Three new cytotoxic Diels-Alder-type adducts from Morus australis

Three new natural products, australisines A-C (1-3, resp.), were isolated from the stem bark of Morus australis, together with eight related compounds, including mulberrofurans E-G, J, and Q, mongolicin C, chalcomoracin, and kuwanon G. Their structures were fully characterized by spectroscopic methods. Compounds 1-3, mulberrofuran G, mongolicin C, and chalcomoracin showed moderate cytotoxic activities against five human cancer cell lines, with IC50 values ranging from 4.6-9.2 microg/ml, as determined by MTT assay.     

Genetic and environmental correlations between bone mineral density and bone size in Caucasians

To explore the magnitude of common genetic and environmental effects shared by bone mineral density (BMD) and bone size (BS) in a large sample of 4,489 subjects (2,667 females and 1,822 males) from 582 Caucasian pedigrees, we performed a bivariate variance decomposition analysis to evaluate genetic correlation (rhoG), environmental correlation (rhoE), and phenotypic correlation (rhoP) between BMD and BS at the spine and hip, as well as their "synthesized" skeletal site (bone mineral density principal component, bone size principal component) generated by principal components analysis. Significant rhoG, rhoE, and rhoP were detected, but the shared genetic influence on BMD and BS was only 21%, 1.3%, and 11.6% at the spine, hip, and their joint variable, respectively. The results suggest that it may be important to choose both BMD and BS, especially at the hip, as surrogate phenotypes for osteoporosis genetic studies in Caucasians.     

角蒿的离体培养与快速繁殖

1植物名称角蒿（Incarvillea sinensis Lam.）。 2材料类别种子萌发的无菌苗下胚轴和子叶。 3培养条件基本培养基为MS。（1）种子萌发培养基：1/2MS;（2）丛生芽诱导培养基：MS＋6-BA2mg·L-1（单位下同）＋NAA0.2;（3）丛生芽增殖培养基：MS＋     

Synthesis,characterization, and studies on DNA binding of a new Mg(II) complex with N<Superscript>1</Superscript>,N<Superscript>8</Superscript>-bis(1-methyl-4-nitropyrrole-2-carbonyl)triethylenetetramine

A new Mg(II) complex of MgL(NO3)2 (here L = N(1),N(8)-bis(1-methyl-4-nitropyrrole-2-carbonyl)triethylenetetramine) has been synthesized and characterized. The interactions between the Mg(II) complex and calf thymus DNA has been investigated using UV spectra, fluorescent spectra, viscosity, thermal denaturation, and molecular modeling. The cleavage reaction on plasmid DNA has been monitored by agarose gel electrophoresis. The experimental results show that the mode of binding of the complex to DNA is non-classical electrostatic action and the complex can cleave pBR322 DNA.     

腹毛类纤毛虫杆形戴维虫的形态学和细胞发生

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Effective induction of antitumor immunity by immunization with plasmid DNA encoding TRP-2 plus neutralization of TGF-β

Plasmid DNA vaccine is an appealing cancer immunotherapy. However, it is a weak immunogen and immunization with plasmid DNA encoding self-antigens, such as melanoma-associated antigens, could not induce antitumor immunity because of tolerance. In this study, we investigated the feasibility of using a plasmid DNA encoding Xenopus laevis transforming growth factor-beta 5 (aTGF-5) as an immunogen to induce neutralizing antibodies against murine TGF-1 (mTGF-1) and thus enhance the efficacy of plasmid DNA vaccine encoding murine tyrosinase-related protein 2 (mTRP-2) through neutralization of TGF-. The results showed that immunization with aTGF-5 resulted in the generation of mTGF-1-neutralizing antibodies, and immunization with a combination of aTGF-5 and mTRP-2 induced specific cytotoxic T lymphocytes (CTLs). On the contrary, immunization with mTRP-2 alone could not elicit the CTL response. Moreover, immunization of C57BL/6 wild-type mice with a combination of aTGF-5 and mTRP-2 induced the protective and therapeutic antitumor immunity to B16F10 melanoma, whereas the antitumor activity was abrogated in both CD4-deficient mice and CD8-deficient mice on the C57BL/6 background. Our results indicate that immunization with aTGF-5 is capable of breaking immune tolerance and induces mTGF-1-neutralizing antibodies. Neutralization of TGF- can enhance the efficacy of DNA vaccine encoding mTRP-2 and the induction of antitumor immunity by this immunization strategy is associated with CD4⁺ and CD8⁺ T cells.     

Fourier transform IR and Fourier transform Raman spectroscopy studies of metallothionein-III: amide I band assignments and secondary structural comparison with metallothioneins-I and -II

The secondary structures of porcine brain Cu(4)Zn(3)-metallothionein (MT)-III and Cd(5)Zn(2)MT-I, Cd(5)Zn(2)MT-II, and Zn(7)MT-I from rabbit livers in the solid state are investigated by Fourier transform IR spectroscopy (FTIR) and Fourier transform Raman spectroscopy (FT-Raman). The Cu(4)Zn(3)MT-III contains 26-28% beta-turns and half-turns, 13-14% 3(10)-helices, 47-49% random coils, and 11-12% beta-extended chains. The structural comparison of porcine brain Cu(4)Zn(3)MT-III with rabbit liver Cd(5)Zn(2)MT-I (II) and Zn(7)MT-I shows that the contents of the random coil structure are obviously increased. The results indicate that the insert of an acidic hexapeptide in the alpha domain of Cu(4)Zn(3)MT-III possibly forms an alpha helix. However, because the bands assigned to the alpha-helix and random coil structures are overlapped in the spectra, the content of random coil structures in Cu(4)Zn(3)MT-III is therefore higher than those in Cd(5)Zn(2)MT-I, Cd(5)Zn(2)MT-II, and Zn(7)MT-I.     

假单胞菌降解微囊藻毒素的效能及酶作用机理

以从福州市某富营养化水库底泥中筛选出的假单胞菌M-6为研究对象,分别考察接种量、温度、供氧量(转速)、pH值、微囊藻毒素MCLR初始浓度等条件因素对假单胞菌M-6降解MCLR的影响,并探讨假单胞菌M-6降解MCLR的分子生物学机理.结果表明,当接种量为10%时,菌体的降解效果较好,6d的降解率可达90%;降解反应的最适pH为7.0,最佳温度为30℃,摇床转速控制在150 r/min;MCLR初始浓度过高都将影响假单胞菌M-6对碳源和氮源的吸收和利用,最佳浓度为15.7 mg/L.SDS-PAGE电泳分析表明,假单胞菌M-6降解藻毒素过程中,主要有3种酶参与反应,且这3种酶都是细胞内本身所含有的组织酶.     

盐碱地马蔺光合生理特性的研究

研究了盐碱地生长的马蔺叶片净光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Gs）和水分利用效率（WUE）以及环境因素的日变化。结果表明,马蔺叶片Pn和Tr均呈现双峰曲线,具有光合午休现象。这种现象出现的原因是由于较高的太阳辐射引起叶片温度的升高,叶片的羧化效率(CE)和表观量子产额(AQY)的下降造成的。     

Monitoring of the bacterial and fungal biodiversity and dynamics during Massa Medicata Fermentata fermentation

The microbial community dynamics play an important role during Massa Medicata Fermentata (MMF) fermentation. In this study, bacterial and fungal communities were investigated based on the culture-dependent method and polymerase chain reaction-denaturing gradient gel electrophoresis analysis. Meanwhile the dynamic changes of digestive enzyme activities were also examined. Plating results showed that MMF fermentation comprised two stages: pre-fermentation stage (0–4 days) was dominated by bacterial community and post-fermentation stage (5–9 days) was dominated by fungal community. The amount of bacteria reached the highest copy number 1.2?×?10¹⁰ CFU/g at day 2, but the fungi counts reached 6.3?×?10⁵ CFU/g at day 9. A total of 170 isolates were closely related to genera Enterobacter, Klebsiella, Acinetobacter, Pseudomonas, Mucor, Saccharomyces, Rhodotorula, and Amylomyces. DGGE analysis showed a clear reduction of bacterial and fungal diversity during fermentation, and the dominant microbes belonged to genera Enterobacter, Pediococcus, Pseudomonas, Mucor, and Saccharomyces. Digestive enzyme assay showed filter paper activity; the activities of amylase, carboxymethyl cellulase, and lipase reached a peak at day 4; and the protease activity constantly increased until the end of the fermentation. In this study, we carried out a detailed and comprehensive analysis of microbial communities as well as four digestive enzymes' activities during MMF fermentation process. The monitoring of bacterial and fungal biodiversity and dynamics during MMF fermentation has significant potential for controlling the fermentation process.