BACKGROUND:Lipoic acid, with a closed circle structure composed by sulphur and carbon atoms, exerts strong anti-oxidation, and has been extensively applied in the prevention and treatment of oxidative stress, diabetic cataract, diabetic neuropathy and cardiovascular diseases. OBJECTIVE:To investigate the protective effect of lipoic acid on peripheral nerve function during peripheral nerve ischemia/reperfusion injury. METHODS:Models of peripheral nerve ischemia/reperfusion injury were established in rabbits, and then rabbit models were then allotted to treatment and non-treatment groups. The treatment group was subdivided into experimental (injection of lippoic acid) and control groups according to the use of lipoic acid at 1, 3 and 6 hours after ischemia and before reperfusion. The ultrastructural changes of the sciatic nerve were observed under electron microscope, and the electrophysiological changes of the sciatic nerve were detected using evoked potential instrument. RESULTS AND CONCLUSION:With the ischemic time increasing, the number of vacuoles in the axon increased gradually, accompanied by axonal atrophy, and Waller's degeneration in the aggregated microfilaments. The myelin sheath thickening and dissolving were visible. All above phenomena became severest at 6 hours after ischemia. Compared with the control groups, lipoic acid reduced the number of the vacuoles in the axon and all eviated axonal atrophy, Waller's degeneration and demyelination. As the ischemic time increasing, the latency of sciatic nerve was significantly increased, and peaked at 6 hours of ischemia;while the amplitude was significantly decreased, and reached a minimum at 6 hours of ischemia. Compared with the control groups, in the experimental groups, the latency of sciatic nerve was significantly decreased, but the amplitude was significantly increased. These results suggest that lipoic acid provides neuroprotection against peripheral nerve ischemia/reperfusion injury.

Objective To establish a rabbit model of restenosis and analyze the expressions of VEGFmRNA and TGF-?_1mRNA during the intimal proliferation.We also explored the relationship between VEGFmRNA,TGF-?_1mRNA and restenosis.Methods 40 healthy male New Zealand white rabbits were evenly divided into three injury groups and one control group.Right carotid arteries were injured with PCI balloon in the injury groups.10 rabbits of each injury group were sacrificed on weeks 1,2 and 4 after the injury.VEGFmRNA and TGF-?_1mRNA were examined by in situ hybridization.All the samples were analyzed using a computerized imaging analysis system.Results In the injury groups,neointimal areas were significantly larger than those in control group(P

OBJECTIVETo screen and characterize the short peptides which bind specifically to interleukin-2 (IL-2) receptor alpha chain (IL-2Ralpha) for acquisition of small antagonists for blocking the binding of IL-2 with IL-2Ralpha.

METHODS12-mer phage displayed peptide library was screened with the target cells of MT-2 cells which expressed IL-2Ralpha at high levels. The binding phage clones were eluted by anti-IL-2Ralpha monoclonal antibody. After 3 rounds of screening, the positive phage clones were identified by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry, and the amino acid sequences of the positive clones were deduced from the DNA sequences.

RESULTSSeven positive clones were screened out of the 17 phage clones bound to MT-2 cells. The positive clone M15 could bind specifically to MT-2 cell and PHA-activated peripheral blood monouclear cells. Amino acid sequence analysis identified 6 sequences, all of which contained hydrophilic residues, and 5 of these 6 sequences included Tyr, Phe and Leu conservative residues.

CONCLUSIONThe peptide sequences containing Tyr, Phe conservative residues identified in this study can bind to cell surface IL-2Ralpha.

Amino Acid Sequence ; Cell Line, Transformed ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunohistochemistry ; Interleukin-2 ; metabolism ; Interleukin-2 Receptor alpha Subunit ; metabolism ; Peptide Library ; Peptides ; genetics ; metabolism ; Protein Binding ; Receptors, Cell Surface ; metabolism ; T-Lymphocytes ; cytology ; metabolism

Administration, Oral ; Adult ; Alanine Transaminase ; blood ; Antiviral Agents ; administration & dosage ; therapeutic use ; DNA, Viral ; blood ; Female ; Guanine ; administration & dosage ; analogs & derivatives ; pharmacology ; therapeutic use ; Hepatitis B e Antigens ; blood ; Hepatitis B virus ; drug effects ; Hepatitis B, Chronic ; drug therapy ; immunology ; Humans ; Lamivudine ; administration & dosage ; pharmacology ; therapeutic use ; Male ; Treatment Outcome ; Young Adult

OBJECTIVETo observe the cell apoptosis after tractive spinal cord injury in rats, determine expression of apoptosis correlative genes, and study the molecular mechanism of cell apoptosis.

METHODSThe T(13)-L(2) spinal cord of rats was injured by traction after the amplitude of P1-N1 wave decreased to 70% in postoperation than in preoperation through cortical somatosensory evoked potential (CSEP) monitor. Then rats were killed in 30 min, 6 h, 1, 4, 7, 14 and 21 d respectively after operation (n = 4). Cell apoptosis was examined by the flow cytometer and terminal deoxynucleotidyl transferase-mediated DUTP-biotin nick end labeling (TUNEL) reaction, the expression of p53, bax and bc1-2 genes was tested with immunohistochemistry.

RESULTSThe flow cytometer test and TUNEL method showed that the apoptosis cell ratio raised in 6 h and reached at peak in 7 d after injury, and then declined till 21 d, they showed significant difference (P < 0.05, 0.01). TUNEL method showed that injured group had a large number of apoptosis glial cells in white matter. Immunohistochemical staining showed that the positive expression of p53, bax and bc1-2 protein raised at 6 h, expression of p53 protein reached at peak in 4 d, bax and bc1-2 protein reached at peak in 7 d after injury. Compared with control group and laminectomy group, the injured group showed significant difference (P < 0.05, 0.01).

CONCLUSIONThere is cell apoptosis phenomenon after tractive spinal cord injury in rats. Morphology indicates that apoptosis includes neurons and glialcytes, which is an important form of cell death and pathological changes in secondary lesion period after tractive spinal cord. There exist high expression of apoptosis correlative gene p53 and bax after spinal cord injury, they may play an important role in reduction of cells to apoptosis.

Animals ; Apoptosis ; genetics ; Disease Models, Animal ; Female ; Gene Expression ; Genes, bcl-2 ; genetics ; Genes, p53 ; genetics ; Male ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries ; genetics ; pathology ; bcl-2-Associated X Protein

OBJECTIVETo explore the effects of manganese poisoning on the proliferation of neural stem cells (NSCs) in mice's hippocampus.

METHODSThe mice (weight 8 approximately 10 g) were divided into control group(CG) low-dose group(LDG) middle-dose group(MDG) and high-dose group(HDG)by intraperitoneal injection of 0, 5, 20, 50 mg x kg(-1) x d(-1) of manganese chloride dissolved in physiological saline. The ability of learning and memory was detected by Morris Water Maze, and the proliferation of NSCs in subgranular zone (SGZ) in these mice's hippocampus was also detected by immunohistochemistry.

RESULTS1) Compared with the CG, the ability of learning and memory in all manganism group decreased significantly (P < 0.01) and this phenomenon in HDG was most notable (P < 0.01). Meanwhile, the ability of memory was negatively correlated with the dose of manganese chloride (r(s) = -0.598, P < 0.01), but the difference of swimming speed in every group was of no statistic significance. (2) The numbers of NSCs in proliferation period in SGZ of all manganism groups was much lower than that of CG (P < 0.01) negatively correlated with the dose of manganese chloride (r(s) = -0.666, P < 0.01). (3) The reduction of NSCs had a positive correlation to the depression of learning and memory (r(s) = 0.734, P < 0.01).

CONCLUSIONSManganismus can affect the ability of learning and memory, which is probably caused by the inhalation of manganese on NSCs in hippocampus.

Animals ; Cell Proliferation ; drug effects ; Cells, Cultured ; Disease Models, Animal ; Hippocampus ; cytology ; drug effects ; Male ; Manganese Poisoning ; pathology ; Maze Learning ; drug effects ; Memory ; drug effects ; Mice ; Neural Stem Cells ; cytology ; drug effects

To investigate the interaction between tumor necrosis factor alpha (TNF alpha) mimotopes and TNF alpha-binding peptides screened from random phage display peptide library with TNF alpha mimotopes displayed on phage clone as the target, the computational docking program AutoDock (with confirmation calculations using Discover) was used to predict and analyze the binding modes of LLT-18 (TNF alpha binding peptide, sequence EHMALTYPFRPP) with TNF alpha, after which LCS-7 (TNF alpha mimic phage clone, displayed positive sequence c-RRPAQSG-c) was docked to LLT-18 manually. The binding between LLT-18 and TNF alpha or LCS-7 was stabilized predominantly through electrostatic interaction and H-bond formation. The Arg residues in TNF alpha or LCS-7 were important for their interaction with LLT-18. For LLT-18, the key amino acid residues were Glu1, His2, Met3 and Tyr7. These results suggest the feasibility of screening ligand to single epitope with specific phage clone as the target, and of predicting the interaction between small peptides by computer-aided molecular modeling.
Amino Acid Sequence ; Animals ; Antibodies, Monoclonal ; immunology ; Biotinylation ; Computer Simulation ; Drug Evaluation, Preclinical ; methods ; Epitopes ; immunology ; Humans ; Ligands ; Models, Molecular ; Oligopeptides ; chemistry ; metabolism ; Peptide Library ; Protein Conformation ; Solubility ; Tumor Necrosis Factor-alpha ; chemistry ; immunology ; metabolism

Objective To investigate the relationship between APE1, XRCC1 gene polymorphisms and hepatocellular carcinoma(HCC) susceptibility and to explore the correlation of APE1, XRCC1 gene polymorphisms with the sensitivity to platinum-based drugs .Methods Seventy-eight HCC patients and 80 controls were selected .By PCR and RFLP , the single nucleotide polymorphism of APE1 Asp148Glu and XRCC1 Arg194Trp genes and the susceptibility of HCC or platinum drug sensitivity were analyzed.Results The Glu/Glu genotype of APE1 could increase in the risk of HCC by 7.21 times (95%CI:1.325-29.109) (P<0.05).APE1 and XRCC1 gene polymorphisms could also affect the platinum drug resistance of HCC patients.Conclusion APE1 Asp148Glu is correlated with the susceptibility to HCC .APE1 and XRCC1 genes can be considered a target for therapy to improve the sensitivity of HCC platinum drugs .

The purpose of the present study was to investigate the effects of advanced glycation end products (AGEs) modified protein on the permeability of endothelium monolayers and morphological changes of actin cytoskeleton. The roles of receptor for AGEs (RAGE), oxidant stress and the activation of p38 MAPK pathway in this pathological procedure were elucidated. Human umbilical vein endothelial cells (HUVECs)-derived cell line (ECV304) were incubated with AGEs modified human serum albumin (AGE-HSA) in concentrations of 12.5, 25, 50, and 100 microg/ml respectively, for 2, 4, 8, 12 and 24 h. As control, HSA of the same concentration was administered to cells. Then TRITC-albumin was added to evaluate Pa value that reflects the permeability of endothelial monolayer. Furthermore, to visualize the morphological changes of actin cytoskeleton, the treated cells were incubated with rhodamine-phalloidin to stain F-actin. The results showed that the trans-endothelial membrane flux of albumin was significantly increased in a concentration- and time-dependent manner upon the stimulation of AGE-HSA, accompanying with actin reorganization. The blockage of AGE and RAGE binding with anti-RAGE IgG and the pharmacological inhibition of NADPH oxidase or p38 MAP kinase greatly attenuated the AGE-induced hyperpermeability response, respectively. These results indicate that RAGE, NADPH oxidase and p38 MAPK are possibly involved in the mediation of AGEs-induced barrier dysfunction and actin cytoskeleton reorganization in endothelial cells.
Actin Cytoskeleton ; physiology ; Capillary Permeability ; physiology ; Cell Line ; Cells, Cultured ; Endothelium, Vascular ; cytology ; Glycation End Products, Advanced ; physiology ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; Oxidative Stress ; physiology ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; physiology ; p38 Mitogen-Activated Protein Kinases ; metabolism

Action Potentials ; Animals ; Electromyography ; Environmental Exposure ; Hypothermia ; Rats ; Rats, Wistar ; Seawater ; Thigh ; physiology ; physiopathology