Temporal Adjusters Can Reduce Pain During the Video Head Impulse Test for Patients With Mongoloid Facial Features, Without Increasing the Slippage-Induced Artifacts

BACKGROUND

The aim of this study was to determine whether the extent and intensity of pain caused by wearing goggles during the video head impulse test (vHIT) could be reduced by adjusting the direction in which the band pulls the goggles, without increasing the number of artifacts recorded during vHIT.

METHODS

vHIT tests were performed in 65 healthy adult subjects, and the Visual Analog Scale (VAS) and Numerical Rating Scale (NRS) were used to evaluate pain intensity. Temporal adjusters were used to adjust the direction in which the band pulls the goggles, without decreasing the tightness of the temple straps. Artifacts were compared by calculating the instantaneous gains at 40 ms, 60 ms, and 80 ms of head movement.

RESULTS

Maximum VAS and NRS of pain were significantly reduced from 22.0 ± 2.3 to 13.0 ± 1.7 and from 3.0 ± 0.2 to 2.0 ± 0.2 (both P < .0001). The VAS score without adjusters was significantly correlated with the improvement of the VAS score with temporal adjusters (P < .0001, r = 0.61). The higher the VAS score without adjusters, the greater the improvement in the VAS score with temporal adjusters. The instantaneous gains were close to 1.0 under both conditions.

CONCLUSION

The pain induced by the goggle was significantly mitigated with temporal adjusters in the bilateral temple strap. Using temporal adjusters is a useful and easy solution to reduce discomfort during vHIT, while maintaining the tightness of the strap to decrease the slippageinduced artifacts.

Tricellulin Expression and its Deletion Effects in the Endolymphatic Sac

OBJECTIVES

Tricellulin is a tight junction (TJ)-forming protein that participates in the sealing function of tricellular TJs. Tricellulin-knockout (Tric-/-) mice show progressive hearing loss with degeneration of hair cells in the cochlea without physiological or physical disorders. In the present study, we investigated the tricellulin expression and its deletion effects in the endolymphatic sac (ES) using Tric-/- mice.

MATERIALS AND METHODS

The ES epithelia from wild-type (WT) mice were laser-microdissected, and RT-PCR was performed. The ES sections from Tric-/- and WT mice were immunostained with an anti-tricellulin antibody. Hematoxylin and eosin staining was performed for morphological examination. The inner ear of Tric-/- mice was perfused with biotinylation reagents, and the ES sections were observed for tracer permeability assay after applying streptavidin-Alexa Fluor 488 conjugate.

RESULTS

The tricellulin expression was confirmed by RT-PCR and by immunohistochemistry in the WT ES. The ES in Tric-/- mice showed normal morphology and revealed no biotin leakage from the lumen.

CONCLUSION

The ES in Tric-/- mice showed no changes in morphology or disruption in macromolecular barrier function. The effects of solute leakages in the ES of Tric-/- mice may be very limited and compensatable, or that the ES epithelia may have other sealing system covering the lack of tricellulin.

The difference in endolymphatic hydrostatic pressure elevation induced by isoproterenol between the ampulla and the cochlea

OBJECTIVE

The purpose of the study was to investigate the difference in the responses of endolymphatic hydrostatic pressure to isoproterenol, β-adrenergic receptor agonist, between pars superior and pars inferior.

METHODS

The hydrostatic pressure of endolymph and perilymph and endolymphatic potential in the ampulla and the cochlea during the intravenous administration of isoproterenol were recorded using a servo-null system in guinea pigs.

RESULTS

The hydrostatic pressure of endolymph and perilymph in the ampulla and cochlea was similar in magnitude. Isoproterenol significantly increased hydrostatic pressure of ampullar and cochlear endolymph and perilymph with no change in the ampullar endolymphatic potential and endocochlear potential, respectively. The isoproterenol-induced maximum change of endolymphatic hydrostatic pressure in ampulla was significantly (p<0.01) smaller than that in the cochlea. In ears with an obstructed endolymphatic sac, the action of isoproterenol on endolymphatic hydrostatic pressure in the ampulla disappeared like that in the cochlea.

CONCLUSION

Isoproterenol elevates endolymphatic hydrostatic pressure in different manner between the vestibule and the cochlea.

Clinical outcomes of nedaplatin and S-1 treatment with concurrent radiotherapy in advanced head and neck cancer

CONCLUSION

Nedaplatin and S-1 treatment with concurrent radiotherapy was effective, with acceptable toxicities. This regimen does not require extensive intravenous hydration and continuous infusion. Nedaplatin and S-1 may contribute to better clinical outcomes and improve quality of life for patients.

OBJECTIVES

We retrospectively analyzed the clinical efficacy and toxicity of concurrent chemoradiotherapy with nedaplatin and S-1 for head and neck squamous cell cancer.

METHODS

Forty-six patients with oropharyngeal, hypopharyngeal, and laryngeal cancer were treated with S-1 on days 1 through 14 and nedaplatin on day 1 every 4 weeks for two cycles of radiotherapy. Therapeutic responses and adverse events were assessed.

RESULTS

Primary site tumors and neck lymph nodes exhibited complete response rates of 91% and 64.3%, respectively. The 4-year relapse-free survival and overall survival rates were 76.2% and 85.3%, respectively. The main grade 3 and 4 toxicities were mucositis (30%), leukopenia (30%), anorexia (22%), dermatitis (15%), and thrombocytopenia (9%).

Cystic fibrosis transmembrane conductance regulator in the endolymphatic sac of the rat

OBJECTIVE

Na(+) and Cl(-) are dominant ions in the endolymphatic fluid in the endolymphatic sac and are important for volume regulation in the endolymphatic sac. An epithelial sodium channel (ENaC) and other Na(+) transporters have been identified in the endolymphatic sac epithelia, and they are involved in the regulation of endolymph. Although the presence of Cl(-) channels in the endolymphatic sac epithelia has been speculated, no Cl(-) channels have been identified. In this study, we confirmed the expression of cystic fibrosis transmembrane conductance regulator (CFTR) in the endolymphatic sac by reverse transcriptase polymerase chain reaction (RT-PCR) and by immunohistochemical staining.

METHODS

Pure mRNA from endolymphatic sac epithelia was prepared using laser capture microdissection (LCM) and examined using RT-PCR. Localization of CFTR and ENaC in the endolymphatic sac was examined using immunohistochemistry.

RESULTS

mRNA of the CFTR was expressed in the endolymphatic sac. Immunohistochemical analysis showed the expression of the CFTR on apical side of the endolymphatic sac epithelia and co-localization with the ENaC.

CONCLUSION

RT-PCR and immunohistochemistry were used to identify the expression of CFTR in the endolymphatic sac epithelia, which gives us a clue for understanding Cl(-) transport in the endolymphatic sac. These results suggest a pathway for Cl(-), possibly through interaction with the ENaC, which may regulate the endolymph in the endolymphatic sac.

Comparison of ( 18 ) F-FLT PET and ( 18 ) F-FDG PET for detection of cervical lymph node metastases in head and neck cancers

CONCLUSION

Despite low uptake of tracer, 3'-deoxy-3'-(18)F-fluorothymidine (FLT) PET could detect cervical lymph node metastases as well as 2-deoxy-2-(18)F-fluoro-d-glucose (FDG) PET.

OBJECTIVE

The diagnostic efficacy of FLT PET was compared with that of FDG PET regarding nodal staging of head and neck squamous cell cancers.

METHODS

Twenty-three patients were examined with FLT PET and FDG PET. PET images were evaluated qualitatively for regions of focally increased metabolism and maximum standardized uptake values (SUV) were calculated for semiquantitative analysis.

RESULTS

The mean (± SD) FLT SUV in visualized metastatic lymph nodes was 4.8 ± 2.9 as compared with 6.9 ± 4.9 for FDG SUV (p < 0.001). Significant correlations were found between the area of metastatic lymph nodes and both FLT SUV (r = 0.8; p < 0.0001) and FDG SUV (r = 0.84; p < 0.0001). The false-positive (over-staged) and false-negative (under-staged) rates for lymph node staging by FLT PET were 4% (1/23) and 17% (4/23), respectively. Those for FDG PET were 9% (2/23) and 13% (3/23). All metastatic lymph nodes measuring more than 9 mm in short-axis diameter were correctly detected by FLT PET. However, both FLT and FDG PET had low sensitivity for detecting the lymph node metastases ≤ 9 mm in short-axis diameter and tumor deposits < 5 mm.

Presence of adrenergic receptors in rat endolymphatic sac epithelial cells

Intravenous application of catecholamines produces a depression in the endolymphatic sac direct current potential (ESP) and increases endolymphatic pressure via the β-adrenergic receptor (AR) in guinea pigs, suggesting that catecholamines play a role in the endolymphatic system. However, the localization of ARs in the endolymphatic sac (ES) is still undetermined. The presence of ARs in the rat ES was investigated by reverse transcriptase-polymerase chain reaction using laser capture microdissection (LCM) and immunohistochemical analysis. Expression of α(1A)-, α(1B)-, α(2A)-, α(2B)-, β(1)-, β(2)- and β(3)-ARs was observed in LCM samples of ES epithelia. Immunohistochemical analysis using specific antibodies showed immunofluorescence of β(2)- and β(3)-ARs in epithelial cells of the ES intermediate portion, and no specific staining results were obtained for α(1)-, α(2A)-, α(2B)- and β(1)-ARs. The presence of β(2)-AR with no clear immunostaining of β(1)-AR in ES epithelial cells is in accordance with previous electrophysiological and pharmacological results, which suggests that β(2)-AR mediates the action of catecholamines on the ESP. The presence of β(3)-AR in the ES epithelial cells and its absence in the stria vascularis implies that β(3)-AR plays a specific role in the ES.

The mRNA of claudins is expressed in the endolymphatic sac epithelia

OBJECTIVE

Claudins are a family of membrane proteins which localize to tight junctions (TJs). Recent studies have shown that claudins can form pores for ions in the TJs and regulate the permeability of epithelial paracellular ion transport. The endolymphatic sac (ES) is a part of the inner ear, absorbing the endolymphatic fluid. ES dysfunction may result in endolymphatic hydrops. In this study, we focused on the paracellular transport and examined claudin mRNA expression in the ES epithelia.

MATERIALS AND METHODS

Total RNA was isolated from whole ES epithelia of rats by laser capture microdissection. RT-PCR was used to evaluate the expression of claudins. The expression of each claudin mRNA in the epithelial cells of rat ES was confirmed by in situ hybridization.

RESULTS

RT-PCR indicated the expression of cldn2, cldn4, cldn6, cldn7, cldn9, cldn11, cldn12, and cldn14. The expression of these claudin mRNAs in the epithelial cells of rat ES was confirmed by in situ hybridization.

CONCLUSION

We demonstrated mRNA expression of multiple claudins in the rat ES epithelia. These results in the ES epithelia were consistent with a role of claudins in paracellular ion transport.

Expression and localization of 11beta-hydroxysteroid dehydrogenase (11betaHSD) in the rat endolymphatic sac

CONCLUSIONS

11beta-Hydroxysteroid dehydrogenase type 2 (11bHSD-2) enables aldosterone to bind to mineralocorticoid receptors (MRs) selectively by converting cortisol (corticosterone) into inactive metabolites. Its expression in the endolymphatic sac (ES) suggests that aldosterone may selectively act on the ES through its binding to MRs by the action of 11betaHSD-2, and supports the notion that ES is an aldosterone target organ. We propose that 11betaHSD-2 is a dominant isoform of 11betaHSDs in the ES, and the ES (especially the intermediate portion of the ES) may be the main aldosterone target in the inner ear.

OBJECTIVE

The purpose of this study was to examine 11bHSD isoform expression in the rat inner ear, mainly 11betaHSD-2 in the ES.

MATERIALS AND METHODS

In the ES and whole cochlea, 11betaHSDs were examined by RT-PCR using highly specific ES RNA by laser capture microdissection. In addition, 11betaHSD-2 localization in the rat ES was determined by immunohistochemistry.

RESULTS

RT-PCR demonstrated 11betaHSD-2 expressed in the rat ES. In addition, its localization was observed mainly in the intermediate portion and a faint immune positive signal was observed in other parts of the ES. In contrast, 11bHSD-1 was undetectable in the ES by RT-PCR. Both types of 11betaHSDs were expressed in rat cochlea.

Endolymphatic sac is involved in the regulation of hydrostatic pressure of cochlear endolymph

To clarify the role of the endolymphatic sac (ES) in the regulation of endolymphatic pressure, the effects of isoproterenol, a beta-adrenergic receptor agonist, and acetazolamide, a potent carbonic anhydrase inhibitor, both of which decrease ES direct current potential on cochlear hydrostatic pressure, were examined in guinea pigs. When isoproterenol was applied intravenously, hydrostatic pressures of cochlear endolymph and perilymph were significantly increased with no change in endocochlear potential or the hydrostatic pressure of cerebrospinal fluid. Acetazolamide produced no marked change in the hydrostatic pressure of cochlear endolymph. In ears with an obstructed ES, the action of isoproterenol on the hydrostatic pressure of cochlear endolymph and perilymph was suppressed. These results suggest that the ES may regulate the hydrostatic pressure of the endolymphatic system via the action of the agents such as catecholamines on the ES.

The expression of P2Y1, 2, 4, and 6 receptors in rat endolymphatic sac epithelia

Earlier studies have suggested that activation of the purinergic receptor causes Na absorption from the endolymph through nonselective cation channels in endolymphatic sac (ES) epithelia. In this study, the mRNA expression patterns of the P2Y(1, 2, 4, and 6) receptors in the rat ES were examined by conventional reverse-transcription PCR. Their cellular localization was investigated by high-specificity reverse-transcription PCR using laser capture microdissection and in-situ hybridization. Our experiments showed that the mRNA of these receptors is expressed in ES epithelia. These results indicate that extracellular nucleotides may regulate ion transport by several purinergic pathways that operate through these receptors in the ES and that some of these receptors may be responsible for regulating Na+ absorption through the activation of nonselective cation channels.

A new approach for selective rat endolymphatic sac epithelium collection to obtain pure specific RNA

The endolymphatic sac (ES) is an organ that is located in the temporal bone. Its anatomical location makes ES tissue collection without any contamination very difficult, and sometimes accurate molecular analyses of the ES are prevented due to this matter. In the present study, a new selective ES epithelial tissue collection method was attempted using laser capture microdissection to obtain pure ES RNA without any contamination. The validity of this method was demonstrated by RT-PCR with three specific primer pairs against osteocalcin, calponin H1, and NKCC2, which are specific proteins in bone, smooth muscle, and kidney/ES cells, respectively. From the RT-PCR results, the high specificity and sufficient sensitivity of the new method was indicated. It is considered that the new method is optimal for ES collection without contamination and it will be able to contribute to future analyses of the ES.