The imprinted mouse gene Gnas produces the G protein ␣-subunit G S ␣ and several other gene products by using alternative promoters and first exons. G S ␣ is maternally expressed in some tissues and biallelically expressed in most other tissues, while the gene products NESP55 and XL␣s are maternally and paternally expressed, respectively. We investigated the mechanisms of Gnas imprinting. The G S ␣ promoter and first exon are not methylated on either allele. A further upstream region (approximately from positions ؊3400 to ؊939 relative to the G S ␣ translational start site) is methylated only on the maternal allele in all adult somatic tissues and in early postimplantation development. Within this region lies a fourth promoter and first exon (exon 1A) that generates paternal-specific mRNAs of unknown function. Exon 1A and G S ␣ mRNAs have similar expression patterns, making competition between their promoters unlikely. Differential methylation in this region is established during gametogenesis, being present in oocytes and absent in spermatozoa, and is maintained in preimplantation E3.5d blastocysts. Therefore, this region is a methylation imprint mark. In contrast, differential methylation of the NESP55 and XL␣s promoter regions (Nesp and Gnasxl) is not established during gametogenesis. The methylation imprint mark that we identified may be important for the tissue-specific imprinting of G S ␣.
Osteoarthritis (OA) is a progressive condition that causes significant disability and impairment. In 2005, arthritis affected nearly 60% of Americans aged 65 years and older. The American College of Rheumatology, the American Geriatrics Society, and the American Pain Society have published guidelines on management of mild to moderate OA. These organizations advocate use of a comprehensive management program, which includes nonpharmacologic modalities (eg, education, use of assistive devices) as the cornerstone of therapy and pharmacologic intervention, such as over-the-counter or prescription analgesia, in patients needing pain relief. The purpose of this article is to outline a comprehensive management program for patients with an established diagnosis of mild to moderate OA of the hip or knee, which can be initiated by primary care providers and then collaboratively maintained by the patient and healthcare practitioners. Strategies to improve patient compliance with the program are described so that maximum benefit can be derived from the comprehensive approach.
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