Objective To investigate the expression of Smad5 gene in the cochlea and to identify its location. Methods Reverse transcription polymerase chain reaction (RT-PCR) was employed to detect the expression of Smad5, the in situ hybridization and the immunohistochemical technique were used to localize the Smad5 messenger RNA and the Smad5 protein in mouse cochlea. Results Smad5 gene expressed in cochlea at a high level. Smad5 expression was concentrated in supporting cell, hair cell, spiral ganglion, epithelium of stria vascularis and basilar membrane. Conclusion The Smad5 proteins exist in the mouse cochlea and it may be involved in the cochlear formation and the differentiation of hair cell. Smad5 might be an essential factor for the development of normal cochlea.

Objective To construct the bFGF/Math1 f usion gene expression vector and to investigate its expression in the cochlea of rat. Methods Using the recombinant DNA technique to construct the bFGF/Math1 gene expression vector and the restriction enzyme analysis to ide ntify the correct construction. The mRNA expression was detected by the RT-PCR m ethod after being transfected into the cochlea of rat using lipofectin reagent. Results The recombinant was correct and the bFGF/Math1 wa s expressed in the cochlea of rat.Conclusion The PRK5-bFGF-Math1 eukaryotic expression plas mid was successfully constructed and the bFGF/Math1 was expressed in the mammali an cochlea.

AIM To investigate the protective effect of sodium gamma-hydroxybutyrate (?-OH) against cerebral ischemia-reperfusion injury in gerbils and the neuroprotective mechanism of ?-OH. METHODS The occlusion of bilateral carotid arteries of gerbil was used to make the cerebral ischemia-reperfusion models. Different doses of ?-OH were administered intraperitoneally 40 min prior to the onset of ischemia. After 10 min ischemia and 1 h reperfusion, bilateral hippocampus, cortex and striatum were taken out to measure ATPase, SOD and MDA. RESULTS The contents of MDA markedly elevated while Na +,K +-ATPase, Ca 2+ -ATPase and SOD activities decreased in hippocampus, cortex and striatum 1 h after ischemia-reperfusion. ?-OH administered prior to ischemia can partly reverse the elevation of MDA contents and the reduction of SOD activities. ?-OH given after ischemia can still provide partly protective effect. CONCLUSION ?-OH provides significant protective effect against cerebral ischemia-reperfusion injury by protecting ATPase and SOD activities, deleting free radicals and reducing the lipid peroxidation.

Objective To study the co-relation of radiological and histopathological features of lung cancer. Methods X-ray CT and histopathological features of 36 cases of lung cancer were analyzed retrospectively. Results High-density mass with strengthened edge was found to be paralleled with lung atery at lung gate in 6 cases. As a result, bronchial tubes became narrow with mucus in it. Squamous carcinoma tissues of 22 cases were showed growing within bronchial tubes. Local lung emphysema in early stage obstructive pneumonia and 19 cases of lung collapse in mid/late stage(86.4%) were brought out because of narrow cavity of bronchi. Megaly lymph nodes were seen by mediastina window in 12 cases. Peripheral mass with leaf-like edge were found in 8 cases,and the diameter of each was less than 2cm,while irregular deviated cavitative was seen in one case. Conlusion It is suggested that close combination of X-ray CT and histopathological can improve the accurate rate of diagnosis in lung cancer.

Objective To investigate the effects of antisense recombinant euraryotic expression vector of HCCR-2 on the proliferation and apoptosis of HepG2. Methods The antisense recombinant eukaryotic expression vector of HCCR-2 was constructed. The vector was stably transfected to the HepG2 cells, and positive clones were selected by G418 (antiseuse vector group), pIRES2-EGFP vector was transfected into the HepG2 cells in the same way (pIRES2-EGFP group). The conditions of the nontransfected HepG2 cells were used as control (HepG2 group). Changes in cell growth curve, cell cycle, cell apoptosis and morphology of HepG2 cells after the transfec-tion were detected by MTT method, flow cytometry and transmission electron microscopy, respectively. All the data were analyzed by one-way ANOVA and chi-square test. Results The expression level of HCCR-2 mRNA was down-regulated to 0.39±0.04 in antisense vector group, and the expression level of HCCR-2 mRNA in pIRES2-EGFP group and HepG2 group were 0.62±0.06 and 0.72±0.03, respectively, with significant difference among the 3 groups (F=43.701, P<0.05). The apoptotic rate of HepG2 cells in antisense vector group, pIRES2-EGFP grop and HepG2 group were 13.30%, 2.51% and 2.07%, respectively, with significant difference among the 3 group (χ2=6.793, 8.721, P<0.05). The growth of HepG2 cells in antisense vector group was retarded, and was blocked in G0/G1 stage. Conclusions The HCCR-2 antisense recombinant eukaryotic expression vector can inhibit the mRNA expression of HCCR-2 and promote the apoptosis of cells. HCCR-2 may be involved in cell regulation and the proliferation of hepatocellular carcinoma cells.

Objective To investigate the clinical significance of lymphatic mapping and sentinel lymph nodes (SLNs) biopsy in the diagnosis and treatment of gastric cancer. Methods A retrospective analysis was carried out based on the data of 46 patients who had received D2 gastrectomy from January 2003 to June 2006. The SLNs stained by methylene blue were resected for biopsy. Results The success rate of SLNs biopsy was 83% (38/46). The sensitivity, false-negative rate, accuracy, specificity, negative predictive value and positive predic-tive value of SLNs were 69% (18/26), 31% (8/26), 79% (30/38), 100% (12/12), 60% (12/20) and 100% (12/12). The sensitivity, accuracy and negative predictive value were 100% in patients with tumor in pT1 stage or TNM I stage, or with the diameters of the tumors under 4 era. The tumor site, and the degree of lymph node metastasis affected the success rate of biopsy, and the invasion depth, clinical stage and the degree of lymph node metastasis affected the sensitivity, accuracy and negative predictive value of biopsy. Conclusions The application of sentinel lymph node biopsy using methylene blue in gastrie cancer is feasible. The sensitivity, accuracy and reliability are high in patients at early stage of gastric cancer.

Objective To investigate the relationship between polymorphisms of N-acetyltransferase 2(NAT2)genes and anti-tuberculosis drug induced hepatic-injury(ADIH).Methods A 1:1 matched case-control study was conducted.One hundred and six cases fulfilling the criteria of ADIH were selected as ADIH group from the patients who received anti-tuberculosis therapy.whereas those patients without any hepatic inj ury related elinical symptoms during three months of follow-up period were selected as control.The genetic polymorphisms of the loci,NAT2481C/T,NAT2-590G/A and NAT2-857G/A,were determined by polymerase chain reaction and restriction fragment length polymorphism technique(PCR-RFLP)in patients who received antituberculosis therapy.The major environmental factors and genotypes were analyzed by univariate and multivariate conditional Logistic analyses.Results The T,AA allele frequencies of NAT2-481C/T,NAT2-590G/A and NAT2-857G/A were 7.5%,28.8%and 17.9%respectively in ADIH group,and 6.6%,18.9%and 17.5%,respectively in the control group.Univariate analysis demonstrated that the frequency of NAT2 slow acetylation genotype in ADIH group was significantly higher than that in control group with a crude OR(95%CI)of 2.250(1.140-4.441).Among 6 potential risk factors,i.e.education level,occupation,body mass index(BMI),smoking,drinking and the type of tuberculosis,the low BMI and drinking were two risk factors for ADIH.In multivariate analysis,ADIH remained associated with acetylation genotype after adjusting for BMI and drinking status.The adjusted OR(95%CI)was 2.246(1.086-4.644).Conclusion NAT2 slow acetylation genotype may be associated with the occurrence of ADIH.

Objective To obtain the auditory brainstem response (ABR)wave of normal adult mice ,and to analyze the thresholds ,latency and amplitudes to provide reference for future mice auditory research .Methods To determine the thresholds according to the high occurrence rate wave of click ABR at high (90 dB SPL) ,moderate (40 dB SPL)and low(20 dB SPL)sound intensities .thresholds ,latencies and amplitudes decreased as the wave with high occurrence rate .Results The occurrence rates of wave I ,II ,III ,IV ,and V were 100% ,100% ,100% ,75% 65% at high levels ;75% ,100% ,100% ,45% ,40% at moderate levels ,and 30% ,90% ,40% ,5% ,0% at low levels ,respec-tively .The results showed wave morphology was suitable to judging thresholds :the average threshold was 20 ± 5 .62 dB SPL ,latency and amplitude ranged from 2 .71 ± 0 .17~3 .08 ± 021 ms and 6 .20 ± 2 .24~1 .63 ± 0 .85 μV ,respectively , when sound intensities changed from 90 to 20 dB SPL .Conclusion Wave II is regarded as the best wave to determine threshold latency and amplitude .It will help future researches about mice auditory under pathophysiology conditions .

Objective: To investigate the mechanisms of nuclear export signal of androgen receptor (NESAR) in the regulation of androgen receptor (AR) protein expression and stability in prostate cancer.Methods: The green fluorescent protein fusion protein expression vectors pEGFP-AR(1-918aa), pEGFP-NESAR (743-817aa), pEGFP-NAR (1-665aa) and pEGFP-NAR-NESAR, and lysine mutants of NESAR pEGFP-NESAR K776R, pEGFP-NESAR K807R and pEGFP-NESAR K776R/K807R, were transiently transfec-ted into prostate cancer cell line PC3.Fluorescence microscopy, Western blot and immunoprecipitation were used to detect NESAR regulation of androgen receptor stability.Results: Under the fluorescence microscope, NESAR-containing fusion proteins were cytoplasmic localization, and their fluorescence intensities were much weaker than those without NESAR.The expression levels of NESAR-containing fusion proteins were significantly lower than those without NESAR.The half-lives of GFP-NESAR and GFP-NAR-NESAR were less than 6 h, while the expression of GFP and GFP-NAR was relatively stable and the half-life was more than 24 h in the presence of cycloheximide.The expression levels of GFP-NESAR were significantly increased by proteasome inhibitor MG132 treatment in a dose-dependent manner;in contrast, MG132 did not show any significant effect on the protein levels of GFP.When new protein synthesis was blocked, MG132 could also prevent the degradation of GFP-NESAR in the transfected cells in the presence of cycloheximide, while it had no significant effect on GFP protein stability in the parallel experiment.GFP immunoprecipitation showed that the ubiquitination level of GFP-NESAR fusion protein was significantly higher than that of the GFP control.The mutations of lysine sites K776 and K807 in NESAR significantly reduced the level of ubiquitination, and showed increased protein stability, indicating that they were the key amino acid residues of NESAR ubiquitination.Conclusion: NESAR was unstable and decreased the stability of its fusion proteins.NESAR was the target of polyubiquitination and mediated the degradation of its fusion proteins through the ubiquitin-proteasome pathway in prostate cancer cells.Our research provides a new way to regulate the level and/or activity of AR proteins, thus helping us understand the molecular mechanisms of AR degradation and strict control of AR in the progression to castration-resistance.