钙调素化学发光标记的研究

用发光物质N-氨基丁基N-乙基异鲁米诺(ABEI),采用碳二亚胺缩合法,成功地标记了动物及植物钙调素(CaM),标记率为[ABEI]/[CaM]≈0.8-0.9.对ABEI标记CaM的反应条件、结合物的质量和保存时间进行了观察.此标记物稳定,-20℃可保存10个月以上,适用于化学发光免疫法测定生物样品中CaM含量.     

Novel quantitative trait loci (QTL) for Fusarium head blight resistance in wheat cultivar Chokwang

Fusarium head blight (FHB) is one of the most destructive diseases in wheat. This study was to identify new quantitative trait loci (QTL) for FHB resistance and the molecular markers closely linked to the QTL in wheat cultivar Chokwang. The primers of 612 simple sequence repeats (SSRs) and 12 target-region-amplified polymorphism (TRAP) marker were analyzed between resistant (Chokwang) and susceptible (Clark) parents. One hundred and seventy-two polymorphic markers were used to screen a population of 79 recombinant inbred lines (RILs) derived from the cross of Chokwang and Clark. One major QTL, Qfhb.ksu-5DL1, was identified on chromosome 5DL. The SSR marker Xbarc 239 was mapped in the QTL region, and also physically located to the bin of 5DL1-0.60-0.74 by using Chinese Spring deletion lines. Another QTL Qfhb.ksu-4BL1was linked to SSR Xbarc 1096 and tentatively mapped on 4BL. A QTL on 3BS, Qfhb.ksu-3BS1, was also detected with marginal significance in this population. Different marker alleles for these QTL were detected between Chokwang and Sumai 3 and its derivatives. These results suggested that Chokwang contains new QTL for FHB resistance that are different from those in Sumai 3. Pyramiding resistance QTL from various sources may enhance FHB resistance in wheat cultivars.     

Population Differences in Brain Morphology and Microstructure among Chinese,Malay, and Indian Neonates

We studied a sample of 75 Chinese, 73 Malay, and 29 Indian healthy neonates taking part in a cohort study to examine potential differences in neonatal brain morphology and white matter microstructure as a function of ethnicity using both structural T2-weighted magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). We first examined the differences in global size and morphology of the brain among the three groups. We then constructed the T2-weighted MRI and DTI atlases and employed voxel-based analysis to investigate ethnic differences in morphological shape of the brain from the T2-weighted MRI, and white matter microstructure measured by fractional anisotropy derived from DTI. Compared with Malay neonates, the brains of Indian neonates’ tended to be more elongated in anterior and posterior axis relative to the superior-inferior axis of the brain even though the total brain volume was similar among the three groups. Although most anatomical regions of the brain were similar among Chinese, Malay, and Indian neonates, there were anatomical variations in the spinal-cerebellar and cortical-striatal-thalamic neural circuits among the three populations. The population-related brain regions highlighted in our study are key anatomical substrates associated with sensorimotor functions.     

Transarterial chemoembolization combined with sorafenib for unresectable hepatocellular carcinoma: a systematic review and meta-analysis

Sorafenib in combination with Transarterial chemoembolization (TACE) is increasingly used in patients with unresectable hepatocellular carcinoma (HCC), but the current evidence is still controversial. The aim of this systematic review was to evaluate the effectiveness and safety of TACE plus sorafenib versus TACE alone for unresectable HCC. We searched PubMed, EMBASE and the Cochrane Library for clinical trials comparing TACE plus sorafenib with TACE alone for unresectable HCC. The study outcomes included overall survival (OS), time to progression (TTP), objective response and adverse events (AEs). Six studies including 1,181 patients were included. Meta-analysis of all studies suggested that the combination therapy group had significant longer OS than TACE group [hazard ratio (HR) = 0.64, 95 % confidence interval (CI) = 0.43–0.97], but the pooled HR of randomized controlled trials (RCTs) failed to achieve statistical significance. For TTP, meta-analysis in both RCTs subgroup and retrospective studies subgroup suggested that combination therapy was superior to TACE group. The combination therapy was also associated with better response to treatment (risk ratio = 1.45, 95 % CI = 1.04–2.02) when both RCTs and retrospective studies were pooled. However, the sorafenib associated AEs were more frequent in the combination therapy group. In conclusion, the combination of TACE and sorafenib is likely to improve OS, TTP and response to treatment when compared with TACE monotherapy. The combination group is also associated with more sorafenib-related AEs.     

Refolding and purification of recombinant human (Pro)renin receptor from Escherichia coli by ion exchange chromatography

Purification of the recombinant human renin receptor (rhRnR) is a major aspect of its biological or biophysical analysis, as well as structural research. A simple and efficient method for the refolding and purification of rhRnR expressed in Escherichia coli with weak anion‐exchange chromatography (WAX) was presented in this work. The solution containing denatured rhRnR in 8.0 mol/L urea extracted from the inclusion bodies was directly injected into the WAX column. The aggregation was prevented and the soluble form of renatured rhRnR in aqueous solution was obtained after desorption from the column. Effects of the extracting solutions, the pH values and urea concentrations in the mobile phase, as well as the sample size on the refolding and purification of rhRnR were investigated, indicating that the above mentioned factors had remarkable influences on the efficiency of refolding, purification and mass recovery of rhRnR. Under the optimal conditions, rhRnR was successfully refolded and purified simultaneously by WAX in one step within only 30 min. The result was satisfactory with mass recovery of 71.8% and purity of 94.8%, which was further tested by western blotting. The specific binding of the purified rhRnR to recombinant human renin was also determined using surface plasmon resonance (SPR). The association constant of rhRnR to recombinant human renin was calculated to be 3.25 × 10⁸ L/mol, which demonstrated that rhRnR was already renatured and simultaneously purified in one step using WAX. All of the above demonstrate that protein folding liquid chromatography (PFLC) should be a powerful tool for the purification and renaturation of rhRnR. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:864–871, 2014     

Shorter GT repeat polymorphism in the heme oxygenase-1 gene promoter has protective effect on ischemic stroke in dyslipidemia patients

Background  

The microsatellite polymorphism of heme oxygenase (HO)-1 gene promoter has been shown to be associated with the susceptibility to ischemic event, including coronary artery disease (CAD), myocardial infarction, and peripheral vascular disease. We aimed to examine whether the length of (GT)_n repeats in HO-1 gene promoter is associated with ischemic stroke in people with CAD risk factors, especially low level of HDL.     

长白山阔叶红松林乔木树种幼苗组成及其年际动态

为了解阔叶红松(Pinus koraiensis)林乔木树种幼苗的组成及其年际动态, 以长白山阔叶红松林25 ha动态监测样地为平台, 在样地内150个种子收集器周围设置了600个5 m×5 m幼苗样方。基于2006–2008年连续3年的幼苗样方调查数据, 对乔木幼苗的树种组成、数量组成、空间分布特征、年际动态、新增和死亡幼苗组成等进行了分析。结果表明: (1)从树种组成来看, 该群落乔木树种的幼苗组成种类较为丰富, 共记录到21个树种, 这些树种也是样地内胸径1 cm以上乔木树种的主要组成成分。树种组成在年际间变化不大, 但各样方间表现出极大的空间变异。(2)从数量组成来看, 共记录到11,959株乔木幼苗, 以水曲柳(Fraxinus mandshurica)和紫椴(Tilia amurensis)幼苗数最多, 占总幼苗数的72.75%; 水曲柳、紫椴和红松的幼苗数量在年际间有明显波动, 其他树种年际间波动较小。(3)从新增和死亡幼苗的数量与组成来看, 共记录到15个乔木树种的新增幼苗, 其中紫椴、水曲柳、色木槭(Acer mono)、红松等10个树种在每次调查中都有新苗记录, 新苗数量在年际间随物种和样方位置表现出明显差异。(4)对各树种的幼苗、种子和大树的组成和空间分布的比较发现, 各树种的幼苗、种子和大树之间的数量组成和比例差异较大, 其中紫椴、水曲柳、色木槭和假色槭(A. pseudo-sieboldianum)的幼苗、种子在整个样地内都有分布, 春榆(Ulmus japonica)和怀槐(Maackia amurensis)幼苗的空间分布与种子和大树不一致, 糠椴(T. mandshurica)和山丁子(Malus baccata)等的幼苗、种子和大树的个体数相对都较少, 且它们的分布是一致的。     

Pea powdery mildew <Emphasis Type="Italic">er1</Emphasis> resistance is associated to loss-of-function mutations at a <Emphasis Type="Italic">MLO</Emphasis> homologous locus

The powdery mildew disease affects several crop species and is also one of the major threats for pea (Pisum sativum L.) cultivation all over the world. The recessive gene er1, first described over 60 years ago, is well known in pea breeding, as it still maintains its efficiency as a powdery mildew resistance source. Genetic and phytopathological features of er1 resistance are similar to those of barley, Arabidopsis, and tomato mlo powdery mildew resistance, which is caused by the loss of function of specific members of the MLO gene family. Here, we describe the obtainment of a novel er1 resistant line by experimental mutagenesis with the alkylating agent diethyl sulfate. This line was found to carry a single nucleotide polymorphism in the PsMLO1 gene sequence, predicted to result in premature termination of translation and a non-functional protein. A cleaved amplified polymorphic sequence (CAPS) marker was developed on the mutation site and shown to be fully co-segregating with resistance in F₂ individuals. Sequencing of PsMLO1 from three powdery mildew resistant cultivars also revealed the presence of loss-of-function mutations. Taken together, results reported in this study strongly indicate the identity between er1 and mlo resistances and are expected to be of great breeding importance for the development of resistant cultivars via marker-assisted selection.