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[PMID]:27228472
[Au] Autor:Freitas MB; Brown CT; Karasov WH
[Ad] Endereço:Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, USA.
[Ti] Título:Warmer temperature modifies effects of polybrominated diphenyl ethers on hormone profiles in leopard frog tadpoles (Lithobates pipiens).
[So] Source:Environ Toxicol Chem;36(1):120-127, 2017 Jan.
[Is] ISSN:1552-8618
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Amphibian populations have been declining, and climate change and exposure to environmental contaminants are thought to be involved. Higher water temperature accelerates larval development; however, its combined effects with contaminants and their influence on hormones during metamorphosis are poorly understood. The authors investigated changes in whole-body triiodothyronine (T3) and corticosterone concentrations in developing leopard frogs reared at 23 °C and 28 °C on diets with 0 ng g , 6 ng g , and 37 ng g of a technical mixture of polybrominated diphenyl ethers (PBDE; DE-71) from 10 d to 44 d (premetamorphosis to late climax; Gosner Stages 28 to 46). Unlike controls, PBDE-exposed tadpoles (6 ng g ) reared at 23 °C failed to show any increase in T3 concentrations throughout metamorphosis, and exposed tadpoles reared at 28 °C showed a lower peak at climax compared to controls. Corticosterone levels progressively increased throughout metamorphosis, but the levels were higher in PBDE-exposed tadpoles compared to controls at both temperatures. At the warmer temperature, corticosterone increase occurred earlier (at early climax) in controls and exposed tadpoles compared to tadpoles reared at the cooler temperature (late climax), coinciding with the faster development observed at 28 °C. Tadpoles reared at 28 °C were longer and developed faster than tadpoles reared at 23 °C. At both temperatures, PBDE exposure decreased T3 and increased corticosterone concentrations, which can potentially impair developing tadpoles. Environ Toxicol Chem 2017;36:120-127. © 2016 SETAC.
[Mh] Termos MeSH primário: Corticosterona/metabolismo
Disruptores Endócrinos/toxicidade
Poluentes Ambientais/toxicidade
Éteres Difenil Halogenados/toxicidade
Larva/efeitos dos fármacos
Temperatura Ambiente
Tri-Iodotironina/metabolismo
[Mh] Termos MeSH secundário: Animais
Mudança Climática
Larva/metabolismo
Metamorfose Biológica/efeitos dos fármacos
Rana pipiens
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Endocrine Disruptors); 0 (Environmental Pollutants); 0 (Halogenated Diphenyl Ethers); 06LU7C9H1V (Triiodothyronine); 7REL09ZX35 (pentabromodiphenyl ether); W980KJ009P (Corticosterone)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170717
[Lr] Data última revisão:
170717
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160527
[St] Status:MEDLINE
[do] DOI:10.1002/etc.3506


  2 / 5647 MEDLINE  
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[PMID]:27475300
[Au] Autor:Szuroczki D; Koprivnikar J; Baker RL
[Ad] Endereço:Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada. Electronic address: dszuroczki@brocku.ca.
[Ti] Título:Dietary antioxidants enhance immunocompetence in larval amphibians.
[So] Source:Comp Biochem Physiol A Mol Integr Physiol;201:182-188, 2016 Nov.
[Is] ISSN:1531-4332
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Dietary antioxidants have been shown to confer a variety of benefits through their ability to counter oxidative stress, including increased immunocompetence and reduced susceptibility to both infectious and non-infectious diseases. However, little is known about the effects of dietary antioxidants on immune function in larval amphibians, a group experiencing worldwide declines driven by factors that likely involve altered immunocompetence. We investigated the effects of dietary antioxidants (quercetin, vitamin E, and ß-carotene) on two components of the immune system, as well as development and growth. Lithobates pipiens tadpoles fed diets with supplemental ß-carotene or vitamin E exhibited an enhanced swelling response as measured with a phytohemagglutinin assay (PHA), but there was no induced antibody response. Effects were often dose-dependent, with higher antioxidant levels generally conferring stronger swelling that possibly corresponds to the innate immune response. Our results indicate that the antioxidant content of the larval amphibian diets not only had a detectable effect on their immune response capability, but also promoted tadpole growth (mass gain), although developmental stage was not affected. Given that many environmental perturbations may cause oxidative stress or reduce immunocompetence, it is critical to understand how nutrition may counter these effects.
[Mh] Termos MeSH primário: Antioxidantes/administração & dosagem
Dieta
Rana pipiens/imunologia
[Mh] Termos MeSH secundário: Fenômenos Fisiológicos da Nutrição Animal
Animais
Imunidade Inata/efeitos dos fármacos
Imunidade Inata/fisiologia
Imunocompetência/efeitos dos fármacos
Imunocompetência/fisiologia
Larva/imunologia
Estresse Oxidativo
Quercetina/administração & dosagem
Rana pipiens/crescimento & desenvolvimento
Rana pipiens/fisiologia
Vitamina E/administração & dosagem
beta Caroteno/administração & dosagem
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antioxidants); 01YAE03M7J (beta Carotene); 1406-18-4 (Vitamin E); 9IKM0I5T1E (Quercetin)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:171008
[Lr] Data última revisão:
171008
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160801
[St] Status:MEDLINE


  3 / 5647 MEDLINE  
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[PMID]:27064110
[Au] Autor:Skorina LK; Recktenwald EW; Dudkin EA; Saidel WM; Gruberg ER
[Ad] Endereço:Temple University, Department of Biology, 1900 North 12th Street, Philadelphia, PA 19122, USA. Electronic address: lskor@temple.edu.
[Ti] Título:Representation of the visual field in the anterior thalamus of the leopard frog, Rana pipiens.
[So] Source:Neurosci Lett;621:34-38, 2016 May 16.
[Is] ISSN:1872-7972
[Cp] País de publicação:Ireland
[La] Idioma:eng
[Ab] Resumo:We used physiological and anatomical methods to elucidate how the visual field is represented in the part of the dorsal anterior thalamus of the leopard frog that receives direct retinal projections. We recorded extracellularly while presenting visual stimuli, and characterized a physiologically defined region that encompasses the retinal projections as well as an extended zone beyond them. We probed the area systematically to determine if the zone is organized in a visuotopic map: we found that it is not. We found that units in this region respond only to stimuli in the contralateral half of the visual field, which is similar to what is seen in the dorsal lateral geniculate nucleus in mammals. When we backfilled retinal ganglion cells from application of HRP to the anterior thalamus, we found labeled cells only in those parts of the retina corresponding to the contralateral hemifield, confirming our physiological observations.
[Mh] Termos MeSH primário: Núcleos Anteriores do Tálamo/fisiologia
Rana pipiens/fisiologia
Campos Visuais/fisiologia
[Mh] Termos MeSH secundário: Animais
Mapeamento Encefálico
Lateralidade Funcional
Estimulação Luminosa
Retina/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170807
[Lr] Data última revisão:
170807
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160412
[St] Status:MEDLINE


  4 / 5647 MEDLINE  
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[PMID]:26976602
[Au] Autor:Alluri RK; Rose GJ; Hanson JL; Leary CJ; Vasquez-Opazo GA; Graham JA; Wilkerson J
[Ad] Endereço:Department of Biology, University of Utah, Salt Lake City, UT 84112;
[Ti] Título:Phasic, suprathreshold excitation and sustained inhibition underlie neuronal selectivity for short-duration sounds.
[So] Source:Proc Natl Acad Sci U S A;113(13):E1927-35, 2016 Mar 29.
[Is] ISSN:1091-6490
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Sound duration is important in acoustic communication, including speech recognition in humans. Although duration-selective auditory neurons have been found, the underlying mechanisms are unclear. To investigate these mechanisms we combined in vivo whole-cell patch recordings from midbrain neurons, extraction of excitatory and inhibitory conductances, and focal pharmacological manipulations. We show that selectivity for short-duration stimuli results from integration of short-latency, sustained inhibition with delayed, phasic excitation; active membrane properties appeared to amplify responses to effective stimuli. Blocking GABAA receptors attenuated stimulus-related inhibition, revealed suprathreshold excitation at all stimulus durations, and decreased short-pass selectivity without changing resting potentials. Blocking AMPA and NMDA receptors to attenuate excitation confirmed that inhibition tracks stimulus duration and revealed no evidence of postinhibitory rebound depolarization inherent to coincidence models of duration selectivity. These results strongly support an anticoincidence mechanism of short-pass selectivity, wherein inhibition and suprathreshold excitation show greatest temporal overlap for long duration stimuli.
[Mh] Termos MeSH primário: Mesencéfalo/fisiologia
Neurônios/fisiologia
Som
[Mh] Termos MeSH secundário: Estimulação Acústica/métodos
Animais
Percepção Auditiva/fisiologia
Limiar Auditivo
Feminino
Antagonistas de Receptores de GABA-A/farmacologia
Masculino
Mesencéfalo/citologia
Modelos Biológicos
Neurônios/efeitos dos fármacos
Técnicas de Patch-Clamp
Rana pipiens
Receptores de AMPA/antagonistas & inibidores
Receptores de AMPA/fisiologia
Receptores de GABA-A/fisiologia
Receptores de N-Metil-D-Aspartato/antagonistas & inibidores
Receptores de N-Metil-D-Aspartato/fisiologia
Fatores de Tempo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (GABA-A Receptor Antagonists); 0 (Receptors, AMPA); 0 (Receptors, GABA-A); 0 (Receptors, N-Methyl-D-Aspartate)
[Em] Mês de entrada:1609
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160316
[St] Status:MEDLINE
[do] DOI:10.1073/pnas.1520971113


  5 / 5647 MEDLINE  
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[PMID]:26858418
[Au] Autor:Jung JH; Szule JA; Marshall RM; McMahan UJ
[Ad] Endereço:Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305; Department of Physics, Stanford University School of Humanities and Sciences, Stanford, CA 94305; Department of Biology, Texas A&M University, College Station, TX 77845.
[Ti] Título:Variable priming of a docked synaptic vesicle.
[So] Source:Proc Natl Acad Sci U S A;113(8):E1098-107, 2016 Feb 23.
[Is] ISSN:1091-6490
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The priming of a docked synaptic vesicle determines the probability of its membrane (VM) fusing with the presynaptic membrane (PM) when a nerve impulse arrives. To gain insight into the nature of priming, we searched by electron tomography for structural relationships correlated with fusion probability at active zones of axon terminals at frog neuromuscular junctions. For terminals fixed at rest, the contact area between the VM of docked vesicles and PM varied >10-fold with a normal distribution. There was no merging of the membranes. For terminals fixed during repetitive evoked synaptic transmission, the normal distribution of contact areas was shifted to the left, due in part to a decreased number of large contact areas, and there was a subpopulation of large contact areas where the membranes were hemifused, an intermediate preceding complete fusion. Thus, fusion probability of a docked vesicle is related to the extent of its VM-PM contact area. For terminals fixed 1 h after activity, the distribution of contact areas recovered to that at rest, indicating the extent of a VM-PM contact area is dynamic and in equilibrium. The extent of VM-PM contact areas in resting terminals correlated with eccentricity in vesicle shape caused by force toward the PM and with shortness of active zone material macromolecules linking vesicles to PM components, some thought to include Ca(2+) channels. We propose that priming is a variable continuum of events imposing variable fusion probability on each vesicle and is regulated by force-generating shortening of active zone material macromolecules in dynamic equilibrium.
[Mh] Termos MeSH primário: Canais de Cálcio/metabolismo
Tomografia com Microscopia Eletrônica
Membranas Sinápticas
Vesículas Sinápticas
[Mh] Termos MeSH secundário: Animais
Rana pipiens
Membranas Sinápticas/metabolismo
Membranas Sinápticas/ultraestrutura
Vesículas Sinápticas/metabolismo
Vesículas Sinápticas/ultraestrutura
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Calcium Channels)
[Em] Mês de entrada:1607
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160210
[St] Status:MEDLINE
[do] DOI:10.1073/pnas.1523054113


  6 / 5647 MEDLINE  
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[PMID]:26412569
[Au] Autor:Stigge HA; Bolek MG
[Ad] Endereço:Department of Integrative Biology, Oklahoma State University, Stillwater, Oklahoma 74078.
[Ti] Título:Anuran Host Species Influences Site Fidelity of Halipegus occidualis.
[So] Source:J Parasitol;102(1):47-53, 2016 Feb.
[Is] ISSN:1937-2345
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Helminths often demonstrate preferential site selection in which a parasite will only occur in 1 microhabitat or a restricted portion of its fundamental niche within its host. However, factors responsible for helminth site specificity are poorly understood, and very little is known about how these factors vary among multiple host species. Some helminths, such as Halipegus occidualis, have been reported from different habitats (stomach or under the tongue) within multiple anuran host species, suggesting that the site selected varies within anuran species. This study examined the site selection by H. occidualis in 7 definitive anuran host species using experimental infections. Then, the site fidelity of H. occidualis was further tested by transplanting worms from under the tongue to the stomach and vice versa in different anuran host combinations, and the movement of worms was recorded. Halipegus occidualis individuals occupied the habitat under the tongue in 6 of 7 anuran species. However, worms always occupied the stomach of American bullfrogs (Lithobates catesbeianus) and were never found under the tongue or in the mouth of these hosts. More importantly, all worms remained in the original habitat when transplanted from the stomach to the stomach or the buccal cavity to the buccal cavity within another individual of the same amphibian species. However, when worms were transplanted from the stomach to the buccal cavity or vice versa in the same host species, the worms always migrated back to the original habitat. The main contribution of this study is that it experimentally documented the variability in the site fidelity of H. occidualis within multiple definitive host species and determined that site fidelity is not as strongly conserved in this genus as suggested previously. Additionally, this work suggests that the variation in site selection in different host species could lead to speciation of the parasites.
[Mh] Termos MeSH primário: Anuros/parasitologia
Trematódeos/fisiologia
Infecções por Trematódeos/veterinária
[Mh] Termos MeSH secundário: Animais
Boca/parasitologia
Prevalência
Rana catesbeiana/parasitologia
Rana pipiens/parasitologia
Caramujos/parasitologia
Estômago/parasitologia
Infecções por Trematódeos/epidemiologia
Infecções por Trematódeos/parasitologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Em] Mês de entrada:1607
[Cu] Atualização por classe:160218
[Lr] Data última revisão:
160218
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150929
[St] Status:MEDLINE
[do] DOI:10.1645/15-790


  7 / 5647 MEDLINE  
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[PMID]:26329298
[Au] Autor:Leduc J; Echaubard P; Trudeau V; Lesbarrères D
[Ad] Endereço:Department of Biology, Laurentian University, Sudbury, Ontario, Canada.
[Ti] Título:Copper and nickel effects on survival and growth of northern leopard frog (Lithobates pipiens) tadpoles in field-collected smelting effluent water.
[So] Source:Environ Toxicol Chem;35(3):687-94, 2016 Mar.
[Is] ISSN:1552-8618
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Trace metals can have subtle yet chronic impacts on organisms by inducing physiological stress that reduces their survival or impedes their ability to tolerate additional environmental stressors. The toxicity literature indicates, however, that aquatic organisms react differently to trace metals depending on the environments in which they reside. The objective of the present study was to understand the response of northern leopard frog (Lithobates pipiens) larvae to ionic copper (Cu), nickel (Ni), and their combination within an effluent water collected downstream of a tailings wetland area. Tadpoles were assigned randomly to 1 of 8 Cu concentrations (8-200 µg/L), 7 Ni concentrations (160-1200 µg/L), or 8 Cu and Ni combined concentrations (8:160-200:1200 µg/L) and showed significant differences in survival and life history traits among treatments. In the Cu and Cu and Ni combined treatments, tadpole survival decreased with increased Cu exposure starting at Cu = 160 µg/L and in the Ni treatment, tadpole survival decreased with increased Ni exposure starting at Ni = 650 µg/L. All Cu-exposed treatments induced a growth increase as the concentration increased, whereas the tadpoles showed a significant decrease in growth rate in Ni treatments. These contrasting outcomes suggest a plastic response to trace metals whereby tadpoles allocate energy reserves toward either escaping or coping with stress. Finally, the authors' argue that future studies will benefit from examining the impacts of multiple stressors in aquatic ecosystems to provide better environmental mitigation.
[Mh] Termos MeSH primário: Cobre/toxicidade
Metalurgia
Níquel/toxicidade
Rana pipiens/crescimento & desenvolvimento
Poluentes Químicos da Água/toxicidade
[Mh] Termos MeSH secundário: Animais
Homeostase
Resíduos Industriais/análise
Larva
Análise de Sobrevida
Oligoelementos/toxicidade
Zonas Úmidas
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Industrial Waste); 0 (Trace Elements); 0 (Water Pollutants, Chemical); 789U1901C5 (Copper); 7OV03QG267 (Nickel)
[Em] Mês de entrada:1610
[Cu] Atualização por classe:161230
[Lr] Data última revisão:
161230
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150903
[St] Status:MEDLINE
[do] DOI:10.1002/etc.3227


  8 / 5647 MEDLINE  
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[PMID]:26782589
[Au] Autor:Yang GG; Xu XY; Ding Y; Cui QQ; Wang Z; Zhang QY; Shi SH; Lv ZY; Wang XY; Zhang JH; Zhang RG; Xu CS
[Ad] Endereço:College of Life Science, Henan Normal University, Xinxiang, Henan, China.
[Ti] Título:Linker length affects expression and bioactivity of the onconase fusion protein in Pichia pastoris.
[So] Source:Genet Mol Res;14(4):19360-70, 2015 Dec 29.
[Is] ISSN:1676-5680
[Cp] País de publicação:Brazil
[La] Idioma:eng
[Ab] Resumo:The aim of this study was to analyze the effect of linker length on the expression and biological activity of recombinant protein onconase (ONC) in fusion with human serum albumin (HSA) in Pichia pastoris. Four flexible linkers with different lengths namely Linker L0, L1: (GGGGS)1, L2: (GGGGS)2, and L3:(GGGGS)3 were inserted into the fusion gene and referred to as HSA-n-ONC, where N = 0, 5, 10, or 15. The sequence of the fusion gene HSA-ONC was designed based on the GC content and codon bias in P. pastoris; the signal peptide of albumin was used as the secretion signal. Gene sequences coding for the fusion protein with different linkers were inserted into pPICZα-A to form recombinant plasmids pPICZα-A/HSA-n-ONC, which were then transformed into P. pastoris X-33 for protein expression. Ideal conditions for expression of the fusion proteins were optimized at a small scale, using shake flasks before proceeding to mass production in 10-L fermenters. The recombinant fusion proteins were purified by aqueous two-phase extraction coupled with DEAE anion exchange chromatography, and their cytotoxic effect on the tumor cell was evaluated by the sulforhodamine B assay. The results showed that the expressed amount of fusion proteins had no significant relationship with the length of different linkers and rHSA-0-ONC had no cytotoxic effect on the tumor cells. While rHSA-5-ONC and rHSA-10-ONC had a weak cytotoxic effect, rHSA-15-ONC could kill various tumor cells in vitro. In summary, the biological activity of the fusion protein gradually improved with increasing length of the linker.
[Mh] Termos MeSH primário: Proteínas de Anfíbios/genética
Antineoplásicos/farmacologia
Clonagem Molecular/métodos
Pichia/genética
Proteínas Recombinantes de Fusão/genética
Ribonucleases/genética
[Mh] Termos MeSH secundário: Proteínas de Anfíbios/biossíntese
Proteínas de Anfíbios/farmacologia
Animais
Antineoplásicos/química
Antineoplásicos/metabolismo
Técnicas de Cultura Celular por Lotes
Reatores Biológicos
Linhagem Celular Tumoral
Sobrevivência Celular/efeitos dos fármacos
Expressão Gênica
Seres Humanos
Concentração Inibidora 50
Extração Líquido-Líquido
Pichia/metabolismo
Plasmídeos/química
Plasmídeos/metabolismo
Engenharia de Proteínas
Sinais Direcionadores de Proteínas
Rana pipiens/metabolismo
Proteínas Recombinantes de Fusão/biossíntese
Proteínas Recombinantes de Fusão/farmacologia
Rodaminas/química
Ribonucleases/biossíntese
Ribonucleases/farmacologia
Albumina Sérica/biossíntese
Albumina Sérica/genética
Relação Estrutura-Atividade
Transformação Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Amphibian Proteins); 0 (Antineoplastic Agents); 0 (Protein Sorting Signals); 0 (Recombinant Fusion Proteins); 0 (Rhodamines); 0 (Serum Albumin); 2609-88-3 (lissamine rhodamine B); EC 3.1.- (Ribonucleases); ZE15FIT23E (ranpirnase)
[Em] Mês de entrada:1610
[Cu] Atualização por classe:170103
[Lr] Data última revisão:
170103
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160120
[St] Status:MEDLINE
[do] DOI:10.4238/2015.December.29.46


  9 / 5647 MEDLINE  
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[PMID]:26346456
[Au] Autor:Rhoden HR; Bolek MG
[Ad] Endereço:Department of Integrative Biology, Oklahoma State University, Stillwater, OK, 74078, USA.
[Ti] Título:Helminth community structure in tadpoles of northern leopard frogs (Rana pipiens) and Woodhouse's toads (Bufo woodhousii) from Nebraska.
[So] Source:Parasitol Res;114(12):4685-92, 2015 Dec.
[Is] ISSN:1432-1955
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Currently, little information is available on helminth community structure in tadpoles, the ephemeral, feeding, non-reproductive larva stages of anurans. We examined the helminth community structure in tadpoles of northern leopard frogs, Rana pipiens, and Woodhouse's toads, Bufo woodhousii, from a first-order stream in Western Nebraska. Specifically, we were interested in how species-specific difference in size, time to metamorphosis, and habitat partitioning among larval anurans affect their helminth community structure. From June-July 2009, we collected 30 tadpoles of northern leopard frogs, R. pipiens, and 50 tadpoles of Woodhouse's toads, B. woodhousii, from Cedar Creek, Keith County, NE, USA. The compound helminth community was dominated by trematode metacercarial stages (echinostomatids and plagiorchids) and the nematode Gyrinicola batrachiensis with only a single non-gravid adult trematode, Gorgoderina attenuata, present in low numbers. The helminth component communities were depauperate and isolationist in nature, with a maximum of four helminth species/types per component community. Although no species-specific helminth infections were observed, clear differences were found in overall abundance of nematode versus trematode infections among tadpoles of these two anuran species. The component community of tadpoles of R. pipiens was dominated by nematodes, whereas the component community of tadpoles of B. woodhousii was dominated by trematodes. Although differences in tadpole susceptibility of these two anuran species could not be ruled out, differences in the reproductive strategy of G. batrachiensis in tadpoles of R. pipiens and B. woodhousii and anuran species-specific habitats partitioning among tadpoles of these two anuran species were important factors in structuring their helminth communities. Our study indicates that time to metamorphosis (older tadpoles) play a significant role in structuring helminth communities of tadpoles within species at the infracommunity level with older tadpoles having higher helminth species richness and/or abundances. However, species-specific differences in anuran tadpole habitat partitioning outweighed the effects of differences in time to metamorphosis at the component community level. Finally, our study is the first to report deformities in hind limb development in a tadpole from Nebraska. Of the 30 northern leopard frog tadpoles collected, a single individual contained an extra hind limb and was infected with two plagiorchid metacercariae located in the musculature above the hind limbs.
[Mh] Termos MeSH primário: Bufonidae/parasitologia
Helmintíase Animal/parasitologia
Helmintos/isolamento & purificação
Rana pipiens/parasitologia
[Mh] Termos MeSH secundário: Animais
Feminino
Helmintos/classificação
Helmintos/genética
Helmintos/fisiologia
Larva/parasitologia
Masculino
Nebraska
Rana pipiens/crescimento & desenvolvimento
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Em] Mês de entrada:1606
[Cu] Atualização por classe:171007
[Lr] Data última revisão:
171007
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150909
[St] Status:MEDLINE
[do] DOI:10.1007/s00436-015-4716-4


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[PMID]:26253169
[Au] Autor:Tatiersky L; Rollins-Smith LA; Lu R; Jardine C; Barker IK; Clark ME; Caswell JL
[Ad] Endereço:Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada. laetitiatatiersky@gmail.com.
[Ti] Título:Effect of glucocorticoids on expression of cutaneous antimicrobial peptides in northern leopard frogs (Lithobates pipiens).
[So] Source:BMC Vet Res;11:191, 2015 Aug 08.
[Is] ISSN:1746-6148
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Many species of frogs secrete cutaneous antimicrobial peptides that are capable of killing Batrachochytrium dendrobatidis. Some of these species are nonetheless susceptible to chytridiomycosis, suggesting that host factors causing dysregulation of this innate immune response may be important in pathogenesis. Since stresses, such as from environmental perturbations, are a potential cause of such dysregulation, this study investigated the effect of glucocorticoid on cutaneous gene expression of these antimicrobial peptides. RESULTS: Northern leopard frogs (Lithobates pipiens) were injected with either the corticosteroid methylprednisolone or saline every 48 h. Norepinephrine-elicited cutaneous secretions were collected every 8 days for 40 days. Gene expression of antimicrobial peptides (brevinin-1P and ranatuerin-2P) in the cutaneous secretions was measured relative to the reference genes EF1-α and RPL8 using quantitative RT-PCR. Corticosteroid treatment was associated with a significant increase in brevinin-1P gene expression, which was most notable at 24-40 days of corticosteroid administration. Ranatuerin-2P expression followed a similar but non-significant trend. CONCLUSION: This treatment protocol, including corticosteroid-administration and frequent norepinephrine-induced secretion, increased AMP gene expression in the skin of L. pipiens under these experimental conditions. The findings do not support the hypothesis that environmental stress predisposes frogs to chytridiomycosis by causing glucocorticoid-induced suppression of antimicrobial peptide defences.
[Mh] Termos MeSH primário: Peptídeos Catiônicos Antimicrobianos/metabolismo
Regulação da Expressão Gênica/efeitos dos fármacos
Metilprednisolona/farmacologia
Rana pipiens/metabolismo
Pele/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Anfíbios/genética
Proteínas de Anfíbios/metabolismo
Animais
Glucocorticoides/farmacologia
Pele/efeitos dos fármacos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Amphibian Proteins); 0 (Antimicrobial Cationic Peptides); 0 (Glucocorticoids); X4W7ZR7023 (Methylprednisolone)
[Em] Mês de entrada:1603
[Cu] Atualização por classe:150810
[Lr] Data última revisão:
150810
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150809
[St] Status:MEDLINE
[do] DOI:10.1186/s12917-015-0506-6



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