Biomedical subjects

Ying Jia

Publications and source records attributed to Ying Jia.

14 recordsLinked to original sources

PubMed2006

Potential roles for autophosphorylation, kinase activity, and abundance of a CDK-activating kinase (Ee;CDKF;1) during growth in leafy spurge.

Leafy spurge (Euphorbia esula L.) is a deep-rooted perennial weed that propagates both by seeds and underground adventitious buds located on the crown and roots. To enhance our understanding of growth and development during seed germination and vegetative propagation, a leafy spurge gene (Accession No. AF230740) encoding a CDK-activating kinase (Ee;CDKF;1) involved in cell-cycle progression was identified, and its function was confirmed based on its ability to rescue a yeast temperature-sensitive CAK mutant (GF2351) and through in vitro kinase assays. Site-directed mutagenesis of Ee;CDKF;1 indicated that two threonine residues (Thr291 and Thr296) were mutually responsible for intra-molecular autophosphorylation and for phosphorylating its substrate protein, cyclin-dependent kinase (CDK). Polyclonal antibodies generated against the Ee;CDKF;1 protein or against a phosphorylated Ee;CDKF;1 peptide [NERYGSL(pT)SC] were used to examine abundance and phosphorylation of CDKF;1 during seed germination and bud growth. The levels of CDKF;1 were lower in dry or imbibed seeds than in germinating seeds or seedlings. Differences in CDKF;1 were also observed during adventitious bud development; small buds appeared to have greater levels of CDKF;1 than large buds. Similar patterns of CDKF;1 expression were detected with either the polyclonal antibody developed using the CDKF;1 protein or the phosphorylated peptide. These results indicated that Thr291 is constitutively phosphorylated in vivo and associated with Ee;CDKF;1 activity. Our results further suggest that a certain level of CDKF;1 activity is maintained in most tissues and may be an important phenomenon for enzymes that regulate early steps in cell-cycle signaling pathways.

Amino Acid Sequence↗

PubMed2006

Determination and pharmacokinetic study of syringin and chlorogenic acid in rat plasma after administration of Aidi lyophilizer.

A high-performance liquid chromatographic (HPLC) method was developed for the first time to simultaneously quantify syringin and chlorogenic acid in rat plasma using wavelength-transfer technology. The analysis was performed on a Diamonsil C(18) column (200 x 4.6 mm i.d., 5 microm particle size) with isocratic mobile phase consisting of acetonitrile-0.05% phosphoric acid (12:88, v/v). The linear ranges were 0.20-10 and 0.25-30 microg/mL, respectively. The lower limits of quantification were 0.20 and 0.25 microg/mL, respectively. The method was shown to be reproducible and reliable with intraday precision below 8.5 and 6.1%, interday precision below 7.1 and 5.5%, accuracy within +/-7.1 and +/-8.6%, and mean extraction recovery excess of 92.1 and 80.9%, respectively, which were all calculated from the blank plasma sample spiked with syringin and chlorogenic acid at three concentrations of 0.20, 1.0 and 6.0 microg/mL for syringin and 0.25, 2.0 and 20 microg/mL for chlorogenic acid. This method was validated for specificity, accuracy and precision and was successfully applied to the pharmacokinetic study of syringin and chlorogenic acid in rat plasma after intravenous administration of Aidi lyophilizer.

Animals↗

PubMed2006

Subtractive cDNA libraries identify differentially expressed genes in dormant and growing buds of leafy spurge (Euphorbia esula).

Two subtractive cDNA libraries were developed to study genes associated with bud dormancy (reverse library) and initiation of shoot growth (forward library) in leafy spurge. To identify unique sequences represented in each library, 15744 clones were screened to reduce the level of redundancy within both libraries. A total of 516 unique sequences were obtained from 2304 minimally redundant clones. Radioactive probes developed from RNAs extracted from crown buds of either intact (para-dormant control) or a series of growth-induced (2 h, 2, and 4 d after decapitation) plants were used to identify differentially expressed genes by macroarray analysis. Semi-quantitative RT-PCR was used to confirm results obtained by macroarray analysis and to determine the expression profiles for other transcripts identified within the subtractive libraries. Selected clones were also used to examine gene expression in crown buds after growth induction and/or during normal seasonal growth. In this study, four distinct patterns of gene expression were observed during the transition from para-dormancy to growth-induction. Many of the differentially regulated genes identified have unknown or hypothetical functions while others are known to play important roles in molecular functions. Gene ontology analysis identified a greater proportion of genes involved with catalytic activity in the forward library while the reverse library had a greater proportion of genes involved in DNA/RNA binding.

Cluster Analysis↗

PubMed2006

Transcription of a 'photosynthetic' T4-type phage during infection of a marine cyanobacterium.

The transcription of S-PM2 phage following infection of Synechococcus sp. WH7803, a marine cyanobacterium, was analysed by quantitative real-time PCR. Unlike the distantly related coliphage T4, there were only two (early and late) instead of three (early, middle and late) classes of transcripts during the developmental cycle of the phage. This difference is consistent with the absence from the S-PM2 genome of T4-like middle mode promoter sequences and the transcription factors associated with their recognition. Phage S-PM2 carries the 'photosynthetic' genes psbA and psbD that encode homologues of the host photosystem II proteins D1 and D2. Transcripts of the phage psbA gene appeared soon after infection and remained at high levels until lysis. Throughout the course of infection, the photosynthetic capacity of the cells remained constant. A considerable transient increase in the abundance of the host psbA transcripts occurred shortly after infection, suggesting that the host responds to the trauma of phage infection in a similar way as it does to a variety of other environmental stresses. The very substantial transcription of the phage psbA gene during the latter phase of phage infection suggests that S-PM2 has acquired this cellular gene to ensure that D1 levels and thus photosynthesis are fully maintained until the infected cell finally lyses. Unexpectedly, transcripts of a phage-encoded S-layer protein gene were among the earliest and most abundant detected, suggesting that this partial homologue of a host protein plays an important role in the S-PM2 infection process.

Bacteriophages↗

PubMed2006

Simultaneous determination of protocatechuic acid, syringin, chlorogenic acid, caffeic acid, liriodendrin and isofraxidin in Acanthopanax senticosus Harms by HPLC-DAD.

A high performance liquid chromatography (HPLC) method was developed for the first time to quantify simultaneously the six major active ingredients in Acanthopanax senticosus (Rupr. et Maxim.) Harms, namely protocatechuic acid, syringin, chlorogenic acid, caffeic acid, liriodendrin and isofraxidin. The analysis was performed by a reverse phase gradient elution with an aqueous mobile phase (containing 0.05% phosphoric acid) modified by acetonitrile and diode-array multiple-wavelength UV detector (DAD). Six regression equations showed good linear relationships between the peak area of each marker and concentration. The recoveries of the markers listed above were 92.3%, 93.9%, 90.3%, 93.1%, 94.3% and 90.7%, respectively. The relative standard deviation of intra-day and inter-day were less than 2.7% and 3.1%, respectively. This method was validated for specificity, accuracy, precision and limits of quantification. Medicinal materials of ten commercial brands were analyzed and found to contain different amounts of the six bioactive markers. The method developed can be used for the quality control of Acanthopanax senticosus (Rupr. et Maxim.) Harms.

Caffeic Acids↗

PubMed2005

Mitogen-activated protein kinases control cardiac KChIP2 gene expression.

Hypertrophied myocardium is associated with reductions in the transient outward K(+) current (Ito) and expression of pore-forming Kv4.2/4.3 and auxiliary KChIP2 subunits. Here we show that KChIP2 mRNA and protein levels are dramatically decreased to 10% to 30% of control levels in the left ventricle of aorta-constricted rats in vivo and phenylephrine (PE)-treated myocytes in vitro. PE also markedly decreases Ito density. Inhibition of protein kinase Cs (PKCs) does not affect the PE-induced reduction in KChIP2 mRNA level, whereas activation of PKC with phorbol ester (phorbol myristate [PMA]) causes a marked reduction in KChIP2 mRNA level. Pharmacological inhibition of MEKs or overexpression of a dominant-negative MEK1 increases the basal KChIP2 mRNA expression and blocks the PMA-induced decrease in auxiliary subunit mRNA level. In addition, a constitutively active MEK1 decreases the basal KChIP2 mRNA level, and PMA causes no further reduction in auxiliary subunit mRNA level in active MEK1-expressing cells. Furthermore, pharmacological inhibition of JNKs or overexpression of a dominant-negative JNK1 prevents the PE-induced, but not PMA-induced, reduction in KChIP2 mRNA expression. These results suggest that downregulation of KChIP2 expression significantly contributes to the hypertrophy-associated reduction in Ito density. They also indicate that the expression of KChIP2 mRNA is controlled by the 2 branches of mitogen-activated protein kinase pathways: JNKs play a predominant role in mediating the PE-induced reduction, whereas the MEK-ERK pathway influences the basal expression and mediates the PKC-mediated downregulation.

Animals↗

PubMed2005

Cancellation phenomenon of barrier escape driven by a non-Gaussian noise.

The Lévy noise, with a long-tail distribution induced particle escape from a metastable potential, is shown to display a feature called a cancellation phenomenon, as compared to the Brownian motion case. As a consequence, the escape rate is found to be a nonmonotonous function of the Lévy index mu and the Arrhenius law is not obeyed. We have also derived a rate expression using the reactive flux method, which supports our numerical findings, namely, with the decrease of mu, a large positive flow is allowed to establish at the barrier, however, the probability passing over the saddle point decreases. This implies that the particles outside the barrier come back to the inside and cancel with themselves.

Journal Article↗

PubMed2005

Neural network learning algorithms for tracking minor subspace in high-dimensional data stream.

A novel random-gradient-based algorithm is developed for online tracking the minor component (MC) associated with the smallest eigenvalue of the autocorrelation matrix of the input vector sequence. The five available learning algorithms for tracking one MC are extended to those for tracking multiple MCs or the minor subspace (MS). In order to overcome the dynamical divergence properties of some available random-gradient-based algorithms, we propose a modification of the Oja-type algorithms, called OJAm, which can work satisfactorily. The averaging differential equation and the energy function associated with the OJAm are given. It is shown that the averaging differential equation will globally asymptotically converge to an invariance set. The corresponding energy or Lyapunov functions exhibit a unique global minimum attained if and only if its state matrices span the MS of the autocorrelation matrix of a vector data stream. The other stationary points are saddle (unstable) points. The globally convergence of OJAm is also studied. The OJAm provides an efficient online learning for tracking the MS. It can track an orthonormal basis of the MS while the other five available algorithms cannot track any orthonormal basis of the MS. The performances of the relative algorithms are shown via computer simulations.

Algorithms↗

PubMed2005

LC-MS determination and pharmacokinetic studies of ursolic acid in rat plasma after administration of the traditional chinese medicinal preparation Lu-Ying extract.

Sambucus chinensis L. is a native perennial herb distributed throughout China. In traditional Chinese medicine (TCM), this herb is known as Lu-Ying. Ursolic acid is the major effective constituent of Lu-Ying. A rapid, sensitive, and accurate liquid chromatography-mass spectrometry (LC-MS) method for the determination of ursolic acid in rat plasma was developed and validated. Plasma samples taken from rats that had received Lu-Ying extract orally were acidified with acetic acid and then extracted with a mixture of hexane-dichloromethane-2-propanol (20:10:1, v/v/v). Separation of ursolic acid was accomplished on a C(18) column interfaced with a single quadrupole mass spectrometer. The mobile phase consisting of methanol and water (95:5, v/v) was delivered at a flow rate of 1.0 ml/min. Atmospheric pressure chemical ionization was operated in negative-ion mode. Using selected ion-monitoring mode, the deprotonated molecules [M-H](-) at m/z 455 and 469 were used to quantify ursolic acid and glycyrrhetic acid (internal standard), respectively. The assay was shown to be linear over the range of 10-1000 ng/ml (r> or =0.9960) with a lower limit of quantification of 10 ng/ml. The method was shown to be reproducible and reliable with intraday precision below 7.8%, interday precision below 8.1%, accuracy within +/-4.3%, and mean extraction recovery excess of 83.6%, which were all calculated from the blank plasma sample spiked with ursolic acid at three concentrations of 20, 200, and 800 ng/ml. The LC-MS method has been successfully applied to pharmacokinetic studies of ursolic acid after oral administration of Lu-Ying ethanolic extract (at a dose containing 80.32 mg/kg ursolic acid) to rats. The main pharmacokinetic parameters were: t(1/2), 4.3 h; K(e), 0.16 1/h; t(max), 1.0 h; C(max), 294.8 ng/ml; AUC(0-t) and AUC(0-infinity), 1007.1 ng.h/ml and 1175.3 ng.h/ml, respectively.

Administration, Oral↗

PubMed2005

Analysis of the essential oil from radix bupleuri using capillary gas chromatography.

A simple and rapid capillary gas chromatographic (CGC) method with flame ionization detection has been newly developed for analysis of the essential oil from Radix Bupleuri. Twenty components were identified with gas chromatography-mass spectrometry. E-2-heptenal, furan, 2-pentyl, and E-2-nonenal were quantified simultaneously using the internal standard method. Decane was used as an internal standard. Separation and quantification were achieved on a DB-5 capillary column (30 m x 0.25 mm i. d., 0.25-microm film thickness). The oven temperature was programmed as follows: 60 degrees C to 70 degrees C at 1 degree C/min rate, 70 degrees C for 10 min, 3 degrees C/min to 120 degrees C, 20 degrees C/min to 250 degrees C, and held at 250 degrees C for 5 min. The oven pressure was programmed as follows: 46.1 kPa for 25 min, 20.0 kPa/min to 77.6 kPa, and then held for 22 min. Split injection was conducted with a split ratio of 10:1; flow-rate, 1.00 ml/min; carrier gas, nitrogen; injector temperature, 280 degrees C; and detector temperature, 280 degrees C. The system proved effective in resolving E-2-heptenal, furan, 2-pentyl, and E-2-nonenal peaks from their interfering components. The method displayed excellent linearity in the range of 26.8-1072 microg/ml (E-2-heptenal), 6.5-1292 microg/ml (furan, 2-pentyl), and 7.8-1564 microg/ml (E-2-nonenal). The average recovery rates of E-2-heptenal, furan, 2-pentyl, and E-2-nonenal were 100.3%, 102.8%, and 97%, respectively. CGC is a quick and accurate method for analysis of the essential oil from Radix Bupleuri.

Bupleurum↗

PubMed2005

[Effects of mechanical stress on the proliferation kinetics of the human periodontal fibroblast cells in vitro].

OBJECTIVE: The purpose of this study was to explore the possible principles for remodeling of periodontal tissues under mechanical stretching by investigating the effects of intermittent mechanical stretching delivered by a new invented type of cell stress machine on the proliferation kinetics of the human periodontal fibroblast cells (hPDLFs) in vitro. METHODS: hPDLFs were cultured in vitro. The 4 - 7th generation of hPDLFs were undergone mechanical stretching. All cells were grouped as strained and unstrained (controls). Strained groups cells were gathered after 2, 4 and 6 hours with the stress 1 000, 2 000 and 3 000 mustrain. Flow cytometry (FCM) was used to examine the ratio of DNA (S%) and the index of proliferation(PI). RESULTS: Mechanical force would lead to the change of hPDLFs proliferation. Within the experiment, both 1 000 mustrain and 2 000 mustrain could increase the proliferation index (PI) (P < 0.05). While under 3 000 mustrain, DNA synthesis was significantly decreased( P < 0.05). CONCLUSION: Some range of mechanical stretching accelerates hPDLFs proliferation. This research discusses the remodeling process of periodontal tissues undergoing the mechanical stretching on cytological view, and it makes a basement for further revealing the mechanical strain induced periodontal biological principles. Also it provides a useful direction for clinical orthodontic therapy.

Cell Proliferation↗

PubMed2004

Reverse-phase HPLC determination and pharmacokinetic study of vanillic acid in the plasma of rats treated with the traditional Chinese medicinal preparation Di-Gu-Pi decoction.

A sensitive, simple, and accurate method for the determination and pharmacokinetic study of vanillic acid in rat plasma was developed using reverse-phase HPLC with UV detection after oral administration of the traditional Chinese medicine preparation of the Di-Gu-Pi decoction. Plasma samples taken from rats were extracted with methanol. The constituent vanillic acid was separated on a C(18) stationary phase and a mobile phase of acetonitrile-water (15:85, v/v) (adjusted to pH 3.0 using phosphoric acid), with a UV detector setting at 260 nm. The validated HPLC method developed was used to determine the pharmacokinetic profile of vanillic acid in rat plasma after administration of the Di-Gu-Pi decoction.

Administration, Oral↗

PubMed2003

GATA and FOG2 transcription factors differentially regulate the promoter for Kv4.2 K(+) channel gene in cardiac myocytes and PC12 cells.

OBJECTIVE: Kv4.2 subunits are major components of transient outward K(+) channels in cardiac myocytes and somatodendritic A-type channels in neurons. To identify molecular mechanisms underlying transcriptional regulation of Kv4.2 gene, we have isolated and characterized the promoter for the rat Kv4.2 gene. METHODS: PCR-based amplification of cDNA end (5'RACE) and RNase protection assays were used to determine transcription start sites. Transient transfection of Kv4.2 promoter-luciferase reporter constructs into neonatal cardiac myocytes and PC12 cells was employed to measure activity of the Kv4.2 promoter. Cotransfection of expression vectors for the transcription factors, GATA and/or FOG2, was performed to determine the effects of these transcription factors on the Kv4.2 promoter. RESULTS: Transcription of the gene initiates at 552 bp upstream from the translation initiation site in the brain and heart. Deletion analysis revealed that the approximately 200-bp fragment encompassing this start site drives significant transcription in neonatal cardiac myocytes and PC12 cells. The transcription factors GATA4 and 6 differentially enhance activity of the minimum promoter in the two cell types: GATA4 produces a larger increase than GATA6 in cardiac myocytes, whereas the latter results in a more substantial enhancement in PC12 cells. Furthermore, the coregulator of GATA, FOG2, markedly suppresses the GATA-induced increase in myocytes, but enhances it in PC12 cells. The use of GATA mutants that are incapable of forming complexes with FOG2 indicates that the formation of GATA-FOG complexes is required for the FOG2-induced suppression in myocytes, but not for the FOG2-mediated enhancement in PC12 cells. CONCLUSION: These results indicate that GATA and FOG2 transcription factors use distinct mechanisms to control the expression of Kv4.2 gene in cardiac myocytes and PC12 cells. The lack of a GATA-binding consensus sequence in the Kv4.2 minimum promoter suggests that these transcription factors indirectly influence the channel gene transcription.

5' Flanking Region↗

PubMed2002

[Study on enrichment process of Cornus officinalis glycosides with macroporous resin and active carbon].

OBJECTIVE: To study the technological parameters of the enrichment purification of Cornus officinalis glycosides (COG) with macroporous resin and active carbon. METHODS: COG was isolated and purified by active carbon and macroporous resin HPD100. The enrichment of COG was evaluated by HPLC method. RESULTS: The optimum process was that 10 ml extract of Fructus Corni was absorbed with columns of macroporous resin and active carbon(R25 mm x H300 mm) and the columns were washed with 600 ml distilled water, then the morroniside and loganin was eluted from the macroporous resin and active carbon with ethanol. CONCLUSION: The elutive rate of morroniside and logann was about 85% by the macroporous resin, 96% by the active carbon. So this method enriching COG from Fructus Corni is practical.

Anion Exchange Resins↗