Strovel ET et al. (JAN 2000)
The Journal of biological chemistry 275 4 2399--403
Protein phosphatase 2Calpha dephosphorylates axin and activates LEF-1-dependent transcription.
The Dishevelled (Dvl) gene family encodes cytoplasmic proteins that are necessary for Wnt signal transduction. Utilizing the yeast two-hybrid system,we identified protein phosphatase 2Calpha (PP2C) as a Dvl-PDZ domain-interacting protein. PP2C exists in a complex with Dvl,beta-catenin,and Axin,a negative regulator of Wnt signaling. In a Wnt-responsive LEF-1 reporter gene assay,expression of PP2C activates transcription and also elicits a synergistic response with beta-catenin and Wnt-1. In addition,PP2C expression relieves Axin-mediated repression of LEF-1-dependent transcription. PP2C utilizes Axin as a substrate both in vitro and in vivo and decreases its half-life. These results indicate that PP2C is a positive regulator of Wnt signal transduction and mediates its effects through the dephosphorylation of Axin.
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产品号#：
03800
03801
03802
03803
03804
03805
03806
产品名：
ClonaCell™-HY 杂交瘤试剂盒
ClonaCell™-HY Medium
ClonaCell™-HY Medium
ClonaCell™-HY Medium
ClonaCell™-HY Medium
ClonaCell™-HY Medium
ClonaCell™-HY PEG (融合)
Abramovitz M et al. (JAN 2000)
Biochimica et biophysica acta 1483 2 285--93
The utilization of recombinant prostanoid receptors to determine the affinities and selectivities of prostaglandins and related analogs.
Stable cell lines that individually express the eight known human prostanoid receptors (EP(1),EP(2),EP(3),EP(4),DP,FP,IP and TP) have been established using human embryonic kidney (HEK) 293(EBNA) cells. These recombinant cell lines have been employed in radioligand binding assays to determine the equilibrium inhibitor constants of known prostanoid receptor ligands at these eight receptors. This has allowed,for the first time,an assessment of the affinity and selectivity of several novel compounds at the individual human prostanoid receptors. This information should facilitate interpretation of pharmacological studies that employ these ligands as tools to study human tissues and cell lines and should,therefore,result in a greater understanding of prostanoid receptor biology.
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产品号#：
72192
72194
产品名：
前列腺素E2（Prostaglandin E2）
前列腺素E2（Prostaglandin E2）
Donahue RE et al. (JAN 2000)
Blood 95 2 445--52
High levels of lymphoid expression of enhanced green fluorescent protein in nonhuman primates transplanted with cytokine-mobilized peripheral blood CD34(+) cells.
We have used a murine retrovirus vector containing an enhanced green fluorescent protein complimentary DNA (EGFP cDNA) to dynamically follow vector-expressing cells in the peripheral blood (PB) of transplanted rhesus macaques. Cytokine mobilized CD34(+) cells were transduced with an amphotropic vector that expressed EGFP and a dihydrofolate reductase cDNA under control of the murine stem cell virus promoter. The transduction protocol used the CH-296 recombinant human fibronectin fragment and relatively high concentrations of the flt-3 ligand and stem cell factor. Following transplantation of the transduced cells,up to 55% EGFP-expressing granulocytes were obtained in the peripheral circulation during the early posttransplant period. This level of myeloid marking,however,decreased to 0.1% or lower within 2 weeks. In contrast,EGFP expression in PB lymphocytes rose from 2%-5% shortly following transplantation to 10% or greater by week 5. After 10 weeks,the level of expression in PB lymphocytes continued to remain at 3%-5% as measured by both flow cytometry and Southern blot analysis,and EGFP expression was observed in CD4(+),CD8(+),CD20(+),and CD16/56(+) lymphocyte subsets. EGFP expression was only transiently detected in red blood cells and platelets soon after transplantation. Such sustained levels of lymphocyte marking may be therapeutic in a number of human gene therapy applications that require targeting of the lymphoid compartment. The transient appearance of EGFP(+) myeloid cells suggests that transduction of a lineage-restricted myeloid progenitor capable of short-term engraftment was obtained with this protocol. (Blood. 2000;95:445-452)
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产品号#：
04436
04064
04100
04230
04236
04431
04434
04444
04464
04531
04535
04545
04536
04564
04035
04330
04034
04044
04435
04445
04534
04544
产品名：
MethoCult™ SF H4436
MethoCult™ H4034 Optimum启动试剂盒套装
MethoCult™ H4100
MethoCult™H4230
MethoCult™SF H4236
MethoCult™H4431
MethoCult™H4434经典
MethoCult™H4434经典
MethoCult™ H4434 Classic启动试剂盒套装
MethoCult™H4531
MethoCult™H4535富集无EPO
MethoCult™ H4535 Enriched，不含EPO
MethoCult™ SF H4536
入门套件MethoCult™H4534经典无EPO
MethoCult™H4035 Optimum无EPO
MethoCult™H4330
MethoCult™H4034 Optimum
MethoCult™H4034 Optimum
MethoCult™H4435富集
MethoCult™H4435富集
MethoCult™H4534经典无EPO
MethoCult™H4534经典无EPO
Galy A et al. (JAN 2000)
Blood 95 1 128--37
Distinct signals control the hematopoiesis of lymphoid-related dendritic cells.
The molecular and cellular requirements for the development of different populations of human dendritic cells (DC) were studied. Conditions were defined that support DC production from lymphoid progenitors but that fail to induce DC formation from peripheral monocytes. The production of these lymphoid-related DC was severely blocked when hematopoietic progenitors overexpressed Ik7,a mutant dominant-negative Ikaros protein. In contrast,Ik7 did not block the formation of DC in conditions supporting the development of monocyte-derived DC. Furthermore,Ik7 did not block the formation of monocyte/macrophages and enhanced granulopoiesis. One of the molecular mechanisms mediated by Ik7 appears to be down-regulation of the flt3-receptor mRNA. Thus,distinct signals control the formation of DC demonstrating that some aspects of DC diversity are determined in part by distinct molecular cues at the hematopoietic level. (Blood. 2000;95:128-137)
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产品号#：
04431
产品名：
MethoCult™H4431
Yoshida H et al. (DEC 1999)
Biochemical pharmacology 58 11 1695--703
Inhibitory effect of tea flavonoids on the ability of cells to oxidize low density lipoprotein.
Dietary flavonoid intake has been reported to be inversely related to mortality from coronary heart disease,and the anti-atherosclerotic effect of flavonoids is considered to be due probably to their antioxidant properties. Oxidation of low density lipoprotein (LDL) has been reported to be induced by the constituent cells of the arterial wall. Accordingly,we examined the effect of pretreatment with tea flavonoids,such as theaflavin digallate,on the ability of cells to oxidize LDL. Theaflavin digallate pretreatment of macrophages or endothelial cells reduced cell-mediated LDL oxidation in a concentration- (0-400 microM) and time- (0-4 hr) dependent manner. This inhibitory effect of flavonoids on cell-mediated LDL oxidation was in the order of theaflavin digallate textgreater theaflavin textgreater or = epigallocatechin gallate textgreater epigallocatechin textgreater gallic acid. Further,we investigated the mechanisms by which flavonoids inhibited cell-mediated LDL oxidation using macrophages and theaflavin digallate. Theaflavin digallate pretreatment decreased superoxide production of macrophages and chelated iron ions significantly. These results suggest that tea flavonoids attenuate the ability of the cell to oxidize LDL,probably by reducing superoxide production in cells and chelating iron ions.
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产品号#：
73644
产品名：
(-)-Epigallocatechin Gallate
Gribaldo L et al. (NOV 1999)
Experimental hematology 27 11 1593--8
Comparison of in vitro drug-sensitivity of human granulocyte-macrophage progenitors from two different origins: umbilical cord blood and bone marrow.
Predictive in vitro hematotoxicity assays using human cells will provide estimation of tolerable level and aid considerably the development of agents with greater therapeutic activity and less toxicity. Human hematopoietic cells can be derived from three sources: human bone marrow by sternal or femoral aspiration,mobilized peripheral blood,or umbilical cord blood samples collected from placentas after deliveries. Because of the difficulties to have a continuous supply of bone marrow cells from normal human donors and the related ethical problems,we performed a study to compare the sensitivity of human bone marrow cells (h-BMC) and human cord blood cells (h-CBC) to chemicals in order to confirm if h-CBC can readily replace bone marrow cells in checking the sensitivity of GM-CFU progenitors to drugs as preliminarily reported in literature. Our results showed that the prediction of IC50 values in human model is quite similar by using h-BMC or h-CBC. On the contrary,the type of medium influenced in a significant way the ICs determination of some drugs.
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产品号#：
04436
04064
04100
04230
04236
04431
04434
04444
04464
04531
04535
04545
04536
04564
04035
04330
04034
04044
04435
04445
04534
04544
产品名：
MethoCult™ SF H4436
MethoCult™ H4034 Optimum启动试剂盒套装
MethoCult™ H4100
MethoCult™H4230
MethoCult™SF H4236
MethoCult™H4431
MethoCult™H4434经典
MethoCult™H4434经典
MethoCult™ H4434 Classic启动试剂盒套装
MethoCult™H4531
MethoCult™H4535富集无EPO
MethoCult™ H4535 Enriched，不含EPO
MethoCult™ SF H4536
入门套件MethoCult™H4534经典无EPO
MethoCult™H4035 Optimum无EPO
MethoCult™H4330
MethoCult™H4034 Optimum
MethoCult™H4034 Optimum
MethoCult™H4435富集
MethoCult™H4435富集
MethoCult™H4534经典无EPO
MethoCult™H4534经典无EPO
Xaus J et al. (OCT 1999)
Journal of immunology (Baltimore,Md. : 1950) 163 8 4140--9
Adenosine inhibits macrophage colony-stimulating factor-dependent proliferation of macrophages through the induction of p27kip-1 expression.
Adenosine is produced during inflammation and modulates different functional activities in macrophages. In murine bone marrow-derived macrophages,adenosine inhibits M-CSF-dependent proliferation with an IC50 of 45 microM. Only specific agonists that can activate A2B adenosine receptors such as 5'-N-ethylcarboxamidoadenosine,but not those active on A1 (N6-(R)-phenylisopropyladenosine),A2A ([p-(2-carbonylethyl)phenylethylamino]-5'-N-ethylcarboxamido adenosine),or A3 (N6-(3-iodobenzyl)adenosine-5'-N-methyluronamide) receptors,induce the generation of cAMP and modulate macrophage proliferation. This suggests that adenosine regulates macrophage proliferation by interacting with the A2B receptor and subsequently inducing the production of cAMP. In fact,both 8-Br-cAMP (IC50 85 microM) and forskolin (IC50 7 microM) inhibit macrophage proliferation. Moreover,the inhibition of adenylyl cyclase and protein kinase A blocks the inhibitory effect of adenosine and its analogues on macrophage proliferation. Adenosine causes an arrest of macrophages at the G1 phase of the cell cycle without altering the activation of the extracellular-regulated protein kinase pathway. The treatment of macrophages with adenosine induces the expression of p27kip-1,a G1 cyclin-dependent kinase inhibitor,in a protein kinase A-dependent way. Moreover,the involvement of p27kip-1 in the adenosine inhibition of macrophage proliferation was confirmed using macrophages from mice with a disrupted p27kip-1 gene. These results demonstrate that adenosine inhibits macrophage proliferation through a mechanism that involves binding to A2B adenosine receptor,the generation of cAMP,and the induction of p27kip-1 expression.
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产品号#：
73602
73604
产品名：
8-Bromo-cAMP
8-Bromo-cAMP
Komarov PG et al. (SEP 1999)
Science (New York,N.Y.) 285 5434 1733--7
A chemical inhibitor of p53 that protects mice from the side effects of cancer therapy.
Chemotherapy and radiation therapy for cancer often have severe side effects that limit their efficacy. Because these effects are in part determined by p53-mediated apoptosis,temporary suppression of p53 has been suggested as a therapeutic strategy to prevent damage of normal tissues during treatment of p53-deficient tumors. To test this possibility,a small molecule was isolated for its ability to reversibly block p53-dependent transcriptional activation and apoptosis. This compound,pifithrin-alpha,protected mice from the lethal genotoxic stress associated with anticancer treatment without promoting the formation of tumors. Thus,inhibitors of p53 may be useful drugs for reducing the side effects of cancer therapy and other types of stress associated with p53 induction.
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产品号#：
72062
72064
产品名：
环状 Pifithrin-α（Cyclic Pifithrin-Alpha）
环状 Pifithrin-α (Hydrobromide)
Storms RW et al. (AUG 1999)
Proceedings of the National Academy of Sciences of the United States of America 96 16 9118--23
Isolation of primitive human hematopoietic progenitors on the basis of aldehyde dehydrogenase activity.
Because hematopoietic stem cells are rich in aldehyde dehydrogenase (ALDH) activity,we developed a fluorescent substrate for ALDH,termed BODIPY aminoacetaldehyde (BAAA),and tested its potential for isolating primitive human hematopoietic cells. A population of cells with low orthogonal light scattering and bright fluorescence intensity (SSC(lo)ALDH(br) cells) could be readily fractionated from human umbilical cord blood cells costained with BAAA and the multidrug-resistance inhibitor verapamil. The SSC(lo)ALDH(br) population was depleted of lineage-committed cells,40-90% pure for CD34(+)CD38(lo/-) cells,and enriched 50- to 100-fold for primitive hematopoietic progenitors detected in short- and long-term culture analyses. Together,these observations indicate that fractionating human hematopoietic stem cells on the basis of ALDH activity using BAAA is an effective method for isolating primitive human hematopoietic progenitors. This technique may be useful for isolating stem cells from other tissues as well.
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产品号#：
01700
01702
01705
产品名：
ALDEFLUOR™ 试剂盒
ALDEFLUOR™测定缓冲液
ALDEFLUOR™ DEAB试剂
Brandl M et al. (AUG 1999)
Experimental hematology 27 8 1264--70
Bispecific antibody fragments with CD20 X CD28 specificity allow effective autologous and allogeneic T-cell activation against malignant cells in peripheral blood and bone marrow cultures from patients with B-cell lineage leukemia and lymphoma.
Bispecific antibodies directed against tumor-associated target antigens and to surface receptors mediating T-cell activation,such as the TCR/CD3 complex and the costimulatory receptor CD28,are capable of mediating T-cell activation resulting in tumor cell killing. In this study,we used the B-cell-associated antigens CD19 and CD20 as target structures on human leukemic cells. We found that a combination of bispecific antibody fragments (bsFab2) with target x CD3 and target x CD28 specificity induces vigorous autologous T-cell activation and killing of malignant cells in peripheral blood and bone marrow cultures from patients with chronic lymphocytic leukemia and follicular lymphoma. The bsFab2 targeting CD20 were considerably more effective than those binding to CD19. The colony-forming capacity of treated bone marrow was impaired due to large amounts of tumor necrosis factor alpha produced during bsFab2-induced T-cell activation. Neutralizing tumor necrosis factor alpha antibodies were found to reverse this negative effect without affecting T-cell activation and tumor cell killing. CD20 x CD28 bsFab2,when used alone rather than in combination,markedly improved the recognition of leukemic cells by allogeneic T cells. Therefore,these reagents may be capable of enhancing the immunogenicity of leukemic cells in general and,in particular,of increasing the antileukemic activity of allogeneic donor buffy coat cells in relapsed bone marrow transplanted patients.
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产品号#：
04431
产品名：
MethoCult™H4431
Gentry T and Smith C (AUG 1999)
Experimental hematology 27 8 1244--54
Retroviral vector-mediated gene transfer into umbilical cord blood CD34brCD38-CD33- cells.
In this report,we sought to optimize gene transfer into primitive human umbilical cord blood (UCB) cells. Initially,we found that fresh UCB isolated with the CD34brCD38 CD33 phenotype were highly enriched for hematopoietic progenitors detected in extended long-term cultures (8-week LTCs). In addition,following ex vivo gene transfer,this population possessed virtually all the 8-week LTC activity of the cultured cells. A multiparameter FACS assay was developed to efficiently screen the effects of alternative retroviral vector gene transfer procedures on the transduction efficiency and maintenance of CD34brCD38 CD33 cells. Proliferation of the CD34brCD38 CD33 cells was found to be a prerequisite for efficient transduction. However,in all conditions tested,proliferation of the CD34brCD38 CD33 cells was associated with a progressive loss of primitive cell properties including a reduction in CD34 expression,an increase in CD38/CD33 expression,and a decline in the ability to sustain 8-week LTCs. These observations indicate that it will be necessary to define conditions that more effectively support the self-renewal capacity of CD34brCD38 CD33 cells to optimize retroviral vector gene transfer in these cells. Evaluating these conditions and reagents will be facilitated by the multiparameter FACS assay described in this report.
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产品号#：
04431
产品名：
MethoCult™H4431
Fré et al. (JAN 1999)
Life sciences 64 26 2511--21
Antioxidant activity of resveratrol and alcohol-free wine polyphenols related to LDL oxidation and polyunsaturated fatty acids.
Wine polyphenols were examined for their capacity to protect the lipid and protein moieties of porcine low density lipoproteins (LDL) during oxidation. The efficiency of resveratrol (3,4',5,trihydroxystilbene) and defined flavonoids was compared to that of a wine extract (WE) containing 0.5 g/g proanthocyanidols. The efficiency of resveratrol for protecting polyunsaturated fatty acids (PUFA) was higher than that of flavonoids in copper-induced oxidation and lower in AAPH (radical initiator)-induced oxidation. The LDL receptor activity was evaluated by flow cytometry using LDL labeled with fluorescein isothiocyanate (FITC) and Chinese hamster ovary cells (CHO-K1). The incubation of CHO-K1 with FITC-LDL oxidized for 16 h reduced the proportion of fluorescent cells from 97% to 4%. At a concentration of 40 microM,resveratrol and flavonoids completely restored the uptake of copper-oxidized LDL and AAPH-oxidized LDL respectively. Total fluorescence could also be obtained with 20 mg/L of WE with both oxidation systems. These data are consistent with previous findings relative to the formation of degradative products from PUFA. They confirm that resveratrol was more effective than flavonoids as a chelator of copper and less effective as a free-radical scavenger. Moreover,they show that WE,which contained monomeric and oligomeric forms of flavonoids and phenolic acids,protected LDL by both mechanisms.
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