Search PubMed⌕ Search

Biomedical subjects

R D Eavey

Publications and source records attributed to R D Eavey.

At least 19 recordsLinked to original sources
PubMed1992

Chronic ear pathology in a model of neonatal amniotic fluid ear inoculation.

Human histopathologic studies have demonstrated that amniotic fluid cellular contents, keratinized squamous epithelial cells and lanugo hair, induce an intense inflammatory reaction including granulation tissue in the neonatal temporal bone. To investigate this reaction over a prolonged period, an animal model was studied. An aliquot of sterilized autologous hair and keratinized epithelial cells was placed into 14 gerbil bullae; saline was used as a contralateral control. The animals were sacrificed at intervals up to 6 months and the temporal bones were studied by light microscopy. All animals demonstrated nonpurulent inflammatory changes on the experimental side including granulation tissue, osteoneogenesis, tympanosclerosis, and cholesteatoma; the control side demonstrated minimal middle ear changes. We conclude that in this model autologous keratinized tissue provokes a foreign body response similar to the granulation tissue observed in human infants and, further, that over a prolonged period the middle ear demonstrates more severe pathologic consequences.

Amniotic Fluid↗
PubMed1992

Orbital complications of acute sinusitis: comparison of computed tomography scan and surgical findings.

The accuracy of computed tomography (CT) in distinguishing an abscess from cellulitis in children who present with orbital manifestations of paranasal sinus infection remains in question. In this 10-year retrospective study, CT results are compared with surgical findings in 19 patients with orbital complications who underwent surgical exploration within 24 hours of their CT scans. Fifteen of the 19 CT scan interpretations indicated abscesses that were verified intraoperatively. Two patients had negative surgical explorations despite CT interpretations predicting abscesses. An abscess was also surgically documented in 1 of 2 patients whose preoperative scans indicated cellulitis alone. We conclude that the correlation between radiologic and operative findings in 16 of these 19 cases, although not absolute, does substantiate the use of CT scanning as a therapeutic guide in children presenting with orbital disease secondary to paranasal sinusitis.

Abscess↗
PubMed1992

Skull base dumbbell tumor: surgical experience with two adolescents.

Pediatric skull base tumors are rare and until recently were considered unresectable. We present two patients with tumors of similar anatomic position with an extracranial component in the infratemporal fossa and parapharyngeal space, an isthmus at the foramen ovale, and a superior component in the middle cranial fossa in the region of the cavernous sinus. A 15-year-old girl experienced contiguous spread of a spindle cell sarcoma; an 18-year-old boy developed a chondrosarcoma. A middle fossa approach provided the advantage of surgical avoidance of structures such as the middle ear and mastoid, facial nerve, and mandible. Postoperative recovery was rapid. Our impression is that preoperative carotid artery occlusion and a middle fossa approach for tumor resection can be performed in a young patient with acceptable morbidity and at least short-term benefit. Surgery can, therefore, provide an additional therapeutic approach to complement irradiation and chemotherapy.

Adolescent↗
PubMed1989

Clinical experience with electroneurography in the pediatric patient.

Electroneurography (ENoG) has demonstrated utility in adults with facial nerve paralysis. We wished to evaluate the possible usefulness of this test in children. Twenty-six patients, aged 3 months through 16 years, were studied. Initial measurements were obtainable in all but two patients; they were successfully tested on a second attempt. All subsequent patient testing efforts were completed, for an overall successful test rate of 95%. Waveform amplitude and morphology were consistent with adult values, except in infants. The most clinically helpful use of this test was to objectively assess facial nerve function, once spontaneous motion was lost in acquired paralysis or if it had never been seen in congenital paralysis. Surprisingly, analysis of the "normal" side of the face proved most informative for three patients. Use of the test as an absolute predictor for return of function is not possible; however, the ENoG results add data that can be incorporated into the clinical information to make such predictions more rational. We conclude that ENoG can be performed on children, and that the measurements, within bounds of interpretation, can offer objective data not usually available in this age population.

Action Potentials↗
PubMed1989

Meconium contamination of the neonatal middle ear.

The neonatal middle ear and mastoid cavity are frequently contaminated by cells and hair of the amniotic fluid. This amniotic fluid cellular content provokes a foreign body inflammatory reaction that can persist for months. To evaluate whether clinical and postmortem findings might correlate with the amount of amniotic fluid cellular content in the middle ear, we compared temporal bones of nine patients born through meconium-contaminated amniotic fluid with those of 10 patients born through clear amniotic fluid. All patients were examined at less than 17 days postpartum and provided 37 temporal bones for histologic analysis. The volume of contaminant was quantified for each patient. The cases were arranged according to volume of contaminant in the middle ear and compared with clinical information and autopsy findings. Patients with larger volumes of contaminant in the middle ear were born through thick, meconium-stained amniotic fluid (1.9-38 mm3; average 9.3 mm3). Conversely, patients with lesser volumes of contaminant in the middle ear were born through unstained amniotic fluid (none to 3.2 mm3; average 0.9 mm3). We speculate that patients born through thick, meconium-stained amniotic fluid may be at greater risk of sequelae such as otitis media from this foreign body inflammatory reaction in the middle ear and mastoid cavity.

Amniotic Fluid↗
PubMed1989

Management strategies for congenital ear malformations.

Congenital malformations of the ear vary in appearance and significance. This article provides practical information for the pediatrician to assist with diagnosis, counsel for parents, pediatric management issues, and timing for referral. Recent surgical developments are illustrated for even severe malformations.

Adolescent↗
PubMed1989

Pathologic correlation of the unknown solid parotid mass in children.

A parotid mass in a pediatric patient is stated to have an approximately 50% likelihood of being malignant. To evaluate our experience in light of this suggested incidence, we conducted a retrospective study, which included 22 patients treated over an 8-year period, 1979 to 1987. Patients' ages ranged from 16 months to 19 years, and all patients presented with an unknown, solid parotid mass. One patient had a malignancy, mucoepidermoid carcinoma. Eight patients were diagnosed with benign pleomorphic adenoma. Thirteen patients had an inflammatory process consisting of one of the following conditions: cat-scratch disease (4); atypical mycobacteria (4); benign follicular hyperplasia of a lymph node (4); and toxoplasmosis (1). The histologic findings in this series suggest that unknown solid parotid masses that occur in children or adolescents are frequently the result of inflammatory conditions and are not likely to be malignant. We therefore recommend a reconsideration of the reputed estimation of malignancy in the parotid gland in children. The majority of pathologic conditions discovered, however, are still best diagnosed and treated by surgical excision.

Adenoma↗
PubMed1988

Intrinsic and extrinsic controls of the hypertrophic program of chondrocytes in the avian columella.

Immunohistochemical studies of the chick columella have shown that the extracellular matrix of this ossicular cartilage template is composed largely of type II collagen. As development proceeds, synthesis of type X collagen, a hypertrophic cartilage-specific molecule, is initiated by endochondral chondrocytes within the zone of cartilage cell hypertrophy. Subsequently, these cells and their surrounding extracellular matrix are removed, resulting in marrow cavity formation. We have examined which of these processes are programmed within the columella chondrocytes themselves, and which require involvement of exogenous factors. Prehypertrophic columella from 12-day chick embryos were grown either in organ culture on Nuclepore filters or as explants on the chorioallantoic membrane of host embryos. Chondrocytes from the same source were grown in monolayer cell cultures. In both organ culture and cell culture, chondrocytes developed to the stage at which some of them entered the hypertrophic program and initiated the production of type X collagen as determined by immunofluorescence histochemistry with a monoclonal antibody specific for that collagen type. The organ cultures, however, did not progress to the next stage, in which detectable removal of the type X collagen-containing matrix occurs. When identical columella were grown on the chorioallantoic membrane of host chicks, the type X collagen-containing matrix which formed was rapidly removed, resulting in the formation of a marrow cavity. Thus, progression of endochondral chondrocytes to the deposition of type X collagen-containing matrix seems to be programmed within the cells themselves. Subsequent removal of this matrix requires the involvement of exogenous factors.

Animals↗
PubMed1988

Infantile vomiting due to a disappearing hairy polyp.

Infantile vomiting can occur from many causes. A mass in the nasopharynx is an obscure reason for emesis. Maternal detection of an intermittently visible mass secured a diagnosis that had eluded observation, even after the patient had been hospitalized. "Hairy polyp" has received almost no attention in the Pediatrics literature. This report is both for information about the unusual tumor and for reaffirmation of the value of parental observation.

Cysts↗
PubMed1988

Cricothyroid membrane puncture: oxygenation and ventilation in a dog model using an intravenous catheter.

A method for pediatric airway support was evaluated for the situation when mask ventilation or intubation is impossible. Mongrel dogs were sedated, intubated, and allowed to breathe room air for 30 min. Baseline variables were recorded, and the airway obstructed. After 2 to 3 min of hypoxia, arterial blood gas and hemodynamic data were again recorded. A percutaneous cricothyroid membrane puncture (PCMP) was then performed with a 12-ga iv catheter. Studies were carried out both in the presence and absence of spontaneous ventilatory efforts. With spontaneous ventilation, continuous low flow (1.0 L/min) oxygen insufflation provided oxygenation for 30 min and reversed increases in mean arterial pressure, pulmonary artery pressure (PAP), and systemic and pulmonary vascular resistance that had been produced by the obstruction. Respiratory acidosis occurred but was well tolerated. With paralyzed animals, whose ventilation was supported by a self-inflating bag with 10.0 L/min of oxygen, all hemodynamic variables except PAP returned to normal, oxygenation was excellent, and PaCO2 values were maintained at steady, but elevated levels. Complications included bilateral tension pneumothorax in one animal. This experimental study supports anecdotal experiences where PCMP has been used and has proven lifesaving when standard resuscitative measures to establish a clear airway have failed.

Airway Obstruction↗
PubMed1987

Development of the chick columella: immunohistochemical studies with anti-collagen monoclonal antibodies.

Developmentally regulated changes in the extracellular matrices of the columella have been immunohistochemically analyzed with anti-collagen, type-specific monoclonal antibodies. In the 12-day chick embryo, the ossicle is entirely cartilagenous. By using immunohistochemical methods, we found that the 12-day columella contains type II collagen within the cartilagenous matrix and type I collagen in the surrounding perichondrium, but no type X collagen. Previous studies have shown that type X collagen is specific for hypertrophic cartilage (i.e., the site of future marrow cavity formation and ossification). By 16 days, hypertrophic cartilage is evident, type X collagen is present, and ossification has started medially adjacent to the oval window. These results both confirm and extend those of other chick endochondral bones that have been studied. Thus, the columella can serve as a model system for analysis of ossicular development and the associated temporal and spatial changes which occur within its extracellular matrices.

Animals↗
PubMed1987

Otolaryngological manifestations of the Stickler syndrome.

The Stickler syndrome is a dominantly inherited, connective tissue disorder associated with retinal detachments, joint and skeletal abnormalities, and characteristic facies. We wished to evaluate patients with this disorder to ascertain the frequency of otolaryngological manifestations. Fourteen patients, 4-17 years of age, were evaluated when admitted for retinal detachment. Findings included: midface hypoplasia in all patients; mandibular hypoplasia in 11 patients; palatal anomalies in 10 patients (frank cleft in 6, submucous cleft in two, highly arched palate in two); and hearing loss in 6 patients (mixed loss in 3, sensorineural loss in 3). Hearing loss appeared more commonly in the higher frequencies; no apparent correlation was found between the presence of hearing loss and orofacial anomalies. Our experience suggests that the Stickler syndrome is not rare. Craniofacial dysmorphic features and otologic findings are sufficiently frequent to warrant otolaryngological evaluation.

Abnormalities, Multiple↗