We have studied the appearance of single strand breaks (SSB) in DNA of mouse keratinocytes exposed in vitro to various tumor promoters. Mouse basal keratinocytes were selectively cultured in low calcium medium, prelabeled with [14C]thymidine, exposed to test agents, and SSB quantified by alkaline elution. 12-O-Tetradecanoylphorbol-13-acetate (TPA) caused a dose-dependent (10(-9)-10(-7) M) incre...

Genetic differences in susceptibility to two-stage skin carcinogenesis have been known for many years. Studies of genetic crosses of sensitive DBA/2 with resistant C57BL/6 mice suggested that multiple autosomal genes determine the sensitivity of these mice to 12-O-tetradecanoylphorbol-13-acetate (TPA) skin tumor promotion. Previous studies mapped one promotion susceptibility locus, Psl1, to dis...

BACKGROUND AND PURPOSE Interhospital transfer after use of intravenous tissue-type plasminogen activator (tPA) in acute stroke (drip and ship) is increasingly frequent. Small studies have suggested that drip and ship tPA is safe and increases rates of tPA use; however, little is known about real-world practice patterns. We sought to evaluate temporal trends in drip and ship tPA use and to compa...

BACKGROUND Bolus thrombolytic therapy is a simplified means of administering thrombolysis that facilitates rapid time to treatment. TNK-tissue plasminogen activator (TNK-tPA) is a highly fibrin-specific single-bolus thrombolytic agent. METHODS AND RESULTS In TIMI 10B, 886 patients with acute ST-elevation myocardial infarction presenting within 12 hours were randomized to receive either a sing...

The treatment of human U-937 leukemia cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) is associated with induction of monocytic differentiation. However, the signaling pathways responsible for induction of the differentiated monocytic phenotype remain unclear. The present studies demonstrate that dexamethasone blocks TPA-induced U-937 cell growth inhibition, adherence, and alpha-naphthyl ...

Tetraprenylacetone (TPA: teprenon, geranylgeranylacetone) is a novel anti-ulcer agent developed in Japan. The aim of this study was to test whether TPA has the ability to promote the healing process of rat gastric mucosal injury induced by absolute ethanol (ET). Fasted rats received orally 5 ml/kg of absolute ET. Sixty minutes later, TPA (200 mg/kg) or saline (control) was administered intragas...

TPA (12-O-tetradecanoylphorbol-13-acetate), a potent tumor promoter, has been shown to stimulate or inhibit cell growth depending on the cell type investigated. We recently found that RT101 cells, a transformed mouse JB6 epidermal cell line, acquired a greater growth inhibition response to TPA during conventional subcultivation. The growth of low-passage RT101 cells was slightly inhibited by TP...

We studied the effect of lipoprotein(a) [Lp(a)], low-density lipoprotein (LDL), and high-density lipoprotein (HDL) on tissue plasminogen activator (TPA) secretion from human endothelial cells. At 1 mumol/L, Lp(a) inhibited constitutive TPA secretion by 50% and phorbol myristate acetate- and histamine-enhanced TPA secretion by 40%. LDL and HDL also depressed TPA secretion by 45% and 35% (constit...

12-O-Tetradecanoylphorbol-13-acetate (TPA), a potent tumor promoter, induced phenotypic differentiation in the human thymic acute lymphocytic leukemia cell line, HPB-ALL. Within 30 min of seeding in the presence of TPA, the cells formed a smooth round shape. After a 7-day exposure to TPA, most of the cells became smaller and reminiscent of large or atypical lymphocytes. Electron microscopic ana...