Human monocyte colony-stimulating factor stimulates the gene expression of monocyte chemotactic protein-1 and increases the adhesion of monocytes to endothelial monolayers.

The stimulation of the human umbilical vein endothelial cell (HUVEC) with recombinant human monocyte-derived colony-stimulating factor (MCSF) increased the gene expression of monocyte chemotactic protein (MCP-1). Northern blot analysis indicated that 50 U/ml of MCSF is the optimal concentration for this effect. The elevation of MCP-1 mRNA started as early as 1 h after stimulation and was maintained for at least 8 h. An increased MCP-1 level in MCSF-treated HUVEC was also demonstrated at the protein level by immunocytochemical staining using a polyclonal MCP-1-specific antibody. HUVEC activated by 50 U/ml of MCSF for 5 h showed a stronger immunofluorescence staining than control cells. Micropipette separation of THP-1 monocytes from HUVEC showed that the activation of both THP-1 and endothelium by MCSF led to an increase in the separation force by more than three times (36.2 +/- 6.7 x 10(-4) vs. 9.6 +/- 3.6 x 10(-4) dyn). An increased adhesiveness was also observed after MCSF activation of peripheral blood monocytes and HUVEC (16.7 +/- 2.7 x 10(-4) vs. 5.2 +/- 0.9 x 10(-4) dyn). The increased adhesive force in both systems was blocked by the use of anti-MCP-1 (5.5 +/- 0.8 x 10(-4) and 6.8 +/- 1.1 x 10(-4) dyn). Similar results were obtained in experiments in which only HUVEC, but not monocytes, were activated by MCSF. This increased adhesion of untreated monocytes to MCSF-activated HUVEC was also blocked by the addition of anti-MCP-1. In contrast, experiments in which only THP-1 or peripheral blood monocytes, but not HUVEC, were treated with MCSF did not show a significant increase of adhesion between these cells. These results indicate that MCSF augments monocyte-endothelium interaction primarily by its action on the endothelial cell and that this function is probably mediated through an increased expression of MCP-1. The MCSF/MCP-1-dependent adhesive mechanism might be operative in the arterial wall in vivo to lead to the trapping of the infiltrated monocyte-macrophage in the subendothelial space during atherogenesis.

Cochlin isoforms and their interaction with CTL2 (SLC44A2) in the inner ear.

Choline transporter-like protein 2 (CTL2) is a multi-transmembrane protein expressed on inner ear supporting cells that was discovered as a target of antibody-induced hearing loss. Its function is unknown. A 64 kDa band that consistently co-precipitates with CTL2 from inner ear extracts was identified by mass spectroscopy as cochlin. Cochlin is an abundant inner ear protein expressed as multiple isoforms. Its function is also unknown, but it is suspected to be an extracellular matrix component. Cochlin is mutated in individuals with DFNA9 hearing loss. To investigate the CTL2-cochlin interaction, antibodies were raised to a cochlin-specific peptide. The antibodies identify several cochlin polypeptides on western blots and are specific for cochlin. We show that the heterogeneity of the cochlin isoforms is caused, in part, by in vivo post-translational modification by N-glycosylation and, in part, caused by alternative splicing. We verified that antibody to CTL2 co-immunoprecipitates cochlin from the inner ear and antibody to cochlin co-immunoprecipitates CTL2. Using cochlear cross-sections, we show that CTL2 is more widely distributed than previously described, and its prominent expression on cells facing the scala media suggests a possible role in homeostasis. A prominent but previously unreported ribbon-like pattern of cochlin in the basilar membrane was demonstrated, suggesting an important role for cochlin in the structure of the basilar membrane. CTL2 and cochlin are expressed in close proximity in the inner sulcus, the spiral prominence, vessels, limbus, and spiral ligament. The possible functional significance of CTL2-cochlin interactions remains unknown.

Absent semicircular canals in CHARGE syndrome: radiologic spectrum of findings.

BACKGROUND AND PURPOSE: This paper describes the CT findings that characterize the middle and inner ear anomalies in coloboma, heart defects, choanal atresia, mental retardation, genitourinary, and ear anomalies (CHARGE) syndrome. With this information, neuroradiologists will be better prepared to provide clinically relevant information to their referring physicians regarding this rare syndrome. MATERIALS AND METHODS: CT studies from 13 patients were reviewed by 2 neuroradiologists with Certificate of Additional Qualification. Each ear was counted separately for a total of 26 ears. Middle and inner ear anomalies associated with CHARGE syndrome were categorized. Investigational review board approval was obtained. RESULTS: Twenty of 26 (77%) ears demonstrated cochlear aperture atresia. Four of these ears were evaluated with MR imaging and were found to lack a cochlear nerve. Twenty-one of 26 (81%) cochlea had some form of dysplasia. Six of 26 (23%) round windows were aplastic. Three of 26 (12%) round windows were hypoplastic. Twenty-one of 26 (81%) oval windows were atretic or aplastic. Fifteen of 26 (58%) vestibules were hypoplastic or dysplastic. There were 5 of 26 (19%) enlarged vestibular aqueducts. Twelve of 26 (46%) vestibular aqueducts had an anomalous course. All cases demonstrated absent semicircular canals. Twenty-three of 26 (88%) facial nerve canals had an anomalous course. Four of 26 (15%) tympanic segments were prolapsed. Three of 26 (12%) temporal bones had an anomalous emissary vein referred to as a petrosquamosal sinus. Twenty-one of 26 (81%) middle ear cavities were small. Twenty-three of 26 (93%) ossicles were dysplastic with ankylosis. Three of 26 (12%) internal auditory canals were small. CONCLUSION: The CT findings that correlate to the anomalies of CHARGE syndrome affect conductive as well as sensorineural hearing. Stenosis of the aperture for the cochlear nerve aperture on CT is suggestive of hypoplasia or absence of the cochlear nerve, which has been demonstrated in some cases by MR. Absence of the cochlear nerve would be a contraindication to cochlear implantation.

AP30, a differential protein marker for perilymph and cerebrospinal fluid in middle ear fluid, has been purified and identified as human apolipoprotein D.

Using two-dimensional (2-D) gel electrophoresis, human perilymph and cerebrospinal fluid have been shown to be highly enriched for an acidic protein with MR 30,000, we designated it as AP30. The protein exhibits charge heterogeneity, with at least eight isoforms visible between pI 4.5 to 5.5 on 2-D gels. Purification of the protein was carried out by ammonium sulfate precipitation, polybuffer exchanger column chromatofocusing, and acetone fractional precipitation. The resulting preparation also contains eight spots in the acidic area of 2-D gels, and one broad band located at Mr 30,000 by SDS-PAGE. Digestion of AP30 with neuraminidase causes the isoforms to shift to a more basic position and to consolidate into two primary spots, indicating that AP30 is a variably sialylated glycoprotein. Amino acid analysis of AP30 revealed an amino acid content very similar to that of human apolipoprotein D. Attempts to determine the amino acid sequence demonstrated that the N-terminus is blocked. Edman sequencing of two peptide fragments, generated by cyanogen bromide cleavage of AP30, both revealed sequences having 100% identity to human apolipoprotein D. Western blot analysis of AP30 with the antibody against authentic human apolipoprotein D demonstrated a high degree of cross-reactivity. These studies indicate that AP30 from human perilymph and cerebrospinal fluid is a member of the apolipoprotein D family.

Human autoantibodies and monoclonal antibody KHRI-3 bind to a phylogenetically conserved inner-ear-supporting cell antigen.

Autoimmunity is thought to be one cause of sensorineural hearing loss (SNHL). Sera from patients with rapidly progressive hearing loss have been shown to contain antibodies to a 68-kD protein in heterologous inner-ear tissue. Using guinea pig inner-ear tissue as the antigenic substrate and either Western blot or immunofluorescence (IF) or both, we tested sera from 74 patients suspected to have autoimmune hearing loss for inner-ear antibodies. Sera from 73 patients were tested by Western blot, and sera from 36 were tested by IF. Thirty-seven of 73 (51%) had antibody to a 68-70-kD protein by Western blot. Sera positive by IF stained supporting cells with a staining pattern like that previously observed with the KHRI-3 monoclonal antibody. There was concordance between Western blot and IF assays. Of 36 patients tested by both assays, 29/31 (94%) that were positive in Western blot were also positive by IF, three were negative by both tests, and two each were positive by one assay but negative by the other. Absorption of patient sera with human inner-ear tissue removed antibody reactivity to the guinea pig supporting cells, indicating that the antigen detected by the autoantibody is also present in the human inner ear. Absorption with an equal volume of white or red blood cells from the tissue donor did not remove the antibody reactivity to inner ear, showing that the absorption by inner-ear tissue is specific. Sera from three patients positive in both assays also stained a 68-70-kD inner-ear protein immunoprecipitated by the KHRI-3 monoclonal antibody, indicating that the monoclonal and human antibodies recognize the same antigen. The results support the hypothesis that patients with autoimmune sensorineural hearing loss produce autoantibodies to an inner-ear supporting cell antigen that is phylogenetically conserved and defined by the murine monoclonal antibody KHRI-3. Since KHRI-3 can induce hearing loss after infusion into the inner ear, it is likely that autoantibodies with the same antigenic target are also pathogenic in humans.

The cochlear nuclear complex: MR location and abnormalities.

PURPOSE: To determine the usefulness of MR imaging in locating known structural landmarks of the cochlear nuclear complex (CNC), and to determine the frequency of CNC abnormalities, based on these landmarks, in patients referred for MR evaluation of unilateral sensorineural hearing loss. SUBJECTS AND METHODS: We studied 12 consecutive months of temporal bone/posterior fossa MR images retrospectively to find four known structural landmarks of the CNC: the vestibulocochlear nerve root entry zone; the cerebellar flocculus; the curvilinear choroid plexus along and protruding from the foramen of Luschka; and the bulge of the CNC into the lateral recess of the fourth ventricle and the foramen of Luschka. We tabulated the number of landmarks located per CNC and the number and type of CNC MR abnormalities. Medical records were then reviewed to tabulate clinical indication for MR imaging, type of hearing deficit, and etiology of the hearing deficit and clinical-pathologic proof. RESULTS: 175 patients (ages 15-75 years) provided 350 CNCs for study. All 350 CNCs showed at least three of the four landmarks. Thirteen of the 175 patients (7.4%) had focal CNC MR abnormalities; 136 of these 175 patients had been referred for MR evaluation of unilateral sensorineural hearing loss. In 10 of these 136 patients (7.4%), the CNC abnormalities shown on MR proved to be the cause of the sensorineural hearing loss. CONCLUSIONS: MR reliably delineates the CNC. Over 1 year, approximately 7% of patients referred for MR evaluation of unilateral sensorineural hearing loss had MR-determined focal CNC abnormalities that caused the sensorineural hearing loss.

Spontaneous chronic epidural pneumocephalus resulting from hyperpneumatization of the cranium causing mass effect: case report.

OBJECTIVE AND IMPORTANCE: We report a rare case of spontaneous epidural pneumocephalus resulting from an unusual boney defect caused by hyperpneumatization of the cranium. The pneumocephalus was also unusual for its chronicity and significant mass effect. CLINICAL PRESENTATION: A 49-year-old man presented with a 3-year history of diffuse headaches and sensation of air movement in his sinuses on the right side. An evaluation for suspected sinusitis using computed tomography determined extensive pneumatization of most of the cranium, a large accumulation of epidural air, and a critical degree of brain shift. INTERVENTION: A right frontoparietal-temporal craniotomy with an osteoplastic bone flap was performed. The floor of the middle cranial fossa and the inner table of the bone flap were extensively debrided of air cells. A large pericranial flap was turned down over the floor of the middle cranial fossa and was held in place by a fat graft. After closing the craniotomy, a tympanostomy tube was placed into the right tympanic membrane. CONCLUSION: The incidence of hyperpneumatization of the cranium seems to be very low. Hyperpneumatization when present, however, can cause spontaneous intracranial pneumocephalus. Based on the literature and the success of this case, the optimal management is surgical obliteration of the involved air cells.

Aggressive papillary middle ear tumors: a report of two cases with review of the literature.

Adenomatous tumors of the middle ear are rare, with only approximately 100 cases reported. A distinct subclass of this tumor demonstrates microscopic papillary architecture and has a propensity to erode the petrous bone and extend intracranially. The term "aggressive papillary middle ear tumor" has recently been proposed to describe this more invasive type of middle ear tumor. Thirty-seven cases of aggressive papillary middle ear tumors have been reported. We present two additional cases and discuss the clinical, radiologic, histologic, and operative features of this locally aggressive neoplasm. The tumor affects adults of both sexes. The clinical prodrome is prolonged. Presenting signs and symptoms most often relate to the involvement of cranial nerves V-VIII. Imaging studies reveal large, enhancing, destructive tumors with a generous vascular supply. Intraoperatively, the tumors are bloody, fibrous, and adherent to surrounding structures. Various surgical approaches in combination or in series may be used. Preoperative embolization may be helpful. The role of adjunctive radiation is unclear. Aggressive papillary middle ear tumors are histologically benign tumors with clinically destructive behavior. However, it appears that aggressive surgical management affords prolonged survival with minimal worsening of cranial nerve deficits.

Normal auditory brainstem response in patients with acoustic neuroma.

Auditory brainstem response testing has been a major breakthrough in audiologic screening for acoustic neuroma because of its high degree of sensitivity. Although it is not uncommon for other cerebellopontine angle masses to present with normal ABR findings, reports of eighth nerve tumors with false-negative auditory brainstem response tests are quite rare. A series of 120 acoustic neuromas resected at the University of Michigan was reviewed and revealed two such patients. These two patients presented with asymmetric sensorineural hearing loss and unilateral tinnitus and were found to have completely normal auditory brainstem response. The diagnosis of acoustic neuroma would have been delayed if a comprehensive evaluation had not been pursued.

Bacteriology of tonsil surface and core in children.

The tonsils of 97 children undergoing tonsillectomy were studied to determine the correlation between surface culture swab and culture of tonsillar core. In many cases, pathogenic organisms were found in the tonsil core, despite the fact that surface cultures revealed only normal respiratory flora. The tonsil core cultures showed a high incidence of Hemophilus influenzae and Staphylococcus aureus, which was rarely reflected on surface culture. The study indicates that pharyngeal swab cultures do not reliably reflect the presence of pathogens in the tonsil core. The value of parameters such as history of recurrent bouts of tonsillitis and presence of erythema or cryptic debris on physical examination for predicting the differential bacteriology of the tonsil is studied. The implications for treatment of children with adenotonsillar hypertrophy are discussed.

Retrolabyrinthine vestibular nerve section: efficacy in disorders other than Menière's disease.

The retrolabyrinthine vestibular nerve section has evolved as an effective treatment for intractable vertigo of peripheral vestibular origin when hearing preservation is desired. This report studies the efficacy of retrolabyrinthine vestibular nerve section for control of vertigo due to causes other than Meniere's disease. This report details our experience with 42 patients with a wide variety of diagnoses. The reduced success rate of retrolabyrinthine vestibular nerve section in these patients is difficult to evaluate, as very few patients have been analyzed with respect to their specific diagnoses. Of patients who underwent retrolabyrinthine vestibular nerve section for control of vertigo, 23 patients had uncompensated vestibular neuritis and 19 others had a wide range of other diagnoses. For patients with uncompensated vestibular neuritis (n = 23), the physician record noted that 39% of patients were cured and 30% improved. This compares to our series of patients with Meniere's disease (n = 48), where 94% were cured and 2% improved. The true vestibular abnormality may be less reliably identified in patients with uncompensated vestibular neuritis, contributing to the less effective results. Since the development of a vestibular rehabilitation program, retrolabyrinthine vestibular nerve section for uncompensated vestibular neuritis has been all but abandoned. Retrolabyrinthine vestibular nerve section appears to achieve a high cure rate in patients with sensorineural hearing loss associated with their vestibular abnormalities. While retrolabyrinthine vestibular nerve section is helpful for control of vertigo in some diagnoses, a substantial incidence of persistent postoperative dysequilibrium was noted.

Hearing preservation following suboccipital removal of acoustic neuromas.

Advances in the diagnosis and intraoperative management of acoustic neuromas have greatly reduced the incidence of neurologic deficits following their removal. Ninety-three patients underwent acoustic tumor removal during a 41/2-year period, and hearing preservation was attempted in 20 cases. Hearing was preserved in 65% of the entire series, and excellent results were obtained in tumors less than 1.5 cm. No patient with a tumor greater than 1.5 cm had serviceable hearing preserved when total tumor removal was performed. Two patients, one with neurofibromatosis and one with an acoustic neuroma in an only-hearing ear, had planned partial tumor removal with preservation of hearing. Preoperative auditory brainstem response results were not predictive of postoperative hearing preservation. Intraoperative auditory brainstem response monitoring demonstrated that loss of wave V consistently correlated with loss of hearing postoperatively, whereas persistence of wave V (with a latency prolongation not exceeding 3.00 ms) was predictive of successful hearing preservation regardless of latency increases.

Evaluation of clinical measures of equilibrium.

OBJECTIVE: Evaluate the clinical utility of several simple measures of static and dynamic equilibrium in human subjects. In particular, one proposed clinical measure, the Clinical Test of Sensory Integration and Balance (CTSIB) was compared with dynamic posturography for the measurement of postural control capabilities. STUDY DESIGN: Cross-sectional study of normal subjects and prospective observational study of the same performance measures in vestibular disorder patients. SETTING: Academic tertiary care referral center. PARTICIPANTS: Data were collected for all test measures from a group of normal subjects (ages, 20 to 79 years), as well as for a group of patients undergoing treatment for vestibular dysfunction. RESULTS: Data suggest that several semiquantitative clinical tests of static and dynamic equilibrium can be helpful in evaluating and monitoring patients with chronic vestibular dysfunction. The CTSIB results seem to correlate well with dynamic posturography, suggesting that this measure may be useful in identifying patients with abnormal postural control. Formal dynamic posturography testing appears to be more sensitive in detecting abnormal postural control and more exact in defining the specific pattern of dysfunction. CONCLUSION: Simple clinical measures of static and dynamic equilibrium can reliably distinguish vestibular disorder patients from normal subjects. Dynamic posturography continues to play an important role in the functional evaluation and management of vestibular disorder patients.

Anatomic basis for labyrinthine preservation during posterior fossa acoustic tumor surgery.

Earlier diagnosis of acoustic tumors promises to increase our opportunity to identify patients with serviceable hearing. Critical to a posterior fossa transmeatal approach for acoustic tumor resection is preservation of the underlying labyrinth. Although the labyrinth has been recognized as a limiting factor in exposure of tumor in the internal auditory canal, few reports have detailed the microscopic surgical anatomy posterior to the internal auditory canal. An anatomic study was undertaken to determine consistent relationships between critical structures within the temporal bone relevant to hearing preservation surgery. The results of this study indicate that, whereas topographic landmarks are helpful for orientation, the more consistent relationship of the labyrinth to the vestibular aqueduct and singular canal allows a more accurate localization of the underlying labyrinth. Although the vestibule frequently prevents direct visualization of the transverse crest, a dissection based upon the microsurgical anatomy will maximize visualization of the lateral fundus while preserving the integrity of the labyrinth.

Local control of auricular, periauricular, and external canal cutaneous malignancies with Mohs surgery.

Three hundred ninety-seven patients with 407 cutaneous malignancies of the auricle, periauricular region, and cartilaginous external ear canal were reviewed. Tumors were most commonly located in the preauricular and postauricular regions, followed by the helix, concha, antihelix, and ear canal. All lesions were excised with Mohs microscopic control of margins. For lesions requiring lateral temporal bone resection, an adaptation of fresh-tissue microscopic control was used to analyze deep and anterior margins suspected of harboring residual tumor. Two-year minimum follow-up of 229 patients with periauricular and auricular tumors (N = 231 tumors) and 14 patients with cartilaginous ear canal tumors (N = 14 tumors) revealed recurrence rates of 6.9% and 14.3%, respectively. Recurrences were most common in cases of large tumors (greater than 2.5 cm), basal cell carcinomas with morphea elements, and multiply recurrent lesions. We conclude that Mohs surgery is comparatively effective, though not uniformly curative, and can be adapted to supplement excision of large tumors in these regions.

Familial Mondini dysplasia.

OBJECTIVES/HYPOTHESIS: To determine the mode of inheritance of familial nonsyndromic Mondini dysplasia. STUDY DESIGN: Correlative clinical genetic analysis of a single kindred. METHODS: Clinical history, physical examination, audiologic analysis, computed tomography of the temporal bones, and cytogenetic analysis. RESULTS: The male proband, three affected sisters, and an affected brother are offspring of unaffected parents. The mother and an unaffected brother have audiologic findings suggestive of heterozygous carrier status for a recessive hearing loss gene. CONCLUSIONS: Pedigree analysis indicates autosomal recessive inheritance in this family. The observed inheritance and clinical, audiologic, and radiologic findings are different from those previously described for another family with nonsyndromic Mondini dysplasia. The phenotype in this study family therefore represents a distinct subtype, indicating clinical and genetic heterogeneity of this disorder. This information should facilitate future molecular linkage analyses and genetic counselling of patients with inner ear malformations.

Antibodies to HSP-70 in normal donors and autoimmune hearing loss patients.

OBJECTIVE: To evaluate serum antibody to heat shock protein (HSP) 70 as a marker for autoimmune sensorineural hearing loss (AISNHL). DESIGN: Sera from 20 patients with rapidly progressive sensorineural HL and 20 control volunteers without HL were tested for antibody reactivity against multiple HSP 70 substrates. Substrates included recombinant human HSP (rHuHSP) 72, purified bovine brain heat shock cognate (HSC) 73 and HSP 72, as well as heat-shocked and non-heat-shocked protein extracts from bovine kidney (MDBK) cells. All serum donors were previously tested for antibody to guinea pig inner ear supporting cells; 17 of 20 patients but none (0 of 20) of the controls were positive. METHODS: Sera were tested using Western blots. RESULTS: Reactivity with rHuHSP 70 was observed in 16 patients and 17 controls. Similarly, 15 of 20 patients and 17 of 20 controls stained for both HSP 72 and HSC 73 from the bovine brain. When tested against the heat-shock-induced and control MDBK extracts, six patients and nine controls had greater reactivity with the induced HSP 72. CONCLUSION: The frequency of antibodies to HSP substrates did not differ in patients and controls. Prior studies reported that HSP 72 is the 68 kD antigen commonly detected by AISNHL sera. However, we show that HSP 72 antibodies are no more prevalent in patients than in normal controls. Thus, it is unlikely that the 68 kD protein is HSP 72. Therefore, HSPs are not appropriate substrates for serodiagnosis of AISNHL.

Habituation and balance retraining therapy. A retrospective review.

The results presented indicate that rehabilitation therapy for balance disorders can be of significant benefit for a wide range of patients as a singular management tool or in combination with medical or surgical techniques. Although more investigative work is needed to adequately address the issue of customized versus generic programs, the present data begin to suggest some possible advantages to an approach individualized to each patient.

Hearing recovery following suboccipital excision of acoustic neuroma.

Improvement of hearing after excision of an acoustic neuroma has been observed infrequently. We present a case of dramatic recovery of hearing in a patient with a 1-cm acoustic neuroma whose pure-tone thresholds and speech discrimination had profoundly deteriorated while she awaited surgical therapy. Postoperatively, her hearing in the affected ear is equal to that in her other ear, and her speech discrimination exceeds that of her best preoperative audiogram. Issues related to hearing preservation and improvement after acoustic tumor surgery are discussed.

Electrically evoked auditory brain-stem response in pediatric patients with cochlear implants.

OBJECTIVE: To study the feasibility and clinical applicability of preoperative, transtympanic electrically evoked auditory brain-stem response (EABR) in a pediatric patient population with cochlear implants. DESIGN: A descriptive study using repeated measures analyses of variance to determine if EABR measures were affected by response configuration or cochlear status. SETTING: The operating room before cochlear implant surgery. PATIENTS: A population-based sample of 43 patients aged 2.5 to 14.5 years who were candidates for cochlear implantation. INTERVENTION: Stimuli consisting of brief balanced biphasic current pulses were provided by a transtympanically placed promontory needle electrode; EABR was recorded with subdermal needle electrodes on the forehead and contralateral mastoid. MAIN OUTCOME MEASURE: Presence or absence of postoperative electrical excitability with a cochlear implant. RESULTS: Electrically evoked auditory brain-stem responses were available from 41 of the 43 patients tested. Mean EABR threshold was 406.5 microA (SD = 118.1) for 31 patients with patent cochleas and 472 microA (SD = 91) for 10 patients with cochlear ossification. Mean wave V latency at threshold was 4.69 milliseconds (SD = 0.57). CONCLUSION: Preoperative EABR is an integral component of the preoperative selection process for pediatric patients with cochlear implants.