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Biomedical subjects

R M DeDio

Publications and source records attributed to R M DeDio.

9 recordsLinked to original sources
PubMed1993

The growth of hearing loss in neonatal chicks exposed to intense pure tones.

One-day-old chicks were exposed to an intense pure tone (0.9 kHz, 120 dB SPL) and assigned to one of eight groups based on continuous exposure durations from 1 to 200 h. As each animal was removed from the exposure, it was anesthetized and an electrode was placed in the nucleus magnocellularis. Sound-evoked potentials were used to measure absolute thresholds and frequency selectivity. Thresholds were measured at 10 frequencies between 0.1 and 4.5 kHz while frequency selectivity was assessed by a simultaneous masking tuning-curve procedure at five probe-tone frequencies between 0.3 and 2.5 kHz. Threshold shift was greatest at 1.3 kHz and reached a maximum loss of approximately 57 dB between 48 and 200 h of exposure. The shape of the threshold-shift curve as a function of exposure duration (for frequencies between 0.9 and 2.5 KHz) suggested the presence of an early and late effect. The loss in tuning sharpness was evaluated by comparing the values of Q10 dB for control and exposed tuning curves and expressing the difference between them as a percent change. Probe-tone tuning curves above 0.9 kHz became less selective as exposure duration increased. A maximum decrease in tuning of about 54 percent was reached by 48 h and this remained constant to 200 h. The low-frequency tuning curves (below 0.9 kHz) did not show any systematic loss in selectivity. The changes in sensitivity and selectivity are discussed in relation to the patterns of cochlear injury that occurred on the basilar papilla as exposure duration lengthened.

Acoustic Stimulation↗
PubMed1992

Is outpatient tonsillectomy appropriate for young children?

The current literature suggests that outpatient tonsillectomy is a safe, cost-effective procedure. These reports have based their conclusions on the low rates of postoperative bleeding and dehydration. Generally, they have not examined other factors that may influence the postoperative course or identified groups of patients in whom outpatient management may not be appropriate. The literature regarding tonsillectomy in young children is conflicting. A retrospective analysis of the records of 223 children, 36 months of age and younger who had tonsillectomies, was performed. Postoperative airway complications including oxygen desaturation and airway obstruction developed in 115 patients. Seventeen (7.6%) children required postoperative care in an intensive care unit while an additional 117 (52.5%) patients received more than standard management. Preoperative apnea, an age of less than 12 months, and the presence of accompanying medical conditions were associated with a higher incidence of postoperative airway complications. It is recommended that tonsillectomy in patients under 36 months of age be planned as an inpatient procedure.

Age Factors↗
PubMed1991

The Chiari-I malformation.

We have described the important clinical features and aspects of the Chiari-I malformations, with particular emphasis on Chiari-I malformation. Previously thought to be a rare finding with only minor significance, Chiari-I malformation is an important cause of a variety of symptoms, and will be diagnosed even more frequently as the use of MRI increases. The clinician must consider Chiari-I malformation in any patient with unexplained sensorineural hearing loss, headache, vertigo, ataxia, dysequilibrium, dysphagia or other cranial nerve symptom, especially if accompanied by more classic symptoms of this disorder, such as cervical pain or weakness.

Arnold-Chiari Malformation↗
PubMed1990

The use of diagnostic testing in asymmetric sensorineural hearing loss.

The etiology of an asymmetric sensorineural hearing loss can often be difficult to determine. Because a wide variety of pathologic processes may be responsible for the hearing loss, numerous diagnostic tests are usually used in the initial evaluation, including pure-tone audiometry, acoustic reflex testing, imaging, serologic testing, and auditory brainstem response testing. The diagnostic evaluations of 225 consecutive cases of asymmetric sensorineural hearing loss are reviewed. A cochlear site-of-lesion was demonstrated in the majority (194) of patients. Because all retrocochlear lesions (31) were associated with an abnormal auditory brainstem response, imaging should be performed in that group of patients. Magnetic resonance imaging offers greater specificity than computed tomography. Reflex decay, acoustic reflex testing, and rollover were all associated with a high false-negative rate. Whereas serologic testing for syphilis yielded several cases of otosyphilis, thyroid function testing was of little value. A diagnostic protocol for asymmetric sensorineural hearing loss is presented.

Adolescent↗
PubMed1990

Angiotensin-converting enzyme inhibitor induced angioedema of the head and neck.

Angiotensin-converting enzyme (ACE) inhibitors are now in widespread use for the treatment of essential and renovascular hypertension. Consequently, angioedema, an uncommon complication of ACE inhibitor therapy is being encountered with increasing frequency. Since ACE inhibitor angioedema predominantly involves the face, lips, oral cavity, and occasionally the larynx the otolaryngologist is often consulted to evaluate affected patients. Treatment ranges from simple cessation of the drug to emergent airway intervention. The pertinent pharmacologic properties of ACE inhibitors and the pathophysiology of angioedema are discussed. The authors' experience with the evaluation and treatment of ACE inhibitor induced angioedema is presented.

Adrenal Cortex Hormones↗
PubMed1988

Microbiology of the tonsils and adenoids in a pediatric population.

To investigate the microbial flora of the tonsils and adenoids, the core tissue from the tonsils and adenoids of 50 children undergoing tonsillectomy and adenoidectomy for either recurrent infection or airway obstruction was cultured aerobically and anaerobically, and the number of bacterial colonies was quantitated. The most common organisms isolated were alpha-hemolytic streptococci, nonpathogenic Neisseria species, Haemophilus species, Staphylococcus aureus, and Corynebacterium species. No anaerobes were identified. Bacterial isolates from the tonsils and adenoids were similar in number and frequency of occurrence. Potential pathogenic bacteria (Haemophilus species, S aureus, beta-hemolytic streptococci, and Streptococcus pneumoniae) were identified in 40 patients. Seventy-three percent of these patients shared a common pathogen in tonsil and adenoid tissue. Haemophilus species were recovered in 54% of patients and S aureus in 46%. No significant difference exists between the type and number of pathogens in patients undergoing adenotonsillectomy for recurrent infection or obstruction.

Adenoidectomy↗