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Biomedical subjects

M M Paparella

Publications and source records attributed to M M Paparella.

At least 217 records · Page 12Linked to original sources

Normal and metastatic melanin in the temporal bone.

PURPOSE: Malignant melanoma is known to metastasize to the temporal bone. However, melanocytes exist in the normal inner ear and may be difficult to distinguish from metastatic melanotic cells. This study describes distribution of normal melanin in the ear and metastatic melanoma to the temporal bone. MATERIALS AND METHODS: Normal melanin distribution is described in 48 temporal bones from White (18), Native-American (19), and African-American (11) individuals and metastatic melanoma to the temporal bone is described in four cases (seven temporal bones). Temporal bones were removed at autopsy, fixed in 10% buffered formalin, and processed for routine celloidin embedding. Sections were cut at a thickness of 20 microns and every tenth section was stained with hematoxylin-eosin for light microscopic evaluation. RESULTS: Normal melanin was found in the inner ear, mainly around terminal neural structures and blood vessels, and occurred in greater quantities in African-American individuals. Metastatic melanotic cells reached the temporal bone by hematological dissemination, and by neural invasion from the central nervous system. No correlation was found between histopathological findings and clinical symptoms of patients. CONCLUSIONS: Metastatic melanoma to the temporal bone may be seen in the same areas as normal melanin. They may also be observed in bone marrow cells of the petrous bone and along the course of nerves of the internal auditory canal and cochlear vestibular labyrinth, either by following neural sheaths or blood vessels that run along the nerve. Metastatic disease to the temporal bone is often asymptomatic, or it may present with uncharacteristic symptoms that may delay diagnosis.

Adult↗

Congenital malformations of middle and inner ears of parabiotic twins.

We describe herein the congenital malformations of the middle and inner ears in temporal bones of parabiotic, monozygotic twins. Temporal bones were removed from twin B, who had no fetal cardiac activity and was born dead at 23-4/7 weeks, and twin A, the donor or "pump" twin in intrauterine life, who died shortly after birth at 20-6/7 weeks. The temporal bones were processed routinely in celoidin, stained with hematoxylin and eosin, and examined by light microscopy. We found that twin B had Mondini's dysplasia with associated deformities of the middle ear and in general showed more developmental anomalies than twin A, and we conclude that Mondini's dysplasia with anomalies of the middle ear may occur in the parabiotic twin syndrome, and the abnormalities may be explainable as the result of vascular disturbance, which also causes other lesions in these unusual cases.

Ear, Inner↗

Petrous high jugular bulb: a histological study.

PURPOSE: A high jugular bulb (JB) is thought to affect structures of the inner ear and possibly cause symptoms there, but clear histological findings of an anatomical relationship between a high JB and the inner ear have not yet been described. MATERIALS AND METHODS: We surveyed horizontal sections of 1,591 temporal bones from the collection of the Otopathology Laboratory at the University of Minnesota in Minneapolis, Minnesota, defining a high JB as a JB extending above the inferior margin of the basal cochlear turn. RESULTS: In 65 specimens (16%), we found a high JB with its vascular wall obviously thinner than that of a low JB. Bony resorption was occasionally observed around high JBs. Sixteen specimens showed a bony deshiscence between the JB and the endolymphatic sac. Clinical charts showed no obvious symptoms associated with a high JB. CONCLUSIONS: Our findings suggest that the JB may have potential to expand upward postnatally. Although our study confirmed occasional bony dehiscence between the JB and the endolymphatic sac, JBs with this involvement may have only a minor effect on function in the inner ear.

Adolescent↗

Outgrowing schwannomas arising from tympanic segments of the facial nerve.

PURPOSE: Although there have been numerous reports of clinical cases of facial nerve schwannoma, histopathologic studies of its early stages of development are rare. The purpose of this study was to describe the incidence, origin, and pathology of small, asymptomatic schwannomas of the facial nerve. MATERIALS AND METHODS: Fifteen hundred twenty-six ears from the human temporal bone collection of the Otitis Media Research Center Otopathology Laboratory at the University of Minnesota were studied under light microscopy. RESULTS: Twelve bones with morphologic indications of type A Antoni tissue that mimics facial schwannoma in the tympanic cavity were selected. The 12 ears were from nine individuals with asymptomatic histories. The twelve schwannomas developed from perineurium at dehiscences in the facial canal near the oval window, forming defects in the epineurium by growth of Schwann cells downward and outward toward the stapes. No obvious compressions or lesions within fibers in the facial nerve were observed. CONCLUSION: Because these tumors grow slowly without hearing loss or facial nerve symptoms, they may be mistaken for granulation tissue during surgery for chronic otitis media.

Adult↗

Autoimmune sensorineural hearing loss: a human temporal bone study.

PURPOSE: To describe histopathologic findings in temporal bones of a patient whose clinical history suggests a sensorineural hearing loss (SNHL) of autoimmune origin. MATERIALS AND METHODS: Temporal bones from a patient with a history of ulcerative colitis, leukemia, and SNHL were examined by light microscopy. RESULTS: Histopathologic findings included: (1) organs of Corti missing or absent in all cochlear turns; (2) cells decreased in spiral ganglia, and lymphocytic infiltration; (3) absence of portions of the spiral prominence; (4) endolymphatic hydrops in basal, middle, and apical cochlear turns and in the saccule and utricle; (5) fibrosis and osteoneogenesis of a scala tympani of the basal turn of the cochlea, the posterior semicircular canal, and the canal of Cotugno; (6) fibrosis of the vestibular aqueduct and endolymphatic sac; and (7) lymphocytes in the endolymphatic sac, perisaccular area, inferior cochlear vein, and Rosenthal's canal. CONCLUSION: Histopathologic findings in the temporal bones of this patient with ulcerative colitis, sensorineural hearing loss, and vestibular symptoms closely parallel those in a previously reported animal study of autoimmunity and suggest the possibility of a SNHL of autoimmune origin.

Adolescent↗

Residual mesenchyme persisting into adulthood.

PURPOSE: (1) To detect the presence of residual mesenchyme in temporal bones of adults and children above 5 years of age; (2) to evaluate its regression with increasing age, and; (3) to detect pathologic conditions associated with the presence of unresolved mesenchyme. MATERIALS AND METHODS: We examined 1,404 human temporal bones of donors from 5 to 94 years of age for histopathologic evidence of mesenchyme. The presence of stellate (star-shaped) cells with interdigitating processes and large nuclei embedded in a structureless ground substance was labeled as "pure mesenchyme." Temporal bones showing these features and focal areas of fibrosis, fibroblasts, and capillaries were classified as showing "transitional mesenchyme." Selected sections were stained with Gomori's trichrome. Pathological features indicating otitis media and congenital anomalies of the ear were also documented. Case histories were reviewed, and any otologic complaints were noted. Statistical analysis was performed with the Chi-square test, analysis of variance, regression analysis, and confidence interval. RESULTS: Mesenchyme was found in 2.07% of temporal bones of patients from 5 to 81 years of age. Of these, 92.1% had transitional mesenchyme, whereas 7.9% had pure mesenchyme. Seventy-six percent of the bones showed mesenchyme in the mastoid air cells. In all 3 bones with pure mesenchyme, it was present in the round window niche. Otitis media was associated with residual mesenchyme in 84.2% of the temporal bones. No pattern of regression of mesenchyme with increasing age was observed in temporal bones from patients over the age of 5 years. CONCLUSIONS: Residual mesenchyme can be present in patients older than 5 years of age and can persist into adulthood, especially in the mastoid air cells. Persistence of mesenchyme is closely associated with evidence of otitis media.

Adolescent↗

Genetic sensorineural deafness in adults.

Progressive genetic sensorineural hearing loss is a common problem in adults which is frequently incorrectly diagnosed or escapes diagnosis as to etiology altogether. If the hearing problem becomes manifest in the twilight of the patient's life it is often identified with the nondescriptive term "presbycusis." In all patients with sensorineural hearing loss, extrinsic (environmental) causes should be ruled out after which intrinsic or genetic etiology should strongly be considered, recognizing that extrinsic factors can be superimposed. A group of young adults was studied and diagnosed as having genetic progressive hearing loss. Polytomography ruled out the theoretical possibility of chochlear otosclerosis. The diagnosis of this disorder tests most heavily on the history and audiometric configuration which is characteristically flat or basin shaped with fairly good discrimination. Of further diagnostic significance was the fact that some patients, early in the course of their difficulty, presented with a predominantly low- or high-frequency loss which, over time, assumed a flat audiometric shape. The most important pathological finding from human temporal bone studies was atrophy of the stria vascularis.

Adult↗

Middle ear effusions: definitions and terminology.

There are many confusing terms which presently apply to the group of clinical problems accompanied by middle ear effusion manifestations. Out of this chaos there is a need for logic and simplicity. All of the middle ear effusions are examples of the broadly descriptive categorical term "otitis media" meaning "inflammation" of the middle ear which includes examples of frank "infection" as well. Based upon clinical and laboratory observations there are essentially four types of intrinsically occurring middle ear fluid which, along with clinical findings, provide the means of identifying the clinically descriptive term which should be used: 1) serous fluid (serous otitis media); 2) mucoid fluid (mucoid otitis media, secretory otitis media, glue ear); 3) bloody fluid (barotrauma, aerotitis); 4) purulent fluid (purulent or suppurative otitis media); and 5) any combination of the above four (e.g., seropurulent otitis media, serosanguineous otitis media, mucopurulent otitis media, etc.).

Acute Disease↗

Pathogenesis of middle ear effusions.

Detailed morphological and physiological studies are necessary as a basis for understanding normal, near normal and abnormal conditions of the middle ear cleft. Animal and human studies are essential. Animal studies provide a means of controlling and isolating variables. Herein we describe methods of producing acute and chronic middle ear effusions in animals. An animal model has also been developed for purulent otitis media. Corollary comprehensive studies are underway in humans. A multidisciplinary effort including pathology, microbiology, immunology, histochemistry, etc., yields interesting information which helps explain the pathogenesis of these common clinical problems.

Acute Disease↗

Blue ear drum and its management.

The "blue ear drum" generally refers to a condition in which blood or blood products are found in the middle ear. After all possible causes for hemotympanum, including blood dyscrasias and trauma are searched for and ruled out, the patient may have chronic serous otitis media accompanied by bloody effusion. Treatment for all of these patients is conservative, consisting of medical therapy and, if need be, myringotomy and insertion of ventilation tubes. In spite of proper treatment, rarely the condition may progress, over a long period of time, to a state of intractability. Characteristic findings are a hypocellular mastoid, hyperplastic and metaplastic mucoperiosteal lining, including the presence of glands and cysts and cholesterin granuloma. The recommended procedure is a modified radical mastoidectomy, placement of silicone rubber sheeting in the middle ear and insertion of a ventilation tube. It is to be emphasized that mastoid surgery is rarely indicated for these patients and only after all else has failed.

Ear Diseases↗

Pathology of chronic otitis media.

A review of 800 pathological temporal bones collected from autopsy cases revealed 333 ((41.6%) to have some type of otitis media; purulent otitis media (52.5%), serous otitis media (6%), mucoid otitis media (4.5%), and chronic otitis media (36.9%). The 123 temporal bones with chronic otitis media were further studied and found to have granulation tissue, cholesteatoma, cholesterin granuloma, bone changes, and fibrosis. Other findings included tympanic membrane perforation, tympanosclerosis, metaplasia of the epithelium with subepithelial glandular formation, suppuration, labyrinthitis, and evidence of complications of chronic otitis media (meningitis, subdural abscess, brain abscess, petrositis, and endolymphatic hydrops). From this study it was concluded: 1) chronic otitis media occurred quite frequently, from a histological standpoint, in the absence of tympanic membrane perforation; 2) granulation tissue in temporal bones was found much more frequently in chronic otitis media than was cholesteatoma; and 3) complications and sequelae of otitis media tended to occur more commonly secondary to granulation tissue than to cholesteatoma.

Adult↗

Hypercholesterolemia and auditory dysfunction. Experimental studies.

Rabbits were used for the long-term study of auditory function associated with experimental hypertension and hypercholesterolemia. Auditory dysfunction (threshold changes of sound evoked responses) was monitored with an electrode, chronically implanted into the contralateral inferior colliculus. Hypertension was created using the renal encapsulation technique. Auditory function in the hypertension trial demonstrated a dip at higher frequencies as well as improvement at lower frequencies. One gram of cholesterol fed daily for three months was capable of making rabbits atherosclerotic. Cholesterol-fed rabbits showed increasing auditory dysfunction over time at all frequencies. When experimental hypertension was combined with hypercholesterolemia, the auditory changes appeared additive. This work, although in preliminary stages, seems to provide experimental evidence that auditory dysfunction is associated with cholesterol diet.

Animals↗

Cells involved in the middle ear defense system.

Despite the high incidence and prevalence of otitis media, its pathogenesis is not thoroughly understood. In the last decade, many efforts have been made to provide a better understanding, and abundant information has become available. At the same time the field of immunology has advanced at an extremely rapid pace. We have followed the gradual cellular events in the defense reaction of the middle ear, utilizing eustachian tube obstruction to induce otitis. Seventy-five cats were divided in groups and sacrificed at intervals between one day and six months, and their temporal bones were studied. During an initial phase of inflammation, polymorphonuclears appear at three days in connective tissue; at the same time active fibroblasts synthesize tropocollagen and ground substance while epithelial cells secrete mucus and lysozymes. These cells, together with those involved in the mucociliary transport system and a patent functional eustachian tube, constitute the nonspecific system of defense. The transition cells are the macrophages which appear at one week to interact with T and B cells to produce the specific immune response. Plasma cells appear at two weeks to peak at one month with synthesis of immunoglobulins A, G and M. A secretory immune system is observed. At three and six months, lymphocytes are the predominant cells and occasional accumulations of mononuclears are observed. The reaction involves the entire middle ear, including mucoperiosteum, middle ear muscles and round window membrane. We believe that a better understanding of the middle ear defense system will lead in time to a practical clinical assessment of the immunological status during the evolution of each particular process or disease involving the middle ear, and a more rational approach to the treatment and, hopefully, prevention of chronic ear disease.

Animals↗

Inner ear pathology and otitis media. A review.

Insidious inner ear complications of otitis media have been and are being studied in our laboratory. The purpose of this paper is to review these studies, coordinate, capsulize and highlight the results with emphasis on the transport role of the round window membrane.

Animals↗