Petrous apex cholesterol granuloma treated via the endoscopic transsphenoidal approach.

Numerous surgical approaches have been used to treat petrous apex cholesterol granulomas. They are usually treated via the transtemporal- or middle fossa approach; some are managed endoscopically. We present a patient treated by the endoscopic transsphenoidal approach and review the literature.

Identification of the protein product of the Coch gene (hereditary deafness gene) as the major component of bovine inner ear protein.

In order to better understand the cause of hereditary hearing impairment, we have performed a proteomic analysis of the inner ear proteins using two-dimensional gel electrophoresis. In the process of analysis, we have found very unique properties of the bovine homologue of the human COCH gene product. The COCH gene is responsible for one of the hereditary hearing impairments, DFNA9, and was recently suggested to be a possible genetic factor contributing to Ménière's disease. The Coch protein constitutes 70% of bovine inner ear proteins and is composed of 16 different protein spots, with charge and size heterogeneity. Heterogeneity of this protein suggests that the Coch gene is processed in several ways, at the transcriptional and/or posttranslational level. Much knowledge has accumulated about the hereditary hearing impairment genes; however, little research has been done regarding the protein products of those genes. This is the first report to characterize the Coch protein. Study of the Coch protein might provide more information on the mechanism of hearing and vestibular disorders.

Passive transfer of experimental autoimmune labyrinthitis.

The aim of the present study was to establish an animal model of autoimmune labyrinthitis using heterologous inner ear antigen (IEAg) and to elucidate whether the experimentally induced labyrinthitis could be passively transferred. Cochlear and vestibular membranous labyrinthine tissues from bovine temporal bones were used as IEAg. Donor mice were inoculated intracutaneously at multiple sites with an emulsion consisting of equal parts of IEAg and complete Freund's adjuvant. After 10 days, mononuclear cells were collected from lymph nodes, spleen and blood of the donor mice and injected intravenously into naive recipient mice. Cellular infiltration was observed in the perilymphatic space of the cochlea of all donor and recipient mice. Endolymphatic hydrops was also observed in 63% of donor and 42% of recipient mice. These findings suggest that the experimentally induced labyrinthitis observed in this animal model was probably due to an autoimmune reaction to the IEAg and was passively transferred by a cell-mediated immune reaction.

Experimental autoimmune labyrinthitis induced by cell-mediated immune reaction.

This study was designed to establish an experimental cell-mediated autoimmune labyrinthitis model in C57BL/6 mice, which could exhibit high reproducibility and be adopted for precise immunological analysis. Inner ear antigen (IEA) was prepared from bovine membranous labyrinth. Following pretreatment with cyclophosphamide (CP) and primary sensitization with IEA/FCA, many inflammatory cells infiltrated transiently into the perilymphatic and endolymphatic regions of the cochlea, vestibule and the endolymphatic sac, but not into the kidney, lung, brain or liver. This reaction occurred from day 7 and peaked on day 12 in all animals, and then rapidly reduced. This reaction occurred in all experimental mice during day 10 to day 12. The control mice showed no cellular reaction in the inner ear. These results suggest that the inner ear may possess cross-species organ-specific antigen and that a cell-mediated immune reaction may play an important role in the induction of autoimmune labyrinthitis.

Interferon-gamma stimulates human Clara cell secretory protein production by human airway epithelial cells.

Clara cell secretory protein (CCSP) is an inhibitor of secretory phospholipase A2. It is produced by airway epithelial cells and is present in airway secretions. Because interferon (IFN)-gamma can induce gene expression in airway epithelial cells and may modulate the inflammatory response in the airway, it was of interest to study the effect of this cytokine on epithelial cell CCSP mRNA expression and CCSP protein synthesis. A human bronchial epithelial cell line (BEAS-2B) was used for this study. CCSP mRNA was detected by ribonuclease protection assay. IFN-gamma was found to increase CCSP mRNA expression in a time- and dose-dependent manner. The CCSP mRNA level increased after IFN-gamma (300 U/ml) treatment for 8-36 h, with the peak increase at 18 h. Immunobloting of CCSP protein also demonstrated that IFN-gamma induced the synthesis and secretion of CCSP protein in a time-dependent manner. Nuclear run-on, CCSP reporter gene activity assay, and CCSP mRNA half-life assay demonstrated that IFN-gamma-induced increases in CCSP gene expression were mediated, at least in part, at the posttranscriptional level. The present study demonstrates that IFN-gamma can induce increases in steady-state mRNA levels and protein synthesis of human CCSP protein in airway epithelial cells and may modulate airway inflammatory responses in this manner.

Intercellular adhesion molecule-1 expression in the inner ear of rats following secondary immune reaction in the endolymphatic sac.

An immunological aetiology for inner ear diseases has long been proposed. The endolymphatic sac (ES) is the only immunoprivileged site in the inner ear with a resident population of immunocompetent cells. By keyhole limpet hemocyanin (KLH) challenge into the ES of systemically pre-immunized guinea pigs, we previously demonstrated an infiltration of inflammatory cells into the perilymphatic space of the cochlea. In order to understand the mechanisms involved in the recruitment of immunocompetent cells into the inner ear, and their relation to the development of endolymphatic hydrops (EH), we investigated the expression and time-kinetics of intercellular adhesion molecule 1 (ICAM-1) in the inner ear of systemically pre-immunized rats after antigen (KLH) challenge into the ES, its relation to cell infiltration in the cochlea and subsequent development of EH. By immunohistochemistry, strong ICAM-1 expression was detected in the spiral ligament, suprastrial region, spiral prominence, spiral modiolar veins, spiral collecting venules, surface membrane of the perilymphatic compartment, perilymphatic space and ES of immunized rats, but not of control rats. ICAM-1 expression was detected at 5-6 h, peaked at 10-15 h, and gradually reduced by 2 weeks. Cell infiltration into the cochlea started at 6-12 h and peaked at day one. By 6 h, 50% of challenged rats developed EH. This figure rose to 70% at 12 h, and then gradually reduced. However, immunoreactivity for KLH (antigen) was only detected in the ES. These results emphasize that the sac is the central immunological organ of the inner ear, and suggest that ICAM-1 may play a pivotal role in the aetiology of immune-mediated inner ear diseases through the recruitment of immunocompetent cells into the inner ear and subsequent development of EH.

Leukemia inhibitory factor induces the 85-kDa cytosolic phospholipase A2 gene expression in cultured human bronchial epithelial cells.

Leukemia inhibitory factor (LIF) has become increasingly recognized as an important regulator of inflammation. This study is designed to determine whether LIF has an effect on arachidonate metabolism in human airway epithelial cells. LIF (100 ng/ml) induced a significantly increased release of prelabeled [3H] arachidonic acid (AA) from the human bronchial epithelial cell line (BEAS 2B cell) as well as from the primary cultures of human bronchial epithelial cells. Exposure of the LIF stimulated BEAS 2B cells to calcium ionophore A23187 (10(-5) M, 15 min) caused a further increase of [3H]AA release. To identify the role of cytosolic phospholipase A2 (cPLA2) in this upregulation of AA release, further experiments were performed to determine the expression of cPLA2 in the BEAS 2B cells. Immunoblot analysis indicated that LIF increased cPLA2 protein expression. Ribonuclease protection assay showed that LIF induced an increase of cPLA2 mRNA levels following 3 h to 24 h treatment. Nuclear run-on experiments suggested that LIF upregulated cPLA2 gene expression through post-translational regulation. These results demonstrate that LIF induces cPLA2 gene expression and modulates arachidonate metabolism in airway epithelial cells.

Distribution of endothelin-1-like activity in the cochlea of normal guinea pigs.

Distribution of endothelin-1 (ET-1) in the cochlea of normal guinea pigs was determined by immunohistochemistry. ET-1 activity was identified with the mouse anti-human ET-1 IgG1 monoclonal antibody. ET-1 activity was distributed in the modiolus, spiral ligament, stria vascularis, spiral prominence. Reissner's membrane, supporting cells of the organ of Corti and spiral ganglion cells. These findings suggest that ET-1 may be involved in the regulation of fluid volume and ions of the cochlea.

Tumor necrosis factor-alpha induces the 85-kDa cytosolic phospholipase A2 gene expression in human bronchial epithelial cells.

Phospholipase A2 (PLA2) activity has been suggested to mediate some of the tumor necrosis factor (TNF) induced cellular responses including cytotoxicity. We evaluated the induction of both the 85-kDa cytosolic phospholipase A2 (cPLA2) and non-pancreatic group II PLA2 gene expression by TNF-alpha in a human bronchial epithelial cell line (BEAS 2B cell). TNF-alpha (20 ng/ml) induced a significantly increased release of prelabeled [3H]arachidonic acid (AA) following 4-24 h incubation. Calcium ionophore A23187 (10(-5) M) further increased the [3H]AA release from the TNF-alpha-treated cells. In vitro activity assay revealed that TNF-alpha increased the dithiothreitol (DTT)-resistant PLA2 activity which was blocked by the cPLA2 inhibitor AACOCF3. Treatment with TNF-alpha for 4-24 h increased the cPLA2 protein and mRNA levels which were blocked by the broad inhibitor of protein kinases staurosporine, the protein kinase C (PKC) inhibitor calphostin C, and to a lesser extent the calcium/calmodulin-dependent protein kinase inhibitor W-7. Reverse transcription and polymerase chain reaction amplification of the group II PLA2 mRNA showed that it is expressed in human lung but not in the bronchial epithelial cell line. TNF-alpha failed to induce the expression of group II PLA2 in the BEAS 2B cells. These results demonstrate that the cPLA2 gene expression is up-regulated by TNF-alpha and this effect may contribute to the TNF-alpha stimulated AA release in airway epithelial cells.

Fluctuating hearing loss following immune reaction in the endolymphatic sac of guinea pigs.

This study has investigated immune injuries to the inner ear auditory system of guinea pigs. Following secondary antigen challenge to the endolymphatic sac, the mean hearing threshold significantly increased in the early phase from day 1 to day 3 and thereafter recovered. In the early phase, hearing threshold significantly increased simultaneously to the elevation of perilymph antibody levels. The size of hydrops was not the only factor that causes an increase in hearing loss as well as in AP/SP ratio. Scale-out hearing loss was seen in 2 animals with severe degeneration of the stria vascularis as well as the organ of Corti associated with the inflammatory cellular infiltration especially in the perilymphatic space, even in the absence of keyhole limpet hemocyanin antigen in the cochlea. On the other hand, control animals did not suffer hearing loss. These results suggest that an immune reaction in the endolymphatic sac is a possible pathogenic etiology of Ménière's disease or sudden deafness.

Characterization of the promoter for the human 85 kDa cytosolic phospholipase A2 gene.

The 85 kDa cytosolic phospholipase A2 (cPLA2) plays a key role in the production of arachidonic acid and lysophospholipids, the precursors of eicosanoids and platelet-activating factor. Here we report the cloning of the promoter of the human cPLA2 gene. A 5.7 kb EcoRI fragment containing the most 5' region of the cPLA2 cDNA was sequenced. The transcription initiation site was identified by rapid amplification of 5'-cDNA ends (5'-RACE) and primer extension analysis. DNA sequence analysis of the 595 base pairs 5' of the transcription start site reveals a 48 base purine-pyrimidine dinucleotide repeat (CA repeat), five interferon-gamma response elements (gamma-IRE), one interferon-gamma activated sequence (GAS) and two glucocorticoid response elements (GRE). The promoter lacks a TATA box. It contains a possible CAAT box at -111 and two octamer binding motifs. The 595 base fragment located immediately upstream of the transcriptional start site exhibited functional promoter activity in transient transfection assays in a bronchial epithelial cell line (BEAS 2B cells). Deletion analysis revealed that the CA repeat may confer an inhibitory effect on the cPLA2 promoter activity. The characterization of the human cPLA2 promoter sequence will allow further studies defining the molecular events regulating the expression of the cPLA2 enzyme, especially the cytokine mediated cPLA2 gene expression.

Immunological approach to Ménière's disease: vestibular immune injury following immune reaction of the endolymphatic sac.

Following direct antigen challenge to the endolymphatic sac (sac), the relation of caloric test results and spontaneous nystagmus to the histological changes of the sensory epithelium of the vestibular organ and perilymph antibody levels was investigated in the guinea pig. In a secondary keyhole limpet hemocyanin (KLH) challenge to the sac, irritative nystagmus was followed by paralytic nystagmus and a suppression of caloric reaction. These findings correlated well with the degree of degeneration of the sensory epithelium of the vestibular organ and the levels of perilymph antibody. On the other hand, neither phosphate-buffered saline inoculation nor primary KLH challenge to the sac nor a secondary KLH challenge to the intradural space resulted in a disturbance of the vestibular function. These results suggest that the immune response of the sac may possibly be an important key to the pathogenesis of Ménière's disease.

[Cochlear immune injury following direct antigen challenge to the endolymphatic sac].

Following direct KLH antigen challenge to the endolymphatic sac (e. sac) in guinea pigs, degeneration of the cochlea was examined histologically by light microscopy. Degeneration was seen in 21 out of 140 animals presensitized systemically from day 1 to 5 weeks post secondary KLH challenge to the e. sac. Degeneration of the organ of Corti, stria vascularis and spiral ganglion cells was seen from day 1 in 19, 17 and 7 animals, respectively. There was no increase in these degenerative processes during the time course. In the period from day 1 to day 4, severe bleeding in the perilymphatic space occurred simultaneously with cochlear deterioration. Three animals showed perilymphatic fibrosis which was noted after the first week post KLH secondary challenge. In contrast, animals primarily challenged with KLH (locally administered to the e. sac) showed no cochlear degeneration. These results suggest that a locally mounted immune response in the e. sac can cause direct immune injury to cochlear tissues.

Vestibular disorders following immune response of the endolymphatic sac in the guinea pig.

The effect of a direct antigen challenge to the endolymphatic sac on vestibular function was investigated in guinea pigs. Following keyhole limpet hemocyanin (KLH) challenge to the sac in systemically presensitized guinea pigs, caloric responses were examined in 18 animals on days 1, 7, 14, 21, and 28. Caloric responses were significantly suppressed in 13 animals by day 7; of these, 5 animals had recovered by day 14 and 8 animals had not yet recovered by day 28. The behavior of spontaneous nystagmus was examined every hour in 10 animals at intervals of 3 to 56 hours after sac challenge. Irritative spontaneous nystagmus preceding paralytic nystagmus appeared in 5 animals, for which the mean onset was 14.6 +/- 3.1 hours and the mean duration was 4.4 +/- 6.5 hours. Paralytic spontaneous nystagmus appeared in all animals, for which the mean onset time was 23.3 +/- 12.3 hours. Neither direct KLH primary challenge of the sac nor phosphate-buffered saline injection to the sac caused significant changes in the vestibular function. These results suggest that an immune response of the sac induces a vestibular disorder and may produce an attack of vertigo similar to that of Meniere's disease.

[Development of acute endolymphatic hydrops following secondary endolymphatic sac immune response. I: Short-term observation].

The development of endolymphatic hydrops (e. hydrops) following secondary e. sac immune response was investigated in Hartley guinea pigs, for a period of 5 weeks. E. hydrops immediately developed to a maximum from day 2 to day 7 and then gradually reduced in the next 4 weeks. In the e. sac, numerous inflammatory cellular infiltrates, mainly polymorphonuclear cells and macrophages, were seen from day 1 to day 2. Lymphocytes and plasma cells appeared from day 3 and increased to a maximum by day 7 and then gradually decreased in the next 4 weeks. Neither primary e. sac KLH challenge nor e. sac PBS inoculation could derive e. hydrops. Development of e. hydrops was considerably parallel to the grade of immune reaction within the e. sac, suggesting that immuno-pathological reaction of the e. sac has an important effect on regulation of the endolymph volume.

Relation of regional asynchrony to global left ventricular systolic and diastolic function in patients with angina pectoris without previous myocardial infarction.

To assess left ventricular (LV) systolic and diastolic function globally and regionally and to study the relationship between regional asynchrony and global LV function in patients with stable effort angina pectoris (AP) without previous myocardial infarction, we conducted a resting gated radionuclide ventriculographic study in 15 control subjects (N group) and 22 AP patients with isolated disease of the left anterior descending coronary artery (LAD). In nine of these 22 AP patients, LV systolic and diastolic function before surgical revascularization (Aorto-Coronary Bypass) were compared with those after surgical revascularization. A computer program subdivided the image of the LV into four regions (septal, basal, lateral and apical) by our previously reported method. The time-activity and first-derivative curves of the global LV and three regions (septal, lateral, apical; the basal region was not computed) LV were computed. In the global LV, the peak filling rate (PFR) normalized to LV end-diastolic volume (EDV) and the ratio of increment of filling volume at 100 msec from global end-systole (ES) to the EDV (%EFV), which was correlated with the time constant of LV pressure decay during isovolumic relaxation, decreased (p less than 0.01, p less than 0.001, respectively) and time to PFR (time interval from global ES to PFR) was greater (p less than 0.001) in the AP group than that in the N group. However, in the AP group, the ejection fraction (EF), normalized peak ejection rate (PFR) and %1/3SV, which was defined as the percent stroke volume ejected during the first third of the global LV ejection phase, were not different from these in the N group.(ABSTRACT TRUNCATED AT 250 WORDS)

Severity of the regional wall motion and its effects on global left ventricular diastolic filling in patients with single-vessel coronary artery disease and previous myocardial infarction: assessment with radionuclide ventriculography.

The severity of the regional wall motion and its effects on the global left ventricular diastolic filling were analyzed with use of radionuclide techniques in 19 patients with isolated disease of the left anterior descending coronary artery with previous myocardial infarction. Regional maximum inward movements in the noninfarcted lateral region occurred at a time close to the global end-systole, but occurred far beyond the global end-systole in the infarcted septal and apical regions, resulting in the occurrence of the regional asynchronous wall motion between the infarcted and noninfarcted regions after the global end-systole. A positive correlation between this end-systolic asynchronous wall motion and the asynchronous filling in early diastole was found (r = 0.69, p less than 0.001). A negative correlation between the asynchronous filling in early diastole and the global peak filling rate was also found (r = -0.58, p less than 0.01). Thus, the end-systolic regional asynchronous wall motion causes the subsequent regional asynchronous filling in early diastole, which may cause impairment of the global left ventricular filling in patients with single-vessel coronary artery disease with previous myocardial infarction.

Inhomogeneous contribution of late diastolic filling to filling volume in patients with isolated disease of the left anterior descending coronary artery: assessment with radionuclide ventriculography.

Contributions of late diastolic filling (slow filling and atrial systolic phases) to total filling volume in both global and regional left ventricle were analyzed using radionuclide techniques in 21 patients with isolated left anterior descending coronary artery disease without previous myocardial infarction. A computer program subdivided the image of the left ventricle into four regions at a geometric center of the area. The time-activity and its first-derivative curves of the global and regional left ventricles were computed. In the global left ventricle, the percent contributions of late diastolic filling to total filling volume were significantly increased in patients with one-vessel disease than in control subjects (20 +/- 5%, 28 +/- 4%; p less than 0.001). In the regional left ventricle, in patients with one-vessel disease, the percent contributions of late diastolic filling to total filling volume were significantly increased in the septal (25 +/- 5%, 34 +/- 8%; p less than 0.001) and in the apical regions (21 +/- 4%, 28 +/- 4%; p less than 0.001) which were perfused by stenosed vessel. In contrast, there were no significant differences in this value between the two groups in the normally perfused lateral region (22 +/- 6%, 25 +/- 5%; p = NS). These results indicate that the late diastolic filing makes a larger contribution to the left ventricular filling in the affected regions than in the normally perfused regions, and that the increased late diastolic filling in the affected regions are the cause for the increased late diastolic filling in the global left ventricle in patients with one-vessel disease.