51V magic angle spinning NMR spectroscopy of Keggin anions [PVnW12-nO40](3+n)-: effect of countercation and vanadium substitution on fine structure constants.

Vanadium environments in Keggin oxopolytungstates were characterized by (51)V solid-state MAS NMR spectroscopy. (C(4)H(9))(4)N(+)-, K(+)-, Cs(+)-, as well as mixed Na(+)/Cs(+)- salts of the mono-, di-, and trivanadium substituted oxotungstates, [VW(11)O(40)](4-), [V(2)W(10)O(40)](5-), and [V(3)W(9)O(40)](6-), have been prepared as microcrystalline and crystalline solids. Solid-state NMR spectra report on the local environment of the vanadium site in these Keggin ions via their anisotropic quadrupolar and chemical-shielding interactions.

Comparison of 1-hydroxypyrene exposure in the US population with that in occupational exposure studies.

Urine samples collected in 1999 and 2000 as part of the National Health and Nutrition Examination Survey (NHANES) were analyzed for 14 monohydroxy polycyclic aromatic hydrocarbons (PAHs), and, for the first time, reference range values were calculated for these metabolites in the US population. Pyrene is a major component of most PAH mixtures and often is used as a surrogate for total PAH exposure. We detected 1-hydroxypyrene (1-OHpyrene), a metabolite of pyrene, in more than 99% of the samples.

Endostatin gene therapy for liver cancer by a recombinant adenovirus delivery.

Aim: To investigate the expression of adenovirus-mediated human endostatin (Ad/hEndo) gene transfer and its effect on the growth of hepatocellular carcinoma (HCC) BEL-7402 xenografted tumors.

Methods: Immunohistochemistry analysis with an anti-endostatin antibody was preformed to detect endostatin protein expression in HCC BEL-7402 cells infected with Ad/hEndo. MTT assay was used to investigate the effects of Ad/hEndo on proliferation of human umbilical vein endothelial cells (HUVEC).

[Inhibition of tongue cancer development in nude mice transfected with adenovirus carrying human endostatin gene].

Background & Objective: The squamous cell carcinoma of tongue is one of the most common malignant tumors of oral cavity. Surgical therapy is now the mainstay of combined treatment for tongue squamous cell Carcinoma with chemotherapy and radiotherapy. The overall 5-year survival rate was about 50%.

[Inhibitive effects of recombinant adenovirus-mediated human endostatin on the growth of human hepatocellular carcinoma xenograft in nude mice].

Objective: To investigate the inhibitive effect on the growth of hepatocellular carcinoma (HCC) xenografted in nude mice by adenovirus-mediated human endostatin gene.

Methods: The expression efficiency of endostatin was examined after ECV-304 cells infected with Ad/hEndo by western blot. The hepatoma BEL-7402 cells were injected into Balb/c nude mice to detect the inhibition of Ad/hEndo on the growth of HCC xenografted in nude mice.

51V magic angle spinning NMR spectroscopy of six-coordinate Lindqvist oxoanions: a sensitive probe for the electronic environment in vanadium-containing polyoxometalates. Counterions dictate the 51V fine structure constants in polyoxometalate solids.

Geometric and electronic environments of vanadium have been addressed by (51)V magic angle spinning NMR spectroscopy of six-coordinated polyoxometalate solids. (C(4)H(9))(4)N(+) and mixed Na(+)/Cs(+) salts of the Lindqvist-type mono- and divanadium-substituted oxotungstates, [VW(5)O(19)](3-) and [V(2)W(4)O(19)](4-), have been prepared as microcrystalline and crystalline solids. The solid-state NMR spectra reflect the details of the local environment of the vanadium site in these hexametalate solids via the anisotropic quadrupolar and chemical shielding interactions.

Unusual properties of adenovirus E2E transcription by RNA polymerase III.

In adenovirus type 5-infected cells, RNA polymerase III transcription of a gene superimposed on the 5' end of the E2E RNA polymerase II transcription unit produces two small (<100-nucleotide) RNAs that accumulate to low steady-state concentrations (W. Huang, R. Pruzan, and S.

[A method to detect gene transfection efficacy by flow cytometry].

Background & Objective: Analysis of gene transfer and expression is conventionally inferred from the percentage of positive cells expressing reporter gene in total cells, referred as transfection rate, by investigators counting under a microscope or fluoroscope, which was called as manual counting. But in many cases, it is not accurate and easily influenced by the subjectivity of observer. This study was designed to seek a convenient method to assess objectively and accurately the efficacy of gene transfer and expression.

Determination of selected monohydroxy metabolites of 2-, 3- and 4-ring polycyclic aromatic hydrocarbons in urine by solid-phase microextraction and isotope dilution gas chromatography-mass spectrometry.

Eighteen monohydroxy polycyclic aromatic hydrocarbon metabolites (OH-PAHs) representing polycyclic aromatic hydrocarbons (PAHs) containing up to four rings in human urine have been measured. The method includes the addition of carbon-13 labeled internal standards, enzymatic hydrolysis, and solid-phase microextraction followed by gas chromatography with high-resolution mass spectrometry. By using response factors calculated with the carbon-13 labeled standards, results are presented for calibration, relative standard deviations and analyte levels from an unspiked human urine pool.

Quantification of monohydroxy-PAH metabolites in urine by solid-phase extraction with isotope dilution-GC-MS.

For measurement of biomarkers from polycyclic aromatic hydrocarbon (PAH) exposure, an analytical method is described quantifying hydroxylated PAH (OH-PAH) in urine samples. This method determined monohydroxy metabolites of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, chrysene, benzo[c]phenanthrene, and benz[a]anthracene. The sample preparation consisted of enzymatic hydrolysis, solid-phase extraction and derivatization with a silylating reagent.