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Biomedical subjects

G A Gates

Publications and source records attributed to G A Gates.

At least 127 records · Page 7Linked to original sources
PubMed1978

Early effects of ethacrynic acid on cochlear histochemistry.

We have investigated the histochemical changes in the succinodehydrogenase (SDH) and adenosine triphosphatase (ATPase) enzyme systems of the guinea pig cochlea at 30, 60, and 240 minutes following the intracardiac injection of ethacrynic acid. In control animals, there is intense SDH activity in the stria vascularis, spiral prominence, and hair cells. At all periods after ethacrynic acid injection, there was decreased activity of SDH in the outer hair cells in the basal turn. The activity of SDH in the stria vascularis and spiral prominence was equally as intense as in control animals at all periods, however. Strong ATPase activity in control animals was demonstrated by dark-brown precipitations in the external sulcus cells, stria vascularis, and hair cells. The ATPase activity was decreased at 60 minutes after ethacrynic acid injection only in the stria vascularis. The importance of these results is discussed.

Adenosine Triphosphatases↗
PubMed1978

Laryngotracheoplasty for acquired subglottic stenosis in infants and children: experience with six cases.

Six children aged 6-50 months with acquired subglottic stenosis persisting after medical and endoscopic treatment underwent 7 open resections of the stenotic tissue followed by internal stenting. Five were successfully decannulated after an average treatment time of 6.8 months; the sixth died after accidental extubation. All 5 have satisfactory vocal and respiratory function 11 to 36 months postoperatively (6-18 months postextubation). Transcartilaginous open resection of subglottic stenosis is a feasible treatment option which can be used, even in the infant, when expectant observation is not advisable.

Child, Preschool↗
PubMed1977

Pulmonary edema as a complication of acute airway obstruction.

Acute fulminating pulmonary edema developed in three patients after acute airway obstruction secondary to tumor, strangulation, and interrupted hanging (one case each). The common etiologic factor was vigorous inspiratory effort against a totally obstructed upper airway. Acute pulmonary edema followed the event in minutes to hours and required ventilatory assistance to maintain oxygenation. All patients eventually responded to fluid restriction, diuretics, and steroids. One case was complicated by aspiration of gastric contents following respiratory failure. To our knowledge, this condition is previously unreported in English literature. We presume that the pathogenesis is related to alveolar and capillary damage, induced by the severe negative pressure generated by attempting to inspire against the closed upper airway.

Acute Disease↗
PubMed1977

Scanning ultrastructure of the stria vascularis.

In the eleven years since the introduction of the first commercially available scanning electron microscope, a number of otologic studies have made use of this new technique. However, the literature contains only one report of scanning ultrastructure of the endolymphatic surface of the stria vascularis. We have studied the stria vascularis with a technique allowing examination of the mid-modiolar cut surface as well as the endolymphatic surface.

Animals↗
PubMed1977

Effect of ethacrynic acid on the stria vascularis.

The stria vascularis of young albino guinea pigs was examined by scanning electron microscopy at intervals of 30, 60, and 240 minutes after the intracardiac administration of ethacrynic acid (70 mg/kg). Results from this study showed that the appearance of large intercellular spaces in the intermediate region of the stria vascularis was due to acute separation of these cells rather than atrophy, as described by previous investigators. It was probable that these spaces were due to an accumulation of extracellular fluid. In some marginal cells, extrusions of cytoplasm into the endolymphatic space were noted in the 240-minute group of animals. The importance of these extrusions is not apparent at this time.

Animals↗
PubMed1977

The significance of negative middle ear pressure.

An increasing body of experience is defining the value of the impedance bridge for the detection and diagnosis of otologic disorders. In this study the audiometric status of 1,133 ears is correlated with the tympanometric configuration and middle ear pressure. It is noted that the air-bone gap systematically increases as the middle ear pressure decreases from 0 to -400 mm Ho. Mildly negative middle ear pressure (Jerger's Type A Tympanogram) produces air-bone gaps statistically greater than at atmospheric pressure. These data demonstrate the magnitude of the adverse effect of negative middle ear pressure upon middle ear auditory function.

Audiometry↗
PubMed1977

Pseudomonas mastoiditis.

Opportunistic infections of the external auditory canal or the middle ear due to Pseudomonas aeruginosa occurring in patients with low resistance to infection have a 35 percent mortality rate. Once the process extends into the pneumatized temporal bone, eradication becomes more difficult and the mortality rate increases to 72 percent because of the high incidence of involvement of cranial nerves, adjacent intracranial vessels, and meningitis. Treatment is directed towards the underlying condition, administration of systemic carbenicillin and gentamicin, topical colistin therapy, and judicious surgical debridement. Pseudomonas vaccine may be of help. Fifteen cases are presented. Nine follow the pattern of malignant external otitis and six began as a primary acute otitis media.

Adult↗
PubMed1977

Sialography and scanning of the salivary glands.

This discussion is a brief review of the current status of sialography and salivary gland scanning in the diagnosis of salivary disorders. Both techniques are in current use; the contrast sialogram is most useful in evaluating recurrent inflammatory disorders, and the radiosialogram finds its greatest value in evaluating patients with suspected neoplasms. These examinations should not be used in lieu of a histologic diagnosis in tumor cases except when a smooth margined radiopositive lesion corresponding with a clinically evident Warthin tumor is noted; in this case a presumptive diagnosis of a benign neoplasm may be established. The utilization of these radiographic techniques depends upon the facilities available, the needs of the particular patient, and the experience and clinical judgment of the salivary gland surgeon.

Adenocarcinoma↗
PubMed1976

Maggot therapy for subacute mastoiditis.

We describe a patient with intractable subacute mastoiditis who was treated successfully by maggot therapy. Maggot debridement of intractable wounds was very successful before the introduction of antibiotics. We describe the indications for use, materials and methods for the rearing of sterile larvae, the modes of action, and the complications of maggot debridement.

Aged↗
PubMed1975

An abbreviated impedance bridge technique for school screening.

The hearing of 539 children were screened by conventional audiometric techniques and an abbreviated form of impedance audiometry. Otoscopic examination and estimates of the cost to accurately detect hearing loss were used as critieria for comparing the two methods. The impedance technique detected 94% of hearing disorders, the audiometric, 24%. Projections of cost included a factor for number screened. These demonstrated that the impedance technique was less expensive and approached one-sixth the cost of the audiometric technique at a rate of 10,000 children per year. A routine application of the impedance technique in an ongoing hearing conservation program (N = 2712) supported the initial conclusion that it was more effective and more easily employable than audiometric screening. One child who passed impedance screening was shown to have a 50-dB sensorineural loss. It was concluded that an abbreviated form of impedance audiometry that includes a single high-frequency screening tone is the technique of choice for school screening.

Audiometry↗