摘要:

AbstractA systematic treatment approach for nasopharyngeal angiofibromas is presented. Surgery, as the primary treatment modality is advocated. Routine pre‐operative angiography is utilized for diagnosis and delineation of tumor extent. The surgical approach or approaches is dependent upon the tumor exten

ISSN:0023-852X    

DOI:10.1288/00005537-197405000-00001

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

摘要:

AbstractAcquired Nasopharyngeal Stenosis is a rare lesion. In the pre‐antibiotic era it was most commonly caused by infections, chiefly syphilis. Since improved control of infectious diseases has been obtained, the most common cause is nasopharyngeal surgery, primarily T and A. The symptoms are those of complete postnasal obstruction. Its treatment is surgical, utilizing various techniques, depending upon the precise nature of the lesion. The use of regional mucosal flaps is one of the most satisfactory methods of repai

ISSN:0023-852X    

DOI:10.1288/00005537-197405000-00002

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

摘要:

AbstractContinuous and impulse noises, considered “safe” by existing damage risk criteria were combined to model more realistic noise environments. Monaural chinchilla were exposed to one of the following conditions:a.50 impulses with a 40 m̈, sec A‐duration at 158 db SPL peak pressure, 1/ minute;b.95 db SPL continuous noise at 2–4 kHz for one hour; andc.superimposed combination of the continuous and impulse noise. Quiet thresholds were measured before and after exposure using the auditory evoked response, and histology was obtained, using the surface preparation technique. The audiometric and histological findings agree in showing that the superimposed combination of two “safe” noises produces traumatic effects that more than exceed the additive effects of either component. The existing damage risk criteria do not provide guidelines for such noise

ISSN:0023-852X    

DOI:10.1288/00005537-197405000-00003

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

摘要:

AbstractFluids from various inner ear compartments were taken from 77 ears of 70 normal, healthy cats and were analyzed for glucose concentration by the microchemical technique employing the hexokinase method. Perilymph of the scala vestibuli, perilymph of the scala tympani and C.S.F. had almost identical concentrations of glucose with the values approximately 80 mg/100 ml. Glucose concentrations of each fluid showed the significant relationship with serum glucose level except that of utricular and cochlear endolymph. Utricular endolymph glucose level was found to be lower (41.9 mg/100 ml) than the above three fluids and higher than cochlear endolymph (11.2 mg/100 ml). The significant difference of glucose concentration found between cochlear and utricular endolymph in the present study is further support for the independent nature of each endolymphatic compartment.Sodium, potassium and glucose were analyzed in serum, C.S.F. and inner ear fluids up to five hours after intravenous regular insulin (30 units/kg). Sodium, potassium and glucose concentrations were unchanged in both cochlear and utricular endolymph during hypoglycemia. In contrast glucose concentrations in C.S.F., scala tympani perilymph, and scala vestibuli perilymph began to decrease at 90 minutes after regular insulin infusion and fell to their lowest levels in the period during 180 to 300 minutes after the infusion. A significant decrease of potassium concentration was found first in serum and later in the C.S.F., scala vestibuli, and scala tympani perilymph. For five hours after insulin infusion there is no significant change in cochlear microphonics during hypoglycemia (20 mg percent).

ISSN:0023-852X    

DOI:10.1288/00005537-197405000-00004

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

摘要:

AbstractTwelfth gestation day kreisler otocysts were explanted into an organ culture system and allowed to develop for nine days. The homozygotic (kr/kr) kreisler otocysts showed significant developmental differences when compared to the development that occurred in the organ culture specimens of the otocysts of its heterozygotic (+ /kr) litter mates. The differences in development observedin vitrowere the same major developmental differences that had been observedin vivo.The phenotypic expression of the kreisler genome has expressed itselfin vitroin the homozygotic kreisler otocyst.

ISSN:0023-852X    

DOI:10.1288/00005537-197405000-00005

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

摘要:

AbstractRecent investigations have shown that nonsusceptible strains of mice can be made susceptible to audiogenic seizures by exposing them to intense sound during a “sensitive period.” The parameters of seizures behavior that accompany this priming procedure have been studied extensively and more recently the physiological processes that are associated with this phenomenon have received attention. The results indicate that priming causes a severe loss in cochlear microphonic sensitivity and extensive damage to basal turn hair cells. The patterns of evoked response activity in peripheral auditory nuclei show a loss in threshold sensitivity at low stimulus levels and over recruitment of response amplitude at high stimulus levels. Although there is a severe loss of cochlear function in these animals, intense stimuli paradoxically evoke exceptionally large re‐responses and precipitate seizure behavior. Several hypotheses concerning this paradox are offered, and the potential significance of the priming phenomenon is consi

ISSN:0023-852X    

DOI:10.1288/00005537-197405000-00006

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

摘要:

AbstractLaboratory investigations on the squirrel monkey demonstrated that cryosurgery of the labyrinth was able to attenuate consistently the sensitivity of the vestibular end organ to caloric stimulation. The post surgical rate of decline in semicircular canal function was found to be directly related to the temperature and exposure time employed. For a given exposure time, decreasing cryosurgical temperatures provided loss of function in fewer days. When temperature was held constant, increases in duration of cryosurgical application produced a more rapid decline in semicircular canal function.Examination of the temporal bone of these animals showed that morphological alterations were restricted to the place of contact of the cryosurgical probe on the horizontal semicircular canal. These changes appeared in the form of fibrosis and bony obliteration in the perilymphatic space. Although this blockage could conceivably inhibit the movement of endolymph within the horizontal canal, the posterior and superior canals should remain functional. The absence of nystagmus in response to either caloric or rotational stimuli suggested that cryosurgery did more than just produce an obstruction of the horizontal canal.A series of experiments were then performed on the vestibular end organ of the pigeon, in an attempt to study further the effects of cryosurgery of the labyrinth.In order to eliminate the tissue reaction observed in the monkey, the site of cryosurgical application was moved from the thinned horizontal canal to the bony crista ampullaris, and the cryoprobe temperature adjusted to produce the same intralabyrinthine temperature that had eliminated semicircular canal function in the earlier studies.Using this new technique, a normal rotatory reaction was observed after the horizontal crista was cooled to ‐30d̀ and ‐40d̀ C for nine minutes. The animals exposed to ‐70d̀ and ‐90d̀ C for nine minutes demonstrated marked reduction in rotatory reaction three weeks after the cryosurgery. Rotatory responses were abolished in those animals which were exposed to ‐120d̀ and ‐190d̀ C for nine minutes.Pigeons exposed to ‐30d̀ and ‐40d̀ C for nine minutes failed to show any structural changes in the horizontal crista, and surrounding area.Pigeons exposed to ‐70d̀ C showed the presence of exudate in the endolymphatic space and shrinkage of cupula.Cooling the horizontal crista to ‐90d̀ C produced partial degeneration of the specialized cells and the sensori‐epithelia. The membranous wall of the horizontal canal was ruptured (one of four animals) and the cupula detached.Pigeons exposed to ‐120d̀ and ‐190d̀ C demonstrated severe degeneration of the sensori‐neural and specialized cells. Ruptures of the membranous wall were present in every specimen. The cupula was not present and exudate was commonly found in the endolymphatic space.A definite correlation seems to exist between histologic and functional changes of the semicircular canals following cryosurgery. It appears that the critical threshold dosage necessary to alter the morphology and function of the semicircular canal system is approximately ‐70d̀ C for nine minutes (intralabyrinthine temperature +18d̀ C) in the experimental animal. Temperature measurements were performed on two patients with Ménière's disease prior to performing a total labyrinthectomy. The cryosurgical probe was positioned on the thinned bony wall of the horizontal canal at a temperature of ‐160d̀ C. The temperature of the horizontal crista ampullaris in both patients ranged from +17d̀ to +20d̀ C. These intralabyrinthine temperature measurements correlate well with the experimental data.The clinical use of labyrinthine cryosurgery began in May of 1965. The surgical technique has been described in previously published reports. Using a temperature of ‐160d̀ C, a cryogenic application is made to the thin bony wall of the horizontal semicircular canal for a total of six minutes (three applications of two minutes each).Since cryosurgery has a dual objective of relieving vertigo and preserving hearing, a case is considered successful only if both objectives have been accomplished. There are 134 cases in which an adequate follow‐up has been maintained for one year or more. The results indicate that 100 operations (75 percent) were successful, and seven patients (5 percent) were considered as being improved. Twenty‐seven procedures (20 percent) were considered surgical failures, due to inadequate relief of the vertigo attacks.Since experimental animals were rendered unresponsive to caloric stimulation following cryosurgery, it seemed reasonable to assume that the successful clinical cases could be attributed to an attenuation of the sensitivity of the semicircular canal system. Although this change did occur in the majority of the operated cases, 36 percent of the successful cases demonstrated little or no change in the postoperative caloric tests. A change in the sensitivity of the semicircular canal system, therefore, could not completely explain the mechanism by which cryosurgery produces its effect. Based upon the more recent experimental observations, it is entirely possible that changes in the dark and light cells, or the creation of an otic‐periotic shunt secondary to rupture of the membranous labyrinth may explain a successful clinical result when little

ISSN:0023-852X    

DOI:10.1288/00005537-197405000-00007

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

摘要:

AbstractHistological examination of 910 temporal bones from 582 individuals reveals 92 specimens with clinical otosclerosis (stapes fixation) and 32 with histological otosclerosis (without stapes fixation). The incidence of histological otosclerosis in ears from white individuals over the age of five (734 ears) was 4.4 percent. The otosclerotic focus involved the endosteum of the cochlear wall (cochlear otosclerosis) in three of the latter group for an incidence of 0.3 percent.The atrophic changes in one of the ears with cochlear otosclerosis cannot be attributed to the otosclerosis, for the same changes are present in the other ear which does not have an otosclerotic focus; neither can the mild hearing loss in the other two ears showing cochlear otosclerosis be attributed to the otosclerosis, for the atrophic changes are identical to those observed in aging individuals without otosclerosis.In conclusion, this study shows that sensori‐neural hearing loss occurring in pure form without a conductive loss cannot be attributed to otosclerosis, for when the otosclerotic lesion is sufficiently severe to cause atrophy of the supporting, sensory, and neural structures within the cochlea, it invariably also fixes the stape

ISSN:0023-852X    

DOI:10.1288/00005537-197405000-00008

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

摘要:

AbstractThe objectives of tympanomastoid surgery are elimination of irreversible middle ear and mastoid disease, usually cholesteatoma, and maintenance or restoration of serviceable unaided hearing. There are a surprising number of techniques described in the literature but in essence they break down into two schools of thought, those who favor an intact posterior canal wall technique in most cases and those who feel that the possibly improved hearing results obtained with an intact posterior canal wall technique do not warrant the additional risks involved. Sheehy recently has reported an incidence of 35 percent persistence or regrowth of cholesteatoma found in mastoid re‐explorations following the intact posterior canal wall technique for management of epitympanic and mastoid cholesteatoma.We believe there are excellent reasons for removing the posterior canal wall routinely in dealing with mastoid cholesteatoma. This technique is far superior in obtaining permanent control of the disease process, usually results in a small trouble‐free mastoid cavity, and does not seriously interfere with reconstruction of a serviceable sound conducting mechanism in the majority of cases.In analyzing the results of 100 consecutive mastoid operations for the period from 1970 through 1972, it was possible to maintain or reconstruct the sound conducting mechanism in 94 percent. In those cases which had preoperative bone conduction of 35 db ISO or better for the speech frequencies, the type and percentage hearing results obtained are presented. Endaural modified radical mastoidectomy combined with tympanoplastic repair at the time of definitive surgery permits maximum visualization of the middle ear space. Because most mastoids which harbor cholesteatoma are sclerotic, small trouble‐free mastoid cavities result from this type of surgery and the open mastoid technique offers the best prospects to the patient for obtaining a dry safe ear without danger of persistent or recurrent cholesteatoma in the mastoid segment. It does not seriously preclude tympanoplastic reconstruction of a functioning sound conduction mechanism. When feasible, tympanoplastic repair should be done at the same time definitive mastoid surgery is done. This can usually be accomplished in one brief hospitalization and a minimum of postoperative visits to the physician's o

ISSN:0023-852X    

DOI:10.1288/00005537-197405000-00009

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

摘要:

AbstractTwo main purposes in the present study were:1.to determine the feasibility of using the tissue adhesive isobutyl 2‐cyanoacrylate in reconstructive middle ear surgery; and2.to learn whether a potent topical corticosteroid (0.1 percent dexamethasone) would have beneficial anti‐inflammatory effects when placed in the tympanic cavity at the time of middle ear surgery.Tympanoplastic surgery was performed on 26 cat ears and six squirrel monkey ears; the animals were followed for six weeks to nine months postoperatively.The conclusions to be drawn from this experimental study are that presently the tissue adhesive isobutyl cyanoacrylate appears too toxic for use on the delicate middle ear structures; likewise, corticosteroids placed in the middle ear do not appear to have any beneficial effects in tympanoplasty surg

ISSN:0023-852X    

DOI:10.1288/00005537-197405000-00010

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY