Advancing Methods of Assessing Bone Quality to Expand Screening for Osteoporosis.

Context: Dual-energy x-ray absorptiometry (DXA) limits osteoporosis screening because of machine size, technical requirements for operation, and exposure to ionizing radiation.

Objective: To establish data ranges from calcaneus ultrasonography (US) that correspond to bone mineral density (BMD) stratification identified by DXA and to determine whether vitamin D concentration adds to US bone health assessment.

Methods: Patients scheduled for DXA at the Robert C.

Immunohistochemical techniques to identify and localize proteins of interest in paraffin embedded tissue sections.

Proteins carry out cellular functions. Identifying proteins within tissues, which are characteristically comprised of various cell types, is critical to understanding how the tissue functions. Being able to assess protein expression in tissues is also essential to gaining insight into how tissues change under different physiological conditions, in pathological states, in response to treatments, etc.

Initiation of the expression of peroxisome proliferator-activated receptor gamma (PPAR gamma) in the rat ovary and the role of FSH.

PPARgamma is highly expressed in granulosa cells by 23 days post-partum (pp) and is down-regulated in response to the LH surge. We tested the hypothesis that high levels of FSH during the neonatal period trigger the expression of PPARgamma. To determine when PPARgamma expression is initiated, ovaries were collected from neonatal rats.

Polarized ovaries of the long-tongued bat, Glossophaga soricina: a novel model for studying ovarian development, folliculogenesis, and ovulation.

Glossophaga soricina is a spontaneously ovulating, monovular, polyestrous bat with a simplex uterus, exhibiting true menstruation. Studies conducted on reproductively active, captive-maintained animals established that G. soricina also has polarized ovaries, with the ovarian surface epithelium (OSE) restricted to the medial side of the ovary, and primordial follicles limited to an immediately adjacent zone.

Potential role for peroxisome proliferator-activated receptor gamma in regulating luteal lifespan in the rat.

Peroxisome proliferator-activated receptor gamma (PPARgamma) has been shown to stimulate progesterone production by bovine luteal cells. We previously reported higher expression of PPARgamma in old compared with new luteal tissue in the rat. The following studies were conducted to determine the role of PPARgamma in rat corpora lutea (CL) and test the hypothesis that PPARgamma plays a role in the metabolism of progesterone and/or luteal lifespan.

Effects of luteinizing hormone on peroxisome proliferator-activated receptor gamma in the rat ovary before and after the gonadotropin surge.

We have shown previously that mRNA for peroxisome proliferator-activated receptor gamma (PPARgamma) is expressed in granulosa cells and downregulated by the luteinizing hormone (LH) surge. The current studies were undertaken to test the hypothesis that LH stimulates a decrease in the expression of PPARgamma, as well as its activity, in granulosa cells. Ovaries were collected from immature rats 0 and 48 h after they received pregnant mares' serum gonadotropin (PMSG), and 4 and 24 h after administration of human chorionic gonadotropin (hCG), and used for protein isolation or processed for immunolocalization of PPARgamma.

Peroxisome proliferator-activated receptors (PPARs) and ovarian function--implications for regulating steroidogenesis, differentiation, and tissue remodeling.

The peroxisome proliferator-activated receptors (PPARs) are a family of transcription factors involved in varied and diverse processes such as steroidogenesis, angiogenesis, tissue remodeling, cell cycle, apoptosis, and lipid metabolism. These processes are critical for normal ovarian function, and all three PPAR family members--alpha, delta, and gamma, are expressed in the ovary. Most notably, the expression of PPARgamma is limited primarily to granulosa cells in developing follicles, and is regulated by luteinizing hormone (LH).

Expression of messenger RNA for ADAMTS subtypes changes in the periovulatory follicle after the gonadotropin surge and during luteal development and regression in cattle.

Extensive remodeling of the extracellular matrix occurs in the ovary during the periovulatory period. Matrix metalloproteinases and their endogenous inhibitors, tissue inhibitors of metalloproteinases, are believed to play integral roles in this highly regulated series of cellular events, but their specific roles remain unclear. Recent cloning studies have identified a novel family of metalloproteinases, the ADAMTS (A Disintegrin And Metalloproteinase with ThromboSpondin motifs) family.

Inverse relationship between the expression of messenger ribonucleic acid for peroxisome proliferator-activated receptor gamma and P450 side chain cleavage in the rat ovary.

Messenger RNA for peroxisome proliferator-activated receptor gamma (PPARgamma) has been found in granulosa cells, and its expression decreases after the LH surge. We determined which developmental stage of ovarian follicle expresses mRNA for PPARgamma and evaluated the impact of PPARgamma agonists on steroidogenesis. Ovaries were collected from immature eCG/hCG-treated rats at 0 (no eCG), 24, and 48 h post-eCG and 4 and 24 h post-hCG.

Localization and expression of tissue inhibitor of metalloproteinase-4 in the immature gonadotropin-stimulated and adult rat ovary.

The tissue inhibitors of metalloproteinases (TIMPs) are important regulators of the matrix metalloproteinases (MMPs), proteolytic enzymes essential for controlling the coordinated tissue remodeling that takes place in the ovary. In the present study, we characterized the ovarian expression pattern of TIMP-4. The localization of TIMP-4 mRNA was determined by in situ hybridization in adult cycling rats.

Localization and expression of messenger RNAs for the peroxisome proliferator-activated receptors in ovarian tissue from naturally cycling and pseudopregnant rats.

Structural and functional development of the corpus luteum (CL) involves tissue remodeling, angiogenesis, lipid metabolism, and steroid production. The peroxisome proliferator-activated receptors (PPARs) have been shown to play a role in these as well as in a multitude of other cellular processes. To examine the expression of mRNA corresponding to the PPAR family members (alpha, delta, and gamma) in luteal tissue, ovaries were collected from gonadotropin-treated, immature rats on Days 1, 4, 8, and 14 of pseudopregnancy and from adult, cycling animals on each day of the estrous cycle.