共查询到20条相似文献,搜索用时 0 毫秒
1.
Anna Zita Mehira Kamptner Christoph-Erik Mayer Hedwig Sutterlüty 《International journal of molecular sciences》2021,22(21)
Sprouty proteins are widely accepted modulators of receptor tyrosine kinase-associated pathways and fulfill diversified roles in cancerogenesis dependent on the originating cells. In this study we detected a high expression of Sprouty3 in osteosarcoma-derived cells and addressed the question of whether Sprouty3 and Sprouty1 influence the malignant phenotype of this bone tumor entity. By using adenoviruses, the Sprouty proteins were expressed in two different cell lines and their influence on cellular behavior was assessed. Growth curve analyses and Scratch assays revealed that Sprouty3 accelerates cell proliferation and migration. Additionally, more colonies were grown in Soft agar if the cells express Sprouty3. In parallel, Sprouty1 had no significant effect on the measured endpoints of the study in osteosarcoma-derived cells. The promotion of the tumorigenic capacities in the presence of Sprouty3 coincided with an increased activation of signaling as measured by evaluating the phosphorylation of extracellular signal-regulated kinases (ERKs). Ectopic expression of a mutated Sprouty3 protein, in which the tyrosine necessary for its activation was substituted, resulted in inhibited migration of the treated cells. Our findings identify Sprouty3 as a candidate for a tumor promoter in osteosarcoma. 相似文献
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超声波、牛血清蛋白和吐温试剂辅助玉米秸秆酶水解 总被引:1,自引:0,他引:1
研究了超声波、牛血清蛋白(BSA)、表面活性剂Tween20和Tween80作为辅助手段对玉米秸秆酶水解过程的影响。结果显示:虽然三者作用机理不同,但是均能够提高酶水解得糖率。未加辅助方法时酶解48h后的得糖率为26.2%;经30W、10min超声波辐射辅助的酶解得糖率上升为35.7%;添加0.5g/LBSA时的酶解得糖率提高到32.8%;而加入1%的Tween20和Tween80后酶解得糖率分别增加到35.2%和35.9%。 相似文献
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Poly(L ‐lactic acid) (PLLA), poly(ε‐caprolactone) (PCL), and their films without or blended with 50 wt% poly(ethylene glycol) (PEG) were prepared by solution casting. Porous films were obtained by water‐extraction of PEG from solution‐cast phase‐separated PLLA‐blend‐PCL‐blend‐PEG films. The effects of PLLA/PCL ratio on the morphology of the porous films and the effects of PLLA/PCL ratio and pores on the physical properties and biodegradability of the films were investigated. The pore size of the blend films decreased with increasing PLLA/PCL ratio. Polymer blending and pore formation gave biodegradable PLLA‐blend‐PCL materials with a wide variety of tensile properties with Young's modulus in the range of 0.07–1.4 GPa and elongation at break in the range 3–380%. Pore formation markedly increased the PLLA crystallinity of porous films, except for low PLLA/PCL ratio. Polymer blending as well as pore formation enhanced the enzymatic degradation of biodegradable polyester blends. Copyright © 2006 Society of Chemical Industry 相似文献
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Lucero A. Ramon-Luing Claudia Carranza Norma A. Tllez-Navarrete Karen Medina-Quero Yolanda Gonzalez Martha Torres Leslie Chavez-Galan 《International journal of molecular sciences》2022,23(1)
In mycobacterial infections, the number of cells from two newly discovered subpopulations of CD3+ myeloid cells are increased at the infection site; one type expresses the T cell receptor (CD3+TCRαβ+) and the other does not (CD3+TCRαβ−). The role of Mycobacterium tuberculosis (Mtb) virulence in generating these subpopulations and the ability of these cells to migrate remains unclear. In this study, monocyte-derived macrophages (MDMs) infected in vitro with either a virulent (H37Rv) or an avirulent (H37Ra) Mtb strain were phenotypically characterized based on three MDM phenotypes (CD3−, CD3+TCRαβ+, and CD3+TCRαβ−); then, their migration ability upon Mtb infection was evaluated. We found no differences in the frequency of CD3+ MDMs at 24 h of infection with either Mtb strain. However, H37Rv infection increased the frequency of CD3+TCRαβ+ MDMs at a multiplicity of infection of 1 and altered the expression of CD1b, CD1c, and TNF on the surface of cells from both the CD3+ MDM subpopulations; it also modified the expression of CCR2, CXCR1, and CCR7, thus affecting CCL2 and IL-8 levels. Moreover, H37Rv infection decreased the migration ability of the CD3− MDMs, but not CD3+ MDMs. These results confirm that the CD3+ macrophage subpopulations express chemokine receptors that respond to chemoattractants, facilitating cell migration. Together, these data suggest that CD3+ MDMs are a functional subpopulation involved in the immune response against Mtb. 相似文献
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Martyna Seta Katarzyna Hara
na Kaja Kasareo Daria Solarz-Keller Agnieszka Cudnoch-Jdrzejewska Tomasz Witko Zenon Rajfur Maciej Guzik 《International journal of molecular sciences》2022,23(24)
The human body’s natural protective barrier, the skin, is exposed daily to minor or major mechanical trauma, which can compromise its integrity. Therefore, the search for new dressing materials that can offer new functionalisation is fully justified. In this work, the development of two new types of dressings based on poly(3-hydroxyoctanoate) (P(3HO)) is presented. One of the groups was supplemented with conjugates of an anti-inflammatory substance (diclofenac) that was covalently linked to oligomers of hydroxycarboxylic acids (Oli-dicP(3HO)). The novel dressings were prepared using the solvent casting/particulate leaching technique. To our knowledge, this is the first paper in which P(3HO)-based dressings were used in mice wound treatment. The results of our research confirm that dressings based on P(3HO) are safe, do not induce an inflammatory response, reduce the expression of pro-inflammatory cytokines, provide adequate wound moisture, support angiogenesis, and, thanks to their hydrophobic characteristics, provide an ideal protective barrier. Newly designed dressings containing Oli-dicP(3HO) can promote tissue regeneration by partially reducing the inflammation at the injury site. To conclude, the presented materials might be potential candidates as excellent dressings for wound treatment. 相似文献
7.
Kangyi Zhang Yuanfa Liu Xingguo Wang 《European Journal of Lipid Science and Technology》2012,114(11):1254-1260
L ‐α‐Glycerylphosphorylcholine (L ‐α‐GPC) was successfully prepared from phosphatidylcholine (PC) of food‐grade soy lecithin powder using a novel enzymatic reaction in an aqueous medium. 94.5% yield of L ‐α‐GPC was obtained under the optimal conditions of 55°C, 6.67 mg/mL substrate, 2 mM CaCl2, and 33.4 U/mL phospholipase A1 (Lecitase Ultra). L ‐α‐GPC at 98% purity, 73.4% (wt%) recovery, and specific rotation ( ) of ?2.5° was achieved by silica gel column chromatography. Owing to its excellent catalytic efficiency, low cost, and ready availability, phospholipase A1 (Lecitase Ultra) provides a very satisfactory option for converting PC to L ‐α‐GPC. Practical applications: L ‐α‐Glycerylphosphorylcholine (L ‐α‐GPC) has been studied recently for its potential use as a supplement that may support neurological functions, but it is only found in trace amounts in nature. The present results indicate that Lecitase Ultra can be used for producing L ‐α‐GPC from aqueous PC and suggest encouraging prospects for practical or industrial applications utilizing its notable catalytic performance, economy, and convenience. 相似文献
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D. Khatib 《Ferroelectrics Letters Section》1994,18(5):173-179
The microscopic mechanism of optical anisotropy in the tetragonal phase of BaTiO3 is discussed taking account of the dipole-dipole effect due to the ionic and electronic polarizations of the crystal and the spontaneous Kerr effect. The last effect is a cause of the strong local field acting on the constituent ions. For the spontaneous polarization we use only the first effect. In this molecular model, only the Ti ions situated at the center of the lattice are assumed to have the spontaneous shift. It is found that the spontaneous polarization and the birefringence are in good agreement with the experimental data. 相似文献
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Rosiglitazone,but Not Epigallocatechin‐3‐Gallate,Attenuates the Decrease in PGC‐1α Protein Levels in Palmitate‐Induced Insulin‐Resistant C2C12 Cells 下载免费PDF全文
Alteration of lipid metabolism is an important mechanism for the treatment of insulin resistance. PGC‐1α, a key regulator of mitochondrial biogenesis and function, plays an important role in the improvement of insulin sensitivity by increasing fatty acids β‐oxidation. In the present study, the effects of epigallocatechin‐3‐gallate (EGCG), an anti‐obesity agent and enhancer of lipid catabolism, on PGC‐1α protein expression was examined and compared with anti‐diabetic drug rosiglitazone (RGZ). After differentiation of C2C12 myoblasts to myotubes, insulin resistance was induced by palmitate treatment. Then the expression of the PGC‐1a gene and glucose uptake were evaluated before and after treatment with RGZ and EGCG. Palmitate treatment significantly decreased PGC‐1α protein expression in C2C12 cells (P < 0.05). RGZ could restore the expression of PGC‐1α in palmitate treated cells (P > 0.05), while EGCG had no significant effect on the expression of this gene (P < 0.05). RGZ and EGCG significantly improved glucose uptake (by 2‐ and 1.54‐fold, respectively) in myotubes treated with palmitate. These data suggest that RGZ and EGCG both exert their anti‐diabetic activity by increasing insulin sensitivity, but with different molecular mechanisms. This effect of RGZ, unlike EGCG, is mediated, at least partly, by increasing PGC‐1α protein expression. 相似文献
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Abstract Thermodynamic parameters (ΔG, ΔH, and ΔS) for the extraction of trivalent f-elements, M(III) (M = Am, Eu), with N,N,N',N'-tetraoctyl-3-oxapentane-1,5-diamide (TODGA) were determined in nitric acid/n-dodecane extraction system. The extraction of M(III) with TODGA was more exothermic than those with octyl(phenyl)-N,N-diisobutylcarbamoylmethyl phosphine oxide (CMPO) and dihexyl-N,N-diethylcarbamoylmethyl phosphonate (DHDECMP). The difference in ΔH between the extractants was attributed to the difference in the binding mode between them, i.e. tridentate (TODGA) and bidentate (CMPO and DHDECMP). In addition, from the results of luminescence lifetime measurement, it was found that the inner-sphere of extracted Eu(III) was dehydrated completely, and occupied by TODGA and/or NO3 ?. 相似文献
11.
Wan‐Xia Wu 《Polymer International》2019,68(11):1848-1855
A series of novel aliphatic poly(β‐thioether ester)s with various methylene group contents were prepared by direct lipase‐catalyzed polycondensation of the monomer with an acid‐labile β‐thiopropionate group. The polycondensation reaction using immobilized lipase B from Candida antarctica was carried out in diphenyl ether at 90 °C. Poly(β‐thioether ester)s with high molecular weights of 20 500–57 000 Da and narrow polydispersities in the range 1.40–1.48 were obtained. Thermogravimetric analysis, differential scanning calorimetry and wide‐angle X‐ray diffraction were used to investigate the thermal properties and crystal structures of these polyesters. All the poly(β‐thioether ester)s were semicrystalline polymers and thermally stable up to at least 200 °C. In vitro degradation studies showed that they can rapidly degrade under acidic conditions by the hydrolysis of the β‐thiopropionate groups, suggesting their potential as acid‐degradable polymeric materials. © 2019 Society of Chemical Industry 相似文献
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Thermodynamic calculations disclose that significant changes of the AFm and AFt phases and amount of Ca(OH)2 occur between 0 and 40 °C; the changes are affected by added calcite. Hydrogarnet, C3AH6, is destabilised at low carbonate contents and/or low temperatures < 8 °C and is unlikely to form in calcite-saturated Portland cement compositions cured at < 40 °C. The AFm phase actually consists of several structurally-related compositions which form incomplete solid solutions. The AFt phase is close to its ideal stoichiometry at 25 °C but at low temperatures, < 20 °C, extensive solid solutions occur with CO3-ettringite. A nomenclature scheme is proposed and AFm-AFt phase relations are presented in isothermal sections at 5, 25 and 40 °C. The AFt and AFm phase relations are depicted in terms of competition between OH, CO3 and SO4 for anion sites. Diagrams are presented showing how changing temperatures affect the volume of the solid phases with implications for space filling by the paste. Specimen calculations are related to regimes likely to occur in commercial cements and suggestions are made for testing thermal impacts on cement properties by defining four regimes. It is concluded that calculation provides a rapid and effective tool for exploring the response of cement systems to changing composition and temperature and to optimise cement performance. 相似文献
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Mehri Sohrabi Bijan Eftekhari Yekta Hamid Reza Rezaie Mohammad Reza Naimi-Jamal 《应用聚合物科学杂志》2021,138(38):50963
The effect of cross-linker 3-glycidyloxypropyl trimethoxysilane (GPTMS) on the injectability, bioactivity, rheology, washout resistance, and cellular behavior of bio-nano composite pastes containing a sol–gel derived bioactive glass (BG), chitosan (Cn), and gelatin (Gel), were studied. The results indicated that the structural integrity of the samples in the stimulated body fluid (SBF) was improved from 80% to 90% with the increase in the GPTMS content. In addition, the viscosity and injectability of the paste were affected, so that the later changed from 96% to 73% and the former changed from 132 × 103 to 210 × 103 Pa.s, with addition of 20 wt% GPTMS. Furthermore, the bioactivity of the pastes was improved with the use of GPTMS. No toxicity was observed in the cellular studies of the GPTMS containing paste after 7 days, and the cells kept their shape and were attached firmly to the paste surface. The results of the present work showed that the use of GPTMS was beneficial in enhancing the properties of injectable paste. 相似文献
16.
Alexander Becker Claudia Gtz Mathias Montenarh Stephan E. Philipp 《International journal of molecular sciences》2021,22(23)
In pancreatic β-cells of the line INS-1, glucose uptake and metabolism induce the openings of Ca2+-permeable TRPM3 channels that contribute to the elevation of the intracellular Ca2+ concentration and the fusion of insulin granules with the plasma membrane. Conversely, glucose-induced Ca2+ signals and insulin release are reduced by the activity of the serine/threonine kinase CK2. Therefore, we hypothesized that TRPM3 channels might be regulated by CK2 phosphorylation. We used recombinant TRPM3α2 proteins, native TRPM3 proteins from INS-1 β-cells, and TRPM3-derived oligopeptides to analyze and localize CK2-dependent phosphorylation of TRPM3 channels. The functional consequences of CK2 phosphorylation upon TRPM3-mediated Ca2+ entry were investigated in Fura-2 Ca2+-imaging experiments. Recombinant TRPM3α2 channels expressed in HEK293 cells displayed enhanced Ca2+ entry in the presence of the CK2 inhibitor CX-4945 and their activity was strongly reduced after CK2 overexpression. TRPM3α2 channels were phosphorylated by CK2 in vitro at serine residue 1172. Accordingly, a TRPM3α2 S1172A mutant displayed enhanced Ca2+ entry. The TRPM3-mediated Ca2+ entry in INS-1 β-cells was also strongly increased in the presence of CX-4945 and reduced after overexpression of CK2. Our study shows that CK2-mediated phosphorylation controls TRPM3 channel activity in INS-1 β-cells. 相似文献
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Atactic poly(3‐hydroxybutyrate) (a‐PHB) and block copolymers of poly(ethylene glycol) (PEG) with poly(ε‐caprolactone) (PCL‐b‐PEG) were synthesized through anionic polymerization and coordination polymerization, respectively. As demonstrated by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) measurements, both chemosynthesized a‐PHB and biosynthesized isotactic PHB (i‐PHB) are miscible with the PEG segment phase of PCL‐b‐PEGs. However, there is no evidence showing miscibility between both PHBs and the PCL segment phase of the copolymer even though PCL has been block‐copolymerized with PEG. Based on these results, PCL‐b‐PEG was added, as a compatibilizer, to both the PCL/a‐PHB blends and the PCL i‐PHB blends. The blend films were obtained through the evaporation of chloroform solutions of mixed components. Excitingly, the improvement in mechanical properties of PCL/PHB blends was achieved as anticipated initially upon the addition of PCL‐b‐PEG. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2600–2608, 2001 相似文献
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Katja Seipel Carolyn Graber Laura Flückiger Ulrike Bacher Thomas Pabst 《International journal of molecular sciences》2021,22(15)
The FMS-like tyrosine kinase 3 (FLT3) gene is mutated in one-third of patients with de novo acute myeloid leukemia (AML). Mutated FLT3 variants are constitutively active kinases signaling via AKT kinase, MAP kinases, and STAT5. FLT3 inhibitors have been approved for the treatment of FLT3-mutated AML. However, treatment response to FLT3 inhibitors may be short-lived, and resistance may emerge. Compounds targeting STAT5 may enhance and prolong effects of FLT3 inhibitors in this subset of patients with FLT3-mutated AML. Here STAT5-inhibitor AC-4-130, FLT3 inhibitor midostaurin (PKC412), BMI-1 inhibitor PTC596, MEK-inhibitor trametinib, MCL1-inhibitor , and BCL-2 inhibitor venetoclax were assessed as single agents and in combination for their ability to induce apoptosis and cell death in leukemic cells grown in the absence or presence of bone marrow stroma. Synergistic effects on cell viability were detected in both FLT3-mutated and FLT3-wild-type AML cells treated with AC-4-130 in combination with the MCL1 inhibitor S63845. AML patient samples with a strong response to AC-4-130 and S63845 combination treatment were characterized by mutated FLT3 or mutated TET2 genes. Susceptibility of AML cells to AC-4-130, PTC596, trametinib, PKC412, and venetoclax was altered in the presence of HS-5 stroma. Only the MCL1 inhibitor S63845 induced cell death with equal efficacy in the absence or presence of bone marrow stroma. The combination of the STAT5-inhibitor AC-4-130 and the MCL1 inhibitor S63845 may be an effective treatment targeting FLT3-mutated or TET2-mutated AML. S63845相似文献
19.
涡旋脉冲式反应装置制备纳米碳酸钙的碳化特性研究 总被引:2,自引:0,他引:2
介绍了涡旋脉冲式反应装置的基本结构和特点,并选择Ca(OH)2-H2O-CO2这一多相反应体系,利用涡旋脉冲式反应装置制备纳米碳酸钙。实验研究了气液比h、喷口速度up、Ca(OH)2悬浮液初始浓度Ci、混合气体中CO2气体含量j、脉冲发生器的频率f等操作条件对碳化反应时间Rt的影响。实验结果表明,随h、pu、j增大,Rt明显减小;Ci增加导致Rt增大;在5Hzf<的范围内,随f增大,与液滴在涡旋室内的飞行时间相比,液滴表面更新速率增大占优势,导致Rt减小,在5Hzf>的范围内,随f增大,相撞的瞬间液滴的相对速度及在涡旋室内的飞行时间降低,导致Rt逐渐增大。 相似文献
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Hydration reactions of C3A with various amounts of calcium sulfate hemihydrate, gypsum or a mixture of the two, were investigated by isothermal microcalorimetry, and a monitoring of the ionic concentrations of diluted suspensions. This study shows that sulfate type used modifies the early C3A–CaSO4 hydration products and the rate of this hydration. The fast initial AFm formation observed before ettringite precipitation in the C3A–gypsum system is avoided as soon as hemihydrate is present in the suspension. This was attributed to higher super saturation degrees and then higher nucleation frequency with regard to the ettringite obtained in the presence of hemihydrate. Moreover, replacement of gypsum by hemihydrate also leads to an increase of the ettringite formation rate during at least the five first hours under experimental conditions. 相似文献