The molecular mechanisms controlling the course of TM regeneration are far from being elucidated.

Methods: Twenty rats had their tympanic membranes perforated, while four served as a control. Animals were sacrificed on either days 1, 2, 3, 5 and 10 post injury, and TMs were immediately dissected and frozen in liquid nitrogen.

Total TM RNA was isolated and reversely transcribed. qPCR was performed AZD1152 in vitro using Rat Wound Healing RT2 Profiler PCR Array (QIAGEN) containing primers for 84 genes.

Results: Statistically significant changes in the expression of 42 genes were found in various stages of TM healing. The increased expression of genes taking part in the inflammatory reaction (interleukin 6, granulocyte and macrophage chemotactic proteins) was observed from day 2. The expression of DZNeP several genes of extracellular matrix components and their remodeling

enzymes was also changed. Among growth factor genes: Vegfa, Igf1 and Hbegf showed increased expression at the beginning of the healing process, while Hgf expression was highest on day 3.

Conclusions: Several changes in the expression of genes involved in remodeling of extracellular matrix point to important role of connective tissue in TM healing. The molecules accelerating this process, like HbEGF and HGF, seem to be good candidates for further evaluation of their

possible use in clinical treatment. (C) 2013 Elsevier Ireland Ltd. All rights reserved.”
“In this study, we investigated the time-course changes of hormone levels and sperm numbers in male Sprague-Dawley (SD) rats after neonatal exposure learn more to 3,3′,4,4′,5,5′-hexachlorobiphenyl (PCB169). Neonatal rats were given (through oral gavages) doses of 0, 0.025, 0.25, or 0.5 mg/kg-day of PCB169 in corn oil from postnatal day 1 (PND1) to PND7. The rats were sacrificed at PND8, PND21, and PND90. PCB169 exposure was confirmed by the marked induction of liver CYP1A1 mRNA expression at these three time points. The testicular daily sperm production and the sperm counts of the epididymis cauda significantly decreased at PND90 compared to that of control. Although reductions in serum thyroxine and triiodothyronine levels occurred at all these three time points and at both PND21 and PND90, respectively, the mRNA expression of testicular thyroid hormone receptor alpha 1 was suppressed significantly only at PND8. The serum and testicular testosterone (T) levels declined markedly at PND90 compared to the controls, but there was no effect at PND21.