Biomedical subjects

H G Goycoolea

Publications and source records attributed to H G Goycoolea.

6 recordsLinked to original sources

PubMed1993

Multifrequency tympanometry in normal adults.

Multifrequency tympanograms were recorded from 56 ears of 28 normal-hearing adult subjects to obtain normative data and to determine abnormal criteria for tympanometric measures. Static admittance, tympanometric width, and tympanometric peak pressure at 226 Hz were analyzed along with eight different estimates of the resonant frequency of the middle ear. Based on test-retest reliability and normal distribution characteristics, preferred methods for clinical estimation of resonant frequency were determined. The sweep pressure mode (ear canal pressure is swept while probe frequency is held constant) is preferred for detection of abnormally high resonant frequencies. The sweep frequency mode (probe frequency is swept while ear canal air pressure is held constant) is preferred for identification of abnormally low resonant frequencies. Compensation for ear canal volume at +200 daPa was preferred over other compensation methods for estimation of middle ear resonant frequency.

Acoustic Impedance Tests↗

PubMed1991

Otitis media. 16 years of pathogenesis approach.

The authors describe 16 years of their approach to research in otitis media, their rationale, and the concepts that have evolved from their experiments and clinical work. The authors suggest that interest is the key to progress and not laboratory facilities. They extend an invitation to individuals with different backgrounds but common interest in otitis media to work together from the standpoint of pathogenesis.

Animals↗

PubMed1990

Anatomical perspective, approach, and experience with multichannel intracochlear implantation.

An overall review of the authors' anatomical perspective, approach, and experience with multichannel intracochlear implantation is presented. This report includes pertinent anatomical observations and experimental surgical procedures on fresh temporal bones. Although the scala tympani in the basal turn of the cochlea has an adequate space laterally for the insertion of electrodes, in the upper turns the adequate space is located medially. This is, in practice, the single-most limiting factor for an electrode, inserted via the round window, to reach the apical turns without damaging the basilar membrane. An experimental surgical procedure is described in which a second electrode is inserted in the middle turn via a mastoidotomy-tympanotomy approach and reaches a point near the apex. Studies of horizontal sections of human temporal bones include a review of potential structures that could be stimulated by the electrical currents generated by electrodes. The wall of the carotid artery, located at 750 microns from the basal turn at the level of the round window niche, is considered a potential structure to be affected by long-term stimulation. Anatomical principles and surgical considerations for the mastoidotomy-tympanotomy approach are described as an alternative to the facial recess approach. In the authors' experience, this procedure is technically easier, eliminates the possibility of postauricular flap complications, provides a better angle for insertion of electrodes, requires shorter hospitalization, and permits faster recovery than the facial recess approach. The authors' clinical approach, results, and observations are reviewed. Of note is a successful home-based rehabilitation program.

Adult↗

PubMed1988

Racial and familial factors in otitis media. A point prevalence study on Easter Island.

Of the 249 children aged 5 to 9 years who live on Easter Island, 220 underwent complete otolaryngological evaluation. Twenty children were found to have otitis media (acute, chronic, or both). Three of these children were genetically impure natives, nine were of mixed parentage, and eight were "continentals" (with a birth origin other than the island). None of the genetically pure natives had otitis media. Our data show that, in a population with all factors in common except for familial and racial background, the point prevalence of otitis media is higher in children of mixed or continental origin than in genetically pure native children. The high prevalence of otitis media in children of mixed parentage and in one particular family of European ancestry suggests the presence of intrinsic or pronicity factors that are seemingly transmissible.

Acute Disease↗

PubMed1988

Permeability of the human round-window membrane to cationic ferritin.

An ultrastructural study was done in three sequential steps to determine if the human round-window membrane was permeable to macromolecules. Cationic ferritin was first placed for one hour in the round-window niche of two live rhesus monkeys. The same tracer was then placed in the same manner in two rhesus monkeys that had been dead for one hour. In both groups, cationic ferritin was observed to traverse the round-window membrane through pinocytotic vesicles into the scala tympani. After establishing that the transport capabilities of the round-window membrane of the monkey remained present one hour after death, cationic ferritin was placed for one hour in the round-window niche of two humans who had been dead for 30 minutes and one hour. The tracer was observed to traverse the round-window membrane through pinocytotic vesicles into the scala tympani in both humans. This report may be the first to document morphologically the permeability of human round-window membranes to macromolecules.

Animals↗

PubMed1986

Effect of life in industrialized societies on hearing in natives of Easter Island.

In an effort to determine whether life in industrialized societies can have an effect on hearing, 90 natives from Easter Island over 45 years old were evaluated. They underwent complete clinical and audiological assessment and were divided into groups according to those having lived only on the island or those having lived in modern civilization. With all factors being equal, except exposure to modern civilization, our results showed that living in civilized societies has a significant negative effect on hearing; the severity is directly proportional to the years of exposure. The median hearing thresholds of natives always living on the island (men and women combined) was found to be similar to those of female citizens of the United States; there was no significant difference in hearing thresholds between men and women among these natives. These results suggest that there are no significant inherent racial differences nor significant inherent differences between males and females in the sensitivity of hearing. A relationship between aging and hearing was noted and interpreted as true or intrinsic presbycusis. There were no cases of otosclerosis, Meniere's disease, or exostoses of the external ear canal among natives who had always lived on the island. Pure natives were found not to be prone to otitis media in spite of having an extremely high incidence of severe upper respiratory tract allergies.

Aged↗