[Analysis and prospect of correlation between relative molecular weight and efficacy of polysaccharides from medicinal plant resources].

Polysaccharides from medicinal plant resources are a kind of polymers extracted from medicinal plants. They are complex long chains formed by different monosaccharides connected via glucosidic bonds. These polysaccharides usually have straight chain and branched chain structures, and their relative molecular weight changes greatly. Modern studies have shown that the biological activi-ty of polysaccharides from medicinal plant resources is closely related to their relative molecular weight. This paper first reviewed the preparation and detection methods of polysaccharides from medicinal plant resources with different relative molecular weights. Then, the paper summarized and analyzed the general experience of the correlation between efficacy and relative molecular weight of polysaccharides from medicinal plant resources with different molecular weights. It was considered that polysaccharides with large relative molecular weights(>100 kDa) play a leading role in immune regulation. Polysaccharides with medium relative molecular weights(10-100 kDa) play a leading role in immune regulation and the protection of the liver. Polysaccharides with small relative molecular weights(<10 kDa) play a leading role in anti-oxidation, regulation of intestinal flora, regulation of blood glucose and lipids, anti-fatigue, and the protection of nerves. Therefore, precise development of polysaccharides from medicinal plant resources based on relative molecular weight is expected to improve their biological activity and application value.

Comparison of content-toxicity-activity of six ingenane-type diterpenoids between Euphorbia kansui before and after stir-fried with vinegar by using UFLC-MS/MS, zebrafish embryos and HT-29 cells.

The dried roots of Euphorbia kansui (EK) are especially beneficial for the treatment of edema, but the severe toxicity limits their clinical applications. Euphorbia kansui stir-fried with vinegar (VEK) is traditionally employed to reduce the toxicity of EK. However, the material basis for the toxicity reduction with effectivity conservation is still unclear. Therefore, in this study, a rapid, sensitive, and reliable ultra-fast liquid chromatography tandem mass spectrometry (UFLC-MS/MS) method was firstly established to simultaneously determine six ingenane-type diterpenoids, i.e. kansuiphorin C (1), 5-O-benzoyl-20-deoxyingenol (2), 20-deoxyingenol (3), 3-O-(2'E,4'E-decadienoyl)-20-O-acetylingenol (4), 20-O-(2'E,4'Z-decadienoyl)ingenol (5), and ingenol (6), in EK and VEK based on the processing conversion. Then, the toxicity evaluation on zebrafish embryos and modulation of the expression of aquaporin-3 (AQP3) proteins in HT-29 cells were employed to investigate the toxicity-activity of six compounds. Chromatographic separation was obtained on Waters BEH RP18 column (2.1 mm × 100 mm, 2.5 µm) with the mobile phase composed of 0.1 % formic acid in acetonitrile and water, respectively. The column temperature was 35 ℃ at a flow rate of 0.4 mL min-1. Multiple reaction monitoring was conducted in both positive and negative modes for quantitative analysis. The method was then successfully used for the determination of six compounds in EK and VEK. In addition, 1, 2, 4, and 5 had evident cardiotoxicity, intestinal irritation and nutrient absorption disorders on zebrafish larvae, while no in-vivo toxicity was seen for groups given 3 and 6 (LC50 > 200 µM). Meanwhile, 1, 2, 4, 5, and 6 significantly increased the expression of AQP3 protein (p < 0.05) to promote the excretion of water in the colon. This study demonstrated that toxic ingenane-type diterpenoids converted into the less toxic compounds with the same core structure through the breakage of multiple ester bonds in the side chain. At the same time, the laxative effect was retained, providing useful information for the optimization of the process of EK and quality evaluation of other similar toxic Chinese herbal medicines.

[Short-term effects of litter treatment on soil C and N transformation and microbial community structure in Erythrophleum fordii plantation.] / æž¯è½ç‰©å¤„ç†å¯¹æ ¼æœ¨æž—åœŸå£¤ç¢³æ°®è½¬åŒ–å’Œå¾®ç”Ÿç‰©ç¾¤è½ç»“æž„çš„çŸ­æœŸå½±å“.

In southern subtropical China, the seasonal variations of soil carbon (C) and nitrogen (N) transformation rates and microbial community structure under different litter treatments (control, litter removal, litter double) in Erythrophleum fordii plantation were studied by the methods of barometric process separation (BaPS) and phospholipid fatty acids (PLFAs) profiles. The results showed that there were significant seasonal variations in soil respiration and gross nitrification rates under different litter treatments, with significantly higher rates in the rainy season than in the dry season. In the initial stage of litter treatment, soil respiration and gross nitrification rates decreased with increasing litter inputs. With prolonged litter treatment, both of them increased with increasing litter inputs. The total microbial PLFAs and each microbial group PLFAs under different litter treatments were significantly higher in the dry season than those in the rainy season. The fungal PLFAs/bacterial PLFAs in the rainy season were significantly higher than that in the dry season. In the dry season, litter removal significantly increased the total microbial PLFAs, bacterial PLFAs, fungal PLFAs and arbuscular mycorrhizal fungal (AMF) PLFAs by 30.9%, 28.8%, 44.4% and 31.6%, respectively. In the rainy season, litter removal significantly decreased the bacterial PLFAs and AMF PLFAs by 10.6% and 33.3%, respectively. Soil microbial community structure was affected by both litter input treatments and seasons. Soil temperature and NH4+-N were the key determinants influencing the microbial community structure. The litter input treatments in E. fordii plantation had significant impacts on soil C and N transformation rate and microbial community structure in short-term, which were dependent on seasons.

Stimulation of ganglionated plexus attenuates cardiac neural remodeling and heart failure progression in a canine model of acute heart failure post-myocardial infarction.

BACKGROUND: Heart failure (HF) is associated with autonomic dysfunction. Vagus nerve stimulation has been shown to improve cardiac function both in HF patients and animal models of HF. The purpose of this present study is to investigate the effects of ganglionated plexus stimulation (GPS) on HF progression and autonomic remodeling in a canine model of acute HF post-myocardial infarction. METHODS AND RESULTS: Eighteen adult mongrel male dogs were randomized into the control (n=8) and GPS (n=10) groups. All dogs underwent left anterior descending artery ligation followed by 6-hour high-rate (180-220bpm) ventricular pacing to induce acute HF. Transthoracic 2-dimensional echocardiography was performed at different time points. The plasma levels of norepinephrine, B-type natriuretic peptide (BNP) and Ang-II were measured using ELISA kits. C-fos and nerve growth factor (NGF) proteins expressed in the left stellate ganglion as well as GAP43 and TH proteins expressed in the peri-infarct zone were measured using western blot. After 6h of GPS, the left ventricular end-diastolic volume, end-systolic volume and ejection fraction showed no significant differences between the 2 groups, but the interventricular septal thickness at end-systole in the GPS group was significantly higher than that in the control group. The plasma levels of norepinephrine, BNP, Ang-II were increased 1h after myocardial infarction while the increase was attenuated by GPS. The expression of c-fos and NGF proteins in the left stellate ganglion as well as GAP43 and TH proteins in cardiac peri-infarct zone in GPS group were significantly lower than that in control group. CONCLUSIONS: GPS inhibits cardiac sympathetic remodeling and attenuates HF progression in canines with acute HF induced by myocardial infarction and ventricular pacing.

Global transcriptome and gene regulation network for secondary metabolite biosynthesis of tea plant (Camellia sinensis).

BACKGROUND: Major secondary metabolites, including flavonoids, caffeine, and theanine, are important components of tea products and are closely related to the taste, flavor, and health benefits of tea. Secondary metabolite biosynthesis in Camellia sinensis is differentially regulated in different tissues during growth and development. Until now, little was known about the expression patterns of genes involved in secondary metabolic pathways or their regulatory mechanisms. This study aimed to generate expression profiles for C. sinensis tissues and to build a gene regulation model of the secondary metabolic pathways. RESULTS: RNA sequencing was performed on 13 different tissue samples from various organs and developmental stages of tea plants, including buds and leaves of different ages, stems, flowers, seeds, and roots. A total of 43.7 Gbp of raw sequencing data were generated, from which 347,827 unigenes were assembled and annotated. There were 46,693, 8446, 3814, 10,206, and 4948 unigenes specifically expressed in the buds and leaves, stems, flowers, seeds, and roots, respectively. In total, 1719 unigenes were identified as being involved in the secondary metabolic pathways in C. sinensis, and the expression patterns of the genes involved in flavonoid, caffeine, and theanine biosynthesis were characterized, revealing the dynamic nature of their regulation during plant growth and development. The possible transcription factor regulation network for the biosynthesis of flavonoid, caffeine, and theanine was built, encompassing 339 transcription factors from 35 families, namely bHLH, MYB, and NAC, among others. Remarkably, not only did the data reveal the possible critical check points in the flavonoid, caffeine, and theanine biosynthesis pathways, but also implicated the key transcription factors and related mechanisms in the regulation of secondary metabolite biosynthesis. CONCLUSIONS: Our study generated gene expression profiles for different tissues at different developmental stages in tea plants. The gene network responsible for the regulation of the secondary metabolic pathways was analyzed. Our work elucidated the possible cross talk in gene regulation between the secondary metabolite biosynthetic pathways in C. sinensis. The results increase our understanding of how secondary metabolic pathways are regulated during plant development and growth cycles, and help pave the way for genetic selection and engineering for germplasm improvement.

Phosphorus metabolism and population dynamics in a biological phosphate-removal system with simultaneous anaerobic phosphate stripping.

In this study, the metabolism of phosphorus and changes in population dynamics were investigated via simultaneous chemical stripping in sidestream in an acetate-fed sequencing batch reactor. The synthesized intracellular polyphosphate (poly-P) by polyphosphate-accumulating organisms (PAOs) gradually decreased when the biomass was subjected to 83 d of P stripping. Initially, the P removal efficiency of the system improved from 94.3% to 96.9%. Thereafter, a relatively high level of P in effluent was observed, during which time the stoichiometric ratios of Prelease/HAcuptake decreased, Glycogendegraded/HAcuptake and poly-ß-hydroxyvalerate/PHA increased. The results revealed that a metabolic shift from polyphosphate-accumulating metabolism to glycogen-accumulating metabolism. Correspondingly, PAOs declined to less than 1% of the population, glycogen-accumulating organisms proliferated to almost 20% instead. The results of PCR­DGGE also indicated that the microbial community structure considerably changed in response to the gradually decreasing poly-P content. These findings imply that intracellular poly-P level is important for the stable of P removal system. Furthermore, it suggests that it is not a stable and effective way for P recycling from anaerobic stage of the biological P removal system in sidestream.

[Characteristics of soil microbial biomass and community composition in three types of plantations in southern subtropical area of China].

By using fumigation-extraction method and phospholipid fatty acids (PLFAs) analysis, this paper studied the characteristics of soil microbial biomass and community composition in the Erythrophleum fordii, Castanopsis hystrix, and Pinus massoniana plantations in south subtropical China. The soil microbial biomass, total PLFAs, bacterial PLFAs, and fungal PLFAs in the plantations were significantly affected by the plantation type and season, and the soil microbial biomass, total PLFAs, and individual PLFA signatures were higher in dry season than in rainy season. The C. hystrix plantation had the highest soil microbial biomass carbon and total PLFAs, while the E. fordii plantation had the highest soil microbial biomass nitrogen. There was a significant positive correlation between the soil pH and arbuscular mycorrhizal fungal (AMF) PLFA (16:1omega5c). The soil total PLFAs, gram-positive bacterial PLFAs, saprophytic fungal PLFA (18:2omega6,9c), and the ratio of gram-positive to gram-negative bacterial PLFAs were significantly positively correlated with soil organic carbon, total nitrogen, and total phosphorus, suggesting that the soil organic carbon, total nitrogen, and total phosphorus contents were the most important nutrient factors affecting the numbers and types of the soil microorganisms. In addition, the ectomycorrhizae fungal PLFA (18:1omega9c) and AMF PLFA were significantly correlated with the soil C/N ratio.

[Applicability of lives saved tool in projecting effects of scaling up interventions on reducing maternal mortality rates in the rural area of Guangxi province in China].

OBJECTIVE: To evaluate applicability of lives saved tool (LiST) in projecting effects of maternal health interventions on reducing maternal mortality in the rural area of Guangxi Zhuang Autonomous Region in China, and provide evidence for promoting LiST in China. METHODS: By using maternal intervention coverage and other information collected through the cross-sectional household survey, literature review and expert consultation, LiST projection was performed and modeled. The maternal mortality reduction and causes of death were measured and compared, and the differences were analyzed. SPSS 19.0 was used in the household survey data analysis. RESULTS: Coverage of calcium supplementation, MgSO4-management of pre-eclampsia and institutional delivery reached 51.9%, 99.0% and 98.4% respectively in rural Guangxi in 2011. The LiST captured the general trend of maternal mortality in rural Guangxi. The modeled maternal mortality rate was 4.71%, lower than the measured in 2009 and 10.43% higher in 2010. Maternal mortality rate would decreased to 18/100 000 in 2015 assuming all relevant interventions reached full coverage, and 90% of the maternal morality reduction was attributed to the labor and delivery management. CONCLUSION: LiST can be applied to project effects of maternal health interventions on reducing the maternal mortality in rural Guangxi, but its accuracy was limited by the fact that the effect of relevant interventions on some major causes of maternal death, such as amniotic embolism, was not calculated in LiST and maternal deaths caused by those causes varied by the year in the area. Based on the LiST projection, labor and delivery management was found to be the priority intervention in improving maternal health in rural Guangxi. Improving the quality of obstetric care in township hospitals and facilitating referral of high-risk pregnant women were highly recommended.

SUI-family genes encode phosphatidylserine synthases and regulate stem development in rice.

In vascular plants, the regulation of stem cell niche determines development of aerial shoot which consists of stems and lateral organs. Intercalary meristem (IM) controls internode elongation in rice and other grasses, however little attention has been paid to the underlying mechanism of stem cell maintenance. Here, we investigated the stem development in rice and showed that the Shortened Uppermost Internode 1 (SUI1) family of genes are pivotal for development of rice stems. We demonstrated that SUI-family genes regulate the development of IM for internode elongation and also the cell expansion of the panicle stem rachis in rice. The SUI-family genes encoded base-exchange types of phosphatidylserine synthases (PSSs), which possessed enzymatic activity in a yeast complementary assay. Overexpression of SUI1 and SUI2 caused outgrowths of internodes during vegetative development, and we showed that expression patterns of Oryza Sativa Homeobox 15 (OSH15) and Histone4 were impaired. Furthermore, genome-wide gene expression analysis revealed that overexpression and RNA knockdown of SUI-family genes affected downstream gene expression related to phospholipid metabolic pathways. Moreover, using Ultra-performance liquid chromatography-quadrupole time of flight-mass spectrometry, we analyzed PS contents in different genetic backgrounds of rice and showed that the quantity of very long chain fatty acids PS is affected by transgene of SUI-family genes. Our study reveals a new mechanism conveyed by the SUI1 pathway and provides evidence to link lipid metabolism with plant stem cell maintenance.

Optimizing de novo transcriptome assembly from short-read RNA-Seq data: a comparative study.

BACKGROUND: With the fast advances in nextgen sequencing technology, high-throughput RNA sequencing has emerged as a powerful and cost-effective way for transcriptome study. De novo assembly of transcripts provides an important solution to transcriptome analysis for organisms with no reference genome. However, there lacked understanding on how the different variables affected assembly outcomes, and there was no consensus on how to approach an optimal solution by selecting software tool and suitable strategy based on the properties of RNA-Seq data. RESULTS: To reveal the performance of different programs for transcriptome assembly, this work analyzed some important factors, including k-mer values, genome complexity, coverage depth, directional reads, etc. Seven program conditions, four single k-mer assemblers (SK: SOAPdenovo, ABySS, Oases and Trinity) and three multiple k-mer methods (MK: SOAPdenovo-MK, trans-ABySS and Oases-MK) were tested. While small and large k-mer values performed better for reconstructing lowly and highly expressed transcripts, respectively, MK strategy worked well for almost all ranges of expression quintiles. Among SK tools, Trinity performed well across various conditions but took the longest running time. Oases consumed the most memory whereas SOAPdenovo required the shortest runtime but worked poorly to reconstruct full-length CDS. ABySS showed some good balance between resource usage and quality of assemblies. CONCLUSIONS: Our work compared the performance of publicly available transcriptome assemblers, and analyzed important factors affecting de novo assembly. Some practical guidelines for transcript reconstruction from short-read RNA-Seq data were proposed. De novo assembly of C. sinensis transcriptome was greatly improved using some optimized methods.

[Cloning and expression of L-like cysteine protease of Anisakis simplex].

OBJECTIVE: To clone and express the full lenth of L-like cysteine protease gene of Anisakis simplex (AsCP). METHODS: According to L-like cysteine protease encoding gene of A. simplex from GenBank EST database, specific primers were designed to amplify 3'-end of AsCP gene using rapid-amplification of cDNA ends (RACE), and the full lenth of the L-like cysteine protease gene was obtained. Specific primers were designed according to the full length of the gene. Using total RNA of A. simplex third-stage larvae, coding sequence of the AsCP gene was amplified by RT-PCR. The PCR product was digested by EcoR I and Sal I, and cloned into pET32a(+) vector. The recombinant plasmid was checked by double enzyme digestion and sequencing, and the positive recombinant plasmid was transformed into Escherichia coli BL21 (DE3). Expression of the protein induced by IPTG of gradient concentration (0.2, 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2 mmol/L) and by the same concentration (1 mmol/L) of IPTG at different time(0, 1, 1.5, 2, 2.5, 3, 3.5, and 4 h) was conducted. The expression situation of recombinant protein was analyzed by SDS-PAGE. RESULTS: A 1211 bp of 3'-end of AsCP gene was amplified by 3'RACE, full length of the gene was 1462 bp and coding 411 amino acids. It showed 36.4% identity with the L-cysteine protease of Caenorhabditis elegans. Double enzyme digestion of the constructed recombinant plasmid pET32a(+)-AsCP showed that there was about 1150 bp fragment, the constructed recombinant plasmid was then identified by sequencing. SDS-PAGE showed that the recombinant protein (Mr 60,000) was identical with the target. IPTG showed little effect on the protein expression, and the production of protein was up to maximum after 2 hours induction. CONCLUSION: The AsCP gene has been cloned and expressed.

Modeling the heat transfer problem for the novel combined cryosurgery and hyperthermia system.

A multidimensional, finite element analysis (FEA) for the freezing, holding, rewarming and heating processes of biological tissues during the cryosurgery process of the new Combined Cryosurgery/Hyperthermia System is presented to theoretically test its validity. The tissues are treated as nonideal materials freezing over a temperature range, and the thermophysical properties of which are temperature dependent. The enthalpy method is applied to solve the highly nonlinear problem. It was found that when the same boundary condition and the same target tissue presented, the novel Cryosurgery/Hyperthermia System could supply the target tissue an approximative cooling rate, a much lower minimal temperature, a much greater warming rate, and a much greater thermal gradients compared with that of the simplified Endocare system. The numerical simulation indicates that the novel combined cryosurgery and hyperthermia system can provide an excellent curative effect in the corresponding cryotherapy. And the most attractive feature of this FEA framework is that it can be easily mastered by the surgeon without in-depth theory of heat transfer to analyze the cryosurgery process beforehand due to the friendly GUI (graphical user interface) of Ansys software.

OsPIPK 1, a rice phosphatidylinositol monophosphate kinase, regulates rice heading by modifying the expression of floral induction genes.

A rice gene, OsPIPK 1, encoding a 792-aa putative phosphatidylinositol 4-phosphate 5-kinase (PIPK), was identified and characterized. Comparison between the cDNA and genomic sequences revealed the presence of 10 exons (39-1050 bp) and 9 introns (88-745 bp) in OsPIPK 1 gene. The deduced amino acid sequence of OsPIPK1 contains a lipid kinase domain that is highly homologous to those of previously isolated PIPKs, and structural analysis revealed the intriguing presence of multiple MORN motifs at the N-terminus. The MORN motifs have also been detected in PIPKs from Arabidopsis thaliana and Oryza sativa, but not in the well-characterized PIPKs from animal and yeast cells. RT-PCR analysis indicated that OsPIPK 1 was expressed almost constitutively in roots, shoots, stems, leaves and flowers, and up-regulated following treatment with plant hormones or application of various stresses. An antisense transgenic strategy was used to suppress the expression of OsPIPK 1, and homozygous transgenic plants showed earlier heading (7-14 days earlier) than control plants, suggesting that OsPIPK 1 negatively regulates floral initiation. This was further confirmed by morphologic observation showing earlier floral development in antisense plants, as well as leaf emergence measurement indicating delayed leaf development under OsPIPK 1 deficiency, a common phenotype observed with earlier flowering. RT-PCR analysis and cDNA chip technology were used to examine transcripts of various genes in the transgenic plants and the results showed altered transcriptions of several flowering-time or -identity related genes, suggesting that OsPIPK 1 is involved in rice heading through regulation of floral induction genes, signaling and metabolic pathways.

Gibberellin regulates Arabidopsis floral development via suppression of DELLA protein function.

The phytohormone gibberellin (GA) regulates the development and fertility of Arabidopsis flowers. The mature flowers of GA-deficient mutant plants typically exhibit reduced elongation growth of petals and stamens. In addition, GA-deficiency blocks anther development, resulting in male sterility. Previous analyses have shown that GA promotes the elongation of plant organs by opposing the function of the DELLA proteins, a family of nuclear growth repressors. However, it was not clear that the DELLA proteins are involved in the GA-regulation of stamen and anther development. We show that GA regulates cell elongation rather than cell division during Arabidopsis stamen filament elongation. In addition, GA regulates the cellular developmental pathway of anthers leading from microspore to mature pollen grain. Genetic analysis shows that the Arabidopsis DELLA proteins RGA and RGL2 jointly repress petal, stamen and anther development in GA-deficient plants, and that this function is enhanced by RGL1 activity. GA thus promotes Arabidopsis petal, stamen and anther development by opposing the function of the DELLA proteins RGA, RGL1 and RGL2.