0.05). CONCLUSION: Early diagnosis is important to prevent peripheral and central hearing loss. Children with biotinidase deficiency who have hearing loss are likely at increased risk for having speech and language problems. If hearing aids do not provide sufficient amplification, cochlear implantation may be indicated in these children. Therefore, it is important to test the hearing thresholds of these children with hearing aids and evaluate their language development.

Cochlear implants: is there any relationship between stimulation rates and adaptation?

OBJECTIVE: To determine the relationship between stimulation rate and adaptation in cochlear implant users. STUDY DESIGN: A prospective clinical study. SETTING: This study was conducted at Hacettepe University Medical Faculty, which is a tertiary care and cochlear implant center in Ankara, Turkey. PATIENTS: Seven patients (three women, four men) who were using Nucleus CI 24 M cochlear implants (Cochlear Corp., Lane Cove, NSW, Australia). Two of them had become deaf after developing language skills, and five had congenitally deafness. RESULTS: Six patients demonstrated no tone decay. Only one patient, who had congenital hearing loss, demonstrated tone decay at stimulation rates of 250, 500, 720, 900 pulses per second. There is no statistically significant relationship between the stimulation rate and the selected electrode. CONCLUSION: The majority of the cochlear implant patients sustained the perception of a continuous electrical signal for 1 minute at 5 to 10 current levels above threshold.

Audiological findings in pregnancy.

This investigation was carried out in the Audiology and Speech Pathology Section of the Department of Otorhinolaryngology of Hacettepe University. The pregnant group comprised of 20 women followed by the Department of Gynaecology and Obstetrics of the same university; 18 non-pregnant women comprised the control group. The aim of this investigation was to study the relationship between hormonal changes in pregnancy and cochlear functions. All subjects underwent ENT examination, audiologic and acoustic immitance measurements and auditory brain stem response (ABR) tests. Results from each trimester and post-partum period of the pregnant group were compared. These results demonstrated that there was a decrease in hearing levels for 125 Hz, beginning in the first trimester and increasing in the second and third trimesters. Hearing returned to normal in the post-partum period. Similar findings were also obtained for 250 and 500 Hz; however, frequencies higher than 500 Hz demonstrated no significant correlation. Uncomfortable loudness was statistically significant between the third trimester and post-partum period. ABR tests did not reveal any differences. In conclusion, there is a low-frequency hearing loss and tolerance problem in pregnancy mimicking cochlear pathology. However, this hearing loss did not reach pathologic levels in any case and returned to normal in the post-partum period.

Investigation of the ototoxic effects of interferon alpha2A on the mouse cochlea.

This prospective randomized study investigates the possible toxic effects of interferon (IFN) alpha2A on the mouse cochlea. Thirty-six albino Swiss mice that were randomly assigned to 3 groups underwent baseline auditory brain stem response testing bilaterally to objectively assess baseline hearing levels. The first group received a single dose of 50,000 units, and the second group received 100,000 units of IFN-alpha2A intraperitoneally, whereas the third group was given no medication. Repeat auditory brain stem response testing revealed a significant rise in mean baseline peak equivalent sound pressure level thresholds in the groups that received IFN (P < 0.001). Histologically, the cochleae of mice that received IFN had a decreased number of fibroblasts in the spiral limbus, as well as prominent cytoplasmic vacuolation of these cells, compared with control animals. Loss of hair cells was not observed. It is possible that reversible biochemical and metabolic changes in the cochlea, rather than morphologic abnormalities, manifest IFN ototoxicity.

Effect of teflon piston diameter on hearing result after stapedotomy.

This study compares hearing results after stapedotomy by 0.6 mm and 0.8 mm teflon pistons. Retrospective analysis studied 100 patients randomly selected who underwent stapedotomy for otosclerosis with insertion of 0.8 mm teflon piston prosthesis and 100 patients with 0.6 mm teflon piston prosthesis. Air-conduction hearing level in both groups were measured before and after the procedure and the gain of the air conduction between the 2 groups at different frequencies were compared statistically. The group with the 0.8 mm prosthesis had better results that were statistically significant and more pronounced at lower frequencies.

Efficacy of amitriptyline in the treatment of subjective tinnitus.

We investigated the effect of amitriptyline, a tricyclic antidepressant, on patients with subjective tinnitus. The study group consisted of 37 adult patients admitted to the Ear, Nose, and Throat and Audiology Department of Hacettepe University. The amitriptyline group consisted of 20 patients and the placebo group consisted of 17 patients. All of the patients were evaluated using a questionnaire, audiologic evaluation, high-frequency audiometry, impedancemetric tests, auditory brainstem response, tinnitus frequency, and loudness matching assessed by audiometric methods at the beginning and end of the study. The patients in the amitriptyline group received 50 mg/day amitriptyline in the first week and 100 mg/day for the following 5 weeks. In the placebo group, the patients received tablets consisting of lactose starch for 6 weeks, with a dosage of 1 tablet/day. The subjective complaints of the patients in the amitriptyline group decreased, and the "present" symptoms resulted in fewer complaints. The severity of tinnitus decreased in the amitriptyline group by means of subjective and audiometric methods. In the placebo group, no significant change was observed. The success of treatment was 95% in the amitriptyline group and 12% in the placebo group. Amitriptyline therapy was concluded to be effective.

High frequency hearing loss in Ullrich-Turner syndrome.

UNLABELLED: A total of 38 patients with Ullrich-Turner syndrome underwent standard otological and audiometric evaluation as well as high frequency audiological tests. Some 26 (68.4%) patients had a history of middle ear infections, and ten (26.3%) had required otolaryngological surgery. Conventional audiometry (125-8000 Hz) demonstrated normal hearing in only 25 of the ears (33%); between 500-4000 Hz, 16 ears (21.0%) had a mixed type and eight ears (10.5%) had conductive hearing loss. High frequency audiometry (8-18 kHz) revealed sensorineural hearing loss in 98.7% of the ears. Our results for conventional audiometry are in accordance with the literature. CONCLUSION: The detection of a high prevalence of hearing loss in the high frequency range brings a significant new perspective to the pursuit of the aetiology of ear and hearing problems in Ullrich-Turner syndrome. This pathology seems to be a premature variant of presbycusis and it may underlie future hearing impairment which will come to clinical attention only after it progresses to conventional testing frequencies. While further studies are underway to evaluate this aspect, routine otological and audiological follow-up of patients with Ullrich-Turner syndrome is warranted from the time of diagnosis.

Beneficial effects of dexamethasone in children with pneumococcal meningitis.

Fifty-six children older than 2 years with meningitis caused by Streptococcus pneumoniae were enrolled in a prospective, double blind, placebo-controlled trial to evaluate the efficacy of dexamethasone therapy in addition to antimicrobial therapy. Twenty-nine of 56 received dexamethasone (0.6 mg/kg/day iv, divided into 4 daily doses for 4 days) and the remaining 27 received placebo. At the beginning of therapy the clinical and laboratory characteristics of the patients in the treatment groups were comparable, except for the Glasgow coma score (P = 0.004), which was lower in the dexamethasone group. Patients were examined daily during hospitalization and 6 weeks after discharge from the hospital. Hearing was assessed 6 weeks after discharge by means of pure tone audiometry. Two patients in the dexamethasone group and one patient in the placebo group died. There were no differences between the two groups with regard to the duration of fever, the incidence of secondary fever and electrolyte imbalance, seizure activities occurring during hospitalization and rash. Although the differences were statistically insignificant, moderate or severe unilateral or bilateral sensorineural hearing loss at 6 weeks and the overall neurologic sequelae, including hearing loss, at 1 year were higher in the placebo group, at 23% vs. 7.4% (P = 0.11) and 26.9% vs. 7.4% (P = 0.062), respectively. At 3 months after discharge, because of the improvement in hearing loss in one dexamethasone-treated patient the incidence of hearing impairment was significantly less than that in the placebo group, at 3.7% vs. 23%, respectively (P = 0.044). No improvement in hearing loss was observed after 3 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Audiologic and impedancemetric findings within thalassaemic patients.

The objective of this study is to investigate hearing losses in thalassaemic patients. This study was conducted on 34 thalassemic patients of which 27 of them had thalassaemia major and the remaining 7 had thalassaemia intermedia. Six (11.11%) of the 54 ears with thalassaemia major were found to have normal hearing. Thirty-two ears (59.26%) had conductive hearing loss, 8 ears (14.81%) had mixed type of hearing loss. Moreover, in this group, there was no ear which had pure sensorineural hearing loss. Of the majority of patients having thalassaemia major and thalassaemia intermedia, an air bone gap was found even though there was no negative pressure in the middle ear. In these patients a high degree of static compliance and normal shaped, stiff amplitude, normal pressure tympanograms were observed. Moreover, in most of these patients acoustic reflexes were not obtained. These findings are rather interesting since they show the pathological changes which may cause stiffness in the middle ear sound transmission system.

[Speech intelligibility in various types of obturators constructed after maxillary resections]. / Ust çene rezeksiyonlarindan sonra uygulanan degisik tip obtüratörlerin fonetik olarak karsilastirilmasi.

Six patients who had undergone partial maxillary resection for the removal of oral neoplasms were studied. For each patient two types of obturators were made one being buccal flange and the other hollow-bulb. Speech evaluations were made under three conditions: 1- with the hollow-bulb 2- with the buccal flange and 3- with no obturator. Speech evaluations were made both audiovisually and from tape recordings. In both audiovisual and tape recorded speech evaluations, the buccal flange obturator produced speech which was significantly superior to speech with hollow-bulb obturator.

[Postoperative focal salmonella infections of hydatid cysts]. / Postoperatif kist hidatik lojunda, fokal salmonella enfeksiyonlarl.

S. typhi and S. typhimurium were isolated from postoperative cavities of hydatid cysts of two patients. Both focal salmonella infections were cured by using appropriate antibiotics.