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At least 631 records · Page 35Linked to original sources
PubMed1998

[Acute promyelocytic leukemia accompanied by scrotal Fournier's gangrene during ATRA treatment and relapsed as external ear tumor].

A 43-year-old man was admitted because of gingival bleeding. A diagnosis of acute promyelocytic leukemia (APL) was made. He was given combination chemotherapy including all-trans retinoic acid (ATRA). During the myelosuppression stage, the patient developed Fournier's gangrene of the scrotum. He achieved complete remission and underwent a hemicastration procedure. Seven months later, bilateral external ear tumors developed. Biopsy specimens of the tumors revealed infiltration of APL cells. A second remission was obtained by chemotherapy including ATRA. However, bilateral ear tumors developed again 5 months later despite indications of normal marrow without proliferation of leukemic blasts. Irradiation successfully reduced the ear tumors, but the patient died of cerebral hemorrhage from a left frontal extramedullary tumor. This was a rare case of APL accompanied by Fournier's gangrene of the scrotum during ATRA treatment, and by extramedullary tumors of the external ear and brain during leukemic relapse.

Adult↗
PubMed2004

Behçet's disease: external ear involvement.

Behçet's disease is an autoimmune vasculitis characterized by recurrent episodes of oral and genital ulcerations, skin lesions and uveitis. It also affects neurological, vascular, articular and gastrointestinal systems. Although etiology and pathogenesis are under investigation, studies have shown that HLA-B51 influences genetic susceptibility. The development of the disease is associated to neutrophil activation. Treatment depends on the severity of the disease and immunosuppressive drugs are often used. Blindness and dementia are long-term concerns. We report an unprecedented case of a child with Behçet's disease presenting a skin lesion with necrosis of the external ear canal, facial paresis, Horner's syndrome and rupture of the internal carotid artery.

Behcet Syndrome↗
PubMed1988

Delayed oto-acoustic emissions evoked by bone-conduction stimulation: experimental data on their origin, characteristics and transfer to the external ear in man.

1) BCEOE have been obtained in subjects with normal hearing by 1 kHz tone-bursts; 2) the morphology of BCEOE varies from one subject to another, and is stable over the course of time. BCEOE do not display a linear relation between their amplitude and the intensity of the stimulus, whose spectral composition is the same as theirs; 3) by contrast with ACEOE, whose mean threshold is the same as that of the subjective tonal threshold for the same stimulus presented by the same stimulation modality, BCEOE threshold, on overage, is about 10 dB HTL higher; 4) this difference in threshold is not due to interference on the part of the controlateral ear, via the efferent fibres, since it is also observed in persons with unilateral anacusis. It is probably the outcome of unilateral competitive inhibition between two stimuli presented to the same ear at the same time. By bone-conduction stimulation in fact, when the meatus is occluded by the probe, as in our experimental situations, Corti's organ is reached by a supplementary contingent of mechanical energy generated by the vibration of the bony part of the meatus and transmitted by air conduction; 5) ACEOE cannot be obtained in otosclerotic subjects whereas they appear after surgery. BCEOE are obtained before surgery and increase in amplitude post-operatively; 6) the findings mentioned in point 5) clearly demonstrate that the ossicular chain plays an important, but not an essential role in the transfer of EOE from the inner to the external ear.

Acoustic Stimulation↗
PubMed1993

[The phylogenic imprinting on the morphogenesis of the middle and external ear].

The AA. present a review of the embryologic development of both external and middle ear and its relationship with the phylogenesis. They consider the trascendence of this linkage in the shaping and in the physiology of the conductive apparatus of the sound and even admit the possibility of determine diseases like the cholesteatoma.

Ear, External↗
PubMed1988

Corynebacterium pseudotuberculosis infection in adult ewes by inoculation in the external ear.

Caseous lymphadenitis, caused by Corynebacterium pseudotuberculosis, was studied in ewes to devise a reliable method of induced infection that would help to understand mechanisms by which abscesses develop in lymph nodes or internal organs, especially the lungs. Fifteen adult ewes, from a flock where the occurrence of caseous lymphadenitis was unknown, were inoculated SC in the auricle with various doses of a virulent strain of C pseudotuberculosis. Ewes inoculated with at least 10(8) viable corynebacteria develop a strong local reaction that was apparent 4 hours after challenge exposure and lasted 7 to 14 days. Of these ewes, all developed at least 1 abscess and 3 developed multiple abscesses in lymph nodes draining the inoculated auricle and in the lungs. All infected ewes developed a strong antibody response against C pseudotuberculosis exotoxin, which persisted for 3 months. Of 9 ewes infected with 1.2 X 10(8) corynebacteria, 3 developed lesions because of field strains of C pseudotuberculosis and had an increased capacity to limit the dissemination of challenge-inoculum bacteria by developing only one abscess in the draining lymph node (parotid or prescapular lymph node). Seemingly, inoculation in the external ear was a suitable method for obtaining a reproducible infection and indicated that a primary infection might protect against reinfection by limiting dissemination of C pseudotuberculosis.

Abscess↗
PubMed1994

Hearing, vocalization and the external ear of a marsupial, the northern Quoll, Dasyurus hallucatus.

As part of a continuing study of the development of the marsupial auditory system, auditory brainstem responses (ABR) were recorded and an ABR audiogram was constructed for five female Northern Quolls (Dasyurus hallucatus), which are nocturnal carnivores. The best frequency for hearing lies between 8 and 10 kHz, and at 50 dB SPL there is a range from about 0.5 to 40 kHz. Vocalizations of adult quolls and pouch-young were recorded with a digital audio tape recorder, and the power spectra of representative calls were compared with the ABR audiogram. The common adult vocalizations have most energy at the lower end of the hearing range, whereas frequencies that are dominant in the isolation calls of the pouch-young lie close to the best frequency of hearing. Samples of nocturnal sounds of the habitat of the quoll were also recorded and analyzed. Power spectra have peak energy at frequencies between 2 and 5 kHz, with a smaller contribution above 10 kHz. The spectrum contains relatively little power at the best frequency of hearing. Measurements of the sound pressure level at the external ear canal as a function of stimulus frequency and location in space suggest that the directional amplifying properties of the pinna will operate most effectively on sound frequencies at the upper end of the quoll's hearing range, a region that may be important in prey detection. Comparisons are made with other mammalian nocturnal carnivores and with other marsupials. We speculate that, for nocturnal carnivores, one role of the low-frequency part of the hearing range concerns the recognition of adult conspecifics, the mid-frequency range is important for the detection of pouch-young, and the upper range may be particularly concerned with prey/predator detection.

Animals↗
PubMed2003

Changing surgical therapy for melanoma of the external ear.

BACKGROUND: The purpose of this study was to evaluate the prognostic variables and clinical ramifications of melanoma of the ear. METHODS: A retrospective chart review of patients treated since 1985 at the Mayo Clinic in Scottsdale, AZ, and Rochester, MN, identified 78 patients with complete follow-up. RESULTS: Of these 78 patients, 68 (87%) were men; the mean age was 64 years (range, 23-87 years). Melanoma thickness averaged 1.7 mm (range,.2-7.0 mm). Treatment of the primary melanoma included wedge resection (59%), Mohs resection (14%), partial amputation (11%), skin and subcutaneous resection with perichondrium preservation (9%), and total amputation (7%). Nineteen patients underwent an elective lymph node dissection, and lymph node metastases were found in seven (37%). Two patients presented with clinically positive lymph nodes. Sentinel lymph node biopsy was performed in 10 patients. After a mean follow-up of 55.7 months, 10 patients (13%) had local recurrence, 9 patients (12%) had regional recurrence, and systemic metastases had developed in 17 patients (22%). Tumor thickness, lymph node metastases, and local recurrence significantly affected systemic recurrence. CONCLUSIONS: The treatment of malignant melanoma of the external ear should follow current standard guidelines, which require wide local excision with negative margins. Sentinel lymph node biopsy can be used to identify patients with lymph node metastases who are at high risk of recurrence.

Adult↗
PubMedDate not supplied

[Benign necrotizing osteitis of the external ear canal. A report of a clinical case].

Benign necrotizing osteitis of the external ear canal is a process of unknown origin. This necrotic process with sequestration of the tympanic bone occurs in healthy, non-diabetic patients. It should be differentiated from malignant otitis externa and radionecrosis of the tympanic bone. A case is reported and the literature on this rare clinical entity is discussed.

Aged↗
PubMed1995

Incidence of bony outgrowths of the external ear canal in U.S. Navy divers.

Bony outgrowths of the temporal bone into the external ear canal are common in populations that participate in cold water activities. The incidence in professional divers is unknown. Eighty-seven U.S. Navy divers were interviewed and examined to determine the history of aquatic activity and degree of ear canal compromise. An age-matched control population of 42 non-divers without significant history of aquatic activities was also examined. The outgrowths, or exostoses, were found in 23 (26%) divers, and in no controls. Sixteen (70%) of the exostoses were minor, causing 10-20% narrowing of the auditory canal. The largest exostoses were found in divers with an extensive history of aquatic activities. The difference in total hours of aquatic activity was significant between divers and controls. The difference in total hours diving, as well as total time of all aquatic activities, was statistically significant between divers with exostoses and those divers without exostoses. The data confirm the relatively common incidence of this condition in a professional diving community.

Adult↗
PubMed1985

The petrified auricle: comments on ossification, calcification and exostoses of the external ear.

The petrified auricle is a clinical entity in which the auricle, in part or total, has become stone-hard and moves as a rigid unit. This uncommon condition is most often due to ectopic calcification of the auricular cartilage. It may occur as a result of local trauma, in association with various systemic diseases such as Addison's disease, hypopituitarism, thyroid or parathyroid disorders, or following radiation therapy. Auricular ossificans (ectopic ossification) is a rare phenomenon in which the rigidity of the petrified ear is due to replacement of the elastic cartilage by bone. In the literature there are presently nine cases documented histologically. Two more cases are reported here. In most cases, the auricular changes are preceded by acute, severe hypothermia (frostbite). Exostoses of the external auditory canal is another disease of the external ear in which the proliferation of bone follows chronic mild hypothermia of the external auditory canal caused by exposure to cold water while surfing. It is postulated that if surfers who have developed exostoses of the external auditory canal from the cold water continue to enjoy such littoral activities, ossification of the auricle may also occur.

Adult↗
PubMed1996

Maturation of the middle and external ears: acoustic power-based responses and reflectance tympanometry.

OBJECTIVE: The maturation of the external and middle ear in the human infant has significant effects on the interpretation of measured ear-canal responses to acoustic stimuli. A tutorial section is presented of power-based response functions, accompanied by a hierarchy of stimulus specifications contrasting pressure-based and power-based responses. An experimental section follows on reflectance tympanometry, the aims of which are to introduce and assess the feasibility of the technique and to discuss implications for tests of hearing development. DESIGN: A tympanometric measurement of admittance is used with an estimate of ear-canal area to calculate a so-called reflectance tympanogram as a function of frequency and static pressure in the ear canal. Selected results on 226 Hz reflectance tympanograms are reported for normal-hearing adults and for infants of age 3 to 6 mo with both normal and flat 226 Hz admittance tympanograms. A multifrequency reflectance tympanogram is reported for an adult. RESULTS: Measured at ambient ear-canal pressure, the acoustic external- and middle-ear responses of infants of age 1 to 6 mo are compared with those of adults. The admittance level is influenced by the ear-canal area, the interplay of compliant- and inertance-controlled effects in the middle ear, and the presence of losses. Ear-canal area is a major factor in distinguishing infant from adult responses. Energy reflectance provides a measure of middle-ear power transmission that is approximately independent of probe placement in the ear canal and that varies with maturation. These power-based responses, measured at ambient pressure, are contrasted with tympanometric measurements. Reflectance tympanometry is defined and easily measured in infants and adults. Some infants with flat 226 Hz tympanograms have energy reflectance in the normal range at higher frequencies (2 to 4 kHz). CONCLUSION: Acoustic measurements of power-based responses in the ear canal-reflectance, admittance, and impedance-provide insight into the maturation of the external and middle ear. Reflectance tympanometry tests the relative accuracy underlying the tympanometric measurement of compensated eardrum admittance and may have clinical utility.

Acoustic Impedance Tests↗
PubMed1985

An ultrastructural study of the skin of the tympanic membrane and external ear canal of the guinea pig.

The ultrastructure of the skin covering the tympanic membrane and external ear canal has been studied in eight guinea pigs, to identify any features which could be related to the rapid movement of the epidermal surface at this site. Migratory epidermis showed evidence of reduced intercellular adhesion in the deeper layers and reduced differentiation in all layers. Differentiation was more evident in cell ridges found at the junctional zone between migratory and non-migratory skin. The findings agree with those of previous authors, and indicate that migration is most likely to occur within the deeper layers of the epidermis.

Animals↗
PubMed1994

Mycoplasma auris sp. nov., Mycoplasma cottewii sp. nov., and Mycoplasma yeatsii sp. nov., new sterol-requiring mollicutes from the external ear canals of goats.

Three mycoplasma strains, designated GIHT (T = type strain), UIAT, and VIST, were isolated from the external ear canals of goats and were shown to be serologically distinct from each other and from previously described Acholeplasma, Entomoplasma, Mesoplasma, and Mycoplasma species. Using light and transmission electron microscopy, we showed that the cells of these organisms were small, pleomorphic, coccoid, nonmotile, and nonhelical and that each cell was surrounded by a single cytoplasmic membrane. There was no evidence of a cell wall, and the organisms grew freely in media containing penicillin at concentrations of 1,000 U/ml or more and thallous acetate (final concentration, 1:4,000) and produced the "fried-egg" morphology typical of most mollicutes. Growth occurred both aerobically and anaerobically (as determined by the GasPak method). The ability to catabolize glucose and mannose and the ability to hydrolyze arginine varied among the three strains. All three strains required sterol for growth, and none of the strains hydrolyzed urea. The guanine-plus-cytosine contents of the DNAs of strains UIAT, VIST, and GIHT were determined to be 26.9, 27.0, and 26.6 mol%, respectively. Our data indicate that the three strains represent new Mycoplasma species, for which we propose the names Mycoplasma auris, Mycoplasma cottewii, and Mycoplasma yeatsii. The type strain of M. auris is UIA (= ATCC 51348 = NCTC 11731), the type strain of M. cottewii is VIS (= ATCC 51347 = NCTC 11732), and the type strain of M. yeatsii is GIH (= ATCC 51346 = NCTC 11730).

Animals↗
PubMed2000

An animal model for external ear canal inflammation.

OBJECTIVE: To develop an animal model for testing efficacy of anti-inflammatory drugs designed to treat external ear canal (EAC) disease. METHODS: Histological and morphometric methods were used to characterize EAC inflammation produced by topical application of tetradecanoylphorbol acetate (TPA) in mice. The effects of both single and repeated TPA applications were studied. A treatment trial was performed to evaluate the effects of a ciprofloxacin/hydrocortisone suspension on TPA-induced EAC inflammation. In 10 animals, two bilateral applications of TPA were made, spaced 24 hours apart. Immediately after the second TPA application, otic suspension was applied unilaterally four times over a 48-hour period. The contralateral EACs were left untreated to provide TPA-only controls. RESULTS: Twenty-four hours after a single TPA application, EAC skin showed polymorphonuclear (PMN) leukocyte infiltration, vascular dilation, and thickening of the dermis and epidermis. Dermal and epidermal thickening were more pronounced after two TPA applications and PMN leukocyte infiltration remained high 48 hours after a second TPA placement. After treatment with the otic suspension, PMN leukocyte counts were reduced by an average of 76% relative to EACs that received TPA only. There was also statistically significant reduction of dermal swelling and a trend toward reduced epidermal thickness. Vascular dilation was clearly reduced as well EACs that received four applications of the suspension alone showed no adverse effects compared with those that received saline. CONCLUSION: TPA-induced inflammation of the mouse EAC provides a suitable model for testing the therapeutic efficacy of anti-inflammatory agents being considered for clinical use.

Administration, Topical↗
PubMed1990

[Fungal flora of the external ear canal--influence of cancer progressing].

In order to observe the influence of host immunity on fungal flora of the external ear canals, a group of 22 patients (44 ears) with stage IV head and neck cancer was investigated. The opportunistic fungi, Candida and Aspergillus, were found to have increased statistically (21.2%----43.1%, P less than 0.025). In addition, C. albicans (11.3%), not existing in the normal ear canal, was found with a tendency of increase. Although a recent report revealed that radiation and chemotherapy appear to be directly or indirectly related to fungal flora, the relevancy of host immune defect seems to be more evident in this study.

Adult↗
PubMed2006

Gerbilline cholesteatoma development Part III. Increased proliferation index of basal keratinocytes of the tympanic membrane and external ear canal.

OBJECTIVE: To quantify the rate of basal cell division for keratinizing epithelium (KE) of the tympanic membrane (TM) and external ear canal (EAC) in spontaneous and induced gerbilline cholesteatomas. STUDY DESIGN AND SETTING: Cholesteatomas (3 spontaneous and 5 by induction) were labeled with tritiated thymidine for autoradiography and a KE proliferation index (PI) was determined. The PI was defined as the average number of labeled cells/mm overall and per anatomic region. RESULTS: For all regions combined, the PI was 27.3 in ears with cholesteatoma and 4.1 in normal ears (P < 0.0001). Additionally, there were significant regional differences in the PI in both normal ears and ears with cholesteatoma. CONCLUSION: The KE of cholesteatomas in gerbils proliferates at approximately 7 times the rate measured in control ears. SIGNIFICANCE: Hyperproliferation of keratinocytes is a causative factor in the development and progression of spontaneous and experimental cholesteatomas in gerbils.

Animals↗