Biomedical subjects

Jing Yang

Publications and source records attributed to Jing Yang.

At least 199 records · Page 11Linked to original sources

PubMed2003

[Detection of 29 types of fusion gene in leukemia by multiplex RT-PCR].

OBJECTIVE: To analyze the fusion genes derived from 29 types of chromosome structural aberrations in children with leukemia. METHODS: Bone marrow samples from 191 children with leukemia were analyzed with a novel multiplex nested RT-PCR. RESULTS: Of the 191 leukemic samples, 86 (45.0%) carried 14 types of fusion genes including SIL/TAL1, MLL/AF1q, E2A/PBX1, MLL/AF6, AML1/ETO, MLL/AF9, TEL/ABL, BCR/ABL, MLL/AF10, dupMLL, MLL/ENL, TEL/AML1, PML/RARalpha and CBFbeta/MYH11. The activation of oncogene HOX11 was detected in 31 cases, with or without other chromosome aberrations in 15 (7.8%) and 16 cases (8.4%), respectively. CONCLUSION: This multiplex nested RT-PCR reaction could screen 29 types of chromosome structural aberrations at the same time. It may be helpful for the detection of minimal residual diseases after chemotherapy and bone marrow transplantation.

Adolescent↗

PubMed2003

[Research advances on inhibitor of apoptosis, survivin].

Survivin, a novel inhibitor of apoptosis, expressing in a cell cycle-dependent manner,regulates the G(2)/M phase of the cell cycle by associating with mitotic spindle microtubules; it directly inhibits caspase-3 and caspase-7activity. During tumorigenesis, survivin expression is inversely correlated with apoptosis and is positively correlated with proliferation and angiogenesis. Survivin expression up-regulation predicts short survival and poor prognosis in human cancers. Survivin targeting antisense nucleotide and survivin mutants induce apoptosis, reduce tumor growth potential, and sensitize tumor cells to chemotherapeutic drugs and X-irradiation in vitro and in vivo. These results suggest that survivin may has the potential function as a new target for the diagnosis and treatment of cancer.

Animals↗

PubMed2003

[Prokaryotic expression and characterization of an antigenic gene of adult Trichinella spiralis].

OBJECTIVE: To obtain a purified Ts87 gene expression product of adult Trichinella spiralis and identify its immunogenicity. METHODS: Ts87 cDNA was subcloned into PET-28a(+) expression vector. The transformed bacteria bearing PET-28a(+)/Ts87 plasmids were induced by IPTG for production of fusion proteins. The expression product purified with His-binding affinity chromatography and electro-elution assay was analyzed by SDS-PAGE, ELISA and Western blot, and was used to immunize the rabbits. RESULTS: PET-28a(+)/Ts87 transformed bacteria produced the desired fusion protein with a relative molecular weight of 40 kDa. The antisera with high titer were obtained by immunizing rabbit with Ts87 recombinant protein. Ts87 expression protein was detected as positive reaction with infected rabbit sera, infected swine sera and antisera against Ts87 by ELISA. Ts87 protein was also recognized by above-mentioned sera with Western blotting. However, Ts87 protein failed to react with the patient sera infected with Cysticercus cellulosae or Echinococcus granulosus, and rabbit sera infected with Schistosoma japonicum. CONCLUSION: A new Trichinella recombinant protein with specific antigenicity was obtained.

Animals↗

PubMed2003

[Construction and expression of the recombinant plasmid pcDNA3.1/Ts87 of Trichinella spiralis].

OBJECTIVE: To construct and express DNA plasmid of Trichinella spiralis. METHODS: The BamHI and HindIII enzyme sites and KOZAK sequences were introduced at both ends of Ts87 gene by PCR. Ts87 gene was ligated into pcDNA3.1(+) vector with T4 ligase. The recombinant plasmid pcDNA3.1/Ts87 and plasmid pcDNA3.1 were transfected into an eukaryotic cell line COS7 through Lipofectamine, respectively. The BALB/c mice were immunized with the purified plasmid DNA pcDNA3.1/Ts87 through two routes: intramuscular injection and gene-gun injection. RESULTS AND CONCLUSION: The pcDNA3.1/Ts87 was expressed both in COS7 and in the BALB/c mice.

Animals↗

PubMed2003

[Analysis of genetic structure of Magnaporthe grisea in the fields of different rice varieties].

The DNA of 251 Magnaporthe grisea isolates from Shiping County, which originated from monoculture and mixture fields, was extracted and amplified by rep-PCR which primer was from palindromes Pot2 of Magnaporthe grisea. The result showed that all isolates were amplified 9-17 DNA bands, the size was about from 400 bp to 23 kb, but mainly between 5-10 kb. 65% bands were polymorphism bands, and 35% were the same bands. Genetic structures of Magnaporthe grisea in the different rice varieties fields were compared by clustering analysis. The complexions of isolates genetic lineages were related to culture patterns. There were more genetic lineages in mixture field than in monoculture one. The dominant lineages were not distinct in mixture field. The result proved that biodiversity might provide a convincing basis for the steady selection of rice variety to pathogen.

Genetic Structures↗

PubMed2003

[Survivin antisense RNA enhances taxol-induced apoptosis in leukemia cell line HL-60].

OBJECTIVE: To explore the effects of survivin antisense RNA on taxol-induced apoptosis in leukemia cell line HL-60. METHODS: A survivin antisense eukaryotic vector pcDNA3-SVVas was transferred into HL-60 cells by electroporation. The live fraction was determined by trypan blue dye exclusion assay. Cell counting and MTT assay were performed to evaluate the sensibility of the transfected cells to taxol. Apoptosis was detected by DNA gel electrophoresis and nuclear staining. RESULTS: Two positive cell clones, HL-60 SVVas and HL-60 neo were obtained. Compared to HL-60 and HL-60 neo cells, HL-60 SVVas cells growth was significantly reduced (P < 0.05). By MTT assay, the IC(50) of taxol to HL-60 SVVas, HL-60 neo and HL-60 cells were (14.4 +/- 1.87) ng/ml, (31.9 +/- 6.38) ng/ml and (32.0 +/- 3.52) ng/ml, respectively, the difference was significant by statistic analysis (P < 0.01). Agarose gel electrophoresis of genomic DNA from HL-60 SVVas showed typical DNA ladder, but DNA from HL-60 neo and HL-60 did not. Nuclei become condense in HL-60 SVVas cells. CONCLUSION: Survivin antisense RNA could enhance taxol-induced apoptosis in leukemia cell line HL-60. This may lay an experimental foundation for further research of gene therapy in leukemia.

Antineoplastic Agents, Phytogenic↗

PubMed2003

[Epstein-Barr virus inhibits P16INK4a expression in human fetal nasopharyngeal epithelial cells escaping from the replicative senenscence].

Cell cycle deregulation is regarded as an important event to involve in cellular immortalization. To confirm the role of cell cycle deregulation in human fetal nasopharyngeal epithelial cells escaping from the replicative senescence induced by Epstein-Barr virus infection, we detected expression of cell cycle regulators, such as p16INK4a, p21WAF1/CIP1, p53, and E2F1 with Western blotting and immunocytochemisty in this study. Our results found that Epstein-Barr virus inhibited the expression of p16INK4a, at the same time, E2F1 expression were strongly increased in EBV-infected cells, however, as for the expression of p53 and p21WAF1/CIP1, there was no difference between EBV-infected cells and non-infected cells. The results show that EBV inactivates p16INK4a/pRB pathway and then induces E2F1 activity and it is implicated that Epstein-Barr virus-medicated cell cycle deregulation plays an important role in the immortalization of human nasopharyngeal epithelial cells. These data will be helpful for further studying the carcinogenesis of nasopharyngeal carcinoma.

Cell Transformation, Neoplastic↗

PubMed2003

Shenfu injection reduces toxicity of bupivacaine in rats.

OBJECTIVE: To investigate the effects of injecting Shenfu, an extract of traditional Chinese herbal medicines, on the central nervous system (CNS) and the cardiac toxicity of bupivacaine in rats. METHODS: Sixteen male Sprague-Dawley rats, weighing form 280 to 320 g, were randomly assigned to two groups (n = 8 in each group). Animals in the control group received a saline injection 10 ml/kg while animals in the Shenfu group received an injection of Shenfu 10 ml/kg intraperitoneally 30 minutes before intravenous infusion of bupivacaine. Lead II of an electrocardiogram (EEG) was continuously monitored after 3 needles were inserted into the skin of both forelimbs and the left hind-leg of each rat. The femoral artery was cannulated for measurement of arterial blood pressure and blood sampling. The femoral vein was cannulated for the infusion of bupivacaine. After baseline measurement (arterial blood pressure, heart rate and arterial blood gas), 0.5% bupivacaine was infused intravenously at a rate of 2 mg.kg(-1).min(-1) to all animals until asystole occurred. The time of bupivacaine-induced convulsions, arrhythmia and asystole were determined. The dose of bupivacaine was then calculated at the corresponding time point. RESULTS: The doses of bupivacaine that induced convulsions, arrhythmia and cardiac arrest were remarkably larger in Shenfu injection-treated animals than in saline-treated rats [convulsions, (10.5 +/- 1.9) mg/kg vs (7.2 +/- 1.5) mg/kg; arrhythmia (10.5 +/- 2.0) mg/kg vs (7.2 +/- 1.9) mg/kg; asystole, (32.8 +/- 8.5) mg/kg vs (25.0 +/- 5.0) mg/kg; P = 0.006, 0.009 and 0.044, respectively]. CONCLUSION: The Shenfu injection is able to reduce the toxicity of bupivacaine to CNS and cardiac system in rats.

Anesthetics, Local↗

PubMed2003

[The product identification study on the isolating process of strains produced trehalose].

In the isolating process of stains whose endocellular enzymes can produce trehalose on starch or maltooligosaccharides, we discovered the components of enzymatic reactant were complicated and it was difficult to purify them each other, however, we have to know quickly whether there was tehalose in the enzymatic reactant above. In order to make it clearly, thinner layer chromatography, high performance liquid chromatography-electrospray ionization mass spectrometry and 13C-nuclear magnetic resonance were adopted. The unknown oligosaccharide produced by Arthrobacter nicotinovorus D-97 was identified rapidly and this unknown oligosaccharide needn't be purified from the enzymatic reactant solely. The production on starch or maltooligosaccharides by endocellular enzymes of Arthrobacter nicotinovorus D-97 is trehalose. This research method in our paper can be applied in the isolating process of production trehalose and other functional glucobioses strains.

Arthrobacter↗

PubMed2003

[Production of a novel heparinase from Sphingobacterium sp].

The novel heparinase-producing bacterial strain Sphingobacterium sp. was isolated and screened from soil. The optimum medium composition is (g/L): Soytone 20, NaCl 1, K2HPO4 2.5, MgSO4 0.5, Heparin 2, Sucrose 15, pH 7.5. The optimum temperature for growth and enzyme production was 32 degrees C. When cultured at a rotating shaker at 30 degrees C for 36 hours, 200 r/min, 50 mL medium in 500 mL flask, the production of heparinase reached 4000 U/L.

Bacterial Proteins↗

PubMed2002

Development of high-affinity ligands and photoaffinity labels for the D-fructose transporter GLUT5.

The GLUT5 transporter catalyses the specific uptake of D-fructose and can accept this hexose in its furanose and pyranose ring forms. The transporter does not accept fructose epimers and has very limited tolerance of bulky groups substituted at the 2-, 3-, 4- and 5-OH positions [Tatibouët, Yang, Morin and Holman (2000) Bioorg. Med. Chem. 8, 1825-1833]. To further explore whether bulky groups can be tolerated at the primary OH positions, a D-fructose analogue with an allylamine group substitution to replace the 1-OH group was synthesized and was found to be quite well tolerated ( K (i)=27.1 mM). However, this analogue occurs in multiple ring forms. By contrast, 2,5-anhydro-D-mannitol is a symmetrical molecule that occurs only in a furanose ring form in which C-1 and C-6 are equivalent. We have therefore synthesized new 2,5-anhydro-D-mannitol analogues (substituted at the equivalent of the 6-OH of D-fructose) and from studies in Chinese hamster ovary cells expressing GLUT5 cells report that (i) the allylamine derivative of 2,5-anhydro-D-mannitol is well tolerated ( K (i)=2.66 mM); (ii) introduction of a di-nitrophenyl-substituted secondary amine group enhances affinity ( K (i)=0.56 mM); (iii) introduction of amide-linked biotinylated photolabel moieties is possible without loss of affinity relative to 2,5-anhydro-D-mannitol but a small secondary amine spacer between the biotinylated photolabelling moiety and the fructofuranose ring increases affinity (fructose photolabel 2; K (i)=1.16 mM); (iv) introduction of a hydrophilic tartarate spacer between biotin and the diazirine photoreactive groups can be accomplished without reduction in affinity and (v) photoactivation of biotinylated fructose photolabels leads to specific biotin tagging of GLUT5. These data suggest that substitution of a secondary amine group (-NH) to replace the C-6 (or C-1) -OH of 2,5-anhydro-D-mannitol results in compounds of high affinity; the affinity is enhanced over 10-fold compared with D-fructose.

Affinity Labels↗

PubMed2002

Signaling through Gi family members in platelets. Redundancy and specificity in the regulation of adenylyl cyclase and other effectors.

Platelet responses at sites of vascular injury are regulated by intracellular cAMP levels, which rise rapidly when prostacyclin (PGI(2)) is released from endothelial cells. Platelet agonists such as ADP and epinephrine suppress PGI(2)-stimulated cAMP formation by activating receptors coupled to G(i) family members, four of which are present in platelets. To address questions about the specificity of receptor:G protein coupling, the regulation of cAMP formation in vivo and the contribution of G(i)-mediated pathways that do not involve adenylyl cyclase, we studied platelets from mice that lacked the alpha subunits of one or more of the three most abundantly expressed G(i) family members and compared the results with platelets from mice that lacked the PGI(2) receptor, IP. As reported previously, loss of G(i2)alpha or G(z)alpha inhibited aggregation in response to ADP and epinephrine, respectively, producing defects that could not be reversed by adding an adenylyl cyclase inhibitor. Platelets that lacked both G(i2)alpha and G(z)alpha showed impaired responses to both agonists, but the impairment was no greater than in the individual knockouts. Loss of G(i3)alpha had no effect either alone or in combination with G(z)alpha. Loss of either G(z)alpha or G(i2)alpha impaired the ability of ADP and epinephrine to inhibit PGI(2)-stimulated adenylyl cyclase activity and caused a 40%-50% rise in basal cAMP levels, whereas loss of G(i3)alpha did not. Conversely, deletion of IP abolished responses to PGI(2) and caused cAMP levels to fall by 30%, effects that did not translate into enhanced responsiveness to agonists ex vivo. From these results we conclude that 1) cAMP levels in circulating platelets reflect ongoing signaling through G(i2), G(z), and IP, but not G(i3); 2) platelet epinephrine (alpha(2A)-adrenergic) and ADP (P2Y12) receptors display strong preferences among G(i) family members with little evidence of redundancy; and 3) these receptor preferences do not extend to G(i3). Finally, the failure of ADP and epinephrine to inhibit basal, as opposed to PGI(2)-stimulated, cAMP formation highlights the need during platelet activation for G(i) signaling pathways that involve effectors other than adenylyl cyclase.

Adenylyl Cyclases↗

PubMed2002

Insulin-stimulated cytosol alkalinization facilitates optimal activation of glucose transport in cardiomyocytes.

Abnormalities in intracellular pH regulation have been proposed to be important in type 2 diabetes and the associated cardiomyopathy and hypertension. We have therefore investigated the dependence of insulin-stimulated glucose transport on cytosolic pH in cardiomyocytes. Insulin treatment of cardiomyocytes resulted in a marked alkalinization of the cytoplasm as measured using carboxy-semi-napthorhodofluor-1. The alkalinizing effect of insulin was blocked by treatment with either cariporide (which inhibits the Na+/H+ exchanger) or by bafilomycin A1 (which inhibits H+-ATPase activity). After treatments with cariporide or bafilomycin A1, insulin stimulation of insulin receptor and insulin receptor substrate-1 phosphorylation and Akt activity were normal. In contrast, glucose transport activity and the levels of functional GLUT4 at the plasma membrane (detected using an exofacial photolabel) were reduced by approximately 50%. Immunocytochemical analysis revealed that insulin treatment caused a translocation of the GLUT4 from perinuclear structures and increased its co-localization with cell surface syntaxin 4. However, neither cariporide nor bafilomycin A1 treatment reduced the translocation of immunodetectable GLUT4 to the sarcolemma region of the cell. It is therefore hypothesized that insulin-stimulated cytosol alkalinization facilitates the final stages of translocation and incorporation of fully functional GLUT4 at the surface-limiting membrane.

Animals↗

PubMed2002

Event-related potentials elicited by stimulus spatial discrepancy in humans.

Sixteen subjects were instructed to discriminate whether the spatial locations of two visual stimuli presented in sequence were identical and event-related potentials (ERPs) were recorded from their scalps. The first and the second stimuli were presented in the same location in condition 1, but were in different locations in condition 2. ERP components of P100, N150, late positive component (LPC) and slow negative wave (SNW) were recorded in condition 1; in condition 2, N150 was enhanced and N270 was elicited before LPC. N150, N270 and SNW were all mainly distributed bilaterally over P3, P4, Pz, O1, O2, and Oz. N270 represents the brain activity for processing spatial discrepancy. There are several specialized brain areas involved in the generation of the N270.

Adult↗

PubMed2002

Activation of Rap1B by G(i) family members in platelets.

It has become increasingly appreciated that receptors coupled to G(alpha)(i) family members can stimulate platelet aggregation, but the mechanism for this has remained unclear. One possible mediator is the small GTPase, Rap1, which has been shown to contribute to integrin activation in several cell lines and to be activated by a calcium-dependent mechanism in platelets. Here, we demonstrate that Rap1 is also activated by G(alpha)(i) family members in platelets. First, we show that platelets from mice lacking the G(alpha)(i) family member G(alpha)(z) (which couples to the alpha(2A) adrenergic receptor) are deficient in epinephrine-stimulated Rap1 activation. We also show that platelets from mice lacking G(alpha)(i2), which couples to the ADP receptor, P2Y12, exhibit reduced Rap1 activation in response to ADP. In contrast, platelets from mice that lack G(alpha)(q) show no decrease in the ability to activate Rap1 in response to epinephrine but show a partial reduction in ADP-stimulated Rap1 activation. This result, combined with studies of human platelets treated with ADP receptor-selective inhibitors, indicates that ADP-stimulated Rap1 activation in human platelets is dependent on both the G(alpha)(i)-coupled P2Y12 receptor and the G(alpha)(q)-coupled P2Y1 receptor. G(alpha)(i)-dependent activation of Rap1 in platelets does not appear to be mediated by enhanced intracellular calcium release because no increase in intracellular calcium concentration was detected in response to epinephrine and because the calcium response to ADP was not diminished in platelets from the G(alpha)(i2)-/- mouse. Finally, using human platelets treated with selective inhibitors of phosphatidylinositol 3-kinase (PI3K) and mouse platelets selectively lacking the G(beta)(gamma)-activated form of his enzyme (PI3Kgamma), we show that G(i)-mediated Rap1 activation is PI3K-dependent. In summary, activation of Rap1 can be stimulated by G(alpha)(i)- and PI3K-dependent mechanisms in platelets and by G(q)- and Ca(2+)-dependent mechanisms, both of which may play a role in promoting platelet activation.

Adenosine Diphosphate↗

PubMed2002

Murine Sall1 represses transcription by recruiting a histone deacetylase complex.

The multi-zinc finger proteins of the Sal family regulate organogenesis. Genetic evidence from Drosophila has shown that spalt (sal) can alter gene expression in a cell autonomous fashion, but Sal proteins have never been directly analyzed for their ability to activate or repress transcription. In this report, we show that a member of the Sal family, mouse Sall1, is a potent transcriptional repressor. When fused to a heterologous DNA-binding domain, Sall1 represses transcription of a luciferase reporter by over 100-fold. Expression of the N terminus alone is sufficient for dose-responsive repression that, as shown by deletion analysis, requires the extreme N-terminal amino acids of the protein. The N terminus of Sall1 can repress at both short and long range relative to the promoter, and treatment with the histone deacetylase (HDAC) inhibitor, trichostatin A, alleviates repression by 3-fold. The same regions of the protein that are required for repression physically interact with components of chromatin remodeling complexes, HDAC1, HDAC2, RbAp46/48, MTA-1, and MTA-2. Finally, we demonstrate that Sall1 is localized to discrete nuclear foci and this localization depends on the N-terminal repression domain. Together, these results suggest that the N terminus of mouse Sall1 can recruit HDAC complexes to mediate transcriptional repression.

Amino Acid Sequence↗

PubMed2002

[Measurement of calcium fluorescent intensity in vital brain slice and mechanism of brain injury after circulatory arrest].

OBJECTIVE: To examine the calcium fluorescent intensity of vital brain slice and study the mechanism of brain injury after circulatory arrest. METHODS: Eight pigs underwent 90 minutes' deep hypothermic circulation arrest (DHCA) and eight pigs underwent retrograde cerebral perfusion (RCP) through superior vena cava and then rewarmed for 120 minutes. Vital brain slices were obtained and the calcium fluorescent intensity was examined with laser confocal scanning microscope (LCSM). The morphological change was examined with light microscope and electron microscope. RESULTS: The calcium fluorescent intensity of vital brain slice was lower in RCP group than in DHCA group. The calcium fluorescent intensity of vital brain slice is correlated with the level of moderate and severe eosinophilic degeneration of neuron (r = 0.86, P < 0.05). CONCLUSION: Calcium overload contributes to the injury of neuron after DHCA. RCP remarkably attenuates calcium overload, thus protecting the brain tissue.

Animals↗

PubMed2002

Insulin and isoproterenol have opposing roles in the maintenance of cytosol pH and optimal fusion of GLUT4 vesicles with the plasma membrane.

Insulin treatment of rat adipocytes increases both cytoplasmic alkalinity and glucose transport activity. Both processes are blocked by the phosphatidylinositol 3-kinase inhibitor wortmannin. Isoproterenol pre-treatment reverses the alkalinizing effects of insulin and leads to attenuation of insulin-stimulated glucose transport activity and exposure of GLUT4 to photolabeling reagents at the cell surface. These effects of isoproterenol are mimicked by acid loading and are reversed by cell-alkalinizing conditions. However, neither isoproterenol nor acid loading alters the total level of GLUT4 at the plasma membrane as revealed by Western blotting of plasma membrane fractions or immunodetection of GLUT4 in plasma membrane lawns. GLUT4 is therefore occluded from participation in glucose transport catalysis by a pH-sensitive process. To examine the kinetics of trafficking that lead to these changes in cell surface GLUT4 occlusion, we have utilized a new biotinylated photolabel, GP15. This reagent has a 70-atom spacer between the biotin and the photolabeling diazirine group, and this allows quenching of the surface signal of biotinylated GLUT4 by extracellular avidin. The rates of GLUT4 internalization are only slightly altered by isoproterenol or acidification, mainly due to reduced recycling over long internalization times. By contrast, insulin stimulation of GLUT4 exocytosis is slowed by isoproterenol or acidification pre-treatments. Biphasic time courses are evident, with an initial burst of exposure at the cell surface followed by a slow phase. It is hypothesized that the burst kinetics are a consequence of a two-phase fusion reaction that is rapid in the presence of insulin but slowed by cytosol acidification.

Adipocytes↗