Sinusitis of actinomycosis infection†:†a case report.

Actinomycosis is an infection caused by anaerobic bacteria, primarily from the genus Actinomyces, which normally colonize the several regions including the mouth. Disruption of mucosa may lead to infection of virtually any site, but reports of involvement of the sinuses are rare. We report a case of an actinomycosis infection in the unilateral maxillary sinus. A 47-year-old female visited our hospital with a complaint of mild pain of left buccal region. Computed tomography (CT) revealed that the left maxillary and anterior ethmoidal sinus cavities were opacified along with a calcified fragment located close to the natural ostium. Thus, we provisionally diagnosed as a fungal sinusitis. She underwent trans-nasal endoscopic sinus surgery. The sinuses were opened and the caseous material was removed. The histopathological examination suggested an actinomycosis, but not fungal, infection. The patient's postoperative course was uneventful. No evidence of recurrence has been seen over the 30 months of the postoperative follow-up period. In case of the aggressive actinomycotic sinusitis, extension into the adjacent organs could be occurred. We should be aware that sinusitis of actinomycosis infection could progress in patients with risk factors such as diabetes and immunodeficiency. J. Med. Invest. 68 : 202-204, February, 2021.

Osmotic perception of GABAergic synaptic transmission in the supraoptic nucleus of rats.

Extracellular osmolality plays a crucial role in controlling the activation of neurons. Hypertonic stimulation modulates glutamatergic inputs to the supraoptic nucleus (SON) magnocellular neurosecretory cells (MNCs) putative vasopressin (VP) neurons through capsaicin-insensitive transient receptor potential vanilloid (TRPV) 1 channels on the presynaptic terminals. However, it remains unclear whether osmotic stimulation modulates GABAergic inputs to VP-secreting neurons within punched-out slices containing only the SON and the perinuclear zone. To answer this question, we studied the effects of various osmotic conditions on the miniature GABAergic postsynaptic currents (mGPSCs) using the whole-cell patch-clamp technique on rat SON putative VP-secreting neurons in small slice preparations. We revealed that incubation in hypertonic solution for 2 h reduced both the frequency and amplitude of the mGPSCs to the SON putative VP neurons, whereas the mGPSCs were unaffected when the external osmolality was changed from isotonic to hypotonic. Of interest, we found that changing from a hypertonic to hypotonic environment increased the frequency of the mGPSCs. This effect was independent of TRPV4. We hypothesize that two coordinated mechanisms may play an important role in the regulation of a wide range of physiological functions of VP.: 1) the modulation of GABAA receptor properties by brain-derived neurotrophic factor (BDNF)-induced tyrosine kinase B receptor-mediated signaling under hypertonic conditions, and 2) cell swelling-induced activation of whole-cell anion currents under hypotonic conditions.

Frequency-specific efficacy of intratympanic steroid on idiopathic sudden sensorineural hearing loss.

Background: Hearing recovery would be different in each sound frequency in patients with idiopathic sudden sensorineural hearing loss (ISSNHL).Aims/objectives: To analyze frequency-specific efficacy of intratympanic steroid on ISSNHL.Materials and methods: Of a total of 381 patients with ISSNHL (hearing threshold ≥40 dB; ≤30 days until treatment), 174 patients (174 ears) received systemic steroid plus hyperbaric oxygen therapy (HBO group), and 207 patients (208 ears) received systemic plus intratympanic steroid (IT group). Hearing thresholds at 125-8000 Hz were measured at every octave before and after treatment.Results: % of patients with hearing gains ≥10 dB in the IT group was significantly higher for 500 Hz and the average of 5 mid-frequencies, tended to be higher for 1000 Hz, but was significantly lower for 8000 Hz, compared to the HBO group. Multiple regression analysis showed that hearing recovery was negatively correlated with patients' age for 125/2000/4000/8000 Hz and with days from onset to treatment for all frequencies, and also revealed better hearing recovery at 500/1000 Hz in the IT group than in the HBO group.Conclusions: Intratympanic steroid is more effective than hyperbaric oxygen to yield better hearing outcomes at mid-frequencies and would be advantageous to restore sound/speech perception.Significance: Superiority of intratympanic steroid over hyperbaric oxygen for treating ISSNHL was verified.

Expression of Cl- channels/transporters in nasal polyps.

PURPOSE: Nasal polyp formation is a common sequela of prolonged chronic rhinosinusitis, but the mechanism underlying this disease state is still controversial. We compared the expressions of Cl- channels/transporters in nasal polyps with those in inferior turbinates to explore whether a deficiency in Cl- transport may participate in the pathophysiology of nasal polyp formation as in patients with cystic fibrosis. METHODS: Nasal polyps and inferior turbinates were collected from 12 chronic rhinosinusitis patients with hypertrophic rhinitis and/or nasal polyps. Expressions of cystic fibrosis transmembrane conductance regulator (CFTR), pendrin, Na+-K+-2Cl- cotransporter 1 (NKCC1), SLC26A3, TMEM16A and anion exchanger 2 (AE2) were examined by fluorescence immunohistochemistry using Alexa Fluor 488. RESULTS: CFTR was weakly expressed on the epithelial surface of the turbinate mucosa whereas the nasal polyps showed almost no fluorescence. Pendrin was mainly expressed on the epithelial surface in both tissues. The fluorescence was moderate in the nasal polyps and strong in the turbinate mucosa. For NKCC1, moderate fluorescence was observed throughout the entire epithelial layer of the nasal polyps, but the turbinate mucosa exhibited almost no fluorescence. On the other hand, no fluorescence for SLC26A3, TMEM16A or AE2 was seen in either tissue. CONCLUSION: These results suggest that CFTR, pendrin and NKCC1 may participate in the pathogenesis of nasal mucosal edema and play roles in the mechanism of nasal polyp formation.

Calmodulin and protein kinases A/G mediate ciliary beat response in the human nasal epithelium.

BACKGROUND: Mucociliary clearance of the airway epithelium is an essential function for mucosal defense. We recently proposed a hypothetical mechanism of ciliary beat regulation, in which the pannexin-1 (Panx1)-P2X7 unit serves as an oscillator generating a periodic increase in intracellular Ca2+ ([Ca2+ ]i ). In the present study, we examined the localization of Panx1 and P2X7 at the ultrastructural level, and investigated the regulatory pathway subsequent to [Ca2+ ]i increase. METHODS: The inferior turbinate mucosa was collected from patients with chronic hypertrophic rhinitis during endoscopic sinonasal surgery. The mucosa was examined by transmission immunoelectron microscopy for Panx1 and P2X7. Alternatively, the mucosa was cut into thin strips, and ciliary beat frequency (CBF) was measured under a phase-contrast light microscope with a high-speed digital video camera. RESULTS: In immunoelectron microscopy, immunoreactivities for Panx1 and P2X7 were localized along the plasma membrane of the entire length of the cilia. CBF was significantly increased by stimulation with 100 µM acetylcholine (Ach). The Ach-induced CBF increase was significantly inhibited by calmidazolium (calmodulin antagonist), SQ22536 (adenylate cyclase inhibitor), ODQ (guanylate cyclase inhibitor), KT5720 (protein kinase A inhibitor), and KT5823 (protein kinase G inhibitor). Fluorodinitrobenzene (creatine kinase inhibitor) completely inhibited the ciliary beat in a time- and dose-dependent manner. CONCLUSION: These results indicate that Panx1 and P2X7 coexist at the cilia of the human nasal epithelial cells and that the ciliary beat is regulated by calmodulin, adenylate/guanylate cyclases and protein kinases A/G, and crucially depends on creatine kinase.

Efficacy of Intratympanic Steroid on Idiopathic Sudden Sensorineural Hearing Loss: An Analysis of Cases With Negative Prognostic Factors.

Purpose We retrospectively studied the efficacy of intratympanic steroid administration in comparison with hyperbaric oxygen (HBO) therapy for idiopathic sudden sensorineural hearing loss (ISSNHL) with negative prognostic factors. Method We enrolled 301 patients (302 ears) with ISSNHL (average hearing level at 250-4000 Hz ≥ 40 dB; time from onset to treatment ≤ 30 days). From August 2002 to March 2009, 174 patients (174 ears) received systemic steroid plus HBO therapy (HBO group), and from June 2015 to January 2018, 127 patients (128 ears) received systemic plus intratympanic steroid (IT group). Hearing outcomes were evaluated by 6 indices: cure rate, marked-recovery rate (percent of patients with hearing gain ≥ 30 dB), recovery rate (percent of patients with hearing gain ≥ 10 dB), hearing gain, hearing level after treatment, and percent hearing improvement compared to the unaffected contralateral ear. Results The recovery rate was significantly higher in the IT group than in the HBO group (80.5% vs. 68.4%, p = .019). The IT group showed a higher recovery rate than the HBO group in patients aged ≥ 60 years ( p = .010), patients with early (≤ 7 days from onset) treatment ( p = .005), patients with initial hearing levels ≥ 90 dB ( p = .037), and patients with vertigo/dizziness ( p = .040). The IT group also showed higher hearing gain and percent hearing improvement than the HBO group in patients with vertigo/dizziness ( p = .046 and p = .026, respectively). Conclusions Systemic plus intratympanic steroid is more effective for ISSNHL than systemic steroid plus HBO, particularly in patients with negative prognostic factors, such as old age, profound hearing loss, and/or presence of vertigo/dizziness.

Decreased ciliary beat responsiveness to acetylcholine in the nasal polyp epithelium.

OBJECTIVE: We investigated the difference in ciliary beat responsiveness to acetylcholine in ex vivo and the difference in the expressions of associated molecules (M1/M3 muscarinic receptors, pannexin-1 and P2X7 purinergic receptor) between the nasal polyp and turbinate mucosa. STUDY DESIGN: Laboratorial study. PARTICIPANTS: Nasal polyp and inferior turbinate were collected from patients with hypertrophic rhinitis and/or nasal polyp during endoscopic sinonasal surgery. MAIN OUTCOME MEASURES: The mucosa was cut into thin strips, and ciliary movement was observed under a phase-contrast light microscope equipped with a high-speed digital video camera. The samples were also examined by scanning electron microscopy, fluorescence immunohistochemistry, and quantitative reverse transcription-polymerase chain reaction. RESULTS: Cilia were well preserved in both tissues at the ultrastructural level. The baseline ciliary beat frequency (CBF) was not different between the two tissues. The CBF of the turbinate was significantly increased by stimulation with acetylcholine (P < 0.001), but that of the polyp was not. The ratio of the acetylcholine-stimulated CBF to the baseline CBF was significantly lower in the polyp than in the turbinate (P < 0.001). Immunohistochemical study revealed that immunoreactivities for M3, pannexin-1 and P2X7 were weaker in the polyp than in the turbinate. The mRNA expressions of M1, M3 and P2X7 were significantly lower and that of pannexin-1 tended to be lower in the polyp than in the turbinate. CONCLUSIONS: These results indicate that ciliary beat responsiveness to acetylcholine is decreased in the nasal polyp. This may be explained by the decreased expressions of M3, P2X7 and probably pannexin-1 in this tissue.

Acetylcholine-induced Ciliary Beat of the Human Nasal Mucosa Is Regulated by the Pannexin-1 Channel and Purinergic P2X Receptor.

Background Airway mucociliary transport is an important function for the clearance of inhaled foreign particulates in the respiratory tract. The present study aimed at investigating the regulatory mechanism of acetylcholine (Ach)-induced ciliary beat of the human nasal mucosa in ex vivo. Methods The inferior turbinate mucosa was collected from patients with chronic hypertrophic rhinitis during endoscopic surgery. The mucosa was cut into thin strips, and ciliary movement was observed under a phase-contrast light microscope with a high-speed digital video camera. The sample was alternatively subjected to scanning electron microscopic observation. Results Cilia on the turbinate epithelium were well preserved at the ultrastructural level. The baseline ciliary beat frequency (CBF) was 6.45 ± 0.32 Hz. CBF was significantly increased by stimulation with 100 µM Ach and 100 µM adenosine triphosphate. The Ach-induced CBF increase was completely inhibited by removing extracellular Ca2+. Significant inhibition of the Ach-induced CBF was also observed by the addition of 1 µM atropine, 40 µM 2-aminoethoxydiphenyl borate (inositol trisphosphate [IP3] receptor antagonist), 10 µM carbenoxolone (pannexin-1 blocker), 1 mM probenecid (pannexin-1 blocker), 100 µM pyridoxalphosphate-6-azophenyl-20,40-disulfonic acid (P2X antagonist), and 300 µM flufenamic acid (connexin blocker). Meanwhile, 30 nM bafilomycin A1 (vesicular transport inhibitor) did not inhibit the Ach-induced CBF increase. CONCLUSIONS: These results indicate that the regulatory mechanism of the Ach-induced ciliary beat is dependent on extracellular Ca2+ and involves the muscarinic Ach receptor, IP3 receptor, pannexin-1 channel, purinergic P2X receptor, and connexin channel. We proposed a tentative intracellular signaling pathway of the Ach-induced ciliary beat, in which the pannexin-1-P2X unit may play a central role in ciliary beat regulation.

Synchronized roles of pannexin and connexin in nasal mucosal epithelia.

BACKGROUND: Nasal mucosal epithelial cells express connexins, the prototypical gap junction proteins, and pannexins, a new family of channel proteins homologous to the invertebrate gap junction proteins. The physiological and pathophysiological roles of these transmembrane proteins in nasal mucosa are largely still unknown. PURPOSE: Pannexins participate in ATP release into the extracellular space in various tissues, and ATP plays important roles in mucociliary clearance, especially by regulating ciliary beat activity. Therefore, we focused on the functional relationship between connexins, pannexin-1, ATP release, and mucociliary clearance in nasal epithelia. RESULTS AND CONCLUSIONS: Connexins participate in the generation of intercellular calcium waves, in which calcium-mediated signaling responses spread to contiguous cells through the gap junction formed by connexins to transmit calcium signaling throughout the airway epithelium. Pannexins in the nasal mucosa may contribute to not only ciliary beat modulation via ATP release, but also regulation of mucus blanket components via H2O efflux. The synchronized roles of pannexin and connexin may provide a new insight into effective mucociliary clearance systems in nasal mucosa.

Comparison of 2 and 4 Intratympanic Steroid Injections in the Treatment of Idiopathic Sudden Sensorineural Hearing Loss.

OBJECTIVE: We studied the effect of intratympanic steroid administration with different total injection times on hearing outcomes in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). METHODS: The subjects were 191 consecutive patients (192 ears) with ISSNHL (hearing level ≥40 dB, interval between onset and treatment ≤30 days). They received systemic prednisolone (100 mg followed by tapered doses) combined with intratympanic injection of dexamethasone (4 mg/ml). Intratympanic injection was performed 4 times (days 1, 2, 4, and 7) in 92 patients (92 ears) or 2 times (days 1 and 2) in 99 patients (100 ears). The hearing outcomes were evaluated at 1 week from the start of treatment and 1 to 2 months after the completion of treatment. RESULTS: There was no significant difference in hearing outcomes between the 4- and 2-injection groups at either time point. Multiple regression analysis also showed that the hearing level after treatment did not depend on the total number of intratympanic steroid injections. CONCLUSION: These results indicate that a protocol using only 2 intratympanic steroid injections exerts a sufficient effect on the hearing outcomes of ISSNHL. This simplified treatment protocol would be greatly beneficial to relieve the physical and mental stress of patients.

Expressions of TRPVs in the cholesteatoma epithelium.

OBJECTIVE: We have recently proposed a hypothesis that acid leakage through the cholesteatoma epithelium mediates bone resorption in middle ear cholesteatoma. In the present study, we investigated the expressions of transient receptor potential vanilloid (TRPV) channels, which have been shown to play roles in the regulation of epidermal barrier function, in the cholesteatoma epithelium in comparison with the normal skin. METHODS: Cholesteatoma epithelium and postauricular skin were collected from 17 patients with primary acquired middle ear cholesteatoma who underwent tympanomastoidectomy. Expressions of TRPV1, TRPV3, TRPV4, and TRPV6 were explored by fluorescence immunohistochemistry and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS: TRPV1, TRPV3, TRPV4, and TRPV6 mRNAs were all detected by qRT-PCR both in the skin and cholesteatoma tissue. Immunohistochemical staining showed that TRPV1 and TRPV3 were positive in the viable cell layers of the epidermis of the skin, and only TRPV3 was positive in those of the cholesteatoma epithelium. The immunoreactivity for TRPV3 was significantly weaker in cholesteatoma than in the skin. CONCLUSIONS: The lower expression of TRPV3 in cholesteatoma may be one of the mechanisms underlying the increased permeability of this tissue. On the other hand, TRPV1, TRPV4, and TRPV6 are unlikely to be involved in the regulation of epithelial permeability in cholesteatoma.

Possible contribution of pannexin-1 to capsaicin-induced ATP release in rat nasal columnar epithelial cells.

Current evidence indicates that transient receptor potential (TRP) channel activity involves a relationship between opening of pannexin-1 and release of ATP into the extracellular space. We examined the effects of agonists of thermosensitive TRP channels (TRPM8, TRPA1, TRPV1, and TRPV2) on ATP release from rat nasal mucosa, and measured ciliary beat frequency (CBF) using digital high-speed video imaging. Single-cell patch clamping from dissociated rat nasal columnar epithelial cells was performed to confirm the relationship between pannexin-1 and TRP. We demonstrated that ATP release and CBF were significantly potentiated by the heat-sensitive TRPV1 agonist capsaicin (10 µM), but not by other TRP agonists. Capsaicin-induced ATP release and CBF increase were significantly inhibited by the pannexin-1 blockers carbenoxolone (10 µM) and probenecid (300 µM). In addition, the voltage step-evoked currents in the presence of capsaicin were inhibited by the pannexin-1 blockers in single-cell patch clamping. Our results suggest the participation of TRPV1 and pannexin-1 in the physiologic functions of rat nasal mucosa.

Acetylcholine-induced ex vivo ATP release from the human nasal mucosa.

OBJECTIVE: The present study aimed at investigating ATP release in response to acetylcholine (Ach) and pharmacologically elucidating the intracellular signal transduction pathway of this reaction in an ex vivo experiment. METHODS: The inferior turbinate mucosa was collected from 21 patients with chronic hypertrophic rhinitis who underwent endoscopic turbinectomy. The mucosa was shaped into a filmy round piece, and incubated with chemical(s) in Hank's balanced salt solution for 10min. After incubation, the ATP concentration was measured by a luciferin-luciferase assay. RESULTS: The baseline release of ATP without stimulus was 57.2±10.3fM. The ATP release was significantly increased by stimulation with 100µM Ach. The Ach-induced ATP release was completely inhibited by removing extracellular Ca2+. Significant inhibition of the Ach-induced ATP release was also observed by the addition of 1µM atropine, 40µM 2-APB, 10µM CBX, and 100µM PPADS, whereas 30nM bafilomycin A1 did not affect the ATP release. CONCLUSION: These results indicate that the Ach-induced ATP release from the human nasal mucosa is dependent on the pannexin-1 channel and purinergic P2X7 receptor, suggesting that these two molecules constitute a local autocrine/paracrine signaling system in the human nasal epithelium.

Transgenic approach to express the channelrhodopsin 2 gene in arginine vasopressin neurons of rats.

Optogenetics provides a powerful tool to regulate neuronal activity by light-sensitive ion channels such as channelrhodopsin 2 (ChR2). Arginine vasopressin (AVP; also known as the anti-diuretic hormone) is a multifunctional hormone which is synthesized in the magnocellular neurosecretory cells (MNCs) of the hypothalamus. Here, we have generated a transgenic rat that expresses an AVP-ChR2-enhanced green fluorescent protein (eGFP) fusion gene in the MNCs of the hypothalamus. The eGFP fluorescence that indicates the expression of ChR2-eGFP was observed in the supraoptic nucleus (SON) and in the magnocellular division of the paraventricular nucleus (PVN) that is known to contain AVP-secreting neurons. The eGFP fluorescence intensities in those nuclei and posterior pituitary were markedly increased after chronic salt loading (2% NaCl in drinking water for 5days). ChR2-eGFP was localized mainly in the membrane of AVP-positive MNCs. Whole-cell patch-clamp recordings were performed from single MNCs isolated from the SON of the transgenic rats, and blue light evoked repetitive action potentials. Our work provides for the first time an optogenetic approach to selectively activate AVP neurons in the rat.

Osteoclasts are not activated in middle ear cholesteatoma.

It is unclear whether osteoclasts are present and activated in cholesteatomas. We explored the expression of messenger RNA (mRNA) for osteoclast biomarkers and regulating factors in middle ear cholesteatomas to elucidate the level of osteoclast activity in this disease. Bone powder was collected from 14 patients with cholesteatomatous and noncholesteatomatous chronic otitis media during tympanomastoidectomy, separately from cortical bone of the mastoid (clean bone powder), from bone neighboring cholesteatoma (cholesteatomatous bone powder), and from bone of the air cells and antrum of noncholesteatomatous chronic otitis media patients (noncholesteatomatous bone powder). The samples collected were soaked in TRIzol reagent, and total RNA was extracted and purified by the acid guanidinium thiocyanate-phenol-chloroform method, followed by the use of magnetic bead technology. The sample was then subjected to quantitative reverse transcription polymerase chain reaction for receptor activator of nuclear factor κB (RANK), tartrate-resistant acid phosphatase (TRAP), cathepsin K (CTSK), osteoclast-associated receptor (OSCAR), calcitonin receptor (CALCR), matrix metalloproteinase 9 (MMP9), receptor activator of nuclear factor κB ligand (RANKL), and osteoprotegerin (OPG). There was no significant difference in the expression of TRAP, CTSK, OSCAR, CALCR, MMP9, or OPG among the clean, cholesteatomatous, and noncholesteatomatous bone powder. On the other hand, the expression of RANK and RANKL was significantly lower in the cholesteatomatous bone powder than in the noncholesteatomatous bone powder (P = 0.003 and P = 0.028, respectively). The RANKL mRNA/OPG mRNA ratio did not differ among the three samples. These results indicate that osteoclasts are unlikely to be activated in cholesteatomas. Bone resorption mechanisms not mediated by osteoclasts may need to be reappraised in cholesteatoma research in future studies.

Regulation of Neuronal Activity in Hypothalamic Vasopressin Neurons.

Vasopressin is a peptide hormone secreted from the posterior pituitary gland in response to various physiological and/or pathological stimuli, including changes in body fluid volume and osmolality and stress exposure. Vasopressin secretion is controlled by the electrical activity of the vasopressinergic magnocellular neurosecretory cells located in the hypothalamic supraoptic nucleus and paraventricular nucleus. Vasopressin release can occur somatodendritically in the hypothalamus or at the level of pituitary axon terminals. The electrical activity of the vasopressin neurons assumes specific patterns of electrical discharge that are under the control of several factors, including the intrinsic properties of the neuronal membrane and synaptic and hormonal inputs. It is increasingly clear that glial cells perform critical signaling functions that contribute to signal transmission in neural circuits. Astrocytes contribute to neuronal signaling by regulating synaptic and extrasynaptic neurotransmission, as well as by mediating bidirectional neuronal-glial transmission. We recently discovered a novel form of neuronal-glial signaling that exploits the full spatial domain of astrocytes to transmit dendritic retrograde signals from vasopressin neurons to distal upstream neuronal targets. This retrograde trans-neuronal-glial transmission allows the vasopressin neurons to regulate their synaptic inputs by controlling upstream presynaptic neuron firing, thus providing a powerful means of controlling hormonal output.

Relationship between sleep apnea and thyroid function.

PURPOSE: Sleep apnea is sometimes associated with hypothyroidism, but the significance of thyroid function screening in sleep apnea patients has been controversial. In the present study, we investigated the relationship between thyroid function and sleep apnea in subjects who were suspected to have sleep apnea. METHODS: We enrolled 156 consecutive subjects suspected of having sleep apnea. Subjects included 117 men and 39 women aged 21 to 84 years. They underwent nocturnal multichannel polysomnography during a one-night hospitalization. The examined indices of sleep apnea were apnea-hypopnea index (AHI), lowest oxygen saturation, oxygen desaturation index, longest apnea duration, mean apnea duration, and the percent of apnea time to sleep time. Serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were concomitantly measured by electrochemiluminescence immunoassays. RESULTS: Three subjects (1.9 %) were diagnosed with primary hypothyroidism (high TSH and low FT4), and one subject (0.6 %) with subclinical hypothyroidism (high TSH and normal FT4). No significant difference in the level of TSH, FT3, or FT4 was seen among subjects with different severity of sleep apnea. The mean apnea duration significantly correlated with TSH in both simple and multiple regression analyses. Subjects with lower FT3 (≤3.75 pg/ml) showed longer mean apnea time compared to those with higher FT3 (>3.75 pg/ml) (24.9 ± 0.8 vs. 20.2 ± 1.2 s; P = 0.009). The other indices of sleep apnea did not show significant correlation with thyroid function. CONCLUSIONS: These results suggest that the mean apnea duration and TSH/FT3 may be helpful in understanding reciprocity between the two disease states, and for evaluating the validity of thyroid function tests in patients with sleep apnea.

Differences in acid-induced currents between oxytocin-mRFP1 and vasopressin-eGFP neurons isolated from the supraoptic and paraventricular nuclei of transgenic rats.

The hypothalamic supraoptic nucleus (SON) and paraventricular nucleus (PVN) consists of two types of magnocellular neurosecretory cells, oxytocin (OXT) and arginine vasopressin (AVP). We generated and characterized rats that express an OXT-monomeric red fluorescent protein 1 (mRFP1) and an AVP-enhanced green fluorescent protein (eGFP) fusion transgene. These transgenic rats enable the visualization of OXT or AVP neurons. Taking advantage of this, we examined the differences between OXT-mRFP1 neurons and AVP-eGFP neurons in response to acid. Acid-sensing ion channels (ASICs) are neuronal voltage-insensitive cationic channels that are activated by extracellular acidification. Although functional ASICs have been identified in AVP neurons, differences in acid-induced currents between OXT and AVP neurons in SON have not been reported. In the present study, we used the whole-cell patch-clamp technique to investigate differences between OXT-mRFP1 neurons and AVP-eGFP neurons reaction to acid in SON and PVN. In voltage clamp mode, lowering extracellular pH evoked inward currents in both OXT-mRFP1 neurons and AVP-eGFP neurons. In our findings, the acid-induced currents in the OXT-mRFP1 neurons were significantly smaller than those in the AVP-eGFP neurons. These acid-induced currents were inhibited by amiloride, a known blocker of ASICs. Further, to compare the response to acid between OXT-mRFP1 and AVP-eGFP neurons in the same transgenic rat, we used a double transgenic rat by mating an OXT-mRFP1 transgenic rat with an AVP-eGFP transgenic rat. The acid-induced currents of OXT-mRFP1 neurons were significantly smaller than those of AVP-eGFP neurons from the double transgenic rats. These currents were almost completely inhibited by amiloride. The difference of acid-sensitivity between OXT and AVP neurons might contribute to maintaining systematic order in hypothalamic function.

Prediction of hearing outcomes by multiple regression analysis in patients with idiopathic sudden sensorineural hearing loss.

OBJECTIVE: This study aimed to create a multiple regression model for predicting hearing outcomes of idiopathic sudden sensorineural hearing loss (ISSNHL). METHODS: The participants were 205 consecutive patients (205 ears) with ISSNHL (hearing level ≥ 40 dB, interval between onset and treatment ≤ 30 days). They received systemic steroid administration combined with intratympanic steroid injection. Data were examined by simple and multiple regression analyses. Three hearing indices (percentage hearing improvement, hearing gain, and posttreatment hearing level [HLpost]) and 7 prognostic factors (age, days from onset to treatment, initial hearing level, initial hearing level at low frequencies, initial hearing level at high frequencies, presence of vertigo, and contralateral hearing level) were included in the multiple regression analysis as dependent and explanatory variables, respectively. RESULTS: In the simple regression analysis, the percentage hearing improvement, hearing gain, and HLpost showed significant correlation with 2, 5, and 6 of the 7 prognostic factors, respectively. The multiple correlation coefficients were 0.396, 0.503, and 0.714 for the percentage hearing improvement, hearing gain, and HLpost, respectively. Predicted values of HLpost calculated by the multiple regression equation were reliable with 70% probability with a 40-dB-width prediction interval. CONCLUSION: Prediction of HLpost by the multiple regression model may be useful to estimate the hearing prognosis of ISSNHL.