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171.
172.
Youssef Zaim Wadghiri Jialin Li Jinhuan Wang Dung Minh Hoang Yanjie Sun Hong Xu Wai Tsui Yongsheng Li Allal Boutajangout Andrew Wang Mony de Leon Thomas Wisniewski 《PloS one》2013,8(2)
Amyloid plaques are a key pathological hallmark of Alzheimer’s disease (AD). The detection of amyloid plaques in the brain is important for the diagnosis of AD, as well as for following potential amyloid targeting therapeutic interventions. Our group has developed several contrast agents to detect amyloid plaques in vivo using magnetic resonance microimaging (µMRI) in AD transgenic mice, where we used mannitol to enhance blood brain barrier (BBB) permeability. In the present study, we used bifunctional ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles, chemically coupled with Aβ1-42 peptide to image amyloid plaque deposition in the mouse brain. We coupled the nanoparticles to polyethylene glycol (PEG) in order to improve BBB permeability. These USPIO-PEG-Aβ1-42 nanoparticles were injected intravenously in AD model transgenic mice followed by initial in vivo and subsequent ex vivo μMRI. A 3D gradient multi-echo sequence was used for imaging with a 100 µm isotropic resolution. The amyloid plaques detected by T2*-weighted μMRI were confirmed with matched histological sections. The region of interest-based quantitative measurement of T2* values obtained from the in vivo μMRI showed contrast injected AD Tg mice had significantly reduced T2* values compared to wild-type mice. In addition, the ex vivo scans were examined with voxel-based analysis (VBA) using statistical parametric mapping (SPM) for comparison of USPIO-PEG-Aβ1-42 injected AD transgenic and USPIO alone injected AD transgenic mice. The regional differences seen by VBA in the USPIO-PEG-Aβ1-42 injected AD transgenic correlated with the amyloid plaque distribution histologically. Our results indicate that USPIO-PEG-Aβ1-42 can be used for amyloid plaque detection in vivo by intravenous injection without the need to co-inject an agent which increases permeability of the BBB. This technique could aid the development of novel amyloid targeting drugs by allowing therapeutic effects to be followed longitudinally in model AD mice. 相似文献
173.
Steam gasification of waste biomass has been studied in a two-stage fluidized bed reactor, which has the primary pyrolysis fluidized bed using silica sand as bed material and the secondary reforming fixed bed with catalyst. The main objectives are parametric investigation and performance improvement especially at low temperature of around 600 °C using the wood chip and the pig manure compost as feedstock. Main operating variables studied are pyrolysis temperature, catalytic temperature, steam/biomass-C ratio, space velocity and different catalyst. Reaction temperatures and steam/C ratio have important role on the gasification process. About 60 vol.% H2 (dry and N2 free) and about 2.0 Nm3/kg biomass (dry and ash free basis) can be obtained under good conditions. Compared to Ni/Al2O3, Ni/BCC (Ni-loaded brown coal char) has a better ability and a hopeful prospect for the stability with coking resistance. 相似文献
174.
Doanh PN Dung do T Thach DT Horii Y Shinohara A Nawa Y 《Parasitology international》2011,60(4):534-537
Parasitological and sero-epidemiological surveys for human paragonimiasis were conducted in three provinces of Viet Nam. A total of 590 participants from two known endemic areas of human paragonimiasis (Sinho district of Laichau province and Lucyen district of Yenbai province) and from Dakrong district of Quangtri province where we recently found crab hosts heavily infected with Paragonimus westermani metacercariae. By multiple dot-ELISA screening, 28 (12.7%) out of 220 participants in Sinho district of Laichau province and 4 (3.3%) out of 120 participants in Lucyen district of Yenbai province were proven to be antibody-positive against the Paragonimus antigen. None of the 250 sera of the residents in Dakrong, Quangtri province, gave sero-positivity. Among a total of 32 sero-positive patients Paragonimus eggs were found in 6 cases. ITS2 sequences were successfully determined from a single Paragonimus egg from each patient. The results of homology search by BLAST and alignment clearly confirmed that Paragonimus eggs collected from 6 patients were all of Paragonimus heterotremus. The pathogenicity of P. westermani for human paragonimiasis in Viet Nam is still questionable and needs to be explored in the future. 相似文献
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176.
L. Prokešová Dinh Huu Dung I. Trebichavský E. Formánková V. Štěpánková C. John 《Folia microbiologica》1994,39(5):428-434
Human mononuclear leukocytes killStaphylococcus aureus cellsin vitro. The killing of the bacteria takes place even in the absence of antibodies. The presence of antibodies (in an autologous
inactivated serum) usually enhances the antibacterial activity of mononuclear leukocytes. In some cases, however, this activity
is markedly decreased by the serum, probably depending of the spectrum of antibodies contained in the serum. The antibacterial
activity of mononuclear leukocytes is mostly due to monocytes because their depletion causes substantial drop or the activity
disappearance. We failed to demonstrate in the case ofS. aureus the antibacterial cytotoxicity of T lymphocytes described by some authors dealing with Gram-negative bacteria. Large differences
in the structure of the bacterial cell wall underlie apparently the different sensitivity of G+ and G− bacteria to some protective mechanisms of the host. In the antibacterial assay againstS. aureus, electron microscopy revealed a maximal activation of monocytes which phagocytized the bacteria although extracellular killing
is not excluded. Electronoptical findings point also to a possible participation of NK cells in the antibacterial cytotoxicity
againstS. aureus. 相似文献
177.
Quinazoline‐Based Hydroxamic Acids: Design,Synthesis, and Evaluation of Histone Deacetylase Inhibitory Effects and Cytotoxicity 下载免费PDF全文
Doan Thanh Hieu Duong Tien Anh Pham‐The Hai Le‐Thi‐Thu Huong Eun Jae Park Jeong Eun Choi Jong Soon Kang Phan Thi Phuong Dung Sang‐Bae Han Nguyen‐Hai Nam 《化学与生物多样性》2018,15(6)
In our search for novel histone deacetylases inhibitors, we have designed and synthesized a series of novel hydroxamic acids and N‐hydroxybenzamides incorporating quinazoline heterocycles ( 4a – 4i , 6a – 6i ). Bioevaluation showed that these quinazoline‐based hydroxamic acids and N‐hydroxybenzamides were potently cytotoxic against three human cancer cell lines (SW620, colon; PC‐3, prostate; NCI‐H23, lung). In term of cytotoxicity, several compounds, e.g., 4g , 4c , 4g – 4i , 6c , and 6h , displayed from 5‐ up to 10‐fold higher potency than SAHA (suberoylanilidehydroxamic acid, vorinostat). The compounds were also generally comparable to SAHA in inhibiting HDACs with IC50 values in sub‐micromolar range. Some compounds, e.g., 4g , 6c , 6e , and 6h , were even more potent HDAC inhibitors compared to SAHA in HeLa extract assay. Docking studies demonstrated that the compounds tightly bound to HDAC2 at the active binding site with binding affinities higher than that of SAHA. Detailed investigation on the estimation of absorption, distribution, metabolism, excretion, and toxicity (ADMET) suggested that compounds 4g , 6c , and 6g , while showing potent HDAC2 inhibitory activity and cytotoxicity, also potentially displayed ADMET characteristics desirable to be expected as promising anticancer drug candidates. 相似文献
178.
Sooyoun Nam Marino Hiraoka Takashi Gomi Bui Xuan Dung Yuichi Onda Hiroaki Kato 《Landscape and Ecological Engineering》2016,12(2):197-208
We examined changes in suspended-sediment yields (SSY) after a 50 % strip thinning in headwater streams draining a Japanese cedar (Cryptomeria japonica) and cypress (Chamaecyparis obtusa) plantation forest. We applied a paired-catchment analysis to treated (K T : 17.1 ha) and control (K C : 8.9 ha) catchments. Annual suspended-sediment yield (SSYan) in the prethinning period in the K T and K C catchments was 110.0 and 142.1 kg/ha per year. For the postthinning period, SSYan in the K T catchment became 5055.6 kg/ha per year, whereas that in the K C catchment increased 893.2 kg/ha per year. The paired-catchment analysis revealed that SSY in the K T catchment increased 17.0-fold compared with the prethinning period. However, the dominant hysteresis pattern remained clockwise in both pre- and postthinning periods. Sequences of large storm events in the postthinning period elevated SSY in both catchments. Increase in suspended sediment in the K T catchment was associated with the combined impacts of thinning and sequences of storm events during the period of thinning operation. 相似文献
179.
三种鳞翅目夜蛾科昆虫α-微管蛋白基因的克隆与mRNA表达水平 总被引:1,自引:1,他引:1
根据昆虫微管蛋白的分子特征筛选对昆虫微管有效的抑制剂来控制昆虫的生长发育或不同器官的有效功能的表达来达到控制害虫的目的,在未来的害虫综合治理中具有广泛的应用前景。以预蛹期甜菜夜蛾Spodoptera exigua、小地老虎Agrotis ypsilon和八字地老虎Agrotis c-nigrum为材料提取总RNA,利用RT-PCR和cDNA末端快速扩增技术(RACE),分别扩增得到以上3种夜蛾科昆虫的α-微管蛋白基因的cDNA序列,3种昆虫的该基因序列均包括1个1353个碱基的开放阅读框。这3个cDNA序列均编码1个含450个氨基酸的蛋白,分子量约为50kDa。氨基酸的142~148位存在1个微管蛋白信号片段GGGTGSG,在氨基酸序列的C-端都有1个酪氨酸残基,N-端存在1个对转录后调控非常重要的保守区MRECI序列,以上特点与其他昆虫α-微管蛋白氨基酸序列保守区序列相同。序列比对表明,克隆得到的α-微管蛋白基因的核苷酸序列是高度保守的,同源性为94.4%~97.0%,而氨基酸的序列同源性达到100%。利用RT-PCR技术在3种昆虫4龄、5龄、6龄幼虫、蛹期4个不同发育阶段和6龄期的肠道、体壁、脂肪体3种不同组织中都检测到了α-微管蛋白基因在mRNA水平的表达。 相似文献
180.
Török ME Nguyen DB Tran TH Nguyen TB Thwaites GE Hoang TQ Nguyen HD Tran TH Nguyen TC Hoang HT Wolbers M Farrar JJ 《PloS one》2011,6(12):e27821