Diversity of the cochlear and vestibular pathologies in human temporal bones of newborns infected with cytomegalovirus.

Hypothesis: Human temporal bones of newborns with congenital cytomegalovirus (cCMV) infection can be characterized by diverse cochlear and vestibular histopathologies associated with the variability in sensorineural hearing loss (SNHL) and vestibular dysfunction in these newborns.

Background: Only a small number of studies on the cochlear and vestibular pathologies in human temporal bones with cCMV infection have been previously reported.

Methods: Cochleovestibular histopathologies were evaluated in 4 temporal bones from 3 infants with cCMV infection by light microscopy.

Formations of Host Fibers and Bacteria in Human Temporal Bones With Otitis Media.

Hypothesis: In temporal bones with otitis media, fibrin and neutrophil extracellular traps (NETs) form a fibrous network with bacteria, which is involved in growth of bacterial clusters/biofilms and chronicity of disease.

Background: NETs and fibrin are important in host defense against pathogens; however, their role in otitis media is not well understood.

Methods: Eight human temporal bones with serous otitis media, 30 with serous-purulent otitis media, 7 with mucoid otitis media, 23 with mucoid-purulent otitis media (OM), 30 with purulent OM, and 30 with chronic otitis media were selected based on histopathologic findings.

Cytomegalovirus-induced pathology in human temporal bones with congenital and acquired infection.

Objective: Publications on histopathology of human temporal bones with cytomegalovirus (CMV) infection are limited. We aim to determine histopathology of the inner ears and the middle ears in human temporal bones with congenital and acquired CMV infections.

Methods: Temporal bones from 2 infants with congenital and 2 adults with acquired CMV infection were evaluated by light microscopy.

Neutrophil Extracellular Traps and Fibrin in Otitis Media: Analysis of Human and Chinchilla Temporal Bones.

Background: Bacterial resistance in acute otitis can result in bacterial persistence and biofilm formation, triggering chronic and recurrent infections.

Objective: To investigate the middle ear inflammatory response to bacterial infection in human and chinchilla temporal bones.

Design, Setting, And Participants: Six chinchillas underwent intrabullar inoculations with 0.

Deterioration of Vestibular Cells in Labyrinthitis.

Objective: To quantitatively assess the effect of serous labyrinthitis, suppurative labyrinthitis, and labyrinthitis ossificans on vestibular hair cells, dark cells, and transitional cells.

Methods: We examined human temporal bone specimens with serous labyrinthitis, suppurative labyrinthitis, and labyrinthitis ossificans, then compared them with age-matched control groups without labyrinthitis. We evaluated the density of type I and II vestibular hair cells, dark cells, and transitional cells in the peripheral sensorial organs.

A three-dimensional analysis of the endolymph drainage system in Ménière disease.

Objectives/hypothesis: To measure the volume of the endolymph drainage system in temporal bone specimens with Ménière disease, as compared with specimens with endolymphatic hydrops without vestibular symptoms and with nondiseased specimens STUDY DESIGN: Comparative human temporal bone analysis.

Methods: We generated three-dimensional models of the vestibular aqueduct, endolymphatic sinus and duct, and intratemporal portion of the endolymphatic sac and calculated the volume of those structures. We also measured the internal and external aperture of the vestibular aqueduct, as well as the opening (if present) of the utriculoendolymphatic (Bast's) valve and compared the measurements in our three study groups.

Pathologic Changes of the Peripheral Vestibular System Secondary to Chronic Otitis Media.

Objective: To evaluate the histopathologic changes of dark, transitional, and hair cells of the vestibular system in human temporal bones from patients with chronic otitis media.

Study Design: Comparative human temporal bone study.

Setting: Otopathology laboratory.

Quantitative Assessment of Cochlear Histopathologic Findings in Patients With Suppurative Labyrinthitis.

Importance: Better understanding of the effects of suppurative labyrinthitis (SL) on cochlear elements will aid the development of new approaches to treat its sequelae and complications in the ear.

Objective: To quantitatively evaluate the effects of SL on cochlear elements in humans.

Design, Setting, And Participants: A comparative study was conducted at a tertiary academic medical center from October 20, 2014, to January 3, 2015, of the histopathologic characteristics of 28 archived human temporal bone samples from 19 deceased patients with SL and 20 temporal bone samples from 14 deceased, age-matched controls.

Cochlear changes in serous labyrinthitis associated with silent otitis media: A human temporal bone study.

Purpose: To determine histopathological findings in the cochlea of human temporal bones with serous labyrinthitis.

Materials And Methods: We compared human temporal bones with serous labyrinthitis (20 cases) associated with silent otitis media and without serous labyrinthitis (20 cases) to study location of serous labyrinthitis, the degree of endolymphatic hydrops, number of spiral ganglion cells and hair cells, loss of fibrocytes in the spiral ligament, and areas of the spiral ligament and stria vascularis.

Results: The serous labyrinthitis caused significant loss of outer hair cells in the lower basal (P=0.

Pneumococcal PspA and PspC proteins: potential vaccine candidates for experimental otitis media.

Objective: Otitis media is the most commonly diagnosed disease in ambulatory care and Streptococcuspneumoniae continues to be the most common bacterial agent. Bacterial resistance to antibiotics underscores the need for better vaccines. Current pneumococcal conjugate vaccines are modestly protective against otitis media; however, limited serotype coverage and serotype replacement have led to the investigation of pneumococcal proteins as potential vaccine candidates.

The pathology of silent otitis media: a predecessor to tympanogenic meningitis in infants.

Objective: To determine the association of bacteria embedded within a fibrous matrix in the middle and inner ear in infants with tympanogenic meningitis.

Methods: Thirty-one cases with meningitis from the human temporal bone collection at the University of Minnesota were screened to select those with tympanogenic meningitis. Inclusion criteria for tympanogenic meningitis were acute meningitis with histopathological evidence of chronic otitis media, and no other source of infection.

Viability and virulence of pneumolysin, pneumococcal surface protein A, and pneumolysin/pneumococcal surface protein A mutants in the ear.

Importance: Understanding how pneumococcal proteins affect the pathology of the middle ear and inner ear is important for the development of new approaches to prevent otitis media and its complications.

Objectives: To determine the viability and virulence of Streptococcus pneumoniae mutants deficient in pneumolysin (Ply-) and pneumococcal surface protein A (PspA-) in the chinchilla middle ear.

Design: Bullae of chinchillas were inoculated bilaterally with wild-type (Wt), Ply-, PspA-, and Ply-/PspA- strains.

Effect of apolactoferrin on experimental pneumococcal otitis media.

Objective: To find the effect of apolactoferrin administration on the middle and inner ears after experimentally induced pneumococcal otitis media.

Design: Histopathologic and morphometric analysis of the middle and inner ears.

Setting: University of Minnesota, Minneapolis.

Cochlear pathology in human temporal bones with otitis media.

Conclusion: Middle and inner ear interactions in otitis media can lead to cochlear pathology. More severe pathological changes observed in the basal turn of the cochlea are consistent with prevalence of sensorineural hearing loss at higher frequencies in patients with otitis media.

Methods: Of 614 temporal bones with otitis media, 47 with chronic and 35 with purulent otitis media were selected following strict exclusion of subjects with a history of acoustic trauma, head trauma, ototoxic drugs, and other diseases affecting the cochlear labyrinth.

Effect of lipooligosaccharide mutations of Haemophilus influenzae on the middle and inner ears.

Objective: The purpose of this study was to determine the virulence of nontypeable Haemophilus influenzae 2019 (NTHi 2019) and its two lipooligosaccharide (LOS) mutant strains, B29 (gene htrB) and DK1 (gene rfaD), and compare their effect on the middle ear, round window membrane, and inner ear.

Results: Fifteen chinchillas were divided into three equal groups and their bullas inoculated bilaterally with 0.5 ml of 10(2)CFU/ml of parent NTHi 2019, B29 or DK1 mutant strains.

Virulence of pneumococcal proteins on the inner ear.

Objective: To investigate the effects of the virulence characteristics of specific pneumococcal proteins on the inner ear.

Main Outcome Measures: A histologic comparison of inflammatory cell infiltration and pathologic changes in the round window membrane and inner ear.

Results: Most of the animals inoculated with high-dose pneumolysin or wild-type bacteria showed severe pathologic changes of the inner ears.

Role of pneumococcal proteins in sensorineural hearing loss due to otitis media.

Hypothesis: Two Streptococcus pneumoniae proteins, pneumococcal surface protein A (PspA) and pneumolysin (Ply), have functional and histopathologic effects on the inner ear.

Background: Temporary or permanent sensorineural hearing loss is known to be a sequela of pneumococcal otitis media. Several pneumococcal proteins such as PspA and Ply have been shown to contribute to the pathogenesis of the middle ear; however, effects of these proteins on the inner ear and hearing loss are unknown.

Up-regulation of macrophage migration inhibitory factor induced by endotoxin in experimental otitis media with effusion in mice.

Conclusion: Injection of endotoxin into the middle ear causes production of macrophage migration inhibitory factor (MIF) in an experimental mouse model of otitis media with effusion (OME). Down-regulation of MIF may become a new approach for the management of OME.

Objective: To determine the role of MIF in OME.

The round window membrane in otitis media: effect of pneumococcal proteins.

Objective: To determine whether mutants of Streptococcus pneumoniae that are deficient in pneumococcal surface protein A (PspA), pneumococcal surface antigen A (PsaA), or pneumolysin (Ply) are less virulent and less likely to penetrate the round window membrane (RWM).

Design: Histopathologic comparison of wild-type S. pneumoniae and its mutants deficient in PspA, PsaA, and Ply.

Pneumococcal peptidoglycan-polysaccharides induce the expression of interleukin-8 in airway epithelial cells by way of nuclear factor-kappaB, nuclear factor interleukin-6, or activation protein-1 dependent mechanisms.

Cell envelope compounds of bacteria trigger immune and inflammatory reactions by way of chemokines/cytokines. In this study, we demonstrated that pneumococcal peptidoglycan-polysaccharides (PGPS) induced the production of interleukin (IL)-8 by way of nuclear factor (NF)-kappaB, nuclear factor interleukin (NF-IL)6, and activation protein (AP)-1 dependent mechanisms in the human bronchial epithelial cells (NL-20) in a dose- and time-dependent manner in vitro, and the mutation of either the NF-kappaB, NF-IL6, or AP-1 binding sites in the promoter of IL-8 abrogated the IL-8 transcriptional activity. In a similar way, lipopolysaccharides induced the promoter activation of IL-8 in NL-20.

Age-related functional and histopathological changes of the ear in the MPS I mouse.

Objective: Mucopolysaccharidosis type I (MPS I) is an autosomal recessive disorder caused by a mutation in the gene encoding the enzyme alpha-L-iduronidase. This enzyme is responsible for degradation of dermatan and heparan sulfates. Enzyme deficiency results in their accumulation in lysosomes of virtually all organs, resulting in severe somatic and neurological changes.

Specificity of aminoacylase III-mediated deacetylation of mercapturic acids.

Trichloroethylene (TCE) and other halogenated alkenes are known environmental contaminants with cytotoxic and nephrotoxic effects, and are potential carcinogens. Their metabolism via the mercapturate metabolic pathway was shown to lead to their detoxification. The final products of this pathway, mercapturic acids or N-acetyl-l-cysteine S-conjugates, are secreted into the lumen in the renal proximal tubule.

Otosclerosis: etiopathogenesis and histopathology.

Otosclerosis is a disease of the bony labyrinth manifesting clinically as a progressive conductive hearing loss, a mixed-type hearing loss, or a sensorineural hearing loss. The age of onset of the hearing loss caused by otosclerosis is principally between 15 and 40 years. Although histopathological inner ear changes due to otosclerosis have been very well documented, the true etiopathogenesis of the disease has yet to be described despite intensive research.

Round window membrane and labyrinthine pathological changes: an overview.

The round window membrane is considered the most likely pathway from the middle to the inner ear. Various substances placed in the middle ear have been seen to pass through the round window membrane. Once toxic substances or inflammatory mediators such as cytokines and nitric oxide enter the inner ear, various inner ear sequelae such as labyrinthitis, endolymphatic hydrops, sensorineural hearing loss or more insidious diseases can occur.

The structure of tip links and kinocilial links in avian sensory hair bundles.

Recent studies have indicated that the tip links and kinocilial links of sensory hair bundles in the inner ear have similar properties and share a common epitope, and that cadherin 23 may also be a component of each link type. Transmission electron microscopy was therefore used to study and compare the fine structure of the tip links and kinocilial links in avian sensory hair bundles. Tannic acid treatment revealed a thin strand, 150-200 nm long and 8-11 nm thick, present in both link types.