Increased circulating of myeloid-derived suppressor cells in myelodysplastic syndrome

Myelodysplastic syndrome (MDS) is a group of clonal hematopoietic stem cell disorders,characterized by varying degrees of peripheral cytopenia caused by ineffective dysplasia of the myeloid lineages.MDS also has a high risk of progression to acute myeloid leukemia.But the role of immune abnormalities in the pathogenesis of MDS is still not clear.     

Feasibility of establishing cerebral ischemia models by using aerocyst-blocking bilateral ascending pharyngeal artery of piglets Imaging assessment

BACKGROUND: The cerebral ischemia and ischemia/reperfusion animal models are used to simulate the human cerebrovascular diseases is one of the popular topics of neurological science recently. To study the pathophysiology, pathogenesis, prophylaxis and treatment of ischemic cerebrovascular diseases and to establish the ideal animal model that is the most similar to the human cerebral ischemia, are the topics that the people generally cared about. OBJECTIVE: To evaluate the effects of aerocyst-blocking bilateral ascending pharyngeal artery on the establishment of cerebral ischemia models by using digital subtraction angiography (DSA), magnetic resonance diffusion-weighted imaging (DWI) and magnetic resonance perfusion-weighted imaging (PWI). DESIGN: Repetitive measure animal experiment. SETTING: Zhongshan Hospital Affiliated to Dalian University. MATERIALS: The experiment was carried out in the Animal Laboratory (Provincial Laboratory), Zhongshan Hospital of Dalian Univeristy from January to May 2006. A total of 14 domestic piglets, of 6 months old, weighing 12–15 kg, of either gender, were selected from Animal Experimental Center, Dalian University. Multistar T.O.P digital subtraction angiography machine was provided by Siemens Company, German. METHODS: Aerocyst-blocking bilateral ascending pharyngeal artery was used to establish cerebral ischemia models. And then, Multistar T.O.P. DSA was used for imaging of cerebral vessels before blocking, during blocking and at 0.5 and 2 hours after ischemia perfusion. GE Signa 1.5 T supraconduction magnetic resonance imaging was used for DWI examination; in addition, PWI was used based on focal sites and areas. Otherwise, magnetic resonance imaging (MRI) was used to detect signal changes of T1WI and T2WI in ischemic areas. MAIN OUTCOME MEASURES: Analytic results of DSA, DWI, PWI and MRI. RESULTS: All 14 experimental piglets were involved in the final analysis. ① DSA: The blood flow of bilateral ascending pharyngeal arteries and its branch were blocked at blocking phase, which restored 0.5 and 2 hours after reperfusion. ② DWI and PWI: There were no observable abnormalities in PWI and DWI at pre-blocking. Abnormal increased signals were found on both DWI and PWI at during and post-blocking. There were reduction in ADC and rCBF and delay in rTTP at all time points except pre-blocking. ③ MRI: There were no abnormal signals observable at any time of pre- and post-blocking in T1WI and T2WI. CONCLUSION: It is feasible to establish this kind of animal experimental models, and it can simulate the ischemic state; meanwhile, the existence and extent can be showed directly by DSA, DWI, and PWI.     

L-3-n-butylphthalide protects against vascular dementia via activation of the Akt kinase pathway

As a neuroprotective drug for the treatment of ischemic stroke, 3-n-butylphthalide, a celery seed ex- tract, has been approved by the State Food and Drug Administration of China as a clinical therapeutic drug for ischemic stroke patients. L-3-n-butylphthalide possesses significant efficacy in the treatment of acute ischemic stroke. The activated Akt kinase pathway can prevent the death of nerve cells and exhibit neuroprotective effects in the brain after stroke. This study provides the hypothesis that I-3-n- butylphthalide has a certain therapeutic effect on vascular dementia, and its mechanism depends on the activation of the Akt kinase pathway. A vascular dementia mouse model was established by cere- bral repetitive ischemia/reperfusion, and intragastrically administered I-3-n-butylphthalide daily for 28 consecutive days after ischemia/repedusion, or 7 consecutive days before ischemia/reperfusion. The Morris water maze test showed significant impairment of spatial learning and memory at 4 weeks after operation, but intragastric administration of I-3-n-butylphthalide, especially pretreatment with I-3-n- butylphthalide, significantly reversed these changes. Thionine staining and western blot analylsis showed that preventive and therapeutic application of I-3-n-butylphthalide can reduce loss of pyrami- dal neurons in the hippocampal CA1 region and alleviate nerve damage in mice with vascular demen- tia. In addition, phosphorylated Akt expression in hippocampal tissue increased significantly after I-3-n- butylphthalide treatment. Experimental findings demonstrate that I-3-n-butylphthalide has preventive and therapeutic effects on vascular dementia, and its mechanism may be mediated by upregulation of phosphorylated Akt in the hippocampus.     

Inhibitory effect of ketamine on lighting amygdala of rats

IN T R O D U C T IO N There are m any kinds of epilepsies and pathogeneses are various. Previous researchers proved thatN -m ethyl-D -aspartic acid (N M D A ) receptor w as closely related to epileptic attack[1]. N ow adays, anim al experim ents are still…     

Identification and Determination of Fructooligosaccharides in Snow Chrysanthemum (Coreopsis tinctoria Nutt.)

Objective: Small molecules in snow chrysanthemum such as flavonoids, phenolic compounds and amino acids have been extensively investigated. No study to date has focused on water-soluble oligosaccharides. The objective of this study is identification and determination of water-soluble oligosaccharides in snow chrysanthemum. Methods: The oligosaccharides in snow chrysanthemum were identified by high performance thin layer chromatography (HPTLC), liquid chromatography-massspectrometry (LC-MS) combined MS library and methylation analysis for the first time. Subsequently the oligosaccharides were determined by high performance liquid chromatography with a charged aerosol detector (HPLC-CAD). Results: The oligosaccharides in snow chrysanthemum were identified as inulin-type fructooligosaccharides (FOS). The yield of FOS (DP3~DP13) in the first extraction was over 97.6%. The RSDs of repeatability in three sample amount levels (0.08 g, 0.1 g, 0.12 g) are lower than 4.8% and the RSDs of stability are less than 3.5%. The recoveries of FOS (DP3~13) were ranging from 96.9% to 105.6%. The contents of FOS (DP3~DP13) in flowers of snow chrysanthemum from different regions of China were greatly variant. Conclusion: This is the first time to identify and quantify FOS in snow chrysanthemum which is helpful for its performance in the in the fields of biomedical, agriculture and functional food industry as well as development of the quality control methods. In addition, the identification approach developed in this work can also be used for screening potential natural sources containing FOS.     

Material Base of in vivo Invigorating Qi and Enriching Blood of Bazhen Decoction by HPLC-ESI-MS

Objective To identify the in vivo metabolized chemical constituents in Bazhen Decoction(BZD) and to study the relationship between Siwu Decoction(SWD) and Sijunzi Decoction(SJZD) with BZD.Methods Analysis and comparison were carried out by HPLC-ESI-MS.Serum samples after ig administration of preparations such as SWD,SJZD,and BZD,with different ingredients were collected for analysis.Results Twenty-two components were detected after ig administration of BZD,and six of them were metabolites and others were original form of the components contained in BZD.The prototype constituents were atractylenolide I,5-hydroxymethyl-furoic acid(5-HMFA),oxypaeoniflorin,atractylenolide III,albiflorin,paeoniflorin,liquiritin,ferulic acid,ligustilide,and ginsenosides Rg1 and Rb1.The metabolized constituents were paeonimetabolin I,glycyrrhetic acid monoglucuronide,glycyrrhetinic acid,and ginsenosides Rh1 and Rd.Conclusion The results also show that 5-HMFA,oxypaeoniflorin,albiflorin,paeoniflorin,ferulic acid,and ligustilide are common components absorbed into blood existing in both BZD and SWD,which are material base of enriching blood;Atractylenolide I,atractylenolide III,and liquiritin are common ingredients absorbed into blood existing in both BZD and SJZD,and they are material base of invigorating Qi.The results provide basic data for the further studies on the effective components,the effecting mechanism,and the quality control of BZD.     

Specificity and mechanism of the histone methyltransferase Pr-Set7

Methylation of lysine residues of histones is an important epigenetic mark that correlates with functionally distinct regions of chromatin. We present here the crystal structure of a ternary complex of the enzyme Pr-Set7 (also known as Set8) that methylates Lys 20 of histone H4 (H4-K20). We show that the enzyme is exclusively a mono-methylase and is therefore responsible for a signaling role quite distinct from that established by other enzymes that target this histone residue. We provide evidence from NMR for the C-flanking domains of SET proteins becoming ordered upon addition of AdoMet cofactor and develop a model for the catalytic cycle of these enzymes. The crystal structure reveals the basis of the specificity of the enzyme for H4-K20 because a histidine residue within the substrate, close to the target lysine, is required for completion of the active site. We also show how a highly variable component of the SET domain is responsible for many of the enzymes' interactions with its target histone peptide and probably also how this part of the structure ensures that Pr-Set7 is nucleosome specific.     

Fibroblast growth factor 23 reduces expression of type IIa Na+/Pi co-transporter by signaling through a receptor functionally distinct from the known FGFRs in opossum kidney cells

Fibroblast growth factor (FGF) 23 is an important phosphaturic factor that inhibits inorganic phosphate (Pi) reabsorption from the renal proximal tubule. Its overproduction and proteolysis-resistant mutation such as R179Q cause tumor-induced osteomalacia and autosomal dominant hypophosphatemic rickets, respectively. To clarify the signaling mechanisms of FGF23 that mediate the reduction of Pi reabsorption, we inhibited the function of the known FGFRs in opossum kidney (OK-E) cells by expressing a dominant-negative (DN) form of FGFR. OK-E cells, which represent the renal proximal tubular cells, expressed all four known FGFRs. FGF23(R179Q) bound to and activated FGFR2, a prominent FGFR expressed in OK-E cells. The activated receptor transmitted a signal to increase the expression of type IIa Na(+)/Pi co-transporter and the Pi uptake. Expression of FGFR2(DN), which suppresses the major FGFR-mediated signal through the FRS2alpha-ERK pathway, reversed the function of FGF23(R179Q). When FGF23(R179Q) was applied to the basolateral side of polarized OK-E cells, regardless of the FGFR2(DN) expression, the apical Pi uptake decreased significantly. The apical application of FGF23(R179Q) in the polarized cells did not show such decrease but increase. The exogenously expressed FGFR2 was detectable only at the apical membrane. These results suggest that an FGF23 receptor, which is functionally distinct from the known FGFRs, is expressed at the basolateral membrane of OK-E cells.     

Synthesis of a novel structural triblock copolymer of poly(gamma -benzyl-l-glutamic acid)-b-poly(ethylene oxide)-b-poly(epsilon-caprolactone)

A novel structural triblock copolymer of poly(gamma-benzyl-l-glutamic acid)-b-poly(ethylene oxide)-b-poly(epsilon-caprolactone) (PBLG-PEO-PCL) was synthesized by a new approach in the following three steps: (1) sequential anionic ring opening polymerization (ROP) of ethylene oxide and epsilon-caprolactone with an acetonitrile/potassium naphthalene initiator system to obtain a diblock copolymer CN-PEO-PCL with a cyano end-group; (2) conversion of the CN end-group into NH2 end-group by hydrogenation to obtain NH2-PEO-PCL; (3) ROP of gamma-benzyl-l-glutamate-N-carboxyanhydrides (Bz-l-GluNCA) with NH2-PEO-PCL as macroinitiator to obtain the target triblock copolymer. The structures from CN-PEO precursor to the triblock copolymers were confirmed by FT-IR and 1H NMR spectroscopy, and their molecular weights were measured by gel permeation chromatography. The monomer of Bz-l-GluNCA can react almost quantitatively with the amino end-groups of NH2-PEO-PCL macroinitiator by ROP.     

HIF-1α对食管癌Eca109细胞体内外侵袭转移的影响及其分子机制

目的:采用RNA干扰技术(RNAi)观察低氧诱导因子-1α(HIF-1α)对食管癌Eca109细胞及其裸鼠移植瘤侵袭转移的影响及其作用机制。方法:CoCl2模拟肿瘤低氧微环境,分别用RT-PCR和免疫细胞化学法检测体外低氧条件下Eca109细胞中HIF-1α、E-钙黏蛋白及基质金属蛋白酶-2(MMP-2)mRNA及蛋白的表达。RT-PCR检测RNAi沉默HIF-1α对E-钙黏蛋白及MMP-2 mRNA表达的影响。通过细胞划痕试验和Transwell试验检测RNAi对Eca109细胞侵袭和转移能力的影响。建立Eca109细胞裸鼠移植瘤模型,观察HIF-1α对肿瘤生长及淋巴结转移的影响;采用Western blot检测各组移植瘤中HIF-1α、E-钙黏蛋白及MMP-2的表达,分析HIF-1α在离体和在体对肿瘤生长、侵袭及转移的影响。结果:低氧诱导Eca109细胞的HIF-1α蛋白表达升高,E-钙黏蛋白的mRNA及蛋白表达降低和MMP-2 mRNA及蛋白表达升高,但对HIF-1αmRNA无明显影响。用RNAi能有效沉默HIF-1α,并可逆转低氧导致的E-钙黏蛋白及MMP-2的降低及升高,使Eca109细胞迁移速度减慢,侵袭穿膜细胞数减少(P<0.05);在体内使移植瘤生长减缓,淋巴结转移率降低(P<0.05)。结论:HIF-1α在体内外通过影响E-钙黏蛋白和MMP-2表达,来影响食管癌Eca109细胞的生长、侵袭和转移。