The ocean is a huge resource of organisms and about 80% of the world species live in it.Marine organisms synthesize various structurally-unique and pharmacologically-active metabolites which differ from those derived from the land organisms and serve as lead compounds for drug development.More than 15 000 new compounds have been isolated and identified from marine animals,plants and microorganisms since decades ago,and drugs like cephalosporins,ziconotide(Prialt),cytarabine(AraC) and vidarabine(AraA) were developed using these compounds as precursors.

The lipid A component of Re-lipopolysaccharide from S.typhimurium SL 1102 was prepared by hydrolysis with a 0.1 mol/L acetate buffer.Chemical as well as advanced l3C-,and 31P-NMR investigations revealed a ?1' ,6-interlinked D-glucosamine diasaccharide, which is substituted by two phosphate(P)groups, one being esterlinked to the non-reducing residue,and another bound glycosidically to the C1 of the reducing residue, is as the central backbone.Its structure is shown as follows:-P-GlcN(?1', 6)GlcN-P-The amino(2 and 2')and hydroxy(3 and 3')groups of the backone are substituted by 3-OH-14: 0, and unhydroxy fatty acids appear to be the subtituents of the hydroxy group of 3-OH-14 :0, in the means of formation of 3-acyloxyacyl ester and amides.

Various chemical and gas-liquid chromatographic analyses indicate that the lipid A backbone of the lipopolysaccharide (LPS) isolated from Bacteriodes fragilis NCTC 9343 is chemically constituted by a ?1, 6-interlinked D-gluco-samine disaccharide. It is phosphorylated at its 1-position by a glycosidic-linkage while the ester-bound phosphate present generally in other lipid A is depleted. The lipid A is lower fatty acylated in the amount of 5.2 fatty acids per lipid A molecule (of which 0.73 forms 3-acyloxyacyl groups). The LPS containing such a lipid A component has been shown endowing with a weaker endotoxicity.

MicroRNA (miRNA) is a family of endogenous,non-coding small RNAs molecules that function as gene regulators.It has been revealed that miRNAs may play a critical role in many biological processes including cell proliferation,differentiation and apoptosis.Recent studies demonstrate that aberrant expression of miRNAs can lead to several human diseases even cancer.These tiny but potent molecules have the function as anti-oncogene or oncogene.Accordingly,further study of miRNAs has opened a novel avenue in the diagnosis and treatment of human cancer.

A typical smooth-form lipopolysaccharide (LPS) isolated from Salmonella abortus equi was fractionated into a S (smooth)-and a R (rough)-fraction and their serological and biological properties were investigated. It was shown that S- fraction expressed an O-antigenicity while R-fraction predominately a Rb-antigenicity. The R-fraction was endowed with higher bioactivities than the S-fraction in lethal toxicity, local Shwartzman reaction and pyrogenicity. Both S-and R-fractions were active in inducing mitogenicity to murine spleen cells. A reconstituted LPS preparation with fractionated S-fraction and a trace amount of R-fraction (1% of the original preparation) exhibited a same extent of lethal toxicity as that of the original one. Antr-Ra and -Rb antiserum with a liter of 1?4096 showed a .highly effective protection against the lethal challenge of LPS, indicating that the R-fraction in the natural LPS preparations plays a critical role to the lethality of LPS.

Effects of Lycium barbarian polysaccharide (LBP), Astragalus polysaccharide (APS), polysaccharide of Acanthopanax senticosus (PAS) and polysaccharide of lipopolysaccharide (PS) on cytotoxicities of LAK cells from splenocytes of C57BL/6 mices were observed with 18 h 125IUdR release assay. Our study demonstrated that the polysaccharides alone were shown to induce no cytotoxicities. When combined with rIL-2, all of 4 kinds of the polysaccharides augrnented LAK activities in dose-dependent manner. The augmentations reached the maximum at 0.01-0.1 mg ? ml-1 LBP, 0.01 mg ? ml-1 APS and PAS, 0.01 mg ? ml-1 PS. They were found to increase LAK activities in short range of rIL-2 concentrations (250-1000U? ml-1). If the polysaccharides were used beyond the suitable concentrations, they were shown to inhibit LAK cell activities.

Superoxide anion releasing from activated murine macrophages stimulated with recombinant human interferon-? (IFN-?), tumour necrosis factor-? (TNF-?) and bacterial lipopolysaccharidc were studied. The results showed that both of the cytokines enhanced superoxide anion release in a dose and time - dependent manner, but lipopolysaccharide had no such an effect as compared with IFN-? and TNF-?. It was also shown that O2- generation from macrophages was highly enhanced after primed with IFN-? or TNF-? for 24 hours. It was concluded from these data that cytokines released from macrophages and lymphocytes during inflammatory reactions could promote O2- generation which may play a crucial role in destruction or kill of intracellular pathogenic bacteria, and tumour cells.

‘University and college students' innovative ability training plan’ were launched from 2009 in Second Military Medical University. The innovative thinking and practical ability of students were improved by participation in research projects, writing scientific papers, academic exchanges and other activities. Students' innovative thinking, practice ability and cooperative spirit were promoted and unifica-tion of teaching and learning was achieved.

Objective To investigate the effects of human interlukin-13 (hIL-13) on the expression of E- selectin and intercellular adhesion molecule-1(ICAM-1) on bovine aortic endothelial cells(BAECs) stimulated by tumor necrosis factor alpha(TNF-?), and to provide experimental basis for hIL-13 inducing immunity endure and relieving the repulsion reaction of xenograft. Methods BAECs were co-cultured with different concentrations of hIL-13 for 2 h and followed by co-cultured with 4 ng/ml TNF-? for 6 h or 18 h. The expressions of E-selectin and ICAM-1 on BAECs were detected by Cell-ELISA. The effect of hIL-13 on activity of BAECs was detected by MTT colorimetry.Results BAECs pretreateded with hIL-13 could inhibit the expression of E-selectin and ICAM-1 induced by TNF-?, and showed a does-dependent manner from 5 ng/ml to 20 ng/ml of hIL-13 (P

This study is to investigate the influence and mechanism of action of asymmetrical dimethylarginine (ADMA) and the induced oxidative stress level on Alzheimer's disease (AD) incidence. ADMA concentration, nitric oxide, Abeta(40)/Abeta(42) ratio, inducible NO synthase (iNOS) activity and the concentrations of the induced free radicals including malondialdehyde (MDA), 3-nitrotyrosine (3-NT) and peroxynitrite (ONOO-) in the cerebrospinal fluid (CSF) from 34 neurologically normal controls and 37 AD patients were quantitatively determined and statistically compared. The results showed that the ADMA concentration significantly decreased in AD patients, and it showed negative correlation with the NO, iNOS activity, and showed positive correlation with MMSE score. ADMA concentration was negatively correlated with Abeta(40)/Abeta(42) ratio (P<0.01) with the observation that Abeta(40)/Abeta(42) ratio increased while ADMA level decreased in CSF in AD patients. The concentration levels of MDA, 3-NT and ROS significantly increased compared with the control with all the P values less than 0.05. These findings suggested that the ADMA disorder and the oxidative damage effect of the induced free radicals in CSF of AD patients are an important mechanism of AD incidence, and their joint regulation may provide new idea for the prevention and clinical treatment of AD.