Biomedical subjects

W Xie

Publications and source records attributed to W Xie.

At least 55 records · Page 3Linked to original sources

PubMed2001

[Clinical observation of the protective effect of oral feeding of glutamine granules on intestinal mucous membrane].

OBJECTIVE: To observe the protective effect of oral feeding of glutamine (Gln) granules on intestinal mucous membrane during early postburn stage. METHODS: Twenty burn patients were randomly divided into test (T) and control (G) groups with 10 patients in each group. Gln granules and placebo were administered in a dose of 10 grams three times a day for 10 days to patients in the two groups respectively. Blood levels of Gln, diamine oxidase (DAO) activity, endotoxin (LPS) and intestinal permeability were monitored before and after the administration of the agents. at the same time, the changes in blood and urine routine and hepatic and renal functional indices were also observed. RESULTS: There was no difference of the general data and the hepatic and renal functional indices between the two groups. The plasma level of Gln before the administration was much lower than that thereafter (P < 0.01) in T group, but all of the values were higher than that in C group (P < 0.05). The DAO activity, intestinal permeability and LPS levels before the administration were much higher than those after it (P < 0.01) in T group. CONCLUSION: Gln might be good to burn patients due to its protective effect on intestinal mucous membrane when given during early postburn stage.

Administration, Oral↗

PubMed2001

[Study on induction of leukemic cell apoptosis by antisense oligodeoxynucleotide of human telomerase RNA].

OBJECTIVE: To explore the antitumor activity of human telomerase RNA antisense oligodeoxynucleotide (As-ODN) to leukemic cells and its mechanisms. METHODS: As-ODN was transfected into HL-60 cells by liposomal transfection. Telomerase activity of HL-60 cells was examined by telomeric repeat amplification protocol (TRAP)-enzyme-linked immunosorbent assay (ELISA). Apoptosis was analyzed by morphology, DNA agarose gel electrophoresis and flow cytometry. RESULTS: The telomerase activity in HL-60 cells, being transfected with 0.1 - 2.0 micromol/L of As-ODN for 1 - 6 days, varied from 1.043 +/- 0.045 to 0.063 +/- 0.011 in a dose- and time-dependent manner. The proliferation of As-ODN-transfected HL-60 cells was lower than that of control, and the cells underwent apoptosis. The Ms-ODN (missense ODN)-transfected HL-60 cells didn't show these changes. CONCLUSION: As-ODN can inhibit the telomerase activity of HL-60 cells specifically and induce apoptosis.

Apoptosis↗

PubMed2001

[Evaluation of the effects of two operative option in the treatment of orbital fractures].

OBJECTIVE: In order to explore the treatment and it's clinical effects of orbital fractures. METHOD: 34 patients were separately treated with nasal endoscopic surgery and external nose incision surgery. RESULT: The total effective rate of nasal endoscopic surgery and external nose incision surgery was 90.0%, 91.6% respectively. There was no significant difference between the two groups (P > 0.05). CONCLUSION: Treating orbital fractures under nasal endoscopic surgery has advantages such as no incision on face, less damage, clear view and easy recheck after operation. It is the best way to treat this kind of disease.

Adolescent↗

PubMed2001

[Effect of new zhengtian pill on expression of whole blood platelet membrane adhesion molecules in patients of migraine].

OBJECTIVE: To investigate the effect of New Zhengtian Pill (NZTP) on expression of whole blood platelet membrane adhesion molecules (PMAM) in patients of migraine. METHODS: Sixty-eight patients were divided into two groups, the 35 patients in the treated group treated by NZTP orally and the 33 patients in the control group treated by Fuguiqin Capsule with a therapeutic course of 30 days for both groups. Changes of PMAM GP II b/III a(CD41) and P-selectin (CD62P) were observed by flow-cytometry and compared with those in healthy persons. RESULTS: The markedly effective rate and total effective rate in the treated group was higher than those in the control group respectively (P < 0.05 and P < 0.01). The PMAM expression was also higher in patients, both at onset stage and intermittent stage, than in healthy persons (P < 0.01), NZTP treatment could reduce their increased expression significantly (P < 0.01). CONCLUSION: NZTP could reduce the PMAM expression and inhibit the activation of platelet.

Adolescent↗

PubMed2001

[Expression and purification of recombinant human interleukin-11 in Pichia pastoris].

OBJECTIVE: To express recombinant human interleukin-11 (rhIL-11) in methylotropic yeast Pichia pastoris. METHODS: By designing and synthesizing an artificial gene for IL-11, the expression vector pPICZ alpha-A-IL-11 was constructed and introduced into Pichia pastoris by linearized electroporation. The rhIL-11 protein was identified by ELISA and SDS-PAGE analysis. The bioactivity was analyzed by B9-11 cell line. A combination of liquid chromatography was developed to purify the rhIL-11 from ferment supernatant. RESULTS: The nucleotide sequence analysis indicated that the sequence of cloned artificial IL-11 gene accorded with that of designed; the secreted yield of rhIL-11 by yeast Pichia pastoris KM71-2424 in flask reached 60 mg/L. The biological activity of IL-11 in yeast supernatant and E. coli standard determined by B9-11 was 5.5 x 10(7) U/mg and 2.2 x 10(7) U/mg respectively. The rhIL-11 was purified to electrophoretic purity by a combination of liquid chromatography. CONCLUSION: The human IL-11 artificial gene was obtained and successfully expressed in the Pichia pastoris(KM71-2424). The biological activity of IL-11 in yeast supernatant was significantly higher than that of E. coli standard. The rhIL-11 was purified to electrophoretic purity.

Electrophoresis, Polyacrylamide Gel↗

PubMed2001

[Study on the inclusion interaction of beta-cyclodextrin with phosphatidylcholine by UV spectra].

A kind of cyclic oligosaccharides, beta-cyclodextrin (beta-CD) was found to possess inclusion ability with phosphatidylcholine (PC). The inclusion compound of beta-CD with PC was studied by elemental analysis of solid inclusion compound and UV spectra of different mole ratios beta-CD/PC in H2O-MeOH solution. The results indicate that two moles of beta-CD include one mole PC to form inclusion compound by Van Der Waals force, hydrophobic interaction and hydrogen bounds, etc. The selective binding ability of beta-CD with PC has been discussed from the viewpoint of size/shape-fitting and geometry fitting between the host cavity and the gust molecular. The solubility in aqueous solution, the oxidation stability of PC was increased by inclusion with beta-CD.

Chemical Phenomena↗

PubMed2000

Structural changes and alteration in expression of TGF-beta1 and its receptors in prostatic intraepithelial neoplasia (PIN) in the ventral prostate of noble rats.

BACKGROUND: Prostatic intraepithelial neoplasia (PIN) is the most likely pre-cancereous lesion and represents the major target for chemoprevention of prostate cancer. The multi-functional role of TGF-beta1, together with its receptors, in normal prostate and development of prostatic neoplasia remains controversial and requires further investigation. METHODS: Ventral prostates were removed from Noble rats treated with a combination of testosterone (T) and estradiol (E(2)) for various periods of time, and processed for ultrastructural examination and histopathological grading. To evaluate the role of TGF-beta1 and TGFbeta receptor types I and II in normal prostate and high-grade PIN development, expression pattern of TGF-beta1 and TGFbeta-RI and TGFbeta-RII were studied on prostate samples with PIN lesions. RESULTS: Pathologically, low-grade PIN (LGPIN) and high-grade PIN (HGPIN) were observed in ducts or alveoli after three and five months of T + E(2) treatment, respectively. EM study revealed that HGPIN cells were characterized by a reduction in abundance of secretory apparatus and the nucleus with highly irregular and undulated membrane and often with inclusion bodies although the basal lamina remained largely normal. This was associated with a high level of expression of TGF-beta1 in stromal tissue subjacent to foci of HGPIN. No definite positive reactivity of TGF-beta1 was identified in glandular epithelial cells of HGPIN. These results implicated that the major site for the TGF-beta1 production remained to be restricted to stromal compartment at the stage of HGPIN, and a paracrine regulation of TGF-beta1 might be involved in the development of HGPIN. Positive staining for the TGFbeta-RI was found in the cytoplasm of luminal epithelial cells of normal ventral prostate. The intense positive reactivity for TGFbeta-RI was also identified in prostates with HGPIN lesions. Similar expression pattern of TGFbeta-RII was also observed. CONCLUSIONS: Based on the EM study, we concluded that HGPIN in ventral prostate was accompanied with alterations in nuclear morphology together with a change in secretory activity. The over expression of TGFbeta-RI and RII in HGPIN cells as well as TGF-beta1 in stromal tissue subjacent to HGPIN implicated a growth-stimulating role instead of inhibiting role of this peptide growth factor during the early stage of prostatic neoplasia.

Animals↗

PubMed2000

Reciprocal activation of xenobiotic response genes by nuclear receptors SXR/PXR and CAR.

The cytochrome P450 (CYP) gene products such as CYP3A and CYP2B are essential for the metabolism of steroid hormones and xenochemicals including prescription drugs. Nuclear receptor SXR/PXR (steroid and xenobiotic receptor/pregnenolone X receptor) has been shown both biochemically and genetically to activate CYP3A genes, while similar studies have established constitutive androstane receptor (CAR) as a CYP2B regulator. The response elements in these genes are also distinct, furthering the concept of independent regulation. Unexpectedly, we found that SXR can regulate CYP2B, both in cultured cells and in transgenic mice via adaptive recognition of the phenobarbital response element (PBRE). In a type of functional symmetry, orphan receptor CAR was also found to activate CYP3A through previously defined SXR/PXR response elements. These observations not only provide a rational explanation for the activation of multiple CYP gene classes by certain xenobiotics, but also reveal the existence of a metabolic safety net that confers a second layer of protection to the harmful effects of toxic compounds and at the same time increases the propensity for drug-drug interactions.

Animals↗

PubMed2000

Dietary P(i) deprivation in rats affects liver cAMP, glycogen, key steps of gluconeogenesis and glucose production.

We previously reported [Xie, Li, Méchin and van de Werve (1999) Biochem. J. 343, 393-396] that dietary phosphate deprivation for 2 days up-regulated both the catalytic subunit and the putative glucose-6-phosphate translocase of the rat liver microsomal glucose-6-phosphatase system, suggesting that increased hepatic glucose production might be responsible for the frequent clinical association of hypophosphataemia and glucose intolerance. We now show that liver cAMP was increased in rats fed with a diet deficient in P(i) compared with rats fed with a control diet. Accordingly, in the P(i)-deficient group pyruvate kinase was inactivated, the concentration of phosphoenolpyruvate was increased and fructose 2, 6-bisphosphate concentration was decreased. Phosphoenolpyruvate carboxykinase activity was marginally increased and glucokinase activity was unchanged by P(i) deprivation. The liver glycogen concentration decreased in the P(i)-deficient group. In the fed state, plasma glucose concentration was increased and plasma P(i) and insulin concentrations were substantially decreased in the P(i)-deficient group. All of these changes, except decreased plasma P(i), were cancelled in the overnight fasted P(i)-deficient group. In the fasted P(i)-deficient group, immediately after a glucose bolus, the plasma glucose level was elevated and the inhibition of endogenous glucose production was decreased. However, this mild glucose intolerance was not sufficient to affect the rate of fall of the glucose level after the glucose bolus. Taken together, these changes are compatible with a stimulation of liver gluconeogenesis and glycogenolysis by the P(i)-deficient diet and further indicate that the liver might contribute to impaired glucose homeostasis in P(i)-deficient states.

Animals↗

PubMed2000

Determination of the DNA sequences of acetylcholinesterase and butyrylcholinesterase from cat and demonstration of the existence of both in cat plasma.

Cat serum contains 0.5 mg/L of butyrylcholinesterase (BChE, EC 3.1.1. 8) and 0.3 mg/L of acetylcholinesterase (AChE, EC 3.1.1.7); this can be compared with 5 mg/mL and < 0.01 mg/L, respectively, in human serum. Cat BChE differed from human BChE in the steady-state turnover of butyrylthiocholine, having a 3-fold higher k(cat) and 2-fold higher K(m) and K(ss) values. Sequencing of the cat BCHE cDNA revealed 70 amino acid differences between cat and human BChE, three of which could account for these kinetic differences. These amino acids, which were located in the region of the active site, were Phe398Ile, Pro285Leu, and Ala277Leu (where the first amino acid was found in human and the second in cat). Sequencing genomic DNA for cat and human ACHE demonstrated that there were 33 amino acid differences between the cat and human AChE enzymes, but that there were no differences in the active site region. In addition, a polymorphism in intron 3 of the human ACHE gene was detected, as well as a silent polymorphism at Y116 of the cat ACHE gene.

Acetylcholinesterase↗

PubMed2000

Characteristics and antifungal activity of a chitin binding protein from Ginkgo biloba.

An antifungal peptide from leaves of Ginkgo biloba, designated GAFP, has been isolated. Its molecular mass of 4244.0 Da was determined by mass spectrometry. The complete amino acid sequence was obtained from automated Edman degradation. GAFP exhibited antifungal activity towards Pellicularia sasakii Ito, Alternaria alternata (Fries) Keissler, Fusarium graminearum Schw. and Fusarium moniliforme. Its activities differed among various fungi. GAFP could also cause increased hyphal membrane permeabilization and a rapid alkalization of the medium when applied at 100 microgram/ml to Pellicularia sasakii Ito hyphae. The amino acid sequence of GAFP shows characteristics of the cysteine/glycine-rich chitin binding domain of many chitin binding proteins. The cysteine residues are well conserved.

Amino Acid Motifs↗

PubMed2000

Humanized xenobiotic response in mice expressing nuclear receptor SXR.

The cytochrome CYP3A gene products, expressed in mammalian liver, are essential for the metabolism of lipophilic substrates, including endogenous steroid hormones and prescription drugs. CYP3A enzymes are extremely versatile and are inducible by many of their natural and xenobiotic substrates. Consequently, they form the molecular basis for many clinical drug-drug interactions. The induction of CYP3A enzymes is species-specific, and we have postulated that it involves one or more cellular factors, or receptor-like xeno-sensors. Here we identify one such factor unequivocally as the nuclear receptor pregnenolone X receptor (PXR) and its human homologue, steroid and xenobiotic receptor (SXR). We show that targeted disruption of the mouse PXR gene abolishes induction of CYP3A by prototypic inducers such as dexamethasone or pregnenolone-16alpha-carbonitrile. In transgenic mice, an activated form of SXR causes constitutive upregulation of CYP3A gene expression and enhanced protection against toxic xenobiotic compounds. Furthermore, we show that the species origin of the receptor, rather than the promoter structure of CYP3A genes, dictates the species-specific pattern of CYP3A inducibility. Thus, we can generate 'humanized' transgenic mice that are responsive to human-specific inducers such as the antibiotic rifampicin. We conclude that SXR/PXR genes encode the primary species-specific xeno-sensors that mediate the adaptive hepatic response, and may represent the critical biochemical mechanism of human xenoprotection.

Animals↗

PubMed2000

O-Alkylation of cupferron: aiming at the design and synthesis of controlled nitric oxide releasing agents.

O-Alkylation of N-nitroso-N-phenylhydroxylamine ammonium salt (cupferron) was studied for the synthesis of novel nitric oxide (NO) releasing agents. The alkylation occurred regioselectively at the terminal oxygen, leading to a single product N-(alkyloxy)-N'-phenyldiimide N'-oxide as indicated by NMR and X-ray analysis. The O-alkyl derivatives exhibited significantly improved stability compared to their parent compound, cupferron. It was demonstrated that the cupferron O-alkyl derivatives could function as photoreleasing NO donor compounds. N-(N"-acetylphenylalanylmethylenyloxy)-N'-phenyldiimide N'-oxide), which linked the cupferron portion with an amino acid via an acetal moiety, was synthesized as an model NO prodrug where controlled NO release would occur either by increasing pH or by a protease-catalyzed hydrolysis.

Alkylation↗

PubMed2000

Correlation of increased apoptosis and proliferation with development of prostatic intraepithelial neoplasia (PIN) in ventral prostate of the Noble rat.

BACKGROUND: Imbalance between cell proliferation and cell apoptosis has been considered a key factor in carcinogenesis. Prostatic intraepithelial neoplasia (PIN) is the most likely precancereous lesion and represents the major target for chemoprevention of prostate cancer. The proliferative and apoptotic activities involved in the development of PIN remain to be elucidated. METHODS: Ventral prostates were removed from Noble rats that were treated with a combination of testosterone (T) and estradiol (E(2)) for certain periods of time, and processed for histopathological grading. To evaluate the relationship between cell proliferation and apoptosis, immunohistochemistry for proliferating cell nuclear antigen (PCNA), Ki-67, and in situ DNA nick labeling (TUNEL) for identifying apoptotic cells, were performed on paraffin sections from prostate samples with PIN lesions. The results were correlated with expression patterns of Bcl-2 and Bax, two proteins related to cell survival and cell apoptosis. RESULTS: Pathologically, low-grade PIN (LGPIN) and high-grade PIN (HGPIN) were observed in ducts or alveoli after 3 and 5 months of T + E(2) treatment, respectively. Quantitative evaluation of Ki-67 showed an increased proliferative activity in HGPIN. In contrast to normal prostatic ducts and alveoli, which showed no positive staining for Ki-67 in the nuclei of luminal cells, 25% Ki-67-positive cells were detected in luminal cells of HGPIN. Only 7.5% Ki-67-positive cells were found belonging to the basal cell type. The Ki-67 index showed a higher growth rate from normal to HGPIN. The PCNA results showed a similar expression pattern to that of Ki-67 in normal prostate, LGPIN, and HGPIN. Apoptotic index (number of apoptotic cells/total number of cell counted) was significantly higher (P = 0.028) in HGPIN (3.23%) than in control prostate (1.19%). In contrast to control prostate, which showed no definite expression of Bcl-2, an intense positive expression of Bcl-2 in HGPIN was observed. Positive expression of Bax protein was observed in glandular epithelial cells of normal control prostate and HGPIN as well. CONCLUSIONS: Overexpression of Bcl-2 and higher Ki-67 or PCNA indices in HGPIN suggest that abnormal growth of premalignant lesions might result from an increase in cell proliferation. An increased apoptotic rate in HGPIN further implicates that active apoptosis may accelerate cell turnover in the development of premalignant lesions of the prostate.

Animals↗

PubMed2000

Interplay of p53 and DNA-repair protein XRCC4 in tumorigenesis, genomic stability and development.

XRCC4 is a non-homologous end-joining protein employed in DNA double strand break repair and in V(D)J recombination. In mice, XRCC4-deficiency causes a pleiotropic phenotype, which includes embryonic lethality and massive neuronal apoptosis. When DNA damage is not repaired, activation of the cell cycle checkpoint protein p53 can lead to apoptosis. Here we show that p53-deficiency rescues several aspects of the XRCC4-deficient phenotype, including embryonic lethality, neuronal apoptosis, and impaired cellular proliferation. However, there was no significant rescue of impaired V(D)J recombination or lymphocyte development. Although p53-deficiency allowed postnatal survival of XRCC4-deficient mice, they routinely succumbed to pro-B-cell lymphomas which had chromosomal translocations linking amplified c-myc oncogene and IgH locus sequences. Moreover, even XRCC4-deficient embryonic fibroblasts exhibited marked genomic instability including chromosomal translocations. Our findings support a crucial role for the non-homologous end-joining pathway as a caretaker of the mammalian genome, a role required both for normal development and for suppression of tumours.

Animals↗

PubMed2000

Soluble polycyclic aromatic hydrocarbons in raw coals.

Polycyclic aromatic hydrocarbons (PAHs) are considered to be a group of compounds that pose potential health hazards since some PAHs are known carcinogens. During coal utilization processes, such as coal combustion and pyrolysis, PAHs released may be divided into two categories according to their formation pathways. One category is derived from complex chemical reactions and the other is from free PAHs transferred from the original coals. PAHs released from complex chemical reactions during combustion and pyrolysis have received considerable attention in recent years. However, free PAHs contained in raw coals have not been seriously considered as a source of these materials to be released during the utilization of coal. The goal of this study was to observe the relation between the content of PAHs in different coals and the elemental composition of the coals. In this study, eight bituminous coals with dry, ash-free carbon values varying from 65% to 90% were selected. Each coal was extracted with dichloromethane in a Soxhlet extractor for 6 h. The extracts were quantitatively analyzed with a gas chromatograph/mass spectrometer (GC-MS). More than 20 kinds of PAHs were identified. The total amount of PAHs determined varied from 1.2 to 28.3 mg/kg from the various coal types. The maximum total PAHs extracted was reached when the carbon content exceeded 84% by weight.

Anthracenes↗

PubMed2000

Roles of PLC-beta2 and -beta3 and PI3Kgamma in chemoattractant-mediated signal transduction.

The roles of phosphoinositide 3-kinase (PI3K) and phospholipase C (PLC) in chemoattractant-elicited responses were studied in mice lacking these key enzymes. PI3Kgamma was required for chemoattractant-induced production of phosphatidylinositol 3,4,5-trisphosphate [PtdIns (3,4,5)P3] and has an important role in chemoattractant-induced superoxide production and chemotaxis in mouse neutrophils and in production of T cell-independent antigen-specific antibodies composed of the immunoglobulin lambda light chain (TI-IglambdaL). The study of the mice lacking PLC-beta2 and -beta3 revealed that the PLC pathways have an important role in chemoattractant-mediated production of superoxide and regulation of protein kinases, but not chemotaxis. The PLC pathways also appear to inhibit the chemotactic activity induced by certain chemoattractants and to suppress TI-IglambdaL production.

Animals↗

PubMed2000

Expression of a kallikrein-like protein in prostatic intraepithelial neoplasia in ventral prostate of the noble rat.

BACKGROUND: In an effort to identify biomarker(s) for prostatic cancer (PCa), we analyzed the changes of secretory proteins in the ventral prostate (VP) of Noble rats at early stages of carcinogenesis. METHODS: Ventral prostates were removed from both control (n = 36) and experimental (n = 88) rats implanted with a known ratio of testosterone (T) and 17beta-estradiol (E(2)). Tissue sections were stained by hematoxylin and eosin (H&E) for pathological screening, and secretions were collected for SDS-PAGE analysis followed by N-terminal microsequencing, antiserum production, Western blot, and immunohistochemical study. RESULTS: Pathologically, low-grade prostatic intraepithelial neoplasia (LGPIN) and high-grade PIN (HGPIN) were observed in ducts or alveoli after 3 and 5 months of T + E(2) treatment, respectively. The results of SDS-PAGE showed an elevated expression of 18-kDa protein (p18) in secretions of VP with HGPIN or cancerous lesions. Analysis of p18 by N-terminal sequencing showed a high score of homology to rat glandular kallikrein. To characterize the expression pattern of the protein in tissue samples, an antiserum was raised against the N-terminus of the p18. The monospecificity of the antiserum against p18 was confirmed by Western blot analysis. Immunohistochemical study showed that in ducts or alveoli of normal and LGPIN samples, a mild positive staining for p18 was observed in secretions. However, the reactivity was intense not only in luminal secretions but also in some luminal secretory cells in HGPIN and cancer cells as well. CONCLUSIONS: The high expression of p18 in connection with neoplastic transformation of cells strongly suggests that the potential application of this protein as a marker for early detection of PCa should be further investigated.

Adenocarcinoma↗