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121.
Dun Wang Xiao‐Fei Li Zheng‐Jian Zhou Xu‐Ping Feng Wan‐Jun Yang De‐An Jiang 《Physiologia plantarum》2010,139(1):55-67
Studies on some plant species have shown that increasing the growth temperature gradually or pretreating with high temperature can lead to obvious photosynthetic acclimation to high temperature. To test whether this acclimation arises from heat adaptation of ribulose 1,5‐bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) activation mediated by Rubisco activase (RCA), gene expression of RCA large isoform (RCAL) and RCA small isoform (RCAS) in rice was determined using a 4‐day heat stress treatment [40/30°C (day/night)] followed by a 3‐day recovery under control conditions [30/22°C (day/night)]. The heat stress significantly induced the expression of RCAL as determined by both mRNA and protein levels. Correlative analysis indicated that RCAS protein content was extremely significantly related to Rubisco initial activity and net photosynthetic rate (Pn) under both heat stress and normal conditions. Immunoblot analysis of the Rubisco–RCA complex revealed that the ratio of RCAL to Rubisco increased markedly in heat‐acclimated rice leaves. Furthermore, transgenic rice plants expressing enhanced amounts of RCAL exhibited higher thermotolerance in Pn and Rubisco initial activity and grew better at high temperature than wild‐type (WT) plants and transgenic rice plants expressing enhanced amounts of RCAS. Under normal conditions, the transgenic rice plants expressing enhanced amounts of RCAS showed higher Pn and produced more biomass than transgenic rice plants expressing enhanced amounts of RCAL and wild‐type plants. Together, these suggest that the heat‐induced RCAL may play an important role in photosynthetic acclimation to moderate heat stress in vivo, while RCAS plays a major role in maintaining Rubisco initial activity under normal conditions. 相似文献
122.
Jing Zhang Ga Liao Chang Liu Lei Sun Yanyou Liu Yuhui Wang Zhou Jiang Zhengrong Wang 《Molecular biology reports》2011,38(1):349-354
Many reports have shown that the biologic rhythm could be altered due to mutations of circadian gene hClock or hPeriod, and
the mutations of circadian genes have some relationship with psychosis according to recent studies. A preliminary study has
been conducted to examine wether the T3111C single nucleotide polymorphism of the hClock gene or the length polymorphism of
the hPer3 gene is associated with the development of schizophrenia. The samples from schizophrenics (n = 148, male: 57.4%, female: 42.6%) and normal controls (n = 199, male: 59.3%, female: 40.7%) were examined. Allele frequencies of T3111C SNP of hClock were significantly different
between schizophrenics and controls (χ2 = 19.738, P < 0.05). Schizophrenics had a significantly higher frequency of the C allele compared with controls (OR = 2.613, 95% CI = 1.693–4.034).
On the other hand, there is no significant difference of allele frequencies of 18 exon of hper3 between schizophrenics and controls (χ2 = 0.192, P > 0.05). Our results suggest that the T3111C (RS1801260) polymorphism of hClock gene is associated with schizophrenia, but
it seems that the length polymorphism of 18 exon of hPer3 may not be associated with schizophrenia. It is important to address
of the relationship between circadian gene polymorphisms and dopamine functions in further study. 相似文献
123.
Boggiano C Jiang S Lu H Zhao Q Liu S Binley J Blondelle SE 《Biochemical and biophysical research communications》2006,347(4):909-915
Entry of human immunodeficiency virus type 1 (HIV-1) virion into host cells involves three major steps, each being a potential target for the development of entry inhibitors: gp120 binding to CD4, gp120-CD4 complex interacting with a coreceptor, and gp41 refolding to form a six-helix bundle. Using a D-amino acid decapeptide combinatorial library, we identified peptide dC13 as having potent HIV-1 fusion inhibitory activity, and effectively inhibiting infection by several laboratory-adapted and primary HIV-1 strains. While dC13 did not block binding of gp120 to CD4, nor disrupt the gp41 six-helix bundle formation, it effectively blocked the binding of an anti-CXCR4 monoclonal antibody and chemokine SDF-1alpha to CXCR4-expressing cells. However, because R5-using primary viruses were also neutralized, the antiviral activity of dC13 implies additional mode(s) of action. These results suggest that dC13 is a useful HIV-1 coreceptor antagonist for CXCR4 and, due to its biostability and simplicity, may be of value for developing a new class of HIV-1 entry inhibitors. 相似文献
124.
Iron scarcity is one of the nutrition limitations that the Gram-positive infectious pathogens Streptococcus pneumoniae encounter in the human host. To guarantee sufficient iron supply, the ATP binding cassette (ABC) transporter Pia is employed to uptake iron chelated by hydroxamate siderophore, via the membrane-anchored substrate-binding protein PiaA. The high affinity towards ferrichrome enables PiaA to capture iron at a very low concentration in the host. We presented here the crystal structures of PiaA in both apo and ferrichrome-complexed forms at 2.7 and 2.1 Å resolution, respectively. Similar to other class III substrate binding proteins, PiaA is composed of an N-terminal and a C-terminal domain bridged by an α-helix. At the inter-domain cleft, a molecule of ferrichrome is stabilized by a number of highly conserved residues. Upon ferrichrome binding, two highly flexible segments at the entrance of the cleft undergo significant conformational changes, indicating their contribution to the binding and/or release of ferrichrome. Superposition to the structure of Escherichia coli ABC transporter BtuF enabled us to define two conserved residues: Glu119 and Glu262, which were proposed to form salt bridges with two arginines of the permease subunits. Further structure-based sequence alignment revealed that the ferrichrome binding pattern is highly conserved in a series of PiaA homologs encoded by both Gram-positive and negative bacteria, which were predicted to be sensitive to albomycin, a sideromycin antibiotic derived from ferrichrome. 相似文献
125.
目的检测非小细胞肺癌(non-small cell lung cancer,NSCLC)中NF-κB P65、p-IκBα(IκBα磷酸化)、p-IKKβ(IKKβ磷酸化)的表达情况及其与NSCLC临床特征的关系。方法采用免疫组化Elivision法检测NF-κB P65、p-IκBα、p-KKβ在56例NSCLC中表达情况,以20例癌旁组织作为对照。结果在NSCLC中NF-κB P65、p-IκBα、p-IKKβ的表达阳性率分别为83.9%(47/56)、55.7%(31/56)、69.6%(39/56),癌旁组织三者分别为20%(4/20)、25%(5/20)、30%(6/20),NF-κB P65、p-IκBα、p-IKKβ的表达与吸烟史、TNM分期、淋巴结转移相关,差异有统计学意义(P<0.05)。结论 NF-κB P65、p-IκBα、p-IKKβ高表达与NSCLC的发生、发展起着重要作用。 相似文献
126.
Cheng ZJ Jiang YF Ding H Severson D Triggle CR 《Canadian journal of physiology and pharmacology》2007,85(3-4):404-412
In this study, we tested the hypothesis that spontaneously diabetic TallyHo (TH) mice, a novel polygenic model for type 2 diabetes, will exhibit endothelial dysfunction associated with an increased contribution from endothelium-derived contractile factors (EDCF). The cellular mechanisms underlying the increased contribution of EDCF were explored in 16 and 30-week-old male TH and age-matched male C57BL/6J mice (n=4-9). Blood glucose and serum lipid profiles were markedly increased in the TH mice. Superoxide generation, assessed with a lucigenin chemiluminescence assay, was markedly increased in the aortae of TH mice. Endothelium-dependent vascular relaxations and contractions to acetylcholine (ACh), but not endothelium-independent relaxations to sodium nitroprusside, were impaired and vascular contractions to phenylephrine were significantly enhanced in aortae from TH mice. Nomega-nitro-L-arginine methyl ester markedly increased the ACh-induced contractions in TH mice, whereas SQ29548, a thromboxane receptor antagonist, and cytochrome P450 (CYP) inhibitors 17-octadecynoic acid and sulfaphenazole, the latter being specific for CYP2C6 and 2C9, decreased and (or) normalized the contractile response to ACh in TH mice. The present study indicates that enhanced contribution of prostaglandin H2/thromboxane A2 receptor and CYP, likely CYP2C6 and 2C9, play a critical role in the pathogenesis of increased EDCF in the aortae of type 2 diabetic TH mice. 相似文献
127.
128.
为防止呼吸机呼气管道中的含菌气体扩散污染病房空气,引发交叉感染。利用HEPA材料、活性炭、特殊的缓释杀菌滤材,研制成一套呼吸机呼气除菌过滤装置。经参照有关标准用物理模拟气溶胶颗粒(0.28-0.34um)及微生物气溶胶测试,过滤效率>99.995%,微生物气溶胶滤除率达100%。气流阻力<230Pa,完全能满足临床呼气机的过滤除菌使用条件。 相似文献
129.
探讨p38蛋白激酶信号传导通路在细胞中的特异性作用机制。应用共聚焦激光扫描技术观察心肌细胞中p38蛋白激酶的分布及LPS对其分布的影响。结果提示未受刺激静止的及EGF刺激的心肌细胞中,p38在胞浆和胞核中荧光强度呈散性分布。LPS刺激30分钟后,细胞核区的荧光强度明显增强,而胞浆区域的荧光强度降低,心肌细胞受LPS刺激激活后,其p38蛋白激酶由胞浆转位到胞核。 相似文献
130.
介绍了对人民教育出版社的高中生物学必修教材第2册103页,实验12“观察二氧化硫对植物的影响”的部分改进。利用洗净的金龙鱼牌5L塑料油瓶和洗净的空矿泉水瓶等废旧物资进行实验操作。材料易于寻找,成本低廉,培养了学生“变废为宝”的节约思想;用NaOH溶液吸收装置内的SO2,避免了环境污染,培养了学生的环保意识。 相似文献