Objective To improve the sensitivity of MR molecular imaging by using targeting and magnifying effects of biotin-avidin system (BAS). Methods After preparing biotinylated monoclonal antibody HAb18, the number of biotin molecules coupled to each antibody and the binding capacity of biotinylated antibody were determined. Two-step pretargeting tumor imaging was first achieved by intravenously injecting biotinylated monoclonal antibody HAb18 into 8 BALB/c nude mice bearing QGY-7723 tumor cells line. 24 h later, Gd-DTAP-streptavidin (Gd-DTPA-SA) was injected. Gd-DTPA-HAb18 and Gd-DTPA were respectively injected intravenously into the other 12 tumor-bearing mice as contrast groups. MR imaging was performed before and 10, 30, 60 min, 3, 6, 12, 24 h, and 48 h after injection of MR contrast agents. All images were obtained using SE T_1-weighted imaging sequence. After MR imaging, enhancement time course of three different groups was determined by using enhancement data measured in the region of interest in the tumor. Enhancement ratio and contrast-to-noise of tumor were also calculated. Results The average number of biotin conjugated with each monoclonal antibody molecular was 20. And the immunoactivity of biotinylated antibody was 91%. In two-step pretargeting strategy, SI of tumor increased slowly and reached the maximum value at 6 h after injection of Gd-DTPA-SA, enhancement ratio and CNR of tumor had significant difference with other two enhancement methods. The enhancing effect of tumor was still perceptible even after 48 h. When using Gd-DTPA-HAb18, the tumor enhancement pattern was slow and slight. Even at 24 h after injection of Gd-DTPA-HAb18, enhancement ratio of tumor was 13.5%. After Gd-DTPA was injected, signal intensity of tumor increased rapidly, and reached the maximum value at 30 min after injection of Gd-DTPA, and then decreased rapidly. Conclusion Two-step pretargeting strategy based on BAS has specific and signal magnifying effects in tumor MR imaging. It can increase the number of gadolinium that bind to the tumor and provide new approach to MR molecular imaging.

Objective To investigate the expression of microRNA-548ah (miR-548ah) and microRNA-4804 (miR-4804) in peripheral blood mononuclear cells (PBMCs) of patients with chronic hepatitis B virus infection and their clinical significance.Methods PBMCs were collected from 29 patients with chronic hepatitis B (CHB),30 hepatitis B virus carriers (HBVC),26 inactive HBsAg carriers (IASC) and 28 healthy controls in Taizhou People's Hospital during September 2012 and August 2013.Expressions of miR-548ah and miR-4804 in PBMCs were detected by fluorescence real-time quantitative RT-PCR (qRT-PCR).Receiver operating characteristic (ROC) curve was used to evaluate the expression of miR-548ah and miR-4804 in distinguishing immune tolerance phase and clearance phase of HBV infection.Pearson correlation analysis was performed to assess the correlations of miRNAs expression with clinical markers alanine aminotrans ferase (ALT) and HBV DNA loads.Results There were significant differences in expressions of miR-548ah and miR-4804 in PBMCs between CHB,HBVC,IASC groups and control group (F =28.16 and 83.17,P ＜ 0.01).Compared with control group,miR-548ah was up-regulated in CHB group(P ＜ 0.01),and down-regulated in HBVC and IASC groups (P ＜ 0.01) ; miR-4804 was up-regulated in CHB group (P ＜ 0.01),down-regulated in HBVC group (P ＜ 0.01),while there was no significant difference between IASC group and control group in miR-4804 expressions(P ＞ 0.05).The areas under ROC curve (AUCs) of miR-548ah and miR4804 in differentiation of immune tolerance and immune clearance were 0.966 and 0.997,and the sensitivities and specificities were 89.7％,96.6％ and 99.6％,100.0％,respectively.No significant correlation was found between the expression of miR-548ah,miR-4804 and ALT,HBV DNA loads (r=0.14,0.18,-0.20 and-0.19,P＞0.05).Conclusion miR-548ah and miR-4804 may be involved in the immunopathogenesis of CHB,and their expression levels in PBMCs are helpful in differentiation of immune tolerance and immune clearance in HBV infection.

Objective To investigate the value of high-frequency ultrasound in diagnosis of thyroid carcinoma by comparative analysis of high-frequency ultrasound and spiral CT imaging results. Methods The imaging results of patients with thyroid carcinoma proved by postoperative pathology or biopsy results were reviewed.High-frequency ultrasound and spiral CT were used to examine the 35 patients in The Tumor Hospital of Harbin Medical University between 2007 and 2009. Results Diagnosis of thyroid carcinoma by application of Highfrequency ultrasound were 27 cases, diagnosis rate was 77.1%(27/35);by spiral CT were 25 cases, diagnosis rate was 71.4% (25/35);comparison of the two methods showed no significant difference (x2= 0.3, P ＞ 0.05). Combined application of high-frequency ultrasound and spiral CT diagnosed 33 patients with thyroid carcinoma, diagnosis rate was 94.3%(33/35), which was significantly higher than that of high-frequency ultrasound alone or that of spiral CT alone(compared with high-frequency ultrasound, x2 = 4.2, P ＜ 0.05;and spiral CT, x2 = 6.4, P ＜ 0.05). Conclusion Combined application of high-frequency ultrasound and spiral CT can improve the diagnosis rate of thyroid carcinoma.

Objective To examine the expression of ATP-binding cassette transporter A1(ABCA1)in eukaryotie cells and the effect of arsenic resistance after the transfection of eukaryotic expression vector containing ABCA1 gene.Methods HeLa cells were transfected with the recombinant plasmid by lipofectaonmine 2000 (recombinant plasmid group),empty plasmid and untransfected HeLa cell as the control group.The level of the mRNA was examined by real-time PCR,and the expression of ABCA1 protein wag examined by Western blot,the change of cell survival rate was examined by methyl thiazolyl tetrazolium(MTT)after exposure in a series of arsenic [0(contro1),4,8,16,32,64,128 μmol/L]for 48 hours.Results Expression level of ABCA1 mRNA in recombinant plasmid,empty plasmid and untransfeeted groups was(2.09±0.08)×10-4,(0.09±0.02)×10-4,(0.08±0.02)×10-4,there was a significant difference between the groups(F=1499.23,P<0.01).The level of ABCA1 mRNA in recombinant plasmid group was higher than empty plasmid and untransfected group(all P<0.01).Western blot showed that specific protein straps existed at 254×103 in all the three groups,with a similar size to the ABCA1 protein.The amount of the recombinant plasmid group was higher than the other two groups.MTT shows that arsenic concentration at 4,8,16,32,64,128 μmol/L,the survival rates of recombinant plasmid group was(94.8±0.9)%,(86.5 ± 2.6)%, (77.8 ± 2.0)%, (56.0 ± 2.0)%, (23.8 ± 1.7)%, (18.6 ± 0.6)%, higher than that of empty plasmid group[ (85.3 ± 1.1)%, (78.7 ± 0.6)%, (67.8 ± 2.4)%, (43.2 ± 1.5)%, (14.5 ± 1.3)%, (8.0 ± 0.4)%], the difference of survival rate had a statistical signifieance(t = 18.985,6.689,5.922,9.504,9.481,32.634, all P < 0.01). Conclusions ABCA1 protein is over expressed in HeLa cells after transfect ABCA1 gene. ABCA1 protein increases resistance of arsenic in HeLa cells.

Permeability is a key factor in the bioavailability of oral drugs. Therefore, in the early stage of drug discovery, accurate and efficient evaluation of drug permeability is essential. The parallel artificial membrane permeability assay (PAMPA) with Caco-2 cells model was used by the industry as early evaluation methods. At present, the Ussing chamber rat model is also widely used. This review summarizes the human data for the in vivo single-pass perfusion technique (Loc-I-Gut) – the gold standard, and then focuses on the basic principles, experimental operation, and efficiency of the three in vitro methods, with correlation to the effective permeability coefficient (P_eff) and fractional absorbed (Fa) in man. We provide recommendations for the use of proper permeability methods at different stages in drug discovery and development.

Objective To investigate the effects of intense pulse light(IPL)on the content of colla- gens and mRNA expression of procollagen in BALB/c mouse skin.Methods The BALB/c mice dorsal skin was irradiated by IPL.Skin specimens were taken at different time points after irradiation.Histopatho- logical changes were observed by hematoxylin-eosin-staining,quantitative assessment of collagenⅠand collagenⅢwas performed with immunohistochemical staining,and mRNA expression levels of procollagen were de- tected by RT-PCR.Results After the irradiation,no obvious change was observed for the staining intensity of collegen at 1 week;however,the thickening of dermis began at 2 week,and continued until 8 week.The staining of collagenⅠandⅢwas also stronger in IPL-irradiated regions than in sham-irradiated areas at 2 week(P

The glutamate dehydrogenase (EC.1.4.1.4) gene which amplified from the genome of Brevibacterium flavum GDK-9 by polymerase chain reaction was linked with pUCm-T for sequence alignment. Analysis of gdh sequences revealed that the whole sequence is 1927 bp, only one ORF existed, which used ATG as the initiation codon and coded a peptide of 448 amino acids with a calculated molecular weight of 48 kD. The comparability between the cloned gdh sequence to the reported sequence is high to 99.55%. Only the 1190th base mutation (C→A) lead to the change of amino acid sequence (Thr→Asn), the others are not. The recombinant plasmid pXG was then transformed into E. coli XL-Blue and Brevibacterium flavum GDK-9 which was induced by IPTG. SDS-PAGE analysis revealed that there was a clear induced protein band with molecular mass of 48.7 kD on expected position. Standard glutamate fermentations indicated that although the level of GDH increases the intracellular glutamate pool, the level of GDH has no influence on glutamate secretion.

Objective To evaluate the effect of two polymorphisms(rs761737 and rs2269058) of RNF8 and the interactions with cigarette smoking and alcohol consumption on sperm DNA fragment index (DFI)and primary male infertility .Methods Based on case-control design ,polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology was used to de-tect the genotype of rs761737 and rs2269058 in RNF8 between 332 primary male infertile patients (composed by 87 patients of azoospermia ,166 patients of oligoasthenozoospermia and 79 patients of normozoospermia ) and 329 controls ,and Sperm Chromatin Dispersion(SCD) assay was used to assess sperm DNA fragment index (DFI) .Results Genotype and allele frequencies distribution of rs761737 and rs2269058 between cases and controls had no statistically significant difference (P>0 .05) .Sperm DFI in infertile group (46 .2 ± 22 .3)% was significantly higher than that of control group (21 .4 ± 9 .2)% (P<0 .05) ,stratified analysis suggested that Sperm DFI in oligoasthenozoospermia group (50 .0 ± 22 .1)% was also significantly higher than that of normozoospermia group (38 .2 ± 20 .7)% .The statistic differences of Sperm DFI in individuals who carried different genotypes of rs 761737 and rs2269058 in oligoasthenozoospermia group and normozoospermia group had no statistically significant difference (P>0 .05) .There was an inter-action between RNF8 rs2269058 and Cigarettes smoking(P<0 .05 ,OR=2 .37 ,95% CI 1 .06-5 .27) .Conclusion Although RNF8 rs761737 and rs2269058 have no effects on primary male infertility and sperm DFI ,cigarettes smoking increase the risk of primary male infertility in individuals who carry RNF8 rs2269058 AC+AA genotype .Sperm DFI is an important test to assess sperm quali-ty ,it is vital to reveal the etiology of primary male infertility and provide therapy guidance to clinicians .

Objective To understand the prevalence,drug resistance and clinical features of children with acute lower respiratory tract infection(ALRI) caused by escherichia coli.Methods From Oct. 2005 to Oct. 2006,659 patients with ALRI who were admitted to hospital were chosen and their nasopharyngeal secretions were obtained and cultured.K-B disc diffusion for antibiotic susceptibility were performed for these clinical isolates.Results Among 659 patients,118 cases were isolated escherichia coli,the rate was 17.99% which had 90 boys and 28 girls.Eighty-seven of 118 E.coli strains were with extended-spectrum ?-lactamase(ESBLs),the rate was 73.73%.All of strains were sensitive to imipenem.For ESBLs-producing strains,the ratio of resistance tocefotaxime,ceftriaxone,cefuroxime,ampicillin,piperacillin were 78.81%,73.73%,73.73%,76.27%,78.81%,respectively.Conclusions The positive rate of ESBLs producing E coli in Kunming area is high and drug resistance is severe gradually.Imipenem can be the first selection for treatment on these infections.

【Objective】 To determine the volume range of suspended erythrocyte and establish its internal control standard. 【Methods】 The theoretical value of suspended erythrocyte volume was calculated according to the screening criteria of healthy blood donors and Quality Requirements for Whole Blood and Blood Components. A total of 2 410 bags of 1 U and 2 U suspended erythrocyte were randomly selected and weighed, and the volume range were formulated by ±2S and ±10% respectively and then compared to determine the volume range in line with the actual situation of our center. 【Results】 The theoretical volume range of 1 U and 2 U suspended erythrocyte were 117-160 mL vs 234-320 mL, and the actual volume range were 142-180 mL vs 276-393 mL. The volume range of 1 U and 2 U suspended erythrocyte formulated by ±2S were 145-181 mL vs 298-358 mL, and by ±10% were 147-179 mL vs 295-361 mL. The hematocrit and hemoglobin content of suspended erythrocyte within the actual volume range met the quality requirements. There were fluctuations in the volume of suspended erythrocyte from different regions. 【Conclusion】 Based on the actual situation of our center and the sampling results of suspended erythrocytes in recent two years, 163 mL±10% and 328 mL±10% were determined as the internal control standards of 1 U and 2 U suspended erythrocyte, respectively. Blood centers should establish accurate and feasible standard of suspended erythrocyte according to the actual situation.