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Biomedical subjects

R D Eavey

Publications and source records attributed to R D Eavey.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1986

Kartagener's syndrome. A blinded, controlled study of cilia ultrastructure.

We investigated respiratory mucosa cilia ultrastructure in patients homozygous for the gene for Kartagener's syndrome (KS) and patients apparently phenotypic for KS who had bronchiectasis and sinusitis but without situs inversus. Parents, as obligate carriers of the recessive KS gene, were also evaluated among other control groups. The four patients with KS had significantly fewer cilia outer dynein arms than normal subjects or parents of patients with KS. Two of five patients apparently phenotypic for KS demonstrated distinctive ultrastructural changes. No other subjects demonstrated explicit ultrastructural abnormalities. Internal control specimens showed that the number of outer dynein arms was consistent within a subject compared with variation between subjects. The outer dynein arm serves as a dependable ultrastructural marker. Carriers of KS do not demonstrate distinctive morphologic cilia abnormalities. Not every patient with chronic bronchiectasis and sinusitis demonstrates abnormal cilia ultrastructure.

Adolescent↗
PubMed1986

Histological observations of amniotic fluid cellular content in the ear of neonates and infants.

Amniotic fluid cellular content (AFCC), especially keratinized, non-nucleated squamous epithelial cells and lanugo hair, have been detected in the fetal and neonatal ear. We wished to evaluate the incidence, amount and histological findings of AFCC in the neonatal and early infant period. Temporal bones (n = 63) from children aged 10 min to 70 days were examined. AFCC was discovered in 39 of 43 bones in neonates. In children of 31-70 days of age, AFCC was present in 11 of 20 bones. A measurement of the amount of AFCC was performed; the maximum was 11.47 mm3 with a mean of 2.40 mm3. Histological findings varied from the mere presence of AFCC to the formation of epithelialized granulation tissue. This granulation tissue was found in 19 of the bones. Theoretical clinical implications are considered for middle ear adhesions, otitis media and cholesteatoma.

Amniotic Fluid↗
PubMed1985

Metabolic facial paralysis in an infant.

A 2-month-old infant developed facial paralysis with a presentation that masqueraded as a possible middle ear tumor. The cause of the paralysis eventually was related to a metabolic consequence of his underlying disorder, cystic fibrosis. To our knowledge, the association of vitamin A imbalance, pseudotumor cerebri, and facial paralysis has not previously been discussed in the otolaryngologic literature.

Cystic Fibrosis↗
PubMed1985

Otologic features of bacterial meningitis of childhood.

Sixteen temporal bones from eight children who had died of meningitis were histopathologically evaluated. Concurrent acute otitis media was demonstrated in 14 bones. In no case could a pathway of infection from the tympanomastoid compartment to the intracranial cavity be located. Further, inner ear infection appeared to be the result of retrograde bacterial invasion from the meninges rather than from an inoculation via the middle ear or mastoid. Should surgical drainage be required, the histopathologic findings indicate that mastoidectomy would have little advantage over myringotomy. We infer that a child with normal temporal bone anatomy is probably not at enhanced risk for development of bacterial meningitis from acute otitis media via a route of direct extension.

Autopsy↗
PubMed1985

Norrie's disease: a study of two families.

Norrie's disease, or congenital progressive oculo-acoustico-cerebral degeneration, is a rare X-linked recessive syndrome of retinal malformation, deafness, and mental retardation and/or deterioration. The natural history of the disorder in two families with five affected males, four living and one deceased, is described. The histopathology of two patients, one from each family, is reported. Differential diagnosis, treatment, and genetic counseling are discussed.

Adolescent↗
PubMed1985

Inverted papilloma of the nose and paranasal sinuses in childhood and adolescence.

Inverted papilloma of the nose and paranasal sinuses is a tumor not usually associated with childhood. These five cases from the Massachusetts Eye and Ear Infirmary provide the only series in the literature. The patients ranged in age from 6 to 20 years. One case involved the septum exclusively; the patient experienced a recurrence. The other four cases were of sinus origin. One of these patients also experienced recurrences before definitive surgery. Another presented with a simultaneous squamous cell carcinoma. Evaluation of these cases demonstrates that the same successful, comprehensive surgical management advised for adults is justifiable in this younger age group.

Adult↗
PubMed1985

Airway interruption in encephalopathic children: a clinical and histological analysis.

Severe, incessant aspiration can be a most troublesome sequel to the already tragic problem of a vegetative mental state in a previously normal child. Three patients, aged 2 to 4 years, underwent surgery to treat their aspiration. A different type of procedure was used for each patient: cord closure combined with an epiglottic flap, cord closure alone, and a laryngeal stent. Laryngeal histopathology of a case is presented for the first time; findings suggest that the theoretical reversibility of that particular type of procedure could prove formidable. Clinically, the immediate cessation of aspiration has provided all parents and health care personnel with a surprising sense of gratification and has enabled each child to be transferred to a less-costly care facility or to home.

Child, Preschool↗
PubMed1985

Familial vocal cord dysfunction.

Vocal cord paralysis is a common cause of neonatal stridor. Familial vocal cord dysfunction, however, is unusual. All three siblings in one family had neonatal stridor. Vocal cord dysfunction was confirmed after endoscopic examination in two of the children; a temporary tracheotomy was required by one child. Results of evaluation, including pulmonary function tests, suggest discrete dysfunction localized to the neuromuscular pathway responsible for vocal cord abduction. Endoscopy is of prime importance in the diagnosis of vocal cord dysfunction. In considering therapy, the physician must weigh both the potentially life-threatening nature of vocal cord paralysis, as well as the likelihood of eventual spontaneous resolution of many familial and idiopathic cases.

Airway Obstruction↗
PubMed1985

Bifid uvula.

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Adenoidectomy↗