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Biomedical subjects

Sebahattin Cureoglu

Publications and source records attributed to Sebahattin Cureoglu.

At least 19 recordsLinked to original sources
PubMed2004

Massive endolymphatic sac and vestibular aqueduct in Mondini dysplasia.

A postmortem study was performed on the bilateral temporal bones of a 90-year-old woman who had a lifelong profound hearing impairment. The histopathologic findings included severe Mondini dysplasia with unusual enlargement of the vestibular aqueducts and endolymphatic sacs. Dehiscent carotid arteries and dehiscent facial nerves were also present. The clinical and surgical aspects of the case are discussed based on the histopathologic findings. The physician should be prepared to diagnose congenital hearing impairment promptly to avoid complications during the clinical and surgical treatment of patients with Mondini dysplasia.

Aged↗
PubMed2004

Effects of aminoglycoside administration on cochlear elements in human temporal bones.

OBJECTIVE: Although there have been numerous reports on the relationship between the period of aminoglycoside administration and cochlear damage in animals, to date there have been no such studies in humans. The purpose of this study is to observe the early and late cochlear effects of aminoglycoside administration on hair cells, spiral ganglion cells, stria vascularis, and spiral ligament. METHODS: Specimens were divided into three groups. Group I included "normal" temporal bones with no histopathologic findings of otitis media and no history of otologic or ototoxic drug administration. Group II consisted of temporal bones that received aminoglycosides within 2 weeks before death and group III of temporal bones that had aminoglycosides from 2 weeks to 6 months prior to death. Patients in groups II and III received gentamycin, kanamycin or tobramycin. Temporal bones were excluded from groups II and III if patients had a history of otologic disease or other ototoxic drugs. All temporal bones were examined under light microscopy. Standard cytocochleograms and spiral ganglion cell reconstructions were done on all temporal bones. Morphometric measurements of areas of stria vascularis were made in all turns of the cochlea on mid-modiolar sections. Spiral ligament was divided into four segments according to the locations of different types of fibrocytes. The mean loss of fibrocytes in each segment was estimated. RESULTS: The percentages of intact outer hair cells in the basal turn were significantly greater in group I compared to groups II and III. The mean area of the stria vascularis in the apical turn was significantly less in groups II and III compared to group I. CONCLUSION: This study demonstrates that in a short period (within 2 weeks) after aminoglycoside administration, a decrease in hair cells and in the area of the stria vascularis occurred.

Administration, Topical↗
PubMed2004

Cellular changes of Reissner's membrane in Meniere's disease: human temporal bone study.

OBJECTIVE: To study the cellular characteristics of Reissner's membrane (RM) in temporal bones (TBs) from patients with endolymphatic hydrops with symptoms of Meniere's disease (EH/+MD) and TBs with endolymphatic hydrops without symptoms of Meniere's disease (EH/-MD) in an effort to understand the role of endolymphatic hydrops in MD symptoms. STUDY DESIGN: Comparative study of human TB histopathology. METHODS AND MATERIALS: Epithelial and mesothelial cellularity of RM from control TBs, TBs from patients with EH/+MD, and TBs from patients with EH/-MD were compared. The cellularity of epithelial and mesothelial cell nuclei (defined as number of cells/100 microm width of RM) were counted along the width of RM. The width of RM was measured from the vestibular crest of the spiral ligament to the limbus spiralis. RESULTS: The cellular densities of epithelial cells in the basal and middle turns of RM were significantly higher in the EH/+MD and EH/-MD groups compared with "controls." There was no difference in epithelial cellularity between EH/+MD and EH/-MD. There was a decrease in the number of mesothelial cells of RM in the basal turn in EH/+MD and EH/-MD groups (statistically significant only in EH/+MD group) when compared with controls. The number of mesothelial cells of RM in the middle turn in EH/+MD and EH/-MD groups were significantly decreased compared with normals. DISCUSSION: Similar findings in cellularity of RM in temporal bones with EH/+MD and EH/-MD suggest that pathophysiologic mechanisms other than hydrops may be responsible for symptoms in Meniere's disease.

Adolescent↗
PubMed2004

Age-related histopathologic changes in the human cochlea: a temporal bone study.

OBJECTIVES: Previous reports on aging of human cochlea included subjects with ear diseases or ototoxic drugs. We studied spiral ganglion cells, hair cells, and lateral wall of cochlea from subjects without ear disease or ototoxic drugs. STUDY DESIGN: This study included 39 temporal bones from 24 subjects aged 1 day to 86 years. We assessed standard cytocochleograms, mean loss of fibrocytes in spiral ligament, and areas of stria vascularis. RESULTS: Losses of outer hair cells and fibrocytes were significantly greater in children, adults, and the elderly compared with infants. Spiral ganglion cell loss was significantly greater in adults and elderly compared with infants and children. Areas of stria vascularis of infants were significantly larger than the elderly. CONCLUSIONS: Degenerative changes of outer hair cells occur in children but spiral ganglion cells remain the same until around 20 years. Degeneration of stria vascularis due to aging appears to be slower than spiral ligament. EBM RATING: C.

Adolescent↗
PubMed2004

Otologic manifestations of metastatic tumors to the temporal bone.

The temporal bone appears to be affected by metastatic tumors in rather characteristic clinical presentations. More effective cancer treatments have interrupted the course of the disease, allowing more time for metastatic spread. This has increased the importance of prompt diagnosis in a group of diseases that may mimic external auditory canal or middle ear infections. In this paper, we review the distinctive patterns of involvement and presentation of metastatic tumors of the temporal bone, with emphasis on measures that should be taken to ensure early diagnosis.

Ear Diseases↗
PubMed2004

Prognostic value of PCNA and mutant p53 expression in laryngeal squamous cell carcinoma.

The objective of this study was to investigate the prognostic significance of p53, and proliferative cell nuclear antigen (PCNA) in laryngeal squamous cell carcinoma (LSCC). Sixty pathologic specimens from the patients with LSCC were examined for the expression of the p53 and PCNA, with complete follow-up data. Sixty-three percent of the cases displayed nuclear p53 overexpression. There was a correlation between p53 overexpression and histological grades (p = 0.03), and localization site (p = 0.05). Median of PCNA index was 42.2 (range 5.9 to 85.2). There was no difference between the p53 overexpression group and the normal group in proliferative activity determined by PCNA (p = 0.73). In univariate analyses, localization site, grade, stage, invasion pattern, lymph node status, were significant factors in estimating disease free survival (DFS). Grade was the most important factor affecting recurrence (p = 0.002). In multivariate analyses, grade was the only significant predictor for DFS (p = 0.001). Grade (p = 0.001) and invasion pattern (p = 0.03) were found to be significant predictors of overall survival. In conclusion, the histological grade was the most reliable important prognostic factor. Further studies are necessary to facilitate understanding of the mechanisms of laryngeal carcinogenesis.

Adult↗
PubMed2004

Cochlear changes in chronic otitis media.

OBJECTIVES/HYPOTHESIS: The objective was to describe the morphological changes in the cochlea in chronic otitis media. STUDY DESIGN: Retrospective human temporal bone analysis. METHODS: Fifteen temporal bones with unilateral chronic otitis media were selected and compared with contralateral normal temporal bones. Standard cytocochleograms and spiral ganglion cell reconstructions were performed on all temporal bones. Spiral ligament was divided into four segments according to the locations of different types of fibrocytes. The average loss of fibrocytes in each segment was estimated. Morphometric measurements of areas of stria vascularis and spiral ligament were made in all turns of the cochlea on mid modiolar sections. RESULTS: Loss of outer and inner hair cells was common in the basal turn of the cochlea in temporal bones with chronic otitis media compared with control ears. There was no difference in the number of spiral ganglion cells in the chronic otitis media and contralateral ears. The areas of stria vascularis and spiral ligament in the basal turn decreased significantly in the ears with chronic otitis media compared with control ears. There were no significant differences between the ears with chronic otitis media and the contralateral ears for any of the regions characterized by the presence of types I-IV fibrocytes. CONCLUSION: The results of the study are consistent with the hypothesis that chronic otitis media causes cochlear disease.

Adolescent↗
PubMed2004

Cochleosaccular dysplasia: a morphometric and histopathologic study in a series of temporal bones.

OBJECTIVE: The objective of this study was to perform a morphometric analysis of a series of temporal bones with cochleosaccular dysplasia to clarify the extent of inner ear changes in this disease. STUDY DESIGN: This human temporal bone histopathologic study of a series of deaf-mute cases involves morphometric analysis, including stria vascularis and spiral ligament area measurements and spiral ganglion and hair cells counts. SUBJECTS: Thirteen temporal bones were selected from 35 with deaf mutism based on the histopathologic findings described by Scheibe. Twenty normal age-matched control subjects were used for comparisons. RESULTS: All temporal bones had the main histopathologic findings described by Scheibe, as well as severe affected stria vascularis. Seven temporal bones had cystic areas in the stria and three had concretions. Cross-sectional strial areas in temporal bones with cochleosaccular dysplasia were smaller than normal in all cochlear turns; however, no difference was found in spiral ligament cross-sectional areas. Reissner's membrane was hydropic in three temporal bones and the organ of Corti was absent in at least one cochlear turn in five. Concretions were present in the macula of seven temporal bones. Twelve temporal bones showed some level of spiral ganglion cell loss. No hair cells were observed in any temporal bone. A familial history of deafness was found in three cases. CONCLUSION: Pathologic findings were variable and limited to the saccule and scala media. The variation, perhaps, reflects the different etiologies involved in the origin of cochleosaccular dysplasia.

Adolescent↗
PubMed2004

Examination of the distribution of mast cells in the nasal mucosa of patients with seasonal allergic rhinitis.

OBJECTIVE: It is known that mast cells play an important role in pathogenesis of allergic rhinitis. In this study, we investigated the distribution of mast cells in the nasal mucosa of patients with seasonal allergic rhinitis during the pollen-season. METHODS: This study was carried out at the Faculty of Medicine, Dicle University, Turkey, during the grass-pollen season between, March and July in 2002. Twenty patients with seasonal allergic rhinitis (12 females and 8 males) and 20 healthy (10 females and 10 males) non-allergic controls were examined for the distribution and abundance of mast cells in nasal biopsies. Biopsies were performed in all patients and controls, once during natural provocation in the spring and were taken from the lower edge of the inferior turbinate using a forceps. The samples of nasal mucosa were fixed in 10% neutral buffered formaline, stained with 0.5% aqueous toluidine blue and hematoxylin and eosin were examined under a light microscope. RESULTS: Mast cells were observed in the nasal mucosa obtained from 12 patients (60%) and 5 patients (25%) controls cases (p=0.025). It was found out that intrapitelial mast cells are present in nasal mucosa samples of patients with SAR (seasonal allergic rhinitis) but not in the epithelium of non-allergic controls. CONCLUSION: The number of submucosal mast cells has considerably increased in the nasal mucosa samples of patients with SAR. Besides this, these cells are determined in great amounts in non-allergic individuals.

Adult↗
PubMed2003

Effect of parenteral aminoglycoside administration on dark cells in the crista ampullaris.

OBJECTIVE: To observe the early and late effects of the parenteral administration of aminoglycosides on the dark cells of ampullae in the inner ear. STUDY DESIGN: Comparative study of the histopathologic characteristic of human temporal bones. SUBJECTS AND METHODS: Sixty-three temporal bones from 44 subjects (age range, 16-81 years) were examined by light microscopy. Three groups of temporal bones were selected for this study: group 1, 30 "normal" temporal bones from 22 subjects (mean age, 59 years; age range, 25-81 years) with no history or histopathologic findings of otologic disease or ototoxic drug use; group 2, 14 temporal bones from patients who received aminoglycoside treatment within 2 weeks before death; and group 3, 19 temporal bones from patients who received aminoglycoside treatment between 2 weeks and 6 months before death. RESULTS: The mean +/- SD number of dark cells in group 1 was 15.0 +/- 2.47; in group 2, it was 17.3 +/- 1.93 in the subjects who received gentamicin sulfate and 15.0 +/- 3.08 in those who received kanamycin sulfate and tobramycin; in group 3, it was 14.6 +/- 1.67 in the subjects who received gentamicin and 15.2 +/- 2.31 in those who received kanamycin and tobramycin. The overall difference between the 3 groups was not statistically significant (P =.07). The cytologic characteristics of dark cells were similar in all 3 groups. The number of dark cells showed a decline with increasing age in group 1. CONCLUSIONS: The result of this study suggests that the treatment period was probably too short to destroy the dark cells. Therefore, long-term aminoglycoside therapy may be necessary to get a more permanent result.

Adolescent↗
PubMed2003

Structure of the stereocilia side links and morphology of auditory hair bundle in relation to noise exposure in the chinchilla.

Stereocilia side links are directly involved in the maintenance of stereociliary bundle integrity in hair cells. The structure of the stereocilia side links and morphology of the auditory hair bundle in relation to noise exposure in the chinchilla was investigated by transmission electron microscopy. The outer hair cell (OHC) stereocilia side link was suggested to consist of extracellular, juxta-membrane and thin filamentous regions. Two beaded filaments were folded at their distal ends and fastened in one globule in the center between stereocilia. An intracellular, submembraneous layer appeared to form a bridge between the actin core and the extracellular, juxta-membrane region of the side link. In normal physiological conditions, most OHC stereocilia had a regular distribution of side links, forming a 'zipper-like' lattice between stereocilium shafts. Side links of the inner hair cell (IHC) stereocilia had a similar filamentous appearance, but were observed less commonly and had decreased structural organization compared to those of the OHC stereocilia. Ultrastructural analysis of OHC and IHC stereocilia showed that a large number of the side links could survive acoustic stimulation of 114 dB SPL for 2 hrs or 123 dB SPL for 15 min, that resulted in temporarily elevated hearing thresholds in all animals. Disarray, separation, close attachment and fusion of stereocilia were more frequently observed for IHC stereocilia and OHC stereocilia that were poorly connected or that lacked side links. Most disarrayed OHC and IHC stereocilia recovered to a normal erect state with restored orientation of the side links after 14-28 days, which correlated with near-complete recovery of auditory sensitivity. However, direct attachment of plasma membranes, ruptured links, fusion and blebs were seen on some stereocilia even after 28 days and appear to be permanent.

Actin Cytoskeleton↗
PubMed2002

The shortened cochlea: its classification and histopathologic features.

INTRODUCTION: The term 'Mondini dysplasia' has been used to describe virtually any congenital abnormality of the osseous labyrinth resulting in confusion and seemingly contradictory observations and conclusions about this type of deformity. The purpose of this study is to histopathologically classify and describe temporal bones whose cochleas have less than 2.5 turns. METHODS: Of the 1800 temporal bones in our collection, 21 from 12 cases were found to have cochleas with less than 2.5 cochlear turns. Ages ranged from stillborn to 50 years. Temporal bones were harvested at autopsy, processed and embedded in celloidin. Sections were cut at a thickness of 20 microm and every 10th section stained with hematoxylin-eosin and examined using light microscopy. The number of turns, length of cochlea, integrity of cochlear base, length of modiolus, abnormalities of the semicircular canals and vestibule, enlargement of the vestibular aqueduct and middle ears were documented. Twenty-one temporal bones from age-matched patients without cochlear deformities were used as controls for modiolar length measurements. RESULTS: Malformation of the shortened cochlea was histopathologically classified into three groups as follows: (1) Common cavity, cochlear dysplasia (one ear)--severe dysplasia of the cochlea without a complete basal turn; (2) Mondini dysplasia (11 ears)--1.5 cochlear turns, a complete basal turn, an incomplete or absent interscalar septum and a complete bone at the base of the modiolus; and (3) Mondini-like dysplasia type A (five ears)--2 turns to the cochlea including a complete basal turn and complete bone at the base of the modiolus; and type B (four ears)--1.5-2 turns to the cochlea, hypoplasia of or a missing bone at the base of the modiolus (either with or without a communication between the internal auditory canal and the cochlea) and a complete basal turn. CONCLUSION: The range of congenital malformations in short cochlea is highly variable. Fundamental to the accurate evaluation of a labyrinthine anomaly, malformations of the inner ear should be classified according to the findings in the labyrinth. We suggest the use of common cavity cochlear dysplasia, Mondini dysplasia and Mondini-like dysplasia to describe these variable anomalies.

Adolescent↗
PubMedDate not supplied

Effects of gentamicin on sensorineural elements of the cochlea in human temporal bones.

PURPOSE: Gentamicin is commonly prescribed for treatment of gram-negative bacterial infections. It has, however, been known to have vestibulotoxic and ototoxic effects in humans. Previous studies were confounded by the use of other types of ototoxic drugs, higher than therapeutic doses, and prolonged time periods between gentamicin administration and death. The purpose of this study is to observe the effects of parenteral gentamicin administration on the sensorineural elements of the cochlea in which the previously described factors did not exist. MATERIALS AND METHODS: Temporal bone specimens were divided into 2 groups. Group 1 included 16 "normal" temporal bones with no history or histopathologic findings of otologic disease or ototoxic drug administration, and group 2 included 17 temporal bones that received gentamicin treatment within 6 months before death. Temporal bones were excluded from group 2 if patients had histopathologic findings or history of otologic disease and/or other ototoxic drugs. All temporal bones were examined under light microscopy. RESULTS: The percentages of intact outer hair cells in the basal turn was significantly greater in group 1 compared with group 2. There was no significant difference in hair cell number between the groups in the other turns. There was no significant difference in the number of spiral ganglion cells between groups in any turn. CONCLUSION: Although gentamicin is primarily considered to be vestibulotoxic, this study showed that gentamicin can damage sensorineural elements of the cochlea, even in younger patients. During the administration of this drug, hearing of the patient should be carefully monitored.

Adolescent↗
PubMedDate not supplied

Occupational safety: effects of workplace radiofrequencies on hearing function.

BACKGROUND: The effects of radio frequency (RF) and microwave radiation on humans have been the subject of continuous investigation. Clinical investigations related to occupational RF/microwave exposure have been reported by investigators (1). Since one of the major groups occupationally exposed to RF and microwave radiation includes those working in radio broadcasting and TV transmitter stations, this study investigates whether RF affects auditory systems of people exposed to RF. METHODS: The study is carried out with people working in radio broadcasting stations and living in employee residential houses close to the broadcasting stations. All subjects in the control group were similar in age, work regime, socioeconomic status, and lack of experience in working with RF sources. Brainstem Evoked Response Audiometer (BERA) and Pure Tone Audiometry (PTA) were used to measure the effects of RF under investigation on hearing functions of the subjects. In BERA measurements, I-III, III-V and I-V interpeak latencies were evaluated. In pure tone audiometric measurements, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz and 8000 Hz frequencies of hearing threshold were measured in subjects of experimental and control groups. Interpeak latencies and bone conduction hearing thresholds of subjects in the experimental group were compared with those of the control group. RESULTS: BERA results showed that I-III, I-V and III-V interpeak latencies of people occupationally exposed to RF were not higher than subjects in control groups (p>0.05). Results of BERA indicated no statistically significant differences between exposure and control subjects. In audiometric evaluation, hearing threshold of people occupationally exposed to RF were found higher than the control group subjects for frequencies of 4000 Hz and 8000 Hz in terms of bone and air conduction of right and left ear (p < 0.01). CONCLUSIONS: The results of traditional audiometer indicated that RF promotes sensorineural hearing loss and affects cochlea parts related to 4000 Hz and 8000 Hz. These findings may have immediate implications and considerations for workplace safety in order to provide an occupationally safe environment to employees working in such settings.

Audiometry, Pure-Tone↗