蛋白质和多肽放射性碘标记方法比对

对氯胺Ｔ（ｃｈ－Ｔ）法、氯甘脲（Ｉｏｄｏｇｅｎ）法和乳过氧化物酶（Ｌａｃｔｏｐｅｒｏｘｉｄａｓｅ，简称ＬＰＯ）法进行了比较研究。结果表明：ＬＰＯ具有碘化反应温和、放射性碘利用率高、反应完全、可控性强、标记产品纯度高等优点；特别是能最大限度的保持被标记物固有的生物活性和免疫活性。

LPS牛奶保鲜剂

ＬＰＳ牛奶保鲜剂由中国在科院畜牧所研究员王鹏等人主持研究的ＬＰＳ牛奶保鲜剂，是利用生奶内固有的天然乳化氧化物酶体系（即ＬＰＳ），加入适量的硫氰酸钠和过碳酸钠或过氧化氰，使其活化，达到保存生奶（含水牛奶）、延迟生奶酸败腐化时间的目的。这项技术已在全国１...

PROTECTIVE EFFECT OF TETRAMETHYLPYRAZINE ON LEARNING AND MEMORY FUNCTION IN D-GALACTOSE-LESIONED MICE

To explore the protective effect of tetramethylpyrazine (TMP) on the learning and memory function in D-galactose (D-gal)-lesioned mice. Methods C57BL/6 mice were injected (s.c.) 2% D-gal for 40 days (100 mg·kg-1·d-1). Normal saline, TMP, and Huper-zine 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. Results 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. Conclusion 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.

Therapeutic effects of flavonoids from Ceylon green tea on hypoxic human brain epithelial cells

We have extracted and purified flavonoids as active ingredients from Ceylon green tea （Dilmah）. In this project, an in vitro hypoxic model using human brain epithelial cells （HBEC） was studied with treatment of the tea extract before inducing hypoxia. We have tested the hypothesis that flavonoids extracted from Ceylon green tea act as potential therapeutic ingredient （s） to reduce oxidative stress in hypoxic cells through its antioxidant properties and its ability to reduce cerebral cellular death. The biochemical antioxidant tests show that the Ceylon green tea has 68% ± 2.8% inhibition property of scavenging of ABTS. The inhibition of pyrogallol red bleaching by HOCI from Ceylon tea was 79% ± 4.5%. After exposing to hypoxia, the cell viability was 29% ± 2.3% in the hypoxia control group but 41% ± 4.7% for flavonoids extract treated group. In LDH assay, flavonoids extract treated group had 75% ± 3.7% reducing of LDH release. The flavonoids extract treated groups significantly increased in antioxidant enzyme activity assays： the activity level of SOD [（1.5 ± 0.6） μmol/min/mg protein], CAT [（0.61 ± 0.06） μmol/min/mg protein], GPx [（2.6 ± 0.41） μmol/min/mg protein] and GST [（6.0 ± 2.4） μmol/min/mg protein] are significantly increased as compared with hypoxic control [（0.5 ± 0.52, 0.51 ± 0.04, 1.2 ± 0.35 and 3.1 ± 1.6） μmol/min/mg protein, respectively]. The study demonstrated a great clinical potential and opened a new avenue to prevent stroke by drinking Ceylon tea.

Antiaging activity of low molecular weight peptide from Paphia undulate

Low molecular weight peptide (LMWP) was prepared from clam Paphia undulate and its antiaging effect on D-galactose-induced acute aging in rats, aged Kunming mice, ultraviolet-exposed rats, and thermally injured rats was investigated. P. undulate flesh was homogenized and digested using papain under optimal conditions, then subjected to Sephadex G-25 chromatography to isolate the LMWP. Administration of LMWP significantly reversed D-galactose-induced oxidative stress by increasing the activities of glutathione peroxidase (GPx) and catalase (CAT), and by decreasing the level of malondialdehyde (MDA). This process was accompanied by increased collagen synthesis. The LMWP prevented photoaging and promoted dermis recovery and remission of elastic fiber hyperplasia. Furthermore, treatment with the LMWP helped to regenerate elastic fibers and the collagen network, increased superoxide dismutase (SOD) in the serum and significantly decreased MDA. Thermal scald-induced inflammation and edema were also relieved by the LWMP, while wound healing in skin was promoted. These results suggest that the LMWP from P. undulate could serve as a new antiaging substance in cosmetics.

Lactobacilli Improve the Antioxidant Activity in Fermented Coriolus versicolor Extract

Coriolus versicolor has been reported to have biological activities such as anticancer, antibacterial, antibiotics and immunopotentiation. The authors tried to ferment using lactobacilli associated with various biological functions and expected that fermented extract by lactobacilli will be superior to non-fermented extract in antioxidant activity. C. versicolor was extracted with 70% ethanol and then it was fermented by Lactobacillus acidophilus KCTC3164 and Lactobacillus plantarum KCTC3099, respectively. 1,l-dipheny｜-2-picrylhydrazyl （DPPH） scavenging activity, superoxide dismutase （SOD）-like activity and tetrazolium salt 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assays were performed. DPPH scavenging activity of fermented extract by L. acidophilus was higher than fermented extract by L. plantarum and antioxidant effect of fermented extract was 20%-30% higher than non-fermented extract. SOD-like activity was represented 18% in fermented extract by L. acidophilus, and was 27% in fermented extract by L. plantarum higher than non-fermented extract. As a result, this study suggests that it may need an efficient protocol for dominant bio-physiological activities such as extract volume or appropriate working volume of cultured cell or mixture condition. The fermented C. versicolor extract should provide with useful antioxidant agent in the human skin.

The Process of Immobilization of ZnO Nanorods Surface with Galactose Oxidase

ZnO nanorods, with the c-axis orientation used for transparent conductors, solar cells, sensors especially the functionalized ZnO nanorods with some kinds of enzymes have been used for biosensor. In this work, we describe the process immobilization of galactose oxidase on ZnO nanorods surface with glutaraldehyde as a cross-linker molecule to make the working electrode in electrochemical biosensor. ZnO nanorods were grown on FTO （Fluorine-doped tin oxide） substrate by solution method at low temperature. The crystalline phase and orientation of ZnO nanorods were identified using X-ray diffraction. The efficiency of the immobilization was calculated by Braford method showed that about 36% enzyme content was immobilized on ZnO nanorods surface. The working electrode based on the immobilized ZnO nanorods was tested in galactose solution by CV （cyclic voltammetry） method indicated the value of current intensity is about 0.14 μA. These results clearly demonstrate the potential of galactose sensor based on ZnO nanorod.