[Progress in the pharmacological study of Chinese herbal drug: polygonum cuspidatum].
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Animals↗
Biomedical subjects
L Xue
Publications and source records attributed to L Xue.
The transmembrane signal transduction in HEp-2 cells induced by bacterial adherence.
In order to understand the role of transmembrane signal transduction of host cells in the early steps of infection, the adherence of E. coli to HEp-2 cells and the change of activity of phospholipase C-gamma (PLC-gamma) induced by the adherence were investigated. The adherence of enteropathogenic E. coli (EPEC), strain E. 7, induced a significant increase of inositol-triphosphat (IP-3) level in HEp-2 cells. The adherence of the bacteria and the increase of IP-3 was kinetically correlated. Whereas the increase of IP3 level induced by the adherence of the control strain EPEC (H511), a non-piliated strain, was much meager than that by E7, a piliated strain. The results highlighted an important role of transmembrane signals like 1P-3 in the pathogenesis of EPEC.
Bacterial Adhesion↗
[Detection of DNA variation after space flight in Datura innoxia by random amplified polymorphic DNA markers].
OBJECTIVE: To substantiate the effect of space environment on medicinal plants, the seeds of Datura innoxia were set up in retrievable satellites. METHODS: After returning to earth, the DNA variation of different groups was detected by random amplified polymorphic DNA (RAPD) markers. RESULTS: From a pre-screening of 65 primers with 20 oligonucleotide lengths, 15 primers that produced distinct profiles for each DNA sample were selected. In contrast with the earth controlled group, 39 polymorphic bands were produced in weightless group, and its degree of gene polymorphism was 23.1%; 45 polymophic bands were produced in hit group, and its degree of gene polymorphism was 24.4%. The polymorphic bands ranged approximately from 200 to 1990 bp. CONCLUSIONS: These results indicate that weightlessness induce DNA variation to some extents in Datura innoxia, while the compound effect of weightlessness and high energy heavy ions is more notable than the effect of single weightlessness.
Cosmic Radiation↗
[A study on Raman and photoluminescence spectra of the aeschynite group minerals].
Raman and photoluminescence spectra of the metamict and annealing recrystallization titanoaeschynite-(Nd) and nioboaeschynite-(Ce), found in Baiyunobo mineral deposit in China, have been measured and discussed. The peaks or bands in the spectra of the metamic minerals are weak, broad and diffuse, but sharpen notably after heating. The results show that the distortion of the structure and disorder state of the elements exist in the minerals when natural crystalline minerals transformed into metamict minerals after a long period self-irradiation structure damaging. And all bands in the photoluminescence spectra of the aeschynite group mineral stem from emission transitions of Nd3+, when 514.5 nm laser is used as the excitation source.
English Abstract↗
Leishmania donovani proton translocating P-type adenosine triphosphatases LDH1A and LDH1B: trans-splicing and polyadenylation of transcripts in amastigotes and promastigotes.
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Adenosine Triphosphatases↗
Nerve growth factor-induced PKB/Akt activity is sustained by phosphoinositide 3-kinase dependent and independent signals in sympathetic neurons.
Phosphoinositide 3-kinase and its downstream effector kinase PKB/Akt have been suggested to have crucial roles in suppressing apoptosis in several classes of neurons. However, few studies have conducted a long-term investigation of either kinase activity, many studies relying instead on use of the phosphoinositide 3-kinase inhibitors wortmannin and LY294002. When we added LY294002 or wortmannin to sympathetic neurons, apoptosis in the presence of nerve growth factor (NGF) was very slow compared to that obtained by NGF deprivation. However, expression of a kinase-inactive mutant of PKB/Akt in the presence of NGF induced apoptosis in a significant proportion of the neurons. To understand this discrepancy, we investigated more closely the regulation of PKB/Akt activity by NGF. NGF stimulation induced a rapid increase in PKB/Akt activity which was sustained at approximately 6-fold up to 24 h. Phosphoinositide 3-kinase was also rapidly activated by NGF. However, concentrations of wortmannin which completely blocked phosphoinositide 3-kinase activity in the neurons inhibited no more than 50-70% of cellular PKB/Akt activity. Similarly, approximately 50% of maximal NGF-stimulated PKB/Akt activity remained elevated at concentrations of LY294002 which completely blocked neurite outgrowth, a process known to be phosphoinositide 3-kinase dependent. We suggest that a proportion of the sustained PKB/Akt activity induced by NGF is mediated by phosphoinositide 3-kinase-independent pathways. These results raise a cautionary note as to the usefulness of LY294002 or wortmannin as tools to dissect the role of PKB/Akt in neuronal survival.
Androstadienes↗
Influence of dietary calcium and vitamin D on diet-induced epithelial cell hyperproliferation in mice.
BACKGROUND: Previous epidemiologic and laboratory studies, including some from our own laboratory, have suggested that a high-fat diet increases risk of cancer development in the pancreas, prostate, colon, and breast and that carcinogenesis in some of these organs may be influenced by alterations in dietary calcium and vitamin D. In this study, we sought to investigate the effect of added dietary calcium or vitamin D on the development of epithelial cell hyperproliferation induced by a Western-style diet in the exocrine pancreas, prostate, and mammary gland of mice. METHODS: Four-week-old C57BL/6J mice were given either a control diet (American Institute of Nutrition [AIN]-76A), a Western-style diet (containing reduced calcium and vitamin D and the fat level of the average human Western diet), or a putative chemopreventive diet (a Western-style diet with the addition of dietary calcium and vitamin D). Nine weeks after dietary intervention, osmotic pumps were implanted in the mice to provide 3 days of bromodeoxyuridine (BrdU) infusion. All P values are two-sided. RESULTS: Mice on the Western-style diet had statistically significant increases in BrdU-labeling indices of epithelial cells in the interlobular (P = .015) and intralobular (P = .012) ducts and centroacinar cells (P = .001) of the pancreatic duct system, the dorsal lobe of the prostate (P = .045), and the terminal ducts of the mammary gland (P = .032), compared with mice in the respective control diet groups. Adding dietary calcium and vitamin D markedly suppressed the Western-style diet-induced hyperproliferation of epithelial cells in those tissues (P = .001-.033). CONCLUSIONS: This study confirms previous findings that a Western-style diet produces hyperproliferation of epithelial cells in several organs and that the changes can be prevented by increasing dietary calcium and vitamin D alone.
Animals↗
Autophagy is activated by apoptotic signalling in sympathetic neurons: an alternative mechanism of death execution.
Autophagy is a mechanism whereby cells digest themselves from within and so may be used in lieu of apoptosis to execute cell death. Little is known about its role in neurons. In newly isolated sympathetic neurons, two independent apoptotic stimuli, NGF-deprivation or cytosine arabinoside added in the presence of NGF, caused a 30-fold increase in autophagic particle numbers, many autophagosomes appearing before any signs of DNA-fragmentation. The anti-autophagic drug 3-methyladenine also delayed apoptosis, its neuroprotection correlating with inhibition of cytochrome c release from mitochondria and prevention of caspase activation. In contrast, autophagic activity remained elevated in neurons treated with the pan-caspase inhibitor Boc-Asp(OMe)fmk, which inhibited morphological apoptosis but did not inhibit cytochrome c release nor prevent cell death. We propose that the same apoptotic signals that cause mitochondrial dysfunction also activate autophagy. Once activated, autophagy may mediate caspase-independent neuronal death.
Adenine↗
Molecular scaffold-based design and comparison of combinatorial libraries focused on the ATP-binding site of protein kinases.
Compound libraries were designed to target specifically the ATP cofactor-binding site in protein kinases by combining knowledge- and diversity-based design elements. A key aspect of the approach is the identification of molecular building blocks or scaffolds that are compatible with the binding site and therefore capture some aspects of target specificity. Scaffolds were selected on the basis of docking calculations and analysis of known inhibitors. We have generated 75 molecular scaffolds and applied different strategies to compute diverse compounds from scaffolds or, alternatively, to screen compound databases for molecules containing these scaffolds. The resulting libraries had a similar degree of molecular diversity, with at most 12% of the compounds being identical. However, their scaffold distributions differed significantly and a small number of scaffolds dominated the majority of compounds in each library.
Adenosine Triphosphate↗
Inactivating mutations and overexpression of BCL10, a caspase recruitment domain-containing gene, in MALT lymphoma with t(1;14)(p22;q32).
Mucosa-associated lymphoid tissue (MALT) lymphomas most frequently involve the gastrointestinal tract and are the most common subset of extranodal non-Hodgkin lymphoma (NHL). Here we describe overexpression of BCL10, a novel apoptotic signalling gene that encodes an amino-terminal caspase recruitment domain (CARD), in MALT lymphomas due to the recurrent t(1;14)(p22;q32). BCL10 cDNAs from t(1;14)-positive MALT tumours contained a variety of mutations, most resulting in truncations either in or carboxy terminal to the CARD. Wild-type BCL10 activated NF-kappaB but induced apoptosis of MCF7 and 293 cells. CARD-truncation mutants were unable to induce cell death or activate NF-kappaB, whereas mutants with C-terminal truncations retained NF-kappaB activation but did not induce apoptosis. Mutant BCL10 overexpression might have a twofold lymphomagenic effect: loss of BCL10 pro-apoptosis may confer a survival advantage to MALT B-cells, and constitutive NF-kappaB activation may provide both anti-apoptotic and proliferative signals mediated via its transcriptional targets.
Adaptor Proteins, Signal Transducing↗
Paclitaxel (Taxol): an inhibitor of angiogenesis in a highly vascularized transgenic breast cancer.
Paclitaxel (Taxol), a promoter of microtubule polymerization and a radiosensitizing agent, is one of the more active anticancer drugs in the current treatment of solid tumors. In this study, we show that paclitaxel possesses an antiangiogenic property associated with a down-regulation of vascular endothelial growth factor (VEGF) in a highly-vascularized transgenic murine breast cancer (Met-1). Paclitaxel, at non-cytotoxic doses of 0, 3 and 6 mg/kg/day, was administered intraperitoneally for 5 days to nude mice bearing the Met-1 breast tumor. Extent of intratumoral angiogenesis, as indicated by microvessel tortuosity and microvessel density, was significantly reduced by paclitaxel in a dose-dependent manner. Paclitaxel also suppressed expression of VEGF in the Met-1 cells transplanted in nude mice or maintained in cell culture. These results indicate that antiangiogenesis associated with a down-regulation of VEGF is an additional mode of action of paclitaxel.
Angiogenesis Inhibitors↗
Preclinical mouse models for cancer chemoprevention studies.
To aid in identifying the ability of chemopreventive agents to inhibit tumor development, new preclinical in vivo rodent models have recently been developed. Some of the models contain targeted mutations capable of increasing the incidence and progression of neoplastic lesions, whereas in other models dietary nutrients induce preneoplastic lesions in normal mice. These new preclinical models are assisting the analysis of genetic and environmental factors leading to neoplasia, and clinical studies to evaluate the chemopreventive efficacy of specific nutrients and pharmacological agents.
Animals↗
ATP is a mediator of the fast inhibitory junction potential in human jejunal circular smooth muscle.
The neurotransmitter(s) that generates the fast component of the inhibitory junction potential (IJP-F) in human jejunal circular smooth muscle is not known. The aim of this study was to determine the role of ATP and purinergic receptors in the generation of the IJP-F in human jejunal circular smooth muscle strips. The P2-receptor antagonist suramin (100 microM) reduced the IJP-F by 28%. Apamin (1 microM) reduced the IJP-F by 25%. Desensitization of muscle strips with the putative P2x-receptor agonist alpha, beta-methylene ATP (alpha,beta-MeATP, 100 microM) decreased the IJP-F by 44%, and desensitization with the putative P2y-receptor agonist adenosine 5'-O-2-thiodiphosphate (ADPbetaS) completely abolished the IJP-F. Desensitization with the putative P2y-receptor agonist 2-methylthioATP had no effect on the IJP-F. Exogenous ATP evoked a hyperpolarization with a time course that matched the IJP-F. The ATP-evoked hyperpolarization was reduced by apamin and suramin, reduced by desensitization with alpha,beta-MeATP (69% decrease), and abolished by desensitization with ADPbetaS. These data suggest that the IJP-F in human jejunal circular smooth muscle is mediated in part by ATP through an ADPbetaS-sensitive P2 receptor.
Adenosine Triphosphate↗
Ethynylestradiol-mediated induction of hepatic CYP3A9 in female rats: implication for cyclosporine metabolism.
Repeated treatment of female rats with the synthetic estrogen ethynylestradiol (EE(2)) increases the formation of the cyclosporine A (CyA) metabolites AM1c and AM9 by 3-fold, whereas the formation of AM1 and AM4N is not significantly enhanced. The formation of all four CyA metabolites was inhibited by greater than 80% by the CYP3A-selective substrate midazolam or polyclonal anti-rat CYP3A IgGs in liver microsomes of untreated and EE(2)-induced rats. In contrast, anti-rat CYP2C6 IgGs had little effect, indicating the involvement of a CYP3A but not 2C6 in this EE(2)-stimulated CyA metabolism. Semiquantitative reverse-transcriptase polymerase chain reaction was used to determine the mRNA content for four CYP3A genes (CYP3A2, CYP3A9, CYP3A18, and CYP3A23) in livers of control and EE(2)-treated female rats. EE(2) selectively induced CYP3A9 by 3.3-fold whereas the expression of CYP3A18 and CYP3A23 was slightly decreased; neither CYP3A2 mRNA nor CYP3A1 mRNA was detectable in these EE(2)-treated livers. To determine whether rat liver microsomal CYP3A9 was indeed responsible for the EE(2)-stimulated CyA metabolism, a recombinant CYP3A9 was heterologously expressed in Escherichia coli. When functionally reconstituted, this enzyme was active in metabolizing CyA preferentially to its AM9 and AM1c metabolites as compared with CYP3A4. These findings thus support the notion that the increased CyA-metabolizing capacity of EE(2)-treated female rat liver microsomes is due to the induction of the CYP3A9 enzyme.
Actins↗
[Effects of space flight on medicinal plant Agastache rugosa (Fisch. et Mey.) O. Ktze].
OBJECTIVE: To substantiate the effect of space conditions on medicinal plants. METHODS: The seeds of Agastache rugosa were set up in retrievable satellites. After returning to earth, the changes of isozymes of peroxidases, esterase and soluble proteins were studied. RESULTS: The peroxidase activity and protein content of the weightless group were a little lower than those of the earth controlled group, while these two items of the hit group were higher than those of the earth controlled group. The electrophoresis patterns of isoperoxidases and isoeasterase of these three groups, as well as the protein patterns of the weightless group and the earth controlled group were found alike. But the protein patterns of the hit group were different from those of the other two groups. CONCLUSION: The effect of weightlessness is smaller than that of the high energy heavy ions on Agastache rugosa. Different plants have different susceptibility to space conditions.
China↗
[The effects of space flight on medicinal plant Datura innoxia].
OBJECTIVE: To probe the effects of space condition on medicinal plants. METHODS: The seeds of Datura innoxia Mill were put in a retrievable satellite. After returning earth, the isozymes of peroxidases, esterase and soluble proteins were studied. RESULTS: The peroxidase activity and the protein content of weightless group were lower than that of the earth controlled group, but these items of the hit group were higher than that of the earth controlled group. The electrophoresis patterns of isozymes and proteins of these three groups were similar. CONCLUSION: The effects of weightlessness and the high energy heavy ions were different on Datura innoxia, and the effects of space conditions were not enough to produce idiovariation in Datura innoxia.
Cosmic Radiation↗
[Influence of vasoactive peptides on homocysteine-induced proliferation of cultured rabbit vascular smooth muscle cell].
OBJECTIVE: To study the effects of vasoactive peptides [adrenomedullin (Adm), C-type natriuretic peptide (CNP), calcitonin gene related peptide (CGRP), somatostatin(SST) and parathyroid hormone-related protein] on homocysteine (Hcy)-induced proliferation of cultured rabbit vascular smooth muscle cell (VSMC). METHODS: Techniques of cell culture, 3H-thymidine incorporation, nuclei, membrane and cytosol fractions were isolated by differential centrifugation and PKC activity was measured. RESULTS: Hcy significantly stimulated DNA synthesis of VSMC. Adm, CNP, CGRP, SST, and PTHrP had no effect on basal 3H-TdR incorporation, but they could inhibit Hcy-induced 3H-TdR incorporation in dose-dependent manner. PKC inhibitor (H7 and Stauroporine) could inhibit VSMC proliferation induced by Hcy with reduction of 3H-TdR incorporation by 50% (P < 0.01) and 56% (P < 0.01), respectively. PKC was found to be distributed equally in nuclear fraction and membrane particulate, and higher in cytosol fraction in untreated VSMC. Treatment of VSMC with 10(-4) mol/L Hcy resulted in a significant increase in membrane-associated PKC combined with a loss of enzyme activity in the cytosol and nuclear fractions. Adm, CNP, CGRP and PTHrP altered the distribution of PKC activity induced by Hcy. CONCLUSION: Adm, CNP, CGRP and PTHrP inhibited VSMC proliferation possibly through PKC pathway.
Adrenomedullin↗
[Deep venous incompetence of legs: experimental studies].
OBJECTIVE: To seek best wrapping materials of valvular wrapping operation of deep veins in the lower limbs and to understand the value of diagnostic value of duplex scanning for incompetence of the deep veins and the function of the popliteal valve. METHODS: Strips of the autogenous saphenous vein, autogenous fascia lata and PEFE graft were used respectively as the material for valve constriction. The results were compared of duplex scanning and trans-popliteal venography. RESULTS: In the saphenous vein and fascia lata groups, diffuse fibrosis and marked narrowing of the femoral vein were found, whereas in the vascular graft group the graft was intact without prominent fibrosis and narrowing of the vein. The accurate rates of duplex scanning and trans-popliteal venography were 91.86%. at the same time the thigh and popliteal valve was closed when held breath. CONCLUSIONS: Vascular graft is the best constriction material. Duplex scanning is a important method. Popliteal valve is an important barrier for protecting the function of the deep vein.
Adult↗