This study demonstrates the ability of tar isolated from environmental tobacco smoke (ETS) to nick DNA in mammalian cells. Solutions of ETS tar behave similarly to aqueous solutions of cigarette tar from mainstream smoke. Both solutions contain the tar semiquinone radical, and this radical associates with the DNA in viable rat alveolar macrophages. Solutions of tar from ETS cause single-strand ...

The ability of aqueous extracts of cigarette tar to nick DNA was investigated using viable mammalian cells. Tar extracts contain a radical with a stable electron spin resonance (ESR) signal at g = 2.0036 characteristic of a semiquinone. The association of the tar component that carries the ESR signal with DNA was demonstrated using viable rat alveolar macrophages. The formation of single-strand...

OBJECTIVE AND HYPOTHESIS To determine whether a temporal relationship exists between the advertising and sales of low-tar cigarettes. It was hypothesised that increases in the advertising of low-tar cigarettes would precede increases in sales for these cigarettes. METHODS The themes of cigarette advertisements were reviewed and coded for 20 low-tar cigarette brands advertised in 13 widely rea...

Objectives: Little is known about the quality of life and clear cut radiographic grades of ankle arthritis in patients with indication for the total ankle replacement (TAR) comparing with patients without indication for TAR. This study was to compare the quality of life and radiographic grades of ankle arthritis in patients who had ankle arthritis with and without indication for TAR. Methods: F...

OBJECTIVE To assess the risk of lung cancer in smokers of medium tar filter cigarettes compared with smokers of low tar and very low tar filter cigarettes. DESIGN Analysis of the association between the tar rating of the brand of cigarette smoked in 1982 and mortality from lung cancer over the next six years. Multivariate proportional hazards analyses used to assess hazard ratios, with adjust...

trans activation of human immunodeficiency virus type 1 (HIV-1) involves the viral trans-activator protein (Tat) and a cellular factor(s) encoded on human chromosome 12 (HuChr12) that targets the trans-activation response element (TAR) in the viral long terminal repeat. Because nascent TAR RNA is predicted to form a secondary structure that specifically binds cellular proteins, we investigated ...

Marine tar residues originate from natural and anthropogenic oil releases into the ocean environment and are formed after liquid petroleum is transformed by weathering, sedimentation, and other processes. Tar balls, tar mats, and tar patties are common examples of marine tar residues and can range in size from millimeters in diameter (tar balls) to several meters in length and width (tar mats)....

Linear TAR RNA has previously been used as a decoy to inhibit HIV-1 transcription in vitro and HIV-1 replication in vivo. A 48 nucleotide circular RNA containing the stem, bulge and loop of the HIV-1 TAR element was synthesized using the self-splicing activity of a group I permuted intron-exon and was tested for its ability to function as a TAR decoy in vitro. This small circular TAR molecule w...

In 1971-3 data on smoking habits, cigarette brand smoked, morning phlegm production, and lung function were recorded for factory workers as part of the Heart Disease Prevention Project. These men were reassessed in 1984 and those who had always smoked cigarettes from the same tar group were compared with those who had dropped one tar group (mean decreases of 6.6 mg tar, 0.1 mg nicotine) and two...

The interaction between human immunodeficiency virus type 1 (HIV-1) and RNA silencing pathways is complex and multifaceted. Essential for efficient viral transcription and supporting Tat-mediated transactivation of viral gene expression, the trans-activation responsive (TAR) element is a structured RNA located at the 5' end of all transcripts derived from HIV-1. Here, we report that this elemen...