[Experimental study on the effect of acid stimulation on human cell characteristics].

Objective:The purpose of the present study was to explore the characteristics and differentiation of somatic cells in vitro undergoing a low pH treatment, so as to provide new therapeutic strategies for treating sensorineural hearing loss.Method: The human mature somatic cells were selected as the target cells, and the cells were treated with different pH values to observe the cell morphology. The cell characteristics were identified from alkaline phosphatase (AKP) activity, immunohistochemical staining and molecular biology, and the most suitable pH value was selected. In addition, a mouse model of the cochlear lesion was constructed using bilirubin. Subsequently, the characteristics and therapeutic effect of somatic cells undergoing low pH treatment were examined by morphology, AKP activity, immunofluorescence assay and Q-PCR.Result:The cell growth of the experimental group was significantly better than those in the control group. The activity of AKP in the experimental group was higher than that in the control group. The expression of Nanog and Oct4 was both positive in the two groups. When the cells were changed to neurobasol medium, the marker of Nestin was positive.Conclusion:The human somatic cells undergoing a low pH treatment showed the similar characteristics as those of induced pluripotent stem (iPS) cells; although the functions and therapeutic effect of these altered human somatic cells need to be further studied.

Sample Grating Distributed Feedback Quantum Cascade Laser Array.

A sample grating distributed feedback quantum cascade laser array aim at broad tunability and enhanced side mode suppression ratios is presented. Utilizing a sample grating dependence on emission wavelength and epitaxial side down bonding technique, the array of laser ridges exhibited three separated single mode emissions centered at 4.760, 4.721, and 4.711 µm respectively, in continuous wave at room temperature. Side mode suppression ratios of >35 dB and continuous wave output powers of >10 mW per laser ridge were obtained.

Scheme for efficient extraction of low-frequency signal beyond the quantum limit by frequency-shift detection.

Low-frequency (Hz~kHz) squeezing is very important in many schemes of quantum precision measurement. But it is more difficult than that at megahertz-frequency because of the introduction of laser low-frequency technical noise. In this paper, we propose a scheme to obtain a low-frequency signal beyond the quantum limit from the frequency comb in a non-degenerate frequency and degenerate polarization optical parametric amplifier (NOPA) operating below threshold with type I phase matching by frequency-shift detection. Low-frequency squeezing immune to laser technical noise is obtained by a detection system with a local beam of two-frequency intense laser. Furthermore, the low-frequency squeezing can be used for phase measurement in Mach-Zehnder interferometer, and the signal-to-noise ratio (SNR) can be enhanced greatly.

Clinical efficacy of nerve growth factor in the treatment of blast-induced hearing loss: a pilot study.

OBJECTIVE: There is no effective therapy for blast-induced hearing loss in the clinic. The present report summaries our case series with using nerve growth factor in the treatment of patients with various blast-induced hearing loss. PATIENTS AND METHODS: This retrospective study analyzed the clinical outcomes of 21 patients (33 ears) seen in our Outpatient Service Clinic who were treated with nerve growth factor (NGF) by intramuscular injection for 10 days. The pure tone audiometry changes before and after NGF treatments were measured for five frequencies. RESULTS: Among the 21 patients with blast-induced hearing loss (33 ears) treated with 10-d NGF injection, the mean value of pure tone audiometry for the 5 frequencies for all the 33 ears after NGF treatment was significantly improved (p = 0.01). Three patients (6 ears) had hearing improved in different degrees, with average hearing being recovered by 15 dB HL. The total effective rate of the treatment was 18%. CONCLUSIONS: Nerve growth factor can be used to treat blast-induced hearing loss in clinic. The key to clinical success is early treatment; the efficacy on the patients with late treatment (more than one-month after injury is poor).

Review of experimental and clinical studies of autoimmune sensorineural hearing loss.

The purpose of this review was to analyze recent studies, both clinical and experimental, on diagnosis and treatment of autoimmune sensorineural hearing loss (ASNHL). Relevant studies were identified by searching Chinese Biomedical Literature Database and China Academic Journals Full-text Database for articles published nationally during the period of 1993-2013. The manuscripts were analyzed for the following aspects: selection of patients, sample size, presence of control group, experimental methods, study outcomes including audiological evaluation results, and efficacy of treatment. Forty-one manuscripts were identified including 12 reviews, 2 case reports, 20 experimental studies, and 7 clinical studies. The patient numbers in clinical studies ranged from 14 to 71 patients. Five clinical studies included control group of healthy individuals, while further two studies had no control group. Patients with ASNHL were treated with corticosteroids (prednisone or dexamethasone) in all seven clinical studies. However, statistical analyses of therapeutic efficacy were not carried out. Animal models were developed by immunization with allogeneic inner ear antigen, and some pathological changes were not specific to the disease. Experimental animals also had various degrees of changes in auditory brainstem response. Treatment guidelines need to be developed, while specific criteria of treatment efficacy need to be established. Further research is needed to demonstrate that experimental ASNHL resembles pathophysiologically the clinical situation.

Establishment of an animal model of spontaneous cervical lymph node metastasis of laryngeal squamous cell carcinoma and obtaining laryngocarcinoma cells with high metastatic potential.

To establish an animal model of spontaneous cervical lymph node metastasis of laryngeal squamous cell carcinoma and obtain laryngocarcinoma cells with high metastatic potential, laryngeal squamous cell carcinoma cell line HEP-2 in logarithmic phase were inoculated under the lingual margin mucosa of nude mice. HEP-2 cells metastasized to the cervical lymph nodes were isolated, cultured, and re-inoculated under the lingual margin mucosa of nude mice twice. The tumor formation in the tongue and in the cervical lymph nodes was confirmed by pathological examination. Carcinoma cells' ability of invasion and migration was detected by transwell assay. Human specific Alu sequences were detected by PCR, which indicated that the tumor cells originated from human laryngeal squamous cell carcinoma cell line HEP-2. Finally, an animal model of spontaneous lymph node metastasis of laryngeal squamous cell carcinoma was successfully established. Laryngeal squamous cell carcinoma cells with high metastatic potential to lymph nodes were obtained through repeated inoculations. .

Protective effects of brain-derived neurotrophic factor on the noise-damaged cochlear spiral ganglion.

OBJECTIVE: To explore the protective effects of brain-derived neurotrophic factor on the noise-damaged cochlear spiral ganglion. METHODS: Recombinant adenovirus brain-derived neurotrophic factor vector, recombinant adenovirus LacZ and artificial perilymph were prepared. Guinea pigs with audiometric auditory brainstem response thresholds of more than 75 dB SPL, measured seven days after four hours of noise exposure at 135 dB SPL, were divided into three groups. Adenovirus brain-derived neurotrophic factor vector, adenovirus LacZ and perilymph were infused into the cochleae of the three groups, variously. Eight weeks later, the cochleae were stained immunohistochemically and the spiral ganglion cells counted. RESULTS: The auditory brainstem response threshold recorded before and seven days after noise exposure did not differ significantly between the three groups. However, eight weeks after cochlear perfusion, the group receiving brain-derived neurotrophic factor had a significantly decreased auditory brainstem response threshold and increased spiral ganglion cell count, compared with the adenovirus LacZ and perilymph groups. CONCLUSION: When administered via cochlear infusion following noise damage, brain-derived neurotrophic factor appears to improve the auditory threshold, and to have a protective effect on the spiral ganglion cells.

A novel DFNA5 mutation, IVS8+4 A>G, in the splice donor site of intron 8 causes late-onset non-syndromic hearing loss in a Chinese family.

We report here the clinical, genetic, and molecular characteristics of a large Chinese family exhibiting non-syndromic, late-onset autosomal dominant sensorineural hearing loss. Clinical evaluation revealed variable phenotypes of hearing loss in terms of severity and age-at-onset of disease in these subjects. Genome-wide linkage analysis mapped the disease gene to the DFNA5 locus with a maximum two-point log odds score of 5.39 at [theta] = 0 for marker D7S2457. DNA sequencing of DFNA5 revealed a novel heterozygous IVS8+4 A>G substitution in the splice donor site of intron 8. Reverse transcriptase-polymerase chain reaction (RT-PCR) showed skipping of exon 8 in the mutant transcript. This mutation faithfully cosegregated with hearing loss in the family. In addition, the mutation was absent in 100 unrelated control DNA samples of Chinese origin. The IVS8+4 A>G mutation is predicted to create a shift in the reading frame and introduce a stop codon at position 372, thereby resulting in a prematurely truncated DFNA5 protein. Up to date, a total of four mutations in DFNA5 have been reported to lead to hearing impairment, all of them result in skipping of exon 8 at the mRNA level. Our findings provide further support for the hypothesis that DFNA5-associated hearing loss is caused by a very specific gain-of-function mutation.

A distinct spectrum of SLC26A4 mutations in patients with enlarged vestibular aqueduct in China.

There is a worldwide interest in studying SLC26A4 mutations that are responsible for enlarged vestibular aqueduct (EVA) in different ethnic background and populations. The spectrum of SLC26A4 mutations in Chinese population is yet to be fully characterized. In this study, all the 21 exons of SLC26A4 were screened in 107 Chinese patients with hearing loss associated with EVA or both EVA and Mondini dysplasia (MD), taken from six multiplex and 95 simplex families. The two types of control populations consisted of 84 normal-hearing subjects and 46 sensorineural hearing loss subjects without inner ear malformations. Biallelic mutations were found in 12 patients from multiplex families and 84 patients (88.4%) from the simplex families. In addition, monoallelic variant was detected in nine patients in the remaining 11 simplex families. Overall, up to 97.9% patients were found having at least one possible pathogenic variant in SLC26A4, with most having biallelic variants consistent with recessive inheritance of this disorder. A total of 40 mutations including 25 novel mutations were identified in the Chinese patients but were not detected in all the controls except for one normal subject. For the Chinese mutation spectrum of SLC26A4 gene, IVS 7-2A>G mutation was the most common form accounting for 57.63% (102/177) of all the mutant alleles.

AUNX1, a novel locus responsible for X linked recessive auditory and peripheral neuropathy, maps to Xq23-27.3.

BACKGROUND: We report here the genetic characterisation of a large five generation Chinese family with the phenotypic features of auditory neuropathy and progressive peripheral sensory neuropathy, and the genetic feature of X linked recessive inheritance. Disease onset was at adolescence (at an average age of 13 years for six affected subjects). The degree of hearing impairment varied from mild to severe, with decreased otoacoustic emissions; auditory brainstem responses were lacking from onset. METHODS: Two-point and multipoint model based linkage analysis using the MILNK and LINKMAP programs of the FASTLINK software package produced maximum two-point and multipoint LOD scores of 2.41 and 2.41, respectively. RESULTS: These findings define a novel X linked auditory neuropathy locus/region (AUNX1, Xq23-q27.3). This region is 42.09 cM long and contains a 28.07 Mb region with flanking markers DXS1220 and DXS8084, according to the Rutgers Combined Linkage-Physical Map, build 35. However, mutation screen of the candidate gene SLC6A14 within the region did not identify the causative genetic determinant for this large Chinese family.

[Testing of related antibodies against inner ear tissues and clinical observation on autoimmune inner ear disease].

Forty-one patients of autoimmune inner ear disease were examined with the clinical audiometry and immunocytochemical method. The results showed that there were sensorineural hearing loss in all patients. Serum immunoglobulins (IgG, IgA, IgM) elevation in 14 of 41 patients and antibodies against inner ear tissue in 4 of 41 patients were observed. It suggests that there is specific antibody against inner ear in the serum of patients with autoimmune inner ear disease, and this disease may be originated from the cochlea or the retrocochlea. The method of clinical analyses, the standards of diagnosis and the principles of treatment were discussed.