The viral G protein-coupled receptor ORF74 unmasks phospholipase C signaling of the receptor tyrosine kinase IGF-1R.

Kaposi's sarcoma-associated herpesvirus (KSHV) encodes the constitutively active G protein-coupled receptor ORF74, which is expressed on the surface of infected host cells and has been linked to the development of the angioproliferative tumor Kaposi's sarcoma. Furthermore, the insulin-like growth factor (IGF)-1 receptor, a receptor tyrosine kinase, also plays an essential role in Kaposi's sarcoma growth and survival. In this study we examined the effect of the constitutively active viral receptor ORF74 on human IGF-1R signaling.

Determination of hemoglobin adducts following oral administration of 1-nitropyrene to rats using gas chromatography-tandem mass spectrometry.

1-Nitropyrene (1-NP) has successfully been used as a marker for environmental monitoring of exposure to diesel exhaust. This study presents a sensitive and selective method for detection of Hb adducts after oral administration of a single dose 1-NP to rats, by measuring 1-aminopyrene (1-AP) after in vitro hydrolysis of the adducts. Released 1-AP was extracted with hexane and derivatized with heptafluorobutyric acid anhydride prior to GC-MS-MS analysis.

1-Nitropyrene as a marker for the mutagenicity of diesel exhaust-derived particulate matter in workplace atmospheres.

The use of 1-nitropyrene (1-NP) as a marker for the occupational exposure to diesel exhaust (DE) mutagens was investigated in workplace atmospheres contaminated with DE from a variety of emission sources, such as power supplies, forklifts, trucks, caterpillar vehicles, trains, ships' engines, and vehicles in city traffic. Total suspended particulate matter was collected by area sampling. The 1-NP content of acetone extracts of these samples as determined by gas chromatography-high resolution mass spectrometry varied from 0.

Role of the intestinal microflora in the formation of DNA and haemoglobin adducts in rats treated with 2-nitrofluorene and 2-aminofluorene by gavage.

The role of the intestinal microflora in the metabolic activation of nitroarenes and arylamines was studied in female Wistar rats that received a dose of 1 mmol/kg 2-aminofluorene (2-AF) in sunflower oil by gavage. Another group received the same dose of 2-nitrofluorene (2-NF). A third group of animals was used as controls.

Solid-phase extraction and gas chromatographic-mass spectrometric determination after hydrolysis of 2-aminofluorene haemoglobin adducts in blood of rats.

2-Nitrofluorene is an environmental pollutant that binds covalently to haemoglobin after nitroreduction and successive N-hydroxylation. these haemoglobin adducts can be cleaved in vitro by mild base-catalysed hydrolysis. For the enrichment of arylamines from the aqueous hydrolysate, an extraction procedure with an organic solvent is widely used.