Biomedical subjects

Ying Chen

Publications and source records attributed to Ying Chen.

At least 91 records · Page 5Linked to original sources

PubMed2006

[Expression of human ERMAP gene in fetal tissues].

Human ERMAP (hERMAP) is a novel gene coding for erythroid membrane-associated protein, which may play a role in erythropoiesis. To explore the role of hERMAP in fetal hematopoiesis, 29 fetuses of inevitable abortion with the fetal ages of 9 - 36 weeks were collected, and the total RNAs were isolated from the liver, spleen, kidney, heart, lung, thymus, brain, bone marrow and skeletal muscle, the RNAs from which at 25(+5) week fetal age were used to detect hERMAP expressions in different fetal tissues with Northern blot, and the hERMAP in various fetal tissues were quantified by FQ-PCR. As a result, Northern blot showed that hERMAP was expressed in liver and bone marrow at 25(+5) fetal age, but not in the other organ tissues. FQ-PCR results indicated that the hERMAP had been still expressed in 9 - 36th week fetal liver, increased starting from 12th-week, reaching a peak between 18 - 20th week and declining slowly starting from 21st-week. In the fetal bone marrow, expression of the hERMAP began from 15th week, reached a highest level between 27 - 32nd week and fell rapidly from 33rd week, the expression level of which was lower than that in liver. The low level expression of this gene was observed in some specimens of kidney, heart, lung, thymus, brain and skeletal muscle. It is concluded that the expression of hERMAP in fetal liver approximately consistent with haematopoiesis of fetal liver, and the expression of this gene in bone marrow aged 15 - 32nd fetal weeks coincides with haematopoiesis of fetal bone marrow. It suggests that the function of the hERMAP is possibly related with the migration of erythroid cells to liver and bone marrow during the fetal development process.

Blood Group Antigens↗

PubMed2006

[Expressions of TGF-betaR I, Smad2, Smad3 and Smad7 in keloids].

OBJECTIVE: To investigate the expression of TGF-betaR I, Smad2, Smad3 and Smad7 in keloids, normal scars and normal skins. Discuss the significance of these proteins in the course of keloid. METHODS: Immunohistochemistry method was used to detect the expression intensity and distribution of these proteins in above 3 kinds of different tissues in 44 cases. Statistics was used to analyze the data. RESULTS: The expression of TGF-betaR I were much stronger in keloid than in the other two tissues. The expression of Smad7 were lower in keloids. The increase expression of Smad2,3 were not obvious, but they were found to accumulate in the nucleus. CONCLUSIONS: The results indicate that over-expression of TGF-betaR I, low-expression of Smad7 and accumulation of Smad2,3 may be one of the etiological factors of keloids. This research may provide a new idea to prevent and treat keloids or other fibrosis diseases in the future.

Adolescent↗

PubMed2006

[Application of SELDI-TOF MS technology analyzing serum protein profiling for distinguishing laryngeal carcinoma from ordinary people].

OBJECTIVE: To analyze the spectrometric serum protein profiling of laryngeal carcinoma and healthy controls by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS), to establish serum marker pattern for the diagnosis of laryngeal carcinoma. METHOD: The serum samples of 46 cases of laryngeal carcinoma, 51 cases of healthy controls on WCX2 proteinchip, were collected. the spectrometric protein profiling was defected by SELDI-TOF-MS, the data were analyzed by Biomarker Patterns Software provided by Ciphergen Corp. A primary diagnosis model of laryngeal carcinoma was set up. This model was further evaluated by blind test with other l2 cases patients and 13 cases healthy controls. RESULT: Seventy-six protein peaks were detected at the molecular range of 2000-20000 Da., among which 27 ones were significantly different between laryngeal carcinoma and controls( P < 0.05). A diagnostic pattern consisting of 3 protein peaks was established with of accuracy 88.7% (86/97), sensitivity 87% (40/46), specificity 90.2% (46/51), Blind test generated a sensitivity of 83.3% (10/12)and specificity of 84.6% (11/13) respectively. CONCLUSION: It is successful to develop and evaluate the different spectrometric protein profiling patterns of laryngeal carcinoma and healthy control by SELDI-TOF-MS. This affords possibly a new method to early diagnosis of laryngeal carcinoma.

Adult↗

PubMed2006

Primary vitrectomy for rhegmatogenous retinal detachment associated with choroidal detachment.

PURPOSE: To evaluate the role and the anatomic and visual results of primary pars plana vitrectomy (PPV) in treating cases with rhegmatogenous retinal detachment associated with choroidal detachment. METHODS: All patients were divided into 2 groups. Each group included 23 consecutive eyes with rhegmatogenous retinal detachment and choroidal detachment with proliferative vitreoretinopathy less than grade C. In the study group, controlled removal of vitreous traction was achieved by primary vitrectomy and augmented by scleral buckling if needed. The breaks were treated by focused endolaser coagulation. Postoperative tamponade was done by SF6 or C3F8 gas. In the control group, all patients underwent regular scleral buckling procedure. The cases were followed up for 6 to 12 months. RESULTS: In the study group, retinal reattachment could be achieved in 21 cases (91.30%) after the first operation and in all cases after the second procedure. No occurrence of choroidal detachment occurred after the first procedure. Retinal reattachment rate and visual results tended to be better compared with conventional surgical techniques in the control group. CONCLUSION: Primary vitrectomy represents a safe, effective method in the management of rhegmatogenous retinal detachment associated with choroidal detachment.

Adult↗

PubMed2006

[Study on bile excretion of scutellarein].

OBJECTIVE: A HPLC-ECD method was established to determine scutellarin in rat bile. METHOD: The analytical column was Prontosil C18 (4.6 mm x 250 mm, 5 microm), and the mobile phase was consisted of methanol, 50 mmol x L(-1) phosphate buffer (adjusted by phosphoric acid to pH 2. 6), and tetrahydrofuran (40: 60: 10) , the flow rate was 1.0 mL x min(-1); the potential electrode voltage was 100 mv. RESULT: Concentration profile of scutellarin in rat bile was shown in this paper after oral administration of scutellarein. CONCLUSION: Only scutellarin was detected in rat bile, while both of scutellarin and scutellarein were detected in rat plasma.

Animals↗

PubMed2005

Degradation of endogenous and exogenous genes of roundup-ready soybean during food processing.

Roundup-Ready soybeans have been genetically modified to resist the effects of the herbicidal glyphosate and have become the most prevalent transgenic crop in the world. In this work, Roundup-Ready soybeans were used as raw material to study the effects of critical processing procedures such as grinding, cooking, blending, homogenization, sterilization, and spray-drying on the length of DNA fragments of an endogenous gene (lectin) and an exogenous gene (epsps) examined in material from three soybean foods of bean curd, soy milk, and soy powder and from samples taken during their processing. The results showed that various processing procedures caused degradations of both the endogenous and exogenous genes to different degrees. In the grinding procedure, endogenous gene DNA was degraded from 1883 to approximately 836 bp, and exogenous gene DNA was degraded from 1512 to approximately 408 bp. In the blending and squeeze-molding procedures, exogenous gene DNA was also degraded from about 408 to 190 bp, but there was no obvious action on the endogenous gene. After the endogenous and exogenous genes had been degraded to some degree, such as 836 and 408 bp, respectively, they were not evidently affected by cooking procedure at 100 degrees C for 15 min. However, the endogenous gene was further considerably degraded from around 836 to 162 bp in the sterilization procedure at 121 degrees C for 30 s. The effect of the homogenization step on endogenous and exogenous genes was similar to that of the cooking procedure. The coagulation procedure, principally a biochemical reaction, did not greatly affect the exogenous gene but did affect endogenous gene, reducing DNA size from about 836 to 407 bp. Furthermore, the spray-drying procedure, a process of physical shearing, high temperature, and sudden high pressure, distinctly caused degradation of both the lectin and epsps genes, rapidly decreasing the sizes from about 836 to 162 bp for the endogenous gene and from about 408 to 190 bp for the exogenous gene.

3-Phosphoshikimate 1-Carboxyvinyltransferase↗

PubMed2005

[Gene expression profiles and proteomics analysis of the cell transfected with the mutant type of COOH-terminal deleted of hepatitis B virus X].

OBJECTIVE: To investigate the mechanism of the different biological impacts of HBx3'-40, an engineered deletion mutant lacking the last 40 C-terminal amino acids. METHOD: Human hepatocellular cells of the line Huh7 were transfected with HBx3'-40 or wtHBx (wild type HBx) constructs. An oligo cDNA microarray containing 21074 human genes and Ests was utilized to examine the different gene expression between HBx3'-40 and paired control wtHBx cells. A series of methods, including immobilized pH gradient two-dimensional polyacrylamide gel electrophoresis (2-DE), silver staining, and PDQuest 2-D analysis software were used to analyze the differential protein-spots between HBx3'-40 and wtHBx cells. Selected differential protein-spots were identified with peptide mass fingerprinting based on matrix-assisted laser desorption/ionization time-of-fight mass spectrometry (MALDI-TOF-MS) and database searching. RESULTS: 165 (0.82%) candidate genes showing aberrant expression under HBx3'-40 induction were identified, of which 144 were up-regulated while 21 were down-regulated. Compared with wtHBx group, there were 135 +/- 13 differently protein spots in HBx3'-40 group by 2-DE. Of them, 7 significantly different protein spots were identified using mass spectrometry and computer matching with protein database. Most of the differently expressed genes and proteins were involved in transcription, oncogenes and tumor suppressor genes or protein, cell adhesion, signal transduction pathways, metabolisms, etc. CONCLUSION: The mutant HBx affects cell genes and proteins involved in various processes, especially in regulation of liver metabolism.

Carcinoma, Hepatocellular↗

PubMed2005

Methylation changes of H19 gene in sperms of X-irradiated mouse and maintenance in offspring.

The nature of imprinting is just differential methylation of imprinted genes. Unlike the non-imprinted genes, the methylation pattern of imprinted genes established during the period of gametogenesis remains unchangeable after fertilization and during embryo development. It implies that gametogenesis is the key stage for methylation pattern of imprinted genes. The imprinting interfered by exogenous factors during this stage could be inherited to offspring and cause genetic effect. Now many studies have proved that ionizing irradiation could disturb DNA methylation. Here we choose BALB/c mice as a research model and X-ray as interfering source to further clarify it. We discovered that the whole-body irradiation of X-ray to male BALB/c mice could influence the methylation pattern of H19 gene in sperms, which resulted in some cytosines of partial CpG islands in the imprinting control region could not transform to methylated cytosines. Furthermore, by copulating the interfered male mice with normal female, we analyzed the promoter methylation pattern of H19 in offspring fetal liver and compared the same to the pattern of male parent in sperms. We found that the majority of methylation changes in offspring liver were related to the ones in their parent sperms. Our data proved that the changes of the H19 gene methylation pattern interfered by X-ray irradiation could be transmitted and maintained in the first-generation offspring.

Animals↗

PubMed2005

RPE65 is an iron(II)-dependent isomerohydrolase in the retinoid visual cycle.

The isomerization of all-trans-retinyl ester to 11-cis-retinol in the retinal pigment epithelium (RPE) is a critical step in the visual cycle and is essential for normal vision. Recently, we have established that protein RPE65 is the isomerohydrolase catalyzing this reaction. The present study investigated if metal ions are required for the isomerohydrolase activity of RPE65. The conversion of all-trans-[3H]retinol to 11-cis-[3H]retinol was used as the measure for isomerohydrolase activity. Metal chelators 2,2'-bipyridine and 1,10-phenanthroline both showed dose-dependent inhibitions of the isomerohydrolase activity in bovine RPE microsomes, with IC50 values of 0.5 and 0.2 mm, respectively. In the same reaction systems, however, lecithin-retinol acyltransferase (LRAT) activity was not affected by these metal chelators. The isomerohydrolase activity inhibited by the metal chelators was restored by FeSO4 but not by CuSO4, ZnCl2, or MgCl2. Moreover, addition of Fe(III) citrate or FeCl3 did not restore the activity, indicating that Fe2+ is the metal ion essential for the isomerohydrolase activity. To confirm this result in recombinant RPE65, we expressed RPE65 in a 293A cell line stably expressing LRAT. In vitro activity assay showed that both metal chelators inhibited isomerohydrolase activity of recombinant RPE65. The addition of FeSO4 restored the enzymatic activity of the recombinant RPE65. Further, two specific iron-staining methods showed that purified RPE65 contains endogenous iron. Inductively coupled plasma mass spectrometry measurements showed that bovine RPE65 binds iron ion with a stoichiometry of 0.8 +/- 0.1. These results indicate that RPE65 is an iron-dependent isomerohydrolase in the visual cycle.

Animals↗

PubMed2005

Genetic characterization of asymmetric somatic hybrids between Bupleurum scorzonerifolium Willd and Triticum aestivum L.: potential application to the study of the wheat genome.

In this paper, we describe how Bupleurum scorzonerifolium/Triticum aestivum asymmetric somatic hybrids can be exploited to study the wheat genome. Protoplasts of B. scorzonerifolium Willd were irradiated with ultraviolet light (UV) and fused with protoplasts of common wheat (T. aestivum L.). All cell clones were similar in appearance to those of B. scorzonerifolium, while the regenerated plantlets were either intermediate or B. scorzonerifolium-like. Genotypic screening using isozymes showed that 39.3% of cell clones formed were hybrid. Some of the hybrid cell clones grew vigorously, and differentiated green leaves, shoots or plantlets. DNA marker analysis of the hybrids demonstrated that wheat DNA was integrated into the nuclear genomes of B. scorzonerifolium and in situ karyotyping cells revealed that a few wheat chromosome fragments had been introgressed into B. scorzonerifolium. The average wheat SSR retention frequency of the RH panel was 20.50%, but was only 6.67% in fusions with a non-irradiated donor. B. scorzonerifolium chromosomes and wheat SSR fragments in most asymmetric hybrid cell lines remained stable over a period of 2.5-3.5 years. We suggest the UV-induced asymmetric somatic hybrids between B. scorzonerifolium Willd and T. aestivum L. have the potential for use in the construction of an RH map of the wheat genome.

Bupleurum↗

PubMed2005

Microstructure formation and property of chitosan-poly(acrylic acid) nanoparticles prepared by macromolecular complex.

We report here a study on the microstructure formation process of polymeric nanoparticles based on polyelectrolyte complexes. When polyanion poly(acrylic acid) (PAA) was dropped into polycation chitosan (CS) solution, CS-PAA nanoparticles with diverse microstructure would be formed under different experimental conditions. The microstructure of CS-PAA nanoparticles changed from solid spherical nanoparticles to core-shell separative ones and turned back to solid spherical ones with the variation of preparation conditions. The influence of molecular weight of CS and PAA, shell cross-linking, dropping temperature on the size, stability and morphology of CS-PAA nanoparticles were also studied. The nanoparticle size was affected by the molecular weight of CS and PAA, the ratio of amino group to carboxyl group (na/nc) and the incubation temperature as well. The shell-cross-linking provides a means to stabilize these nanoparticles. These nanoparticles can encapsulate plasmid DNA very well, which makes them have great potential in gene delivery.

Acrylates↗

PubMed2005

Identification of conserved histidines and glutamic acid as key residues for isomerohydrolase activity of RPE65, an enzyme of the visual cycle in the retinal pigment epithelium.

We have recently reported that RPE65 from the retinal pigment epithelium is the isomerohydrolase, a critical enzyme in the visual cycle for regeneration of 11-cis retinal, the chromophore for visual pigments. Here, we demonstrated that mutation of any one of the absolutely conserved four histidine and one glutamic acid residues to alanine in RPE65 abolished its isomerohydrolase activity. Substitution of the conserved glutamic acid with glutamine also resulted in loss of the activity. Moreover, these mutations significantly reduced protein stability of RPE65. These results indicate that these conserved residues are essential for the isomerohydrolase activity of RPE65 and its stability.

Carrier Proteins↗

PubMed2005

Rapid quantification of semen hepatitis B virus DNA by real-time polymerase chain reaction.

AIM: To examine the sensitivity and accuracy of real-time polymerase chain reaction (PCR) for the quantification of hepatitis B virus (HBV) DNA in semen. METHODS: Hepatitis B viral DNA was isolated from HBV carriers' semen and sera using phenol extraction method and QIAamp DNA blood mini kit (Qiagen, Germany). HBV DNA was detected by conventional PCR and quantified by TaqMan technology-based real-time PCR (quantitative polymerase chain reaction (qPCR)). The detection threshold was 200 copies of HBV DNA for conventional PCR and 10 copies of HBV DNA for real time PCR per reaction. RESULTS: Both methods of phenol extraction and QIAamp DNA blood mini kit were suitable for isolating HBV DNA from semen. The value of the detection thresholds was 500 copies of HBV DNA per mL in the semen. The viral loads were 7.5X10(7) and 1.67X10(7) copies of HBV DNA per mL in two HBV infected patients' sera, while 2.14X10(5) and 3.02X10(5) copies of HBV DNA per mL in the semen. CONCLUSION: Real-time PCR is a more sensitive and accurate method to detect and quantify HBV DNA in the semen.

DNA, Viral↗

PubMed2005

Reelin modulates NMDA receptor activity in cortical neurons.

Reelin, a large protein that regulates neuronal migration during embryonic development, activates a conserved signaling pathway that requires its receptors, very low-density lipoprotein receptor and apolipoprotein E receptor 2, the cytoplasmic adaptor protein Disabled-1 (Dab1), and Src family kinases (SFK). Reelin also markedly enhances long-term potentiation in the adult hippocampus, suggesting that this developmental signaling pathway can physiologically modulate learning and behavior. Here, we show that Reelin can regulate NMDA-type glutamate receptor activity through a mechanism that requires SFKs and Dab1. Reelin mediates tyrosine phosphorylation of and potentiates calcium influx through NMDA receptors in primary wild-type cortical neurons but not in Dab1 knock-out neurons or in cells in which Reelin binding to its receptors is blocked by a receptor antagonist. Inhibition of SFK abolishes Reelin-induced and glutamate-dependent enhancement of calcium influx. We also show that Reelin-induced augmentation of Ca2+ entry through NMDA receptors increases phosphorylation and nuclear translocation of the transcription factor cAMP-response element binding protein. Thus, Reelin may physiologically modulate learning and memory by modulating NMDA receptor functions.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

PubMed2005

RPE65 is the isomerohydrolase in the retinoid visual cycle.

RPE65 is an abundant protein in the retinal pigment epithelium. Mutations in RPE65 are associated with inherited retinal dystrophies. Although it is known that RPE65 is critical for regeneration of 11-cis retinol in the visual cycle, the function of RPE65 is elusive. Here we show that recombinant RPE65, when expressed in QBI-293A and COS-1 cells, has robust enzymatic activity of the previous unidentified isomerohydrolase, an enzyme converting all-trans retinyl ester to 11-cis retinol in the visual cycle. The initial rate for the reaction is 2.9 pmol/min per mg of RPE65 expressed in 293A cells. The isomerohydrolase activity of RPE65 requires coexpression of lecithin retinol acyltransferase in the same cell to provide its substrate. This enzymatic activity is linearly dependent on the expression levels of RPE65. This study demonstrates that RPE65 is the long-sought isomerohydrolase and fills a major gap in our understanding of the visual cycle. Identification of the function of RPE65 will contribute to the understanding of the pathogenesis for retinal dystrophies associated with RPE65 mutations.

Acyltransferases↗

PubMed2005

Pseudo-spin model for the microtubule wall in external field.

Microtubules (MTs) in the cytoskeletons of eukaryotic cells provide a wide range of microskeletal and micromuscular functionalities. Some evidence has indicated that they can serve as a medium for intracellular signaling processing. In this paper, for the inherent symmetry structures and the electric properties of tubulin dimers, the microtubule (MT) is treated as a one-dimensional ferroelectric system. The nonlinear dynamics of the dimer electric dipoles is described by virtue of the double-well potential and the physical problem is further mapped onto the pseudo-spin system. In addition, the effect of the external electric field on the MT has been taken into account.

Dimerization↗

PubMed2005

Signaling pathways of magnolol-induced adrenal steroidogensis.

This study focused on identifying the signalling mediating the effect of magnolol on corticosterone production. Magnolol-induced corticosterone production was completely inhibited by mitogen-activated protein kinase kinase (MEK)-inhibitor PD98059, tyrosine kinase (TK)-inhibitor genistein or Janus tyrosine kinase 2 (JAK2)-inhibitor AG490, suggesting that extracellular signal-regulated kinase (ERK) and JAK2 are both involved in this signaling cascade. Further, magnolol induced the transient phosphorylation of MEK, ERK, cAMP response-element binding protein (CREB) and the expression of 32 and 30 kDa steroidogenic acute regulatory protein (StAR) in a time-dependent manner. Inhibition of TK or JAK2 activities blocked magnolol-induced phosphorylation of MEK and ERK, again supporting the upstream role of JAK2. The activation of JAK2 or MEK apparently mediated the magnolol-induced phosphorylation of CREB and the upregulation of StAR. These findings demonstrate a novel pathway for magnolol to induce the expression of StAR, which regulates the rate-limiting step in sterodiogenesis.

Adrenal Cortex↗

PubMed2005

Glutamate cysteine ligase catalysis: dependence on ATP and modifier subunit for regulation of tissue glutathione levels.

Glutamate cysteine ligase (GCL), which synthesizes gamma-glutamyl-cysteine (gamma-GC), is the rate-limiting enzyme in GSH biosynthesis. gamma-GC may be produced by the catalytic subunit GCLC or by the holoenzyme (GCLholo), which comprises GCLC and the modifier subunit GCLM. The Gclm(-/-) knock-out mouse shows tissue levels of GSH that are between 9 and 40% of the Gclm(+/+) wild-type mouse. In the present study, we used recombinant GCLC and GCLM and Gclm(-/-) mice to examine the role of GCLM on gamma-GC synthesis by GCLholo. GCLM decreased the Km for ATP by approximately 6-fold and, similar to other species, decreased the Km for glutamate and increased the Ki for feedback inhibition by GSH. Furthermore, GCLM increased by 4.4-fold the Kcat for gamma-GC synthesis; this difference in catalytic efficiency of GCLholo versus GCLC allowed us to derive a mathematical relationship for gamma-GC production and to determine the relative levels of GCLholo and GCLC; in homogenates of brain, liver, and lung, the ratio of GCLC to GCLholo was 7.0, 2.0, and 3.5, respectively. In kidney, however, the relationship between GCLC and GCLholo was complicated. Kidney contains GCLholo, free GCLC, and free GCLM, and free GCLC in kidney cannot interact with GCLM. Taken together, we conclude that, in most tissues, GCLM is limiting, suggesting that an increase in GCLM alone would increase gamma-GC synthesis. On the other hand, our results from kidney suggest that gamma-GC synthesis may be controlled post-translationally.

Adenosine Triphosphate↗