目的在32例年龄在60岁以上的慢性病贫血（anemia of chronic disease,AcD）患者中，应用重组人促红细胞生成素（recombinant human erythropoietin,rhEPO）治疗8周后测观察贫血改善情况，并筛选出具有较高临床意义的预测参数。方法32名...目的在32例年龄在60岁以上的慢性病贫血（anemia of chronic disease,AcD）患者中，应用重组人促红细胞生成素（recombinant human erythropoietin,rhEPO）治疗8周后测观察贫血改善情况，并筛选出具有较高临床意义的预测参数。方法32名AcD老年患者应用rhEPO治疗8周，8周内血红蛋白（hemoglobin，Hb）上升20g／L设为治疗有效。选用血清EPO水平、Hb、网状红细胞计数（reticulocyte count, Ret）、总铁结合力（total iron binding capacity,TIBC） 、血清铁（serum iron，SI）、血清铁蛋白（serum ferritin serum，SF）、可溶性转铁蛋白受体（serum transferrin receptor, sTfR）作为观测指标，观察患者8周时血红球蛋白的改变并进一步统计分析其与各观测指标变化之间的关系。结果32例老年AcD患者应用rhEPO治疗8周后Hb升高，SI、LgSF下降，sTfR升高（P〈0．05）。20例患者8周时获得预期疗效，多元回归分析提示rhEPO治疗8周后Hb改变与LgEPO及基线sTfR水平呈负相关（P〈0．05）。根据设定的评价方法将32例患者分为rhEPO治疗有效组及治疗无效组，绘制sTfR及LgEPO的受试者工作特征曲线（receiver operating characteristic curve, ROC曲线）并计算曲线下面积（area under the curve,AUC），后者具有统计学意义并且AUC更大（AUC为0．81，P〈0．05，95％CI：0．627～0．993），并通过最大Youden指数寻找到最佳诊断点为EPO≤58mIU／mL。如患者EPO≤58mIU／mL，可预测其能获得较好的治疗效果。结论rhEPO在老年慢性病贫血中可取得较好的治疗效果，患者的EPO水平是具有较高临床意义的预测参数。展开更多
目的建立上海地区儿童甲状腺功能检测指标——促甲状腺激素(TSH)、游离三碘甲状腺原氨酸(FT3)和游离甲状腺素(FT4)的参考区间。方法选取2014年8月至2015年7月于上海地区9家医院就诊的4 d^17岁健康儿童720名,按年龄分为6组,每组120名。...目的建立上海地区儿童甲状腺功能检测指标——促甲状腺激素(TSH)、游离三碘甲状腺原氨酸(FT3)和游离甲状腺素(FT4)的参考区间。方法选取2014年8月至2015年7月于上海地区9家医院就诊的4 d^17岁健康儿童720名,按年龄分为6组,每组120名。血液收集后离心,血清-20℃冷冻保存,使用贝克曼库尔特Uni Cel Dx I 800免疫分析系统进行测定。依据美国临床实验室标准化协会(CLSI)C28-A3文件及国际临床化学和检验医学联合会(IFCC)的相关要求制定参考区间的合理方法和可靠依据,以非参数法确定TSH、FT3和FT4的95%参考区间(百分位数范围为2.5%~9 7.5%,可信区间为9 0%)。结果各组按年龄段划分参考区间为:A组(4 d~<1个月),TSH 0.53~18.91μIU/m L,FT3 2.42~5.67 pmol/L,FT4 11.85~33.81 pmol/L;B组(1~<12个月),TSH0.7 5~5.7 5μI U/m L,F T3 4.2 1~8.1 6 p m o l/L,F T4 9.4 0~1 9.5 4 p m o l/L;C组(1~<5岁),T S H0.6 3~6.2 0μI U/m L,F T3 3.5 4~6.9 0 p m o l/L,F T4 9.3 2~1 8.4 0 p m o l/L;D组(5~<1 0岁),T S H0.58~5.39μIU/m L,FT3 3.97~7.83 pmol/L,FT4 10.65~19.23 pmol/L;E组(10~<14岁),TSH0.3 9~5.3 6μI U/m L,F T3 4.2 7~8.5 5 p m o l/L,F T4 9.8 0~1 9.6 4 p m o l/L。F组(1 4~1 7岁),T S H0.48~5.06μIU/m L,FT3 3.14~6.15 pmol/L,FT4 9.57~18.27 pmol/L。A组新生儿与相邻的B组参考区间分布比较,差异有统计学意义(Z>3);各组内不同性别间TSH、FT3、FT4水平比较,差异无统计学意义(P>0.05)。结论建立了上海地区4 d^17岁健康儿童按年龄分组TSH、FT3和FT4的参考区间。利用以上参考区间能够解释儿童甲状腺功能的检测结果,有助于诊断、治疗和监测甲状腺功能减低症、甲状腺功能亢进症、甲状腺炎、甲状腺肿及甲状腺肿瘤等疾病。展开更多
This article aims to discuss strategies to operate Moflo XDP high-speed sorting equipment for cell sorting and optimize the instrument to run in the best operating state.Using fluorescent microspheres to quickly calib...This article aims to discuss strategies to operate Moflo XDP high-speed sorting equipment for cell sorting and optimize the instrument to run in the best operating state.Using fluorescent microspheres to quickly calibrate the position of the main liquid flow and the laser beam,adjust the amplitude and frequency according to different size CytoNozzles to find the best breakoff point,and adjust the four-way side flow to achieve the stable maintaining of the equipment,so as to quickly sort sample at high-speed.The absence of air bubbles in the sheath liquid barrel and the liquid path is the key to achieving a stable sorting-maintaining in the sorting process.The accurate calculation of the breakoff point and drop delay is the key to improve sorting efficiency and cell activity.展开更多
Increased evidence shows that normal stem cells may contribute to cancer development and progression by acting as cancer-initiating cells through their interactions with abnormal environmental elements.We postulate th...Increased evidence shows that normal stem cells may contribute to cancer development and progression by acting as cancer-initiating cells through their interactions with abnormal environmental elements.We postulate that normal stem cells and cancer stem cells (CSC) possess similar mechanisms of self-renewal and differentiation.CSC can be the key to the elaboration of anti-cancer-based therapy.In this article,we focus on a controversial new theme relating to CSC.Tumorigenesis may have a critical stage characterized as a "therapeutic window",which can be identified by asso-ciation of molecular,biochemical and biological events.Identifying such a stage can allow the production of more effective therapies (e.g.manipulated stem cells) to treat several cancers.More importantly,confirming the existence of a similar therapeutic window during the conversion of normal stem cells to malignant CSC may lead to targeted therapy specifically against CSC.This conversion information may be derived from investigating the biological behaviour of both normal stem cells and cancerous stem cells.Currently,there is little knowledge about the cellular and molecular mechanisms that govern the initiation and maintenance of CSC.Studies on co-evolution and interdependence of cancer with normal tissues may lead to a useful treatment paradigm of cancer.The crosstalk between normal stem cells and cancer formation may converge developmental stages of different types of stem cells (e.g.normal stem cells,CSC and embryonic stem cells).The differential studies of the convergence may result in novel therapies for treating cancers.展开更多
Objective To examine the relationship between sex hormone–binding globulin (SHBG) and the metabolic syndrome (MetS) in pre-elderly and elderly men in China. Methods A cross-sectional studywas done among 437men, aged ...Objective To examine the relationship between sex hormone–binding globulin (SHBG) and the metabolic syndrome (MetS) in pre-elderly and elderly men in China. Methods A cross-sectional studywas done among 437men, aged 45 to 94 years old. Early morning fasting sera were assayed for total testosterone (TT), SHBG and other biochemical markers. Free testosterone (FT) was calculated. Results The SHBG level of the MetS group was significantly lower than those without MetS 35.70 (25.18, 47.10) nmol/L vs. 41.90 (31.80, 55.20) nmol/L; P < 0.001). As the number of MetS components increases, SHBG and TT levels became lower. SHBG correlated with age, as did TT and most of metabolic components. Body mass index (BMI), high density lipoprotein-cholesterol (HDL-C), triglyceride (TG), and TT remained independently associated with SHBG by multivariate regression analysis. In a logistic regression taking MetS as the dependent variable, SHBG (95% confidence interval (95% CI): 0.975��0.994, P = 0.018) and homeostasis model assessment for insulin resistance (HOMA-IR) (95%CI: 1.535��2.647, P < 0.001) were included in the final model. Conclusions Lower SHBG is independently associated with MetS among pre-elderly and elderly men. SHBG may be an independent predictor of MetS, but the mechanism of how SHBG is involved in MetS requires further studied.展开更多
Characterization of various nanoparticles is on the center stage in nanotechnology development. The subjects for nanoparticles characterization are focused on particle size and particle surface charge determinations. ...Characterization of various nanoparticles is on the center stage in nanotechnology development. The subjects for nanoparticles characterization are focused on particle size and particle surface charge determinations. This article summarizes the latest development in particle size analysis using dynamic light scattering and surface charge determination using electrophoretic light scattering for nano-or even sub-nanoparticles in concentrated suspensions.展开更多
Pretreatment of lower H2O2 doses （0.05, 0.5 and 5 mM） for 24 h was able to dose-dependently attenuate lipid peroxidation in wheat seedling leaves mediated by further oxidative damage elicited by higher dose of H2O2 ...Pretreatment of lower H2O2 doses （0.05, 0.5 and 5 mM） for 24 h was able to dose-dependently attenuate lipid peroxidation in wheat seedling leaves mediated by further oxidative damage elicited by higher dose of H2O2 （150 mM） for 6 h, with 0.5 mM H2O2 being the most effective concentrations. Further results illustrated that 0.5 mM H2O2 pretreatment triggered the biphasic production of H2O2 during a 24 h period. We also noticed that only peak Ⅰ （0.25 h） rather than peak Ⅱ （4 h） was approximately consistent with the enhancement of heme oxygenase （HO） activity, HO-1 gene expression. Meanwhile, enhanced superoxide dismutase （SOD） activity, Mn-SOD and Cu, Zn-SOD transcripts might be a potential source of peak Ⅰ of endogenous H2O2. Further results confirmed that 0.5 mM H2O2 treatment for 0.5 h was able to upregulate HO gene expression, which was detected by enzyme activity determination, semi-quantitative reverse transcription-polymerase chain reaction and western blotting. Meanwhile, the application of N,N＇-dimethylthiourea, a trap for endogenous H2O2, not only blocked the upregulation of HO, but also reversed the corresponding oxidation attenuation. Together, the above results suggest that endogenous H2O2 production （peak Ⅰ） plays a positive role in the induction of HO by enhancing its mRNA level and protein expression, thus leading to the acclimation to oxidative stress.展开更多
Heme oxygenase-1 （HO-1） has been recently identified as an endogenous signaling system in animals. In this study, HO-1 upregulation and its role in acquired salt tolerance （salinity acclimation） were investigated ...Heme oxygenase-1 （HO-1） has been recently identified as an endogenous signaling system in animals. In this study, HO-1 upregulation and its role in acquired salt tolerance （salinity acclimation） were investigated in wheat plants. We discovered that pretreatment with a low concentration of NaCl （25 mmol/L） not only led to the induction of HO-1 protein and gene expression, as well as enhanced HO activity, but also to a salinity acclimatory response thereafter. The effect is specific for HO-1, since the potent HO-1 inhibitor zinc protoporphyrin IX blocks the above cytoprotective actions, and the cytotoxic responses conferred by 200 mmol/L NaCl are reversed partially when HO-1 inducer hemin is added. Heme oxygenase catalytic product, carbon monoxide （CO） aqueous solution pretreatment, mimicked the salinity acclimatory responses. Meanwhile, the CO-triggered re-establishment of reactive oxygen species （ROS） homeostasis was mainly guaranteed by the induction of total and isozymatic activities, or corresponding transcripts of superoxide dismutase, ascorbate peroxidase, and cytosolic peroxidase （POD）, as well as the downregulation of NADPH oxidase expression and cell-wall POD activity. A requirement of hydrogen peroxide homeostasis for HO-1-mediated salinity acclimation was also discovered. Taken together, the above results suggest that the upregulation of HO-1 expression was responsible for the observed salinity acclimation through the regulation of ROS homeostasis.展开更多
The Pto protein kinase from Solanum pimpinellifolium interacts with Pseudomonas syringae effectors AvrPto or AvrPtoB to activate effector-triggered immunity. The previously solved crystal structures of the AvrPto-Pto ...The Pto protein kinase from Solanum pimpinellifolium interacts with Pseudomonas syringae effectors AvrPto or AvrPtoB to activate effector-triggered immunity. The previously solved crystal structures of the AvrPto-Pto and AvrPtoB-Pto complexes revealed that Pro binds each effector through both a shared and a unique interface. Hera we use natural variation in wild species of tomato to further investigate Pto recognition of these two effectors. One species, Solanum chmielewskU, was found to have many accessions that recognize only AvrPtoB. The Pto ortholog from one of these accessions was responsible for recognition of AvrPtoB and it differed from Solanum pimpinellifolium Pto by only 14 amino acids, including two in the AvrPto-specific interface, glutamate-49/glycine-51. Converting these two residues to those in Pro （histidine-49/valine-51） did not restore recognition of AvrPto. Subsequent experiments revealed that a single substitution of a histidine-to-aspartate at position 193 in Pto, which is not near the AvrPto- specific interface, was sufficient for conferring recognRion of AvrPto in plant cells. The reciprocal substi- tution of aspartate-to-histidine-193 in Pto abolished AvrPto recognition, confirming the importance of this residue. Our results reveal new aspects about effector recognition by Pto and demonstrate the value of using natural variation to understand the interaction between resistance proteins and pathogen effectors.展开更多
The empirical Complex Model developed by the US Environmental Protection Agency （EPA） is used by refiners to predict the toxic emissions of reformulated gasoline with respect to gasoline properties. The difficulty i...The empirical Complex Model developed by the US Environmental Protection Agency （EPA） is used by refiners to predict the toxic emissions of reformulated gasoline with respect to gasoline properties. The difficulty in implementing this model in the blending process stems from the implicit definition of Complex Model through a series of disjunctions assembled by the EPA in the form of spreadsheets. A major breakthrough in the refinery-based Complex Model implementation occurred in 2008 and 2010 through the use of generalized disjunctive and mixed- integer nonlinear programming （MINLP）. Nevertheless, the execution time of these MINLP models remains prohibitively long to control emissions with our online gasoline blender. The first objective of this study is to present a new model that decreases the execution time of our online controller. The toxic thresholds as hard second objective is to consider constraints to be verified and search for blends that verify them. Our approach introduces a new way to write the Complex Model without any binary or integer variables. Sigmoid functions are used herein to approximate step functions until the measurement precision for each blend property is reached. By knowing this level of precision, we are able to propose an extremely good and differentiable approximation of the Complex Model. Next, a differentiable objective function is introduced to penalize emission values higher than the threshold emissions. Our optimization module has been implemented and tested with real data. The execution time never exceeded 1 s, which allows the online regulation of emissions the same way as other traditional properties of blended gasoline.展开更多
Protein arginine methyltransferase 5(PRMT5)deregulation has emerged as an important prognostic indicator in human cancers.Through aberrant methylation-mediated epige-netic modification of signaling molecules,PRMT5 ove...Protein arginine methyltransferase 5(PRMT5)deregulation has emerged as an important prognostic indicator in human cancers.Through aberrant methylation-mediated epige-netic modification of signaling molecules,PRMT5 over-expression contributes to dysregulation of a variety of cellular processes related to cancer progression.1 However,the mechanisms governing PRMT5 expression levels in cancer remain largely unknown.In this study,we examined factors that regulate PRMT5 expression at multiple levels.展开更多
文摘目的在32例年龄在60岁以上的慢性病贫血（anemia of chronic disease,AcD）患者中，应用重组人促红细胞生成素（recombinant human erythropoietin,rhEPO）治疗8周后测观察贫血改善情况，并筛选出具有较高临床意义的预测参数。方法32名AcD老年患者应用rhEPO治疗8周，8周内血红蛋白（hemoglobin，Hb）上升20g／L设为治疗有效。选用血清EPO水平、Hb、网状红细胞计数（reticulocyte count, Ret）、总铁结合力（total iron binding capacity,TIBC） 、血清铁（serum iron，SI）、血清铁蛋白（serum ferritin serum，SF）、可溶性转铁蛋白受体（serum transferrin receptor, sTfR）作为观测指标，观察患者8周时血红球蛋白的改变并进一步统计分析其与各观测指标变化之间的关系。结果32例老年AcD患者应用rhEPO治疗8周后Hb升高，SI、LgSF下降，sTfR升高（P〈0．05）。20例患者8周时获得预期疗效，多元回归分析提示rhEPO治疗8周后Hb改变与LgEPO及基线sTfR水平呈负相关（P〈0．05）。根据设定的评价方法将32例患者分为rhEPO治疗有效组及治疗无效组，绘制sTfR及LgEPO的受试者工作特征曲线（receiver operating characteristic curve, ROC曲线）并计算曲线下面积（area under the curve,AUC），后者具有统计学意义并且AUC更大（AUC为0．81，P〈0．05，95％CI：0．627～0．993），并通过最大Youden指数寻找到最佳诊断点为EPO≤58mIU／mL。如患者EPO≤58mIU／mL，可预测其能获得较好的治疗效果。结论rhEPO在老年慢性病贫血中可取得较好的治疗效果，患者的EPO水平是具有较高临床意义的预测参数。
文摘目的建立上海地区儿童甲状腺功能检测指标——促甲状腺激素(TSH)、游离三碘甲状腺原氨酸(FT3)和游离甲状腺素(FT4)的参考区间。方法选取2014年8月至2015年7月于上海地区9家医院就诊的4 d^17岁健康儿童720名,按年龄分为6组,每组120名。血液收集后离心,血清-20℃冷冻保存,使用贝克曼库尔特Uni Cel Dx I 800免疫分析系统进行测定。依据美国临床实验室标准化协会(CLSI)C28-A3文件及国际临床化学和检验医学联合会(IFCC)的相关要求制定参考区间的合理方法和可靠依据,以非参数法确定TSH、FT3和FT4的95%参考区间(百分位数范围为2.5%~9 7.5%,可信区间为9 0%)。结果各组按年龄段划分参考区间为:A组(4 d~<1个月),TSH 0.53~18.91μIU/m L,FT3 2.42~5.67 pmol/L,FT4 11.85~33.81 pmol/L;B组(1~<12个月),TSH0.7 5~5.7 5μI U/m L,F T3 4.2 1~8.1 6 p m o l/L,F T4 9.4 0~1 9.5 4 p m o l/L;C组(1~<5岁),T S H0.6 3~6.2 0μI U/m L,F T3 3.5 4~6.9 0 p m o l/L,F T4 9.3 2~1 8.4 0 p m o l/L;D组(5~<1 0岁),T S H0.58~5.39μIU/m L,FT3 3.97~7.83 pmol/L,FT4 10.65~19.23 pmol/L;E组(10~<14岁),TSH0.3 9~5.3 6μI U/m L,F T3 4.2 7~8.5 5 p m o l/L,F T4 9.8 0~1 9.6 4 p m o l/L。F组(1 4~1 7岁),T S H0.48~5.06μIU/m L,FT3 3.14~6.15 pmol/L,FT4 9.57~18.27 pmol/L。A组新生儿与相邻的B组参考区间分布比较,差异有统计学意义(Z>3);各组内不同性别间TSH、FT3、FT4水平比较,差异无统计学意义(P>0.05)。结论建立了上海地区4 d^17岁健康儿童按年龄分组TSH、FT3和FT4的参考区间。利用以上参考区间能够解释儿童甲状腺功能的检测结果,有助于诊断、治疗和监测甲状腺功能减低症、甲状腺功能亢进症、甲状腺炎、甲状腺肿及甲状腺肿瘤等疾病。
文摘This article aims to discuss strategies to operate Moflo XDP high-speed sorting equipment for cell sorting and optimize the instrument to run in the best operating state.Using fluorescent microspheres to quickly calibrate the position of the main liquid flow and the laser beam,adjust the amplitude and frequency according to different size CytoNozzles to find the best breakoff point,and adjust the four-way side flow to achieve the stable maintaining of the equipment,so as to quickly sort sample at high-speed.The absence of air bubbles in the sheath liquid barrel and the liquid path is the key to achieving a stable sorting-maintaining in the sorting process.The accurate calculation of the breakoff point and drop delay is the key to improve sorting efficiency and cell activity.
基金Supported by CHOC Children’s Foundation and CHOC Neuroscience Institute (to Li SC)Austin Ford Tribute Fund+2 种基金the W.M.Keck Foundation (to Li SC)Grant R21CA134391 from the National Institutes of HealthGrant AW 0852720 from the National Science Foundation (to Zhong JF)
文摘Increased evidence shows that normal stem cells may contribute to cancer development and progression by acting as cancer-initiating cells through their interactions with abnormal environmental elements.We postulate that normal stem cells and cancer stem cells (CSC) possess similar mechanisms of self-renewal and differentiation.CSC can be the key to the elaboration of anti-cancer-based therapy.In this article,we focus on a controversial new theme relating to CSC.Tumorigenesis may have a critical stage characterized as a "therapeutic window",which can be identified by asso-ciation of molecular,biochemical and biological events.Identifying such a stage can allow the production of more effective therapies (e.g.manipulated stem cells) to treat several cancers.More importantly,confirming the existence of a similar therapeutic window during the conversion of normal stem cells to malignant CSC may lead to targeted therapy specifically against CSC.This conversion information may be derived from investigating the biological behaviour of both normal stem cells and cancerous stem cells.Currently,there is little knowledge about the cellular and molecular mechanisms that govern the initiation and maintenance of CSC.Studies on co-evolution and interdependence of cancer with normal tissues may lead to a useful treatment paradigm of cancer.The crosstalk between normal stem cells and cancer formation may converge developmental stages of different types of stem cells (e.g.normal stem cells,CSC and embryonic stem cells).The differential studies of the convergence may result in novel therapies for treating cancers.
文摘Objective To examine the relationship between sex hormone–binding globulin (SHBG) and the metabolic syndrome (MetS) in pre-elderly and elderly men in China. Methods A cross-sectional studywas done among 437men, aged 45 to 94 years old. Early morning fasting sera were assayed for total testosterone (TT), SHBG and other biochemical markers. Free testosterone (FT) was calculated. Results The SHBG level of the MetS group was significantly lower than those without MetS 35.70 (25.18, 47.10) nmol/L vs. 41.90 (31.80, 55.20) nmol/L; P < 0.001). As the number of MetS components increases, SHBG and TT levels became lower. SHBG correlated with age, as did TT and most of metabolic components. Body mass index (BMI), high density lipoprotein-cholesterol (HDL-C), triglyceride (TG), and TT remained independently associated with SHBG by multivariate regression analysis. In a logistic regression taking MetS as the dependent variable, SHBG (95% confidence interval (95% CI): 0.975��0.994, P = 0.018) and homeostasis model assessment for insulin resistance (HOMA-IR) (95%CI: 1.535��2.647, P < 0.001) were included in the final model. Conclusions Lower SHBG is independently associated with MetS among pre-elderly and elderly men. SHBG may be an independent predictor of MetS, but the mechanism of how SHBG is involved in MetS requires further studied.
文摘Characterization of various nanoparticles is on the center stage in nanotechnology development. The subjects for nanoparticles characterization are focused on particle size and particle surface charge determinations. This article summarizes the latest development in particle size analysis using dynamic light scattering and surface charge determination using electrophoretic light scattering for nano-or even sub-nanoparticles in concentrated suspensions.
基金Supported by the fund for Creative Experimental Project of Undergraduate Students in Jiangsu Province of China (96)the program for New Century Excellent Talents in University (NCET-07-0441)+1 种基金the Natural Science Foundation of China (30671248)the grant obtained from the 111 Project of China (B07030)
文摘Pretreatment of lower H2O2 doses （0.05, 0.5 and 5 mM） for 24 h was able to dose-dependently attenuate lipid peroxidation in wheat seedling leaves mediated by further oxidative damage elicited by higher dose of H2O2 （150 mM） for 6 h, with 0.5 mM H2O2 being the most effective concentrations. Further results illustrated that 0.5 mM H2O2 pretreatment triggered the biphasic production of H2O2 during a 24 h period. We also noticed that only peak Ⅰ （0.25 h） rather than peak Ⅱ （4 h） was approximately consistent with the enhancement of heme oxygenase （HO） activity, HO-1 gene expression. Meanwhile, enhanced superoxide dismutase （SOD） activity, Mn-SOD and Cu, Zn-SOD transcripts might be a potential source of peak Ⅰ of endogenous H2O2. Further results confirmed that 0.5 mM H2O2 treatment for 0.5 h was able to upregulate HO gene expression, which was detected by enzyme activity determination, semi-quantitative reverse transcription-polymerase chain reaction and western blotting. Meanwhile, the application of N,N＇-dimethylthiourea, a trap for endogenous H2O2, not only blocked the upregulation of HO, but also reversed the corresponding oxidation attenuation. Together, the above results suggest that endogenous H2O2 production （peak Ⅰ） plays a positive role in the induction of HO by enhancing its mRNA level and protein expression, thus leading to the acclimation to oxidative stress.
基金supported by the Program for New Century Excellent Talents in University(Grant No.NCET-07-0441)the Priority Academic Program Development of Jiangsu Higher Education Institutions,the Education Department of Jiangsu(Grant No.200910)+2 种基金the Technology Support Program in Jiangsu Province,China(Grant No.BE2010382)the National Natural Science Foundation of China(Grant No.30671248the Fundamental Research Funds for the Central Universities(Grant no.KYJ200912 and KYZ200905)
文摘Heme oxygenase-1 （HO-1） has been recently identified as an endogenous signaling system in animals. In this study, HO-1 upregulation and its role in acquired salt tolerance （salinity acclimation） were investigated in wheat plants. We discovered that pretreatment with a low concentration of NaCl （25 mmol/L） not only led to the induction of HO-1 protein and gene expression, as well as enhanced HO activity, but also to a salinity acclimatory response thereafter. The effect is specific for HO-1, since the potent HO-1 inhibitor zinc protoporphyrin IX blocks the above cytoprotective actions, and the cytotoxic responses conferred by 200 mmol/L NaCl are reversed partially when HO-1 inducer hemin is added. Heme oxygenase catalytic product, carbon monoxide （CO） aqueous solution pretreatment, mimicked the salinity acclimatory responses. Meanwhile, the CO-triggered re-establishment of reactive oxygen species （ROS） homeostasis was mainly guaranteed by the induction of total and isozymatic activities, or corresponding transcripts of superoxide dismutase, ascorbate peroxidase, and cytosolic peroxidase （POD）, as well as the downregulation of NADPH oxidase expression and cell-wall POD activity. A requirement of hydrogen peroxide homeostasis for HO-1-mediated salinity acclimation was also discovered. Taken together, the above results suggest that the upregulation of HO-1 expression was responsible for the observed salinity acclimation through the regulation of ROS homeostasis.
基金This research was supported, in part, by National Science Foundation grant IOS-1025642 （G,B.M.）,
文摘The Pto protein kinase from Solanum pimpinellifolium interacts with Pseudomonas syringae effectors AvrPto or AvrPtoB to activate effector-triggered immunity. The previously solved crystal structures of the AvrPto-Pto and AvrPtoB-Pto complexes revealed that Pro binds each effector through both a shared and a unique interface. Hera we use natural variation in wild species of tomato to further investigate Pto recognition of these two effectors. One species, Solanum chmielewskU, was found to have many accessions that recognize only AvrPtoB. The Pto ortholog from one of these accessions was responsible for recognition of AvrPtoB and it differed from Solanum pimpinellifolium Pto by only 14 amino acids, including two in the AvrPto-specific interface, glutamate-49/glycine-51. Converting these two residues to those in Pro （histidine-49/valine-51） did not restore recognition of AvrPto. Subsequent experiments revealed that a single substitution of a histidine-to-aspartate at position 193 in Pto, which is not near the AvrPto- specific interface, was sufficient for conferring recognRion of AvrPto in plant cells. The reciprocal substi- tution of aspartate-to-histidine-193 in Pto abolished AvrPto recognition, confirming the importance of this residue. Our results reveal new aspects about effector recognition by Pto and demonstrate the value of using natural variation to understand the interaction between resistance proteins and pathogen effectors.
基金financial support from TOTAL Refining and Chemicals
文摘The empirical Complex Model developed by the US Environmental Protection Agency （EPA） is used by refiners to predict the toxic emissions of reformulated gasoline with respect to gasoline properties. The difficulty in implementing this model in the blending process stems from the implicit definition of Complex Model through a series of disjunctions assembled by the EPA in the form of spreadsheets. A major breakthrough in the refinery-based Complex Model implementation occurred in 2008 and 2010 through the use of generalized disjunctive and mixed- integer nonlinear programming （MINLP）. Nevertheless, the execution time of these MINLP models remains prohibitively long to control emissions with our online gasoline blender. The first objective of this study is to present a new model that decreases the execution time of our online controller. The toxic thresholds as hard second objective is to consider constraints to be verified and search for blends that verify them. Our approach introduces a new way to write the Complex Model without any binary or integer variables. Sigmoid functions are used herein to approximate step functions until the measurement precision for each blend property is reached. By knowing this level of precision, we are able to propose an extremely good and differentiable approximation of the Complex Model. Next, a differentiable objective function is introduced to penalize emission values higher than the threshold emissions. Our optimization module has been implemented and tested with real data. The execution time never exceeded 1 s, which allows the online regulation of emissions the same way as other traditional properties of blended gasoline.
基金This publication is made possible,in part,with support from National Institutes of Health(NIH)Grants(No.1R01GM120156-01A1 and 1R03CA223906-01 to T.L.)。
文摘Protein arginine methyltransferase 5(PRMT5)deregulation has emerged as an important prognostic indicator in human cancers.Through aberrant methylation-mediated epige-netic modification of signaling molecules,PRMT5 over-expression contributes to dysregulation of a variety of cellular processes related to cancer progression.1 However,the mechanisms governing PRMT5 expression levels in cancer remain largely unknown.In this study,we examined factors that regulate PRMT5 expression at multiple levels.
