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Biomedical subjects

Michael M Paparella

Publications and source records attributed to Michael M Paparella.

At least 37 records · Page 2Linked to original sources
PubMed2004

Age-related histopathologic changes in the human cochlea: a temporal bone study.

OBJECTIVES: Previous reports on aging of human cochlea included subjects with ear diseases or ototoxic drugs. We studied spiral ganglion cells, hair cells, and lateral wall of cochlea from subjects without ear disease or ototoxic drugs. STUDY DESIGN: This study included 39 temporal bones from 24 subjects aged 1 day to 86 years. We assessed standard cytocochleograms, mean loss of fibrocytes in spiral ligament, and areas of stria vascularis. RESULTS: Losses of outer hair cells and fibrocytes were significantly greater in children, adults, and the elderly compared with infants. Spiral ganglion cell loss was significantly greater in adults and elderly compared with infants and children. Areas of stria vascularis of infants were significantly larger than the elderly. CONCLUSIONS: Degenerative changes of outer hair cells occur in children but spiral ganglion cells remain the same until around 20 years. Degeneration of stria vascularis due to aging appears to be slower than spiral ligament. EBM RATING: C.

Adolescent↗
PubMed2004

Otologic manifestations of metastatic tumors to the temporal bone.

The temporal bone appears to be affected by metastatic tumors in rather characteristic clinical presentations. More effective cancer treatments have interrupted the course of the disease, allowing more time for metastatic spread. This has increased the importance of prompt diagnosis in a group of diseases that may mimic external auditory canal or middle ear infections. In this paper, we review the distinctive patterns of involvement and presentation of metastatic tumors of the temporal bone, with emphasis on measures that should be taken to ensure early diagnosis.

Ear Diseases↗
PubMed2004

Cochlear changes in chronic otitis media.

OBJECTIVES/HYPOTHESIS: The objective was to describe the morphological changes in the cochlea in chronic otitis media. STUDY DESIGN: Retrospective human temporal bone analysis. METHODS: Fifteen temporal bones with unilateral chronic otitis media were selected and compared with contralateral normal temporal bones. Standard cytocochleograms and spiral ganglion cell reconstructions were performed on all temporal bones. Spiral ligament was divided into four segments according to the locations of different types of fibrocytes. The average loss of fibrocytes in each segment was estimated. Morphometric measurements of areas of stria vascularis and spiral ligament were made in all turns of the cochlea on mid modiolar sections. RESULTS: Loss of outer and inner hair cells was common in the basal turn of the cochlea in temporal bones with chronic otitis media compared with control ears. There was no difference in the number of spiral ganglion cells in the chronic otitis media and contralateral ears. The areas of stria vascularis and spiral ligament in the basal turn decreased significantly in the ears with chronic otitis media compared with control ears. There were no significant differences between the ears with chronic otitis media and the contralateral ears for any of the regions characterized by the presence of types I-IV fibrocytes. CONCLUSION: The results of the study are consistent with the hypothesis that chronic otitis media causes cochlear disease.

Adolescent↗
PubMed2004

Cochleosaccular dysplasia: a morphometric and histopathologic study in a series of temporal bones.

OBJECTIVE: The objective of this study was to perform a morphometric analysis of a series of temporal bones with cochleosaccular dysplasia to clarify the extent of inner ear changes in this disease. STUDY DESIGN: This human temporal bone histopathologic study of a series of deaf-mute cases involves morphometric analysis, including stria vascularis and spiral ligament area measurements and spiral ganglion and hair cells counts. SUBJECTS: Thirteen temporal bones were selected from 35 with deaf mutism based on the histopathologic findings described by Scheibe. Twenty normal age-matched control subjects were used for comparisons. RESULTS: All temporal bones had the main histopathologic findings described by Scheibe, as well as severe affected stria vascularis. Seven temporal bones had cystic areas in the stria and three had concretions. Cross-sectional strial areas in temporal bones with cochleosaccular dysplasia were smaller than normal in all cochlear turns; however, no difference was found in spiral ligament cross-sectional areas. Reissner's membrane was hydropic in three temporal bones and the organ of Corti was absent in at least one cochlear turn in five. Concretions were present in the macula of seven temporal bones. Twelve temporal bones showed some level of spiral ganglion cell loss. No hair cells were observed in any temporal bone. A familial history of deafness was found in three cases. CONCLUSION: Pathologic findings were variable and limited to the saccule and scala media. The variation, perhaps, reflects the different etiologies involved in the origin of cochleosaccular dysplasia.

Adolescent↗
PubMed2004

Temperature-sensitive SV40-immortalized rat middle ear epithelial cells.

The proliferation and differentiation of middle ear epithelial cells are essential in both normal and diseased middle ears. The normal situation involves physiologic growth and renewal of the epithelium, and the diseased situation involves pathological changes of the epithelium such as mucous cell metaplasia and ciliated cell proliferation in otitis media. In this study, we used a temperature-sensitive large T antigen (the SV40 mutant) to transduce and immortalize the primary culture of middle ear epithelial cells. SV40-immortalized middle ear epithelial cells have been cultured for more than 50 passages and are stable morphologically. Their nonimmortalized parent cells died at the second passage. Immortalized middle ear epithelial cells carrying the SV40 mutant show a monolayer, cobblestonelike morphology. The cell line expresses characteristic middle ear mucosal molecules such as mucins, keratins, and collagens. It also responds to temperature changes; namely, cells proliferate at 33 degrees C, when the SV40 antigen is active, and differentiate at 39 degrees C, when the SV40 antigen is inactive. Therefore, we conclude that a temperature-sensitive middle ear epithelial cell line has successfully been established.

Animals↗
PubMed2004

Abnormal direction of internal auditory canal and vestibulocochlear nerve.

Several internal auditory canal (IAC) anomalies have been reported. To our knowledge, only one case with an abnormal direction of the IAC has been reported in an infant with Pierre Robin syndrome. In this paper, we present the first report of two non-syndromic cases with abnormal IAC direction.

Aged↗
PubMed2003

Effect of parenteral aminoglycoside administration on dark cells in the crista ampullaris.

OBJECTIVE: To observe the early and late effects of the parenteral administration of aminoglycosides on the dark cells of ampullae in the inner ear. STUDY DESIGN: Comparative study of the histopathologic characteristic of human temporal bones. SUBJECTS AND METHODS: Sixty-three temporal bones from 44 subjects (age range, 16-81 years) were examined by light microscopy. Three groups of temporal bones were selected for this study: group 1, 30 "normal" temporal bones from 22 subjects (mean age, 59 years; age range, 25-81 years) with no history or histopathologic findings of otologic disease or ototoxic drug use; group 2, 14 temporal bones from patients who received aminoglycoside treatment within 2 weeks before death; and group 3, 19 temporal bones from patients who received aminoglycoside treatment between 2 weeks and 6 months before death. RESULTS: The mean +/- SD number of dark cells in group 1 was 15.0 +/- 2.47; in group 2, it was 17.3 +/- 1.93 in the subjects who received gentamicin sulfate and 15.0 +/- 3.08 in those who received kanamycin sulfate and tobramycin; in group 3, it was 14.6 +/- 1.67 in the subjects who received gentamicin and 15.2 +/- 2.31 in those who received kanamycin and tobramycin. The overall difference between the 3 groups was not statistically significant (P =.07). The cytologic characteristics of dark cells were similar in all 3 groups. The number of dark cells showed a decline with increasing age in group 1. CONCLUSIONS: The result of this study suggests that the treatment period was probably too short to destroy the dark cells. Therefore, long-term aminoglycoside therapy may be necessary to get a more permanent result.

Adolescent↗
PubMed2003

Expression of mucins in mucoid otitis media.

A hallmark of mucoid otitis media (MOM, i.e., chronic otitis media with mucoid effusion) is mucus accumulation in the middle ear cavity, a condition that impairs transduction of sounds in the ear and causes hearing loss. The mucin identities of mucus and the underlying mechanism for the production of mucins in MOM are poorly understood. In this study, we demonstrated that the MUC5B and MUC4 were major mucins in MOM that formed distinct treelike polymers (mucus strands). The MUC5B and MUC4 mRNAs in the middle ear mucosa with MOM were up regulated 5-fold and 6-fold, compared with the controls. This upregulation was accompanied by the extensive proliferation of the MUC5B- and MUC4-producing cells in the middle ear epithelium. Further study indicated that the mucin hyperproduction was significantly linked to CD4+ and CD8+ T cells and/or CD68+ monocyte macrophages. It suggests that MUC5B and MUC4 expression may be regulated by the products of these cells.

CD4-Positive T-Lymphocytes↗
PubMed2002

The shortened cochlea: its classification and histopathologic features.

INTRODUCTION: The term 'Mondini dysplasia' has been used to describe virtually any congenital abnormality of the osseous labyrinth resulting in confusion and seemingly contradictory observations and conclusions about this type of deformity. The purpose of this study is to histopathologically classify and describe temporal bones whose cochleas have less than 2.5 turns. METHODS: Of the 1800 temporal bones in our collection, 21 from 12 cases were found to have cochleas with less than 2.5 cochlear turns. Ages ranged from stillborn to 50 years. Temporal bones were harvested at autopsy, processed and embedded in celloidin. Sections were cut at a thickness of 20 microm and every 10th section stained with hematoxylin-eosin and examined using light microscopy. The number of turns, length of cochlea, integrity of cochlear base, length of modiolus, abnormalities of the semicircular canals and vestibule, enlargement of the vestibular aqueduct and middle ears were documented. Twenty-one temporal bones from age-matched patients without cochlear deformities were used as controls for modiolar length measurements. RESULTS: Malformation of the shortened cochlea was histopathologically classified into three groups as follows: (1) Common cavity, cochlear dysplasia (one ear)--severe dysplasia of the cochlea without a complete basal turn; (2) Mondini dysplasia (11 ears)--1.5 cochlear turns, a complete basal turn, an incomplete or absent interscalar septum and a complete bone at the base of the modiolus; and (3) Mondini-like dysplasia type A (five ears)--2 turns to the cochlea including a complete basal turn and complete bone at the base of the modiolus; and type B (four ears)--1.5-2 turns to the cochlea, hypoplasia of or a missing bone at the base of the modiolus (either with or without a communication between the internal auditory canal and the cochlea) and a complete basal turn. CONCLUSION: The range of congenital malformations in short cochlea is highly variable. Fundamental to the accurate evaluation of a labyrinthine anomaly, malformations of the inner ear should be classified according to the findings in the labyrinth. We suggest the use of common cavity cochlear dysplasia, Mondini dysplasia and Mondini-like dysplasia to describe these variable anomalies.

Adolescent↗
PubMed2002

Purulent otitis media in children and adults.

This study was designed to compare tympanic membrane (TM) and middle ear (ME) pathologies of temporal bones from children and adults with purulent otitis media (POM). Thirty-four temporal bones were used from 22 subjects ages 2 days to 76 years with histopathologic evidence of POM. There were 55 age-matched controls. Histopathologic findings of the TM and ME in children and adults with POM were compared. Clinical histories and the presence of complications were recorded. The incidence of POM was more common in male children than in females. There was a significant increase in the thickness of the posterosuperior and posteroinferior quadrants in children with POM compared to non-OM children. In adults with POM, there was a significant decrease in the thickness of the posteroinferior and anteroinferior quadrants compared to non-OM adults. Children with POM showed a significant increase in the anterioinferior and posteroinferior quadrants and the umbo compared to adults with POM. Pathology of the TM and ME occurred in adults and children, but severity was greater in children. Residual mesenchyme was frequently observed in temporal bones of children. Serious complications such as labyrinthtis and meningitis were observed more frequently in children. All cases with meningitis had labyrinthitis, previous histories of otitis media and had been treated with antibiotics. Although POM occurs in both children and adults, pathologic changes of the middle ear are more severe, and complications (labyrinthitis and meningitis) occur more often in children. Our findings suggest the need to monitor children carefully under the age of 2 years who have POM.

Adolescent↗
PubMed2002

Etiology, pathophysiology of symptoms, and pathogenesis of Meniere's disease.

Endolymphatic hydrops is the pathologic feature associated with Meniere's disease. The development of endolymphatic hydrops appears to arise from multifactorial inheritance with alteration of endolymphatic homeostasis. Various factors associated with the phenomenon of hydrops include functional or anatomic obstruction of endolymphatic flow, malabsorption of endolymph, genetic anomalies, vasodilation, allergy, viral infection, and autoimmunity.

Animals↗
PubMed2002

Endolymphatic sac enhancement: reversal of pathogenesis.

As this article and many other publications have indicated, many thousands of patients with incapacitating intractable progressive Meniere's disease have had their lives restored through endolymphatic sac enhancement surgery. This is the only nondestructive procedure for Meniere's disease that has stood the test of time. Destructive procedures such as labyrinthectomy (chemical or physical) and vestibular nerve section are reserved for rare cases of failure or recurrence after sac enhancement, despite revision of the enhancement. There is much evidence to support the concept that endolymphatic sac enhancement reverses or enhances the pathogenesis of Meniere's disease. With additional clinical and molecular biologic research, endolymphatic sac enhancement will continue to improve and become more efficacious in the new millennium.

Age Factors↗