Calculation of an Adequate Intake (AI) Value and Safe Range of Selenium (Se) for Chinese Infants 0–3 Months Old Based on Se Concentration in the Milk of Lactating Chinese Women with Optimal Se Intake

Biological Trace Element Research - The required selenium intake for optimal health in Chinese residents was published in 2014. However, the adequate intake (AI) value for Chinese infants...     

Antiinflammatory Activity of a Novel Folic Acid Targeted Conjugate of the mTOR Inhibitor Everolimus

Folate receptor (FR)-β has been identified as a promising target for antimacrophage and antiinflammatory therapies. In the present study, we investigated EC0565, a folic acid–derivative of everolimus, as a FR-specific inhibitor of the mammalian target of rapamycin (mTOR). Because of its amphiphilic nature, EC0565 was first evaluated for water solubility, critical micelle formation, stability in culture and FR-binding specificity. Using FR-expressing macrophages, the effect of EC0565 on mTOR signaling and cellular proliferation was studied. The pharmacokinetics, metabolism and bioavailability of EC0565 were studied in normal rats. The in vivo activity of EC0565 was assessed in rats with adjuvant arthritis, a “macrophage-rich” model with close resemblance to rheumatoid arthritis. EC0565 forms micellar aggregates in physiological buffers and demonstrates good water solubility as well as strong multivalent FR-binding capacity. EC0565 inhibited mTOR signaling in rat macrophages at nanomolar concentrations and induced G0/G1 cell cycle arrest in serum-starved RAW264.7 cells. Subcutaneously administered EC0565 in rats displayed good bioavailability and a relatively long half-life (~12 h). When given at 250 nmol/kg, EC0565 selectively inhibited proliferating cell nuclear antigen expression in thioglycollate-stimulated rat peritoneal cells. With limited dosing regimens, the antiarthritic activity of EC0565 was found superior to that of etanercept, everolimus and a nontargeted everolimus analog. The in vivo activity of EC0565 was also comparable to that of a folate-targeted aminopterin. Folate-targeted mTOR inhibition may be an effective way of suppressing activated macrophages in sites of inflammation, especially in nutrient-deprived conditions, such as in the arthritic joints. Further investigation and improvement upon the physical and biochemical properties of EC0565 are warranted.     

Accumulation of β-catenin by lithium chloride in porcine myoblast cultures accelerates cell differentiation

The Wnt/β-catenin signaling pathway regulates cell proliferation and differentiation to determine cell fate during embryogenesis. Lithium chloride (LiCl) is known to activate canonical Wnt signaling by inhibiting glycogen synthetase kinase-3β and consequently stabilizing free cytosolic β-catenin. To understand the role of the Wnt/β-catenin pathway in the regulation of porcine myoblast differentiation, we studied the effects of LiCl on cultured porcine myoblasts and β-catenin expression. A supplementation of 25 mM LiCl induced myoblast differentiation into myotubes over 3 days of culture. By semi-quantitative RT-PCR analyses, levels of mRNA encoding MyoD, Myogenin, Myf5 and several Wnt-responsive genes in the cultured myoblast cells were significantly increased after LiCl treatment. Using Western blotting and immunofluorescence analysis, we found that the protein levels of β-catenin were consistently increased by LiCl. Meanwhile, phosphorylated GSK-3β at Ser9 levels were also increased as an indicator of GSK-3β inactivation. Additionally, the nuclear staining of endogenous β-catenin was also significantly increased in porcine myoblasts 48 h after LiCl treatment. These results provided additional evidence that Wnt/β-catenin is a significant pathway that regulates myogenic differentiation. An enhanced level of β-catenin plays a positive role in porcine myoblast differentiation.     

根据cpDNA trnL-F非编码区序列变异分析黑桫椤海南和广东种群的遗传结构与系统地理

以黑桫椤分布在海南和广东 9个种群为材料 ,通过 PCR产物直接测序和克隆后再测序的方法测定了叶绿体 DNA(cp DNA) trn L- F非编码区序列。序列长度介于 10 17bp至 10 2 1bp;碱基组成 A T含量较高 ,百分比值为 6 0 .4 3%～ 6 2 .2 6 %。根据序列的核苷酸变异共鉴定出 15个单倍型。黑桫椤具高水平单倍型多样性 (h=0 .880 )和较高水平核苷酸多样性 (Dij=0 .0 0 342 ) ,其悠长的进化历史可能增加了遗传变异在谱系内的积累。单倍型最小生成网图和邻接树、种群间分化度 (FST=0 .12 6 4 5 )和基因流 (N m=3.4 9)、AMOVA分析 (地区间遗传变异占 11.91% ,p>0 .0 5 )以及 DNA歧义度结果一致显示 ,黑桫椤分布在海南和广东的种群彼此间不存在遗传分化。黑桫椤单倍型的系统发育地理式样具“星状”特征 ,提示种群在历史上曾经发生过扩张 ,扩张后的种群还未能获得足够时间去建立更加复杂的结构     

孑遗植物桫椤种群遗传变异的RAPD分析

应用 RAPD标记分析了桫椤分布在海南尖峰岭及霸王岭 ,广东塘朗山、黑石顶及大西山孑遗种群的遗传变异。 2 8个引物共检测到 1 1 8个位点 ,其中多态位点 33个 ,多态位点比率 2 7.97%。Shannon多样性、Nei遗传分化和分子方差分析 ( AMOVA)结果一致显示尖峰岭种群遗传多样性最大 ,霸王岭种群次之、塘郎山种群第三 ,黑石顶种群第四 ,而大西山种群最小。种群的遗传变异主要发生在种群间 ;Shannon指数测出的种群间遗传多样性所占比率为 79.1 0 % (基于表型频率 )和 77.85 % (基于基因频率 ) ,Nei基因分化系数 ( Gst)达 80 .69% ,分子方差分析也表明种群分化极为显著 ( Φst=0 .82 86,P<0 .0 0 1 )。桫椤的种内遗传多样性水平很低 ,种内 Shannon多样性仅为 0 .0 641 (基于表型频率 )和 0 .1 1 2 4 (基于基因频率 ) ,总基因多样性只有 0 .0 770。另外 ,Jaccard相似性系数的 UPGMA分析结果显示 5个种群分为两个分支 :尖峰岭种群和霸王岭种群组成一分支 ;黑石顶、塘郎山和大西山种群组成另一分支 ,并且三者中前两者的遗传关系更为密切。聚类分析结果还得到主成分分析的支持。根据桫椤种群的遗传变异特点 ,初步探讨了保护策略。     

Synthesis and cytotoxicity of diam(m)ineplatinum(II) complexes with 2,2-bis(hydroxymethyl)malonate as the leaving group

Six diam(m)ineplatinum(II) complexes with 2,2-bis(hydroxymethyl)malonate as the leaving group were synthesized and characterized by elemental analysis, FAB-MS, FT-IR, (1)H and (13)C NMR along with a single crystal X-ray diffraction for a representative compound. All the complexes were evaluated for the cytotoxicity against human cancer cell lines A549/ATCC, HT-29, SGC-7901. The activity is related to the nature of the am(m)ine ligand. cis-[Pt(II)(1R,2R-Diaminocyclohexane)·2,2-bis(hydroxymethyl)malonate] (complex 5) exhibits the greatest activity among those six complexes, and is even more active than its parent compound oxaliplatin. LD(50) was found to be 115 mg/kg by iv administration to ICR mice, much larger than that of oxaliplatin (LD(50)=19 mg/kg).     

酿酒葡萄品质评价及其对气象条件的响应

根据2004～2005年我国北方6省酿酒葡萄主要产区葡萄取样和宁夏芦花台园艺场田间试验葡萄化验结果，运用层次分析方法（AHP）对酿酒葡萄主要品质因子总糖、糖酸比pH、单宁进行综合评价，运用主成分分析方法和因子分析法研究影响每个地区酿酒葡萄综合品质的主要气象因子和影响时段。结果表明：2004～2005年贺兰山东麓的御马、玉泉营、广夏三基地、贺东在庄园；河西走廊的高台、武威；新疆石河子酿酒葡萄品质优良，渤海湾的烟台、蓬莱、昌藜等地酿酒葡萄品质表现一般。酿酒葡萄综合品质主要受果实着色期、全生育期和7～8月的降水量和水热系数的影响，其中降水量起主导作用。果实着色期气温日较差和全生育期平均相对湿度对酿酒葡萄综合品质的形成也有重要影响，影响相对较小的是果实着色期的最低气温。采样地区的光照、温度等气象条件基本适宜酿酒葡萄品质形成，对优质酿酒葡萄形成没有大的限制作用。