Genotyping over 100,000 SNPs on a pair of oligonucleotide arrays

We present a genotyping method for simultaneously scoring 116,204 SNPs using oligonucleotide arrays. At call rates >99%, reproducibility is >99.97% and accuracy, as measured by inheritance in trios and concordance with the HapMap Project, is >99.7%. Average intermarker distance is 23.6 kb, and 92% of the genome is within 100 kb of a SNP marker. Average heterozygosity is 0.30, with 105,511 SNPs having minor allele frequencies >5%.     

含铜抗菌不锈钢的抗菌性能研究

对铁素体和奥氏体2种含铜抗菌不锈钢的抗菌性能进行了考察.采用覆膜法检测抗菌率,用透射电镜观察与铁素体抗菌不锈钢作用后的大肠埃希菌细胞形态.2种抗菌不锈钢材料对供试的 17 株常见菌,除产气肠杆菌外均显示较强的抗菌性能,抗菌谱广;铁素体和奥氏体对1×107 cfu/mL及以下浓度的大肠埃希菌在 24 h内杀灭率达到99%;铁素体和奥氏体分别在作用 3 h和 9 h时可将1×107 cfu/mL的大肠埃希菌全部杀灭;打磨次数和环境温度的变化不影响2种抗菌不锈钢的杀菌率;透射电镜结果显示,与抗菌不锈钢作用后的大肠埃希菌菌体结构松散,细胞壁和细胞膜破裂,有内容物漏出.铁素体和奥氏体抗菌不锈钢均具优良的抗菌性能,抗菌谱广,与其作用后的细菌菌体破裂,有内容物溶出,最终致菌死亡.     

水稻田土-水系统中磷素行为及其环境影响研究

土壤测试表明供试土壤已富P.大田试验结果表明,P肥投入提高了土壤树脂P和田面水总P水平,且两者随着时间的推移而下降.但施P后的20d内,有机无机配施P肥对土壤有效P的贡献大于单施化肥P.在施P第7d时,有机无机配施P的田面水总P水平是单施化肥P的3.4倍,是施P量2倍的处理Ⅲ的2.8倍.与有机肥配施的处理,其田表水P素流失潜能较单施化肥大.经33d后,P肥结构对田面水P素的影响不明显.两次水稻季节性排水而导致的P素净流失负荷和P素表观流失率变幅分别为-0.038～0.076kg·hm^-2和0.034～0.100%.从减少水稻田排水P素流失角度考虑,可以认为,施P或土层被搅动后1周内是控制P素流失的主要环节.     

Protein synthesis at synapse versus cell body: Enhanced but transient expression of long‐term facilitation at isolated synapses

Protein synthesis at synaptic terminals contributes to LTP in hippocampus and to the formation of new synaptic connections by sensory neurons (SNs) of Aplysia. Here we report that after removal of the SN cell body, isolated SN synapses of Aplysia in culture express protein‐synthesis dependent long‐term facilitation (LTF) produced by 5‐HT that decays rapidly. Changes in expression of a SN‐specific neuropeptide sensorin in isolated SN varicosities parallel the changes in synaptic efficacy. At 24 h after 5‐HT the magnitude of LTF produced at isolated SN synapses was significantly greater than that produced when SN cell bodies were present. LTF was maintained at 48 h at connections with SN cell bodies, but not at isolated SN synapses. The increase in synaptic efficacy at isolated SN synapses at 24 h was blocked by the protein synthesis inhibitor anisomycin. LTF was accompanied by changes in expression of sensorin. The increase in sensorin level at isolated SN varicosities with 5‐HT was blocked by anisomycin or was reversed 48 h after 5‐HT treatment alone. The results suggest that, as is the case for initial synapse formation between SNs and L7, changes in protein synthesis at synaptic terminals may contribute directly to LTF of stable synapses. Changes in expression within the cell body provide additional contributions for long‐term maintenance of the new level of synaptic efficacy that was initiated directly by local changes in protein synthesis at or near synaptic terminals. © 2003 Wiley Periodicals, Inc. J Neurobiol 56: 275–286, 2003     

Intracoronary allogeneic cardiosphere‐derived stem cells are safe for use in dogs with dilated cardiomyopathy

Cardiosphere‐derived cells (CDCs) have been shown to reduce scar size and increase viable myocardium in human patients with mild/moderate myocardial infarction. Studies in rodent models suggest that CDC therapy may confer therapeutic benefits in patients with non‐ischaemic dilated cardiomyopathy (DCM). We sought to determine the safety and efficacy of allogeneic CDC in a large animal (canine) model of spontaneous DCM. Canine CDCs (cCDCs) were grown from a donor dog heart. Similar to human CDCs, cCDCs express CD105 and are slightly positive for c‐kit and CD90. Thirty million of allogeneic cCDCs was infused into the coronary vessels of Doberman pinscher dogs with spontaneous DCM. Adverse events were closely monitored, and cardiac functions were measured by echocardiography. No adverse events occurred during and after cell infusion. Histology on dog hearts (after natural death) revealed no sign of immune rejection from the transplanted cells.     

Neuroprotective drug riluzole amplifies the heat shock factor 1 (HSF1)- and glutamate transporter 1 (GLT1)-dependent cytoprotective mechanisms for neuronal survival

Heat shock factor 1 (HSF1) mediates the cellular response to stress to increase the production of heat shock protein (HSP) chaperones for proper protein folding, trafficking, and degradation; failure of this homeostatic mechanism likely contributes to neurodegeneration. We show that the neuroprotective drug riluzole increased the amount of HSF1 in NG108-15 neuroprogenitor cells by slowing the specific turnover of HSF1 and supporting a more robust and sustained activation of HSF1. Using Hsp70-luciferase as a functional readout of the activity of HSF1, we show that riluzole amplified the heat shock induction of the reporter gene with an optimal increase at 1 μM. Immunocytochemical staining and Western blot quantitation of HSP70 in NG108-15 neuroprogenitor cells and embryonic spinal cord neurons provided corroborative evidence that riluzole amplified the HSF1-dependent regulation of HSP70 expression. Parallel studies on the GLT1 glutamate transporter showed that riluzole increased GLT1-reporter and GLT1 protein expression and that the increase was enhanced by heat shock and coincident with the increased expression of HSP70 and HSP90. This result is consistent with the anti-glutamatergic profile of riluzole and the presence of multiple heat shock elements on the GLT1 gene promoter, suggesting that riluzole may modulate GLT1 expression through HSF1. The increased HSP chaperones and GLT1 transporter blunted glutamate-induced and N-methyl D-aspartate receptor-mediated excitotoxic death. In summary, we show that riluzole increased the amount and activity of HSF1 to boost the expression of HSPs and GLT1 for neuroprotection under stress.     

Phylogeography of Sophora davidii (Leguminosae) across the ‘Tanaka‐Kaiyong Line’, an important phytogeographic boundary in Southwest China

The ‘Tanaka‐Kaiyong Line’ (TKL) is a major phytogeographic boundary in Southwest China, separating East Asia's Sino‐Himalayan and Sino‐Japanese Floras. However, little is known about the importance of this boundary in promoting intraspecific phylogeographic subdivision and divergence. Using chloroplast (cpDNA) and nuclear‐intron (nDNA) sequence data, we reconstructed the population history of Sophora davidii, a drought‐tolerant riparian shrub widely distributed on either side of the TKL. Specifically, we aimed at testing two long‐standing explanations for possible vicariant events across the TKL: (i) Late Pliocene (c. 3 Ma) geological uplift of the eastern Qinghai‐Tibetan Plateau (QTP) or (ii) a sharp environmental gradient associated with the establishment of different monsoon regimes on either side of the TKL during the (Late) Pleistocene. Our genealogical analyses detected a major west–east split in cpDNA, geographically largely consistent with the TKL, and dated to c. 1.28 Ma (95% HPD: 0.21–2.96 Ma), hence postdating the latest phase of eastern QTP uplift. Furthermore, integrating cpDNA phylogeographic patterns with mismatch analyses, we found multiple refugial isolation and long‐term demographic stability of populations in the west (Hengduan Mountain Range) compared with extensive range expansions in the east, possibly during the last glacial period(s) and followed by differentiation into regional sublineages (southeast: Yunnan‐Guizhou Plateau vs. northeast: Qinling Mts./Loess Plateau). Although nuclear differentiation was less marked, the geographical pattern of nDNA haplotypes provided some further indication of the species' eastward expansion, possibly from source populations located just east of the TKL (lower Jinshajiang region). Overall, the present data reject the geological (tectonic) explanation for the TKL and, instead, provide supportive evidence for its role as a climatically driven barrier to present‐day plant dispersal. In addition, our study highlights changing temperatures and vegetation types during the last glacial period(s), along with aspects of regional topography, to be important determinants of the glacial eastward expansion of S. davidii. In consequence, our study lends support to a ‘glacial out‐of‐Hengduan Mts’. hypothesis for the xerophytic‐riparian flora of Southwest China, which in turn is inconsistent with the traditional view of the TKL as a ‘classical’ vicariant‐biogeographic boundary.