[The experimental study of cryopreserved osteoblasts combined with BGC repairing mandibular defects in rabbits].

Objective: The purpose of this study was to observe the biological characteristics of cultured Periosteal-derived Osteoblasts (POBs) preserved in liquid nitrogen in vitro, and to preliminarily study the osteogenetic capability of bioactive glass ceramic (BGC) combined with POBs.

Methods: The cryopreserved cells were cultured in DMEM medium and examined by morphological and histological assay. The POBs growing well in vitro were seeded into the porous BGC materials.

[Construction of human pLXSN-CD80 retrovirus vector and expression in CHO and PA317 cells].

CD80, a molecule on the antigen presenting cells, provide costimulation signals for T cell activation and play a key role in tumor immune. Based on our previous work of human CD80 full length cDNA cloning, a retrovirus expression vector pLXSN-CD80 was constructed. CD80 expression cells were selected by G418 from pLXSN-CD80 transfected PA317 and CHO cells by calcium phosphate.

Effects of pollen extract EA-10, P5 on chronic prostatitis or infertility with chronic prostatitis.

Aim: To determine the drug action mechanism of pollen extract EA-10, P5 on the treatment of chronic prostatitis (CP) or infertility with CP.

Methods: Malondiadehyde (MDA), superoxide dismutase (SOD), and nitrogen monoxide (NO) were measured by biochemical assay, and zinc content was assayed by atomical spectrophotography in the pre-treatment and post-treatment of CP or infertility with CP.

Results: Compared with control group, leukocytes in expressed protatic secretion (LEPS), MDA, and NO were increased, and zinc content and SOD were decreased significantly in the pre-treatment of CP.

Comparative analysis of PAH:DNA adducts formed in lung of mice exposed to neat coal tar and soils contaminated with coal tar.

7H-Benzo[c]fluorene (benzo[c]fluorene) is a major DNA adduct forming component of coal tar in lung of mice. The present study evaluated the types of PAH:DNA adducts formed from different neat coal tar samples and soils contaminated with coal tar. Mice were fed diets containing coal tar either neat or as a contaminant in an environmental soil sample for 14 days, and the types of chemical:DNA adducts formed in lung were evaluated using 32P-postlabeling and HPLC analysis.

IL-10 and trichosanthin inhibited surface molecule expression of antigen processing cells and T-cell proliferation.

Aim: To study immunoinhibitory effects and preliminary mechanism of IL-10 and trichosanthin.

Methods: Surface molecule expression on antigen processing cells (APC) was stained with fluorescence and analyzed by FACScan. B7-1 mRNA expression was detected with nested RT-PCR.

Active site of trichosanthin acting as a ribosome-inactivating protein.

Aim: To localize the active site of ribosome inactivation of trichosanthin (Tri), a Chinese herb protein.

Methods: Hydroxylamine was used to specifically cleave the unique Asn-Gly peptide bond of Tri. Preparative SDS-polyacrylamide gel electrophoresis was applied to get 2 cleaved fragments, HATf1 and HATf2.

The effects of hydrogen peroxide on DNA repair activities.

Oxygen free radicals generated by H2O2 are involved in the multistage carcinogenic process; mechanisms include carcinogen activation, oxidative DNA damage, and tumor promotion. In this study, we have evaluated another potential mechanism of H2O2 in carcinogenesis--modulation of DNA repair activities. Preexposure of human peripheral mononuclear leukocytes to H2O2 significantly inhibited DNA repair activities in response to damage induced by N-methyl-N'-nitro-N-nitrosoguanidine, measured as unscheduled DNA synthesis.

Trichosanthin, an initiator of the alternative complement activation pathway.

Trichosanthin (TCS), a protein purified from the plant Trichosanthes Kirilowii Maxim, activates normal human serum complement via the alternative pathway, as shown by TCS-induced C3 conversion in normal serum and its prevention by depletion of factor B, but not with the addition of EGTA. Injection of TCS to BALB/c mice consumed the complement alternative pathway (APC) activity in serum, implying in vivo activation of the alternative pathway by TCS. Elevation of peripheral blood leucocyte count as well as protein exudation and neutrophil accumulation in the peritoneal cavities could be induced by peritoneal injection of TCS.

Transcriptional activation of cytochrome P450 2B1/2 genes in rat liver by diallyl sulfide, a compound derived from garlic.

Previous work in our laboratory demonstrated that cytochrome P450 2B1 in rat liver was induced, but P450 2E1 was inhibited and inactivated, by diallyl sulfide (DAS), a compound derived from garlic. Such a selective effect on P450 enzymes is of considerable interest toward the understanding of dietary effects on xenobiotic metabolism. In the present study, the mechanism of P450 2B1 induction by DAS was investigated.

Induction of liver microsomal cytochrome P-450 2B1 by dimethyl diphenyl bicarboxylate in rats.

Dimethyl diphenyl bicarboxylate (dimethyl-4,4'-dimethyloxy-5,6,5',6'-dimethylene-dioxy-di phe nyl-2,2'- bicarboxylate, DDB), a synthetic mimic of the natural product schizandrin C, is used in China as a hepatoprotective agent to improve the liver functions of patients with hepatitis or under cancer chemotherapy. In this study, we investigated the effects of DDB on liver microsomal drug-metabolizing enzymes. When male Sprague-Dawley rats were treated with a daily intragastric dose of DDB (200 mg.

Electron microscopic appearance of the chronic Campylobacter jejuni enteritis of mice.

Campylobacter jejuni is a major cause of human enteritis which mimics the inflammatory bowel disease (IBD). In this study, microstructural changes on the surfaces of the murine gastrointestinal tract persistently colonized by Campylobacter jejuni, strain GJ-S131, were investigated by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results revealed that the appearance of the gastrointestinal mucosa in both BALB/C and KM mice resembled that in human with inflammatory bowel disease.

Metabolism of carcinogenic nitrosamines by rat nasal mucosa and the effect of diallyl sulfide.

Rat nasal cavity is one of the target organs for carcinogenesis induced by N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The present work investigated the metabolism of these nitrosamines by rat nasal microsomes, as well as the possible modulating factors. Microsomes prepared from rat nasal mucosa were efficient in metabolizing these nitrosamines.

Roles of pituitary hormones in the regulation of hepatic cytochrome P450IIE1 in rats and mice.

Cytochrome P450IIE1 (P450IIE1) is responsible for the metabolic activation of N-nitrosodimethylamine (NDMA), a potent environmental carcinogen. This P450 enzyme displays a high-affinity NDMA demethylase (NDMAd) activity and is known to be induced by fasting and acetone administration. In the present work, the effects of pituitary hormones on the regulation of P450IIE1 in the liver were investigated and compared in rats and mice.