Diet composition of post-metamorphic bullfrogs (Rana catesbeiana) in the Zhoushan archipelago, Zhejiang Province, China

Bullfrogs (Rana catesbeiana) are listed as one of the 100 worst invasive alien species in the world. They are generalist predators and thus may affect native species through predation. In previous studies, the food contents of bullfrogs were mostly examined at a single site. In the present study, the diet composition of post-metamorphic bullfrogs on eight islands (Daishan, Liuheng, Xiushan, Fodu, Taohua, Xiashi, Cezi, and Putuoshan) in the Zhoushan Archipelago, Zhejiang Province of China, were examined by using the stomach flushing method from June 30 to August 11 in 2005. A total of 391 individual frogs were measured, including 113 adults and 278 juveniles. The analysis of the stomach contents shows that, for adult bullfrogs, the most important prey (by diet volume) overall were Decapoda, Coleoptera, Odonata, Mesogastropoda, Raniformes, and Cypriniformes. For juvenile bullfrogs, these were Decapoda, Coleoptera, Cypriniformes, Odonata, Orthoptera, Hymenoptera, Lepidoptera larvae, Mesogastropoda, and Raniformes. Moreover, the prey size and diet volume increased with the body size of both adult and juvenile bullfrogs. The diet composition of primary preys of bullfrogs was significantly different among the islands. The results indicate that bullfrogs exert different predatory influences on native fauna at different sites and that bullfrogs are generalist predators with extensive ecological impacts on native fauna. __________ Translated from Biodiversity Science, 2006, 14 (5): 363–371 [译自: 生 物多样性]     

Breeding ecology and oviposition site selection of black-spotted pond frogs (Rana nigromaculata) in Ningbo, China

The black-spotted pond frog (Rana nigromacu-lata) is one of the most widely distributed species in China. However, there have been only a few qualitative descrip-tions of their breeding ecology and oviposition site selec-tion. From 2004 to 2006, we investigated the breeding ecology and oviposition site selection of K nigromaculata in Ningbo, China, quantitatively. Analyses of breeding ecology show that: (1) mean frog density in the breeding season was 0.0903 ± 0.0029 individuals per meter (n = 11) (mean ± SE); (2) R. nigromaculata was a sexually dimorphic species, with females significantly larger than males in both body weight and snout-vent length; (3) the clutch size averaged 4643.04± 235.96 eggs (range 1546-7897, n = 50); and (4) the egg size ranged from 1.50 to 1.74 mm in diameter, with an average egg size of 1.6050 ± 0.0046 mm (n = 226). Oviposition sites differed significantly from random sites in percentages of water, bare ground and vegetation cover, water depth (cm), water temperature (°C) and water turbidity. Rana nigro-maculata preferred microhabitats with higher percentages of water and vegetation cover, while it avoided microha-bitats with deeper water. The results suggest that micro-habitats with higher percentages of water and vegetation cover, but not deeper water, should be priorities for pro-tection and conservation of the breeding habitats of R. nigromaculata.     

Differential cardiovascular effects of synthetic peptides derived from endomorphin-1 in anesthetized rats

Previously, five synthetic peptides derived from endomorphin-1 (Tyr¹-Pro²-Trp³-Phe⁴-NH₂, EM-1), including Tyr-d-Ala-Trp-p-Cl-Phe-NH₂ (HDAPC), Tyr-d-Ala-Trp-Phe-NH₂ (HDADC), N-amidino-Tyr-d-Ala-Trp-p-Cl-Phe-NH₂ (GDAPC), N-amidino-Tyr-d-Ala-Trp-Phe-NH₂ (GDADC) and N-amidino-Tyr-d-Pro-Gly-Trp-p-Cl-Phe-NH₂ (GBDPC), were described to elicit analgesia by subcutaneous administration with enhanced metabolic stabilities. To further our knowledge of the influences of particular modification on the pharmacological activities of EM-1, the present study was undertaken to investigate cardiovascular effects of these peptides in anesthetized rats by intravenous injection. Our results showed that the four d-Ala-containing peptides decreased the systemic arterial pressure (SAP) and heart rate (HR) through a naloxone-sensitive mechanism. Different patterns, potencies and durations of cardiovascular effects were observed among these peptides. When compared to EM-1, the hemodynamic responses to these four tetrapeptides were significantly lower in magnitude but much longer in duration. Surprisingly, intravenous administration of the only pentapeptide GBDPC produced fairly prolonged hypertensive and tachycardiac effects, which was naloxone-insensitive, thus providing evidence that changes in the primary structure of a peptide can profoundly affect its pharmacological activity. Comparisons of the cardiovascular effects between these peptides showed that each modification introduced into EM-1, including N-amidination, chloro-halogenation and unnatural amino acid substitution, played a role in the influence on the cardiovascular regulation of these peptides.     

Structure-based design and structure-activity relationships of 1,2,3,4-tetrahydroisoquinoline derivatives as potential PDE4 inhibitors

This paper describes our medicinal chemistry efforts on 7-(cyclopentyloxy)-6-methoxy1,2,3,4-tetrahydroisoquinoline scaffold: design, synthesis and biological evaluation using conformational restriction approach and bioisosteric replacement strategy. Biological data revealed that the majority of the synthesized compounds of this series displayed moderate to potent inhibitory activity against PDE4B and strong inhibition of LPS-induced TNFα release. Among them, compound 19 exhibited the strongest inhibition against PDE4B with an IC₅₀ of 0.88?µM and 21 times more potent selectivity toward PDE4B over PDE4D when compared to rolipram. A primary structure-activity relationship study showed that the attachment of CH₃O group or CF₃O group to the phenyl ring at the para-position was helpful to enhance the inhibitory activity against PDE4B. Moreover, sulfonamide group played a key role in improving the inhibitory activity against PDE4B and subtype selectivity. In addition, the attachment of the additional rigid substituents at the C-3 position of 1,2,3,4-tetrahydroisoquinoline ring was favored to subtype selectivity, which was consistent well with the observed docking simulation.     

A Multi‐Omics Analysis of Glycine max Leaves Reveals Alteration in Flavonoid and Isoflavonoid Metabolism Upon Ethylene and Abscisic Acid Treatment

Phytohormones are central to plant growth and development. Despite the advancement in our knowledge of hormone signaling, downstream targets, and their interactions upon hormones action remain largely fragmented, especially at the protein and metabolite levels. With an aim to get new insight into the effects of two hormones, ethylene (ET) and abscisic acid (ABA), this study utilizes an integrated proteomics and metabolomics approach to investigate their individual and combined (ABA+ET) signaling in soybean leaves. Targeting low‐abundance proteins, our previously established protamine sulfate precipitation method was applied, followed by label‐free quantification of identified proteins. A total of 4129 unique protein groups including 1083 differentially modulated in one (individual) or other (combined) treatments were discerned. Functional annotation of the identified proteins showed an increased abundance of proteins related to the flavonoid and isoflavonoid biosynthesis and MAPK signaling pathway in response to ET treatment. HPLC analysis showed an accumulation of isoflavones (genistin, daidzein, and genistein) upon ET treatment, in agreement with the proteomics results. A metabolome analysis assigned 79 metabolites and further confirmed the accumulation of flavonoids and isoflavonoids in response to ET. A potential cross‐talk between ET and MAPK signaling, leading to the accumulation of flavonoids and isoflavonoids in soybean leaves is suggested.     

Association Between Chronic Exposure to Tobacco Smoke and Accumulation of Toxic Metals in Hair Among Pregnant Women

Tobacco smoke contains various toxic heavy metals that individuals are exposed to when they smoke. Despite the presence of heavy metals in tobacco smoke, the relationship between smoking and the accumulation of toxic metals in pregnant women after long-term exposure remains under discussion. We examined the association between long-term exposure to tobacco smoke and the accumulation of toxic metals in the hair of female participants. Our study recruited 252 women from the Shanxi and Hebei provinces of Northern China; these participants were self-reported non-active smokers, and had previously delivered healthy babies without birth defects. Scalp hair was collected and analyzed for nicotine and cotinine and five potentially toxic metals (specifically, silver, chromium, cadmium, mercury, and lead). Our results showed significant positive correlations between cotinine and four metals, including silver (r?=?0.369, p?<?0.001), cadmium (r?=?0.185, p?<?0.01), mercury (r?=?0.161, p?<?0.05), and lead (r?=?0.243, p?<?0.001). Significant positive correlations were also found between nicotine and three metals—specifically silver (r?=?0.331, p?<?0.001), cadmium (r?=?0.176, p?<?0.01), and lead (r?=?0.316, p?<?0.001). A logistic regression model showed significant associations between cotinine and potentially toxic metals including mercury, silver, and lead (with or without adjusting for potential confounders). We thus conclude that long-term passive smoking could potentially increase the exposure level of toxic metals including lead, silver, and mercury in our study, which are especially harmful for pregnant women and their unborn fetus.     

Optimization of culturing conditions for production of somatic embryos and lignins of <Emphasis Type="Italic">Schisandra chinensis</Emphasis> (Turcz.) Baill

Schisandra chinensis (Turcz.) Baill. is a valuable medicinal plant species increasingly used in phytotherapy worldwide. This study systematically detected the lignin content and production during somatic embryogenesis of S. chinensis. The effect of various culture parameters on biomass accumulation and lignin production were also examined to optimize the accumulation of lignins in SEs in bioreactors, including the culture method, inoculum density, aeration volume and photoperiod. An inoculum density of 20 g L^??1 embryogenic calli enhanced production of lignin, while 30 g L^??1 embryogenic calli increased the biomass of somatic embryos. During somatic embryo induction, an aeration volume of 0.2 vvm and photoperiod of 16 h day^??1 were found to be optimal for biomass accumulation and lignin production. An approximately threefold increase in the biomass production rate and a fourfold increase in the total lignin production rate in SEs were achieved in bioreactors than on solid medium. The present study indicated, therefore, that the culturing of S. chinensis somatic embryos in bioreactors is an effective method for the industrialized production of lignin in vitro.     

肥大细胞对重组口蹄疫病毒VP1-VP4应答的蛋白质表达谱检测

为揭示肥大细胞抗口蹄疫病毒VP1-VP4蛋白的天然免疫作用,以重组口蹄疫病毒VP1-VP4蛋白刺激小鼠腹腔肥大细胞(Peritoneal mast cells,PMCs),用高通量ELISA芯片检测PMCs的蛋白质表达谱。结果显示,VP1-VP4蛋白刺激的PMCs(VP1-VP4组)表达CCL19、L-selectin、CCL17和TNF-α的水平极显著低于对照组(PMCs)(P0.001),而VP1-VP4蛋白刺激经甘露糖受体(Mannose receptor,MR)抑制剂预处理的PMCs(MR组)表达CCL19、IL-15、IL-9、G-CSF和Galectin-1的水平则极显著高于对照组(P0.01),IL-10表达水平也有显著升高(P0.05)。MR组与VP1-VP4组相比,PMCs表达IL-10、IL-17、CCL20、IL-15、IL-9、L-selectin、CCL17、TNF-α和CCL19的水平极显著升高(P0.01),CCL21和G-CSF的表达也显著高于VP1-VP4组(P0.05)。生物信息学差异表达分析结果显示,与对照组相比,VP1-VP4组PMCs表达的L-selectin和CCL17为下调性差异表达蛋白(Log2(ratio)≤–1)。MR组与VP1-VP4相比,PMCs表达的CCL20、CCL19、L-selectin和IL-15为上调性差异表达蛋白(Log_2(ratio)≥1)。这表明,PMCs可自发分泌CCL19、L-selectin、CCL17和TNF-α,而VP1-VP4则对PMCs的天然免疫功能具有抑制作用。由于阻断MR后PMCs的蛋白质表达水平显著升高,所以VP1-VP4对小鼠PMCs的免疫抑制作用可能是由MR介导的。     

Chemical speciation of cadmium and lead and their bioavailability to cole (Brassica campestris L.) from multi-metals contaminated soil in northwestern China

A pot experiment was conducted to study the relationship between speciation distribution of cadmium (Cd) and lead (Pb) and their availability to cole (Brassica campestris L.) grown on the Cd–Pb polluted soil in northwest of China. The results showed that Cd in the unpolluted soil was mainly bound to carbonate fraction (F2) and Fe–Mn oxide fraction (F3), and Pb was mainly bound to carbonate fraction (F2) and residual fraction (F5). However, marked change of Cd and Pb fractionation was observed with increasing soil Cd and Pb concentrations, where the concentrations of Cd in F1 (exchangeable fraction), F2 and F3 increased significantly (p < 0.001 for F1, F2 and F3), and Pb in F1, F2, F3 and F4 increased significantly (p < 0.001 for F1, F2, F3 and F4).The correlation analysis between the fraction distribution coefficient of Cd and Pb in the soil and Cd and Pb concentration accumulated in cole showed that both Cd and Pb in F1 fraction in the soil made the greatest contribution on the accumulation of Cd and Pb in cole. Higher bio-concentration factors (BCFs) and translocation factors (TFs) for Cd and lower BCFs and TFs for Pb were observed in the cole, respectively. Cd had higher accumulation in the edible parts of the cole, but Pb had lower accumulation in that. Therefore, Cd has higher risk to human health than Pb when people eat the coles grown in Cd–Pb polluted soil in northwestern China.