Read by QxMD icon Read


E Kamanga-Sollo, K J Thornton, M E White, W R Dayton
In feedlot steers, estradiol-17β (E2) and combined E2 and trenbolone acetate (a testosterone analog) implants enhance rate and efficiency of muscle growth; and, consequently, these compounds are widely used as growth promoters in several countries. Treatment with E2 stimulates protein synthesis rate and suppresses protein degradation rate in fused bovine satellite cell (BSC) cultures; however, the mechanisms involved in these effects are not known with certainty. Although the genomic effects of E2 mediated through the classical estrogen receptors have been characterized, recent studies indicate that binding of E2 to the G protein-coupled estrogen receptor (GPER)-1 mediates nongenomic effects of E2 on cellular function...
September 13, 2016: Domestic Animal Endocrinology
Or Friedman, Ehud Arad, Oded Ben Amotz
In the pursuit of success in sports, some athletes are not deterred by health risks associated with the (mis)use of black market preparations of dubious origin as performance-enhancing agents. Several studies published in the recent years demonstrated that anabolic-androgenic steroids, but also stimulants and growth hormones, are misused by numerous recreational athletes from all over the world. Trenbolone is an anabolic steroid routinely used in the finishing phase of beef production to improve animal performance and feed efficiency...
September 2016: Plastic and Reconstructive Surgery. Global Open
Emad Attalah, Yasmin S Nasr, Hassan A El-Gammal, F A Nour El-Dien
A rapid liquid chromatographic-tandem mass spectrometric method was developed for the simultaneous determination of four natural and synthetic hormone residues (progesterone, testosterone, trenbolone acetate and zeranol) in animal tissue samples. Sample preparation was optimised to minimise time and solvent consumption. Meat samples were mechanically homogenised and digested in a procedure that gave similar recoveries to those enzymatically hydrolysed by Helix pomatia. Efficient extraction was achieved using acidified acetonitrile (1% acetic acid)...
October 2016: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
Yun Zhang, Jodi L Sangster, Lukasz Gauza, Shannon L Bartelt-Hunt
Soil/sediment particle size has been reported to influence the sorption and bioavailability of steroid hormones in the environment. However, the impact of particle size on biotransformation has not been well elucidated. The present study investigated the dissipation of 17β-estradiol and 17β-trenbolone and the formation and degradation of the subsequent transformation products in different size fractions of a sandy and a silt loam sediment. The results showed that the decay of 17β-estradiol and 17β-trenbolone associated with fine particles followed a biphasic pattern with more rapid decay in the initial phase followed by a second phase with slower decay of the residues compared to their decay rates in the sand fraction...
August 4, 2016: Science of the Total Environment
Louisa B Harding, Irvin R Schultz, Denis A M da Silva, Gina M Ylitalo, Dave Ragsdale, Stephanie I Harris, Stephanie Bailey, Barry V Pepich, Penny Swanson
It is well known that endocrine disrupting compounds (EDCs) present in wastewater treatment plant (WWTP) effluents interfere with reproduction in fish, including altered gonad development and induction of vitellogenin (Vtg), a female-specific egg yolk protein precursor produced in the liver. As a result, studies have focused on the effects of EDC exposure on the gonad and liver. However, impacts of environmental EDC exposure at higher levels of the hypothalamic-pituitary-gonad axis are less well understood...
September 2016: Aquatic Toxicology
Sandrine Charles, Virginie Ducrot, Didier Azam, Rachel Benstead, Denise Brettschneider, Karel De Schamphelaere, Sandra Filipe Goncalves, John W Green, Henrik Holbech, Thomas H Hutchinson, Daniel Faber, Filipe Laranjeiro, Peter Matthiessen, Leif Norrgren, Jörg Oehlmann, Evelyn Reategui-Zirena, Anne Seeland-Fremer, Matthias Teigeler, Jean-Pierre Thome, Marysia Tobor Kaplon, Lennart Weltje, Laurent Lagadic
This paper presents the results from two ring-tests addressing the feasibility, robustness and reproducibility of a reproduction toxicity test with the freshwater gastropod Lymnaea stagnalis (RENILYS strain). Sixteen laboratories (from inexperienced to expert laboratories in mollusc testing) from nine countries participated in these ring-tests. Survival and reproduction were evaluated in L. stagnalis exposed to cadmium, tributyltin, prochloraz and trenbolone according to an OECD draft Test Guideline. In total, 49 datasets were analysed to assess the practicability of the proposed experimental protocol, and to estimate the between-laboratory reproducibility of toxicity endpoint values...
July 25, 2016: Regulatory Toxicology and Pharmacology: RTP
Christine Akre, Masahiro Mizuno
Our laboratory has four separate methods for the analysis of trenbolone, stilbenes, resorcyclic acid lactones, and estradiol in bovine urine. The method described in this paper was in response to a client request to consolidate the methods preferably into one method. A multiresidue semi-quantitative method was developed and any suspect positive samples detected by the method were subjected to the method of standard addition to accurately quantify the concentration of the positive analyte. Samples were enzymatically hydrolyzed using β-glucuronidase after which, supported liquid extraction on HM-N cartridges was performed, followed by solvent exchange into methyl tert-butyl ether (MTBE)...
May 2016: Drug Testing and Analysis
Daniel L Villeneuve, Kathleen M Jensen, Jenna E Cavallin, Elizabeth J Durhan, Natàlia Garcia-Reyero, Michael D Kahl, Richard L Leino, Elizabeth A Makynen, Leah C Wehmas, Edward J Perkins, Gerald T Ankley
Triclocarban (TCC) is an antimicrobial agent routinely detected in surface waters which has been hypothesized to interact with the vertebrate endocrine system. The present study examined the effects of TCC alone and in combination with the model endocrine disruptor 17β-trenbolone (TRB) on fish reproductive function. Adult Pimephales promelas were continuously exposed to either 1 or 5 µg TCC/L, 0.5 µg TRB/L or a mixture (MIX) of 5 µg TCC and 0.5 µg TRB/L for 22 d and a variety of reproductive and endocrine-related endpoints were examined...
June 17, 2016: Environmental Toxicology and Chemistry
Joseph A Robinson, Jane P Staveley, Lisa Constantine
17α-Trenbolone and 17α-estradiol are principal metabolites in cattle excreta following the administration of Synovex® ONE, which contains trenbolone acetate (TBA) and estradiol benzoate (EB). As part of the environmental assessment of the use of Synovex(®) ONE, data were generated to characterize the effects of 17α-trenbolone and 17α-estradiol on the reproduction of freshwater fish. These substances are known endocrine disruptors, so the purpose of testing was not to clarify these properties but to identify concentrations representing population-relevant effects for use in risk characterization...
June 15, 2016: Environmental Toxicology and Chemistry
K J Thornton, E Kamanga-Sollo, M E White, W R Dayton
Trenbolone acetate (TBA), a testosterone analog, increases protein synthesis and decreases protein degradation in fused bovine satellite cell (BSC) cultures. However, the mechanism through which TBA alters these processes remains unknown. Recent studies indicate that androgens improve rate and extent of muscle growth through a nongenomic mechanism involving G protein-coupled receptors (GPCR), matrix metalloproteinases (MMP), heparin-binding epidermal growth factor (hbEGF), the epidermal growth factor receptor (EGFR), erbB2, and the insulin-like growth factor-1 receptor (IGF-1R)...
June 2016: Journal of Animal Science
V J Dalbo, M D Roberts, C B Mobley, C Ballmann, W C Kephart, C D Fox, V A Santucci, C F Conover, L A Beggs, A Balaez, F J Hoerr, J F Yarrow, S E Borst, D T Beck
The androgen-induced alterations in adult rodent skeletal muscle fibre cross-sectional area (fCSA), satellite cell content and myostatin (Mstn) were examined in 10-month-old Fisher 344 rats (n = 41) assigned to Sham surgery, orchiectomy (ORX), ORX + testosterone (TEST; 7.0 mg week(-1) ) or ORX + trenbolone (TREN; 1.0 mg week(-1) ). After 29 days, animals were euthanised and the levator ani/bulbocavernosus (LABC) muscle complex was harvested for analyses. LABC muscle fCSA was 102% and 94% higher in ORX + TEST and ORX + TREN compared to ORX (p < ...
June 1, 2016: Andrologia
Jonathan T Haselman, Patricia A Kosian, Joseph J Korte, Allen W Olmstead, Taisen Iguchi, Rodney D Johnson, Sigmund J Degitz
The Larval Amphibian Growth and Development Assay (LAGDA) is a globally harmonized test guideline developed by the U.S. Environmental Protection Agency in collaboration with Japan's Ministry of the Environment. The LAGDA was designed to evaluate apical effects of chronic chemical exposure on growth, thyroid-mediated amphibian metamorphosis and reproductive development. During the validation phase, two well-characterized endocrine-disrupting chemicals were tested to evaluate the performance of the initial assay design: xenoestrogen 4-tert-octylphenol (tOP) and xenoandrogen 17β-trenbolone (TB)...
May 3, 2016: Journal of Applied Toxicology: JAT
K Nadira De Abrew, Raghunandan M Kainkaryam, Yuqing K Shan, Gary J Overmann, Raja S Settivari, Xiaohong Wang, Jun Xu, Rachel L Adams, Jay P Tiesman, Edward W Carney, Jorge M Naciff, George P Daston
Connectivity mapping is a method used in the pharmaceutical industry to find connections between small molecules, disease states, and genes. The concept can be applied to a predictive toxicology paradigm to find connections between chemicals, adverse events, and genes. In order to assess the applicability of the technique for predictive toxicology purposes, we performed gene array experiments on 34 different chemicals: bisphenol A, genistein, ethinyl-estradiol, tamoxifen, clofibrate, dehydorepiandrosterone, troglitazone, diethylhexyl phthalate, flutamide, trenbolone, phenobarbital, retinoic acid, thyroxine, 1α,25-dihydroxyvitamin D3, clobetasol, farnesol, chenodeoxycholic acid, progesterone, RU486, ketoconazole, valproic acid, desferrioxamine, amoxicillin, 6-aminonicotinamide, metformin, phenformin, methotrexate, vinblastine, ANIT (1-naphthyl isothiocyanate), griseofulvin, nicotine, imidacloprid, vorinostat, 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) at the 6-, 24-, and 48-hour time points for 3 different concentrations in the 4 cell lines: MCF7, Ishikawa, HepaRG, and HepG2 GEO (super series accession no...
June 2016: Toxicological Sciences: An Official Journal of the Society of Toxicology
Theresa K Johnston, Edward Perkins, Duncan C Ferguson, Donald M Cropek
Endocrine disrupting compounds (EDCs) can impact the reproductive system by interfering with the hypothalamic-pituitary-gonadal (HPG) axis. While in vitro testing methods have been developed to screen chemicals for endocrine disruption, extrapolation of in vitro response to in vivo action shows inconsistent accuracy. We describe here our tissue co-culture of the fathead minnow (Pimephales promelas) HPG axis and liver (HPG-L) as a tissue explant model that mimics in vivo results. Brain (hypothalamus), pituitary, gonad, and liver tissue explants from adult fish were examined for function both individually and in co-culture to determine combinations and conditions that could replicate in vivo behavior...
March 2, 2016: Environmental Toxicology and Chemistry
Joseph A Robinson, Qingli Ma, Jane P Staveley, Walter J Smolenski, Jon Ericson
17α-Estradiol is one of the principal metabolites in cattle excreta following the administration of Synovex® ONE, which contains estradiol benzoate (EB) and trenbolone acetate (TBA). As part of the environmental assessment of the use of Synovex(®) ONE, data were generated to characterize the fate of 17α-estradiol in the environment. Studies were conducted to determine the degradation and transformation of 17α-[(14) C]-estradiol in two representative water-sediment systems each under aerobic and anaerobic conditions...
January 23, 2016: Environmental Toxicology and Chemistry
Joseph A Robinson, Qingli Ma, Jane P Staveley, Walter J Smolenski, Jon Ericson
Synovex® ONE is an extended-release implant containing the active ingredients estradiol benzoate (EB) and trenbolone acetate (TBA) for use in beef steers and heifers. TBA is rapidly hydrolyzed in cattle to form 17β-trenbolone and its isomer, 17α-trenbolone, which are further transformed to a secondary metabolite, trendione. As part of the environmental assessment for the use of Synovex(®) ONE, data were generated to characterize the fate of 17α-trenbolone, which is the principal metabolite found in cattle excreta, in the environment...
January 23, 2016: Environmental Toxicology and Chemistry
Jonas Baltrusaitis, Eric V Patterson, Meghan O'Connor, Shen Qu, Edward P Kolodziej, David M Cwiertny
Photolysis experiments (in H2O and D2O) and quantum chemical calculations were performed to explore the pH-dependent, reversible photohydration of trenbolone acetate (TBA) metabolites. Photohydration of 17α-trenbolone (17α-TBOH) and 17β-trenbolone (17β-TBOH) occurred readily in simulated sunlight to yield hydrated products with incorporated H(+) at C4 and OH(-) at either C5 (5-OH-TBOH) or C12 (12-OH-TBOH) in the tetracyclic steroid backbone. Although unable to be elucidated analytically, theory suggests preferred orientations of cis-12-OH-TBOH (relative to C13 methyl) and trans-5-OH-TBOH, with the former most thermodynamically stable overall...
July 5, 2016: Environmental Science & Technology
Stefan Örn, Henrik Holbech, Leif Norrgren
Environmental estrogens and androgens can be present simultaneously in aquatic environments and thereby interact to disturb multiple physiological systems in organisms. Studies on interaction effects in fish of androgenic and estrogenic chemicals are limited. Therefore, the aim of the present study was to evaluate feminization and masculinization effects in zebrafish (Danio rerio) exposed to combinations of two synthetic steroid hormones detected in environmental waters: the androgen 17β-trenbolone (Tb) and the oestrogen 17α-ethinylestradiol (EE2)...
January 2016: Environmental Toxicology and Pharmacology
Daniel G Donner, Grace E Elliott, Belinda R Beck, Andrew C Bulmer, Alfred K Lam, John P Headrick, Eugene F Du Toit
The increasing prevalence of obesity adds another dimension to the pathophysiology of testosterone (TEST) deficiency (TD) and potentially impairs the therapeutic efficacy of classical TEST replacement therapy. We investigated the therapeutic effects of selective androgen receptor modulation with trenbolone (TREN) in a model of TD with the metabolic syndrome (MetS). Male Wistar rats (n=50) were fed either a control standard rat chow (CTRL) or a high-fat/high-sucrose (HF/HS) diet. After 8 weeks of feeding, rats underwent sham surgery or an orchiectomy (ORX)...
January 2016: Endocrinology
Ramy Elgendy, Mery Giantin, Clara Montesissa, Mauro Dacasto
We investigated the transcriptomic signature of some anabolic steroids in cattle. Our main objective was to evaluate the effect of a combined trenbolone acetate (TBA, 200mg) and estradiol-17β (E2, 40 mg) implant (Revalor-XS®, REV) on the transcriptome of muscle (target tissue for anabolic steroids) and liver (main biotransformation site). Transcriptomic profiling was performed on 60 samples (30 per tissue) representing 2 groups of animals: REV (sustained release implant for 71 days, n=15), and a control group (CTR, n=15)...
February 2016: Steroids
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"