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Sample records for juvenile hormone influence

  1. THE INFLUENCE OF INSECT JUVENILE HORMONE AGONISTTS ON METAMORPHOSIS AND REPRODUCTION IN ESTUARINE CRUSTACEANS

    EPA Science Inventory

    Comparative developmental and reproductive studies were performed on several species of estuarine crustaceans in response to three juvenile hormone agonists (JHAs) (methoprene, fenoxycarb, and pyriproxyfen). Larval development of the grass shrimp, Palaemonetes pugio, was greater ...

  2. Light exposure leads to reorganization of microglomeruli in the mushroom bodies and influences juvenile hormone levels in the honeybee.

    PubMed

    Scholl, Christina; Wang, Ying; Krischke, Markus; Mueller, Martin J; Amdam, Gro V; Rössler, Wolfgang

    2014-11-01

    Honeybees show a remarkable behavioral plasticity at the transition from nursing inside the hive to foraging for nectar and/or pollen outside. This plasticity is important for age-related division of labor in honeybee colonies. The behavioral transition is associated with significant volume and synaptic changes in the mushroom bodies (MBs), brain centers for sensory integration, learning, and memory. We tested whether precocious sensory exposure to light leads to changes in the density of synaptic complexes [microglomeruli (MG)] in the MBs. The results show that exposure to light pulses over 3 days induces a significant decrease in the MG density in visual subregions (collar) of the MB. Earlier studies had shown that foragers have increased levels of juvenile hormone (JH) co-occurring with a decrease of vitellogenin (Vg). Previous work further established that RNAi-mediated knockdown of vg and ultraspiracle (usp) induced an upregulation of JH levels, which can lead to precocious foraging. By disturbing both Vg and JH pathways using gene knockdown of vg and usp, we tested whether the changes in the hormonal system directly affect MG densities. Our study shows that MG numbers remained unchanged when Vg and JH pathways were perturbed, suggesting no direct hormonal influences on MG densities. However, mass spectrometry detection of JH revealed that precocious light exposure triggered an increase in JH levels in the hemolymph (HL) of young bees. This suggests a dual effect following light exposure via direct effects on MG reorganization in the MB calyx and a possible positive feedback on HL JH levels.

  3. Sex hormones in juvenile nasopharyngeal angiofibroma tissue.

    PubMed

    Kumagami, H

    1993-01-01

    Five cases of juvenile nasopharyngeal angiofibroma were studied in terms of the presence of progesterone, estradiol, testosterone, and dihydrotestosterone in the juvenile nasopharyngeal angiofibroma tissue using the peroxidase-antiperoxidase method. Progesterone and estradiol were positive in all cases. Testosterone was positive in 2 of the 5 patients. Dihydrotestosterone was positive in 3 of the 5 patients. Hormone in the juvenile nasopharyngeal angiofibroma tissue seems to change by the activity of nasopharyngeal angiofibroma.

  4. Influence of age and juvenile hormone on brain dopamine level in male honeybee (Apis mellifera): association with reproductive maturation.

    PubMed

    Harano, Ken-ichi; Sasaki, Ken; Nagao, Takashi; Sasaki, Masami

    2008-05-01

    Dopamine (DA) is a major functional biogenic amine in insects and has been suggested to regulate reproduction in female honeybees. However, its function has not been investigated in male drones. To clarify developmental changes of DA in drones, brain DA levels were investigated at various ages and showed a similar pattern to the previously reported juvenile hormone (JH) hemolymph titer. The DA level was lowest at emergence and peaked at day 7 or 8, followed by decline. Application of JH analog increased brain DA levels in young drones (2-4-days-old), suggesting regulation of DA by JH in drones. In young drones, maturation of male reproductive organs closely matched the increase in brain DA. The dry weight of testes decreased and that of seminal vesicles increased from emergence to day 8. The dry weight of mucus glands increased up to day 4. Consequently, DA regulated by JH might have reproductive behavior and/or physiological functions in drones.

  5. Behavioural effects of juvenile hormone and their influence on division of labour in leaf-cutting ant societies.

    PubMed

    Norman, Victoria C; Hughes, William O H

    2016-01-01

    Division of labour in social insects represents a major evolutionary transition, but the physiological mechanisms that regulate this are still little understood. Experimental work with honey bees, and correlational analyses in other social insects, have implicated juvenile hormone (JH) as a regulatory factor, but direct experimental evidence of behavioural effects of JH in social insects is generally lacking. Here, we used experimental manipulation of JH to show that raised JH levels in leaf-cutting ants results in workers becoming more active, phototactic and threat responsive, and engaging in more extranidal activity - behavioural changes that we show are all characteristic of the transition from intranidal work to foraging. These behavioural effects on division of labour suggest that the JH mediation of behaviour occurs across multiple independent evolutions of eusociality, and may be a key endocrine regulator of the division of labour which has produced the remarkable ecological and evolutionary success of social insects. PMID:26739685

  6. IRS and TOR nutrient-signaling pathways act via juvenile hormone to influence honey bee caste fate

    PubMed Central

    Mutti, Navdeep S.; Dolezal, Adam G.; Wolschin, Florian; Mutti, Jasdeep S.; Gill, Kulvinder S.; Amdam, Gro V.

    2011-01-01

    SUMMARY Regardless of genetic makeup, a female honey bee becomes a queen or worker depending on the food she receives as a larva. For decades, it has been known that nutrition and juvenile hormone (JH) signaling determine the caste fate of the individual bee. However, it is still largely unclear how these factors are connected. To address this question, we suppressed nutrient sensing by RNA interference (RNAi)-mediated gene knockdown of IRS (insulin receptor substrate) and TOR (target of rapamycin) in larvae reared on queen diet. The treatments affected several layers of organismal organization that could play a role in the response to differential nutrition between castes. These include transcript profiles, proteomic patterns, lipid levels, DNA methylation response and morphological features. Most importantly, gene knockdown abolished a JH peak that signals queen development and resulted in a worker phenotype. Application of JH rescued the queen phenotype in either knockdown, which demonstrates that the larval response to JH remains intact and can drive normal developmental plasticity even when IRS or TOR transcript levels are reduced. We discuss our results in the context of other recent findings on honey bee caste and development and propose that IRS is an alternative substrate for the Egfr (epidermal growth factor receptor) in honey bees. Overall, our study describes how the interplay of nutritional and hormonal signals affects many levels of organismal organization to build different phenotypes from identical genotypes. PMID:22071189

  7. IRS and TOR nutrient-signaling pathways act via juvenile hormone to influence honey bee caste fate.

    PubMed

    Mutti, Navdeep S; Dolezal, Adam G; Wolschin, Florian; Mutti, Jasdeep S; Gill, Kulvinder S; Amdam, Gro V

    2011-12-01

    Regardless of genetic makeup, a female honey bee becomes a queen or worker depending on the food she receives as a larva. For decades, it has been known that nutrition and juvenile hormone (JH) signaling determine the caste fate of the individual bee. However, it is still largely unclear how these factors are connected. To address this question, we suppressed nutrient sensing by RNA interference (RNAi)-mediated gene knockdown of IRS (insulin receptor substrate) and TOR (target of rapamycin) in larvae reared on queen diet. The treatments affected several layers of organismal organization that could play a role in the response to differential nutrition between castes. These include transcript profiles, proteomic patterns, lipid levels, DNA methylation response and morphological features. Most importantly, gene knockdown abolished a JH peak that signals queen development and resulted in a worker phenotype. Application of JH rescued the queen phenotype in either knockdown, which demonstrates that the larval response to JH remains intact and can drive normal developmental plasticity even when IRS or TOR transcript levels are reduced. We discuss our results in the context of other recent findings on honey bee caste and development and propose that IRS is an alternative substrate for the Egfr (epidermal growth factor receptor) in honey bees. Overall, our study describes how the interplay of nutritional and hormonal signals affects many levels of organismal organization to build different phenotypes from identical genotypes.

  8. Aedes aegypti juvenile hormone acid methyl transferase, the ultimate enzyme in the biosynthetic pathway of juvenile hormone III, exhibits substrate control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report on the cloning, sequencing, characterization, 3D modeling and docking of Aedes aegypti juvenile hormone acid methyl transferase (AeaJHAMT), the enzyme that converts juvenile hormone acid (JHA) into juvenile hormone (JH). Purified recombinant AeaJHAMT was extensively characterized for enzym...

  9. A Photorhabdus natural product inhibits insect juvenile hormone epoxide hydrolase.

    PubMed

    Nollmann, Friederike I; Heinrich, Antje K; Brachmann, Alexander O; Morisseau, Christophe; Mukherjee, Krishnendu; Casanova-Torres, Ángel M; Strobl, Frederic; Kleinhans, David; Kinski, Sebastian; Schultz, Katharina; Beeton, Michael L; Kaiser, Marcel; Chu, Ya-Yun; Phan Ke, Long; Thanwisai, Aunchalee; Bozhüyük, Kenan A J; Chantratita, Narisara; Götz, Friedrich; Waterfield, Nick R; Vilcinskas, Andreas; Stelzer, Ernst H K; Goodrich-Blair, Heidi; Hammock, Bruce D; Bode, Helge B

    2015-03-23

    Simple urea compounds ("phurealipids") have been identified from the entomopathogenic bacterium Photorhabdus luminescens, and their biosynthesis was elucidated. Very similar analogues of these compounds have been previously developed as inhibitors of juvenile hormone epoxide hydrolase (JHEH), a key enzyme in insect development and growth. Phurealipids also inhibit JHEH, and therefore phurealipids might contribute to bacterial virulence. PMID:25711603

  10. Growth hormone producing prolactinoma in juvenile cystinosis: a simple coincidence?

    PubMed Central

    Besouw, Martine T. P.; Willemsen, Michèl A. A. P.; Noordam, Kees

    2007-01-01

    Juvenile cystinosis was diagnosed in a patient who presented with severe headache attacks and photophobia. Treatment with oral cysteamine and topical cysteamine eye drops was started. One-and-a-half years later, he developed unilateral gynecomastia and elevated prolactin and growth hormone levels. A pituitary macroprolactinoma was discovered and successfully treated with the dopamine agonist cabergoline. Increased serum growth hormone levels were attributed to enhanced growth hormone production by the prolactinoma and somatostatin inhibition by cysteamine. Although the occurrence of prolactinoma in this patient could be a simple coincidence, it might also be a rare yet unrecognised complication of cystinosis. PMID:17638022

  11. Modeling resistance to juvenile hormone analogs: linking evolution, ecology and management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Juvenile hormone analogs (JHAs) are insecticides that mimic insect juvenile hormone and interfere with normal insect development. JHAs disrupt a hormonal system that is specific to insects and thus kill some target pests while causing little or no harm to most non-target organisms. Because of thei...

  12. Moulting hormone, juvenile hormone and the ultrastructure of the fat body of adult Sarcophaga bullata (Diptera).

    PubMed

    Stoppie, P; Briers, T; Huybrechts, R; De Loof, A

    1981-01-01

    In the ovoviviparous fly, Sarcophaga bullata, vitellogenesis in cyclic; a process reflected in ultrastructural changes in the fat body cells and oenocytes. At eclosion the larval fat body has not yet completely disappeared. During vitellogenesis the fat body cells are specialized for intensive protein synthesis showing a very extensive RER and numerous invaginations of the plasma membrane. These features disappear when the eggs descend into the oviducts to complete embryogenesis. The predominant feature of the oenocytes is their very prominent SER. The fat body cells of the males are never as specialized for protein synthesis as those of the females. Feeding of ecdysterone to males for 3 or more days induces a rather extensive subcellular apparatus for protein synthesis, i.e., invaginations of the plasma membrane and an extensive RER. Juvenile hormone is completely ineffective in this respect. Both ecdysterone and juvenile hormone have pronounced but different effects on the oenocytes of males.

  13. Juvenile Hormone Is Required in Adult Males for Drosophila Courtship

    PubMed Central

    Wijesekera, Thilini P.; Saurabh, Sumit; Dauwalder, Brigitte

    2016-01-01

    Juvenile Hormone (JH) has a prominent role in the regulation of insect development. Much less is known about its roles in adults, although functions in reproductive maturation have been described. In adult females, JH has been shown to regulate egg maturation and mating. To examine a role for JH in male reproductive behavior we created males with reduced levels of Juvenile Hormone Acid O-Methyl Transferase (JHAMT) and tested them for courtship. JHAMT regulates the last step of JH biosynthesis in the Corpora Allata (CA), the organ of JH synthesis. Males with reduced levels of JHAMT showed a reduction in courtship that could be rescued by application of Methoprene, a JH analog, shortly before the courtship assays were performed. In agreement with this, reducing JHAMT conditionally in mature flies led to courtship defects that were rescuable by Methoprene. The same result was also observed when the CA were conditionally ablated by the expression of a cellular toxin. Our findings demonstrate that JH plays an important physiological role in the regulation of male mating behavior. PMID:27003411

  14. Socially selected ornaments influence hormone titers of signalers and receivers.

    PubMed

    Tibbetts, Elizabeth A; Crocker, Katherine; Huang, Zachary Y

    2016-07-26

    Decades of behavioral endocrinology research have shown that hormones and behavior have a bidirectional relationship; hormones both influence and respond to social behavior. In contrast, hormones are often thought to have a unidirectional relationship with ornaments. Hormones influence ornament development, but little empirical work has tested how ornaments influence hormones throughout life. Here, we experimentally alter a visual signal of fighting ability in Polistes dominulus paper wasps and measure the behavioral and hormonal consequences of signal alteration in signalers and receivers. We find wasps that signal inaccurately high fighting ability receive more aggression than controls and receiving aggression reduces juvenile hormone (JH) titers. As a result, immediately after contests, inaccurate signalers have lower JH titers than controls. Ornaments also directly influence rival JH titers. Three hours after contests, wasps who interacted with rivals signaling high fighting ability have higher JH titers than wasps who interacted with rivals signaling low fighting ability. Therefore, ornaments influence hormone titers of both signalers and receivers. We demonstrate that relationships between hormones and ornaments are flexible and bidirectional rather than static and unidirectional. Dynamic relationships among ornaments, behavior, and physiology may be an important, but overlooked factor in the evolution of honest communication. PMID:27402762

  15. Paralogous genes involved in juvenile hormone action in Drosophila melanogaster.

    PubMed

    Baumann, Aaron; Barry, Joshua; Wang, Shaoli; Fujiwara, Yoshihiro; Wilson, Thomas G

    2010-08-01

    Juvenile hormone (JH) is critical for multiple aspects of insect development and physiology. Although roles for the hormone have received considerable study, an understanding of the molecules necessary for JH action in insects has been frustratingly slow to evolve. Methoprene-tolerant (Met) in Drosophila melanogaster fulfills many of the requirements for a hormone receptor gene. A paralogous gene, germ-cell expressed (gce), possesses homology and is a candidate as a Met partner in JH action. Expression of gce was found to occur at multiple times and in multiple tissues during development, similar to that previously found for Met. To probe roles of this gene in JH action, we carried out in vivo gce over- and underexpression studies. We show by overexpression studies that gce can substitute in vivo for Met, alleviating preadult but not adult phenotypic characters. We also demonstrate that RNA interference-driven knockdown of gce expression in transgenic flies results in preadult lethality in the absence of MET. These results show that (1) unlike Met, gce is a vital gene and shows functional flexibility and (2) both gene products appear to promote JH action in preadult but not adult development.

  16. Differential Juvenile Hormone Variations in Scale Insect Extreme Sexual Dimorphism

    PubMed Central

    Vea, Isabelle Mifom; Tanaka, Sayumi; Shiotsuki, Takahiro; Jouraku, Akiya; Tanaka, Toshiharu; Minakuchi, Chieka

    2016-01-01

    Scale insects have evolved extreme sexual dimorphism, as demonstrated by sedentary juvenile-like females and ephemeral winged males. This dimorphism is established during the post-embryonic development; however, the underlying regulatory mechanisms have not yet been examined. We herein assessed the role of juvenile hormone (JH) on the diverging developmental pathways occurring in the male and female Japanese mealybug Planococcus kraunhiae (Kuwana). We provide, for the first time, detailed gene expression profiles related to JH signaling in scale insects. Prior to adult emergence, the transcript levels of JH acid O-methyltransferase, encoding a rate-limiting enzyme in JH biosynthesis, were higher in males than in females, suggesting that JH levels are higher in males. Furthermore, male quiescent pupal-like stages were associated with higher transcript levels of the JH receptor gene, Methoprene-tolerant and its co-activator taiman, as well as the JH early-response genes, Krüppel homolog 1 and broad. The exposure of male juveniles to an ectopic JH mimic prolonged the expression of Krüppel homolog 1 and broad, and delayed adult emergence by producing a supernumeral pupal stage. We propose that male wing development is first induced by up-regulated JH signaling compared to female expression pattern, but a decrease at the end of the prepupal stage is necessary for adult emergence, as evidenced by the JH mimic treatments. Furthermore, wing development seems linked to JH titers as JHM treatments on the pupal stage led to wing deformation. The female pedomorphic appearance was not reflected by the maintenance of high levels of JH. The results in this study suggest that differential variations in JH signaling may be responsible for sex-specific and radically different modes of metamorphosis. PMID:26894583

  17. Differential Juvenile Hormone Variations in Scale Insect Extreme Sexual Dimorphism.

    PubMed

    Vea, Isabelle Mifom; Tanaka, Sayumi; Shiotsuki, Takahiro; Jouraku, Akiya; Tanaka, Toshiharu; Minakuchi, Chieka

    2016-01-01

    Scale insects have evolved extreme sexual dimorphism, as demonstrated by sedentary juvenile-like females and ephemeral winged males. This dimorphism is established during the post-embryonic development; however, the underlying regulatory mechanisms have not yet been examined. We herein assessed the role of juvenile hormone (JH) on the diverging developmental pathways occurring in the male and female Japanese mealybug Planococcus kraunhiae (Kuwana). We provide, for the first time, detailed gene expression profiles related to JH signaling in scale insects. Prior to adult emergence, the transcript levels of JH acid O-methyltransferase, encoding a rate-limiting enzyme in JH biosynthesis, were higher in males than in females, suggesting that JH levels are higher in males. Furthermore, male quiescent pupal-like stages were associated with higher transcript levels of the JH receptor gene, Methoprene-tolerant and its co-activator taiman, as well as the JH early-response genes, Krüppel homolog 1 and broad. The exposure of male juveniles to an ectopic JH mimic prolonged the expression of Krüppel homolog 1 and broad, and delayed adult emergence by producing a supernumeral pupal stage. We propose that male wing development is first induced by up-regulated JH signaling compared to female expression pattern, but a decrease at the end of the prepupal stage is necessary for adult emergence, as evidenced by the JH mimic treatments. Furthermore, wing development seems linked to JH titers as JHM treatments on the pupal stage led to wing deformation. The female pedomorphic appearance was not reflected by the maintenance of high levels of JH. The results in this study suggest that differential variations in JH signaling may be responsible for sex-specific and radically different modes of metamorphosis.

  18. Synthesis and binding affinity of an iodinated juvenile hormone

    SciTech Connect

    Prestwich, G.D.; Eng, W.S.; Robles, S.; Vogt, R.G.; Wisniewski, J.R.; Wawrzenczyk, C.

    1988-01-25

    The synthesis of the first iodinated juvenile hormone (JH) in enantiomerically enriched form is reported. This chiral compound, 12-iodo-JH I, has an iodine atom replacing a methyl group of the natural insect juvenile hormone, JH I, which is important in regulating morphogenesis and reproduction in the Lepidoptera. The unlabeled compound shows approximately 10% of the relative binding affinity for the larval hemolymph JH binding protein (JHBP) of Manduca sexta, which specifically binds natural /sup 3/H-10R,11S-JH I (labeled at 58 Ci/mmol) with a KD of 8 X 10(-8) M. It is also approximately one-tenth as biologically active as JH I in the black Manduca and epidermal commitment assays. The 12-hydroxy and 12-oxo compounds are poor competitors and are also biologically inactive. The radioiodinated (/sup 125/I)12-iodo-JH I can be prepared in low yield at greater than 2500 Ci/mmol by nucleophilic displacement using no-carrier-added /sup 125/I-labeled sodium iodide in acetone; however, synthesis using sodium iodide carrier to give the approximately 50 Ci/mmol radioiodinated ligand proceeds in higher radiochemical yield with fewer by-products and provides a radioligand which is more readily handled in binding assays. The KD of (/sup 125/I)12-iodo-JH I was determined for hemolymph JHBP of three insects: M. sexta, 795 nM; Galleria mellonella, 47 nM; Locusta migratoria, 77 nM. The selectivity of 12-iodo-JH I for the 32-kDa JHBP of M. sexta was demonstrated by direct autoradiography of a native polyacrylamide gel electrophoresis gel of larval hemolymph incubated with the radioiodinated ligand. Thus, the in vitro and in vivo activity of 12-iodo-JH I indicate that it can serve as an important new gamma-emitting probe in the search for JH receptor proteins in target tissues.

  19. [Hormone therapy of the juvenile angiofibroma (author's transl)].

    PubMed

    Kũttner, K; Katenkamp, D; Stiller, D

    1977-02-15

    Four juvenile angiofibromas were examined with the electron microscope. Preceding the operation a hormonal therapy with stilbestrol disphosphate (Cytonal, Honvan) was carried out in the cases. The therapeutical effect after application of this drug is clearly correlated to especial changes in histology and cytology. The changes comprise reactions of the vascular component and of the stromal fibroblasts. Endothelial cells and pericytes show a markedly diminished cellular activity, a proliferation of vascular wall cells is not to be proved. The stromal fibroblasts may predominantly be classified as fibroblasts with histiocyte-like features, at which the organelle equipment speaks for a high activity of their metabolism. Furthermore an increased number of myofibroblasts and smooth muscle-like elements are encountered in the stroma. The striking diminution of lesion size and the reduction of disposition to bleeding from the beginning of the hormone therapy is suggested as a direct consequence of cellular contraction. Additionally alterations of synthesis of collagen fibers and ground substance by fibroblasts with histiocyte-like features contribute to a further gradual decrease of the growths.

  20. Insecticidal properties of genetically engineered baculoviruses expressing an insect juvenile hormone esterase gene.

    PubMed Central

    Eldridge, R; O'Reilly, D R; Hammock, B D; Miller, L K

    1992-01-01

    Exploring the possibility of enhancing the properties of baculoviruses as biological control agents of insect pests, we tested the effect of expressing an insect gene (jhe) encoding juvenile hormone esterase. Juvenile hormone esterase inactivates juvenile hormone, which regulates the outcome of an insect molt. A cDNA encoding the juvenile hormone esterase of Heliothis virescens was inserted into the genome of Autographa californica nuclear polyhedrosis virus such that the gene was expressed under the control of a strong, modified viral promoter. This virus, however, naturally encodes an ecdysteroid UDP-glucosyltransferase which inactivates ecdysone, the hormone which initiates molting. Since ecdysteroid UDP-glucosyltransferase could mask the effects of jhe expression by blocking molting entirely, jhe-expressing viruses in which the ecdysteroid UDP-glucosyltransferase gene was deleted or disrupted were constructed. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of proteins from infected cells revealed several intracellular proteins and two major secreted proteins which reacted with antibodies to authentic juvenile hormone esterase. Western blot analysis coupled with tunicamycin treatment indicated that differential glycosylation was responsible for the multiple products. Hemolymph of recombinant virus-infected fourth-instar Trichoplusia ni larvae contained levels of juvenile hormone esterase activity 40-fold higher than maximal levels found in uninfected larvae. However, little or no difference in developmental characteristics, weight gain, or time of mortality was observed between insects infected with the jhe-expressing viruses and control viruses. Images PMID:1622228

  1. TRANSGENERATIONAL EFFECTS OF A JUVENILE HORMONE MIMIC ON THE ESTUARINE MYSID, MYSIDOPSIS BAHIA (CRUSTACEA: MYSIDACEA)

    EPA Science Inventory

    Fenoxycarb is a juvenile hormone (JH) mimic used to control insect pests by interfering with reproductive and developmental processes mediated by JH. Crustaceans are ideal organisms to monitor environmental effects of these endocrine disruptors, since they are dominant aquatic ar...

  2. Ecdysis triggering hormone ensures proper timing of juvenile hormone biosynthesis in pharate adult mosquitoes.

    PubMed

    Areiza, Maria; Nouzova, Marcela; Rivera-Perez, Crisalejandra; Noriega, Fernando G

    2014-11-01

    Juvenile hormones (JHs) are synthesized by the corpora allata (CA) and play a key role in insect development. A decrease of JH titer in the last instar larvae allows pupation and metamorphosis to proceed. As the anti-metamorphic role of JH comes to an end, the CA of the late pupa (or pharate adult) becomes again "competent" to synthesize JH, which would play an essential role orchestrating reproductive maturation. In the present study, we provide evidence that ecdysis triggering hormone (ETH), a key endocrine factor involved in ecdysis control, acts as an allatotropic regulator of JH biosynthesis, controlling the exact timing of CA activation in the pharate adult mosquito. Analysis of the expression of Aedes aegypti ETH receptors (AeaETHRs) revealed that they are present in the CA and the corpora cardiaca (CC), and their expression peaks 4 h before eclosion. In vitro stimulation of the pupal CA glands with ETH resulted in an increase in JH synthesis. Consistent with this finding, silencing AeaETHRs by RNA interference (RNAi) in pupa resulted in reduced JH synthesis by the CA of one day-old adult females. Stimulation with ETH resulted in increases in the activity of juvenile hormone acid methyltransferase (JHAMT), a key JH biosynthetic enzyme. Furthermore, inhibition of IP3R-operated mobilization of endoplasmic reticulum Ca(2+) stores prevented the ETH-dependent increases of JH biosynthesis and JHAMT activity. All together these findings provide compelling evidence that ETH acts as a regulatory peptide that ensures proper developmental timing of JH synthesis in pharate adult mosquitoes.

  3. Molecular impact of juvenile hormone agonists on neonatal Daphnia magna.

    PubMed

    Toyota, Kenji; Kato, Yasuhiko; Miyakawa, Hitoshi; Yatsu, Ryohei; Mizutani, Takeshi; Ogino, Yukiko; Miyagawa, Shinichi; Watanabe, Hajime; Nishide, Hiroyo; Uchiyama, Ikuo; Tatarazako, Norihisa; Iguchi, Taisen

    2014-05-01

    Daphnia magna has been used extensively to evaluate organism- and population-level responses to pollutants in acute toxicity and reproductive toxicity tests. We have previously reported that exposure to juvenile hormone (JH) agonists results in a reduction of reproductive function and production of male offspring in a cyclic parthenogenesis, D. magna. Recent advances in molecular techniques have provided tools to understand better the responses to pollutants in aquatic organisms, including D. magna. DNA microarray was used to evaluate gene expression profiles of neonatal daphnids exposed to JH agonists: methoprene (125, 250 and 500 ppb), fenoxycarb (0.5, 1 and 2 ppb) and epofenonane (50, 100 and 200 ppb). Exposure to these JH analogs resulted in chemical-specific patterns of gene expression. The heat map analyses based on hierarchical clustering revealed a similar pattern between treatments with a high dose of methoprene and with epofenonane. In contrast, treatment with low to middle doses of methoprene resulted in similar profiles to fenoxycarb treatments. Hemoglobin and JH epoxide hydrolase genes were clustered as JH-responsive genes. These data suggest that fenoxycarb has high activity as a JH agonist, methoprene shows high toxicity and epofenonane works through a different mechanism compared with other JH analogs, agreeing with data of previously reported toxicity tests. In conclusion, D. magna DNA microarray is useful for the classification of JH analogs and identification of JH-responsive genes. PMID:24038158

  4. Molecular impact of juvenile hormone agonists on neonatal Daphnia magna.

    PubMed

    Toyota, Kenji; Kato, Yasuhiko; Miyakawa, Hitoshi; Yatsu, Ryohei; Mizutani, Takeshi; Ogino, Yukiko; Miyagawa, Shinichi; Watanabe, Hajime; Nishide, Hiroyo; Uchiyama, Ikuo; Tatarazako, Norihisa; Iguchi, Taisen

    2014-05-01

    Daphnia magna has been used extensively to evaluate organism- and population-level responses to pollutants in acute toxicity and reproductive toxicity tests. We have previously reported that exposure to juvenile hormone (JH) agonists results in a reduction of reproductive function and production of male offspring in a cyclic parthenogenesis, D. magna. Recent advances in molecular techniques have provided tools to understand better the responses to pollutants in aquatic organisms, including D. magna. DNA microarray was used to evaluate gene expression profiles of neonatal daphnids exposed to JH agonists: methoprene (125, 250 and 500 ppb), fenoxycarb (0.5, 1 and 2 ppb) and epofenonane (50, 100 and 200 ppb). Exposure to these JH analogs resulted in chemical-specific patterns of gene expression. The heat map analyses based on hierarchical clustering revealed a similar pattern between treatments with a high dose of methoprene and with epofenonane. In contrast, treatment with low to middle doses of methoprene resulted in similar profiles to fenoxycarb treatments. Hemoglobin and JH epoxide hydrolase genes were clustered as JH-responsive genes. These data suggest that fenoxycarb has high activity as a JH agonist, methoprene shows high toxicity and epofenonane works through a different mechanism compared with other JH analogs, agreeing with data of previously reported toxicity tests. In conclusion, D. magna DNA microarray is useful for the classification of JH analogs and identification of JH-responsive genes.

  5. Exploring the role of juvenile hormone and vitellogenin in reproduction and social behavior in bumble bees

    PubMed Central

    2014-01-01

    Background The genetic and physiological pathways regulating behavior in solitary species are hypothesized to have been co-opted to regulate social behavior in social species. One classic example is the interaction between vitellogenin (an egg-yolk and storage protein) and juvenile hormone, which are positively correlated in most insect species but have modified interactions in highly eusocial insects. In some of these species (including some termites, ants, and the honey bee), juvenile hormone and vitellogenin levels are negatively correlated and juvenile hormone has shifted its role from a gonadotropin to a regulator of maturation and division of labor in the primarily sterile workers. The function of vitellogenin also seems to have broadened to encompass similar roles. Thus, the functions and molecular interactions of juvenile hormone and vitellogenin are hypothesized to have undergone changes during the evolution of eusociality, but the mechanisms underlying these changes are unknown. Bumble bees offer an excellent model system for testing how the relationship between juvenile hormone and vitellogenin evolved from solitary to social species. Bumble bee colonies are primitively eusocial and comprised of a single reproductive queen and facultatively sterile workers. In Bombus terrestris, juvenile hormone retains its ancestral role as a gonadotropin and is also hypothesized to regulate aggressive behavior. However, the function of vitellogenin and its interactions with juvenile hormone have not yet been characterized. Results By characterizing vitellogenin RNA expression levels (vg) in B. terrestris we show that vg is not associated with task and only partially associated with worker age, queen presence, and caste (queen vs worker). The correlations of vg with ovarian activation were not consistent across experiments, but both vg and ovarian activation were significantly associated with levels of aggression experienced by workers. Treatment with juvenile hormone

  6. Evolutionary Endocrinology of Hormonal Rhythms: Juvenile Hormone Titer Circadian Polymorphism in Gryllus firmus.

    PubMed

    Zera, Anthony J

    2016-08-01

    Daily rhythms for hormonal traits are likely widespread and important aspects of organismal (e.g., life history) adaptation. Yet they remain substantially understudied, especially with respect to variable rhythms within species. The cricket, Gryllus firmus, exhibits a genetically polymorphic circadian rhythm for the blood titer of the key hormone, juvenile hormone (JH). Gryllus firmus is also wing-polymorphic, consisting of a dispersing morph that delays reproduction and a flightless morph with substantially enhanced egg production. JH circadian phenotype strongly covaries with morph type: The blood JH titer is strongly rhythmic in multiple populations artificially-selected for the dispersing morph (LW(f) = long wings with functional flight muscles) and is essentially arrhythmic in populations selected for the SW (short-winged) morph. Association between JH titer cycle and LW(f) morph is also found in natural populations of G. firmus and in several related species in the field. This is one of the very few studies of endocrine titer variation in natural populations of an insect. The morph-specific cycle is underlain by a circadian rhythm in hormone biosynthesis, which in turn is underlain by a rhythm in a brain neuropeptide regulator of JH biosynthesis. The morph-specific JH titer circadian cycle is also strongly correlated with a morph-specific daily rhythm in global gene expression. This is currently the only example of a genetically-variable hormone circadian rhythm in both the laboratory and field that is strongly associated with an ecologically important polymorphism. The extensive information on the underlying causes of the morph-specific JH titer rhythm, coupled with the strong association between the JH circadian rhythm and wing polymorphism makes this system in G. firmus an exceptional experimental model to investigate the mechanisms underlying circadian hormonal adaptations. Genetic polymorphism for the JH titer circadian rhythm in G. firmus is discussed

  7. Microarray Analysis of Juvenile Hormone Response in Drosophila melanogaster S2 cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A microchip array encompassing probes for 14,010 genes of Drosophila melanogaster was used to analyze the effect of juvenile hormone (JH) on genome-wide gene expression. JH is a member of a key group of insect hormones involved in regulating larval development and adult reproductive processes. Altho...

  8. Juvenile hormone regulates extreme mandible growth in male stag beetles.

    PubMed

    Gotoh, Hiroki; Cornette, Richard; Koshikawa, Shigeyuki; Okada, Yasukazu; Lavine, Laura Corley; Emlen, Douglas J; Miura, Toru

    2011-01-01

    The morphological diversity of insects is one of the most striking phenomena in biology. Evolutionary modifications to the relative sizes of body parts, including the evolution of traits with exaggerated proportions, are responsible for a vast range of body forms. Remarkable examples of an insect trait with exaggerated proportions are the mandibular weapons of stag beetles. Male stag beetles possess extremely enlarged mandibles which they use in combat with rival males over females. As with other sexually selected traits, stag beetle mandibles vary widely in size among males, and this variable growth results from differential larval nutrition. However, the mechanisms responsible for coupling nutrition with growth of stag beetle mandibles (or indeed any insect structure) remain largely unknown. Here, we demonstrate that during the development of male stag beetles (Cyclommatus metallifer), juvenile hormone (JH) titers are correlated with the extreme growth of an exaggerated weapon of sexual selection. We then investigate the putative role of JH in the development of the nutritionally-dependent, phenotypically plastic mandibles, by increasing hemolymph titers of JH with application of the JH analog fenoxycarb during larval and prepupal developmental periods. Increased JH signaling during the early prepupal period increased the proportional size of body parts, and this was especially pronounced in male mandibles, enhancing the exaggerated size of this trait. The direction of this response is consistent with the measured JH titers during this same period. Combined, our results support a role for JH in the nutrition-dependent regulation of extreme mandible growth in this species. In addition, they illuminate mechanisms underlying the evolution of trait proportion, the most salient feature of the evolutionary diversification of the insects.

  9. Juvenile hormone regulation of male accessory gland activity in the red flour beetle, Tribolium castaneum

    PubMed Central

    Parthasarathy, R.; Tan, A.; Sun, Z.; Chen, J.; Rainkin, M.; Palli, S. R.

    2009-01-01

    Male accessory gland proteins (Acps) act as key modulators of reproductive success in insects by influencing the female reproductive physiology and behavior. We used custom microarrays and identified 112 genes that were highly expressed in male accessory glands (MAG) in the red flour beetle, Tribolium castaneum. Out of these 112 identified genes, 59 of them contained sequences coding for signal peptide and cleavage site and the remaining 53 contained transmembrane domains. The expression of 14 these genes in the MAG but not in other tissues of male or female was confirmed by quantitative real-time PCR. In virgin males, juvenile hormone (JH) levels increased from second day post adult emergence (PAE), remained high on third day PAE and declined on fourth day PAE. The ecdysteroid titers were high soon after adult emergence but declined to minimal levels from 1-5 days PAE. Feeding of juvenile hormone analog, hydroprene, but not the ecdysteroid analog, RH-2485, showed an increase in size of MAGs, as well as an increase in total RNA and protein content of MAG. Hydroprene treatment also increased the expression Acp genes in the MAG. RNAi-mediated knock-down in the expression of JHAMT gene decreased the size of MAGs and expression of Acps. JH deficiency influenced male reproductive fitness as evidenced by a less vigor in mating behavior, poor sperm transfer, low egg and the progeny production by females mated with the JH deficient males. These data suggest a critical role for JH in the regulation of male reproduction especially through MAG secretions. PMID:19324087

  10. ISOLATION OF JUVENILE HORMONES ESTERASE AND ITS PARTIAL CDNA CLONE FROM THE BEETLE, TENEBRIO MOLITOR. (R825433)

    EPA Science Inventory

    Juvenile hormone esterase (JHE) plays an essential role in insect development. It is partially responsible for the clearance of juvenile hormone (JH) which regulates various aspects of insect development and reproduction. Because of its role in regulating JH titer, this enzyme...

  11. High specific activity enantiomerically enriched juvenile hormones: synthesis and binding assay

    SciTech Connect

    Prestwich, G.D.; Wawrzenczyk, C.

    1985-08-01

    A stereoselective total synthesis of chiral juvenile hormone I is described that allows stoichiometric introduction of two tritium atoms in the final step. Both optical antipodes of the pivotal epoxy alcohol intermediate were prepared in 95% enantiomeric excess by the Sharpless epoxidation of a (Z)-allylic alcohol. Elaboration of the hydroxy-methyl group to a vinyl group followed by selective homogeneous tritiation affords optically active juvenile hormone I analogs at 58 Ci/mmol. Competitive binding of the labeled 10R, 11S and 10S,11R enantiomers with unlabeled enantiomers to the hemolymph binding protein of Manduca sexta larvae was determined by using a dextran-coated charcoal assay. The natural 10R,11S enantiomer has twice the relative binding affinity of the 10S,11R enantiomer. The availability of such high specific activity optically pure hormones will contribute substantially to the search for high-affinity receptors for juvenile hormones in the nuclei of cells. Moreover, the chiral 12-hydroxy-(10R,11S)-epoxy intermediate allows modification of juvenile hormone for solid-phase biochemical and radioimmunochemical work without altering either the biologically important carbomethoxy or epoxy recognition sites.

  12. High specific activity enantiomerically enriched juvenile hormones: synthesis and binding assay.

    PubMed Central

    Prestwich, G D; Wawrzeńczyk, C

    1985-01-01

    A stereoselective total synthesis of chiral juvenile hormone I is described that allows stoichiometric introduction of two tritium atoms in the final step. Both optical antipodes of the pivotal epoxy alcohol intermediate were prepared in 95% enantiomeric excess by the Sharpless epoxidation of a (Z)-allylic alcohol. Elaboration of the hydroxy-methyl group to a vinyl group followed by selective homogeneous tritiation affords optically active juvenile hormone I analogs at 58 Ci/mmol. Competitive binding of the labeled 10R, 11S and 10S,11R enantiomers with unlabeled enantiomers to the hemolymph binding protein of Manduca sexta larvae was determined by using a dextran-coated charcoal assay. The natural 10R,11S enantiomer has twice the relative binding affinity of the 10S,11R enantiomer. The availability of such high specific activity optically pure hormones will contribute substantially to the search for high-affinity receptors for juvenile hormones in the nuclei of cells. Moreover, the chiral 12-hydroxy-(10R,11S)-epoxy intermediate allows modification of juvenile hormone for solid-phase biochemical and radioimmunochemical work without altering either the biologically important carbomethoxy or epoxy recognition sites. PMID:3860862

  13. Evolutionary endocrinology of juvenile hormone esterase in Gryllus assimilis: direct and correlated responses to selection.

    PubMed

    Zera, A J; Zhang, C

    1995-11-01

    Hemolymph juvenile hormone esterase (JHE) activity on the third day of the last stadium in the cricket, Gryllus assimilis, exhibited a significant response to selection in each of six replicate lines. Mean realized heritability was 0.26 +/- 0.04. The response was due to changes in whole-organism enzyme activity as well as to changes in the proportion of enzyme allocated to the hemolymph compartment. In vivo juvenile hormone metabolism differed between some lines selected for high vs. low enzyme activity. Only minimal differences were observed between lines with respect to hemolymph protein concentration or whole-cricket activity of juvenile hormone epoxide hydrolase, the other major JH-degrading enzyme. Dramatic correlated responses to selection, equal in magnitude to the direct response, were observed for JHE activity on each of three other days of the last juvenile stadium. In contrast, no correlated responses in JHE activity were observed in adults. This indicates that JHE activities throughout the last stadium will evolve as a highly correlated unit independent of adult activities and the evolution of endocrine mechanisms regulating juvenile development can be decoupled from those controlling adult reproduction. This study represents the first quantitative-genetic analysis of naturally occurring endocrine variation in an insect species.

  14. Juvenile Hormone Regulation of Drosophila Epac - A Guanine Nucleotide Exchange Factor for Rap1 Small GTPase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously, we utilized a microchip array encompassing probes for 14,010 genes of Drosophila melanogaster to analyze the effect of (10R) juvenile hormone III (JH) on genome-wide gene expression in Drosophila S2 cells. Treatment with JH yielded a collection of 32 gene transcripts that demonstrated a ...

  15. EXPRESSION AND CHARACTERIZATION OF THE RECOMBINANT JUVENILE HORMONE EPOXIDE HYDROLASE (JHEH) FROM MANDUCA SEXTA. (R825433)

    EPA Science Inventory

    The cDNA of the microsomal Juvenile Hormone Epoxide Hydrolase (JHEH) from Manduca sexta was expressed in vitro in the baculovirus system. In insect cell culture, the recombinant enzyme (Ms-JHEH) was produced at a high level (100 fold over background EH catalytic activit...

  16. Effects of experience and juvenile hormone on the organization of the mushroom bodies of honey bees.

    PubMed

    Withers, G S; Fahrbach, S E; Robinson, G E

    1995-01-01

    There is an age-related division of labor in the honey bee colony that is regulated by juvenile hormone. After completing metamorphosis, young workers have low titers of juvenile hormone and spend the first several weeks of their adult lives performing tasks within the hive. Older workers, approximately 3 weeks of age, have high titers of juvenile hormone and forage outside the hive for nectar and pollen. We have previously reported that changes in the volume of the mushroom bodies of the honey bee brain are temporally associated with the performance of foraging. The neuropil of the mushroom bodies is increased in volume, whereas the volume occupied by the somata of the Kenyon cells is significantly decreased in foragers relative to younger workers. To study the effect of flight experience and juvenile hormone on these changes within the mushroom bodies, young worker bees were treated with the juvenile hormone analog methoprene but a subset was prevented from foraging (big back bees). Stereological volume estimates revealed that, regardless of foraging experience, bees treated with methoprene had a significantly larger volume of neuropil in the mushroom bodies and a significantly smaller Kenyon cell somal region volume than did 1-day-old bees. The bees treated with methoprene did not differ on these volume estimates from untreated foragers (presumed to have high endogenous levels of juvenile hormone) of the same age sampled from the same colony. Bees prevented from flying and foraging nonetheless received visual stimulation as they gathered at the hive entrance. These results, coupled with a subregional analysis of the neuropil, suggest a potentially important role of visual stimulation, possibly interacting with juvenile hormone, as an organizer of the mushroom bodies. In an independent study, the brains of worker bees in which the transition to foraging was delayed (overaged nurse bees) were also studied. The mushroom bodies of overaged nurse bees had a Kenyon

  17. A Structural Equation Modeling Analysis of Influences on Juvenile Delinquency

    ERIC Educational Resources Information Center

    Barrett, David E.; Katsiyannis, Antonis; Zhang, Dalun; Zhang, Dake

    2014-01-01

    This study examined influences on delinquency and recidivism using structural equation modeling. The sample comprised 199,204 individuals: 99,602 youth whose cases had been processed by the South Carolina Department of Juvenile Justice and a matched control group of 99,602 youth without juvenile records. Structural equation modeling for the…

  18. The effect of juvenile hormone on Polistes wasp fertility varies with cooperative behavior.

    PubMed

    Tibbetts, Elizabeth A; Sheehan, Michael J

    2012-04-01

    Social insects provide good models for studying how and why the mechanisms that underlie reproduction vary, as there is dramatic reproductive plasticity within and between species. Here, we test how the effect of juvenile hormone (JH) on fertility covaries with cooperative behavior in workers and nest-founding queens in the primitively eusocial wasp Polistes metricus. P. metricus foundresses and workers appear morphologically similar and both are capable of reproduction, though there is variation in the extent of social cooperation and the probability of reproduction across castes. Do the endocrine mechanisms that mediate reproduction co-vary with cooperative behavior? We found dramatic differences in the effect of JH on fertility across castes. In non-cooperative nest-founding queens, all individuals responded to JH by increasing their fertility. However, in cooperative workers, the effect of JH on fertility varies with body weight; large workers increase their fertility in response to JH while small workers do not. The variation in JH response may be an adaptation to facilitate resource allocation based on the probability of independent reproduction. This work contrasts with previous studies in closely related Polistes dominulus paper wasps, in which both foundresses and workers form cooperative associations and both castes show similar, condition-dependent JH response. The variation in JH responsiveness within and between species suggests that endocrine responsiveness and the factors influencing caste differentiation are surprisingly evolutionarily labile.

  19. Characterization of the Juvenile Hormone Pathway in the Viviparous Cockroach, Diploptera punctata

    PubMed Central

    Huang, Juan; Marchal, Elisabeth; Hult, Ekaterina F.; Tobe, Stephen S.

    2015-01-01

    Juvenile hormones (JHs) are key regulators of insect development and reproduction. The JH biosynthetic pathway is known to involve 13 discrete enzymatic steps. In the present study, we have characterized the JH biosynthetic pathway in the cockroach Diploptera punctata. The effect of exogenous JH precursors on JH biosynthesis was also determined. Based on sequence similarity, orthologs for the genes directly involved in the pathway were cloned, and their spatial and temporal transcript profiles were determined. The effect of shutting down the JH pathway in adult female cockroaches was studied by knocking down genes encoding HMG-CoA reductase (HMGR) and Juvenile hormone acid methyltransferase (JHAMT). As a result, oocyte development slowed as a consequence of reduction in JH biosynthesis. Oocyte length, fat body transcription of Vg and ovarian vitellin content significantly decreased. In addition, silencing HMGR and JHAMT resulted in a decrease in the transcript levels of other genes in the pathway. PMID:25706877

  20. Endocrine and immunological responses to adrenocorticotrophic hormone (ACTH) administration in juvenile harbor seals (Phoca vitulina) during winter and summer.

    PubMed

    Keogh, Mandy J; Atkinson, Shannon

    2015-10-01

    There is increasing interest in measuring endocrine and immune parameters in free-ranging seals and sea lions, but there is a lack of understanding in how an acute stress response, often associated with capture and handling, influences these parameters of interest. The main objective of this study was to assess the impact of a simulated stressor on both endocrine and immune parameters. During two seasons, exogenous adrenocorticotrophic hormone (ACTH) was administered to seven female juvenile harbor seals and the response of several hormones (cortisol, aldosterone, total and free thyroxine and total triiodothyronine) and immunological parameters (total and differential leukocyte counts and peripheral blood mononuclear cells (PBMC) proliferation) were assessed. Cortisol peaked at 165 min (winter 203.1±84.7 ng/ml; summer 205.3±65.7 ng/ml) and remained significantly elevated 240 min after ACTH infusion in both seasons. Aldosterone peaked at 90 min (winter 359.3±249.3 pg/ml; summer 294.1±83.7 pg/ml) and remained elevated 240 min after administration of ACTH in both seasons. An increase in circulating total white blood cells was driven primarily by the increase in neutrophils which occurred simultaneously with a decrease in lymphocytes leading to an overall increase in neutrophil to lymphocyte ratio. These findings demonstrate that a simulated stress response in juvenile harbor seals results in a predictable increase in both cortisol and aldosterone concentrations, and were associated with altered immunological parameters.

  1. Endocrine and immunological responses to adrenocorticotrophic hormone (ACTH) administration in juvenile harbor seals (Phoca vitulina) during winter and summer.

    PubMed

    Keogh, Mandy J; Atkinson, Shannon

    2015-10-01

    There is increasing interest in measuring endocrine and immune parameters in free-ranging seals and sea lions, but there is a lack of understanding in how an acute stress response, often associated with capture and handling, influences these parameters of interest. The main objective of this study was to assess the impact of a simulated stressor on both endocrine and immune parameters. During two seasons, exogenous adrenocorticotrophic hormone (ACTH) was administered to seven female juvenile harbor seals and the response of several hormones (cortisol, aldosterone, total and free thyroxine and total triiodothyronine) and immunological parameters (total and differential leukocyte counts and peripheral blood mononuclear cells (PBMC) proliferation) were assessed. Cortisol peaked at 165 min (winter 203.1±84.7 ng/ml; summer 205.3±65.7 ng/ml) and remained significantly elevated 240 min after ACTH infusion in both seasons. Aldosterone peaked at 90 min (winter 359.3±249.3 pg/ml; summer 294.1±83.7 pg/ml) and remained elevated 240 min after administration of ACTH in both seasons. An increase in circulating total white blood cells was driven primarily by the increase in neutrophils which occurred simultaneously with a decrease in lymphocytes leading to an overall increase in neutrophil to lymphocyte ratio. These findings demonstrate that a simulated stress response in juvenile harbor seals results in a predictable increase in both cortisol and aldosterone concentrations, and were associated with altered immunological parameters. PMID:26086360

  2. Cyp15F1: A novel cytochrome P450 gene linked to juvenile hormone-dependent caste differention in the termite R. flavipes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Termites are eusocial insects that perform social interactions that facilitate chemical signaling. Previous research identified two cytochrome P450s that have homology to other insect p450s responsible for the production of juvenile hormone. Juvenile hormone is an important morphogenic hormone tha...

  3. Juvenile Hormone Regulates the Expression of Drosophila Epac– a Guanine Nucleotide Exchange Factor for Rap1 Small GTPase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The juvenile hormones (JH) are a key group of insect hormones involved in regulating larval development and adult reproductive processes. Although well-studied from the physiological standpoint, the molecular actions of JH remain unclear. Using cDNA microchip array technology, we previously identifi...

  4. Resistance to juvenile hormone and an insect growth regulator in Drosophila is associated with an altered cytosolic juvenile hormone-binding protein

    SciTech Connect

    Shemshedini, L.; Wilson, T.G. )

    1990-03-01

    The Met mutant of Drosophila melanogaster is highly resistant to juvenile hormone III (JH III) or its chemical analog, methoprene, an insect growth regulator. Five major mechanisms of insecticide resistance were examined in Met and susceptible Met{sup +} flies. These two strains showed only minor differences when penetration, excretion, tissue sequestration, or metabolism of ({sup 3}H)JH III was measured. In contrast, when we examined JH III binding by a cytosolic binding protein from a JH target tissue, Met strains had a 10-fold lower binding affinity than did Met{sup +} strains. Studies using deficiency-bearing chromosomes provide strong evidence that the Met locus controls the binding protein characteristics and may encode the protein. These studies indicate that resistance in Met flies results from reduced binding affinity of a cytosolic binding protein for JH III.

  5. Influence of Thyroid Hormones on Tendon Homeostasis.

    PubMed

    Oliva, Francesco; Piccirilli, Eleonora; Berardi, Anna C; Tarantino, Umberto; Maffulli, Nicola

    2016-01-01

    Tendinopathies have a multifactorial etiology driven by extrinsic and intrinsic factors. Recent studies have elucidated the importance of thyroid hormones in the alteration of tendons homeostasis and in the failure of tendon healing after injury. The effects of thyroid hormones are mediated by receptors (TR)-α and -β that seem to be ubiquitous. In particular, T3 and T4 play an antiapoptotic role on tenocytes, causing an increase in vital tenocytes isolated from tendons in vitro and a reduction of apoptotic ones; they are also able to influence extra cellular matrix proteins secretion in vitro from tenocytes, enhancing collagen production. From a clinical point of view, disorders of thyroid function have been investigated only for rotator cuff calcific tendinopathy and tears. In this complex scenario, further research is needed to clarify the role of thyroid hormones on the onset of tendinopathies. PMID:27535255

  6. Juvenile hormone-binding proteins of Melanoplus bivittatus identified by EFDA photoaffinity labeling

    SciTech Connect

    Winder, B.S.

    1988-01-01

    Proteins that bind juvenile hormone in the hemolymph and fat body of the grasshopper, Melanoplus bivittatus were identified by photoaffinity labeling with radiolabeled epoxyfarnesyl diazoacetate ({sup 3}H-EFDA), and were characterized by electrophoretic analysis. A protocol was developed which allowed detection of {sup 3}H-EFDA that was covalently linked to proteins upon exposure to ultraviolet light at 254 nm. Quantification of protein-linked {sup 3}H-EFDA by liquid scintillation spectrometry took advantage of the differential solubility of unlinked {sup 3}H-EFDA in toluene alone, and of the protein-linked {sup 3}H-EFDA in toluene plus the detergent, Triton X-100. Competition between EFDA and juvenile hormone (JH) for binding to JH-specific binding sites was measured by hydroxyapatite protein binding assays in the presence of radiolabeled JH or EFDA and competing non-radiolabeled hormone. The protein-linked EFDA was detected on fluorograms of SDS or nondenaturing polyacrylamide gels (PAGE), and by liquid scintillation spectrometry of membranes to which the proteins had been electrophoretically transferred. Proteins which specifically bound JH were identified by photolabeling proteins in the presence and absence of nonlabeled JH-III.

  7. The POU factor ventral veins lacking/Drifter directs the timing of metamorphosis through ecdysteroid and juvenile hormone signaling.

    PubMed

    Cheng, CeCe; Ko, Amy; Chaieb, Leila; Koyama, Takashi; Sarwar, Prioty; Mirth, Christen K; Smith, Wendy A; Suzuki, Yuichiro

    2014-06-01

    Although endocrine changes are known to modulate the timing of major developmental transitions, the genetic mechanisms underlying these changes remain poorly understood. In insects, two developmental hormones, juvenile hormone (JH) and ecdysteroids, are coordinated with each other to induce developmental changes associated with metamorphosis. However, the regulation underlying the coordination of JH and ecdysteroid synthesis remains elusive. Here, we examined the function of a homolog of the vertebrate POU domain protein, Ventral veins lacking (Vvl)/Drifter, in regulating both of these hormonal pathways in the red flour beetle, Tribolium castaneum (Tenebrionidae). RNA interference-mediated silencing of vvl expression led to both precocious metamorphosis and inhibition of molting in the larva. Ectopic application of a JH analog on vvl knockdown larvae delayed the onset of metamorphosis and led to a prolonged larval stage, indicating that Vvl acts upstream of JH signaling. Accordingly, vvl knockdown also reduced the expression of a JH biosynthesis gene, JH acid methyltransferase 3 (jhamt3). In addition, ecdysone titer and the expression of the ecdysone response gene, hormone receptor 3 (HR3), were reduced in vvl knockdown larvae. The expression of the ecdysone biosynthesis gene phantom (phm) and spook (spo) were reduced in vvl knockdown larvae in the anterior and posterior halves, respectively, indicating that Vvl might influence ecdysone biosynthesis in both the prothoracic gland and additional endocrine sources. Injection of 20-hydroxyecdysone (20E) into vvl knockdown larvae could restore the expression of HR3 although molting was never restored. These findings suggest that Vvl coordinates both JH and ecdysteroid biosynthesis as well as molting behavior to influence molting and the timing of metamorphosis. Thus, in both vertebrates and insects, POU factors modulate the production of major neuroendocrine regulators during sexual maturation.

  8. Could hormones make a difference in the treatment of juvenile rheumatoid arthritis?

    PubMed

    Khalkhali-Ellis, Z; Moore, T L; Hendrix, M J

    2000-02-01

    Adrenal androgens dehydroepiandrosterone (DHEA; prasterone) and its sulphated form (DHEA-S) are among the most abundant hormonal steroids in men and nonpregnant women. Deficiencies of these adrenal androgens are associated with autoimmune disorders such as rheumatoid arthritis (RA). Recent studies from our laboratory have also identified low levels of adrenal androgens in the serum and synovial fluid of patients with juvenile rheumatoid arthritis (JRA). These findings support and complement those already published for RA and other autoimmune diseases. Because of the paucity of data on the hormonal status of patients with JRA, studies on the relationship between hypoandrogenicity and predisposition to develop JRA, and/or disease progression have not been conducted. In addition, despite the rapid expansion of research in the clinical use of these adrenal androgens in hyperlipidaemia, atherosclerosis, obesity, diabetes mellitus, insulin resistance and hypertension, their potential beneficial effects in JRA/RA have not been fully investigated. In fact, clinical trials of adrenal androgens in RA have only been conducted for the treatment of systemic lupus erythematosus. Further studies using prospective approaches are necessary to provide a unified consensus on the hormonal status of patients with JRA (as well as those with RA). This overview of our knowledge of the putative role(s) of hormones in arthritis will hopefully stimulate researchers in basic science and rheumatologists to synergistically collaborate in the effective translation of such knowledge to new clinical approaches. PMID:18034514

  9. New insights into the roles of juvenile hormone and ecdysteroids in honey bee reproduction.

    PubMed

    Wegener, Jakob; Huang, Zachary Y; Lorenz, Matthias W; Lorenz, Judith I; Bienefeld, Kaspar

    2013-07-01

    In workers of the Western honeybee, Apis mellifera, juvenile hormone (JH) and ecdysteroids regulate many aspects of age polyphenism. Here we investigated whether these derived functions in workers have developed by an uncoupling of endocrine mechanisms in adult queens and workers, or whether parallels can be found between the roles of the two hormones in both castes. We looked at yolk protein metabolism as a process central to the physiology of both queens and workers, and at sperm storage as a feature of the queen alone. Queens of differing fertility status (virgin, virgin but CO2-treated, inseminated, freshly laying and 1-2 years-old) were compared regarding vitellogenin (Vg), JH and ecdysteroid-titers in their hemolymph, as well as ovarian yolk protein and spermathecal gland composition. Our results showed that hormone titres were unrelated to the composition of spermathecal glands. JH-concentrations in the hemolymph were low in the groups of queens characterized by yolk uptake into the ovaries, and high in pre-vitellogenic queens or animals that were forced to interrupt egg-laying by caging. Ecdysteroid-concentrations were higher in untreated virgins than after insemination or during egg-laying. They were not affected by the caging of queens. These patterns of hormone changes were parallel to those known from worker bees. Together, these findings suggest a conserved role for JH as repressor of vitellogenin uptake into tissues, and for ecdysteroids in preparing tissues for this process. An involvement of the two hormones in the regulation of sperm storage seems unlikely. Our results add to the view that JH and ecdysteroids act similarly on the yolk protein metabolism of both castes of A. mellifera. This may imply that it was the biochemical versatility of Vg rather than that of hormonal regulatory circuits that allowed for the functional separation of the two castes.

  10. Sex Determination in Bees. IV. Genetic Control of Juvenile Hormone Production in MELIPONA QUADRIFASCIATA (Apidae)

    PubMed Central

    Kerr, Warwick Estevam; Akahira, Yukio; Camargo, Conceição A.

    1975-01-01

    Cell number and volume of corpora allata was determined for 8 phases of development, the first prepupal stage to adults 30 days old, in the social Apidae Melipona quadrifasciata. In the second prepupal stage a strong correlation was found between cell number and body weight ( r=0.651**), and cell number and corpora allata volume in prepupal stage (r=0.535*), which indicates that juvenile hormone has a definite role in caste determination in Melipona. The distribution of the volume of corpus allatum suggest a 3:1 segregation between bees with high volume of corpora allata against low and medium volume. This implies that genes xa and xb code for an enzyme that directly participates in juvenile hormone production. It was also concluded that the number of cells in the second prepupal stage is more important than the weight of the prepupa for caste determination. A scheme summarizing the genic control of sex and caste determination in Melipona bees in the prepupal phase is given. PMID:1213273

  11. Morphological and functional maturation of a skeletal muscle regulated by juvenile hormone.

    PubMed

    Rose, Uwe

    2004-01-01

    Reproductive behaviour of animals requires a well-adapted muscular system. This study examines the structural and functional development of ovipositor muscle properties in female locusts during reproductive development. A possible regulation by juvenile hormone (JH) was assessed by comparing muscle properties in immature and mature females and with those whose JH production was inhibited by allatectomy early in adult life. The results are related to the reproductive behaviour of locusts. Histological and ultrastructural comparison of muscle fibres and their associated cuticular structures (apodemes) revealed dramatic growth during the first 2 weeks of reproductive development. The cross-sectional area of muscle fibres increased sevenfold, and their mass-per-length 5.3-fold. Ultrastructural examination showed growth of mitochondria, development of sarcoplasmic reticulum and increasing levels of structural organisation of myofibrils. Muscles of mature females displayed pronounced fatigue resistance, contracted more powerfully (twitch, 33.22+/-10.8 mN; 50 Hz, 623.66+/-115.77 mN) and had almost two times faster kinetics than those of immature females (twitch, 6.5+/-2.6 mN; 50 Hz, 14.19+/-2.58 mN). Together with muscular maturation, cuticular apodemes, which serve as attachment sides for ovipositor muscles, grow considerably in length and width and assume a complex surface structure. Most of the described changes were suppressed in females deprived of JH (allatectomised). The results demonstrate an adaptation of muscle properties to the requirements of reproductive behaviour that is largely regulated by juvenile hormone.

  12. Identification of two juvenile hormone inducible transcription factors from the silkworm, Bombyx mori.

    PubMed

    Matsumoto, Hitoshi; Ueno, Chihiro; Nakamura, Yuki; Kinjoh, Terunori; Ito, Yuka; Shimura, Sachiko; Noda, Hiroaki; Imanishi, Shigeo; Mita, Kazuei; Fujiwara, Haruhiko; Hiruma, Kiyoshi; Shinoda, Tetsuro; Kamimura, Manabu

    2015-09-01

    Juvenile hormone (JH) regulates many physiological processes in insects. However, the signal cascades in which JH is active have not yet been fully elucidated, particularly in comparison to another major hormone ecdysteroid. Here we identified two JH inducible transcription factors as candidate components of JH signaling pathways in the silkworm, Bombyx mori. DNA microarray analysis showed that expression of two transcription factor genes, E75 and Enhancer of split mβ (E(spl)mβ), was induced by juvenile hormone I (JH I) in NIAS-Bm-aff3 cells. Real time RT-PCR analysis confirmed that expression of four E75 isoforms (E75A, E75B, E75C and E75D) and E(spl)mβ was 3-8 times greater after JH I addition. Addition of the protein synthesis inhibitor cycloheximide did not suppress JH-induced expression of the genes, indicating that they were directly induced by JH. JH-induced expression of E75 and E(spl)mβ was also observed in four other B. mori cell lines and in larval hemocytes of final instar larvae. Notably, E75A expression was induced very strongly in larval hemocytes by topical application of the JH analog fenoxycarb; the level of induced expression was comparable to that produced by feeding larvae with 20-hydroxyecdysone. These results suggest that E75 and E(spl)mβ are general and direct target genes of JH and that the transcription factors encoded by these genes play important roles in JH signaling.

  13. 20-Hydroxyecdysone stimulation of juvenile hormone biosynthesis by the mosquito corpora allata.

    PubMed

    Areiza, Maria; Nouzova, Marcela; Rivera-Perez, Crisalejandra; Noriega, Fernando G

    2015-09-01

    Juvenile hormone III (JH) is synthesized by the corpora allata (CA) and plays a key role in mosquito development and reproduction. JH titer decreases in the last instar larvae allowing pupation and metamorphosis to progress. As the anti-metamorphic role of JH comes to an end, the CA of the late pupa (or pharate adult) becomes again "competent" to synthesize JH, which plays an essential role orchestrating reproductive maturation. 20-hydroxyecdysone (20E) prepares the pupae for ecdysis, and would be an ideal candidate to direct a developmental program in the CA of the pharate adult mosquito. In this study, we provide evidence that 20E acts as an age-linked hormonal signal, directing CA activation in the mosquito pupae. Stimulation of the inactive brain-corpora allata-corpora cardiaca complex (Br-CA-CC) of the early pupa (24 h before adult eclosion or -24 h) in vitro with 20E resulted in a remarkable increase in JH biosynthesis, as well as increase in the activity of juvenile hormone acid methyltransferase (JHAMT). Addition of methyl farnesoate but not farnesoic acid also stimulated JH synthesis by the Br-CA-CC of the -24 h pupae, proving that epoxidase activity is present, but not JHAMT activity. Separation of the CA-CC complex from the brain (denervation) in the -24 h pupae also activated JH synthesis. Our results suggest that an increase in 20E titer might override an inhibitory effect of the brain on JH synthesis, phenocopying denervation. All together these findings provide compelling evidence that 20E acts as a developmental signal that ensures proper reactivation of JH synthesis in the mosquito pupae.

  14. Nutrient limitation results in juvenile hormone-mediated resorption of previtellogenic ovarian follicles in mosquitoes

    PubMed Central

    Clifton, Mark E.; Noriega, Fernando G.

    2011-01-01

    Juvenile hormone (JH) is a central hormonal regulator of previtellogenic development in female Aedes aegypti mosquitoes. JH levels are low at eclosion and increase during the first day after adult emergence. This initial rise in JH is essential for female reproductive maturation. After previtellogenic maturation is complete, the mosquito enters a ‘state-of-arrest’ during which JH synthesis continues at a slower pace and further ovary development is repressed until a blood meal is taken. By examining the relationships between juvenile hormone, follicular resorption and nutrition in A. aegypti, we were able to define a critical role of JH during the previtellogenic resting stage. The rate of follicular resorption in resting stage mosquitoes is dependent on nutritional quality. Feeding water alone caused the rate of follicular resorption to reach over 20% by day 7 after emergence. Conversely, feeding a 20% sucrose solution caused resorption to remain below 5% during the entire experimental period. Mosquitoes fed 3% sucrose show rates of resorption intermediate between water and 20% sucrose and only reached 10% by day 7 after emergence. Follicular resorption is related to JH levels. Ligated abdomens separated from a source of JH (the corpora allata) showed an increase in resorption comparable to similarly aged starved mosquitoes (16%). Resorption in ligated abdomens was reduced to 6% by application of methoprene. The application of methoprene was also sufficient to prevent resorption in intact mosquitoes starved for 48 hours (14% starved vs. 4% starved with methoprene). Additionally, active caspases were localized to resorbing follicles indicating that an apoptotic cell-death mechanism is responsible for follicular resorption during the previtellogenic resting stage. Taken together, these results indicate that JH mediates reproductive trade-offs in resting stage mosquitoes in response to nutrition. PMID:21708165

  15. BLACK SPOT INFESTATION IN JUVENILE COHO SALMON AND THE INFLUENCE OF OREGON COASTAL STREAM SUMMER TEMPERATURES

    EPA Science Inventory

    Freshwater survival and growth of juvenile salmon are affected by many factors, including high summer temperatures and other stressors such as parasitism. Delayed or suppressed growth related to stress can influence subsequent survival of juvenile salmonids in freshwater and mar...

  16. Juvenile hormone receptors in insect larval epidermis: Identification by photoaffinity labeling

    SciTech Connect

    Palli, S.R.; Osir, E.O.; Edwards, M.; Hiruma, K.; Riddiford, L.M. ); Eng, W.; Boehm, M.F.; Kulscar, P.; Ujvary, I.; Prestwich, G.D. )

    1990-01-01

    Tritiated photoaffinity analogs of the natural lepidopteran juvenile hormones, JH I and II (epoxy({sup 3}H)bishomofarnesyl diazoacetate (({sup 3}H)EHDA) and epoxy({sup 3}H)homofarnesyl diazoacetate (({sup 3}H)EHDA)), and of the JH analog methoprene (({sup 3}H)methoprene diazoketone (({sup 3}H)MDK)) were synthesized and used to identify specific JH binding proteins in the larval epidermis of the tobacco hornworm (Manduca sexta). EBDA and EHDA specifically photolabeled a 29-kDa nuclear protein (pI 5.8). This protein and a second 29-kDa protein (pI 6.0) were labeled by MDK, but excess unlabeled methoprene or MDK only prevented binding to the latter. These 29-kDa proteins are also present in larval fat body but not in epidermis from either wandering stage or allatectomized larvae, which lack high-affinity JH binding sites. A 29-kDa nuclear protein with the same developmental specificity as this JH binder bound the DNA of two larval endocuticle genes. A 38-kDa cytosolic protein was also specifically photolabeled by these photoaffinity analogs. The 29-kDa nuclear protein is likely the high-affinity receptor for JH that mediates its genomic action, whereas the 38-kDa cytosolic protein may serve as an intracellular carrier for these highly lipophilic hormones and hormone analogs.

  17. Ecdysone differentially regulates metamorphic timing relative to 20-hydroxyecdysone by antagonizing juvenile hormone in Drosophila melanogaster.

    PubMed

    Ono, Hajime

    2014-07-01

    In insects, a steroid hormone, 20-hydroxyecdysone (20E), plays important roles in the regulation of developmental transitions by initiating signaling cascades via the ecdysone receptor (EcR). Although 20E has been well characterized as the molting hormone, its precursor ecdysone (E) has been considered to be a relatively inactive compound because it has little or no effect on classic EcR mediated responses. I found that feeding E to wild-type third instar larvae of Drosophila melanogaster accelerates the metamorphic timing, which results in elevation of lethality during metamorphosis and reduced body size, while 20E has only a minor effect. The addition of a juvenile hormone analog (JHA) to E impeded their precocious pupariation and thereby rescued the reduced body size. The ability of JHA impeding the effect of E was not observed in the Methoprene-tolerant (Met) and germ-cell expressed (gce) double mutant animals lacking JH signaling, indicating that antagonistic action of JH against E is transduced via a primary JH receptor, Met, or a product of its homolog, Gce. I also found that L3 larvae are susceptible to E around the time when they reach their minimum viable weight. These results indicate that E, and not just 20E, is also essential for proper regulation of developmental timing and body size. Furthermore, the precocious pupariation triggered by E is impeded by the action of JH to ensure that animals attain body size to survive metamorphosis.

  18. Subacute microcystin-LR exposure alters the metabolism of thyroid hormones in juvenile zebrafish (Danio Rerio).

    PubMed

    Liu, Zidong; Tang, Rong; Li, Dapeng; Hu, Qing; Wang, Ying

    2015-02-01

    Microcystin-LR (MC-LR) has been detected extensively in the aquatic environment and has the potential to disturb the thyroid endocrine system. However, limited information is available on the effects of subacute MC-LR exposure on fish thyroid hormone (TH) metabolism. In the present study, juvenile zebrafish (Danio rerio) were exposed to MC-LR at environmentally relevant concentrations (0, 1, 5, and 25 μg/L) for 28 days. Whole-body TH content and thyroid follicle histology were used as direct endpoints to assess thyroid disruption. The activities of iodothyronine deiodinases (IDs) and the transcription of selected genes associated with TH synthesis were also investigated to study the underlying mechanisms of endocrine disruption. Exposure of zebrafish to MC-LR significantly increased whole-body thyroxine (T4) content but decreased whole-body triiodothyronine (T3) content. We also observed hypertrophy and hyperplasia of the thyroid follicle epithelial cells, as well as up-regulation of corticotropin-releasing hormone (CRH), thyroid-stimulating hormone (TSH), thyroid peroxidase (TPO), and transthyretin (TTR) genes. The decreases in ID1 and ID2 activities coupled with an increase in ID3 activity were observed in MC-LR treatment groups. These results demonstrate that exposure to MC-LR at environmental concentrations results in the disturbance of TH homeostasis by disrupting the synthesis and conversion of THs. PMID:25647779

  19. Subacute microcystin-LR exposure alters the metabolism of thyroid hormones in juvenile zebrafish (Danio Rerio).

    PubMed

    Liu, Zidong; Tang, Rong; Li, Dapeng; Hu, Qing; Wang, Ying

    2015-01-30

    Microcystin-LR (MC-LR) has been detected extensively in the aquatic environment and has the potential to disturb the thyroid endocrine system. However, limited information is available on the effects of subacute MC-LR exposure on fish thyroid hormone (TH) metabolism. In the present study, juvenile zebrafish (Danio rerio) were exposed to MC-LR at environmentally relevant concentrations (0, 1, 5, and 25 μg/L) for 28 days. Whole-body TH content and thyroid follicle histology were used as direct endpoints to assess thyroid disruption. The activities of iodothyronine deiodinases (IDs) and the transcription of selected genes associated with TH synthesis were also investigated to study the underlying mechanisms of endocrine disruption. Exposure of zebrafish to MC-LR significantly increased whole-body thyroxine (T4) content but decreased whole-body triiodothyronine (T3) content. We also observed hypertrophy and hyperplasia of the thyroid follicle epithelial cells, as well as up-regulation of corticotropin-releasing hormone (CRH), thyroid-stimulating hormone (TSH), thyroid peroxidase (TPO), and transthyretin (TTR) genes. The decreases in ID1 and ID2 activities coupled with an increase in ID3 activity were observed in MC-LR treatment groups. These results demonstrate that exposure to MC-LR at environmental concentrations results in the disturbance of TH homeostasis by disrupting the synthesis and conversion of THs.

  20. Subacute Microcystin-LR Exposure Alters the Metabolism of Thyroid Hormones in Juvenile Zebrafish (Danio Rerio)

    PubMed Central

    Liu, Zidong; Tang, Rong; Li, Dapeng; Hu, Qing; Wang, Ying

    2015-01-01

    Microcystin-LR (MC-LR) has been detected extensively in the aquatic environment and has the potential to disturb the thyroid endocrine system. However, limited information is available on the effects of subacute MC-LR exposure on fish thyroid hormone (TH) metabolism. In the present study, juvenile zebrafish (Danio rerio) were exposed to MC-LR at environmentally relevant concentrations (0, 1, 5, and 25 μg/L) for 28 days. Whole-body TH content and thyroid follicle histology were used as direct endpoints to assess thyroid disruption. The activities of iodothyronine deiodinases (IDs) and the transcription of selected genes associated with TH synthesis were also investigated to study the underlying mechanisms of endocrine disruption. Exposure of zebrafish to MC-LR significantly increased whole-body thyroxine (T4) content but decreased whole-body triiodothyronine (T3) content. We also observed hypertrophy and hyperplasia of the thyroid follicle epithelial cells, as well as up-regulation of corticotropin-releasing hormone (CRH), thyroid-stimulating hormone (TSH), thyroid peroxidase (TPO), and transthyretin (TTR) genes. The decreases in ID1 and ID2 activities coupled with an increase in ID3 activity were observed in MC-LR treatment groups. These results demonstrate that exposure to MC-LR at environmental concentrations results in the disturbance of TH homeostasis by disrupting the synthesis and conversion of THs. PMID:25647779

  1. Control of larval and egg development in Aedes aegypti with Ribonucleic acid interference (RNAi) against juvenile hormone acid methyl transferase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ribonucleic acid interference (RNAi) is a powerful approach for elucidating gene functions in a variety of organisms, including mosquitoes and many other insects. Little has been done, however, to harness this approach in order to control adult and larval mosquitoes. Juvenile hormone (JH) plays a pi...

  2. Precocious sexual signalling and mating in Anastrepha fraterculus (Diptera: Tephritidae) sterile males achieved through juvenile hormone treatment and protein supplements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sexual maturation of Anastrepha fraterculus is a long process. Methoprene (a mimic of juvenile hormone) considerably reduces the time for sexual maturation in males. However, in other Anastrepha species, this effect depends on protein intake at the adult stage. Here, we evaluated the mating competit...

  3. Gustatory perception and fat body energy metabolism are jointly affected by vitellogenin and juvenile hormone in honey bees.

    PubMed

    Wang, Ying; Brent, Colin S; Fennern, Erin; Amdam, Gro V

    2012-06-01

    Honey bees (Apis mellifera) provide a system for studying social and food-related behavior. A caste of workers performs age-related tasks: young bees (nurses) usually feed the brood and other adult bees inside the nest, while older bees (foragers) forage outside for pollen, a protein/lipid source, or nectar, a carbohydrate source. The workers' transition from nursing to foraging and their foraging preferences correlate with differences in gustatory perception, metabolic gene expression, and endocrine physiology including the endocrine factors vitellogenin (Vg) and juvenile hormone (JH). However, the understanding of connections among social behavior, energy metabolism, and endocrine factors is incomplete. We used RNA interference (RNAi) to perturb the gene network of Vg and JH to learn more about these connections through effects on gustation, gene transcripts, and physiology. The RNAi perturbation was achieved by single and double knockdown of the genes ultraspiracle (usp) and vg, which encode a putative JH receptor and Vg, respectively. The double knockdown enhanced gustatory perception and elevated hemolymph glucose, trehalose, and JH. We also observed transcriptional responses in insulin like peptide 1 (ilp1), the adipokinetic hormone receptor (AKHR), and cGMP-dependent protein kinase (PKG, or "foraging gene" Amfor). Our study demonstrates that the Vg-JH regulatory module controls changes in carbohydrate metabolism, but not lipid metabolism, when worker bees shift from nursing to foraging. The module is also placed upstream of ilp1, AKHR, and PKG for the first time. As insulin, adipokinetic hormone (AKH), and PKG pathways influence metabolism and gustation in many animals, we propose that honey bees have conserved pathways in carbohydrate metabolism and conserved connections between energy metabolism and gustatory perception. Thus, perhaps the bee can make general contributions to the understanding of food-related behavior and metabolic disorders.

  4. Hemolymph juvenile hormone titers in worker honey bees under normal and preswarming conditions.

    PubMed

    Zeng, Zhijiang; Huang, Zachary Y; Qin, Yuchuan; Pang, Huizhong

    2005-04-01

    Swarming is an important mechanism by which honey bee, Apis mellifera L., colonies reproduce, yet very little is known about the physiological changes in workers that are preparing to swarm. In this study, we determined the endocrine status of worker honey bees in preswarming colonies and in normal (nonswarming) colonies. Juvenile hormone (JH) titers in worker bees were similar in both groups before queen cells were present, but they became significantly lower in preswarming colonies compared with normal colonies when queen cells occurred in preswarming colonies. The lower JH titers in the preswarming colonies suggest that behavioral development is delayed in these colonies, consistent with previous reports that preswarming colonies have reduced foraging activities. Understanding the endocrine status of bees preparing for swarming will help us to better understand the biology of swarming. PMID:15889713

  5. The effect of juvenile hormone III, methyl farnesoate, and methoprene on Na/K-ATPase activity in larvae of the brine shrimp, Artemia.

    PubMed

    Ahl, J S; Brown, J J

    1991-01-01

    1. Ion transport enzyme (Na/K-ATPase) activity in stage III larvae of the brine shrimp, Artemia, remains elevated throughout the stadium when populations are exposed to methoprene in artificial seawater. 2. Infusion of methoprene, juvenile hormone, or methyl farnesoate causes increased Na/K-ATPase activity in homogenates of mid-stadium larvae that would otherwise exhibit low activity. 3. The sensitivity of the enzyme system to extremely low concentrations of the juvenoids suggests that this may be a common mode of action of these compounds. Additionally it suggests that the enzyme may be under the influence of a similar compound present in the larvae. PMID:1682091

  6. Is Juvenile Hormone a potential mechanism that underlay the "branched Y-model"?

    PubMed

    Márquez-García, Armando; Canales-Lazcano, Jorge; Rantala, Markus J; Contreras-Garduño, Jorge

    2016-05-01

    Trade-offs are a central tenet in the life-history evolution and the simplest model to understand it is the "Y" model: the investment of one arm will affect the investment of the other arm. However, this model is by far more complex, and a "branched Y-model" is proposed: trade-offs could exist within each arm of the Y, but the mechanistic link is unknown. Here we used Tenebrio molitor to test if Juvenile Hormone (JH) could be a mechanistic link behind the "branched Y-model". Larvae were assigned to one of the following experimental groups: (1) low, (2) medium and (3) high doses of methoprene (a Juvenile Hormone analogue, JHa), (4) acetone (methoprene diluents; control one) or (5) näive (handled in the same way as other groups; control two). The JHa lengthened the time of development from larvae to pupae and larvae to adults, resulting in adults with a larger size. Males with medium and long JHa treatment doses were favored with female choice, but had smaller testes and fewer viable sperm. There were no differences between groups in regard to the number of spermatozoa of males, or the number of ovarioles or eggs of females. This results suggest that JH: (i) is a mechanistic link of insects "branched Y model", (ii) is a double ended-sword because it may not only provide benefits on reproduction but could also impose costs, and (iii) has a differential effect on each sex, being males more affected than females. PMID:27013379

  7. Knockout silkworms reveal a dispensable role for juvenile hormones in holometabolous life cycle

    PubMed Central

    Daimon, Takaaki; Uchibori, Miwa; Nakao, Hajime; Sezutsu, Hideki; Shinoda, Tetsuro

    2015-01-01

    Insect juvenile hormones (JHs) prevent precocious metamorphosis and allow larvae to undergo multiple rounds of status quo molts. However, the roles of JHs during the embryonic and very early larval stages have not been fully understood. We generated and characterized knockout silkworms (Bombyx mori) with null mutations in JH biosynthesis or JH receptor genes using genome-editing tools. We found that embryonic growth and morphogenesis are largely independent of JHs in Bombyx and that, even in the absence of JHs or JH signaling, pupal characters are not formed in first- or second-instar larvae, and precocious metamorphosis is induced after the second instar at the earliest. We also show by mosaic analysis that a pupal specifier gene broad, which is dramatically up-regulated in the late stage of the last larval instar, is essential for pupal commitment in the epidermis. Importantly, the mRNA expression level of broad, which is thought to be repressed by JHs, remained at very low basal levels during the early larval instars of JH-deficient or JH signaling-deficient knockouts. Therefore, our study suggests that the long-accepted paradigm that JHs maintain the juvenile status throughout larval life should be revised because the larval status can be maintained by a JH-independent mechanism in very early larval instars. We propose that the lack of competence for metamorphosis during the early larval stages may result from the absence of an unidentified broad-inducing factor, i.e., a competence factor. PMID:26195792

  8. Knockout silkworms reveal a dispensable role for juvenile hormones in holometabolous life cycle.

    PubMed

    Daimon, Takaaki; Uchibori, Miwa; Nakao, Hajime; Sezutsu, Hideki; Shinoda, Tetsuro

    2015-08-01

    Insect juvenile hormones (JHs) prevent precocious metamorphosis and allow larvae to undergo multiple rounds of status quo molts. However, the roles of JHs during the embryonic and very early larval stages have not been fully understood. We generated and characterized knockout silkworms (Bombyx mori) with null mutations in JH biosynthesis or JH receptor genes using genome-editing tools. We found that embryonic growth and morphogenesis are largely independent of JHs in Bombyx and that, even in the absence of JHs or JH signaling, pupal characters are not formed in first- or second-instar larvae, and precocious metamorphosis is induced after the second instar at the earliest. We also show by mosaic analysis that a pupal specifier gene broad, which is dramatically up-regulated in the late stage of the last larval instar, is essential for pupal commitment in the epidermis. Importantly, the mRNA expression level of broad, which is thought to be repressed by JHs, remained at very low basal levels during the early larval instars of JH-deficient or JH signaling-deficient knockouts. Therefore, our study suggests that the long-accepted paradigm that JHs maintain the juvenile status throughout larval life should be revised because the larval status can be maintained by a JH-independent mechanism in very early larval instars. We propose that the lack of competence for metamorphosis during the early larval stages may result from the absence of an unidentified broad-inducing factor, i.e., a competence factor. PMID:26195792

  9. Determination of juvenile hormone titers by means of LC-MS/MS/MS and a juvenile hormone-responsive Gal4/UAS system in Aedes aegypti mosquitoes.

    PubMed

    Zhao, Bo; Hou, Yuan; Wang, Jianjun; Kokoza, Vladimir A; Saha, Tusar T; Wang, Xue-Li; Lin, Ling; Zou, Zhen; Raikhel, Alexander S

    2016-10-01

    In anautogenous mosquitoes, juvenile hormone III (JH) plays an essential role in female post-eclosion (PE) development, preparing them for subsequent blood feeding and egg growth. We re-examined the JH titer during the reproductive cycle of female Aedes aegypti mosquitoes. Using liquid chromatography coupled with triple tandem mass spectrometry (LC-MS/MS/MS), we have shown that it reaches its peak at 48-54 h PE in the female hemolymph and at 72 h PE in whole body extracts. This method represents an effective assay for determination of JH titers. The 2.1-kb 5' promoter region of the Early Trypsin (ET) gene, which is specifically expressed in the female midgut under the control of JH during the PE phase, was utilized to genetically engineer the Ae. aegypti mosquito line with the ET-Gal4 activator. We then established the ET-GAL4>UAS-enhanced green fluorescent protein (EGFP) system in Ae. aegypti. In ET-Gal4>UAS-EGFP female mosquitoes, the intensity of the midgut-specific EGFP signal was observed to correspond to the ET gene transcript level and follow the JH titer during the PE phase. The EGFP signal and the EGFP transcript level were significantly diminished in midguts of transgenic female mosquitoes after RNA interference depletion of the JH receptor Methoprene-tolerant (Met), providing evidence of the control of ET gene expression by Met. Topical JH application caused premature enhancement of the EGFP signal and the EGFP transcript level in midguts of newly eclosed ET-Gal4>UAS-EGFP female mosquitoes, in which endogenous JH titer is still low. Hence, this novel ET-Gal4>UAS system permits JH-dependent gene overexpression in the midgut of Ae. aegypti female mosquitoes prior to a blood meal. PMID:27530057

  10. The influence of sex hormones on acne.

    PubMed

    Förström, L

    1980-01-01

    The sebaceous glands are stimulated by androgens produced in the skin itself. This explains why elevated androgen levels are seldom found in blood and urine from patients with acne. The most potent androgen is dihydrotestosterone (DHT), which is formed in the target cells, i.e. in the sebaceous glands, by a 5 alpha-reduction of testosterone. DHT is then bound to a specific receptor protein and translocated into the cell nucleus. In young persons genetically predisposed to acne a temporarily increased local DHT-formation has been postulated. In women androstenedione appears to be the major pre-hormone for DHT-formation. Adrenal androgens may account for prepubertal acne. Estrogens and progesterone influence acne only in high, unphysiological doses. Therapeutically we are waiting for a safe effective anti-androgen for topical use. PMID:6258368

  11. Regulatory roles of biogenic amines and juvenile hormone in the reproductive behavior of the western tarnished plant bug (Lygus hesperus).

    PubMed

    Brent, Colin S; Miyasaki, Katelyn; Vuong, Connor; Miranda, Brittany; Steele, Bronwen; Brent, Kristoffer G; Nath, Rachna

    2016-02-01

    Mating induces behavioral and physiological changes in the plant bug Lygus hesperus Knight (Hemiptera: Miridae). After receiving seminal products, which include the systemic regulator juvenile hormone (JH), females enter a post-mating period lasting several days during which they enhance their oviposition rate and lose interest in remating. To elucidate the regulation of these behavioral changes in L. hesperus, biogenic amines were quantified in the heads of females at 5 min, 1 h and 24 h after copulation and compared to levels in virgins using high-performance liquid chromatography coupled with electrochemical detection. Mating significantly increased dopamine (DA) after 1 and 24 h, and decreased octopamine (OA) after 5 min and 1 h. Serotonin did not change with mating, but tyramine was significantly reduced after 5 min. While injection of amines into virgin females did not influence sexual receptivity, OA caused a decrease in oviposition during the 24 h following injection. Topical application of the JH analog methoprene to virgins caused an increase in DA, and a decline in mating propensity, but did not influence other amines or the oviposition rate. The results suggest the decline in OA observed immediately after mating may promote egg laying, and that male-derived JH may induce an increase in DA that could account for the post-mating loss of sexual receptivity.

  12. The mode of action of juvenile hormone and ecdysone: towards an epi-endocrinological paradigm?

    PubMed

    De Loof, Arnold; Boerjan, Bart; Ernst, Ulrich R; Schoofs, Liliane

    2013-07-01

    In some insect species, two sites of juvenile hormone (JH) synthesis have been reported: the very well documented corpora allata that secrete JH for "general use", and the reproductive system, in particular the male accessory glands, in which the function of the sometimes huge amounts of JH (e.g. in Hyalophora cecropia) remains to be clarified. A recent finding in Schistocerca gregaria, namely that suppression of the ecdysteroid peak preceding a molt by RNAi of the Halloween genes spook, phantom and shade does not impede normal molting, challenges the (never experimentally proven) classical concept that such a peak is causally linked to a molt. Recent developments in epigenetic control of gene expression in both the honey bee and in locusts suggest that, in addition to the classical scheme of hormone-receptor (membrane- and/or nuclear) mode of action, there may be a third way. Upon combining these and other orphan data that do not fit in the commonly accepted textbook schemes, we here advance the working hypothesis that both JH and ecdysone might be important but overlooked players in epigenetic control of gene expression, in particular at extreme concentrations (peak values or total absence). In this review, we put forward how epi-endocrinology can complement classical arthropod endocrinology. PMID:23454668

  13. Juvenile hormone regulation of female reproduction in the common bed bug, Cimex lectularius

    PubMed Central

    Gujar, Hemant; Palli, Subba Reddy

    2016-01-01

    To begin studies on reproduction in common bed bug, Cimex lectularius, we identified three genes coding for vitellogenin (Vg, a protein required for the reproductive success of insects) and studied their hormonal regulation. RNA interference studied showed that expression of Vg3 gene in the adult females is a prerequisite for successful completion of embryogenesis in the eggs laid by them. Juvenile hormone (JH) receptor, Methoprene-tolerant (Met), steroid receptor coactivator (SRC) and GATAa but not ecdysone receptor (EcR) or its partner, ultraspiracle (USP) are required for expression of Vg genes. Feeding and mating working through Vg, Met, SRC, EcR, and GATAa regulate oocyte development. Knockdown of the expression of Met, SRC, EcR, USP, BR-C (Broad-Complex), TOR (target of rapamycin), and GATAa in female adults resulted in a reduction in the number eggs laid by them. Interestingly, Kruppel homolog 1 (Kr-h1) knockdown in the adult females did not reduce their fecundity but affected the development of embryos in the eggs laid by females injected with Kr-h1 double-stranded RNA. These data suggest that JH functioning through Met and SRC regulate both vitellogenesis and oogenesis in C. lectularius. However, JH does not work through Kr-h1 but may work through transcription factors not yet identified. PMID:27762340

  14. Evolution of Ecdysis and Metamorphosis in Arthropods: The Rise of Regulation of Juvenile Hormone.

    PubMed

    Cheong, Sam P S; Huang, Juan; Bendena, William G; Tobe, Stephen S; Hui, Jerome H L

    2015-11-01

    Arthropods are the most successful group of animals, and are found in diverse habitats; they account for more than 80% of described animal species. A rigid exoskeleton is a common feature that is shared across the different groups of arthropods. The exoskeleton offers protection and is shed between developmental stages via a unique evolutionarily conserved process known as molting/ecdysis. Molting is triggered by steroid hormones, the ecdysteroids, and the regulation of their biosynthesis has long been proposed as a contributor to the success of arthropods during evolution. Nevertheless, how novelties arose that contributed to the diversifications of arthropods remain unclear. Juvenile hormones (JHs) are sequiterpenoids that were thought to be unique to insects, modulating the timing of metamorphosis in conjunction with the actions of ecdysteroids. Here, we revisit the old question of "the role that the sesquiterpenoids play in arthropod evolution" with a focus on the neglected non-insect arthropods. We hypothesize that the sesquiterpenoid, methyl farnesoate (MF), had already established regulatory functions in the last common ancestor of arthropods, and the difference in the regulation of biosynthesis and degradation of sesquiterpenoids, such as MF and JH, was another major driving force in the successful radiation of insects.

  15. The mode of action of juvenile hormone and ecdysone: towards an epi-endocrinological paradigm?

    PubMed

    De Loof, Arnold; Boerjan, Bart; Ernst, Ulrich R; Schoofs, Liliane

    2013-07-01

    In some insect species, two sites of juvenile hormone (JH) synthesis have been reported: the very well documented corpora allata that secrete JH for "general use", and the reproductive system, in particular the male accessory glands, in which the function of the sometimes huge amounts of JH (e.g. in Hyalophora cecropia) remains to be clarified. A recent finding in Schistocerca gregaria, namely that suppression of the ecdysteroid peak preceding a molt by RNAi of the Halloween genes spook, phantom and shade does not impede normal molting, challenges the (never experimentally proven) classical concept that such a peak is causally linked to a molt. Recent developments in epigenetic control of gene expression in both the honey bee and in locusts suggest that, in addition to the classical scheme of hormone-receptor (membrane- and/or nuclear) mode of action, there may be a third way. Upon combining these and other orphan data that do not fit in the commonly accepted textbook schemes, we here advance the working hypothesis that both JH and ecdysone might be important but overlooked players in epigenetic control of gene expression, in particular at extreme concentrations (peak values or total absence). In this review, we put forward how epi-endocrinology can complement classical arthropod endocrinology.

  16. Precocious metamorphosis in the juvenile hormone-deficient mutant of the silkworm, Bombyx mori.

    PubMed

    Daimon, Takaaki; Kozaki, Toshinori; Niwa, Ryusuke; Kobayashi, Isao; Furuta, Kenjiro; Namiki, Toshiki; Uchino, Keiro; Banno, Yutaka; Katsuma, Susumu; Tamura, Toshiki; Mita, Kazuei; Sezutsu, Hideki; Nakayama, Masayoshi; Itoyama, Kyo; Shimada, Toru; Shinoda, Tetsuro

    2012-01-01

    Insect molting and metamorphosis are intricately governed by two hormones, ecdysteroids and juvenile hormones (JHs). JHs prevent precocious metamorphosis and allow the larva to undergo multiple rounds of molting until it attains the proper size for metamorphosis. In the silkworm, Bombyx mori, several "moltinism" mutations have been identified that exhibit variations in the number of larval molts; however, none of them have been characterized molecularly. Here we report the identification and characterization of the gene responsible for the dimolting (mod) mutant that undergoes precocious metamorphosis with fewer larval-larval molts. We show that the mod mutation results in complete loss of JHs in the larval hemolymph and that the mutant phenotype can be rescued by topical application of a JH analog. We performed positional cloning of mod and found a null mutation in the cytochrome P450 gene CYP15C1 in the mod allele. We also demonstrated that CYP15C1 is specifically expressed in the corpus allatum, an endocrine organ that synthesizes and secretes JHs. Furthermore, a biochemical experiment showed that CYP15C1 epoxidizes farnesoic acid to JH acid in a highly stereospecific manner. Precocious metamorphosis of mod larvae was rescued when the wild-type allele of CYP15C1 was expressed in transgenic mod larvae using the GAL4/UAS system. Our data therefore reveal that CYP15C1 is the gene responsible for the mod mutation and is essential for JH biosynthesis. Remarkably, precocious larval-pupal transition in mod larvae does not occur in the first or second instar, suggesting that authentic epoxidized JHs are not essential in very young larvae of B. mori. Our identification of a JH-deficient mutant in this model insect will lead to a greater understanding of the molecular basis of the hormonal control of development and metamorphosis.

  17. Molecular Determinants of Juvenile Hormone Action as Revealed by 3D QSAR Analysis in Drosophila

    PubMed Central

    Beňo, Milan; Farkaš, Robert

    2009-01-01

    Background Postembryonic development, including metamorphosis, of many animals is under control of hormones. In Drosophila and other insects these developmental transitions are regulated by the coordinate action of two principal hormones, the steroid ecdysone and the sesquiterpenoid juvenile hormone (JH). While the mode of ecdysone action is relatively well understood, the molecular mode of JH action remains elusive. Methodology/Principal Findings To gain more insights into the molecular mechanism of JH action, we have tested the biological activity of 86 structurally diverse JH agonists in Drosophila melanogaster. The results were evaluated using 3D QSAR analyses involving CoMFA and CoMSIA procedures. Using this approach we have generated both computer-aided and species-specific pharmacophore fingerprints of JH and its agonists, which revealed that the most active compounds must possess an electronegative atom (oxygen or nitrogen) at both ends of the molecule. When either of these electronegative atoms are replaced by carbon or the distance between them is shorter than 11.5 Å or longer than 13.5 Å, their biological activity is dramatically decreased. The presence of an electron-deficient moiety in the middle of the JH agonist is also essential for high activity. Conclusions/Significance The information from 3D QSAR provides guidelines and mechanistic scope for identification of steric and electrostatic properties as well as donor and acceptor hydrogen-bonding that are important features of the ligand-binding cavity of a JH target protein. In order to refine the pharmacophore analysis and evaluate the outcomes of the CoMFA and CoMSIA study we used pseudoreceptor modeling software PrGen to generate a putative binding site surrogate that is composed of eight amino acid residues corresponding to the defined molecular interactions. PMID:19547707

  18. National Implications in Juvenile Justice: The Influence of Juvenile Mentoring Programs on At Risk Youth.

    ERIC Educational Resources Information Center

    Belshaw, Scott H.; Kritsonis, William Allan

    2007-01-01

    In 1972 the federal government created the Juvenile Justice Delinquency Prevention Act that procured funding for various governmental programs to combat the sudden increase in juvenile crime. A provision of this Act set out the creation of mentoring programs to help decrease the juvenile crime rate and dropout rates in secondary schools. This…

  19. Common and Distinct Roles of Juvenile Hormone Signaling Genes in Metamorphosis of Holometabolous and Hemimetabolous Insects

    PubMed Central

    Jindra, Marek

    2011-01-01

    Insect larvae metamorphose to winged and reproductive adults either directly (hemimetaboly) or through an intermediary pupal stage (holometaboly). In either case juvenile hormone (JH) prevents metamorphosis until a larva has attained an appropriate phase of development. In holometabolous insects, JH acts through its putative receptor Methoprene-tolerant (Met) to regulate Krüppel-homolog 1 (Kr-h1) and Broad-Complex (BR-C) genes. While Met and Kr-h1 prevent precocious metamorphosis in pre-final larval instars, BR-C specifies the pupal stage. How JH signaling operates in hemimetabolous insects is poorly understood. Here, we compare the function of Met, Kr-h1 and BR-C genes in the two types of insects. Using systemic RNAi in the hemimetabolous true bug, Pyrrhocoris apterus, we show that Met conveys the JH signal to prevent premature metamorphosis by maintaining high expression of Kr-h1. Knockdown of either Met or Kr-h1 (but not of BR-C) in penultimate-instar Pyrrhocoris larvae causes precocious development of adult color pattern, wings and genitalia. A natural fall of Kr-h1 expression in the last larval instar normally permits adult development, and treatment with an exogenous JH mimic methoprene at this time requires both Met and Kr-h1 to block the adult program and induce an extra larval instar. Met and Kr-h1 therefore serve as JH-dependent repressors of deleterious precocious metamorphic changes in both hemimetabolous and holometabolous juveniles, whereas BR-C has been recruited for a new role in specifying the holometabolous pupa. These results show that despite considerable evolutionary distance, insects with diverse developmental strategies employ a common-core JH signaling pathway to commit to adult morphogenesis. PMID:22174880

  20. Effect of an insect juvenile hormone analogue, Fenoxycarb on development and oxygen uptake by larval lobsters Homarus gammarus (L.).

    PubMed

    Arnold, Katie E; Wells, Colin; Spicer, John I

    2009-04-01

    Little attention has been focused on the effect of anthropogenic compounds that disrupt the endocrine systems in crustaceans. Consequently, this study investigated the effects of the juvenile hormone analogue (JHA), Fenoxycarb on selected physiological and developmental processes of the zoeal stages in the European lobster, Homarus gammarus. Chronic exposure to Fenoxycarb (50microg L(-1)) resulted in a significant (p < 0.05) reduction in moult frequency and size at moult. Fenoxycarb exposure extended zoeal duration between zoea I to II (p<0.05) and resulted in total inhibition of the moult from zoea II to III. Significantly greater rates of O2 uptake were observed in Fenoxycarb-exposed larvae in comparison with controls (p<0.05). All rates of O2 uptake decreased significantly between 7 and 12d of exposure (p<0.05). At 12d, exposure to the solvent control no longer influenced rates of O2 uptake, but it was not possible to attribute increased O2 uptake to Fenoxycarb exposure directly, as treated individuals did not moult beyond zoea III. The low exposure concentrations of Fenoxycarb, comparable to those used in plant protection, resulted in endocrine disrupted responses in H. gammarus (albeit with little clear, demonstrable effect on metabolism) a finding that could have important ecological and commercial implications. PMID:18835588

  1. Waterborne exposure to microcystin-LR causes thyroid hormone metabolism disturbances in juvenile Chinese rare minnow (Gobiocypris rarus).

    PubMed

    Liu, Zidong; Li, Dapeng; Wang, Ying; Guo, Wei; Gao, Yu; Tang, Rong

    2015-09-01

    Microcystin-LR (MC-LR) has the potential to disturb thyroid hormone homeostasis, but little is known about the underlying mechanisms of MC-LR in fish. In the present study, juvenile Chinese rare minnows (Gobiocypris rarus) were exposed to various concentrations of MC-LR (0 µg/L, 50 µg/L, 100 µg/L, and 500 µg/L) for 7 d. The whole-body thyroid hormone content, the histology of thyroid follicle epithelial cells, the activities of hepatic iodothyronine deiodinases, and the transcription of selected genes associated with thyroid hormone synthesis, transport, and metabolism were analyzed. Following exposure to MC-LR, whole-body concentrations of both thyroxine (T4 ) and triiodothyronine (T3 ) were significantly decreased. The levels of messenger RNA for sodium/iodide symporter, transthyretin, thyroid hormone receptor-α, iodothyronine deiodinase2, and iodothyronine deiodinase3 were significantly down-regulated after exposure to 500 µg/L MC-LR. A significant decrease in ID2 activity was also observed in the 500-µg/L MC-LR exposure group. Moreover, hypertrophy of thyroid follicle epithelial cells was observed after exposure to MC-LR. The results indicate that acute MC-LR exposure has the potential to disturb the homeostasis of thyroid hormone metabolism, leading to a hypothyroidism state in the juvenile Chinese rare minnow. PMID:25900717

  2. Waterborne exposure to microcystin-LR causes thyroid hormone metabolism disturbances in juvenile Chinese rare minnow (Gobiocypris rarus).

    PubMed

    Liu, Zidong; Li, Dapeng; Wang, Ying; Guo, Wei; Gao, Yu; Tang, Rong

    2015-09-01

    Microcystin-LR (MC-LR) has the potential to disturb thyroid hormone homeostasis, but little is known about the underlying mechanisms of MC-LR in fish. In the present study, juvenile Chinese rare minnows (Gobiocypris rarus) were exposed to various concentrations of MC-LR (0 µg/L, 50 µg/L, 100 µg/L, and 500 µg/L) for 7 d. The whole-body thyroid hormone content, the histology of thyroid follicle epithelial cells, the activities of hepatic iodothyronine deiodinases, and the transcription of selected genes associated with thyroid hormone synthesis, transport, and metabolism were analyzed. Following exposure to MC-LR, whole-body concentrations of both thyroxine (T4 ) and triiodothyronine (T3 ) were significantly decreased. The levels of messenger RNA for sodium/iodide symporter, transthyretin, thyroid hormone receptor-α, iodothyronine deiodinase2, and iodothyronine deiodinase3 were significantly down-regulated after exposure to 500 µg/L MC-LR. A significant decrease in ID2 activity was also observed in the 500-µg/L MC-LR exposure group. Moreover, hypertrophy of thyroid follicle epithelial cells was observed after exposure to MC-LR. The results indicate that acute MC-LR exposure has the potential to disturb the homeostasis of thyroid hormone metabolism, leading to a hypothyroidism state in the juvenile Chinese rare minnow.

  3. Sex-steroid and thyroid hormone concentrations in juvenile alligators (Alligator mississippiensis) from contaminated and reference lakes in Florida, USA

    USGS Publications Warehouse

    Grain, D.A.; Guillette, L.J.; Pickford, D.B.; Percival, H.F.; Woodward, A.R.

    1998-01-01

    Sex-steroid and thyroid hormones are critical regulators of growth and reproduction in all vertebrates, and several recent studies suggest that environmental chemicals can alter circulating concentrations of these hormones. This study examines plasma concentrations of estradiol-171?? (E2), testosterone (T), triiodothyronine (T3), and thyroxine (T4) in juvenile alligators (60-140 cm total length) from two contaminated lakes and one reference lake in Florida. First, the data were analyzed by comparing hormone concentrations among males and females from the different lakes. Whereas there were no differences in plasma E2 concentrations among animals of the three lakes, male alligators from the contaminated lakes (Lake Apopka and Lake Okeechobee) had significantly lower plasma T concentrations compared 10 males from the reference take (Lake Woodruff). Concentrations of thyroid hormones also differed in animals of the three lakes, with T4 concentrations being elevated in Lake Okeechobee males compared to Lake Woodruff males. Second, the relationship between body size and hormone concentration was examined using regression analysis. Most notably for steroid hormones, no clear relationship was detected between E2 and total length in Apopka females (r2 0.09, p = 0.54) or between T and total length in Apopka males (r2 = 0.007, p = 0.75). Females from Apopka (r2 = 0.318, p = 0.09) and Okeechobee (r2 = 0.222, p = 0.09) exhibited weak correlations between T3 and total length. Males from Apopka (r2 = 0.015, p = 0.66) and Okeechobee (r2 = 0.128, p = 0.19) showed no correlation between T4 and total length. These results indicate: some of the previously reported abnormalities in steroid hormones of hatchling alligators persist, at least, through the juvenile years; steroid and thyroid hormones are related to body size in juvenile alligators from the reference lake, whereas alligators living in lakes Apopka and Okeechobee experience alterations in circulating thyroid and steroid

  4. Ecdysteroids and juvenile hormones of whiteflies, important insect vectors for plant viruses.

    PubMed

    Gelman, Dale B; Pszczolkowski, Maciej A; Blackburn, Michael B; Ramaswamy, Sonny B

    2007-03-01

    Ecdysteroids and juvenile hormones (JHs) regulate many physiological events throughout the insect life cycle, including molting, metamorphosis, ecdysis, diapause, reproduction, and behavior. Fluctuation of whitefly ecdysteroid levels and the identity of the whitefly molting hormone (20-hydroxyecdysone) have only been reported within the last few years. An ecdysteroid commitment peak that is associated with the reprogramming of tissues for a metamorphic molt in many holometabolous and some hemimetabolous insect species was not observed in last nymphal instars of either the sweet potato whitefly, Bemisia tabaci (Biotype B), or the greenhouse whitefly, Trialeurodes vaporariorum. Ecdysteroids reach peak levels 1-2 days prior to the initiation of the nymphal-adult metamorphic molt. Adult eye and wing differentiation which signal the onset of this molt begin earlier in 4th instar T. vaporariorum (Stages 4 and 5, respectively) than in B. tabaci (Stage 6), and the premolt peak is 3-4 times greater in B. tabaci ( approximately 400 fg/microg protein) than in T. vaporariorum ( approximately 120 fg/microg protein). The JH of B. tabaci nymphs and eggs was found to be JH III, supporting the view that JHs I and II are, with rare exception, only present in lepidopteran insects. In B. tabaci eggs, JH levels were approximately 10 times greater on day 2/3 (0.44 fg/egg or 0.54 ng/g) than on day 5 (0.04 fg/egg or 0.054 ng/g) post-oviposition. Approximately, 1.4 fg/2nd-3rd instar nymph (0.36 ng/g) was detected. It is probable that the relatively high level of JH in day 2/3 eggs is associated with the differentiation of various whitefly tissues during embryonic development.

  5. Growth hormone overexpression generates an unfavorable phenotype in juvenile transgenic zebrafish under hypoxic conditions.

    PubMed

    Almeida, Daniela Volcan; Bianchini, Adalto; Marins, Luis Fernando

    2013-12-01

    Growth hormone (GH) has numerous functions in different organisms. A recently described function for GH is its role in protecting against damage caused by a decrease in oxygen levels. To evaluate the effects of GH-transgenesis on hypoxia tolerance, we used a GH-transgenic zebrafish model. We found that the transgenic fish have higher mortality rates when exposed to low oxygen levels (1.5 mg O₂L(-1)) for 24 h. The lower capacity of GH-transgenic fish to manage a hypoxic environment was investigated by analyzing different metabolic and molecular factors. The transgenic fish showed increased oxygen consumption, which confirms the larger oxygen demand imposed by transgenesis. At the gene expression level, transgenesis increased lactate dehydrogenase (LDH) and creatine kinase muscle (CKM) expression in fish under normoxic conditions. This result suggests that excessive GH expression stimulates the synthesis of enzymes involved in anaerobic metabolism. Conversely, the interaction between transgenesis and hypoxia caused an increased expression of hemoglobin (Hb), hypoxia-inducible factor (HIF1a) and prolyl-4-hydroxylase (PHD) genes. Additionally, GH-transgenesis increased LDH activity and increased lactate content. Taken together, these findings indicate that GH-transgenesis impaired the ability of juvenile zebrafish to sustain an aerobic metabolism and induced anaerobic metabolism when the fish were challenged with low oxygen levels.

  6. Identification of plant compounds that disrupt the insect juvenile hormone receptor complex.

    PubMed

    Lee, Seok-Hee; Oh, Hyun-Woo; Fang, Ying; An, Saes-Byeol; Park, Doo-Sang; Song, Hyuk-Hwan; Oh, Sei-Ryang; Kim, Soo-Young; Kim, Seonghyun; Kim, Namjung; Raikhel, Alexander S; Je, Yeon Ho; Shin, Sang Woon

    2015-02-10

    Insects impact human health through vector-borne diseases and cause major economic losses by damaging crops and stored agricultural products. Insect-specific growth regulators represent attractive control agents because of their safety to the environment and humans. We identified plant compounds that serve as juvenile hormone antagonists (PJHANs). Using the yeast two-hybrid system transformed with the mosquito JH receptor as a reporter system, we demonstrate that PJHANs affect the JH receptor, methoprene-tolerant (Met), by disrupting its complex with CYCLE or FISC, formation of which is required for mediating JH action. We isolated five diterpene secondary metabolites with JH antagonist activity from two plants: Lindera erythrocarpa and Solidago serotina. They are effective in causing mortality of mosquito larvae at relatively low LD50 values. Topical application of two diterpenes caused reduction in the expression of Met target genes and retardation of follicle development in mosquito ovaries. Hence, the newly discovered PJHANs may lead to development of a new class of safe and effective pesticides.

  7. Synthesis and bioassay of radiolabeled, chiral probes for juvenile hormone receptor study

    SciTech Connect

    Eng, W.

    1987-01-01

    Four different types of compounds were synthesized for the detailed study on interactions between insect juvenile hormone (JH) and the corresponding binding proteins, receptor proteins and catabolic enzymes: (1) High specific activity /sup 3/H-labeled, chiral alkyldiazoacetates with their skeletons approaching those of natural JH I and JH II were synthesized as photoaffinity labels for probing JH receptor proteins in Lepidoptera. Compared with epoxy farnesyl diazoacetate (EFDA), epoxy bishomofarnesyl diazoacetate (EBDA) and epoxy homofarnesyl diazoacetate (EHDA) have largely increased affinity to Manduca sexta JH binding proteins (JHBP) as demonstrated by gel electrophoresis. (2) Chiral JH I and JH II acids, as well as 12-hydroxy-JH I and JH II were synthesized. The hydroxy groups in these compounds provide tether points for attachment to proteins to serve as antigens with most of the recognition sites preserved to be used in JH radioimmunoassays. (3) The first radioiodine-labeled JH, (/sup 125/I)-12-iodo-JH I, was synthesized, both in no-carrier-added and carrier-added forms, as one of the probes for JH receptor study. (4) Four alkylthioltrifluoropropanones with skeletons approaching that of JH III and functional groups mimicking the JH epoxide moiety were synthesized as inhibitors for JH esterase (JHE).

  8. Behavioral Deficits in Juveniles Mediated by Maternal Stress Hormones in Mice

    PubMed Central

    Maguire, Jamie; Mody, Istvan

    2016-01-01

    Maternal depression has been shown to negatively impact offspring development. Investigation into the impact of maternal depression and offspring behavior has relied on correlative studies in humans. Further investigation into the underlying mechanisms has been hindered by the lack of useful animal models. We previously characterized a mouse model which exhibits depression-like behaviors restricted to the postpartum period and abnormal/fragmented maternal care (Gabrd−/− mice). Here we utilized this unique mouse model to investigate the mechanism(s) through which maternal depression-like behaviors adversely impact offspring development. Cross-fostering experiments reveal increased anxiety-like and depression-like behaviors in mice reared by Gabrd−/− mothers. Wild type and Gabrd−/− mice subjected to unpredictable stress during late pregnancy exhibit decreased pup survival and depression-like behavior in the postpartum period. Exogenous corticosterone treatment in wild type mice during late pregnancy is sufficient to decrease pup survival and induce anxiety-like and depression-like behaviors in the offspring. Further, the abnormal behaviors in juvenile mice reared by Gabrd−/− mice are alleviated by treatment of the mothers with the corticotropin-releasing hormone (CRH) antagonist, Antalarmin. These studies suggest that hyperresponsiveness of the HPA axis is associated with postpartum depression and may mediate the adverse effects of maternal depression on offspring behavior. PMID:26819762

  9. Diofenolan induces male offspring production through binding to the juvenile hormone receptor in Daphnia magna.

    PubMed

    Abe, Ryoko; Toyota, Kenji; Miyakawa, Hitoshi; Watanabe, Haruna; Oka, Tomohiro; Miyagawa, Shinichi; Nishide, Hiroyo; Uchiyama, Ikuo; Tollefsen, Knut Erik; Iguchi, Taisen; Tatarazako, Norihisa

    2015-02-01

    Juvenile hormone (JH) and JH agonists have been reported to induce male offspring production in various daphnid species including Daphnia magna. We recently established a short-term in vivo screening assay to detect chemicals having male offspring induction activity in adult D. magna. Diofenolan has been developed as a JH agonist for insect pest control, but its male offspring induction activity in daphnids has not been investigated yet. In this study, we found that the insect growth regulator (IGR) diofenolan exhibited a potent male offspring induction activity at low ng/L to μg/L concentrations, as demonstrated by the short-term in vivo screening assay and the recently developed TG211 ANNEX 7 test protocol. A two-hybrid assay performed using the D. magna JH receptor confirmed that diofenolan had a strong JH activity. Global whole body transcriptome analysis of D. magna exposed to 10 ng/L diofenolan showed an up-regulation of JH-responsive genes and modulation of several genes involved in the ecdysone receptor signaling pathway. These results clearly demonstrate that diofenolan has strong JH activity and male offspring induction activity, and that a combination of modified standardized regulatory testing protocols and rapid in vitro and in vivo screening assays are able to identify potential endocrine disruptors in D. magna. The observation that diofenolan modulates multiple endocrine signaling pathways in D. magna suggests that further investigation of potential interference with growth, development and reproduction is warranted.

  10. Fast, ultra-trace detection of juvenile hormone III from mosquitoes using mass spectrometry.

    PubMed

    Ramirez, Cesar E; Nouzova, Marcela; Benigni, Paolo; Quirke, J Martin E; Noriega, Fernando G; Fernandez-Lima, Francisco

    2016-10-01

    In the present work, a new protocol for fast separation and quantification of JH III from biological samples using liquid chromatography coupled to electrospray tandem mass spectrometry is described. In particular, the proposed protocol improves existing methodologies by combining a limited number of sample preparation steps with fast LC-MS/MS detection, providing lower limits of detection and demonstrated matrix effect control, together with high inter and intraday reproducibility. A limit of detection of 8pg/mL (0.32pg on column) was achieved, representing a 15-fold gain in sensitivity with respect to previous LC-MS based protocols. The performance of the LC-MS/MS protocol is comparable to previously described JH III quantitation protocol based on fluorescence detection, with the added advantage that quantification is independent of the availability of fluorescent tags that are often unavailable or show quite diverse responses on a batch-to-batch basis. Additionally, a detailed description of the JH III fragmentation pathway is provided for the first time, based on isolation of the molecular ion and their intermediate fragments using in-source MS/MS, MS/MS(n) and FT-ICR MS/MS measurements. The JH III workflow was evaluated as a function of developmental changes, sugar feeding and farnesoic acid stimulation in mosquitoes and can be applied to the detection of other juvenile hormones.

  11. Gonadotropic and physiological functions of juvenile hormone in Bumblebee (Bombus terrestris) workers.

    PubMed

    Shpigler, Hagai; Amsalem, Etya; Huang, Zachary Y; Cohen, Mira; Siegel, Adam J; Hefetz, Abraham; Bloch, Guy

    2014-01-01

    The evolution of advanced sociality in bees is associated with apparent modifications in juvenile hormone (JH) signaling. By contrast to most insects in which JH is a gonadotropin regulating female fertility, in the highly eusocial honey bee (Apis mellifera) JH has lost its gonadotrophic function in adult females, and instead regulates age-related division of labor among worker bees. In order to shed light on the evolution of JH signaling in bees we performed allatectomy and replacement therapies to manipulate JH levels in workers of the "primitively eusocial" bumblebee Bombus terrestris. Allatectomized worker bees showed remarkable reduction in ovarian development, egg laying, Vitellogenin and Krüppel homolog 1 fat body transcript levels, hemolymph Vitellogenin protein abundance, wax secretion, and egg-cell construction. These effects were reverted, at least partially, by treating allatectomized bees with JH-III, the natural JH of bees. Allatectomy also affected the amount of ester component in Dufour's gland secretion, which is thought to convey a social signal relating to worker fertility. These findings provide a strong support for the hypothesis that in contrast to honey bees, JH is a gonadotropin in bumblebees and lend credence to the hypothesis that the evolution of advanced eusociality in honey bees was associated with major modifications in JH signaling.

  12. Effects of juvenile hormone analogs on new reproductives and colony growth of Pharaoh ant (Hymenoptera: Formicidae).

    PubMed

    Lim, S P; Lee, C Y

    2005-12-01

    Two juvenile hormone analogs (JHAs), pyriproxyfen and S-methoprene, were impregnated into dried tuna fish and fed to colonies of Monomorium pharaonis (L.) at very low concentrations (1.0, 2.0, 3.0, 4.0, and 5.0 microg/ml). Its effects on the production of sexuals and colonial growth were observed. Colonies treated with pyriproxyfen yielded sexuals with physical abnormalities. Both female and male sexuals developed bulbous wings, decreased melanization, and died shortly after emergence. Sexuals emerged from colonies treated with S-methoprene did not possess anomalous characteristics. Both pyriproxyfen and S-methoprene did not have significant effects on colonial growth because of the low concentrations of the baits. A commercial bait containing 0.3% S-methoprene (Bioprene-BM) also was evaluated for its efficacy on Pharaoh's ant colonies. Results showed that Pharaoh's ant colonies succumbed to the lethal effects of S-methoprene. Colony members were reduced significantly. Production of queens also decreased significantly in treated colonies and treated queens were unable to lay eggs. JHAs are slow acting and eliminate ant colonies at a relatively slow rate. At low concentrations, pyriproxyfen recorded baffling results, i.e., bulbous wings and demelanized exoskeleton, and it is vital that further studies are initiated to solidify these findings.

  13. Identification of plant compounds that disrupt the insect juvenile hormone receptor complex.

    PubMed

    Lee, Seok-Hee; Oh, Hyun-Woo; Fang, Ying; An, Saes-Byeol; Park, Doo-Sang; Song, Hyuk-Hwan; Oh, Sei-Ryang; Kim, Soo-Young; Kim, Seonghyun; Kim, Namjung; Raikhel, Alexander S; Je, Yeon Ho; Shin, Sang Woon

    2015-02-10

    Insects impact human health through vector-borne diseases and cause major economic losses by damaging crops and stored agricultural products. Insect-specific growth regulators represent attractive control agents because of their safety to the environment and humans. We identified plant compounds that serve as juvenile hormone antagonists (PJHANs). Using the yeast two-hybrid system transformed with the mosquito JH receptor as a reporter system, we demonstrate that PJHANs affect the JH receptor, methoprene-tolerant (Met), by disrupting its complex with CYCLE or FISC, formation of which is required for mediating JH action. We isolated five diterpene secondary metabolites with JH antagonist activity from two plants: Lindera erythrocarpa and Solidago serotina. They are effective in causing mortality of mosquito larvae at relatively low LD50 values. Topical application of two diterpenes caused reduction in the expression of Met target genes and retardation of follicle development in mosquito ovaries. Hence, the newly discovered PJHANs may lead to development of a new class of safe and effective pesticides. PMID:25624480

  14. Homeodomain Protein Scr Regulates the Transcription of Genes Involved in Juvenile Hormone Biosynthesis in the Silkworm.

    PubMed

    Meng, Meng; Liu, Chun; Peng, Jian; Qian, Wenliang; Qian, Heying; Tian, Ling; Li, Jiarui; Dai, Dandan; Xu, Anying; Li, Sheng; Xia, Qingyou; Cheng, Daojun

    2015-11-02

    The silkworm Dominant trimolting (Moltinism, M³) mutant undergoes three larval molts and exhibits precocious metamorphosis. In this study, we found that compared with the wild-type (WT) that undergoes four larval molts, both the juvenile hormone (JH) concentration and the expression of the JH-responsive gene Krüppel homolog 1 (Kr-h1) began to be greater in the second instar of the M³ mutant. A positional cloning analysis revealed that only the homeodomain transcription factor gene Sex combs reduced (Scr) is located in the genomic region that is tightly linked to the M³ locus. The expression level of the Scr gene in the brain-corpora cardiaca-corpora allata (Br-CC-CA) complex, which controls the synthesis of JH, was very low in the final larval instar of both the M³ and WT larvae, and exhibited a positive correlation with JH titer changes. Importantly, luciferase reporter analysis and electrophoretic mobility shift assay (EMSA) demonstrated that the Scr protein could promote the transcription of genes involved in JH biosynthesis by directly binding to the cis-regulatory elements (CREs) of homeodomain protein on their promoters. These results conclude that the homeodomain protein Scr is transcriptionally involved in the regulation of JH biosynthesis in the silkworm.

  15. Gonadotropic and Physiological Functions of Juvenile Hormone in Bumblebee (Bombus terrestris) Workers

    PubMed Central

    Shpigler, Hagai; Amsalem, Etya; Huang, Zachary Y.; Cohen, Mira; Siegel, Adam J.; Hefetz, Abraham; Bloch, Guy

    2014-01-01

    The evolution of advanced sociality in bees is associated with apparent modifications in juvenile hormone (JH) signaling. By contrast to most insects in which JH is a gonadotropin regulating female fertility, in the highly eusocial honey bee (Apis mellifera) JH has lost its gonadotrophic function in adult females, and instead regulates age-related division of labor among worker bees. In order to shed light on the evolution of JH signaling in bees we performed allatectomy and replacement therapies to manipulate JH levels in workers of the "primitively eusocial" bumblebee Bombus terrestris. Allatectomized worker bees showed remarkable reduction in ovarian development, egg laying, Vitellogenin and Krüppel homolog 1 fat body transcript levels, hemolymph Vitellogenin protein abundance, wax secretion, and egg-cell construction. These effects were reverted, at least partially, by treating allatectomized bees with JH-III, the natural JH of bees. Allatectomy also affected the amount of ester component in Dufour's gland secretion, which is thought to convey a social signal relating to worker fertility. These findings provide a strong support for the hypothesis that in contrast to honey bees, JH is a gonadotropin in bumblebees and lend credence to the hypothesis that the evolution of advanced eusociality in honey bees was associated with major modifications in JH signaling. PMID:24959888

  16. The influence of turbidity on juvenile marine fish in the estuaries of Natal, South africa

    NASA Astrophysics Data System (ADS)

    Cyrus, D. P.; Blaber, S. J. M.

    1987-11-01

    Results from field studies in Natal estuaries show that the distribution of juvenile marine fish is influenced by turbidity. Laboratory studies on turbidity preference, with other variables excluded, showed good correlation with the field data for eight of ten species tested. The importance of turbidity and other factors to juvenile fish is discussed in relation to the role which estuaries play as nursery areas for juveniles of numerous marine species.

  17. Characterization of two juvenile hormone epoxide hydrolases by RNA interference in the Colorado potato beetle.

    PubMed

    Lü, Feng-Gong; Fu, Kai-Yun; Guo, Wen-Chao; Li, Guo-Qing

    2015-10-10

    In insect, juvenile hormone (JH) titers are tightly regulated in different development stages through synthesis and degradation pathways. During JH degradation, JH epoxide hydrolase (JHEH) converts JH to JH diol, and hydrolyses JH acid to JH acid diol. In this study, two full length LdJHEH cDNAs were cloned from Leptinotarsa decemlineata, and were provisionally designated LdJHEH1 and LdJHEH2. Both mRNAs were detectable in the thoracic muscles, brain-corpora cardiaca-corpora allata complex, foregut, midgut, hindgut, ventral ganglia, Malpighian tubules, fat bodies, epidermis, and hemocytes of the day 2 fourth-instar larvae, and in female ovaries as well as male reproductive organs of the adults. Moreover, both LdJHEH1 and LdJHEH2 were expressed throughout all larval life, with the highest peaks occurring 32h after ecdysis of the final (fourth) instar larvae. Four double-stranded RNAs (dsRNAs) (dsJHEH1-1, dsJHEH1-2, dsJHEH2-1, dsJHEH2-2) respectively targeting LdJHEH1 and LdJHEH2 were constructed and bacterially expressed. Ingestion of dsJHEH1-1, dsJHEH1-2, dsJHEH2-1, dsJHEH2-2, and a mixture of dsJHEH1-1+dsJHEH2-1 successfully knocked down corresponding target gene function, and significantly increased JH titer and upregulated Krüppel homolog 1 (LdKr-h1) mRNA level. Knockdown of either LdJHEH1 or LdJHEH2, or both genes slightly reduced larval weight and delayed larval development, and significantly impaired adult emergence. Therefore, it is suggested that knockdown LdJHEH1 and LdJHEH2 affected JH degradation in the Colorado potato beetle. PMID:26079572

  18. Hairy and Groucho mediate the action of juvenile hormone receptor Methoprene-tolerant in gene repression.

    PubMed

    Saha, Tusar T; Shin, Sang Woon; Dou, Wei; Roy, Sourav; Zhao, Bo; Hou, Yuan; Wang, Xue-Li; Zou, Zhen; Girke, Thomas; Raikhel, Alexander S

    2016-02-01

    The arthropod-specific juvenile hormone (JH) controls numerous essential functions. Its involvement in gene activation is known to be mediated by the transcription factor Methoprene-tolerant (Met), which turns on JH-controlled genes by directly binding to E-box-like motifs in their regulatory regions. However, it remains unclear how JH represses genes. We used the Aedes aegypti female mosquito, in which JH is necessary for reproductive maturation, to show that a repressor, Hairy, is required for the gene-repressive action of JH and Met. The RNA interference (RNAi) screen for Met and Hairy in the Aedes female fat body revealed a large cohort of Met- and Hairy-corepressed genes. Analysis of selected genes from this cohort demonstrated that they are repressed by JH, but RNAi of either Met or Hairy renders JH ineffective in repressing these genes in an in vitro fat-body culture assay. Moreover, this JH action was prevented by the addition of the translational inhibitor cycloheximide (CHX) to the culture, indicating the existence of an indirect regulatory hierarchy. The lack of Hairy protein in the CHX-treated tissue was verified using immunoblot analysis, and the upstream regions of Met/Hairy-corepressed genes were shown to contain common binding motifs that interact with Hairy. Groucho (gro) RNAi silencing phenocopied the effect of Hairy RNAi knockdown, indicating that it is involved in the JH/Met/Hairy hierarchy. Finally, the requirement of Hairy and Gro for gene repression was confirmed in a cell transfection assay. Thus, our study has established that Hairy and its cofactor Gro mediate the repressive function of JH and Met. PMID:26744312

  19. Properties and sequence of a female-specific, juvenile hormone-induced protein from locust hemolymph.

    PubMed

    Zhang, J; McCracken, A; Wyatt, G R

    1993-02-15

    In the fat body of Locusta migratoria, an RNA transcript of about 800 nucleotides has been detected that is specific to the adult female and dependent on induction by juvenile hormone (JH) or an analog. The corresponding cDNA has been cloned (lambda 21) and a 718-base pair sequence determined. It encodes a 196-amino acid polypeptide, including a signal peptide. An NH2-terminal sequence has 24 out of 28 amino acids identical with those of a previously described 19K locust hemolymph protein, but the remainder of the sequence shows no similarity. From adult female hemolymph, a 21-kDa protein, designated 21K protein, has been purified, with an NH2-terminal sequence exactly matching that deduced from clone lambda 21. This 21K protein is found only in the adult female, is dependent on induction by JH, and is assumed to represent the product of the lambda 21 gene. It shows no immunochemical cross-reaction with locust 19K protein, apolipophorin III, nor with vitellogenin (Vg). Its isoelectric point is pH 5.4; it contains some carbohydrate. 21K protein is synthesized in adult female fat body, accumulates in hemolymph, and is taken up into the developing oocytes in parallel with Vg. In locusts deprived of JH with precocene, production of 21K protein and of lambda 21-hybridizing transcripts is induced by the JH analog, methoprene, in parallel with Vg and its mRNA. Because of its sex-, stage-, and JH-dependent regulation, coordinate with Vg, the 21K protein will be valuable for analysis of gene expression. PMID:7679110

  20. Juvenile hormone, reproduction, and worker behavior in the neotropical social wasp Polistes canadensis

    PubMed Central

    Giray, Tugrul; Giovanetti, Manuela; West-Eberhard, Mary Jane

    2005-01-01

    Previous studies of the division of labor in colonies of eusocial Hymenoptera (wasps and bees) have led to two hypotheses regarding the evolution of juvenile hormone (JH) involvement. The novel- or single-function hypothesis proposes that the role of JH has changed from an exclusively reproductive function in primitively eusocial species (those lacking morphologically distinct queen and worker castes), to an exclusively behavioral function in highly eusocial societies (those containing morphologically distinct castes). In contrast, the split-function hypothesis proposes that JH originally functioned in the regulation of both reproduction and behavior in ancestral solitary species. Then, when reproductive and brood-care tasks came to be divided between queens and workers, the effects of JH were divided as well, with JH involved in regulation of reproductive maturation of egg-laying queens, and behavioral maturation, manifested as age-correlated changes in worker tasks, of workers. We report experiments designed to test these hypotheses. After documenting age-correlated changes in worker behavior (age polyethism) in the neotropical primitively eusocial wasp Polistes canadensis, we demonstrate that experimental application of the JH analog methoprene accelerates the onset of guarding behavior, an age-correlated task, and increases the number of foraging females; and we demonstrate that JH titers correlate with both ovarian development of queens and task differentiation in workers, as predicted by the split-function hypothesis. These findings support a view of social insect evolution that sees the contrasting worker and queen phenotypes as derived via decoupling of reproductive and brood-care components of the ancestral solitary reproductive physiology. PMID:15728373

  1. Hairy and Groucho mediate the action of juvenile hormone receptor Methoprene-tolerant in gene repression

    PubMed Central

    Saha, Tusar T.; Shin, Sang Woon; Dou, Wei; Roy, Sourav; Zhao, Bo; Hou, Yuan; Wang, Xue-Li; Zou, Zhen; Girke, Thomas; Raikhel, Alexander S.

    2016-01-01

    The arthropod-specific juvenile hormone (JH) controls numerous essential functions. Its involvement in gene activation is known to be mediated by the transcription factor Methoprene-tolerant (Met), which turns on JH-controlled genes by directly binding to E-box–like motifs in their regulatory regions. However, it remains unclear how JH represses genes. We used the Aedes aegypti female mosquito, in which JH is necessary for reproductive maturation, to show that a repressor, Hairy, is required for the gene-repressive action of JH and Met. The RNA interference (RNAi) screen for Met and Hairy in the Aedes female fat body revealed a large cohort of Met- and Hairy-corepressed genes. Analysis of selected genes from this cohort demonstrated that they are repressed by JH, but RNAi of either Met or Hairy renders JH ineffective in repressing these genes in an in vitro fat-body culture assay. Moreover, this JH action was prevented by the addition of the translational inhibitor cycloheximide (CHX) to the culture, indicating the existence of an indirect regulatory hierarchy. The lack of Hairy protein in the CHX-treated tissue was verified using immunoblot analysis, and the upstream regions of Met/Hairy-corepressed genes were shown to contain common binding motifs that interact with Hairy. Groucho (gro) RNAi silencing phenocopied the effect of Hairy RNAi knockdown, indicating that it is involved in the JH/Met/Hairy hierarchy. Finally, the requirement of Hairy and Gro for gene repression was confirmed in a cell transfection assay. Thus, our study has established that Hairy and its cofactor Gro mediate the repressive function of JH and Met. PMID:26744312

  2. Juvenile hormone-activated phospholipase C pathway enhances transcriptional activation by the methoprene-tolerant protein

    PubMed Central

    Liu, Pengcheng; Peng, Hong-Juan; Zhu, Jinsong

    2015-01-01

    Juvenile hormone (JH) is a key regulator of a wide diversity of developmental and physiological events in insects. Although the intracellular JH receptor methoprene-tolerant protein (MET) functions in the nucleus as a transcriptional activator for specific JH-regulated genes, some JH responses are mediated by signaling pathways that are initiated by proteins associated with plasma membrane. It is unknown whether the JH-regulated gene expression depends on the membrane-mediated signal transduction. In Aedes aegypti mosquitoes, we found that JH activated the phospholipase C (PLC) pathway and quickly increased the levels of inositol 1,4,5-trisphosphate, diacylglycerol, and intracellular calcium, leading to activation and autophosphorylation of calcium/calmodulin-dependent protein kinase II (CaMKII). When abdomens from newly emerged mosquitoes were cultured in vitro, the JH-activated gene expression was repressed substantially if specific inhibitors of PLC or CaMKII were added to the medium together with JH. In newly emerged female mosquitoes, RNAi-mediated depletion of PLC or CaMKII considerably reduced the expression of JH-responsive genes, including the Krüppel homolog 1 gene (AaKr-h1) and the early trypsin gene (AaET). JH-induced loading of MET to the promoters of AaKr-h1 and AaET was weakened drastically when either PLC or CaMKII was inactivated in the cultured tissues. Therefore, the results suggest that the membrane-initiated signaling pathway modifies the DNA-binding activity of MET via phosphorylation and thus facilitates the genomic responses to JH. In summary, this study reveals an interplay of genomic and nongenomic signaling mechanisms of JH. PMID:25825754

  3. MiR-2 family regulates insect metamorphosis by controlling the juvenile hormone signaling pathway.

    PubMed

    Lozano, Jesus; Montañez, Raúl; Belles, Xavier

    2015-03-24

    In 2009 we reported that depletion of Dicer-1, the enzyme that catalyzes the final step of miRNA biosynthesis, prevents metamorphosis in Blattella germanica. However, the precise regulatory roles of miRNAs in the process have remained elusive. In the present work, we have observed that Dicer-1 depletion results in an increase of mRNA levels of Krüppel homolog 1 (Kr-h1), a juvenile hormone-dependent transcription factor that represses metamorphosis, and that depletion of Kr-h1 expression in Dicer-1 knockdown individuals rescues metamorphosis. We have also found that the 3'UTR of Kr-h1 mRNA contains a functional binding site for miR-2 family miRNAs (for miR-2, miR-13a, and miR-13b). These data suggest that metamorphosis impairment caused by Dicer-1 and miRNA depletion is due to a deregulation of Kr-h1 expression and that this deregulation is derived from a deficiency of miR-2 miRNAs. We corroborated this by treating the last nymphal instar of B. germanica with an miR-2 inhibitor, which impaired metamorphosis, and by treating Dicer-1-depleted individuals with an miR-2 mimic to allow nymphal-to-adult metamorphosis to proceed. Taken together, the data indicate that miR-2 miRNAs scavenge Kr-h1 transcripts when the transition from nymph to adult should be taking place, thus crucially contributing to the correct culmination of metamorphosis.

  4. TGF-β signaling in insects regulates metamorphosis via juvenile hormone biosynthesis

    PubMed Central

    Ishimaru, Yoshiyasu; Tomonari, Sayuri; Matsuoka, Yuji; Watanabe, Takahito; Miyawaki, Katsuyuki; Bando, Tetsuya; Tomioka, Kenji; Ohuchi, Hideyo; Noji, Sumihare; Mito, Taro

    2016-01-01

    Although butterflies undergo a dramatic morphological transformation from larva to adult via a pupal stage (holometamorphosis), crickets undergo a metamorphosis from nymph to adult without formation of a pupa (hemimetamorphosis). Despite these differences, both processes are regulated by common mechanisms that involve 20-hydroxyecdysone (20E) and juvenile hormone (JH). JH regulates many aspects of insect physiology, such as development, reproduction, diapause, and metamorphosis. Consequently, strict regulation of JH levels is crucial throughout an insect’s life cycle. However, it remains unclear how JH synthesis is regulated. Here, we report that in the corpora allata of the cricket, Gryllus bimaculatus, Myoglianin (Gb’Myo), a homolog of Drosophila Myoglianin/vertebrate GDF8/11, is involved in the down-regulation of JH production by suppressing the expression of a gene encoding JH acid O-methyltransferase, Gb’jhamt. In contrast, JH production is up-regulated by Decapentaplegic (Gb’Dpp) and Glass-bottom boat/60A (Gb’Gbb) signaling that occurs as part of the transcriptional activation of Gb’jhamt. Gb’Myo defines the nature of each developmental transition by regulating JH titer and the interactions between JH and 20E. When Gb’myo expression is suppressed, the activation of Gb’jhamt expression and secretion of 20E induce molting, thereby leading to the next instar before the last nymphal instar. Conversely, high Gb’myo expression induces metamorphosis during the last nymphal instar through the cessation of JH synthesis. Gb’myo also regulates final insect size. Because Myo/GDF8/11 and Dpp/bone morphogenetic protein (BMP)2/4-Gbb/BMP5–8 are conserved in both invertebrates and vertebrates, the present findings provide common regulatory mechanisms for endocrine control of animal development. PMID:27140602

  5. TGF-β signaling in insects regulates metamorphosis via juvenile hormone biosynthesis.

    PubMed

    Ishimaru, Yoshiyasu; Tomonari, Sayuri; Matsuoka, Yuji; Watanabe, Takahito; Miyawaki, Katsuyuki; Bando, Tetsuya; Tomioka, Kenji; Ohuchi, Hideyo; Noji, Sumihare; Mito, Taro

    2016-05-17

    Although butterflies undergo a dramatic morphological transformation from larva to adult via a pupal stage (holometamorphosis), crickets undergo a metamorphosis from nymph to adult without formation of a pupa (hemimetamorphosis). Despite these differences, both processes are regulated by common mechanisms that involve 20-hydroxyecdysone (20E) and juvenile hormone (JH). JH regulates many aspects of insect physiology, such as development, reproduction, diapause, and metamorphosis. Consequently, strict regulation of JH levels is crucial throughout an insect's life cycle. However, it remains unclear how JH synthesis is regulated. Here, we report that in the corpora allata of the cricket, Gryllus bimaculatus, Myoglianin (Gb'Myo), a homolog of Drosophila Myoglianin/vertebrate GDF8/11, is involved in the down-regulation of JH production by suppressing the expression of a gene encoding JH acid O-methyltransferase, Gb'jhamt In contrast, JH production is up-regulated by Decapentaplegic (Gb'Dpp) and Glass-bottom boat/60A (Gb'Gbb) signaling that occurs as part of the transcriptional activation of Gb'jhamt Gb'Myo defines the nature of each developmental transition by regulating JH titer and the interactions between JH and 20E. When Gb'myo expression is suppressed, the activation of Gb'jhamt expression and secretion of 20E induce molting, thereby leading to the next instar before the last nymphal instar. Conversely, high Gb'myo expression induces metamorphosis during the last nymphal instar through the cessation of JH synthesis. Gb'myo also regulates final insect size. Because Myo/GDF8/11 and Dpp/bone morphogenetic protein (BMP)2/4-Gbb/BMP5-8 are conserved in both invertebrates and vertebrates, the present findings provide common regulatory mechanisms for endocrine control of animal development. PMID:27140602

  6. Characterization of two juvenile hormone epoxide hydrolases by RNA interference in the Colorado potato beetle.

    PubMed

    Lü, Feng-Gong; Fu, Kai-Yun; Guo, Wen-Chao; Li, Guo-Qing

    2015-10-10

    In insect, juvenile hormone (JH) titers are tightly regulated in different development stages through synthesis and degradation pathways. During JH degradation, JH epoxide hydrolase (JHEH) converts JH to JH diol, and hydrolyses JH acid to JH acid diol. In this study, two full length LdJHEH cDNAs were cloned from Leptinotarsa decemlineata, and were provisionally designated LdJHEH1 and LdJHEH2. Both mRNAs were detectable in the thoracic muscles, brain-corpora cardiaca-corpora allata complex, foregut, midgut, hindgut, ventral ganglia, Malpighian tubules, fat bodies, epidermis, and hemocytes of the day 2 fourth-instar larvae, and in female ovaries as well as male reproductive organs of the adults. Moreover, both LdJHEH1 and LdJHEH2 were expressed throughout all larval life, with the highest peaks occurring 32h after ecdysis of the final (fourth) instar larvae. Four double-stranded RNAs (dsRNAs) (dsJHEH1-1, dsJHEH1-2, dsJHEH2-1, dsJHEH2-2) respectively targeting LdJHEH1 and LdJHEH2 were constructed and bacterially expressed. Ingestion of dsJHEH1-1, dsJHEH1-2, dsJHEH2-1, dsJHEH2-2, and a mixture of dsJHEH1-1+dsJHEH2-1 successfully knocked down corresponding target gene function, and significantly increased JH titer and upregulated Krüppel homolog 1 (LdKr-h1) mRNA level. Knockdown of either LdJHEH1 or LdJHEH2, or both genes slightly reduced larval weight and delayed larval development, and significantly impaired adult emergence. Therefore, it is suggested that knockdown LdJHEH1 and LdJHEH2 affected JH degradation in the Colorado potato beetle.

  7. Influences of Neighborhood Context, Individual History and Parenting Behavior on Recidivism among Juvenile Offenders

    ERIC Educational Resources Information Center

    Grunwald, Heidi E.; Lockwood, Brian; Harris, Philip W.; Mennis, Jeremy

    2010-01-01

    This study examined the effects of neighborhood context on juvenile recidivism to determine if neighborhoods influence the likelihood of reoffending. Although a large body of literature exists regarding the impact of environmental factors on delinquency, very little is known about the effects of these factors on juvenile recidivism. The sample…

  8. The influence of growth hormone on bone and adipose programming.

    PubMed

    Oberbauer, Anita M

    2014-01-01

    In utero growth hormone exposure is associated with distinct immediate growth responses and long term impacts on adult physiological parameters that include obesity, insulin resistance, and bone function. Growth hormone accelerates cellular proliferation in many tissues but is exemplified by increases in the number of cells within the cartilaginous growth plate of bone. In some cases growth hormone also potentiates differentiation as seen in the differentiation of adipocytes that rapidly fill upon withdrawal of growth hormone. Growth hormone provokes these changes either by direct action or through intermediaries such as insulin-like growth factor-I and other downstream effector molecules. The specific mechanism used by growth hormone in programming tissues is not yet fully characterized and likely represents a multipronged approach involving DNA modification, altered adult hormonal milieu, and the development of an augmented stem cell pool capable of future engagement as is seen in adipose accrual. This review summarizes findings of growth hormone's influence on in utero and neonatal cellular and metabolic profiles related to bone and adipose tissue.

  9. The competitive ability and fitness components of the Methoprene-tolerant (Met) Drosophila mutant resistant to juvenile hormone analog insecticides.

    PubMed

    Minkoff, C; Wilson, T G

    1992-05-01

    The Methoprene-tolerant (Met) mutation of Drosophila melanogaster results in a high (100-fold) level of resistance to the insecticide methoprene, a chemical analog of juvenile hormone. Pest species that are under control with methoprene may therefore have the potential to evolve resistance via a mutation homologous to Met. To evaluate the potential of such mutants to persist in wild populations, we must understand the fitness of flies carrying Met. In the absence of methoprene, Met flies were outcompeted by a wild-type strain both in a multigeneration population cage and in single-generation competition experiments. To determine which fitness component(s) is responsible for the competitive disadvantage, the survival, time of development, and fecundity of flies homozygous for each of five Met alleles were compared with wild type. Small but significant differences were found between the pooled Met alleles and wild type for pupal development time, pupal mortality, and early adult fecundity. These differences result in a large competitive disadvantage. Although Met flies were found to have reduced fitness by these measures, the phenotype is not as severe as might be expected from a knowledge of the disruption of juvenile hormone regulation seen in Met flies. It is concluded that (1) although Met flies have a large advantage under methoprene selection, they will quickly become outcompeted upon relaxation of methoprene usage, (2) even a seemingly severe disruption of juvenile hormone regulation has no drastic effect on the vital functions of the insect and (3) small differences in fitness components can translate into a large competitive disadvantage.

  10. Pleiotropic effects of juvenile hormone in ant queens and the escape from the reproduction-immunocompetence trade-off.

    PubMed

    Pamminger, Tobias; Treanor, David; Hughes, William O H

    2016-01-13

    The ubiquitous trade-off between survival and costly reproduction is one of the most fundamental constraints governing life-history evolution. In numerous animals, gonadotropic hormones antagonistically suppressing immunocompetence cause this trade-off. The queens of many social insects defy the reproduction-survival trade-off, achieving both an extraordinarily long life and high reproductive output, but how they achieve this is unknown. Here we show experimentally, by integrating quantification of gene expression, physiology and behaviour, that the long-lived queens of the ant Lasius niger have escaped the reproduction-immunocompetence trade-off by decoupling the effects of a key endocrine regulator of fertility and immunocompetence in solitary insects, juvenile hormone (JH). This modification of the regulatory architecture enables queens to sustain a high reproductive output without elevated JH titres and suppressed immunocompetence, providing an escape from the reproduction-immunocompetence trade-off that may contribute to the extraordinary lifespan of many social insect queens.

  11. The influence of hormone therapies on colon and rectal cancer.

    PubMed

    Mørch, Lina Steinrud; Lidegaard, Øjvind; Keiding, Niels; Løkkegaard, Ellen; Kjær, Susanne Krüger

    2016-05-01

    Exogenous sex hormones seem to play a role in colorectal carcinogenesis. Little is known about the influence of different types or durations of postmenopausal hormone therapy (HT) on colorectal cancer risk. A nationwide cohort of women 50-79 years old without previous cancer (n = 1,006,219) were followed 1995-2009. Information on HT exposures was from the National Prescription Register and updated daily, while information on colon (n = 8377) and rectal cancers (n = 4742) were from the National Cancer Registry. Potential confounders were obtained from other national registers. Poisson regression analyses with 5-year age bands included hormone exposures as time-dependent covariates. Use of estrogen-only therapy and combined therapy were associated with decreased risks of colon cancer (adjusted incidence rate ratio 0.77, 95 % confidence interval 0.68-0.86 and 0.88, 0.80-0.96) and rectal cancer (0.83, 0.72-0.96 and 0.89, 0.80-1.00), compared to never users. Transdermal estrogen-only therapy implied more protection than oral administration, while no significant influence was found of regimen, progestin type, nor of tibolone. The benefit of HT was stronger for long-term hormone users; and hormone users were at lower risk of advanced stage of colorectal cancer, which seems supportive for a causal association between hormone therapy and colorectal cancer. PMID:26758900

  12. Influence of prostaglandins and thyrotropin releasing hormone (TRH) on hormone secretion and growth in wether lambs.

    PubMed

    Davis, S L; Anfinson, M S; Klindt, J; Ohlson, D L

    1977-06-01

    A series of experiments were conducted in ewes and whether (castrate male) lambs to evaluate the influence of prostaglandins on secretion of anabolic hormones and to determine if repeated injections of prostaglandin (PG) F2alpha would chronically influence the secretion of these hormones and perhaps growth rate as well. A single intravenous injection of PGA1 and PGB1 (100 microgram/kg) exerted no significant (P greater than .10) influence on plasma concentrations of prolactin (PRL), growth hormone (GH) or thyrotropin (TSH) in ewes. PGA1, but not PGB1, stimulated an increase in the plasma concentration of insulin. Infusion of PGF2alpha for 5.5 hr into ewes resulted in increased (P less than .05) plasma concentrations of both GH and ARL while TSH and insulin were not significantly influenced. Prostaglandin F2alpha, when injected subcutaneously into wether lambs (10 mg twice weekly) stimulated (P less than .05) plasma GH concentrations after the first injection, but not after 3 weeks of treatment. Changes in plasma PRL or TSH were not observed consistently in the lambs treated chronically with PGF2alpha or TRH. Prostaglandin F2alpha, in the present studies, and PGE1 in previously reported studies (1-3), has been demonstrated to be stimulatory to the secretion of PRL and GH. In contrast, PGA1 and PGB1, which lack an 11-hydroxyl group, failed to influence the secretion of either PRL or GH. It would, therefore, appear that the 11-hydroxyl group is a structural requirement for prostaglandins to influence the secretion of these two hormones in sheep. Treatment with thyrotropin releasing hormone (TRH), alone or in combination with PGF 2alpha, significantly (P less than .05) increased growth rate (average daily gains) while PGF2alpha did not, despite the fact that both compounds exerted similar effects on plasma GH.

  13. Nutritional Signaling Regulates Vitellogenin Synthesis and Egg Development through Juvenile Hormone in Nilaparvata lugens (Stål)

    PubMed Central

    Lu, Kai; Chen, Xia; Liu, Wen-Ting; Zhang, Xin-Yu; Chen, Ming-Xiao; Zhou, Qiang

    2016-01-01

    Insect female reproduction which comprises the synthesis of vitellogenein (Vg) in the fat body and its incorporation into developing oocytes, needs a large amount of energy and food resources. Our previous studies found that juvenile hormone (JH) regulates vitellogenesis in the brown planthopper, Nilaparvata lugens. Here, we report on the role of JH in nutrient-regulated Vg synthesis and egg development. We first cloned the genes coding for juvenile hormone acid methyltransferase (JHAMT) which is involved in JH biosynthesis and methoprene-tolerant (Met) for JH action. Amino acids (AAs) induced the expression of jmtN, while showing no effects on the expression of met using an artificial diet culture system. Reduction in JH biosynthesis or its action by RNA interference (RNAi)-mediated silencing of jmtN or met led to a severe inhibition of AAs-induced Vg synthesis and oocyte maturation, together with lower fecundity. Furthermore, exogenous application of JH III partially restored Vg expression levels in jmtN RNAi females. However, JH III application did not rescue Vg synthesis in these met RNAi insects. Our results show that AAs induce Vg synthesis in the fat body and egg development in concert with JH biosynthesis in Nilaparvata lugens (Stål), rather than through JH action. PMID:26927076

  14. TOR Pathway-Mediated Juvenile Hormone Synthesis Regulates Nutrient-Dependent Female Reproduction in Nilaparvata lugens (Stål).

    PubMed

    Lu, Kai; Chen, Xia; Liu, Wen-Ting; Zhou, Qiang

    2016-01-01

    The "target of rapamycin" (TOR) nutritional signaling pathway and juvenile hormone (JH) regulation of vitellogenesis has been known for a long time. However, the interplay between these two pathways regulating vitellogenin (Vg) expression remains obscure. Here, we first demonstrated the key role of amino acids (AAs) in activation of Vg synthesis and egg development in Nilaparvata lugens using chemically defined artificial diets. AAs induced the expression of TOR and S6K (S6 kinase), whereas RNAi-mediated silencing of these two TOR pathway genes and rapamycin application strongly inhibited the AAs-induced Vg synthesis. Furthermore, knockdown of Rheb (Ras homologue enriched in brain), TOR, S6K and application of rapamycin resulted in a dramatic reduction in the mRNA levels of jmtN (juvenile hormone acid methyltransferase, JHAMT). Application of JH III on the RNAi (Rheb and TOR) and rapamycin-treated females partially rescued the Vg expression. Conversely, knockdown of either jmtN or met (methoprene-tolerant, JH receptor) and application of JH III had no effects on mRNA levels of Rheb, TOR and S6K and phosphorylation of S6K. In summary, our results demonstrate that the TOR pathway induces JH biosynthesis that in turn regulates AAs-mediated Vg synthesis in N. lugens. PMID:27043527

  15. TOR Pathway-Mediated Juvenile Hormone Synthesis Regulates Nutrient-Dependent Female Reproduction in Nilaparvata lugens (Stål)

    PubMed Central

    Lu, Kai; Chen, Xia; Liu, Wen-Ting; Zhou, Qiang

    2016-01-01

    The “target of rapamycin” (TOR) nutritional signaling pathway and juvenile hormone (JH) regulation of vitellogenesis has been known for a long time. However, the interplay between these two pathways regulating vitellogenin (Vg) expression remains obscure. Here, we first demonstrated the key role of amino acids (AAs) in activation of Vg synthesis and egg development in Nilaparvata lugens using chemically defined artificial diets. AAs induced the expression of TOR and S6K (S6 kinase), whereas RNAi-mediated silencing of these two TOR pathway genes and rapamycin application strongly inhibited the AAs-induced Vg synthesis. Furthermore, knockdown of Rheb (Ras homologue enriched in brain), TOR, S6K and application of rapamycin resulted in a dramatic reduction in the mRNA levels of jmtN (juvenile hormone acid methyltransferase, JHAMT). Application of JH III on the RNAi (Rheb and TOR) and rapamycin-treated females partially rescued the Vg expression. Conversely, knockdown of either jmtN or met (methoprene-tolerant, JH receptor) and application of JH III had no effects on mRNA levels of Rheb, TOR and S6K and phosphorylation of S6K. In summary, our results demonstrate that the TOR pathway induces JH biosynthesis that in turn regulates AAs-mediated Vg synthesis in N. lugens. PMID:27043527

  16. TOR Pathway-Mediated Juvenile Hormone Synthesis Regulates Nutrient-Dependent Female Reproduction in Nilaparvata lugens (Stål).

    PubMed

    Lu, Kai; Chen, Xia; Liu, Wen-Ting; Zhou, Qiang

    2016-03-28

    The "target of rapamycin" (TOR) nutritional signaling pathway and juvenile hormone (JH) regulation of vitellogenesis has been known for a long time. However, the interplay between these two pathways regulating vitellogenin (Vg) expression remains obscure. Here, we first demonstrated the key role of amino acids (AAs) in activation of Vg synthesis and egg development in Nilaparvata lugens using chemically defined artificial diets. AAs induced the expression of TOR and S6K (S6 kinase), whereas RNAi-mediated silencing of these two TOR pathway genes and rapamycin application strongly inhibited the AAs-induced Vg synthesis. Furthermore, knockdown of Rheb (Ras homologue enriched in brain), TOR, S6K and application of rapamycin resulted in a dramatic reduction in the mRNA levels of jmtN (juvenile hormone acid methyltransferase, JHAMT). Application of JH III on the RNAi (Rheb and TOR) and rapamycin-treated females partially rescued the Vg expression. Conversely, knockdown of either jmtN or met (methoprene-tolerant, JH receptor) and application of JH III had no effects on mRNA levels of Rheb, TOR and S6K and phosphorylation of S6K. In summary, our results demonstrate that the TOR pathway induces JH biosynthesis that in turn regulates AAs-mediated Vg synthesis in N. lugens.

  17. No effect of juvenile hormone on task performance in a bumblebee (Bombus terrestris) supports an evolutionary link between endocrine signaling and social complexity.

    PubMed

    Shpigler, Hagai Y; Siegel, Adam J; Huang, Zachary Y; Bloch, Guy

    2016-09-01

    A hallmark of insect societies is a division of labor among workers specializing in different tasks. In bumblebees the division of labor is related to body size; relatively small workers are more likely to stay inside the nest and tend ("nurse") brood, whereas their larger sisters are more likely to forage. Despite their ecological and economic importance, very little is known about the endocrine regulation of division of labor in bumblebees. We studied the influence of juvenile hormone (JH) on task performance in the bumblebee Bombus terrestris. We first used a radioimmunoassay to measure circulating JH titers in workers specializing in nursing and foraging activities. Next, we developed new protocols for manipulating JH titers by combining a size-adjusted topical treatment with the allatotoxin Precocene-I and replacement therapy with JH-III. Finally, we used this protocol to test the influence of JH on task performance. JH levels were either similar for nurses and foragers (three colonies), or higher in nurses (two colonies). Nurses had better developed ovaries and JH levels were typically positively correlated with ovarian state. Manipulation of JH titers influenced ovarian development and wax secretion, consistent with earlier allatectomy studies. These manipulations however, did not affect nursing or foraging activity, or the likelihood to specialize in nursing or foraging activity. These findings contrast with honeybees in which JH influences age-related division of labor but not adult female fertility. Thus, the evolution of complex societies in bees was associated with modifications in the way JH influences social behavior.

  18. Developmental abnormalities of the gonad and abnormal sex hormone concentrations in juvenile alligators from contaminated and control lakes in Florida.

    PubMed Central

    Guillette, L J; Gross, T S; Masson, G R; Matter, J M; Percival, H F; Woodward, A R

    1994-01-01

    The reproductive development of alligators from a contaminated and a control lake in central Florida was examined. Lake Apopka is adjacent to an EPA Superfund site, listed due to an extensive spill of dicofol and DDT or its metabolites. These compounds can act as estrogens. Contaminants in the lake also have been derived from extensive agricultural activities around the lake that continue today and a sewage treatment facility associated with the city of Winter Garden, Florida. We examined the hypothesis that an estrogenic contaminant has caused the current failure in recruitment of alligators on Lake Apopka. Supporting data include the following: At 6 months of age, female alligators from Lake Apopka had plasma estradiol-17 beta concentrations almost two times greater than normal females from the control lake, Lake Woodruff. The Apopka females exhibited abnormal ovarian morphology with large numbers of polyovular follicles and polynuclear oocytes. Male juvenile alligators had significantly depressed plasma testosterone concentrations comparable to levels observed in normal Lake Woodruff females but more than three times lower than normal Lake Woodruff males. Additionally, males from Lake Apopka had poorly organized testes and abnormally small phalli. The differences between lakes and sexes in plasma hormone concentrations of juvenile alligators remain even after stimulation with luteinizing hormone. Our data suggest that the gonads of juveniles from Lake Apopka have been permanently modified in ovo, so that normal steroidogenesis is not possible, and thus normal sexual maturation is unlikely. Images p680-a Figure 1. Figure 2. Figure 3. A Figure 3. B Figure 3. C Figure 4. A Figure 4. B Figure 4. C Figure 4. D Figure 5. A Figure 5. B Figure 5. C PMID:7895709

  19. Gender Differences in Cardiovascular Disease: Hormonal and Biochemical Influences

    PubMed Central

    Pérez-López, Faustino R.; Larrad-Mur, Luis; Kallen, Amanda; Chedraui, Peter; Taylor, Hugh S.

    2011-01-01

    Objective Atherosclerosis is a complex process characterized by an increase in vascular wall thickness owing to the accumulation of cells and extracellular matrix between the endothelium and the smooth muscle cell wall. There is evidence that females are at lower risk of developing cardiovascular disease (CVD) as compared to males. This has led to an interest in examining the contribution of genetic background and sex hormones to the development of CVD. The objective of this review is to provide an overview of factors, including those related to gender, that influence CVD. Methods Evidence analysis from PubMed and individual searches concerning biochemical and endocrine influences and gender differences, which affect the origin and development of CVD. Results Although still controversial, evidence suggests that hormones including estradiol and androgens are responsible for subtle cardiovascular changes long before the development of overt atherosclerosis. Conclusion Exposure to sex hormones throughout an individual's lifespan modulates many endocrine factors involved in atherosclerosis. PMID:20460551

  20. Evolutionary genetics of juvenile hormone and ecdysteroid regulation in Gryllus: a case study in the microevolution of endocrine regulation.

    PubMed

    Zera, Anthony J

    2006-07-01

    During the past 15 years the first detailed synthesis of endocrinology and population genetics has begun, in which natural genetic variations for endocrine regulators have been characterized, almost exclusively in species of the cricket genus Gryllus. Artificial selection studies have documented that regulators of the juvenile hormone titer can rapidly evolve and exhibit levels of genetic variability similar to other physiological traits. Strong genetic correlations exist between some but not all regulators of the JH titer during the juvenile stage. No genetic correlation exists between regulators functioning in juvenile and adult stages, and thus, endocrine regulation can evolve independently in these stages. Genetic variation in the JH titer, the ecdysteroid titer, and JHE activity, in adult and juvenile stages, have been documented in genetic stocks of wing-polymorphic crickets; morph-specific differences in these endocrine traits are potentially responsible for genetically based differences in aspects of wing and flight muscle development, adult egg production, and adult dispersal. An unexpected morph-specific, genetic polymorphism for a circadian rhythm for the JH titer was observed in both the laboratory and field. Few comparable studies exist in non-Gryllus species, in which in vivo endocrine-genetic variation has been directly quantified using reliable analytical methods; many reported cases of endocrine variation in these species have been obtained using an inappropriate method and thus should be considered unsubstantiated. Obtaining basic information on the characteristics of natural genetic variation for endocrine regulators still remains one of the most important tasks of the fledgling subdiscipline of evolutionary endocrinology. Single gene endocrine mutants in Drosophila are promising candidates for investigating molecular-genetic variation in natural populations. Future studies should also focus on endocrine traits studied in the field and geographic

  1. Nutrition-dependent fertility response to juvenile hormone in non-social Euodynerus foraminatus wasps and the evolutionary origin of sociality.

    PubMed

    Tibbetts, Elizabeth A; Mettler, Alexander; Donajkowski, Kellie

    2013-03-01

    The reproductive ground plan hypothesis (RGPH) proposes that the ovarian cycle in solitary insects provides the basis for social evolution, so similar mechanisms are predicted to influence reproductive plasticity in social and solitary species. Specifically, reproductive plasticity in social species originated via modification of nutrition-dependent fertility response to juvenile hormone (JH) in solitary insects. Testing this prediction requires information about the factors that influence fertility in non-social relatives of the eusocial hymenoptera. However, no previous studies have examined how JH or nutritional condition influence fertility in Eumenines, the non-social group most closely related to social wasps. Here, we find support for the RGPH, as JH increases Euodynerus foraminatus fertility. Fertility is also condition-dependent, as heavy E. foraminatus are more fertile than light E. foraminatus. In addition, we measure the factors associated with mating success in E. foraminatus, finding that multiple factors influence mating success, including male weight, male mating experience, and female age. There is also higher variance in male than female reproductive success, suggesting that males may experience substantial sexual selection in this species. Overall, the relationships between JH, body weight, and fertility in E. foraminatus support the RGPH for the origin of sociality by demonstrating that there are strong parallels in the mechanisms that mediate fertility of social and non-social wasps. PMID:23247338

  2. Nutrition-dependent fertility response to juvenile hormone in non-social Euodynerus foraminatus wasps and the evolutionary origin of sociality.

    PubMed

    Tibbetts, Elizabeth A; Mettler, Alexander; Donajkowski, Kellie

    2013-03-01

    The reproductive ground plan hypothesis (RGPH) proposes that the ovarian cycle in solitary insects provides the basis for social evolution, so similar mechanisms are predicted to influence reproductive plasticity in social and solitary species. Specifically, reproductive plasticity in social species originated via modification of nutrition-dependent fertility response to juvenile hormone (JH) in solitary insects. Testing this prediction requires information about the factors that influence fertility in non-social relatives of the eusocial hymenoptera. However, no previous studies have examined how JH or nutritional condition influence fertility in Eumenines, the non-social group most closely related to social wasps. Here, we find support for the RGPH, as JH increases Euodynerus foraminatus fertility. Fertility is also condition-dependent, as heavy E. foraminatus are more fertile than light E. foraminatus. In addition, we measure the factors associated with mating success in E. foraminatus, finding that multiple factors influence mating success, including male weight, male mating experience, and female age. There is also higher variance in male than female reproductive success, suggesting that males may experience substantial sexual selection in this species. Overall, the relationships between JH, body weight, and fertility in E. foraminatus support the RGPH for the origin of sociality by demonstrating that there are strong parallels in the mechanisms that mediate fertility of social and non-social wasps.

  3. Effects of juvenile hormone (JH) analog insecticides on larval development and JH esterase activity in two spodopterans.

    PubMed

    El-Sheikh, El-Sayed A; Kamita, Shizuo G; Hammock, Bruce D

    2016-03-01

    Juvenile hormone analog (JHA) insecticides are biological and structural mimics of JH, a key insect developmental hormone. Toxic and anti-developmental effects of the JHA insecticides methoprene, fenoxycarb, and pyriproxyfen were investigated on the larval and pupal stages of Spodoptera littoralis and Spodoptera frugiperda. Bioassays showed that fenoxycarb has the highest toxicity and fastest speed of kill in 2nd instar S. littoralis. All three JHAs affected the development of 6th instar (i.e., final instar) and pupal S. frugiperda. JH esterase (JHE) is a critical enzyme that helps to regulate JH levels during insect development. JHE activity in the last instar S. littoralis and S. frugiperda was 11 and 23 nmol min(-1) ml(-1) hemolymph, respectively. Methoprene and pyriproxyfen showed poor inhibition of JHE activity from these insects, whereas fenoxycarb showed stronger inhibition. The inhibitory activity of fenoxycarb, however, was more than 1000-fold lower than that of OTFP, a highly potent inhibitor of JHEs. Surprisingly, topical application of methoprene, fenoxycarb or pyriproxyfen on 6th instars of S. littoralis and S. frugiperda prevented the dramatic reduction in JHE activity that was found in control insects. Our findings suggest that JHAs may function as JH agonists that play a disruptive role or a hormonal replacement role in S. littoralis and S. frugiperda. PMID:26969437

  4. Hormonal influences on neuroimmune responses in the CNS of females

    PubMed Central

    Monasterio, Nela; Vergara, Edgar; Morales, Teresa

    2014-01-01

    Particular reproductive stages such as lactation impose demands on the female. To cope with these demands, her physiology goes through numerous adaptations, for example, attenuation of immune and stress responses. Hormonal fluctuation during lactation exerts a strong influence, inducing neuroplasticity in the hypothalamus and extrahypothalamic regions, and diminishing the stress and inflammatory responses. Thus, hormones confer decreased vulnerability to the female brain. This mini-review focuses on the adaptations of the immune and stress response during maternity, and on the neuroprotective actions of progesterone and prolactin and their effects on inflammation. The importance of pregnancy and lactation as experimental models to study immune responses and disease is also highlighted. PMID:24478642

  5. VARIATION IN GROWTH, LIPID CLASS AND FATTY ACID COMPOSITION OF THE MUD CRAB, RHITHROPANOPEUS HARRISII (GOULD) DURING LARVAL DEVELOPMENT FOLLOWING EXPOSURE TO AN INSECT JUVENILE HORMONE ANALOG (FENOXYCARB)

    EPA Science Inventory

    This study examines the effects of fenoxycarb?, an insect juvenile hormone analog, on larval growth, and lipid class and fatty acid composition in first crabs of the mud crab Rhithropanopeus harrisii reared through total larval development in nominal water concentrations from 1 ...

  6. Precocene-I inhibits juvenile hormone biosynthesis, ovarian activation, aggression and alters sterility signal production in bumble bee (Bombus terrestris) workers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Juvenile hormone (JH) is an important regulator of development and physiology in insects. While in many insect species, including bumble bees, JH function as gonadotropin in adults, in some highly eusocial insects its role has shifted to regulate social behavior including division of labor, dominanc...

  7. SEX DIFFERENCES AND REPRODUCTIVE HORMONE INFLUENCES ON HUMAN ODOR PERCEPTION

    PubMed Central

    Doty, Richard L.; Cameron, E. Leslie

    2009-01-01

    The question of whether men and women differ in their ability to smell has been the topic of scientific investigation for over a hundred years. Although conflicting findings abound, most studies suggest that, for at least some odorants, women outperform men on tests of odor detection, identification, discrimination, and memory. Most functional imaging and electrophysiological studies similarly imply that, when sex differences are present, they favor women. In this review we examine what is known about sex-related alterations in human smell function, including influences of the menstrual cycle, pregnancy, gonadectomy, and hormone replacement therapy on a range of olfactory measures. We conclude that the relationship between reproductive hormones and human olfactory function is complex and that simple associations between circulating levels of gonadal hormones and measures of olfactory function are rarely present. PMID:19272398

  8. Photoperiod regulates growth of male accessory glands through juvenile hormone signaling in the linden bug, Pyrrhocoris apterus.

    PubMed

    Urbanová, Veronika; Bazalová, Olga; Vaněčková, Hanka; Dolezel, David

    2016-03-01

    Adult reproductive diapause is characterized by lower behavioral activity, ceased reproduction and absence of juvenile hormone (JH). The role of JH receptor Methoprene-tolerant (Met) in female reproduction is well established; however, its function in male reproductive development and behavior is unclear. In the bean bug, Riptortus pedestris, circadian genes are essential for mediating photoperiodically-dependent growth of the male accessory glands (MAGs). The present study explores the role of circadian genes and JH receptor in male diapause in the linden bug, Pyrrhocoris apterus. These data indicate that circadian factors Clock, Cycle and Cry2 are responsible for photoperiod measurement, whereas Met and its partner protein Taiman participate in JH reception. Surprisingly, knockdown of the JH receptor neither lowered locomotor activity nor reduced mating behavior of males. These data suggest existence of a parallel, JH-independent or JH-upstream photoperiodic regulation of reproductive behavior. PMID:26826599

  9. Central administration of corticotropin-releasing hormone alters downstream movement in an artificial stream in juvenile chinook salmon (Oncorhynchus tshawytscha).

    PubMed

    Clements, Shaun; Schreck, Carl B

    2004-05-15

    We evaluated the effect of corticotropin-releasing hormone (CRH) on spatial distribution and downstream movement in an artificial stream in juvenile Chinook salmon (Oncorhynchus tshawytscha) during the period when the fish were able to tolerate seawater. An intracerebroventricular (ICV) injection of CRH (500 ng) to hatchery fish significantly increased the proportion of fish that were distributed downstream of a mid-stream release site. A second group of hatchery fish were given ICV injections of saline (control) or CRH (500 ng) and released near the top of the stream. The time taken to enter a trap at the lower end of the stream was recorded. In all cases the groups given CRH had a higher proportion of fish that did not enter the trap within 60 min of release. However, in those fish that did enter the trap, treatment with CRH increased the speed of downstream movement to this point relative to control fish. Wild sub-yearling Chinook salmon were captured during their downstream migration to the estuary and given ICV injections of saline or CRH (500 ng) either 2, 3, or 7 days after transport from the river. As with hatchery fish, a significantly higher proportion of wild fish that were administered CRH did not enter the trap at the lower end of the stream. The mean time of passage for control fish decreased on each successive day (day 2 > day 3 > day 7). In contrast, the mean passage time of the wild fish that were given CRH was relatively constant through time, and was only significantly faster than control fish on day 2. The current study provides evidence that CRH alters the downstream movement of juvenile Chinook in a simulated stream environment, and produces behavioral effects similar to those of juvenile salmonids that are stressed during their downstream migration. PMID:15094330

  10. Involvement of a putative allatostatin in regulation of juvenile hormone titer and the larval development in Leptinotarsa decemlineata (Say).

    PubMed

    Meng, Qing-Wei; Liu, Xin-Ping; Lü, Feng-Gong; Fu, Kai-Yun; Guo, Wen-Chao; Li, Guo-Qing

    2015-01-01

    Juvenile hormone III (JH III) plays primary roles in regulation of metamorphosis, reproduction and diapause in Leptinotarsa decemlineata, a notorious defoliator of potato. The neurosecretory cell-borne substance(s) negatively affects the final two steps in JH biosynthesis, catalyzed respectively by an epoxidase CYP15A1 and a juvenile hormone acid methyltransferase (JHAMT). In a few insect species other than L. decemlineata, the inhibitory substance is allatostatin (AS) neuropeptide. In this study, two putative AS genes encoding LdAS-C and LdAS-B precursors were cloned. Both LdAS-C and LdAS-B were expressed in the egg, larvae, pupae and adults, and highly expressed in the brain and the gut. Dietary introduction of double-stranded RNAs (dsRNAs) targeting LdAS-C and LdAS-B successfully knocked down respective target genes. Ingestion during 3 and 6 consecutive days of dsLdAS-C significantly increased the LdJHAMT mRNA levels by 3.8 and 9.9 fold respectively. In contrast, ingestion of dsLdAS-B only slightly increased the LdJHAMT expression level by 1.1 and 1.7 fold. Moreover, after one, two and three days' ingestion of dsLdAS-C, the relative JH levels in the hemolymph of treated larvae were 2.5, 4.2 and 1.9 fold higher than those in control beetles. Furthermore, ingestion of dsLdAS-C and dsLdAS-B significantly affected larval growth and delayed larval development. Thus, we provide a line of experimental evidence in L. decemlineata to support the concept that AS-C acts as an allatostatin and inhibit JH biosynthesis. PMID:25452193

  11. The potential role of juvenile hormone acid methyltransferase in methyl farnesoate (MF) biosynthesis in the swimming crab, Portunus trituberculatus.

    PubMed

    Xie, Xi; Tao, Tian; Liu, Mingxin; Zhou, Yanqi; Liu, Zhiye; Zhu, Dongfa

    2016-05-01

    Juvenile hormone (JH) and methyl farnesoate (MF) play essential roles in the development and reproduction of insects and crustaceans respectively. Juvenile hormone acid methyltransferase (JHAMT) catalyzes the methyl esterification in insect JH biosynthesis, while the corresponding step in crustacean MF biosynthesis was long thought to be catalyzed by farnesoic acid O-methyltransferase (FAMeT). However, the new discovery of JHAMT orthologs in crustaceans indicates that JHAMT may also play essential role in the MF biosynthesis in crustaceans. Here we cloned and characterized the full-length cDNA encoding JHAMT in the swimming crab Portunus trituberculatus (PtJHAMT). Sequence and structure analysis of PtJHAMT revealed that it was composed of a 6-stranded β sheet with 9 α helices, and contained a signature Sadenosyl-L-methionine (SAM) binding motif, which is the hallmark in all SAM dependent methyltransferases (SAM-MTs). Several active sites that are critical for the interaction of SAM and JH/FA substrate were also conserved in PtJHAMT. The gene expression of PtJHAMT was highly specific to the mandibular organ, which is the sole site of MF synthesis. PtJHAMT expression significantly increased in the late-vitellogenic stage and mature stage, which suggests a possible role of PtJHAMT in modulating ovarian development. The role of PtJHAMT and PtFAMeT in MF biosynthesis was further investigated by RNA interfering (RNAi). Injection of PtJHAMT and PtFAMeT dsRNA both led to a decrease in hemolymph MF titers. Injection of PtHMGR dsRNA caused the decrease in PtJHAMT expression, but had no effect on mRNA level of PtFAMeT. Together these results suggested that JHAMT and FAMeT are both involved in the MF biosynthesis in crustaceans, while the JHAMT is highly specific to FA substrate, and FAMeT may have more catalytic functions. PMID:26952760

  12. Hormone-dependent neural plasticity in the juvenile and adult song system: what makes a successful male?

    PubMed

    Gahr, Manfred

    2004-06-01

    The sexual quality of adult song is the result of genetic and epigenetic mechanisms shaping the neural song system throughout life. Genetic brain-intrinsic mechanisms determine the neuron pools that develop into forebrain song control areas independent of gonadal steroid hormones, androgens and estrogens. One fate of these neurons is the potential to express sex steroid receptors, such as androgen and estrogen receptors. Genetic brain-intrinsic mechanisms, too, determine the activity of hypothalamic-pituitary-gonad (HPG) axis, i.e., the working range and responsiveness of HPG axis to produce gonadal hormones. The epigenetic action of gonadal steroid hormones (androgens and estrogens) on determined vocal neurons is required to maintain and increase the pool of determined vocal neurons and to complete the connections of the vocal system, i.e., to make it function motorically. The subsequent influence of environmental information, including both external (socio-sexual and physical) and internal (body physiology) signals, specify the further neural phenotype of vocal areas either through acting on the HPG axis and differential release of gonadal hormones or through non-gonadal hormone systems, both of which have target neurons in the functional vocal system. Despite the clear evidence of hormone dependency of the development of both the adult song phenotype and song system phenotype, their causal relation is complex.

  13. Juvenile hormone prevents 20-hydroxyecdysone-induced metamorphosis by regulating the phosphorylation of a newly identified broad protein.

    PubMed

    Cai, Mei-Juan; Liu, Wen; Pei, Xu-Yang; Li, Xiang-Ru; He, Hong-Juan; Wang, Jin-Xing; Zhao, Xiao-Fan

    2014-09-19

    The steroid hormone 20-hydroxyecdysone (20E) initiates insect molting and metamorphosis. By contrast, juvenile hormone (JH) prevents metamorphosis. However, the mechanism by which JH inhibits metamorphosis remains unclear. In this study, we propose that JH induces the phosphorylation of Broad isoform Z7 (BrZ7), a newly identified protein, to inhibit 20E-mediated metamorphosis in the lepidopteran insect Helicoverpa armigera. The knockdown of BrZ7 in larvae inhibited metamorphosis by repressing the expression of the 20E response gene. BrZ7 was weakly expressed and phosphorylated during larval growth but highly expressed and non-phosphorylated during metamorphosis. JH regulated the rapid phosphorylation of BrZ7 via a G-protein-coupled receptor-, phospholipase C-, and protein kinase C-triggered pathway. The phosphorylated BrZ7 bound to the 5'-regulatory region of calponin to regulate its expression in the JH pathway. Exogenous JH induced BrZ7 phosphorylation to prevent metamorphosis by suppressing 20E-related gene transcription. JH promoted non-phosphorylated calponin interacting with ultraspiracle protein to activate the JH pathway and antagonize the 20E pathway. This study reveals one of the possible mechanisms by which JH counteracts 20E-regulated metamorphosis by inducing the phosphorylation of BrZ7.

  14. Changes in juvenile hormone biosynthetic rate and whole body content in maturing virgin queens of Solenopsis invicta.

    PubMed

    Brent, Colin S; Vargo, Edward L

    2003-10-01

    Studies were conducted on the physiological and hormonal changes following the release of alates from developmentally suppressive pheromones produced by mature queens of the fire ant Solenopsis invicta Buren. Winged virgin queens were removed from the pheromonal signal and placed in colony fragments. The time for dealation, degree of ovarian development, and biosynthesis rate and whole body content of juvenile hormone (JH) were measured. The production rate and content of JH were highly correlated. Dealation and the initiation of oviposition corresponded to peak production of JH. JH production rose sharply following separation from the natal nest, peaking after 3 days. After 8 days of isolation, JH production gradually subsided to levels similar to that found in pre-release queens, but began to increase again after 12 days. Mature queens had highly elevated levels of JH relative to recently dealate females, probably reflecting the increased reproductive capability of these older females. The results support the hypothesis that the pheromone released by functional queens inhibits reproduction in virgin alates by suppressing corpora allata activity and the production of JH. PMID:14511829

  15. Farnesol-Like Endogenous Sesquiterpenoids in Vertebrates: The Probable but Overlooked Functional “Inbrome” Anti-Aging Counterpart of Juvenile Hormone of Insects?

    PubMed Central

    De Loof, Arnold; Marchal, Elisabeth; Rivera-Perez, Crisalejandra; Noriega, Fernando G.; Schoofs, Liliane

    2014-01-01

    Literature on the question whether the juvenile stage of vertebrates is hormonally regulated is scarce. It seems to be intuitively assumed that this stage of development is automated, and does not require any specific hormone(s). Such reasoning mimics the state of affairs in insects until it was shown that surgical removal of a tiny pair of glands in the head, the corpora allata, ended larval life and initiated metamorphosis. Decades later, the responsible hormone was found and named “juvenile hormone” (JH) because when present, it makes a larva molt into another larval stage. JH is a simple ester of farnesol, a sesquiterpenoid present in all eukaryotes. Whereas vertebrates do not have an anatomical counterpart of the corpora allata, their tissues do contain farnesol-like sesquiterpenoids (FLS). Some display typical JH activity when tested in appropriate insect bioassays. Some FLS are intermediates in the biosynthetic pathway of cholesterol, a compound that insects and nematodes (=Ecdysozoa) cannot synthesize by themselves. They ingest it as a vitamin. Until a recent (2014) reexamination of the basic principle underlying insect metamorphosis, it had been completely overlooked that the Ca2+-pump (SERCA) blocker thapsigargin is a sesquiterpenoid that mimics the absence of JH in inducing apoptosis. In our opinion, being in the juvenile state is primarily controlled by endogenous FLS that participate in controlling the activity of Ca2+-ATPases in the sarco(endo)plasmic reticulum (SERCAs), not only in insects but in all eukaryotes. Understanding the control mechanisms of being in the juvenile state may boost research not only in developmental biology in general, but also in diseases that develop after the juvenile stage, e.g., Alzheimer’s disease. It may also help to better understand some of the causes of obesity, a syndrome that holometabolous last larval insects severely suffer from, and for which they found a very drastic but efficient solution, namely

  16. No effect of juvenile hormone on task performance in a bumblebee (Bombus terrestris) supports an evolutionary link between endocrine signaling and social complexity.

    PubMed

    Shpigler, Hagai Y; Siegel, Adam J; Huang, Zachary Y; Bloch, Guy

    2016-09-01

    A hallmark of insect societies is a division of labor among workers specializing in different tasks. In bumblebees the division of labor is related to body size; relatively small workers are more likely to stay inside the nest and tend ("nurse") brood, whereas their larger sisters are more likely to forage. Despite their ecological and economic importance, very little is known about the endocrine regulation of division of labor in bumblebees. We studied the influence of juvenile hormone (JH) on task performance in the bumblebee Bombus terrestris. We first used a radioimmunoassay to measure circulating JH titers in workers specializing in nursing and foraging activities. Next, we developed new protocols for manipulating JH titers by combining a size-adjusted topical treatment with the allatotoxin Precocene-I and replacement therapy with JH-III. Finally, we used this protocol to test the influence of JH on task performance. JH levels were either similar for nurses and foragers (three colonies), or higher in nurses (two colonies). Nurses had better developed ovaries and JH levels were typically positively correlated with ovarian state. Manipulation of JH titers influenced ovarian development and wax secretion, consistent with earlier allatectomy studies. These manipulations however, did not affect nursing or foraging activity, or the likelihood to specialize in nursing or foraging activity. These findings contrast with honeybees in which JH influences age-related division of labor but not adult female fertility. Thus, the evolution of complex societies in bees was associated with modifications in the way JH influences social behavior. PMID:27503109

  17. Ecdysteroids, juvenile hormone and insect neuropeptides: Recent successes and remaining major challenges.

    PubMed

    De Loof, Arnold

    2008-01-01

    In the recent decade, tremendous progress has been realized in insect endocrinology as the result of the application of a variety of advanced methods in neuropeptidome- and receptor research. Hormones of which the existence had been shown by bioassays four decades ago, e.g. bursicon (a member of the glycoprotein hormone family) and pupariation factor (Neb-pyrokinin 2, a myotropin), could be identified, along with their respective receptors. In control of diurnal rhythms, clock genes got company from the neuropeptide Pigment Dispersing Factor (PDF), of which the receptor could also be identified. The discovery of Inka cells and their function in metamorphosis was a true hallmark. Analysis of the genomes of Caenorhabditis elegans, Drosophila melanogaster and Apis mellifera yielded about 75, 100 and 200 genes coding for putative signaling peptides, respectively, corresponding to approximately 57, 100 and 100 peptides of which the expression could already be proven by means of mass spectrometry. The comparative approach invertebrates-vertebrates recently yielded indications for the existence of counterparts in insects for prolactin, atrial natriuretic hormone and Growth Hormone Releasing Hormone (GRH). Substantial progress has been realized in identifying the Halloween genes, a membrane receptor(s) for ecdysteroids, a nuclear receptor for methylfarnesoate, and dozens of GPCRs for insect neuropeptides. The major remaining challenges concern the making match numerous orphan GPCRs with orphan peptidic ligands, and elucidating their functions. Furthermore, the endocrine control of growth, feeding-digestion, and of sexual differentiation, in particular of males, is still poorly understood. The finding that the prothoracic glands produce an autocrine factor with growth factor-like properties and secrete proteins necessitates a reevaluation of their role in development. PMID:17716674

  18. Ecdysteroids, juvenile hormone and insect neuropeptides: Recent successes and remaining major challenges.

    PubMed

    De Loof, Arnold

    2008-01-01

    In the recent decade, tremendous progress has been realized in insect endocrinology as the result of the application of a variety of advanced methods in neuropeptidome- and receptor research. Hormones of which the existence had been shown by bioassays four decades ago, e.g. bursicon (a member of the glycoprotein hormone family) and pupariation factor (Neb-pyrokinin 2, a myotropin), could be identified, along with their respective receptors. In control of diurnal rhythms, clock genes got company from the neuropeptide Pigment Dispersing Factor (PDF), of which the receptor could also be identified. The discovery of Inka cells and their function in metamorphosis was a true hallmark. Analysis of the genomes of Caenorhabditis elegans, Drosophila melanogaster and Apis mellifera yielded about 75, 100 and 200 genes coding for putative signaling peptides, respectively, corresponding to approximately 57, 100 and 100 peptides of which the expression could already be proven by means of mass spectrometry. The comparative approach invertebrates-vertebrates recently yielded indications for the existence of counterparts in insects for prolactin, atrial natriuretic hormone and Growth Hormone Releasing Hormone (GRH). Substantial progress has been realized in identifying the Halloween genes, a membrane receptor(s) for ecdysteroids, a nuclear receptor for methylfarnesoate, and dozens of GPCRs for insect neuropeptides. The major remaining challenges concern the making match numerous orphan GPCRs with orphan peptidic ligands, and elucidating their functions. Furthermore, the endocrine control of growth, feeding-digestion, and of sexual differentiation, in particular of males, is still poorly understood. The finding that the prothoracic glands produce an autocrine factor with growth factor-like properties and secrete proteins necessitates a reevaluation of their role in development.

  19. Influence of food availability on the spatial distribution of juvenile fish within soft sediment nursery habitats

    NASA Astrophysics Data System (ADS)

    Tableau, A.; Brind'Amour, A.; Woillez, M.; Le Bris, H.

    2016-05-01

    Soft sediments in coastal shallow waters constitute nursery habitats for juveniles of several flatfishes. The quality of a nursery is defined by its capacity to optimize the growth and the survival of juvenile fish. The influence of biotic factors, such as food availability, is poorly studied at the scale of a nursery ground. Whether food availability limits juvenile survival is still uncertain. A spatial approach is used to understand the influence of food availability on the distribution of juvenile fish of various benthic and demersal species in the Bay of Vilaine (France), a productive nursery ground. We quantified the spatial overlap between benthic macro-invertebrates and their predators (juvenile fish) to assess if the latter were spatially covering the most productive areas of the Bay. Three scenarios describing the shapes of the predator-prey spatial relationship were tested to quantify the strength of the relationship and consequently the importance of food availability in determining fish distribution. Our results underline that both food availability and fish densities vary greatly over the nursery ground. When considering small organisational levels (e.g., a single fish species), the predator-prey spatial relationship was not clear, likely because of additional environmental effects not identified here; but at larger organisational level (the whole juvenile fish community), a strong overlap between the fish predators and their prey was identified. The evidence that fish concentrate in sectors with high food availability suggests that either food is the limiting factor in that nursery or/and fish display behavioural responses by optimising their energetic expenditures associated with foraging. Further investigations are needed to test the two hypotheses and to assess the impact of benthic and demersal juvenile fish in the food web of coastal nurseries.

  20. Insulin receptor-mediated nutritional signalling regulates juvenile hormone biosynthesis and vitellogenin production in the German cockroach.

    PubMed

    Abrisqueta, Marc; Süren-Castillo, Songül; Maestro, José L

    2014-06-01

    Female reproductive processes, which comprise, amongst others, the synthesis of yolk proteins and the endocrine mechanisms which regulate this synthesis, need a considerable amount of energy and resources. The role of communicating that the required nutritional status has been attained is carried out by nutritional signalling pathways and, in particular, by the insulin receptor (InR) pathway. In the present study, using the German cockroach, Blattella germanica, as a model, we analysed the role of InR in different processes, but mainly those related to juvenile hormone (JH) synthesis and vitellogenin production. We first cloned the InR cDNA from B. germanica (BgInR) and then determined that its expression levels were constant in corpora allata and fat body during the first female gonadotrophic cycle. Results showed that the observed increase in BgInR mRNA in fat body from starved compared to fed females was abolished in those females treated with systemic RNAi in vivo against the transcription factor BgFoxO. RNAi-mediated BgInR knockdown during the final two nymphal stages produced significant delays in the moults, together with smaller adult females which could not spread the fore- and hindwings properly. In addition, BgInR knockdown led to a severe inhibition of juvenile hormone synthesis in adult female corpora allata, with a concomitant reduction of mRNA levels corresponding to 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase-1, HMG-CoA synthase-2, HMG-CoA reductase and methyl farnesoate epoxidase. BgInR RNAi treatment also reduced fat body vitellogenin mRNA and oocyte growth. Our results show that BgInR knockdown produces similar phenotypes to those obtained in starved females in terms of corpora allata activity and vitellogenin synthesis, and indicate that the InR pathway mediates the activation of JH biosynthesis and vitellogenin production elicited by nutrition signalling. PMID:24657890

  1. A whole genome screening and RNA interference identify a juvenile hormone esterase-like gene of the diamondback moth, Plutella xylostella.

    PubMed

    Gu, Xiaojun; Kumar, Sunil; Kim, Eunjin; Kim, Yonggyun

    2015-09-01

    Juvenile hormone (JH) plays a crucial role in preventing precocious metamorphosis and stimulating reproduction. Thus, its hemolymph titer should be under a tight control. As a negative controller, juvenile hormone esterase (JHE) performs a rapid breakdown of residual JH in the hemolymph during last instar to induce a larval-to-pupal metamorphosis. A whole genome of the diamondback moth (DBM), Plutella xylostella, has been annotated and proposed 11 JHE candidates. Sequence analysis using conserved motifs commonly found in other JHEs proposed a putative JHE (Px004817). Px004817 (64.61 kDa, pI=5.28) exhibited a characteristic JHE expression pattern by showing high peak at the early last instar, at which JHE enzyme activity was also at a maximal level. RNA interference of Px004817 reduced JHE activity and interrupted pupal development with a significant increase of larval period. This study identifies Px004817 as a JHE-like gene of P. xylostella.

  2. Thyroid hormone-regulated gene expression in juvenile mouse liver: identification of thyroid response elements using microarray profiling and in silico analyses

    PubMed Central

    2011-01-01

    Background Disruption of thyroid hormone signalling can alter growth, development and energy metabolism. Thyroid hormones exert their effects through interactions with thyroid receptors that directly bind thyroid response elements and can alter transcriptional activity of target genes. The effects of short-term thyroid hormone perturbation on hepatic mRNA transcription in juvenile mice were evaluated, with the goal of identifying genes containing active thyroid response elements. Thyroid hormone disruption was induced from postnatal day 12 to 15 by adding goitrogens to dams' drinking water (hypothyroid). A subgroup of thyroid hormone-disrupted pups received intraperitoneal injections of replacement thyroid hormones four hours prior to sacrifice (replacement). An additional group received only thyroid hormones four hours prior to sacrifice (hyperthyroid). Hepatic mRNA was extracted and hybridized to Agilent mouse microarrays. Results Transcriptional profiling enabled the identification of 28 genes that appeared to be under direct thyroid hormone-regulation. The regulatory regions of the genome adjacent to these genes were examined for half-site sequences that resemble known thyroid response elements. A bioinformatics search identified 33 thyroid response elements in the promoter regions of 13 different genes thought to be directly regulated by thyroid hormones. Thyroid response elements found in the promoter regions of Tor1a, 2310003H01Rik, Hect3d and Slc25a45 were further validated by confirming that the thyroid receptor is associated with these sequences in vivo and that it can bind directly to these sequences in vitro. Three different arrangements of thyroid response elements were identified. Some of these thyroid response elements were located far up-stream (> 7 kb) of the transcription start site of the regulated gene. Conclusions Transcriptional profiling of thyroid hormone disrupted animals coupled with a novel bioinformatics search revealed new thyroid

  3. Hormones

    MedlinePlus

    Hormones are your body's chemical messengers. They travel in your bloodstream to tissues or organs. They work ... glands, which are special groups of cells, make hormones. The major endocrine glands are the pituitary, pineal, ...

  4. Larval Exposure to the Juvenile Hormone Analog Pyriproxyfen Disrupts Acceptance of and Social Behavior Performance in Adult Honeybees

    PubMed Central

    Fourrier, Julie; Deschamps, Matthieu; Droin, Léa; Alaux, Cédric; Fortini, Dominique; Beslay, Dominique; Le Conte, Yves; Devillers, James; Aupinel, Pierrick; Decourtye, Axel

    2015-01-01

    Background Juvenile hormone (JH) plays an important role in honeybee development and the regulation of age-related division of labor. However, honeybees can be exposed to insect growth regulators (IGRs), such as JH analogs developed for insect pest and vector control. Although their side effects as endocrine disruptors on honeybee larval or adult stages have been studied, little is known about the subsequent effects on adults of a sublethal larval exposure. We therefore studied the impact of the JH analog pyriproxyfen on larvae and resulting adults within a colony under semi-field conditions by combining recent laboratory larval tests with chemical analysis and behavioral observations. Oral and chronic larval exposure at cumulative doses of 23 or 57 ng per larva were tested. Results Pyriproxyfen-treated bees emerged earlier than control bees and the highest dose led to a significant rate of malformed adults (atrophied wings). Young pyriproxyfen-treated bees were more frequently rejected by nestmates from the colony, inducing a shorter life span. This could be linked to differences in cuticular hydrocarbon (CHC) profiles between control and pyriproxyfen-treated bees. Finally, pyriproxyfen-treated bees exhibited fewer social behaviors (ventilation, brood care, contacts with nestmates or food stocks) than control bees. Conclusion Larval exposure to sublethal doses of pyriproxyfen affected several life history traits of the honeybees. Our results especially showed changes in social integration (acceptance by nestmates and social behaviors performance) that could potentially affect population growth and balance of the colony. PMID:26171610

  5. Synchronous vitellogenin expression and sexual maturation during migration are negatively correlated with juvenile hormone levels in Mythimna separata

    PubMed Central

    Xiao, Hai-Jun; Fu, Xiao-Wei; Liu, Yong-Qiang; Wu, Kong-Ming

    2016-01-01

    Annual migration of pests between different seasonal habitats can lead to serious crop damage. Reproductive immaturity is generally associated with the migratory process (oogenesis-flight syndrome), but the mechanism of reproductive development during migration varies unpredictably. Here, the vitellogenin gene (MsVg) and three key regulatory enzyme genes (MsJhamt, MsJheh and MsJhe) related to juvenile hormone (JH) synthesis and degradation were identified and characterized in Mythimna separata. The relative expression of MsVg varied significantly in response to seasonal changes and was significantly correlated with stages of ovarian development. The relatively low levels of JH titer did not differ significantly in male moths but slightly increased in female adults during the migratory season, which was consistent with changes in mRNA levels for MsJhamt, MsJheh and MsJhe. JH titer was negatively associated with relative seasonal levels of vitellogenin mRNA transcripts and with ovarian development in migrating M. separata. The synchrony of MsVg expression with sexual maturation highlighted the potential of MsVg transcript levels to serve as an index to monitor the adult reproductive status. In addition, the level of JH and sexual maturity were correlated with the extent of JH in regulating the MsVg expression and reproduction during seasonal northern and southern migration. PMID:27629246

  6. Sequences of elongation factors-1 alpha and -1 gamma and stimulation by juvenile hormone in Locusta migratoria.

    PubMed

    Zhou, S; Zhang, J; Fam, M D; Wyatt, G R; Walker, V K

    2002-11-01

    Two cDNAs encoding the alpha and gamma subunits of translation elongation factor-1 (EF-1) have been cloned and sequenced from the African migratory locust, Locusta migratoria. Southern blotting and real-time PCR analyses indicated that these sequences represent single copy genes. Comparison with sequences from other species indicated greater conservation for EF-1 alpha than for EF-1 gamma. The developmental profiles for EF-1 alpha and -1 gamma mRNA expression in the fat body paralleled reported changes in the hemolymph juvenile hormone (JH) titer in the fifth instar and were elevated during early reproductive maturation in the female adult. In maturing adults, there was a greater accumulation of EF-1 alpha and -1 gamma transcripts in females than in males. The levels of both transcripts were greatly increased by an enriched diet, previously shown to elevate JH titers and accelerate vitellogenin production. Treating JH-deprived adult females with the JH analog, methoprene, resulted in more than doubling of transcript levels of both genes, supporting the hypothesis that JH could stimulate the accumulation of LmEF-1 alpha and -1 gamma transcripts. We suggest that production of elongation factors, increased by JH, may contribute to the massive protein synthesis required for egg production. PMID:12530224

  7. Juvenile hormone biosynthesis gene expression in the corpora allata of honey bee (Apis mellifera L.) female castes.

    PubMed

    Bomtorin, Ana Durvalina; Mackert, Aline; Rosa, Gustavo Conrado Couto; Moda, Livia Maria; Martins, Juliana Ramos; Bitondi, Márcia Maria Gentile; Hartfelder, Klaus; Simões, Zilá Luz Paulino

    2014-01-01

    Juvenile hormone (JH) controls key events in the honey bee life cycle, viz. caste development and age polyethism. We quantified transcript abundance of 24 genes involved in the JH biosynthetic pathway in the corpora allata-corpora cardiaca (CA-CC) complex. The expression of six of these genes showing relatively high transcript abundance was contrasted with CA size, hemolymph JH titer, as well as JH degradation rates and JH esterase (jhe) transcript levels. Gene expression did not match the contrasting JH titers in queen and worker fourth instar larvae, but jhe transcript abundance and JH degradation rates were significantly lower in queen larvae. Consequently, transcriptional control of JHE is of importance in regulating larval JH titers and caste development. In contrast, the same analyses applied to adult worker bees allowed us inferring that the high JH levels in foragers are due to increased JH synthesis. Upon RNAi-mediated silencing of the methyl farnesoate epoxidase gene (mfe) encoding the enzyme that catalyzes methyl farnesoate-to-JH conversion, the JH titer was decreased, thus corroborating that JH titer regulation in adult honey bees depends on this final JH biosynthesis step. The molecular pathway differences underlying JH titer regulation in larval caste development versus adult age polyethism lead us to propose that mfe and jhe genes be assayed when addressing questions on the role(s) of JH in social evolution.

  8. Juvenile hormone-dopamine systems for the promotion of flight activity in males of the large carpenter bee Xylocopa appendiculata

    NASA Astrophysics Data System (ADS)

    Sasaki, Ken; Nagao, Takashi

    2013-12-01

    The reproductive roles of dopamine and dopamine regulation systems are known in social hymenopterans, but the knowledge on the regulation systems in solitary species is still needed. To test the possibility that juvenile hormone (JH) and brain dopamine interact to trigger territorial flight behavior in males of a solitary bee species, the effects on biogenic amines of JH analog treatments and behavioral assays with dopamine injections in males of the large carpenter bee Xylocopa appendiculata were quantified. Brain dopamine levels were significantly higher in methoprene-treated males than in control males 4 days after treatment, but were not significantly different after 7 days. Brain octopamine and serotonin levels did not differ between methoprene-treated and control males at 4 and 7 days after treatment. Injection of dopamine caused significantly higher locomotor activities and a shorter duration for flight initiation in experimental versus control males. These results suggest that brain dopamine can be regulated by JH and enhances flight activities in males. The JH-dopamine system in males of this solitary bee species is similar to that of males of the highly eusocial honeybee Apis mellifera.

  9. Juvenile hormone-dopamine systems for the promotion of flight activity in males of the large carpenter bee Xylocopa appendiculata.

    PubMed

    Sasaki, Ken; Nagao, Takashi

    2013-12-01

    The reproductive roles of dopamine and dopamine regulation systems are known in social hymenopterans, but the knowledge on the regulation systems in solitary species is still needed. To test the possibility that juvenile hormone (JH) and brain dopamine interact to trigger territorial flight behavior in males of a solitary bee species, the effects on biogenic amines of JH analog treatments and behavioral assays with dopamine injections in males of the large carpenter bee Xylocopa appendiculata were quantified. Brain dopamine levels were significantly higher in methoprene-treated males than in control males 4 days after treatment, but were not significantly different after 7 days. Brain octopamine and serotonin levels did not differ between methoprene-treated and control males at 4 and 7 days after treatment. Injection of dopamine caused significantly higher locomotor activities and a shorter duration for flight initiation in experimental versus control males. These results suggest that brain dopamine can be regulated by JH and enhances flight activities in males. The JH-dopamine system in males of this solitary bee species is similar to that of males of the highly eusocial honeybee Apis mellifera.

  10. Control of larval and egg development in Aedes aegypti with RNA interference against juvenile hormone acid methyl transferase.

    PubMed

    Van Ekert, Evelien; Powell, Charles A; Shatters, Robert G; Borovsky, Dov

    2014-11-01

    RNA interference (RNAi) is a powerful approach for elucidating gene functions in a variety of organisms, including mosquitoes and many other insects. Little has been done, however, to harness this approach in order to control adult and larval mosquitoes. Juvenile hormone (JH) plays a pivotal role in the control of reproduction in adults and metamorphism in larval mosquitoes. This report describes an approach to control Aedes aegypti using RNAi against JH acid methyl transferase (AeaJHAMT), the ultimate enzyme in the biosynthetic pathway of JH III that converts JH acid III (JHA III) into JH III. In female A. aegypti that were injected or fed jmtA dsRNA targeting the AeaJHAMT gene (jmtA) transcript, egg development was inhibited in 50% of the treated females. In mosquito larvae that were fed transgenic Pichia pastoris cells expressing long hair pin (LHP) RNA, adult eclosion was delayed by 3 weeks causing high mortality. Northern blot analyses and qPCR studies show that jmtA dsRNA causes inhibition of jmtA transcript in adults and larvae, which is consistent with the observed inhibition of egg maturation and larval development. Taken together, these results suggest that jmtA LHP RNA expressed in heat inactivated genetically modified P. pastoris cells could be used to control mosquito populations in the marsh.

  11. Effects of a juvenile hormone analogue pyriproxyfen on monogynous and polygynous colonies of the Pharaoh ant Monomorium pharaonis (Hymenoptera: Formicidae).

    PubMed

    Tay, J W; Lee, C Y

    2015-09-01

    To evaluate the effects of the juvenile hormone analogue pyriproxyfen on colonies of the Pharaoh ant Monomorium pharaonis (L.), peanut oil containing different concentrations (0.3, 0.6, or 0.9%) of pyriproxyfen was fed to monogynous (1 queen, 500 workers, and 0.1 g of brood) and polygynous (8 queens, 50 workers, and 0.1 g of brood) laboratory colonies of M. pharaonis. Due to its delayed activity, pyriproxyfen at all concentrations resulted in colony elimination. Significant reductions in brood volume were recorded at weeks 3 - 6, and complete brood mortality was observed at week 8 in all treated colonies. Brood mortality was attributed to the disruption of brood development and cessation of egg production by queens. All polygynous colonies exhibited significant reduction in the number of queens present at week 10 compared to week 1. Number of workers was significantly lower in all treated colonies compared to control colonies at week 8 due to old-age attrition of the workers without replacement. At least 98.67 ± 1.33% of workers were dead at week 10 in all treated colonies. Thus, treatment with slow acting pyriproxyfen at concentrations of 0.3 - 0.9% is an effective strategy for eliminating Pharaoh ant colonies.

  12. Control of larval and egg development in Aedes aegypti with RNA interference against juvenile hormone acid methyl transferase.

    PubMed

    Van Ekert, Evelien; Powell, Charles A; Shatters, Robert G; Borovsky, Dov

    2014-11-01

    RNA interference (RNAi) is a powerful approach for elucidating gene functions in a variety of organisms, including mosquitoes and many other insects. Little has been done, however, to harness this approach in order to control adult and larval mosquitoes. Juvenile hormone (JH) plays a pivotal role in the control of reproduction in adults and metamorphism in larval mosquitoes. This report describes an approach to control Aedes aegypti using RNAi against JH acid methyl transferase (AeaJHAMT), the ultimate enzyme in the biosynthetic pathway of JH III that converts JH acid III (JHA III) into JH III. In female A. aegypti that were injected or fed jmtA dsRNA targeting the AeaJHAMT gene (jmtA) transcript, egg development was inhibited in 50% of the treated females. In mosquito larvae that were fed transgenic Pichia pastoris cells expressing long hair pin (LHP) RNA, adult eclosion was delayed by 3 weeks causing high mortality. Northern blot analyses and qPCR studies show that jmtA dsRNA causes inhibition of jmtA transcript in adults and larvae, which is consistent with the observed inhibition of egg maturation and larval development. Taken together, these results suggest that jmtA LHP RNA expressed in heat inactivated genetically modified P. pastoris cells could be used to control mosquito populations in the marsh. PMID:25111689

  13. Synchronous vitellogenin expression and sexual maturation during migration are negatively correlated with juvenile hormone levels in Mythimna separata.

    PubMed

    Xiao, Hai-Jun; Fu, Xiao-Wei; Liu, Yong-Qiang; Wu, Kong-Ming

    2016-01-01

    Annual migration of pests between different seasonal habitats can lead to serious crop damage. Reproductive immaturity is generally associated with the migratory process (oogenesis-flight syndrome), but the mechanism of reproductive development during migration varies unpredictably. Here, the vitellogenin gene (MsVg) and three key regulatory enzyme genes (MsJhamt, MsJheh and MsJhe) related to juvenile hormone (JH) synthesis and degradation were identified and characterized in Mythimna separata. The relative expression of MsVg varied significantly in response to seasonal changes and was significantly correlated with stages of ovarian development. The relatively low levels of JH titer did not differ significantly in male moths but slightly increased in female adults during the migratory season, which was consistent with changes in mRNA levels for MsJhamt, MsJheh and MsJhe. JH titer was negatively associated with relative seasonal levels of vitellogenin mRNA transcripts and with ovarian development in migrating M. separata. The synchrony of MsVg expression with sexual maturation highlighted the potential of MsVg transcript levels to serve as an index to monitor the adult reproductive status. In addition, the level of JH and sexual maturity were correlated with the extent of JH in regulating the MsVg expression and reproduction during seasonal northern and southern migration. PMID:27629246

  14. Juvenile Hormone Biosynthesis Gene Expression in the corpora allata of Honey Bee (Apis mellifera L.) Female Castes

    PubMed Central

    Rosa, Gustavo Conrado Couto; Moda, Livia Maria; Martins, Juliana Ramos; Bitondi, Márcia Maria Gentile; Hartfelder, Klaus; Simões, Zilá Luz Paulino

    2014-01-01

    Juvenile hormone (JH) controls key events in the honey bee life cycle, viz. caste development and age polyethism. We quantified transcript abundance of 24 genes involved in the JH biosynthetic pathway in the corpora allata-corpora cardiaca (CA-CC) complex. The expression of six of these genes showing relatively high transcript abundance was contrasted with CA size, hemolymph JH titer, as well as JH degradation rates and JH esterase (jhe) transcript levels. Gene expression did not match the contrasting JH titers in queen and worker fourth instar larvae, but jhe transcript abundance and JH degradation rates were significantly lower in queen larvae. Consequently, transcriptional control of JHE is of importance in regulating larval JH titers and caste development. In contrast, the same analyses applied to adult worker bees allowed us inferring that the high JH levels in foragers are due to increased JH synthesis. Upon RNAi-mediated silencing of the methyl farnesoate epoxidase gene (mfe) encoding the enzyme that catalyzes methyl farnesoate-to-JH conversion, the JH titer was decreased, thus corroborating that JH titer regulation in adult honey bees depends on this final JH biosynthesis step. The molecular pathway differences underlying JH titer regulation in larval caste development versus adult age polyethism lead us to propose that mfe and jhe genes be assayed when addressing questions on the role(s) of JH in social evolution. PMID:24489805

  15. Sources of propionate for the biogenesis of ethyl-braced insect juvenile hormones: role of isoleucine and valine

    SciTech Connect

    Brindle, P.A.; Baker, F.C.; Tsai, L.W.; Reuter, C.C.; Schooley, D.A.

    1987-11-01

    Corpora allata from adult female Manduca sexta biosynthesis the sesquiterpenoid juvenile hormone (JH) III and the unusual ethyl-branched homologue JH II in vitro. The authors maintained corpora allata in medium 199 using (methyl-/sup 3/H)methionine as the source of the JH methyl ester moiety and as a mass marker. This allowed measurement of the relative contributions of /sup 14/C-labeled precursors to the biogenesis of JH II and III carbon skeletons. They showed efficient incorporation of a propionate equivalent, from isoleucine or valine catabolism, into the ethyl-branched portion of JH II, using double-label liquid scintillation counting of isolated JHs and gas chromatography/mass spectrometry with selected ion monitoring of JH deuteromethoxyhydrin derivatives. Methionine was a poor source of propionate for JH II biosynthesis, while glucose, succinate, threonine, and ..beta..-alanine did not contribute propionate at all. Leucine, isoleucine, and glucose incorporated into JH III and the acetate-derivative portion of JH II.

  16. Periotest values: Its reproducibility, accuracy, and variability with hormonal influence

    PubMed Central

    Chakrapani, Swarna; Goutham, Madireddy; Krishnamohan, Thota; Anuparthy, Sujitha; Tadiboina, Nagarjuna; Rambha, Somasekhar

    2015-01-01

    Tooth mobility can be assessed by both subjective and objective means. The use of subjective measures may lead to bias and hence it becomes imperative to use objective means to assess tooth mobility. It has also been observed that hormonal fluctuations may have significantly influence tooth mobility. Aims: The study was undertaken to assess the reproducibility of periotest in the assessment of tooth mobility and, to unravel the obscurity associated with the hormonal influence on tooth mobility. Materials and Methods: 100 subjects were included in the study and were divided equally into two groups based on their age, group I (11-14 years) and group II(16-22 years). Results: There was no statistical significant difference between the periotest values (PTV) taken at two different time periods with a time difference of 20 minutes. PTV of group I was found to have a statistical significant greater PTV than group II. Conclusion: Periotest can reliably measure tooth mobility. Tooth mobility is greater during puberty as compared to adolescence and during adolescence mobility was slightly greater in males. PMID:25684904

  17. The influence of ovarian factors on the somatostatin-growth hormone system during the postnatal growth and sexual development in lambs.

    PubMed

    Wańkowska, Marta; Polkowska, Jolanta; Misztal, Tomasz; Romanowicz, Katarzyna

    2012-07-01

    The aim of the study was to elucidate the effects of ovarian hormones on somatostatin in the hypothalamic neurons and growth hormone (GH) secretion during the postnatal growth and development of sheep. The study was performed on 9-week-old (infantile) lambs that were ovary-intact (OVI) or ovariectomized (OVX) at 39 days of age, and on 16-week-old (juvenile) lambs that were OVI or OVX at 88 days of age. Hormones in neurons and somatotropic cells were assayed with immunohistochemistry and radioimmunoassay. Following ovariectomy, immunoreactive somatostatin was more abundant (p<0.05) in the hypothalamus of infantile lambs, whereas in juvenile lambs it was more abundant (p<0.05) in the periventricular nucleus but reduced (p<0.01) in the median eminence. In contrast to somatostatin in the hypothalamus, the content of immunoreactive GH in the hypophysis was less in OVX infantile lambs, but greater in OVX juvenile lambs (p<0.05). Basal blood serum concentrations of GH were greater (p<0.05) in OVX infantile lambs, whereas in OVX juvenile lambs, mean and basal concentrations of GH and amplitude of GH pulses were less than in OVI lambs (p<0.05). The postnatal increase in body weight was greatest in middle-late infancy (p<0.01). The body weight did not differ (p>0.05) between OVI and OVX lambs. In conclusion, ovarian factors may inhibit the GH secretion in infantile lambs but enhance the GH secretion in juvenile lambs. Transition to puberty, as related to the growth rate, appears to be due mainly to change in gonadal influence on the somatostatin neurosecretion. A stimulation of somatostatin output in the median eminence by gonadal factors in infancy is followed by a stimulation of somatostatin accumulation after infancy. Thus, ovarian factors modulate mechanisms within the somatotropic system of lambs to synchronize the somatic growth with sexual development.

  18. Sex Hormones and Cognition: Neuroendocrine Influences on Memory and Learning.

    PubMed

    Hamson, Dwayne K; Roes, Meighen M; Galea, Liisa A M

    2016-06-13

    Sex differences in neurological disease exist in incidence, severity, progression, and symptoms and may ultimately influence treatment. Cognitive disturbances are frequent in neuropsychiatric disease with men showing greater cognitive impairment in schizophrenia, but women showing more severe dementia and cognitive decline with Alzheimer's disease. Although there are no overall differences in intelligence between the sexes, men, and women demonstrate slight but consistent differences in a number of cognitive domains. These include a male advantage, on average, in some types of spatial abilities and a female advantage on some measures of verbal fluency and memory. Sex differences in traits or behaviors generally indicate the involvement of sex hormones, such as androgens and estrogens. We review the literature on whether adult levels of testosterone and estradiol influence spatial ability in both males and females from rodent models to humans. We also include information on estrogens and their ability to modulate verbal memory in men and women. Estrone and progestins are common components of hormone therapies, and we also review the existing literature concerning their effects on cognition. We also review the sex differences in the hippocampus and prefrontal cortex as they relate to cognitive performance in both rodents and humans. There has been greater recognition in the scientific literature that it is important to study both sexes and also to analyze study findings with sex as a variable. Only by examining these sex differences can we progress to finding treatments that will improve the cognitive health of both men and women. © 2016 American Physiological Society. Compr Physiol 6:1295-1337, 2016.

  19. Sex Hormones and Cognition: Neuroendocrine Influences on Memory and Learning.

    PubMed

    Hamson, Dwayne K; Roes, Meighen M; Galea, Liisa A M

    2016-01-01

    Sex differences in neurological disease exist in incidence, severity, progression, and symptoms and may ultimately influence treatment. Cognitive disturbances are frequent in neuropsychiatric disease with men showing greater cognitive impairment in schizophrenia, but women showing more severe dementia and cognitive decline with Alzheimer's disease. Although there are no overall differences in intelligence between the sexes, men, and women demonstrate slight but consistent differences in a number of cognitive domains. These include a male advantage, on average, in some types of spatial abilities and a female advantage on some measures of verbal fluency and memory. Sex differences in traits or behaviors generally indicate the involvement of sex hormones, such as androgens and estrogens. We review the literature on whether adult levels of testosterone and estradiol influence spatial ability in both males and females from rodent models to humans. We also include information on estrogens and their ability to modulate verbal memory in men and women. Estrone and progestins are common components of hormone therapies, and we also review the existing literature concerning their effects on cognition. We also review the sex differences in the hippocampus and prefrontal cortex as they relate to cognitive performance in both rodents and humans. There has been greater recognition in the scientific literature that it is important to study both sexes and also to analyze study findings with sex as a variable. Only by examining these sex differences can we progress to finding treatments that will improve the cognitive health of both men and women. © 2016 American Physiological Society. Compr Physiol 6:1295-1337, 2016. PMID:27347894

  20. Plant-derived juvenile hormone III analogues and other sesquiterpenes from the stem bark of Cananga latifolia.

    PubMed

    Yang, Heejung; Kim, Hye Seong; Jeong, Eun Ju; Khiev, Piseth; Chin, Young-Won; Sung, Sang Hyun

    2013-10-01

    Juvenile hormone III (JH III) is a larval metamorphosis-regulating hormone present in most insect species. JH III was first isolated from the plant, Cyperus iria L., but the presence of JH III has not been reported in other plant species. In the present study, proof of the existence of JH III and its analogues from Cananga latifolia was established. From an aqueous MeOH extract of C. latifolia stem bark, six compounds were isolated along with nine known compounds. These were identified by using spectroscopic analyses as: (2E,6E,10R)-11-butoxy-10-hydroxy-3,7,11-trimethyldodeca-2,6-dienoic acid methyl ester, (2E,6E)-3,7,11-trimethyl-10-oxododeca-2,6-dienoic acid methyl ester, (2E)-3-methyl-5-[(1S,2R,6R)-1,2,6-trimethyl-3-oxocyclohexyl]-pent-2-enoic acid methyl ester, 1β-hydroxy-3-oxo-4β, 5α,7α-H-eudesmane 11-O-α-l-rhamnopyranoside, 4-epi-aubergenone 11-O-2',3'-di-O-acetyl-α-l-rhamnopyranoside and 4-epi-aubergenone 11-O-2',4'-di-O-acetyl-α-l-rhamnopyranoside. Three of the previously known compounds, (2E,6E,10R)-10-hydroxy-3,7,11-trimethyldodeca-2,6,11-trienoaic acid methyl ester, (2E,6E,10R)-10,11-dihydroxy-3,7,11-trimethyldodeca-2,6-dienoic acid and (2E,6S)-3-methyl-6-hydroxy-6-[(2R,5R)-5-(2-hydroxypropan-2-yl)-2-methyltetrahydrofuran-2-yl]-hex-2-enoaic acid methyl ester have now been found in a plant species. Ultra performance liquid chromatography-quadruple time-of-flight mass spectroscopy (UPLC-QTOF/MS) analysis of the chemical constituents of C. latifolia showed that several were predominant in the sub-fractions of a C. latifolia stem bark extract.

  1. Plant-derived juvenile hormone III analogues and other sesquiterpenes from the stem bark of Cananga latifolia.

    PubMed

    Yang, Heejung; Kim, Hye Seong; Jeong, Eun Ju; Khiev, Piseth; Chin, Young-Won; Sung, Sang Hyun

    2013-10-01

    Juvenile hormone III (JH III) is a larval metamorphosis-regulating hormone present in most insect species. JH III was first isolated from the plant, Cyperus iria L., but the presence of JH III has not been reported in other plant species. In the present study, proof of the existence of JH III and its analogues from Cananga latifolia was established. From an aqueous MeOH extract of C. latifolia stem bark, six compounds were isolated along with nine known compounds. These were identified by using spectroscopic analyses as: (2E,6E,10R)-11-butoxy-10-hydroxy-3,7,11-trimethyldodeca-2,6-dienoic acid methyl ester, (2E,6E)-3,7,11-trimethyl-10-oxododeca-2,6-dienoic acid methyl ester, (2E)-3-methyl-5-[(1S,2R,6R)-1,2,6-trimethyl-3-oxocyclohexyl]-pent-2-enoic acid methyl ester, 1β-hydroxy-3-oxo-4β, 5α,7α-H-eudesmane 11-O-α-l-rhamnopyranoside, 4-epi-aubergenone 11-O-2',3'-di-O-acetyl-α-l-rhamnopyranoside and 4-epi-aubergenone 11-O-2',4'-di-O-acetyl-α-l-rhamnopyranoside. Three of the previously known compounds, (2E,6E,10R)-10-hydroxy-3,7,11-trimethyldodeca-2,6,11-trienoaic acid methyl ester, (2E,6E,10R)-10,11-dihydroxy-3,7,11-trimethyldodeca-2,6-dienoic acid and (2E,6S)-3-methyl-6-hydroxy-6-[(2R,5R)-5-(2-hydroxypropan-2-yl)-2-methyltetrahydrofuran-2-yl]-hex-2-enoaic acid methyl ester have now been found in a plant species. Ultra performance liquid chromatography-quadruple time-of-flight mass spectroscopy (UPLC-QTOF/MS) analysis of the chemical constituents of C. latifolia showed that several were predominant in the sub-fractions of a C. latifolia stem bark extract. PMID:23859262

  2. Somatic growth effects of intramuscular injection of growth hormone in androgen-treated juvenile Nile tilapia, Oreochromis niloticus (Perciformes: Cichlidae).

    PubMed

    Liñán-Cabello, Marco A; Robles-Basto, Cindy M; Mena-herrera, Alfredo

    2013-03-01

    Little is known about the effects of the interaction of growth hormone (GH) with 17 alpha-methyltestosterone (17-MT) during fish growth. We evaluated this in the present study to assess the effect on fish growth. Fish in two batches of juvenile tilapia (Oreochromis niloticus) (approximately 5.0cm in length) were randomly assigned in triplicate to three treatments and a control group, distributed among 12 fiberglass tanks of 1 000L capacity (50 fish per tank) in an experiment covering a period of six weeks. The experimental groups were: a) fish treated with 17-MT and GH in mineral oil (RGH); b) fish treated with 17-MT and mineral oil without the addition of GH (R); c) fish treated with GH in mineral oil but not 17-MT (NGH); and d) fish of the control group, which were treated with mineral oil but not 17-MT or GH (N). The GH was injected into the fish at a rate of 0.625mg/g body weight. Morphometric data were recorded at the beginning of the experiment (T0) and at 15, 30 and 45 days (T15, T30 and T45), and various indicators of growth were assessed: condition factor (K); survival percentage (S), feed conversion rate (FCR), percentage weight gain (WG) and (v) daily weight gain. The optimum dietary level was calculated assuming 5% food conversion to total weight in each group. During the experiment, the fish were provided with a commercial food containing 45% protein. The data showed that GH injection resulted in a greater weight gain in fish treated with 17-MT (the RGH treatment group), being particularly significant increase in weight during T15 and T30 (p<0.05). High values of K were found in the R and RGH treatments during the initial days of the experiment, which may have been a consequence of the better nutritional status affecting both weight gain and growth in body length, as a result of the additive effects of 17-MT and GH. The fish in groups not treated with 17-MT and treated with 17-MT and added GH showed greater increases in WG per day, higher K values and

  3. CHARACTERIZATION AND FUNCTIONAL STUDY OF A PUTATIVE JUVENILE HORMONE DIOL KINASE IN THE COLORADO POTATO BEETLE Leptinotarsa decemlineata (Say).

    PubMed

    Fu, Kai-Yun; Lü, Feng-Gong; Guo, Wen-Chao; Li, Guo-Qing

    2015-11-01

    Juvenile hormone diol kinase (JHDK) is an enzyme involved in JH degradation. In the present article, a putative JHDK cDNA (LdJHDK) was cloned from the Colorado potato beetle Leptinotarsa decemlineata. The cDNA consists of 814 bp, containing a 555 bp open reading frame encoding a 184 amino acid protein. LdJHDK reveals a high degree of identity to the previously reported insect JHDKs. It possesses three conserved purine nucleotide-binding elements, and contains three EF-hand motifs (helix-loop-helix structural domains). LdJHDK mRNA was mainly detected in hindgut and Malpighian tubules. Besides, a trace amount of LdJHDK mRNA was also found in thoracic muscles, brain-corpora cardiaca-corpora allata complex, foregut, midgut, ventral ganglia, fat body, epidermis, and hemocytes. Moreover, LdJHDK was expressed throughout all developmental stages. Within the first, second, and third larval instar, the expression levels of LdJHDK were higher just before and right after the molt, and were lower in the intermediate instar. In the fourth larval instar, the highest peak of LdJHDK occurred 56 h after ecdysis. Ingestion of double-stranded RNA (dsRNA) against LdJHDK successfully knocked down the target gene, increased JH titer, and significantly upregulated LdKr-h1 mRNA level. Knockdown of LdJHDK significantly impaired adult emergence. Thus, we provide a line of experimental evidence in L. decemlineata to support that LdJHDK encodes function protein involved in JH degradation. PMID:26280246

  4. Expressional and functional analysis of CYP15A1, a juvenile hormone epoxidase, in the red flour beetle Tribolium castaneum.

    PubMed

    Minakuchi, Chieka; Ishii, Fumika; Washidu, Yumiko; Ichikawa, Akio; Tanaka, Toshiharu; Miura, Ken; Shinoda, Tetsuro

    2015-09-01

    Juvenile hormone (JH) is synthesized and secreted by the corpora allata. In the final two steps of JH biosynthesis, farnesoic acid (FA) is converted to JH through methylation by JH acid O-methyltransferase (JHAMT) and epoxidation by the cytochrome P450 enzyme CYP15. In the present study, we identified a homolog of CYP15 from the red flour beetle Tribolium castaneum (TcCYP15A1), and analyzed its expression as well as its role in JH biosynthesis. Quantitative RT-PCR analysis showed that the level of TcCYP15A1 mRNA was high in the embryonic stage as well as in the middle of the final larval instar. In the embryonic stage, the transcript level of TcCYP15A1 started to increase 30h after egg laying (AEL), peaked 54-60h AEL, and was followed by an increase of TcJHAMT mRNA, suggesting that JH biosynthesis started at this time point. TcCYP15A1 mRNA was present, but not exclusively so in the larval corpora allata. The recombinant TcCYP15A1 protein epoxidized both FA and methyl farnesoate (MF) in highly stereo-specific manners. These results confirmed that TcCYP15A1 is involved in JH biosynthesis. The RNAi-mediated knockdown of TcCYP15A1 in the pre-final larval instar did not result in precocious metamorphosis to pupa, indicating that MF may exhibit JH-like activity in order to maintain the larval status. The double knockdown of TcJHAMT and TcCYP15A1 resulted in pupae and adults with shorter wings, suggesting that the precursors of JH, JH acid and MF, may be essential for wing expansion.

  5. Krüppel homolog 1 (Kr-h1) mediates juvenile hormone action during metamorphosis of Drosophila melanogaster.

    PubMed

    Minakuchi, Chieka; Zhou, Xiaofeng; Riddiford, Lynn M

    2008-01-01

    Juvenile hormone (JH) given at pupariation inhibits bristle formation and causes pupal cuticle formation in the abdomen of Drosophila melanogaster due to its prolongation of expression of the transcription factor Broad (BR). In a microarray analysis of JH-induced gene expression in abdominal integument, we found that Krüppel homolog 1 (Kr-h1) was up-regulated during most of adult development. Quantitative real-time PCR analyses showed that Kr-h1 up-regulation began at 10h after puparium formation (APF), and Kr-h1 up-regulation occurred in imaginal epidermal cells, persisting larval muscles, and larval oenocytes. Ectopic expression of Kr-h1 in abdominal epidermis using T155-Gal4 to drive UAS-Kr-h1 resulted in missing or short bristles in the dorsal midline. This phenotype was similar to that seen after a low dose of JH or after misexpression of br between 21 and 30 h APF. Ectopic expression of Kr-h1 prolonged the expression of BR protein in the pleura and the dorsal tergite. No Kr-h1 was seen after misexpression of br. Thus, Kr-h1 mediates some of the JH signaling in the adult abdominal epidermis and is upstream of br in this pathway. We also show for the first time that the JH-mediated maintenance of br expression in this epidermis is patterned and that JH delays the fusion of the imaginal cells and the disappearance of Dpp in the dorsal midline.

  6. CHARACTERIZATION AND FUNCTIONAL STUDY OF A PUTATIVE JUVENILE HORMONE DIOL KINASE IN THE COLORADO POTATO BEETLE Leptinotarsa decemlineata (Say).

    PubMed

    Fu, Kai-Yun; Lü, Feng-Gong; Guo, Wen-Chao; Li, Guo-Qing

    2015-11-01

    Juvenile hormone diol kinase (JHDK) is an enzyme involved in JH degradation. In the present article, a putative JHDK cDNA (LdJHDK) was cloned from the Colorado potato beetle Leptinotarsa decemlineata. The cDNA consists of 814 bp, containing a 555 bp open reading frame encoding a 184 amino acid protein. LdJHDK reveals a high degree of identity to the previously reported insect JHDKs. It possesses three conserved purine nucleotide-binding elements, and contains three EF-hand motifs (helix-loop-helix structural domains). LdJHDK mRNA was mainly detected in hindgut and Malpighian tubules. Besides, a trace amount of LdJHDK mRNA was also found in thoracic muscles, brain-corpora cardiaca-corpora allata complex, foregut, midgut, ventral ganglia, fat body, epidermis, and hemocytes. Moreover, LdJHDK was expressed throughout all developmental stages. Within the first, second, and third larval instar, the expression levels of LdJHDK were higher just before and right after the molt, and were lower in the intermediate instar. In the fourth larval instar, the highest peak of LdJHDK occurred 56 h after ecdysis. Ingestion of double-stranded RNA (dsRNA) against LdJHDK successfully knocked down the target gene, increased JH titer, and significantly upregulated LdKr-h1 mRNA level. Knockdown of LdJHDK significantly impaired adult emergence. Thus, we provide a line of experimental evidence in L. decemlineata to support that LdJHDK encodes function protein involved in JH degradation.

  7. Examination of the influence of juvenile Atlantic salmon on the feeding mode of juvenile steelhead in Lake Ontario tributaries

    USGS Publications Warehouse

    Johnson, James H.; Waldt, Emily M.

    2014-01-01

    We examined diets of 1204 allopatric and sympatric juvenile Atlantic salmon (Salmo salar) and steelhead (Oncorhynchus mykiss) in three tributaries of Lake Ontario. The diet composition of both species consisted primarily of ephemeropterans, trichopterans, and chironomids, although juvenile steelhead consumed more terrestrial invertebrates, especially at the sympatric sites. Subyearlings of both species consumed small prey (i.e. chironomids) whereas large prey (i.e. perlids) made up a higher percentage of the diet of yearlings. The diet of juvenile steelhead at the allopatric sites was more closely associated with the composition of the benthos than with the drift, but was about equally associated with the benthos and drift at the sympatric sites. The diet of both subyearling and yearling Atlantic salmon was more closely associated with the benthos than the drift at the sympatric sites. The evidence suggests that juvenile steelhead may subtly alter their feeding behavior in sympatry with Atlantic salmon. This behavioral adaptation may reduce competitive interactions between these species.

  8. Does sex influence intraspecific aggression and dominance in Nile tilapia juveniles?

    PubMed

    Pinho-Neto, Cândido Ferreira; Miyai, Caio Akira; Sanches, Fabio Henrique Carretero; Giaquinto, Percília Cardoso; Delicio, Helton Carlos; Barcellos, Leonardo José Gil; Volpato, Gilson Luiz; Barreto, Rodrigo Egydio

    2014-06-01

    Although sex of mature fish is known to influence aggression, this issue has so far been neglected in juveniles. Here, we tested this sex effect and showed that it does not significantly affect intraspecific aggression in juveniles of the cichlid Nile tilapia. To reach this conclusion, we measured the latency period before onset of confrontation, the frequency and types of aggressive interactions, the duration of a dispute, and the probability of becoming dominant. This was done on pairs of Nile tilapia that varied by sex: females×females, males×males, and females×males. In a double blind approach, after pairing, the sex of each individual was histologically verified and contrasted with behavioral data.

  9. SEX-STEROID AND THYROID HORMONE CONCENTRATIONS IN JUVENILE ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS) FROM CONTAMINATED AND REFERENCE LAKES IN FLORIDA, USA

    EPA Science Inventory

    Sex-steroid and thyroid hormones are critical regulators of growth and reproduction in all vertebrates, and several recent studies suggest that environmental chemicals can alter circulating concentrations of these hormones. This study examines plasma concentrations of estradiol-...

  10. Sexual difference in juvenile-hormone titer in workers leads to sex-biased soldier differentiation in termites.

    PubMed

    Toga, Kouhei; Hanmoto, Shutaro; Suzuki, Ryutaro; Watanabe, Dai; Miura, Toru; Maekawa, Kiyoto

    2016-04-01

    In termites, the soldier caste, with its specialized defensive morphology, is one of the most important characteristics for sociality. Most of the basal termite species have both male and female soldiers, and the soldier sex ratio is almost equal or only slightly biased. However, in the apical lineages (especially family Termitidae), there are many species that have soldiers with strongly biased sex ratio. Generally in termites, since high juvenile hormone (JH) titer is required for soldier differentiation from a worker via a presoldier stage, it was hypothesized that the biased soldier-sex ratio was caused by differences in JH sensitivity and/or JH titer between male and female workers. Therefore, we focused on the presoldier differentiation and the worker JH titer in species with only male soldiers (Nasutitermes takasagoensis) and with both male and female soldiers (Reticulitermes speratus) in natural conditions. In the former species, there are four types of workers; male minor, male medium, female medium and female major workers, and presoldiers differentiate from male minor workers. First, we tried to artificially induce presoldiers from male and female workers. In N. takasagoensis, the presoldier differentiation rate and mortality was significantly higher in male minor workers. Morphological analyses showed that both male and female induced presoldiers possessed normal soldier-specific morphologies. It was suggested that female workers, from which soldiers do not differentiate under natural conditions, also maintained the physiological and developmental potential for soldier differentiation. In R. speratus, however, no differences were observed in solder differentiation rate and mortality between male and female workers. Second, the JH titers of each sex/type of workers were quantified by high performance liquid chromatography-mass spectrometry in two different seasons (April and December). The results showed that, in N. takasagoensis, JH titer in male minor

  11. Sexual difference in juvenile-hormone titer in workers leads to sex-biased soldier differentiation in termites.

    PubMed

    Toga, Kouhei; Hanmoto, Shutaro; Suzuki, Ryutaro; Watanabe, Dai; Miura, Toru; Maekawa, Kiyoto

    2016-04-01

    In termites, the soldier caste, with its specialized defensive morphology, is one of the most important characteristics for sociality. Most of the basal termite species have both male and female soldiers, and the soldier sex ratio is almost equal or only slightly biased. However, in the apical lineages (especially family Termitidae), there are many species that have soldiers with strongly biased sex ratio. Generally in termites, since high juvenile hormone (JH) titer is required for soldier differentiation from a worker via a presoldier stage, it was hypothesized that the biased soldier-sex ratio was caused by differences in JH sensitivity and/or JH titer between male and female workers. Therefore, we focused on the presoldier differentiation and the worker JH titer in species with only male soldiers (Nasutitermes takasagoensis) and with both male and female soldiers (Reticulitermes speratus) in natural conditions. In the former species, there are four types of workers; male minor, male medium, female medium and female major workers, and presoldiers differentiate from male minor workers. First, we tried to artificially induce presoldiers from male and female workers. In N. takasagoensis, the presoldier differentiation rate and mortality was significantly higher in male minor workers. Morphological analyses showed that both male and female induced presoldiers possessed normal soldier-specific morphologies. It was suggested that female workers, from which soldiers do not differentiate under natural conditions, also maintained the physiological and developmental potential for soldier differentiation. In R. speratus, however, no differences were observed in solder differentiation rate and mortality between male and female workers. Second, the JH titers of each sex/type of workers were quantified by high performance liquid chromatography-mass spectrometry in two different seasons (April and December). The results showed that, in N. takasagoensis, JH titer in male minor

  12. Family-specific differences in growth rate and hepatic gene expression in juvenile triploid growth hormone (GH) transgenic Atlantic salmon (Salmo salar).

    PubMed

    Xu, Qingheng; Feng, Charles Y; Hori, Tiago S; Plouffe, Debbie A; Buchanan, John T; Rise, Matthew L

    2013-12-01

    Growth hormone transgenic (GHTg) Atlantic salmon (Salmo salar) have enhanced growth when compared to their non-transgenic counterparts, and this trait can be beneficial for aquaculture production. Biological confinement of GHTg Atlantic salmon may be achieved through the induction of triploidy (3N). The growth rates of triploid GH transgenic (3NGHTg) Atlantic salmon juveniles were found to significantly vary between families in the AquaBounty breeding program. In order to characterize gene expression associated with enhanced growth in juvenile 3NGHTg Atlantic salmon, a functional genomics approach (32K cDNA microarray hybridizations followed by QPCR) was used to identify and validate liver transcripts that were differentially expressed between two fast-growing 3NGHTg Atlantic salmon families (AS11, AS26) and a slow-growing 3NGHTg Atlantic salmon family (AS25); juvenile growth rate was evaluated over a 45-day period. Of 687 microarray-identified differentially expressed features, 143 (116 more highly expressed in fast-growing and 27 more highly expressed in slow-growing juveniles) were identified in the AS11 vs. AS25 microarray study, while 544 (442 more highly expressed in fast-growing and 102 more highly expressed in slow-growing juveniles) were identified in the AS26 vs. AS25 microarray study. Forty microarray features (39 putatively associated with fast growth and 1 putatively associated with slow growth) were present in both microarray experiment gene lists. The expression levels of 15 microarray-identified transcripts were studied using QPCR with individual RNA samples to validate microarray results and to study biological variability of transcript expression. The QPCR results agreed with the microarray results for 12 of 13 putative fast-growth associated transcripts, but QPCR did not validate the microarray results for 2 putative slow-growth associated transcripts. Many of the 39 microarray-identified genes putatively associated at the transcript expression

  13. Youth pathways to placement: the influence of gender, mental health need and trauma on confinement in the juvenile justice system.

    PubMed

    Espinosa, Erin M; Sorensen, Jon R; Lopez, Molly A

    2013-12-01

    Although the juvenile crime rate has generally declined, the involvement of girls in the juvenile justice system has been increasing. Possible explanations for this gender difference include the impact of exposure to trauma and mental health needs on developmental pathways and the resulting influence of youth's involvement in the justice system. This study examined the influence of gender, mental health needs and trauma on the risk of out-of-home placement for juvenile offenders. The sample included youth referred to three urban juvenile probation departments in Texas between January 1, 2007 and December 31, 2008 and who received state-mandated mental health screening (N = 34,222; 30.1 % female). The analysis revealed that, for both genders, elevated scores on the seven factor-analytically derived subscales of a mental health screening instrument (Alcohol and Drug Use, Depressed-Anxious, Somatic Complaints, Suicidal Ideation, Thought Disturbance, and Traumatic Experiences), especially related to past traumatic experiences, influenced how deeply juveniles penetrated the system. The findings suggest that additional research is needed to determine the effectiveness of trauma interventions and the implementation of trauma informed systems for youth involved with the juvenile justice system. PMID:23824982

  14. The Influence of Sex Hormones on Functional Cerebral Asymmetries in Postmenopausal Women

    ERIC Educational Resources Information Center

    Bayer, Ulrike; Erdmann, Gisela

    2008-01-01

    Studies investigating changes in functional cerebral asymmetries (FCAs) with hormonal fluctuations during the menstrual cycle in young women have led to controversial hypotheses about an influence of estrogen (E) and/or progesterone (P) on FCAs. Based on methodical, but also on principal problems in deriving conclusions about hormone effects from…

  15. How hormones influence composition and physiological function of the brain-blood barrier.

    PubMed

    Hampl, R; Bičíková, M; Sosvorová, L

    2015-01-01

    Hormones exert many actions in the brain. Their access and effects in the brain are regulated by the blood-brain barrier (BBB). Hormones as other substances may enter the brain and vice versa either by paracellular way requiring breaching tight junctions stitching the endothelial cells composing the BBB, or by passage through the cells (transcellular way). Hormones influence both ways through their receptors, both membrane and intracellular, present on/in the BBB. In the review the main examples are outlined how hormones influence the expression and function of proteins forming the tight junctions, as well as how they regulate expression and function of major protein transporters mediating transport of various substances including hormone themselves.

  16. Naturally occurring insect growth regulators. II. Screening of insect and plant extracts as insect juvenile hormone mimics.

    PubMed

    Jacobson, M; Redfern, R E; Mills, G D

    1975-01-01

    Ethereal extracts prepared from the larvae, pupae, or eggs of 10 species of insects and from various parts of 343 species of higher plants were screened for juvenilizing effects against Tenebrio molitor and Oncopeltus fasciatus. Activity in both species was shown by an extract of the larvae of the stable fly, Stomoxys calcitrans, whereas an extract of the pupae was active in O. fasiatus only. Extracts of two plant species (Echinacea angustifolia roots and Chamaecyparis lawsoniana seeds) showed high juvenilizing activity in T. MOLITOR, AND EXtracts of five plant species (Clethra alnifolia stems, leaves, and fruits, Sassafras albidum roots and root bark, Eucalyptus camaldulensis stems and bark, Pinus rigida twigs and leaves, and Iris douglasiana roots, stems, and fruits) were highly active in O. fasciatus an extract of Tsuga canadensis leaves showed lower activity in this insect. Extracts of 16 species of plants showed high insecticidal activity (mortality) in O. fasciatus but lacked juvenilizing properties in both species of test insects.

  17. COMPARATIVE EMBRYONIC AND LARVAL DEVELOPMENTAL RESPONSES OF THE ESTUARINE GRASS SHRIMP (PALAEMONETES PUGIO) TO THE JUVENILE HORMONE AGONIST FENOXYCARB

    EPA Science Inventory

    This work was undertaken in order to develop a sensitive bioassay which indicates adverse effects of estuarine-applied insecticides on nontarget species. Newly developed 'third generation' insecticides are designed to act as hormone agonists and bind to endogenous insect hormone...

  18. VARIATION IN GROWTH, LIPID CLASS AND FATTY ACID COMPOSITION OF THE MUD CRAB, RHITHROPANOPEUS HARRISII (GOULD) DURING LARVAL DEVELOPMENT FOLLOWING EXPOSURE TO AN INSECT JUVENILE HORMONE ANALOG (FENOXYCARB(R))

    EPA Science Inventory

    This study examines the effects of fenoxycarb?, an insect juvenile hormone (JH) analog, on larval growth, and lipid class and fatty acid composition in first crabs of the mud crab Rhithropanopeus harrisii reared through total larval development in nominal water concentrations fr...

  19. Hypermetabolic Conversion of Plant Oil into Water: Endothermic Biochemical Process Stimulated by Juvenile Hormone in the European Firebug, Pyrrhocoris apterus L.

    PubMed Central

    Sláma, Karel; Lukáš, Jan

    2016-01-01

    The physiological and biochemical mechanisms that enable insects to feed on dry food to secure enough water for larval growth were investigated. The study was carried out with a plethora of physiological methods, ranging from the simple volumetric determination of O2 consumption and water intake to more advanced methods such as scanning microrespirography and thermovision imaging of insect’s body temperature. The experiments were done on the European firebug, Pyrrhocoris apterus, which feeds exclusively on dry linden seeds. In order to survive, it needs to drink water or suck a sap from plants occasionally. It was found that the young larval instars compensate the occasional water deficiency by the increased production of metabolic water. The juvenile hormone (JH)-dependent production of metabolic water, which was previously found in other species consuming dry food, was achieved in P. apterus by total metabolic combustion of the dietary lipid (neutral seed oil). The water-producing, hypermetabolic larvae were heated from inside by endothermic energy released from the uncoupling of oxidation from oxidative phosphorylation. The “warm”, hypermetabolic larvae burning the dietary oil into CO2 and water showed the increased rates of respiratory metabolism. Microrespirographic recording of these larvae revealed the ratio of the respiratory quotient (RQ, CO2/O2) of 0.7, which indicated the breakdown of a pure triglyceride. The warm hypermetabolic larvae could be easily spotted and distinguished from the “cold” larvae on the screen of a thermovision camera. The last instar larvae lacking the JH were always only cold. They metabolized a carbohydrate substrate exclusively (RQ = 1.0), while the dietary lipid was stored in the fat body. In comparison with the hypermetabolic larvae of some other species fed on dry food, which exhibited the highest rates of O2 consumption ever recorded in a living organism (10–20 mL O2/g per hour), the metabolic difference between

  20. Early Hormonal Influences on Cognitive Functioning in Congenital Adrenal Hyperplasia.

    ERIC Educational Resources Information Center

    Resnick, Susan M.; And Others

    1986-01-01

    Reports the results of cognitive test performance and early childhood activities in individuals with congenital adrenal hyperplasia, an autosomal recessive disorder associated with elevated prenatal adrenal androgen levels, demonstrating the effects of early exposure to excess androgenizing hormones on sexually dimorphic cognitive functioning.…

  1. Establishment of a short-term, in vivo screening method for detecting chemicals with juvenile hormone activity using adult Daphnia magna.

    PubMed

    Abe, Ryoko; Watanabe, Haruna; Yamamuro, Masumi; Iguchi, Taisen; Tatarazako, Norihisa

    2015-01-01

    Juvenile hormone (JH) and JH agonists have been shown to induce male offspring production in various daphnids, including Daphnia magna using OECD TG211. The critical period (about 1h) for JH action on ova in the parent's ovary to induce male offspring is existing at 7-8h later from ovulation. Therefore, we considered that adult D. magna could be used to produce a short-term screening method for detecting JH analogs. Using this method, we successfully demonstrated male offspring induction in the second broods after exposure to JH or JH agonists. After investigating the exposure time, the number of repetitions and the exposure concentration, we established a short-term, in vivo screening method for detecting JH analogs using adult D. magna. We examined positive and negative control chemicals using a previously developed method and verified the validity of our new testing method.

  2. The essence of insect metamorphosis and aging: electrical rewiring of cells driven by the principles of juvenile hormone-dependent Ca(2+)-homeostasis.

    PubMed

    De Loof, Arnold; De Haes, Wouter; Janssen, Tom; Schoofs, Liliane

    2014-04-01

    In holometabolous insects the fall to zero of the titer of Juvenile Hormone ends its still poorly understood "status quo" mode of action in larvae. Concurrently it initiates metamorphosis of which the programmed cell death of all internal tissues that actively secrete proteins, such as the fat body, midgut, salivary glands, prothoracic glands, etc. is the most drastic aspect. These tissues have a very well developed rough endoplasmic reticulum, a known storage site of intracellular Ca(2+). A persistent high [Ca(2+)]i is toxic, lethal and causal to apoptosis. Metamorphosis becomes a logical phenomenon if analyzed from: (1) the causal link between calcium toxicity and apoptosis; (2) the largely overlooked fact that at least some isoforms of Ca(2+)-ATPases have a binding site for farnesol-like endogenous sesquiterpenoids (FRS). The Ca(2+)-ATPase blocker thapsigargin, like JH a sesquiterpenoid derivative, illustrates how absence of JH might work. The Ca(2+)-homeostasis system is concurrently extremely well conserved in evolution and highly variable, enabling tissue-, developmental-, and species specificity. As long as JH succeeds in keeping [Ca(2+)]i low by keeping the Ca(2+)-ATPases pumping, it acts as "the status quo" hormone. When it disappears, its various inhibitory effects are lifted. The electrical wiring system of cells, in particular in the regenerating tissues, is subject to change during metamorphosis. The possibility is discussed that in vertebrates an endogenous farnesol-like sesquiterpenoid, probably farnesol itself, acts as a functional, but hitherto completely overlooked Juvenile anti-aging "Inbrome", a novel concept in signaling.

  3. Influence of diabetes surgery on gut hormones and incretins.

    PubMed

    Papamargaritis, D; Miras, A D; le Roux, Carel W

    2013-03-01

    The dramatic rise in the prevalence of obesity and type 2 diabetes mellitus (T2DM) has become a major global public health issue. There is increasing evidence that metabolic surgery is more effective than diet and exercise for diabetes remission and weight loss. Moreover, the rapid time course and disproportional degree of T2DM improvement after metabolic procedures compared with equivalent weight loss with conservative treatment, suggest surgery-specific, weight-independent effects on glucose homeostasis. Gut hormones has been proposed as one of the potential mechanisms for the weight-independent diabetes remission and long-term weight loss after these procedures. In this review we discuss the available current metabolic procedures and we review the current human data on changes in gut hormones after each metabolic procedure.

  4. Hormonal response to exercise in humans: influence of hypoxia and physical training.

    PubMed

    Kjaer, M; Bangsbo, J; Lortie, G; Galbo, H

    1988-02-01

    Hypoxia and physical training alter the responses of glucoregulatory hormones to absolute work loads in opposite directions. These effects have tentatively been ascribed to changes in maximal O2 consumption (VO2 max) and ensuing changes in relative work loads. However, hypoxia as well as training may more specifically influence the hormonal response. We therefore differentiated the influence of hypoxia, training, and VO2 max, respectively, on the hormonal response to bicycle exercise. Responses to hypoxia in a low-pressure chamber (PB = 465 vs. 730 Torr) were studied at given absolute and relative (85% VO2 max) work loads in seven endurance-trained athletes (T) and 7 age and weight-matched sedentary subjects (C). Concentrations in plasma of norepinephrine, growth hormone, adrenocorticotropic hormone, and cortisol were always closely related to the relative work load. However, the epinephrine response in T, but not in C, was at the same relative work load higher during hypoxia (5.84 +/- 0.83 nmol/l) than during normoxia (4.26 +/- 0.44, P less than 0.05). These results indicate that the hormonal response is influenced by hypoxia and physical training, mainly via changes in the relative work load. However, in trained subjects both at rest and during exercise, an enhancing effect of hypoxia per se on the epinephrine response is seen, probably due to an increased adrenal medullary secretory responsiveness in long-term endurance-trained subjects.

  5. Effects of the juvenile hormone analogue methoprene on rate of behavioural development, foraging performance and navigation in honey bees (Apis mellifera).

    PubMed

    Chang, Lun-Hsien; Barron, Andrew B; Cheng, Ken

    2015-06-01

    Worker honey bees change roles as they age as part of a hormonally regulated process of behavioural development that ends with a specialised foraging phase. The rate of behavioural development is highly plastic and responsive to changes in colony condition such that forager losses, disease or nutritional stresses accelerate behavioural development and cause an early onset of foraging in workers. It is not clear to what degree the behavioural development of workers can be accelerated without there being a cost in terms of reduced foraging performance. Here, we compared the foraging performance of bees induced to accelerate their behavioural development by treatment with the juvenile hormone analogue methoprene with that of controls that developed at a normal rate. Methoprene treatment accelerated the onset of both flight and foraging behaviour in workers, but it also reduced foraging span, the total time spent foraging and the number of completed foraging trips. Methoprene treatment did not alter performance in a short-range navigation task, however. These data indicate a limitation to the physiological plasticity of bees, and a trade off between forager performance and the speed at which bees begin foraging. Chronic stressors will be expected to reduce the mean age of the foraging force, and therefore also reduce the efficiency of the foraging force. This interaction may explain why honey bee colonies react to sustained stressors with non-linear population decline.

  6. A Juvenile Hormone Transcription Factor Bmdimm-Fibroin H Chain Pathway Is Involved in the Synthesis of Silk Protein in Silkworm, Bombyx mori*

    PubMed Central

    Zhao, Xiao-Ming; Liu, Chun; Jiang, Li-Jun; Li, Qiong-Yan; Zhou, Meng-Ting; Cheng, Ting-Cai; Mita, Kazuei; Xia, Qing-You

    2015-01-01

    The genes responsible for silk biosynthesis are switched on and off at particular times in the silk glands of Bombyx mori. This switch appears to be under the control of endogenous and exogenous hormones. However, the molecular mechanisms by which silk protein synthesis is regulated by the juvenile hormone (JH) are largely unknown. Here, we report a basic helix-loop-helix transcription factor, Bmdimm, its silk gland-specific expression, and its direct involvement in the regulation of fibroin H-chain (fib-H) by binding to an E-box (CAAATG) element of the fib-H gene promoter. Far-Western blots, enzyme-linked immunosorbent assays, and co-immunoprecipitation assays revealed that Bmdimm protein interacted with another basic helix-loop-helix transcription factor, Bmsage. Immunostaining revealed that Bmdimm and Bmsage proteins are co-localized in nuclei. Bmdimm expression was induced in larval silk glands in vivo, in silk glands cultured in vitro, and in B. mori cell lines after treatment with a JH analog. The JH effect on Bmdimm was mediated by the JH-Met-Kr-h1 signaling pathway, and Bmdimm expression did not respond to JH by RNA interference with double-stranded BmKr-h1 RNA. These data suggest that the JH regulatory pathway, the transcription factor Bmdimm, and the targeted fib-H gene contribute to the synthesis of fibroin H-chain protein in B. mori. PMID:25371208

  7. Juvenile hormone-stimulated synthesis of acyl-glycerols and vitamin E in female accessory sexual glands of the fire bug, Pyrrhocoris apterus L.

    PubMed

    Jedlicka, Pavel; Cvacka, Josef; Sláma, Karel

    2009-09-01

    Secretory cells of the female accessory sexual glands (AG) of P. apterus grow and produce yellow oily exocrine secretion in response to stimulation by endogenous juvenile hormone (JH) or exogenous treatments by JH analogues. The secretion determines the property of future egg shells by coating the chorion surface of the oocytes that are passing individually through the common uterus during oviposition. Diapausing females with a physiologically inhibited endocrine system or females with artificially removed hormonal sources show inactive ovaries and empty AG without the secretory products. Ovary-ectomised females with the intact neuroendocrine system develop hypertrophic AG loaded with the oily secretion. This shows that there is no direct dependence between formation of the oily secretion in AG and ovarian growth. Chemical analysis of the secretory products revealed the presence of acetylated glycerols, with the most abundant stearoyl-diacetyl-glycerol, stearoyl-acetyl-propionyl-glycerol, and the corresponding derivatives of arachidonic acid. In addition to this, the JH-activated secretory cells of AG also produced gamma- and delta-tocopherols. The possible antioxidant or antimutagenic action of these vitamin E compounds in insect reproduction has been emphasized.

  8. Effects of the juvenile hormone analogue methoprene on rate of behavioural development, foraging performance and navigation in honey bees (Apis mellifera).

    PubMed

    Chang, Lun-Hsien; Barron, Andrew B; Cheng, Ken

    2015-06-01

    Worker honey bees change roles as they age as part of a hormonally regulated process of behavioural development that ends with a specialised foraging phase. The rate of behavioural development is highly plastic and responsive to changes in colony condition such that forager losses, disease or nutritional stresses accelerate behavioural development and cause an early onset of foraging in workers. It is not clear to what degree the behavioural development of workers can be accelerated without there being a cost in terms of reduced foraging performance. Here, we compared the foraging performance of bees induced to accelerate their behavioural development by treatment with the juvenile hormone analogue methoprene with that of controls that developed at a normal rate. Methoprene treatment accelerated the onset of both flight and foraging behaviour in workers, but it also reduced foraging span, the total time spent foraging and the number of completed foraging trips. Methoprene treatment did not alter performance in a short-range navigation task, however. These data indicate a limitation to the physiological plasticity of bees, and a trade off between forager performance and the speed at which bees begin foraging. Chronic stressors will be expected to reduce the mean age of the foraging force, and therefore also reduce the efficiency of the foraging force. This interaction may explain why honey bee colonies react to sustained stressors with non-linear population decline. PMID:25883376

  9. Modelling the Influence of Long-Term Hydraulic Conditions on Juvenile Salmon Habitats in AN Upland Scotish River

    NASA Astrophysics Data System (ADS)

    Fabris, L.; Malcolm, I.; Millidine, K. J.; Buddendorf, B.; Tetzlaff, D.; Soulsby, C.

    2015-12-01

    Wild Atlantic salmon populations in Scottish rivers constitute an important economic and recreational resource, as well as being a key component of biodiversity. Salmon have very specific habitat requirements at different life stages and their distribution is therefore strongly influenced by a complex suite of biological and physical controls. Previous research has shown that stream hydrodynamics and channel morphology have a strong influence on the distribution and density of juvenile salmon. Here, we utilise a unique 20 year data set of spatially distributed juvenile salmon densities derived from annual electro-fishing surveys in an upland Scottish river. We examine to what extent the spatial and temporal variability of in-stream hydraulics regulates the spatial and temporal variability in the performance and density of juvenile salmon. A 2-D hydraulic model (River2D) is used to simulate water velocity and water depth under different flow conditions for seven different electro-fishing sites. The selected sites represent different hydromorphological environments including plane-bed, step-pool and pool riffle reaches. The bathymetry of each site was characterised using a total station providing an accurate DTM of the bed, and hydraulic simulations were driven by 20 year stream flow records. Habitat suitability curves, based on direct observations during electro-fishing surveys, were produced for a range of hydraulic indices for juvenile salmon. The hydraulic simulations showed marked spatial differences in juvenile habitat quality both within and between reaches. They also showed marked differences both within and between years. This is most evident in extreme years with wet summers when salmon feeding opportunities may be constrained. Integration of hydraulic habitat models, with fish preference curves and the long term hydrological data allows us to assess whether long-term changes in hydroclimate may be affecting juvenile salmonid populations in the study stream

  10. Body size and condition influence migration timing of juvenile Arctic grayling

    USGS Publications Warehouse

    Heim, Kurt C.; Wipfli, Mark S.; Whitman, Matthew S.; Seitz, Andrew C

    2016-01-01

    Freshwater fishes utilising seasonally available habitats within annual migratory circuits time movements out of such habitats with changing hydrology, although individual attributes of fish may also mediate the behavioural response to environmental conditions. We tagged juvenile Arctic grayling in a seasonally flowing stream on the Arctic Coastal Plain in Alaska and recorded migration timing towards overwintering habitat. We examined the relationship between individual migration date, and fork length (FL) and body condition index (BCI) for fish tagged in June, July and August in three separate models. Larger fish migrated earlier; however, only the August model suggested a significant relationship with BCI. In this model, 42% of variability in migration timing was explained by FL and BCI, and fish in better condition were predicted to migrate earlier than those in poor condition. Here, the majority (33%) of variability was captured by FL with an additional 9% attributable to BCI. We also noted strong seasonal trends in BCI reflecting overwinter mass loss and subsequent growth within the study area. These results are interpreted in the context of size and energetic state-specific risks of overwinter starvation and mortality (which can be very high in the Arctic), which may influence individuals at greater risk to extend summer foraging in a risky, yet prey rich, habitat. Our research provides further evidence that heterogeneity among individuals within a population can influence migratory behaviour and identifies potential risks to late season migrants in Arctic beaded stream habitats influenced by climate change and petroleum development.

  11. Dietary contaminant exposure affects plasma testosterone, but not thyroid hormones, vitamin A, and vitamin E, in male juvenile arctic foxes (Vulpes lagopus).

    PubMed

    Hallanger, Ingeborg G; Jørgensen, Even H; Fuglei, Eva; Ahlstrøm, Øystein; Muir, Derek C G; Jenssen, Bjørn Munro

    2012-01-01

    Levels of persistent organic pollutants (POP), such as polychlorinated biphenyls (PCB), are high in many Arctic top predators, including the Arctic fox (Vulpes lagopus). The aim of this study was to examine possible endocrine-disruptive effects of dietary POP exposure in male juvenile Arctic foxes in a controlled exposure experiment. The study was conducted using domesticated farmed blue foxes (Vulpes lagopus) as a model species. Two groups of newly weaned male foxes received a diet supplemented with either minke whale (Baleneoptera acutorostrata) blubber that was naturally contaminated with POP (exposed group, n = 5 or 21), or pork (Sus scrofa) fat (control group, n = 5 or 21). When the foxes were 6 mo old and had received the 2 diets for approximately 4 mo (147 d), effects of the dietary exposure to POP on plasma concentrations of testosterone (T), thyroid hormones (TH), thyroid-stimulating hormone (TSH), retinol (vitamin A), and tocopherol (viramin E) were examined. At sampling, the total body concentrations of 104 PCB congeners were 0.1 ± 0.03 μg/g lipid weight (l.w.; n = 5 [mean ± standard deviation]) and 1.5 ± 0.17 μg/g l.w. (n = 5) in the control and exposed groups, respectively. Plasma testosterone concentrations in the exposed male foxes were significantly lower than in the control males, being approximately 25% of that in the exposed foxes. There were no between-treatment differences for TH, TSH, retinol, or tocopherol. The results suggest that the high POP levels experienced by costal populations of Arctic foxes, such as in Svalbard and Iceland, may result in delayed masculine maturation during adolescence. Sex hormone disruption during puberty may thus have lifetime consequences on all aspects of reproductive function in adult male foxes. PMID:23030655

  12. Neuronal influence on hormone release from anglerfish islet cells.

    PubMed

    Milgram, S L; McDonald, J K; Noe, B D

    1991-10-01

    Pancreatic islets in anglerfish (AF) are macroscopic collections of nearly pure endocrine cells that are densely innervated. Immunohistochemical staining for neurotransmitter biosynthetic enzymes revealed noradrenergic and cholinergic innervation of AF islets. An in vitro preparation of perifused dispersed AF islet cells was developed to study nutrient and neural control of islet hormone secretion. Glucose stimulated insulin and somatostatin-14 (SS-14) secretion in a dose-dependent manner, and 16.7 mM glucose inhibited glucagon secretion. In 2 mM glucose, norepinephrine and isoproterenol stimulated glucagon and SS-14 release. Isoproterenol stimulated insulin secretion, and norepinephrine stimulated or inhibited insulin release, depending on the concentration. Clonidine potently inhibited glucose-stimulated insulin secretion but stimulated glucagon release. Methacholine, a muscarinic cholinergic agonist, stimulated insulin, glucagon, and SS-14 release. The control of AF hormone release by neurotransmitter agonists in vitro was similar to that in higher vertebrate species. Therefore we used this tissue preparation to study postsynaptic interactions between glucose and neurotransmitters in islets. PMID:1681734

  13. Effect of a peri-juvenile exposure to Triclosan on serum androgens and thyroid hormone in the male Wistar rat

    EPA Science Inventory

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is a potent antibacterial and antifungal compound that is widely used in personal care products. Studies testing triclosan exposure in the bullfrog showed altered thyroid hormone homeostasis. More recently, triclosan has been s...

  14. [Juvenile angiofibroma].

    PubMed

    Thuesen, Anne Daugaard; Jakobsen, John; Nepper-Rasmussen, Jørgen

    2005-08-22

    Juvenile angiofibroma is a rare, benign, rich vascular tumor, and approximately one new case is diagnosed in Denmark each year. It sits in the foramen sphenopalatinum and occurs in boys from 14 to 25 years of age. The most frequent initial symptoms are nasal obstruction and epistaxis. Through the years, the treatment of juvenile angiofibroma has included many methods, including surgical excision, electrocoagulation, interstitial or external radiation therapy, cryosurgery, hormone administration and chemotherapy. Radiation, chemotherapy and surgery have proven to be the most effective treatments. The most serious complication has been preoperative bleeding, but since the introduction of preoperative particle embolization the blood loss has been greatly reduced. Today, surgery preceded by embolization is the primary standard treatment. It is important to diagnose the tumor early, when radical surgery is easier and the frequency of recurrence is lower.

  15. Influence of infant and juvenile diets on serum cholesterol, lipoprotein cholesterol, and apolipoprotein concentrations in juvenile baboons (Papio sp.).

    PubMed

    Mott, G E; McMahan, C A; Kelley, J L; Farley, C M; McGill, H C

    1982-11-01

    The long-term effects of infant diet (breast milk or formula containing 2, 30, or 60 mg/dl cholesterol) and subsequent dietary cholesterol (1 mg/kcal) and fat (saturated or unsaturated) on serum lipid and apolipoprotein concentrations were estimated using 82 juvenile baboons 4-6 years of age. A significant interaction of infant diet (breast vs formula) with type of fat (saturated vs unsaturated) at 4-6 years of age was observed on HDL cholesterol and apolipoprotein A-I (apoA-I) concentrations. That is, animals breast-fed as infants had higher HDL cholesterol and apoA-I concentrations when fed unsaturated fat from weaning to 4-6 years of age than those fed saturated fat (77 vs 68 mg/dl). In contrast, animals fed formulas in infancy followed by a diet containing unsaturated fat had lower HDL cholesterol and apoA-I concentrations at 4-6 years of age than did those fed saturated fat (67 vs 78 mg/dl). However, breast feeding or feeding formulas containing various levels of cholesterol for 3 months during infancy did not result in statistically significant differences in total serum cholesterol, VLDL + LDL cholesterol and apolipoprotein B (apoB) concentrations. Dietary cholesterol after infancy significantly increased serum total cholesterol, VLDL + LDL and HDL cholesterol, apoA-I and apoB concentrations. All of these response variables also were higher in animals fed saturated fat compared to those fed unsaturated fat on the same level of cholesterol. At 4-6 years of age, regardless of diet, females had significantly higher serum VLDL + LDL cholesterol (57 vs 43 mg/dl) and apoB concentrations (39 vs 30 mg/dl) than did males.

  16. Molecular Cloning and Characterization of Juvenile Hormone Acid Methyltransferase in the Honey Bee, Apis mellifera, and Its Differential Expression during Caste Differentiation

    PubMed Central

    Li, Wenfeng; Huang, Zachary Y.; Liu, Fang; Li, Zhiguo; Yan, Limin; Zhang, Shaowu; Chen, Shenglu; Zhong, Boxiong; Su, Songkun

    2013-01-01

    Juvenile hormone acid methyltransferase (JHAMT) is an enzyme involved in one of the final steps of juvenile hormone biosynthesis in insects. It transfers a methyl group from S-adenosyl-L-methionine (SAM) to the carboxyl group of either farnesoic acid (FA) or JH acid (JHA). Several genes coding for JHAMT have been cloned and characterized from insects from different orders, and they have been shown to play critical roles in metamorphosis and reproduction. However, the significance of JHAMT in Hymenopteran insects is unknown. We used RACE amplification method to clone JHAMT cDNA from the honey bee, Apis mellifera (AmJHAMT). The full length cDNA of AmJHAMT that we cloned is 1253bp long and encodes a 278-aa protein that shares 32-36% identity with known JHAMTs. A SAM-binding motif, conserved in the SAM-dependent methyltransferase (SAM-MT) superfamily, is present in AmJHAMT. Its secondary structure also contains a typical SAM-MT fold. Most of the active sites bound with SAM and substrates (JHA or FA) are conserved in AmJHAMT as in other JHAMT orthologs. Phylogenetic analysis clustered AmJHAMT with the other orthologs from Hymenoptera to form a major clade in the phylogenetic tree. Purified recombinant AmJHAMT protein expressed in E. coli was used to produce polyclonal antibodies and to verify the identity of AmJHAMT by immunoblotting and mass spectrometry. Quantitative RT-PCR and immunoblotting analyses revealed that queen larvae contained significantly higher levels of AmJHAMT mRNA and protein than worker larvae during the periods of caste development. The temporal profiles of both AmJHAMT mRNA and protein in queens and workers showed a similar pattern as the JH biosynthesis. These results suggest that the gene that we cloned codes for a functional JHAMT that catalyzes the final reactions of JH biosynthesis in honey bees. In addition, AmJHAMT may play an important role in honey bee caste differentiation. PMID:23874662

  17. Juvenile angiofibroma

    MedlinePlus

    Nasal tumor; Angiofibroma - juvenile; Benign nasal tumor; Juvenile nasal angiofibroma; JNA ... Juvenile angiofibroma is not very common. It is most often found in adolescent boys. The tumor contains ...

  18. Influence of Thyroid Hormone Disruption on the Incidence of Shingles

    PubMed Central

    Ajavon, Amakoe; Killian, Dennis; Odom, Randy; Figliozzi, Robert W.; Chen, Feng; Balish, Matthew; Parmar, Jayesh; Freeman, Robert; Snitzer, Jack; Hsia, S. Victor

    2015-01-01

    SUMMARY The reactivation of dormant alpha-Human Herpes Virus (αHHV) has been attributed to various causes often referred to as stressors. However, no clinical study investigating the relationship between stressors and reactivation exists in humans at this time. Herpes Simplex Virus Type-1 (HSV-1), an important αHHV, was shown to have its gene expression and replication regulated by Thyroid hormone (TH) using molecular biology approaches. Varicella Zoster Virus (VZV) is categorized in αHHV superfamily and shares similar homology with HSV-1. We hypothesize that a history of TH imbalance may be associated with the incidence of shingles (VZV reactivation). This current pilot study, based on a hospital medical claim database, was conducted as a retrospective case-controlled investigation to determine if a putative link between TH imbalance and incidence of shingles is present. An OR of 2.95 with a Chi-square of 51.74 was calculated for the total population diagnosed with TH disruption and shingles. Further analyses indicated that African American males exhibited much higher chance of simultaneous diagnoses. These results showed that a TH imbalance history may affect VZV reactivation at different incidence rates in different races and age groups. PMID:26189668

  19. Precocene-I inhibits juvenile hormone biosynthesis, ovarian activation, aggression and alters sterility signal production in bumble bee (Bombus terrestris) workers.

    PubMed

    Amsalem, E; Teal, P; Grozinger, C M; Hefetz, A

    2014-09-01

    Juvenile hormone (JH) is an important regulator of development and physiology in insects. While in many insect species, including bumble bees, JH functions as gonadotropin in adults, in some highly eusocial insects its role has shifted to regulate social behavior including division of labor, dominance and aggression. Studying JH functions across social insect species is important for understanding the evolution of sociality; however, these studies have been limited because of the inability to reduce JH levels without surgically removing its glandular source, the corpora allata. Precocene is known to inhibit JH biosynthesis in several non-social insects, but has been poorly studied in social insects. Here, we tested whether precocene-I can effectively reduce JH levels in Bombus terrestris workers, and examined its effects on their physiology and behavior. Precocene-I treatment of three-worker groups decreased JH titer and ovarian activation, irrespective of the bees' dominance rank within the group, and was remedied by JH replacement therapy. Precocene-I also decreased aggressiveness and increased ester-sterility signal production; these changes were rank-dependent, and affected mainly the most reproductive and the least aggressive workers, respectively, and could not be remedied by JH replacement therapy. These results clearly confirm the role of JH as a gonadotropin and mediator of aggression in B. terrestris, and indicate that JH effects are associated with worker dominance rank. The ability to chemically reduce JH titer provides us with a non-intrusive method to probe the evolutionary changes associated with JH and the hormonal mechanisms that are associated with reproduction and behavior in social insects.

  20. Influence of past breast feeding on pattern and severity of presentation of juvenile idiopathic arthritis.

    PubMed

    Hyrich, Kimme L; Baildam, Eileen; Pickford, Hannah; Chieng, Alice; Davidson, Joyce E; Foster, Helen; Gardner-Medwin, Janet; Wedderburn, Lucy R; Thomson, Wendy

    2016-04-01

    This analysis aimed to study the influence of breast feeding on the pattern and severity of juvenile idiopathic arthritis (JIA) at presentation. The association between ever versus never breast feeding and disease severity at onset was compared in 923 children with JIA recruited to the UK Childhood Arthritis Prospective Study at first presentation to rheumatology. Fifty six per cent of children were ever breast fed (median 3.7 months). Breastfed children reported a lower median age at onset, a lower Childhood Health Assessment Questionnaire (CHAQ), a measure of disease severity, lower parent general evaluation scores and lower pain at presentation. There was a trend towards a higher proportion of breastfed children with rheumatoid factor-negative polyarthritis, but lesser enthesitis-related and psoriatic arthritis. There was a statistically significant inverse association between breast feeding and high CHAQ, even after adjusting for differences in socioeconomic status (adjusted OR 0.61 (95% CI 0.39 to 0.95)). Further work to understand the reasons behind these associations is required.

  1. Inhibition of insect juvenile hormone epoxide hydrolase: asymmetric synthesis and assay of glycidol-ester and epoxy-ester inhibitors of trichoplusia ni epoxide hydrolase.

    PubMed

    Linderman, R J; Roe, R M; Harris, S V; Thompson, D M

    2000-01-01

    Juvenile hormone (JH) undergoes metabolic degradation by two major pathways involving JH esterase and JH epoxide hydrolase (EH). While considerable effort has been focussed on the study of JH esterase and the development of inhibitors for this enzyme, much less has been reported on the study of JH-EH. In this work, the asymmetric synthesis of two classes of inhibitors of recombinant JH-EH from Trichoplusia ni, a glycidol-ester series and an epoxy-ester series is reported. The most effective glycidol-ester inhibitor, compound 1, exhibited an I(50) of 1.2x10(-8) M, and the most effective epoxy-ester inhibitor, compound 11, exhibited an I(50) of 9.4x10(-8) M. The potency of the inhibitors was found to be dependent on the absolute configuration of the epoxide. In both series of inhibitors, the C-10 R-configuration was found to be significantly more potent that the corresponding C-10 S-configuration. A mechanism for epoxide hydration catalyzed by insect EH is also presented.

  2. Krüppel homolog 1 and E93 mediate Juvenile hormone regulation of metamorphosis in the common bed bug, Cimex lectularius.

    PubMed

    Gujar, Hemant; Palli, Subba Reddy

    2016-01-01

    The common bed bug is an obligate hematophagous parasite of humans. We studied the regulation of molting and metamorphosis in bed bugs with a goal to identify key players involved. qRT-PCR studies on the expression of genes known to be involved in molting and metamorphosis showed high levels of Krüppel homolog 1 [Kr-h1, a transcription factor that plays key roles in juvenile hormone (JH) action] mRNA in the penultimate nymphal stage (N4). However, low levels of Kr-h1 mRNA were detected in the fifth and last nymphal stage (N5). Knockdown of Kr-h1 in N4 resulted in a precocious development of adult structures. Kr-h1 maintains the immature stage by suppressing E93 (early ecdysone response gene) in N4. E93 expression increases during the N5 in the absence of Kr-h1 and promotes the development of adult structures. Knockdown of E93 in N5 results in the formation of supernumerary nymphs. The role of JH in the suppression of adult structures through interaction with Kr-h1 and E93 was also studied by the topical application of JH analog, methoprene, to N5. Methoprene induced Kr-h1 and suppressed E93 and induced formation of the supernumerary nymph. These data show interactions between Kr-h1, E93 and JH in the regulation of metamorphosis in the bed bugs. PMID:27185064

  3. Juvenile hormone enhances aversive learning performance in 2-day old worker honey bees while reducing their attraction to queen mandibular pheromone.

    PubMed

    McQuillan, H James; Nakagawa, Shinichi; Mercer, Alison R

    2014-01-01

    Previous studies have shown that exposing young worker bees (Apis mellifera) to queen mandibular pheromone (QMP) reduces their aversive learning performance, while enhancing their attraction to QMP. As QMP has been found to reduce the rate of juvenile hormone (JH) synthesis in worker bees, we examined whether aversive learning in 2-day old workers exposed to QMP from the time of adult emergence could be improved by injecting JH (10 µg in a 2 µl volume) into the haemolymph. We examined in addition, the effects of JH treatment on worker attraction to QMP, and on the levels of expression of amine receptor genes in the antennae, as well as in the mushroom bodies of the brain. We found that memory acquisition and 1-hour memory recall were enhanced by JH. In contrast, JH treatment reduced the bees' attraction towards a synthetic strip impregnated with QMP (Bee Boost). Levels of expression of the dopamine receptor gene Amdop1 were significantly lower in the mushroom bodies of JH-treated bees than in bees treated with vehicle alone (acetone diluted with bee ringer). Expression of the octopamine receptor gene, Amoa1, in this brain region was also affected by JH treatment, and in the antennae, Amoa1 transcript levels were significantly lower in JH-treated bees compared to controls. The results of this study suggest that QMP's effects on JH synthesis may contribute to reducing aversive learning performance and enhancing attraction to QMP in young worker bees.

  4. Genome-wide comparison of genes involved in the biosynthesis, metabolism, and signaling of juvenile hormone between silkworm and other insects.

    PubMed

    Cheng, Daojun; Meng, Meng; Peng, Jian; Qian, Wenliang; Kang, Lixia; Xia, Qingyou

    2014-06-01

    Juvenile hormone (JH) contributes to the regulation of larval molting and metamorphosis in insects. Herein, we comprehensively identified 55 genes involved in JH biosynthesis, metabolism and signaling in the silkworm (Bombyx mori) as well as 35 in Drosophila melanogaster, 35 in Anopheles gambiae, 36 in Apis mellifera, 47 in Tribolium castaneum, and 44 in Danaus plexippus. Comparative analysis showed that each gene involved in the early steps of the mevalonate (MVA) pathway, in the neuropeptide regulation of JH biosynthesis, or in JH signaling is a single copy in B. mori and other surveyed insects, indicating that these JH-related pathways or steps are likely conserved in all surveyed insects. However, each gene participating in the isoprenoid branch of JH biosynthesis and JH metabolism, together with the FPPS genes for catalyzing the final step of the MVA pathway of JH biosynthesis, exhibited an obvious duplication in Lepidoptera, including B. mori and D. plexippus. Microarray and real-time RT-PCR analysis revealed that different copies of several JH-related genes presented expression changes that correlated with the dynamics of JH titer during larval growth and metamorphosis. Taken together, the findings suggest that duplication-derived copy variation of JH-related genes might be evolutionarily associated with the variation of JH types between Lepidoptera and other insect orders. In conclusion, our results provide useful clues for further functional analysis of JH-related genes in B. mori and other insects.

  5. Juvenile Hormone Activates the Transcription of Cell-division-cycle 6 (Cdc6) for Polyploidy-dependent Insect Vitellogenesis and Oogenesis.

    PubMed

    Wu, Zhongxia; Guo, Wei; Xie, Yingtian; Zhou, Shutang

    2016-03-01

    Although juvenile hormone (JH) is known to prevent insect larval metamorphosis and stimulate adult reproduction, the molecular mechanisms of JH action in insect reproduction remain largely unknown. Earlier, we reported that the JH-receptor complex, composed of methoprene-tolerant and steroid receptor co-activator, acts on mini-chromosome maintenance (Mcm) genes Mcm4 and Mcm7 to promote DNA replication and polyploidy for the massive vitellogenin (Vg) synthesis required for egg production in the migratory locust (Guo, W., Wu, Z., Song, J., Jiang, F., Wang, Z., Deng, S., Walker, V. K., and Zhou, S. (2014) PLoS Genet. 10, e1004702). In this study we have investigated the involvement of cell-division-cycle 6 (Cdc6) in JH-dependent vitellogenesis and oogenesis, as Cdc6 is essential for the formation of prereplication complex. We demonstrate here that Cdc6 is expressed in response to JH and methoprene-tolerant, and Cdc6 transcription is directly regulated by the JH-receptor complex. Knockdown of Cdc6 inhibits polyploidization of fat body and follicle cells, resulting in the substantial reduction of Vg expression in the fat body as well as severely impaired oocyte maturation and ovarian growth. Our data indicate the involvement of Cdc6 in JH pathway and a pivotal role of Cdc6 in JH-mediated polyploidization, vitellogenesis, and oogenesis. PMID:26728459

  6. Four-way regulation of mosquito yolk protein precursor genes by juvenile hormone-, ecdysone-, nutrient-, and insulin-like peptide signaling pathways

    PubMed Central

    Hansen, Immo A.; Attardo, Geoffrey M.; Rodriguez, Stacy D.; Drake, Lisa L.

    2014-01-01

    Anautogenous mosquito females require a meal of vertebrate blood in order to initiate the production of yolk protein precursors by the fat body. Yolk protein precursor gene expression is tightly repressed in a state-of-arrest before blood meal-related signals activate it and expression levels rise rapidly. The best understood example of yolk protein precursor gene regulation is the vitellogenin-A gene (vg) of the yellow fever mosquito Aedes aegypti. Vg-A is regulated by (1) juvenile hormone signaling, (2) the ecdysone-signaling cascade, (3) the nutrient sensitive target-of-rapamycin signaling pathway, and (4) the insulin-like peptide (ILP) signaling pathway. A plethora of new studies have refined our understanding of the regulation of yolk protein precursor genes since the last review on this topic in 2005 (Attardo et al., 2005). This review summarizes the role of these four signaling pathways in the regulation of vg-A and focuses upon new findings regarding the interplay between them on an organismal level. PMID:24688471

  7. Juvenile hormone enhances aversive learning performance in 2-day old worker honey bees while reducing their attraction to queen mandibular pheromone.

    PubMed

    McQuillan, H James; Nakagawa, Shinichi; Mercer, Alison R

    2014-01-01

    Previous studies have shown that exposing young worker bees (Apis mellifera) to queen mandibular pheromone (QMP) reduces their aversive learning performance, while enhancing their attraction to QMP. As QMP has been found to reduce the rate of juvenile hormone (JH) synthesis in worker bees, we examined whether aversive learning in 2-day old workers exposed to QMP from the time of adult emergence could be improved by injecting JH (10 µg in a 2 µl volume) into the haemolymph. We examined in addition, the effects of JH treatment on worker attraction to QMP, and on the levels of expression of amine receptor genes in the antennae, as well as in the mushroom bodies of the brain. We found that memory acquisition and 1-hour memory recall were enhanced by JH. In contrast, JH treatment reduced the bees' attraction towards a synthetic strip impregnated with QMP (Bee Boost). Levels of expression of the dopamine receptor gene Amdop1 were significantly lower in the mushroom bodies of JH-treated bees than in bees treated with vehicle alone (acetone diluted with bee ringer). Expression of the octopamine receptor gene, Amoa1, in this brain region was also affected by JH treatment, and in the antennae, Amoa1 transcript levels were significantly lower in JH-treated bees compared to controls. The results of this study suggest that QMP's effects on JH synthesis may contribute to reducing aversive learning performance and enhancing attraction to QMP in young worker bees. PMID:25390885

  8. Liquid chromatography coupled to ion trap-tandem mass spectrometry to evaluate juvenile hormone III levels in bee hemolymph from Nosema spp. infected colonies.

    PubMed

    Ares, A M; Nozal, M J; Bernal, J L; Martín-Hernández, R; M Higes; Bernal, J

    2012-06-15

    It has been described a fast, simple and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to measure juvenile hormone III (JH III), which was used to study of the effects of Nosema spp. infection on JH III levels in bee hemolymph. Honey bee hemolymph was extracted by centrifugation and mixed with a solution of phenylthiourea in methanol. This mixture was then centrifuged and the supernatant removed and evaporated to dryness. The residue was reconstituted in methanol containing the internal standard (methoprene) and injected onto an LC-MS/MS (ion-trap) system coupled to electrospray ionization (ESI) in positive mode. Chromatography was performed on a Synergi Hydro-RP column (4 μm, 30 mm × 4.60 mm i.d.) using a mobile phase of 20 mM ammonium formate and methanol in binary gradient elution mode. The method was fully validated and it was found to be selective, linear from 15 to 14,562 pg/μL, precise and accurate, with %RSD values below 5%. The limits of detection and quantification were: LOD, 6 pg/μL; LOQ, 15 pg/μL. Finally, the proposed LC-MS/MS method was used to analyze JH III levels in the hemolymph of worker honey bees (Apis mellifera iberiensis) experimentally infected with different Nosema spp. (Nosema apis, Spanish and Dutch Nosema ceranae strains). The highest concentrations of JH III were detected in hemolymph from bees infected with Spanish N. ceranae.

  9. Juvenile Hormone-Receptor Complex Acts on Mcm4 and Mcm7 to Promote Polyploidy and Vitellogenesis in the Migratory Locust

    PubMed Central

    Song, Jiasheng; Jiang, Feng; Wang, Zhiming; Deng, Shun; Walker, Virginia K.; Zhou, Shutang

    2014-01-01

    Juvenile hormone (JH), a sesquiterpenoid produced by the corpora allata, coordinates insect growth, metamorphosis, and reproduction. While JH action for the repression of larval metamorphosis has been well studied, the molecular basis of JH in promoting adult reproduction has not been fully elucidated. Methoprene-tolerant (Met), the JH receptor, has been recently shown to mediate JH action during metamorphosis as well as in vitellogenesis, but again, the precise mechanism underlying the latter has been lacking. We have now demonstrated using Met RNAi to phenocopy a JH-deprived condition in migratory locusts, that JH stimulates DNA replication and increases ploidy in preparation for vitellogenesis. Mcm4 and Mcm7, two genes in the DNA replication pathway were expressed in the presence of JH and Met. Depletion of Mcm4 or Mcm7 inhibited de novo DNA synthesis and polyploidization, and resulted in the substantial reduction of vitellogenin mRNA levels as well as severely impaired oocyte maturation and ovarian growth. By using luciferase reporter and electrophoretic mobility shift assays, we have shown that Met directly regulates the transcription of Mcm4 and Mcm7 by binding to upstream consensus sequences with E-box or E-box-like motifs. Our work suggests that the JH-receptor complex acts on Mcm4 and Mcm7 to regulate DNA replication and polyploidy for vitellogenesis and oocyte maturation. PMID:25340846

  10. Proteome analysis of male accessory gland secretions in oriental fruit flies reveals juvenile hormone-binding protein, suggesting impact on female reproduction.

    PubMed

    Wei, Dong; Li, Hui-Min; Tian, Chuan-Bei; Smagghe, Guy; Jia, Fu-Xian; Jiang, Hong-Bo; Dou, Wei; Wang, Jin-Jun

    2015-01-01

    In insects, the accessory gland proteins (Acps) secreted by male accessory glands (MAGs) account for the majority of seminal fluids proteins. Mixed with sperm, they are transferred to the female at mating and so impact reproduction. In this project, we identified 2,927 proteins in the MAG secretions of the oriental fruit fly Bactrocera dorsalis, an important agricultural pest worldwide, using LC-MS analysis, and all sequences containing open reading frames were analyzed using signalP. In total, 90 Acps were identified. About one third (26) of these 90 Acps had a specific functional description, while the other two thirds (64) had no functional description including dozens of new classes of proteins. Hence, several of these novel Acps were abundant in the MAG secretions, and we confirmed their MAG-specific expression by qPCR. Finally and interestingly, one of these novel proteins was functionally predicted as juvenile hormone-binding protein, suggesting the impact of Acps with reproductive events in the female. Our results will aid in the development of an experimental method to identify Acps in insects, and in turn this information with new Acps in B. dorsalis will pave the way of further exploration their function in reproduction and potential development as new insecticide targets.

  11. Proteome analysis of male accessory gland secretions in oriental fruit flies reveals juvenile hormone-binding protein, suggesting impact on female reproduction

    PubMed Central

    Wei, Dong; Li, Hui-Min; Tian, Chuan-Bei; Smagghe, Guy; Jia, Fu-Xian; Jiang, Hong-Bo; Dou, Wei; Wang, Jin-Jun

    2015-01-01

    In insects, the accessory gland proteins (Acps) secreted by male accessory glands (MAGs) account for the majority of seminal fluids proteins. Mixed with sperm, they are transferred to the female at mating and so impact reproduction. In this project, we identified 2,927 proteins in the MAG secretions of the oriental fruit fly Bactrocera dorsalis, an important agricultural pest worldwide, using LC-MS analysis, and all sequences containing open reading frames were analyzed using signalP. In total, 90 Acps were identified. About one third (26) of these 90 Acps had a specific functional description, while the other two thirds (64) had no functional description including dozens of new classes of proteins. Hence, several of these novel Acps were abundant in the MAG secretions, and we confirmed their MAG-specific expression by qPCR. Finally and interestingly, one of these novel proteins was functionally predicted as juvenile hormone-binding protein, suggesting the impact of Acps with reproductive events in the female. Our results will aid in the development of an experimental method to identify Acps in insects, and in turn this information with new Acps in B. dorsalis will pave the way of further exploration their function in reproduction and potential development as new insecticide targets. PMID:26582577

  12. Krüppel homolog 1 and E93 mediate Juvenile hormone regulation of metamorphosis in the common bed bug, Cimex lectularius

    PubMed Central

    Gujar, Hemant; Palli, Subba Reddy

    2016-01-01

    The common bed bug is an obligate hematophagous parasite of humans. We studied the regulation of molting and metamorphosis in bed bugs with a goal to identify key players involved. qRT-PCR studies on the expression of genes known to be involved in molting and metamorphosis showed high levels of Krüppel homolog 1 [Kr-h1, a transcription factor that plays key roles in juvenile hormone (JH) action] mRNA in the penultimate nymphal stage (N4). However, low levels of Kr-h1 mRNA were detected in the fifth and last nymphal stage (N5). Knockdown of Kr-h1 in N4 resulted in a precocious development of adult structures. Kr-h1 maintains the immature stage by suppressing E93 (early ecdysone response gene) in N4. E93 expression increases during the N5 in the absence of Kr-h1 and promotes the development of adult structures. Knockdown of E93 in N5 results in the formation of supernumerary nymphs. The role of JH in the suppression of adult structures through interaction with Kr-h1 and E93 was also studied by the topical application of JH analog, methoprene, to N5. Methoprene induced Kr-h1 and suppressed E93 and induced formation of the supernumerary nymph. These data show interactions between Kr-h1, E93 and JH in the regulation of metamorphosis in the bed bugs. PMID:27185064

  13. Remating behavior in Anastrepha fraterculus (Diptera: Tephritidae) females is affected by male juvenile hormone analog treatment but not by male sterilization.

    PubMed

    Abraham, S; Liendo, M C; Devescovi, F; Peralta, P A; Yusef, V; Ruiz, J; Cladera, J L; Vera, M T; Segura, D F

    2013-06-01

    The sterile insect technique (SIT) has been proposed as an area-wide method to control the South American fruit fly, Anastrepha fraterculus (Wiedemann). This technique requires sterilization, a procedure that affects, along with other factors, the ability of males to modulate female sexual receptivity after copulation. Numerous pre-release treatments have been proposed to counteract the detrimental effects of irradiation, rearing and handling and increase SIT effectiveness. These include treating newly emerged males with a juvenile hormone mimic (methoprene) or supplying protein to the male's diet to accelerate sexual maturation prior to release. Here, we examine how male irradiation, methoprene treatment and protein intake affect remating behavior and the amount of sperm stored in inseminated females. In field cage experiments, we found that irradiated laboratory males were equally able to modulate female remating behavior as fertile wild males. However, females mated with 6-day-old, methoprene-treated males remated more and sooner than females mated with naturally matured males, either sterile or wild. Protein intake by males was not sufficient to overcome reduced ability of methoprene-treated males to induce refractory periods in females as lengthy as those induced by wild and naturally matured males. The amount of sperm stored by females was not affected by male irradiation, methoprene treatment or protein intake. This finding revealed that factors in addition to sperm volume intervene in regulating female receptivity after copulation. Implications for SIT are discussed.

  14. Variability in Migration Routes Influences Early Marine Survival of Juvenile Salmon Smolts

    PubMed Central

    Furey, Nathan B.; Vincent, Stephen P.; Hinch, Scott G.; Welch, David W.

    2015-01-01

    Variability in animal migratory behavior is expected to influence fitness, but few empirical examples demonstrating this relationship exist. The initial marine phase in the migration of juvenile salmon smolts has been identified as a potentially critical life history stage to overall population productivity, yet how fine-scale migration routes may influence survival are unknown. Large-scale acoustic telemetry studies have estimated survival rates of outmigrant Pacific salmon smolts through the Strait of Georgia (SOG) along the British Columbian coastline to the Pacific Ocean, but these data have not been used to identify and characterize fine-scale movements. Data collected on over 850 sockeye salmon (Oncorhynchus nerka) and steelhead (Oncorhynchus mykiss) smolts detected at an array in the Strait of Georgia in 2004–2008 and 2010–2013 were analyzed to characterize migration routes and link movements to subsequent survival at an array 250 km further along the marine migration pathway. Both species exhibited disproportionate use of the most eastern route in the Strait of Georgia (Malaspina Strait). While many smolts moved across the northern Strait of Georgia acoustic array with no indication of long-term milling or large-scale east-to-west movements, large proportions (20–40% of sockeye and 30–50% of steelhead) exhibited a different behavior, apparently moving in a westward or counterclockwise pattern. Variability in migratory behavior for both species was linked to subsequent survival through the Strait of Georgia. Survival for both species was influenced by initial east-to-west location, and sockeye were further influenced by migration timing and duration of time spent near the northern Strait of Georgia array. Westward movements result in a net transport of smolts from Malaspina Strait to the Strait of Georgia, particularly for steelhead. Counterclockwise movements may be due to the currents in this area during the time of outmigration, and the higher

  15. Variability in Migration Routes Influences Early Marine Survival of Juvenile Salmon Smolts.

    PubMed

    Furey, Nathan B; Vincent, Stephen P; Hinch, Scott G; Welch, David W

    2015-01-01

    Variability in animal migratory behavior is expected to influence fitness, but few empirical examples demonstrating this relationship exist. The initial marine phase in the migration of juvenile salmon smolts has been identified as a potentially critical life history stage to overall population productivity, yet how fine-scale migration routes may influence survival are unknown. Large-scale acoustic telemetry studies have estimated survival rates of outmigrant Pacific salmon smolts through the Strait of Georgia (SOG) along the British Columbian coastline to the Pacific Ocean, but these data have not been used to identify and characterize fine-scale movements. Data collected on over 850 sockeye salmon (Oncorhynchus nerka) and steelhead (Oncorhynchus mykiss) smolts detected at an array in the Strait of Georgia in 2004-2008 and 2010-2013 were analyzed to characterize migration routes and link movements to subsequent survival at an array 250 km further along the marine migration pathway. Both species exhibited disproportionate use of the most eastern route in the Strait of Georgia (Malaspina Strait). While many smolts moved across the northern Strait of Georgia acoustic array with no indication of long-term milling or large-scale east-to-west movements, large proportions (20-40% of sockeye and 30-50% of steelhead) exhibited a different behavior, apparently moving in a westward or counterclockwise pattern. Variability in migratory behavior for both species was linked to subsequent survival through the Strait of Georgia. Survival for both species was influenced by initial east-to-west location, and sockeye were further influenced by migration timing and duration of time spent near the northern Strait of Georgia array. Westward movements result in a net transport of smolts from Malaspina Strait to the Strait of Georgia, particularly for steelhead. Counterclockwise movements may be due to the currents in this area during the time of outmigration, and the higher proportion

  16. Variability in Migration Routes Influences Early Marine Survival of Juvenile Salmon Smolts.

    PubMed

    Furey, Nathan B; Vincent, Stephen P; Hinch, Scott G; Welch, David W

    2015-01-01

    Variability in animal migratory behavior is expected to influence fitness, but few empirical examples demonstrating this relationship exist. The initial marine phase in the migration of juvenile salmon smolts has been identified as a potentially critical life history stage to overall population productivity, yet how fine-scale migration routes may influence survival are unknown. Large-scale acoustic telemetry studies have estimated survival rates of outmigrant Pacific salmon smolts through the Strait of Georgia (SOG) along the British Columbian coastline to the Pacific Ocean, but these data have not been used to identify and characterize fine-scale movements. Data collected on over 850 sockeye salmon (Oncorhynchus nerka) and steelhead (Oncorhynchus mykiss) smolts detected at an array in the Strait of Georgia in 2004-2008 and 2010-2013 were analyzed to characterize migration routes and link movements to subsequent survival at an array 250 km further along the marine migration pathway. Both species exhibited disproportionate use of the most eastern route in the Strait of Georgia (Malaspina Strait). While many smolts moved across the northern Strait of Georgia acoustic array with no indication of long-term milling or large-scale east-to-west movements, large proportions (20-40% of sockeye and 30-50% of steelhead) exhibited a different behavior, apparently moving in a westward or counterclockwise pattern. Variability in migratory behavior for both species was linked to subsequent survival through the Strait of Georgia. Survival for both species was influenced by initial east-to-west location, and sockeye were further influenced by migration timing and duration of time spent near the northern Strait of Georgia array. Westward movements result in a net transport of smolts from Malaspina Strait to the Strait of Georgia, particularly for steelhead. Counterclockwise movements may be due to the currents in this area during the time of outmigration, and the higher proportion

  17. Hormonal state influences aspects of female mate choice in the Túngara Frog (Physalaemus pustulosus).

    PubMed

    Lynch, Kathleen S; Crews, David; Ryan, Michael J; Wilczynski, Walter

    2006-04-01

    Females alter their mate choices as they transition through different reproductive stages; however, the proximal mechanisms for such behavioral fluctuation are unclear. In many taxa, as females transition through different reproductive stages, there is an associated change in hormone levels; therefore, we examined whether fluctuation in hormone levels serves as a proximal mechanism for within-individual variation in mate choice in female túngara frogs (Physalaemus pustulosus). We manipulated hormone levels of females by administering 0, 10, 100, 500 or 1,000 IU of human chorionic gonadotropin (HCG), which is a ligand for luteinizing hormone (LH) receptors and will therefore cause increased gonadal hormone production. Phonotaxis assays were conducted to measure three aspects of mate choice behavior before and after HCG administration; receptivity (response to a conspecific mate signal), permissiveness (response to a signal that is less attractive than conspecific signals) and discrimination (ability to discern signal differences). The probability of response to a conspecific and an artificial hybrid signal significantly increased at the highest HCG doses. The difference in mean response time between pre- and post-HCG tests was significantly different for both the receptivity and permissiveness tests among the five doses. Increased permissiveness, however, was not due to decreased discrimination because females could discriminate between calls even at the highest HCG doses. These hormonal manipulations caused the same behavioral pattern we reported in females as they transitioned through different reproductive stages (Lynch, K.S., Rand, A.S., Ryan, M.J., Wilczynski, W., 2005. Plasticity in female mate choice associated with changing reproductive states. Anim. Behav. 69, 689-699), suggesting that changes in hormone levels can influence the female's mate choice behavior.

  18. Juveniles in court.

    PubMed

    Soulier, Matthew F; Scott, Charles L

    2010-01-01

    Nineteenth-century American reformers were concerned about the influence of immaturity and development in juvenile offenses. They responded to their delinquent youths through the creation of juvenile courts. This early American juvenile justice system sought to treat children as different from adults and to rehabilitate wayward youths through the state's assumption of a parental role. Although these rehabilitative goals were never fully realized, the field of American child psychiatry was spawned from these efforts on behalf of delinquent youths. Early child psychiatrists began by caring for juvenile offenders. The function of a child psychiatrist with juvenile delinquents expanded beyond strictly rehabilitation, however, as juvenile courts evolved to resemble criminal adult courts-due to landmark Supreme Court decisions and also juvenile legislation between 1966 and 1975. In response to dramatically increased juvenile violence and delinquency rates in the 1980s, juvenile justice became more retributional, and society was forced to confront issues such as capital punishment for juveniles, their transfer to adult courts, and their competency to stand trial. In the modern juvenile court, child psychiatrists are often asked to participate in the consideration of such issues because of their expertise in development. In that context we review the role of psychiatrists in assisting juvenile courts.

  19. Environmental stressors influencing hormones and systems physiology in cattle

    PubMed Central

    2014-01-01

    Environmental stressors undoubtedly influence organismal biology, specifically the endocrine system that, in turn, impact cattle at the systems physiology level. Despite the significant advances in understanding the genetic determinants of the ideal dairy or beef cow, there is a grave lack of understanding of the systems physiology and effects of the environmental stressors that interfere with the endocrine system. This is a major problem because the lack of such knowledge is preventing advances in understanding gene-environment interactions and developing science-based solutions to these challenges. In this review, we synthesize the current knowledge on the nature of the major environmental stressors, such as climate (heat, cold, wind, and humidity), nutrition (feeds, feeding systems, and endocrine disruptors) and management (housing density and conditions, transportation, weaning practices). We summarize the impact of each one of these factors on cattle at the systems level, and provide solutions for the challenges. PMID:24996419

  20. Environmental stressors influencing hormones and systems physiology in cattle.

    PubMed

    Bova, Toree L; Chiavaccini, Ludovica; Cline, Garrett F; Hart, Caitlin G; Matheny, Kelli; Muth, Ashleigh M; Voelz, Benjamin E; Kesler, Darrel; Memili, Erdoğan

    2014-07-04

    Environmental stressors undoubtedly influence organismal biology, specifically the endocrine system that, in turn, impact cattle at the systems physiology level. Despite the significant advances in understanding the genetic determinants of the ideal dairy or beef cow, there is a grave lack of understanding of the systems physiology and effects of the environmental stressors that interfere with the endocrine system. This is a major problem because the lack of such knowledge is preventing advances in understanding gene-environment interactions and developing science-based solutions to these challenges. In this review, we synthesize the current knowledge on the nature of the major environmental stressors, such as climate (heat, cold, wind, and humidity), nutrition (feeds, feeding systems, and endocrine disruptors) and management (housing density and conditions, transportation, weaning practices). We summarize the impact of each one of these factors on cattle at the systems level, and provide solutions for the challenges.

  1. The Influence of Gonadal Hormones on Neuronal Excitability, Seizures, and Epilepsy in the Female

    PubMed Central

    Scharfman, Helen E.; MacLusky, Neil J.

    2007-01-01

    Summary It is clear from both clinical observations of women, and research in laboratory animals, that gonadal hormones exert a profound influence on neuronal excitability, seizures, and epilepsy. These studies have led to a focus on two of the primary ovarian steroid hormones, estrogen and progesterone, to clarify how gonadal hormones influence seizures in women with epilepsy. The prevailing view is that estrogen is proconvulsant, whereas progesterone is anticonvulsant. However, estrogen and progesterone may not be the only reproductive hormones to consider in evaluating excitability, seizures, or epilepsy in the female. It seems unlikely that estrogen and progesterone would exert single, uniform actions given our current understanding of their complex pharmacological and physiological relationships. Their modulatory effects are likely to depend on endocrine state, relative concentration, metabolism, and many other factors. Despite the challenges these issues raise to future research, some recent advances have helped clarify past confusion in the literature. In addition, testable hypotheses have developed for complex clinical problems such as “catamenial epilepsy.” Clinical and animal research, designed with the relevant endocrinological and neurobiological issues in mind, will help advance this field in the future. PMID:16981857

  2. Influence of antiopioids on luteinizing hormone pulsatility in aging men.

    PubMed

    Vermeulen, A; Deslypere, J P; Kaufman, J M

    1989-01-01

    To investigate whether changes in opioid tone play a role in the age-associated changes in LH release in men, the influence of an antiopioid, naltrexone, on plasma LH levels and LH pulses was studied in a group of young and elderly normal men. The young and elderly men had similar basal LH pulse frequencies, but the frequency of high amplitude (greater than 2 IU/L) LH pulses, mean LH pulse amplitude, maximal LH pulse amplitude and pulse area, were lower in the elderly men. Naltrexone administration (40 mg at 0630 and 2200 h the day before blood sampling and at 0630 h, 30 min before starting frequent blood sampling at 10-min intervals for 12 h) to young men (n = 8) induced a significant increase in individual mean baseline plasma LH levels, LH pulse frequency, and the sum of LH pulse amplitudes. In elderly men (n = 11) only a borderline significant increase in baseline plasma LH levels occurred, and neither LH pulse frequency nor the sum of the amplitudes of LH pulses increased. We suggest that in elderly men either opioid tone or the response of the gonadotrophs to endogenous LHRH is decreased. PMID:2909555

  3. Differential impacts of juvenile hormone, soldier head extract and alternate caste phenotypes on host and symbiont transcriptome composition in the gut of the termite Reticulitermes flavipes

    PubMed Central

    2013-01-01

    Background Termites are highly eusocial insects and show a division of labor whereby morphologically distinct individuals specialize in distinct tasks. In the lower termite Reticulitermes flavipes (Rhinotermitidae), non-reproducing individuals form the worker and soldier castes, which specialize in helping (e.g., brood care, cleaning, foraging) and defense behaviors, respectively. Workers are totipotent juveniles that can either undergo status quo molts or develop into soldiers or neotenic reproductives. This caste differentiation can be regulated by juvenile hormone (JH) and primer pheromones contained in soldier head extracts (SHE). Here we offered worker termites a cellulose diet treated with JH or SHE for 24-hr, or held them with live soldiers (LS) or live neotenic reproductives (LR). We then determined gene expression profiles of the host termite gut and protozoan symbionts concurrently using custom cDNA oligo-microarrays containing 10,990 individual ESTs. Results JH was the most influential treatment (501 total ESTs affected), followed by LS (24 ESTs), LR (12 ESTs) and SHE treatments (6 ESTs). The majority of JH up- and downregulated ESTs were of host and symbiont origin, respectively; in contrast, SHE, LR and LS treatments had more uniform impacts on host and symbiont gene expression. Repeat “follow-up” bioassays investigating combined JH + SHE impacts in relation to individual JH and SHE treatments on a subset of array-positive genes revealed (i) JH and SHE treatments had opposite impacts on gene expression and (ii) JH + SHE impacts on gene expression were generally intermediate between JH and SHE. Conclusions Our results show that JH impacts hundreds of termite and symbiont genes within 24-hr, strongly suggesting a role for the termite gut in JH-dependent caste determination. Additionally, differential impacts of SHE and LS treatments were observed that are in strong agreement with previous studies that specifically investigated soldier caste

  4. Repeated, Intermittent Social Defeat across the Entire Juvenile Period Resulted in Behavioral, Physiological, Hormonal, Immunological, and Neurochemical Alterations in Young Adult Male Golden Hamsters

    PubMed Central

    Yu, Wei-Chun; Liu, Ching-Yi; Lai, Wen-Sung

    2016-01-01

    The developing brain is vulnerable to social defeat during the juvenile period. As complements of human studies, animal models of social defeat provide a straightforward approach to investigating the functional and neurobiological consequences of social defeats. Taking advantage of agonist behavior and social defeat in male golden hamster, a set of 6 experiments was conducted to investigate the consequences at multiple levels in young adulthood resulting from repeated, intermittent social defeats or “social threats” across the entire juvenile period. Male hamsters at postnatal day 28 (P28) were randomly assigned to either the social defeat, “social threat”, or arena control group, and they correspondingly received a series of nine social interaction trials (i.e., either social defeat, “social threat”, or arena control conditions) from P33 to P66. At the behavioral level (Experiment 1), we found that repeated social defeats (but not “social threats”) significantly impacted locomotor activity in the familiar context and social interaction in the familiar/unfamiliar social contexts. At the physiological and hormonal levels (Experiments 2 and 3), repeated social defeat significantly enhanced the cortisol and norepinephrine concentrations in blood. Enlargement of the spleen was also found in the social defeat and “social threat” groups. At the immunological level (Experiment 4), the social defeat group showed lower levels of pro-inflammatory cytokines in the hypothalamus and hippocampus but higher concentration of IL-6 in the striatum compared to the other two groups. At the neurochemical level (Experiment 5), the socially defeated hamsters mainly displayed reductions of dopamine, dopamine metabolites, and 5-HT levels in the striatum and decreased level of 5-HT in the hippocampus. In Experiment 6, an increase in the spine density of hippocampal CA1 pyramidal neurons was specifically observed in the “social threat” group. Collectively, our

  5. Repeated, Intermittent Social Defeat across the Entire Juvenile Period Resulted in Behavioral, Physiological, Hormonal, Immunological, and Neurochemical Alterations in Young Adult Male Golden Hamsters.

    PubMed

    Yu, Wei-Chun; Liu, Ching-Yi; Lai, Wen-Sung

    2016-01-01

    The developing brain is vulnerable to social defeat during the juvenile period. As complements of human studies, animal models of social defeat provide a straightforward approach to investigating the functional and neurobiological consequences of social defeats. Taking advantage of agonist behavior and social defeat in male golden hamster, a set of 6 experiments was conducted to investigate the consequences at multiple levels in young adulthood resulting from repeated, intermittent social defeats or "social threats" across the entire juvenile period. Male hamsters at postnatal day 28 (P28) were randomly assigned to either the social defeat, "social threat", or arena control group, and they correspondingly received a series of nine social interaction trials (i.e., either social defeat, "social threat", or arena control conditions) from P33 to P66. At the behavioral level (Experiment 1), we found that repeated social defeats (but not "social threats") significantly impacted locomotor activity in the familiar context and social interaction in the familiar/unfamiliar social contexts. At the physiological and hormonal levels (Experiments 2 and 3), repeated social defeat significantly enhanced the cortisol and norepinephrine concentrations in blood. Enlargement of the spleen was also found in the social defeat and "social threat" groups. At the immunological level (Experiment 4), the social defeat group showed lower levels of pro-inflammatory cytokines in the hypothalamus and hippocampus but higher concentration of IL-6 in the striatum compared to the other two groups. At the neurochemical level (Experiment 5), the socially defeated hamsters mainly displayed reductions of dopamine, dopamine metabolites, and 5-HT levels in the striatum and decreased level of 5-HT in the hippocampus. In Experiment 6, an increase in the spine density of hippocampal CA1 pyramidal neurons was specifically observed in the "social threat" group. Collectively, our findings indicate that repeated

  6. Comparative metabolism of branched-chain amino acids to precursors of juvenile hormone biogenesis in corpora allata of lepidopterous versus nonlepidopterous insects

    SciTech Connect

    Brindle, P.A.; Schooley, D.A.; Tsai, L.W.; Baker, F.C.

    1988-08-05

    Comparative studies were performed on the role of branched-chain amino acids (BCAA) in juvenile hormone (JH) biosynthesis using several lepidopterous and nonlepidopterous insects. Corpora cardiaca-corpora allata complexes (CC-CA, the corpora allata being the organ of JH biogenesis) were maintained in culture medium containing a uniformly /sup 14/C-labeled BCAA, together with (methyl-/sup 3/H)methionine as mass marker for JH quantification. BCAA catabolism was quantified by directly analyzing the medium for the presence of /sup 14/C-labeled propionate and/or acetate, while JHs were extracted, purified by liquid chromatography, and subjected to double-label liquid scintillation counting. Our results indicate that active BCAA catabolism occurs within the CC-CA of lepidopterans, and this efficiently provides propionyl-CoA (from isoleucine or valine) for the biosynthesis of the ethyl branches of JH I and II. Acetyl-CoA, formed from isoleucine or leucine catabolism, is also utilized by lepidopteran CC-CA for biosynthesizing JH III and the acetate-derived portions of the ethyl-branched JHs. In contrast, CC-CA of nonlepidopterans fail to catabolize BCAA. Consequently, exogenous isoleucine or leucine does not serve as a carbon source for the biosynthesis of JH III by these glands, and no propionyl-CoA is produced for genesis of ethyl-branched JHs. This is the first observation of a tissue-specific metabolic difference which in part explains why these novel homosesquiterpenoids exist in lepidopterans, but not in nonlepidopterans.

  7. The Drosophila FTZ-F1 Nuclear Receptor Mediates Juvenile Hormone Activation of E75A Gene Expression through an Intracellular Pathway*

    PubMed Central

    Dubrovsky, Edward B.; Dubrovskaya, Veronica A.; Bernardo, Travis; Otte, Valerie; DiFilippo, Robert; Bryan, Heather

    2011-01-01

    Juvenile hormone (JH) regulates a wide variety of biological activities in holometabolous insects, ranging from vitellogenesis and caste determination in adults to the timing of metamorphosis in larvae. The mechanism of JH signaling in such a diverse array of processes remains either unknown or contentious. We previously found that the nuclear receptor gene E75A is activated in S2 cells as a primary response to JH. Here, by expressing an intracellular form of JH esterase, we demonstrate that JH must enter the cell in order to activate E75A. To find intracellular receptors involved in the JH response, we performed an RNAi screen against nuclear receptor genes expressed in this cell line and identified the orphan receptor FTZ-F1. Removal of FTZ-F1 prevents JH activation of E75A, whereas overexpression enhances activation, implicating FTZ-F1 as a critical component of the JH response. FTZ-F1 is bound in vivo to multiple enhancers upstream of E75A, suggesting that it participates in direct JH-mediated gene activation. To better define the role of FTZ-F1 in JH signaling, we investigated interactions with candidate JH receptors and found that the bHLH-PAS proteins MET and GCE both interact with FTZ-F1 and can activate transcription through the FTZ-F1 response element. Removal of endogenous GCE, but not MET, prevents JH activation of E75A. We propose that FTZ-F1 functions as a competence factor by loading JH signaling components to the promoter, thus facilitating the direct regulation of E75A gene expression by JH. PMID:21832074

  8. Effects of juvenile hormone on 20-hydroxyecdysone-inducible EcR, HR3, E75 gene expression in imaginal wing cells of Plodia interpunctella lepidoptera.

    PubMed

    Siaussat, David; Bozzolan, Françoise; Queguiner, Isabelle; Porcheron, Patrick; Debernard, Stéphane

    2004-07-01

    The IAL-PID2 cells derived from imaginal wing discs of the last larval instar of Plodia interpunctella were responsive to 20-hydroxyecdysone (20E). These imaginal cells respond to 20E by proliferative arrest followed by a morphological differentiation. These 20E-induced late responses were inhibited in presence of juvenile hormone (JH II). From these imaginal wing cells, we have cloned a cDNA sequence encoding a P. interpunctella ecdysone receptor-B1 isoform (PIEcR-B1). The amino acid sequence of PIEcR-B1 showed a high degree of identity with EcR-B1 isoforms of Bombyx mori, Manduca sexta and Choristoneura fumiferana. The pattern of PIEcR-B1mRNA induction by 20E was characterized by a biphasic response with peaks at 2 h and 18 h. The presence of the protein synthesis inhibitor anisomycin induced a slight reduction in level of PIEcR-B1 mRNA and prevented the subsequent declines observed in 20E-treated cells. Therefore, PIEcR-B1 mRNA was directly induced by 20E and its downregulation depended on protein synthesis. An exposure of imaginal wing cells to 20E in the presence of JH II caused an increased expression of Plodia E75-B and HR3 transcription factors but inhibited the second increase of PIEcR-B1 mRNA. These findings showed that in vitro JH II was able to prevent the 20E-induced differentiation of imaginal wing cells. This effect could result from a JH II action on the 20E-induced genetic cascade through a modulation of EcR-B1, E75-B and HR3 expression.

  9. Knockdown of the juvenile hormone receptor gene inhibits soldier-specific morphogenesis in the damp-wood termite Zootermopsis nevadensis (Isoptera: Archotermopsidae).

    PubMed

    Masuoka, Yudai; Yaguchi, Hajime; Suzuki, Ryutaro; Maekawa, Kiyoto

    2015-09-01

    The Methoprene-tolerant (Met) protein has been established as a juvenile hormone (JH) receptor. Knockdown of the Met gene caused precocious metamorphosis and suppression of ovarian development. However, the function of Met in caste development of social insects is unclear. In termites, JH acts as a central factor for caste development, especially for soldier differentiation, which involves two molts from workers via a presoldier stage. Increased JH titer in workers is needed for the presoldier molt, and the high JH titer is maintained throughout the presoldier period. Although presoldiers have the fundamental morphological features of soldiers, the nature of the cuticle is completely different from that of soldiers. We expected that JH signals via Met are involved in soldier-specific morphogenesis of the head and mandibles during soldier differentiation, especially in the presoldier period, in natural conditions. To test this hypothesis, we focused on soldier differentiation in an incipient colony of the damp-wood termite Zootermopsis nevadensis. Met homolog (ZnMet) expression in heads increased just after the presoldier molt. This high expression was reduced by ZnMet double stranded (dsRNA) injection before the presoldier molt. Although this treatment did not cause any morphological changes in presoldiers, it caused strong effects on soldiers, their mandibles being significantly shorter and head capsules smaller than those of control soldiers. Injection of ZnMet dsRNA throughout the presoldier stage did not affect the formation of soldier morphology, including cuticle formation. These results suggested that the rapid increase in ZnMet expression and subsequent activation of JH signaling just after the presoldier molt are needed for the formation of soldier-specific weapons. Therefore, besides its established role in insect metamorphosis, the JH receptor signaling also underlies soldier development in termites.

  10. Juvenile hormone facilitates the antagonism between adult reproduction and diapause through the methoprene-tolerant gene in the female Colaphellus bowringi.

    PubMed

    Liu, Wen; Li, Yi; Zhu, Li; Zhu, Fen; Lei, Chao-Liang; Wang, Xiao-Ping

    2016-07-01

    In insects, the process whereby juvenile hormone (JH) regulates short-day (SD)-induced reproductive diapause has been previously investigated. However, we still do not understand the mechanism by which JH regulates long-day (LD)-induced reproductive diapause. In this study, we use a cabbage beetle, Colaphellus bowringi, which is a serious pest of cruciferous vegetables in Asia capable of entering reproductive diapause under LD conditions, as a model to test whether JH regulates female reproductive diapause similar to the mechanism of SD-induced diapause. Our results showed that the JH analog (JHA) methoprene significantly induced ovarian development but inhibited lipid accumulation of diapause-destined adults. Meanwhile, the transcripts of the vitellogenin (Vg) genes were upregulated, whereas the expression of the fat synthesis and stress tolerance genes were downregulated. RNA interference of the JH candidate receptor gene methoprene-tolerant (Met) blocked JH-induced ovarian development and Vg transcription, suggesting a positive regulatory function for JH-Met signaling in reproduction. Furthermore, under reproduction-inducing conditions, Met depletion promoted a diapause-like phenotype, including arrested ovarian development and increased lipid storage, and stimulated the expression of diapause-related genes involved in lipid synthesis and stress tolerance, suggesting JH-Met signaling plays an important role in the inhibition of diapause. Accordingly, our data indicate that JH acts through Met to facilitate development of the reproductive system by upregulating Vg expression while inhibiting diapause by suppressing lipid synthesis and stress tolerance in the cabbage beetle. Combined with previous studies in SD-induced reproductive diapause, we conclude that JH may regulate female reproductive diapause using a conserved Met-dependent pathway, regardless of the length of the photoperiod inducing diapause in insects.

  11. The influence of sex hormones on seizures in dogs and humans.

    PubMed

    Van Meervenne, Sofie A E; Volk, Holger A; Matiasek, Kaspar; Van Ham, Luc M L

    2014-07-01

    Epilepsy is the most common chronic neurological disorder in both humans and dogs. The effect of sex hormones on seizures is well documented in human medicine. Catamenial epilepsy is defined as an increase in frequency and severity of seizures during certain periods of the menstrual cycle. Oestradiol increases seizure activity and progesterone is believed to exhibit a protective effect. The role of androgens is controversial and there is a lack of research focusing on androgens and epilepsy. Indeed, little is known about the influence of sex hormones on epilepsy in dogs. Sterilisation is believed to improve seizure control, but no systematic research has been conducted in this field. This review provides an overview of the current literature on the influence of sex hormones on seizures in humans. The literature on idiopathic epilepsy in dogs was assessed to identify potential risk factors related to sex and sterilisation status. In general, there appears to be an over-representation of male dogs with idiopathic epilepsy but no explanation for this difference in prevalence between sexes has been reported. In addition, no reliable conclusions can be drawn on the effect of sterilisation due to the lack of focused research and robust scientific evidence.

  12. Inflammation influences steroid hormone receptors targeted by progestins in endometrial stromal cells from women with endometriosis.

    PubMed

    Grandi, Giovanni; Mueller, Michael D; Papadia, Andrea; Kocbek, Vida; Bersinger, Nick A; Petraglia, Felice; Cagnacci, Angelo; McKinnon, Brett

    2016-09-01

    Endometriosis is an estrogen-dependent disease characterised by the growth of endometrial epithelial and stromal cells outside the uterus creating a chronic inflammatory environment that further contributes to disease progression. The first choice treatment for endometriosis is currently progestin mediated hormone modulation. In addition to their progestogenic activity however, progestins also have the potential to bind to other nuclear receptors influencing their local activity on endometriotic cells. This local activity will be dependent on the steroid hormone receptor expression that occurs in endometrial cells in a chronic inflammatory environment. We therefore aimed to quantify receptors targeted by progestins in endometrial stromal cells after exposure to inflammation. Using primary endometrial stromal cells isolated from women with endometriosis we examined the mRNA and protein expression of the progesterone receptors A and B, membrane progesterone receptors 1 and 2, androgen receptors, mineralocorticoid receptors and glucocorticoid receptors after exposure to the inflammatory cytokines tumor necrosis factor α (TNFα) and interleukin 1β (IL-1β). The results indicate that both cytokines reduced the expression of progesterone receptors and increased the expression of the glucocorticoid receptors in the endometrial stromal cells. The change in expression of progestin targets in endometrial stromal cells in an inflammatory environment could contribute to the progesterone resistance observed in endometriotic cells and ultimately influence the design of hormonal therapies aimed at treating this disease. PMID:27371899

  13. The influence of androgenic steroid hormones on female aggression in 'atypical' mammals.

    PubMed

    French, Jeffrey A; Mustoe, Aaryn C; Cavanaugh, Jon; Birnie, Andrew K

    2013-01-01

    Dimorphism on dominance and agonistic behaviour in mammals tends to be strongly biased toward males. In this review, we focus on a select few species of mammals in which females are as or more aggressive than males, and/or are dominant to males, and explore the role of androgenic hormones in mediating this important difference. While the data are not as clear-cut as those published on traditional laboratory mammals, our review highlights important endocrine substrates for both organizational and activational influences of steroids on female aggressive behaviour. We highlight areas in which further observations and experiments are crucial, especially the potential facilitative effects of androgens on female aggression. Finally, new and innovative techniques, including molecular genetics and receptor pharmacology, portend important insights into the ways in which androgenic hormones regulate aggressive behaviour in 'atypical' female mammals. PMID:24167314

  14. The influence of androgenic steroid hormones on female aggression in 'atypical' mammals.

    PubMed

    French, Jeffrey A; Mustoe, Aaryn C; Cavanaugh, Jon; Birnie, Andrew K

    2013-01-01

    Dimorphism on dominance and agonistic behaviour in mammals tends to be strongly biased toward males. In this review, we focus on a select few species of mammals in which females are as or more aggressive than males, and/or are dominant to males, and explore the role of androgenic hormones in mediating this important difference. While the data are not as clear-cut as those published on traditional laboratory mammals, our review highlights important endocrine substrates for both organizational and activational influences of steroids on female aggressive behaviour. We highlight areas in which further observations and experiments are crucial, especially the potential facilitative effects of androgens on female aggression. Finally, new and innovative techniques, including molecular genetics and receptor pharmacology, portend important insights into the ways in which androgenic hormones regulate aggressive behaviour in 'atypical' female mammals.

  15. The influence of androgenic steroid hormones on female aggression in ‘atypical’ mammals

    PubMed Central

    French, Jeffrey A.; Mustoe, Aaryn C.; Cavanaugh, Jon; Birnie, Andrew K.

    2013-01-01

    Dimorphism on dominance and agonistic behaviour in mammals tends to be strongly biased toward males. In this review, we focus on a select few species of mammals in which females are as or more aggressive than males, and/or are dominant to males, and explore the role of androgenic hormones in mediating this important difference. While the data are not as clear-cut as those published on traditional laboratory mammals, our review highlights important endocrine substrates for both organizational and activational influences of steroids on female aggressive behaviour. We highlight areas in which further observations and experiments are crucial, especially the potential facilitative effects of androgens on female aggression. Finally, new and innovative techniques, including molecular genetics and receptor pharmacology, portend important insights into the ways in which androgenic hormones regulate aggressive behaviour in ‘atypical’ female mammals. PMID:24167314

  16. How type of parturition and health status influence hormonal and metabolic profiles in newborn foals.

    PubMed

    Panzani, S; Comin, A; Galeati, G; Romano, G; Villani, M; Faustini, M; Veronesi, M C

    2012-04-01

    Thyroid hormones, insulin growth factor I (IGF-I) and non-esterified fatty acids (NEFA) represent important hormonal and metabolic factors associated with perinatal growth and maturation. Their action could be influenced by the type of parturition and the health status of the foal and therefore the aim of this work is to evaluate their plasma concentrations in newborn foals during the first 2 wks of life. Three groups of subjects were enrolled: 15 healthy foals born by spontaneous parturition, 24 healthy foals born by induced parturition and 26 pathologic foals. From each of the healthy foals, blood was collected at 10, 20 and 30 minutes, 3 and 12 hours from birth, daily from Day 1 to Day 7, and at Day 10 and 14 of life. In pathologic foals samples were collected twice a day from the day of admission at the hospital until the day of discharge or death. Thyroid hormones (T3 and T4) and IGF-I were analyzed by radioimmunoassay and NEFA by enzymatic-colorimetric methods. In all the three groups a declining trend of T3 and T4 plasma concentrations was detectable, with lower levels in the pathologic group compared to healthy foals. Spontaneous foals showed higher levels of T3 at 7 d compared to induced foals, while T4 levels were higher in spontaneous vs. induced foals before 6 h of life, at three and seven days. IGF-I showed increasing plasma concentrations in all three considered groups. No differences were found between healthy and pathologic foals. NEFA in spontaneous and induced healthy foals showed a declining trend with higher levels during the first hours of life. Pathologic foals presented higher levels compared to spontaneous foals only at 24 h and 10 d. These data suggest that the type of foaling could influence the reference ranges for thyroid hormones. Moreover, pathologic foals showed some hormonal and metabolic differences related to their health status. Above all changes of thyroid hormones levels, early in postnatal life, could be a cause, and not only a

  17. Influence of thyrotrophin-releasing hormone on thermoregulation in newborn lambs.

    PubMed

    Bird, J A; Clarke, L; Symonds, M E

    1998-01-01

    This study examined the effect of thyrotrophin-releasing hormone (TRH) administration on thermoregulation in the newborn. Twin lambs were either delivered near-term by caesarean section or born vaginally at term. Colonic temperature, O2 consumption, CO2 production, breathing and heart rates, plus plasma thyroid hormone and nonesterified fatty acid (NEFA) concentrations and thermogenic activity (i.e. GDP binding) of brown adipose tissue (BAT) were measured. In caesarean section delivered lambs colonic temperature decreased rapidly after birth, a response that was greater in the group designated for TRH treatment, in which colonic temperature fell to below 36.0 degrees C at 80 min of life, prior to TRH administration. At this age colonic temperature had been restored to a mean of 38.70 degrees C in controls. TRH had no influence on the composition or thermogenic activity of BAT. The incidence of shivering was not influenced by TRH, but treated lambs maintained a higher rate of O2 consumption and ventilation compared with controls after colonic temperature had been restored to 38.56 degrees C. TRH appeared to promote fat oxidation as O2 consumption remained unchanged and CO2 production declined by a greater rate in treated lambs, resulting in a lower respiratory quotient compared to controls. Heart rate and plasma concentrations of NEFA increased following TRH administration although this did not result in values greater than controls. Normothermic lambs born vaginally had BAT with a greater thermogenic activity, higher plasma thyroid hormone and NEFA concentrations compared with caesarean section delivered lambs, but a thermogenic response was not observed to TRH despite a rise in thyroid hormone concentrations. In conclusion, TRH can improve thermoregulation, an effect that could be linked to an increase in fat oxidation.

  18. The influence of hormone therapies on type I and II endometrial cancer: A nationwide cohort study.

    PubMed

    Mørch, Lina S; Kjaer, Susanne K; Keiding, Niels; Løkkegaard, Ellen; Lidegaard, Øjvind

    2016-03-15

    The influence of hormone therapy (HT) on risk for endometrial cancer is still casting which type of HT the clinicians recommend. It is unrevealed if HT has a differential influence on Type I versus Type II endometrial tumors, and little is known about the influence of, e.g., different routes of administration and about the influence of tibolone. We followed all Danish women aged 50-79 years without previous cancer or hysterectomy (n = 914,595) during 1995-2009. From the National Prescription Register, we computed HT exposures as time-dependent covariates. Incident endometrial cancers (n = 6,202) were identified from the National Cancer Registry: 4,972 Type I tumors and 500 Type II tumors. Incidence rate ratios (RRs) and 95% confidence intervals (Cls) were estimated by Poisson regression. Compared with women never on HT, the RR of endometrial cancer was increased with conjugated estrogen: 4.27 (1.92-9.52), nonconjugated estrogen: 2.00 (1.87-2.13), long cycle combined therapy: 2.89 (2.27-3.67), cyclic combined therapy: 2.06 (1.88-2.27), tibolone 3.56 (2.94-4.32), transdermal estrogen: 2.77 (2.12-3.62) and vaginal estrogen: 1.96 (1.77-2.17), but not with continuous combined therapy: 1.02 (0.87-1.20). In contrast, the risk of Type II tumors appeared decreased with continuous combined therapy: 0.45 (0.20-1.01), and estrogen therapy implied a nonsignificantly altered risk of 1.43 (0.85-2.41). Our findings support that continuous combined therapy is risk free for Type I tumors, while all other hormone therapies increase risk. In contrast, Type II endometrial cancer was less convincingly associated with hormone use, and continuous combined therapy appeared to decrease the risk.

  19. Influence of Dietary Ascorbic Acid on the Immune Responses of Juvenile Korean Rockfish Sebastes schlegelii.

    PubMed

    Kim, Jun-Hwan; Kang, Ju-Chan

    2015-09-01

    Juvenile Korean Rockfish Sebastes schlegelii (length, 13.6 ± 1.4 cm [mean ± SD]; weight, 53.6 ± 4.2 g) were fed twice daily with diets containing varying levels of ascorbic acid (0, 50, 100, 200, and 400 mg/kg) for 4 weeks. Significant increases in daily weight and length occurred in fish fed more than 50 mg/kg ascorbic acid. The lysozyme activity of fish fed diets containing ascorbic acid was considerably increased in rockfish plasma at 400 mg/kg ascorbic acid and in kidney at over 50 mg/kg ascorbic acid. Total plasma immunoglobulin M (IgM) levels were markedly elevated in fish fed 400 mg/kg ascorbic acid. The results suggest that dietary ascorbic acid supplementation in juvenile rockfish can induce a significant increase in growth and in immunological features such as lysozyme activity and plasma IgM levels.

  20. Influence of externally attached trasmitters on the swimming performance of juvenile white sturgeon

    USGS Publications Warehouse

    Counihan, T.D.; Frost, C.N.

    1999-01-01

    We measured the critical swimming speed of juvenile white sturgeons Acipenser transmontanus equipped with externally attached dummy ultrasonic transmitters and of untagged control fish in the laboratory. White sturgeons ranging from 31.9 to 37.0 cm fork length were subjected to one of three treatments: Control (handled but not tagged), tag attached below the dorsal fin, and tag attached with the anterior insertion point between the fourth and fifth dorsal scutes. Although transmitters were of recommended weight, we found that the swimming performance of tagged white sturgeons was significantly less than that of untagged control fish. Swimming performance of tagged fish was not differentially affected by tag location. Our results suggest that data from ultrasonic telemetry studies of externally tagged juvenile white sturgeons should be interpreted with caution due to the reduced swimming performance caused by external transmitters.

  1. Influence of externally attached transmitters on the swimming performance of juvenile white sturgeon

    USGS Publications Warehouse

    Counihan, T.D.; Frost, C.N.

    1999-01-01

    We measured the critical swimming speed of juvenile white sturgeons Acipenser transmontanus equipped with externally attached dummy ultrasonic transmitters and of untagged control fish in the laboratory. White sturgeons ranging from 31.9 to 37.0 cm fork length were subjected to one of three treatments: control (handled but not tagged), tag attached below the dorsal fin, and tag attached with the anterior insertion point between the fourth and fifth dorsal scutes. Although transmitters were of recommended weight, we found that the swimming performance of tagged white sturgeons was significantly less than that of untagged control fish. Swimming performance of tagged fish was not differentially affected by tag location. Our results suggest that data from ultrasonic telemetry studies of externally tagged juvenile white sturgeons should be interpreted with caution due to the reduced swimming performance caused by external transmitters.

  2. Climate-driven coral reorganisation influences aggressive behaviour in juvenile coral-reef fishes

    NASA Astrophysics Data System (ADS)

    Kok, Judith E.; Graham, Nicholas A. J.; Hoogenboom, Mia O.

    2016-06-01

    Globally, habitat degradation is altering the abundance and diversity of species in a variety of ecosystems. This study aimed to determine how habitat degradation, in terms of changing coral composition under climate change, affected abundance, species richness and aggressive behaviour of juveniles of three damselfishes ( Pomacentrus moluccensis, P. amboinensis and Dischistodus perspicillatus, in order of decreasing reliance on coral). Patch reefs were constructed to simulate two types of reefs: present-day reefs that are vulnerable to climate-induced coral bleaching, and reefs with more bleaching-robust coral taxa, thereby simulating the likely future of coral reefs under a warming climate. Fish communities were allowed to establish naturally on the reefs during the summer recruitment period. Climate-robust reefs had lower total species richness of coral-reef fishes than climate-vulnerable reefs, but total fish abundance was not significantly different between reef types (pooled across all species and life-history stages). The nature of aggressive interactions, measured as the number of aggressive chases, varied according to coral composition; on climate-robust reefs, juveniles used the substratum less often to avoid aggression from competitors, and interspecific aggression became relatively more frequent than intraspecific aggression for juveniles of the coral-obligate P. moluccensis. This study highlights the importance of coral composition as a determinant of behaviour and diversity of coral-reef fishes.

  3. EFFECT OF ACUTE STRESS ON PLASMA CONCENTRATIONS OF SEX AND STRESS HORMONES IN JUVENILE ALLIGATORS LIVING IN CONTROL AND CONTAMINATED LAKES

    EPA Science Inventory

    Environmental contaminants can act as stressors, inducing elevated circulating concentrations of stress hormones such as corticosterone and cortisol. Development in contaminated eggs has been reported to modify circulating sex steroid hormone concentrations in alligators (Alligat...

  4. Quantitative structure-activity relationship modeling of juvenile hormone mimetic compounds for Culex pipiens larvae, with a discussion of descriptor-thinning methods.

    PubMed

    Basak, Subhash C; Natarajan, Ramanathan; Mills, Denise; Hawkins, Douglas M; Kraker, Jessica J

    2006-01-01

    Quantitative structure-activity relationship (QSAR) modelers often encounter the problem of multicollinearity owing to the availability of large numbers of computable molecular descriptors. Sparsity of the variables while using descriptors such as atom pairs increases the complexity. Three different predictor-thinning methods, namely, a modified Gram-Schmidt algorithm, a marginal soft thresholding algorithm, and LASSO (least absolute shrinkage and selection operator), were utilized to reduce the number of descriptors prior to developing linear models. Juvenile hormone (JH) activity of 304 compounds on Culex pipiens larvae was taken as the model data set, and predictor trimming of a large number of diverse descriptors comprising 268 global molecular descriptors (topostructural, topochemical, and geometrical), 13 quantum chemical descriptors, and 915 atom pairs (substructural counts) was applied prior to linear regression by the ridge regression method. The data set (N = 304) was split into five calibration data sets of random samples of sizes 60/110/160/210/260, and the remaining 244/194/144/94/44 compounds were used for validations. LASSO was not found to be a very effective method in handling a large set of descriptors because the number of predictors retained could not exceed the number of observations. The results indicated that the modified Gram-Schmidt algorithm could be used to trim the number of predictors in the global molecular descriptor set where collinearity of the descriptors was the major concern. On the contrary, the soft thresholding approach was found to be an effective tool in subset selection from a diverse set of descriptors having both sparsity and multicollinearity, as in the case of the combined set of atom pairs and global molecular descriptors. The final model developed after variable selection was dominated more by atom pairs, which indicated the important structural moieties that affect JH activity of the compounds. The success of the

  5. Novel NAD+-Farnesal Dehydrogenase from Polygonum minus Leaves. Purification and Characterization of Enzyme in Juvenile Hormone III Biosynthetic Pathway in Plant

    PubMed Central

    Mohamed-Hussein, Zeti-Azura; Ng, Chyan Leong

    2016-01-01

    Juvenile Hormone III is of great concern due to negative effects on major developmental and reproductive maturation in insect pests. Thus, the elucidation of enzymes involved JH III biosynthetic pathway has become increasing important in recent years. One of the enzymes in the JH III biosynthetic pathway that remains to be isolated and characterized is farnesal dehydrogenase, an enzyme responsible to catalyze the oxidation of farnesal into farnesoic acid. A novel NAD+-farnesal dehydrogenase of Polygonum minus was purified (315-fold) to apparent homogeneity in five chromatographic steps. The purification procedures included Gigacap S-Toyopearl 650M, Gigacap Q-Toyopearl 650M, and AF-Blue Toyopearl 650ML, followed by TSK Gel G3000SW chromatographies. The enzyme, with isoelectric point of 6.6 is a monomeric enzyme with a molecular mass of 70 kDa. The enzyme was relatively active at 40°C, but was rapidly inactivated above 45°C. The optimal temperature and pH of the enzyme were found to be 35°C and 9.5, respectively. The enzyme activity was inhibited by sulfhydryl agent, chelating agent, and metal ion. The enzyme was highly specific for farnesal and NAD+. Other terpene aldehydes such as trans- cinnamaldehyde, citral and α- methyl cinnamaldehyde were also oxidized but in lower activity. The Km values for farnesal, citral, trans- cinnamaldehyde, α- methyl cinnamaldehyde and NAD+ were 0.13, 0.69, 0.86, 1.28 and 0.31 mM, respectively. The putative P. minus farnesal dehydrogenase that’s highly specific towards farnesal but not to aliphatic aldehydes substrates suggested that the enzyme is significantly different from other aldehyde dehydrogenases that have been reported. The MALDI-TOF/TOF-MS/MS spectrometry further identified two peptides that share similarity to those of previously reported aldehyde dehydrogenases. In conclusion, the P. minus farnesal dehydrogenase may represent a novel plant farnesal dehydrogenase that exhibits distinctive substrate specificity

  6. Novel NAD+-Farnesal Dehydrogenase from Polygonum minus Leaves. Purification and Characterization of Enzyme in Juvenile Hormone III Biosynthetic Pathway in Plant.

    PubMed

    Seman-Kamarulzaman, Ahmad-Faris; Mohamed-Hussein, Zeti-Azura; Ng, Chyan Leong; Hassan, Maizom

    2016-01-01

    Juvenile Hormone III is of great concern due to negative effects on major developmental and reproductive maturation in insect pests. Thus, the elucidation of enzymes involved JH III biosynthetic pathway has become increasing important in recent years. One of the enzymes in the JH III biosynthetic pathway that remains to be isolated and characterized is farnesal dehydrogenase, an enzyme responsible to catalyze the oxidation of farnesal into farnesoic acid. A novel NAD+-farnesal dehydrogenase of Polygonum minus was purified (315-fold) to apparent homogeneity in five chromatographic steps. The purification procedures included Gigacap S-Toyopearl 650M, Gigacap Q-Toyopearl 650M, and AF-Blue Toyopearl 650ML, followed by TSK Gel G3000SW chromatographies. The enzyme, with isoelectric point of 6.6 is a monomeric enzyme with a molecular mass of 70 kDa. The enzyme was relatively active at 40°C, but was rapidly inactivated above 45°C. The optimal temperature and pH of the enzyme were found to be 35°C and 9.5, respectively. The enzyme activity was inhibited by sulfhydryl agent, chelating agent, and metal ion. The enzyme was highly specific for farnesal and NAD+. Other terpene aldehydes such as trans- cinnamaldehyde, citral and α- methyl cinnamaldehyde were also oxidized but in lower activity. The Km values for farnesal, citral, trans- cinnamaldehyde, α- methyl cinnamaldehyde and NAD+ were 0.13, 0.69, 0.86, 1.28 and 0.31 mM, respectively. The putative P. minus farnesal dehydrogenase that's highly specific towards farnesal but not to aliphatic aldehydes substrates suggested that the enzyme is significantly different from other aldehyde dehydrogenases that have been reported. The MALDI-TOF/TOF-MS/MS spectrometry further identified two peptides that share similarity to those of previously reported aldehyde dehydrogenases. In conclusion, the P. minus farnesal dehydrogenase may represent a novel plant farnesal dehydrogenase that exhibits distinctive substrate specificity towards

  7. Yolk hormones influence in ovo chemosensory learning, growth, and feeding behavior in domestic chicks.

    PubMed

    Bertin, Aline; Meurisse, Maryse; Arnould, Cécile; Leterrier, Christine; Constantin, Paul; Cornilleau, Fabien; Vaudin, Pascal; Burlot, Thierry; Delaveau, Joel; Rat, Christophe; Calandreau, Ludovic

    2016-03-01

    In this study, we assessed whether prenatal exposure to elevated yolk steroid hormones can influence in ovo chemosensory learning and the behavior of domestic chicks. We simulated a maternal environmental challenge by experimentally enhancing yolk progesterone, testosterone, and estradiol concentrations in hen eggs prior to incubation. The embryos from these hormones-treated eggs (HO) as well as sham embryos (O) that had received the vehicle-only were exposed to the odor of fish oil (menhaden) between embryonic Days 11 and 20. An additional group of control embryos (C) was not exposed to the odor. All chicks were tested following hatching for their feeding preferences between foods that were or were not odorized with the menhaden odor. In the 3-min choice tests, the behavior of O chicks differed significantly according to the type of food whereas C and HO chicks showed no preference between odorized and non-odorized food. Our result suggests weaker response in HO chicks. In addition, HO chicks showed impaired growth and reduced intake of an unfamiliar food on the 24-h time scale compared to controls. Our data suggest that embryonic exposure to increased yolk hormone levels can alter growth, chemosensory learning, and the development of feeding behaviors.

  8. Female hormone influences on sexual assaults in Northern Ireland from 2002 to 2009.

    PubMed

    Beirne, Patricia; Hall, Janet; Grills, Claire; Moore, Tara

    2011-10-01

    In Northern Ireland 1 in every 454 women of 13 years and over during 2008/09 reported to police that they had suffered a sexual assault. This study considered the possibility that women may be more likely to be victims of sexual assault during the fertile phase of their reproductive cycle. Evolutionary psychology suggests that women would have suffered more negative consequences if sexually assaulted when fertile and that specific psychological mechanisms may have evolved in women to combat male coercion. Female behaviours towards men vary across the reproductive cycle and men's behaviour towards women may vary also as a result of changes in female hormones. Hormones play a major role in producing the characteristic cyclical changes throughout a woman's reproductive life. This study is the first study of female hormone influences on sexual assaults. The data for the study was collated retrospectively from the records of 105 females with regular, spontaneous menstrual cycles. These females alleged recent sexual assault and were examined in Belfast during the period 2002-2009. The study concluded that young girls in the middle of their cycle, i.e. the fertile phase, were most at risk of sexual assault. It is possible that both sexes are sensitive to signs, albeit subtle behavioural signs, indicating high risk of conception. PMID:21907935

  9. Yolk hormones influence in ovo chemosensory learning, growth, and feeding behavior in domestic chicks.

    PubMed

    Bertin, Aline; Meurisse, Maryse; Arnould, Cécile; Leterrier, Christine; Constantin, Paul; Cornilleau, Fabien; Vaudin, Pascal; Burlot, Thierry; Delaveau, Joel; Rat, Christophe; Calandreau, Ludovic

    2016-03-01

    In this study, we assessed whether prenatal exposure to elevated yolk steroid hormones can influence in ovo chemosensory learning and the behavior of domestic chicks. We simulated a maternal environmental challenge by experimentally enhancing yolk progesterone, testosterone, and estradiol concentrations in hen eggs prior to incubation. The embryos from these hormones-treated eggs (HO) as well as sham embryos (O) that had received the vehicle-only were exposed to the odor of fish oil (menhaden) between embryonic Days 11 and 20. An additional group of control embryos (C) was not exposed to the odor. All chicks were tested following hatching for their feeding preferences between foods that were or were not odorized with the menhaden odor. In the 3-min choice tests, the behavior of O chicks differed significantly according to the type of food whereas C and HO chicks showed no preference between odorized and non-odorized food. Our result suggests weaker response in HO chicks. In addition, HO chicks showed impaired growth and reduced intake of an unfamiliar food on the 24-h time scale compared to controls. Our data suggest that embryonic exposure to increased yolk hormone levels can alter growth, chemosensory learning, and the development of feeding behaviors. PMID:26419601

  10. [The influence of 24-epibrassidinole on the hormone status of wheat plants under sodium chloride].

    PubMed

    Aval'baev, A M; Iuldashev, R A; Fatkhutdinova, R A; Urusov, F A; Safutdinova, Iu V; Shakirova, F M

    2010-01-01

    We studied the influence of the preconditioning of wheat germ (Triticum aestivum L.) with 0.4 microM 24-epibrassidinole (EB) on the growth and hormone status of plants under the influence of 2% NaCl. The preconditioning with EB promoted the lowering of the extent of the damaging influence of pickling on the growth of germs. The important contribution to the realization of the protective action of EB in the preconditioning of plants is probably that of its ability to lower the level of stress-induced abscisic acid accumulation and the decrease in the content of indole-acetic acid. At the same time, the cytokinin concentration in plants preconditioned with EB under pickling was practically the same as in plants without stress. This fact combined with data about the ability of EB to induce the increase in cytokinin content in wheat, obtained before, allowed us to assume that the protective action of EB on plants is connected, first of all, with the prevention of the increase in level of hormones of cytokinin nature under pickling. PMID:20198927

  11. SEASONAL VARIATION IN PLASMA SEX STEROID CONCENTRATION IN JUVENILE ALLIGATORS

    EPA Science Inventory

    Seasonal variation in plasma sex steroid concentrations is common in mature vertebrates, and is occasionally seen in juvenile animals. In this study, we examine the seasonal pattern of sex hormone concentration in juvenile American alligators (Alligator mississippiensis) and make...

  12. Determine the Influence of Time Held in “Knockdown” Anesthesia on Survival and Stress of Surgically Implanted Juvenile Salmonids

    SciTech Connect

    Woodley, Christa M.; Wagner, Katie A.; Knox, Kasey M.

    2012-01-31

    The Juvenile Salmon Acoustic Telemetry System (JSATS) was developed for the U.S. Army Corp of Engineers Portland District (USACE) to address questions related to survival and performance measures of juvenile salmonids as they pass through the Federal Columbia River Power System (FCRPS). Researchers using JSATS acoustic transmitters (ATs) were tasked with standardizing the surgical implantation procedure to ensure that the stressors of handling and surgery on salmonids were consistent and less likely to cause effects of tagging in survival studies. Researchers questioned whether the exposure time in 'knockdown' anesthesia (or induction) to prepare fish for surgery could influence the survival of study fish (CBSPSC 2011). Currently, fish are held in knockdown anesthesia after they reach Stage 4 anesthesia until the completion of the surgical implantation of a transmitter, varies from 5 to 15 minutes for studies conducted in the Columbia Basin. The Columbia Basin Surgical Protocol Steering Committee (CBSPSC ) expressed concern that its currently recommended 10-minute maximum time limit during which fish are held in anesthetic - tricaine methanesulfonate (MS-222, 80 mg L-1 water) - could increase behavioral and physiological costs, and/or decrease survival of outmigrating juvenile salmonids. In addition, the variability in the time fish are held at Stage 4 could affect the data intended for direct comparison of fish within or among survival studies. Under the current recommended protocol, if fish exceed the 10-minute time limit, they are to be released without surgical implantation, thereby increasing the number of fish handled and endangered species 'take' at the bypass systems for FCRPS survival studies.

  13. Influence of pH on the acute toxicity of ammonia to juvenile freshwater mussels (fatmucket, Lampsills siliquoidea)

    USGS Publications Warehouse

    Wang, N.; Erickson, R.J.; Ingersoll, C.G.; Ivey, C.D.; Brunson, E.L.; Augspurger, T.; Barnhart, M.C.

    2008-01-01

    The objective of the present study was to evaluate the influence of pH on the toxicity of ammonia to juvenile freshwater mussels. Acute 96-h ammonia toxicity tests were conducted with 10-d-old juvenile mussels (fatmucket, Lampsilis siliquoidea) at five pH levels ranging from 6.5 to 9.0 in flow-through diluter systems at 20??C. Acute 48-h tests with amphipods (Hyalella azteca) and 96-h tests with oligochaetes (Lumbriculus variegatus) were conducted concurrently under the same test conditions to determine the sensitivity of mussels relative to these two commonly tested benthic invertebrate species. During the exposure, pH levels were maintained within 0.1 of a pH unit and ammonia concentrations were relatively constant through time (coefficient of variation for ammonia concentrations ranged from 2 to 30% with a median value of 7.9%). The median effective concentrations (EC50s) of total ammonia nitrogen (N) for mussels were at least two to six times lower than the EC50s for amphipods and oligochaetes, and the EC50s for mussels decreased with increasing pH and ranged from 88 mg N/L at pH 6.6 to 0.96 mg N/L at pH 9.0. The EC50s for mussels were at or below the final acute values used to derive the U.S. Environmental Protection Agency's acute water quality criterion (WQC). However, the quantitative relationship between pH and ammonia toxicity to juvenile mussels was similar to the average relationship for other taxa reported in the WQC. These results indicate that including mussel toxicity data in a revision to the WQC would lower the acute criterion but not change the WQC mathematical representation of the relative effect of pH on ammonia toxicity. ?? 2008 SETAC.

  14. Hormonal effects on women's facial masculinity preferences: the influence of pregnancy, post-partum, and hormonal contraceptive use.

    PubMed

    Cobey, Kelly D; Little, Anthony C; Roberts, S Craig

    2015-01-01

    Here, we investigate changes in women's facial masculinity preferences across pregnancy and the post-partum period. The majority of previous research demonstrating changes in women's masculinity preferences has examined the impact of hormonal variation across the female menstrual cycle. Hormonal changes experienced during pregnancy and the post-partum period, critical periods in women's reproductive life histories, are considerably more extreme than the variation that occurs across the menstrual cycle, suggesting that differences in preferences may also be displayed during these times. We find that women's preference for masculinity in men's faces, but not women's faces, decreases in the post-partum period relative to pregnancy. Furthermore, when compared to a sample of nulliparous control participants, post-partum participants showed different masculinity preferences compared with women who were using hormonal contraception, with the direction of this difference dependent upon the sex of the face assessed.

  15. Influence of methionine oxidation on the aggregation of recombinant human growth hormone.

    PubMed

    Mulinacci, Filippo; Poirier, Emilie; Capelle, Martinus A H; Gurny, Robert; Arvinte, Tudor

    2013-09-01

    Oxidation of methionine (Met) residues is one of the major chemical degradations of therapeutic proteins. This chemical degradation can occur at various stages during production and storage of a biotherapeutic drug. During the oxidation process, the side chain of methionine residue undergoes a chemical modification, with the thioether group substituted by a sulfoxide group. In previous papers, we showed that oxidation of the two most accessible methionine residues of recombinant human growth hormone (r-hGH), Met¹⁴ and Met¹²⁵, has no influence on the conformation of the protein [1]. However, the oxidized r-hGH is less thermally stable than the native protein [2]. In the current work, the consequences of the oxidation of these two methionine residues on the aggregation of r-hGH were investigated. The aggregation properties and kinetics of the native and oxidized r-hGH were measured in different buffers with both spectroscopic and chromatographic methods. Stabilities of oxidized and non-oxidized r-hGH were studied after storage at 37°C and freeze/thawing cycles. Methionine oxidation influenced the aggregation properties of r-hGH. In accelerated stability studies at 37°C, oxidized hormone aggregated more and faster than non-oxidized hormone. In freezing/thawing stability studies, it was found that oxidized r-hGH was less stable than its non-oxidized counterpart. In case of hGH, we have shown that chemical degradations such as oxidation can affect its physical stability and can induce aggregation.

  16. Influences of hormone replacement therapy on olfactory and cognitive function in postmenopausal women.

    PubMed

    Doty, Richard L; Tourbier, Isabelle; Ng, Victoria; Neff, Jessica; Armstrong, Deborah; Battistini, Michelle; Sammel, Mary D; Gettes, David; Evans, Dwight L; Mirza, Natasha; Moberg, Paul J; Connolly, Tim; Sondheimer, Steven J

    2015-06-01

    Olfactory dysfunction can be an early sign of Alzheimer's disease. Since hormone replacement therapy (HRT) may protect against Alzheimer's disease in postmenopausal women, the question arises as to whether it also protects against olfactory dysfunction in such women. A total of three olfactory and 12 neurocognitive tests were administered to 432 healthy postmenopausal women with varied HRT histories. Serum levels of reproductive hormones were obtained for all subjects; APOE-ε4 haplotype was determined for 77 women. National Adult Reading Test and Odor Memory/Discrimination Test scores were positively influenced by HRT. Odor Identification and Odor Memory/Discrimination Test scores were lower for women who scored poorly on a delayed recall test, a surrogate for mild cognitive impairment. The Wechsler Adult Intelligence Scale, Revised, as a Neuropsychological Instrument Spatial Span Backwards Test scores were higher in women receiving estrogen and progestin HRT and directly correlated with serum testosterone levels, the latter implying a positive effect of testosterone on spatial memory. APOE-ε4 was associated with poorer odor threshold test scores. These data suggest that HRT positively influences a limited number of olfactory and cognitive measures during menopause. PMID:25850354

  17. Influence of metabolic hormones and nutrition on ovarian follicle development in cattle: practical implications.

    PubMed

    Gong, J G

    2002-07-01

    Nutrition has long been known to have a profound influence on reproductive performance of female cattle, but the underlying mechanism remains poorly understood. Whilst early investigations focused on the modulation of nutrition on hypothalamic-pituitary axis, more recent studies have tested the hypothesis that metabolic hormones as nutritional signals exert a direct effect at the ovarian level. In cattle, treatment with recombinant bovine somatotrophin (rGH) significantly increases the population of small ovarian follicles. This is associated with increases in circulating concentrations of insulin and insulin-like growth factor-I (IGF-I). Subsequent studies, both in vitro and in vivo, have highlighted the importance of IGF-I and/or insulin acting in synergy with FSH and LH. More recently, we demonstrated that feeding heifers with 200% maintenance requirements for a short period significantly increases circulating insulin concentrations and population of small ovarian follicles. Based on these findings, our recent work has aimed at addressing some practical problems in cattle production. Firstly, we showed that both rGH pretreatment and increased dietary intake significantly enhance the response to standard superovulatory regimes. Secondly, we have demonstrated that feeding a diet to increase circulating insulin concentrations during the early lactation can advance the first ovulation postpartum and increase conception rate to the first service in dairy cows. In summary, nutrition influences ovarian follicle development in cattle possibly through changes in metabolic hormones. These interactions can be manipulated to improve reproductive performance.

  18. Hormonal and cholinergic influences on pancreatic lysosomal and digestive enzymes in rats.

    PubMed

    Evander, A; Ihse, I; Lundquist, I

    1983-01-01

    Hormonal and cholinergic influences on lysosomal and digestive enzyme activities in pancreatic tissue were studied in normal adult rats. Hormonal stimulation by the cholecystokinin analogue, caerulein, induced a marked enhancement of the activities of cathepsin D and N-acetyl-beta-D-glucosaminidase in pancreatic tissue, whereas the activities of amylase and lipase tended to decrease. Acid phosphatase activity was not affected. Further, caerulein was found to induce a significant increase of cathepsin D output in bile-pancreatic juice. This output largely parallelled that of amylase. Cholinergic stimulation by the muscarinic agonist carbachol, at a dose level giving the same output of amylase as caerulein, did not affect pancreatic activities of cathepsin D and N-acetyl-beta-D-glucosaminidase. Further, cholinergic stimulation induced an increase of amylase activity and a slight decrease of acid phosphatase activity in pancreatic tissue. Lipase activity was not affected. No apparent effect on cathepsin D output in bile-pancreatic juice was encountered after cholinergic stimulation. The activities of neither the digestive nor the lysosomal enzymes were influenced by the administration of secretin. The results suggest a possible lysosomal involvement in caerulein-induced secretion and/or inactivation of pancreatic digestive enzymes, whereas cholinergic stimulation seems to act through different mechanisms.

  19. Animal housing influences the response of bone to spaceflight in juvenile rats.

    PubMed

    Morey-Holton, E R; Halloran, B P; Garetto, L P; Doty, S B

    2000-04-01

    The rat has been used extensively as an animal model to study the effects of spaceflight on bone metabolism. The results of these studies have been inconsistent. On some missions, bone formation at the periosteal bone surface of weight-bearing bones is impaired and on others it is not, suggesting that experimental conditions may be an important determinant of bone responsiveness to spaceflight. To determine whether animal housing can affect the response of bone to spaceflight, we studied young growing (juvenile) rats group housed in the animal enclosure module and singly housed in the research animal holding facility under otherwise identical flight conditions (Spacelab Life Science 1). Spaceflight reduced periosteal bone formation by 30% (P < 0.001) and bone mass by 7% in single-housed animals but had little or no effect on formation (-6%) or mass (-3%) in group-housed animals. Group housing reduced the response of bone to spaceflight by as much as 80%. The data suggest that housing can dramatically affect the skeletal response of juvenile rats to spaceflight. These observations explain many of the discrepancies in previous flight studies and emphasize the need to study more closely the effects of housing (physical-social interaction) on the response of bone to the weightlessness of spaceflight.

  20. Maternal and environmental influences on egg size and juvenile life-history traits in Pacific salmon.

    PubMed

    Braun, Douglas C; Patterson, David A; Reynolds, John D

    2013-06-01

    Life-history traits such as fecundity and offspring size are shaped by investment trade-offs faced by mothers and mediated by environmental conditions. We use a 21-year time series for three populations of wild sockeye salmon (Oncorhynchus nerka) to test predictions for such trade-offs and responses to conditions faced by females during migration, and offspring during incubation. In years when their 1100 km upstream migration was challenged by high water discharges, females that reached spawning streams had invested less in gonads by producing smaller but not fewer eggs. These smaller eggs produced lighter juveniles, and this effect was further amplified in years when the incubation water was warm. This latter result suggests that there should be selection for larger eggs to compensate in populations that consistently experience warm incubation temperatures. A comparison among 16 populations, with matching migration and rearing environments but different incubation environments (i.e., separate spawning streams), confirmed this prediction; smaller females produced larger eggs for their size in warmer creeks. Taken together, these results reveal how maternal phenotype and environmental conditions can shape patterns of reproductive investment and consequently juvenile fitness-related traits within and among populations. PMID:23789081

  1. Influence of stress hormones on the auxin homeostasis in Brassica rapa seedlings.

    PubMed

    Salopek-Sondi, Branka; Šamec, Dunja; Mihaljević, Snježana; Smolko, Ana; Pavlović, Iva; Janković, Iva; Ludwig-Müller, Jutta

    2013-07-01

    KEY MESSAGE : Stress hormones, particularly jasmonic acid, influenced root growth, auxin levels, and transcription of auxin amidohydrolase BrIAR3 in Brassica rapa seedlings, while auxin conjugate synthetases BrGH3.1 and BrGH3.9 were down-regulated by all treatments. The influence of stress hormones: jasmonic acid (JA), salicylic acid (SA), and abscisic acid (ABA) on 1-day-old seedlings of Chinese cabbage (Brassica rapa L. ssp. pekinensis) was investigated with particular focus on auxin levels and the regulation of reversible auxin conjugation as a mechanism of auxin homeostasis. At the physiological level, stress hormones inhibited root growth, where JA was the most prominent inhibitor with an IC50 value 3.1 μM, which is one and two orders of magnitude lower than that found for ABA and SA, respectively. JA treatment significantly increased the total auxin content, by induction of free and conjugated forms. Also, the stress hormones affected the transcription of genes involved in the process of the reversible auxin conjugation: auxin amidohydrolases BrIAR3 and BrILL2, and auxin conjugate synthetases BrGH3.1 and BrGH3.9. JA treatment increased the transcript level of BrIAR3 two-fold, while it did not affect the transcription of BrILL2. SA and ABA down-regulated the transcription of both auxin amidohydrolase genes by 30 %. Transcription of both auxin conjugate synthetases was significantly down-regulated by all treatments by 30-70 %. Among the investigated biochemical stress markers, glutathione along with protein carbonylation appeared the most affected upon treatments. The redox status of the seedlings was shifted to the more oxidized state upon JA and ABA treatments, whereas SA caused more reduced redox state in comparison to the control. The principal component analysis visualized relationship among auxin and stress parameters upon treatments. Accordingly, the role of auxin in stress response of Brassica seedlings was discussed.

  2. Habitat selection influences sex distribution, morphology, tissue biochemistry, and parasite load of juvenile coho salmon in the West Fork Smith River, Oregon

    EPA Science Inventory

    Given the strong influence of water temperature on salmonid physiology and behavior, in the summers of 2004 and 2005 we studied juvenile male and female coho salmon Oncorhynchus kisutch in two reaches of Oregon’s West Fork Smith River with different thermal profiles. Our goals we...

  3. Hormones and pheromones in regulation of insect behavior

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Both pheromones and hormones are well recognized regulators of insect biology. However, the interactions between hormones and pheromones in coordinating insect biology are less well understood. We have studied the interactions between juvenile hormone, its precursor methyl farnesoate, and pheromon...

  4. Investigating probation strategies with juvenile offenders: the influence of officers' attitudes and youth characteristics.

    PubMed

    Schwalbe, Craig S; Maschi, Tina

    2009-10-01

    Probation officers are the focal point for most interventions with delinquent youths in the juvenile justice system. The present study examines probation strategies and interventions in a sample of 308 probation officers who completed the Probation Practices Assessment Survey (PPAS) in a web-based survey. The PPAS measures six probation approaches: deterrence, restorative justice, treatment, confrontation, counseling, and behavioral tactics. Structural equation models and latent class analyses showed that probation officers use multiple approaches with delinquent youths consistent with the balanced and restorative justice movement. Younger youths, high-risk youths, and youths with prior social service involvements are likely to receive more intensive interventions. The implications of these findings for improving probation practices with delinquent youth are discussed.

  5. In Vitro Growth and Steroidogenesis of Dog Follicles as Influenced by the Physical and Hormonal Microenvironment

    PubMed Central

    Songsasen, N; Woodruff, TK; Wildt, DE

    2011-01-01

    The present study examined the influences of physical and hormonal microenvironment on in vitro growth and steroidogenesis of dog follicles. Follicles were enzymatically-isolated and individually-encapsulated in 0.5% (w/v; n = 17) or 1.5% (n = 10) alginate and cultured with 0.5 IU/ml equine chorionic gonadotropin for 192 h. In a separate experiment, follicles were encapsulated in 0.5% alginate and cultured with 0 (n = 22), 1 (n= 23), 10 (n = 20) or 100 (n = 21) µg/ml FSH for 240 h. Follicle diameter and steroid production were assessed every 48 h in both studies. Follicles encapsulated in the 0.5% alginate grew faster (P < 0.05) than those cultured in the 1.5% concentration. Oestradiol (E2) and progesterone (P4) increased consistently (P < 0.05) over time, and follicles in the 1.5% alginate produced more (P < 0.05) P4 than those in the 0.5% solution. Follicles cultured in the highest FSH concentration (100 µg/ml) increased 100% in size after 240 h compared to 50 to 70% in lower dosages. E2 concentration remained unchanged over time (P > 0.05) across FSH dosages. However, P4 increased (P < 0.05) as culture progressed and with increasing FSH concentration. Results demonstrate that dog follicles cultured in alginate retain structural integrity, grow in size and are hormonally active. Lower alginate and increasing FSH concentrations promote in vitro follicle growth. However, the absence of an E2 rise in follicles cultured in FSH alone suggests the need for luteinizing hormone supplementation to support thecal cell differentiation and granulosa cell function. PMID:21502334

  6. Transcriptional Regulation of the Human P450 Oxidoreductase Gene: Hormonal Regulation and Influence of Promoter Polymorphisms

    PubMed Central

    Tee, Meng Kian; Huang, Ningwu; Damm, Izabella

    2011-01-01

    P450 oxidoreductase (POR) is the flavoprotein that acts as the obligatory electron donor to all microsomal P450 enzymes, including those involved in hepatic drug metabolism as well as three steroidogenic P450 enzymes. The untranslated first exon of human POR was located recently, permitting analysis of human POR transcription. Expression of deletional mutants containing up to 3193 bp of the human POR promoter in human adrenal NCI-H295A and liver Hep-G2 cells located the proximal promoter at −325/−1 bp from the untranslated exon. Common human POR polymorphisms at −208 and −173 had little influence on transcription, but the polymorphism at −152 reduced transcription significantly in both cell lines. EMSA and supershift assays identified binding of Smad3/Smad4 between −249 and −261 and binding of thyroid hormone receptor-β (TRβ) at −240/−245. Chromatin immunoprecipitation showed that Smad3, Smad4, TRα, TRβ, and estrogen receptor-α were bound between −374 and −149. Cotransfection of vectors for these transcription factors and POR promoter-reporter constructs into both cell types followed by hormonal treatment showed that T3 exerts major tropic effects via TRβ, with TRα, estrogen receptor-α, Smad3, and Smad4 exerting lesser, modulatory effects. T3 also increased POR mRNA in both cell lines. Thyroid hormone also is essential for rat liver POR expression but acts via different transcription factor complexes. These are the first data on human POR gene transcription, establishing roles for TRβ and Smad3/4 in its expression and indicating that the common polymorphism at −152 may play a role in genetic variation in steroid biosynthesis and drug metabolism. PMID:21393444

  7. Sex hormone influence on hepatitis in young male A/JCr mice infected with Helicobacter hepaticus.

    PubMed

    Theve, Elizabeth J; Feng, Yan; Taghizadeh, Koli; Cormier, Kathleen S; Bell, David R; Fox, James G; Rogers, Arlin B

    2008-09-01

    Hepatitis B virus (HBV), the leading cause of human hepatocellular carcinoma, is especially virulent in males infected at an early age. Likewise, the murine liver carcinogen Helicobacter hepaticus is most pathogenic in male mice infected before puberty. We used this model to investigate the influence of male sex hormone signaling on infectious hepatitis. Male A/JCr mice were infected with H. hepaticus or vehicle at 4 weeks and randomized into surgical and pharmacologic treatment groups. Interruption of androgen pathways was confirmed by hormone measurements, histopathology, and liver gene and Cyp4a protein expression. Castrated males and those receiving the competitive androgen receptor antagonist flutamide had significantly less severe hepatitis as determined by histologic activity index than intact controls at 4 months. Importantly, the powerful androgen receptor agonist dihydrotestosterone did not promote hepatitis. No effect on hepatitis was evident in males treated with the 5alpha-reductase inhibitor dutasteride, the peroxisome proliferator-activated receptor-alpha agonist bezafibrate, or the nonsteroidal anti-inflammatory drug flufenamic acid. Consistent with previous observations of hepatitis-associated liver-gender disruption, transcriptional alterations involved both feminine (cytochrome P450 4a14) and masculine (cytochrome P450 4a12 and trefoil factor 3) genes, as well gender-neutral (H19 fetal liver mRNA, lipocalin 2, and ubiquitin D) genes. Hepatitis was associated with increased unsaturated C(18) long-chain fatty acids (oleic acid and linoleic acid) relative to saturated stearic acid. Our results indicate that certain forms of androgen interruption can inhibit H. hepaticus-induced hepatitis in young male mice, whereas androgen receptor agonism does not worsen disease. This raises the possibility of targeted hormonal therapy in young male patients with childhood-acquired HBV.

  8. Understanding the influence of predation by introduced fishes on juvenile salmonids in the Columbia River Basin: Closing some knowledge gaps. Interim Report of Research 2010

    USGS Publications Warehouse

    Rose, Brien P.; Hansen, Gabriel S.; Mesa, Matthew G.

    2011-01-01

    In response to these recent concerns about the potential predatory impact of non-native piscivores on salmon survival, the Bonneville Power Administration (BPA) and the Columbia Basin Fish and Wildlife Authority (CBFWA) co-hosted a workshop to address predation on juvenile salmonids in the CRB by non-native fish (Halton 2008). The purpose of the workshop was to review, evaluate, and develop strategies to reduce predation by non-native fishes on juvenile salmonids. In the end, discussion at the workshop and at subsequent meetings considered two potential ideas to reduce predation by non-native fish on juvenile salmonids; (1) understanding the role of juvenile American shad Alosa sapidissima in the diet of non-native predators in the fall; and (2) the effects of localized, intense reductions of smallmouth bass in areas of particularly high salmonid predation. In this report, we describe initial efforts to understand the influence of juvenile American shad as a prey item for introduced predators in the middle Columbia River. Our first objective, addressed in Chapter 1, was to evaluate the efficacy of nonlethal methods to describe the physiological condition of smallmouth bass, walleye, and channel catfish from late summer through late fall. Such information will be used to understand the contribution of juvenile American shad to the energy reserves of predaceous fish prior to winter. In Chapter 2, we describe the results of some limited sampling to document the food habits of smallmouth bass, walleye, and channel catfish in three reservoirs of the middle Columbia River during late fall. Collectively, we hope to increase our understanding of the contribution of juvenile American shad to the diets of introduced predators and the contribution of this diet to their energy reserves, growth, and perhaps over-winter survival. Managers should be able to use this information for deciding whether to control the population of American shad in the CRB or for managing introduced

  9. Do sex hormones influence emotional modulation of pain and nociception in healthy women?

    PubMed

    Rhudy, Jamie L; Bartley, Emily J; Palit, Shreela; Kerr, Kara L; Kuhn, Bethany L; Martin, Satin L; Delventura, Jennifer L; Terry, Ellen L

    2013-12-01

    Sex hormones may contribute to inter- and intra-individual differences in pain by influencing emotional modulation of pain and nociception. To study this, a well-validated picture-viewing paradigm was used to assess emotional modulation of pain and the nociceptive flexion reflex (NFR; physiologic measure of nociception) during mid-follicular, ovulatory, and late-luteal phases of the menstrual cycle in healthy normally cycling women (n=40). Salivary estradiol, progesterone, and testosterone were assessed at each testing session. Emotional modulation of pain/NFR did not differ across menstrual phases, but low estradiol was associated with weaker emotional modulation of NFR (during all phases) and emotional modulation of pain (ovulatory and late-luteal phases). Given evidence that a failure to emotionally modulate pain might be a risk factor for chronic pain, low estradiol may promote chronic pain via this mechanism. However, future research is needed to extend these findings to women with disturbances of pain, emotion, and/or sex hormones.

  10. Juvenile Arthritis

    MedlinePlus

    Juvenile arthritis (JA) is arthritis that happens in children. It causes joint swelling, pain, stiffness, and loss ... common type of JA that children get is juvenile idiopathic arthritis. There are several other forms of ...

  11. Influence of activating hormones on human platelet membrane Ca/sup 2 +/-ATPase activity

    SciTech Connect

    Resink, T.J.; Dimitrov, D.; Stucki, S.; Buehler, F.R.

    1986-07-16

    Intact platelets were pretreated with hormones and thereafter membranes were prepared and Ca/sup 2 +/-ATPase activity determined. Thrombin decreased the V/sub max/ of Ca/sup 2 +/-ATPase after pretreatment of intact platelets. Platelet activating factor, vasopressin and ADP also decreased Ca/sup 2 +/-ATPase activity. 12-O-tetradecanoylphorbol-13-acetate (TPA) or A23187 or ionomycin alone had no effect, while the simultaneous pretreatment with TPA and Ca/sup 2 +/-ionophore decreased Ca/sup 2 +/-ATPase activity. cAMP elevating agents prostaglandin E/sub 1/ (PGE/sub 1/) and forskolin had no influence per se on Ca/sup 2 +/-ATPase, but antagonized the inhibitory effect of thrombin. The data suggest a close connection between phosphoinositide metabolism and the Ca/sup 2 +/-ATPase system.

  12. CIRCULATING CONCENTRATIONS OF THYROID HORMONE IN BELUGA WHALES (DELPHINAPTERUS LEUCAS): INFLUENCE OF AGE, SEX, AND SEASON.

    PubMed

    Flower, Jennifer E; Allender, Matthew C; Giovanelli, Richard P; Summers, Sandra D; Spoon, Tracey R; St Leger, Judy A; Goertz, Caroline E C; Dunn, J Lawrence; Romano, Tracy A; Hobbs, Roderick C; Tuttle, Allison D

    2015-09-01

    Thyroid hormones play a critical physiologic role in regulating protein synthesis, growth, and metabolism. To date, because no published compilation of baseline values for thyroid hormones in beluga whales (Delphinapterus leucas) exists, assessment of thyroid hormone concentrations in this species has been underused in clinical settings. The purpose of this study was to document the concentrations of total thyroxine (tT4) and total triiodothyronine (tT3) in healthy aquarium-maintained and free-ranging beluga whales and to determine the influence of age, sex, and season on the thyroid hormone concentrations. Archived serum samples were collected from healthy aquarium-maintained (n=43) and free-ranging (n=39) belugas, and serum tT4 and tT3 were measured using chemiluminescence immunoassay. The mean tT4 concentration in aquarium-maintained belugas was 5.67±1.43 μg/dl and the mean tT3 concentration was 70.72±2.37 ng/dl. Sex comparisons showed that aquarium-maintained males had significantly greater tT4 and tT3 (9.70±4.48 μg/dl and 92.65±30.55 ng/dl, respectively) than females (7.18±2.82 μg/dl and 77.95±20.37 ng/dl) (P=0.004 and P=0.013). Age comparisons showed that aquarium-maintained whales aged 1-5 yr had the highest concentrations of tT4 and tT3 (8.17±0.17 μg/dl and 105.46±1.98 ng/dl, respectively) (P=0.002 and P<0.001). tT4 concentrations differed significantly between seasons, with concentrations in winter (4.59±1.09 μg/dl) being significantly decreased compared with spring (P=0.009), summer (P<0.0001), and fall (P<0.0001) concentrations. There was a significant difference in tT4 and tT3 concentrations between aquarium-maintained whales (5.67±1.43 μg/dl and 70.72±15.57 ng/dl, respectively) and free-ranging whales (11.71±3.36 μg/dl and 103.38±26.45 ng/dl) (P<0.0001 and P<0.001). Clinicians should consider biologic and environmental influences (age, sex, and season) for a more accurate interpretation of thyroid hormone concentrations in belugas

  13. CIRCULATING CONCENTRATIONS OF THYROID HORMONE IN BELUGA WHALES (DELPHINAPTERUS LEUCAS): INFLUENCE OF AGE, SEX, AND SEASON.

    PubMed

    Flower, Jennifer E; Allender, Matthew C; Giovanelli, Richard P; Summers, Sandra D; Spoon, Tracey R; St Leger, Judy A; Goertz, Caroline E C; Dunn, J Lawrence; Romano, Tracy A; Hobbs, Roderick C; Tuttle, Allison D

    2015-09-01

    Thyroid hormones play a critical physiologic role in regulating protein synthesis, growth, and metabolism. To date, because no published compilation of baseline values for thyroid hormones in beluga whales (Delphinapterus leucas) exists, assessment of thyroid hormone concentrations in this species has been underused in clinical settings. The purpose of this study was to document the concentrations of total thyroxine (tT4) and total triiodothyronine (tT3) in healthy aquarium-maintained and free-ranging beluga whales and to determine the influence of age, sex, and season on the thyroid hormone concentrations. Archived serum samples were collected from healthy aquarium-maintained (n=43) and free-ranging (n=39) belugas, and serum tT4 and tT3 were measured using chemiluminescence immunoassay. The mean tT4 concentration in aquarium-maintained belugas was 5.67±1.43 μg/dl and the mean tT3 concentration was 70.72±2.37 ng/dl. Sex comparisons showed that aquarium-maintained males had significantly greater tT4 and tT3 (9.70±4.48 μg/dl and 92.65±30.55 ng/dl, respectively) than females (7.18±2.82 μg/dl and 77.95±20.37 ng/dl) (P=0.004 and P=0.013). Age comparisons showed that aquarium-maintained whales aged 1-5 yr had the highest concentrations of tT4 and tT3 (8.17±0.17 μg/dl and 105.46±1.98 ng/dl, respectively) (P=0.002 and P<0.001). tT4 concentrations differed significantly between seasons, with concentrations in winter (4.59±1.09 μg/dl) being significantly decreased compared with spring (P=0.009), summer (P<0.0001), and fall (P<0.0001) concentrations. There was a significant difference in tT4 and tT3 concentrations between aquarium-maintained whales (5.67±1.43 μg/dl and 70.72±15.57 ng/dl, respectively) and free-ranging whales (11.71±3.36 μg/dl and 103.38±26.45 ng/dl) (P<0.0001 and P<0.001). Clinicians should consider biologic and environmental influences (age, sex, and season) for a more accurate interpretation of thyroid hormone concentrations in belugas

  14. Influence of high ovarian hormones on QT interval duration in young African women.

    PubMed

    Balayssac-Siransy, Edwige; Ouattara, Soualiho; Adoubi, Anicet; Kouamé, Chantal; Hauhouot-Attoungbré, Marie-Laure; Dah, Cyrille; Bogui, Pascal

    2014-01-01

    Abstract The longer QT interval duration observed in women compared to men is usually attributed to sexual hormones. The aim of our study was to investigate, among black African women, the influence of hormonal variations during the menstrual cycle on the duration of the QT interval. Fourteen young black African women, healthy, sedentary, aged 24 ± 1.7 years, with a regular menstrual cycle (28 ± 1 days) were selected from 59 volunteers. At each phase of their menstrual cycle, menstrual 2.9 ± 0.6 days, follicular 13 ± 1.5 days, and luteal 23.1 ± 1.4 days, an electrocardiogram was performed in supine position after a resting period of 30 min, to measure QT interval duration. QT interval was corrected by Bazett's (QTcb) and Fridericia's (QTcf) formulae. Then, blood samples were obtained to measure estradiol, progesterone, and serum electrolytes (K(+), Ca(2+), Mg(2+)). There was no significant difference in uncorrected QT intervals between the three phases of the menstrual cycle. It was the same for QTcb and QTcf. Moreover, during the menstrual cycle, we did not observe any correlation between each QT, QTcb, QTcf, and estradiol levels which raised during the follicular phase (356.61 ± 160.77 pg/mL) and progesterone levels which raised during the luteal phase (16.38 ± 5.88 ng/mL). Finally, the method of Bland and Altman demonstrated that the corrections of QT by Bazett and Fridericia formulae were not interchangeable. The results of this study showed that high levels of estradiol and progesterone in young black African women did not influence the QT, QTcb and QTcf intervals duration during the menstrual cycle.

  15. Influence of infection with Renibacterium salmoninarum on susceptibility of juvenile spring chinook salmon to gas bubble trauma

    USGS Publications Warehouse

    Weiland, L.K.; Mesa, M.G.; Maule, A.G.

    1999-01-01

    During experiments in our laboratory to assess the progression and severity of gas bubble trauma (GBT) in juvenile spring chinook salmon Oncorhynchus tshawytscha, we had the opportunity to assess the influence of Renibacterium salmoninarum (Rs), the causative agent of bacterial kidney disease, on the susceptibility of salmon to GBT. We exposed fish with an established infection of Rs to 120% total dissolved gas (TDG) for 96 h and monitored severity of GBT signs in the fins and gills, Rs infection level in kidneys by using an enzyme-linked immunosorbent assay (ELISA), and mortality. Mortality occurred rapidly after exposure to 120% TDG, with a LT20 (time necessary to kill 20% of the population) of about 37 h, which is at a minimum about 16% earlier than other bioassays we have conducted using fish that had no apparent signs of disease. Fish that died early (from 31 to 36 h and from 49 to 52 h) had significantly higher infection levels (mean ?? SE ELISA absorbance = 1.532 ?? 0.108) than fish that survived for 96h (mean ?? SE ELISA absorbance = 0.828 ?? 0.137). Fish that died early also had a significantly greater number of gill filaments occluded with bubbles than those that survived 96 h. Conversely, fish that survived for 96 h had a significantly higher median fin severity ranking than those that died early. Our results indicate that fish with moderate to high levels of Rs infection are more vulnerable to the effects of dissolved gas supersaturation (DGS) and die sooner than fish with lower levels of Rs infection. However, there is a substantial amount of individual variation in susceptibility to the apparent cumulative effects of DGS and Rs infection. Collectively, our findings have important implications to programs designed to monitor the prevalence and severity of GBT in juvenile salmonids in areas like the Columbia River basin and perhaps elsewhere.

  16. Environmental influences on the spatial ecology of juvenile smalltooth sawfish (Pristis pectinata): results from acoustic monitoring.

    PubMed

    Simpfendorfer, Colin A; Yeiser, Beau G; Wiley, Tonya R; Poulakis, Gregg R; Stevens, Philip W; Heupel, Michelle R

    2011-01-01

    To aid recovery efforts of smalltooth sawfish (Pristis pectinata) populations in U.S. waters a research project was developed to assess how changes in environmental conditions within estuarine areas affected the presence, movements, and activity space of this endangered species. Forty juvenile P. pectinata were fitted with acoustic tags and monitored within the lower 27 km of the Caloosahatchee River estuary, Florida, between 2005 and 2007. Sawfish were monitored within the study site from 1 to 473 days, and the number of consecutive days present ranged from 1 to 125. Residency index values for individuals varied considerably, with annual means highest in 2005 (0.95) and lowest in 2007 (0.73) when several P. pectinata moved upriver beyond detection range during drier conditions. Mean daily activity space was 1.42 km of river distance. The distance between 30-minute centers of activity was typically <0.1 km, suggesting limited movement over short time scales. Salinity electivity analysis demonstrated an affinity for salinities between 18 and at least 24 psu, suggesting movements are likely made in part, to remain within this range. Thus, freshwater flow from Lake Okeechobee (and its effect on salinity) affects the location of individuals within the estuary, although it remains unclear whether or not these movements are threatening recovery.

  17. Environmental Influences on the Spatial Ecology of Juvenile Smalltooth Sawfish (Pristis pectinata): Results from Acoustic Monitoring

    PubMed Central

    Simpfendorfer, Colin A.; Yeiser, Beau G.; Wiley, Tonya R.; Poulakis, Gregg R.; Stevens, Philip W.; Heupel, Michelle R.

    2011-01-01

    To aid recovery efforts of smalltooth sawfish (Pristis pectinata) populations in U.S. waters a research project was developed to assess how changes in environmental conditions within estuarine areas affected the presence, movements, and activity space of this endangered species. Forty juvenile P. pectinata were fitted with acoustic tags and monitored within the lower 27 km of the Caloosahatchee River estuary, Florida, between 2005 and 2007. Sawfish were monitored within the study site from 1 to 473 days, and the number of consecutive days present ranged from 1 to 125. Residency index values for individuals varied considerably, with annual means highest in 2005 (0.95) and lowest in 2007 (0.73) when several P. pectinata moved upriver beyond detection range during drier conditions. Mean daily activity space was 1.42 km of river distance. The distance between 30-minute centers of activity was typically <0.1 km, suggesting limited movement over short time scales. Salinity electivity analysis demonstrated an affinity for salinities between 18 and at least 24 psu, suggesting movements are likely made in part, to remain within this range. Thus, freshwater flow from Lake Okeechobee (and its effect on salinity) affects the location of individuals within the estuary, although it remains unclear whether or not these movements are threatening recovery. PMID:21347294

  18. Environmental influences on the spatial ecology of juvenile smalltooth sawfish (Pristis pectinata): results from acoustic monitoring.

    PubMed

    Simpfendorfer, Colin A; Yeiser, Beau G; Wiley, Tonya R; Poulakis, Gregg R; Stevens, Philip W; Heupel, Michelle R

    2011-01-01

    To aid recovery efforts of smalltooth sawfish (Pristis pectinata) populations in U.S. waters a research project was developed to assess how changes in environmental conditions within estuarine areas affected the presence, movements, and activity space of this endangered species. Forty juvenile P. pectinata were fitted with acoustic tags and monitored within the lower 27 km of the Caloosahatchee River estuary, Florida, between 2005 and 2007. Sawfish were monitored within the study site from 1 to 473 days, and the number of consecutive days present ranged from 1 to 125. Residency index values for individuals varied considerably, with annual means highest in 2005 (0.95) and lowest in 2007 (0.73) when several P. pectinata moved upriver beyond detection range during drier conditions. Mean daily activity space was 1.42 km of river distance. The distance between 30-minute centers of activity was typically <0.1 km, suggesting limited movement over short time scales. Salinity electivity analysis demonstrated an affinity for salinities between 18 and at least 24 psu, suggesting movements are likely made in part, to remain within this range. Thus, freshwater flow from Lake Okeechobee (and its effect on salinity) affects the location of individuals within the estuary, although it remains unclear whether or not these movements are threatening recovery. PMID:21347294

  19. Influence of pelage insulation and ambient temperature on energy intake and growth of juvenile Siberian hamsters.

    PubMed

    Batavia, Mariska; Matsushima, Ayako; Eboigboden, Osaretin; Zucker, Irving

    2010-10-01

    Both growth and thermoregulation are energetically costly, and many studies implicate an energetic tradeoff between them. Moreover, fur is known to ameliorate thermoregulatory costs in adult mammals, but its role in maintaining energy balance during growth is unclear. This study tested for an energetic tradeoff between growth and thermoregulation in juvenile Siberian hamsters (Phodopus sungorus) and the effect of an insulative pelage on intrinsic growth rate. Hamsters weaned at 18 days of age and left fully furred or deprived of all dorsal fur by shaving at 20 days of age, were housed at 10 degrees C or 23 degrees C. Body mass, length, and food consumption were measured until hamsters were 35 days old. Thermal challenge, whether by low ambient temperature or shaving, resulted in increased food intake and decreased efficiency at converting food into body mass. Body mass and length were not affected by the thermal challenges. These results suggest that there is no mandatory tradeoff between growth and thermoregulation in this species, particularly when food is in abundant supply. Although fur was not necessary for normal growth to proceed, it ameliorated energetic costs associated with thermoregulation, and may play a role in maintaining energy balance under conditions of limited food availability.

  20. Urinary iodine and stable isotope analysis to examine habitat influences on thyroid hormones among coastal dwelling American alligators.

    PubMed

    Boggs, Ashley S P; Hamlin, Heather J; Nifong, James C; Kassim, Brittany L; Lowers, Russell H; Galligan, Thomas M; Long, Stephen E; Guillette, Louis J

    2016-01-15

    The American alligator, generally a freshwater species, is known to forage in marine environments despite the lack of a salt secreting gland found in other crocodylids. Estuarine and marine foraging could lead to increased dietary uptake of iodine, a nutrient necessary for the production of thyroid hormones. To explore the influence of dietary iodine on thyroid hormone health of coastal dwelling alligators, we described the seasonal plasma thyroxine and triiodothyronine concentrations measured by radioimmunoassay and urinary iodine (UI) concentrations measured by inductively coupled plasma mass spectrometry. We also analyzed long-term dietary patterns through stable isotope analysis of scute tissue. Snout-to-vent length (SVL) was a significant factor among UI and stable isotope analyses. Large adult males greater than 135cm SVL had the highest UI concentrations but did not display seasonality of thyroid hormones. Alligators under 135 SVL exhibited seasonality in thyroid hormones and a positive relationship between UI and triiodothyronine concentrations. Isotopic signatures provided supporting evidence that large males predominantly feed on marine/estuarine prey whereas females showed reliance on freshwater/terrestrial prey supplemented by marine/estuarine prey. UI measurement provided immediate information that correlated to thyroid hormone concentrations whereas stable isotope analysis described long-term dietary patterns. Both techniques demonstrate that adult alligators in coastal environments are utilizing estuarine/marine habitats, which could alter thyroid hormone physiology.

  1. Urinary iodine and stable isotope analysis to examine habitat influences on thyroid hormones among coastal dwelling American alligators.

    PubMed

    Boggs, Ashley S P; Hamlin, Heather J; Nifong, James C; Kassim, Brittany L; Lowers, Russell H; Galligan, Thomas M; Long, Stephen E; Guillette, Louis J

    2016-01-15

    The American alligator, generally a freshwater species, is known to forage in marine environments despite the lack of a salt secreting gland found in other crocodylids. Estuarine and marine foraging could lead to increased dietary uptake of iodine, a nutrient necessary for the production of thyroid hormones. To explore the influence of dietary iodine on thyroid hormone health of coastal dwelling alligators, we described the seasonal plasma thyroxine and triiodothyronine concentrations measured by radioimmunoassay and urinary iodine (UI) concentrations measured by inductively coupled plasma mass spectrometry. We also analyzed long-term dietary patterns through stable isotope analysis of scute tissue. Snout-to-vent length (SVL) was a significant factor among UI and stable isotope analyses. Large adult males greater than 135cm SVL had the highest UI concentrations but did not display seasonality of thyroid hormones. Alligators under 135 SVL exhibited seasonality in thyroid hormones and a positive relationship between UI and triiodothyronine concentrations. Isotopic signatures provided supporting evidence that large males predominantly feed on marine/estuarine prey whereas females showed reliance on freshwater/terrestrial prey supplemented by marine/estuarine prey. UI measurement provided immediate information that correlated to thyroid hormone concentrations whereas stable isotope analysis described long-term dietary patterns. Both techniques demonstrate that adult alligators in coastal environments are utilizing estuarine/marine habitats, which could alter thyroid hormone physiology. PMID:26684734

  2. Factors influencing the survival of outmigrating juvenile salmonids through multiple dam passages: an individual-based approach.

    PubMed

    Elder, Timothy; Woodley, Christa M; Weiland, Mark A; Strecker, Angela L

    2016-08-01

    Substantial declines of Pacific salmon populations have occurred over the past several decades related to large-scale anthropogenic and climatic changes in freshwater and marine environments. In the Columbia River Basin, migrating juvenile salmonids may pass as many as eight large-scale hydropower projects before reaching the ocean; however, the cumulative effects of multiple dam passages are largely unknown. Using acoustic transmitters and an extensive system of hydrophone arrays in the Lower Columbia River, we calculated the survival of yearling Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) passing one, two, or three dams. We applied a unique index of biological characteristics and environmental exposures, experienced by each fish individually as it migrated downstream, in order to examine which factors most influence salmonid survival. High outflow volumes led to involuntary spill in 2011 and created an environment of supersaturated dissolved gas concentrations. In this environment, migrating smolt survival was strongly influenced by barometric pressure, fish velocity, and water temperature. The effect of these variables on survival was compounded by multiple dam passages compared to fish passing a single dam. Despite spatial isolation between dams in the Lower Columbia River hydrosystem, migrating smolt appear to experience cumulative effects akin to a press disturbance. In general, Chinook salmon and steelhead respond similarly in terms of survival rates and responses to altered environmental conditions. Management actions that limit dissolved gas concentrations in years of high flow will benefit migrating salmonids at this life stage. PMID:27547362

  3. Influence of swimming speed on metabolic rates of juvenile pacific bluefin tuna and yellowfin tuna.

    PubMed

    Blank, Jason M; Farwell, Charles J; Morrissette, Jeffery M; Schallert, Robert J; Block, Barbara A

    2007-01-01

    Bluefin tuna are endothermic and have higher temperatures, heart rates, and cardiac outputs than tropical tuna. We hypothesized that the increased cardiovascular capacity to deliver oxygen in bluefin may be associated with the evolution of higher metabolic rates. This study measured the oxygen consumption of juvenile Pacific bluefin Thunnus orientalis and yellowfin tuna Thunnus albacares swimming in a swim-tunnel respirometer at 20 degrees C. Oxygen consumption (Mo2) of bluefin (7.1-9.4 kg) ranged from 235+/-38 mg kg(-1) h(-1) at 0.85 body length (BL) s(-1) to 498+/-55 mg kg(-1) h(-1) at 1.80 BL s(-1). Minimal metabolic rates of swimming bluefin were 222+/-24 mg O(2) kg(-1) h(-1) at speeds of 0.75 to 1.0 BL s(-1). Mo2 of T. albacares (3.7-7.4 kg) ranged from 164+/-18 mg kg(-1) h(-1) at 0.65 BL s(-1) to 405+/-105 mg kg(-1) h(-1) at 1.8 BL s(-1). Bluefin tuna had higher metabolic rates than yellowfin tuna at all swimming speeds tested. At a given speed, bluefin had higher metabolic rates and swam with higher tailbeat frequencies and shorter stride lengths than yellowfin. The higher M dot o2 recorded in Pacific bluefin tuna is consistent with the elevated cardiac performance and enhanced capacity for excitation-contraction coupling in cardiac myocytes of these fish. These physiological traits may underlie thermal-niche expansion of bluefin tuna relative to tropical tuna species. PMID:17252513

  4. Influence of Hormonal Changes on Audiologic Examination in Normal Ovarian Cycle Females: An Analytic Study

    PubMed Central

    Adriztina, Indri; Adnan, Adlin; Adenin, Ichwanul; Haryuna, Siti Hajar; Sarumpaet, Sorimuda

    2015-01-01

    Introduction There is only limited information from previous studies that suggest that auditory function may be influenced by hormones. Recent advances in the field have exposed the potential role of hormones in modulating the auditory system. Objective This study aims to investigate the relationship between menstrual cycle and outer hair cell function with audiological examination. Methods This is an analytic study with a cross-sectional design. The sampling was a systematic random sampling. We found 49 women with normal menstrual cycle and collected their data through interviews, physical examination, and examination of the ear, with otoscopic and other routine otorhinolaryngology examinations. We evaluated Tympanometry, distortion-product otoacoustic emissions (DPOAE), and pure tone audiometry. Results We found the audiometric threshold worse in the follicular phase than other phases at 4000 Hz of the right ear, and in the ovulation was found best than any other phases at 1000 Hz of the left ear with significant difference. We found significant difference of DPOAE between ovulation time and follicular phase at 3000 Hz and 1000 Hz in the left ear and between ovulation and luteal phased at 2000 Hz, 3000 Hz and 5000 Hz in the right ear and at 1000 Hz in the left ear with p < 0.05. Conclusion The result of this study showed that only a small part of audiometry threshold had a significant difference between each menstrual phase. In other words, we found no correlation between menstrual and audiometry threshold. Nonetheless, there is a correlation between menstrual cycle phase and DPOAE amplitude.

  5. Neonatal thyroid-stimulating hormone level is influenced by neonatal, maternal, and pregnancy factors.

    PubMed

    Trumpff, Caroline; Vandevijvere, Stefanie; Moreno-Reyes, Rodrigo; Vanderpas, Jean; Tafforeau, Jean; Van Oyen, Herman; De Schepper, Jean

    2015-11-01

    The percentage of newborns with a neonatal whole blood thyroid-stimulating hormone (TSH) greater than 5 mIU/L has been used as an indicator of iodine deficiency at the population level. However, TSH levels in newborns may be influenced by many factors other than iodine status. The objective of this study was to identify neonatal, maternal, and pregnancy-related determinants of neonatal TSH levels in a retrospective cohort study. The study sample included 313 Belgian mothers and their 4- to 5-year-old children. The children had a neonatal TSH concentration between 0 and 15 mIU/L at neonatal screening, and blood samples were collected 3 to 5 days after birth. Children with suspected congenital hypothyroidism (neonatal TSH level >15 mIU/L), prematurely born (i.e., <37 weeks), or with a low birth weight (i.e., <2500 g) were excluded. Information about maternal and birth-related determinants was collected from the neonatal screening center via a self-administered questionnaire filled in by the mother together with the child's health booklet. Higher TSH levels were found in spring and winter compared to summer and autumn (P = .011). Higher TSH levels were associated with lifetime smoking behavior (up to child birth) in the mother (P = .005), lower weight gain during pregnancy (P = .014), and longer pregnancies (P = .003). This study showed that several neonatal, maternal, and pregnancy-related determinants are influencing neonatal TSH level. PMID:26428622

  6. What is the influence of hormone therapy on homocysteine and crp levels in postmenopausal women?

    PubMed Central

    Lakryc, Eli Marcelo; Machado, Rogério Bonassi; Soares, José Maria; Fernandes, César Eduardo; Baracat, Edmund Chada

    2015-01-01

    OBJECTIVE: To evaluate the influence of estrogen therapy and estrogen-progestin therapy on homocysteine and C-reactive protein levels in postmenopausal women. METHODS: In total, 99 postmenopausal women were included in this double-blind, randomized clinical trial and divided into three groups: Group A used estrogen therapy alone (2.0 mg of 17β-estradiol), Group B received estrogen-progestin therapy (2.0 mg of 17 β-estradiol +1.0 mg of norethisterone acetate) and Group C received a placebo (control). The length of treatment was six months. Serum measurements of homocysteine and C-reactive protein were carried out prior to the onset of treatment and following six months of therapy. RESULTS: After six months of treatment, there was a 20.7% reduction in homocysteine levels and a 100.5% increase in C-reactive protein levels in the group of women who used estrogen therapy. With respect to the estrogen-progestin group, there was a 12.2% decrease in homocysteine levels and a 93.5% increase in C-reactive protein levels. CONCLUSION: Our data suggested that hormone therapy (unopposed estrogen or estrogen associated with progestin) may have a positive influence on decreasing cardiovascular risk due to a significant reduction in homocysteine levels. PMID:25789519

  7. Influence of light and feeding conditions on swimming activity rhythms of larval and juvenile turbot. Scophthalmus maximus L.: An experimental study

    NASA Astrophysics Data System (ADS)

    Champalbert, Gisèle; Le Direach-Boursier, Laurence

    1998-12-01

    Turbot larvae are transported towards coastal nursery areas and live in very shallow waters. Food availability is assumed to be an important factor that retains them in such areas. To study the effects of a biotic factor (food) and an abiotic factor (light) that strongly influence behavioural mechanisms, experiments were carried out on laboratory-reared animals: larvae (1 cm), post-larvae (1.2 to 2.5 cm) and early juveniles (6 to 7 cm). Three kinds of apparatus and methods were used to record variations in swimming activity: (1) a phototaxis device to study orientation reactions in horizontal tanks; (2) actographs with infrared photoelectric barriers fitted around vertical cylindrical tanks; and (3) video cameras and cylindrical tanks. Observations were performed in total darkness and under dark-light regimes. Different types and quantities of food were provided to the fish. Larvae and juveniles of turbot exhibited a positive phototaxis from 1 to 1000 μW cm -2. At intensities lower than or equal to 0.1 μW cm -2, they did not exhibit clear reactions toward or away from the light. Turbot larvae and juveniles kept in total darkness did not show a clear rhythm of activity. Under natural illumination as well as in artificial LD conditions of similar periodicity, larvae swam by day and night. Live food ( Artemia nauplii or juvenile mysids) induced an immediate increase in activity or the maintenance of a high level of activity, which decreased over the following days. Recently metamorphosed turbot kept under LD conditions exhibited a clear rhythm with a nocturnal maximum. Food given at night did not induce swimming changes as long as food density remained low. At higher prey concentrations, increased activity during feeding was followed by reduced activity for more than 24 hours. A similar response pattern was noted when active food was given in large quantities during the day: juveniles displayed an immediate increase in activity, which subsequently decreased. Regular

  8. Influence of species, size and relative abundance on the outcomes of competitive interactions between brook trout and juvenile coho salmon

    USGS Publications Warehouse

    Thornton, Emily J; Duda, Jeff; Quinn, Thomas P

    2016-01-01

    Resource competition between animals is influenced by a number of factors including the species, size and relative abundance of competing individuals. Stream-dwelling animals often experience variably available food resources, and some employ territorial behaviors to increase their access to food. We investigated the factors that affect dominance between resident, non-native brook trout and recolonizing juvenile coho salmon in the Elwha River, WA, USA, to see if brook trout are likely to disrupt coho salmon recolonization via interference competition. During dyadic laboratory feeding trials, we hypothesized that fish size, not species, would determine which individuals consumed the most food items, and that species would have no effect. We found that species, not size, played a significant role in dominance; coho salmon won 95% of trials, even when only 52% the length of their brook trout competitors. As the pairs of competing fish spent more time together during a trial sequence, coho salmon began to consume more food, and brook trout began to lose more, suggesting that the results of early trials influenced fish performance later. In group trials, we hypothesized that group composition and species would not influence fish foraging success. In single species groups, coho salmon consumed more than brook trout, but the ranges overlapped. Brook trout consumption remained constant through all treatments, but coho salmon consumed more food in treatments with fewer coho salmon, suggesting that coho salmon experienced more intra- than inter-specific competition and that brook trout do not pose a substantial challenge. Based on our results, we think it is unlikely that competition from brook trout will disrupt Elwha River recolonization by coho salmon.

  9. Prenatal alcohol exposure and adolescent stress increase sensitivity to stress and gonadal hormone influences on cognition in adult female rats.

    PubMed

    Comeau, Wendy L; Lee, Kristen; Anderson, Katie; Weinberg, Joanne

    2015-09-01

    Abnormal activity of stress hormone (hypothalamic-pituitary-adrenal [HPA]), and gonadal hormone (hypothalamic-pituitary-gonadal [HPG]) systems is reported following prenatal alcohol exposure (PAE). PAE increases vulnerability of brain regions involved in regulation of these systems to stressors or challenges during sensitive periods of development, such as adolescence. In addition, HPA and HPG functions are linked to higher order functions such as executive function (EF), with dysregulation of either system adversely affecting EF processes, including attention and response inhibition, that influence cognition. However, how HPA and HPG systems interact to influence cognitive performance in individuals with an FASD is not fully understood. To investigate, we used a rat model of moderate PAE. Adolescent female PAE and control offspring were exposed to 10days of chronic mild stress (CMS) and cognitive function was assessed on the radial arm maze (RAM) in adulthood. On the final test day, animals were sacrificed, with blood collected for hormone analyses, and vaginal smears taken to assess estrus stage at the time of termination. Analyses showed that adolescent CMS significantly increased levels of CORT and RAM errors during proestrus in adult PAE but not control females. Moreover, CORT levels were correlated with estradiol levels and with RAM errors, but only in PAE females, with outcome dependent on adolescent CMS condition. These results suggest that PAE increases sensitivity to the influences of stress and gonadal hormones on cognition, and thus, in turn, that HPA and HPG dysregulation may underlie some of the deficits in executive function described previously in PAE females.

  10. Effects of microplastics on juveniles of the common goby (Pomatoschistus microps): confusion with prey, reduction of the predatory performance and efficiency, and possible influence of developmental conditions.

    PubMed

    Carlos de Sá, Luís; Luís, Luís G; Guilhermino, Lúcia

    2015-01-01

    Microplastics (MP) are ubiquitous contaminants able to cause adverse effects on organisms. Three hypotheses were tested here: early Pomatoschistus microps juveniles can ingest MP; the presence of MP may reduce fish predatory performance and efficiency; developmental conditions may influence the preyselection capability of fish. Predatory bioassays were carried out with juveniles from two estuaries with differences in environmental conditions: Minho (M-est) and Lima (L-est) Rivers (NW Iberian coast). Polyethylene MP spheres (3 types) alone and in combination with Artemia nauplii were offered as prey.All the MP types were ingested, suggesting confusion with food. Under simultaneous exposure to MP and Artemia, L-est fish showed a significant reduction of the predatory performance (65%) and efficiency (upto 50%), while M-est fish did not, suggesting that developmental conditions may influence the preyselection capability of fish. The MP-induced reduction of food intake may decrease individual and population fitness. PMID:25463733

  11. Effects of microplastics on juveniles of the common goby (Pomatoschistus microps): confusion with prey, reduction of the predatory performance and efficiency, and possible influence of developmental conditions.

    PubMed

    Carlos de Sá, Luís; Luís, Luís G; Guilhermino, Lúcia

    2015-01-01

    Microplastics (MP) are ubiquitous contaminants able to cause adverse effects on organisms. Three hypotheses were tested here: early Pomatoschistus microps juveniles can ingest MP; the presence of MP may reduce fish predatory performance and efficiency; developmental conditions may influence the preyselection capability of fish. Predatory bioassays were carried out with juveniles from two estuaries with differences in environmental conditions: Minho (M-est) and Lima (L-est) Rivers (NW Iberian coast). Polyethylene MP spheres (3 types) alone and in combination with Artemia nauplii were offered as prey.All the MP types were ingested, suggesting confusion with food. Under simultaneous exposure to MP and Artemia, L-est fish showed a significant reduction of the predatory performance (65%) and efficiency (upto 50%), while M-est fish did not, suggesting that developmental conditions may influence the preyselection capability of fish. The MP-induced reduction of food intake may decrease individual and population fitness.

  12. Does the presence of microplastics influence the acute toxicity of chromium(VI) to early juveniles of the common goby (Pomatoschistus microps)? A study with juveniles from two wild estuarine populations.

    PubMed

    Luís, Luís G; Ferreira, Pedro; Fonte, Elsa; Oliveira, Miguel; Guilhermino, Lúcia

    2015-07-01

    Toxicological interactions between microplastics (MP) and other environmental contaminants are of grave concern. Here, the potential influence of MP in the short-term toxicity of chromium to early juveniles of Pomatoschistus microps was investigated. Three null hypotheses were tested: (1) exposure to Cr(VI) concentrations in the low ppm range does not induce toxic effects on juveniles; (2) the presence of microplastics in the water does not influence the acute toxicity of Cr(VI) to juveniles; (3) the environmental conditions of the natural habitat where fish developed do not influence their sensitivity to Cr(VI)-induced acute stress. Fish were collected in the estuaries of Minho (M-est) and Lima (L-est) Rivers (NW Iberian Peninsula) that have several abiotic differences, including in the water and sediment concentrations of various environmental contaminants. After acclimatization to laboratory conditions, two 96h acute bioassays were carried out with juveniles from both estuaries to: (i) investigate the effects of Cr(VI) alone; (ii) investigate the effects of Cr(VI) in the presence of MP (polyethylene spheres 1-5μm ∅). Cr(VI) alone induced mortality (96h-LC50s: 14.4-30.5mg/l) and significantly decreased fish predatory performance (≤74%). Thus, in the range of concentrations tested (5.6-28.4mg/l) Cr(VI) was found to be toxic to P. microps early juveniles, therefore, we rejected hypothesis 1. Under simultaneous exposure to Cr(VI) and MP, a significant decrease of the predatory performance (≤67%) and a significant inhibition of AChE activity (≤31%) were found. AChE inhibition was not observed in the test with Cr(VI) alone and MP alone caused an AChE inhibition ≤21%. Mixture treatments containing Cr(VI) concentration ≥3.9mg/l significantly increased LPO levels in L-est fish, an effect that was not observed under Cr(VI) or MP single exposures. Thus, toxicological interactions between Cr(VI) and MP occurred, therefore, we rejected hypothesis 2. In the

  13. Does the presence of microplastics influence the acute toxicity of chromium(VI) to early juveniles of the common goby (Pomatoschistus microps)? A study with juveniles from two wild estuarine populations.

    PubMed

    Luís, Luís G; Ferreira, Pedro; Fonte, Elsa; Oliveira, Miguel; Guilhermino, Lúcia

    2015-07-01

    Toxicological interactions between microplastics (MP) and other environmental contaminants are of grave concern. Here, the potential influence of MP in the short-term toxicity of chromium to early juveniles of Pomatoschistus microps was investigated. Three null hypotheses were tested: (1) exposure to Cr(VI) concentrations in the low ppm range does not induce toxic effects on juveniles; (2) the presence of microplastics in the water does not influence the acute toxicity of Cr(VI) to juveniles; (3) the environmental conditions of the natural habitat where fish developed do not influence their sensitivity to Cr(VI)-induced acute stress. Fish were collected in the estuaries of Minho (M-est) and Lima (L-est) Rivers (NW Iberian Peninsula) that have several abiotic differences, including in the water and sediment concentrations of various environmental contaminants. After acclimatization to laboratory conditions, two 96h acute bioassays were carried out with juveniles from both estuaries to: (i) investigate the effects of Cr(VI) alone; (ii) investigate the effects of Cr(VI) in the presence of MP (polyethylene spheres 1-5μm ∅). Cr(VI) alone induced mortality (96h-LC50s: 14.4-30.5mg/l) and significantly decreased fish predatory performance (≤74%). Thus, in the range of concentrations tested (5.6-28.4mg/l) Cr(VI) was found to be toxic to P. microps early juveniles, therefore, we rejected hypothesis 1. Under simultaneous exposure to Cr(VI) and MP, a significant decrease of the predatory performance (≤67%) and a significant inhibition of AChE activity (≤31%) were found. AChE inhibition was not observed in the test with Cr(VI) alone and MP alone caused an AChE inhibition ≤21%. Mixture treatments containing Cr(VI) concentration ≥3.9mg/l significantly increased LPO levels in L-est fish, an effect that was not observed under Cr(VI) or MP single exposures. Thus, toxicological interactions between Cr(VI) and MP occurred, therefore, we rejected hypothesis 2. In the

  14. Dual-axis hormonal covariation in adolescence and the moderating influence of prior trauma and aversive maternal parenting.

    PubMed

    Simmons, Julian G; Byrne, Michelle L; Schwartz, Orli S; Whittle, Sarah L; Sheeber, Lisa; Kaess, Michael; Youssef, George J; Allen, Nicholas B

    2015-09-01

    Adversity early in life can disrupt the functioning of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axes and increase risk for negative health outcomes. The interplay between these axes and the environment is complex, and understanding needs to be advanced by the investigation of the multiple hormonal relationships underlying these processes. The current study examined basal hormonal associations between morning levels of cortisol, testosterone, and dehydroepiandrosterone in a cohort of adolescents (mean age 15.56 years). The moderating influence of childhood adversity was also examined, as indexed by self-reported trauma (at mean age 14.91), and observed maternal aggressive parenting (at mean age 12.41). Between-person regressions revealed significant associations between hormones that were moderated by both measures of adversity. In females, all hormones positively covaried, but also interacted with adversity, such that positive covariation was typically only present when levels of trauma and/or aggressive parenting were low. In males, hormonal associations and interactions were less evident; however, interactions were detected for cortisol-testosterone - positively covarying at high levels of aggressive parenting but negatively covarying at low levels - and DHEA-cortisol - similarly positively covarying at high levels of parental aggression. These results demonstrate associations between adrenal and gonadal hormones and the moderating role of adversity, which is likely driven by feedback mechanisms, or cross-talk, between the axes. These findings suggest that hormonal changes may be the pathway through which early life adversity alters physiology and increases health risks, but does so differentially in the sexes; however further study is necessary to establish causation.

  15. Dual-axis hormonal covariation in adolescence and the moderating influence of prior trauma and aversive maternal parenting.

    PubMed

    Simmons, Julian G; Byrne, Michelle L; Schwartz, Orli S; Whittle, Sarah L; Sheeber, Lisa; Kaess, Michael; Youssef, George J; Allen, Nicholas B

    2015-09-01

    Adversity early in life can disrupt the functioning of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axes and increase risk for negative health outcomes. The interplay between these axes and the environment is complex, and understanding needs to be advanced by the investigation of the multiple hormonal relationships underlying these processes. The current study examined basal hormonal associations between morning levels of cortisol, testosterone, and dehydroepiandrosterone in a cohort of adolescents (mean age 15.56 years). The moderating influence of childhood adversity was also examined, as indexed by self-reported trauma (at mean age 14.91), and observed maternal aggressive parenting (at mean age 12.41). Between-person regressions revealed significant associations between hormones that were moderated by both measures of adversity. In females, all hormones positively covaried, but also interacted with adversity, such that positive covariation was typically only present when levels of trauma and/or aggressive parenting were low. In males, hormonal associations and interactions were less evident; however, interactions were detected for cortisol-testosterone - positively covarying at high levels of aggressive parenting but negatively covarying at low levels - and DHEA-cortisol - similarly positively covarying at high levels of parental aggression. These results demonstrate associations between adrenal and gonadal hormones and the moderating role of adversity, which is likely driven by feedback mechanisms, or cross-talk, between the axes. These findings suggest that hormonal changes may be the pathway through which early life adversity alters physiology and increases health risks, but does so differentially in the sexes; however further study is necessary to establish causation. PMID:25754696

  16. INFLUENCE OF SUMMER TEMPERATURE SPATIAL VARIABILITY ON DISTRIBUTION AND CONDITION OF JUVENILE COHO SALMON

    EPA Science Inventory

    abstract

    Temperature during the summer months can influence the distribution, abundance and physiology of stream salmonids such as coho salmon (Oncorhynchus kisutch). Effects can be direct, via physiological responses, as well as indirect, via limited food resources, alter...

  17. Diagnostic Labeling in Juvenile Court: How Do Descriptions of Psychopathy and Conduct Disorder Influence Judges?

    ERIC Educational Resources Information Center

    Murrie, Daniel C.; Boccaccini, Marcus T.; McCoy, Wendy; Cornell, Dewey G.

    2007-01-01

    This study examined the influence of diagnostic criteria and diagnostic labels for psychopathy or conduct disorder on judicial decisions. A national sample of judges (N = 326) rendered hypothetical dispositions based on 1 of 12 mock psychological evaluations. The evaluations varied the presence of 2 sets of diagnostic criteria (antisocial…

  18. The influence of hormonal and neuronal factors on rat heart adrenoceptors

    PubMed Central

    Kunos, George; Mucci, Lucia; O'Regan, Seana

    1980-01-01

    1 The influence of hormonal and neuronal factors on adrenoceptors mediating increased cardiac force and rate of contraction were studied in rat isolated atria. The pharmacological properties of these receptors were deduced from the relative potencies of agonists and from the effects of selective α- and β-adrenoceptor antagonists. The numbers and affinities of α- and β-adrenoceptors were also determined by radioligand binding to ventricular membrane fragments. 2 Hypophysectomy reduced the inotropic potency of isoprenaline and increased the potency of phenylephrine and methoxamine in left atria. The effect of phenylephrine was inhibited by propranolol less effectively and by phentolamine or phenoxybenzamine more effectively in hypophysectomized than in control rats. The difference in block was smaller at low than at high antagonist concentrations. Similar but smaller changes were observed for chronotropic responses of right atria. 3 The decreased β- and increased α-receptor response after hypophysectomy was similar to that observed earlier in thyroidectomized rats (Kunos, 1977). These changes developed slowly after hypophysectomy (>2 weeks), they were both reversed within 2 days of thyroxine treatment (0.2 mg/kg daily), but were not affected by cortisone treatment (50 mg/kg every 12 h for 4 days). 4 Treatment of hypophysectomized rats for 2 days with thyroxine increased the density of [3H]-dihydroalprenolol ([3H]-DHA) binding sites from 27.5 ± 2.7 to 45.5 ± 5.7 fmol/mg protein and decreased the density of [3H]-WB-4101 binding sites from 38.7 ± 3.1 to 18.7 ± 2.5 fmol/mg protein. The affinity of either type of binding site for agonists or antagonist was not significantly altered by thyroxine treatment and the sum total of α1- and β-receptors remained the same. 5 Sympathetic denervation of thyroidectomized rats by 6-hydroxydopamine increased the inotropic potency of isoprenaline and noradrenaline and the blocking effect of propranolol, and decreased the

  19. Influence of gonadal hormones on the behavioral effects of intermittent hypoxia in mice

    PubMed Central

    Jenkins, Richelle; Magalang, Ulysses J.; Nelson, Randy J.

    2014-01-01

    Obstructive sleep apnea (OSA) is characterized by repetitive upper airway obstruction resulting in cyclic intermittent hypoxia (IH) during sleep in affected individuals. OSA occurs more frequently in postmenopausal than premenopausal women and the severity of OSA increases after menopause. Gonadal hormones can influence brain and behavior; testosterone and estrogens in particular can enhance spatial learning and memory. We hypothesized that estrogens may protect mice from IH-induced hippocampal morphological and behavioral changes. To test this hypothesis we exposed intact or gonadectomized male and female mice to room air or IH [15 cycles/h, 8 h/day, fraction of inspired oxygen (FiO2) nadir of 5%] for a total of 30 days. During the final 4 days of IH, mice were tested for anxiety- and depressive-like behaviors. After cessation of IH exposure mice were tested on the Barnes maze and passive avoidance tests to assess learning and memory. Ovariectomy paired with IH treatment, impaired spatial learning and memory compared to all other female groups. Intact male mice receiving IH treatment also had impaired learning and memory compared with intact or castrated male mice exposed to room air. Learning and memory changes were mirrored by changes in basilar dendritic length of the CA1 region of the hippocampus. These data suggest that estrogens provide protection against IH-induced deficits, whereas androgens partially exacerbate IH-induced deficits on learning and memory. PMID:25552660

  20. Influence of gonadal hormones on the behavioral effects of intermittent hypoxia in mice.

    PubMed

    Aubrecht, Taryn G; Jenkins, Richelle; Magalang, Ulysses J; Nelson, Randy J

    2015-03-15

    Obstructive sleep apnea (OSA) is characterized by repetitive upper airway obstruction resulting in cyclic intermittent hypoxia (IH) during sleep in affected individuals. OSA occurs more frequently in postmenopausal than premenopausal women and the severity of OSA increases after menopause. Gonadal hormones can influence brain and behavior; testosterone and estrogens in particular can enhance spatial learning and memory. We hypothesized that estrogens may protect mice from IH-induced hippocampal morphological and behavioral changes. To test this hypothesis we exposed intact or gonadectomized male and female mice to room air or IH [15 cycles/h, 8 h/day, fraction of inspired oxygen (FiO 2) nadir of 5%] for a total of 30 days. During the final 4 days of IH, mice were tested for anxiety- and depressive-like behaviors. After cessation of IH exposure mice were tested on the Barnes maze and passive avoidance tests to assess learning and memory. Ovariectomy paired with IH treatment, impaired spatial learning and memory compared to all other female groups. Intact male mice receiving IH treatment also had impaired learning and memory compared with intact or castrated male mice exposed to room air. Learning and memory changes were mirrored by changes in basilar dendritic length of the CA1 region of the hippocampus. These data suggest that estrogens provide protection against IH-induced deficits, whereas androgens partially exacerbate IH-induced deficits on learning and memory.

  1. Growth Hormone Influence on the Morphology and Size of the Mouse Meibomian Gland.

    PubMed

    Liu, Yang; Knop, Erich; Knop, Nadja; Sullivan, David A; List, Edward O; Kopchick, John J; Kam, Wendy R; Ding, Juan

    2016-01-01

    Purpose. We hypothesize that growth hormone (GH) plays a significant role in the regulation of the meibomian gland. To test our hypothesis, we examined the influence of GH on mouse meibomian gland structure. Methods. We studied four groups of mice, including (1) bovine (b) GH transgenic mice with excess GH; (2) GH receptor (R) antagonist (A) transgenic mice with decreased GH; (3) GHR knockout (-/-) mice with no GH activity; and (4) wild type (WT) control mice. After mouse sacrifice, eyelids were processed for morphological and image analyses. Results. Our results show striking structural changes in the GH-deficient animals. Many of the GHR-/- and GHA meibomian glands featured hyperkeratinized and thickened ducts, acini inserting into duct walls, and poorly differentiated acini. In contrast, the morphology of WT and bGH meibomian glands appeared similar. The sizes of meibomian glands of bGH mice were significantly larger and those of GHA and GHR-/- mice were significantly smaller than glands of WT mice. Conclusions. Our findings support our hypothesis that the GH/IGF-1 axis plays a significant role in the control of the meibomian gland. In addition, our data show that GH modulates the morphology and size of this tissue. PMID:26981277

  2. Growth Hormone Influence on the Morphology and Size of the Mouse Meibomian Gland

    PubMed Central

    Liu, Yang; Knop, Erich; Knop, Nadja; Sullivan, David A.; List, Edward O.; Kopchick, John J.; Kam, Wendy R.; Ding, Juan

    2016-01-01

    Purpose. We hypothesize that growth hormone (GH) plays a significant role in the regulation of the meibomian gland. To test our hypothesis, we examined the influence of GH on mouse meibomian gland structure. Methods. We studied four groups of mice, including (1) bovine (b) GH transgenic mice with excess GH; (2) GH receptor (R) antagonist (A) transgenic mice with decreased GH; (3) GHR knockout (−/−) mice with no GH activity; and (4) wild type (WT) control mice. After mouse sacrifice, eyelids were processed for morphological and image analyses. Results. Our results show striking structural changes in the GH-deficient animals. Many of the GHR−/− and GHA meibomian glands featured hyperkeratinized and thickened ducts, acini inserting into duct walls, and poorly differentiated acini. In contrast, the morphology of WT and bGH meibomian glands appeared similar. The sizes of meibomian glands of bGH mice were significantly larger and those of GHA and GHR−/− mice were significantly smaller than glands of WT mice. Conclusions. Our findings support our hypothesis that the GH/IGF-1 axis plays a significant role in the control of the meibomian gland. In addition, our data show that GH modulates the morphology and size of this tissue. PMID:26981277

  3. Influence of competition playing venue on the hormonal responses, state anxiety and perception of effort in elite basketball athletes.

    PubMed

    Arruda, Ademir F S; Aoki, Marcelo S; Freitas, Camila G; Drago, Gustavo; Oliveira, Roney; Crewther, Blair T; Moreira, Alexandre

    2014-05-10

    This study examined the influence of competition playing venue on the hormonal responses, state anxiety and perception of effort in elite basketball players. Eighteen males from two basketball teams were monitored during two competitive matches that were played against each other on a home and away basis. Salivary testosterone (T) and cortisol (C) concentrations were measured before and after each match. The Competitive State Anxiety Inventory-2 (CSAI-2) test was also administrated prior to each match and session ratings of perceived exertion (RPE) were taken post-game. Playing at home was accompanied by elevated pre-match T concentration, as compared to playing away (p<0.05). The matches played at home were also won. Salivary T and C concentrations were similarly elevated across the matches (percent changes from pre to post) played either at home or away. No significant differences in state anxiety and perception of effort were identified between the playing venues. Pre-match T and C concentrations and the percent changes in these hormones were significantly related to somatic anxiety, especially when playing at home (p<0.05). In conclusion, the competition playing venue appeared to influence athlete salivary hormonal responses prior to elite basketball matches. These hormonal responses were associated with player's anxiety state, which might contribute to performance and the eventual match outcomes.

  4. Gastrointestinal hormones (anorexigenic peptide YY and orexigenic ghrelin) influence neural tube development.

    PubMed

    Yuzuriha, Hideki; Inui, Akio; Asakawa, Akihiro; Ueno, Naohiko; Kasuga, Masato; Meguid, Michael M; Miyazaki, Jun-ichi; Ninomiya, Maiko; Herzog, Herbert; Fujimiya, Mineko

    2007-07-01

    Gastrointestinal (GI) hormones play an important role in GI secretion, motility, and eating behaviors. It was recently suggested that GI hormones may have a trophic role in GI tract. Here we demonstrate that two principal GI hormones, anorexigenic peptide YY (PYY) and orexigenic ghrelin, affect neural tube development. Chronic administration into the pregnant mice or transgenic overexpression of PYY led to a neural tube defect (NTD) in the embryos that was blocked by ghrelin. PYY Y1 receptor antagonist prevented the occurrence of NTD induced not only by PYY but also by vitamin A, a well-known teratogen in humans and animals. Y1 receptor deficiency also engendered NTDs, indicating the need to maintain normal Y1 receptor signaling. The present study is the first linking GI hormones to the leading cause of infant mortality and provides a novel insight for neurogenesis in which materno-fetal communication through GI hormones appears to be important. PMID:17400914

  5. [Influence of nutrition on hormone secretion. I. Study in Agua Preta (author's transl)].

    PubMed

    Chaves, N; Guimarães, E D; Aguiar, F; Viana, T; Matos, E; Basto de Medeiros, R; Martins, G C; Bazante, M O; Pimenta, P P

    1975-01-01

    A positive correlation between the circulating growth hormone levels and the nutritional status was reported in 9 children of both sexes, aged 1 to 6 years, suffering from 2nd degree malnutrition. The mean serum insulin levels, the mean urinary 17-KS and 17-OHCS levels were low before the dietary therapy. No significant correlation between the levels of these hormones and the nutritional status was found. The hormone levels gradually returned to normal after the dietary therapy and the nutritional status of the children improved, according to the observed biochemical, clinical and anthropometric data.

  6. Mutual influences between partners' hormones shape conflict dialog and relationship duration at the initiation of romantic love.

    PubMed

    Schneiderman, Inna; Kanat-Maymon, Yaniv; Zagoory-Sharon, Orna; Feldman, Ruth

    2014-01-01

    Early-stage romantic love involves reorganization of neurohormonal systems and behavioral patterns marked by mutual influences between the partners' physiology and behavior. Guided by the biobehavioral synchrony conceptual frame, we tested bidirectional influences between the partners' hormones and conflict behavior at the initiation of romantic love. Participants included 120 new lovers (60 couples) and 40 singles. Plasma levels of five affiliation and stress-related hormones were assessed: oxytocin (OT), prolactin (PRL), testosterone (T), cortisol (CT), and dehydroepiandrosterone sulfate (DHEAS). Couples were observed in conflict interaction coded for empathy and hostility. CT and DHEAS showed direct actor effects: higher CT and DHEAS predicted greater hostility. OT showed direct partner effects: individuals whose partners had higher OT showed greater empathy. T and CT showed combined actor-partner effects. High T predicted greater hostility only when partner also had high T, but lower hostility when partner had low T. Similarly, CT predicted low empathy only in the context of high partner's CT. Mediational analysis indicated that combined high CT in both partners was associated with relationship breakup as mediated by decrease in empathy. Findings demonstrate the mutual influences between hormones and behavior within an attachment bond and underscore the dynamic, co-regulated, and systemic nature of pair-bond formation in humans.

  7. [Influence of pineal hormone melatonin on behavioral disturbances and neurological status of animals after hemorrhagic stroke].

    PubMed

    Arushanian, E B; Naumov, S S

    2011-01-01

    Experimental hemorrhagic stroke causes behavior and locomotor activity with memory impairment and neurological disturbances in rats. These shifts are weaker in the evening hours than after morning testing. The repeated administration of the pineal gland hormone melatonin (melaxen) during one week significantly decreases behavior and neurological deficits as well as pathomorphological signs in the lesion focus. The normalizing effect of the hormone is more distinct in the evening.

  8. Factors affecting attitudes toward juvenile sex offenders.

    PubMed

    Sahlstrom, Kimberly J; Jeglic, Elizabeth L

    2008-01-01

    This study investigated attitudes toward juvenile sex offenders and factors influencing those attitudes. Additionally, the influences of perpetrator characteristics such as age, gender, and ethnicity on societal attitudes towards intervention requirements were also investigated. Overall, attitudes toward juvenile sex offenders and their treatment amenability were negative. No differences in attitudes toward juvenile sex offenders were found between those who had been victims of sexual abuse and those that had not. Sex offenses committed by juvenile female sex offenders were viewed to be more serious and require more intervention than those committed by juvenile male sex offenders. PMID:19042245

  9. Dynamics of liver GH/IGF axis and selected stress markers in juvenile gilthead sea bream (Sparus aurata) exposed to acute confinement: differential stress response of growth hormone receptors.

    PubMed

    Saera-Vila, Alfonso; Calduch-Giner, Josep Alvar; Prunet, Patrick; Pérez-Sánchez, Jaume

    2009-10-01

    The time courses of liver GH/IGF axis and selected stress markers were analyzed in juvenile gilthead sea bream (Sparus aurata) sampled at zero time and at fixed intervals (1.5, 3, 6, 24, 72 and 120 h) after acute confinement (120 kg/m(3)). Fish remained unfed throughout the course of the confinement study, and the fasting-induced increases in plasma growth hormone (GH) levels were partially masked by the GH-stress inhibitory tone. Hepatic mRNA levels of growth hormone receptor-I (GHR-I) were not significantly altered by confinement, but a persistent 2-fold decrease in GHR-II transcripts was found at 24 and 120 h. A consistent decrease in circulating levels of insulin-like growth factor-I (IGF-I) was also found through most of the experimental period, and the down-regulated expression of GHR-II was positively correlated with changes in hepatic IGF-I and IGF-II transcripts. This stress-specific response was concurrent with plasma increases in cortisol and glucose levels, reflecting the cortisol peak (60-70 ng/mL), the intensity and duration of the stressor when data found in the literature were compared. Adaptive responses against oxidative damage were also found, and a rapid enhanced expression was reported in the liver tissue for mitochondrial heat-shock proteins (glucose regulated protein 75). At the same time, the down-regulated expression of proinflammatory cytokines (tumour necrosis factor-alpha) and detoxifying enzymes (cytochrome P450 1A1) might dictate the hepatic depletion of potential sources of reactive oxygen species. These results provide suitable evidence for a functional partitioning of hepatic GHRs under states of reduced IGF production and changing cellular environment resulting from acute confinement.

  10. Juvenile Firesetting.

    PubMed

    Peters, Brittany; Freeman, Bradley

    2016-01-01

    Juvenile firesetting is a significant cause of morbidity and mortality in the United States. Male gender, substance use, history of maltreatment, interest in fire, and psychiatric illness are commonly reported risk factors. Interventions that have been shown to be effective in juveniles who set fires include cognitive behavior therapy and educational interventions, whereas satiation has not been shown to be an effective intervention. Forensic assessments can assist the legal community in adjudicating youth with effective interventions. Future studies should focus on consistent assessment and outcome measures to create more evidence for directing evaluation and treatment of juvenile firesetters. PMID:26593122

  11. The influence of trilostane on steroid hormone metabolism in canine adrenal glands and corpora lutea-an in vitro study.

    PubMed

    Ouschan, C; Lepschy, M; Zeugswetter, F; Möstl, E

    2012-03-01

    Trilostane is widely used to treat hyperadrenocorticism in dogs. Trilostane competitively inhibits the enzyme 3-beta hydroxysteroid dehydrogenase (3β-HSD), which converts pregnenolone (P5) to progesterone (P4) and dehydroepiandrosterone (DHEA) to androstendione (A4). Although trilostane is frequently used in dogs, the molecular mechanism underlying its effect on canine steroid hormone biosynthesis is still an enigma. Multiple enzymes of 3β-HSD have been found in humans, rats and mice and their presence might explain the contradictory results of studies on the effectiveness of trilostane. We therefore investigated the influence of trilostane on steroid hormone metabolism in dogs by means of an in vitro model. Canine adrenal glands from freshly euthanized dogs and corpora lutea (CL) were incubated with increasing doses of trilostane. Tritiated P5 or DHEA were used as substrates. The resulting radioactive metabolites were extracted, separated by thin layer chromatography and visualized by autoradiography. A wide variety of radioactive metabolites were formed in the adrenal glands and in the CL, indicating high metabolic activity in both tissues. In the adrenal cortex, trilostane influences the P5 metabolism in a dose- and time-dependent manner, while DHEA metabolism and metabolism of both hormones in the CL were unaffected. The results indicate for the first time that there might be more than one enzyme of 3β-HSD present in dogs and that trilostane selectively inhibits P5 conversion to P4 only in the adrenal gland.

  12. The influence of trilostane on steroid hormone metabolism in canine adrenal glands and corpora lutea-an in vitro study.

    PubMed

    Ouschan, C; Lepschy, M; Zeugswetter, F; Möstl, E

    2012-03-01

    Trilostane is widely used to treat hyperadrenocorticism in dogs. Trilostane competitively inhibits the enzyme 3-beta hydroxysteroid dehydrogenase (3β-HSD), which converts pregnenolone (P5) to progesterone (P4) and dehydroepiandrosterone (DHEA) to androstendione (A4). Although trilostane is frequently used in dogs, the molecular mechanism underlying its effect on canine steroid hormone biosynthesis is still an enigma. Multiple enzymes of 3β-HSD have been found in humans, rats and mice and their presence might explain the contradictory results of studies on the effectiveness of trilostane. We therefore investigated the influence of trilostane on steroid hormone metabolism in dogs by means of an in vitro model. Canine adrenal glands from freshly euthanized dogs and corpora lutea (CL) were incubated with increasing doses of trilostane. Tritiated P5 or DHEA were used as substrates. The resulting radioactive metabolites were extracted, separated by thin layer chromatography and visualized by autoradiography. A wide variety of radioactive metabolites were formed in the adrenal glands and in the CL, indicating high metabolic activity in both tissues. In the adrenal cortex, trilostane influences the P5 metabolism in a dose- and time-dependent manner, while DHEA metabolism and metabolism of both hormones in the CL were unaffected. The results indicate for the first time that there might be more than one enzyme of 3β-HSD present in dogs and that trilostane selectively inhibits P5 conversion to P4 only in the adrenal gland. PMID:22113849

  13. The Influence of Tag Presence on the Mortality of Juvenile Chinook Salmon Exposed to Simulated Hydroturbine Passage: Implications for Survival Estimates and Management of Hydroelectric Facilities

    SciTech Connect

    Carlson, Thomas J.; Brown, Richard S.; Stephenson, John R.; Pflugrath, Brett D.; Colotelo, Alison HA; Gingerich, Andrew J.; Benjamin, Piper L.; Langeslay, Mike; Ahmann, Martin L.; Johnson, Robert L.; Skalski, John R.; Seaburg, Adam; Townsend, Richard L.

    2012-05-01

    Each year, millions of fish have telemetry tags (acoustic, radio, inductive) surgically implanted to assess their passage and survival through hydropower facilities. One route of passage of particular concern is through hydro turbines, in which fish may be exposed to a range of potential injuries, including barotraumas from rapid decompression. The change in pressure from acclimation to exposure (nadir) has been found to be an important factor in predicting the likelihood of mortality and injury for juvenile Chinook salmon undergoing rapid decompression associated with simulated turbine passage. The presence of telemetry tags has also been shown to influence the likelihood of injury and mortality for juvenile Chinook salmon. This research investigated the likelihood of mortality and injury for juvenile Chinook salmon carrying telemetry tags and exposed to a range of simulated turbine passage. Several factors were examined as predictors of mortal injury for fish undergoing rapid decompression, and the ratio of pressure change and tag burden were determined to be the most predictive factors. As the ratio of pressure change and tag burden increase, the likelihood of mortal injury also increases. The results of this study suggest that previous survival estimates of juvenile Chinook salmon passing through hydro turbines may have been biased due to the presence of telemetry tags, and this has direct implications to the management of hydroelectric facilities. Realistic examples indicate how the bias in turbine passage survival estimates could be 20% or higher, depending on the mass of the implanted tags and the ratio of acclimation to exposure pressures. Bias would increase as the tag burden and pressure ratio increase, and have direct implications on survival estimates. It is recommended that future survival studies use the smallest telemetry tags possible to minimize the potential bias that may be associated with carrying the tag.

  14. Antigen-presenting cells in the female reproductive tract: influence of sex hormones on antigen presentation in the vagina.

    PubMed Central

    Wira, C R; Rossoll, R M

    1995-01-01

    We report here that the stage of the reproductive cycle and the administration of physiological amounts of oestradiol to ovariectomized rats influences antigen presentation by macrophage/dendritic cells in the vagina. Antigen presentation is elevated when oestradiol levels in blood are low, and reduced just prior to ovulation. Of those hormones tested, only oestradiol lowered vaginal antigen presentation. When progesterone was given along with oestradiol, the inhibitory effect of oestradiol on vaginal antigen presentation was reversed. These studies demonstrate that the vagina is an inductive site and that antigen presentation is under hormonal control. Our results suggest that immunization studies designed to enhance mucosal immunity in the female reproductive tract should take into account the stage of the reproductive cycle when antigen is deposited. PMID:7790022

  15. Juvenile Prostitution.

    ERIC Educational Resources Information Center

    Csapo, Marg

    1986-01-01

    Recent research and Canadian government committee reports concerning juvenile prostitution are reviewed. Proposals are made in the realms of law and social policy; and existing programs are described. (DB)

  16. Quantitative determination of juvenile hormone III and 20-hydroxyecdysone in queen larvae and drone pupae of Apis mellifera by ultrasonic-assisted extraction and liquid chromatography with electrospray ionization tandem mass spectrometry.

    PubMed

    Zhou, Jinhui; Qi, Yitao; Hou, Yali; Zhao, Jing; Li, Yi; Xue, Xiaofeng; Wu, Liming; Zhang, Jinzhen; Chen, Fang

    2011-09-01

    In this paper, a method for the rapid and sensitive analysis of juvenile hormone III (JH III) and 20-hydroxyecdysone (20E) in queen larvae and drone pupae samples was presented. Ultrasound-assisted extraction provided a significant shortening of the leaching time for the extraction of JH III and 20E and satisfactory sensitivity as compared to the conventional shake extraction procedure. After extraction, determination was carried out by liquid chromatography-tandem mass spectrometry (LC-MS/MS) operating in electrospray ionization positive ion mode via multiple reaction monitoring (MRM) without any clean-up step prior to analysis. A linear gradient consisting of (A) water containing 0.1% formic acid and (B) acetonitrile containing 0.1% formic acid, and a ZORBAX SB-Aq column (100 mm × 2.1 mm, 3.5 μm) were employed to obtain the best resolution of the target analytes. The method was validated for linearity, limit of quantification, recovery, matrix effects, precision and stability. Drone pupae samples were found to contain 20E at concentrations of 18.0 ± 0.1 ng/g (mean ± SD) and JH III was detected at concentrations of 0.20 ± 0.06 ng/g (mean ± SD) in queen larvae samples. This validated method provided some practical information for the actual content of JH III and 20E in queen larvae and drone pupae samples.

  17. Quantitative determination of juvenile hormone III and 20-hydroxyecdysone in queen larvae and drone pupae of Apis mellifera by ultrasonic-assisted extraction and liquid chromatography with electrospray ionization tandem mass spectrometry.

    PubMed

    Zhou, Jinhui; Qi, Yitao; Hou, Yali; Zhao, Jing; Li, Yi; Xue, Xiaofeng; Wu, Liming; Zhang, Jinzhen; Chen, Fang

    2011-09-01

    In this paper, a method for the rapid and sensitive analysis of juvenile hormone III (JH III) and 20-hydroxyecdysone (20E) in queen larvae and drone pupae samples was presented. Ultrasound-assisted extraction provided a significant shortening of the leaching time for the extraction of JH III and 20E and satisfactory sensitivity as compared to the conventional shake extraction procedure. After extraction, determination was carried out by liquid chromatography-tandem mass spectrometry (LC-MS/MS) operating in electrospray ionization positive ion mode via multiple reaction monitoring (MRM) without any clean-up step prior to analysis. A linear gradient consisting of (A) water containing 0.1% formic acid and (B) acetonitrile containing 0.1% formic acid, and a ZORBAX SB-Aq column (100 mm × 2.1 mm, 3.5 μm) were employed to obtain the best resolution of the target analytes. The method was validated for linearity, limit of quantification, recovery, matrix effects, precision and stability. Drone pupae samples were found to contain 20E at concentrations of 18.0 ± 0.1 ng/g (mean ± SD) and JH III was detected at concentrations of 0.20 ± 0.06 ng/g (mean ± SD) in queen larvae samples. This validated method provided some practical information for the actual content of JH III and 20E in queen larvae and drone pupae samples. PMID:21803004

  18. Influence of sugars and hormones on the genes involved in sucrose metabolism in maize endosperms.

    PubMed

    Ren, X D; Liu, H M; Liu, Y H; Hu, Y F; Zhang, J J; Huang, Y B

    2015-01-01

    Starch is the major storage product in the endosperm of cereals. Its synthesis is closely related to sucrose metabolism. In our previous study, we found that the expression of most of the genes involved in starch synthesis might be regulated by sugars and hormones in the maize endosperm. However, little is known regarding the transcriptional regulation of genes involved in sucrose metabolism. Thus, in this study, maize endosperms were treated with different sugars and hormones and the expression of genes involved in sucrose metabolism (including synthesis, degradation, and transport) were evaluated using real-time quantitative reverse transcription-polymerase chain reaction. We found that genes affected by different sugars and hormones were primarily regulated by abscisic acid. Sucrose and abscisic acid showed an additive effect on the expression of some genes. Differences in the transcriptional regulation of genes involved in sucrose metabolism and starch biosynthesis were observed. PMID:25867309

  19. INFLUENCE OF OREGON COASTAL STREAM TEMPERATURES ON THE OCCURRENCE OF BLACK SPOT INFESTATION IN JUVENILE COHO SALMON

    EPA Science Inventory

    We quantified the occurrence of black-spot infestation of juvenile salmonids in the West Fork Smith River stream network during the summer 2002 through summer 2003 period. In this Oregon Coast Range watershed, highest summer seven-day average daily maximum (ADM) temperatures were...

  20. Influence of Parent-Child Relationships on the Global Self-Worth and Morality of Juvenile Delinquents

    ERIC Educational Resources Information Center

    Forney, William Scott; Crutsinger, Christy; Forney, Judith Cardona

    2006-01-01

    This study explored the effects of parent-child relationships on the global self-worth and morality of juvenile delinquents. Participants were adjudicated as first-time shoplifting/theft offenders. Factor analyses of three self-esteem scales revealed two reliable parent-child relationship (conduct around parents and interactions with parents) and…

  1. Hormone therapy in acne.

    PubMed

    Lakshmi, Chembolli

    2013-01-01

    Underlying hormone imbalances may render acne unresponsive to conventional therapy. Relevant investigations followed by initiation of hormonal therapy in combination with regular anti-acne therapy may be necessary if signs of hyperandrogenism are present. In addition to other factors, androgen-stimulated sebum production plays an important role in the pathophysiology of acne in women. Sebum production is also regulated by other hormones, including estrogens, growth hormone, insulin, insulin-like growth factor-1, glucocorticoids, adrenocorticotropic hormone, and melanocortins. Hormonal therapy may also be beneficial in female acne patients with normal serum androgen levels. An understanding of the sebaceous gland and the hormonal influences in the pathogenesis of acne would be essential for optimizing hormonal therapy. Sebocytes form the sebaceous gland. Human sebocytes express a multitude of receptors, including receptors for peptide hormones, neurotransmitters and the receptors for steroid and thyroid hormones. Various hormones and mediators acting through the sebocyte receptors play a role in the orchestration of pathogenetic lesions of acne. Thus, the goal of hormonal treatment is a reduction in sebum production. This review shall focus on hormonal influences in the elicitation of acne via the sebocyte receptors, pathways of cutaneous androgen metabolism, various clinical scenarios and syndromes associated with acne, and the available therapeutic armamentarium of hormones and drugs having hormone-like actions in the treatment of acne.

  2. Habitat Type Influences the Microhabitat Preference of Juvenile Tiger Prawns ( Penaeus esculentusHaswell and Penaeus semisulcatusDe Haan)

    NASA Astrophysics Data System (ADS)

    Kenyon, R. A.; Loneragan, N. R.; Hughes, J. M.; Staples, D. J.

    1997-09-01

    The microhabitat preferences of juvenile tiger prawns (3-10 mm carapace length),Penaeus esculentusandPenaeus semisulcatus, were tested in the field at Groote Eylandt, in the western Gulf of Carpentaria, Australia. A partitioned apparatus containing live seagrass was used. Both species of prawns selected seagrass (Syringodium isoetifolium) over bare substrate. JuvenileP. esculentus, the most abundant species in this region, were also given paired choices of seagrasses with different leaf morphologies (representing a range of structural complexity) and sediments of different particle size. They selected a seagrass with broad, long leaves (Cymodocea serrulata) over one with narrow, long leaves (S. isoetifolium), which in turn was selected over the seagrasses with narrow, short leaves (Halodule uninervisand shortenedS. isoetifolium). Predation experiments have shown that juvenileP. esculentusare detected and eaten less often in broad, long-leaved seagrass than in narrow, short-leaved seagrass or bare substrate, so their preference for the former may shelter them from predators. No habitat preference was evident forP. esculentuswhen offered a choice between sediments consisting mainly of sand (71% sand particles) and silt (60% of silt and clay). The selection by both species of tiger prawn of seagrass over bare substrate, andP. esculentus's selection of seagrass with long, broad leaves, provides an explanation for the distribution of juvenile tiger prawns in the field. Thus, in the seagrass beds around Groote Eylandt,P. esculentusis more abundant in seagrass with broad, long leaves than in seagrass with short, thin leaves. In addition, its distribution in this region is relatively independent of sediment type. Leaf surface area (or habitat structural complexity) appears to be the main determinant of distribution for juvenileP. esculentus.

  3. Effects of prenatal dexamethasone treatment on physical growth, pituitary-adrenal hormones, and performance of motor, motivational, and cognitive tasks in juvenile and adolescent common marmoset monkeys.

    PubMed

    Hauser, Jonas; Knapman, Alana; Zürcher, Nicole R; Pilloud, Sonia; Maier, Claudia; Diaz-Heijtz, Rochellys; Forssberg, Hans; Dettling, Andrea; Feldon, Joram; Pryce, Christopher R

    2008-12-01

    Synthetic glucocorticoids such as dexamethasone (DEX) are commonly used to prevent respiratory distress syndrome in preterm infants, but there is emerging evidence of subsequent neurobehavioral abnormalities (e.g. problems with inattention/hyperactivity). In the present study, we exposed pregnant common marmosets (Callithrix jacchus, primates) to daily repeated DEX (5 mg/kg by mouth) during either early (d 42-48) or late (d 90-96) pregnancy (gestation period of 144 days). Relative to control, and with a longitudinal design, we investigated DEX effects in offspring in terms of physical growth, plasma ACTH and cortisol titers, social and maintenance behaviors, skilled motor reaching, motivation for palatable reward, and learning between infancy and adolescence. Early DEX resulted in reduced sociability in infants and increased motivation for palatable reward in adolescents. Late DEX resulted in a mild transient increase in knee-heel length in infants and enhanced reversal learning of stimulus-reward association in adolescents. There was no effect of either early or late DEX on basal plasma ACTH or cortisol titers. Both treatments resulted in impaired skilled motor reaching in juveniles, which attenuated in early DEX but persisted in late DEX across test sessions. The increased palatable-reward motivation and decreased social motivation observed in early DEX subjects provide experimental support for the clinical reports that prenatal glucocorticoid treatment impairs social development and predisposes to metabolic syndrome. These novel primate findings indicate that fetal glucocorticoid overexposure can lead to abnormal development of motor, affective, and cognitive behaviors. Importantly, the outcome is highly dependent upon the timing of glucocorticoid overexposure.

  4. The Influence of Hormonal Fluctuations on Womens' Selection and Enjoyment of Television Programs.

    ERIC Educational Resources Information Center

    Meadowcroft, Jeanne; Zillmann, Dolf

    Existing theory suggests that women in the premenstrual and menstrual phases of their hormonal cycle would select and enjoy nonarousing television programs, sucy as nonhostile comedy and game shows, and would avoid action drama and hostile and arousing programs. To test this theory, female undergraduates from telecommunications and journalism…

  5. Luteinizing hormone secretion as influenced by age and estradiol in the prepubertal gilt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study was to determine if there is an age related reduction in the sensitivity of the negative feedback action of estradiol on luteinizing hormone (LH) secretion in the prepubertal gilt. Ovariectomized gilts at 90 (n = 12), 150 (n = 11) or 210 (n = 12) days of age received estradiol ...

  6. Sex differences in ischemic stroke sensitivity are influenced by gonadal hormones, not by sex chromosome complement.

    PubMed

    Manwani, Bharti; Bentivegna, Kathryn; Benashski, Sharon E; Venna, Venugopal Reddy; Xu, Yan; Arnold, Arthur P; McCullough, Louise D

    2015-02-01

    Epidemiologic studies have shown sex differences in ischemic stroke. The four core genotype (FCG) mouse model, in which the testes determining gene, Sry, has been moved from Y chromosome to an autosome, was used to dissociate the effects of sex hormones from sex chromosome in ischemic stroke outcome. Middle cerebral artery occlusion (MCAO) in gonad intact FCG mice revealed that gonadal males (XXM and XYM) had significantly higher infarct volumes as compared with gonadal females (XXF and XYF). Serum testosterone levels were equivalent in adult XXM and XYM, as was serum estrogen in XXF and XYF mice. To remove the effects of gonadal hormones, gonadectomized FCG mice were subjected to MCAO. Gonadectomy significantly increased infarct volumes in females, while no change was seen in gonadectomized males, indicating that estrogen loss increases ischemic sensitivity. Estradiol supplementation in gonadectomized FCG mice rescued this phenotype. Interestingly, FCG male mice were less sensitive to effects of hormones. This may be due to enhanced expression of the transgene Sry in brains of FCG male mice. Sex differences in ischemic stroke sensitivity appear to be shaped by organizational and activational effects of sex hormones, rather than sex chromosomal complement.

  7. Influence of Hormonal Contraceptive Use and Health Beliefs on Sexual Orientation Disparities in Papanicolaou Test Use

    PubMed Central

    Corliss, Heather L.; Missmer, Stacey A.; Frazier, A. Lindsay; Rosario, Margaret; Kahn, Jessica A.; Austin, S. Bryn

    2014-01-01

    Objectives. Reproductive health screenings are a necessary part of quality health care. However, sexual minorities underutilize Papanicolaou (Pap) tests more than heterosexuals do, and the reasons are not known. Our objective was to examine if less hormonal contraceptive use or less positive health beliefs about Pap tests explain sexual orientation disparities in Pap test intention and utilization. Methods. We used multivariable regression with prospective data gathered from 3821 females aged 18 to 25 years in the Growing Up Today Study (GUTS). Results. Among lesbians, less hormonal contraceptive use explained 8.6% of the disparities in Pap test intention and 36.1% of the disparities in Pap test utilization. Less positive health beliefs associated with Pap testing explained 19.1% of the disparities in Pap test intention. Together, less hormonal contraceptive use and less positive health beliefs explained 29.3% of the disparities in Pap test intention and 42.2% of the disparities in Pap test utilization. Conclusions. Hormonal contraceptive use and health beliefs, to a lesser extent, help to explain sexual orientation disparities in intention and receipt of a Pap test, especially among lesbians. PMID:23763393

  8. Ovarian hormones influence odor cues emitted by female meadow voles, Microtus pennsylvanicus.

    PubMed

    Ferkin, M H; Gorman, M R; Zucker, I

    1991-12-01

    During the spring-summer breeding season female meadow voles emit odors that are preferred by males, whereas in the autumn-winter season of reproductive quiescence females emit odors that are not preferred by males, but are attractive to females. The effects of daylength and ovarian hormones on salience of female odors were determined by assaying male responses to odors. Females housed in long and short photoperiods transmitted odors that elicited responses similar to those of spring and autumn female voles, respectively. The odor cues emitted by ovariectomized (OVX) females, irrespective of photoperiodic history, were similar to those generated by females during the nonbreeding season. In the absence of ovarian hormones, long daylengths were not sufficient to induce females to broadcast the spring odors preferred by males. Spring-type odor cues were, however, emitted by OVX voles housed in either photoperiod and treated with estradiol. Ovarian hormones appear necessary and sufficient to generate breeding season odor cues and sufficient to induce production of such cues during the nonbreeding season. We conclude that daylength affects odor cues emitted by females by altering ovarian hormone activity. PMID:1813382

  9. [Influence of 50% proximal or distal small bowel resection on gut hormone release after test meal loading in dogs].

    PubMed

    Kato, M; Sasaki, I; Naito, H; Takahashi, M; Matsuno, S

    1991-10-01

    The effect of proximal and distal small bowel resection on gut hormone release after test meal loading in dogs was studied. Ten beagle dogs were subjected to 50% proximal or distal small bowel resection, and test meal loading was performed after one night fasting to examine gut hormone release. Fasting levels of plasma gastrin were not changed after both proximal and distal resection, but response to test meal was increased at 18 weeks of postoperative period in 50% proximal resection. Postprandial release of plasma GIP was significantly decreased in both proximal and distal resection compared with preoperative period. Postprandial release of enteroglucagon was increased at 4 and 8 weeks in proximal resection. In distal resection, it was increased at 4 weeks but returned to preoperative levels at 8 weeks. Villus height of middle part of the intestine was increased in both proximal and distal resection, and significant change was observed in the duodenal mucosa of proximal resection at 4 weeks. These findings suggest that part of the resection of small bowel influences gut hormone release, and these may play an important role in intestinal adaptation.

  10. The influence of endogenous and exogenous sex hormones in adolescents with attention to oral contraceptives and anabolic steroids.

    PubMed

    Lane, J R; Connor, J D

    1994-12-01

    The endogenous sex hormones produce dispositional changes in the developing child as well as imparting unique male and female dispositional patterns. Age-related changes have been observed for digoxin disposition and caffeine and theophylline metabolism. These age-related dispositional changes have led to age-dependent dosing recommendations. Studies with caffeine and antipyrine indicate that this change in drug disposition occurs over a short period of time, is seen earlier in girls than in boys, and is related to pubertal (Tanner) stage and the "growth spurt". Significant changes in endogenous sex hormone concentrations occur during the menstrual cycle and during pregnancy, leading to alterations in drug binding, distribution, and clearance. Oral contraceptives (OCs) inhibit the metabolism of certain drugs resulting in toxicity or lack of efficacy. Rifampin induces the OC metabolism, resulting in decreased clinical effectiveness. Most studies did not examine these kinetic and dynamic interactions between adult and adolescent users. It is estimated that there are over 45 anabolic steroid compounds available for abuse by athletes, and their use is increasing among male and female adolescents. Although the adolescent is at increased risk of developing adverse effects from these agents, a systematic evaluation of the long-term effects of anabolic steroid abuse has not been undertaken in this population. Further research is needed regarding the influence of endogenous and exogenous hormones on adolescent drug kinetics and dynamics. Because of their frequency of use among adolescents, OCs and anabolic steroids require particular emphasis.

  11. Juvenile idiopathic arthritis

    MedlinePlus

    Juvenile rheumatoid arthritis (JRA); Juvenile chronic polyarthritis; Still disease; Juvenile spondyloarthritis ... The cause of juvenile idiopathic arthritis (JIA) is not known. It is thought to be an autoimmune illness . This means the body attacks ...

  12. Two-hit exposure to polychlorinated biphenyls at gestational and juvenile life stages: 2. Sex-specific neuromolecular effects in the brain.

    PubMed

    Bell, Margaret R; Hart, Bethany G; Gore, Andrea C

    2016-01-15

    Exposures to polychlorinated biphenyls (PCBs) during early development have long-lasting, sexually dimorphic consequences on adult brain and behavior. However, few studies have investigated their effects during juvenile development, a time when increases in pubertal hormones influence brain maturation. Here, male and female Sprague Dawley rats were exposed to PCBs (Aroclor 1221, 1 mg/kg/day) or vehicle prenatally, during juvenile development, or both, and their effects on serum hormone concentrations, gene expression, and DNA methylation were assessed in adulthood. Gene expression in male but not female brains was affected by 2-hits of PCBs, a result that paralleled behavioral effects of PCBs. Furthermore, the second hit often changed the effects of a first hit in complex ways. Thus, PCB exposures during critical fetal and juvenile developmental periods result in unique neuromolecular phenotypes, with males most vulnerable to the treatments.

  13. Influence of daily calcium and vitamin D supplementation on parathyroid hormone secretion.

    PubMed

    Reginster, J Y; Zegels, B; Lejeune, E; Micheletti, M C; Taquet, A N; Albert, A

    2001-02-01

    Calcium and vitamin D supplementation have been shown to reduce secondary hyperparathyroidism and play a role in age-related osteoporosis. In order to define the optimal regimen of calcium and vitamin D supplementation to produce the maximal inhibition of parathyroid hormone secretion, we compared the administration of a calcium-vitamin D supplement as a single morning dose with the administration of two divided doses at 6-hour intervals. Twelve healthy male volunteers were assigned to three investigational procedures, which were alternated at weekly intervals. After a 'blank' control procedure, when they were not exposed to any supplements, they received one of two calcium-vitamin D supplement regimens: either two doses of Orocal D3 (500 mg calcium and 400 IU vitamin D3) with a 6-hour interval between doses, or one water-soluble effervescent powder pack of Cacit vitamin D3, taken in the morning (1000 mg calcium and 880 IU vitamin D3). During the three procedures (control and the two calcium-vitamin D supplementation protocols), veinous blood was drawn every 60 minutes for up to 9 hours, for serum calcium and parathyroid hormone measurements. The order of administration of the two calcium and vitamin D supplementation regimens was allocated by randomization. No significant changes in serum calcium were observed during the study. During the first 6 hours following calcium-vitamin D supplementation, a statistically significant decrease in serum parathyroid hormone was observed with both regimens, compared with baseline and the control procedure. During this first period, no differences were observed between the two treatment regimens. However, between the 6th and the 9th hour, serum parathyroid hormone levels remained significantly decreased compared to baseline with the twice-daily Orocal D3 administration, while they returned to baseline values with the once-daily Cacit D3 preparation. During this period, the percentage decrease in serum parathyroid hormone

  14. Influence of multiple dam passage on survival of juvenile Chinook salmon in the Columbia River estuary and coastal ocean.

    PubMed

    Rechisky, Erin L; Welch, David W; Porter, Aswea D; Jacobs-Scott, Melinda C; Winchell, Paul M

    2013-04-23

    Multiple dam passage during seaward migration is thought to reduce the subsequent survival of Snake River Chinook salmon. This hypothesis developed because juvenile Chinook salmon from the Snake River, the Columbia River's largest tributary, migrate >700 km through eight hydropower dams and have lower adult return rates than downstream populations that migrate through only 3 or 4 dams. Using a large-scale telemetry array, we tested whether survival of hatchery-reared juvenile Snake River spring Chinook salmon is reduced in the estuary and coastal ocean relative to a downstream, hatchery-reared population from the Yakima River. During the initial 750-km, 1-mo-long migration through the estuary and coastal ocean, we found no evidence of differential survival; therefore, poorer adult returns of Snake River Chinook may develop far from the Columbia River. Thus, hydrosystem mitigation efforts may be ineffective if differential mortality rates develop in the North Pacific Ocean for reasons unrelated to dam passage.

  15. Influence of multiple dam passage on survival of juvenile Chinook salmon in the Columbia River estuary and coastal ocean.

    PubMed

    Rechisky, Erin L; Welch, David W; Porter, Aswea D; Jacobs-Scott, Melinda C; Winchell, Paul M

    2013-04-23

    Multiple dam passage during seaward migration is thought to reduce the subsequent survival of Snake River Chinook salmon. This hypothesis developed because juvenile Chinook salmon from the Snake River, the Columbia River's largest tributary, migrate >700 km through eight hydropower dams and have lower adult return rates than downstream populations that migrate through only 3 or 4 dams. Using a large-scale telemetry array, we tested whether survival of hatchery-reared juvenile Snake River spring Chinook salmon is reduced in the estuary and coastal ocean relative to a downstream, hatchery-reared population from the Yakima River. During the initial 750-km, 1-mo-long migration through the estuary and coastal ocean, we found no evidence of differential survival; therefore, poorer adult returns of Snake River Chinook may develop far from the Columbia River. Thus, hydrosystem mitigation efforts may be ineffective if differential mortality rates develop in the North Pacific Ocean for reasons unrelated to dam passage. PMID:23576733

  16. Hormone levels

    MedlinePlus

    Blood or urine tests can determine the levels of various hormones in the body. This includes reproductive hormones, thyroid hormones, adrenal hormones, pituitary hormones, and many others. For more information, see: ...

  17. Does thyroid-stimulating hormone influence the prognosis of patients with endometrial cancer? A multicentre trial

    PubMed Central

    Seebacher, V; Hofstetter, G; Polterauer, S; Reinthaller, A; Grimm, C; Schwameis, R; Taucher, S; Wagener, A; Marth, C; Concin, N

    2013-01-01

    Background: Thyroid function has been suggested to interfere with tumour biology and prognosis in different cancers. The present study was performed to investigate the impact of pre-therapeutic serum thyroid-stimulating hormone (TSH) levels on the prognosis of patients with endometrial cancer. Methods: Pre-therapeutic serum TSH was investigated in 199 patients with endometrial cancer. After stratification in TSH risk groups, univariate and multivariable survival analyses were performed. Results: Elevated TSH was independently associated with poor disease-specific survival in univariate/multivariable survival analyses (P=0.01 and P=0.03, respectively). Conclusion: Thyroid-stimulating hormone may serve as a novel and independent prognostic parameter for disease-specific survival in patients with endometrial cancer. PMID:23764750

  18. The influence of stress and gonadal hormones on neuronal structure and function.

    PubMed

    Farrell, Mollee R; Gruene, Tina M; Shansky, Rebecca M

    2015-11-01

    This article is part of a Special Issue "SBN 2014". The brain is highly plastic, allowing us to adapt and respond to environmental and physiological challenges and experiences. In this review, we discuss the relationships among alterations in dendritic arborization, spine morphology, and behavior due to stress exposure, endogenous hormone fluctuation, or exogenous hormonal manipulation. Very few studies investigate structure-function associations directly in the same cohort of animals, and there are notable inconsistencies in evidence of structure-function relationships in the prefrontal cortex and hippocampus. Moreover, little work has been done to probe the causal relationship between dendritic morphology and neuronal excitability, leaving only speculation about the adaptive versus maladaptive nature of experience-dependent dendritic remodeling. We propose that future studies combine electrophysiology with a circuit-level approach to better understand how dendritic structure contributes to neuronal functional properties and behavioral outcomes.

  19. The influence of stress and gonadal hormones on neuronal structure and function

    PubMed Central

    Farrell, Mollee R.; Gruene, Tina M.; Shansky, Rebecca M.

    2015-01-01

    The brain is highly plastic, allowing us to adapt and respond to environmental and physiological challenges and experiences. In this review, we discuss the relationships among alterations in dendritic arborization, spine morphology, and behavior due to stress exposure, endogenous hormone fluctuation, or exogenous hormonal manipulation. Very few studies investigate structure-function associations directly in the same cohort of animals, and there are notable inconsistencies in evidence of structure-function relationships in the prefrontal cortex and hippocampus. Moreover, little work has been done to probe the causal relationship between dendritic morphology and neuronal excitability, leaving only speculation about the adaptive versus maladaptive nature of experience-dependent dendritic remodeling. We propose that future studies combine electrophysiology with a circuit-level approach to better understand how dendritic structure contributes to neuronal functional properties and behavioral outcomes. PMID:25819727

  20. Juvenile hormone biosynthesis and secretion by the female Corpora allata of the larval gypsy moth, Lymantria dispar (L. ) utilizing in vitro organ culture

    SciTech Connect

    Jones, G.L.

    1986-01-01

    Junvenile hormone synthesis and secretion in the female larval gypsy moth was investigated. In vitro culturing methods were developed including: incubating 2 pair of CC-CA gland complexes in 50 ul of osmotically balanced Grace's insect medium containing 1 uCi /sup 3/H-methyl-methionine for 6 hr. JH homologues were identified and quantified using TLC and HPLC. In vitro methods were employed to investigate trends of JH secretion in 4th and ultimate female larval instar CA. Fourth instar CA produced JH peaks of 0.15 pmole/pr/hr between days 2 and 3, but the rate declined to half by day 4. Ultimate instar larvae began secreting 0.48 pmole/pr/hr, but by day 10, had decreased JH output to negligible levels which continued until pupation. Effects upon in vitro JH secretion produced by precocene II and caffeine were examined. Feulgen staining techniques revealed an equal number of cells (30) in 4th and last instar CA. Last instar Ca were 3 times larger than 4th in volume but their actual in vitro JH secretion at peak levels was only 20% greater. In vitro methods demonstrated that JH secretory trends differ in younger versus mature larval instars. Glandular volume increased in last instars but JH secretion was only 20% greater than in 4th's when compared on the basis of volume. Precocene II elicited a negative response on in vivo JH secretion at levels 10 times less than caffeine. Caffeine was judged not to significantly alter JH secretion.

  1. Sexual differentiation of the adolescent rodent brain: hormonal influences and developmental mechanisms.

    PubMed

    Juraska, Janice M; Sisk, Cheryl L; DonCarlos, Lydia L

    2013-07-01

    This article is part of a Special Issue "Puberty and Adolescence". Sexual differentiation is the process by which the nervous system becomes structurally and functionally dissimilar in females and males. In mammals, this process has been thought to occur during prenatal and early postnatal development, when a transient increase in testosterone secretion masculinizes and defeminizes the developing male nervous system. Decades of research have led to the views that structural sexual dimorphisms created during perinatal development are passively maintained throughout life, and that ovarian hormones do not play an active role in feminization of the nervous system. Furthermore, perinatal testosterone was thought to determine sex differences in neuron number by regulating cell death and cell survival, and not by regulating cell proliferation. As investigations of neural development during adolescence became more prominent in the late 20th century and revealed the extent of brain remodeling during this time, each of these tenets has been challenged and modified. Here we review evidence from the animal literature that 1) the brain is further sexually differentiated during puberty and adolescence; 2) ovarian hormones play an active role in the feminization of the brain during puberty; and 3) hormonally modulated, sex-specific addition of new neurons and glial cells, as well as loss of neurons, contribute to sexual differentiation of hypothalamic, limbic, and cortical regions during adolescence. This architectural remodeling during the adolescent phase of sexual differentiation of the brain may underlie the known sex differences in vulnerability to addiction and psychiatric disorders that emerge during this developmental period.

  2. The influence of estrogens on the biological and therapeutic actions of growth hormone in the liver.

    PubMed

    de Mirecki-Garrido, Mercedes; Guerra, Borja; Mateos-Díaz, Carlos; Jiménez-Monzón, Roberto; Díaz-Chico, Nicolás; Díaz-Chico, Juan C; Fernández-Pérez, Leandro

    2012-07-19

    GH is main regulator of body growth and composition, somatic development, intermediate metabolism and gender-dependent dimorphism in mammals. The liver is a direct target of estrogens because it expresses estrogen receptors which are connected with development, lipid metabolism and insulin sensitivity, hepatic carcinogenesis, protection from drug-induced toxicity and fertility. In addition, estrogens can modulate GH actions in liver by acting centrally, regulating pituitary GH secretion, and, peripherally, by modulating GHR-JAK2-STAT5 signalling pathway. Therefore, the interactions of estrogens with GH actions in liver are biologically and clinically relevant because disruption of GH signaling may cause alterations of its endocrine, metabolic, and gender differentiated functions and it could be linked to dramatic impact in liver physiology during development as well as in adulthood. Finally, the interplay of estrogens with GH is relevant because physiological roles these hormones have in human, and the widespread exposition of estrogen or estrogen-related compounds in human. This review highlights the importance of these hormones in liver physiology as well as how estrogens modulate GH actions in liver which will help to improve the clinical use of these hormones.

  3. Sex hormone influence on human infants' sound characteristics: melody in spontaneous crying.

    PubMed

    Wermke, Kathleen; Hain, Johannes; Oehler, Klaus; Wermke, Peter; Hesse, Volker

    2014-05-01

    The specific impact of sex hormones on brain development and acoustic communication is known from animal models. Sex steroid hormones secreted during early development play an essential role in hemispheric organization and the functional lateralization of the brain, e.g. language. In animals, these hormones are well-known regulators of vocal motor behaviour. Here, the association between melody properties of infants' sounds and serum concentrations of sex steroids was investigated. Spontaneous crying was sampled in 18 healthy infants, averaging two samples taken at four and eight weeks, respectively. Blood samples were taken within a day of the crying samples. The fundamental frequency contour (melody) was analysed quantitatively and the infants' frequency modulation skills expressed by a melody complexity index (MCI). These skills provide prosodic primitives for later language. A hierarchical, multiple regression approach revealed a significant, robust relationship between the individual MCIs and the unbound, bioactive fraction of oestradiol at four weeks as well as with the four-to-eight-week difference in androstenedione. No robust relationship was found between the MCI and testosterone. Our findings suggest that oestradiol may have effects on the development and function of the auditory-vocal system in human infants that are as powerful as those in vocal-learning animals.

  4. Sex hormone influence on human infants' sound characteristics: melody in spontaneous crying

    PubMed Central

    Wermke, Kathleen; Hain, Johannes; Oehler, Klaus; Wermke, Peter; Hesse, Volker

    2014-01-01

    The specific impact of sex hormones on brain development and acoustic communication is known from animal models. Sex steroid hormones secreted during early development play an essential role in hemispheric organization and the functional lateralization of the brain, e.g. language. In animals, these hormones are well-known regulators of vocal motor behaviour. Here, the association between melody properties of infants' sounds and serum concentrations of sex steroids was investigated. Spontaneous crying was sampled in 18 healthy infants, averaging two samples taken at four and eight weeks, respectively. Blood samples were taken within a day of the crying samples. The fundamental frequency contour (melody) was analysed quantitatively and the infants' frequency modulation skills expressed by a melody complexity index (MCI). These skills provide prosodic primitives for later language. A hierarchical, multiple regression approach revealed a significant, robust relationship between the individual MCIs and the unbound, bioactive fraction of oestradiol at four weeks as well as with the four-to-eight-week difference in androstenedione. No robust relationship was found between the MCI and testosterone. Our findings suggest that oestradiol may have effects on the development and function of the auditory–vocal system in human infants that are as powerful as those in vocal-learning animals. PMID:24806423

  5. Sex and stress hormone influences on the expression and activity of brain-derived neurotrophic factor.

    PubMed

    Carbone, D L; Handa, R J

    2013-06-01

    The neurotrophin, brain-derived neurotrophic factor (BDNF), is recognized as a key component in the regulation of CNS ontogeny, homeostasis and adult neuroplasticity. The importance of BDNF in CNS development and function is well documented by numerous reports from animal studies linking abnormal BDNF signaling to metabolic disturbances and anxiety or depressive-like behavior. Despite the diverse roles for BDNF in nearly all aspects of CNS physiology, the regulation of BDNF expression, as well as our understanding of the signaling mechanisms associated with this neurotrophin, remains incomplete. However, links between sex hormones such as estradiol and testosterone, as well as endogenous and synthetic glucocorticoids (GCs), have emerged as important mediators of BDNF expression and function. Examples of such regulation include brain region-specific induction of Bdnf mRNA in response to estradiol. Additional studies have also documented regulation of the expression of the high-affinity BDNF receptor Tropomyosin-Related Kinase B by estradiol, thus implicating sex steroids not only in the regulation of BDNF expression, but also in mechanisms of signaling associated with it. In addition to gonadal steroids, further evidence also suggests functional interaction between BDNF and GCs, such as in the regulation of corticotrophin-releasing hormone and other important neuropeptides. In this review, we provide an overview of the roles played by selected sex or stress hormones in the regulation of BDNF expression and signaling in the CNS. PMID:23211562

  6. Influence of gonadal hormones on odours emitted by male meadow voles (Microtus pennsylvanicus).

    PubMed

    Ferkin, M H; Gorman, M R; Zucker, I

    1992-08-01

    Free-living male meadow voles (Microtus pennsylvanicus) emit odours that are attractive to females at the beginning, but not at the end, of the breeding season. The effect of gonadal hormones on female-attractant cues was examined in males born and reared in long (14 h light day-1) and short (10 h light day-1) photoperiods that simulate daylengths in the breeding and nonbreeding seasons, respectively. Gonadectomy affected the attractant properties of odours emitted by long photoperiod, but not short photoperiod, males. Long photoperiod females preferred odours of intact rather than those of gonadectomized long photoperiod males, and odours of gonadectomized long photoperiod males rather than those of intact short photoperiod males. Females did not show a preference between the odours of intact and castrated short photoperiod males. Gonadal hormone replacement in males affected female responses to the odours emitted by long photoperiod, but not short photoperiod, gonadectomized males. Long photoperiod females did not display a preference between odours of intact long photoperiod males and gonadectomized long photoperiod males treated with testosterone or oestradiol. We conclude that in spring and summer gonadal hormones increase attractiveness of male odours; this effect may require aromatization of testosterone to oestradiol. Substrates that control attractiveness of odour cues in male voles appear to be unresponsive to androgens during the nonbreeding season. PMID:1404090

  7. Influences of the environment on the endocrine and paracrine fish growth hormone-insulin-like growth factor-I system.

    PubMed

    Reinecke, M

    2010-04-01

    Insulin-like growth factor-I (IGF-I) is a key component of the complex system that regulates differentiation, development, growth and reproduction of fishes. The IGF-I gene is mainly expressed in the liver that represents the principal source of endocrine IGF-I but also in numerous other organs where the hormone most probably acts in an autocrine-paracrine manner. The primary stimulus for synthesis and release of IGF-I is growth hormone (GH) from the anterior pituitary. Thus, in analogy to mammals, it is usual to speak of a fish 'GH-IGF-I axis'. The GH-IGF-I system is affected by changes in the environment and probably represents a target of endocrine disrupting compounds (EDC) that impair many physiological processes in fishes. Thus, the review deals with the influences of changes in different environmental factors, such as food availability, temperature, photoperiod, season, salinity and EDCs, on GH gene expression in pituitary, IGF-I gene expression in liver and extrahepatic sites and the physiological effects resulting from the evoked alterations in endocrine and local IGF-I. Environmental influences certainly interact with each other but for convenience of the reader they will be dealt with in separate sections. Current trends in GH-IGF-I research are analysed and future focuses are suggested at the end of the sections. PMID:20537012

  8. Factors Affecting Attitudes toward Juvenile Sex Offenders

    ERIC Educational Resources Information Center

    Sahlstrom, Kimberly J.; Jeglic, Elizabeth L.

    2008-01-01

    This study investigated attitudes toward juvenile sex offenders and factors influencing those attitudes. Additionally, the influences of perpetrator characteristics such as age, gender, and ethnicity on societal attitudes towards intervention requirements were also investigated. Overall, attitudes toward juvenile sex offenders and their treatment…

  9. Short neuropeptide F (sNPF) is a stage-specific suppressor for juvenile hormone biosynthesis by corpora allata, and a critical factor for the initiation of insect metamorphosis.

    PubMed

    Kaneko, Yu; Hiruma, Kiyoshi

    2014-09-15

    Molting and metamorphosis are essential events for arthropod development, and juvenile hormone (JH) and its precursors play critical roles for these events. We examined the regulation of JH biosynthesis by the corpora allata (CA) in Bombyx mori, and found that intact brain-corpora cardiaca (CC)-CA complexes produced a smaller amount of JH than that in CC-CA complexes and CA alone throughout the 4th and 5th (last) instar stadium. The smaller amount of synthesis was due to allatostatin-C (AST-C) produced by the brain. The CC synthesized short neuropeptide F (sNPF) that also suppressed the JH synthesis, but only in day 3 4th stadium and after the last larval ecdysis. For the suppression, both peptides prevented the expression of some of the distinct JH biosynthetic enzymes in the mevalonate pathway. Allatotropin (AT) stimulated sNPF expression in the CC of day 1 5th instar stadium, not of day 3 4th; therefore the stage-specific inhibition of JH synthesis by sNPF was partly due to the stimulative action of AT on the sNPF expression besides the stage-specific expression of the sNPF receptors in the CA, the level of which was high in day 2 4th and day 0 5th instar larvae. The cessation of JH biosynthesis in the last instar larvae is a key event to initiate pupal metamorphosis, and both sNPF and AST-C are key factors in shutting down JH synthesis, along with the decline of ecdysone titer and dopamine.

  10. The Influence of a 12-Week Conditioning Program on Growth Hormone and Somatomedin C Concentrations in Moderately Overweight Males.

    ERIC Educational Resources Information Center

    Kinard, James D.; Bazzarre, Terry L.

    The growth hormone is a lipolytic hormone and somatomedin C mediates the metabolic effects of the growth hormone in many tissues. Growth hormone plasma levels are often depressed in obese individuals, and this low plasma level has been postulated as a reason for perpetuation of excess weight. Substantial weight loss in obese subjects improves…

  11. [Impact of microsporidia on hormonal balance in insect hosts].

    PubMed

    Issi, I V; Tokarev, Iu S

    2002-01-01

    Microsporidia (M) is a phylum of protists parasitizing obligatory in animal cells. Long way of adaptation of M to intracellular parasitism resulted in establishment of quite close relationships between the parasite and its host. Different species of M induce in their hosts symptoms similar to those caused by misbalance of juvenile hormone (JH) and ecdysone. M infection leads to pathology of different hormone-dependent functions such as cell differentiation and specialization, molting, metamorphosis, diapause and reproduction of insects. The signs of hormonal dysfunction evidence for elevated titer of JH in M-infected insects. Two possible explanation of this could be offered: JH secretion by M or specific influence of the parasites on the insect endocrine systems. Impact on insect endogenous JH titer by M could be mediated by affection of secretory activity of corpora allata or by suppression of enzymatic degradation of JH. According to different hypotheses, insect hormonal status during microsporidiosis could be modified by a) insect host stress-reaction, b) exhaustion of insect host reserves, characteristic for acute phase of the disease, c) destruction of infected insect cells and tissues during mass sporogenesis of M. Data found in literature and provided by our experiments evidence for presence of JH analogues or juvenilizing substance in the extracts of M spores. From detailed examination of pathological process it is also seen that juvenilizing effect of M infection is usually restricted to the invaded regions of tissues (i.e. expressed locally) but not a systemic one. Ability of M to modify morpho-functional features of infected tissues at the level of hormonal regulation is undoubtfully a prominent adaptation for stabilizing "microsporidia-insect" parasite-host systems.

  12. Juvenile Spondyloarthritis

    PubMed Central

    Gmuca, Sabrina; Weiss, Pamela F.

    2015-01-01

    Purpose of review To provide a comprehensive update of the pathogenesis, diagnostic imaging, treatments, and disease activity measurements of juvenile spondyloarthritis (JSpA). Recent findings Genetic and microbiome studies have provided new information regarding possible pathogenesis of JSpA. Recent work suggests that children with JSpA have decreased thresholds for pain in comparison to healthy children. Additionally, pain on physical examination and abnormalities on ultrasound of the entheses are not well correlated. Treatment guidelines for juvenile arthritis, including JSpA, were published by the American College of Rheumatology and are based on active joint count and presence of sacroiliitis. Recent studies have established the efficacy of tumor necrosis factor inhibitors in the symptomatic treatment of axial disease, though their efficacy for halting progression of structural damage is less clear. Newly developed disease activity measures for JSpA include the Juvenile Arthritis Disease Activity Score and the JSpA Disease Activity index. In comparison to other categories of juvenile arthritis, children with JSpA are less likely to attain and sustain inactive disease. Summary Further microbiome and genetic research may help elucidate JSpA pathogenesis. More randomized therapeutic trials are needed and the advent of new composite disease activity measurement tools will hopefully allow for the design of these greatly needed trials. PMID:26002028

  13. The Emergence of Gonadal Hormone Influences on Dopaminergic Function during Puberty

    PubMed Central

    Kuhn, Cynthia; Johnson, Misha; Thomae, Alex; Luo, Brooke; Simon, Sid; Zhou, Guiying; Walker, Q. David

    2010-01-01

    Adolescence is the developmental epoch during which children become adults-intellectually, physically, hormonally and socially. Brain development in critical areas is ongoing. Adolescents are risk-taking and novelty-seeking and they weigh positive experiences more heavily and negative experiences less than adults. This inherent behavioral bias can lead to risky behaviors like drug taking. Most drug addictions start during adolescence and early drug-taking is associated with an increased rate of drug abuse and dependence. The hormonal changes of puberty contribute to physical, emotional, intellectual and social changes during adolescence. These hormonal events do not just cause maturation of reproductive function and the emergence of secondary sex characteristics. They contribute to the appearance of sex differences in non-reproductive behaviors as well. Sex differences in drug use behaviors are among the latter. The male predominance in overall drug use appears by the end of adolescence, while girls develop the rapid progression from first use to dependence (telescoping) that represent a female-biased vulnerability. Sex differences in many behaviors including drug use have been attributed to social and cultural factors. A narrowing gap in drug use between adolescent boys and girls supports this thesis. However, some sex differences in addiction vulnerability reflect biologic differences in brain circuits involved in addiction. The purpose of this review is to summarize the contribution of sex differences in the function of ascending dopamine systems that are critical to reinforcement, to briefly summarize the behavioral, neurochemical and anatomical changes in brain dopaminergic functions related to addiction that occur during adolescence and to present new findings about the emergence of sex differences in dopaminergic function during adolescence. PMID:19900453

  14. Influence of male gonadal hormones and familiarity on pregnancy interruption in prairie voles.

    PubMed

    Smale, L

    1988-08-01

    Pregnancy interruption (PI) was examined in female prairie voles, Microtus ochrogaster, exposed to stimuli from males 7 to 12 days after pairing. Urine from unfamiliar males interrupted pregnancy when placed directly on the external nares of newly mated females, but urine from familiar stud males was without effect. Castration of males did not reduce the efficacy of unfamiliar male urine in interrupting pregnancy. The neuroendocrine system of female prairie voles responded selectively to male urine as a function of its familiarity; the efficacy of male stimuli leading to PI was not dependent on gonadal hormones. PMID:3061485

  15. Does macroalgal vegetation cover influence post-settlement survival and recruitment potential of juvenile black rockfish Sebastes cheni?

    NASA Astrophysics Data System (ADS)

    Kamimura, Yasuhiro; Shoji, Jun

    2013-09-01

    Seasonal change in vegetation coverage affected cohort-specific mortality of post-settlement juvenile black rockfish Sebastes cheni in a temperate macroalgal bed. A total of 14 fish and environmental surveys were conducted at an interval of one to two weeks from February to May, 2008 in the central Seto Inland Sea, southwestern Japan. The birth date of S. cheni was estimated by use of the otolith daily rings and then fish were divided into 7 cohorts (A to F), each covering a 7-day birth date period. Cohort-specific growth coefficient (G, d-1) of juvenile S. cheni from 20 to 60 mm in total length (TL) ranged between 0.031 and 0.048 and mortality coefficient (M, d-1) between 0.038 and 0.081, with significant increases in both values as the season progressed. The ratio of G:M, which is a proxy of the recruitment potential, ranged between 0.59 and 0.99 and was lower in later cohorts. Water temperature increased from 10.9 °C in March to 18.2 °C in May and vegetation coverage (bulk volume of Sargassum spp., %: as an index of the function for predation refuge) decreased from 60% in March to 2% in May. The later cohorts of juvenile S. cheni had high growth and mortality rates related to high temperature and low vegetation coverage. Since the seasonal increase in M was greater than that of G, the recruitment potential of the later cohorts was lower than that of the earlier cohorts.

  16. The influence of fall-spawning coho salmon (Oncorhynchus kisutch) on growth and production of juvenile coho salmon rearing in beaver ponds on the Copper River Delta, Alaska

    USGS Publications Warehouse

    Lang, D.W.; Reeves, G.H.; Hall, J.D.; Wipfli, M.S.

    2006-01-01

    This study examined the influence of fall-spawning coho salmon (Oncorhynchus kisutch) on the density, growth rate, body condition, and survival to outmigration of juvenile coho salmon on the Copper River Delta, Alaska, USA. During the fall of 1999 and 2000, fish rearing in beaver ponds that received spawning salmon were compared with fish from ponds that did not receive spawners and also with fish from ponds that were artificially enriched with salmon carcasses and eggs. The response to spawning salmon was variable. In some ponds, fall-spawning salmon increased growth rates and improved the condition of juvenile coho salmon. The enrichment with salmon carcasses and eggs significantly increased growth rates of fish in nonspawning ponds. However, there was little evidence that the short-term growth benefits observed in the fall led to greater overwinter growth or survival to outmigration when compared with fish from the nonspawning ponds. One potential reason for this result may be that nutrients from spawning salmon are widely distributed across the delta because of hydrologic connectivity and hyporheic flows. The relationship among spawning salmon, overwinter growth, and smolt production on the Copper River Delta does not appear to be limited entirely to a simple positive feedback loop. ?? 2006 NRC.

  17. Thyroid hormone balance in beluga whales, Delphinapterus leucas: dynamics after capture and influence of thyrotropin.

    PubMed Central

    St Aubin, D J; Geraci, J R

    1992-01-01

    Ten beluga whales, Delphinapterus leucas, were captured in the Churchill River, Manitoba, held for up to five days, and then released. Blood samples were obtained immediately after capture and at 6-7 h intervals thereafter to monitor changes in circulating levels of thyroid hormones (TH). In six of the whales, total and free thyroxine (T4) and triiodothyronine (T3) declined steadily, whereas reverse-T3 (rT3) showed a transient increase during the first 24-36 h, followed by a decrease to below initial values. The changes in TH may have been due to glucocorticoid-mediated reduction in endogenous thyroid stimulating hormone (TSH), and inhibition of 5'-monodeiodinase in peripheral tissue. Two whales were given 10 IU of bovine TSH immediately after capture, and again one and two days later, resulting in successive increases in all TH, which remained elevated for at least 24 h after the last injection. Thereafter, circulating levels declined as in the untreated whales. Two whales receiving a single TSH injection on the fourth day responded with an increase in plasma TH comparable to that observed following the first TSH injection in the other two animals. Average (+/- SD) circulating level of rT3 at capture was 6.3 +/- 3.1 nmol/L, which is higher than reported for any other mammal and was significantly correlated with the naturally elevated levels of T4 that occur in belugas occupying estuaries during the summer. PMID:1586888

  18. Development of an LC-MS/MS method to quantify sex hormones in bovine milk and influence of pregnancy in their levels.

    PubMed

    Regal, P; Cepeda, A; Fente, C

    2012-01-01

    Hormones work in harmony in the body, and this status must be maintained to avoid metabolic disequilibrium and the subsequent illness. Besides, it has been reported that exogenous steroids (presence in the environment and food products) influence the development of several important illnesses in humans. Endogenous steroid hormones in food of animal origin are unavoidable as they occur naturally in these products. The presence of hormones in food has been connected with several human health problems. Bovine milk contains considerable quantities of hormones and it is of particular concern. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, based on hydroxylamine derivatisation, has been developed and validated for the quantification of six sex hormones in milk [pregnenolone (P₅), progesterone (P₄), estrone (E₁), testosterone (T), androstenedione (A) and dehydroepiandrosterone (DHEA)]. This method has been applied to real raw milk samples and the existence of differences between milk from pregnant and non-pregnant cows has been statistically confirmed. Basing on a revision of existing published data, it could be concluded that maximum daily intakes for hormones are not reached through milk ingestion. Although dairy products are an important source of hormones, other products of animal origin must be considered as well for intake calculations.

  19. The influence of intrauterine exposure to immunosuppressive treatment on changes in the immune system in juvenile Wistar rats

    PubMed Central

    Kabat-Koperska, Joanna; Kolasa-Wołosiuk, Agnieszka; Wojciuk, Bartosz; Wojciechowska-Koszko, Iwona; Roszkowska, Paulina; Krasnodębska-Szponder, Barbara; Paczkowska, Edyta; Safranow, Krzysztof; Gołembiewska, Edyta; Machaliński, Bogusław; Ciechanowski, Kazimierz

    2016-01-01

    Background In our study, we assessed the impact of immunosuppressive drug combinations on changes in the immune system of juvenile Wistar rats exposed to these drugs during pregnancy. We primarily concentrated on changes in two organs of the immune system – the thymus and the spleen. Methods The study was conducted on 40 (32+8) female Wistar rats administered full and half dose of drugs, respectively, subjected to regimens commonly used in therapy of human kidney transplant recipients ([1] cyclosporine A, mycophenolate mofetil, and prednisone; [2] tacrolimus, mycophenolate mofetil, and prednisone; [3] cyclosporine A, everolimus, and prednisone). The animals received drugs by oral gavage 2 weeks before pregnancy and during 3 weeks of pregnancy. Results There were no statistically significant differences in the weight of the thymus and spleen, but changes were found in the results of blood hematology, cytometry from the spleen, and a histologic examination of the examined immune organs of juvenile Wistar rats. In the cytokine assay, changes in the level of interleukine 17 (IL-17) after increasing amounts of concanavaline A were dose-dependent; the increase of IL-17 was blocked after administration of higher doses of immunosuppressive drugs. However, after a reduction of doses, its increase resumed. Conclusion Qualitative, quantitative, and morphological changes in the immune system of infant rats born to pharmacologically immunosuppressed females were observed. Thymus structure, spleen composition, and splenocyte IL-17 production were mostly affected in a drug regimen–dependent manner. PMID:27471376

  20. Influence of Incision Location on Transmitter Loss, Healing, Incision Lengths, Suture Retention, and Growth of Juvenile Chinook Salmon

    SciTech Connect

    Panther, Jennifer L.; Brown, Richard S.; Gaulke, Greggory L.; Woodley, Christa M.; Deters, Katherine A.

    2010-05-11

    In this study, conducted by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District, we measured differences in survival and growth, incision openness, transmitter loss, wound healing, and erythema among abdominal incisions on the linea alba, lateral and parallel to the linea alba (muscle-cutting), and following the underlying muscle fibers (muscle-sparing). A total of 936 juvenile Chinook salmon were implanted with both Juvenile Salmon Acoustic Tracking System transmitters (0.43 g dry) and passive integrated transponder tags. Fish were held at 12°C (n = 468) or 20°C (n = 468) and examined once weekly over 98 days. We found survival and growth did not differ among incision groups or between temperature treatment groups. Incisions on the linea alba had less openness than muscle-cutting and muscle-sparing incisions during the first 14 days when fish were held at 12°C or 20°C. Transmitter loss was not different among incision locations by day 28 when fish were held at 12°C or 20°C. However, incisions on the linea alba had greater transmitter loss than muscle-cutting and muscle-sparing incisions by day 98 at 12°C. Results for wound closure and erythema differed among temperature groups. Results from our study will be used to improve fish-tagging procedures for future studies using acoustic or radio transmitters.

  1. Influence of multiple dam passage on survival of juvenile Chinook salmon in the Columbia River estuary and coastal ocean

    PubMed Central

    Rechisky, Erin L.; Welch, David W.; Porter, Aswea D.; Jacobs-Scott, Melinda C.; Winchell, Paul M.

    2013-01-01

    Multiple dam passage during seaward migration is thought to reduce the subsequent survival of Snake River Chinook salmon. This hypothesis developed because juvenile Chinook salmon from the Snake River, the Columbia River’s largest tributary, migrate >700 km through eight hydropower dams and have lower adult return rates than downstream populations that migrate through only 3 or 4 dams. Using a large-scale telemetry array, we tested whether survival of hatchery-reared juvenile Snake River spring Chinook salmon is reduced in the estuary and coastal ocean relative to a downstream, hatchery-reared population from the Yakima River. During the initial 750-km, 1-mo-long migration through the estuary and coastal ocean, we found no evidence of differential survival; therefore, poorer adult returns of Snake River Chinook may develop far from the Columbia River. Thus, hydrosystem mitigation efforts may be ineffective if differential mortality rates develop in the North Pacific Ocean for reasons unrelated to dam passage. PMID:23576733

  2. Influence of Incision Location on Transmitter Loss, Healing, Survival, Growth, and Suture Retention of Juvenile Chinook Salmon

    SciTech Connect

    Panther, Jennifer L.; Brown, Richard S.; Gaulke, Greg L.; Deters, Katherine A.; Woodley, Christa M.; Eppard, M. Brad

    2011-11-01

    Fisheries research involving surgical implantation of transmitters necessitates the use of methods that minimize transmitter loss and fish mortality and optimize healing of the incision. We evaluated the effects of three incision locations on transmitter loss, healing, survival, growth, and suture retention in juvenile Chinook salmon Oncorhynchus tshawytscha. The three incision locations were (1) on the linea alba (LA incision), (2) adjacent and parallel to the LA (muscle-cutting [MC] incision), and (3) extending from the LA towards the dorsum at a 45° angle, between the parallel lines of myomeres (muscle-sparing [MS] incision). A Juvenile Salmon Acoustic Telemetry System acoustic transmitter (0.44 g in air) and a passive integrated transponder tag (0.10 g in air) were implanted into each fish (total N = 936 fish). The fish were held at 12°C or 20°C and were examined weekly for 98 d. The progression of healing among incision locations and the variability in transmitter loss made it difficult to identify one incision location as the best choice. The LA incisions had a much smaller wound extent (area of visible subepidermal tissue) than MC and MS incisions during the first 28 d of the study. In both temperature treatments, apposition of incisions through day 14 was better for LA incisions than for MC and MS incisions. However, MC and MS incisions were less likely than LA incisions to reopen over time and thus were less likely to allow transmitter loss through the incision.

  3. Juvenile morphology in baleen whale phylogeny.

    PubMed

    Tsai, Cheng-Hsiu; Fordyce, R Ewan

    2014-09-01

    Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.

  4. Juvenile morphology in baleen whale phylogeny

    NASA Astrophysics Data System (ADS)

    Tsai, Cheng-Hsiu; Fordyce, R. Ewan

    2014-09-01

    Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.

  5. Influence of chronic dopamine transporter inhibition by RTI-336 on motor behavior, sleep, and hormone levels in rhesus monkeys.

    PubMed

    Andersen, Monica L; Sawyer, Eileen K; Carroll, F Ivy; Howell, Leonard L

    2012-04-01

    Dopamine transporter (DAT) inhibitors have been developed as a promising treatment approach for cocaine dependence. However, the stimulant effects of DAT inhibitors have the potential to disrupt sleep patterns, and the influence of long-term treatment on dopamine neurochemistry is still unknown. The objectives of this study were to (1) explore the stimulant-related effects of chronic DAT inhibitor (RTI-336) treatment on motor activity and sleep-like measures in male rhesus monkeys (Macaca mulatta; n = 4) and (2) to determine the effect of drug treatment on prolactin and cortisol levels. Subjects were fitted with a collar-mounted activity monitor to evaluate their motor activity, with 4 days of baseline recording preceding 21 days of daily saline or RTI-336 (1 mg/kg/day; intramuscular) injections. Blood samples were collected immediately prior to and following chronic treatment to assess hormone levels. RTI-336 produced a significant increase in locomotor activity at the end of the daytime period compared to saline administration. During the 3-week treatment period, sleep efficiency was decreased and the fragmentation index and latency to sleep onset were significantly increased. Hormone levels were not changed throughout the study. Chronic treatment with RTI-336 has a mild but significant stimulant effect, as evidenced by the significant increase in activity during the evening period which may cause minor disruptions in sleep measures. PMID:22023668

  6. The influence of lactation, occupational exposures and postmenopausal hormone use on the incidence of breast cancer

    SciTech Connect

    Yang, C.P.

    1992-01-01

    A self-administered questionnaire was completely by 1,018 women diagnosed with breast cancer during 1988-1989 identified through the British Columbia Cancer Registry and by 1,025 controls selected at random from the Provincial Voters List. Data were collected on demographic characteristics, lifestyle factors, occupational and reproductive history as well as hormone use. Premenopausal women who ceased lactation within the first month had a relative risk of 3.0, adjusted for age and parity (95% C.I. = 1.6-5.4), compared to women who had breast fed two months or longer. Among women who nursed for at least two months, there was an indication of decreasing risk with increasing duration of nursing. Among post-menopausal women, no relation between lactation history and breast cancer risk was evident. Premenopausal women who reported ever having been a data processing operator (OR = 3.8), hairdresser (OR = 5.5), janitor/housekeeper (OR = 2.1), or having worked in the food processing (OR = 2.7) were found to have an excess risk of breast cancer. Among postmenopausal women, an excess risk was seen for nursing or medical workers (OR = 1.4) whereas a reduced risk was observed among waitresses/bartenders (OR = 0.5), textile workers (OR = 0.5) or defense industry personnel (OR = 0.4). The effect of menopausal hormone use was evaluated among 699 cases and 685 controls who were postmenopausal due to natural causes or to a hysterectomy. There was no overall increase in risk of breast cancer associated with ever use of unopposed estrogen (OR = 1.0, 95% CI = 0.8-1.3). For estrogen use of ten years or longer, the relative risk was 1.6 (95% CI = 1.1-2.5). The risk estimate for current users was somewhat elevated (OR = 1.4, 95% CI = 1.0-2.0). Compared to women who never used hormone preparations, women who had used estrogen plus progestogen had a relative risk of 1.2 (95% CI = 0.6-2.2).

  7. Influence of microbial diversity and plant growth hormones in compost and vermicompost from fermented tannery waste.

    PubMed

    Ravindran, Balasubramani; Wong, Jonathan W C; Selvam, Ammaiyappan; Sekaran, Ganesan

    2016-10-01

    This study focuses on the effect of the epigeic earthworm Eudrilus eugeniae (with and without addition) to transform solid state fermented (SSF) and submerged (SmF) state fermented TFL mixed with cow dung and leaf litter into value added products in compost and vermicompost bioreactors respectively. The significant role of microbes was identified during compost and vermicompost process. In addition, three important phytohormones (Indole 3-acetic acid, Gibberellic acid, Kinetin) were also detected in the compost and vermicompost products. The results revealed that the maximum amount of plant hormones were available in the vermicompost products which may be due to the joint action of earthworm and microorganisms. The overall results confirmed that the vermicomposting process produced a greater value added product.

  8. Influence of microbial diversity and plant growth hormones in compost and vermicompost from fermented tannery waste.

    PubMed

    Ravindran, Balasubramani; Wong, Jonathan W C; Selvam, Ammaiyappan; Sekaran, Ganesan

    2016-10-01

    This study focuses on the effect of the epigeic earthworm Eudrilus eugeniae (with and without addition) to transform solid state fermented (SSF) and submerged (SmF) state fermented TFL mixed with cow dung and leaf litter into value added products in compost and vermicompost bioreactors respectively. The significant role of microbes was identified during compost and vermicompost process. In addition, three important phytohormones (Indole 3-acetic acid, Gibberellic acid, Kinetin) were also detected in the compost and vermicompost products. The results revealed that the maximum amount of plant hormones were available in the vermicompost products which may be due to the joint action of earthworm and microorganisms. The overall results confirmed that the vermicomposting process produced a greater value added product. PMID:27013190

  9. Photoperiod and gonadal hormones influence odor preferences of the male meadow vole, Microtus pennsylvanicus.

    PubMed

    Ferkin, M H; Gorman, M R

    1992-05-01

    Male meadow voles housed in a long photoperiod (14 h light/day, LP) preferred female to male odors, whereas males maintained in a short photoperiod (10 h light/day, SP) did not display preferences for odors of either sex. These odor-preference patterns matched those of free-living males during spring and autumn, respectively. The preference of LP male voles for female over male odors was eliminated by gonadectomy and reinstated by treatment with testosterone. In SP males, although gonadectomy did not affect odor choices, a preference for female odors was induced by testosterone treatment. Treatment with estradiol did not alter odor preferences of LP or SP males. In conjunction with previous result, the present findings suggest that hormonal responsiveness of neural substrates that control odor preferences are sexually dimorphic and may reflect sex differences in reproductive strategies. PMID:1615048

  10. Influence of diet and stress on reproductive hormones in Nigerian olive baboons.

    PubMed

    Lodge, E; Ross, C; Ortmann, S; MacLarnon, A M

    2013-09-15

    A female mammal's reproductive function and output are limited by the energy she is able to extract from her environment. Previous studies of the interrelationships between energetic circumstances and reproductive function in a variety of mammal species have produced varied results, which do not all support the common assumption that higher female reproductive hormone levels, specifically progesterone, indicate better ovarian function and greater reproductive potential, and are associated with lower energetic stress. In the present study faecal progesterone and glucocorticoid levels were assessed in two troops of olive baboons (Papio anubis) in the same population. They face similar ecological challenges, except that one troop crop-raids, potentially affecting its energetic intake and stress levels. The energy intake of individual females was assessed by combining detailed feeding observations with nutritional analysis of food samples. The crop-raiding troop experienced 50% higher energy intake rates and 50% lower glucocorticoid levels compared to the non-crop-raiding troop alongside substantially lower progesterone levels. This suggests that energetic stress is associated with elevated progesterone levels and may be the cause of the non-crop-raiding troop's lower reproductive output. By comparing groups which differ little, except in terms of food access, and also by directly assessing energy intake, our study addresses some of the design limitations of previous research investigating variation in progesterone levels and energetic stress. It therefore has the potential to contribute to greater understanding of the factors affecting differences in reproductive and stress hormone levels and reproductive function in mammals experiencing different energetic circumstances.

  11. Balance between salt stress and endogenous hormones influence dry matter accumulation in Jerusalem artichoke.

    PubMed

    Shao, Tianyun; Li, Lingling; Wu, Yawen; Chen, Manxia; Long, Xiaohua; Shao, Hongbo; Liu, Zhaopu; Rengel, Zed

    2016-10-15

    Salinity is one of the most serious environmental stresses limiting agricultural production. Production of Jerusalem artichoke on saline land is strategically important for using saline land resources. The interaction between plant hormones and salinity stress in governing Jerusalem artichoke (Helianthus tuberosus) growth is unclear. Jerusalem artichoke (variety Nanyu-1) was grown under variable salinity stress in the field, and a role of endogenous hormones [zeatin (ZT), auxins (IAA), gibberellins (GA3) and abscisic acid (ABA)] in regulating sugar and dry matter accumulation in tubers was characterized. Under mild salt stress (≤2.2gNaClkg(-1) soil), Nanyu-1 grew well with no significant alteration of dry matter distribution to stems and tubers. In contrast, under moderate salt stress (2.7gNaClkg(-1) soil), the distribution to stem decreased and to tubers decreased significantly. Mild salt stress induced sugar accumulation in tubers at the beginning of the tuber-expansion period, but significantly inhibited (i) transfer of non-reducing sugars to tubers, and (ii) polymerization and accumulation of fructan during the tuber-expansion stage. Under different salinity stress, before the stolon growth, the ratio of IAA/ABA in leaves increased significantly and that of GA3/ABA increased slightly; during tuber development, these ratios continued to decrease and reached the minimum late in the tuber-expansion period. While, salt stress inhibited (i) underground dry matter accumulation, (ii) tuber dry matter accumulation efficiency, (iii) transport of non-reducing sugars to tubers, and (iv) fructan accumulation efficiency during the tuber-expansion period; these effects were accompanied by significantly decreased tuber yield with an increase in salinity. With soil salinity increasing, the synthesis of IAA and GA3 was inhibited in leaves and tubers, while ABA synthesis was stimulated. In brief, tuber yield would significantly decreased with the increase of salinity. PMID

  12. Neovascularization is influenced by androgenic hormones in the tissue implant response.

    PubMed

    Butler Jr Phd, Kenneth R; Benghuzzi Phd, Hamed; Tucci Phd, Michelle; Puckett Phd, Aaron

    2012-01-01

    The objective of this investigation was to demonstrate the effect of androgens on the neovascularization of the fibrous tissue surrounding tricalcium phosphate (TCP) implants. Sixteen animals in four experimental groups (n = 4/group) were implanted with one TCP implant each. Group I animals were implanted with the sham TCP ceramic (Control). Group II animals received a testosterone-loaded ceramic. Group III animals were implanted with a dihydrotestosterone containing bioceramic. Group IV animals received the androstenedione filled bioceramic. At 90 days post-implantation, the fibrous tissue surrounding the implants were evaluated microscopically following staining with routine hematoxylin and eosin (H&E), Masson’s trichrome, and Papanicolaou stains. Using Image Pro (Media Cybernetics, Silver Spring, MD) digital analysis software, data were collected to compare the hormonal effects on the number (per high power field) and size of blood vessels (micrometers, µm) within the fibrous tissue surrounding all four groups. The presence of androgens greatly affected the angiogenic response within the fibrous tissue. All three hormones exhibited less neovascularization compared to the control. Though not as dramatic as androstenedione (3±0), both testosterone (12±1) and dihydrotestosterone (10±1) suppressed the number of blood vessels present in the fibrous tissue capsule compared to control (13±1). However, the circumference of the vessels was much larger for the testosterone (236µm ±8µm) and dihydrotestosterone (256µm±4µm) treated groups compared to the androstenedione (146µm ±7µm) or control (163µm±3µm) groups. The results of this study demonstrate androgens strongly vary in their effect on neovascularization by limiting the number of new vessels developed while contributing to the presence of larger vessels within the fibrous tissue surrounding TCP implants loaded with testosterone and dihydrotestosterone.

  13. Balance between salt stress and endogenous hormones influence dry matter accumulation in Jerusalem artichoke.

    PubMed

    Shao, Tianyun; Li, Lingling; Wu, Yawen; Chen, Manxia; Long, Xiaohua; Shao, Hongbo; Liu, Zhaopu; Rengel, Zed

    2016-10-15

    Salinity is one of the most serious environmental stresses limiting agricultural production. Production of Jerusalem artichoke on saline land is strategically important for using saline land resources. The interaction between plant hormones and salinity stress in governing Jerusalem artichoke (Helianthus tuberosus) growth is unclear. Jerusalem artichoke (variety Nanyu-1) was grown under variable salinity stress in the field, and a role of endogenous hormones [zeatin (ZT), auxins (IAA), gibberellins (GA3) and abscisic acid (ABA)] in regulating sugar and dry matter accumulation in tubers was characterized. Under mild salt stress (≤2.2gNaClkg(-1) soil), Nanyu-1 grew well with no significant alteration of dry matter distribution to stems and tubers. In contrast, under moderate salt stress (2.7gNaClkg(-1) soil), the distribution to stem decreased and to tubers decreased significantly. Mild salt stress induced sugar accumulation in tubers at the beginning of the tuber-expansion period, but significantly inhibited (i) transfer of non-reducing sugars to tubers, and (ii) polymerization and accumulation of fructan during the tuber-expansion stage. Under different salinity stress, before the stolon growth, the ratio of IAA/ABA in leaves increased significantly and that of GA3/ABA increased slightly; during tuber development, these ratios continued to decrease and reached the minimum late in the tuber-expansion period. While, salt stress inhibited (i) underground dry matter accumulation, (ii) tuber dry matter accumulation efficiency, (iii) transport of non-reducing sugars to tubers, and (iv) fructan accumulation efficiency during the tuber-expansion period; these effects were accompanied by significantly decreased tuber yield with an increase in salinity. With soil salinity increasing, the synthesis of IAA and GA3 was inhibited in leaves and tubers, while ABA synthesis was stimulated. In brief, tuber yield would significantly decreased with the increase of salinity.

  14. Influence of diet and stress on reproductive hormones in Nigerian olive baboons.

    PubMed

    Lodge, E; Ross, C; Ortmann, S; MacLarnon, A M

    2013-09-15

    A female mammal's reproductive function and output are limited by the energy she is able to extract from her environment. Previous studies of the interrelationships between energetic circumstances and reproductive function in a variety of mammal species have produced varied results, which do not all support the common assumption that higher female reproductive hormone levels, specifically progesterone, indicate better ovarian function and greater reproductive potential, and are associated with lower energetic stress. In the present study faecal progesterone and glucocorticoid levels were assessed in two troops of olive baboons (Papio anubis) in the same population. They face similar ecological challenges, except that one troop crop-raids, potentially affecting its energetic intake and stress levels. The energy intake of individual females was assessed by combining detailed feeding observations with nutritional analysis of food samples. The crop-raiding troop experienced 50% higher energy intake rates and 50% lower glucocorticoid levels compared to the non-crop-raiding troop alongside substantially lower progesterone levels. This suggests that energetic stress is associated with elevated progesterone levels and may be the cause of the non-crop-raiding troop's lower reproductive output. By comparing groups which differ little, except in terms of food access, and also by directly assessing energy intake, our study addresses some of the design limitations of previous research investigating variation in progesterone levels and energetic stress. It therefore has the potential to contribute to greater understanding of the factors affecting differences in reproductive and stress hormone levels and reproductive function in mammals experiencing different energetic circumstances. PMID:23800561

  15. An evaluation of the influence of substrate on the response of juvenile freshwater mussels (fatmucket, Lampsilis siliquoidea) in acute water exposures to ammonia

    USGS Publications Warehouse

    Miao, J.; Barnhart, M.C.; Brunson, E.L.; Hardesty, D.K.; Ingersoll, C.G.; Wang, N.

    2010-01-01

    Acute 96-h ammonia toxicity to three-month-old juvenile mussels (Lampsilis siliquoidea) was evaluated in four treatments (water-only, water-only with feeding, water and soil, and water and sand) using an exposure unit designed to maintain consistent pH and ammonia concentrations in overlying water and in pore water surrounding the substrates. Median effect concentrations (EC50s) for total ammonia nitrogen in the four treatments ranged from 5.6 to 7.7mg/L and median lethal concentrations (LC50s) ranged from 7.0 to 11mg/L at a mean pH of 8.4. Similar EC50s or LC50s with overlapping 95% confidence intervals among treatments indicated no influence of substrate on the response of mussels in acute exposures to ammonia. ?? 2010 SETAC.

  16. Blood supply to the brain and. beta. -endorphin and acth levels under the influence of thyrotrophin releasing hormone

    SciTech Connect

    Mirzoyan, R.S.; Ganshina, T.S.; Mirzoyan, R.A.; Ragimov, K.S.

    1985-08-01

    The authors studied beta-endorphin because of its possible mediator role in terms of the cerebrovascular effects of thyrotrophin releasing hormone (TRH), and also because of data in the literature on antagonistic relations between TRH and the endogenous opioid system of the brain. Beta-endorphin was determined by radioimmunoassay; its level was determined after its separation from the beta-lipotrophin fraction. The investigation showed that TRH has a marked depressant effect on cerebrovascular vasoconstrictor refleces. Elevation of the blood ACTH level causes an increase in BP and in the tone of the cerebral vessels. An absence of correlation between the beta-endorphin and ACTH levels in the blood and CSF under the influence of TRH is shown.

  17. Distribution and diets of larval and juvenile fishes: Influence of salinity gradient and turbidity maximum in a temperate estuary in upper Ariake Bay, Japan

    NASA Astrophysics Data System (ADS)

    Islam, Md. Shahidul; Hibino, Manabu; Tanaka, Masaru

    2006-06-01

    We investigated the fish assemblage and distribution, diversity, and diets in relation to copepod prey communities along the Chikugo estuarine gradient in the Ariake Bay, Japan. Larval and juvenile fish samples, ambient copepod samples were collected and major hydrographic parameters were recorded at seven selected sampling stations (salinity range: 0.4-28.8 psu) during four sampling cruises in spring 2001. A zone of estuarine turbidity maximum (ETM) was identified in the upper part of the estuary which was characterized by low salinity. Two different fish and copepod communities based on the spatial distribution patterns were identified: the oligohaline community in the upper estuary, which was associated with the ETM; and the euryhaline community in the lower estuary, downstream of the ETM. The oligohaline fish community was composed of Acanthogobius flavimanus, Acanthogobius hasta, Coilia nasus, Neosalanx reganius, and Trachidermus fasciatus while the euryhaline community was composed of Engraulis japonicus and Sebastes inermis. Lateolabrax japonicus was distributed over wide spatial areas. Sinocalanus sinensis was the single dominant member of the oligohaline copepod community while the euryhaline community was dominated by Oithona davisae, Acartia omorii and Paracalanus parvus. Strong dietary relationships were identified between fishes and copepods in the same community. ETM appears to have significant influence on the distribution and abundance of the oligohaline copepod S. sinensis and this prey copepod appears to have strong influence on the fishes in the oligohaline regions. Most of the fishes were distributed in the low saline upper estuary where they foraged on the single dominant copepod S. sinensis which contributes the majority of the copepod standing biomass of the estuary and thus appear to support nursery for fishes. It was concluded that the ETM-based copepod S. sinensis plays a key role in survival and distribution of larval and juvenile fishes

  18. Influence of Matrix metalloproteinase 1 and 3 genetic variations on susceptibility and severity of juvenile idiopathic arthritis.

    PubMed

    Abd-Allah, Somia H; El-Shal, Amal S; Shalaby, Sally M; Pasha, Heba F; Abou El-Saoud, Amany M; Abdel Galil, Sahar M; Mahmoud, Tysser A

    2015-12-01

    Juvenile idiopathic arthritis (JIA) is a chronic rheumatic disease affecting children aged less than 16 years, characterized by chronic synovitis, cartilage damage, and bony erosions mediated by matrix metalloproteinases (MMPs), mainly MMP-1 and MMP-3. The purpose of this study was to investigate MMP-1 and MMP-3 gene polymorphisms in patients with JIA, the role of genes in susceptibility to JIA, and their associations with JIA activity and prognosis. Case-control study included 100 patients diagnosed with JIA, according to the criteria of the International League of Associations for Rheumatology (ILAR), and 100 healthy children, age and sex matched, as controls. The MMP-1 (-1607 1G/2G) and MMP-3 (-1171 5A/6A) polymorphisms were screened by polymerase chain reaction-restriction fragment length polymorphism. The serum levels of MMP-1 and MMP 3 were measured by enzyme-linked immunosorbent assay. There were significant differences between patients with JIA and control groups regarding the genotype and allele frequencies distributions of both MMP-1 1G/2G and MMP-3 5A/6A polymorphisms. The haplotype 2G-6A, which carries the abnormal alleles, showed higher frequencies in patients with JIA than in controls (OD = 2.8, P = 0.002). The prevalence of MMP-1 2G and 6A allele for MMP-3 polymorphism was found to be significantly associated with persistent oligoarticular, rheumatoid factor (RF)-positive polyarthritis, and systemic JIA groups. There were significantly increased serum levels of MMP-1 and MMP-3 associated with 2G/6A haplotype in the patient group, especially with the polyarticular RF (+ve) group than in other groups and the control group. MMP-1 and MMP-3 haplotypes could be useful genetic markers for JIA susceptibility and severity in the juvenile Egyptian population. Moreover, our data further support the use of serum MMP-3 and MMP-1 as specific markers of disease activity in JIA.

  19. Efficacy of treatment of cattle for liver fluke at housing: influence of differences in flukicidal activity against juvenile Fasciola hepatica.

    PubMed

    Forbes, A B; Reddick, D; Stear, M J

    2015-03-28

    Flukicides are commonly administered at housing to cattle that have grazed fluke-infected pastures or that have been purchased from endemic areas. The choice of product is determined by numerous factors, one of which is the stages of Fasciola hepatica that are killed. Flukicides can be categorised into three main groups: (A) those that kill all juvenile stages and adults; (B) those that kill juveniles from six to eight weeks of age and adults and (C) those that kill adults only. This study was conducted on a commercial beef farm in Scotland and was designed to compare the efficacy of flukicides from each of these three classes in terms of their effects on faecal egg output, coproantigen and liveweight gain. The majority of animals in the untreated control group were positive for coproantigen, fluke eggs or both throughout the study duration of 16 weeks. Egg reappearance interval following housing treatment was eight weeks for clorsulon and 13 weeks for nitroxynil, though patent infections in both groups developed in only a small minority of animals; no fluke eggs were recovered from cattle treated with triclabendazole. Coproantigen was detected four weeks before the reappearance of fluke eggs in the dung. Animals treated with flukicides had significantly fewer faecal samples positive for eggs (P<0.006) and coproantigen (P<0.05) following treatment compared with the controls. Despite differences in the efficacy profiles among the flukicide-treated groups, there were no significant differences (P>0.05) in growth rates among any of the four treatment groups. There was, however, a significant negative association (P<0.001) between fluke positivity at housing and subsequent growth performance, irrespective of treatment group.

  20. Tagging Juvenile Pacific Lamprey with Passive Integrated Transponders: Methodology, Short-Term Mortality, and Influence on Swimming Performance

    SciTech Connect

    Mueller, Robert P.; Moursund, Russell A.; Bleich, Matthew D.

    2006-05-01

    This study was conducted to determine the feasibility (i.e., efficiency and onintrusiveness) of tagging juvenile Pacific lampreys Lampetra tridentata with passive integrated transponder (PIT) tags and to determine any associated impacts on survivorship and swimming ability. Juvenile Pacific lampreys were obtained from the John Day Dam fish collection facility and tests were conducted at the Pacific Northwest National Laboratory in 2001 and 2002. A new PIT-tagging procedure was used to inject 12-mm tags 5 mm posterior to the gill openings. ampreys were allowed to recover for 3–4 d following surgery before postmortality and swimming tests were conducted. The PIT tagging procedure during 2001 did not include a suture, and 2.6% of the tags were shed after 40 d. During 2002 a single suture was used to close the opening after inserting a tag, and no tag shedding was observed. Overall short-term mortality rates for lampreys 120–155 mm (total length) held for 40 d at 88C was 2.2% for tagged and 2.7% for untagged fish. Mortality increased significantly when tagged and untagged groups were held in warmer (19–238C) river water: 50% for tagged and 60% for untagged animals. Lengths did not significantly affect survival for either the tagged or untagged group held in warm water. A fungal infection was observed to be the cause of death when water temperature increased. Swimming tests to determine any adverse effects due to tag insertion showed no significant difference (P ¼ 0.12) between tagged and untagged lampreys for mean burst speed; however, maximum burst speeds were significantly lower for the PIT-tagged group.

  1. Tagging Juvenile Pacific Lamprey with Passive Integrated Transponders: Methodology, Short-Term Mortality, and Influence on Swimming Performance

    SciTech Connect

    Mueller, Robert P.; Moursund, Russell A.; Bleich, Matthew D.

    2006-05-31

    Populations of Pacific lamprey (Lampetra tridentata) in the Columbia River basin have declined drastically over the past 20 years. Possible causes include habitat degradation and instream flow obstacles, such as the mainstem hydroelectric dams on the Columbia River. To determine why lamprey populations have declined a monitoring system to track their movements was needed to determine possible impacts. Juvenile lamprey were implanted with passive integrated transponder (PIT) tags and their detection rates determined while migrating through fish bypass facilities at McNary in 2001 and 2005 and John Day Dam in 2002. Juvenile Pacific lamprey (115–178 mm) were obtained from the John Day Dam fish collection facility, transported to Pacific Northwest National Laboratory, and surgically PIT-tagged. Lamprey were allowed to recover for 3 to 4 days following PIT tag implantation and subsequently were released upstream of the PIT tag detectors at both dams. Primary detector efficiency was 98% at McNary Dam and 97% at John Day Dam. Average in-river travel time for fish released at McNary Dam and detected at John Day Dam was 16.1 d in 2001 and 10 d in 2005. Mean detection rates at McNary Dam varied from 74% for gatewell releases to 69% for the collection channel. Follow up tests in 2005 at McNary Dam showed detections rates near 100% from collection channel releases. Detection rates from forebay releases at McNary Dam were lower, ranging from 0% to 38% (mean = 21%). Mean travel times from release point to the primary detectors at McNary Dam were; forebay (492 min), gatewell (323 min), and collection channel (245 min). The detection efficiency at the primary detectors was similar to that of PIT-tagged smolts and travel time within the bypass system showed that lamprey can hold in the bypass system for prolonged periods.

  2. Influence of modified transdermal hormone replacement therapy on the concentrations of hormones, growth factors, and bone mineral density in women with osteopenia.

    PubMed

    Stanosz, Staniaław; Zochowska, Ewa; Safranow, Krzysztof; Sieja, Krzysztof; Stanosz, Małgorzta

    2009-01-01

    The metabolic and therapeutic action of estrogens depends on their type, dosage, form, route of administration, and treatment-free interval during the therapeutic cycle. Hormone therapy is generally subclassified into 2 forms that differ in the type of hormones. In hormonal replacement therapy (HRT), estrogens and progesterone components do not differ in chemical structure and molecular mass from those naturally produced by the female organism. In hormonal supplementary therapy (HST), the estrogen and progestagen components do differ from the natural hormones in structure and mass. The aim of the study was to compare 2 kinds of hormonal therapy in early postmenopausal women with osteopenia. These forms of therapy are modified transdermal HRT and orally given HST. The objective of this study was the estimation of sex hormone, insulin-like growth factor I (IGF-I), prolactin (PRL), osteocalcin, and procollagen concentration in serum as well as the degree of mineralization of the lumbar spine in women in the early postmenopausal period with osteopenia under different kinds of hormonal therapy. The study was conducted in 75 women with an average age of 52.4 +/- 3.5 years and with primary osteopenia, in the early postmenopausal period, who were randomly assigned to 3 groups depending on the form and route of administration of therapy: Group I (n = 25, control) was receiving placebo in the form of patches. Group II (n = 25) was treated with modified transdermal HRT. This group obtained micronized 17beta-estradiol at increasing-decreasing doses and progesterone in the second phase of the therapeutic cycle. Group III (n = 25) was receiving orally given HST and obtained Cyclo-Menorette (Wyeth, Munster, Germany). The therapeutic cycle in each group lasted 21 days, followed by a 7-day medication-free interval. Estradiol concentration in serum was increased 5-fold and estrone (E(1)) was increased about 11-fold in the group of women receiving orally given HST (P < .0001

  3. Uptake of Pharmaceuticals Influences Plant Development and Affects Nutrient and Hormone Homeostases.

    PubMed

    Carter, Laura J; Williams, Mike; Böttcher, Christine; Kookana, Rai S

    2015-10-20

    The detection of a range of active pharmaceutical ingredients (APIs) in the soil environment has led to a number of publications demonstrating uptake by crops, however very few studies have explored the potential for impacts on plant development as a result of API uptake. This study investigated the effect of carbamazepine and verapamil (0.005-10 mg/kg) on a range of plant responses in zucchini (Cucurbita pepo). Uptake increased in a dose-dependent manner, with maximum leaf concentrations of 821.9 and 2.2 mg/kg for carbamazepine and verapamil, respectively. Increased carbamazepine uptake by zucchini resulted in a decrease in above (<60%) and below (<30%) ground biomass compared to the controls (p < 0.05). At soil concentrations >4 mg/kg the mature leaves suffered from burnt edges and white spots as well as a reduction in photosynthetic pigments but no such effects were seen for verapamil. For both APIs, further investigations revealed significant differences in the concentrations of selected plant hormones (auxins, cytokinins, abscisic acid and jasmonates), and in the nutrient composition of the leaves in comparison to the controls (p < 0.05). This is some of the first research to demonstrate that the exposure of plants to APIs is likely to cause impacts on plant development with unknown implications.

  4. Influence of morphine during pregnancy on neuroendocrine regulation of pituitary hormone secretion.

    PubMed

    Litto, W J; Griffin, J P; Rabii, J

    1983-08-01

    The effects of exposure to morphine during pregnancy on postnatal neuroendocrine systems were investigated. Rats received morphine sulphate or 0.9% (w/v) NaCl twice daily on days 5-12 of pregnancy. A dose of 5 mg morphine sulphate/kg was administered for the first three injections while 10 mg/kg was used for each of the remaining 13. This treatment regimen led to a significant delay in the onset of vaginal opening in the female offspring. Mothers treated with morphine sulphate showed a marked attenuation of their prolactin response to the suckling stimulus, although they still released significant amounts of the hormone. Both male and female offspring of the opiate-treated dams showed a major reduction in the sensitivity of their hypothalamic-pituitary axis to gonadal steroids at 15 days of age. No significant differences were found in the acute thyrotrophin response to single injection of morphine sulphate of prepuberal male and female pups of morphine- and saline-treated dams. These data show that exposure to opiates during critical periods of prenatal development lead to long-lasting alterations in the neuroendocrine control systems of the animal. These alterations may then have significant consequences on the physiological maturation and adult behaviour of the animal.

  5. Water stress, CO2 and photoperiod influence hormone levels in wheat

    NASA Technical Reports Server (NTRS)

    Nan, Rubin; Carman, John G.; Salisbury, Frank B.; Campbell, W. F. (Principal Investigator)

    2002-01-01

    'Super Dwarf' wheat (Triticum aestivum L.) plants have been grown from seed to maturity in the Mir space station where they were periodically exposed, because of microgravity and other constraints, to water deficit, waterlogging, high CO2 levels, and low light intensities. The plants produced many tillers, but none of them produced viable seed. Studies have been initiated to determine why the plants responded in these ways. In the present study, effects of the listed stresses on abscisic acid (ABA), indole-3-acetic acid (IAA) and isopentenyl adenosine ([9R]iP) levels in roots and leaves of plants grown under otherwise near optimal conditions on earth were measured. Hormones were extracted, purified by HPLC, and quantified by noncompetitive indirect ELISA. In response to water deficit, ABA levels increased in roots and leaves, IAA levels decreased in roots and leaves, and [9R]iP levels increased in leaves but decreased in roots. In response to waterlogging, ABA, IAA and [9R]iP levels briefly increased in roots and leaves and then decreased. When portions of the root system were exposed to waterlogging and/or water deficit, ABA levels in leaves increased while [9R]iP and IAA levels decreased. These responses were correlated with the percentage of the root system stressed. At a low photosynthetic photon flux (100 micromoles m-2 s-1), plants grown in continuous light had higher leaf ABA levels than plants grown using an 18 or 21 h photoperiod.

  6. Influence of Parathyroid Hormone-Loaded PLGA Nanoparticles in Porous Scaffolds for Bone Regeneration

    PubMed Central

    Gentile, Piergiorgio; Nandagiri, Vijay Kumar; Pabari, Ritesh; Daly, Jacqueline; Tonda-Turo, Chiara; Ciardelli, Gianluca; Ramtoola, Zebunnissa

    2015-01-01

    Biodegradable poly(lactide-co-glycolide) (PLGA) nanoparticles, containing human parathyroid hormone (PTH (1–34)), prepared by a modified double emulsion-solvent diffusion-evaporation method, were incorporated in porous freeze-dried chitosan-gelatin (CH-G) scaffolds. The PTH-loaded nanoparticles (NPTH) were characterised in terms of morphology, size, protein loading, release kinetics and in vitro assessment of biological activity of released PTH and cytocompatibility studies against clonal human osteoblast (hFOB) cells. Structural integrity of incorporated and released PTH from nanoparticles was found to be intact by using Tris-tricine SDS-PAGE. In vitro PTH release kinetics from PLGA nanoparticles were characterised by a burst release followed by a slow release phase for 3–4 weeks. The released PTH was biologically active as evidenced by the stimulated release of cyclic AMP from hFOB cells as well as increased mineralisation studies. Both in vitro and cell studies demonstrated that the PTH bioactivity was maintained during the fabrication of PLGA nanoparticles and upon release. Finally, a content of 33.3% w/w NPTHs was incorporated in CH-G scaffolds, showing an intermittent release during the first 10 days and, followed by a controlled release over 28 days of observation time. The increased expression of Alkaline Phosphatase levels on hFOB cells further confirmed the activity of intermittently released PTH from scaffolds. PMID:26343649

  7. Influence of Parathyroid Hormone-Loaded PLGA Nanoparticles in Porous Scaffolds for Bone Regeneration.

    PubMed

    Gentile, Piergiorgio; Nandagiri, Vijay Kumar; Pabari, Ritesh; Daly, Jacqueline; Tonda-Turo, Chiara; Ciardelli, Gianluca; Ramtoola, Zebunnissa

    2015-08-28

    Biodegradable poly(lactide-co-glycolide) (PLGA) nanoparticles, containing human parathyroid hormone (PTH (1-34)), prepared by a modified double emulsion-solvent diffusion-evaporation method, were incorporated in porous freeze-dried chitosan-gelatin (CH-G) scaffolds. The PTH-loaded nanoparticles (NPTH) were characterised in terms of morphology, size, protein loading, release kinetics and in vitro assessment of biological activity of released PTH and cytocompatibility studies against clonal human osteoblast (hFOB) cells. Structural integrity of incorporated and released PTH from nanoparticles was found to be intact by using Tris-tricine SDS-PAGE. In vitro PTH release kinetics from PLGA nanoparticles were characterised by a burst release followed by a slow release phase for 3-4 weeks. The released PTH was biologically active as evidenced by the stimulated release of cyclic AMP from hFOB cells as well as increased mineralisation studies. in vitro and cell studies demonstrated that the PTH bioactivity was maintained during the fabrication of PLGA nanoparticles and upon release. Finally, a content of 33.3% w/w NPTHs was incorporated in CH-G scaffolds, showing an intermittent release during the first 10 days and, followed by a controlled release over 28 days of observation time. The increased expression of Alkaline Phosphatase levels on hFOB cells further confirmed the activity of intermittently released PTH from scaffolds.

  8. Uptake of Pharmaceuticals Influences Plant Development and Affects Nutrient and Hormone Homeostases.

    PubMed

    Carter, Laura J; Williams, Mike; Böttcher, Christine; Kookana, Rai S

    2015-10-20

    The detection of a range of active pharmaceutical ingredients (APIs) in the soil environment has led to a number of publications demonstrating uptake by crops, however very few studies have explored the potential for impacts on plant development as a result of API uptake. This study investigated the effect of carbamazepine and verapamil (0.005-10 mg/kg) on a range of plant responses in zucchini (Cucurbita pepo). Uptake increased in a dose-dependent manner, with maximum leaf concentrations of 821.9 and 2.2 mg/kg for carbamazepine and verapamil, respectively. Increased carbamazepine uptake by zucchini resulted in a decrease in above (<60%) and below (<30%) ground biomass compared to the controls (p < 0.05). At soil concentrations >4 mg/kg the mature leaves suffered from burnt edges and white spots as well as a reduction in photosynthetic pigments but no such effects were seen for verapamil. For both APIs, further investigations revealed significant differences in the concentrations of selected plant hormones (auxins, cytokinins, abscisic acid and jasmonates), and in the nutrient composition of the leaves in comparison to the controls (p < 0.05). This is some of the first research to demonstrate that the exposure of plants to APIs is likely to cause impacts on plant development with unknown implications. PMID:26418514

  9. Influence of the thyroid hormone status on tyrosine hydroxylase in central and peripheral catecholaminergic structures.

    PubMed

    Claustre, J; Balende, C; Pujol, J F

    1996-03-01

    We investigated the effect of hyper- and hypothyroidism on tyrosine hydroxylase protein concentration in the locus coeruleus (divided into anterior and posterior parts), the substantia nigra and the adrenals of adult rats. Rats were made hypothyroid with propylthiouracile (PTU, 0.02% in drinking water for 21 days) or hyperthyroid by thyroxine injection (100 or 250 micrograms/kg/day), for 3 or 17 days. PTU treatment resulted in statistically significant decrease of tyrosine hydroxylase in the anterior locus coeruleus (-13%) and the adrenals (-14%). After thyroxine treatment, in the anterior locus coeruleus, tyrosine hydroxylase was significantly higher (2 way ANOVA) after the 3 day treatment than after the 17 day treatment: tyrosine hydroxylase showed a trend to increase the 3 day treatment (+20% with the 250 micrograms/kg dose) and to decrease after the 17 day treatment (-15% with the 250 micrograms/kg dose). In the adrenals, tyrosine hydroxylase was increased by the 3 day treatment (+42% after the 250 micrograms/kg dose), but this increase was not observed after 17 days of treatment. Tyrosine hydroxylase was not altered in the posterior locus coeruleus and the substantia nigra, whatever the treatment. Together, our results support the hypothesis that in the anterior locus coeruleus and in the adrenals tyrosine hydroxylase level is positively modulated by thyroid hormones. After long-term treatment (17 days) this effect is not observed. PMID:8813245

  10. Ovarian hormones differentially influence immunoreactivity for dopamine beta- hydroxylase, choline acetyltransferase, and serotonin in the dorsolateral prefrontal cortex of adult rhesus monkeys.

    PubMed

    Kritzer, M F; Kohama, S G

    1999-07-01

    Recent studies have shown that ovariectomy reduces, and subsequent hormone replacement restores the density of axons immunoreactive for tyrosine hydroxylase in the dorsolateral prefrontal cortex of adult female rhesus monkeys. The present study indicates that three additional extrathalamic frontal lobe afferents are also sensitive to changes in the ovarian hormone environment. Specifically, the combination of hormone manipulation with qualitative and quantitative analysis of immunocytochemistry for dopamine beta-hydroxylase, choline acetyltransferase, and serotonin in the primate prefrontal cortex revealed quantitative responses in both cholinergic and monoaminergic axons to changing ovarian hormone levels. However, whereas ovariectomy produced a modest net decrease in the density of fibers immunoreactive for choline acetyltransferase, this same treatment markedly increased the density of axons immunoreactive for dopamine beta-hydroxylase and for serotonin. Further, the effects of ovariectomy on these afferent systems were differentially attenuated by estrogen verses estrogen plus progesterone hormone replacement. Estrogen was as effective as estrogen plus progesterone in stimulating normal prefrontal immunoreactivity for choline acetyltransferase and dopamine beta-hydroxylase. The dual replacement of estrogen plus progesterone, however, was a much more potent influence than estrogen alone for serotonin immunoreactivity. Thus, ovarian hormones appear to provide stimulation that differentially affects each of four chemically identified extrathalamic prefrontal afferent systems examined to date, and may have roles in maintaining the normal balance and functional interactions between these neurotransmitter systems.

  11. Influence of menstrual cycle, parity and oral contraceptive use on steroid hormone receptors in normal breast.

    PubMed Central

    Battersby, S.; Robertson, B. J.; Anderson, T. J.; King, R. J.; McPherson, K.

    1992-01-01

    Steroid receptor was assessed immunohistochemically in 158 samples of normal breast for variation through the menstrual cycle. Patterns and intensity of reaction were used in a semi-quantitative scoring system to examine the influence of cycle phase, cycle type, parity and age. The changes in oestrogen receptor for natural cycle and oral contraceptive (OC) cycles indicated down-regulation by progestins. Progesterone receptor did not vary significantly in natural cycles, but increased steadily through OC cycles. This study provides strong evidence that both oestrogen and progesterone influence breast epithelium, but dissimilarities from the endometrium are apparent. The interval since pregnancy had a significant negative effect on frequency and score of oestrogen receptor and score of progesterone receptor. Multivariate analysis established the phase of cycle and OC use as independent significant influences on oestrogen receptor. The interval since pregnancy was an independent significant factor for both oestrogen and progesterone receptor presence. Images Figure 1 Figure 2 PMID:1562470

  12. Influence of the mother's reproductive state on the hormonal status of daughters in marmosets (Callithrix kuhlii).

    PubMed

    Puffer, Alyssa M; Fite, Jeffrey E; French, Jeffrey A; Rukstalis, Michael; Hopkins, Elizabeth C; Patera, Kimberly J

    2004-09-01

    Behavioral and endocrine suppression of reproduction in subordinate females produces the high reproductive skew that characterizes callitrichid primate mating systems. Snowdon et al. [American Journal of Primatology 31:11-21, 1993] reported that the eldest daughters in tamarin families exhibit further endocrinological suppression immediately following the birth of siblings, and suggested that dominant females exert greater control over subordinate endocrinology during this energetically challenging phase of reproduction. We monitored the endocrine status of five Wied's black tufted-ear marmoset daughters before and after their mother delivered infants by measuring concentrations of urinary estradiol (E(2)), pregnanediol glucuronide (PdG), testosterone (T), and cortisol (CORT). Samples were collected from marmoset daughters 4 weeks prior to and 9 weeks following three consecutive sibling-litter births when the daughters were prepubertal (M=6.1 months of age), peripubertal (M=11.9 months), and postpubertal (M=17.6 months). The birth of infants was associated with reduced ovarian steroid excretion only in the prepubertal daughters. In contrast, ovarian steroid levels tended to increase in the postpubertal daughters. Urinary E(2) and T levels in the postpubertal daughters were 73.8% and 37.6% higher, respectively, in the 3 weeks following the birth of infants, relative to prepartum levels. In addition, peak urinary PdG concentrations in peri- and postpubertal daughters were equivalent to luteal phase concentrations in nonpregnant, breeding adult females, and all of the peri- and postpubertal daughters showed clear ovulatory cycles. Cortisol excretion did not change in response to the reproductive status of the mother, nor did the concentrations change across age. Our data suggest that marmoset daughters of potential breeding age are not hormonally suppressed during the mother's peripartum period or her return to fertility. These findings provide an additional example

  13. Hormonal receptors in juvenile nasopharyngeal angiofibroma.

    PubMed

    Farag, M M; Ghanimah, S E; Ragaie, A; Saleem, T H

    1987-02-01

    Specific thermostable androgen receptors were detected in the tissues of nasopharyngeal angiofibroma. The receptors seemed to be specific with high affinity toward DHT more than testosterone. No abnormalities in serum levels of DHT, testosterone, and estradiol-17 beta could be detected in the patients studied. A concept of pathogenesis of the tumor in relation to that reported in literature recently is interpreted in the text.

  14. Race, Legal Representation, and Juvenile Justice: Issues and Concerns

    ERIC Educational Resources Information Center

    Guevara, Lori; Spohn, Cassia; Herz, Denise

    2004-01-01

    The objective of this study was to examine the influence of type of counsel across race on juvenile court outcomes. Using data from a sample of juvenile court referrals from two midwestern juvenile courts, this study examined the interaction of race and type of counsel on disposition outcome. The results indicated that youth without an attorney…

  15. Gender Development in 46,XY DSD: Influences of Chromosomes, Hormones, and Interactions with Parents and Healthcare Professionals

    PubMed Central

    Wisniewski, Amy B.

    2012-01-01

    Variables that impact gender development in humans are difficult to evaluate. This difficulty exists because it is not usually possible to tease apart biological influences on gender from social variables. People with disorders of sex development, or DSD, provide important opportunities to study gender within individuals for whom biologic components of sex can be discordant with social components of gender. While most studies of gender development in people with 46,XY DSD have historically emphasized the importance of genes and hormones on gender identity and gender role, more recent evidence for a significant role for socialization exists and is considered here. For example, the influence of parents' perceptions of, and reactions to, DSD are considered. Additionally, the impact of treatments for DSD such as receiving gonadal surgeries or genitoplasty to reduce genital ambiguity on the psychological development of people with 46,XY DSD is presented. Finally, the role of multi-disciplinary care including access to peer support for advancing medical, surgical and psychosexual outcomes of children and adults with 46,XY DSD, regardless of sex of rearing, is discussed. PMID:24278745

  16. Influence of structured counseling on women’s selection of hormonal contraception in Israel: results of the CHOICE study

    PubMed Central

    Yeshaya, Arie; Ber, Amos; Seidman, Daniel S; Oddens, Bjorn J

    2014-01-01

    Background The multinational CHOICE (Contraceptive Health Research Of Informed Choice Experience) study evaluated the effects of structured counseling on women’s contraceptive decisions, their reasons for making those decisions, and their perceptions of combined hormonal contraceptive (CHC) methods in eleven countries. The aim of this paper to present data from the 1,802 women participating in Israel’s CHOICE program. Methods Women (aged 17–40 years) who consulted their health care providers about contraception and who would consider a CHC method qualified to participate. After indicating their intended CHC method, the women received counseling about the daily pill, weekly patch, and monthly vaginal ring. After counseling, the women completed a questionnaire about their contraceptive decisions. Results Before counseling, 67%, 6%, and 5% of women (mean age 27 years) intended to use the pill, patch, or ring, respectively. Counseling significantly influenced the women’s CHC choice, with 56%, 12%, and 23% of women selecting the pill, patch, or ring (P<0.0001 for all contraceptive methods versus before counseling). Logistic regression analysis suggested that age significantly increased the probability of switching from the pill to the ring. Conclusion Although the pill was the most popular choice overall, counseling appeared to influence Israeli women’s contraceptive decisions, with significantly more women selecting the patch. More than four times as many women selected the ring after counseling than before counseling. PMID:25187739

  17. Influence of nutritional stress on digestive enzyme activities in juveniles of two marine clam species, Ruditapes decussatus and Venerupis pullastra

    NASA Astrophysics Data System (ADS)

    Albentosa, Marina; Moyano, Francisco J.

    2008-08-01

    The potential use of digestive activities as indicators of the nutritional status in bivalves is discussed in relation to the results obtained in two clam species exposed to starvation and refeeding. Activities of some digestive enzymes (amylase, laminarinase, cellulase, and protease) were measured in juveniles of two commercially interesting species of clams, Ruditapes decussatus and Venerupis pullastra. The specimens were fed normally, being after subjected to a 15-days starvation and a further refeeding period. Samples were obtained at different moments of such feeding schedule to evaluate enzymes as well as weight (live, dry and organic) and length, in order to calculate growth rates and feeding efficiencies. Starvation led to a major decrease in clam growth as measured by dry weight and a negative growth as measured by organic weight, this coinciding with a certain degree of growth of the shell and a consumption of soft tissue. This response occurred more rapidly in R. decussatus but was of a lower magnitude than in V. pullastra. Activity of carbohydrases decreased rapidly in both species with starvation, although protease activity was maintained in R. decussatus. Recovery after the end of starvation was not similar in both species; while R. decussatus attained similar growth rates and enzyme activities to those measured prior to nutritional stress, V. pullastra only recovered 50% of its initial values. For both species of bivalves it can be concluded that digestive enzymes, and more specifically amylase, could be used as indicative of their nutritional condition.

  18. Size and age distributions of Juvenile Connecticut River American shad above Hadley Falls: Influence on outmigration representation and timing

    USGS Publications Warehouse

    O'Donnell, M. J.; Letcher, B.H.

    2008-01-01

    Age- and size-based habitat use and movement patterns of young-of-year American shad in rivers are not well understood. Adult females reach their natal rivers at different times and ascend the river at different rates, which may lead to variation of hatch dates at a single location. Also, shad are serial spawners, so eggs of the same female may be released at different distances from the river mouth. It has long been hypothesized that juvenile shad emigration is a function of size or age, and not necessarily keyed only to a decrease in water temperature during the fall. We seined three sites in the Connecticut River biweekly to collect pre-migrant shad during river residence (spring to fall). During emigration, samples were also collected weekly at two hydroelectric facilities. Otoliths were removed from ???20% of the fish to obtain age and growth rate information. We found increases in length and age over time until late in the season, after which such increases were mostly insigniftlant. Cohorts collected early in the year as pre-migrants were never sampled as migrants later in the year at the hydroelectric projects. Cohorts collected late in the year as migrants were never collected earlier in the year as pre-migrants. Only during a narrow window of time were fish collected as both pre-migrants and migrants. Fish that were hatched later in the season exhibited higher growth rates than fish that were hatched earlier in the season. Copyright ?? 2008 John Wiley & Sons, Ltd.

  19. Fighting Juvenile Gun Violence. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Sheppard, David; Grant, Heath; Rowe, Wendy; Jacobs, Nancy

    This bulletin describes the Office of Juvenile Justice and Delinquency Prevention's efforts to fight juvenile gun violence. The Office awarded four community demonstration grants to implement "Partnerships To Reduce Juvenile Gun Violence." Partnership goals include increasing the effectiveness of existing strategies by enhancing and coordinating…

  20. [Phytoecdysteroids influence on the hormonal status and apoptosis in growing rats].

    PubMed

    Sidorova, Iu S; Seliaskin, K E; Zorin, S N; Vasilevskaia, L S; Bogachuk, M N; Volodin, V V; Mazo, V K

    2014-01-01

    The impact of the 15-day consumption of Serratula coronata extract containing phytoecdysteroids on some indicators of hormonal status and activity of apoptosis in various organs of growing male Wistar rats (initial body weight 127.8 +/-2.5 sigma) has been studied. The extract from the leaves of Serratula coronata was added to the water of animals of experimental groups 2 and 3 (n = 8 in each group) daily at the dose of 5 and 15 mg phytoecdysteroids per kg of body weight respectively. Animals of the control group 1 (n = 8) received water alone throughout the experiment. Daily volume of drunk fluid was recorded. At the 15th day of the experiment animals were taken out using the decapitation under the light ether anesthesia. The content of corticosterone, prostaglandin E2 and beta-endorphin in rat blood plasma were determined by ELISA test. Plasma level of noradrenaline was determined by HPLC. DNA damage and percentage of apoptotic cells (apoptotic index) were measured in isolated cells of the thymus, heart and brain by single-cell gel electrophoresis (the comet assay). Significantly lower concentration of norepinephrine was detected in plasma of experimental animals from groups 2 and 3 (10.3 +/- 1.1 and 7.2 +/- 0.8 ng/ml, respectively) compared to the same index in the control group (20.4 +/- 3.4 ng/ml). Significant differences of other biochemical parameters for all groups of animals have not been identified. Statistical significant difference in the ratio of corticosterone/norepinephrine compared with control animals was detected for a group of rats consumed the highest dose of phytoecdysteroids. There was no statistically significant difference in DNA fragmentation and apoptosis index in animals consumed phytoecdysteroids in compare with the control group of animals. The absence of the activity of apoptosis in cells of the heart, brain and thymus of rats treated with phytoecdysteroid extract may indicate the safety of its use in the diet of the animals. PMID

  1. Influence of daily regimen calcium and vitamin D supplementation on parathyroid hormone secretion.

    PubMed

    Reginster, J-Y; Zegels, B; Lejeune, E; Micheletti, M C; Kvsaz, A; Seidel, L; Sarlet, N

    2002-02-01

    Calcium and vitamin D supplementation has been shown to reduce secondary hyperparathyroidism and play a role in the management of senile osteoporosis. In order to define the optimal regimen of calcium and vitamin D supplementation to produce the maximal inhibition of parathyroid hormone secretion, we have compared the administration of a similar amount of Ca and vitamin D, either as a single morning dose or split in two doses, taken 6 hours apart. Twelve healthy volunteers were assigned to three investigational procedures, at weekly intervals. After a blank control procedure, when they were not exposed to any drug intake, they received two calcium-vitamin D supplement regimens including either two doses of Orocal D3 (500 mg Ca and 400 IU vitamin D) 6 hours apart or one water-soluble effervescent powder pack of Cacit D3 in a single morning dose (1000 mg Ca and 880 IU vitamin D). During the three procedures (control and the two calcium-vitamin D supplementations), venous blood was drawn every 60 minutes for up to 9 hours, for serum Ca and serum PTH measurements. The order of administration of the two Ca and vitamin D supplementation sequences was allocated by randomization. No significant changes in serum Ca were observed during the study. During the 6 hours following Ca and vitamin D supplementation, a statistically significant decrease in serum PTH was observed with both regimens, compared with baseline and with the control procedure. Over this period of time, no differences were observed between the two treatment regimens. However, between the sixth and the ninth hour, serum PTH levels were still significantly decreased compared with baseline with split dose Orocal D3 administration, while they returned to baseline value with the Cacit D3 preparation. During this period, the percentage decrease in serum PTH compared with baseline was significantly more pronounced with Orocal D3 than with Cacit D3 (P = 0.0021). We therefore conclude that the administration of two

  2. HORMONAL PROCESSES IN DECAPOD CRUSTACEAN LARVAE AS BIOMARKERS OF ENDOCRINE DISRUPTING CHEMICALS IN THE MARINE ENVIRONMENT

    EPA Science Inventory

    Knowledge of endocrine control of the complex larval developmental processes in insects (metamorphosis) has led to the introduction of insect hormones and their analogues as insecticides known as insect growth regulators (IGRs) with the largest group being juvenile hormone analog...

  3. Influence of processing and cooking of carrots in mixed meals on satiety, glucose and hormonal response.

    PubMed

    Gustafsson, K; Asp, N G; Hagander, B; Nyman, M; Schweizer, T

    1995-02-01

    The influence of processing and cooking on the metabolic response to carrots in mixed meals was explored in two consecutive harvest years. The contribution of dietary fibre (4.4 g 1989 and 6.6 g 1990) from carrots was chosen to be different in order to compare effects with varying doses. The meals, composed of carrots, creamed potatoes, meat balls, lingonberry jam, white bread and light beer, were served in the morning after an overnight fast to 10 healthy male volunteers. Carrots were investigated raw, processed (blanched and frozen) and variously cooked (thawed, boiled and microwaved). The amount of dietary fibre from the vegetable, and the content of energy, digestible carbohydrates, fat and protein were similar in the meals compared. Significantly lower glucose, insulin and C-peptide responses and higher satiety scores were elicited with raw carrots than with microwaved ones, harvest year 1989. The next year, with a higher dietary fibre intake from carrots, there were significant effects of processing only on the glucose response. Plasma beta-carotene levels tended to be higher postprandially with raw carrots than with microwaved ones. Hence, ordinary processing and cooking of vegetables can affect the metabolic response to a mixed meal. However, the influence seems to be varying and of minor importance in ordinary meals. Increasing vegetable portions entailing a higher soluble fibre content and a higher viscosity could further reduce the influence of processing.

  4. Influence of hormonal status on enkephalin-degrading aminopeptidase activity in the HPA axis of female mice.

    PubMed

    García-López, M J; Martínez-Martos, J M; Mayas, M D; Carrera, M P; Ramírez-Expósito, M J

    2005-04-01

    Opioids are involved in the regulation of hypothalamus-pituitary-adrenal (HPA) axis activity under physiological conditions. In the present work, we analyzed the influence of ovariectomy and estradiol (E), progesterone (P) or estradiol plus progesterone (E+P) replacement on soluble (S) and membrane-bound (MB) enkephalin-degrading aminopeptidase activity (EDA) in the HPA axis. Female mice (Balb/C) were distributed in 15 groups of 10 animals each: sham-operated controls (C), ovariectomized controls (OV-C), and ovariectomized mice treated with increasing doses of E (10, 20 or 40 mg/kg), P (100, 200 or 400 mg/kg) or E+P (10+100, 20+200 or 40+400 mg/kg). In hypothalamus, ovariectomy increased both S and MB EDA activities, whereas E replacement returned them to control levels, although MB EDA activity increased again after the replacement with 40 mg/kg E. P replacement increased S EDA activity, but returned MB EDA activity to control levels. The replacement of E+P returned both S and MB EDA activities to control levels, although MB EDA activity was lower than control values after the replacement with 10+100 mg/kg E+P. In pituitary, neither ovariectomy nor the replacement of E or E+P changed S EDA, although the highest concentrations of P increased S EDA activity. However, ovariectomy increased MB EDA and E replacement returned the activity to control or below control levels, depending on the concentration used. However, P administration returned the activity to control or below control levels depending on the concentration used, although 200 mg/kg P had no effects on MB EDA. E+P replacement returned pituitary MB EDA activity to control levels. In adrenal glands, ovariectomy did change either S or MB EDA. However, E, P or E+P replacement decreased S EDA activity in different degrees, depending of the dose administrated. No changes were detected in MB EDA after hormone replacement. These results indicate that female steroid hormones influence EDA activity at different

  5. The influence of insulin, beta-estradiol, dexamethasone and thyroid hormone on the secretion of coagulant and anticoagulant proteins by HepG2 cells.

    PubMed

    Niessen, R W; Pfaffendorf, B A; Sturk, A; Lamping, R J; Schaap, M C; Hack, C E; Peters, M

    1995-08-01

    As a basis for regulatory studies on the influence of hormones on (anti)coagulant protein production by hepatocytes, we examined the amounts of the plasma proteins antithrombin III (AT III), protein C, protein S, factor II, factor X, fibrinogen, and prealbumin produced by the hepatoma cell line HepG2, into the culture medium, in the absence and presence of insulin, beta-estradiol, dexamethasone and thyroid hormone. Without hormones these cells produced large amounts of fibrinogen (2,452 +/- 501 ng/mg cell protein), AT III (447 +/- 16 ng/mg cell protein) and factor II (464 +/- 31 ng/mg cell protein) and only small amounts of protein C (50 +/- 7 ng/mg cell protein) and factor X (55 +/- 5 ng/mg cell protein). Thyroid hormone had a slight but significant effect on the enrichment in the culture medium of the anticoagulant protein AT III (1.34-fold) but not on protein C (0.96-fold) and protein S (0.91-fold). This hormone also significantly increased the amounts of the coagulant proteins factor II (1.28-fold), factor X (1.45-fold) and fibrinogen (2.17-fold). Insulin had an overall stimulating effect on the amounts of all the proteins that were investigated. Neither dexamethasone nor beta-estradiol administration did substantially change the amounts of these proteins. We conclude that the HepG2 cell is a useful tool to study the hormonal regulation of the production of (anti)coagulant proteins. We studied the overall process of protein production, i.e., the amounts of proteins produced into the culture medium. Detailed studies have to be performed to establish the specific hormonal effects on the underlying processes, e.g., transcription, translation, cellular processing and transport, and secretion.

  6. Juvenile Justice & Youth Violence.

    ERIC Educational Resources Information Center

    Howell, James C.

    Youth violence and the juvenile justice system in the United States are explored. Part 1 takes stock of the situation. The first chapter discusses the origins and evaluation of the juvenile justice system, and the second considers the contributions of the Federal Juvenile Justice and Delinquency Prevention Act to the existing juvenile justice…

  7. INFLUENCE OF LARVAL EXPOSURE TO SALINITY AND CADMIUM STRESS ON JUVENILE PERFORMANCE OF TWO MARINE INVERTEBRATES, CAPITELLA SP I AND CREPIDULA FORNICATA

    EPA Science Inventory

    Delayed metamorphosis and short-term food limitation reduce juvenile or adult fitness in a number of marine invertebrate species. In this study, we tested the ability of pollutant and salinity stress to bring about similar effects on juvenile or adult performance. Larvae of the p...

  8. The influence of dietary salt and energy on the response to low pH in juvenile rainbow trout.

    PubMed

    D'Cruz, L M; Wood, C M

    1998-01-01

    This study evaluated the role of diet, specifically the relative importance of salt content versus energy content, in the response of juvenile rainbow trout to environmental acid stress in soft water ([Ca2+] = 0.057 mmol L-1, [Na+] = 0.047 mmol L-1). Diets were formulated at two energy levels (regular, 16.3 MJ kg-1, and low, 9.8 MJ kg-1) and two levels of NaCl (regular, approximately 263 mmol kg-1, and low, approximately 64 mmol kg-1), yielding four treatment combinations, each fed at a ration of 0.6% body weight d-1. A fifth group of fish was not fed during the experiment. All groups were subjected to an initial acid challenge (24 h at pH 5.0 plus 12 h at pH 4.0), followed by 28 d of exposure to pH 5.2. Following the initial acid challenge, typical ionoregulatory disturbances were seen, but most effects had attenuated or disappeared by day 20 of chronic low-pH exposure. However, after 28 d, fish fed the regular-salt diets maintained the restored ionic homeostasis, whereas those fed low-salt diets did not, regardless of the energy content of the diet. Growth and food conversion efficiency were greatest in trout fed the regular-energy/regular-salt diet, negative in fish fed the low-energy/regular-salt diet, and intermediate in trout on the other diets; starved fish lost weight. Fish maintained on the regular-energy/low-salt diet exhibited the most deleterious effects, including elevated cortisol levels and a 4.1% d-1 mortality rate. Fish fed the low-energy/low-salt diet, those fed regular-salt diets, and starved fish were not as adversely affected by the acid stress. Following a regular-energy meal, fish tended to exhibit an elevated rate of oxygen consumption, but this did not occur after a low-energy meal, regardless of its salt content. Elevated oxygen consumption may be accompanied by a loss of ions via the osmorespiratory compromise. We hypothesize that fish fed the regular-energy/low-salt diets were most deleteriously affected in an acidified environment

  9. Influence of converting enzyme inhibition on the hormonal and renal adaptation to hyper- and hyponatraemic dehydration.

    PubMed

    Gardes, J; Gonzalez, M F; Corvol, P; Ménard, J

    1986-04-01

    The present study was designed to investigate in rats the influence of converting enzyme inhibition with captopril on blood pressure, plasma urea, plasma renin concentration (PRC), plasma aldosterone and plasma vasopressin, and to define the interrelationships between PRC and these variables during equal degrees of either hyponatraemic (furosemide, 40 mg/kg for 2 days) or hypernatraemic (48-h water deprivation) dehydration. Chronic treatment with captopril (40 mg/kg daily) decreased blood pressure by 19% in normally hydrated treated rats, by 27% in water-deprived treated rats and by 40% in furosemide-treated rats. Plasma renin concentration, plasma aldosterone and plasma vasopressin were increased during both hypo- and hypernatraemic dehydration. Captopril decreased plasma aldosterone in water-deprived and furosemide-treated rats, whereas plasma vasopressin was unchanged. The significant correlation observed between plasma aldosterone and PRC in non-treated rats persisted in treated rats, the same level of plasma aldosterone being observed at values of PRC 10 times higher. On the other hand, the correlation between plasma vasopressin and PRC did not persist in captopril-treated rats. An increase in plasma urea was observed in both water-deprived treated rats and furosemide-treated rats. These data indicate that during hypo- and hypernatraemic dehydration, the renin-angiotensin system plays a role in regulating blood pressure, urea elimination and plasma aldosterone, but vasopressin regulation is not modified by its inhibition.

  10. Headaches and hormones.

    PubMed

    Pakalnis, Ann; Gladstein, Jack

    2010-06-01

    It is clear that hormones play an important role in modulating and exacerbating headaches. From an epidemiologic standpoint, we know that before puberty, incidence of new headache is similar for boys and girls. By age 18, however, most new cases of migraine occur in young women. The role of sex hormones in headache is described in the context of pubertal development. Obesity and Pseudotumor also impact headache through hormonal influences. Menstrual migraine will often present in the teenage years. Oral contraceptives may worsen or ameliorate headache. This article will introduce these concepts and help the reader become familiar with the role of hormones in headache.

  11. Corticotropin-Releasing Hormone Receptor Type 1 (CRHR1) Genetic Variation and Stress Interact to Influence Reward Learning

    PubMed Central

    Bogdan, Ryan; Santesso, Diane L.; Fagerness, Jesen; Perlis, Roy H.; Pizzagalli, Diego A.

    2011-01-01

    Stress is a general risk factor for psychopathology but the mechanisms underlying this relationship remain largely unknown. Animal studies and limited human research suggest that stress can induce anhedonic behavior. Moreover, emerging data indicate that genetic variation within the corticotropin-releasing hormone type 1 receptor gene (CRHR1) at rs12938031 may promote psychopathology, particularly in the context of stress. Using an intermediate phenotypic neurogenetics approach, we assessed how stress and CRHR1 genetic variation (rs12938031) influence reward learning, an important component of anhedonia. Psychiatrically healthy female participants (n = 75) completed a probabilistic reward learning task during stress and no-stress conditions while 128-channel event-related potentials were recorded. Fifty-six participants were also genotyped across CRHR1. Response bias, an individual’s ability to modulate behavior as a function of reward, was the primary behavioral variable of interest. The feedback-related positivity (FRP) in response to reward feedback was used as a neural index of reward learning. Relative to the no-stress condition, acute stress was associated with blunted response bias as well as a smaller and delayed FRP (indicative of disrupted reward learning) and reduced anterior cingulate and orbitofrontal cortex activation to reward. Critically, rs12938031 interacted with stress to influence reward learning: both behaviorally and neurally, A homozygotes showed stress-induced reward learning abnormalities. These findings indicate that acute, uncontrollable stressors reduce participants’ ability to modulate behavior as a function of reward, and that such effects are modulated by CRHR1 genotype. Homozygosity for the A allele at rs12938031 may increase risk for psychopathology via stress-induced reward learning deficits. PMID:21917807

  12. Corticotropin-releasing hormone receptor type 1 (CRHR1) genetic variation and stress interact to influence reward learning.

    PubMed

    Bogdan, Ryan; Santesso, Diane L; Fagerness, Jesen; Perlis, Roy H; Pizzagalli, Diego A

    2011-09-14

    Stress is a general risk factor for psychopathology, but the mechanisms underlying this relationship remain largely unknown. Animal studies and limited human research suggest that stress can induce anhedonic behavior. Moreover, emerging data indicate that genetic variation within the corticotropin-releasing hormone type 1 receptor gene (CRHR1) at rs12938031 may promote psychopathology, particularly in the context of stress. Using an intermediate phenotypic neurogenetics approach, we assessed how stress and CRHR1 genetic variation (rs12938031) influence reward learning, an important component of anhedonia. Psychiatrically healthy female participants (n = 75) completed a probabilistic reward learning task during stress and no-stress conditions while 128-channel event-related potentials were recorded. Fifty-six participants were also genotyped across CRHR1. Response bias, an individual's ability to modulate behavior as a function of reward, was the primary behavioral variable of interest. The feedback-related positivity (FRP) in response to reward feedback was used as a neural index of reward learning. Relative to the no-stress condition, acute stress was associated with blunted response bias as well as a smaller and delayed FRP (indicative of disrupted reward learning) and reduced anterior cingulate and orbitofrontal cortex activation to reward. Critically, rs12938031 interacted with stress to influence reward learning: both behaviorally and neurally, A homozygotes showed stress-induced reward learning abnormalities. These findings indicate that acute, uncontrollable stressors reduce participants' ability to modulate behavior as a function of reward, and that such effects are modulated by CRHR1 genotype. Homozygosity for the A allele at rs12938031 may increase risk for psychopathology via stress-induced reward learning deficits.

  13. Differentiating the Influences of Aging and Adiposity on Brain Weights, Levels of Serum and Brain Cytokines, Gastrointestinal Hormones, and Amyloid Precursor Protein.

    PubMed

    Banks, William A; Abrass, Christine K; Hansen, Kim M

    2016-01-01

    Aging and obesity exert important effects on disease. Differentiating these effects is difficult, however, because weight gain often accompanies aging. Here, we used a nested design of aged, calorically restricted, and refed rats to measure changes in brain and blood levels of cytokines and gastrointestinal hormones, brain amyloid precursor protein levels, and brain and body weights. By comparing groups and using path analysis, we found divergent influences of chronological aging versus body weight, our main findings being (i) changes in whole brain weight and serum macrophage colony-stimulating factor levels correlated better with body weight than with chronological aging, (ii) a decrease in brain cytokines and brain plasminogen activator inhibitor levels correlated better with chronological aging than with body weight, (iii) serum erythropoietin levels were influenced by both body weight and aging, (iv) serum plasminogen activator inhibitor, serum cytokines, and brain tumor necrosis factor were not influenced by aging or body weight, and (v) brain amyloid precursor protein more closely related to body weight and serum levels of gastrointestinal hormones than to brain weight, chronological aging, or cytokines. These findings show that although aging and body weight interact, their influences are distinct not only among various cytokines and hormones but also between the central nervous system and the peripheral tissue compartments.

  14. Ovarian Hormone Influences on Dysregulated Eating: A Comparison of Associations in Women with versus without Binge Episodes

    PubMed Central

    Klump, Kelly L.; Racine, Sarah E.; Hildebrandt, Britny; Burt, S. Alexandra; Neale, Michael; Sisk, Cheryl L.; Boker, Steven; Keel, Pamela K.

    2014-01-01

    Changes in ovarian hormones predict changes in emotional eating across the menstrual cycle. However, prior studies have not examined whether the nature of associations varies across dysregulated eating severity. The current study determined whether the strength and/or nature of hormone/dysregulated eating associations differ based on the presence of clinically diagnosed binge episodes (BEs). Participants included 28 women with BEs and 417 women without BEs who provided salivary hormone samples, ratings of emotional eating, and BE frequency for 45 days. Results revealed stronger associations between dysregulated eating and ovarian hormones in women with BEs as compared to women without BEs. The nature of associations also differed, as progesterone moderated the effects of lower estradiol levels on dysregulated eating in women with BEs only. Although hormone/dysregulated eating associations are present across the spectrum of pathology, the nature of associations may vary in ways that have implications for etiological models and treatment. PMID:25343062

  15. Ovarian Hormone Influences on Dysregulated Eating: A Comparison of Associations in Women with versus without Binge Episodes.

    PubMed

    Klump, Kelly L; Racine, Sarah E; Hildebrandt, Britny; Burt, S Alexandra; Neale, Michael; Sisk, Cheryl L; Boker, Steven; Keel, Pamela K

    2014-09-01

    Changes in ovarian hormones predict changes in emotional eating across the menstrual cycle. However, prior studies have not examined whether the nature of associations varies across dysregulated eating severity. The current study determined whether the strength and/or nature of hormone/dysregulated eating associations differ based on the presence of clinically diagnosed binge episodes (BEs). Participants included 28 women with BEs and 417 women without BEs who provided salivary hormone samples, ratings of emotional eating, and BE frequency for 45 days. Results revealed stronger associations between dysregulated eating and ovarian hormones in women with BEs as compared to women without BEs. The nature of associations also differed, as progesterone moderated the effects of lower estradiol levels on dysregulated eating in women with BEs only. Although hormone/dysregulated eating associations are present across the spectrum of pathology, the nature of associations may vary in ways that have implications for etiological models and treatment. PMID:25343062

  16. Hormones and endometrial carcinogenesis.

    PubMed

    Kamal, Areege; Tempest, Nicola; Parkes, Christina; Alnafakh, Rafah; Makrydima, Sofia; Adishesh, Meera; Hapangama, Dharani K

    2016-02-01

    Endometrial cancer (EC) is the commonest gynaecological cancer in the Western World with an alarmingly increasing incidence related to longevity and obesity. Ovarian hormones regulate normal human endometrial cell proliferation, regeneration and function therefore are implicated in endometrial carcinogenesis directly or via influencing other hormones and metabolic pathways. Although the role of unopposed oestrogen in the pathogenesis of EC has received considerable attention, the emerging role of other hormones in this process, such as androgens and gonadotropin-releasing hormones (GnRH) is less well recognised. This review aims to consolidate the current knowledge of the involvement of the three main endogenous ovarian hormones (oestrogens, progesterone and androgens) as well as the other hormones in endometrial carcinogenesis, to identify important avenues for future research. PMID:26966933

  17. [Hormonal contraception in autoimmpne diseases].

    PubMed

    Matyszkiewicz, Anna; Jach, Robert; Rajtar-Ciosek, Agnieszka; Basta, Tomasz

    2016-01-01

    The onset and the course of autoimmune diseases is influenced among other factors by the sex hormones. Hormonal contraception might affect the course of the autoimmune disease. The paper summarises the manner of save application of hormonal contraception in patients with autoimmune disease. PMID:27526427

  18. Sex differences in fuel use and metabolism during development in fasting juvenile northern elephant seals.

    PubMed

    Kelso, Elizabeth J; Champagne, Cory D; Tift, Michael S; Houser, Dorian S; Crocker, Daniel E

    2012-08-01

    Many polygynous, capital breeders exhibit sexual dimorphism with respect to body size and composition. Sexual dimorphism is often facilitated by sex differences in foraging behavior, growth rates and patterns of nutrient deposition during development. In species that undergo extended fasts during development, metabolic strategies for fuel use have the potential to influence future reproductive success by directly impacting somatic growth and acquisition of traits required for successful breeding. We investigated sexual dimorphism associated with metabolic strategies for fasting in developing northern elephant seals. Thirty-one juvenile seals of both sexes were sampled over extended fasts during annual autumn haul-outs. Field metabolic rate (FMR) and the contribution of protein catabolism to energy expenditure were estimated from changes in mass and body composition over 23±5 days of fasting (mean ± s.d.). Protein catabolism was assessed directly in a subset of animals based on urea flux at the beginning and end of the fast. Regulatory hormones and blood metabolites measured included growth hormone, cortisol, thyroxine, triiodothyronine, insulin, glucagon, testosterone, estradiol, glucose, urea and β-hydroxybutyrate. Males exhibited higher rates of energy expenditure during the fast but spared body protein stores more effectively than females. Rates of protein catabolism and energy expenditure were significantly impacted by hormone levels, which varied between the sexes. These data suggest that sex differences in fuel metabolism and energy expenditure during fasting arise early in juvenile development and may play an important role in the development of adult traits associated with reproductive success.

  19. STAT4 rs7574865 G/T and PTPN22 rs2488457 G/C Polymorphisms Influence the Risk of Developing Juvenile Idiopathic Arthritis in Han Chinese Patients

    PubMed Central

    Fan, Zhi-Dan; Wang, Fei-Fei; Huang, Hui; Huang, Na; Ma, Hui-Hui; Guo, Yi-Hong; Zhang, Ya-Yuan; Qian, Xiao-Qing; Yu, Hai-Guo

    2015-01-01

    Juvenile idiopathic arthritis (JIA) is a common autoimmune disease characterized by environmental influences along with several predisposing genes in the pathogenesis. The protein tyrosine phosphatase nonreceptor 22 (PTPN22) and signal transducer and activator of transcription factor 4 (STAT4) have been recognized as susceptibility genes for numerous autoimmune diseases. Associations of STAT4 rs7574865 G/T and PTPN22 (rs2488457 G/C and rs2476601 C/T) polymorphisms with JIA have repeatedly been replicated in several Caucasian populations. The aim of this study was to investigate the influence of three polymorphisms mentioned above on the risk of developing JIA in Han Chinese patients. Genotyping was performed on a total of 137 Chinese patients with JIA (JIA group) and 150 sex and age frequency-matched healthy volunteers (Control group). The single-nucleotide polymorphisms (SNP) were determined by using direct sequencing of PCR-amplified products. There were significant differences of PTPN22 rs2488457 G/C and STAT4 rs7574865 G/T polymorphisms between both groups. However, no significant difference was observed in distribution frequencies of PTPN22 rs2476601 polymorphism. The association with the PTPN22 rs2488457 G/C polymorphism remained significant in the stratifications by age at onset, ANA status, splenomegaly, lymphadenectasis and involvement joints. As with the STAT4 rs7574865 G/T polymorphisms, the enthesitis-related arthritis and presence of hepatomegaly had strong effect on the association. Our data strengthen STAT4 rs7574865 G/T and PTPN22 rs2488457 G/C polymorphisms as susceptibility factors for JIA. PMID:25781893

  20. RESTORATION OF STREAM PHYSICAL HABITAT AND FOOD RESOURCES: INFLUENCE ON JUVENILE COHO GROWTH AND SALMON DERIVED NUTRIENT INCORPORATION IN COASTAL OREGON STREAMS

    EPA Science Inventory

    ABSTRACT - Stream restoration in Western Oregon and Washington includes physical habitat improvement and salmon carcass additions. However, few studies examine the effects of carcass placement on juvenile fish in western Oregon, and in particular the interaction with physical hab...

  1. The orexigenic effect of melanin-concentrating hormone (MCH) is influenced by sex and stage of the estrous cycle.

    PubMed

    Santollo, Jessica; Eckel, Lisa A

    2008-03-18

    Recently, it was shown that the orexigenic effect of melanin-concentrating hormone (MCH) is attenuated by estradiol treatment in ovariectomized (OVX) rats. This suggests that female rats may be less responsive than male rats to the behavioral effects of MCH. To investigate this hypothesis, the effects of lateral ventricular infusions of MCH on food intake, water intake, meal patterns, and running wheel activity were examined in male and female rats. To further characterize the impact of estradiol on MCH-induced food intake, female rats were OVX and tested with and without 17-beta-estradiol benzoate (EB) replacement. In support of our hypothesis, food and water intakes following MCH treatment were greater in male rats, relative to female rats. Specifically, the orexigenic effect of MCH was maximal in male rats and minimal in EB-treated OVX rats. In both sexes, the orexigenic effect of MCH was mediated by a selective increase in meal size, which was attenuated in EB-treated OVX rats. MCH-induced a short-term (2 h) decrease in wheel running that, unlike its effects on ingestive behavior, was similar in males and females. Thus, estradiol decreases some, but not all, of the behavioral effects of MCH. To examine the influence of endogenous estradiol, food intake was monitored following MCH treatment in ovarian-intact, cycling rats. As predicted by our findings in OVX rats, the orexigenic effect of MCH was attenuated in estrous rats, relative to diestrous rats. We conclude that the female rat's reduced sensitivity to the orexigenic effect of MCH may contribute to sex- and estrous cycle-related differences in food intake. PMID:18191424

  2. Juvenile dermatomyositis.

    PubMed

    Quartier, Pierre; Gherardi, Romain K

    2013-01-01

    Juvenile dermatomyositis (JDM) is a systemic, inflammatory, idiopathic disease, mainly affecting the skin and the muscles, starting before the age of 16, with an incidence around one case per 1 million children. Some patients display typical features of JDM without skin involvement, or even without muscle involvement; however, both tissues are affected over time in most cases. Diagnosis criteria were established by Bohan and Peter 35 years ago, based on the presence of typical skin rash and proximal muscle involvement. Other conditions have to be ruled out before making a diagnosis of JDM, such as other connective tissue diseases, polymyositis, infectious/postinfectious myositis, genetic diseases, or metabolic or drug-induced myopathies. Unlike adult-onset dermatomyositis, JDM is exceptionally associated with a malignant disease. JDM may also affect several organs, including the lungs and the digestive tract. In a subset of patients, glucose intolerance, lipodystrophia and/or calcinosis develop. Delay in treatment initiation or inadequate treatment may favor diffuse, debilitating calcinosis. JDM patients have to be referred to reference pediatric centers to properly assess disease activity and disease-related damage (including low bone density in most cases), and to define the best treatment. Long-lasting corticosteroid therapy remains the gold standard, together with physiotherapy. Ongoing clinical trials are assessing the effect of several immunosuppressive and immunomodulatory drugs, which may help to control the disease and possibly demonstrate a corticosteroid-sparing effect. Most patients respond to treatment; relapses are frequent but a complete disease remission is achieved in most cases before adulthood.

  3. Juvenile Delinquency: An Introduction

    ERIC Educational Resources Information Center

    Smith, Carolyn A.

    2008-01-01

    Juvenile Delinquency is a term which is often inaccurately used. This article clarifies definitions, looks at prevalence, and explores the relationship between juvenile delinquency and mental health. Throughout, differences between males and females are explored. (Contains 1 table.)

  4. Juvenile Arrests, 2000. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Snyder, Howard N.

    This bulletin examines the national and state juvenile arrest rate in 2000 using data reported annually by local law enforcement agencies nationwide to the FBI's Uniform Crime Reporting program. Results indicate that the murder rate in 2000 was the lowest since 1965; juvenile arrests for violence in 2000 were the lowest since 1988; few juveniles…

  5. Juvenile Arrests 1996. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Snyder, Howard N.

    In 1996, law enforcement agencies in the United States made an estimated 2.9 million arrests of persons under the age of 18. According to Federal Bureau of Investigation (FBI) figures, juveniles accounted for 19% of all arrests and 19% of all violent crime in 1996. The substantial growth in juvenile crime that began in the late 1980s peaked in…

  6. Juvenile Arrests, 1999. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Snyder, Howard N.

    This bulletin presents a summary and analysis of national and state juvenile arrest data for 1999. Data come from the FBI's annual "Crime in the United States" report, which offers the estimated number of crimes reported to law enforcement agencies. The 1999 murder rate was the lowest since 1966. Of the nearly 1,800 juveniles murdered in 1999, 33…

  7. Juvenile Arrests, 1998. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Snyder, Howard N.

    This report provides a summary and analysis of national and state juvenile arrest data in the United States. In 1998, law enforcement agencies made an estimated 2.6 million arrests of persons under age 18. Federal Bureau of Investigations statistics indicate that juveniles account for 18% of all arrests, and 17% of all violent crime arrests in…

  8. Juvenile Arrests, 2007. Juvenile Justice Bulletin

    ERIC Educational Resources Information Center

    Puzzanchera, Charles

    2009-01-01

    This Bulletin summarizes 2007 juvenile crime and arrest data reported by local law enforcement agencies across the country and cited in the FBI report, "Crime in the United States 2007." The Bulletin describes the extent and nature of juvenile crime that comes to the attention of the justice system. It serves as a baseline for comparison for…

  9. Concepts Shaping Juvenile Justice

    ERIC Educational Resources Information Center

    White, Rob

    2008-01-01

    Rob White's paper explores ways in which community building can be integrated into the practices of juvenile justice work. He provides a model of what can be called "restorative social justice", one that builds upon the juvenile conferencing model by attempting to fuse social justice concerns with progressive juvenile justice practices.

  10. The Influence of Alcohol Consumption in Conjunction with Sex Hormone Deficiency on Ca/P Ratio in Rats

    PubMed Central

    Lodi, Karina Bortolin; Marchini, Adriana Mathias Pereira da Silva; Santo, Ana Maria do Espírito; Rode, Sigmar de Mello; Marchini, Leonardo; da Rocha, Rosilene Fernandes

    2016-01-01

    Deficiency of sex hormones and excessive alcohol consumption are factors that have been related to alterations in the pattern of bone mineralization and osteoporosis. The aim of this study was to evaluate possible alterations in the calcium/phosphorus (Ca/P) ratio in the femur of rats subjected to sex hormone deficiency and/or alcohol consumption. Methods. Female and male Wistar rats (n = 108) were divided into ovariectomized (Ovx), orchiectomized (Orx), or sham-operated groups and subdivided according to diet: alcoholic diet (20% alcohol solution), isocaloric diet, and ad libitum diet. The diets were administered for 8 weeks. The Ca/P ratio in the femur was analyzed by energy dispersive micro-X-ray spectrometer (μEDX). Results. Consumption of alcohol reduced the Ca/P ratio in both females and males. The isocaloric diet reduced the Ca/P ratio in females. In groups with the ad libitum diet, the deficiency of sex hormones did not change the Ca/P ratio in females or males. However, the combination of sex hormone deficiency and alcoholic diet presented the lowest values for the Ca/P ratio in both females and males. Conclusions. There was a reduced Ca/P ratio in the femur of rats that consumed alcohol, which was exacerbated when combined with a deficiency of sex hormones. PMID:27073396

  11. Influence of adrenocorticotrophin hormone challenge and external factors (age, sex, and body region) on hair cortisol concentration in Canada lynx (Lynx canadensis).

    PubMed

    Terwissen, C V; Mastromonaco, G F; Murray, D L

    2013-12-01

    Land use changes are a significant factor influencing the decline of felid populations. However, additional research is needed to better understand how these factors influence populations in the wild. Hormone analysis can provide valuable information on the basic physiology and overall health of an animal, and enzyme immunoassays (EIA) are generally used for hair hormone analysis but must first be validated for the substrate of choice and species of interest. To date, hormone assays from hair have not been validated for Felidae, despite that the method holds considerable promise for non-invasive sampling of free-ranging animals. We sought to: (1) evaluate whether increased adrenocorticotrophin hormone (ACTH) during the period of hair growth results in elevated hair cortisol; (2) validate the enzyme immunoassay used; and (3) identify any variations in hair cortisol between age, sex and body regions, using Canada lynx. We quantified hair cortisol concentrations in captive animals through an ACTH challenge and collected samples from legally harvested lynx to compare variability between body regions. An EIA was validated for the analysis of hair cortisol. Lynx (n=3) had a qualitative increase in hair cortisol concentration following an ACTH challenge in captive animals (20 IU/kg of body weight weekly for 5 weeks), thereby supporting the use of an EIA to quantify cortisol values in hair. Based on our analysis of sampled lynx pelts, we found that hair cortisol did not vary between age and sex, but varied within the foot/leg region to a greater extent than between individuals. We recommend that future studies identify a standardized location for hair cortisol sampling.

  12. Ovarian hormones influence corticotropin releasing factor receptor colocalization with delta opioid receptors in CA1 pyramidal cell dendrites

    PubMed Central

    Williams, Tanya J.; Akama, Keith T.; Knudsen, Margarete G.; McEwen, Bruce S.; Milner, Teresa A.

    2011-01-01

    receptor-ir colocalization with DOR-ir in the same neuron using the hormone responsive neuronal cell line NG108-15, which endogenously express DORs, and assayed intracellular cAMP production in response to CRF receptor and DOR agonists. Results demonstrated that short-term application of DOR agonist SNC80 inhibited CRF-induced cAMP accumulation in NG108-15 cells transfected with the CRF receptor. These studies provide new insights on opioid-stress system interaction in the hippocampus of both males and females and establish potential mechanisms through which DOR activation may influence CRF receptor activity. PMID:21549703

  13. ALTERED HISTOLOGY OF THE THYMUS AND SPLEEN IN CONTAMINANT-EXPOSED JUVENILE AMERICAN ALLIGATORS

    EPA Science Inventory

    Morphological difference in spleen and thymus are closely related to functional immune differences. Hormonal regulation of the immune system has been demonstrated in reptilian splenic and thymic tissue. Spleens and thymus were obtained from juvenile alligators at two reference si...

  14. Juveniles on trial.

    PubMed

    Quinn, Kathleen M

    2002-10-01

    This article describes common forensic evaluations requested of juvenile court mental health evaluators. There has been a legal shift toward criminalization of juvenile court, with a greater emphasis on rights, abandonment of the rehabilitative model, and greater movement of adolescents into the adult criminal court. A resulting shift has been the redefinition of juvenile court forensic evaluations toward the specificity of adult forensic work. The challenge for evaluators is to refine their knowledge of the forensic standards and bring knowledge of development, assessment, and diagnosis in juveniles and interview techniques appropriate to juveniles to improve the evaluation and forensic reports.

  15. Influence of dioxin exposure upon levels of prostate-specific antigen and steroid hormones in Vietnamese men.

    PubMed

    Sun, Xian Liang; Kido, Teruhiko; Honma, Seijiro; Okamoto, Rie; Manh, Ho Dung; Maruzeni, Shoko; Nishijo, Muneko; Nakagawa, Hideaki; Nakano, Takeshi; Koh, Eitetsu; Takasuga, Takumi; Nhu, Dang Duc; Hung, Nguyen Ngoc; Son, Le Ke

    2016-04-01

    Most studies on the relationship between Agent Orange and prostate cancer have focused on US veterans of the Vietnam War. There have been few studies focusing on the relationship between levels of prostate-specific antigen (PSA) and dioxins or steroid hormones in Vietnamese men. In 2009-2011, we collected blood samples from 97 men who had resided in a "dioxin hotspot" and 85 men from a non-sprayed region in Vietnam. Then levels of PSA, dioxins, and steroid hormones were analyzed. Levels of most dioxins, furans, and non-ortho polychlorinated biphenyls were higher in the hotspot than those in the non-sprayed region. Levels of testosterone, dehydroepiandrosterone, and estradiol differed significantly between the hotspot and the non-sprayed region, but there were no correlations between levels of PSA and steroid hormones and dioxins in either of the two regions. Our findings suggest that PSA levels in Vietnamese men are not associated with levels of dioxin or steroid hormones in these two regions. PMID:26758301

  16. Paroxetine administration failed [corrected] to influence human exercise capacity, perceived effort or hormone responses during prolonged exercise in a warm environment.

    PubMed

    Strachan, A T; Leiper, J B; Maughan, R J

    2004-11-01

    The purpose of the experiment was to examine whether selective serotonin (5-HT) re-uptake transporter blockade by paroxetine has any effect on perceived effort (RPE) during exercise or the time to reach volitional fatigue and on the prolactin and cortisol responses during prolonged exercise performed in a warm environment. Eight healthy males performed two cycle rides to exhaustion in a warm (32 degrees C) environment at 60% of maximum oxygen uptake. Paroxetine (20 mg) or placebo was administered 5 h before exercise trials in a randomised double blind fashion. Time to exhaustion was not significantly influenced by administration of paroxetine: median (range) time to exhaustion was 93.3 (76.2-175.0) min on the placebo trial and 92.5 (66.0-151.0) min on the paroxetine trial. Rectal temperature was higher at rest and throughout exercise on the paroxetine trial. The serum concentrations of prolactin and cortisol were determined throughout exercise as peripheral markers of central 5-HT activity. RPE increased over time but was not influenced by paroxetine administration. Prolactin and cortisol levels increased over time but paroxetine administration did not influence the hormone responses during exercise. In conclusion, acute administration of paroxetine failed to alter RPE, exercise capacity or the response of the determined peripheral hormone markers of central 5-HT activity during prolonged exercise in a warm environment. PMID:15328306

  17. Paroxetine administration failed [corrected] to influence human exercise capacity, perceived effort or hormone responses during prolonged exercise in a warm environment.

    PubMed

    Strachan, A T; Leiper, J B; Maughan, R J

    2004-11-01

    The purpose of the experiment was to examine whether selective serotonin (5-HT) re-uptake transporter blockade by paroxetine has any effect on perceived effort (RPE) during exercise or the time to reach volitional fatigue and on the prolactin and cortisol responses during prolonged exercise performed in a warm environment. Eight healthy males performed two cycle rides to exhaustion in a warm (32 degrees C) environment at 60% of maximum oxygen uptake. Paroxetine (20 mg) or placebo was administered 5 h before exercise trials in a randomised double blind fashion. Time to exhaustion was not significantly influenced by administration of paroxetine: median (range) time to exhaustion was 93.3 (76.2-175.0) min on the placebo trial and 92.5 (66.0-151.0) min on the paroxetine trial. Rectal temperature was higher at rest and throughout exercise on the paroxetine trial. The serum concentrations of prolactin and cortisol were determined throughout exercise as peripheral markers of central 5-HT activity. RPE increased over time but was not influenced by paroxetine administration. Prolactin and cortisol levels increased over time but paroxetine administration did not influence the hormone responses during exercise. In conclusion, acute administration of paroxetine failed to alter RPE, exercise capacity or the response of the determined peripheral hormone markers of central 5-HT activity during prolonged exercise in a warm environment.

  18. Short-Period Influence of Chronic Morphine Exposure on Serum Levels of Sexual Hormones and Spermatogenesis in Rats

    PubMed Central

    Ahmadnia, Hasan; Akhavan Rezayat, Alireza; Hoseyni, Mahmood; Sharifi, Nooriye; Khajedalooee, Mohhamad; Akhavan Rezayat, Arash

    2016-01-01

    Background Increased rates of addiction and its broad societal complications are well known. One of the most important systems that may malfunction in drug abusers is the reproductive system, and evaluating patients for this potential risk may lead to increased awareness. Materials and Methods Thirty 60-day-old male rats were divided into control and target groups. The target group underwent 5 mg/kg intraperitoneal injections of morphine twice a day while the control group underwent normal saline injections (at the same dosage). After 60 days, the rats were anesthetized, and after blood sampling, they underwent bilateral orchiepididymectomy. Histological and hormonal evaluations were performed on the samples. Results Levels of sex hormonal features and spermatogenesis were significantly reduced in the target group compared to the control group. LH levels showed a meaningful decrease in the target group, but FSH and testosterone levels did not. On histological section analysis, mature sperm were meaningfully decreased in the target group. Conclusions Chronic use of opioids may lead to alterations in sexual features and sexual hormones. Therefore, opioids have the potential to cause infertility. These changes may result from the effect of the drugs on the hypophysis or hypothalamus, the direct effect of the drugs on the seminiferous tubules, or a combination of both. The findings suggest that public awareness about addiction may cause decreased infertility rates. PMID:27713869

  19. Neural Activation During Mental Rotation in Complete Androgen Insensitivity Syndrome: The Influence of Sex Hormones and Sex Chromosomes.

    PubMed

    van Hemmen, Judy; Veltman, Dick J; Hoekzema, Elseline; Cohen-Kettenis, Peggy T; Dessens, Arianne B; Bakker, Julie

    2016-03-01

    Sex hormones, androgens in particular, are hypothesized to play a key role in the sexual differentiation of the human brain. However, possible direct effects of the sex chromosomes, that is, XX or XY, have not been well studied in humans. Individuals with complete androgen insensitivity syndrome (CAIS), who have a 46,XY karyotype but a female phenotype due to a complete androgen resistance, enable us to study the separate effects of gonadal hormones versus sex chromosomes on neural sex differences. Therefore, in the present study, we compared 46,XY men (n = 30) and 46,XX women (n = 29) to 46,XY individuals with CAIS (n = 21) on a mental rotation task using functional magnetic resonance imaging. Previously reported sex differences in neural activation during mental rotation were replicated in the control groups, with control men showing more activation in the inferior parietal lobe than control women. Individuals with CAIS showed a female-like neural activation pattern in the parietal lobe, indicating feminization of the brain in CAIS. Furthermore, this first neuroimaging study in individuals with CAIS provides evidence that sex differences in regional brain function during mental rotation are most likely not directly driven by genetic sex, but rather reflect gonadal hormone exposure.

  20. Influence of substituting dietary soybean for air-classified sunflower (Helianthus annuus L.) meal on egg production and steroid hormones in early-phase laying hens.

    PubMed

    Laudadio, V; Ceci, E; Nahashon, S N; Introna, M; Lastella, N M B; Tufarelli, V

    2014-02-01

    Soybean meal (SBM) is the most widely and expensive protein source used in the formulation of poultry diets; however, when the price of SBM increases, poultry nutritionists seek alternative sources that are more economical in formulating least-cost rations. This research aimed to evaluate the effects of dietary air-classified sunflower meal (SFM) on some productive parameters and plasma steroid hormones in laying hens. In this trial, 20-week-old laying hens (ISA Brown strain) in the early phase of production were randomly assigned to two groups and fed wheat middlings-based diets containing soybean (135 g/kg; 48% CP) or air-classified SFM (160 g/kg; 41% CP) as the main protein source. Laying performance, egg size and feed conversion ratio were evaluated for 10 week. Plasma steroid hormones (progesterone and oestradiol) in the hens were quantified weekly. Substituting SBM with air-classified SFM did not change (p > 0.05) the hens' growth performance, whereas feed consumption and efficiency were positively influenced (p < 0.05) by SFM treatment. Egg production rate was improved in hens fed the SFM diet (p < 0.05), as well as the percentage of medium-size eggs that was higher for SFM treatment (p < 0.05). Steroid hormones levels were affected by dietary treatment (p < 0.01). From our findings, it could be effective to include air-classified SFM in early-phase laying hen diets as an alternative protein source substituting SBM, without negative influence on productive performance and egg traits, reducing also the production costs.

  1. Acne: hormonal concepts and therapy.

    PubMed

    Thiboutot, Diane

    2004-01-01

    Acne vulgaris is the most common skin condition observed in the medical community. Although we know that hormones are important in the development of acne, many questions remain unanswered regarding the mechanisms by which hormones exert their effects. Androgens such as dihydrotestosterone (DHT) and testosterone, the adrenal precursor dehydroepiandrosterone sulfate (DHEAS), estrogens such as estradiol, and other hormones, including growth hormone and insulin-like growth factors (IGFs), may be important in acne. It is not known whether these hormones are taken up from the serum by the sebaceous gland, whether they are produced locally within the gland, or whether a combination of these processes is involved. Finally, the cellular and molecular mechanisms by which these hormones exert their influence on the sebaceous gland have not been fully elucidated. Hormonal therapy is an option in women with acne not responding to conventional treatment or with signs of endocrine abnormalities. PMID:15556729

  2. Movements of juvenile common ravens in an arid landscape

    USGS Publications Warehouse

    Webb, W.C.; Boarman, W.I.; Rotenberry, J.T.

    2009-01-01

    Movement patterns of juvenile birds are poorly understood, yet critically important ecological phenomena, especially for species with a prolonged juvenile period. We evaluated postfledging movements of juvenile common ravens (Corvus corax) in a western Mojave Desert landscape composed of a mosaic of natural and anthropogenic elements. Generally, ravens do not begin breeding until after their fourth year. We marked 2 annual cohorts of juvenile ravens and followed them from dispersal from their natal territory for up to 33 months. Movements of juvenile common ravens were similar for males and females. Conspecifics and confined livestock feeding operations represented important resources for juvenile ravens, and juveniles were rarely located in open desert. However, initial movements from the natal territory to the nearest communal point subsidy rather than the closest anthropogenic resource suggested juvenile dispersal was influenced by the combination of conspecifics and anthropogenic resources, rather than the distribution of those resources. Land managers concerned with growing raven populations should reduce access to concentrated anthropogenic resources such as landfills and dairies, which serve as important resources for juveniles. Because juvenile ravens rarely venture into open desert, reducing their numbers by lethal removal or other means is unlikely to lessen raven predation of desert tortoises (Gopherus agassizii).

  3. Influence of Benthic Macrofauna as a Spatial Structuring Agent for Juvenile Haddock (Melanogrammus aeglefinus) on the Eastern Scotian Shelf, Atlantic Canada

    PubMed Central

    2016-01-01

    We examined the habitat of juvenile haddock on the eastern Scotian Shelf (off Nova Scotia, Canada) in relation to grab-sampled benthic macrofaunal invertebrate species assemblages in order to determine whether there were significant differences in benthic macrofauna between areas of historically persistent high and low juvenile haddock abundance. Our analyses were conducted over two spatial scales in each of two years: among banks (Emerald, Western and Sable Island), approximately 60 km distant from each other, and between areas of high and low juvenile haddock abundance at distances of 10 to 30 km–all in an area that had not experienced groundfishing in the decade prior to sampling. We also examined fine-scale (10s of metres) within-site variability in the macrofauna and used surficial sediment characteristics, along with hydrographic variables, to identify environmental correlates. PERMANOVA identified statistically significant differences in biomass, density and composition of the benthos associated with juvenile haddock abundance; however it was difficult to determine whether the results had biological relevance. Post hoc tests showed that these differences occurred only on Sable Island Bank where both fish and benthos may have been independently responding to sediment type which was most different there (100% sand in the area of low haddock abundance vs. 22% gravel in the area of high haddock abundance). In total, 383 benthic taxa representing 13 phyla were identified. Annelida was the most specious phylum (36.29% of taxa, representing 33 families), followed by Arthropoda (with Crustaceans, mostly Amphipoda, accounting for 25.07% of the total number of taxa). The strongest pattern in the macrofauna was expressed at the largest scale, between banks, accounting for approximately 25% of the variation in the data. Emerald Bank, deeper, warmer and saltier than the Western and Sable Island Banks, had a distinctive fauna. PMID:27649419

  4. Influence of Benthic Macrofauna as a Spatial Structuring Agent for Juvenile Haddock (Melanogrammus aeglefinus) on the Eastern Scotian Shelf, Atlantic Canada.

    PubMed

    Rincón, Beatriz; Kenchington, Ellen L

    2016-01-01

    We examined the habitat of juvenile haddock on the eastern Scotian Shelf (off Nova Scotia, Canada) in relation to grab-sampled benthic macrofaunal invertebrate species assemblages in order to determine whether there were significant differences in benthic macrofauna between areas of historically persistent high and low juvenile haddock abundance. Our analyses were conducted over two spatial scales in each of two years: among banks (Emerald, Western and Sable Island), approximately 60 km distant from each other, and between areas of high and low juvenile haddock abundance at distances of 10 to 30 km-all in an area that had not experienced groundfishing in the decade prior to sampling. We also examined fine-scale (10s of metres) within-site variability in the macrofauna and used surficial sediment characteristics, along with hydrographic variables, to identify environmental correlates. PERMANOVA identified statistically significant differences in biomass, density and composition of the benthos associated with juvenile haddock abundance; however it was difficult to determine whether the results had biological relevance. Post hoc tests showed that these differences occurred only on Sable Island Bank where both fish and benthos may have been independently responding to sediment type which was most different there (100% sand in the area of low haddock abundance vs. 22% gravel in the area of high haddock abundance). In total, 383 benthic taxa representing 13 phyla were identified. Annelida was the most specious phylum (36.29% of taxa, representing 33 families), followed by Arthropoda (with Crustaceans, mostly Amphipoda, accounting for 25.07% of the total number of taxa). The strongest pattern in the macrofauna was expressed at the largest scale, between banks, accounting for approximately 25% of the variation in the data. Emerald Bank, deeper, warmer and saltier than the Western and Sable Island Banks, had a distinctive fauna. PMID:27649419

  5. Influence of freshwater discharges and tides on the abundance and distribution of larval and juvenile Munida gregaria in the Baker river estuary, Chilean Patagonia

    NASA Astrophysics Data System (ADS)

    Meerhoff, Erika; Castro, Leonardo; Tapia, Fabián

    2013-07-01

    Zooplankton time series collected with different temporal resolution and coverage were examined to characterize seasonal and diel patterns in the abundance of Munida gregaria larvae and juveniles in the Baker river estuary. Zoeae were more abundant in late winter and spring, coinciding with the season of lower sediment transport and higher primary production in the region. The occurrence of juveniles was exclusively in summer. There was a significant correlation between the abundance of zoeae and high-frequency temperature variability near the pycnocline over periods of 7-20 and 26-30 days prior to each plankton sampling. These time scales of correlation suggest that internal motions may be a proximal environmental cue for lunar rhythms in larval hatching, rather than directly causing the aggregation of larvae at the sampling area. To characterize shorter-term patterns in larval abundance and vertical distribution, stratified samples were collected every 3 h over a full late-spring day (November 2008) near one of the monitoring stations. Zoeae were significantly more abundant at 10-25 m depth (p=0.039), and changes in depth-integrated abundance of both zoea and megalopae were strongly associated with the tidal cycle. Together, these results suggest that the spatial structure and population dynamics of M. gregaria in this region may respond to the combined forcing of seasonal changes in freshwater inputs, tidally-driven processes such as lateral transport of larvae and juveniles, and internal-wave mediated changes in local conditions.

  6. Influence of Spinal and General Anesthesia on the Metabolic, Hormonal, and Hemodynamic Response in Elective Surgical Patients

    PubMed Central

    Milosavljevic, Snezana B.; Pavlovic, Aleksandar P.; Trpkovic, Sladjana V.; Ilić, Aleksandra N.; Sekulic, Ana D.

    2014-01-01

    Background The aim of the study was to determine the significance of spinal anesthesia in the suppression of the metabolic, hormonal, and hemodynamic response to surgical stress in elective surgical patients compared to general anesthesia. Material/Methods The study was clinical, prospective, and controlled and it involved 2 groups of patients (the spinal and the general anesthesia group) who underwent the same surgery. We monitored the metabolic and hormonal response to perioperative stress based on serum cortisol level and glycemia. We also examined how the different techniques of anesthesia affect these hemodynamic parameters: systolic arterial pressure (AP), diastolic AP, heart rate (HR), and arterial oxygen saturation (SpO2). These parameters were measured before induction on anesthesia (T1), 30 min after the surgical incisions (T2), 1 h postoperatively (T3) and 24 h after surgery (T4). Results Serum cortisol levels were significantly higher in the general anesthesia group compared to the spinal anesthesia group (p<0.01). Glycemia was significantly higher in the general anesthesia group (p<0.05). There was a statistically significant, positive correlation between serum cortisol levels and glycemia at all times observed (p<0.01). Systolic and diastolic AP did not differ significantly between the groups (p=0.191, p=0.101). The HR was significantly higher in the general anesthesia group (p<0.01). SpO2 values did not differ significantly between the groups (p=0.081). Conclusions Based on metabolic, hormonal, and hemodynamic responses, spinal anesthesia proved more effective than general anesthesia in suppressing stress response in elective surgical patients. PMID:25284266

  7. Influence of music on steroid hormones and the relationship between receptor polymorphisms and musical ability: a pilot study

    PubMed Central

    Fukui, Hajime; Toyoshima, Kumiko

    2013-01-01

    Studies have shown that music confers plasticity to the brain. In a preliminary pilot study, we examined the effect of music listening on steroid hormones and the relationship between steroid hormone receptor polymorphisms and musical ability. Twenty-one subjects (10 males and 11 females) were recruited and divided into musically talented and control groups. The subjects selected (1) music they preferred (chill-inducing music) and (2) music they did not like. Before and after the experiments, saliva was collected to measure the levels of steroid hormones such as testosterone, estradiol, and cortisol. DNA was also isolated from the saliva samples to determine the androgen receptor (AR) and arginine vasopressin receptor 1A genotypes. Advanced Measures of Music Audiation (AMMA) was used to determine the musical ability of the subjects. With both types of music, the cortisol levels decreased significantly in both sexes. The testosterone (T) levels declined in males when they listened to both types of music. In females, the T levels increased in those listening to chill-inducing music but declined when they listened to music they disliked. However, these differences were not significant. The 17-beta estradiol levels increased in males with both types of music, whereas the levels increased with chill-inducing music but declined with disliked music in females. The AMMA scores were higher for the short repeat length-type AR than for the long repeat length-type. Comparisons of AR polymorphisms and T levels before the experiments showed that the T levels were within the low range in the short repeat length-type group and there was a positive relationship with the repeat length, although it was not significant. This is the first study conducted in humans to analyze the relationships between the AR gene, T levels, and musical ability. PMID:24348454

  8. Juvenile Confinement in Context

    ERIC Educational Resources Information Center

    Mendel, Richard A.

    2012-01-01

    For more than a century, the predominant strategy for the treatment and punishment of serious and sometimes not-so-serious juvenile offenders in the United States has been placement into large juvenile corrections institutions, alternatively known as training schools, reformatories, or youth corrections centers. America's heavy reliance on…

  9. Juvenile nasopharyngeal angiofibroma.

    PubMed

    Karthikeya, Patil; Mahima, V G; Bagewadi, Shivanand B

    2005-01-01

    Juvenile nasopharyngeal angiofibroma is a rare, histologically benign yet locally aggressive, vascular tumor that typically affects adolescent males. It accounts for 0.5 percent of all neoplasms of the head and neck. A case of juvenile nasopharyngeal angiofibroma manifesting in the oral cavity in a 20-year-old male patient is presented and discussed.

  10. Renewing Juvenile Justice

    ERIC Educational Resources Information Center

    Macallair, Daniel; Males, Mike; Enty, Dinky Manek; Vinakor, Natasha

    2011-01-01

    The Center on Juvenile and Criminal Justice (CJCJ) was commissioned by Sierra Health Foundation to critically examine California's juvenile justice system and consider the potential role of foundations in promoting systemic reform. The information gathered by CJCJ researchers for this report suggests that foundations can perform a key leadership…

  11. The influence of natural short photoperiodic and temperature conditions on plasma thyroid hormones and cholesterol in male Syrian hamsters

    NASA Astrophysics Data System (ADS)

    Vaughan, M. K.; Brainard, G. C.; Reiter, R. J.

    1984-09-01

    Adult male Syrian hamsters were subjected to 1, 3, 5, 7 or 11 weeks of either natural winter conditions or rigorously controlled laboratory conditions (LD 10∶14; 22 ± 2‡C). Although both groups of hamsters gained weight over the course of the experiment, hamsters housed indoors were significantly heavier after 5 weeks of treatment compared to their outdoors counterparts. Animals housed under natural conditions exhibited a significant decrease in circulating levels of thyroxine (T4) and a rapid rise in triiodothyronine (T3) levels; the free T4 and free T3 index (FT4I and FT3I) mirrored the changes in circulating levels of the respective hormones. Laboratory-housed animals had a slight rise in T4 and FT4I at 3 weeks followed by a slow steady decline in these values; T3 and FT3I values did not change remarkably in these animals. Plasma cholesterol declined steadily over the course of the experiment in laboratory-maintained animals but increased slightly during the first 5 weeks in animals under natural conditions. Since the photoperiodic conditions were approximately of the same duration in these 2 groups, it is concluded that the major differences in body weight, thyroid hormone values and plasma cholesterol are due to some component (possibly temperature) in the natural environment.

  12. Influence of head-down bed rest on the circadian rhythms of hormones and electrolytes involved in hydroelectrolytic regulation

    NASA Technical Reports Server (NTRS)

    Millet, C.; Custaud, M. A.; Allevard, A. M.; Zaouali-Ajina, M.; Monk, T. H.; Arnaud, S. B.; Claustrat, B.; Gharib, C.; Gauquelin-Koch, G.

    2001-01-01

    We investigated in six men the impact of a 17-day head-down bed rest (HDBR) on the circadian rhythms of the hormones and electrolytes involved in hydroelectrolytic regulation. This HDBR study was designed to mimic an actual spaceflight. Urine samples were collected at each voiding before, during and after HDBR. Urinary excretion of aldosterone, arginine vasopressin (AVP), cyclic guanosine monophosphate (cGMP), cortisol, electrolytes (Na+ and K+) and creatinine were determined. HDBR resulted in a significant reduction of body mass (P < 0.01) and of caloric intake [mean (SEM) 2,778 (37) kcal.24 h(-1) to 2,450 (36) kcal.24 h(-1), where 1 kcal.h(-1) = 1.163 J.s(-1); P< 0.01]. There was a significant increase in diastolic blood pressure [71.8 (0.7) mmHg vs 75.6 (0.91) mmHg], with no significant changes in either systolic blood pressure or heart rate. The nocturnal hormonal decrease of aldosterone was clearly evident only before and after HDBR, but the day/night difference did not appear during HDBR. The rhythm of K+ excretion was unchanged during HDBR, whereas for Na+ excretion, a large decrease was shown during the night as compared to the day. The circadian rhythm of cortisol persisted. These data suggest that exposure to a 17-day HDBR could induce an exaggeration of the amplitude of the Na+ rhythm and abolition of the aldosterone rhythm.

  13. Influence of head-down bed rest on the circadian rhythms of hormones and electrolytes involved in hydroelectrolytic regulation.

    PubMed

    Millet, C; Custaud, M A; Allevard, A M; Zaouali-Ajina, M; Monk, T H; Arnaud, S B; Claustrat, B; Gharib, C; Gauquelin-Koch, G

    2001-07-01

    We investigated in six men the impact of a 17-day head-down bed rest (HDBR) on the circadian rhythms of the hormones and electrolytes involved in hydroelectrolytic regulation. This HDBR study was designed to mimic an actual spaceflight. Urine samples were collected at each voiding before, during and after HDBR. Urinary excretion of aldosterone, arginine vasopressin (AVP), cyclic guanosine monophosphate (cGMP), cortisol, electrolytes (Na+ and K+) and creatinine were determined. HDBR resulted in a significant reduction of body mass (P < 0.01) and of caloric intake [mean (SEM) 2,778 (37) kcal.24 h(-1) to 2,450 (36) kcal.24 h(-1), where 1 kcal.h(-1) = 1.163 J.s(-1); P< 0.01]. There was a significant increase in diastolic blood pressure [71.8 (0.7) mmHg vs 75.6 (0.91) mmHg], with no significant changes in either systolic blood pressure or heart rate. The nocturnal hormonal decrease of aldosterone was clearly evident only before and after HDBR, but the day/night difference did not appear during HDBR. The rhythm of K+ excretion was unchanged during HDBR, whereas for Na+ excretion, a large decrease was shown during the night as compared to the day. The circadian rhythm of cortisol persisted. These data suggest that exposure to a 17-day HDBR could induce an exaggeration of the amplitude of the Na+ rhythm and abolition of the aldosterone rhythm.

  14. Ovariectomy during the luteal phase influences secretion of prolactin, growth hormone, and insulin-like growth factor-I in the bitch.

    PubMed

    Lee, W M; Kooistra, H S; Mol, J A; Dieleman, S J; Schaefers-Okkens, A C

    2006-07-15

    A decline in circulating progesterone concentration plays an important role in the ethiopathogenesis of pseudopregnancy in the bitch. Because growth hormone (GH) and prolactin (PRL) are essential for normal mammogenesis and the secretion of these hormones is influenced by changes in the circulating progesterone concentration, the purpose of this study was to investigate the effects of mid-luteal phase ovariectomy on the 6-h pulsatile plasma profiles of GH and PRL and the basal plasma concentrations of GH, PRL, and insulin-like growth factor-I (IGF-I) in six beagle bitches. Ovariectomy was followed by only mild or covert signs of pseudopregnancy. The sharp decrease of the plasma progesterone concentration was accompanied by decreased basal plasma concentrations of GH and IGF-I and a rise in basal plasma PRL concentration. GH and PRL were secreted in a pulsatile fashion both prior to and after ovariectomy. The mean basal plasma GH concentration was significantly higher before ovariectomy than on days 1 and 7 after ovariectomy. The mean area under the curve above the zero level (AUC(0)) for GH was significantly higher before than at 7 days after ovariectomy. The mean area under the curve above basal level (AUC(b)) and the frequency of GH pulses at 7 days after ovariectomy were significantly higher than before and 1 day after ovariectomy. Both the mean basal plasma PRL concentration and the mean AUC(0) for PRL increased after ovariectomy. In conclusion, ovariectomy of bitches in the mid-luteal phase stops progesterone-induced GH release from the mammary gland, as evidenced by the lowering of basal plasma GH levels, the recurrence of GH pulsatility, and the lowering of circulating IGF-I levels. The sudden lowering of plasma progesterone concentration is probably a primary cause of a prolonged increase in PRL secretion. These observations underscore the importance of similar, albeit less abrupt, hormonal changes in the cyclical physiological alterations in the mammary

  15. Relationships between concentrations of selected organohalogen contaminants and thyroid hormones and vitamins A, E and D in Faroese pilot whales.

    PubMed

    Hoydal, Katrin S; Ciesielski, Tomasz M; Borrell, Asunción; Wasik, Andrzej; Letcher, Robert J; Dam, Maria; Jenssen, Bjørn M

    2016-07-01

    Pilot whales (Globicephala melas) from the Faroe Islands, North-East Atlantic, have high body concentrations of organohalogenated compounds (OHCs), such as polychlorinated biphenyls (PCBs), organochlorinated pesticides (OCPs) and brominated flame retardants (BFRs). The aim of the present study was to examine if and to what extent blood plasma and liver concentrations of several groups of these OHCs are related to concentrations of relevant nutritional and hormonal biomarkers in pilot whales. Thyroid hormones (THs: total and free thyroxine and total and free triiodothyronine) and vitamin A (retinol), D (25-hydroxyvitamin D3) and E (α-tocopherol) were analysed in plasma (n=27) and vitamin A (total vitamin A, retinol and retinyl palmitate) and E (α- and γ-tocopherol) were analysed in liver (n=37) of Faroe Island pilot whales. Correlative relationships between the biomarkers and OHC concentrations previously analysed in the same tissues in these individuals were studied. The TH concentrations in plasma were significantly higher in juveniles than in adults. Vitamin D concentrations in plasma and α- and γ-tocopherol in liver were higher in adults than in juveniles. Multivariate statistical modelling showed that the age and sex influenced the relationship between biomarkers and OHCs. Some significant positive relationships were found between OHCs and thyroid hormone concentrations in the youngest juveniles (p<0.05). In plasma of juvenile whales α-tocopherol was also positively correlated with all the OHCs (p<0.05). Only few significant correlations were found between single OHCs and retinol and vitamin D in plasma within the age groups. There were significant negative relationships between hepatic PBDE concentrations and retinol (BDE-47) and γ-tocopherol (BDE-49, -47, -100, -99, -153) in liver. The relationships between OHCs and THs or vitamins suggest that in pilot whales OHCs seem to have minor effects on TH and vitamin concentrations.

  16. Relationships between concentrations of selected organohalogen contaminants and thyroid hormones and vitamins A, E and D in Faroese pilot whales.

    PubMed

    Hoydal, Katrin S; Ciesielski, Tomasz M; Borrell, Asunción; Wasik, Andrzej; Letcher, Robert J; Dam, Maria; Jenssen, Bjørn M

    2016-07-01

    Pilot whales (Globicephala melas) from the Faroe Islands, North-East Atlantic, have high body concentrations of organohalogenated compounds (OHCs), such as polychlorinated biphenyls (PCBs), organochlorinated pesticides (OCPs) and brominated flame retardants (BFRs). The aim of the present study was to examine if and to what extent blood plasma and liver concentrations of several groups of these OHCs are related to concentrations of relevant nutritional and hormonal biomarkers in pilot whales. Thyroid hormones (THs: total and free thyroxine and total and free triiodothyronine) and vitamin A (retinol), D (25-hydroxyvitamin D3) and E (α-tocopherol) were analysed in plasma (n=27) and vitamin A (total vitamin A, retinol and retinyl palmitate) and E (α- and γ-tocopherol) were analysed in liver (n=37) of Faroe Island pilot whales. Correlative relationships between the biomarkers and OHC concentrations previously analysed in the same tissues in these individuals were studied. The TH concentrations in plasma were significantly higher in juveniles than in adults. Vitamin D concentrations in plasma and α- and γ-tocopherol in liver were higher in adults than in juveniles. Multivariate statistical modelling showed that the age and sex influenced the relationship between biomarkers and OHCs. Some significant positive relationships were found between OHCs and thyroid hormone concentrations in the youngest juveniles (p<0.05). In plasma of juvenile whales α-tocopherol was also positively correlated with all the OHCs (p<0.05). Only few significant correlations were found between single OHCs and retinol and vitamin D in plasma within the age groups. There were significant negative relationships between hepatic PBDE concentrations and retinol (BDE-47) and γ-tocopherol (BDE-49, -47, -100, -99, -153) in liver. The relationships between OHCs and THs or vitamins suggest that in pilot whales OHCs seem to have minor effects on TH and vitamin concentrations. PMID:27131793

  17. Influence of Occupational and Environmental Exposure to Low Concentrations of Polychlorobiphenyls and a Smoking Habit on the Urinary Excretion of Corticosteroid Hormones.

    PubMed

    D'Errico, Maria Nicolà; Lovreglio, Piero; Drago, Ignazio; Apostoli, Pietro; Soleo, Leonardo

    2016-04-01

    The effects of occupational exposure to low concentrations of polychlorobiphenyls (PCBs) on the urinary excretion of corticosteroid hormones were evaluated, taking into account the influence of cigarette smoking. The study included 26 males working as electrical maintenance staff in a steel factory, previously exposed to a mixture of PCBs (exposed workers), and 30 male workers with no occupational exposure to PCBs (controls). Serum PCBs (33 congeners), urinary 17-hydroxycorticosteroids, 17-ketosteroids (KS) and pregnanes, and their respective glucuronidated and sulfonated compounds, were determined for each subject. PCBs were significantly higher in the exposed workers than controls, and were correlated with age. Both the urinary concentrations of the total 17-KS and pregnanes, and those of some single steroids and their glucuronidated compounds, were significantly lower in the exposed workers than controls, but higher in smokers than the non-smokers + ex-smokers. Two-way analysis of variance showed a negative association between serum PCBs and both total glucuronidated 17-KS and total and glucuronidated pregnanes, and a positive association between cigarette smoking and both total and glucuronidated 17-KS. PCBs seem to act as endocrine disruptors by reducing the urinary excretion of corticosteroid hormones, particularly of the glucuronidated fraction. Cigarette smoking could boost these effects of PCBs in smokers. PMID:27023579

  18. Influence of Occupational and Environmental Exposure to Low Concentrations of Polychlorobiphenyls and a Smoking Habit on the Urinary Excretion of Corticosteroid Hormones

    PubMed Central

    D’Errico, Maria Nicolà; Lovreglio, Piero; Drago, Ignazio; Apostoli, Pietro; Soleo, Leonardo

    2016-01-01

    The effects of occupational exposure to low concentrations of polychlorobiphenyls (PCBs) on the urinary excretion of corticosteroid hormones were evaluated, taking into account the influence of cigarette smoking. The study included 26 males working as electrical maintenance staff in a steel factory, previously exposed to a mixture of PCBs (exposed workers), and 30 male workers with no occupational exposure to PCBs (controls). Serum PCBs (33 congeners), urinary 17-hydroxycorticosteroids, 17-ketosteroids (KS) and pregnanes, and their respective glucuronidated and sulfonated compounds, were determined for each subject. PCBs were significantly higher in the exposed workers than controls, and were correlated with age. Both the urinary concentrations of the total 17-KS and pregnanes, and those of some single steroids and their glucuronidated compounds, were significantly lower in the exposed workers than controls, but higher in smokers than the non-smokers + ex-smokers. Two-way analysis of variance showed a negative association between serum PCBs and both total glucuronidated 17-KS and total and glucuronidated pregnanes, and a positive association between cigarette smoking and both total and glucuronidated 17-KS. PCBs seem to act as endocrine disruptors by reducing the urinary excretion of corticosteroid hormones, particularly of the glucuronidated fraction. Cigarette smoking could boost these effects of PCBs in smokers. PMID:27023579

  19. Novel estradiol derivatives labeled with Ru, W, and Co complexes. Influence on hormone-receptor affinity of several organometallic groups at the 17 alpha position.

    PubMed

    Top, Siden; el Hafa, Hassane; Vessiéres, Anne; Huché, Michel; Vaissermann, Jacqueline; Jaouen, Gérard

    2002-11-15

    In order to elucidate the extent to which recognition of the estrogen receptor is influenced by addition of an organometallic substituent at the 17 alpha position, modification of 17 beta-estradiol at this position was carried out by using the organometallic groups -C identical to C(eta 5-C5H4)RuCp, CH2-(eta 5-C5H4)RuCp, -C identical to C-(eta 5-C5H4)-W(CO)3(Me), -(C identical to CCHO)Co2(CO)6, and -(C identical to CCH2OH)Co2(CO)6. The relative binding affinity (RBA) values for estradiol receptor alpha showed that recognition was good (RBA between 20 and 13.5%) when the organometallic moiety was attached at the end of a rigid alkyne spacer. However, the affinity of the modified hormone for the receptor was severely reduced (RBA = 1%) for a substituent such as -CH2-(eta 5-C5H4)RuCP, in which the spacer is reduced to a single flexible sp3 carbon atom, allowing the organometallic moiety greater freedom of movement around the attachment point. The RBA values found were in agreement with results obtained from a molecular-modeling study in which 5, an organometallic hormone with a rigid spacer, or 7, a molecule with a flexible spacer, was inserted into the cavity of the recently characterized Ligand-Binding Domain of estrogen receptor alpha.

  20. Free and polymerized tubulin in cultured bone cells and Chinese hamster ovary cells: the influence of cold and hormones

    PubMed Central

    Beertsen, W; Heersche, JNM; Aubin, JE

    1982-01-01

    Free and polymerized tubulin were measured in bone cells and Chinese hamster ovary (CHO) cells cultured on plastic substrata. Polymerized tubulin was stabilized in a microtubule- stabilizing medium (MSM) containing 50 percent glycerol and separated from free tubulin by centrifugation. Tubulin content was assayed in both fractions by the colchicines- binding assay. The measured degree of polymerization in both bone cells and CHO cells varied with stabilixation conditions. The degree of polymerization in both bone cells and CHO cells varied with stabilization conditions. The degree of polymerization in both bone cells and CHO cells varied with stabilization conditions. The degree of polymerization in attached cells was found to increase up to 73 percent during the first 20 min after addition of the MSM at 24 degrees C, and remained constant thereafter. Stabilization of 0 degrees C resulted in a decrease down to 62 percent in the degree of constant thereafter. Stabilization at 0 degrees C resulted in a decrease down to 62 percent in the degree of polymerization during the first 20 min after addition of the MSM at 24 degrees C, and remained constant thereafter. Confluent bone cells maintained at 0 degrees C for 1 h before stabilization contained significantly less polymerized tubulin than control cells kept at 37 degrees C using stabilization both at 0 degrees C and at 24 degrees C. Changes in bone cell morphology induced by incubation of cells with prostaglandin E(1) or E(2), parthyroid hormone, and dibutyryl cyclic AMP were not associated with a change in the degree of tubulin polymerization. This was confirmed morphologically by immunofluorescence using affinity-purified tubulin antibodies: microtubules in hormone- treated cells were not noticeably reorganized when compared to microtubule organization in control cells. They were, however, squeezed closer together in cellular pseudopods due to the altered cell shape. This altered cell shape appears to be correlated

  1. Diurnal pattern of pulsatile luteinizing hormone and testosterone secretion in adult male rhesus monkeys (Macaca mulatta): influence of the timing of daily meal intake.

    PubMed

    Mattern, L G; Helmreich, D L; Cameron, J L

    1993-03-01

    Adult male rhesus monkeys have a diurnal pattern of reproductive hormone secretion that is characterized by significantly elevated LH and testosterone secretion in the evening hours and a nadir in secretion of these hormones in the morning. To test the hypothesis that the daily pattern of food intake may play a role in regulating the diurnal pattern of reproductive hormone secretion we performed three studies. First, to determine the relationship between the timing of the diurnal rise in LH secretion and meal consumption, blood samples were collected from 13 adult male rhesus monkeys via chronically indwelling venous catheters (samples every 15-20 min from 0800-0800 h) while monkeys were maintained on the standard feeding regimen in our colony (one meal of Purina monkey chow fed between 1100 and 1200 h). On a day of normal feeding there was a significant diurnal rhythm in mean LH concentrations with elevated levels at night (nadir: 13.41 +/- 0.82 ng/ml from 0800-1100 h; peak: 21.34 +/- 1.56 ng/ml from 2000-2300 h, P < or = 0.05). The rising phase of the diurnal rhythm in LH secretion was apparent starting in the early afternoon, shortly after the daily meal, at 1400 h (5 h before lights went off at 1900 h), and the diurnal rise in LH secretion was no longer apparent by 0500 h (several hours before the lights went on at 0700 h). Second, we examined the influence of missing the daily meal on the diurnal pattern of LH and testosterone secretion. Blood samples were collected for a 24-h period on a day of fasting from 9 monkeys. On a day of fasting there was no diurnal rise in plasma LH or testosterone concentrations; plasma concentrations of these hormones remained at the low morning levels throughout the day. Third, we examined the diurnal pattern of LH and testosterone secretion after adapting 5 monkeys (for 6-8 weeks) to a new meal time that was 6 h later in the day than the standard meal time (i.e. at 1700 h). After adaptation to this later feeding time monkeys

  2. Influence of the nature of calcium salts on serum calcium, phosphorus, calcitonin, growth hormone, and somatomedin C.

    PubMed

    Reginster, J Y; Denis, D; Albert, A; Gaspar, S; Heynen, G; Deroisy, R; Franchimont, P

    1988-01-01

    Twenty healthy males were randomly divided into three groups. Each subject received either 405 mg elemental calcium (Ca) as a salt linked to an amino acid precursor, 405 mg CaC12 or 1000 mg Ca as Ca gluconolactate and carbonate. In all three cases, Ca intake led to an increase of serum Ca and TCT production and a decrease of PTH liberation. However, when Ca is linked to the amino acid precursor, an elective stimulation of growth hormone (GH) and somatomedin C (SmC) occurs. Due to the nature of its amino acid precursor, this salt seems to stimulate GH and SmC liberation through hypophysis. This could be a major pathway in decoupling of the sequence resorption-formation and therapy of metabolic bone diseases. PMID:3375576

  3. Estuarine Habitats for Juvenile Salmon in the Tidally-Influenced Lower Columbia River and Estuary : Reporting Period September 15, 2008 through May 31, 2009.

    SciTech Connect

    Baptista, António M.

    2009-08-02

    This work focuses on the numerical modeling of Columbia River estuarine circulation and associated modeling-supported analyses conducted as an integral part of a multi-disciplinary and multi-institutional effort led by NOAA's Northwest Fisheries Science Center. The overall effort is aimed at: (1) retrospective analyses to reconstruct historic bathymetric features and assess effects of climate and river flow on the extent and distribution of shallow water, wetland and tidal-floodplain habitats; (2) computer simulations using a 3-dimensional numerical model to evaluate the sensitivity of salmon rearing opportunities to various historical modifications affecting the estuary (including channel changes, flow regulation, and diking of tidal wetlands and floodplains); (3) observational studies of present and historic food web sources supporting selected life histories of juvenile salmon as determined by stable isotope, microchemistry, and parasitology techniques; and (4) experimental studies in Grays River in collaboration with Columbia River Estuary Study Taskforce (CREST) and the Columbia Land Trust (CLT) to assess effects of multiple tidal wetland restoration projects on various life histories of juvenile salmon and to compare responses to observed habitat-use patterns in the mainstem estuary. From the above observations, experiments, and additional modeling simulations, the effort will also (5) examine effects of alternative flow-management and habitat-restoration scenarios on habitat opportunity and the estuary's productive capacity for juvenile salmon. The underlying modeling system is part of the SATURN1coastal-margin observatory [1]. SATURN relies on 3D numerical models [2, 3] to systematically simulate and understand baroclinic circulation in the Columbia River estuary-plume-shelf system [4-7] (Fig. 1). Multi-year simulation databases of circulation are produced as an integral part of SATURN, and have multiple applications in understanding estuary

  4. Proline with or without hydroxyproline influences collagen concentration and regulates prolyl 4-hydroxylase α (I) gene expression in juvenile turbo ( Scophthalmus maximus L.)

    NASA Astrophysics Data System (ADS)

    Zhang, Kaikai; Mai, Kangsen; Xu, Wei; Zhou, Huihui; Liufu, Zhiguo; Zhang, Yanjiao; Peng, Mo; Ai, Qinghui

    2015-06-01

    This study was conducted to investigate the effect of dietary proline (Pro), and Pro and hydroxyproline (Hyp) in combination on the growth performance, total Hyp and collagen concentrations of tissues, and prolyl 4-hydroxylase α(I) (P4H α(I)) gene expression in juvenile turbot feeding high plant protein diets. A diet containing 50% crude protein and 12% crude lipid was formulated as the basal and control, on which other two protein and lipid contents identical experimental diets were formulated by supplementing the basal with either 0.75% Pro (Pro-0.75) or 0.75% Pro and 0.75% Hyp (Pro+Hyp). Four groups of fish in indoor seawater recirculating systems, 35 individuals each, were fed twice a day to apparent satiation for 10 weeks. The results showed that dietary Pro and Hyp supplementation had no significant effect on growth performance and feed utilization of juvenile turbot (P > 0.05). Total Hyp and collagen concentrations in muscle were significantly increased when dietary Pro and Hyp increased (P <0.05), and fish fed diet Pro+Hyp showed significantly higher free Hyp content in plasma than those fed other diets (P <0.05). The expression of P4H a(I) gene in liver and muscle was significantly up regulated in fish fed diet Pro-0.75 in comparison with control (P <0.05); however the gene was significantly down regulated in fish fed diet Pro+Hyp in muscle in comparison with fish fed diet Pro-0.75 (P <0.05). It can be concluded that supplement of crystal L-Pro and L-Hyp to high plant protein diets did not show positive effects on growth performance of juvenile turbot, but enhanced total collagen concentrations in muscle.

  5. Reproductive hormones and bone.

    PubMed

    Nicks, Kristy M; Fowler, Tristan W; Gaddy, Dana

    2010-06-01

    Hypothalamic gonadotropin-releasing hormone (GnRH) stimulates secretion of pituitary luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which directly regulate ovarian function. Pituitary FSH can modulate osteoclast development, and thereby influence bone turnover. Pituitary oxytocin and prolactin effects on the skeleton are not merely limited to pregnancy and lactation; oxytocin stimulates osteoblastogenesis and bone formation, whereas prolactin exerts skeletal effects in an age-dependent manner. Cyclic levels of inhibins and estrogen suppress FSH and LH, respectively, and also suppress bone turnover via their suppressive effects on osteoblast and osteoclast differentiation. However, continuous exposure to inhibins or estrogen/androgens is anabolic for the skeleton in intact animals and protects against gonadectomy-induced bone loss. Alterations of one hormone in the hypothalamic-pituitary-gonadal (HPG) axis influence other bone-active hormones in the entire feedback loop in the axis. Thus, we propose that the action of the HPG axis should be extended to include its combined effects on the skeleton, thus creating the HPG skeletal (HPGS) axis.

  6. Reporting Crimes Against Juveniles. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Finkelhor, David; Ormrod, Richard

    This bulletin addresses the issue of reporting crimes against juveniles, describing findings from the National Crime Victimization Survey, which gathers information from citizens on crime, including whether and how they are reported. The survey also collects information about characteristics of victimizations, the nature of the incident location,…

  7. Influence of season and nutritional status on the direct effects of leptin, orexin-A and ghrelin on luteinizing hormone and growth hormone secretion in the ovine pituitary explant model.

    PubMed

    Kirsz, K; Szczesna, M; Dudek, K; Bartlewski, P M; Zieba, D A

    2014-07-01

    The aim of this study was to examine whether leptin (anorexigenic peptide), orexin-A, and ghrelin (orexigenic peptides) could directly (ie, independently of hypothalamic influences) affect the secretion of luteinizing hormone (LH) and growth hormone (GH) by adenohypophyseal (AP) explants obtained from normally fed or fasted (48 h) ewes during the breeding and nonbreeding seasons. In addition, a specific ovine super leptin antagonist (SLAN-3) was used to assess the interactions between leptin and ghrelin and/or orexin-A. Pituitary glands from 16 ovariectomized Polish Longwool ewes that had received estradiol-releasing subcutaneous implants were collected in the breeding (November; n = 8) and nonbreeding (May; n = 8) seasons. The AP explants were incubated for 240 min in a gas-liquid interface and treated with leptin (50 ng/mL), ghrelin (100 ng/mL), orexin-A (100 ng/mL), and SLAN-3 (500 ng/mL) with orexin-A or ghrelin. Treatments with leptin and SLAN-3 + orexin-A increased (P < 0.05) LH concentrations in the cultures of AP explants from fasted animals in the breeding season. Orexin-A increased (P < 0.05) LH secretion by AP explants from both fasted and fed animals in the breeding season. Ghrelin stimulated (P < 0.05) GH secretion by AP explants collected from fasted animals in nonbreeding season and from normally fed ewes in both seasons. Leptin decreased (P < 0.05) GH secretion by AP explants collected from fasted ewes in both seasons and from nonfasted ewes in the breeding season. However, the treatment with SLAN-3 + ghrelin resulted in greater (P < 0.05) GH concentrations compared with leptin treatment of AP explants from fasted ewes in the breeding season and from normally fed ewes in nonbreeding season. In summary, leptin, orexin-A, and ghrelin exerted direct effects on AP secretory function in an ex situ model and both the reproductive season and nutritional status of the animals impinged on the direct effects of the peptides on LH and GH release

  8. Growth Hormone

    MedlinePlus

    ... the dose of glucose. Growth hormone stimulates the production of insulin-like growth factor-1 (IGF-1) . ... regular intervals for years afterward to monitor GH production and to detect tumor recurrence. Other blood tests ...

  9. Hormone Therapy

    MedlinePlus

    ... based lubricants include petroleum jelly, baby oil, or mineral oil. Oil-based types should not be used ... caused by low levels of these hormones. Hysterectomy: Removal of the uterus. Menopause: The time in a ...

  10. Semiquantitative hormone receptor level influences response to trastuzumab-containing neoadjuvant chemotherapy in HER2-positive breast cancer.

    PubMed

    Bhargava, Rohit; Dabbs, David J; Beriwal, Sushil; Yildiz, Isil A; Badve, Preeti; Soran, Atilla; Johnson, Ronald R; Brufsky, Adam M; Lembersky, Barry C; McGuire, Kandace P; Ahrendt, Gretchen M

    2011-03-01

    Pathologic complete response to neoadjuvant chemotherapy without trastuzumab in hormone receptor-negative/HER2+ tumors is seen in 27-45% of cases. In contrast, estrogen receptor (ER)+/HER2+ tumors demonstrate pathologic complete response in ∼ 8% of cases and is generally limited to weak-to-moderate ER+/HER2+ tumors. It is speculated that addition of trastuzumab to neoadjuvant chemotherapy regimen will increase the pathologic complete response rates in all HER2+ tumors. A list of HER2+ patients who received neoadjuvant chemotherapy (with trastuzumab) in the years 2007-2010 was obtained from our hospital database. The 104 HER2+ tumors were classified into three groups based on semiquantitative hormone receptor and HER2 results as follows: ERBB2 (ER-/PR-[H-score ≤10]/HER2+), Luminal B-HER2 Hybrid (LBHH; weak to moderate ER+ [H-score 11-199]/HER2+), and Luminal A-HER2 Hybrid (LAHH; strong ER+[H-score ≥200]/HER2+). Pathologic complete response was defined as absence of invasive carcinoma in the resection specimen and in the lymph nodes. Percentage tumor volume reduction was also calculated based on pretherapy size and detailed evaluation of the resection specimen. In all, 52% (25 of 48 cases) of ERBB2 tumors showed pathologic complete response, which was significantly higher than the pathologic complete response rate in LBHH (33%; 10 of 30) and LAHH (8%; 2 of 26) tumors. Average percentage tumor volume reduction was also highest in ERBB2 tumors (86%), followed by LBHH (74%) and LAHH (64%) tumors. We conclude that addition of trastuzumab to neoadjuvant chemotherapy regimen significantly increases the pathologic complete response rates in all HER2+ tumors. However, the benefit of trastuzumab is highest in ER-negative tumors and progressively decreases with increase in tumor ER expression. This information can be utilized to counsel patients considered for neoadjuvant chemotherapy and the same principle could be applied in the adjuvant setting. PMID:21102420

  11. Movies and juvenile delinquency: an overview.

    PubMed

    Snyder, S

    1991-01-01

    Film viewing may affect the juvenile delinquent through the processes known as social learning and instigation. Identification with the movie and its characters by the delinquent viewer is common, and studies have consistently demonstrated that films can affect delinquents, although in some cases the effects are small. Numerous examples of how films may serve as either the initiator or the final common pathway of delinquent acts are presented. However, prosocial aspects of films dealing with delinquency may exert a positive influence on the juvenile delinquent. Treatment implications of these observations are discussed from social learning and other perspectives.

  12. Influence of iodothyronine conjugates of bovine serum albumin and horseradish peroxidase on enzyme immunosorbent assay of thyroid hormones.

    PubMed

    Kumari, G Lakshmi; Kumar, Sachin; Gupta, Satish; Saini, Anuradha; Sharma, Sudesh K; Kaur, Navneet

    2014-01-01

    Enzyme-linked immunosorbent assays (ELISA's) reported for thyroxine (T₄) and 3,5,3'-triiodothyronine (T₃), involved coupling of the haptens through (i) carboxylic group to carrier protein for producing antibodies and (ii) amino group to detection labels. To improve the titer and specificity of antibodies, immunogens were prepared by coupling of carboxyl group to bovine serum albumin (BSA) either directly or through adipic acid dihydrazide (ADH), after protecting amino group through acetylation of T₄ and T₃. Direct coupling resulted in the incorporation of 40-50 moles of T₄ and T₃ per BSA molecule and helped in improving immunogenic response and specificity, especially of T₄. High epitope density of immunogens evoked better antibody response, since attachement of ADH as spacer, introduced 18-27 moles of haptens into carrier protein and had less effect on antibody development, with T₃ being exception. Detection labels were prepared by coupling horseradish peroxidase (HRP) to amino group of thyroid hormones directly and after preparing their methyl esters, which provided sensitive displacement curves in combination with the antibodies developed against N-acetylated-T₄ and T₃. Unlike methyl esters, T₄-HRP and T₃-HRP showed higher sensitivity and seemed to be related to the affinity of the labels for binding the antibody.

  13. Influence of iodothyronine conjugates of bovine serum albumin and horseradish peroxidase on enzyme immunosorbent assay of thyroid hormones.

    PubMed

    Kumari, G Lakshmi; Kumar, Sachin; Gupta, Satish; Saini, Anuradha; Sharma, Sudesh K; Kaur, Navneet

    2014-01-01

    Enzyme-linked immunosorbent assays (ELISA's) reported for thyroxine (T₄) and 3,5,3'-triiodothyronine (T₃), involved coupling of the haptens through (i) carboxylic group to carrier protein for producing antibodies and (ii) amino group to detection labels. To improve the titer and specificity of antibodies, immunogens were prepared by coupling of carboxyl group to bovine serum albumin (BSA) either directly or through adipic acid dihydrazide (ADH), after protecting amino group through acetylation of T₄ and T₃. Direct coupling resulted in the incorporation of 40-50 moles of T₄ and T₃ per BSA molecule and helped in improving immunogenic response and specificity, especially of T₄. High epitope density of immunogens evoked better antibody response, since attachement of ADH as spacer, introduced 18-27 moles of haptens into carrier protein and had less effect on antibody development, with T₃ being exception. Detection labels were prepared by coupling horseradish peroxidase (HRP) to amino group of thyroid hormones directly and after preparing their methyl esters, which provided sensitive displacement curves in combination with the antibodies developed against N-acetylated-T₄ and T₃. Unlike methyl esters, T₄-HRP and T₃-HRP showed higher sensitivity and seemed to be related to the affinity of the labels for binding the antibody. PMID:24295178

  14. Juvenile Sex Offenders.

    PubMed

    Ryan, Eileen P; Otonichar, Joseph M

    2016-07-01

    Sexual offending by juveniles accounts for a sizable percentage of sexual offenses, especially against young children. In this article, recent research on female juvenile sex offenders (JSOs), risk factors for offending in juveniles, treatment, and the ways in which these youth may differ from general delinquents will be reviewed. Most JSOs do not go on to develop paraphilic disorders or to commit sex offenses during adulthood, and as a group, they are more similar to nonsexual offending juvenile delinquents than to adult sex offenders. Recent research has elucidated some differences between youth who commit sex offenses and general delinquents in the areas of atypical sexual interests, the use of pornography, and early sexual victimization during childhood. PMID:27222141

  15. Gibberellin-producing Promicromonospora sp. SE188 improves Solanum lycopersicum plant growth and influences endogenous plant hormones.

    PubMed

    Kang, Sang-Mo; Khan, Abdul Latif; Hamayun, Muhammad; Hussain, Javid; Joo, Gil-Jae; You, Young-Hyun; Kim, Jong-Guk; Lee, In-Jung

    2012-12-01

    Plant growth-promoting rhizobacteria (PGPR) producing gibberellins (GAs) can be beneficial to plant growth and development. In the present study, we isolated and screened a new strain of Promicromonospora sp., SE188, isolated from soil. Promicromonospora sp. SE188 secreted GAs into its growth medium and exhibited phosphate solubilization potential. The PGPR produced physiologically active (GA(1) and GA(4)) and inactive (GA(9), GA(12), GA(19), GA(20), GA(24), GA(34), and GA(53)) GAs in various quantities detected by GC/MS-SIM. Solanum lycopersicum (tomato) plants inoculated with Promicromonospora sp. SE188 showed a significantly higher shoot length and biomass as compared to controls where PGPR-free nutrient broth (NB) and distilled water (DW) were applied to plants. The presence of Promicromonospora sp. SE188 significantly up-regulated the non C-13 hydroxylation GA biosynthesis pathway (GA(12)→GA(24)→GA(9)→GA(4)→ GA(34)) in the tomato plants as compared to the NB and DW control plants. Abscisic acid, a plant stress hormone, was significantly down-regulated in the presence of Promicromonospora sp. SE188. Contrarily, salicylic acid was significantly higher in the tomato plant after Promicromonospora sp. SE188 inoculation as compared to the controls. Promicromonospora sp. SE188 showed promising stimulation of tomato plant growth. From the results it appears that Promicromonospora sp. SE188 has potential as a bio-fertilizer and should be more broadly tested in field trials for higher crop production in eco-friendly farming systems.

  16. The influence of sex and gonadectomy on the growth hormone and corticosterone response to hexarelin in the rat.

    PubMed

    Sibilia, V; Cocchi, D; Pagani, F; Pecile, A; Netti, C

    2000-12-01

    The present study is designed to investigate the role of sex and gonadal status in the growth hormone (GH) and corticosterone response to hexarelin (HEXA), a GH-releasing peptide, which also causes a stimulatory action on the hypothalamic-pituitary-adrenal (HPA) axis. HEXA (80 microg/Kg) was administered intracarotid to anesthetized intact or gonadectomized male (ORC) and female (OVX) middle-aged rats. The GH stimulatory response to HEXA was gender-related since the GH increase was significantly (p < 0.001) higher in intact males (area under the curve, AUC= 12560 +/- 1784 ng/ml.45 min) than in females (AUC= 4628 +/- 257 ng/ml.45 min). This sex difference does not depend on circulating gonadal steroids since it persists in ORC (AUC = 11980 +/- 1136 ng/ml.45 min) and OVX (AUC = 5539 +/- 614 ng/ml.45 min) rats. The different effects of HEXA on corticosterone secretion detected in male and female rats are probably dependent on the prevailing activity of the HPA axis. In fact, in male rats that have low basal corticosterone levels, HEXA caused an increase in corticosterone secretion, which was significantly (p< 0.05) higher in ORC than in intact rats. The increase in corticosterone secretion by HEXA both in intact and OVX females was delayed, probably due to the elevated initial corticosterone levels, which could have activated the glucocorticoid negative feedback. We suggest that gender-specific patterns in the regulation of the hypothalamus-pituitary function could be responsible for the GH and corticosterone sexually differentiated responses to HEXA.

  17. Gibberellin-producing Promicromonospora sp. SE188 improves Solanum lycopersicum plant growth and influences endogenous plant hormones.

    PubMed

    Kang, Sang-Mo; Khan, Abdul Latif; Hamayun, Muhammad; Hussain, Javid; Joo, Gil-Jae; You, Young-Hyun; Kim, Jong-Guk; Lee, In-Jung

    2012-12-01

    Plant growth-promoting rhizobacteria (PGPR) producing gibberellins (GAs) can be beneficial to plant growth and development. In the present study, we isolated and screened a new strain of Promicromonospora sp., SE188, isolated from soil. Promicromonospora sp. SE188 secreted GAs into its growth medium and exhibited phosphate solubilization potential. The PGPR produced physiologically active (GA(1) and GA(4)) and inactive (GA(9), GA(12), GA(19), GA(20), GA(24), GA(34), and GA(53)) GAs in various quantities detected by GC/MS-SIM. Solanum lycopersicum (tomato) plants inoculated with Promicromonospora sp. SE188 showed a significantly higher shoot length and biomass as compared to controls where PGPR-free nutrient broth (NB) and distilled water (DW) were applied to plants. The presence of Promicromonospora sp. SE188 significantly up-regulated the non C-13 hydroxylation GA biosynthesis pathway (GA(12)→GA(24)→GA(9)→GA(4)→ GA(34)) in the tomato plants as compared to the NB and DW control plants. Abscisic acid, a plant stress hormone, was significantly down-regulated in the presence of Promicromonospora sp. SE188. Contrarily, salicylic acid was significantly higher in the tomato plant after Promicromonospora sp. SE188 inoculation as compared to the controls. Promicromonospora sp. SE188 showed promising stimulation of tomato plant growth. From the results it appears that Promicromonospora sp. SE188 has potential as a bio-fertilizer and should be more broadly tested in field trials for higher crop production in eco-friendly farming systems. PMID:23274975

  18. Influence of breed and diet on growth, nutrient digestibility, body composition and plasma hormones of Brangus and Angus steers.

    PubMed

    Beaver, E E; Williams, J E; Miller, S J; Hancock, D L; Hannah, S M; O'Connor, D L

    1989-09-01

    Two split-plot designed experiments were conducted to determine the effects of breed (Angus, A, or Brangus, B) and diet (fescue hay, FH; corn silage, CS; or concentrate) on composition and rate of growth, diet digestibility and plasma hormones of steers. In Exp. 1, 10 steers (five of each breed) were fed a CS-based diet followed by a FH-based diet for two consecutive 60-d periods. Both breeds had lower (P less than .01) DM intake and digestibility when fed FH than when fed CS diets. The B steers had higher (P less than .01) plasma insulin concentrations than A steers when fed the CS diet. In Exp. 2, during two consecutive years, 10 steers previously fed CS- and FH-based diets were finished with a corn silage-whole shelled corn-based diet. During yr 1, A steers had higher (P less than .01) DM intake and plasma triiodothyronine (T3) and thyroxine (T4) concentrations (P less than .05) than B steers did. Although final weights were similar (P greater than .10), A steers had heavier (P less than .05) carcass weights than B steers did. During yr 2, A steers had higher (P less than .07) DM and starch digestibilities and higher (P less than .01) plasma T4 concentrations than B steers did. The greater (P less than .01) energetic efficiency of A steers was attributed to the greater rates of fat deposition during yr 2. Regardless of type of diet fed, A steers were more efficient at depositing energy. Higher circulating T4 concentrations of A than B steers may explain some of the physiological differences between these breeds. PMID:2689419

  19. The influence of time in captivity, food intake and acute trauma on blood analytes of juvenile Steller sea lions, Eumetopias jubatus

    PubMed Central

    Skinner, John P.; Tuomi, Pam A.; Mellish, Jo-Ann E.

    2015-01-01

    The Steller sea lion, Eumetopias jubatus, has experienced regionally divergent population trends over recent decades. One potential mechanism for this disparity is that local factors cause reduced health and, therefore, reduced survival of individuals. The use of blood parameters to assess sea lion health may help to identify whether malnutrition, disease and stress are important drivers of current trends, but such assessments require species-specific knowledge of how parameters respond to various health challenges. We used principal components analysis to identify which key blood parameters (principal analytes) best described changes in health for temporarily captive juvenile Steller sea lions in known conditions. Generalized additive mixed models were used to estimate the changes in principal analytes with food intake, time in captivity and acute trauma associated with hot-iron branding and transmitter implant surgery. Of the 17 blood parameters examined, physiological changes for juvenile