John J. Kopchick

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To gain insight into the pathways by which caloric restriction (CR) slows aging, gene expression levels were assessed for each of 2,352 genes in the livers of 9-month-old CR and control mice. A total of 352 genes were found to be significantly increased or decreased by CR. The distribution of affected genes among functional classes was similar to the(More)
CONTEXT Recombinant human GH (rhGH) therapy in Prader-Willi syndrome (PWS) has been used by the medical community and advocated by parental support groups since its approval in the United States in 2000 and in Europe in 2001. Its use in PWS represents a unique therapeutic challenge that includes treating individuals with cognitive disability, varied(More)
Growth hormone receptor gene-disrupted (GHR-/-) mice exhibit increased life span and adipose tissue mass. Although this obese phenotype has been reported extensively for young adult male GHR-/- mice, data for females and for other ages in either gender are lacking. Thus, the purpose of this study was to evaluate body composition longitudinally in both male(More)
  • Valter D Longo, Adam Antebi, Andrzej Bartke, Nir Barzilai, Holly M Brown-Borg, Calogero Caruso +24 others
  • 2015
The workshop entitled 'Interventions to Slow Aging in Humans: Are We Ready?' was held in Erice, Italy, on October 8-13, 2013, to bring together leading experts in the biology and genetics of aging and obtain a consensus related to the discovery and development of safe interventions to slow aging and increase healthy lifespan in humans. There was consensus(More)
  • Michael S. Bonkowski, Fernando P. Dominici, Oge Arum, Juliana S. Rocha, Khalid A. Al Regaiey, Reyhan Westbrook +5 others
  • 2009
Most mutations that delay aging and prolong lifespan in the mouse are related to somatotropic and/or insulin signaling. Calorie restriction (CR) is the only intervention that reliably increases mouse longevity. There is considerable phenotypic overlap between long-lived mutant mice and normal mice on chronic CR. Therefore, we investigated the interactive(More)
The role of insulin-like growth factor-I (IGF-I) in the initiation of puberty and testicular function is poorly understood. Growth hormone (GH) receptor (R) gene-disrupted mice or GHR gene "knockouts" (GHR-KO) are GH resistant and IGF-I deficient. To assess whether the age of sexual maturation is affected by the absence of IGF-I, various parameters of(More)
Liver regeneration is a fundamental mechanism by which the liver responds to injury. This process is regulated by endogenous growth factors and cytokines, and it involves proliferation of all mature cells that exist within the intact organ. To understand the role of the GH/IGF-I axis in liver regeneration, we performed partial hepatectomies in three groups(More)
OBJECTIVE With the increasing rates of obesity, many people diet in an attempt to lose weight. As weight loss is seldom maintained in a single effort, weight cycling is a common occurrence. Unfortunately, reports from clinical studies that have attempted to determine the effect of weight cycling on mortality are in disagreement, and to date, no controlled(More)
BACKGROUND Erythropoietin receptors have been identified in human skeletal muscle tissue, but downstream signal transduction has not been investigated. We therefore studied in vivo effects of systemic erythropoietin exposure in human skeletal muscle. METHODOLOGY/PRINCIPAL FINDINGS The protocols involved 1) acute effects of a single bolus injection of(More)
Unintentional weight loss (wasting) in the elderly is a major health concern as it leads to increased mortality. Several studies have focused on muscle loss, but little is known about the mechanisms giving rise to loss of fat mass at old ages. To investigate potential mechanisms, white adipose tissue (WAT) characteristics and proteomic profiles were(More)