Do mRNAs act as direct sensors of small molecules to control their expression?
Explore the source record for details and available documents.
Bacillus subtilis↗
Biomedical subjects
Y Ji
Publications and source records attributed to Y Ji.
Novel syntheses of 2,3-disubstituted benzofurans.
Explore the source record for details and available documents.
Benzofurans↗
Molecular identification and sequence analysis of Hillarin, a novel protein localized at the axon hillock.
The monoclonal antibody Lan3-15 identifies a novel protein, Hillarin, that is localized to the axon hillock of leech neurons. Using this antibody we have identified a full length cDNA coding for leech Hillarin and determined its sequence. The gene encodes a 1274 residue protein with a predicted molecular mass of 144013 Da. Data base searches revealed that leech Hillarin has potential orthologues in fly and nematode and that these proteins share two novel protein domains. The W180 domain is characterized by five conserved tryptophans whereas the H domains share 21 invariant residues. In contrast to the arrangement in fly and nematode the cassette containing the W180 and H domains is repeated twice in leech Hillarin. This suggests that the leech Hillarin sequence originated from a duplication event of an ancestral protein with single cassette structure.
Amino Acid Sequence↗
Determination of the spin polarization of half-metallic CrO(2) by point contact Andreev reflection.
Andreev reflection at a Pb/CrO(2) point contact has been used to determine the spin polarization of single-crystal CrO(2) films made by chemical vapor deposition. The spin polarization is found to be 0.96 +/- 0.01, which confirms that CrO(2) is a half-metallic ferromagnet, as theoretically predicted.
Journal Article↗
Inhibition of Th1- and enhancement of Th2-initiating cytokines and chemokines in trichosanthin- treated macrophages.
Trichosanthin (TCS), the major effective component from Chinese herb Trichosanthes Kirilowii Maxim, is also a potent allergen. Our previous work has shown that TCS can upregulate interleukin-4 (IL-4) and interleukin-13 (IL-13) while inhibit interferon-gamma (IFN-gamma) in mesenteric lymph node cells after TCS immunization. Thus, TCS can arouse a T helper 2 (Th2) response in the draining lymph node. However, little is known about the early effects of TCS on antigen-presenting cells, the initiator of T cell response. In the current study, the effects of TCS on macrophage cytokines and chemokine expression were investigated. Peritoneal macrophages were treated with or without TCS in the presence of lipopolysaccharide (LPS). We found that TCS increased macrophage interleukin-10 (IL-10) and monocyte chemoattractant protein-1 (MCP-1) expression, whereas it decreased interleukin-12 (IL-12) and tumor necrosis factor-alpha (TNF-alpha) expression. Our study clearly demonstrated that TCS, as an allergen, has differential effects on macrophage Th1/Th2 initiative factors, effects that are likely to facilitate its inducing of Th2 and immunoglobulin E (IgE) response.
Allergens↗
Bacterial fatty-acid biosynthesis: a genomics-driven target for antibacterial drug discovery.
In this review we demonstrate how the interplay of genomics, bioinformatics and genomic technologies has enabled an in-depth analysis of the component enzymes of the bacterial fatty-acid biosynthesis pathway as a source of novel antibacterial targets. This evaluation has revealed that many of the enzymes are potentially selective, broad-spectrum antibacterial targets. We also illustrate the suitability of some of these targets for HTS. Furthermore, we discuss how the availability of a robust selectivity assay, mode-of-action assays and numerous crystal structures provide an excellent set of tools with which to initiate integrated programs of research to identify novel antibiotics targeted at these enzymes.
Journal Article↗
Expression profiling suggested a regulatory role of liver-enriched transcription factors in human hepatocellular carcinoma.
By using a cDNA array representing 14,000 cDNA clusters, we studied the expression profiles in paired clinical hepatocellular carcinoma (HCC) samples and the distal nontumorous liver tissues from the same patients. Despite the significant heterogeneity among the clinical samples, 72 genes (including 30 novel genes) were down-regulated and 84 genes (including 48 novel genes) were up-regulated in >50% of the cancer samples that were identified. The alterations in gene expression levels were confirmed by Northern blot and reverse-transcription PCR in all of 4 randomly selected genes. It was conspicuous that 21 of 38 hepatocarcinoma (HCC) down-regulated genes studied previously were reportedly regulated by a group of liver-enriched transcription factors (LETFs), and 12 of 36 HCC up-regulated genes studied previously were involved in protein translation. Reexamination of the cDNA array data further revealed that most of the genes known to be regulated by LETFs were down-regulated in at least a portion of the HCC samples. Among the LETFs, the expression level of CCAAT/enhancer-binding protein (C/EBP) alpha was down-regulated in cancer, whereas hepatocyte nuclear factor 1 (HNF-1), HNF-3beta, HNF-4alpha, and HNF-4gamma were up-regulated. The expression profiling thus suggested multiple regulatory pathways involved in HCC, especially that related to LETFs.
Basic Helix-Loop-Helix Leucine Zipper Transcriptio↗
Preparation and mass spectrometric study of egg yolk antibody (IgY) against rabies virus.
Rabies virus was used as the antigen to immunize laying chickens. Anti-rabies virus immunoglobulin Y(IgY) was isolated from yolks of the eggs laid by these chickens using a two-step salt precipitation and one-step gel filtration protocol. The purified IgY was reduced with dithiothreitol, and heavy chains (HC) and light chains (LC) were obtained. In addition, the purified IgY was digested with pepsin and the fragment with specific antigen binding properties (Fab) was produced. Using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOFMS), the average molecular weights of IgY, HC, LC, and Fab were determined as 167 250, 65 105, 18 660, and 45,359 Da, respectively. IgY has two structural differences compared with mammalian IgGs. First, the molecular weight of the heavy chain of IgY is larger than that of its mammalian counterpart, while the molecular weight of the light chain of IgY is smaller. Second, upon pepsin digestion, anti-rabies virus IgY is degraded into Fab, in contrast to mammalian IgG, which has been reported to be degraded into F(ab')(2) under the same conditions.
Alkylation↗
Use of nitrocellulose films for affinity-directed mass spectrometry for the analysis of antibody/antigen interactions.
Combination of affinity extraction procedures with mass spectrometric analyses is termed affinity-directed mass spectrometry, a technique that has gained broad interest in immunology and is extended here with several improvements from methods used in previous studies. A monoclonal antibody was immobilized on a nitrocellulose (NC) membrane, allowing the corresponding antigen to be selectively captured from a complex solution for analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). This method was also used to rapidly determine the approximate binding region responsible for the antibody/antigen interaction. The tryptic fragments of antigen protein in buffer were applied to the antibody immobilized on NC film and allowed to interact. The NC film was then washed to remove salts and other unbound components, and subjected to analysis by MALDI-TOFMS. Using interferon-alpha(2a) and anti-interferon-alpha(2a) monoclonal antibody IgG as a model system, we successfully extracted the antigen protein and determined the approximate binding region for the antigen/antibody interaction (i.e., the tryptic fragment responsible).
Amino Acid Sequence↗
The potential of plasma thrombomodulin as a biomarker of portal vein tumor thrombus in hepatocellular carcinoma.
PURPOSE: To study the relationship between thrombomodulin (TM) plasma levels and the formation of portal vein tumor thrombus (PVTT) in patients with hepatocellular carcinoma (HCC). METHODS: Pre- and-postoperative plasma TM levels of 45 patients with HCC and six patients with benign liver-occupying lesion were measured by enzyme-linked immunosorbent assay (ELISA), and the expression of TM in human HCC tissues was determined by immunohistochemistry assay. RESULTS: The preoperative plasma TM level of patients with HCC (10.2+/-5.7 ng/ml) was significantly higher than that of those patients with benign liver-occupying lesion (6.1+/-2.2 ng/ml) and that of normal controls (5.7+/-1.0 ng/ml), respectively (P<0.05). The postoperative TM level of 40 patients with HCC whose tumors had been removed decreased significantly than the preoperative TM level (10.8+/-5.3 ng/ml versus 7.6+/-4.2 ng/ ml, P < 0.05), whereas there was no significant difference between the preoperative and postoperative TM level of six patients with benign liver-occupying lesion (6.1+/-2.2 ng/ml versus 5.9+/-1.8 ng/ml, P>0.05). The preoperative plasma TM level of patients with single HCC (11.5+/-5.9 ng/ml) or no PVTT (11.4+/-5.6 ng/ml) was significantly higher than that of those patients with multiple HCC (8.1+/-4.6 ng/ml) or PVTT (6.9+/-4.5 ng/ ml), respectively (P<0.05). The preoperative plasma TM level of the patients with HCC tissue that stained positive for TM was significantly higher than those with tissue that stained negative for TM (12.2+/-6.5 ng/ ml versus 8.7+/-4.6 ng/ml, P<0.05). The postoperative plasma TM level showed no difference between the patients with HCC tissue stained positive and negative for TM (8.3+/-4.1 ng/ml versus 7.6+/-4.4 ng/ml, P>0.05). There was also no significant difference between the plasma TM level and other clinicopathological futures. CONCLUSIONS: Plasma TM increases in patients with HCC and can be a biomarker of the formation of PVTT.
Adult↗
Calcium uptake by sarcoplasmic reticulum is impaired during the hypodynamic phase of sepsis in the rat heart.
Alterations of the ATP-dependent Ca2+ uptake in the cardiac sarcoplasmic reticulum (SR) during the 2 hemodynamically distinct phases of sepsis were investigated. Sepsis was induced by cecal ligation and puncture (CLP). Control rats were sham-operated. The SR vesicles were isolated by sucrose gradient centrifugation. The results show that the rates of ATP-dependent Ca2+ uptake in the cardiac SR were unaffected during the early hyperdynamic phase, whereas they were decreased by 41-46% (P < 0.01) during the late hypodynamic phase of sepsis. Analysis of the kinetics of Ca2+ transport indicates that during the late phase of sepsis, the Vmax values of Ca2+ pump for ATP and Ca2+ were decreased, whereas the affinities of Ca2+ pump for ATP and Ca2+ were unaffected. Magnesium stimulated, whereas vanadate inhibited the ATP-dependent Ca2+ uptake, but the Mg2+-stimulated and the vanadate-inhibited Ca2+ uptake activities were significantly lower during the late sepsis. Phosphorylation of SR by the cAMP-dependent and the calmodulin-dependent protein kinases stimulated the ATP-dependent Ca2+ uptake in the control and the early septic experiments, whereas it failed to stimulate Ca2+ uptake in the late sepsis. The extent of the phosphorylation-stimulated Ca2+ uptake activities was reduced by 65-69% (P < 0.01) during the early sepsis, and they were completely abolished during the late sepsis. These data indicate that the ATP-dependent Ca2+ uptake in cardiac SR was impaired during the late hypodynamic phase of sepsis. The impaired Ca2+ uptake during late sepsis was associated with a defective phosphorylation of SR proteins. Because the ATP-dependent Ca2+ uptake by cardiac SR plays an important role in the regulation of contraction-relaxation coupling, our findings may contribute to the understanding of the pathogenesis of altered cardiac function during the progression of sepsis.
Adenosine Triphosphate↗
Impairment of the ryanodine-sensitive calcium release channels in the cardiac sarcoplasmic reticulum and its underlying mechanism during the hypodynamic phase of sepsis.
Changes in Ca2+-induced Ca2+ release in cardiac sarcoplasmic reticulum (SR) during different phases of sepsis were studied. Sepsis was induced by cecal ligation and puncture (CLP). The 45Ca2+ release studies show that the amount of Ca2+ released from the passively and the actively loaded SR vesicles was unaffected during the early sepsis (9 h after CLP), but it was significantly decreased during the late phase (18 h after CLP) of sepsis. The [3H]ryanodine binding assays reveal that the Bmax for ryanodine binding was unaffected during the early phase, but was decreased by 32.1% during the late phase of sepsis. The affinity of ryanodine receptor for Ca2+ remained unchanged during sepsis. ATP, AMP-PCP, and caffeine stimulated binding, while MgCl2 and ruthenium red inhibited [3H]ryanodine binding in control, early sepsis, and late sepsis groups. The EC50 and IC50 values for these regulators were unaffected during the progression of sepsis. Digestion of control SR with phospholipase A2 decreased [3H]ryanodine binding and the decrease was reversible by the addition of phosphatidylcholine (PC), phosphatidylethanolamine (PE), or phosphatidylserine (PS). Addition of PC, PE, or PS to the SR isolated from septic rats stimulated [3H]ryanodine binding. These data demonstrate that Ca2+-induced Ca2+ release from cardiac SR remained relatively unaffected during the early phase, but was significantly impaired during the late phase of sepsis. The sepsis-induced impairment in SR Ca2+ release is a result of a quantitative reduction in the number of Ca2+ release channels. Furthermore, the reduction is associated with a mechanism involving a modification of membrane lipid profile in response to certain stimuli such as activation of phospholipase A2.
Adenosine Triphosphate↗
Spinal NMDA receptors contribute to neuronal processing of acute noxious and nonnoxious colorectal stimulation in the rat.
The present study investigated the role of NMDA receptors in the spinal processing of acute noxious and nonnoxious colorectal stimulation using extracellular single-unit recording in the rat. Fifty-three neurons in the L6-S2 dorsal horn of the spinal cord were studied. Neurons were identified using touch and light pinch of the ipsilateral perianal/scrotal area and colorectal distention (CRD). All neurons had excitatory responses to CRD. Thirty neurons were studied using a search stimulus of 80-mmHg CRD. The effects of a systemically administered N-methyl-D-aspartate (NMDA) receptor channel blocker, dizocilpine maleate (MK-801) (0.1, 0.5, 1.0, and 5.0 mg/kg), were tested on the CRD-evoked responses of 13 neurons. The lowest dose had no effect on the neuronal responses to CRD, while greater doses lowered the CRD-evoked responses at all distention pressures tested (20, 40, 60, and 80 mmHg). Similarly, spinal application of MK-801 (20, 50, 100, and 200 nmol) attenuated CRD-evoked activity (n = 9). In addition, a spinally administered competitive NMDA receptor antagonist, 2-amino-5-phosphonovaleric acid (APV) (30, 60, 120, and 240 nmol), dose-dependently attenuated the CRD-evoked response at all distention pressures (n = 5). Systemically administered APV did not affect neuronal responses to CRD (n = 3). Twenty-three neurons were studied in animals that never received distention pressures exceeding 30 mmHg; the search stimulus ranged between 20- and 30-mmHg CRD. These neurons were tested using 20-mmHg CRD. Systemically administered MK-801 facilitated the response to 20-mmHg CRD in three neurons and inhibited the response in five neurons, and the response of five neurons was not affected. Spinally administered MK-801 had no effect on neuronal responses to 20-mmHg CRD in six neurons. However, spinally administered APV dose-dependently decreased the response to 20-mmHg CRD in four neurons. These results are consistent with our previous observations that used Fos expression as the index, suggesting that spinal NMDA receptors contribute to processing of both noxious and nonnoxious CRD.
2-Amino-5-phosphonovalerate↗
[Anti-oxidation effect of water extract of Flos chrysanthemi on heart and brain in vivo and in vitro].
This paper reported the effect of water extract of Flos Chrysanthemi on lipid per-oxidation (LPO) of heart and cerebral homogenate from rats incubated in 37 +/- 0.5 degrees C, of heart and cerebral homogenate from mice induced by .OH, of heart and cerebral mitochondria member induced by .OH, which was compared with Radix Salviae Miltiorrhizae. The results showed that the inhibition effect of water extract of Flos Chrysanthemi on above-mentioned LPO was equal to Radix Salviae Miltiorrhizae. It was concluded that water extract of Flos Chrysanthemi could restrain the produce of free radicals and LPO induced by free radicals.
Animals↗
[Effects of fruits of Hovenia dulcis Thunb on acute alcohol toxicity in mice].
OBJECT: To study the effects of fruits of Hovenia dulcis (FHD) on acute alcohol toxicity in mice. METHOD: Acute alcohol toxicity in mice was used to observe the effects of FHD on sleep time and alcohol concentration in blood. RESULTS: FHD could shorten sleep time distinctly and reduce alcohol concentration in blood of acute alcohol toxicity mice. CONCLUSION: FHD has an obvious effect on acute alcohol toxicity.
Alcoholic Intoxication↗
[Analysis of several genes using primer extension preamplification based on individual cell].
OBJECTIVE: To analyze several genes at the same time in one individual cell using primer extension preamplification (PEP). METHODS: The whole genome of individual cell was preamplified by PEP using 10 base random oligonucleotides. The aliquots(5 mu liter) from PEP were used to amplify SRY, ZP(3), RhCE, RhD and F VIII genes by nested PCR. RESULTS: The five genes could be amplified following PEP-PCR. Lymphocyte of four genotypes were diagnosed by PEP-PCR; correct diagnoses were obtained in 95.6%. CONCLUSION: At least five genes can be analyzed by PEP-PCR based on one individual cell in this laboratory. This method could be used in preimplantation genetic diagnosis and noninvasive prenatal diagnosis.
Female↗
[Studies on mimotopes of hepatitis C virus E1 protein].
OBJECTIVE: To study the B-cell epitope of E1 protein of hepatitis C virus. METHODS: By induction of IPTG, the E.coli M15 strains harboring the pQE30-HCVe118 expressed truncated C-terminal HCV E1 protein (Pte1). The proteins were purified with preparative electrophoreses system, which captured anti-E1 IgG in HCV (+) sera. By applying the antibodies as selective molecular 12 mers random peptide libraries were panned, and positive clones were obtained by ELISA. Amino acid sequences of display peptide were compared with that of HCV E1 protein. RESULTS: The purified HCV E1 proteins could react specifically with partly anti-HCV sera by ELISA. Among 10 phage display peptides, 6, 6, 2 were the most homologous to HCV E1 protein at position 320-336aa, 251-263aa, 225-248, respectively. CONCLUSIONS: There exist multiple B-cell epitopes in HCV E1 protein. At least one preponderant epitope is mapped at residues 320-336 of HCV E1 protein.
Amino Acid Motifs↗
Modulation of BmKAS-1 and BmK1-3-2 to sodium channel in rat dorsal root ganglion neurons.
OBJECTIVE: To investigate what effects BmKAS-1 (a polypeptide purified from the Chinese scorpion Buthus martensi Karsch [BmK] and named as BmK activator of skeletal-muscle ryanodine receptor) and its upstream mixture BmK1-3-2 have on Na+ channels in dorsal root ganglion (DRG) small diameter neurons. METHODS: The whole-cell patch-clamp technique was used to investigate the effects of BmKAS-1 and BmK1-3-2 on Na+ current in rat small diameter DRG neurons. RESULTS: About 50% peak Na+ current was suppressed by 10 micrograms/ml of BmK1-3-2. 1.62 micrograms/ml of BmKAS-1 also blocked 50% peak Na+ current, and there was an obvious dose-dependent relationship. CONCLUSION: Both BmK1-3-2 and BmKAS-1 have a blocking effect on Na+ channels, and this may one of the mechanisms for the analgetic effect of BmK1-3-2 and BmKAS-1.
Animals↗