Quantum dots,as nanometer-sized semiconductor crystals,are widely used in life sciences for their excellent optical characteristics.This article introduces the unique optical characteristics of quantum dots and their application in labeling cancer cells and tumor markers as well as in the targeting and imaging of tumor vasculature.

OBJECTIVE:To study the pharmacokinetics and the bioequivalence of cefdinir dispersible tablets in healthy volunteers.METHODS:Microbiological assay method was used to determine the plasma concentration at different time in 20 healthy volunteers after oral administration of single dose of 400mg of cefdinir dispersible tablets(test preparation) and cefdinir capsule(reference preparation) by cross-over way.RESUTLS:The concentration-time curves of test preparation and reference preparation of cefdinir fitted one compartment open model.The pharmacokinetic parameters of the test preparation vs.the reference preparation were as follows:tmax(3.48?0.53)h vs.(3.60?0.48)h,Cmax(2.10?0.32)mg?L-1 vs.(2.15?0.26)mg?L-1.t1/2ke(2.41?0.39)h vs.(2.33?0.41)h,AUC0～12(9.51?1.65)mg?h?L-1 vs.(10.05?1.72)mg?h?L-1,AUC0～∞(10.43?1.62)mg?h?L-1 vs.(11.01?1.81)mg?h?L-1,respectively.The relative bioavailability of cefdinir dispersible tablet as against its reference preparation was(96.03?14.89)%.CONCLUSION:The two preparations of cefdinir were proved to be bioequivalent.

The low sensibility of MR molecular imaging to signals makes signal amplification exceptionally important.This paper reviews the strategy of the reporter gene signal amplification in MR molecular imaging.

Objective:To investigate the expression of multidrug resistance (MDR1) gene and multidrug resistance-associated pro-tein (MRP) gene in patients with non-small-cell lung cancer (NSCLC) and its relation to histopathological type. Methods:The MDRi and MRP genes were determined by reverse transcription-polymerase chain reaction (RT-PCR) in 48 NSCLCspecimens. Results:The positive rates of the MDR1 and MRP gene expression were 62.5％ and 66.7％ respectively in the48 patients. Twenty-one of the 48 NSCLCs (43.8％) expressed both MDR1 and MRP genes. The positive rates of the MRPgene expression in squamous cell carcinoma was significantly higher than those in adenocarcinoma (P＜0.01), and therewas no significant difference in MDR1 gene expression between the two groups (P＞0.05). Conclusion: The MDR1 andMRP gene expressions were both or respectively in the NSCLCs. The incidence of the MRP gene expression in squamous cellcarcinoma was higher than that in adenocarcinoma.

The dual source computed tomography is equipped with two X-ray tubes and two corresponding detectors.With its 83 ms-temporal resolution of single segment reconstruction,high quality coronary artery CT angiography can be acquired without heart rate control.Dual energy output by two x-ray tubes improves the differentiation of body tissues,clinical application and lesion diagnostic accuracy of CT.

Objective To discuss the construction and principal of dual-source CT,as well as its superiorities in imaging of heart coronary artery and the clinical application of dual energy technique.Methods The structure of Siemens 64-slice CT was analyzed.The superiorities of dual-source CT in imaging of heart coronary artery were compared with conventional multi-slice CT,and the clinical value of dual energy technique was discussed.Results The dual-source computed tomography had high temporal resolution superiority,and high quality coronary artery CT angiography could be acquired without heart rate control.Dual energy technique could be applied to differentiate tissue component,display given tissue,evaluate the content of iodine in tissue.Conclusion Dual-source CT can not only enhance the diagnosis veracity of pathological changes of heart coronary artery but improve the ability of CT in tissue differentiation.

Objective To investigate the occurrence of p16 gene methylation in the population chronically exposed to arsenic in Inner Mongolia,and to study the molecular mechanisms of carcinogenesis associated with arsenic exposure.Methods The study group was composed of 40 cases of typical arseniasis selected from the epidemic area,and the two control groups consisting respectively of 40 non-arseniasis cases selected from the same epidemic area,and 40 healthy persons enrolled from non-epidemic area.Methylation of p16 gene in the blood specimens were analyzed for all the subjects with MS-PCR techniques,and statistical analysis was performed using chi square test.Results The positive rates of p16 hypermethylation in blood specimens were 65.0%,47.5% and 20.0% respectively in study group and two control groups,and the rate of hypermethylation increased with the increase in arsenic exposure with drinking water in epidemic areas.The positive rate of p16 hypermethylation showed significant differences(P

Mesial temporal lobe epilepsy (mTLE) is the most common type of refractory focal epilepsy. Diffusion tensor imaging (DTI) can provide qualitative and quantitative information on the microstructural arrangement of epileptic brain tissue. DTI is significant for insights to the pathophysiological mechanism of mTLE, and has potential for investigation of changes in structural connectivity of mTLE. The development and application of DTI in research of mTLE were reviewed in this article.

Atypical teratoid/rhabdoid tumor of the central nervous system has aggressive growth with high potential CSF dissemination and frequently affects very young children.The tumor contains rhabdoid cells and primitive neuroectodermal,malignant mesenchymal and epithelial elements.Immunohistochemistry is helpful in differentiating atypical teratoid/rhabdoid tumor from primitive neuroectodermal tumor/medulloblastoma.Atypical teratoid/rhabdoid tumor is cytogenetically characterized by monosomy 22 or deletion of chromosome band 22q11.2.Intensified therapy combined with surgical resection has been suggested for its treatment.Due to the secondary cystic/necrotic changes and hemorrhage,the imaging features of the tumor are variable.

Objective To explore the clinical significance of detection of plasma microRNA-21,-143 in identifying early esophageal cancer and esophageal non-tumor diseases.Methods The expression of plasma microRNA-21,-143 in 27 cases of patients with early esophageal cancer (esophagus cancer group),25 cases of patients with non-esophageal tumor (non-esophageal tumor group)and in the healthy controls were detected by RT-PCR,and detected the levels of plasma CEA and CA72-4 by the electrochemical luminescence technology,which of changes were analysed to observe the relationship between the changes and the esophageal cancer,the benign esophageal diseases for the two markers.Results The expression of plasma microRNA-21,-143 in the esophagus cancer group were 0.93±0.17,0.27±0.05,which of ones in the non-esophagus cancer group were 0.25±0.03,0.99±0.15,and with those in the control group were 0.23±0.03,1.02±0.15.Compared with those in the non-esophagus cancer group,the expression of plasma microRNA-21,-143 were obviously up or down-regulated with significant differences (t=10.87,11.55,P＜0.01).Compared with those in the control group,which of ones were obviously up or down-regulated with significant differences (t=9.20,9.07,P＜0.01),and with no statistical significances in comparison between the esophagus cancer group and the control group (t=1.39,1.19,P＞0.05).The positiverate of plasma microRNA-21,-143 in the esophageal cancer,non-esophagus cancer group and the control group were,81.4 ％ (22/27),4.0 ％(1/25) and 0 (0/24);85.1％ (23/27),4.0％ (1/25),and 0 (0/24),respectively.The positive rate of microRNA-21,-143 in the esophageal group respectively in comparison with those in the non-esophagus cancer group and the control group were significantly higher,the differences had statistical significances (x2 =31.59,34.39,P＜ 0.01;x2 =34.42,37.23,P＜ 0.01).The expression of two markers in the esophagus cancer group were no statistically significant differences compared with control group (x2 =0.980,0.980,P＞0.05).The sensitivity and specificity of microRNA-21,-143 in early diagnosis on the esophageal cancer were 81.4 ％,97.9 ％ and 85.1％,97.9 ％.The sensitivity of microRNA-21,-143 in the esophageal group were significantly higher compared with those of CEA and CA72-4,the differences were statistically significant (x2 =12.79,P＜0.01;x2 =5.33,P＜0.05;x2 =15.03,P＜0.01;x2 =6.95,P＜0.05).The specificity of microRNA-21,-143 in the esophageal cancer group were no statistically significant differences in comparison with those of CEA and CA72-4 (x2 =1.043,0.000,P＞0.05) and (x2=1.043,0.000,P＞0.05),respectively.The analysis results from the spearman correlation test showed that in the esophageal cancer group,the expression of plasma microRNA-21,-143 had a negative correlation (r =0.658,P＜0.01).Which of ones respectively associated with the levels of CEA and CA72-4 (r=0.607,0.623,P＜0.01 and r=0.579,0.610,P＜0.01).Conclution The detection of expression of plasma miRNA-21,miRNA-143 in the patients with the early esophageal cancer and non-esophageal tumor can provide a new train of thought for pathologic diagnosis of early esophageal cancer.