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Yun-Feng Li

Publications and source records attributed to Yun-Feng Li.

At least 19 recordsLinked to original sources
PubMed2006

Theophylline attenuates microwave-induced impairment of memory acquisition.

Numerous studies have shown that acute microwave exposure causes cognitive deficits in animals, possibly via hyperthermia, but the biological effect of microwave exposure on memory processing is still unknown. The release of adenosine is demonstrated to be a general way for the cells to respond to metabolically stressful conditions such as hypoxia and ischemia. The present study aimed to examine whether adenosine mediates biological effects of microwave exposure on memory processing using a continuous multiple-trial inhibitory avoidance task. Results demonstrated that microwave exposure for 20 min before training impaired memory acquisition and retention performance in mice, assessed by the number of training trials and by latency to enter the dark compartment. The mice exposed to microwave radiation showed a dose-dependent hyperthermia. Moreover, the cell numbers of hippocampus were decreased in the mice receiving microwave exposure at an average power density of 50 mW/cm(2), indicating the anatomical correlation to hippocampal-amygdaloid structures corresponding with the memory disrupt of the mice. Administration of theophylline, a nonspecific adenosine receptor antagonist, 30 min before microwave exposure, completely antagonized the impairment of inhibitory avoidance acquisition but not retention. These results suggest that the adenosine regulation pathway was partially involved in microwave-induced impairment of inhibitory avoidance memory.

Adenosine↗
PubMed2006

Anxiolytic effect of agmatine in rats and mice.

In mammalian brain, agmatine is an endogenous neurotransmitter and/or neuromodulator. In this study, the anxiolytic action of agmatine (p.o. or s.c.) was evaluated in three animal behavioral models in mice or rats. In the light-dark transition test, agmatine in a single dose (80 mg/kg, s.c) or repeated administration (20 mg/kg, s.c. or 10 mg/kg, p.o., once a day for 3 days) significantly increased the number of light-dark transitions in mice. Furthermore, treatment with agmatine (20-80 mg/kg, s.c or 10-40 mg/kg, p.o) three times in 24 h significantly increased the number of licks in the Vogel's drinking conflict test in rats. In the social interaction test, agmatine (10-40 mg/kg, p.o, three times in 24 h prior to test) increased the active social interaction of rats. All these results indicate that agmatine exerts a significant anxiolytic effect in both rats and mice.

Agmatine↗
PubMed2006

Agrobacterium-mediated transformation of cotton (Gossypium hirsutum L. cv. Zhongmian 35) using glyphosate as a selectable marker.

The most economically significant Chinese cotton cultivar (Gossypium hirsutum L. cv. Zhongmian 35) was transformed via Agrobacterium tumefaciens-mediated DNA transfer. The aroA-M1 gene that confers resistance to the glyphosate was fused with a chloroplast-transit peptide of Arabidopsis thaliana 5-enolpyruvyl-3-phosphoshikimate synthase (ASP) and expressed in cotton plants under the control of a CaMV35S promoter. Transgenic plants were directly selected on medium containing glyphosate. Thirty-four independent transgenic lines were obtained after selection, giving a maximal 1.9% transformation frequency. The integration and expression of the aroA-M1 gene in T(0) plants and T(1) progeny were confirmed using DNA hybridization, Western blot and PCR techniques. An increased resistance of T(0) and T(1 )transgenic plants towards glyphosate was also observed.

3-Phosphoshikimate 1-Carboxyvinyltransferase↗
PubMed2006

Inhibition of N-methyl-D-aspartate receptor function appears to be one of the common actions for antidepressants.

In order to explore the possible common action mechanisms of three kinds of classical antidepressants, inhibition of drugs on the N-methyl-D-aspartate (NMDA)-Ca(2)-nitric oxide synthase (NOS) signal pathway was observed. With 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and lactic dehydrogenase (LDH) assay, classical antidepressants, desipramine (1, 10 microM), fluoxetine (0.625-10 microM) or moclobemide (2.5, 10 microM) antagonized NMDA 300 M induced-lesion in PC12 cells. Using fura-2/AM (acetoxymethyl ester) labelling assay, desipramine or fluoxetine at doses 1, 5 microM attenuated the intracellular Ca(2) overload induced by NMDA 200 microM for 24 h in PC12 cells. Meanwhile, using confocal microscope, it was also found that desipramine 5 microM, fluoxetine 2.5 microM or moclobemide 10 microM decreased the NMDA 20 microM induced intracellular Ca(2) overload in primarily cultured rat hippocampal neurons. Furthermore, desipramine (1, 5 microM), fluoxetine (1, 5 microM) or moclobemide (2.5, 10 microM) significantly inhibited NOS activity in NMDA (300 microM) treated PC12 cells for 4h. In summary, we suggest that inhibition on the function of NMDA-Ca(2) -NOS signal pathway appears to be one of the common actions for antidepressants despite their remarkably different structures, which is expected to have great implication for the evaluation and screening in vitro of new antidepressants.

Animals↗
PubMed2006

Expression, purification, crystallization and preliminary crystallographic analysis of the human intracellular chloride channel protein CLIC4.

The human chloride intracellular channel protein CLIC4 has been crystallized by the hanging-drop vapour-diffusion technique using trisodium citrate as the precipitant. The best crystals were obtained by the microseeding method. The crystals diffracted to 2.2 A resolution and were found to belong to space group P121, with unit-cell parameters a = 73.19, b =86.05, c = 73.38 A, beta = 112.99 degrees and three molecule per asymmetric unit.

Chloride Channels↗
PubMed2006

[Purification and identification of a glycoprotein elicitor (CSBI) from Magnaporthe grisea].

A glycoprotein elicitor, CSBI, isolated from hyphal cell walls of the strain 97-151a of M. grisea race ZC(13) was purified by centrifugation, ultra-filtration, gel filtration and anion exchange chromatography (Fig.1). CSBI appeared as a single band on silver-stained SDS-PAGE (Fig.2). Anthrone-colorimetric assay and Coomassie blue G-250 staining showed that the carbohydrate-to-protein ratio was 9.32 (Table 1). The induction of peroxidase activity in incompatible interactions was stronger than in compatible interactions (P<0.05) after treatment with CSBI on rice leaves (Fig.3). The N-terminal sequence of CSBI was determined to be ITPEAMLSANCCSD, which showed high homology to a 78.671-kD hypothetical protein MG07877.4 (accession No. gi38107424) from M. grisea in NCBI databases. CSBI was either identified as hypothetical protein MG07877.4 by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) with 9 matching peptides (Fig.4, Table 2).

Cell Wall↗
PubMed2005

Activation of the gene promoter of barley beta-1,3-glucanase isoenzyme GIII is salicylic acid (SA)-dependent in transgenic rice plants.

Pathogenesis-related proteins (PR), including beta-1,3-glucanases may provide the first line of defense against fungal pathogens. Many PR proteins are activated by salicylic acid (SA), which acts as an endogenous signal. We have previously isolated seven members of the beta-1,3-glucanase gene family in barley (Hordeum vulgare). In this paper, we characterized the beta-1,3-glucanase isoenzyme GIII for SA-responsive elements in the GIII gene promoter. A series of deletion mutations of the promoter were fused to the reporter gene beta-glucuronidase (gus). The GUS activity was analyzed in rice calli (Oryza sativa L.) in response to SA. A deletion fragment between -362 and +106 bp showed the highest level of GUS activity in these assays. This promoter fused with gus was further introduced into rice plants for stable transformation. Histochemical staining and fluorometric quantitation of GUS activity in leaves of transgenic plants revealed prominent GUS expression after SA induction. RNA analysis by Northern blotting confirmed the importance of this region, indicating that cis-acting elements required for SA-inducible expression exist within 362 bp upstream from the transcriptional start site.

Base Sequence↗
PubMed2005

[Inducible expression of a promoter of the gene encoding barley beta-1, 3-glucanase isoenzyme GIII in transgenic rice].

A promoter of the gene encoding beta-1, 3-glucanase isoenzyme GIII was amplified from barley genomic DNA using PCR. The GIII gene promoter, designated P(GIII), was ligated upstream of the gus report gene and pGIII-gus fusion fragment was then cloned into a binary vector pCAMBIA1300 for Agrobacterium-mediated transformation of rice (Oryza sativa L. cv. Taipei 309). PCR analyses indicated that the fusion gene was present in all T0 transgenic plants. The integration of the gene into rice genomic DNA was further confirmed by Southern blot. Histochemical staining and spectrofluorophotometric analyses of transgenic rice leaves showed that the GUS activity was increased after treatment with SA and fungal elicitor. Northern blot analysis also showed expression of such induction. Histochemical staining of T(1) rice seeds displayed marked GUS activity after induction with SA and elicitor, while no GUS activity was detected in untreated T(1) rice seeds. The results presented here strongly suggested that P(GIII) could be pathogen-inducible promoter.

Blotting, Northern↗
PubMed2005

[Neural network detection of abnormalities in fed-batch fermentation].

During fermentation, it is often difficult to detect the abnormalities, for example, caused by contamination on-line. Instead, the faults were detected usually by off-line laboratory analysis or other ways, which in most cases, is too late to remedy the situation. In this paper, a simple three-layers BP network was used for the early prediction of the amount of product, based on the difference in prediction errors between normal and abnormal charges and other accessorial information, such as profit function and pH value. In addition, three indications characteristic to abnormal charge are incorporated in practical operation. The prediction for Cephalosporin C Fed-batch Fermentation in a Chinese pharmaceutical factory was studied in details as an example and the result shows the abnormal charge can be discovered early successfully using the method.

Bioreactors↗
PubMed2005

[Neurogenesis: a novel strategy for the treatment of depression].

It is now generally accepted that the birth of new neurons occurs in brain areas such as hippocampus throughout the lifespan. The waning and waxing of neurogenesis in hippocampus is proposed as a key factor in the decent into and recovery from depression. If hippocampal neurogenesis was blocked, antidepressant would lose its behavioral effects in behavioral models of depression. Long-term, but not short-term, treatment with different classes of antidepressant could stimulate neurogenesis in the hippocampus remarkably. As the regulation of adult neurogenesis continues to be identified, it will provide novel avenues of studying the mechanism and developing pharmacological agents for depressive disorder.

Animals↗
PubMed2004

Effect of SNPs in protein kinase C zeta gene on gene expression in the reporter gene detection system.

AIM: To investigated the effects of the SNPs (rs411021, rs436045, rs427811, rs385039 and rs809912) on gene expression and further identify the susceptibility genes of type 2 diabetes. METHODS: Ten allele fragments (49 bp each) were synthesized according to the 5 SNPs mentioned above. These fragments were cloned into luciferase reporter gene vector and then transfected into HepG2 cells. The activity of the luciferase was assayed. Effects of the SNPs on RNA splicing were analyzed by bioinformatics. RESULTS: rs427811T allele and rs809912G allele enhanced the activity of the reporter gene expression. None of the 5 SNPs affected RNA splicing. CONCLUSION: SNPs in protein kinase Cz (PKCZ) gene probably play a role in the susceptibility to type 2 diabetes by affecting the expression level of the relevant genes.

Base Sequence↗
PubMed2004

The cytoprotective effect of inulin-type hexasaccharide extracted from Morinda officinalis on PC12 cells against the lesion induced by corticosterone.

High concentration of corticosterone (Cort) 0.2 mM was incubated with PC12 cells to simulate the lesion state of brain neurons in depressive illness, it was found that the inulin-type oligosaccharides extracted from Morinda officinalis, inulin-type hexasaccharide (IHS) at the doses of 0.625, 1.25 microM or desipramine (DIM) 0.25, 1 microM protected the PC12 cells from the lesion induced by Cort. With Fura-2/AM labeling assay, DIM 0.25, 1 microM or IHS 2.5, 10 microM attenuated the intracellular Ca2+ overloading induced by Cort 0.1 mM for 48 h in PC12 cells. Using RT-PCR, treatment with Cort 0.1 mM for 48 h decreased the nerve growth factor (NGF) mRNA level in PC12 cells, IHS 5, 10 microM reversed this change. In summary, IHS attenuate the intracellular Ca2+ overloading and thereby up-regulate the NGF mRNA expression in Cort-treated PC12 cells, which may be consisted at least part of the cytopretective effect of IHS. These results also extend evidence for our hypothesis that neuroprotective action is one of the common mechanisms for antidepressants.

Analysis of Variance↗
PubMed2004

S-100B and neuron specific enolase in outcome prediction of severe head injury.

OBJECTIVE: To elucidate the role of S-100B and neuron specific enolase (NSE) in predicting the outcomes of patients with severe head injury. METHODS: Forty patients with severe head injury were included in this study. The serum concentrations of S-100B and NSE were measured within 12 hours after head injury to investigate the correlation between serum levels of S-100B and NSE and outcome. Validity of both S-100B and NSE in outcome prediction was assessed with Receiver Operator Characteristic (ROC) curve. RESULTS: The serum concentrations of S-100B and NSE of both groups, with favorable or unfavorable outcomes, were significantly higher than those of the normal group. The serum concentrations within 12 hours after head injury were closely correlated with the prognosis. Furthermore, according to the ROC curves of S-100B and NSE, S-100B was found better in predicting outcomes than NSE. CONCLUSIONS: S-100B and NSE may play important roles in outcome prediction after severe head injury. Moreover, S-100B is clearly superior to NSE in terms of predictive value and appears to be a more promising serum marker in outcome prediction after severe head injury.

Craniocerebral Trauma↗
PubMed2004

[Membrane lipid peroxidation and hypersensitive reaction induced by a glycoprotein elicitor from Magnaporthe grisea in rice leaves].

With a series of four near-isogenic lines (NIL) of rice, studies were carried out in the interaction between rice and a specific glycoprotein elicitor from Magnaporthe grisea. After treatment with the elicitor, O(-.)(2) generation rate increased more remarkably on the leaves of incompatible interaction of rice, than compatible interaction of rice. Change in SOD activity and CAT activity was similar in leaves of rice with different resistance after inoculation with the elicitor. On the contrary, POD activity was positive relative to rice resistance. And changes in LOX activity were increased more remarkably and rapidly on the leaves of incompatibly interacting rice. These changes led to lipid peroxidation in the leaves of incompatibly interacting rice. Relative conductance rate and MDA content were also increased more remarkably and rapidly in leaves of incompatibly interacting rice. Our results also showed that elicitor could induce hypersensitive reaction (HR reaction) in leaves of completely or highly incompatible interacting rice, but not in the two NIL rice varieties (one with moderately incompatible interactions and another with compatible ones). The results suggest that lipid peroxidation and HR reaction in rice leaves induced by the elicitor may play an important role in the resistance of rice seedlings.

Catalase↗
PubMed2004

[Glyphosate-resistant cotton (Gossypium hirsutum L.) Transformed with aroAM12 gene via Agrobacterium tumefaciens].

A mutant, aroAM12, exhibiting resistance to glyphosate produced in a previous study using the staggered extension process with aroA genes from Salmonella typhimurium and Eschrichia coli. In this paper, we constructed a vector pGRA1300 carrying aroAM12 gene, comprising transit peptide of Arabidopsis EPSPS, under the control of the CaMV35S promoter and used as selectable marker for cotton plant (Gossypium hirsutum L.) transformation. Transgenic cottons with increased resistance to glyphosate were obtained by cotransformtion of hypocotyl segments with Agrobacterium tumefaciens and selected directly on medium containing glyphosate. Regeneration of glyphosate-resistant calli was carried out on a MS basic medium containing 2,4-D 0.1 mg/L, KT 0.1 mg/L, cefotaxime 500 mg/L and glyphosate 60 micromol/L. Globular embryos were induced and then developed by culturing on MSB (MS salts+B(5) vitamins) medium supplemented with asparagine 1 g/L and glutamine 2 g/L, but not containing hormone, for 40 d. The developed plantlets were then removed and cultured on an MS medium. After about 20 d, the deeply-rooted shoots were in soil. PCR analysis showed that the aroAM12 gene was present in all T(0) transgenic plants. The integration of the aroAM12 gene in the genomic DNA of cotton was further confirmed by Southern blot, which showed that the transgenic plants carried one or two copies of the aroAM12 genes. Western blot analysis showed that a 48-kD band of was detected in all T(0) transgenic plants. There was no apparent corelation between copy numbers and the expression level of the aroAM12 gene. Greenhouse screening for glyphosate resistance was performed to test 65 independent T(0) plants by spraying (three times) with an aqueous suspension at a dose corresponding to 9.317 kg/ha of Roundup (once every 5 d). After 15 d, phenotype examination was carried out of the plants in comparison with untransformed control plants. Under these conditions, it was observed that the plants transformed with pGRA1300 showed high resistance to glyphosate whereas the control plants were all killed. The glyphosate resistance of T(1) generation was measured by spraying with Roundup, the numbers of glyphosate resistance and sensitive phenotypes showed Mendelian segregation ratio.

Agrobacterium tumefaciens↗
PubMed2003

Up-regulation of microtubule-associated protein 4 and drebrin A mRNA expression by antidepressants in rat hippocampus following chronic stress.

We used the differential display-polymerase chain reaction (DD-PCR) protocol to identify genes related to antidepressant effects. Rats were subjected to different kinds of stress for 20 days, and then the antidepressants desipramine and fluoxetine were administered (10 mg/kg per day, i.p.) for 20 days. DD-PCR was performed and differentially expressed cDNAs were further confirmed by dot-blot hybridization. cDNA homology analysis revealed that desipramine up-regulated the expression of microtubule-associated protein 4 (MAP-4) mRNA and fluoxetine up-regulated the expression of drebrin A mRNA in the rat hippocampus compared with the chronically stressed group. This result suggests that MAP-4 and drebrin may be involved in the antidepressant like effects of desipramine and fluoxetine.

Animals↗
PubMed2003

Expression of a bacterial aroA mutant, aroA-M1, encoding 5-enolpyruvylshikimate-3-phosphate synthase for the production of glyphosate-resistant tobacco plants.

Glyphosate is a non-selective broad-spectrum herbicide that inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), a key enzyme in the aromatic amino acid biosynthetic pathway in microorganisms and plants. We have previously reported a strategy for engineering glyphosate-resistant class I EPSPS based on staggered-PCR technology. Selected mutant enzymes exhibited high K(i)[glyphosate] and low K(m)[PEP] values compared to the parental enzymes from Escherichia coli ( EcaroA) and Salmonella typhimurium ( StaroA). One mutant, aroA-M1, was further engineered with a tobacco chloroplast leader sequence, and then placed in the binary vector pCAMBIA1300 for Agrobacterium-mediated gene transfer to tobacco ( Nicotiana tabacum cv. Xanthi). Transgenic plants with increased resistance to glyphosate were generated.

3-Phosphoshikimate 1-Carboxyvinyltransferase↗