Here, we investigate the role of polarization interactions in providing a framework for Understanding the wrapping/unwrapping of nucleosomal DNA. The effective
electrostatic potential energy is found to decrease as the nucleosomal DNA minor Cyclopamine in vitro groove width is decreased. This results in bending of DNA which gives rise to its folding, with narrow minor grooves facing in toward the octamer. Changes in the structure of tire nucleosome, through its intrinsic dynamics, ATP-dependent remodeling factors or covalent modifications of the histone tails, and/or in the strength of hydration would exert profound effects on the strength of the polarization interactions and thereby could modulate the folding of DNA and the transcription process. These considerations have led LIS to Suggest a potential epigenetic mechanism according to which the grip of DNA on the histone core could be controlled by the width of the minor groove in conjunction with the local compactness of the nucleosome and the strength of hydration. (C) 2009 Elsevier Ltd. All rights reserved.”
“Nelumbo
nucifera semen (NNS) is a traditional herb with anti-diarrheal, anti-ganacratia, ARS-1620 cell line and tranquilizer-like pharmacological activities. In this study, we examined the anti-amnesic effect of NNS on rats with scopolamine-induced amnesia. Passive avoidance tests, acetylcholinesterase (ACHE) activity, and choline acetyltransferase (CHAT) expression were used to evaluate the NNS anti-amnesic effects. The rats were divided into five groups: the normal group, scopolamine-treated group (1 mg/kg; control), NNS (1 g/kg) and scopolamine (I mg/kg) co-treatment group, and the ARICEPT (I mg/kg) and scopolamine (I mg/kg) co-treatment group (positive control). The rats were administered the compounds orally for 14 days. The latency time of passive avoidance significantly increased by 54% in the NNS-treated
group compared to the scopolamine-treated group. The ACHE activity in the NNS-treated group significantly decreased to 7.35% than that of the control group. CHAT-positive neurons increased by 51.02% in the NNS group Selleck CA3 compared to the control group. These results suggest that NNS extract improves scopolamine-induced dementia by inhibiting ACHE activity and inducing CHAT expression. (C) 2009 Elsevier Ireland Ltd. All rights reserved.”
“Delayed host self-regulation using a Beverton-Holt function and delayed logistic self-regulation are included in a host-pathogen model with free-living infective stages (Anderson and May’s model G) with the purpose of investigating whether adding the relatively complex self-regulations decrease the likelihood of population cycles. The main results indicate that adding delayed self-regulation to the baseline model increases the likelihood of population cycles.