Application of 99Tc(m)-annexinV in predicting the therapeutic effect of chemical agent on lung cancer / 中国医学科学院学报

<p><b>OBJECTIVE</b>To prepare 99Tcm-annexinV and evaluate its application in the early prediction of therapeutic effect of chemical agent on lung cancer.</p><p><b>METHODS</b>Annexin V was obtained by recombinant pichia pastoris expression, ammonium sulfate precipitation, and size-exclusion chromatography. The purified protein was labeled with 99Tc(m) at the N-terminal site by stannous chloride reduction and purified by desalting. The labeling yield and radiochemical purity of 99Tc(m)-annexinV were determined by instant thin-layer chromatography. The biological activity of 99Tc(m)-annexinV was tested by phosphatidylserine-exposed erythrocytes bound radioactivity counting. The lung cancer mice models were established by inoculating LA795 cells to right flank of 615 mice subcutaneously and tumor tissue transplantation. The biodistribution of 99Tc(m)-annexinV in lung cancer mice models were investigated at 6, 12, 24, and 48 h after cyclophosphamide administration.</p><p><b>RESULTS</b>The annexin V was secreted from pichia pastoris and purified by ammonium sulfate precipitation and size-exclusion chromatography with high yield. The annexin V could be labeled at room temperature with 50.2% radioactivity yield. The radiochemical purity of 99Tc(m)-annexinV reached up to 93.9% with intact biological activity. The biodistribution analysis demonstrated that 99Tc(m)-annexinV was excreted from kidney. The uptake of 99Tc(m)-annexinV at tumor reached maximum 48 h after cyclophosphamide administration while tumor to muscle ratio was 6.34 and tumor to blood ratio was 4.09.</p><p><b>CONCLUSIONS</b>99Tc(m)-annexinV derived from pichia pastoris was successfully prepared. It is useful in predicting the therapeutic effect of chemical agent on lung cancer.</p>

Bioluminescent imaging monitoring of a anti-angiogenesis therapeutic gene vasostatin in tumor cell PC3 / 中国医学科学院学报

<p><b>OBJECTIVE</b>To generate a sensitive tool for noninvasive monitoring of a therapeutic gene vasostatin.</p><p><b>METHODS</b>We fused the bioluminescent reporter gene firefly luciferase to the therapeutic transgene vasostatin and ensured that these two proteins would not interrupt each other and kept their own natural character.</p><p><b>RESULTS</b>We therefore examined clones of PC3 cells stably expressing fusion gene and positive controlfluc with bioluminescence. In vivo imaging of PC3-Fluc subcutaneous tumors showed that the mean tumor bioluminescence increased in animals over several weeks.</p><p><b>CONCLUSION</b>Noninvasive monitoring facilitates the detection of gene expression in vivo and in vitro.</p>

Biological activity of human single-chain antibody against amyloid beta peptide involved in Alzheimer's disease / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the biological activity of recombinant human single-chain antibody against amyloid beta peptide in vitro.</p><p><b>METHODS</b>Human single-chain antibody against amyloid beta peptide was obtained from recombinant bacteria. The antigen-binding activity of this antibody was measured by enzyme-linked immunosorbent assay (ELISA) and competitive ELISA. Human neuroblastoma SH-SY5Y cells were used as cell models to test the protective role of human single-chain antibody against amyloid beta peptide.</p><p><b>RESULTS</b>Recombinant human single-chain antibody was mainly located in the insoluble inclusion bodies of bacteria. The antibody was dissolved by urea and purified by metal affinity chromatography as active form to bind synthetic amyloid beta peptide 40 or amyloid beta peptide 42. The improvement of the survival rates of human neuroblastoma cells was significantly superior in amyloid peptide 42 plus equimolar antibody group than in amyloid peptide 42 group (P < 0.05), and was significantly superior in the amyloid peptide 40 plus equimolar antibody group than in amyloid peptide 40 group (P < 0.01).</p><p><b>CONCLUSION</b>The recombinant human single-chain antibody against beta amyloid peptide 40 from E. coli can partially inhibit the neurotoxicity effect of amyloid beta peptide in vitro.</p>

Synthesis and animal imaging of 99mTc-hydrazinonicotinamide-folate as a new folate receptor-targeted tumor imaging agent / 中国医学科学院学报

<p><b>OBJECTIVE</b>The synthesis, biodistribution, and animal imaging of 99mTc- hydrazinonicotinamide-folate (99mTc-HYNIC-Folate) were studied as a folate receptor-targeted tumor imaging agent.</p><p><b>METHODS</b>HYNIC-Folate was synthesized by a muti-step reaction and radiolabeled with 99mTc using tricine and trisodium phenylphosphine-3, 3', 3"-trisulfonate (TPPTS) as coligands. The radiochemical purity and stability of 99mTc HYNIC-Folate was measured. The biodistributions of 99mTc-HYNIC-Folate in normal mice and tumor-bearing mice were detected. Whole-body gamma imaging was performed using an athymic mouse tumor xenograft model.</p><p><b>RESULTS</b>The ligand HYNIC-Folate was successfully synthesized and characterized by hydrogen nuclear magnetic resonance (1HNMR) and mass spectrometry (MS). The radiochemical purity of 99mTc-HYNIC-Folate was 96% under optimal conditions. Data from gamma scintigraphy and the biodistribution in tumor-bearing mice showed that 99mTc-HYNIC-Folate predominantly accumulated in tumor, its uptake rate per gram tissue alpham was 5. 620+/- 0. 753. The uptakes of 99mTc-HYNIC-Folate in the other non-target tissues were very low, except it was high in the kidneys ( am was 41. 959 +/-6. 759) .</p><p><b>CONCLUSION</b>99mTc-HYNIC-Folate has the potential to be used as a noninvasive radiodiagnostic imaging agent for the detection of folate receptor-positive human cancers.</p>

Association between endothelial nitric oxide synthase gene (G894T) polymorphism and essential hypertension in Uygur populations / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the association between G894T polymorphism and essential hypertension (EH) in Uygur population in Xinjiang province.</p><p><b>METHODS</b>In this case-control study, G894T genotypes in 375 hypertension patients (EH group) and 414 normotensive control subjects (NT group) from the rural area of Tuluafan of Xinjiang was investigated by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.</p><p><b>RESULTS</b>(1) Significant differences were found in GG, GT and TT frequencies of G894T genotypes between the EH and NT groups (56.5%, 28.3%, 15.2% in EH group and 65.9%, 22.5%, 11.6% in NT group, OR = 2.97, 95% CI 1.393 - 6.358). T allele frequencies were significantly higher in EH group (29.33%) than that in NT group (22.83%, P < 0.05). (2) SBP, DBP in patients with T allele of eNOS gene [(171.36 +/- 22.30) mm Hg and (103.63 +/- 13.22) mm Hg] were significantly higher than that of GG genotype [(158.07 +/- 20.850) mm Hg and (89.90 +/- 10.39) mm Hg] (P < 0.01).</p><p><b>CONCLUSIONS</b>eNOS gene exon7 G894T polymorphism might relate to essential hypertension in Uygur population in Xinjiang province.</p>

Association of the T(-344)C polymorphism of aldosterone synthase gene CYP11B2 with essential hypertension in Xinjiang Kazakh isolated group / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the association of the T(-344)C polymorphism of aldosterone synthase gene CYP11B2 with essential hypertension in Xinjiang Kazakh isolated population.</p><p><b>METHODS</b>The study covered 186 hypertensives and 168 normotensive controls in Xinjiang Kazakh population. The segment of CYP11B2 was amplified from DNA by polymerase chain reaction(PCR). The PCR products were digested by restriction endonuclease.</p><p><b>RESULTS</b>The frequencies of C and T in hypertensive group (0.45 and 0.55) were not significantly different from those in the control group (0.43 and 0.57; chi-square test=0.380, P=0.537). The frequencies of CYP11B2 genotypes of CC, CT and TT were 0.20, 0.50 and 0.30 in hypertensives respectively, and 0.12, 0.61 and 0.27 in controls respectively. There was no significant difference in genotypes between hypertensive group and normotensive group (chi-square test=4.838, P=0.089). But the frequencies of CC genotype were higher in the female hypertensives than in the normotensive controls (chi-square test=6.104, P<0.05).</p><p><b>CONCLUSION</b>The results suggested that the T(-344)C polymorphism of CYP11B2 gene may be associated with hypertension in female Kazakh population of Xinjiang Barlikun area.</p>

Protective effect of tetramethylpyrazine on learning and memory function in D-galactose-lesioned mice / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To explore the protective effect of tetramethylpyrazine (TMP) on the learning and memory function in D-galactose (D-gal)-lesioned mice.</p><p><b>METHODS</b>C57BL/6 mice were injected (s.c.) 2% D-gal for 40 days (100 mg x kg(-1) x d(-1)). Normal saline, TMP, and Huperzine A were respectively given by intragastric administration in different groups from the third week. Learning and memory ability was tested with Morris water maze for 5 days at the sixth week. After completion of behavioral test, the mice were sacrificed by decapitation. The brain was rapidly removed, and the cortex and hippocampus were separated. The superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in the cortex were determined. At the same time, the activity of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE), the binding sites (Bmax) and the affinity (KD) of M-cholinergic receptor in the cortex, and Bmax and KD of N-methyl-D-aspartate (NMDA) receptor in the hippocampus were determined.</p><p><b>RESULTS</b>In this model group, (1) The deficit of learning and memory ability, (2) elevated MDA content and lowered SOD activity, (3) decreased AChE activity and M-cholinergic receptor binding sites in the cortex, and (4) lowered NMDA receptor binding sites were observed in the hippocampus, as compared with the normal control. TMP could markedly (1) attenuate cognitive dysfunction, (2) lower MDA content and elevate SOD activity, (3) increase the activity of ChAT and AChE, and M-cholinergic receptor binding sites in the cortex in the mice treated with D-gal. NMDA receptor binding sites were also increased in the hippocampus in the treated mice.</p><p><b>CONCLUSION</b>TMP can significantly strengthen antioxidative function, improve central cholinergic system function, protect NMDA receptor activity, and thus enhance the learning and memory ability in D-gal-lesioned mice.</p>

Effect of tetramethylpyrazine on learning, memory and cholinergic system in D-galactose-lesioned mice / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the effect of tetramethylpyrazine on learning, memory, and cholinergic system in D-galactose-lesioned mice.</p><p><b>METHODS</b>C57BL/6J mice were given subcutaneous injection of 2% D-galactose for 40 days (100 mg.kg-1.d-1). Normal saline, tetramethylpyrazine (TMP) and Huperzine A (HupA) were given respectively by intragastric administration in different study groups from the third week on. Learning and memory ability were tested by Morris water maze for 5 days at the sixth week. Acetylcholinesterase (AchE) activity, the binding sites (Bmax) and the affinity (KD) of M-cholinergic receptor were determined.</p><p><b>RESULTS</b>The learning and memory dysfunction, with lowered AchE activity and M-cholinergic receptor binding sites were found in the model group as compared with the normal control group. The tetramethylpyrazine, especially at the dose of 100 mg.kg-1.d-1, could markedly attenuate cognitive dysfunction, while elevate the lowered AchE activity (P < 0.05) and M-cholinergic receptor binding sites (P < 0.005) in the cerebral cortex of mice treated with D-galactose.</p><p><b>CONCLUSIONS</b>The tetramethylpyrazine can significantly improve central cholinergic system function, and thus enhance the learning and memory ability in D-galactose-lesioned mice.</p>

Cloning and expression of human single-chain Fv antibody against amyloid beta peptide involved in Alzheimer's disease / 中国医学科学院学报

<p><b>OBJECTIVE</b>To screen out the specific antibody clones against amyloid beta peptide 40, and clone the antibody gene and express it in a bacterial system, so as to provide a solid basis for novel diagnostic and therapeutic methods for Alzheimer's Disease.</p><p><b>METHODS</b>beta amyloid peptide 40 was bound on the solid surface of Nunc plates as antigen to screen the binding clones from a phage-display human single-chain Fv antibody library. After five rounds of bio-panning, the host E. coli TG1 was infected with eluted filamentous phage from the last turn of selection. 55 well-separated colonies were picked randomly from the plates and the specific positive clones were identified by ELISA test. The single-chain Fv antibody gene was sequenced and their amino acids sequence was deduced. The scFv antibody gene was sub-cloned into a protokayotic expression vector pGEX-6P-1 and transformed into bacteria strain BL21 to express the glutathione-S-transferase (GST) fusion single-chain antibody.</p><p><b>RESULTS</b>ELISA test showed that 33 of the 55 clones could bind amyloid beta peptide 40 and 10 of the 33 clones could be inhibited by amyloid beta peptide 40 itself to below 50% of its original binding activities. Five of the 10 clones could also be inhibited by amyloid beta peptide 1-16 to the same level, which meant that the binding epitope of the antibody from the 5 clones was between first to sixteenth amino acids at amino-end of amyloid beta peptide 40. DNA sequencing data demonstrated that the gene of the single-chain antibody specifically against amyloid beta peptide 40 was consisted of 768 bp and the deduced amino acids sequence confirmed its typical antibody structure. The complement determinant regions and framework regions were discriminated empirically. After cloning the antibody gene into a protokayotic system, the GST fusion antibody was expressed as the expected size.</p><p><b>CONCLUSIONS</b>After five rounds of bio-panning and subsequently serial ELISA testing, the specific antibody clones against amyloid beta peptide 40 were screened out successfully. The antibody gene DNA sequence and amino acids sequence were analyzed and confirmed. The fusion antibody was expressed as expected in the bacterial system.</p>

Relationship of I/D polymorphism of angiotensin converting enzyme gene with hypertension in Xinjiang Kazakh isolated group / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate whether the insertion/deletion(I/D) polymorphism in the angiotensin converting enzyme(ACE) gene is associated with essential hypertension in Xinjiang Kazakh isolated population.</p><p><b>METHODS</b>The study covered 201 hypertensives and 151 normotensive controls in Xinjiang Barlikun Kazakh population. The I/D polymorphism of ACE gene was determined by polymerase chain reaction.</p><p><b>RESULTS</b>The frequencies of D and I in the hypertensive group (0.44 and 0.56, respectively) were not significantly different from the controls(0.39 and 0.61, respectively, P=0.16). The frequencies of ACE genotypes of DD, ID, and II were 0.18, 0.52, 0.30 in hypertensives respectively and 0.17, 0.43, 0.40 in control group respectively. There was no significant difference in genotypes between hypertensive group and normotensive group (P=0.14).</p><p><b>CONCLUSION</b>The results suggested that the I/D polymorphism of ACE gene might not be associated with hypertension in the Kazakh population of Xinjiang Barlikun area.</p>

Synthesis and preliminary studies of O-(2-18F fluoroethyl)-L-tyrosine as a positron emission tomography imaging agent / 中国医学科学院学报

<p><b>OBJECTIVE</b>To develop a 18F-labeled amino acid, O-(2-[18F]fluoroethyl) - L-tyrosine(18F-FET), as a positron emission tomography (PET) tracer for imaging cerebral tumors.</p><p><b>METHODS</b>18F-FET was synthesized. Preclinical studies including sterility, endotoxin, and toxicity tests were performed. Two brain tumor cases were studied using 18F-FET and compared with 18F-FDG.</p><p><b>RESULTS</b>Radiochemical purity of 18F-FET was over 95% which remained stable for 6 hours. The 18F-FET injection was sterile and its endotoxin content accorded with the standards of Chinese Pharmacopoeia. The uptake of 18F-FET in the normal brain tissues was significantly lower than that of the tumor, and the images of the brain tumor were clearer than those of 18F-FDG.</p><p><b>CONCLUSION</b>18F-FET can accumulate in the tumor tissues to give high quality images. It suggests that 18F-FET may be a safe and effective tracer for brain tumor imaging.</p>