EMF AND EARLY BONE DEVELOPMENT

描述：暴露于极低频（ELF）场， 对生物系统有许多重要影响 人们开始担心 有这样的曝光。ELF的全部生物活性 不知道是谁，也不知道是谁。 一方面是潜在的致癌性，另一方面是潜在的治疗益处 另一边。 本提案中计划进行的研究将检验以下假设： 暴露于60 Hz不同振幅的磁场和暴露 持续时间可能会产生细胞关系的变化， 增殖和分化的体内发育模型， 软骨内骨化该模型显示了发育序列 增殖和分化，因为它已经很好地 它具有形态学、生物化学和分子生物学特征， 作为一个很好的测试系统来检查ELF场的效果 暴露于增殖的基因组调节， 分化该模式适用于细胞调控问题 在一般情况下，并具有重要的细胞类比骨骼 胚胎发生和畸形学，生长和修复，通过外推， 到肿瘤发生 Stein和Lian的观察表明，一种增殖- 实验性软骨内分泌存在分化关系 骨化，这种关系可以通过激素和 其他影响，例如可以加速分化或 对增殖具有相互影响的延迟。的意见 Aaron和Ciombor，使用相同的实验性软骨内分泌系统， 骨化，表明细胞外基质的加工 蛋白多糖及其核心蛋白mRNA的表达 暴露在极低频磁场中会加速这种刺激 存在于祖细胞库中。这两组观察结果 形成了本提案实验方法的基础。 他们的实验方法将测量相关基因的表达， 并将评估ELF字段是否可以充当信令机制， 改变增殖和分化的基因组调节。 这些结果将有助于深入了解ELF场对基本 具有广泛生物适用性的调节过程。

DESCRIPTION: Exposure to extremely low frequency (ELF) fields has been shown to have a number of significant effects upon biological systems and concern has been raised about possible health hazards associated with that exposure. The full spectrum of biological activities of ELF fields is not known, and varying claims have been made regarding oncogenic potential on the one hand, and potential therapeutic benefits on the other. The studies planned in this proposal will examine the hypothesis that exposure to 60 Hz magnetic fields of varying amplitude and exposure duration may produce changes in the relationship of cellular proliferation and differentiation in an in vivo developmental model of endochondral ossification. This model exhibits developmental sequences of proliferation and differentiation and, since it has been well characterized in morphological, biochemical and molecular terms, it serves as an excellent test system to examine the effects of ELF field exposure upon the genomic regulation of proliferation and differentiation. The mode is applicable to issues of cell regulation in general and has important cellular analogies to skeletal embryogenesis and teratology, growth and repair and, by extrapolation, to oncogenesis. The observations of Stein and Lian indicate that a proliferation- differentiation relationship exists in experimental endochondral ossification and that this relationship can be modified by hormonal and other influences such that differentiation can be accelerated or retarded with reciprocal effects on proliferation. The observations of Aaron and Ciombor, with the same system of experimental endochondral ossification, indicate that the elaboration of extracellular matrix proteoglycan and the expression of mRNA for proteoglycan core protein can be accelerated by exposure to ELF fields and that this stimulation resides in the progenitor cell pool. These two sets of observations form the basis for the experimental approach for this proposal. Their experimental approach will measure expression of pertinent genes and will assess whether ELF fields can act as a signaling mechanism and alter the genomic regulation of proliferation and differentiation. These results will lend insight into ELF field effects upon fundamental regulatory processes with broad biological applicability.