Clinical observation on hearing conditions of centenarians in northern district of China.

Conclusion: The hearing conditions of the centenarians were quite poor as regards hearing thresholds and speech detection ability.

Objective: To investigate hearing conditions of centenarians.

Methods: A total of 54 centenarians in Rizhao and Linyi Districts in Shandong Province were investigated to assess hearing conditions of centenerians comprehensively by questionnaire investigation, pure-tone audiometry, acoustic immitance, intelligence evaluation, and speech detection scores.

Effect of Binghuang ear drop treatment on otitis externa in guinea pigs.

To investigate the pharmacodynamic effects of Binghuang ear drop on acute suppurative otitis externa in guinea pig model. Thirty guinea pigs were randomly divided into three groups, with ten animals in each group. Group A animals had normal ear canal and Binghuang ear drops (two drops, B.

The differentiation of mesenchymal stem cells into inner ear hair cell-like cells in vitro.

Conclusion: Bone marrow mesenchymal stem cells (MSCs) have the ability to differentiate into hair cells, and this method of culturing MSCs provides a useful tool for studies on mammalian cochlear hair cell regeneration.

Objective: To investigate a method to induce bone marrow MSCs to differentiate into inner ear hair cells.

Methods: Rat bone marrow MSCs were isolated from healthy rats and cultured in vitro.

[Preliminary clinical research of cochlear implantation in elderly and pre-elderly patients with profound hearing loss].

Objective: To explore the safety and efficacy of cochlear implantation among elderly patients with severe to profound hearing loss.

Methods: Eight pre-elderly and elderly patients with an medium age of 58 years who suffered from bilateral severe to profound sensorineural hearing loss received cochlear implantation between November 2008 and November 2009. The patients' tolerance to implant surgery and the occurrence of complications were observed.

Math1 gene transfer based on the delivery system of quaternized chitosan/Na-carboxymethyl-beta-cyclodextrin nanoparticles.

Mammalian cochlear hair cells don't regenerate naturally after injury, which usually leave permanent hearing loss. Math1 gene is a positive regulator of hair cell differentiation during cochlear development and was proved to be very critical in hair cell regeneration in deaf animals. Generating new cochlear hair cells by forced Math1 expression may be a cure for hearing loss.

The role of Smad4 in vestibular development in mice.

The regulation of the bone morphogenetic protein (BMP) signal transduction pathway is important in the development of the inner ear and vestibular system. We reported previously that small mothers against decapentaplegic homolog-4 (Smad4) is required for inner ear cochlear development and normal auditory function in mammals; however, the distribution and functional mechanisms of Smad4 at various stages of vestibular development remained unclear. To investigate the relationship between the Smad4 gene and vestibular organ development, we measured changes in the expression of BMP4 and Smad4 during vestibular development in C57BL/6 mice.

Death mode-dependent reduction in succinate dehydrogenase activity in hair cells of aging rat cochleae.

Background: Our previous studies have shown that both apoptosis and necrosis are involved in hair cell (HC) pathogenesis in aging cochleae. To better understand the biological mechanisms responsible for the regulation of HC death, we examined the activity of succinate dehydrogenase (SDH), a mitochondrial bioenergetic enzyme, in the HCs of aging cochleae.

Methods: The auditory brainstem response thresholds elicited by tone bursts at 4, 10 and 20 kHz were measured in both young (2-3 months) and aging (22-23 months) Wistar rats.

Smad5 haploinsufficiency leads to hair cell and hearing loss.

The Smads are a group of related intracellular proteins critical for transmitting the signals to the nucleus from the transforming growth factor-beta superfamily at the cell surface. Knockout of the Smad5 is embryonic lethal. However, the Smad5 knockout of single allele (+/-) could survive.

[Overexpression of Hath1 induces production of hair cell-like cells in greater epithelial ridge cell cultures from postnatal rat cochlea].

Objective: To investigate the effect of Hath1 (human atonal homolog 1) overexpression on greater epithelial ridge (GER) cells from postnatal rat cochlea in vitro.

Methods: GER cells were isolated by using a combinatorial approach of enzymatic digestion and mechanical separation from P1 rat cochlear. The GER cell cultures were infected by adenovirus containing Hath1 and enhanced green fluorescent protein (ad-Hath1-EGFP), while transfecting EGFP(ad-EGFP) was as controls.

[In vitro culture of greater epithelial ridge cells from rat cochleae].

Objective: To establish in vitro culture systems of greater epithelial ridge (GER) cells from rat cochlear and to investigate the characterization, growth pattern and ultrastructure of GER cells.

Methods: Using a combinatorial approach of enzymatic digestion and mechanical separation to allow isolation and culture of GER cells from P1 rat cochleae. The dissociated GER cells were cultured in serum-free or 10% fetal bovine serum DMEM respectively.

[Genetic counseling and instruction for deaf couples directed by genetic testing].

Objective: To analyze the molecular pathogenesis of deaf couples by means of genetic testing. To provide accurate genetic counseling and instruction for deaf couples with different etiology based upon results of genetic testing.

Methods: Four deaf families from July 2005 to May 2006.

[Genetic counseling and intervention for families with deaf-mute patients based on genetic testing: analysis of 5 families].

Objective: To analyze the molecular genetic mechanisms of pathogenesis of deafness in the families with deaf-mute patients and analyze the strategies of genetic counseling and intervention for these families.

Methods: Peripheral blood samples were collected from the probands with deaf-muteness and their parents of five families and genetic tests were conducted to analyze the GJB2, SLC26A4 (PDS), and mitochondrial DNA (mtDNA) A 1555G genes for the existence of mutation. Families 1-3 had one child with hearing loss each while the parents had normal hearing and the mothers had been pregnant for 6-18 weeks.

Isolation, growth and differentiation of hair cell progenitors from the newborn rat cochlear greater epithelial ridge.

Mammalian cochlear hair cell loss is irreversible and leads to permanent hearing loss. To restore hearing physiologically, it is necessary to generate new functional hair cells either from endogenous cells or from exogenously transplanted hair cells/progenitors. Previous studies suggest that cochlear greater epithelial ridge (GER) and lesser epithelial ridge (LER) cells are capable of differentiating into hair cells.

[Expression of liposome-mediated PEDF-GFP gene in the retina of the BN rats through different gene delivery route].

Objective: Transducing PEDF-GFP plasmid to the retina of the BN rats with cationic liposome through different gene delivery route, then observe the expression and location of the PEDF-GFP.

Methods: PEDF-GFP plasmid with cationic liposome was delivered to the retina of the BN rat through subretinal injection and intravitreal injection. The expression of GFP was observed under fluorescence microscope, and the mRNA of PEDF gene was detected by RT-PCR.

[Patients suffered from enlarged vestibular aqueduct syndrome in Chifeng deaf and dumb school detected by Pendred's syndrome gene hot spot mutation screening].

Objective: To investigate the incidence of hot spot mutation of PDS gene by genetic screening testing method in Chifeng City, Inner Mongolia. The feasibility and effectiveness of genetic screening method in finding enlarged vestibular aqueduct syndrome were confirmed by temporal bone CT scan.

Methods: DNA were extracted from peripheral blood of 141 students of Chifeng Deaf and Dumb school.

[Expression of three kinds of transcription factors in greater epithelial ridge cells of rat cochlear].

Objective: To detect the expression of Math1, Hes1 and Hes5 in greater epithelial ridge (GER) cells of rat cochlear and explore their influence on hair cell differentiation.

Methods: Postnatal day 0 (P0), day 1 (P1) , day 3 (P3) day 4 (P4) and day 5 (P5) rat cochlear were dissected respectively and then pure GER cells were separated by a combinatorial approach of attachment and mechanical separation. The total RNA of GER cells was extracted by Trizol one step method and the expression of Math1, Hes1 and Hes5 in GER cells was detected with reverse transcription polymerase chain reaction.

Basic fibroblast growth factor protects auditory neurons and hair cells from glutamate neurotoxicity and noise exposure.

Objective: To determine the protective effects of basic fibroblast growth factor (bFGF) on cochlear neurons and hair cells in vitro and in vivo.

Material And Methods: In Experiment I, cultured spiral ganglion neurons (SGNs) prepared from postnatal Day 3 mice were exposed to 20 mM glutamate for 2 h before the culture medium was replaced with fresh medium containing 0, 25, 50 or 100 ng/ml bFGF. Fourteen days later, all cultures were fixed with 4% paraformaldehyde and stained with 1% toluidine blue.

Histological study of experimental reconstructive materials for repair of lateral skull base and dura mater defects in dogs.

Objective: In order to assess the reconstructive properties of fascia lata, superficial fascia lata and bone morphogenetic protein (BMP) in skull base surgery, lateral skull base bone and dura mater defect models were established in dogs

Material And Methods: As a repair material we selected fascia lata, either alone or in combination with BMP, for reconstructing large cranial defects in dogs. Twenty dogs undergoing a 3.0 x 4.

[Construction of bicistronic eukaryotic vector containing basic fibroblast growth factor and study of their functions in gene therapy for hearing impairment].

Objective: To construct basic fibroblast growth factor(bFGR) and enhance green fluorescence protein(EGFP) fusion gene eukaryotic expression vector internal ribosome entry site (pIRES)-bFGF-GFP and to evaluate the effect of transduction bFGF gene on noise induced hearing-loss in inner ear hair cells of guinea pigs.

Methods: Human bFGF cDNA was inserted into mammalian expressed plasmid pIRES-EGFP. The recombinant expression plasmid pIRES-bFGF-EGFP was transfected into inner ear of guinea pigs, using lipofectin method.

Protective effect of basic fibroblast growth factor on auditory hair cells after noise exposure.

The purpose of this study was to observe the protective effects of basic fibroblast growth factor (bFGF) on the cells of the inner ear using in vivo experiments. The studies were carried out using guinea pigs in which bFGF or artificial perilymph was perfused into the cochlea. The compound action potential (CAP) was measured before and after exposure to a sound simulating an explosion.

[Adenovirus-mediated NT3 gene transfer protects spiral ganglion neurons from degeneration after noise trauma].

Numerous studies have shown that the health of spiral ganglion neurons is highly important for hearing. As a trophic factor of spiral ganglion neurons, neurotrophin 3 (NT3) is a potential candidate for prevention of spiral ganglion neuron degeneration in human. In our experiments, efficient transduction and long term expression of foreign gene of cochlea cells has been found with adenovirus carried lacZ gene (Ad-lacZ).