Fractions of a water insoluble α-(1→3)-D-glucan (GL) extracted from Ganoderma lucidum were carboxy-methylated (CM) to obtain water-soluble carboxymethylated derivatives (CM-GL) having a degree of substitution (DS) o...Fractions of a water insoluble α-(1→3)-D-glucan (GL) extracted from Ganoderma lucidum were carboxy-methylated (CM) to obtain water-soluble carboxymethylated derivatives (CM-GL) having a degree of substitution (DS) of0.38~0.51. Weight-average molecular weight M_w and intrinsic viscosity [η] of the samples CM-GL were measured by gelpermeation chromatography combined with laser light scattering (GPC-LLS) and viscometry. The CM-GL exhibits a stifferchain in aqueous solution at 25℃ than the original glucan, The antitumor activities against Ehrlich ascites carcinoma (EAC,5×10~6) of the carboxymethylated derivatives from the α-glucan and curdlan, a β-glucan, are significantly higher than thoseof the original glucans. The effects of the relatively low molecular weight, expanded chains and better water-solubility of theCM-GL on the enhancement of antitumor activity could not be neglected. The chain stiffness decreased speedily withincrease of temperature from 40 to 60℃ or NaOH concentration from 0.1 to 0.4 in the solution, respectively, and the changeof the chain stiffness is reversible.展开更多
N,O-bis(trimethylsily)trifluoroacetamide (BSTFA) and N-methyl-N(trimethylsily) trifluoroacetamide (MSTFA) are common derivatization reagents used in the GC-MS analysis of estrogen steroids such as estrone (El...N,O-bis(trimethylsily)trifluoroacetamide (BSTFA) and N-methyl-N(trimethylsily) trifluoroacetamide (MSTFA) are common derivatization reagents used in the GC-MS analysis of estrogen steroids such as estrone (El) and 17α-ethinylestradiol (EE2). In this study, three trimethylsilyl (TMS) steroid derivatives, mono- and di-trimethylsilyl EE2 and mono-trimethylsilyl El, were observed during the derivatization of EE2 with BSTFA or MSTFA and/or GC separation. Factors influencing the production of multiple TMS derivatives and their relative abundance were examined. It was found that both methanol and bisphenol A competed with estrogenic esteroids when reacting with silylation reagents, and thus affected the formation of TMS derivatives and their relative abundance in the derivatization products. Methanol was found to be more reactive than bisphenol A with the BSTFA reagent. None of the three solvents tested in this study could prevent the generation of multiple TMS derivatives during the derivatization of EE2 with BSTFA, followed by GC analysis. A similar result was observed using MSTFA as the derivative reagent followed by GC analysis. Thus, the suitability of BSTFA or MSTFA as the derivatization reagent for the determination of E1 and EE2 by GC-MS, under the conditions reported here, is questionable. This problem can be solved by adding trimethylsilylimidaz (TMSI) in the BSTFA reagent as recommended, and the performance of the method has been proved in this study.展开更多
Two new a-aminophosphonate derivatives containing thieno[2,3-d]pyrimidine, diethyl(((6-ethyl-2-methyl-4-oxothieno[2,3-d]pyrimidin-3 (4H)-yl)amino)(4-methoxyphenyl)methyl) phosphonate (1) and diethyl((4-b...Two new a-aminophosphonate derivatives containing thieno[2,3-d]pyrimidine, diethyl(((6-ethyl-2-methyl-4-oxothieno[2,3-d]pyrimidin-3 (4H)-yl)amino)(4-methoxyphenyl)methyl) phosphonate (1) and diethyl((4-bromophenyl)((6-ethyl-2-methyl-4-oxothieno[2,3-d]pyrimidin-3 (4//)-yl)amino)methyl)phosphonate (2), have been synthesized by a facial phosphorylated reaction, and their structures were characterized by NMR, IR, HRMS and X-ray single-crystal diffraction. Compound 1 (C21H28N3O5PS, Mr = 465.49) belongs to the orthorhombic system, space group P212121, with a = 10.83653(16), b = 12.04906(19), c = 18.0061(3) A, V= 2351.06(6) A3, Z= 4, Dc= 1.315 g/cm3, p = 2.177 mm-1, F(000) = 984.0, the final R = 0.0389 and wR = 0.0985 for all data. Compound 2 (C20H25BrN304PS, Mr = 514.37) belongs to the orthorhombic system, space group P212121, with a = 10.9187(5), b = 11.9522(4), c = 17.7667(7) A, V= 2318.60(16) A3, Z = 4, Dc= 1.474 g/cm3,μ = 4.175 mm^-1, F(000) = 1056.0, the final R = 0.0367 and wR = 0.0946 for all data.展开更多
Tamoxifen resistance(TamR)is the underlying cause of treatment failure in many breast cancer patients receiving tamoxifen.In order to look for noncytotoxic natural products with the ability to reverse TamR,an extract ...Tamoxifen resistance(TamR)is the underlying cause of treatment failure in many breast cancer patients receiving tamoxifen.In order to look for noncytotoxic natural products with the ability to reverse TamR,an extract from strain Streptomyces sp.KIB-H0495 was detected to be active.Subsequent large scale fermentation and isolation led to the isolation of four a-pyrone derivatives including two new compounds,violapyrones J(2)and K(3),and two known analogues,violapyrones B(1)and I(4).Further bioactivity assays indicated that only 1 and 3 exerted potent resensitization effects on MCF-7/TamR cells at a concentration of 1 lM.Owing to the simple structures of 1 and 3,these two compounds might have potential for further investigation as novel tamoxifen resensitization agent in breast cancer chemotherapy.展开更多
The object of the present paper is to prove distortion theorems for the n-th order derivative of starlike and convex functions of order a. In addition. a related conjecture involving the fractional derivative of the ...The object of the present paper is to prove distortion theorems for the n-th order derivative of starlike and convex functions of order a. In addition. a related conjecture involving the fractional derivative of the convex function f(z) by Owa S and Srivastava H M is investigated.展开更多
A three-dimensional diagram shows that the association constants (Ka) for the inclusionof a- and 6-CD with substitUted benzene are mainly correIated with the molar refraction (R.) andhydrophobic constant (%) of the su...A three-dimensional diagram shows that the association constants (Ka) for the inclusionof a- and 6-CD with substitUted benzene are mainly correIated with the molar refraction (R.) andhydrophobic constant (%) of the substitUents of guest compounds. It reveals that the inclusion ofcyclodextrin with the substitUted benzene is dondnantly driYen by van der Waals forces andhydrophobic interactions.展开更多
Fifteen title compounds 3a-0 were synthesized by condensation of 2chloro-benzothiazole with a-hydroxyphosphonates in good yields us- ing potassium iodide/tetrabutyl ammonium bromide as catalyst.All new com- pounds hav...Fifteen title compounds 3a-0 were synthesized by condensation of 2chloro-benzothiazole with a-hydroxyphosphonates in good yields us- ing potassium iodide/tetrabutyl ammonium bromide as catalyst.All new com- pounds have been identified by ~1H-NMR,IR and elemental analysis.展开更多
A series of novel phosphonoacetic acid derivatives, N-(ethoxycarbonylmethy-ethoxyphosphonyl)-α-amino acid esters and α-amino phosphonates, were synthesized via the reaction of the corresponding phosphonyl chloride ...A series of novel phosphonoacetic acid derivatives, N-(ethoxycarbonylmethy-ethoxyphosphonyl)-α-amino acid esters and α-amino phosphonates, were synthesized via the reaction of the corresponding phosphonyl chloride with amino acid ester hydrochlorides or amino phosphonates in the presence of a base. The preliminary bioassay shows that some compounds show significant anti-viral activity against tobacco mosaic virus (TMV)展开更多
α-Hederagenin(H),derived from Hedera nepalensis var.sinensis,is a pentacyclic oleane-type triterpenoid that exhibits clear cytotoxicity to different tumor cell lines.In this study,a series of novel C-28 derivatives o...α-Hederagenin(H),derived from Hedera nepalensis var.sinensis,is a pentacyclic oleane-type triterpenoid that exhibits clear cytotoxicity to different tumor cell lines.In this study,a series of novel C-28 derivatives of hederagenin(H) were designed and synthesized in attempt to develop potent tumor resistance reverse activities agents.Previous research showed that H6 displayed robust reverse activity for paclitaxel resistance in KBV cells.Importantly,Co-treatment of paclitaxel with H6 significantly reduced the tumor weight to 42%.Pleasingly,H6 enhanced the efficacy of paclitaxel against KBV cancer cell-derived xenograft tumors in nude mice.Mechanism studies had found that H6 activated permeability glycoprotein(P-gp) ATPase,reduced intracellular ATP levels and inhibited efflux of P-gp substrates,thus enhancing the antitumor activity of paclitaxel on KBV cells.Molecular docking analysis of homology P-gp and H6 then conducted using the Surflex-Dock module.H6 showed a high binding affinity docking score with a total score of 5.4148,much higher than that of H(0.1414).The nov.el C-28 derivatives of H was synthesized from H6 via three-step reaction.The reversal activity of all synthesized H derivatives were tested using the MTT assay.The results showed that the derivatives of nitrogen groups at C-28 displayed same even potent activity than parent compound H6.In addition,its underlying mechanism of action and in vivo activity are in explore.展开更多
Let A be a subalgebra of B(X) containing the identity operator I and an idempotent P. Suppose that α,β: A →A are ring epimorphisms and there exists some nest N on 2( such that α(P)(X) and β(P)(X) are ...Let A be a subalgebra of B(X) containing the identity operator I and an idempotent P. Suppose that α,β: A →A are ring epimorphisms and there exists some nest N on 2( such that α(P)(X) and β(P)(X) are non-trivial elements of N. Let A contain all rank one operators in AlgN and δ : A→ B(X) be an additive mapping. It is shown that, if δ is (α, β)-derivable at zero point, then there exists an additive (α, β)-derivation τ : A →β(X) such that δ(A) =τ(A) + α(A)δ(I) for all A∈A. It is also shown that if δ is generalized (α,β)-derivable at zero point, then δ is an additive generalized (α, β)-derivation. Moreover, by use of this result, the additive maps (generalized) (α,β)-derivable at zero point on several nest algebras, are also characterized.展开更多
BACKGROUND Intervertebral disc(IVD) degeneration is a condition characterized by a reduction in the water and extracellular matrix content of the nucleus pulposus(NP) and is considered as one of the dominating contrib...BACKGROUND Intervertebral disc(IVD) degeneration is a condition characterized by a reduction in the water and extracellular matrix content of the nucleus pulposus(NP) and is considered as one of the dominating contributing factors to low back pain. Recent evidence suggests that stromal cell-derived factor 1α(SDF-1α) and its receptor CX-C chemokine receptor type 4(CXCR4) direct the migration of stem cells associated with injury repair in different musculoskeletal tissues.AIM To investigate the effects of SDF-1α on recruitment and chondrogenic differentiation of nucleus pulposus-derived stem cells(NPSCs).METHODS We performed real-time RT-PCR and enzyme-linked immunosorbent assay to examine the expression of SDF-1α in nucleus pulposus cells after treatment with pro-inflammatory cytokines in vitro. An animal model of IVD degeneration was established using annular fibrosus puncture in rat coccygeal discs. Tissue samples were collected from normal control and degeneration groups.Differences in the expression of SDF-1α between the normal and degenerative IVDs were analyzed by immunohistochemistry. The migration capacity of NPSCs induced by SDF-1α was evaluated using wound healing and transwell migration assays. To determine the effect of SDF-1α on chondrogenic differentiation of NPSCs, we conducted cell micromass culture and examined the expression levels of Sox-9, aggrecan, and collagen II. Moreover, the roles of SDF-1/CXCR4 axis in the migration and chondrogenesis differentiation of NPSCs were analyzed by immunofluorescence, immunoblotting, and real-time RT-PCR.RESULTS SDF-1α was significantly upregulated in the native IVD cells cultured in vitro with pro-inflammatory cytokines, such as interleukin-1β and tumor necrosis factor-α, mimicking the degenerative settings. Immunohistochemical staining showed that the level of SDF-1α was also significantly higher in the degenerative group than in the normal group. SDF-1α enhanced the migration capacity of NPSCs in a dose-dependent manner. In addition, SDF-1α induced chondrogenic differentiation of NPSCs, as evidenced by the increased expression of chondrogenic markers using histological and immunoblotting analyses. Realtime RT-PCR, immunoblotting, and immunofluorescence showed that SDF-1αnot only increased CXCR4 expression but also stimulated translocation of CXCR4 from the cytoplasm to membrane, accompanied by cytoskeletal rearrangement.Furthermore, blocking CXCR4 with AMD3100 effectively suppressed the SDF-1α-induced migration and differentiation capacities of NPSCs.CONCLUSION These findings demonstrate that SDF-1α has the potential to enhance recruitment and chondrogenic differentiation of NPSCs via SDF-1/CXCR4 chemotaxis signals that contribute to IVD regeneration.展开更多
Pigment epithelium-derived factor (PEDF) is an antiangiogenic factor which is effective in tumour inhibition in a variety of tumours and has not yet been studied in bladder tumour before. In this study the expressio...Pigment epithelium-derived factor (PEDF) is an antiangiogenic factor which is effective in tumour inhibition in a variety of tumours and has not yet been studied in bladder tumour before. In this study the expression of PEDF, interleukin-1α (IL-1α) and -8 (IL-8) in bladder tumours was investigated. Immunohistochemistry was performed on 64 bladder tumour and 23 normal uroepithelium samples. Expression change of the factors was compared with clinicopathological parameters. Correlations between PEDF, IL-1α and IL-8 were analyzed. None of the factors was in relation to gender, tumour occurrence, and size or onset pattern. PEDF (P=0.014) and IL-1α (P=0.049) expression was down-regulated with grade progression. PEDF expression was lower in normal uroepithelium than in papillary urothelial neoplasm of low malignant potential (PUNLMP) (P=0.000) and carcinoma (P=0.009) whilst IL-1α (P=0.000 and P=0.000 respectively) and IL-8 (P=0.000 and P=0.023 respectively) expression was higher in the same grouping. PEDF expression had a negative correlation with IL-8 in PUNLMP (P=0.049, r=-0.578) as well as in tumour grouping (P=0.033, r=-0.276). Deranged expressional change of PEDF, IL-1α and IL-8 could be in relation to loss of differentiation from normal uroepithelium to papillary lesion and eventually to carcinoma.展开更多
A classical problem in ring theory is to study conditions under which a ring is forced to become commutative. Stimulated from Jacobson's famous result, several tech- niques are developed to achieve this goal. In the ...A classical problem in ring theory is to study conditions under which a ring is forced to become commutative. Stimulated from Jacobson's famous result, several tech- niques are developed to achieve this goal. In the present note, we use a pair of rings, which are the ingredients of a Morita context, and obtain that if one of the ring is prime with the generalized (α β)-derivations that satisfy certain conditions on the trace ideal of the ring, which by default is a Lie ideal, and the other ring is reduced, then the trace ideal of the reduced ring is contained in the center of the ring. As an outcome, in case of a semi-projective Morita context, the reduced ring becomes commutative.展开更多
BACKGROUND Gastrointestinal stromal tumors(GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1(NF-1) have an increased risk of ...BACKGROUND Gastrointestinal stromal tumors(GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1(NF-1) have an increased risk of developing gastrointestinal tumors, including rare types such as GIST.CASE SUMMARY A 60-year-old male Chinese patient was diagnosed with NF-1 10 years ago and presented with upper abdominal discomfort and black stools. Endoscopic ultrasonography and an enhanced abdominal computed tomography scan revealed a mass located 4 cm from the muscular layer of the descending duodenum. A 59-year-old Chinese woman who was diagnosed with NF-1 25 years ago presented with sudden unconsciousness and black stools. Multiple masses in the duodenum were noted by echogastroscopy and an enhanced abdominal computed tomography scan. Both patients presented with cutaneous neurofibromas. The histologic examination of tumors from both patients revealed spindle cells and low mitotic activity. Immunohistochemically, the tumor cells showed strong positivity for KIT(CD117), DOG-1, CD34, and Dehydrogenase Complex Subunit B, and negativity for SMA, desmin, S-100, and β-catenin. None of the six tumors from two patients had KIT exon 9, 11, 13, or 17 or platelet-derived growth factor receptor α exon 12 or 18 mutation, which is a typical finding for sporadic GISTs. None of the six tumors from the two patients had a BRAFV600 E mutation. The patients were alive and well during the follow-up period(range:0.6-5 yr).CONCLUSION There have been only a few previous reports of GISTs associated with NF-1.Although GISTs associated with NF-1 have morphologic and immunohistochemical similarities with GISTs, the pathogenesis, incidence,genetic background, and prognosis are not completely known. A medical history of NF-1 in a patient who has gastrointestinal bleeding or anemia and an intraabdominal mass with nonspecific computed tomography features may help in diagnosing GIST by virtue of the well-known association of these two entities.Molecular genetic studies of cases indicated that GISTs in NF-1 patients have a different pathogenesis than sporadic GISTs.展开更多
AIM: To investigate whether the expression of platelet-derived growth factor receptor-α-positive (PDGFRα<sup>+</sup>)-cells is altered in Hirschsprung’s disease (HD).MET...AIM: To investigate whether the expression of platelet-derived growth factor receptor-α-positive (PDGFRα<sup>+</sup>)-cells is altered in Hirschsprung’s disease (HD).METHODS: HD tissue specimens (n = 10) were collected at the time of pull-through surgery, while colonic control samples were obtained at the time of colostomy closure in patients with imperforate anus (n = 10). Immunolabelling of PDGFRα<sup>+</sup>-cells was visualized using confocal microscopy to assess the distribution of these cells, while Western blot analysis was undertaken to quantify PDGFRα protein expression.RESULTS: Confocal microscopy revealed PDGFRα<sup>+</sup>-cells within the mucosa, myenteric plexus and smooth muscle in normal controls, with a marked reduction in PDGFRα<sup>+</sup>-cells in the HD specimens. Western blotting revealed high levels of PDGFRα protein expression in normal controls, while there was a striking decrease in PDGFRα protein expression in the HD colon.CONCLUSION: These findings suggest that the altered distribution of PDGFRα<sup>+</sup>-cells in both the aganglionic and ganglionic HD bowel may contribute to the motility dysfunction in HD.展开更多
Objective:To investigate the interference and expression of human glial cell line-derived neurotrophic factor(hCDNF) and soluble TNF alpha(sTMFRⅠ) receptor genes in neural stem cells and to evaluate the roles of thes...Objective:To investigate the interference and expression of human glial cell line-derived neurotrophic factor(hCDNF) and soluble TNF alpha(sTMFRⅠ) receptor genes in neural stem cells and to evaluate the roles of these proteins in the genetic treatment of spinal cord injury.Methods:Full-length of GDNF cDNA(538 bp) and sTMFRⅠcDNA(504 bp) were inserted into the early 1 region of adenovirus genomic DNA respectively and were immediated by the human cytomegalovirus(gene promoter/enhancer). These adenoviruses were propagated in HEK293 cells via homologous recombination for 7-10 days in vivo,then they were used to infect human neural stem ceils.The infection and expression of gene were tested under immunofluorescence.ELISA and Westem-blot after 48 hours.Results:Almost all the cultured cells showed the nestin immunofluorescence positive staining,which was the characteristics of neural stem cell.A great quantity of EGFP and KFP were observed in neural stem cells,which indicated the expression of GDNF and sTMFRⅠ.After transfection of GDNF and sTMFRⅠgenes,many neural stem cells show GFAP and tubulin immunofluorescence positive staining,which meant that most neural stem cells differentiated into neuron at that condition.Conclusions:The infective efficiency of adenovirus is greatly acceptable to neural stem cell,thus adenovirus provide a useful vector for exogenous GDNF and sTMFRⅠgenes expressing in neural stem cells,which is useful for differentiation of neural stem cell.展开更多
基金This work was financially supported by the Research Fund for the Doctoral program of Higher Education (RFDP) and the National Natural Science Foundation of China (No. 20074025)
文摘Fractions of a water insoluble α-(1→3)-D-glucan (GL) extracted from Ganoderma lucidum were carboxy-methylated (CM) to obtain water-soluble carboxymethylated derivatives (CM-GL) having a degree of substitution (DS) of0.38~0.51. Weight-average molecular weight M_w and intrinsic viscosity [η] of the samples CM-GL were measured by gelpermeation chromatography combined with laser light scattering (GPC-LLS) and viscometry. The CM-GL exhibits a stifferchain in aqueous solution at 25℃ than the original glucan, The antitumor activities against Ehrlich ascites carcinoma (EAC,5×10~6) of the carboxymethylated derivatives from the α-glucan and curdlan, a β-glucan, are significantly higher than thoseof the original glucans. The effects of the relatively low molecular weight, expanded chains and better water-solubility of theCM-GL on the enhancement of antitumor activity could not be neglected. The chain stiffness decreased speedily withincrease of temperature from 40 to 60℃ or NaOH concentration from 0.1 to 0.4 in the solution, respectively, and the changeof the chain stiffness is reversible.
基金Project supported by the National Basic Research Program (973) of China(No. 2007CB407301)Beijing Municipal Natural Science Foundation(No. 8061004).
文摘N,O-bis(trimethylsily)trifluoroacetamide (BSTFA) and N-methyl-N(trimethylsily) trifluoroacetamide (MSTFA) are common derivatization reagents used in the GC-MS analysis of estrogen steroids such as estrone (El) and 17α-ethinylestradiol (EE2). In this study, three trimethylsilyl (TMS) steroid derivatives, mono- and di-trimethylsilyl EE2 and mono-trimethylsilyl El, were observed during the derivatization of EE2 with BSTFA or MSTFA and/or GC separation. Factors influencing the production of multiple TMS derivatives and their relative abundance were examined. It was found that both methanol and bisphenol A competed with estrogenic esteroids when reacting with silylation reagents, and thus affected the formation of TMS derivatives and their relative abundance in the derivatization products. Methanol was found to be more reactive than bisphenol A with the BSTFA reagent. None of the three solvents tested in this study could prevent the generation of multiple TMS derivatives during the derivatization of EE2 with BSTFA, followed by GC analysis. A similar result was observed using MSTFA as the derivative reagent followed by GC analysis. Thus, the suitability of BSTFA or MSTFA as the derivatization reagent for the determination of E1 and EE2 by GC-MS, under the conditions reported here, is questionable. This problem can be solved by adding trimethylsilylimidaz (TMSI) in the BSTFA reagent as recommended, and the performance of the method has been proved in this study.
基金supported by the National Natural Science Foundation of China(Nos.21105091 and 21171149)
文摘Two new a-aminophosphonate derivatives containing thieno[2,3-d]pyrimidine, diethyl(((6-ethyl-2-methyl-4-oxothieno[2,3-d]pyrimidin-3 (4H)-yl)amino)(4-methoxyphenyl)methyl) phosphonate (1) and diethyl((4-bromophenyl)((6-ethyl-2-methyl-4-oxothieno[2,3-d]pyrimidin-3 (4//)-yl)amino)methyl)phosphonate (2), have been synthesized by a facial phosphorylated reaction, and their structures were characterized by NMR, IR, HRMS and X-ray single-crystal diffraction. Compound 1 (C21H28N3O5PS, Mr = 465.49) belongs to the orthorhombic system, space group P212121, with a = 10.83653(16), b = 12.04906(19), c = 18.0061(3) A, V= 2351.06(6) A3, Z= 4, Dc= 1.315 g/cm3, p = 2.177 mm-1, F(000) = 984.0, the final R = 0.0389 and wR = 0.0985 for all data. Compound 2 (C20H25BrN304PS, Mr = 514.37) belongs to the orthorhombic system, space group P212121, with a = 10.9187(5), b = 11.9522(4), c = 17.7667(7) A, V= 2318.60(16) A3, Z = 4, Dc= 1.474 g/cm3,μ = 4.175 mm^-1, F(000) = 1056.0, the final R = 0.0367 and wR = 0.0946 for all data.
基金the National Natural Science Foundation of China to S-X.H(No.81522044)and to X.W(No.31471226)High-end Science and Technology Talents Program of Yunnan Province to S-X.H(No.2013HA022)a Grant from the Thousand Youth Talents Program of China.
文摘Tamoxifen resistance(TamR)is the underlying cause of treatment failure in many breast cancer patients receiving tamoxifen.In order to look for noncytotoxic natural products with the ability to reverse TamR,an extract from strain Streptomyces sp.KIB-H0495 was detected to be active.Subsequent large scale fermentation and isolation led to the isolation of four a-pyrone derivatives including two new compounds,violapyrones J(2)and K(3),and two known analogues,violapyrones B(1)and I(4).Further bioactivity assays indicated that only 1 and 3 exerted potent resensitization effects on MCF-7/TamR cells at a concentration of 1 lM.Owing to the simple structures of 1 and 3,these two compounds might have potential for further investigation as novel tamoxifen resensitization agent in breast cancer chemotherapy.
文摘The object of the present paper is to prove distortion theorems for the n-th order derivative of starlike and convex functions of order a. In addition. a related conjecture involving the fractional derivative of the convex function f(z) by Owa S and Srivastava H M is investigated.
文摘A three-dimensional diagram shows that the association constants (Ka) for the inclusionof a- and 6-CD with substitUted benzene are mainly correIated with the molar refraction (R.) andhydrophobic constant (%) of the substitUents of guest compounds. It reveals that the inclusion ofcyclodextrin with the substitUted benzene is dondnantly driYen by van der Waals forces andhydrophobic interactions.
文摘Fifteen title compounds 3a-0 were synthesized by condensation of 2chloro-benzothiazole with a-hydroxyphosphonates in good yields us- ing potassium iodide/tetrabutyl ammonium bromide as catalyst.All new com- pounds have been identified by ~1H-NMR,IR and elemental analysis.
文摘A series of novel phosphonoacetic acid derivatives, N-(ethoxycarbonylmethy-ethoxyphosphonyl)-α-amino acid esters and α-amino phosphonates, were synthesized via the reaction of the corresponding phosphonyl chloride with amino acid ester hydrochlorides or amino phosphonates in the presence of a base. The preliminary bioassay shows that some compounds show significant anti-viral activity against tobacco mosaic virus (TMV)
基金supported by State Key Laboratory of Drug Research(SIMM1705KF-07)
文摘α-Hederagenin(H),derived from Hedera nepalensis var.sinensis,is a pentacyclic oleane-type triterpenoid that exhibits clear cytotoxicity to different tumor cell lines.In this study,a series of novel C-28 derivatives of hederagenin(H) were designed and synthesized in attempt to develop potent tumor resistance reverse activities agents.Previous research showed that H6 displayed robust reverse activity for paclitaxel resistance in KBV cells.Importantly,Co-treatment of paclitaxel with H6 significantly reduced the tumor weight to 42%.Pleasingly,H6 enhanced the efficacy of paclitaxel against KBV cancer cell-derived xenograft tumors in nude mice.Mechanism studies had found that H6 activated permeability glycoprotein(P-gp) ATPase,reduced intracellular ATP levels and inhibited efflux of P-gp substrates,thus enhancing the antitumor activity of paclitaxel on KBV cells.Molecular docking analysis of homology P-gp and H6 then conducted using the Surflex-Dock module.H6 showed a high binding affinity docking score with a total score of 5.4148,much higher than that of H(0.1414).The nov.el C-28 derivatives of H was synthesized from H6 via three-step reaction.The reversal activity of all synthesized H derivatives were tested using the MTT assay.The results showed that the derivatives of nitrogen groups at C-28 displayed same even potent activity than parent compound H6.In addition,its underlying mechanism of action and in vivo activity are in explore.
文摘Let A be a subalgebra of B(X) containing the identity operator I and an idempotent P. Suppose that α,β: A →A are ring epimorphisms and there exists some nest N on 2( such that α(P)(X) and β(P)(X) are non-trivial elements of N. Let A contain all rank one operators in AlgN and δ : A→ B(X) be an additive mapping. It is shown that, if δ is (α, β)-derivable at zero point, then there exists an additive (α, β)-derivation τ : A →β(X) such that δ(A) =τ(A) + α(A)δ(I) for all A∈A. It is also shown that if δ is generalized (α,β)-derivable at zero point, then δ is an additive generalized (α, β)-derivation. Moreover, by use of this result, the additive maps (generalized) (α,β)-derivable at zero point on several nest algebras, are also characterized.
基金the National Natural Science Foundation of China,No.81772399
文摘BACKGROUND Intervertebral disc(IVD) degeneration is a condition characterized by a reduction in the water and extracellular matrix content of the nucleus pulposus(NP) and is considered as one of the dominating contributing factors to low back pain. Recent evidence suggests that stromal cell-derived factor 1α(SDF-1α) and its receptor CX-C chemokine receptor type 4(CXCR4) direct the migration of stem cells associated with injury repair in different musculoskeletal tissues.AIM To investigate the effects of SDF-1α on recruitment and chondrogenic differentiation of nucleus pulposus-derived stem cells(NPSCs).METHODS We performed real-time RT-PCR and enzyme-linked immunosorbent assay to examine the expression of SDF-1α in nucleus pulposus cells after treatment with pro-inflammatory cytokines in vitro. An animal model of IVD degeneration was established using annular fibrosus puncture in rat coccygeal discs. Tissue samples were collected from normal control and degeneration groups.Differences in the expression of SDF-1α between the normal and degenerative IVDs were analyzed by immunohistochemistry. The migration capacity of NPSCs induced by SDF-1α was evaluated using wound healing and transwell migration assays. To determine the effect of SDF-1α on chondrogenic differentiation of NPSCs, we conducted cell micromass culture and examined the expression levels of Sox-9, aggrecan, and collagen II. Moreover, the roles of SDF-1/CXCR4 axis in the migration and chondrogenesis differentiation of NPSCs were analyzed by immunofluorescence, immunoblotting, and real-time RT-PCR.RESULTS SDF-1α was significantly upregulated in the native IVD cells cultured in vitro with pro-inflammatory cytokines, such as interleukin-1β and tumor necrosis factor-α, mimicking the degenerative settings. Immunohistochemical staining showed that the level of SDF-1α was also significantly higher in the degenerative group than in the normal group. SDF-1α enhanced the migration capacity of NPSCs in a dose-dependent manner. In addition, SDF-1α induced chondrogenic differentiation of NPSCs, as evidenced by the increased expression of chondrogenic markers using histological and immunoblotting analyses. Realtime RT-PCR, immunoblotting, and immunofluorescence showed that SDF-1αnot only increased CXCR4 expression but also stimulated translocation of CXCR4 from the cytoplasm to membrane, accompanied by cytoskeletal rearrangement.Furthermore, blocking CXCR4 with AMD3100 effectively suppressed the SDF-1α-induced migration and differentiation capacities of NPSCs.CONCLUSION These findings demonstrate that SDF-1α has the potential to enhance recruitment and chondrogenic differentiation of NPSCs via SDF-1/CXCR4 chemotaxis signals that contribute to IVD regeneration.
基金sponsored in part by Science and Technology Commission of Shanghai Municipality, China (No. 07ZR14018)
文摘Pigment epithelium-derived factor (PEDF) is an antiangiogenic factor which is effective in tumour inhibition in a variety of tumours and has not yet been studied in bladder tumour before. In this study the expression of PEDF, interleukin-1α (IL-1α) and -8 (IL-8) in bladder tumours was investigated. Immunohistochemistry was performed on 64 bladder tumour and 23 normal uroepithelium samples. Expression change of the factors was compared with clinicopathological parameters. Correlations between PEDF, IL-1α and IL-8 were analyzed. None of the factors was in relation to gender, tumour occurrence, and size or onset pattern. PEDF (P=0.014) and IL-1α (P=0.049) expression was down-regulated with grade progression. PEDF expression was lower in normal uroepithelium than in papillary urothelial neoplasm of low malignant potential (PUNLMP) (P=0.000) and carcinoma (P=0.009) whilst IL-1α (P=0.000 and P=0.000 respectively) and IL-8 (P=0.000 and P=0.023 respectively) expression was higher in the same grouping. PEDF expression had a negative correlation with IL-8 in PUNLMP (P=0.049, r=-0.578) as well as in tumour grouping (P=0.033, r=-0.276). Deranged expressional change of PEDF, IL-1α and IL-8 could be in relation to loss of differentiation from normal uroepithelium to papillary lesion and eventually to carcinoma.
文摘A classical problem in ring theory is to study conditions under which a ring is forced to become commutative. Stimulated from Jacobson's famous result, several tech- niques are developed to achieve this goal. In the present note, we use a pair of rings, which are the ingredients of a Morita context, and obtain that if one of the ring is prime with the generalized (α β)-derivations that satisfy certain conditions on the trace ideal of the ring, which by default is a Lie ideal, and the other ring is reduced, then the trace ideal of the reduced ring is contained in the center of the ring. As an outcome, in case of a semi-projective Morita context, the reduced ring becomes commutative.
基金Supported by National Natural Science Foundation of China,No.81601692Program of Liaoning Province Department of Education,No.LK2016002
文摘BACKGROUND Gastrointestinal stromal tumors(GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1(NF-1) have an increased risk of developing gastrointestinal tumors, including rare types such as GIST.CASE SUMMARY A 60-year-old male Chinese patient was diagnosed with NF-1 10 years ago and presented with upper abdominal discomfort and black stools. Endoscopic ultrasonography and an enhanced abdominal computed tomography scan revealed a mass located 4 cm from the muscular layer of the descending duodenum. A 59-year-old Chinese woman who was diagnosed with NF-1 25 years ago presented with sudden unconsciousness and black stools. Multiple masses in the duodenum were noted by echogastroscopy and an enhanced abdominal computed tomography scan. Both patients presented with cutaneous neurofibromas. The histologic examination of tumors from both patients revealed spindle cells and low mitotic activity. Immunohistochemically, the tumor cells showed strong positivity for KIT(CD117), DOG-1, CD34, and Dehydrogenase Complex Subunit B, and negativity for SMA, desmin, S-100, and β-catenin. None of the six tumors from two patients had KIT exon 9, 11, 13, or 17 or platelet-derived growth factor receptor α exon 12 or 18 mutation, which is a typical finding for sporadic GISTs. None of the six tumors from the two patients had a BRAFV600 E mutation. The patients were alive and well during the follow-up period(range:0.6-5 yr).CONCLUSION There have been only a few previous reports of GISTs associated with NF-1.Although GISTs associated with NF-1 have morphologic and immunohistochemical similarities with GISTs, the pathogenesis, incidence,genetic background, and prognosis are not completely known. A medical history of NF-1 in a patient who has gastrointestinal bleeding or anemia and an intraabdominal mass with nonspecific computed tomography features may help in diagnosing GIST by virtue of the well-known association of these two entities.Molecular genetic studies of cases indicated that GISTs in NF-1 patients have a different pathogenesis than sporadic GISTs.
基金Supported by National Children’s Research Centre/Children’s Medical Research Foundation,Ireland
文摘AIM: To investigate whether the expression of platelet-derived growth factor receptor-α-positive (PDGFRα<sup>+</sup>)-cells is altered in Hirschsprung’s disease (HD).METHODS: HD tissue specimens (n = 10) were collected at the time of pull-through surgery, while colonic control samples were obtained at the time of colostomy closure in patients with imperforate anus (n = 10). Immunolabelling of PDGFRα<sup>+</sup>-cells was visualized using confocal microscopy to assess the distribution of these cells, while Western blot analysis was undertaken to quantify PDGFRα protein expression.RESULTS: Confocal microscopy revealed PDGFRα<sup>+</sup>-cells within the mucosa, myenteric plexus and smooth muscle in normal controls, with a marked reduction in PDGFRα<sup>+</sup>-cells in the HD specimens. Western blotting revealed high levels of PDGFRα protein expression in normal controls, while there was a striking decrease in PDGFRα protein expression in the HD colon.CONCLUSION: These findings suggest that the altered distribution of PDGFRα<sup>+</sup>-cells in both the aganglionic and ganglionic HD bowel may contribute to the motility dysfunction in HD.
基金Shenzhen Science and Technology Project(No.201103061)
文摘Objective:To investigate the interference and expression of human glial cell line-derived neurotrophic factor(hCDNF) and soluble TNF alpha(sTMFRⅠ) receptor genes in neural stem cells and to evaluate the roles of these proteins in the genetic treatment of spinal cord injury.Methods:Full-length of GDNF cDNA(538 bp) and sTMFRⅠcDNA(504 bp) were inserted into the early 1 region of adenovirus genomic DNA respectively and were immediated by the human cytomegalovirus(gene promoter/enhancer). These adenoviruses were propagated in HEK293 cells via homologous recombination for 7-10 days in vivo,then they were used to infect human neural stem ceils.The infection and expression of gene were tested under immunofluorescence.ELISA and Westem-blot after 48 hours.Results:Almost all the cultured cells showed the nestin immunofluorescence positive staining,which was the characteristics of neural stem cell.A great quantity of EGFP and KFP were observed in neural stem cells,which indicated the expression of GDNF and sTMFRⅠ.After transfection of GDNF and sTMFRⅠgenes,many neural stem cells show GFAP and tubulin immunofluorescence positive staining,which meant that most neural stem cells differentiated into neuron at that condition.Conclusions:The infective efficiency of adenovirus is greatly acceptable to neural stem cell,thus adenovirus provide a useful vector for exogenous GDNF and sTMFRⅠgenes expressing in neural stem cells,which is useful for differentiation of neural stem cell.