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Biomedical subjects

Wei Song

Publications and source records attributed to Wei Song.

At least 37 records · Page 2Linked to original sources
PubMed2006

[Analysis of air caloric testing results for patients suffering from tympanic membrane perforation with vertigo].

OBJECTIVE: To analyze characteristic of air caloric testing for patients with tympanic membrane perforation and to assess the availability of this testing for the patients. METHOD: Forty-three cases of chronic otitis media with tympanic membrane perforation and vertigo were investigated, in which there were 37 cases with single ear perforation and 6 cases with bilateral perforation. The patients were performed by air caloric testing, to observe the characteristic of nystagmus,slow phase velocity (SPV) and unilateral weakness (UW). RESULT: Four types of nystagmus, including enhancing, "normal", weakening and inversion, were observed with bilateral caloric air stimulation in ears with tympanic membrane perforation. Nystagmus of perforated ear presented SPV increased exceeding normal range or non-perforated ear and UW > 15% (15 cases, 17 ears), which was called enhancing type; normal nystagmus SPV in bilateral ear and UW < 15% (7 cases) was called "normal" type; weakened nystagmus SPV in perforated ear to non-perforated ear and UW > 15% (9 cases) was called weakening type; normal nystagmus in non-perforated ear and inverted caloric nystagmus in perforated ear (12 cases, 14 ears) was called inversion type. In patients with chronic otitis media recurring lately, inverted nystagmus was observed in perforated ears with effusion and humidity in the tympanic cavity, the other types were observed in patients in stillness stage of otitis media. CONCLUSION: Bilateral caloric air became strong stimulation for the perforated ear, nystagmus of perforated ear with normal function of semicircular canal was stronger than that of the non-perforated ear. While the perforated ear with undermined function of semicircular canal, nystagmus could present normal or weakened. In the patients with otitis media in active stage, hot air stimulation could be turned to cool stimulation response so as to cause inverted nystagmus. Air caloric testing can be used to assess vestibular function of the patients with tympanic membrane perforation and vertigo.

Adult↗
PubMed2006

[Prognostic value of plasma brain natriuretic peptide and C-reactive protein in patients with acute coronary syndromes underwent percutaneous coronary intervention].

OBJECTIVE: To evaluate the prognostic value of plasma brain natriuretic peptide (BNP) and C-reactive protein (CRP) in patients with acute coronary syndromes (ACS) underwent percutaneous coronary intervention (PCI). METHODS: Patients with ACS underwent PCI in our hospital from December 2004 to September 2005 were included in this study. Plasma BNP (n = 189) and CRP (n = 141) were measured at a median of (34.2 +/- 16.3) hours from symptom onset, total mortality and the risk for major adverse cardiac events (MACE, including death, recurrent MI, recurrent angina, heart failure, readmission for any reason) at 30 days and at 3 months was analyzed. RESULTS: Patients were divided into 4 groups according to their BNP levels (BNP 100 ng/L to 300 ng/L to 600 ng/L) and the 3-month mortality was 0%, 1.4%, 7.7%, 48.3% and 3-month incidence of MACE was 7.9%, 17.1%, 57.7%, 79.3% respectively. Multivariate logistic regression analyses showed that the plasma BNP level predicted 30-day (r = 0.8515, P < 0.01) and 3-month (r = 0.9201, P < 0.01) mortality and 30-day (r = 0.7066, P < 0.01) and 3-month (r = 0.7090, P < 0.01) incidence of MACE independent of other known prognostic factors such as age, gender, family heredity, hypercholesterolemia diabetes, hypertension, smoking and LVEF. Patients were divided into 3 groups according to their CRP levels (CRP 8.0 mg/L to 32.0 mg/L) and 3-month mortality was 2.7%, 7.7% and 28.6% and 3-month incidence of MACE was 28.4%, 41.0% and 60.7% respectively. CRP predicted 30-day (r = 0.5882, P = 0.0044) and 3-month (r = 0.5235, P = 0.0038) mortality independent of traditional risk factors, and predicted 30-day (r = 0.2705, P = 0.0380) and 3-month (r = 0.2290, P = 0.0429) incidence of MACE after adjustment for patient age. CRP lost its predictive value after BNP was introduced into the model, while BNP was still an independent predictor for mortality and incidence of MACE at 30 days and 3 months in ACS patients underwent PCI. CONCLUSION: Both plasma BNP and CRP are good predictors for early mortality and MACE incidence in ACS patients underwent PCI.

Acute Coronary Syndrome↗
PubMed2006

[Application of distortion product otoacoustic emissions in detection of pseudohypacusis and exaggerated hearing loss].

OBJECTIVE: To explore the role of differential diagnosis of distortion product otoacoustic emissions (DPOAE) in pseudohypacusis and exaggerated hearing loss. METHOD: Detection and analysis of DPOAE were made by ILO96 Otodynamics Analyzer in the patients complaining of post-traumatic hearing loss and in cooperative in pure tone threshold (PTT) examination. RESULT: The detective results of DPOAE in 102 patients (121 ears) in cooperative in PTT examination revealed that pseudohypacusis was 66.12% (80/121 ears), exaggerated hearing loss was 33.88% (41/121 ears). The reactive threshold value determined by auditory brainstem response (ABR) in these patients confirmed that the results of DPOAE were objective and reliable. CONCLUSION: DPOAE can be used as a routine examination method in differential diagnosis of the post-traumatic hearing loss. It gives an objective and reliable diagnosis and differential diagnosis for the pseudohypacusis and exaggerated hearing loss.

Adolescent↗
PubMed2006

[Establishment of conditionally immortalized rat cochlear greater epithelial ridge and lesser epithelial ridge cell lines using a retrovirus-mediated gene transfer technique].

OBJECTIVE: To facilitate further investigation of the function of greater epithelial ridge (GER) and lesser epithelial ridge (LER) cells, a greater a lesser epithelial ridge cell immortal line originated from postnatal rat cochleae were established. METHOD: The GER and LER cells were dissected from P1 rats cochleae and infected with SV40-LT antigen using a retrovirus-mediated method. The established cell lines were purified by monoclone technique and identified following morphology observation and immunocytochemical staining. RESULT: The established cell lines had been stably maintained continuously for more than 20 passages and displayed many features similar to epithelial cells. They grew in patches and assumed a polygonal morphology. Immunocytochemical characterization revealed that these cells could be labeled by GER/LER marker (Isletl) and SV40-LT antigen. CONCLUSION: In the present experiment, the GER and LER cell line from postnatal rat cochleae has been successfully established and this cell line may potentially provide an invaluable system for studying hair cell differentiation and regeneration as well as the therapy of sensory deafness caused by auditory hair cells loss.

Animals↗
PubMed2006

[Comparative study of vestibular autorotation test and caloric test for patients with peripheral vestibular disorders].

OBJECTIVE: To analyse the value of vestibular autorotation test (VAT) for assessing vestibular function. METHOD: VAT (WSR. USA) and caloric test (CT) were performed on 48 patients with peripheral vestibular disorders. Videonystagmograph (Synapsis. France) was used for caloric nystagmus recordings. The results of VAT were compared with that of CT. Parameters analysed in this study included gain, phase and asymmetry of VAT; the canal paresis (CP) and the directional preponderance (DP) of CT. That any of five parameters of VAT was abnormal or one of CP and DP appeared could be defined as abnormal VAT or abnormal CT. RESULT: VAT was found to be abnormal in 36 (75.0%) patients, including 32 (66.7%) patients (21 cases with decreased gain, 24 cases with lagged phase and 6 cases with asymmetry) in horizontal testing and 15 (31.2%) patients (7 cases with decreased or increased gain, 14 cases with lagged phase) in vertical testing. Four patients had abnormal vertical testing alone. Abnormal phase can be observed more frequently than abnormal gain. The abnormal parameters of phase and gain were consistent in the 2.0-6.0 Hz range. Asymmetry appeared in all cases in the 6.0-11.0 Hz range, consistent with the side of vestibular weakness tested by CT. Thirty-three patients (68.8%) showed CP or DP of CT (bilateral or unilateral CP 28 cases and DP 16 cases). VAT and CT showed abnormal results in 25 patients simultaneously, solo abnormal results were found in 11 patients and 8 patients respectively. There were 4 patients with normal results of both VAT and CT. Abnormal results of VAT combined with CT were assessed in 44 (91.7%) patients. When vestibular lesion was complete, results of VAT and CT were all abnormal and the abnormal parameters of VAT were observed at all frequencies of band tested. CONCLUSION: VAT is a vestibular test of high-frequencies and wide-bands and can indicate information of not only vestibular function in higher frequency band, but also vertical semicircular canal function. As the supplement of CT, error diagnosis can be partly avoided by VAT.

Adolescent↗
PubMed2006

[Clinical research of vestibular autorotation test for patients with vertebrobasilar insufficiency].

OBJECTIVE: To explore the diagnostic values of vestibular autorotation test (VAT) for patients with vertebrobasilar insufficiency (VBI). METHODS: VAT and videonystagmography ( VNG) were performed on 73 patients with VBI and 48 patients with peripheral vestibular lesions (contrast group). Parameters analyzed included Gain, phase and asymmetry of VAT, as well as the canal paresis (CP) of caloric test and results of optokinetic-pursuit tests in VNG. Positive result of the test could be defined if anyone of the parameters was abnormal. RESULTS: For VAT test, Gain was enhanced in VBI group and was reduced in contrast group. In VBI group and contrast group, Gain enhanced showed in 47 (64.4%) cases and 5 (10.4%) cases, respectively (chi2 = 31.19, P < 0.01). Simultaneity, Gain reduced in 11 cases (15.5%) and 22 cases (45.8%), respectively (chi2 = 13.82, P < 0.01). But there was no statistics significant for results of the parameters of phase, asymmetry and integration between two groups. For VNG test, results with optokinetic-pursuit tests were more abnormal in VBI group than that in contrast group, which showed central lesions characteristics. Forty-four cases (60.3%) in VBI group and 10 cases (20.8%) in control group showed central lesions results with optokinetic-pursuit tests and visual fixation test (chi2 = 15.89, P < 0.01). Unilateral or bilateral CP showed in 33 cases (68.6%) in control group and 51 cases (69.9%) in VBI group with caloric test. CONCLUSIONS: Gain of VAT is mostly enhanced in VBI group, and Gain as a main characteristic is reduced in patients with peripheral vestibular lesions. The Gain parameter is availability for assessing characteristics of vestibular lesions. Phase and asymmetry can be used to assess the vestibular function but can not indicate the characteristics of vestibular lesions.

Adolescent↗
PubMed2005

Nudel contributes to microtubule anchoring at the mother centriole and is involved in both dynein-dependent and -independent centrosomal protein assembly.

The centrosome is the major microtubule-organizing center in animal cells. Although the cytoplasmic dynein regulator Nudel interacts with centrosomes, its role herein remains unclear. Here, we show that in Cos7 cells Nudel is a mother centriole protein with rapid turnover independent of dynein activity. During centriole duplication, Nudel targets to the new mother centriole later than ninein but earlier than dynactin. Its centrosome localization requires a C-terminal region that is essential for associations with dynein, dynactin, pericentriolar material (PCM)-1, pericentrin, and gamma-tubulin. Overexpression of a mutant Nudel lacking this region, a treatment previously shown to inactivate dynein, dislocates centrosomal Lis1, dynactin, and PCM-1, with little influence on pericentrin and gamma-tubulin in Cos7 and HeLa cells. Silencing Nudel in HeLa cells markedly decreases centrosomal targeting of all the aforementioned proteins. Silencing Nudel also represses centrosomal MT nucleation and anchoring. Furthermore, Nudel can interact with pericentrin independently of dynein. Our current results suggest that Nudel plays a role in both dynein-mediated centripetal transport of dynactin, Lis1, and PCM-1 as well as in dynein-independent centrosomal targeting of pericentrin and gamma-tubulin. Moreover, Nudel seems to tether dynactin and dynein to the mother centriole for MT anchoring.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed2005

Apoptosis of allospecifically activated human helper T cells is blocked by calcineurin inhibition.

BACKGROUND: Classical transplantation immunosuppression relies heavily upon the interruption of interleukin-2 (IL-2) signaling by calcineurin inhibition. However, recent evidence in murine models suggests that IL-2 is necessary for activation-induced cell death (AICD) of allograft-specific lymphocytes. METHODS: We examined the apoptotic effects of the calcineurin inhibitor cyclosporine A and mTOR inhibitor rapamycin on the apoptotic alterations that occur in allospecifically activated human lymphocytes in a one-way mixed lymphocyte culture (MLC). RESULTS: Cyclosporine increased caspase-3 activation in MLC, which corresponded with a decrease in lymphocyte apoptosis in MLC. Cyclosporine also reduced apoptosis in the CD4+ helper T cell subset, while CD8+ cells had similar or increased apoptosis when compared to controls. In contrast, rapamycin-treated cultures had normal levels of CD4+ T cell apoptosis when compared to control MLC, with decreases seen in CD8+ T lymphocytes. CONCLUSIONS: In humans, blockade of IL-2 receptor signal with rapamycin allows apoptosis of allospecifically activated CD4+ lymphocytes to occur, while blockade of IL-2 production with cyclosporine results in decreased apoptosis in this T cell subset. As helper T cells are integral to the immune response, these results may explain the tolerogenic effects of rapamycin.

Apoptosis↗
PubMed2005

Neutralizing human anti-B-cell-activating factor of the TNF family (BAFF) scFv selected from phage antibody library.

Elevated levels of B-cell-activating factor of the TNF family (BAFF) have been implicated in the pathogenesis of autoimmune diseases in human. We now report the isolation by phage display of human single-chain antibody fragment (scFv) anti-BAFF. After four rounds of panning against BAFF, thirty-two out of 92 phage clones displayed BAFF binding activity. One of the positive clones, designated F8, bound to BAFF with relatively high affinity and neutralized BAFF bioactivity in vitro. F8 clone was expressed in soluble form in Escherichia coli HB2151 and purified by immobilized metal affinity chromatography (IMAC). The purified scFv recognized BAFF with the affinity constant (K(aff)) of 2.5 x 10(7)M(-1) without cross-reaction to APRIL. In addition to binding, the purified scFv could does-dependently inhibit BAFF-induced mouse spleen B lymphocyte proliferation. Together with its fully human mature, F8 scFv may have therapeutic implications in therapy of autoimmune disorders mediated by BAFF.

Amino Acid Sequence↗
PubMed2005

Optical properties of Ag/CdTe nanocomposite self-organized by electrostatic interaction.

Ag/CdTe nanocomposite was prepared via self-organization process by electrostatic interaction between positively charged CdTe quantum dots and negatively charged Ag nanoparticles and examined with respect to their optical properties. The positively charged CdTe quantum dots and negatively charged Ag nanoparticles were synthesized separately by modifying nanoparticles surface with cationic and anionic thiol compounds, respectively. The result showed that the mixing ratio of Ag nanoparticles to CdTe quantum dots is an important parameter for controlling resulting composites. The resulting solution is optically transparent if one component is in excess. Photoluminescence of CdTe quantum dots undergoes considerably quenching if CdTe nanocrystals are in excess and SERS spectra of BVPP absorbed on Ag colloid became stronger if Ag nanoparticles are in excess. Nevertheless, while the ratio is approximately 1, micrometer-sized solid composite is obtained with the elapse of 1h after mixing. SERS spectra for solid composite only exhibit the signals of the CdS nanocrystal which reflected that prolonged refluxing during the synthesis leads to a partial hydrolysis of the thiols and to the incorporation of the sulfur from the thiol molecules into the the growing nanoparticles to form mixed CdTe(S) nanocrystal, similar to CdTe/CdS core/shell structure. From the results, we conclude that optical properties of Ag/CdTe are dependent on the mixing ratio of both nanoparticles.

Cadmium Compounds↗
PubMed2005

Correlation of systemic superoxide dismutase deficiency to airflow obstruction in asthma.

RATIONALE: Increased oxidative stress and decreased superoxide dismutase (SOD) activity in the asthmatic airway are correlated to airflow limitation and hyperreactivity. We hypothesized that asthmatic individuals with higher levels of oxidative stress may have greater loss of SOD activity, which would be reflected systemically in loss of circulating SOD activity and clinically by development of severe asthma and/or worsening airflow limitation. METHODS: To investigate this, serum SOD activity and proteins, the glutathione peroxidase/glutathione antioxidant system, and oxidatively modified amino acids were measured in subjects with asthma and healthy control subjects. RESULTS: SOD activity, but not Mn-SOD or Cu,Zn-SOD protein, was lower in asthmatic serum as compared with control, and activity loss was significantly related to airflow limitation. Further, serum SOD activity demonstrated an inverse correlation with circulating levels of 3-bromotyrosine, a posttranslational modification of proteins produced by the eosinophil peroxidase system of eosinophils. Exposure of purified Cu,Zn-SOD to physiologically relevant levels of eosinophil peroxidase-generated reactive brominating species, reactive nitrogen species, or tyrosyl radicals in vitro confirmed that eosinophil-derived oxidative pathways promote enzyme inactivation. CONCLUSION: These findings are consistent with greater oxidant stress in asthma leading to greater inactivation of SOD, which likely amplifies inflammation and progressive airflow obstruction.

Adult↗
PubMed2005

Isolation and culture of hair cell progenitors from postnatal rat cochleae.

Cochlear hair cells are a terminally differentiated cell population that is crucial for hearing. Although recent work suggests that there are hair cell progenitors in postnatal mammalian cochleae, isolation and culture of pure hair cell progenitors from a well-defined cochlear area have not been reported. Here we present an experimental method that allows isolation and culture of hair cell progenitors from postnatal rat cochleae. These progenitor cells are isolated from the lesser epithelial ridge (LER, or outer spiral sulcus cell) area of pre-plated neonatal rat cochlear segments. They express the same markers as LER cells in vivo, including ZO1, Islet1, Hes1, and Hes5. When these cells are induced to express Hath1, they show the potential to differentiate into hair cell-like cells. Interestingly, these cells can be lifted from monolayer cultures and maintained in aggregate cultures in which spheres can be formed. Hair cell progenitors in the spheres display their proliferating capability and express only epithelial markers. Furthermore, when these spheres are mixed with dissociated mesenchymal cells prepared from postnatal rat utricular whole mounts, and replated onto a collagen substratum, the epithelial progenitor cells are able to differentiate into cells expressing markers of hair cells and supporting cells in epithelial islands, which mirrors the inner ear sensory epithelium in vivo. Successful isolation and culture of hair cell progenitors from the mammalian cochlea will facilitate studies on gene expression profiling and mechanism of differentiation/regeneration of hair cells, which are crucial for repairing hearing loss.

Actins↗
PubMed2005

Characterization of a novel plant growth-promoting bacteria strain Delftia tsuruhatensis HR4 both as a diazotroph and a potential biocontrol agent against various plant pathogens.

A novel, plant growth-promoting bacterium Delftia tsuruhatensis, strain HR4, was isolated from the rhizoplane of rice (Oryza sativa L., cv. Yueguang) in North China. In vitro antagonistic assay showed this strain could suppress the growth of various plant pathogens effectively, especially the three main rice pathogens (Xanthomonas oryzae pv. oryzae, Rhizoctonia solani and Pyricularia oryzae Cavara). Treated with strain HR4 culture, rice blast, rice bacterial blight and rice sheath blight for cv. Yuefu and cv. Nonghu 6 were evidently controlled in the greenhouse. Strain HR4 also showed a high nitrogen-fixing activity in N-free Döbereiner culture medium. The acetylene reduction activity and 15N2-fixing activity (N2FA) were 13.06 C2H4 nmolml(-1) h(-1) and 2.052 15Na.e.%, respectively. The nif gene was located in the chromosome of this strain. Based on phenotypic, physiological, biochemical and phylogenetic studies, strain HR4 could be classified as a member of D. tsuruhatensis. However, comparisons of characteristics with other known species of the genus Delftia suggested that strain HR4 was a novel dizotrophic PGPB strain.

Antibiosis↗
PubMed2005

cDNA cloning, functional expression and cellular localization of rat liver mitochondrial electron-transfer flavoprotein-ubiquinone oxidoreductase protein.

A membrane-bound protein was purified from rat liver mitochondria. After being digested with V8 protease, two peptides containing identical 14 amino acid residue sequences were obtained. Using the 14 amino acid peptide derived DNA sequence as gene specific primer, the cDNA of correspondent gene 5'-terminal and 3'-terminal were obtained by RACE technique. The full-length cDNA that encoded a protein of 616 amino acids was thus cloned, which included the above mentioned peptide sequence. The full length cDNA was highly homologous to that of human ETF-QO, indicating that it may be the cDNA of rat ETF-QO. ETF-QO is an iron sulfur protein located in mitochondria inner membrane containing two kinds of redox center: FAD and [4Fe-4S] center. After comparing the sequence from the cDNA of the 616 amino acids protein with that of the mature protein of rat liver mitochondria, it was found that the N terminal 32 amino acid residues did not exist in the mature protein, indicating that the cDNA was that of ETF-QOp. When the cDNA was expressed in Saccharomyces cerevisiae with inducible vectors, the protein product was enriched in mitochondrial fraction and exhibited electron transfer activity (NBT reductase activity) of ETF-QO. Results demonstrated that the 32 amino acid peptide was a mitochondrial targeting peptide, and both FAD and iron-sulfur cluster were inserted properly into the expressed ETF-QO. ETF-QO had a high level expression in rat heart, liver and kidney. The fusion protein of GFP-ETF-QO co-localized with mitochondria in COS-7 cells.

Amino Acid Sequence↗
PubMed2005

[The clinical value of sixteen-detector row computed tomography angiography for the assessment of coronary artery bypass graft].

OBJECTIVE: The aim of this study was to evaluate the value of sixteen-detector row computed tomography angiography (CTA) for the assessment of coronary artery bypass graft (CABG). METHODS: Sixty-two consecutive patients undergoing coronary artery bypass grafting were recruited. Among them, 6 patients were excluded from the study due to unfavorable control of heart rate. A total of 56 patients with 152 coronary artery bypass grafts (internal mammary artery, n = 48; saphenous venous grafts, n = 104) were examined by computed tomography angiography (CTA) with sixteen-detector row CT and by conventional invasive coronary angiography (CAG). All CT procedures were performed with retrospective electrocardiogram gating method. The patients' mean heart rate was 58 +/- 6 beats/minute. 120 ml of Visipaque 320 were continuously injected with the rate of 4.0 ml/sec during the procedure. The patency and the stenosis of coronary artery bypass grafts were evaluated by two experienced readers. RESULTS: All the coronary artery bypass grafts were visualized by CTA, and all the proximal bypass anastomoses and 71% of the distal bypass anastomoses were also visualized by CTA. Furthermore, 29 occlusions and 13 significant stenoses of coronary artery bypass grafts were detected by CTA. The comparison of the results between CTA and CAG showed that among all the 42 occluded and stenosed coronary artery bypass grafts detected by CTA, 34 were confirmed by CAG; among all the 110 normal coronary artery bypass grafts detected by CTA, 108 were confirmed by CAG. There were 8 false positive and 2 false negative findings, resulting in a sensitivity of 94%, a specificity of 95%, a positive predictive value of 86%, and a negative predictive value of 99%. CONCLUSION: Sixteen-detector row CTA technology may provide a reliable visualization and higher diagnostic accuracy of coronary artery bypass grafts lesions. This technique can be used as a noninvasive procedure for the diagnosis of suspected coronary artery bypass grafts dysfunction.

Aged↗
PubMed2005

[Isolation and identification of greater epithelial ridge in rat cochlea].

OBJECTIVE: To investigate the method for isolating greater epithelial ridge by use of thermolysin digestion combined with dissection under microscope. METHOD: The basement membrane prepared from postnatal day 0 to postnatal day 3 rat was placed into D-Hanks solution with thermolysin and DNase, then incubated at 37 degrees C for 25 minute and dissected under microscope. After GER had been isolated, morphological comparison, immunohistochemistry, RT-PCR and GER culture were performed for the purpose of identification of GER. RESULT: Immunohistochemistry indicated that the isolated GER was purely epithelial tissue. RT-PCR analysis certified that the isolated GER expressed Hes1 which was selectively expressed in GER at early postnatal in cochlea. The isolated GER could be successfully cultured in the presence of 5% serum and could survive at least 12 day in the serum-free medium. CONCLUSION: GER isolation can be successfully performed by use of thermolysin combined with microdissection. This method may provide a good technique to establish the GER cell lines or perform series of gene transfection experiments.

Animals↗
PubMed2005

[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. RESULTS: Math1 was expressed in P0 - P5 rat GER cells and Hes1 was expressed only in PO - P3 rat GER cells, while there was no expression of Hes5 in P0 - P5 rat GER cells. CONCLUSIONS: Probably only when the expression of Math1 reaches a certain level can it induce GER cells to differentiate into hair cells. Meanwhile this process might controlled by Hes1 to some extent.

Animals↗