Effect of different plant growth regulators on micro-tuber induction and plant regeneration of Pinellia ternate (Thunb) Briet

An efficient micropropagation system for Pinellia ternate (Thunb) Briet, a traditional Chinese medicinal plant, has been developed. Petiole and lamina of P. ternate were used as explants and cultured on Murashige and Skoog (MS) medium containing different concentrations of different plant growth regulators. The results indicated that low concentration of 2,4-dicholorophenoxy acetic acid (2,4-D), indole-3-acetic acid (IAA) and α-naphthalene acetic acid (NAA) were suitable for micro-tuber induction, but callus induction rate increased with increasing concentrations of growth regulators. Tubers induction rates of petiole and leaf were (81.8 %–100 %) and (89.4 %–96.0 %) respectively, when 0.2 mg l⁻¹ 2, 4-dicholorophenoxy acetic acid, indole-3-acetic acid or α-naphthalene acetic acid were present in the medium. Tubers induction rates of petiole and leaf cultured on MS medium supplemented with 0.2–0.5 mg l⁻¹ 6-benzyl amino purine (6-BAP) were (94.1 %–100 %) and (96.0 %–100 %) respectively. When the concentration of 2,4-dicholorophenoxy acetic acid, α-naphthalene acetic acid and 6-benzyl amino purine was increased to 2.0 mg l⁻¹, callus induction rates of petiole and leaf were 100 % and 98.2 %, 91.0 % and 36.0 %, 62.3 % and 70.0 %, respectively. Different concentration of kinetin (KT) and zeatin (ZT) had no significant effect on micro-tuber induction of petiole. Most petioles showed polarity during the cultivation of explants, when supplemented with different concentrations of auxin or cytokinin in the MS medium.     

一种简单有效且适于土壤微生物多样性分析的DNA提取方法

参照Zhou[11]的方法进行了改进,获得了一种简单、有效的DNA提取方法.此方法操作简单、从大量样品改为小量样品的提取,利用高浓度的PEG沉淀,不作回收纯化,所提DNA片段较大,在23 kb以上,每克土的DNA提取量从3.74～15.28 μg,OD260/OD230比值在0.89～1.21范围内,用真菌和细菌核糖体特异性引物进行PCR扩增,均获得较好的结果,DGGE图谱显示丰富性较高,可用于细菌多样性和真菌多样性的分析.此方法能够从4种不同性质土壤中提取出DNA,但提取盐渍土壤和碱性土壤的效果更好一些,为土壤微生物群落结构的多样性分析奠定良好的基础.     

The oxidation metabolites of endomorphin 1 and its fragments induced by free radicals

Endomorphin 1 (EM1), an endogenous µ‐opioid receptor agonist, acts as a free radical scavenger in vitro and an antioxidant in vivo. The modification of EM1 by ROS and the properties of the OM attracted our attention. In vitro assays were performed via RP‐HPLC, spectrophotometric measurements, EPR and amino acid analysis, Schmorl's reaction to define the formation of melanin‐like compounds transformed from EM1, collectively named EM1–melanin and by solubility assay, radioligand‐binding assay, NADH oxidation, superoxide anion scavenging assay to study some physical and chemical properties of EM1–melanin. Possible pathways of the formation of EM1–melanin were proposed. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.     

NGFI-B targets mitochondria and induces cardiomyocyte apoptosis in restraint-stressed rats by mediating energy metabolism disorder

NGFI-B/Nur77/TR3, originally identified as an immediate-early gene rapidly induced by serum and growth factors, is a member of the steroid hormone nuclear receptor superfamily with no identified endogenous ligand. NGFI-B induces apoptosis in a number of cell lineages exposed to proapoptotic stimuli by directly targeting the mitochondria, inducing cytochrome c release. The present study was designed to determine the role of NGFI-B in cardiomyocytes of restraint-stressed rats. The NGFI-B content was increased in mitochondria and reduced in plasma as apoptosis increased. Analysis showed that NGFI-B induces cardiomyocyte apoptosis in restraint-stressed rats by mediating mitochondrial energy metabolism disorder. Several novel mitochondrial proteins, which correlate with NGFI-B, were reported in cardiomyocyte apoptosis of restraint-stressed rats. Five proteins associated with NGFI-B participate directly in mitochondrial energy metabolism. Studies of mitochondrial respiratory efficiency and ATP synthase activity strongly support the findings. These results provide significant information for comprehensively understanding the cellular mechanism of cardiovascular diseases.     

Antimicrobial activity of essential oils and structurally related synthetic food additives towards Clostridium perfringens

Aims:  To assess the potential of essential oils and structurally related synthetic food additives in inhibiting the growth of Clostridium perfringens for the control of necrotic enteritis in chickens.
Methods and Results:  The antimicrobial activity of essential oils/compounds was measured by determining the inhibition of bacterial growth. Thirty-three of 66 oils/compounds exhibited ≥80% inhibition. Seven with the highest potency were further studied. The oils/compounds had MIC₉₅ values between 167 and 425  μ g ml⁻¹. Most of them were tolerant to low pH (2·0) and exhibited minor or no inhibition of Lactobacillus isolates from the chicken intestine. When mixed with chicken ileal digesta, the oils/compounds retained their efficacy against C . perfringens , but had little effect on the total number of lactobacilli and anaerobic bacteria in the digesta.
Conclusions:  Some essential oils/compounds demonstrated good potential in controlling C . perfringens .
Significance and Impact of the Study:  This study has identified candidates of essential oils/compounds for in vivo studies for the control of necrotic enteritis in chickens.     

Spatial distribution as a measure of conservation needs: an example with Asiatic black bears in south-western China

Aim To create a fine‐scale map of the distribution of Asiatic black bears, identify landscape variables affecting the spatial range of this species and assess population trends using presence–absence data and opinions of local villagers. Location Sichuan Province, south‐western China. Methods We divided the province into 15 × 15 km cells, stratified them by forest cover, elevation and road density and randomly selected 494 cells (21% of province) for surveys. In each cell, we interviewed villagers and ground‐verified their reports of bear presence. We ground‐truthed reports of bear absence by conducting transects for bear sign in the best available habitat. We used logistic regression to identify key variables affecting presence of bears and predict their occurrence in unsampled cells. Results We detected bears in 360 cells (73%). Models correctly predicted bear occurrence in 90.3% of cells where we detected bears and 84.5% of sampled cells where bears were absent. Models predicted 42.7% of Sichuan to be occupied by bears. Bear occurrence was strongly related to forest cover throughout the province. Roads had a negative effect in western region of province. Agricultural lands had a negative effect only when they were distant from forests. Villagers were accurate in their knowledge of bear presence or absence. Interviewed villagers (n = 1816) thought that bears were increasing in 32%, stable in 10%, and decreasing in 58% of cells with bears. Where bear populations were perceived to be declining, villagers identified poaching as the most common cause. Main conclusions Our fine‐scale distribution map can be used for future monitoring and the key landscape factors related to occupancy by bears can be used in management plans for this species. Interviewing local villagers is an efficient and reliable means of assessing distribution, and changes therein, for animals such as bears that often interact with people and leave obvious signs.     

基于微藻的水产养殖废水处理技术研究进展

摘要：利用微藻处理水产养殖废水是一项污水资源化生物技术。近年来,国内外开展了大量有关藻类培养和废水处理的研究,发展了藻类处理技术,包括藻类塘、活性藻、固定化藻类、光生物反应器。本文综述了微藻净化水产养殖废?水的原理、研究成果及应用实例,并对今后的研究方向提出了建议。     

Quercetin up-regulates paraoxonase 1 gene expression with concomitant protection against LDL oxidation

Paraoxonase 1 (PON1) protects the oxidative modification of low-density lipoprotein (LDL) and is a major anti-atherosclerotic protein component of high-density lipoprotein (HDL). Quercetin, a ubiquitous plant flavonoid, has been shown to have a number of bioactivities and may offer a variety of potential therapeutic uses. We explored the roles of quercetin in the regulation of PON1 expression, serum and liver activity and protective capacity of HDL against LDL oxidation in rats. Compared to the pair-fed control group, feeding quercetin (10 mg/L) in the liquid diet for 4 weeks increased (a) hepatic expression of PON1 by 35% (p < 0.01), (b) serum and liver PON1 activities by 29% (p < 0.05) and 57% (p < 0.01), respectively, and (c) serum homocysteine thiolactonase (HCTL) activity by 23% (p < 0.05). Correspondingly, the lag time of low-density lipoprotein (LDL) oxidation was increased by >3-fold (p < 0.001) with plasma HDL from quercetin-fed group compared to the HDL from control group. Our data suggest that quercetin has antiatherogenic effect by up regulating PON1 gene expression and its protective capacity against LDL oxidation.