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Biomedical subjects

G A Gates

Publications and source records attributed to G A Gates.

At least 19 recordsLinked to original sources
PubMed1992

Adjuvant hyperbaric oxygen in malignant external otitis.

Necrotizing invasive pseudomonal infection of the external auditory canal (malignant external otitis) is an uncommon but important disorder in the elderly. The high morbidity, and even mortality, of this disorder has been reduced by the early and intensive use of combination antipseudomonal antibiotics. However, in severely immunocompromised patients or in infection involving the base of the skull, multiple cranial nerves, or the meninges, conventional therapy has been prolonged, intensive, and relatively ineffective. We treated 16 patients with malignant external otitis with adjuvant hyperbaric oxygen therapy. In six patients, infection was in advanced stages, infections were recurrences after previous treatment, and repeated treatment with antipseudomonal antibiotics had failed. All 16 cases responded promptly when a 30-day course of hyperbaric oxygen was added to the antibiotic regimen, and all patients remained free of infection or neurologic deficit during 1 to 4 years of follow-up. No complications of this treatment modality were noted. Hyperbaric oxygen therapy reverses tissue hypoxia, which enhances phagocytic killing of aerobic microorganisms, and stimulates neomicroangiogenesis. In addition, hyperbaric oxygen augments the action of aminoglycoside antibiotics. Adjuvant hyperbaric oxygen therapy should be considered in advanced or recurrent cases of malignant external otitis.

Aged↗
PubMed1992

Central auditory processing disorders in the elderly: the effects of pure tone average and maximum word recognition.

We previously examined central auditory processing disorders and the effect of age in 1026 64- to 93-yr-olds. Here, we correlated three indices of central auditory processing disorders with age, pure tone averages (PTA) and maximum word recognition scores. With one exception, correlations of indices with PTA equaled or exceeded those with age. With one exception, correlations with word recognition scores were insignificant or smaller than those with age. Although statistically significant, the magnitudes of most effects were small (0.003 less than r2 less than 0.146). However, PTA accounted for approximately 30% of the variability in corrected Staggered Spondaic Word test error scores.

Age Factors↗
PubMed1992

Meta-analysis of second malignant tumors in head and neck cancer: the case for an endoscopic screening protocol.

A meta-analysis was performed on data from the Washington University Department of Otolaryngology Head and Neck Tumor Registry and 24 studies reporting synchronous and metachronous malignancies in head and neck cancer patients. The overall second malignant tumor (second primary) prevalence was 14.2% in 40,287 patients, the majority of tumors being metachronous. Site relationships between index tumors and second primaries revealed significantly high risks along the digestive tract axis or the respiratory tract axis, although lung second primaries were prevalent in all groups. Head and neck second primaries were the largest group, being significantly more common in the oral cavity, oropharynx, and hypopharynx than in the larynx. Oral cavity index tumors showed the highest overall rate of second primary formation. Half of all aerodigestive tract second primaries are detected by 2 years from index tumor presentation, but non-aerodigestive tract tumors are common beyond 5 years. A significantly higher detection rate was proven for the prospective panendoscopy studies. We recommend routine interval endoscopic intervention within 2 years of treatment for optimum detection of second primaries in head and neck cancer patients. Also, a lifetime of clinical surveillance is suggested for aerodigestive tract second neoplasms in oral cavity, oropharynx, and hypopharynx cancer patients and for lung and non-aerodigestive tract neoplasms in larynx cancer patients.

Humans↗
PubMed1992

Effect of blood transfusion on recurrence of head and neck carcinoma. Retrospective review and meta-analysis.

To study the effect of transfusion on recurrence of squamous cell carcinoma of the head and neck, we analyzed the records of 143 patients with stage II through IV squamous cell carcinoma of the supraglottic larynx or hypopharynx for whom follow-up to recurrence or 5 years after surgical therapy was available. Variables studied were age, gender, TNM staging, duration of operation, estimated blood loss, units of blood products transfused, surgical margins, number of pathologic nodes, radiotherapy, chemotherapy, hematocrit, and serum albumin. Multivariate logistic regression demonstrated that transfusion, number of pathologic nodes, and preoperative hematocrit were significantly related to recurrence. The univariate odds ratio for tumor recurrence in patients receiving any blood products was 3.2 (95% confidence interval 1.5 to 6.9; p = .004). Based on a meta-analysis of the data from this study and the five published studies, the combined odds ratio for recurrence after transfusion was 2.6 (95% confidence interval 1.9 to 3.7; p less than .0001). These data identify a clinically important adverse effect of transfusion of blood products on tumor recurrence in patients with advanced head and neck cancer. We recommend a policy of blood conservation surgery to enhance cancer control, and we encourage further research to clarify the mechanism(s) of this effect.

Adult↗
PubMed1992

Adenoidectomy and otitis media.

Adenoid enlargement has traditionally been considered a factor in otitis media; adenoid size, however, does not appear to be correlated with otitis media occurrence. Presence of pathogenic bacteria in the adenoids of children with otitis media has been shown, and adenoidectomy appears to affect the middle ear primarily by removal of the source of infection in the nasopharynx. Three recent randomized, controlled studies showed the efficacy of adenoidectomy in the treatment of chronic secretory otitis media. In one study comparing no treatment, adenoidectomy, and adenotonsillectomy, a significant benefit was seen with adenoidectomy that was not enhanced by tonsillectomy. Another study that compared adenoidectomy, tympanostomy tubes, and a combination of the two showed a significant reduction in effusion time and less surgical retreatment over 2 years in the two adenoidectomy groups. The third study demonstrated the effect of adenoidectomy in children with recurrent chronic otitis media with effusion after failure of tympanostomy tube insertion. All three studies showed that the effect of adenoidectomy was independent of adenoid size. This review discusses current concepts of adenoid physiology and pathology, the major adenoidectomy studies, and indications for the procedure.

Adenoidectomy↗
PubMed1992

Flutamide-induced regression of angiofibroma.

Juvenile nasopharyngeal angiofibroma (JNA) appears to be an endocrine-responsive tumor. This concept was tested in five young men with JNA by treating them with a testosterone receptor blocker (flutamide) for 6 weeks preoperatively. Tumor size was evaluated by axial computed tomography both before and after flutamide therapy. Four of the five patients had an average tumor shrinkage of 44%. The patients tolerated the drug well, and the serum testosterone levels 2 or more years posttherapy were normal. This pilot study demonstrate that preoperative hormonal pharmacoreduction of JNA is a feasible adjunct to surgical therapy that offers the possibility of reduced blood loss. However, the authors believe that a formal clinical trial of this treatment approach is warranted and should be done before widespread adoption of this agent.

Adolescent↗
PubMed1992

Neural presbycusis: a diagnostic dilemma.

The combined term, sensorineural, is useful because clinical distinction between sensory and neural lesions is often difficult, and because sensory lesions may lead to secondary neural degeneration or, though rarely, a neural lesion may lead to secondary sensory degeneration. The threat of lawsuits for failure to identify treatable neurologic conditions has led to overuse of tests, while fiscal constraints exert pressure to limit expensive diagnostic testing. The purpose of this review of the relation between sensory and neural hearing loss is to provide a practical method to screen for neural lesions using pure-tone thresholds and a single speech discrimination score. The difference between the articulation index and the word recognition score of a patient provides a statistically reliable index of suspicion that may reduce the diagnostic dilemma of neural presbycusis.

Aged↗
PubMed1991

Hearing in the elderly--the Framingham cohort, 1983-1985: Part II. Prevalence of central auditory processing disorders.

The relation between central auditory processing disorders (CAPD) and age has been described in selected subjects. However, the prevalence of CAPD in the general population has not been established. We tested 1026, 64- to 93-yr-old members of the Framingham Heart Study cohort with Central Institute for the Deaf W-22 lists (CID W-22) in quiet, the Synthetic Sentence Identification test with ipsilateral competing message (SSI-ICM), and the Staggered Spondaic Word test. The presence or absence of CAPD could be established with at least one of three indices in 1018 subjects. The CID W-22 performance-intensity function rollover index was greater than 0.20 in 1.4% of 1009 subjects. The difference between maximum CID W-22 and SSI-ICM (0 dB message-to-competition ratio) scores was greater than 20% in 18.2% of 816 subjects. The Staggered Spondaic Word category was moderately, severely, over-corrected moderately, or over-corrected severely abnormal in 10.7% of 941 subjects (using 12-59-yr-olds' norms and adjusting scores when appropriate). Abnormal results on any one index occurred in 22.6% of the subjects. Thus, we conclude that the prevalence of CAPD in the elderly is less common than previous studies would suggest. Furthermore, although the rate of CAPD increased with age, age accounted for no more than 15% of the variability of any of the three indices. Therefore, its presence is dominated by factors other than chronological age.

Age Factors↗
PubMed1991

Incidence of hearing decline in the elderly.

Pure-tone audiometry was done on 1475 persons on two occasions 6 years apart by the same audiologist in the same facility. The age of the subjects ranged from 58 to 88 years at the initial testing and 63 to 95 at the second. The average 6-year threshold change ranged from 1 to 8 dB at 250-6 kHz and 10-15 dB at 8 kHz. The differences in thresholds fell into two patterns, one for low frequencies (250-1 kHz) and the other for high frequencies (4-8 kHz). For the lows, thresholds worsened at an increasing rate with increasing age independent of the initial hearing level, and women's thresholds worsened more than men's. For the highs, the rate of threshold change decreased with age and with the initial threshold at rates that did not differ between genders. Using a change in PTA (0.5, 1, 2 kHz) of greater than 10 dB as a criterion, significant worsening occurred in the right ear in 8.5%, in the left ear in 13.5%, and in both ears of 4.1% of the subjects over the 6 year period. The rate of significant worsening increased with age. Although hearing loss increased with age, age alone accounted for less than 10% of the variance. Therefore, factors that co-vary with age may be responsible. The difference in phenomena between the low frequencies and the highs suggests that two different processes are occurring. Hair-cell degeneration is the most likely cause for the change in the high frequencies. Strial atrophy or other intracochlear processes may be the cause of the low frequency changes.

Age Factors↗
PubMed1991

Hearing aid evaluation and fitting.

Although many patients with hearing loss benefit from medical or surgical intervention, the vast majority have noncorrectable hearing disorders for which rehabilitation through amplification is indicated. There are three goals for the application of hearing aids: (1) to amplify normal conversational speech to levels that are maximally understandable to the patient; (2) to help the patient hear other environmental sounds; and (3) to assist in the educational or habilitative process for those children who sustain hearing loss prior to language and speech development. In addition, there are certain issues that require medical consideration when a wearable device is placed in the ear. This article describes current hearing aid technology; reviews its benefits, limitations, and application for typical patients; discusses the medical aspects of hearing aid fitting; and describes new hearing aid technology on the horizon.

Correction of Hearing Impairment↗
PubMed1990

Upper airway obstruction due to massive gingival hyperplasia. A case report and description of a new surgical treatment.

Drug-induced gingival hyperplasia is a frequent complication of phenytoin anticonvulsant therapy. In severe cases, gingival hyperplasia can cause marked cosmetic deformity, phonatory abnormalities and significant occlusal changes which severely restrict masticatory function. Airway obstruction has not been previously reported with this condition. We describe a unique case of massive phenytoin-induced gingival overgrowth causing glossoptosis and subsequent upper airway obstruction. Possible medical and surgical treatment options, including laser wedge resection of the base of the tongue, are discussed.

Airway Obstruction↗
PubMed1990

Development of a new in vivo model for head and neck cancer.

We have developed an improved model for studying in vivo nonsurgical treatment of head and neck cancer. In situ oral cavity implantation has been documented, but its natural history is not defined. In light of this, an improved model is described. Forty-two nude mice had tumor cells from one of two established laryngeal squamous cell carcinoma cell lines implanted into the floor of the mouth. The tumor mass was measured and followed. When the tumor burden was great enough to cause cachexia, the animals were killed and submitted for microscopic examination. Pulmonary metastases were noted in 44%, bone invasion in 80%, angioinvasion in 76%, and soft tissue invasion in 96% of the animals. Growth characteristics in the head and neck have not been documented in previous models. Our model not only exhibits the locally invasive activity typically associated with malignant neoplasms, but also closely parallels the results of clinical studies examining the percent of end stage patients and autopsies with pulmonary metastases. Therefore, this model should open the way for more meaningful in vivo studies of nonsurgical treatment modalities for both local and metastatic tumor foci in head and neck cancer.

Animals↗
PubMed1990

Optic nerve decompression via the lateral facial approach.

Two cases of visual loss after lateral orbital wall fracture are presented: one with retrobulbar hematoma and evidence of optic nerve compression who failed to respond to lateral canthotomy and high-dose corticosteroid administration, and the second with immediate, total blindness associated with fracture of the bony optic canal. In both, extradural decompression of the orbit and optic nerve was achieved through the lateral facial approach with partial return of visual acuity and without surgical complications. The role of orbital and optic nerve decompression in the management of patients with blindness following orbital trauma is controversial. Orbital decompression may be of value for cases of post-traumatic visual loss unresponsive to medical management. If optic nerve injury is suspected as the cause, the additional step of decompression of the optic nerve is a logical but unproven procedure. The indications for optic nerve decompression are not established and should be considered only within the context of the specific needs of the individual patient.

Adult↗