Carcinogenicity and mode of action evaluation for alpha-hexachlorocyclohexane: Implications for human health risk assessment.

Alpha-hexachlorocyclohexane (alpha-HCH) is one of eight structural isomers that have been used worldwide as insecticides. Although no longer produced or used agriculturally in the United States, exposure to HCH isomers is of continuing concern due to legacy usage and persistence in the environment. The U.

TLR2- and TLR4-dependent activation of STAT1 serine phosphorylation in murine macrophages is protein kinase C-delta-independent.

Engagement of Toll-like receptor (TLR) proteins activates multiple signal transduction pathways. Previous studies demonstrated that TLR2 and TLR4 engagement leads to rapid phosphorylation of the transcription factor STAT1 at serine 727 (Ser-727 STAT1) in murine macrophages. Only TLR4 engagement induced STAT1 phosphorylation at tyrosine 701, although this response was delayed compared with Ser-727 STAT1 phosphorylation.

Decreased in vitro proliferation of bladder epithelial cells from patients with interstitial cystitis.

Objectives: To determine whether explanted bladder epithelial cells from patients with interstitial cystitis (IC) display intrinsically decreased rates of proliferation in vitro, and to compare the growth rates of untreated IC and normal bladder cells with the rates of normal cells treated with a purified antiproliferative factor (APF) at levels found in urine from patients with IC.

Methods: Epithelial cell explants were prepared from the bladder biopsies of 4 patients with IC and 2 asymptomatic controls. Cell proliferation was determined by serial counting of trypan blue-negative cells.

Comparison of APF activity and epithelial growth factor levels in urine from Chinese, African-American, and white American patients with interstitial cystitis.

Objectives: Interstitial cystitis (IC) is a chronic bladder disorder for which the etiology is unknown. We have previously shown that antiproliferative factor (APF), heparin-binding epidermal growth factor-like growth factor (HB-EGF), and epidermal growth factor (EGF) are sensitive and specific biomarkers for IC in white American patients. Because little is known about the epidemiology of this disorder, it is unclear whether these factors would also be useful biomarkers for IC in patients from different racial groups and/or geographic locations.