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Biomedical subjects

J Elidan

Publications and source records attributed to J Elidan.

At least 37 records · Page 2Linked to original sources
PubMed1998

Cochlear histopathologic analysis in diabetic rats.

HYPOTHESIS: This study aimed to show whether sensorineural hearing loss in diabetes mellitus is secondary to changes in the organ of Corti and stria vascularis. BACKGROUND: The high rate of sensorineural hearing loss in diabetes mellitus has led to much speculation as to whether there is an association between the two. METHODS: A well-established diabetic animal model was used to examine the inner ear histopathologically. RESULTS: No statistical difference in the inner and outer hair cells or in the stria vascularis was shown between the genetic-diabetic rats and control subjects. CONCLUSIONS: If there is hearing loss with diabetes, its pathogenesis does not involve damage to the hair cells or stria vascularis.

Animals↗
PubMed1997

Short latency vestibular evoked potentials (VsEPs) to linear acceleration impulses in rats.

In this study, short latency (t < 12.7 ms) vestibular evoked potentials (VsEPs) in response to linear acceleration impulses were recorded in 37 rats. A new technique (based on a solenoid) was used for generating linear force impulses that were delivered to the animal's head. The impulse had a maximal peak acceleration of 12 g. During the impulse, the displacement was 50 microns (at 4 g) and the rise time was 1.0 ms. A stimulation rate of 2/s was usually used. The VsEPs (averaged responses to 128 stimulations, digital filter: 300-1500 Hz) were recorded with electrodes on pinna and vertex, and were composed of 4-6 clear waves with mean amplitudes (for a 4 g stimulus) of 1-5 microV. The VsEPs were resistant to white noise masking, and were significantly suppressed (P < 0.05) following bilateral application of a saturated KCl solution to the inner ear, showing that contributions of the auditory and somatosensory systems are negligible. The latency of the response decreased as a power law function of stimulus magnitude, and the amplitude of the first wave increased as a sigmoid function of stimulus magnitude. VsEP responses were still present at the lowest intensities attainable (0.06-0.4 g) and reached saturation at 9 g. The amplitude of the later components was reduced when stimulus rate was elevated to 20/s. These results suggest that VsEPs in response to linear accelerations are similar in their nature to VsEPs in response to angular acceleration impulses that were previously recorded. These VsEPs to linear accelerations are most likely initiated in the otolith organs.

Acceleration↗
PubMed1997

Contribution of the eighth nerve and cranial nerve nuclei to the short-latency vestibular evoked potentials in cats.

The object of this study was to assess the contributions of the vestibular nerve and various cranial nerve nuclei to the short-latency vestibular evoked potentials in cat. The following nuclei were investigated: vestibular nuclei and the third, sixth, and tenth cranial nerve nuclei. In unilateral labyrinthectomized cats, we performed suboccipital craniectomy and partial cerebellectomy to place bipolar electrodes into the neural structures under investigation. The surface-recorded vestibular evoked potentials (far field) were compared with the potentials recorded intracranially in response to the same acceleration impulses. The exact locations were later confirmed histologically. Reversible lesions also were induced by injection of lidocaine 2%. The results indicate that the first wave of the vestibular evoked potentials originates in the vestibular nerve, and the second wave is mainly generated in the superior and medial vestibular nuclei. The third, sixth, and tenth cranial nerve nuclei apparently contribute to the later waves of the vestibular evoked potentials, particularly waves 3 and 4.

Abducens Nerve↗
PubMed1996

Audiovestibular findings in patients with deafness caused by a mitochondrial susceptibility mutation and precipitated by an inherited nuclear mutation or aminoglycosides.

OBJECTIVE: To characterize the audiological and vestibular changes associated with a mitochondrial DNA mutation in an Arab-Israeli family and in other families with mitochondrial predisposition to aminoglycoside-induced hearing loss. DESIGN: Evaluation of audiological (pure tone thresholds, speech reception thresholds, speech discrimination, tympanometry, acoustic reflex thresholds, tone decay, and auditory brain-stem evoked response recording) and vestibular (complete history, physical examination, and 2-channel electronystagmography) systems. In 5 patients, structural evaluation of the inner ear was done by magnetic resonance imaging. PATIENTS: Fifteen members of an Arab-Israeli family, and 1 Chinese woman with the same mitochondrial DNA mutation who experienced hearing loss after short-term exposure to streptomycin. RESULTS: Most of the patients had a profound hearing loss due to cochlear involvement. The hearing loss usually was not accompanied by notable peripheral vestibular dysfunction. In the patient with severe hearing loss after exposure to aminoglycoside, the vestibular function was completely normal. CONCLUSIONS: In most of the Arab-Israeli patients with congenital deafness, the vestibular system function was normal, in contrast to the frequency of vestibular abnormality among deaf children, which was described in the literature. This may be related to genetic predisposition to aminoglycoside-induced deafness.

Adult↗
PubMed1996

Parapharyngeal abscess in children: the role of CT for diagnosis and treatment.

Parapharyngeal abscess (PPA) in children is an uncommon deep neck space infection. Computerized tomography (CT) is an important diagnostic aid. However, CT scan is not specific in differentiating an abscess from cellulitis or inflammatory edema. A retrospective review of eight children with a CT diagnosis of PPA was undertaken. In three patients an abscess was surgically confirmed. In two patients surgical exploration did not reveal an abscess and in three the infection resolved with intravenous antibiotic therapy only. Although CT is a useful diagnostic tool for PPA, surgical intervention should be based mainly on the clinical status of the patient and the non-responsiveness to i.v. antibiotic therapy.

Anti-Bacterial Agents↗
PubMed1996

Vertical plane short and middle latency vestibular evoked potentials in humans.

In order to determine whether short and middle latency vestibular evoked potentials (VsEPs) can be recorded in humans in response to angular acceleration stimuli in the vertical plane, a drum, head-holder, and stepper motor were designed to deliver upward acceleration impulses of 10,000 degrees/s2 (1.8 degrees displacement) to the human head. Forehead and mastoid electrodes recorded electrical activity that was filtered, differentially amplified, and averaged in short (12.7 milliseconds) and middle (63.5 milliseconds) latency time frames. Control recordings were used to eliminate various types of artifact. Recordings were conducted in 7 normal subjects and in 4 control patients with congenital, profound hearing loss and absence of caloric responses. Short and middle latency VsEPs with high intrasubject and intersubject consistency were recorded in normal subjects and not in control patients. The middle latency responses were larger in amplitude than the short latency responses. The effects of stimulus intensity and repetition rate on VsEP waveform, latency, and amplitude studied. Experiments have shown that the responses are not electrical artifact, nor are they contaminated by auditory, somatosensory, or passive eye movement potentials.

Acceleration↗
PubMed1996

Fibrosarcoma of the thyroid in a man exposed to fallout from the Chernobyl accident.

Since the Chernobyl accident in April 1986, a dramatic increase in the incidence of thyroid carcinoma has been described, especially in children. A case of sarcoma of the thyroid in a man exposed to the Chernobyl fallout is presented. Sarcoma of the thyroid is a rare finding. The present patient lived in a region that is known to be one of the most exposed to Chernobyl fallout. The case suggests a high probability of a relationship between the sarcoma of the thyroid and the exposure to radiation.

Aged↗
PubMed1995

Peripheral generators of the vestibular evoked potentials in the cat.

OBJECTIVES: The contributions of each of the vertical semicircular canals (SCCs) and otoliths to the short-latency vestibular evoked potentials in response to angular acceleration impulses were studied in the cat. DESIGN: The experiments were conducted on unilateral labyrinthectomized cats. Vestibular activation was achieved by delivering angular acceleration impulses to the animal's head, held in the position presumed to be optimal for maximal stimulation of either the anterior or the posterior SCCs before and after obliteration of the SCC studied, and before and after obliteration of the other SCCs and ablation of the maculae. INTERVENTIONS: Unilateral labyrinthectomy, obliteration of the SCCs, and ablation of the otoliths and section of the commissural vestibular fibers in the brain stem with histologic confirmation were carried out in the experiments. RESULTS: Following selective obliteration of either the anterior or the posterior SCC of the remaining ear and stimulation in the presumed optimal plane of the obliterated canal, the early prominent waves (P1 and P2) disappeared, leaving only much smaller-amplitude waves. These were severely depressed after ablation of the maculae. On the other hand, the vestibular evoked potentials in response to excitatory stimuli were not affected by obliteration of the other two SCCs and ablation of the maculae. CONCLUSION: These results indicate that when the head is stimulated in the optimal plane of each of the SCCs, the vestibular evoked potentials are generated mainly by the cristae ampullaris being stimulated, while the otoliths contribute smaller responses.

Animals↗
PubMed1995

Aerodigestive tract obstruction as a late complication of radiotherapy.

Oedema, fibrosis, and stenosis of the hypopharynx and the oesophageal inlet are described in a few publications as a complication of post-laryngectomy irradiation treatment. In this paper a case of laryngeal carcinoma, treated exclusively by irradiation, where severe laryngeal and hypopharyngeal stenosis with complete occlusion of the oesophageal inlet were manifested as a late complication is described. We have found no similar case described in the English literature.

Adult↗
PubMed1995

Nd:YAG laser turbinate surgery animal experimental study: preliminary report.

The chronically hypertrophic nasal turbinate is a challenging problem for otolaryngologists. Although some success has been achieved with a number of medical and surgical methods, other forms of treatment are still needed. In this study, encouraging results were achieved using the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser on canine turbinates. Clinical and histological results showed that with Nd:YAG laser surgery, coagulation occurs in the deep cavernous vessels and submucosal glands of the turbinate, while the overlying mucosa remains intact.

Animals↗
PubMed1995

The contribution of cranial-nerve nuclei to the short latency vestibular evoked potentials in cat.

The object of this study was to assess the contributions of various cranial nerve nuclei to the short latency vestibular evoked potentials (VsEPs) in cat. The following nuclei were investigated: vestibular nuclei, and 3rd, 6th and 10th cranial nerve nuclei. In unilateral labyrinthectomized cats, suboccipital craniectomy and partial cerebellectomy were carried out in order to place bipolar electrodes into the neural structures under investigation. The surface recorded VsEPs (far-field) were compared with the potentials recorded intracranially in response to the same acceleration impulses. The exact locations were later confirmed histologically. Reversible lesions also were induced by injecting of lignocaine 2%. The results indicate that the 2nd wave (P2) is mainly generated in the superior and medial vestibular nuclei. The 3rd, 6th and 10th cranial nerve nuclei apparently contribute to the later waves of the VsEPs, particularly P3 and P4.

Animals↗
PubMed1994

Giant cranial base tumours.

Thirty-three patients with giant (diameter > or = 4.5 cm) cranial base tumours who underwent surgery at the Hadassah Hospital over the last ten years are described. Twenty-three of the patients had meningiomas, 4 neurinomas, one giant cell tumour, one haemangiopericytoma, and 4 had malignant meningiomas. Four tumours were at the cerebellopontine angle, 9 within the anterior cranial fossa, 8 petroclival, 8 on middle fossa floor, and 4 along the sphenoid ridge. The average pre-operative symptom duration was 31 months, range 3-180 months. Nineteen patients had a radical tumour resection, 10 subtotal, and 4 a partial resection on an average 1.7 operations per patient. The mean follow-up period from the first operation was 39 months (range 2-120). There was no mortality peri-operatively or during the follow-up period. The mean pre-operative Karnofsky score was 68 and at the last follow-up 76. There was no correlation between histology and degree of resection, complications, or status at last follow-up. The best resections (92% radical) and outcome (mean Karnofsky 92) with the least number of operations (mean 1.4) were in the anterior fossa and along the sphenoid wing. The patients requiring the most operations (mean 2.1), having the smallest percentage of radical resections (25%) and the least favourable outcomes (mean Karnofsky 52) were those with petroclival tumours. Patients with giant cranial base tumours have a good overall long-term prognosis, but especially those with petroclival tumours challenge us to improve our techniques.

Adolescent↗
PubMed1994

Fibrosarcoma of the vocal fold: a late complication of radiotherapy.

The carcinogenic effect of ionizing radiation is a well known phenomenon. However, the induction of malignancies following irradiation for head and neck cancers is quite rare (Steeves and Vataini, 1982). Most reported cases are osteogenic sarcomas with soft tissue sarcomas encountered less often. We report a rare case of fibrosarcoma of the larynx, following radiation therapy for glottic carcinoma.

Carcinoma, Squamous Cell↗
PubMed1994

Rhinocerebral aspergillosis in patients undergoing bone marrow transplantation.

Rhinocerebral aspergillosis (RA) is becoming increasingly common in patients undergoing bone marrow transplantation (BMT). The disease can involve nearly all major head and neck structures, including the nose, paranasal sinuses, and orbits. Intracranial extension of the infection is of major concern, since this is usually a fatal complication. Our study population comprised 423 consecutive BMT patients at Hadassah University Hospital from January 1986 to August 1992. Eight patients (1.9%) developed RA, 5 of whom had underlying hematologic malignancies, and 3 of whom had severe aplastic anemia. Only 2 of the 8 patients responded completely to therapy, with a follow-up of 15 months. It appears that RA is a fatal complication in immunocompromised patients post-BMT. Early diagnosis followed by extensive surgical debridement of necrotic tissue and systemic, as well as topical, antifungal therapy with amphotericin B or its new formulations and the patient's recovery of bone marrow function may improve the outcome of this life-threatening complication.

Adolescent↗