摘要:

AbstractThe use of hydroxylapatite for ossicular chain reconstruction is increasing. In this study, hearing results and extrusion rate for 157 consecutive patients receiving hydroxylapatite prostheses were evaluated. Results were compared to those of a control group of patients who had received either homograft hone or Plasti‐Pore prostheses.Four (2.6%) cases of extrusion have occurred. Hearing success was defined as a postoperative pure‐tone average air‐bone gap of ≤ 15 dB for incus prostheses and partial ossicular replacement prostheses (PORPs) or ≤ 25 dB for incus‐stapes prostheses and total ossicular reconstruction prostheses (TORPs). Overall success rate in the hydroxylapatite group was 51.4% for the 140 patients with postoperative data (mean follow‐up, 11.5 months) and 46.7% for 90 patients who were followed for more than 6 months (mean follow‐up, 16 months). PORP results were significantly poorer than those of the other prostheses. The success rate for the control group was 58.6% for 58 patients. The difference between hydroxylapatite and control group success rates appears to be due to the poorer results of the hydro

ISSN:0023-852X    

DOI:10.1288/00005537-199210000-00001

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractSilastic® sheeting is used to restore a mucosally lined middle ear space and to prevent mucosal adhesions between the medial surface of the tympanic membrane and the promontory after surgical procedures involving the removal of middle ear mucosa. To determine the long‐term (1.2 to 21.2 years) effects of Silastic sheeting in the middle ear, six temporal bones from patients with permanent Silastic sheeting in the middle ear cavity after single‐stage tympanoplasty were examined. In all six bones, no histologic evidence of foreign body reaction, rejection, or chronic inflammation in the middle ear surrounding the silicone sheeting was observed. Furthermore, the middle ear space was lined by normal‐appearing, continuous middle ear mucosa. In four temporal bones, there was no evidence of significant submucosal fibrosis. In two bones, significant submucosal fibrosis was attributable to concurrent middle ear disease rather than to the presence of the silicone. It is concluded that Silastic sheeting in the middle ear after single‐stage procedures may prevent adhesions between mucosal surfaces. Given eustachian tube function, Silastic promotes a mucosally lined, aerated middle ear cavity without apparent foreign body reaction, rejection, or chronic inflammatory

ISSN:0023-852X    

DOI:10.1288/00005537-199210000-00002

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractOtorrhea is the most common posttympanostomy complication. This study is designed to determine the efficacy of canal preparation prior to tympanostomy tube placement.One hundred thirty ears were prospectively randomized into prepared (Betadine and alcohol) and nonprepared (control) groups. Cultures obtained before, during, and after preparation were analyzed to determine the external canal flora and effectiveness of sterilization. Prepared ears and nonprepared control ears were examined for relation to otorrhea.Forty percent of the canals were sterile before preparation, and only 8% harbored suspected pathogenic organisms. Canal preparation successfully sterilized only 33% of the ears that contained bacteria. There was no difference in the otorrhea incidence among treatment groups (9.8%). Based on these bacteriologic and clinical findings, it is concluded that canal preparation with Betadine and alcohol does not reduce posttympanostomy otorrhea.

ISSN:0023-852X    

DOI:10.1288/00005537-199210000-00003

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe auditory brainstem response (ABR), as well as associated audiologic and radiographic studies of 175 patients suspected of having cerebellopontine angle tumors were reviewed. The majority of patients presented with asymmetric hearing loss. Eight acoustic neuromas were identified. All eight had abnormal ABRs. The false‐positive rate was 22%. Rollover and acoustic reflex testing played a minimal role in the decision as to whether or not an ABR was ordered and, as a result, are not important in the search for retrocochlear disease. The cost per tumor diagnosed was roughly $7600. A rational approach to tumor screening based on the efficiency and cost of the screening tests, the frequency of abnormal ABRs, and the cost per tumor diagnosed is presente

ISSN:0023-852X    

DOI:10.1288/00005537-199210000-00004

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractTaking advantage of the extended dynamic range of digital analysis of voice the H‐Index represents the first proposed acoustical measure of glottal efficiency. “Hi”/hai/was chosen to evaluate glottal efficiency since it provides an excellent test of glottal transformation from voiceless to voiced sound energy, the upper vocal tract having a neutral effect. Fifteen individuals with normal voices and 30 patients with hoarse voices were asked to say “hi.” The power ratio of/h/to/a/was calculated from peak power of each measure from the power envelope. Voice quality had a highly significant effect on measured values (P<.001). A high degree of correlation (P<.001) was found with the AC/DC ratio, a standard aerodynamic measure of glottal efficiency. The results indicate that the H‐Index represents an excellent measure of glottal efficiency, obviating the need of invasive techniques or expensive, highly specialize

ISSN:0023-852X    

DOI:10.1288/00005537-199210000-00005

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractTime series analysis of glottal airflow was carried out on 26 normal controls and 40 patients with voice disorders, using a modification of Isshiki's original technique which uses a hot‐wire flowmeter, taking cycle‐by‐cycle fluctuations into consideration. The mean flow rate and mean AC/DC were shown to have significant differences among normal and patient groups. The standard deviations of AC/DC and AC/DC perturbation were calculated from the AC/DC value of 50 cycles and shown not to vary significantly among the normal and patient groups. The relationship between AC/DC and perceptual impression of voice was also studied among 20 selected patients with breathy voices. Using Spearman's rank correlation coefficient, this relationship was found to have statistical significance (P

ISSN:0023-852X    

DOI:10.1288/00005537-199210000-00006

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractHemangiomas are a group of pediatric tumors that present at or soon after birth. Rapid proliferation is seen in the neonatal period, and may continue for the first year of life. Involution follows, and may last as long as 12 years. Since hemangiomas invariably involute, the vast majority have been left untreated. At least 10% to 20% of cases, however, will need active intervention, traditionally in the form of oral Prednisone. The frequent occurrence of life‐threatening complications, permanent deformities, and irreversible psychosocial damage in spite of adequate steroid therapy necessitated a fresh look at the management of these lesions. Using recently developed laser technology alone or in combination with surgical excision, the authors have developed guidelines for safe intervention in all stages of the hemangioma cycle. Safe, active intervention in accordance with these guidelines offers an alternative to the more conservative approach previously advocate

ISSN:0023-852X    

DOI:10.1288/00005537-199210000-00007

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractIn large part, malignancy is the end result of aberrant cell growth and differentiation. Control of these processes is anticipated to result in a suppression of oncogenicity. Retinoic acid (RA), a derivative of vitamin A, has been shown to inhibit proliferation, induce cell differentiation and reverse the malignant phenotype of a variety of tumor cell types. In order to further characterize the antitumor potential of RA, this study examined the in vitro and in vivo effects of this retinoid on cell lines derived from human neuroblastoma (NB).The in vitro phase of this study tested the ability of various compounds to raise intracellular cyclic adenosine 3′:5′‐monophosphate (cAMP) levels and either alone or in combination with RA, to promote differentiation of two relatively RA‐resistant cell lines. Direct activation of the synthetic enzyme adenylate cyclase by forskolin or cholera toxin increased intracellular cAMP levels over 10‐fold after 1 hour of treatment, declining over the next 16 to 24 hours. After 5 days of continuous growth in the presence of these agents, cAMP levels remained elevated 2‐ to 7‐fold above control values and were accompanied by a decrease in cell proliferation and an increase in cell differentiation. All these effects were exaggerated in the presence of phosphodiesterase inhibitors. Isoproterenol and epinephrine did not alter cAMP levels and had no discernible biological effects. RA promoted differentiation with little effect on cAMP levels. Combination treatment of cells with RA plus agents that raised cAMP levels resulted in greater degrees of differentiation than seen with single‐agent treatment. From these data, it was concluded that:1.the cAMP synthetic and degradative pathways are functional in the NB cell lines studied;2.elevation of cAMP is a sufficient but not necessary condition for inhibiting proliferation and promoting differentiation in these cells;3.elevation of intracellular cAMP potentiates the differentiation‐inducing activity of RA; and4.overcoming retinoid resistance in some tumor cell lines may be feasible by alterations in the cAMP system. This would be of particular value in treating tumors that have lost retinoid responsiveness.The in vivo phase of this study examined the effects of single‐agent treatment using RA on the development and growth in nude mice of tumors derived from a NB cell line. When cells were treated in culture with 4 × 10−6M retinoic acid and subsequently injected into nude mice, there was a marked reduction in the number of mice developing tumors when compared to solvent‐treated controls. Intragastric administration of RA reduced tumor formation when the retinoid was given for 5 days before tumor injection and continued for 14 days thereafter. In established tumors, RA treatment for 32 days inhibited progressive tumor growth. With the RA regimens used, there was no discernible effect on final morphologic phenotype. These data suggest that oral retinoid treatment may be of value in inhibiting or arresting NB growth, particularly in the face of an initial small tumor burden.In vitro and in vivo studies such as reported here may serve as useful models for understanding the potential use of retinoids in the prevention and treatm

ISSN:0023-852X    

DOI:10.1288/00005537-199210000-00008

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe purpose of this study was to compare apnea and snoring in patients with different patterns of nasal resistance: normal, high unilateral, and high bilateral. The authors examined 683 unselected patients referred for evaluation of snoring and possible sleep apnea. All patients had determination of nasal resistance (performed during wakefulness in the seated posture) and nocturnal polysomnography including quantitative measurement of snoring. Analysis of variance showed no significant difference in apnea and snoring indices among the three nasal resistance groups (normal, high unilateral, and high bilateral). Furthermore, there was no significant difference in the frequency of patients with different severity of apnea and snoring among the three groups. It is concluded that1.unilateral and bilateral elevation of nasal resistance may lead to equally severe snoring or apnea;2.there is no direct relationship between awake seated nasal resistance measurement and sleep disordered breathing; and3.measurements of supine nasal resistance during sleep may be required to elucidate the relationship between sleep‐disordered breathing and nasal obstructio

ISSN:0023-852X    

DOI:10.1288/00005537-199210000-00009

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe surgical results in 78 recent cases of total removal of unilateral acoustic neuroma in which an attempt was made to preserve cochlear function have been added to the authors' previous series of 66 cases to evaluate the factors influencing the ability to preserve useful hearing. Useful hearing was defined by speech reception threshold no poorer than 70 dB and a discrimination score of at least 15%. Analysis using a logistic regression model showed that certain preoperative clinical parameters such as tumor size, speech discrimination score, and gender were significantly correlated with hearing outcome. Favorable outcome was significantly correlated with smaller tumor size, higher preoperative speech discrimination score, and male sex. From this data, an explicit formula was devised for predicting hearing outcome for an individual patient. In four cases with useful hearing preserved, there was improvement of greater than 15 percentage points in speech discrimination scores.While preoperative auditory brainstem responses were not predictive of hearing preservation, monitoring of intraoperative auditory evoked potentials was predictive of hearing outcome in selected cases. Specifically, when wave V was unchanged at the end of the operation, even if it may have been transiently lost during surgery, useful hearing was invariably preserved.

ISSN:0023-852X    

DOI:10.1288/00005537-199210000-00010

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY