Anabolic androgenic steroids reverse the beneficial effect of exercise on tendon biomechanics: An experimental study

Background The effect of anabolic androgenic steroids on tendons has not yet been fully elucidated. Aim of the present study was the evaluation of the impact of anabolic androgenic steroids on the biomechanical and histological characteristics of Achilles tendons. Methods Twenty-four male Wistar rats were randomized into four groups with exercise and anabolic steroids (nandrolone decanoate) serving as variables. Protocol duration was 12 weeks. Following euthanasia, tendons’ biomechanical properties were tested with the use of a modified clamping configuration. Histological examination with light and electron microscopy were also performed. Results In the group of anabolic steroids and exercise the lowest fracture stress values were observed, while in the exercise group the highest ones. Histological examination by light and electron microscopy revealed areas of collagen dysplasia and an increased epitendon in the groups receiving anabolic steroids and exercise. Conclusions These findings suggest that anabolic androgenic steroids reverse the beneficial effect of exercise, thus resulting in inferior maximal stress values

Abstract 12709: Characterization of Growth Hormone Releasing Hormone Receptor During Cardiomyogenesis

Byline: Amarylis Wanschel, Univ of Miami, miami, FL; Konstantinos Chatzistergos, Aristotle Univ Thessaloniki, Thessaloniki; Alessandro Salerno, Univ of Miami, miami, FL; Krystalenia Valasaki, Univ of Miami, Miami, FL; Stefan Kurtenbach, Univ of Miami, Miami, FL; Wayne Balkan, Univ of Miami, Miami, FL; Derek Dykxhoorn, Univ of Miami Med Sch, Miami, FL; Andrew Schally, Univ of Miami, Miami, FL; Joshua M Hare, UNIVERSITY OF MIAMI, Miami, FL Introduction: Differentiation and expansion of cardiomyocytes from human-induced pluripotent stem cells is a poorly understood process, and the signals promoting differentiation of cardiomyocytes toward specific cell fates are not well defined. Here we show that the growth hormone-releasing hormone receptor (GHRH-R) signaling pathway controls this differentiation process and cell fate. Hypothesis: Stimulation of hPSCs with GHRH promotes ð-catenin stabilization through the GH/IGF1 axis. The presence of cell-surface GHRH-R differentiates between atrio-ventricular cardiomyocytes and non-cardiomyogenic cardiac cells, including coronary vascular, neuronal and pacemaker cells, such that selecting for GHRH-R allows for the elimination of pacemaker cells and derivation of a pure population of atrio-ventricular cardiomyocytes. Methods: Using RNA-seq to comprehensively characterize the GHRH-R signaling pathway, we identified that NKX2-5, a transcription factor involved in progenitor specification and differentiation into atrio-ventricular cardiomyocytes, is upregulated in response to GHRH. Results: GHRH-R signaling also upregulated HIF-1ð via the PI3k/Akt/mTOR pathway to enhance NKX2-5 transcription and stimulate a Warburg-like effect in developing cardiomyocytes. Conclusions: Together these findings provide crucial insights into human stem cell differentiation and offer a translationally useful tool to optimize the development of pure cardiomyocyte preparations derived from induced pluripotent stem cells.Professiona

Anabolic androgenic steroids reverse the beneficial effect of exercise on tendon biomechanics: An experimental study

Background: The effect of anabolic androgenic steroids on tendons has not yet been fully elucidated. Aim of the present study was the evaluation of the impact of anabolic androgenic steroids on the biomechanical and histological characteristics of Achilles tendons. Methods: Twenty-four male Wistar rats were randomized into four groups with exercise and anabolic steroids (nandrolone decanoate) serving as variables. Protocol duration was 12 weeks. Following euthanasia, tendons' biomechanical properties were tested with the use of a modified clamping configuration. Histological examination with light and electron microscopy were also performed. Results: In the group of anabolic steroids and exercise the lowest fracture stress values were observed, while in the exercise group the highest ones. Histological examination by light and electron microscopy revealed areas of collagen dysplasia and an increased epitendon in the groups receiving anabolic steroids and exercise. Conclusions: These findings suggest that anabolic androgenic steroids reverse the beneficial effect of exercise, thus resulting in inferior maximal stress values. © 2013 European Foot and Ankle Society

Bone Marrow-Derived c-kit +

Recent studies suggest that bone marrow (BM)-derived stem cells have therapeutic efficacy in neonatal hyperoxia-induced lung injury (HILI). c-kit, a tyrosine kinase receptor that regulates angiogenesis, is expressed on several populations of BM-derived cells. Preterm infants exposed to hyperoxia have decreased lung angiogenesis. Here we tested the hypothesis that administration of BM-derived c-kit(+) cells would improve angiogenesis in neonatal rats with HILI. To determine whether intratracheal (IT) administration of BM-derived c-kit(+) cells attenuates neonatal HILI, rat pups exposed to either normobaric normoxia (21% O(2)) or hyperoxia (90% O(2)) from postnatal day (P) 2 to P15 were randomly assigned to receive either IT BM-derived green fluorescent protein (GFP)(+) c-kit(−) cells (PL) or BM-derived GFP(+) c-kit(+) cells on P8. The effect of cell therapy on lung angiogenesis, alveolarization, pulmonary hypertension, vascular remodeling, cell proliferation, and apoptosis was determined at P15. Cell engraftment was determined by GFP immunostaining. Compared to PL, the IT administration of BM-derived c-kit(+) cells to neonatal rodents with HILI improved alveolarization as evidenced by increased lung septation and decreased mean linear intercept. This was accompanied by an increase in lung vascular density, a decrease in lung apoptosis, and an increase in the secretion of proangiogenic factors. There was no difference in pulmonary vascular remodeling or the degree of pulmonary hypertension. Confocal microscopy demonstrated that 1% of total lung cells were GFP(+) cells. IT administration of BM-derived c-kit(+) cells improves lung alveolarization and angiogenesis in neonatal HILI, and this may be secondary to an improvement in the lung angiogenic milieu

13Th International Conference On Conservative Management Of Spinal Deformities And First Joint Meeting Of The International Research Society On Spinal Deformities And The Society On Scoliosis Orthopaedic And Rehabilitation Treatment – Sosort-Irssd 2016 Meeting

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