Visualization of Alternating Triangular Domains of Charge Density Waves in 2H-NbSe_{2} by Scanning Tunneling Microscopy.

The charge density wave (CDW) state of 2H-NbSe_{2} features commensurate domains separated by domain boundaries accompanied by phase slips known as discommensurations. We have unambiguously visualized the structure of CDW domains using a displacement-field measurement algorithm on a scanning tunneling microscopy image. Each CDW domain is delimited by three vertices and three edges of discommensurations and is designated by a triplet of integers whose sum identifies the types of commensurate structure. The observed structure is consistent with the alternating triangular tiling pattern predicted by a phenomenological Landau theory. The domain shape is affected by crystal defects and also by topological defects in the CDW phase factor. Our results provide a foundation for a complete understanding of the CDW state and its relation to the superconducting state.

Evoked Potentials by Tone Burst on the Auditory Cortices in Cats -Comparison of Off Responses in Awake and Anesthetized Conditions.

BACKGROUND: Auditory Brainstem Response (ABR) recording in awake is essential to detect off-responses. This study clarified whether after-termination responses on ABR were offset responses, off-responses or a mixture of the two. METHODS: Evoked potentials in the auditory cortex of cats in response to tone burst stimuli were recorded, and off responses were examined with chronically implanted electrodes. RESULTS: When the fall time at the end of sound stimuli was 5ms or longer, the amplitude of click responses was extremely small. Under this condition, evoked potentials in response to two types of tone bursts (long and short) were recorded.By calculating the differences in evoked potentials between the two-tone bursts, off responses were separated. Off responses were generated during wakefulness by auditory cortex stimulation but were not observed under anesthesia. Pronounced off responses, which were middle latency responses exhibiting bis positive waves, were obtained in response to sound stimuli with a frequency of 2 kHz or higher. Vertex stimulation did not induce off responses either during wakefulness or under anesthesia. CONCLUSION: Off responses are derived from synchronous responses of neurons in the auditory cortex, which are generated when the neurons detect attenuation in the stimulus strength at the end of tone burst stimuli.

Efficacy of transtympanic infusion of dexamethasone into the tympanic cavity in mice with acute sensorineural hearing loss associated with cytomegalovirus infection.

BACKGROUND: There is no report on acute sensorineural hearing loss with congenital cytomegalovirus (cCMV) infection in basic experiments. AIMS/OBJECTIVES: The aim of this study was to evaluate the effect of dexamethasone, an anti-inflammatory steroid, on acute sensorineural hearing loss in the mouse cytomegalovirus (MCMV) infection model mice. MATERIAL AND METHODS: Sensorineural hearing loss model mice were divided into two groups, one with and one without intratympanic dexamethasone. Dexamethasone was injected into the tympanic cavity of only the right ear, and hearing ability was assessed at the ages of three, six, and eight weeks by auditory brainstem response measurement. RESULTS: Among the 23 mice intratympanically injected with dexamethasone (15 µg/mouse) at the age of three weeks, five (21.7%) had a hearing improvement of at least 10 dB and 18 (78.3%) had no improvement at the age of six weeks. Among the 19 mice that did not receive a dexamethasone injection, one (5.3%) showed improvement and 18 (94.7%) showed no improvement (p = 0.129). CONCLUSIONS AND SIGNIFICANCE: In this study, transtympanic infusion of dexamethasone into the tympanic cavity was effective in some mice with sensorineural hearing loss, suggesting that, in addition to angiogenesis, anti-inflammatory activity might be a mechanism of treatment for hearing loss.

Detailed clinical features and genotype-phenotype correlation in an OTOF-related hearing loss cohort in Japan.

Mutations in the OTOF gene are a common cause of hereditary hearing loss and the main cause of auditory neuropathy spectrum disorder (ANSD). Although it is reported that most of the patients with OTOF mutations have stable, congenital or prelingual onset severe-to-profound hearing loss, some patients show atypical clinical phenotypes, and the genotype-phenotype correlation in patients with OTOF mutations is not yet fully understood. In this study, we aimed to reveal detailed clinical characteristics of OTOF-related hearing loss patients and the genotype-phenotype correlation. Detailed clinical information was available for 64 patients in our database who were diagnosed with OTOF-related hearing loss. As reported previously, most of the patients (90.6%) showed a "typical" phenotype; prelingual and severe-to-profound hearing loss. Forty-seven patients (73.4%) underwent cochlear implantation surgery and showed successful outcomes; approximately 85-90% of the patients showed a hearing level of 20-39 dB with cochlear implant and a Categories of Auditory Performance (CAP) scale level 6 or better. Although truncating mutations and p.Arg1939Gln were clearly related to severe phenotype, almost half of the patients with one or more non-truncating mutations showed mild-to-moderate hearing loss. Notably, patients with p.His513Arg, p.Ile1573Thr and p.Glu1910Lys showed "true" auditory neuropathy-like clinical characteristics. In this study, we have clarified genotype-phenotype correlation and efficacy of cochlear implantation for OTOF-related hearing loss patients in the biggest cohort studied to date. We believe that the clinical characteristics and genotype-phenotype correlation found in this study will support preoperative counseling and appropriate intervention for OTOF-related hearing loss patients.

Case Reports on Effect of Intratympanic Steroid Injection Therapy on Late-Onset Hearing Loss in Congenital Cytomegalovirus Infection.

BACKGROUND: One of the conditions or symptoms caused by congenital cytomegalovirus (cCMV) infection is late-onset hearing loss. This report examines the cases of two children exhibiting late-onset hearing loss after cCMV infection who showed improvement in hearing after undergoing intratympanic steroid injection therapy (IST). CASES: Case1 is girl aged 8 years and 10 months and case2 is girl aged 5 years and 1 month. Cytomegalovirus (CMV) was not detected in the blood or urine of either child at the time of hearing loss despite them having cCMV infection. FINDINGS: The hearing of both children improved as a result of IST on an outpatient basis. Case1 was given first session of IST in left ear immediately on the day of her visit and second session of IST in left ear 2 days later. Tendency for improvement in threshold on left side was observed (the differences were about 20 to 45 dB). Case2 was given a total of 2 sessions of IST on left ear, 3 days and 5 days after visiting the hospital. The test result of distortion product otoacoustic emissions changed from refer to pass. Tendency for improvement in threshold on left side was observed (the differences were about 5 to 25 dB). CONCLUSIONS: Bearing in mind that late-onset hearing loss in patients with cCMV may be caused by other factors besides CMV, consideration of IST as a possible treatment option is proposed.

Efficacy, safety, and pharmacokinetics of oral valganciclovir in patients with congenital cytomegalovirus infection.

OBJECTIVES: Valganciclovir (VGCV) has been shown to improve sensorineural hearing loss (SNHL) and neurological outcomes in patients with neonatal symptomatic congenital cytomegalovirus (cCMV) infection. However, reports on the pharmacokinetics, efficacy and safety of oral VGCV are limited. The aim of this study is to evaluate the pharmacokinetics of VGCV for use in the treatment of cCMV. METHODS: This was a single-center, retrospective observational study conducted at Saitama Children's Medical Center in Japan between 2012 and 2017. CMV DNA copy number, maximum plasma VGCV concentration (Cmax), and adverse events (ADEs) during treatment were evaluated. RESULTS: A total of 26 patients with cCMV who received VGCV were included in this study. The median age at VGCV initiation was 9.5 months (range 0-46). Twenty-one patients (81%) had SNHL at baseline. Of these, five patients (19%) presented with improved SNHL, and none experienced worsened SNHL during treatment. The mean VGCV Cmax was 3.5 µg/mL (range 2-5.3), with no significant variation among individual values, and the values were maintained during treatment. Furthermore, there were no correlations between the Cmax values and age, sex, SNHL improvement or ADEs. Neutropenia (<1000/mm3) was observed in six patients (23%); however, no serious ADEs occurred. CONCLUSIONS: VGCV prevented the progression of SNHL without serious ADEs due to its stable pharmacokinetics. This study provides safety and tolerability of VGCV for the treatment of cCMV patients.

10-year follow-up of congenital cytomegalovirus infection complicated with severe neurological findings in infancy: a case report.

BACKGROUND: Congenital cytomegalovirus (cCMV) infection leads to sensorineural hearing loss (SNHL) and neurodevelopmental delays. However, the long-term outcomes of cCMV infection with severe neurological manifestations in infancy remain unclear. CASE PRESENTATION: The patient was a one-month-old girl visited owing to abnormalities in neonatal hearing screening. Central nervous system involvement including intracranial calcification and extensive white matter abnormalities was identified. Right SNHL (50 dB) was detected by auditory brain response (ABR) testing. The cause of her hearing loss was determined to be cCMV infection by polymerase chain reaction (PCR) using a dried blood spot. At 1.5 months of age, the patient was treated with intravenous ganciclovir (GCV) for 5 weeks followed by oral valganciclovir (VGCV) for an additional 6 weeks. Cytomegalovirus (CMV) loads in her urine continued to be detected until she was 10 years old. Fortunately, during this time, her right hearing loss did not deteriorate, and her left hearing remained normal. Furthermore, the extensive abnormal areas of white matter observed at 1 month of age mostly disappeared by the time the patient was 9 years old. Her neurodevelopmental score was normal, and motor milestones were not delayed as of 10 years of age. CONCLUSIONS: Here, we report the 10-year follow-up of a patient with cCMV who showed normal neurodevelopment, no progression of hearing loss, and ameliorating magnetic resonance imaging (MRI) findings, despite having various complications and severe neurological findings during infancy.

Proton-Driven Intercalation and Ion Substitution Utilizing Solid-State Electrochemical Reaction.

The development of an unconventional synthesis method has a large potential to drastically advance materials science. In this research, a new synthesis method based on a solid-state electrochemical reaction was demonstrated, which can be made available for intercalation and ion substitution. It was referred to as proton-driven ion introduction (PDII). The protons generated by the electrolytic dissociation of hydrogen drive other monovalent cations along a high electric field in the solid state. Utilizing this mechanism, Li+, Na+, K+, Cu+, and Ag+ were intercalated into a layered TaS2 single crystal while maintaining high crystallinity. This liquid-free process of ion introduction allows the application of high voltage around several kilovolts to the sample. Such a high electric field strongly accelerates ion substitution. Actually, compared to conventional solid-state reaction, PDII introduced 15 times the amount of K into Na super ionic conductor (NASICON)-structured Na3-xKxV2(PO4)3. The obtained materials exhibited a thermodynamically metastable phase, which has not been reported so far. This concept and idea for ion introduction is expected to form new functional compounds and/or phases.

Screening for seemingly healthy newborns with congenital cytomegalovirus infection by quantitative real-time polymerase chain reaction using newborn urine: an observational study.

OBJECTIVE: Approximately 8-10% of newborns with asymptomatic congenital cytomegalovirus (cCMV) infection develop sensorineural hearing loss (SNHL). However, the relationship between CMV load, SNHL and central nervous system (CNS) damage in cCMV infection remains unclear. This study aimed to examine the relationship between urinary CMV load, SNHL and CNS damage in newborns with cCMV infection. STUDY DESIGN: The study included 23 368 newborns from two maternity hospitals in Saitama Prefecture, Japan. Urine screening for cCMV infection (quantitative real-time PCR) and newborn hearing screening (automated auditory brainstem response (AABR) testing) were conducted within 5 days of birth to examine the incidence of cCMV infection and SNHL, respectively. CNS damage was assessed by MRI of cCMV-infected newborns. RESULTS: The incidence of cCMV infection was 60/23 368 (0.257%; 95% CI 0.192% to 0.322%). The geometric mean urinary CMV DNA copy number in newborns with cCMV was 1.79×106 copies/mL (95% CI 7.97×105 to 4.02×106). AABR testing revealed abnormalities in 171 of the 22 229 (0.769%) newborns whose parents approved hearing screening. Of these 171 newborns, 22 had SNHL (12.9%), and 5 of these 22 were infected with cCMV (22.7%). Newborns with both cCMV and SNHL had a higher urinary CMV DNA copy number than newborns with cCMV without SNHL (p=0.036). MRI revealed CNS damage, including white matter abnormalities, in 83.0% of newborns with cCMV. Moreover, newborns with CNS damage had a significantly greater urinary CMV load than newborns without CNS damage (p=0.013). CONCLUSIONS: We determined the incidence of cCMV infection and urinary CMV DNA copy number in seemingly healthy newborns from two hospitals in Saitama Prefecture. SNHL and CNS damage were associated with urinary CMV DNA copy number. Quantification of urinary CMV load may effectively predict the incidence of late-onset SNHL and neurodevelopmental disorders.

A child with severe inner ear malformations with favorable hearing utilization and balance functions after wearing hearing aids.

Infants with congenital deafness caused by severe bilateral inner ear malformations frequently suffer from severe hearing loss and poor balance. Unfortunately, the use of hearing aids is usually ineffective in recovering hearing, necessitating cochlear implants. We report a case of a 6-year-old boy with congenital deafness and bilateral inner ear malformations (right side, incomplete partition type I [IP-I]; left side, common cavity deformity). Hearing aids had a remarkable effect in this patient, enabling sufficient and favorable hearing recovery such as to allow the patient to engage in daily conversations. Per-rotatory nystagmus was recorded on an electronystagmogram for both right and left rotations in a damped rotational chair test. It is rare for deaf children with severe bilateral inner ear malformation to demonstrate favorable development in hearing and good equilibrium function. Our findings suggest that auditory-vestibular hair cells in this patient may have been partially preserved despite IP-I in the right ear and common cavity deformity of the left ear.

Constitutive activation of DIA1 (DIAPH1) via C-terminal truncation causes human sensorineural hearing loss.

DIAPH1 encodes human DIA1, a formin protein that elongates unbranched actin. The c.3634+1G>T DIAPH1 mutation causes autosomal dominant nonsyndromic sensorineural hearing loss, DFNA1, characterized by progressive deafness starting in childhood. The mutation occurs near the C-terminus of the diaphanous autoregulatory domain (DAD) of DIA1, which interacts with its N-terminal diaphanous inhibitory domain (DID), and may engender constitutive activation of DIA1. However, the underlying pathogenesis that causes DFNA1 is unclear. We describe a novel patient-derived DIAPH1 mutation (c.3610C>T) in two unrelated families, which results in early termination prior to a basic amino acid motif (RRKR1204-1207) at the DAD C-terminus. The mutant DIA1(R1204X) disrupted the autoinhibitory DID-DAD interaction and was constitutively active. This unscheduled activity caused increased rates of directional actin polymerization movement and induced formation of elongated microvilli. Mice expressing FLAG-tagged DIA1(R1204X) experienced progressive deafness and hair cell loss at the basal turn and had various morphological abnormalities in stereocilia (short, fused, elongated, sparse). Thus, the basic region of the DAD mediates DIA1 autoinhibition; disruption of the DID-DAD interaction and consequent activation of DIA1(R1204X) causes DFNA1.

Discrimination of Japanese monosyllables in patients with high-frequency hearing loss.

OBJECTIVE: To analyze the difficulty of discriminating Japanese nonsense monosyllables in each of several grades of high-frequency hearing loss and to evaluate the limitations of amplification. METHODS: We collected retrospective data on the discrimination of Japanese nonsense monosyllables by patients with three grades of high-frequency hearing loss who fulfilled or nearly fulfilled the Japanese criteria for EAS. Discrimination of the twenty monosyllables included in the 67-S speech audiometric test, which is approved by the Japan Audiological Society, was evaluated under quiet conditions. RESULTS: One hundred and five ears of ninety-one adults with high-frequency hearing loss were tested. We classified the ears according to hearing threshold at 1000 Hz; Group 1: <45 dB; Group 2: ≥45 dB and <70 dB; Group 3: ≥70 dB. Under the best conditions, the best speech discrimination scores were 72.3 ± 18.6% (mean ± SD, N=11), 56.9 ± 19.9% (N=57) and 38.1 ± 22.6% (N=37) in Group 1, Group 2 and Group 3, respectively. For most of the monosyllables, discrimination score declined gradually as high-frequency hearing loss became more severe. The high incidence in the Japanese language of [k], an easy consonant to distinguish, may be an advantage for patients with high-frequency hearing loss who use hearing aids. By employing a new confusion matrix that displays consonants and the following vowels separately, we were able to reveal the interactions of those two components. We observed that discrimination of preceding nasal consonants and that of the following vowels were not independent in patients with high-frequency hearing loss. CONCLUSION: Our classification based on threshold at 1000 Hz was useful to predict the effectiveness and limitations of amplification in high-frequency hearing loss. Threshold at 1000 Hz can be an index enabling us to refine the indications of EAS for native Japanese speakers to maximize its effectiveness against high-frequency hearing loss.

Cisplatin-induced hearing loss: the need for a long-term evaluating system.

Cisplatin is an effective chemotherapeutic agent against pediatric cancers; however, ototoxicity is a concern. This study describes the frequency, severity, and clinical course of hearing loss in Japanese pediatric patients treated with cisplatin-based multimodal therapy. A total of 55 children who received cisplatin-based therapy from 1983 to 2012 underwent audiologic evaluations. Data were analyzed to determine the onset, time-to-progression, and severity of hearing loss. Thirty-five patients, 12 of 16 older patients (4 y or older), and 23 of 39 younger patients (under 4 y), including 7 of 8 patients treated with cisplatin, carboplatin, and radiotherapy, developed hearing loss. Ten of 18 patients who received a cumulative cisplatin dose of <360 mg/m developed hearing loss at a minimum dose of 200 mg/m. Median time to onset after the last cisplatin dose was 71 days; 6 patients developed hearing loss after ≥2 years. Four patients required hearing aids, 6 patients developed progressive hearing loss with time, and 4 patients exhibited persistent hearing failure at low frequencies. Risk factors for acquired hearing loss and its severity may be associated with a combination of factors such as cisplatin and carboplatin therapy, radiotherapy, age at diagnosis, and genetic background. Our results suggested that all pediatric patients treated with cisplatin would have their hearing evaluated regularly, irrespective of the cumulative cisplatin dose as a suggestion, and that further prospective studies regarding ototoxicity including genetic polymorphisms analysis were required.

GJB2-associated hearing loss undetected by hearing screening of newborns.

The hearing loss caused by GJB2 mutations is usually congenital in onset, moderate to profound in degree, and non-progressive. The objective of this study was to study genotype/phenotype correlations and to document 14 children with biallelic GJB2 mutations who passed newborn hearing screening (NHS). Genetic testing for GJB2 mutations by direct sequencing was performed on 924 individuals (810 families) with hearing loss, and 204 patients (175 families) were found to carry biallelic GJB2 mutations. NHS results were obtained through medical records. A total of 18 pathological mutations were identified, which were subclassified as eight inactivating and 10 non-inactivating mutations. p.I128M and p.H73Y were identified as novel missense GJB2 mutations. Of the 14 children with biallelic GJB2 mutations who passed NHS, eight were compound heterozygotes and 3 were homozygous for the c.235delC mutation in GJB2, and the other three combinations of non-c.235delC mutations identified were p.Y136X-p.G45E/p.V37I heterozygous, c.512ins4/p.R143W heterozygous, and p.V37I/p.R143W heterozygous. These 14 cases demonstrate that the current NHS does not identify all infants with biallelic GJB2 mutations. They suggest that the frequency of non-penetrance at birth is approximately 6.9% or higher in DFNB1 patients and provide further evidence that GJB2 hearing loss may not always be congenital in onset.

Etiology and one-year follow-up results of hearing loss identified by screening of newborn hearing in Japan.

OBJECTIVE: To evaluate the incidence of newborn hearing loss in a Japanese population and to elucidate etiological factors and one-year prognosis. STUDY DESIGN: Screening of newborn hearing. SETTING: Children's tertiary referral center. SUBJECTS AND METHODS: Between 1999 and 2008, 101,912 newborn infants were screened, with 693 infants (0.68%) referred. Etiology investigation included CT, detection of cytomegalovirus (CMV) DNA, and connexin 26 mutation. RESULTS: Abnormal results (auditory brainstem response [ABR] threshold > or = 35 normal hearing level [dB nHL] in either side) were observed in 312 infants (0.31%), and 133 subjects (0.13%) with ABR thresholds > or = 50 dB nHL on both sides were classified into the habilitation group. In this group, inner ear/internal auditory meatus anomalies were detected in 20 of 121 subjects (17%) tested, middle/external ear anomalies in 14 of 121 subjects (12%), CMV DNA in 13 of 77 subjects (17%), and connexin 26 mutation in 28 of 89 subjects (31%). In 68 subjects undergoing all three investigations (CT, CMV, and connexin 26), 41 (60%) had positive results in at least one test. With inclusion of otitis media with effusion and perinatal problems, this rate amounted to 78% (53 subjects). Of the 97 infants in the habilitation group successfully followed up to one year, 36 (37%) showed a threshold change of 20 dB or more in either ear: 11 (11%) progression and 25 (26%) improvement, and 15 infants (15%) were reclassified into a less severe classification. CONCLUSION: Considering that 26 percent of infants with bilateral moderate to severe hearing loss showed improvement in one year, habilitation protocols, especially very early cochlear implantation within one year of birth, should be reconsidered.

Risk factors for hearing loss after pediatric meningitis in Japan.

OBJECTIVES: We sought to identify predictors for hearing loss in Japanese children with meningitis. METHODS: We analyzed 155 cases of pediatric meningitis without other entities causing hearing loss in children admitted to Saitama Children's Medical Center between 1990 and 2005 for potential risk factors for hearing loss, using multiple logistic regression. Auditory brain stem response tests were performed to evaluate hearing loss. RESULTS: Of 155 children, 35 (23%) developed hearing loss (21 unilaterally and 14 bilaterally). Profound hearing loss (greater than 90 dB normal hearing level) occurred in 15 patients (9.7%; 4 unilaterally and 11 bilaterally). Of 112 patients with positive cerebrospinal fluid cultures, 27 (24%) developed hearing loss and 13 (12%) showed profound loss. Of 22 patients with Streptococcus pneumoniae meningitis, 11 (50%) developed hearing loss and 7 (32%) showed profound loss. Of 54 patients with Haemophilus influenzae meningitis, 11 (20%) developed hearing loss and 4 (7.4%) showed profound loss. High serum C-reactive protein levels and cerebrospinal fluid cultures positive for Streptococcus pneumoniae were identified as significant risk factors for hearing loss. CONCLUSIONS: A high serum C-reactive protein level was first identified as a risk factor for hearing impairment after pediatric meningitis.