Objective To compare the characteristics of the SP-AP compound wave elicited by click and tone pip.Methods The electrocoehleogram was recorded with round window electrode,and waves were elicited by click and tone pips,respectively.Results The SP-AP compound waves were elicited 1,2,3,4 and 8 kHz tone pip and click.The amplitude of SP at each frequency was-13.56±8.7,-16.61±10.53,-10.13±14.75,-3.71±14.49,-2.99±5.4 and -4.44±10.81 μv,respectively.Conclusion Tone pip at 1,2,3,4,8 kHz can elicit SP,and produce frequency specific SP wave.This is helpful to identify the lesion site of auditory neuropathy.

Objective To explore the relationship between the duration of tone pip with Blackman envelop and morphology or latency of auditory brainstem responses.Methods ABRs were recorded using 0.5,1,2,4 and 8 kHz tone pips with Blackman envelope at different intervals.Results The longer the duration of stimulus was,the better the frequency specificity of stimulus was.However,the ABR morphology were affected and the latencies of wave Ⅲ were prolonged.Conclusion When using tone pips to evokes ABR,stimuli should be well considered in order to produce better frequency specificity and transient state.

Objective To investigate the effect of p21-activated kinase 1 on chemotherapy sensitivity of 5-fluorouracil. Methods Cell proliferation was measured by CCK8 and apoptosis rate by flow cytometry or Hoechst staining; the expression of Bcl-xl, Bcl-2, XIAP were determined by Western Blot. Results 5-FU combined shRNA-Pak1 group (combination group) could be significantly inhibited in terms of proliferation (P <0.05). The percentage of apoptosis rate in combined group was the highest and the difference among groups indicated statistical significance (P < 0.05). The expression of Bcl-xl, Bcl-2, XIAP in combination group was significantly inhibited compared with 5-FU group or shRNA-Pak1 group. Conclusion PAK1 inhibited by RNA interference can enhance chemotherapy sensitivity of 5-Fu on growth inhibition and apoptosis induction in colon cancer significantly.

Objective To combine the active poly lactic co-glycolic acid (PLGA) nanosperes with adriamycin in side (ADM-NP) on the surface of ultrasound micrbubbles in covalent bonding and to prepare a novel drug-loading ultrasound micrbubble,and observe the physicochemical property.To quantify drug encapsulation efficiency and drug-loading amounts and drug-release properties in vitro and the effect of tumor imaging.Methods ADM-NP were prepared with double emulsification method,The surface carboxyl of ADM-NP was activated with carbodiimide method.Amino ultrasound microbubbles (MB-NH2) were prepared with mechanical shaking.The carboxyl of ADM-NP and the MB-NH2 could take place condensation reaction under a certain condition.Light microscope was used to observe the shape and distribution of the novel micrbubble.High performance liquid chromatography (HPLC) was used to quantify drug encapsulation efficiency and drug loading amounts.This novel microbubbles were put in 2 dialysis bag to observe the releasing properties of ADM in vitro,and one of the bag was using low frequency ultrasound irradiation for 120 s.The effect of tumor imaging using this novel microbubble was observed.Results After 48 hours,a number of ADM-NP attacted to the MB-NH2 like a gar land.Determination of entrapment efficiency and drug loading of it by HPLC weare (86.11 ± 6.76)％ and (8.71 ± 0.46)％.The sustained release in vitro can last for more than 48 hours.More than 90％ of ADM encapsulated in the 2 groups was sustained released for 48 hours.And the release characteristics of the 2 groups in vitro was in accord with Higuchi equation,and no difference was observed in the 2 groups (P ＞0.05).The tumor showed typical enhancement pattems of quick wash-in and quick wash-out.Conclusions To combine the nanospheres to the surface of microbubbles with covalent bonding,it could prepare a novel efficient drug-loading microbubbles for a original technique of ultrasound-targeted microbubble destruction(UTMD).

Objective To synthesize a photoacoustic contrast agent loaded with gold nanorod and liquid perflurocarbon which was used to observe its photoacoustic imaging in vitro,and then investigate the variation of the photoacoustic signal during and after the vaporization.Methods The PLGA nanoparticle (GNP)loaded with gold nanorod(GNR) and liquid perflurocarbon was synthesized via double emulsion technology.The experiments were divided into three groups:1)GNP group:PLGA nanoparticle loaded with gold nanorod and liquid perflurocarbon; 2) GNR group:gold nanorod ; 3) control group:PLGA nanoparticle unloaded with gold nanorod.A pulsed laser system was used to trigger the three samples.The photoacoustic image and time-signal intensity kinetics were acquired by the photoacoustic microscope.The optical microscope was used to observe the image after the vaporization.Results The gold nanoparticle was successfully prepared,the average size of the gold nanoparticle was 504.9 nm.after triggered by the pulsed laser system,the vaporized image of the GNP group could be observed by the optical microscope.The photoacoustic signal was detected in both GNP and GNR groups,and the signal intensity increased along with the concentration of the GNR.However,the photoacoustic signal of PLGA group was not detected.The photoacoustic signal kinetics of GNP group showed a descending trend from high signal amplitude to steadystate.The GNR group photoacoustic signal kinetics only showed a steady-state signal amplitude.Conclusions The PLGA nanoparticle loaded with gold nanorod and liquid perflurocarbon emerged a phase transient which produces a strong photoacoustic signal after triggered by pulsed laser system.This kind of phenomenon leads the nanoparticle to be a better photoacoustic contrast agent and lays a foundation for in vivo research and photothermal therapy in vivo.

Objective To compare the diagnostic value of magnifying chromoendoscopy with probebased confocal laser endomicroscopy (pCLE) for differentiation of neoplastic from non-neoplastic colorectal polyps. Methods A total of 16 consecutive patients, who were diagnosed as having polyps with endoscopy between December 2009 and January 2010 at Nanfang Hospital, were included in this study. The pit pattern of the polyp was first determined with magnifying chromoendoscopy in all patients. Then, confocal images of the polyps were recorded and subsequently analyzed offline. Using pathological diagnosis as golden standard,the sensitivity and specificity of the two methods were compared. Results A total of 26 polyps from 16 patients were found. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of magnifying chromoendoscopy was 94. 1%, 77.8%, 88. 8%, 87. 5% and 88.4%, respectively,while those of pCLE were 100. 0%, 88. 8%, 94. 4% ,100. 0% and 96. 1%, respectively. There was no significant difference between pCLE and magnifying chromoendoscopy. Conclusion In differentiation between neoplastic and non-neoplastic colorectal lesions, pCLE shows higher sensitivity and specificity than does magnifying chromoendoscopy, although without significant difference. pCLE can be used as a new real time method to determine the property of colorectal polyps.

Objective To prepare recombinant human adenovirus type 3 expressing Norovirus cap-sid protein gene(Noro-orf2). Methods The cDNA for Noro-orf2 was amplifed by RT-PCR from stool of in-fantile gastroenteritis and cloned into the adenovirus shuttle vector pBSE3CMV-egfp. The vector pBSE3CMV-Nor was linearized with EeoR Ⅴ and Not Ⅰ, and transformed into E. coil BJ5183 with lined edenovirus ge-nomic DNA pLasmid pBRAdv3 by Rsr Ⅱ. The identification of recombinant adenovirus plasmid pBRAdv3E3dNor was performed by PCR, enzyme digestion and DNA sequencing. Then pBRAdv3E3dNor was digested with AsiS Ⅰ and transfeeted into Hep-2 cells with LipofectAMINETM 2000 to package recombi-nant adenovirus particles. Results Noro-orf2 was successfully inserted into the shuttle vector. The recombi-nant adenoviral plasmid pBRAdv3E3dNor was generated by homologous recombination in E. coil BJ5183 and confirmed by PCR and enzyme digestion. The recombinant adenovirus was successfully packaged and puri-fied. Norovirus eapsid protein gene expression was confirmed in Hep-2 cells by immunecytochemistry assay. Conclusion The recombinant type 3 adenovirus expressing Norovirus eapsid protein gene was successfully constructed. This study laid a foundation for developing vaccine against Norovirus.

Objective To evaluate the diagnostic ability of fusion images of SWI and DWI in ischemic penumbra(IP)of patients with acute ischemic stroke(AIS).Methods 47 AIS patients were retrospective analyzed.Two neuroradiologists analyzed the fusion images of SWI and DWI respectively.SDM was defined as that the hypo-intensity signals of intramedullary or sulcal veins were dilated or increased on fusion images compared with contralateral areas.The results compared with the PDM,which was considered as the“gold standard”.Areas under the receiver operating characteristic curve(AUC)were used to assess the efficacy of SDM which determined by fusion images and compared to PDM.Chi-square test was used to analyze the consistency between the two neuroradiologists and also the consistency between SDM and PDM in IP assessment Results The fusion images of SWI and DWI had a high diagnostic efficacy compared to PDM, AUC of the two radiologists were 0.885,0.877,the diagnostic sensitivity were 84.2%,78.9% and specificity were 92.9%,96.4%respectively.There was also a high consistency in SDM assessment through fusion images between the two neuroradiologists (Kappa=0.908,P >0.05). Conclusion Fusion images of SWI and DWI have a high diagnostic efficacy in IP assessment,which may be considered as a simple approach for IP assessment in patients with AIS.

Objective To investigate the value of early?phase enhancement ratio combined with peripheral vascular diameter in the differential diagnosis of benign and malignant breast lesions using 3.0 T dynamic contrast?enhanced magnetic resonance imaging (DCE?MRI). Methods Sixty seven cases of patients (35 with malignant lesions and 32 with benign lesions in the breasts) were retrospectively analyzed. Their diagnoses were confirmed by surgery and pathology and all the patients underwent breast MRI plain scan and DCE?MRI in the two weeks before surgery. Lesion ROIs were drawn and time?signal intensity curves in the DCE?MRI were generated. Early?phase enhancement rate, time to peak, early?phase enhancement ratio, numbers of tumor vessel within 3 cm of the lesion and diameter of the largest vessel were recorded. Mann?Whitney U test was used to compare the difference of DCE?MRI between benign and malignant lesions, and the ROC curve was used to evaluate the efficiency of early?phase enhancement rate, early?phase enhancement ratio and vascular diameter in differentiating benign and malignant lesions. Results With breast malignant lesions, the medians of time to peak, early?phase enhancement rate, early?phase enhancement ratio, numbers of tumor vessel and vascular diameter were 2.2 s, 176.0%, 100.0%, 4 and 2.96 mm respectively, while with benign lesions of these parameters were 4.7 s, 113.3%, 81.9%, 0 and 0.00 mm respectively, and the differences were statistically significant (all P<0.05).When early?phase enhancement rate was used for differential diagnosis of breast benign and malignant lesions, the area under the ROC curve was 0.702 and the sensitivity and specificity were 82.86%and 56.25%with a threshold of 120.0%. When early?phase enhancement ratio was used, the area under the ROC curve was 0.854 and the sensitivity and specificity were 94.29% and 68.75% with a threshold of 86.0%. When peripheral vascular diameter was used, the area under the ROC curve was 0.896 and the sensitivity and specificity were 74.29%and 84.38% with a threshold of 2.78 mm. When early?phase enhancement ratio was combined with peripheral vascular diameter, the area was 0.925 and the sensitivity and specificity were 97.14% and 62.50%. Conclusion In the differential diagnosis of benign and malignant breast lesions under DCE?MRI, early?phase enhancement ratio combining with peripheral vascular diameter has improved sensitivity.

Objective To evaluate the diagnostic value of intra-arterial thrombi under went susceptibility weighted imaging(SWI) in patients with acute ischemic stroke(AIS).Methods The MRI images of 133 patients with AIS was analyzed,included time of flight MR angiography(TOF-MRA )and SWI.The patients were divided into two groups according to the time between onset of symptoms and MR imaging (group A,interval time<24 h;group B,interval time 24-72 h).Two neuroradiologists who were blin-ded to the patients clinical information,documented the number and location of susceptibility vessel sign (SVS)in SWI and embolic occlusion or stenosis on TOF-MRA in AIS patients.Results The thrombus detection rate in group A was higher than that in group B.There was no significant difference in the overall detection rate of thrombi between SWI and TOF-MRA in all AIS patients,but the thrombi detection rate in M3 segement of middle cerebral artery(MCA)with SWI was higher than that with TOF-MRA in group A(P <0.05).Conclusion SWI performs a high diagnostic value for thrombus detection in AIS patients,especially for the thrombus detection of M3 segement in early period of AIS.