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Xiao-Dong Liu

Publications and source records attributed to Xiao-Dong Liu.

At least 19 recordsLinked to original sources
PubMed2007

Pharmacokinetics of the ginkgo B following intravenous administration of ginkgo B emulsion in rats.

Ginkgo B (GB) is an extract from the leaves of Ginkgo biloba, used in the treatment of dementia, cerebral insufficiency or related cognitive decline. In this paper, the main features of the pharmacokinetics of GB emulsion in rats were reviewed and the binding rate of GB to rat plasma and human plasma protein were investigated meanwhile. The concentrations of GB in plasma, tissue, and excretion of rats after i.v. administration of GB were measured using HPLC-ESI-MS. The metabolite was qualitated by LC-MS/MS. Intravenously administered GB was eliminated in a biphasic manner with a prominent initial phase (half-life of 0.3 h) followed by a slower terminal phase (half-life of 1.5 h). After i.v. 4, 12 and 36 mg/kg GB emulsion, the pharmacokinetic parameters from a two compartment model analysis of plasma samples were AUC(0-tau) (microg x min/ml): 53.7, 165.5 and 649.7; CL (l/min/kg): 0.07, 0.07 and 0.05; V(C) (l/kg): 2.27, 3.27 and 2.76, respectively. Peak concentrations generally occurred at 10 min except brain and fat. Tissue concentration then declined by several-fold during 6 h although still present in most tissues at 6 h. Single intravenous dose was mainly excreted in the urine (40-50%), feces contained less than 30%. The binding rate to rat plasma was little higher than to human plasma, but the difference was negligible. Some metabolites were found in urine and bile through qualitative analysis on the urine and bile by LC-MS/MS.

Animals↗
PubMed2006

Ionizing radiation stimulates secretion of pro-inflammatory cytokines: dose-response relationship, mechanisms and implications.

In previous studies we showed a marked increase in secretion of inflammatory cytokines TNFalpha and interleukin (IL)-1beta by mouse macrophages in response to different doses of ionizing radiation (IR). Here we show the stimulation of IL-12 and IL-18 secretion by mouse peritoneal macrophages after whole-body irradiation with exploration of the possible mechanisms and implications in cancer radiotherapy. Both low (0.075 Gy) and high (2 Gy) doses of IR were found to cause sustained stimulation of IL-12 and IL-18 secretion by mouse macrophages; this paralleled the activation of NF-kappaB as well as up-regulated expression of CD14 and TLR4-MD2 on the macrophage surface and MyD88 in the cytoplasm. The expression of CD14, TLR4-MD2 and MyD88 increased in a dose-dependent manner from radiation doses between 0.05 and 2 Gy. The secretion of IL-12 and IL-18 showed a dose-dependent increase from doses between 0.05 and 4 Gy. It is concluded that IR can stimulate the secretion of IL-12 and IL-18 presumably via activation of the Toll signaling pathway in macrophages. The potential harmful effect of repeated doses of radiation used in radiotherapy for certain cancers is discussed.

Animals↗
PubMed2006

Expression, purification and bioactivity of human augmenter of liver regeneration.

AIM: To construct the expression vectors for prokaryotic and eukaryotic human augmenter of liver regeneration (hALR) and to study their biological activity. METHODS: hALRcDNA clone was obtained from plasmid pGEM-T-hALR, and cDNA was subcloned into the prokatyotic expression vector pGEX-4T-2. The recombinant vector and pGEX-4T-2hALR were identified by enzyme digestion and DNA sequencing and transformed into E coli JM109. The positively selected clone was induced by the expression of GST-hALR fusion protein with IPTG, then the fusion protein was purified by glutathine s-transferase (GST) sepharose 4B affinity chromatography, cleaved by thrombin and the hALR monomer was obtained and detected by measuring H thymidine incorporation. RESULTS: The product of PCR from plasmid pGEM-T-hALR was examined by 1.5% sepharose electrophoresis. The specific strap was coincident with the theoretical one. The sequence was accurate and pGEX-4T-hALP digested by enzymes was coincident with the theoretical one. The sequence was accurate and the fragment was inserted in the positive direction. The recombinant vector was transformed into E coli JM109. SDS-PAGE proved that the induced expressive fusion protein showed a single band with a molecular weight of 41 kDa. The product was purified and cleaved. The molecular weights of GST and hALR were 26 kDa, 15 kDa respectively. The recombinant fusion protein accounted for 31% of the total soluble protein of bacterial lysate. HALR added to the culture medium of adult rat hepatocytes in primary culture and HepG2 cell line could significantly enhance the rate of DNA synthesis compared to the relevant control groups (P < 0.01). CONCLUSION: Purified hALR has the ability to stimulate DNA synthesis of adult rat hepatocytes in primary culture and HepG2 cells in vitro, and can provide evidence for its clinical application.

Animals↗
PubMed2006

Fluorinated Alq3 derivatives with tunable optical properties.

This communication reports that not only the emission colour but also the photoluminescence quantum yield of Alq3 can be tuned by introducing fluorine atoms at different positions; with fluorination at C-5 the emission is red-shifted with a tremendously decreased intensity, fluorination at C-6 causes a blue-shift with a significantly increased intensity, and fluorination at C-7 has a minor effect on both the colour and intensity of Alq3's emission.

Journal Article↗
PubMed2006

High-performance liquid chromatographic method for the determination and pharmacokinetic study of wogonoside in rat serum after oral administration of traditional Chinese medicinal preparation Huang-Lian-Jie-Du decoction.

A high-performance liquid chromatographic method for the determination of wogonoside in plasma of rats administrated orally with the traditional Chinese medicinal preparation Huang-Lian-Jie-Du decoction was developed. Sample preparation was carried out by protein precipitation with a mixture of acetonitrile and methanol (1:1, v/v). The extracted sample was separated on a Hypersil C(18) (150 x 5 mm i.d., 5 microm) analytical column by linear gradient elution using 0.05% (v/v) phosphoric acid (containing 5 mm sodium dihydrogen phosphate) and acetonitrile as mobile phase at a flow rate of 1.5 mL/min. The eluate was detected using a UV detector at 276 nm. The assay was linear over the range 0.109-7.0 microg/mL (R(2) = 0.9999, n = 5). Mean recovery was determined as 98.39%. Intra- and inter-day precisions (RSD) were < or =7.59%. The limit of quantitation was 0.109 microg/mL. After validation, the HPLC method developed was applied to investigate the preliminary pharmacokinetics of wogonoside in rat after oral administration of Huang-Lian-Jie-Du decoction.

Administration, Oral↗
PubMed2006

Simple, sensitive and rapid liquid chromatography/atmospheric pressure chemical ionization mass spectrometric method for the quantitation of Ranolazine in rat plasma.

A sensitive and specific method using liquid chromatography with atmospheric pressure chemical ionization mass spectrometry (LC/APCI-MS) has been developed and validated for the identification and quantification of Ranolazine in rat plasma. A simple liquid-liquid extraction procedure was followed by injection of the extracts onto a C18 column with isocratic elution and detection using a single quadrupole mass spectrometer in selected ion monitoring (SIM) mode. The method was tested using six different batches of blank plasma. Linearity was established for the concentration range 0.02-10.0 microg/mL, with a coefficient of determination (r) of 0.9998 and good back-calculated accuracy and precision. The intra- and inter-day precision (relative standard deviation (RSD) %) was lower than 10%, and accuracy ranged from 85 to 115%. The lower limit of quantification was reproducible at 0.01 microg/mL with 20 microL plasma. The proposed method enables the unambiguous identification and quantification of Ranolazine for pre-clinical and clinical studies.

Acetanilides↗
PubMed2006

[Numerical simulations of spatial and temporal characteristics of airborne dust over Asia during springs of 2000 to 2002].

Spatial and temporal characteristics of airborne dust over Asia during springs of 2000, 2001 and 2002 were simulated with a mineral dust entrainment and deposition model (DEAD) embedded in a global model of atmospheric transport and chemistry (MATCH) using the real-time meteorological data as forcing fields. The results show a good agreement of the pattern of model-simulated atmospheric dust concentration with the distribution of surface-observed spring dust storm frequency and a significant correlation between the simulated dust aerosol optical depth (DAOD) and satellite-observed aerosol index (AI). These results validate applicability of the integrated model in simulating dust entrainment, transportation and deposition and describing spatial and temporal characteristics of dust loading over the Asian continent. In addition, an attempt was made to explore possible paths of dust transportation by use of correlation analyses between the simulated dust emission flux (DEF) and DAOD.

Air Movements↗
PubMed2005

Simple, sensitive and rapid LC-ESI-MS method for the quantitation of lafutidine in human plasma--application to pharmacokinetic studies.

A sensitive and specific liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) method has been developed and validated for the identification and quantification of lafutidine in human plasma. Lafutidine and internal standard were isolated from plasma samples by liquid-liquid extraction with diethyl ether. The chromatographic separation was accomplished on a stainless-steel column (C18 Shim-pack 5 microm 150 mm x 2.0 mm i.d. Shimadzu) at a flow rate of 0.2 ml/min by a gradient elution. Detection was performed on a single quadrupole mass spectrometer by selected ion monitoring (SIM) mode via electrospray ionization (ESI) source. The method was proved to be sensitive and specific by testing six different plasma batches. Linearity was established for the range of concentrations 1.0-400.0 ng/ml with a coefficient of determination (r) of 0.9998 and good back-calculated accuracy and precision. The intra- and inter-day precision (R.S.D.%) was lower than 10% and accuracy ranged from 85 to 115%. The lower limit of quantification was identifiable and reproducible at 0.5 ng/ml with 0.2 ml plasma. The proposed method enables the unambiguous identification and quantification of lafutidine for pharmacokinetic, bioavailability or bioequivalence studies.

Acetamides↗
PubMed2005

Determination of limonin in rat plasma by liquid chromatography-electrospray mass spectrometry.

A simple, sensitive and selective liquid chromatography coupled with electrospray ionization mass spectrometry (LC/ESI/MS) method for determination of limonin (LM) in rat plasma has been developed and validated. The method had advantages of a single liquid-liquid extraction with ether and high sensitivity. Analyses were conducted at a flow rate of 0.2 ml/min by a gradient elution. The detection utilized selected ion monitoring in the negative ion mode at m/z 460.00 and 423.15 for the deprotonated molecular ions of LM and the internal standard, respectively. The quantitation limit for LM in rat plasma was 1.0 ng/ml. The linearity was also excellent over the concentration range of 1.9-500 ng/ml of LM. The intra- and inter-day precision (relative standard deviation (R.S.D.%)) was lower than 10% and accuracy ranged from 90 to 110%, showing a good reproducibility. This developed method was successfully applied to analysis of LM in biological fluids.

Animals↗
PubMed2005

A national probability survey of American Medical Association gynecologists and primary care physicians concerning menopause.

OBJECTIVE: This survey intended to clarify physicians' understanding of the issues surrounding women, menopause, alternative medicine, and drug therapy for the treatment of menopause. STUDY DESIGN: This study was designed as a national probability sample survey of primary care physicians and gynecologists nationwide. Its focus was to identify major concerns and issues identified by patients about menopause and perceived communication with effectiveness how to communicate with their patients. Physicians were also asked to rate their comfort level in recommending the use of herbal remedies and which herbal remedy they felt comfortable recommending to interested patients. RESULTS: Data indicated that a patient's complaint about menopausal symptoms was the most common factor leading to discussion of menopausal issues with physicians (91%) and that the primary concern to the patient was management of menopausal symptoms. Other factors were controversies about hormone replacement therapy, long-term health implications of menopause, and hormone replacement therapy. Eighty percent of the physician found confusing messages with regard to menopause to be the most challenging aspect in patient communication. The second most challenging issue is "inconclusive data about hormone replacement therapy" (56%). Seventy-six percent of the physicians found "showing sympathy" to be the most important factor for the physicians to communicate effectively with patients, whereas "being honest and open" was the most important patient attitude cited for the same purpose. When it comes to herbal therapy for menopause symptom control, only 4% of the physicians indicated that none of their patients take any remedies. Only 18% were not very comfortable in discussing or recommending herbal therapies, whereas the rest ranged from fairly comfortable to completely comfortable. CONCLUSION: This study has provided data with regard to physician understanding of menopause treatment options and their primary interaction with patients on this issue. More in-depth studies concerning efficacy and/or side effects of each available treatment will be the relevant next step, given the controversies about both hormone replacement therapy and alternative therapies. The relative efficacy, safety, and cost-effectiveness of different treatments should also be put into the context of both clinical diagnosis and physicians' clinical judgment. Attention to comments by physicians and patients with regard to communication may produce better information exchange and trust between patient and physician.

Attitude of Health Personnel↗
PubMed2005

[Treatment effect of percutaneous vertebroplasty combined with interventional chemotherapy on vertebral metastases].

BACKGROUND & OBJECTIVE: Vertebral metastasis is a common manifestation of patients with advanced cancer without effective treatment. This study was to explore treatment value and efficacy of percutaneous vertebroplasty (PVP) combined with interventional chemotherapy on vertebral metastases. METHODS: Seventy-five patients with vertebral metastases (42 men, 33 women; aged 31-76 years) were divided into 2 groups: 39 were treated by PVP combined with chemotherapy (VPCC group), and 36 were treated by PVP alone (VP group). All procedures were guided by CT scan. The results and complications were evaluated by pain questionnaire and routine follow-up. RESULTS: Response rate was significantly higher in VPCC group than in VP group (93.0% vs. 74.4%, P < 0.05); complete response rates of VPCC group and VP group were 25.6% and 10.3%. Common complication of VPCC was transient aggravation of pain. CONCLUSIONS: PVP may release the pain, and consolidate the vertebrae of patients with vertebral metastases. Its short-term effect may be enhanced by adding drugs into bone cement.

Adult↗
PubMed2005

Preliminary studies on nitrous oxide emissions from the ornithogenic soils on Xi-sha atoll, South China Sea.

The preliminary measurements of nitrous oxide fluxes from the ornithogenic soils on tropical Xi-sha atoll were made using a closed chamber technique for the first time. N2O fluxes from the ornithogenic soils ranged from 1.8 to 40.3 microg/(m2 x h) on Dong Island and 3.2 to 20.4 microg/(m2 x h) on Yongxing Island and their flux averaged 11.0 microg/(m2 x h) and 8.3 microg/(m2 x h), respectively. N2O fluxes from two wetland sites in salt marsh of Dong Island were approximately one order of magnitude lower than those from the ornithogenic soils and averaged 2.1 microg/(m2 x h) and 2.4 microg/(m2 x h). The diurnal variation cycle in the fluxes was obtained at the observation sites; the N2O flux increased with the increase in soil temperature. The sudden increase in soil moisture greatly stimulated N2O emission from the ornithogenic soils on Dong Island due to the heavy rainfall. The undisturbed soils showed the lower N2O fluxes and the average was 4.8 microg/(m2 x h) and the soils via the reclamation showed the higher N2O fluxes and the average was 16.6 microg/(m2 x h) on Yongxing Island, suggesting that the changes of land use have an important effect on N2O fluxes from the ornithogenic soils. In addition, the N2O fluxes at the different sites showed high spatial variations. The fluxes were positively correlated with the concentrations of NO3-, PO4(3-) and Mn in the soils. The negative correlation between the fluxes and total S concentration in the ornithogenic soils was also found for the first time. Coastal soils or sediments constitute an important source of global atmospheric N2O and the increases in nitrogen loading from seabird guanos will lead to significant increases in the flux of this atmospherically active gas.

Nitrous Oxide↗
PubMed2005

Molecular evidence of barley yellow dwarf virus replication/movement suppressed by the resistance gene Bdv2.

A wheat-Thinopyrum intermedium translocation line YW642 possesses the resistance to GAV serotype of barley yellow dwarf virus (BYDV), in which the resistance gene Bdv2 is derived from the chromosome 7X of Thinopyrum intermedium group 7. It is interesting to analyze BYDV accumulation content in the resistant and susceptible wheat plants for controlling BYDV disease and understanding the resistance mechanism against BYDV. In the paper, semi-quantitative reverse-transcription PCR (RT-PCR) was used to detect and quantify BYDV-GAV in the resistant and susceptible plants using specific primers for the coat protein (CP) and RNA-dependent RNA polymerase (RdRp) genes of BYDV-GAV serotype. On the inoculation site, the amount of the virus in the resistant wheat line (YW642) was much lower compared to the susceptible sib line (YW641). There was small amount of the virus could be detected in YW642 at 2-5 days post infestation (dpi), afterwards the amount of virus decreased and no virus could be detected at 14 and 16 dpi. In the uninoculated upper leaves, no BYDV was detected in YW642 from 1 to 14 dpi, while the virus could be detected at 3 dpi and then accumulated rapidly in YW641. These results showed at molecular level that the replication and/or movement of BYDV-GAV were strongly suppressed in YW642, presumably owing to the action of the BdV2 gene.

Chromosome Mapping↗
PubMed2004

Theoretical studies of ground and excited electronic States in a series of rhenium(i) bipyridine complexes containing diarylethynyl-based structure.

The photophysical properties, which vary as X is varied, of Re(I)-halide complexes (X2-bpy)ReICl(CO)3 (where X=ph, DAE, DNE, and DPE; ph = phenyl (1); DAE = di(amineoethynylbenzene) (2); DPE = di(phenylethynylbenzene) (3); DNE = di(nitroethynylbenzene) (4); bpy=2,2'bipyridine), are investigated using density functional theory (DFT). The electronic properties of the neutral molecules, in addition to the positive and negative ions, are studied using B3LYP functional. Excited singlet and triplet states are examined using time-dependent density functional theory (TDDFT). The low-lying excited-state geometries are optimized at the ab initio configuration interaction singlets level. As shown, the diarylethynyl-based structure is an integral component of the bpy pi-conjugated network, which results in a good planar structure. The occupied orbitals involved in the transitions have a significant mixture of metal Re and group Cl, and the lowest unoccupied orbital is a pi orbital, which extends from ligand bpy to diarylethynyl-based substituents. The luminescence for each complex originates from the lowest triplet excited states and is assigned to the mixing of MLCT and LLCT characters. Significant insights on the effects of these diarylethynyl conjugated structure and ending substituents (NH2, ph, and NO2) on absorption and emission spectra are observed by analysis of the results of the TDDFT method. The diarylethynyl-based pi-conjugated network makes both the absorption and emission spectra red-shifted compared with simple complex (bpy)ReICl(CO)3. Furthermore, an electron-releasing group (NH2) makes absorption and emission spectra blue-shift and an electron-withdrawing group (NO2) makes them red-shift.

Journal Article↗
PubMed2004

Effects of tetraethylammonium on Kx channels and simulated light response in rod photoreceptors.

Rod photoreceptors express a unique type of noninactivating potassium channels, Kx channels, which play an important role in setting the dark potential and participate in shaping the light response. Biophysical studies of Kx channels are limited. For example, the effects of a conventional blocker of potassium channels, tetraethylammonium (TEA), on Kx channels have not been extensively studied. Here we demonstrate that TEA blocks Kx channels, one molecule of TEA being sufficient to block the channel. Half of the Kx current was inhibited at K0.5 = 5.6 mM. The TEA-induced block of Kx channels depended on extracellular potassium: the higher the potassium concentration, the stronger the block. Using TEA, we blocked potassium channels to reveal their role in shaping the simulated light response (SLR) of rods. We showed that TEA slowed down SLR and sometimes caused generation of action potentials. We developed a complete computer model of the rod, which accurately reproduced the main features of the light response and allowed us to demonstrate that it was suppression of Kx channels that was essential for slowing SLR and increasing excitability of rods. The results reported in this work further establish the importance of Kx channels in rod photoreceptor function.

Animals↗
PubMed2004

Radiation-induced bystander effect in immune response.

OBJECTIVE: Since most reports on bystander effect have been only concerned with radiation-induced damage, the present paper aimed at disclosing whether low dose radiation could induce a stimulatory or beneficial bystander effect. METHODS: A co-culture system containing irradiated antigen presenting cells (J774A.1) and unirradiated T lymphocytes (EL-4) was established to observe the effect of J774A.1 cells exposed to both low and high doses of X-rays on the unirradiated EL-4 cells. Incorporation of 3H-TdR was used to assess the proliferation of the EL-4 cells, expression of CD80/86 and CD48 on J774A.1 cells was measured with immunohistochemistry and flow cytometry, respectively. NO release from J774A.1 cells was estimated with nitrate reduction method. RESULTS: Low dose-irradiated J774A.1 cells could stimulate the proliferation of the unirradiated EL-4 cells while the high dose-irradiated J774A.1 cells exerted an inhibitory effect on the proliferation of the unirradiated EL-4 cells. Preliminary mechanistic studies illustrated that the differential changes in CD48 expression and NO production by the irradiated J774A.1 cells after high and low dose radiation might be important factors underlying the differential bystander effect elicited by different doses of radiation. CONCLUSION: Stimulatory bystander effect can be induced in immune cells by low dose radiation.

Animals↗