A bursal pentapeptide (BPP-I), a novel bursal-derived peptide, exhibits antiproliferation of tumor cell and immunomodulator activity

The bursa of Fabricius (BF) is the central humoral immune organ unique to birds. Here, we isolated a novel bursal pentapeptide I (BPP-I), LGPGP, from BF. BPP-I could play inhibition effect on MCF-7 but not on CEF or Vero cell proliferation in vitro, and enhance antitumor factor p53 protein expression. Also, BPP-I stimulated antibody production in a dose-dependent manner in hybridoma cell. Furthermore, BPP-I could induce various immune responses in mice immunization experiments, including increase antibody production and cytokines IL-4 and IFN-γ level, and induce T-cell immunophenotyping. These results suggest that BPP-I is a potential immunomodulator of antitumor and immunity. The study could provide some novel insights on the probable candidate reagent for the antitumor and immune improvement.     

Structural and functional insights into the role of a cupin superfamily isomerase in the biosynthesis of Choi moiety of aeruginosin

The 2-carboxy-6-hydroxyoctahydroindole (Choi) moiety is a hallmark of aeruginosins, a class of cyanobacterial derived bioactive linear tetrapeptides that possess antithrombotic activity. The biosynthetic pathway of Choi has yet to be resolved. AerE is a cupin superfamily enzyme that was shown to be involved in the biosynthesis of Choi, but its exact role remains unclear. This study reports the functional characterization and structural analyses of AerE. Enzymatic observation reveals that AerE can dramatically accelerate 1,3-allylic isomerization of the non-aromatic decarboxylation product of prephenate, dihydro-4-hydroxyphenylpyruvate (H₂HPP). This olefin isomerization reaction can occur non-enzymatically and is the second step of the biosynthetic pathway from prephenate to Choi. The results of comparative structural analysis and substrate analogue binding geometry analysis combined with the results of mutational studies suggest that AerE employs an induced fit strategy to bind and stabilize the substrate in a particular conformation that is possibly favorable for 1,3-allylic isomerization of H₂HPP through coordinate bonds, hydrogen bonds, π–π conjugation interaction and hydrophobic interactions. All of these interactions are critical for the catalytic efficiency.     

Unusual lipids and acylglucosylsterols from the roots of Livistona chinensis

A 70% ethanol extract from the roots of Livistona chinensis has been investigated, led to the isolation of 18 compounds, including two new 6′-O-acyl-β-d-glucosyl-β-sitosterols, 6′-O-(2″-hydroxyheptadecanoyl)-β-d-glucosyl-β-sitosterol (1) and 6′-O-(icosa-9″Z,12″Z-dienoyl)-β-d-glucosyl-β-sitosterol (2), two new keto esters, ethyl 16-(dodeca-4″′Z,7″′Z-dienyl)-29-oxo-15-(tetradeca-5″Z,8″Z,11″Z-trienyl) triacontanoate (7), and 16-hydroxy-8-oxohexadecyl tetradecanoate (9), a new unsaturated fatty acid, tetracosa-(11Z,14Z,18Z)-trienoic acid (8), as well as a new fatty alcohol, 10-decylnonadecane-1,19-diol (10). The structures of new compounds were elucidated, based on spectroscopic and chemical methods. The antiproliferative activity against four human tumor cell lines (K562, HL-60, HepG2, and CNE-1) was evaluated. Four compounds (1–3, 5) showed potent antiproliferative effects with the IC₅₀ of 10–100 μM. To our knowledge, this is the first report of the occurrence of 6′-O-acyl-β-d-glucosyl-β-sitosterol and 3-O-acyl-β-sitosterol in the genus Livistona. Keto fatty acids and their esters are also rare in higher plant.     

华南植物的增补

报道华南地区3种植物：山柚子科的茎花山袖（Champereiamanillanavar．longistamined）是新组合的变种,其花序和嫩叶可供蔬食;大朝科的美洲珠子草（Phyllanthusamarus）是具有药用价值的归化种;台湾核果木（Drypetesformosana）生长于珠江口东侧的海岛,为广东新纪录种。     

DNA repair capacity, DNA-strand break repair gene polymorphisms, and the incidence of hepatocellular carcinoma in southwestern Guangxi of China

The associations between DNA repair capacity (DRC), DNA repair gene polymorphisms, and the incidence of hepatocellular carcinoma (HCC) have not been determined in high-risk areas. The aims of this study were to investigate whether DRC is related to the incidence of HCC and to determine whether polymorphisms in the DNA repair genes that regulate DRC are associated with the risk of HCC. First, a small case-control study was conducted to examine the association between DRC and the incidence of HCC and the environmental and genetic factors regulating DRC. Then, a large case-control study was conducted to determine whether those DNA repair gene polymorphisms shown to regulate DRC were related to the risk of HCC. The median DRC was significantly lower among the cases (0.80) than the controls (0.93). A multivariate linear regression analysis showed that the HBsAg status (p<0.01), ethnicity (p=0.01), and polymorphisms in the XRCC3-241 (p=0.01) and APE1-148 (p=0.03) gene loci may be impact factors for DRC. In the large case-control study, a stratified analysis showed that individuals with the APE1-148-combined genotype GT+TT likely had a significantly higher HCC risk compared with those with only the GG genotype (crude odds ratio=1.93, 95% confidence interval=1.17-3.17) among the Zhuang ethnicity. However, nonsignificant differences were observed between XRCC3-241 polymorphisms and the HCC risk. DRC may be related to the incidence of HCC as determined by environmental and genetic factors found in southwestern part of the Guangxi Province. Gene-environment interactions play an important role in the incidence and progression of HCC.     

Negative Affect Mediates Effects of Psychological Stress on Disordered Eating in Young Chinese Women

Background

The bi-relationships between psychological stress, negative affect and disordered eating has been well studied in western culture, while tri-relationship among them, i.e. how some of those factors influence these bi-relationships, has rarely been studied. However, there has been little related study in the different Chinese culture. This study was conducted to investigate the bi-relationships and tri-relationship between psychological stress, negative affect, and disordered eating attitudes and behaviors in young Chinese women.

Methodology

A total of 245 young Chinese policewomen employed to carry out health and safety checks at the 2010 Shanghai World Expo were recruited in this study. The Chinese version of the Perceived Stress Scale (PSS-10), Beck Depression Inventory Revised (BDI-II), Beck Anxiety Inventory (BAI), and Eating Attitude Test (EAT-26) were administered to all participants.

Principal Findings

The total scores of PSS-10, BDI-II and BAI were all highly correlated with that of EAT-26. The PSS-10 score significantly correlated with both BDI-II and BAI scores. There was no statistically significant direct effect from perceived stress to disordered eating (–0.012, 95%CI: –.038∼0.006, p = 0.357), however, the indirect effects from PSS-10 via affect factors were statistically significant, e.g. the estimated mediation effects from PSS to EAT-26 via depression and anxiety were 0.036 (95%CI: 0.022∼0.044, p<0.001) and 0.015 (95%CI: 0.005∼0.023, p<0.01), respectively.

Conclusions

Perceived stress and negative affects of depression and anxiety were demonstrated to be strongly associated with disordered eating. Negative affect mediated the relationship between perceived stress and disordered eating. The findings suggest that effective interventions and preventative programmes for disordered eating should pay more attention to depression and anxiety among the young Chinese female population.     

Design, synthesis of symmetrical bivalent mimetics of annonaceous acetogenins and their cytotoxicities

A new series of linear dimeric compounds mimicking naturally occurring annonaceous acetogenins have been synthesized by bivalent analogue design, and their cytotoxicities have been evaluated against the growth of cancer cells by MTT method. Most of these compounds show selective action favored to human cancer cell lines over normal cell lines, and compound 9 with bis-terminal benzoquinone functionality exhibits an IC₅₀ = 0.40 μM against MCF7 cell lines. This work mentions that appropriate conformational constraints might be a useful optimizing tool for this unique class of anticancer compounds.     

Dinocrocuta gigantea头骨的发现

本文记述了甘肃和政县晚中新世地层中发现的一个完整的巨鬣狗头骨;讨论了它的分类地位,修正了 Schlosser 1903年建种时的一些鉴定错误.巨鬣狗是鬣狗科中一个十分特化的成员,应代表一个独立的属.根据命名规则,我们采用 N. schmidt-Kittler 1976年所创的 Dinocrocuta. 因此,这个种应订正为 Dinocrocuta gigantea (schlosser, 1903).