Drug-receptor interaction plays an important role in a series of biological effects, such as cell pro-liferation, immune response, tumor metastasis, and drug delivery. Therefore, the research on drug-re-ceptor interaction is growing rapidly. The equilibrium dissociation constant (KD) is the basic parameter to evaluate the binding property of the drug-receptor. Thus, a variety of analytical methods have been established to determine the KD values, including radioligand binding assay, surface plasmon resonance method, fluorescence energy resonance transfer method, affinity chromatography, and isothermal ti-tration calorimetry. With the invention and innovation of new technology and analysis method, there is a deep exploration and comprehension about drug-receptor interaction. This review discusses the differ-ent methods of determining the KD values, and analyzes the applicability and the characteristic of each analytical method. Conclusively, the aim is to provide the guidance for researchers to utilize the most appropriate analytical tool to determine the KD values.

Objective To establish the subcutaneous transplantation tumor models with Lewis lung adenocarcinoma in C57BL/6 mice, and to observe the influence of oHSV2, DDP and drug combination on tumor volume, median survival time and weight of tumor-burdened mice.Methods Subcutaneous transplantation tumor models were established with Lewis lung adenocarcinoma in tumor-burdened mice.Tumor-burdened mice were randomly divided into the control group, oHSV2 group, DDP group, oHSV2/DDP sequential group, DDP/oHSV2 sequential group and oHSV2+DDP combination group with 12 rats in each group using the random number table method.The tumor size and weight of mice were measured every 3 days.Results On the 21st day, the tumor size of tumor-burdened mice in every group was as follows: control group (1.82±0.06)cm3, oHSV2 group (0.63±0.05)cm3, DDP group (0.58±0.03)cm3, oHSV2/DDP sequential group (0.49±0.05)cm3, DDP/oHSV2 sequential group (0.42±0.04)cm3, and the difference was statistically significant (F=1 359.01, P=0.000).The data in oHSV2+DDP group were put away because of premature death in mice.The differences were statistically significant between control group and oHSV2 group (P=0.000), control group and DDP group (P=0.000), control group and oHSV2/DDP sequential group (P=0.000), control group and DDP/oHSV2 sequential group (P=0.000), oHSV2 group and DDP group (P=0.017), DDP group and DDP/oHSV2 sequential group (P=0.000), oHSV2/DDP sequential group and DDP/oHSV2 sequential group (P=0.001).The weight of tumor-burdened mice in every group was listed as follows: control group (21.64±0.40)g, oHSV2 group (21.34±0.37)g, DDP group (15.96±0.43)g, oHSV2/DDP sequential group (19.04±0.31)g, DDP/oHSV2 sequential group (16.34±0.30)g, and the difference was statistically significant (F=588.67, P=0.000).The difference was not statistically significant between control group and oHSV2 group (P=0.076).However, the differences were statistically significant between control group and DDP group (P=0.000), control group and oHSV2/DDP sequential group (P=0.000), control group and DDP/oHSV2 sequential group (P=0.000), oHSV2 group and DDP group (P=0.000), oHSV2 group and oHSV2/DDP sequential group (P=0.000), DDP group and DDP/oHSV2 group (P=0.013), oHSV2/DDP sequential group and DDP/oHSV2 sequential group (P=0.000).The median survival time of tumor-burdened mice in every group was displayed as follows: control group 23 d , oHSV2 group 32 d, DDP group 30 d, oHSV2/DDP sequential group 37 d, DDP/oHSV2 sequential group 39 d, oHSV2+DDP combination group 16 d, and the difference was statistically significant (χ2=120.81, P=0.000).The differences were statistically significant between control group and oHSV2 group (χ2=10.88, P=0.001), control group and DDP group (χ2=10.69, P=0.001), oHSV2 group and DDP/oHSV2 sequential group (χ2=10.09, P=0.001), DDP group and DDP/oHSV2 sequential group (χ2=9.67, P=0.002).However, the differences were not statistically significant between oHSV2 group and DDP group (χ2=0.00, P=0.996), oHSV2/DDP sequential group and DDP/oHSV2 sequential group (χ2=2.70, P=0.100).Conclusion On the premise of that the weight of mice is no affected, oHSV2 can inhibit the tumor size and prolong the median survival time of tumor-burdened mice effectively, and the effect of DDP/oHSV2 sequential group is the most significant.This article provides an experimental basis for exploring therapeutic methods of lung adenocarcinoma.

Objective To study the diagnostic value of pencilliosis marneffei (PM)in a non-HIV-infected child with the com-bined detection of aspergillosis galactomannan,fungus Glucan(1-3)-β-D and boold culuture.Methods The venous blood specimen from the child was collected for the quantified detection of aspergillosis galactomannan,fungus Glucan(1-3)-β-D. The growth and colonial morphology of fungus was inspected with the positive blood culture and the characteristics of fun-gus smear were observed under microscope.Results The result of aspergillosis galactomannan was 14.45 μg/L and fungus Glucan (1-3)-β-D 77.14 pg/ml.Penicillium marnrffei was identified using blood culture.It was mycelia form under 25℃ and the salouraud medium produced water soluble claret-red pigment produced.It was mycelia form under 35℃ and the colony was gyri creases,the characteristic broom-like hypha and separation hypha could be found under microscope.Conclusion It is effective for the early diagnosis and therapy of PM with the combination detection of aspergillosis galactomannan,fungus Glucan (1-3)-β-D and boold culuture and have better clinical diagnosis value.

Objective To develop SYBR Green I real-time PCR assay for detection and identification of Hepatitis B virus. Methods Based on the sequences of Hepatitis B virus gp1 gene,primers were designed.The reaction assay and thermal cyc-ling profile were optimized.The positive standard was from recombinant clone.Both the developed assay and Zhejiang kuake biotechnology company’s assay were applied in 100 patients serum.Results The detection limit was between 5×102 copies/ml to 5×108 copies/ml with a good liner correlation and no cross reaction.The whole process just needed 2.5 h.Comparing with the company products,the sensitivity and specificity of the developed assay were 100% and 92.5% respectively.Con-clusion The established assay is rapid,simple,high sensitivity and specificity.It is not only valuable for the identification of Hepatitis B virus patients,but also provide accurate quantitative analysis for HBV patients.

Objective To synthesize 11 C-methyldopamine (MDA) and to explore its feasibility as an agent for cardiac sympathetic nerve imaging.Methods 11 C-MDA was synthesized by direct N-methylation method and purified by semi-preparation reverse HPLC.Thirty Kunming mice were divided into five groups by random number table.The mice were respectively sacrificed at 2,5,10,20 and 30 min after injection of 7.4 MBq 11C-MDA.The lung,liver,spleen,kidney,stomach,intestine,brain,muscle,bone tissues and blood of mice were removed and weighed before radioactive γ-counting.The ％ID/g was calculated.Six Chinese mini-swine were divided into normal group (n=3) and inhibition group (n =3) for myocardial imaging.Mini-swine of inhibition group were injected with 10 mg/kg imipramine hydrochloride at 30 min before 11C-MDA (370 MBq) injection.The data were analyzed with SPSS 15.0 software.Results The synthesis of 11 C-MDA took 45 min with radiochemical yields of (20±3)％.The solution of11 C-MDA was colorless and the pH value was 6.5.The radiochemical purity was more than 98％ and the specific activity was 50 GBq/mmol.The myocardial uptake reached the peak value of (8.78± 1.18) ％ID/g at 2 min after injection of 11 C-MDA in mice.11C-MDA was mainly metabolized through liver and kidney.PET/CT imaging showed that 11 C-MDA was highly uptaken in swine myocardium and could be blocked by imipramine hydrochloride.Conclusions 11C-MDA can be synthesized by a simple and economic method.The high uptake rate of 11 C-MDA in the heart suggests it may be a potential agent for cardiac nerve imaging.

Objective To evaluate 11C-MDA,a cardiac sympathetic nerve presynaptic molecular probe,in acute myocardial ischemia (AMI) and to compare with 13N-Ammonia myocardial perfusion imaging.Methods Twelve Bama miniature pigs were used to establish AMI models.11C-MDA and 13N-Ammonia PET/CT were performed before and after model establishment.The defect fraction,ratio of defect to normal region,defect volume of 11C-MDA and 13N-Ammonia PET/CT were calculated.Paired-t test and twosample t test were used.Results Eight models were established successfully and 4 pigs died.The defect fractions on 11C-MDA and 13N-Ammonia myocardial imaging were significantly different (13.4±3.3 vs 7.4±1.0,18.8±4.4 vs 4.8±1.0,10.5±4.2 vs 4.4±0.9;t values:4.901,8.864,4.030,all P＜0.001) at the first,third and sixth month post-model establishment.The ratios of defect to normal region on 11C-MDA and 13N-Ammonia PET/CT myocardial images were significantly different (0.47±0.14 vs 0.59±0.10,0.43±0.13 vs 0.61±0.09;t values:-2.166,-3.415,both P＜0.05) at the first and third month post-model establishment.The defect volumes on 11C-MDA and 13N-Ammonia PET/CT were significantly different ((4.20±0.34) vs (2.55±0.11) cm3,(10.66±0.71) vs (2.46±0.12) cm3,(5.95±0.50) vs (2.44±0.11) cm3;t values:12.925,32.149,19.440,all P＜0.001) at the first,third and sixth month post-model establishment.Conclusions Myocardial ischemia-reperfusion and cardiac sympathetic restoration might occur at different times.The recovery of myocardial ischemia-reperfusion is earlier than that of the cardiac sympathetic nerve.

ObjectiveTo explore the efficacy and toxicity of nimotuzumab plus chemotherapy in the treatment of metastatic gastrointestinal tumor.MethodsObservationgroup 22 patients with metastatic gastrointestinal tumor with confirmed diagnosis,were treated with nimotuzumab in combination chemotherapy.Nimotuzumab was given 200 mg weekly for at least six weeks. Control group 21 patients with metastatic gastrointestinal tumor with confirmed diagnosis were treated with only chemotherapy.ResultsThe effects of observation group could be observed in 22 patients, the rate of response(RR)was 31.8％ (7/22), and the disease control rate (DCR) was 72.7 ％ (16/22).QOL was improved.The effects of observation group could be observed in 21 patients,RR was 14.3 ％ (3/21),and the disease control rate was 42.8 ％ (19/21).DCR and QOL improvements were statistically significant different between the two groups.(x2=3.939,x2=4.250,P＜0.05).The two groups had no significant difference in RR and toxicity.ConclusionNimotuzumab in combination with chemotherapy is effective and can improve the disease control rate, toxicity, tolerance,quality of life.

Objective To explore the expression level of Tim-3,the marker of activated T_H 1 cells.in T lymphocytes in different sites from recipients with acute rejection.Methods The model of cervical heterotopic heart transplantation was established in mice Two groups were get up:the isograft group(C57BL/6→C57BL/6) and the allograft group (Balb/c→C57BL/6).Lymphocytes were isolated from peripheral blood,spleens,draining lymph nodes and grafts 3 or 6 days after transplantation.The expression of TIM-3 in CD4~+ and CD8~+ T subsets was detected by flow cytometry.Results There was no significant difference in Tim-3~+/CD4~+ and Tim-3~+/CD8~+ ratio in peripheral blood or spleens between two groups.As compared with the isograft group,the proportion of Tirn-3~+/CD4~+ cells was slightly elevated in draining lymph node(P<0.05),but the percentage of Tim-3~+/CD4~+ cells had no significant change between 3 days and 6 days in the allograft group(P>0.05).The expression of Tim-3 in CD4~+ and CD8~+ of graft infiltrating T cells was obviously increased in allograft group(P<0.01),and it was significantly (P<0.01) up-regulated on the 6th day as compared with that on the 3rd day.Conclusion The dynamic changes of Tim-3 expression in T lymphocytes in draining lymph node and graft were correlated with the progresston oi acute rejection in mice.

Objective To explore the subcellular localization of Galectin-9 and its effect on allogeneic immune response.Methods The plasmid pEGFP-N1 was inserted with Galectin-9 fragment which was amplified from pBKCMV-Galectin-9 by PCR.The recombinant plagmid wag then transfected into CHO cells using JetPEI in vitro.The cells were cultured in G418 selecting mediam to obtain the stably-transfected cells.The transcription and expression of Galectin-9 gene were verified by immunohistochemical staining and RT-PCR.The solid-phase transgenic CHO cells or freshly-cultured supernatant wag added into the mixed lymphocyte response system to detect the inhibitory effect of Galectin-9.Galectin-9 protein wag administered intraperitoneally for 7d consecutively.Results The expression of Galectin-9 wag localized in the cytosol of CHO.The allogeneic mix lymphocyte proliferation was dose-dependently inhibited by the freshly-cultured supernatant from stably-transfected CHO cells.Furthermore,the supernatant from stably-transfected CHO cells dose-dependently inhibited the level of IL-2.The inhibitory effect could be reversed by Tim-3-Fc blocking.Administration of Galectin-9 significantly prolonged the survival of allogeneic cardiac transplants[(22.7±1.2)d vs(7.2±0.4)d)].Conclusion Galectin-9 may be secreted in physical situation to exert its immunomodulatory function on allogeneic immune response.Furthermore.Galectin-9 may be a novel therapeutic drug in transplant medicine.

To identify acute renal allograft rejection biomarkers in human serum, two-dimensional differential in-gel electrophoresis (2-D DIGE) and reversed phase high-performance liquid chromatography (RP-HPLC) followed by electrospray ionization mass spectrometry (ESI-MS) were used. Serum samples from renal allograft patients and normal volunteers were divided into three groups: acute rejection (AR), stable renal function (SRF) and normal volunteer (N). Serum samples were firstly processed using Multiple Affinity Removal Column to selectively remove the highest abundance proteins. Differentially expressed proteins were analyzed using 2-D DIGE. These differential protein spots were excised, digested by trypsin, and identified by RP-HPLC-ESI/MS. Twenty-two differentially expressed proteins were identified in serum from AR group. These proteins included complement C9 precursor, apolipoprotein A-IV precursor, vitamin D-binding protein precursor, beta-2-glycoprotein 1 precursor, etc. Vitamin D-binding protein, one of these proteins, was confirmed by ELISA in the independent set of serum samples. In conclusion, the differentially expressed proteins as serum biomarker candidates may provide the basis of acute rejection noninvasive diagnosis. Confirmed vitamin D-binding protein may be one of serum biomarkers of acute rejection. Furthermore, it may provide great insights into understanding the mechanisms and potential treatment strategy of acute rejection.