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Biomedical subjects

W Xue

Publications and source records attributed to W Xue.

71 records · Page 4Linked to original sources
PubMed1991

[Detection and characterization of antigen component of circulating immune complex in sera from patients with lung cancer by monoclonal and polyclonal antibodies].

A total of 117 serum samples from 58 patients with lung cancer, 29 patients with nonmalignant thoracic diseases and 30 healthy donors were tested and analyzed for antigen component in CIC with 5 McAbs and PcAb by Sandwich-ELISA. The results indicated that McAbs were reactive with lung cancer associated CIC (positive rates ranging from 20-32%), while PcAbs were reactive with CIC both from lung cancer patients and from those with non-malignant thoracic diseases (positive rates 45.7% and 41.4% respectively). A combined set using a panel of McAbs to detect CIC will give a higher positive rate (49.2%) than using a single McAb. We anticipate that the McAb-ELISA established in this study to detect antigen-specific CIC will be helpful in the clinical diagnosis and prognosis of lung cancer.

Adenocarcinoma↗
PubMed1990

In vitro interactions of cytokines and bovine viral diarrhea virus in phytohemagglutinin-stimulated bovine mononuclear cells.

Bovine viral diarrhea (BVD) virus inhibited phytohemagglutinin (PHA)-stimulated bovine peripheral blood mononuclear cell (PBMC) proliferation and bovine interleukin-2 (IL-2) production. In the controls, the heat-inactivated BVD virus was not capable of suppressing the PHA-stimulated PBMC proliferation. Presence of exogenous cytokines, such as purified human IL-2, recombinant bovine interleukin-1 (rbovIL-1), recombinant bovine IL-2, and recombinant human IL-6 failed to reverse the BVD virus-induced immunosuppression. Also, we found that the BVD virus inhibited PHA and IL-2 induced proliferation of bovine PBMC in the early and late stages of activation. In summary, our data suggest that BVD virus induced immunosuppression was not due to destruction of the PBMC but may be inhibiting one or more of the important intracellular enzymes that may regulate PBMC proliferation.

Animals↗
PubMed1990

Antigenic variations in bovine viral diarrhea viruses detected by monoclonal antibodies.

Five murine monoclonal antibodies (MAbs) against the NADL strain of bovine viral diarrhea (BVD) virus were developed, identified, and characterized. Four of the MAbs were directed against a 53-kilodalton (kDa) viral protein, and one was specific to a 47-kDa polypeptide. Competitive radioimmunoassay showed that two MAbs were specific to related epitopes of the 53-kDa protein, and the other three MAbs were each specific to a different epitope. The MAbs were used to study heterogeneity among BVD virus strains. Various degrees of reactivity of cytopathic and noncytopathic virus isolates were detected by virus neutralization and immunofluorescence assays. The virus isolates were divided into six groups based on the neutralization test. The results indicated that the 53-kDa glycoprotein of BVD virus is the major protein involved in virus neutralization and that only a few epitopes of the protein contribute to the neutralization. None of the MAbs neutralized all the BVD virus isolates tested in this study, suggesting antigenic variations among BVD virus isolates.

Animals↗
PubMedDate not supplied

Imaging the spatial distribution of membrane receptors during neutrophil phagocytosis.

Optical microscopy and image processing have been employed to study the distribution of several cell surface receptors on living human neutrophils during opsonin-dependent and opsonin-independent phagocytosis. Receptors were labeled using fluorescein-, rhodamine-, or AMCA-conjugated F(ab')2 fragments of anti-Fc gamma RIIIB (CD16), anti-CR3 (CD11b/CD18), and anti-uPAR (urokinase-type plasminogen activator receptor) antibodies, intact phycoerythrin-labeled interleukin 8, and fluorescein- or rhodamine-labeled Con A (concanavalin A), Boc-PLPLP (tert-butyl-oxycarbonyl-Phe(D)-Leu-Phe(D)-Leu-Phe-OH), and N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys. Labeled neutrophils were observed during the phagocytosis of IgG-opsonized erythrocytes and nonopsonized latex beads, Escherichia coli, and Staphylococcus aureus. To quantitate receptor distribution, cells were divided into four quadrants with the first being the point of attachment and the fourth being opposite the point of attachment. Ligated formyl peptide receptors, and to a lesser extent CR3, accumulated at the sites of target internalization for all forms of phagocytosis examined. However, Fc gamma RIIIB, uPAR, IL-8, Con A, and the FPR antagonist FBoc-PLPLP were not polarized on cells during phagocytosis. These data suggest that agonist-labeled formyl peptide receptors may play a broader role in leukocyte function than previously suggested, including possible participation in phagocytosis.

Amino Acid Sequence↗
PubMedDate not supplied

Acetylation of phenolic derivatives of 7H-dibenzo[c,g]carbazole: identification and quantitation of major metabolites by rat liver microsomes.

Acetylation stabilized the phenolic metabolites of 7H-dibenzo[c,g]carbazole (DBC) and made it possible to accumulate greater amounts of metabolites for comprehensive chemical structural elucidation and quantification without the use of radiolabeled DBC. High-resolution mass spectral data and 1H NMR and fluorescence spectra were used to confirm the existence of 5-OH-DBC, 3-OH-DBC, 1-OH-DBC, and the oxidative dimer, 6,6'-bis-(5-OH-DBC), in the acetylated metabolite mixture formed in vitro by 3-methylcholanthrene-induced rat liver microsomes. Using the synthesized acetoxy-DBC derivatives as standards, the HPLC external standard method was employed for quantitation of the major DBC metabolites after acetylation. The quantities of 5-OH-DBC, 3-OH-DBC, 1-OH-DBC, and DBC in the metabolite mixture determined using the external standard method were found to agree with those calculated using the radiometric method. Acetylation is a promising nonradiometric qualitative and quantitative technique for further metabolism studies of DBC and analogues which produce unstable monohydroxylated metabolites.

Acetylation↗
PubMedDate not supplied

Tissue distribution of DNA adducts of 7H-dibenzo[c,g]carbazole and its derivatives in mice following topical application.

7H-Dibenzo[c,g]carbazole (DBC) is a potent liver and skin carcinogen following topical administration. The objective was to determine the pattern of DBC-DNA adducts produced in both target and nontarget tissues when DBC and its metabolites were applied topically at carcinogenic doses. DBC phenolic derivatives 1-hydroxy-DBC, 2-hydroxy-DBC, 3-hydroxy-DBC, 4-hydroxy-DBC, 5-hydroxy-DBC, 6-hydroxy-DBC, 13-c-hydroxy-DBC, and N-methyl-DBC were applied dermally to Hsd:ICR (Br) mice. Tissues were harvested 24 h later, and DBC-DNA adduct levels were determined by 32P-postlabeling. The levels of DBC-DNA adducts were about 25 times greater in liver than in any other tissue. Total DBC-DNA adducts were seen in skin and lung at about equal levels, while adduct levels in kidney and other tissues were no more than one fourth that of lung and skin. Adduct 6 was the predominant adduct in liver, adducts 2 and 3 were formed preferentially in skin, and adduct 3 was formed preferentially in lung. 3-Hydroxy-DBC and 4-hydroxy-DBC produced higher levels of DNA adducts in skin, lung, and liver than did the parent compound or 2-hydroxy-DBC. DNA adducts were not seen in any tissue for the 1-, 5-, 6-, or 13-c-hydroxy compounds. In addition, hepatic DNA adducts were not seen when the nitrogen of DBC was methylated. In lung and skin, N-methyl-DBC induced DNA adducts at levels comparable to DBC, although the adduct profile in these tissues was different from that of DBC itself.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMedDate not supplied

The effects of a binary mixture of benzo(a)pyrene and 7H-dibenzo(c,g)carbazole on lung tumors and K-ras oncogene mutations in strain A/J mice.

Polycyclic aromatic hydrocarbons (PAH) and N-heterocyclic aromatic hydrocarbons (NHA) are environmental pollutants formed during the incomplete combustion of organic materials. Benzo(a)pyrene (BaP) and 7H-dibenzo(c,g)carbazole (DBC) are well-characterized representatives of the PAH and NHA classes of compunds, respectively. Both are demonstrated carcinogens that frequently co-occur in environmental mixtures. This preliminary study was conducted to investigate the effects of a binary mixture of BaP and DBC on lung carcinogenicity in the strain A/J mouse as manifested by tumor development and mutations in the K-ras gene. Male A/J mice were administered the following single intraperitoneal dose (mg/kg) combinations of BaP and DBC dissolved in a 0.2-mL volume of tricaprylin--10 DBC:10 BaP; 2 DBC:10 BaP; 2 DBC:100 BaP; and 10 DBC: 100 BaP, and each of the compounds alone at the same doses. Mice were sacrificed 8 months after carcinogen treatment and lung tumor multiplicity and K-ras mutations determined (high-dose combination). The combination of DBC and BaP produced fewer tumors than the sum of all tumors produced by each compound acting alone. The frequency of tumors with K-ras mutations was also less in a sample of the 10 DBC:100 BaP treatment group than in the same-dose, single compound-treated animals. The dominant mutations produced by BaP and DBC were expressed in tumors from animals treated with the mixture.

Animals↗