响应面分析法优化当归粗多糖提取工艺

选取岷县当归药材为原料,采用水提醇沉法进行多糖提取,以当归粗多糖得率为指标,探讨加水量、回流提取时间、水提液的浓缩比、醇沉后所达含醇比例对当归多糖得率的影响。在单因素分析的基础上,采用响应面分析法(RSM)确定了当归粗多糖最佳提取条件为:加水量837.6 mL/100 g,浓缩后溶液体积为228.12 mL,最终含乙醇浓度为65.80%,回流提取时间2 h,在此条件下预测当归粗多糖得率理论的最佳值为10.44%,实际验证值为10.40%,两者相符,说明RSM法分析的可靠性。     

A specific PCR assay for the diagnosis of Clonorchis sinensis infection in humans, cats and fishes

Clonorchiasis caused by Clonorchis sinensis is a fish-borne parasitic disease which is endemic in a number of countries. Using the sequences of the internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA (rDNA) of C. sinensis as genetic markers, a pair of C. sinensis-specific primers was designed and used to establish a specific PCR assay for the diagnosis of C. sinensis infection in humans, cats and fish. This approach allowed the specific identification of C. sinensis after optimizing amplification conditions, with no amplicons being amplified from related heterogeneous DNA samples, and sequencing of amplicons confirmed the identity of the sequences amplified. The detection limit of this assay was 1.03 pg of adult C. sinensis, 1.1 metacercariae per gram of fish filet, and a single egg in human and cat feces. The PCR assay should provide a useful tool for the diagnosis and molecular epidemiological investigation of clonorchiasis in humans and animals.     

Phospholipase D1 downregulation by α-synuclein: Implications for neurodegeneration in Parkinson's disease

We have previously shown that phospholipase D (PLD) pathways have a role in neuronal degeneration; in particular, we found that PLD activation is associated with synaptic injury induced by oxidative stress. In the present study, we investigated the effect of α-synuclein (α-syn) overexpression on PLD signaling. Wild Type (WT) α-syn was found to trigger the inhibition of PLD1 expression as well as a decrease in ERK1/2 phosphorylation and expression levels. Moreover, ERK1/2 subcellular localization was shown to be modulated by WT α-syn in a PLD1-dependent manner. Indeed, PLD1 inhibition was found to alter the neurofilament network and F-actin distribution regardless of the presence of WT α-syn. In line with this, neuroblastoma cells expressing WT α-syn exhibited a degenerative-like phenotype characterized by a marked reduction in neurofilament light subunit (NFL) expression and the rearrangement of the F-actin organization, compared with either the untransfected or the empty vector-transfected cells. The gain of function of PLD1 through the overexpression of its active form had the effect of restoring NFL expression in WT α-syn neurons. Taken together, our findings reveal an unforeseen role for α-syn in PLD regulation: PLD1 downregulation may constitute an early mechanism in the initial stages of WT α-syn-triggered neurodegeneration.     

Epithelial cell adhesion molecule (EpCAM) is associated with prostate cancer metastasis and chemo/radioresistance via the PI3K/Akt/mTOR signaling pathway

Prostate cancer (CaP) is the second leading malignancy in men. The role of epithelial cell adhesion molecule (EpCAM), also known as CD326, in CaP progression and therapeutic resistance is still uncertain. Here, we aimed to investigate the roles of EpCAM in CaP metastasis and chemo/radioresistance. Expression of EpCAM in CaP cell lines and human CaP tissues was assessed using immunofluorescence and immunohistochemistry, respectively. EpCAM was knocked down (KD) in PC-3, DU145 and LNCaP-C4-2B cells using small interfering RNA (siRNA), and KD results were confirmed by confocal microscope, Western blotting and quantitative real time polymerase chain reaction (qRT-PCR). Cell growth was evaluated by proliferation and colony formation assays. The invasive potential was assessed using a matrigel chamber assay. Tumorigenesis potential was measured by a sphere formation assay. Chemo-/radiosensitivity were measured using a colony formation assay. Over-expression of EpCAM was found in primary CaP tissues and lymph node metastases including cancer cells and surrounding stromal cells. KD of EpCAM suppressed CaP proliferation and invasive ability, reduced sphere formation, enhanced chemo-/radiosensitivity, and down-regulated E-cadherin, p-Akt, p-mTOR, p-4EBP1 and p-S6K expression in CaP cells. Our findings suggest that EpCAM plays an important role in CaP proliferation, invasion, metastasis and chemo-/radioresistance associated with the activation of the PI3K/Akt/mTOR signaling pathway and is a novel therapeutic target to sensitize CaP cells to chemo-/radiotherapy.     

Non‐native mangroves support carbon storage,sediment carbon burial,and accretion of coastal ecosystems

Mangrove forests play an important role in climate change adaptation and mitigation by maintaining coastline elevations relative to sea level rise, protecting coastal infrastructure from storm damage, and storing substantial quantities of carbon (C) in live and detrital pools. Determining the efficacy of mangroves in achieving climate goals can be complicated by difficulty in quantifying C inputs (i.e., differentiating newer inputs from younger trees from older residual C pools), and mitigation assessments rarely consider potential offsets to CO₂ storage by methane (CH₄) production in mangrove sediments. The establishment of non‐native Rhizophora mangle along Hawaiian coastlines over the last century offers an opportunity to examine the role mangroves play in climate mitigation and adaptation both globally and locally as novel ecosystems. We quantified total ecosystem C storage, sedimentation, accretion, sediment organic C burial and CH₄ emissions from ~70 year old R. mangle stands and adjacent uninvaded mudflats. Ecosystem C stocks of mangrove stands exceeded mudflats by 434 ± 33 Mg C/ha, and mangrove establishment increased average coastal accretion by 460%. Sediment organic C burial increased 10‐fold (to 4.5 Mg C ha^?1 year^?1), double the global mean for old growth mangrove forests, suggesting that C accumulation from younger trees may occur faster than previously thought, with implications for mangrove restoration. Simulations indicate that increased CH₄ emissions from sediments offset ecosystem CO₂ storage by only 2%–4%, equivalent to 30–60 Mg CO₂‐eq/ha over mangrove lifetime (100 year sustained global warming potential). Results highlight the importance of mangroves as novel systems that can rapidly accumulate C, have a net positive atmospheric greenhouse gas removal effect, and support shoreline accretion rates that outpace current sea level rise. Sequestration potential of novel mangrove forests should be taken into account when considering their removal or management, especially in the context of climate mitigation goals.     

沉香叶提取工艺及其抗氧化活性实验研究

采用单因素分析方法和正交试验法研究沉香叶提取工艺并评价沉香叶的体外抗氧化活性.沉香叶的最佳提取工艺为:以15倍量的60％乙醇为溶剂,超声提取40 min,提取1次.野生沉香叶和栽培沉香叶的氧化时间分别为(11.53±0.08)s和(9.98±0.16)s;超氧阴离子的清除率分别为(36.26±0.96)％和(35.67±1.25)％,总还原力的吸光度分别为0.188±0.008和0.129±0.011.该提取工艺简单、重复性好、提取液抗氧化活性强、工艺稳定、无污染;野生沉香叶和栽培沉香叶均具有较好的体外抗氧化活性.     

白木香组织培养及快速繁殖

白木香腋芽外植体在含０．０５ｍｇ／ＬＢＡＰ的ＭＳ基本培养基上增殖系数为４．９３。采用间接法诱导芽生根,生根率达９４．４％。白木香试管苗移栽成活率为９３．８％。     

Genetic diversity in three colonizing orchids with contrasting mating systems

Comparative studies on the genetic attributes of colonizing orchids with diverse mating systems are lacking in the literature. Eulophia sinensis, Spiranthes hongkongensis, and Zeuxine strateumatica are colonizing orchids that frequently occupy newly created habitats in Hong Kong. Mating system studies showed that E. sinensis is a self-compatible but pollinator-dependent outcrossing species, S. hongkongensis is a self-pollinating taxon, and Z srateumatica is apomictic. Population genetic attributes of these orchid species were investigated. Despite their contrasting mating systems, electrophoretic surveys revealed a striking lack of allozyme variation, both within and among populations, in all three species. However, gene duplications were evident in these species, due to their likely polyploid origins, The percentage of duplicate loci exhibiting "fixed heterozygosity" was 10, 21.4, and 20% in E. sinensis, S. hongkongensis, and Z. strateumatica, respectively. The genetic attributes of these orchids are compared to those found in other colonizing plant species.