Role of growth factors in ovary organogenesis.

The organogenesis of the ovary encompasses the formation of a great variety of structures, both germinal and nongerminal. Primordial follicle (PF) formation is of the utmost importance because PFs are obligatory for the reproductive cycle and female fertility. The major events involved in PF formation are described.

Bone morphogenetic protein-15 inhibits follicle-stimulating hormone (FSH) action by suppressing FSH receptor expression.

We have recently reported that oocyte-derived bone morphogenetic protein-15 (BMP-15) can directly modulate follicle-stimulating hormone (FSH) action in rat granulosa cells. Here, we investigate underlying mechanisms of this BMP-15 effect. Treatment with BMP-15 alone exerted no significant effect on the basal expression of mRNAs encoding steroidogenic acute regulatory protein, P450 side chain cleavage enzyme, P450 aromatase, 3beta-hydroxysteroid dehydrogenase, luteinization hormone receptor, and inhibin/activin subunits.

Pregnancy-associated plasma protein-A gene expression in human ovaries is restricted to healthy follicles and corpora lutea.

Recently, Pregnancy-Associated Plasma Protein-A (PAPP-A) in human follicular fluid was identified as an insulin-like growth factor binding protein-4 protease (IGFBP-4ase). The ability of IGFBP-4ase to inactivate the FSH antagonist, IGFBP-4, has suggested a possible role for PAPP-A in regulating FSH action. Despite growing interest in this protease, the question of whether the PAPP-A gene is expressed in ovaries of normal cycling women is unknown.

Bone morphogenetic protein-15. Identification of target cells and biological functions.

In developing ovarian follicles, the regulation of cell proliferation and differentiation is tightly coordinated. Precisely how this coordination is achieved is unknown, but recent observations have suggested that molecules emitted by the oocyte are involved in the process. The newly discovered oocyte-specific growth factor, bone morphogenetic protein-15 (BMP-15), is one such molecule.

The role of the oocyte in folliculogenesis.

Novel regulatory proteins have been identified within oocytes that are crucially involved in folliculogenesis. One of the most exciting oocyte signaling molecules is a novel member of the transforming growth factor beta (TGF-beta) superfamily, growth differentiation factor 9 (GDF-9). Loss-of-function studies have established that GDF-9 is obligatory for proper folliculogenesis and fertility in female mice.

Emergence of H3N2 reassortant influenza A viruses in North American pigs.

In late summer through early winter of 1998, there were several outbreaks of respiratory disease in the swine herds of North Carolina, Texas, Minnesota and Iowa. Four viral isolates from outbreaks in different states were analyzed, both antigenically and genetically. All of the isolates were identified as H3N2 influenza viruses with antigenic profiles similar to those of recent human H3 strains.

Changes in insulin-like growth factor-binding protein-3 messenger ribonucleic acid in endothelial cells of the human corpus luteum: a possible role in luteal development and rescue.

In the human menstrual cycle, extensive angiogenesis accompanies luteinization; and the process is physiologically important for corpus luteum (CL) function. During luteolysis, the vasculature collapses, and the endothelial cells die. In a conceptual cycle, the CL persists both functionally and structurally beyond the luteoplacental shift.

Testability of a color vision screening test in a population with mental retardation.

Purpose: The purpose of this study was to determine the testability of the "Co or Vision Testing Made Easy" color vision test, marketed as a screening test for young children, in a population of individuals with mental retardation. The test uses simple geometric figures that are easily identified. Previously, the test has demonstrated validity as a measure of color deficiency.

Viscoelastic properties of intervertebral disc cells. Identification of two biomechanically distinct cell populations.

Study Design: A combined experimental and theoretical biomechanical study to quantify the mechanical properties of living cells of the porcine intervertebral disc.

Objectives: To quantify zonal variations in the mechanical properties and morphology of cells isolated from the intervertebral disc.

Summary Of Background Data: Cellular response to mechanical stimuli is influenced by the mechanical properties of cells and of the extracellular matrix.

Coincident development of sesamoid bones and clues to their evolution.

Sesamoid bones form within tendons in regions that wrap around bony prominences. They are common in humans but variable in number. Sesamoid development is mediated epigenetically by local mechanical forces associated with skeletal geometry, posture, and muscular activity.

Effect of dietary phosphorus on finishing steer performance, bone status, and carcass maturity.

Yearling crossbred steers (n = 60; 386 kg) were individually fed in a completely randomized experimental design to determine their P requirement. Treatments were in a factorial arrangement with two levels of Ca (.35 or .

Genetic reassortment of avian, swine, and human influenza A viruses in American pigs.

In late summer through early winter of 1998, there were several outbreaks of respiratory disease in the swine herds of North Carolina, Texas, Minnesota, and Iowa. Four viral isolates from outbreaks in different states were analyzed genetically. Genotyping and phylogenetic analyses demonstrated that the four swine viruses had emerged through two different pathways.

The effect of the angiogenesis inhibitor TNP-470 on luteal establishment and function in the primate.

Angiogenesis during luteal development is probably essential for normal lutein cell function. Since the angiogenesis inhibitor TNP-470 inhibits pregnancy in mice, the current study investigated its effects on the establishment and function of the primate corpus luteum. Regularly ovulating macaques were treated with TNP-470 (6 mg/kg), i.

Evaluation of nitrogen and organic matter balance in the feedlot as affected by level and source of dietary fiber.

A trial was conducted to determine the effect of level and source of dietary fiber on N and OM excretion by cattle on finishing diets. One hundred twenty steers were stratified by weight and allotted to one of the following treatments: 7.5% roughage (7.

A functional bone morphogenetic protein system in the ovary.

Bone morphogenetic proteins (BMPs) comprise a large group of polypeptides in the transforming growth factor beta superfamily with essential physiological functions in morphogenesis and organogenesis in both vertebrates and invertebrates. At present, the role of BMPs in the reproductive system of any species is poorly understood. Here, we have established the existence of a functional BMP system in the ovary, replete with ligand, receptor, and novel cellular functions.

Mechanically induced calcium waves in articular chondrocytes are inhibited by gadolinium and amiloride.

Chondrocytes in articular cartilage utilize mechanical signals from their environment to regulate their metabolic activity. However, the sequence of events involved in the transduction of mechanical signals to a biochemical signal is not fully understood. It has been proposed that an increase in the concentration of intracellular calcium ion ([Ca2+]i) is one of the earliest events in the process of cellular mechanical signal transduction.

Prevalence of chief complaints in a pediatric clinic population.

Purpose: To determine the type and frequency of chief complaints reported by parents of pediatric patients younger than 8 years of age in an optometry clinic. There have been many reports on prevalence of pediatric eye and vision disorders; however, the frequency of presenting complaints has not been carefully investigated.

Methods: 578 patient charts were retrospectively evaluated to determine the entering chief complaint, representing a 28-month time period between January 1993 and April 1995.

Normal reproductive and macrophage function in Pem homeobox gene-deficient mice.

Interaction between germ cells and the supporting somatic cells guides many of the differentiative processes of gametogenesis. The expression pattern of the Pem homeobox gene suggests that it may mediate specific inductive events in murine reproductive tissues. During gestation, Pem is expressed in migrating and early postmigratory primordial germ cells, as well as in all embryo-derived extraembryonic membranes.

Insulin-like growth factor binding protein-3 mRNA expression in endothelial cells of the primate corpus luteum.

Luteinization is associated with endothelial cell proliferation as part of the extensive angiogenesis necessary to maintain corpus luteum function. However, following luteal demise, the vasculature regresses and the endothelial cells disappear. In the rat corpus luteum, the endothelial cells express high concentrations of insulin-like growth factor-binding protein-3 (IGFBP-3) during luteolysis, suggesting a role of IGFBP-3 during endothelial cell loss.

Evidence for a neutrophil-interleukin-8 system in human folliculogenesis.

Objective: This study was conducted to determine whether polymorphonuclear leukocytes (neutrophils) and the potent chemoattractant interleukin-8 are associated with follicle development in the normal human ovary.

Study Design: We performed a morphometric analysis of neutrophils in 268 human ovarian follicles, of which 199 were preantral and 69 were antral. In each antral follicle the numbers of mitotic, apoptotic, and total granulosa cells were counted to determine healthy and atretic follicles.

Activin-induced inhibin alpha-subunit production by rat granulosa cells requires endogenous insulin-like growth factor-I.

Inhibin-alpha subunit (Inh-alpha) gene expression is important for granulosa cell (GC) differentiation and prevention of ovarian tumorigenesis. Studies on Inh-alpha regulation have implicated activin and insulin-like growth factor-I (IGF-I) in the mechanisms of expression. Here we present evidence that endogenously produced IGF-I plays an obligatory role in activin-induced Inh-alpha production.

von Willebrand factor does not influence atherogenesis in arteries subjected to altered shear stress.

The role of von Willebrand factor (vWF) in arterial neointimal formation that develops in arteries with altered shear stress was investigated using normal, heterozygous, and homozygous von Willebrand disease pigs (ie, vWD, or lacking vWF) that were fed normal pig chow. Shear stress was applied to carotid and femoral arteries with a Goldblatt clamp for 14 days, producing a > or = 80% stenosis. Neointimal lesion size was measured by computer-assisted morphometry.

Endogenous insulin-like growth factor-I is obligatory for stimulation of rat inhibin alpha-subunit expression by follicle-stimulating hormone.

Insulin-like growth factor-I (IGF-I) is essential for FSH-dependent steroidogenesis by rat granulosa cells (GC), but whether IGF-I is required for other FSH-dependent functions is unknown. To investigate the role of IGF-I in the mechanisms of FSH-stimulated inhibin alpha-subunit (Inh-alpha) production, rat GC were cultured with FSH, IGF-I, insulin-like growth factor-binding protein (IGFBP)-4, IGFBP-5, and/or anti-IGF-I antibody. Inh-alpha protein and mRNA levels were measured in conditioned medium and cells by Western immunoblotting and Northern analysis, respectively.

Defining apoptosis: players and systems.

Objective: To summarize the basic principles and concepts of apoptosis and some of the information to date regarding the nature of the regulation of apoptosis at the molecular level.

Methods: In the past few years, research in cell and molecular biology has led to a much better understanding of the underlying mechanisms that regulate apoptosis.

Results: Positive and negative regulatory elements that function in specific cell types to activate apoptosis have been identified.

Transforming growth factor-alpha stimulates insulin-like growth factor binding protein-4 (IGFBP-4) expression and blocks follicle-stimulating hormone regulation of IGFBP-4 production in rat granulosa cells.

The ability of TGF-alpha to regulate insulin-like growth factor binding protein-4 (IGFBP-4), was investigated. Primary cultures of rat granulosa cells (GC) were grown in serum-free medium with rat (r) TGF-alpha and/or rFSH, and secreted IGFBP-4 protein and its steady state mRNA levels were measured by Western immunoblotting and Northern blotting, respectively. Control (untreated) cells secreted IGFBP-4 spontaneously, and the levels were increased by rTGF-alpha in a dose- and time-dependent manner.